diff options
Diffstat (limited to 'fs/btrfs/volumes.c')
| -rw-r--r-- | fs/btrfs/volumes.c | 9034 |
1 files changed, 9034 insertions, 0 deletions
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c new file mode 100644 index 000000000..9b66eb584 --- /dev/null +++ b/fs/btrfs/volumes.c @@ -0,0 +1,9034 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2007 Oracle. All rights reserved. + */ + +#include <linux/sched.h> +#include <linux/sched/mm.h> +#include <linux/slab.h> +#include <linux/ratelimit.h> +#include <linux/kthread.h> +#include <linux/semaphore.h> +#include <linux/uuid.h> +#include <linux/list_sort.h> +#include <linux/namei.h> +#include <linux/fs_struct.h> +#include "misc.h" +#include "disk-io.h" +#include "extent-tree.h" +#include "transaction.h" +#include "volumes.h" +#include "raid56.h" +#include "dev-replace.h" +#include "sysfs.h" +#include "tree-checker.h" +#include "space-info.h" +#include "block-group.h" +#include "discard.h" +#include "zoned.h" +#include "fs.h" +#include "accessors.h" +#include "uuid-tree.h" +#include "ioctl.h" +#include "relocation.h" +#include "scrub.h" +#include "super.h" +#include "raid-stripe-tree.h" + +#define BTRFS_BLOCK_GROUP_STRIPE_MASK (BTRFS_BLOCK_GROUP_RAID0 | \ + BTRFS_BLOCK_GROUP_RAID10 | \ + BTRFS_BLOCK_GROUP_RAID56_MASK) + +struct btrfs_io_geometry { + u32 stripe_index; + u32 stripe_nr; + int mirror_num; + int num_stripes; + u64 stripe_offset; + u64 raid56_full_stripe_start; + int max_errors; + enum btrfs_map_op op; + bool use_rst; +}; + +const struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES] = { + [BTRFS_RAID_RAID10] = { + .sub_stripes = 2, + .dev_stripes = 1, + .devs_max = 0, /* 0 == as many as possible */ + .devs_min = 2, + .tolerated_failures = 1, + .devs_increment = 2, + .ncopies = 2, + .nparity = 0, + .raid_name = "raid10", + .bg_flag = BTRFS_BLOCK_GROUP_RAID10, + .mindev_error = BTRFS_ERROR_DEV_RAID10_MIN_NOT_MET, + }, + [BTRFS_RAID_RAID1] = { + .sub_stripes = 1, + .dev_stripes = 1, + .devs_max = 2, + .devs_min = 2, + .tolerated_failures = 1, + .devs_increment = 2, + .ncopies = 2, + .nparity = 0, + .raid_name = "raid1", + .bg_flag = BTRFS_BLOCK_GROUP_RAID1, + .mindev_error = BTRFS_ERROR_DEV_RAID1_MIN_NOT_MET, + }, + [BTRFS_RAID_RAID1C3] = { + .sub_stripes = 1, + .dev_stripes = 1, + .devs_max = 3, + .devs_min = 3, + .tolerated_failures = 2, + .devs_increment = 3, + .ncopies = 3, + .nparity = 0, + .raid_name = "raid1c3", + .bg_flag = BTRFS_BLOCK_GROUP_RAID1C3, + .mindev_error = BTRFS_ERROR_DEV_RAID1C3_MIN_NOT_MET, + }, + [BTRFS_RAID_RAID1C4] = { + .sub_stripes = 1, + .dev_stripes = 1, + .devs_max = 4, + .devs_min = 4, + .tolerated_failures = 3, + .devs_increment = 4, + .ncopies = 4, + .nparity = 0, + .raid_name = "raid1c4", + .bg_flag = BTRFS_BLOCK_GROUP_RAID1C4, + .mindev_error = BTRFS_ERROR_DEV_RAID1C4_MIN_NOT_MET, + }, + [BTRFS_RAID_DUP] = { + .sub_stripes = 1, + .dev_stripes = 2, + .devs_max = 1, + .devs_min = 1, + .tolerated_failures = 0, + .devs_increment = 1, + .ncopies = 2, + .nparity = 0, + .raid_name = "dup", + .bg_flag = BTRFS_BLOCK_GROUP_DUP, + .mindev_error = 0, + }, + [BTRFS_RAID_RAID0] = { + .sub_stripes = 1, + .dev_stripes = 1, + .devs_max = 0, + .devs_min = 1, + .tolerated_failures = 0, + .devs_increment = 1, + .ncopies = 1, + .nparity = 0, + .raid_name = "raid0", + .bg_flag = BTRFS_BLOCK_GROUP_RAID0, + .mindev_error = 0, + }, + [BTRFS_RAID_SINGLE] = { + .sub_stripes = 1, + .dev_stripes = 1, + .devs_max = 1, + .devs_min = 1, + .tolerated_failures = 0, + .devs_increment = 1, + .ncopies = 1, + .nparity = 0, + .raid_name = "single", + .bg_flag = 0, + .mindev_error = 0, + }, + [BTRFS_RAID_RAID5] = { + .sub_stripes = 1, + .dev_stripes = 1, + .devs_max = 0, + .devs_min = 2, + .tolerated_failures = 1, + .devs_increment = 1, + .ncopies = 1, + .nparity = 1, + .raid_name = "raid5", + .bg_flag = BTRFS_BLOCK_GROUP_RAID5, + .mindev_error = BTRFS_ERROR_DEV_RAID5_MIN_NOT_MET, + }, + [BTRFS_RAID_RAID6] = { + .sub_stripes = 1, + .dev_stripes = 1, + .devs_max = 0, + .devs_min = 3, + .tolerated_failures = 2, + .devs_increment = 1, + .ncopies = 1, + .nparity = 2, + .raid_name = "raid6", + .bg_flag = BTRFS_BLOCK_GROUP_RAID6, + .mindev_error = BTRFS_ERROR_DEV_RAID6_MIN_NOT_MET, + }, +}; + +/* + * Convert block group flags (BTRFS_BLOCK_GROUP_*) to btrfs_raid_types, which + * can be used as index to access btrfs_raid_array[]. + */ +enum btrfs_raid_types __attribute_const__ btrfs_bg_flags_to_raid_index(u64 flags) +{ + const u64 profile = (flags & BTRFS_BLOCK_GROUP_PROFILE_MASK); + + if (!profile) + return BTRFS_RAID_SINGLE; + + return BTRFS_BG_FLAG_TO_INDEX(profile); +} + +const char *btrfs_bg_type_to_raid_name(u64 flags) +{ + const int index = btrfs_bg_flags_to_raid_index(flags); + + if (index >= BTRFS_NR_RAID_TYPES) + return NULL; + + return btrfs_raid_array[index].raid_name; +} + +int btrfs_nr_parity_stripes(u64 type) +{ + enum btrfs_raid_types index = btrfs_bg_flags_to_raid_index(type); + + return btrfs_raid_array[index].nparity; +} + +/* + * Fill @buf with textual description of @bg_flags, no more than @size_buf + * bytes including terminating null byte. + */ +void btrfs_describe_block_groups(u64 bg_flags, char *buf, u32 size_buf) +{ + int i; + int ret; + char *bp = buf; + u64 flags = bg_flags; + u32 size_bp = size_buf; + + if (!flags) + return; + +#define DESCRIBE_FLAG(flag, desc) \ + do { \ + if (flags & (flag)) { \ + ret = snprintf(bp, size_bp, "%s|", (desc)); \ + if (ret < 0 || ret >= size_bp) \ + goto out_overflow; \ + size_bp -= ret; \ + bp += ret; \ + flags &= ~(flag); \ + } \ + } while (0) + + DESCRIBE_FLAG(BTRFS_BLOCK_GROUP_DATA, "data"); + DESCRIBE_FLAG(BTRFS_BLOCK_GROUP_SYSTEM, "system"); + DESCRIBE_FLAG(BTRFS_BLOCK_GROUP_METADATA, "metadata"); + /* Block groups containing the remap tree. */ + DESCRIBE_FLAG(BTRFS_BLOCK_GROUP_METADATA_REMAP, "metadata-remap"); + /* Block group that has been remapped. */ + DESCRIBE_FLAG(BTRFS_BLOCK_GROUP_REMAPPED, "remapped"); + + DESCRIBE_FLAG(BTRFS_AVAIL_ALLOC_BIT_SINGLE, "single"); + for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) + DESCRIBE_FLAG(btrfs_raid_array[i].bg_flag, + btrfs_raid_array[i].raid_name); +#undef DESCRIBE_FLAG + + if (flags) { + ret = snprintf(bp, size_bp, "0x%llx|", flags); + size_bp -= ret; + } + + if (size_bp < size_buf) + buf[size_buf - size_bp - 1] = '\0'; /* remove last | */ + + /* + * The text is trimmed, it's up to the caller to provide sufficiently + * large buffer + */ +out_overflow:; +} + +static int init_first_rw_device(struct btrfs_trans_handle *trans); +static int btrfs_relocate_sys_chunks(struct btrfs_fs_info *fs_info); +static void btrfs_dev_stat_print_on_load(struct btrfs_device *device); + +/* + * Device locking + * ============== + * + * There are several mutexes that protect manipulation of devices and low-level + * structures like chunks but not block groups, extents or files + * + * uuid_mutex (global lock) + * ------------------------ + * protects the fs_uuids list that tracks all per-fs fs_devices, resulting from + * the SCAN_DEV ioctl registration or from mount either implicitly (the first + * device) or requested by the device= mount option + * + * the mutex can be very coarse and can cover long-running operations + * + * protects: updates to fs_devices counters like missing devices, rw devices, + * seeding, structure cloning, opening/closing devices at mount/umount time + * + * global::fs_devs - add, remove, updates to the global list + * + * does not protect: manipulation of the fs_devices::devices list in general + * but in mount context it could be used to exclude list modifications by eg. + * scan ioctl + * + * btrfs_device::name - renames (write side), read is RCU + * + * fs_devices::device_list_mutex (per-fs, with RCU) + * ------------------------------------------------ + * protects updates to fs_devices::devices, ie. adding and deleting + * + * simple list traversal with read-only actions can be done with RCU protection + * + * may be used to exclude some operations from running concurrently without any + * modifications to the list (see write_all_supers) + * + * Is not required at mount and close times, because our device list is + * protected by the uuid_mutex at that point. + * + * balance_mutex + * ------------- + * protects balance structures (status, state) and context accessed from + * several places (internally, ioctl) + * + * chunk_mutex + * ----------- + * protects chunks, adding or removing during allocation, trim or when a new + * device is added/removed. Additionally it also protects post_commit_list of + * individual devices, since they can be added to the transaction's + * post_commit_list only with chunk_mutex held. + * + * cleaner_mutex + * ------------- + * a big lock that is held by the cleaner thread and prevents running subvolume + * cleaning together with relocation or delayed iputs + * + * + * Lock nesting + * ============ + * + * uuid_mutex + * device_list_mutex + * chunk_mutex + * balance_mutex + * + * + * Exclusive operations + * ==================== + * + * Maintains the exclusivity of the following operations that apply to the + * whole filesystem and cannot run in parallel. + * + * - Balance (*) + * - Device add + * - Device remove + * - Device replace (*) + * - Resize + * + * The device operations (as above) can be in one of the following states: + * + * - Running state + * - Paused state + * - Completed state + * + * Only device operations marked with (*) can go into the Paused state for the + * following reasons: + * + * - ioctl (only Balance can be Paused through ioctl) + * - filesystem remounted as read-only + * - filesystem unmounted and mounted as read-only + * - system power-cycle and filesystem mounted as read-only + * - filesystem or device errors leading to forced read-only + * + * The status of exclusive operation is set and cleared atomically. + * During the course of Paused state, fs_info::exclusive_operation remains set. + * A device operation in Paused or Running state can be canceled or resumed + * either by ioctl (Balance only) or when remounted as read-write. + * The exclusive status is cleared when the device operation is canceled or + * completed. + */ + +DEFINE_MUTEX(uuid_mutex); +static LIST_HEAD(fs_uuids); +struct list_head * __attribute_const__ btrfs_get_fs_uuids(void) +{ + return &fs_uuids; +} + +/* + * Allocate new btrfs_fs_devices structure identified by a fsid. + * + * @fsid: if not NULL, copy the UUID to fs_devices::fsid and to + * fs_devices::metadata_fsid + * + * Return a pointer to a new struct btrfs_fs_devices on success, or ERR_PTR(). + * The returned struct is not linked onto any lists and can be destroyed with + * kfree() right away. + */ +static struct btrfs_fs_devices *alloc_fs_devices(const u8 *fsid) +{ + struct btrfs_fs_devices *fs_devs; + + fs_devs = kzalloc_obj(*fs_devs); + if (!fs_devs) + return ERR_PTR(-ENOMEM); + + mutex_init(&fs_devs->device_list_mutex); + + INIT_LIST_HEAD(&fs_devs->devices); + INIT_LIST_HEAD(&fs_devs->alloc_list); + INIT_LIST_HEAD(&fs_devs->fs_list); + INIT_LIST_HEAD(&fs_devs->seed_list); + spin_lock_init(&fs_devs->per_profile_lock); + + if (fsid) { + memcpy(fs_devs->fsid, fsid, BTRFS_FSID_SIZE); + memcpy(fs_devs->metadata_uuid, fsid, BTRFS_FSID_SIZE); + } + + return fs_devs; +} + +static void btrfs_free_device(struct btrfs_device *device) +{ + WARN_ON(!list_empty(&device->post_commit_list)); + /* + * No need to call kfree_rcu() nor do RCU lock/unlock, nothing is + * reading the device name. + */ + kfree(rcu_dereference_raw(device->name)); + btrfs_extent_io_tree_release(&device->alloc_state); + btrfs_destroy_dev_zone_info(device); + kfree(device); +} + +static void free_fs_devices(struct btrfs_fs_devices *fs_devices) +{ + struct btrfs_device *device; + + WARN_ON(fs_devices->opened); + WARN_ON(fs_devices->holding); + while (!list_empty(&fs_devices->devices)) { + device = list_first_entry(&fs_devices->devices, + struct btrfs_device, dev_list); + list_del(&device->dev_list); + btrfs_free_device(device); + } + kfree(fs_devices); +} + +void __exit btrfs_cleanup_fs_uuids(void) +{ + struct btrfs_fs_devices *fs_devices; + + while (!list_empty(&fs_uuids)) { + fs_devices = list_first_entry(&fs_uuids, struct btrfs_fs_devices, + fs_list); + list_del(&fs_devices->fs_list); + free_fs_devices(fs_devices); + } +} + +static bool match_fsid_fs_devices(const struct btrfs_fs_devices *fs_devices, + const u8 *fsid, const u8 *metadata_fsid) +{ + if (memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE) != 0) + return false; + + if (!metadata_fsid) + return true; + + if (memcmp(metadata_fsid, fs_devices->metadata_uuid, BTRFS_FSID_SIZE) != 0) + return false; + + return true; +} + +static noinline struct btrfs_fs_devices *find_fsid( + const u8 *fsid, const u8 *metadata_fsid) +{ + struct btrfs_fs_devices *fs_devices; + + ASSERT(fsid); + + /* Handle non-split brain cases */ + list_for_each_entry(fs_devices, &fs_uuids, fs_list) { + if (match_fsid_fs_devices(fs_devices, fsid, metadata_fsid)) + return fs_devices; + } + return NULL; +} + +static int +btrfs_get_bdev_and_sb(const char *device_path, blk_mode_t flags, void *holder, + int flush, struct file **bdev_file, + struct btrfs_super_block **disk_super) +{ + struct block_device *bdev; + int ret; + + if (holder) + *bdev_file = fs_bdev_file_open_by_path(device_path, flags, + holder, holder); + else + *bdev_file = bdev_file_open_by_path(device_path, flags, NULL, + NULL); + + if (IS_ERR(*bdev_file)) { + ret = PTR_ERR(*bdev_file); + btrfs_err(NULL, "failed to open device for path %s with flags 0x%x: %d", + device_path, flags, ret); + goto error; + } + bdev = file_bdev(*bdev_file); + + if (flush) + sync_blockdev(bdev); + if (holder) { + ret = set_blocksize(*bdev_file, BTRFS_BDEV_BLOCKSIZE); + if (ret) { + fs_bdev_file_release(*bdev_file, holder); + goto error; + } + } + invalidate_bdev(bdev); + *disk_super = btrfs_read_disk_super(bdev, 0, false); + if (IS_ERR(*disk_super)) { + ret = PTR_ERR(*disk_super); + if (holder) + fs_bdev_file_release(*bdev_file, holder); + else + bdev_fput(*bdev_file); + goto error; + } + + return 0; + +error: + *disk_super = NULL; + *bdev_file = NULL; + return ret; +} + +/* + * Search and remove all stale devices (which are not mounted). When both + * inputs are NULL, it will search and release all stale devices. + * + * @devt: Optional. When provided will it release all unmounted devices + * matching this devt only. + * @skip_device: Optional. Will skip this device when searching for the stale + * devices. + * + * Return: 0 for success or if @devt is 0. + * -EBUSY if @devt is a mounted device. + * -ENOENT if @devt does not match any device in the list. + */ +static int btrfs_free_stale_devices(dev_t devt, struct btrfs_device *skip_device) +{ + struct btrfs_fs_devices *fs_devices, *tmp_fs_devices; + struct btrfs_device *device, *tmp_device; + int ret; + bool freed = false; + + lockdep_assert_held(&uuid_mutex); + + /* Return good status if there is no instance of devt. */ + ret = 0; + list_for_each_entry_safe(fs_devices, tmp_fs_devices, &fs_uuids, fs_list) { + + mutex_lock(&fs_devices->device_list_mutex); + list_for_each_entry_safe(device, tmp_device, + &fs_devices->devices, dev_list) { + if (skip_device && skip_device == device) + continue; + if (devt && devt != device->devt) + continue; + if (fs_devices->opened || fs_devices->holding) { + if (devt) + ret = -EBUSY; + break; + } + + /* delete the stale device */ + fs_devices->num_devices--; + list_del(&device->dev_list); + btrfs_free_device(device); + + freed = true; + } + mutex_unlock(&fs_devices->device_list_mutex); + + if (fs_devices->num_devices == 0) { + btrfs_sysfs_remove_fsid(fs_devices); + list_del(&fs_devices->fs_list); + free_fs_devices(fs_devices); + } + } + + /* If there is at least one freed device return 0. */ + if (freed) + return 0; + + return ret; +} + +static struct btrfs_fs_devices *find_fsid_by_device( + struct btrfs_super_block *disk_super, + dev_t devt, bool *same_fsid_diff_dev) +{ + struct btrfs_fs_devices *fsid_fs_devices; + struct btrfs_fs_devices *devt_fs_devices; + const bool has_metadata_uuid = (btrfs_super_incompat_flags(disk_super) & + BTRFS_FEATURE_INCOMPAT_METADATA_UUID); + bool found_by_devt = false; + + /* Find the fs_device by the usual method, if found use it. */ + fsid_fs_devices = find_fsid(disk_super->fsid, + has_metadata_uuid ? disk_super->metadata_uuid : NULL); + + /* The temp_fsid feature is supported only with single device filesystem. */ + if (btrfs_super_num_devices(disk_super) != 1) + return fsid_fs_devices; + + /* + * A seed device is an integral component of the sprout device, which + * functions as a multi-device filesystem. So, temp-fsid feature is + * not supported. + */ + if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_SEEDING) + return fsid_fs_devices; + + /* Try to find a fs_devices by matching devt. */ + list_for_each_entry(devt_fs_devices, &fs_uuids, fs_list) { + struct btrfs_device *device; + + list_for_each_entry(device, &devt_fs_devices->devices, dev_list) { + if (device->devt == devt) { + found_by_devt = true; + break; + } + } + if (found_by_devt) + break; + } + + if (found_by_devt) { + /* Existing device. */ + if (fsid_fs_devices == NULL) { + if (devt_fs_devices->opened == 0) { + /* Stale device. */ + return NULL; + } else { + /* temp_fsid is mounting a subvol. */ + return devt_fs_devices; + } + } else { + /* Regular or temp_fsid device mounting a subvol. */ + return devt_fs_devices; + } + } else { + /* New device. */ + if (fsid_fs_devices == NULL) { + return NULL; + } else { + /* sb::fsid is already used create a new temp_fsid. */ + *same_fsid_diff_dev = true; + return NULL; + } + } + + /* Not reached. */ +} + +/* + * This is only used on mount, and we are protected from competing things + * messing with our fs_devices by the uuid_mutex, thus we do not need the + * fs_devices->device_list_mutex here. + */ +static int btrfs_open_one_device(struct btrfs_fs_devices *fs_devices, + struct btrfs_device *device, blk_mode_t flags, + void *holder) +{ + struct file *bdev_file; + struct btrfs_super_block *disk_super; + u64 devid; + int ret; + + if (device->bdev) + return -EINVAL; + if (!device->name) + return -EINVAL; + + ret = btrfs_get_bdev_and_sb(rcu_dereference_raw(device->name), flags, holder, 1, + &bdev_file, &disk_super); + if (ret) + return ret; + + devid = btrfs_stack_device_id(&disk_super->dev_item); + if (devid != device->devid) + goto error_free_page; + + if (memcmp(device->uuid, disk_super->dev_item.uuid, BTRFS_UUID_SIZE)) + goto error_free_page; + + device->generation = btrfs_super_generation(disk_super); + + if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_SEEDING) { + if (btrfs_super_incompat_flags(disk_super) & + BTRFS_FEATURE_INCOMPAT_METADATA_UUID) { + btrfs_err(NULL, + "invalid seeding and uuid-changed device detected"); + goto error_free_page; + } + + clear_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state); + fs_devices->seeding = true; + } else { + if (bdev_read_only(file_bdev(bdev_file))) + clear_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state); + else + set_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state); + } + + if (bdev_rot(file_bdev(bdev_file))) + fs_devices->rotating = true; + + if (bdev_max_discard_sectors(file_bdev(bdev_file))) + fs_devices->discardable = true; + + device->bdev_file = bdev_file; + device->bdev = file_bdev(bdev_file); + clear_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state); + + if (device->devt != device->bdev->bd_dev) { + btrfs_warn(NULL, + "device %s maj:min changed from %d:%d to %d:%d", + rcu_dereference_raw(device->name), MAJOR(device->devt), + MINOR(device->devt), MAJOR(device->bdev->bd_dev), + MINOR(device->bdev->bd_dev)); + + device->devt = device->bdev->bd_dev; + } + + fs_devices->open_devices++; + if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state) && + device->devid != BTRFS_DEV_REPLACE_DEVID) { + fs_devices->rw_devices++; + list_add_tail(&device->dev_alloc_list, &fs_devices->alloc_list); + } + btrfs_release_disk_super(disk_super); + + return 0; + +error_free_page: + btrfs_release_disk_super(disk_super); + fs_bdev_file_release(bdev_file, holder); + + return -EINVAL; +} + +const u8 *btrfs_sb_fsid_ptr(const struct btrfs_super_block *sb) +{ + bool has_metadata_uuid = (btrfs_super_incompat_flags(sb) & + BTRFS_FEATURE_INCOMPAT_METADATA_UUID); + + return has_metadata_uuid ? sb->metadata_uuid : sb->fsid; +} + +/* + * Add new device to list of registered devices + * + * Returns: + * device pointer which was just added or updated when successful + * error pointer when failed + */ +static noinline struct btrfs_device *device_list_add(const char *path, + struct btrfs_super_block *disk_super, + bool *new_device_added) +{ + struct btrfs_device *device; + struct btrfs_fs_devices *fs_devices = NULL; + const char *name; + u64 found_transid = btrfs_super_generation(disk_super); + u64 devid = btrfs_stack_device_id(&disk_super->dev_item); + dev_t path_devt; + int ret; + bool same_fsid_diff_dev = false; + bool has_metadata_uuid = (btrfs_super_incompat_flags(disk_super) & + BTRFS_FEATURE_INCOMPAT_METADATA_UUID); + + if (btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_CHANGING_FSID_V2) { + btrfs_err(NULL, +"device %s has incomplete metadata_uuid change, please use btrfstune to complete", + path); + return ERR_PTR(-EAGAIN); + } + + ret = lookup_bdev(path, &path_devt); + if (ret) { + btrfs_err(NULL, "failed to lookup block device for path %s: %d", + path, ret); + return ERR_PTR(ret); + } + + fs_devices = find_fsid_by_device(disk_super, path_devt, &same_fsid_diff_dev); + + if (!fs_devices) { + fs_devices = alloc_fs_devices(disk_super->fsid); + if (IS_ERR(fs_devices)) + return ERR_CAST(fs_devices); + + if (has_metadata_uuid) + memcpy(fs_devices->metadata_uuid, + disk_super->metadata_uuid, BTRFS_FSID_SIZE); + + if (same_fsid_diff_dev) { + generate_random_uuid(fs_devices->fsid); + fs_devices->temp_fsid = true; + btrfs_info(NULL, "device %s (%d:%d) using temp-fsid %pU", + path, MAJOR(path_devt), MINOR(path_devt), + fs_devices->fsid); + } + + mutex_lock(&fs_devices->device_list_mutex); + list_add(&fs_devices->fs_list, &fs_uuids); + + device = NULL; + } else { + struct btrfs_dev_lookup_args args = { + .devid = devid, + .uuid = disk_super->dev_item.uuid, + }; + + mutex_lock(&fs_devices->device_list_mutex); + device = btrfs_find_device(fs_devices, &args); + + if (found_transid > fs_devices->latest_generation) { + memcpy(fs_devices->fsid, disk_super->fsid, + BTRFS_FSID_SIZE); + memcpy(fs_devices->metadata_uuid, + btrfs_sb_fsid_ptr(disk_super), BTRFS_FSID_SIZE); + } + } + + if (!device) { + unsigned int nofs_flag; + + if (fs_devices->opened) { + btrfs_err(NULL, +"device %s (%d:%d) belongs to fsid %pU, and the fs is already mounted, scanned by %s (%d)", + path, MAJOR(path_devt), MINOR(path_devt), + fs_devices->fsid, current->comm, + task_pid_nr(current)); + mutex_unlock(&fs_devices->device_list_mutex); + return ERR_PTR(-EBUSY); + } + + nofs_flag = memalloc_nofs_save(); + device = btrfs_alloc_device(NULL, &devid, + disk_super->dev_item.uuid, path); + memalloc_nofs_restore(nofs_flag); + if (IS_ERR(device)) { + mutex_unlock(&fs_devices->device_list_mutex); + /* we can safely leave the fs_devices entry around */ + return device; + } + + device->devt = path_devt; + + list_add_rcu(&device->dev_list, &fs_devices->devices); + fs_devices->num_devices++; + + device->fs_devices = fs_devices; + *new_device_added = true; + + if (disk_super->label[0]) + pr_info( +"BTRFS: device label %s devid %llu transid %llu %s (%d:%d) scanned by %s (%d)\n", + disk_super->label, devid, found_transid, path, + MAJOR(path_devt), MINOR(path_devt), + current->comm, task_pid_nr(current)); + else + pr_info( +"BTRFS: device fsid %pU devid %llu transid %llu %s (%d:%d) scanned by %s (%d)\n", + disk_super->fsid, devid, found_transid, path, + MAJOR(path_devt), MINOR(path_devt), + current->comm, task_pid_nr(current)); + + } else if (!device->name || device->devt != path_devt) { + const char *old_name; + + /* + * When FS is already mounted. + * 1. If you are here and if the device->name is NULL that + * means this device was missing at time of FS mount. + * 2. If you are here and if the device->name is different + * from 'path' that means either + * a. The same device disappeared and reappeared with + * different name. or + * b. The missing-disk-which-was-replaced, has + * reappeared now. + * + * We must allow 1 and 2a above. But 2b would be a spurious + * and unintentional. + * + * Further in case of 1 and 2a above, the disk at 'path' + * would have missed some transaction when it was away and + * in case of 2a the stale bdev has to be updated as well. + * 2b must not be allowed at all time. + */ + + /* + * For now, we do allow update to btrfs_fs_device through the + * btrfs dev scan cli after FS has been mounted. We're still + * tracking a problem where systems fail mount by subvolume id + * when we reject replacement on a mounted FS. + */ + if (!fs_devices->opened && found_transid < device->generation) { + /* + * That is if the FS is _not_ mounted and if you + * are here, that means there is more than one + * disk with same uuid and devid.We keep the one + * with larger generation number or the last-in if + * generation are equal. + */ + mutex_unlock(&fs_devices->device_list_mutex); + btrfs_err(NULL, +"device %s already registered with a higher generation, found %llu expect %llu", + path, found_transid, device->generation); + return ERR_PTR(-EEXIST); + } + + /* + * We are going to replace the device path for a given devid, + * make sure it's the same device if the device is mounted + * + * NOTE: the device->fs_info may not be reliable here so pass + * in a NULL to message helpers instead. This avoids a possible + * use-after-free when the fs_info and fs_info->sb are already + * torn down. + */ + if (device->bdev) { + if (device->devt != path_devt) { + mutex_unlock(&fs_devices->device_list_mutex); + btrfs_warn(NULL, + "duplicate device %s devid %llu generation %llu scanned by %s (%d)", + path, devid, found_transid, + current->comm, + task_pid_nr(current)); + return ERR_PTR(-EEXIST); + } + btrfs_info(NULL, + "devid %llu device path %s changed to %s scanned by %s (%d)", + devid, btrfs_dev_name(device), + path, current->comm, + task_pid_nr(current)); + } else { + btrfs_info(NULL, + "missing devid %llu re-appeared at %s scanned by %s (%d)", + devid, path, current->comm, + task_pid_nr(current)); + } + + name = kstrdup(path, GFP_NOFS); + if (!name) { + mutex_unlock(&fs_devices->device_list_mutex); + return ERR_PTR(-ENOMEM); + } + rcu_read_lock(); + old_name = rcu_dereference(device->name); + rcu_read_unlock(); + rcu_assign_pointer(device->name, name); + kfree_rcu_mightsleep(old_name); + + if (test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state)) { + fs_devices->missing_devices--; + clear_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state); + } + device->devt = path_devt; + } + + /* + * Unmount does not free the btrfs_device struct but would zero + * generation along with most of the other members. So just update + * it back. We need it to pick the disk with largest generation + * (as above). + */ + if (!fs_devices->opened) { + device->generation = found_transid; + fs_devices->latest_generation = max_t(u64, found_transid, + fs_devices->latest_generation); + } + + fs_devices->total_devices = btrfs_super_num_devices(disk_super); + + mutex_unlock(&fs_devices->device_list_mutex); + return device; +} + +static struct btrfs_fs_devices *clone_fs_devices(struct btrfs_fs_devices *orig) +{ + struct btrfs_fs_devices *fs_devices; + struct btrfs_device *device; + struct btrfs_device *orig_dev; + int ret = 0; + + lockdep_assert_held(&uuid_mutex); + + fs_devices = alloc_fs_devices(orig->fsid); + if (IS_ERR(fs_devices)) + return fs_devices; + + fs_devices->total_devices = orig->total_devices; + + list_for_each_entry(orig_dev, &orig->devices, dev_list) { + const char *dev_path = NULL; + + /* + * This is ok to do without RCU read locked because we hold the + * uuid mutex so nothing we touch in here is going to disappear. + */ + if (orig_dev->name) + dev_path = rcu_dereference_raw(orig_dev->name); + + device = btrfs_alloc_device(NULL, &orig_dev->devid, + orig_dev->uuid, dev_path); + if (IS_ERR(device)) { + ret = PTR_ERR(device); + goto error; + } + + if (orig_dev->zone_info) { + struct btrfs_zoned_device_info *zone_info; + + zone_info = btrfs_clone_dev_zone_info(orig_dev); + if (!zone_info) { + btrfs_free_device(device); + ret = -ENOMEM; + goto error; + } + device->zone_info = zone_info; + } + + list_add(&device->dev_list, &fs_devices->devices); + device->fs_devices = fs_devices; + fs_devices->num_devices++; + } + return fs_devices; +error: + free_fs_devices(fs_devices); + return ERR_PTR(ret); +} + +static void __btrfs_free_extra_devids(struct btrfs_fs_devices *fs_devices, + struct btrfs_device **latest_dev) +{ + struct btrfs_device *device, *next; + + /* This is the initialized path, it is safe to release the devices. */ + list_for_each_entry_safe(device, next, &fs_devices->devices, dev_list) { + if (test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state)) { + if (!test_bit(BTRFS_DEV_STATE_REPLACE_TGT, + &device->dev_state) && + !test_bit(BTRFS_DEV_STATE_MISSING, + &device->dev_state) && + (!*latest_dev || + device->generation > (*latest_dev)->generation)) { + *latest_dev = device; + } + continue; + } + + /* + * We have already validated the presence of BTRFS_DEV_REPLACE_DEVID, + * in btrfs_init_dev_replace() so just continue. + */ + if (device->devid == BTRFS_DEV_REPLACE_DEVID) + continue; + + if (device->bdev_file) { + fs_bdev_file_release(device->bdev_file, device->bdev_file->private_data); + device->bdev = NULL; + device->bdev_file = NULL; + fs_devices->open_devices--; + } + if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state)) { + list_del_init(&device->dev_alloc_list); + clear_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state); + fs_devices->rw_devices--; + } + list_del_init(&device->dev_list); + fs_devices->num_devices--; + btrfs_free_device(device); + } + +} + +/* + * After we have read the system tree and know devids belonging to this + * filesystem, remove the device which does not belong there. + */ +void btrfs_free_extra_devids(struct btrfs_fs_devices *fs_devices) +{ + struct btrfs_device *latest_dev = NULL; + struct btrfs_fs_devices *seed_dev; + + mutex_lock(&uuid_mutex); + __btrfs_free_extra_devids(fs_devices, &latest_dev); + + list_for_each_entry(seed_dev, &fs_devices->seed_list, seed_list) + __btrfs_free_extra_devids(seed_dev, &latest_dev); + + fs_devices->latest_dev = latest_dev; + + mutex_unlock(&uuid_mutex); +} + +/* Release a device that was made unfreezable for a membership change. */ +void btrfs_release_device_allow_freeze(struct file *bdev_file) +{ + struct super_block *sb = bdev_file->private_data; + + /* Unregister before re-allowing (strand-safe); file still open (UAF-safe). */ + fs_bdev_unregister(bdev_file, sb); + bdev_allow_freeze(file_bdev(bdev_file)); + bdev_fput(bdev_file); +} + +static void btrfs_close_bdev(struct btrfs_device *device, bool allow_freeze) +{ + if (!device->bdev) + return; + + if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state)) { + sync_blockdev(device->bdev); + invalidate_bdev(device->bdev); + } + + /* @allow_freeze undoes a replace-time deny; unmount-close was never denied. */ + if (allow_freeze) + btrfs_release_device_allow_freeze(device->bdev_file); + else + fs_bdev_file_release(device->bdev_file, + device->bdev_file->private_data); +} + +static void btrfs_close_one_device(struct btrfs_device *device) +{ + struct btrfs_fs_devices *fs_devices = device->fs_devices; + + if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state) && + device->devid != BTRFS_DEV_REPLACE_DEVID) { + list_del_init(&device->dev_alloc_list); + fs_devices->rw_devices--; + } + + if (device->devid == BTRFS_DEV_REPLACE_DEVID) + clear_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state); + + if (test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state)) { + clear_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state); + fs_devices->missing_devices--; + } + + btrfs_close_bdev(device, false); + if (device->bdev) { + fs_devices->open_devices--; + device->bdev = NULL; + device->bdev_file = NULL; + } + clear_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state); + btrfs_destroy_dev_zone_info(device); + + device->fs_info = NULL; + atomic_set(&device->dev_stats_ccnt, 0); + btrfs_extent_io_tree_release(&device->alloc_state); + + /* + * Reset the flush error record. We might have a transient flush error + * in this mount, and if so we aborted the current transaction and set + * the fs to an error state, guaranteeing no super blocks can be further + * committed. However that error might be transient and if we unmount the + * filesystem and mount it again, we should allow the mount to succeed + * (btrfs_check_rw_degradable() should not fail) - if after mounting the + * filesystem again we still get flush errors, then we will again abort + * any transaction and set the error state, guaranteeing no commits of + * unsafe super blocks. + */ + clear_bit(BTRFS_DEV_STATE_FLUSH_FAILED, &device->dev_state); + + /* Verify the device is back in a pristine state */ + WARN_ON(test_bit(BTRFS_DEV_STATE_FLUSH_SENT, &device->dev_state)); + WARN_ON(test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state)); + WARN_ON(!list_empty(&device->dev_alloc_list)); + WARN_ON(!list_empty(&device->post_commit_list)); +} + +static void close_fs_devices(struct btrfs_fs_devices *fs_devices) +{ + struct btrfs_device *device, *tmp; + + lockdep_assert_held(&uuid_mutex); + + if (--fs_devices->opened > 0) + return; + + list_for_each_entry_safe(device, tmp, &fs_devices->devices, dev_list) + btrfs_close_one_device(device); + + WARN_ON(fs_devices->open_devices); + WARN_ON(fs_devices->rw_devices); + fs_devices->opened = 0; + fs_devices->seeding = false; + fs_devices->fs_info = NULL; +} + +void btrfs_close_devices(struct btrfs_fs_devices *fs_devices) +{ + LIST_HEAD(list); + struct btrfs_fs_devices *tmp; + + mutex_lock(&uuid_mutex); + close_fs_devices(fs_devices); + if (!fs_devices->opened && !fs_devices->holding) { + list_splice_init(&fs_devices->seed_list, &list); + + /* + * If the struct btrfs_fs_devices is not assembled with any + * other device, it can be re-initialized during the next mount + * without the needing device-scan step. Therefore, it can be + * fully freed. + */ + if (fs_devices->num_devices == 1) { + list_del(&fs_devices->fs_list); + free_fs_devices(fs_devices); + } + } + + + list_for_each_entry_safe(fs_devices, tmp, &list, seed_list) { + close_fs_devices(fs_devices); + list_del(&fs_devices->seed_list); + free_fs_devices(fs_devices); + } + mutex_unlock(&uuid_mutex); +} + +static int open_fs_devices(struct btrfs_fs_devices *fs_devices, + blk_mode_t flags, void *holder) +{ + struct btrfs_device *device; + struct btrfs_device *latest_dev = NULL; + struct btrfs_device *tmp_device; + s64 __maybe_unused value = 0; + int ret = 0; + + list_for_each_entry_safe(device, tmp_device, &fs_devices->devices, + dev_list) { + int ret2; + + ret2 = btrfs_open_one_device(fs_devices, device, flags, holder); + if (ret2 == 0 && + (!latest_dev || device->generation > latest_dev->generation)) { + latest_dev = device; + } else if (ret2 == -ENODATA) { + fs_devices->num_devices--; + list_del(&device->dev_list); + btrfs_free_device(device); + } + if (ret == 0 && ret2 != 0) + ret = ret2; + } + + if (fs_devices->open_devices == 0) { + if (ret) + return ret; + return -EINVAL; + } + + fs_devices->opened = 1; + fs_devices->latest_dev = latest_dev; + fs_devices->total_rw_bytes = 0; + fs_devices->chunk_alloc_policy = BTRFS_CHUNK_ALLOC_REGULAR; +#ifdef CONFIG_BTRFS_EXPERIMENTAL + fs_devices->rr_min_contig_read = BTRFS_DEFAULT_RR_MIN_CONTIG_READ; + fs_devices->read_devid = latest_dev->devid; + fs_devices->read_policy = btrfs_read_policy_to_enum(btrfs_get_mod_read_policy(), + &value); + if (fs_devices->read_policy == BTRFS_READ_POLICY_RR) + fs_devices->collect_fs_stats = true; + + if (value) { + if (fs_devices->read_policy == BTRFS_READ_POLICY_RR) + fs_devices->rr_min_contig_read = value; + if (fs_devices->read_policy == BTRFS_READ_POLICY_DEVID) + fs_devices->read_devid = value; + } +#else + fs_devices->read_policy = BTRFS_READ_POLICY_PID; +#endif + + return 0; +} + +static int devid_cmp(void *priv, const struct list_head *a, + const struct list_head *b) +{ + const struct btrfs_device *dev1, *dev2; + + dev1 = list_entry(a, struct btrfs_device, dev_list); + dev2 = list_entry(b, struct btrfs_device, dev_list); + + if (dev1->devid < dev2->devid) + return -1; + else if (dev1->devid > dev2->devid) + return 1; + return 0; +} + +int btrfs_open_devices(struct btrfs_fs_devices *fs_devices, + blk_mode_t flags, void *holder) +{ + int ret; + + lockdep_assert_held(&uuid_mutex); + /* + * The device_list_mutex cannot be taken here in case opening the + * underlying device takes further locks like open_mutex. + * + * We also don't need the lock here as this is called during mount and + * exclusion is provided by uuid_mutex + */ + + if (fs_devices->opened) { + fs_devices->opened++; + ret = 0; + } else { + list_sort(NULL, &fs_devices->devices, devid_cmp); + ret = open_fs_devices(fs_devices, flags, holder); + } + + return ret; +} + +void btrfs_release_disk_super(struct btrfs_super_block *super) +{ + struct page *page = virt_to_page(super); + + put_page(page); +} + +struct btrfs_super_block *btrfs_read_disk_super(struct block_device *bdev, + int copy_num, bool drop_cache) +{ + struct btrfs_super_block *super; + struct page *page; + u64 bytenr, bytenr_orig; + struct address_space *mapping = bdev->bd_mapping; + int ret; + + bytenr_orig = btrfs_sb_offset(copy_num); + ret = btrfs_sb_log_location_bdev(bdev, copy_num, READ, &bytenr); + if (ret < 0) { + if (ret == -ENOENT) + ret = -EINVAL; + return ERR_PTR(ret); + } + + if (bytenr + BTRFS_SUPER_INFO_SIZE >= bdev_nr_bytes(bdev)) + return ERR_PTR(-EINVAL); + + if (drop_cache) { + /* This should only be called with the primary sb. */ + ASSERT(copy_num == 0); + + /* + * Drop the page of the primary superblock, so later read will + * always read from the device. + */ + invalidate_inode_pages2_range(mapping, bytenr >> PAGE_SHIFT, + (bytenr + BTRFS_SUPER_INFO_SIZE) >> PAGE_SHIFT); + } + + filemap_invalidate_lock_shared(mapping); + page = read_cache_page_gfp(mapping, bytenr >> PAGE_SHIFT, GFP_NOFS); + filemap_invalidate_unlock_shared(mapping); + if (IS_ERR(page)) + return ERR_CAST(page); + + super = page_address(page); + if (btrfs_super_magic(super) != BTRFS_MAGIC || + btrfs_super_bytenr(super) != bytenr_orig) { + btrfs_release_disk_super(super); + return ERR_PTR(-EINVAL); + } + + /* + * Make sure the last byte of label is properly NUL terminated. We use + * '%s' to print the label, if not properly NUL terminated we can access + * beyond the label. + */ + if (super->label[0] && super->label[BTRFS_LABEL_SIZE - 1]) + super->label[BTRFS_LABEL_SIZE - 1] = 0; + + return super; +} + +int btrfs_forget_devices(dev_t devt) +{ + int ret; + + mutex_lock(&uuid_mutex); + ret = btrfs_free_stale_devices(devt, NULL); + mutex_unlock(&uuid_mutex); + + return ret; +} + +static bool btrfs_skip_registration(struct btrfs_super_block *disk_super, + const char *path, dev_t devt, + bool mount_arg_dev) +{ + struct btrfs_fs_devices *fs_devices; + + /* + * Do not skip device registration for mounted devices with matching + * maj:min but different paths. Booting without initrd relies on + * /dev/root initially, later replaced with the actual root device. + * A successful scan ensures grub2-probe selects the correct device. + */ + list_for_each_entry(fs_devices, &fs_uuids, fs_list) { + struct btrfs_device *device; + + mutex_lock(&fs_devices->device_list_mutex); + + if (!fs_devices->opened) { + mutex_unlock(&fs_devices->device_list_mutex); + continue; + } + + list_for_each_entry(device, &fs_devices->devices, dev_list) { + if (device->bdev && (device->bdev->bd_dev == devt) && + strcmp(rcu_dereference_raw(device->name), path) != 0) { + mutex_unlock(&fs_devices->device_list_mutex); + + /* Do not skip registration. */ + return false; + } + } + mutex_unlock(&fs_devices->device_list_mutex); + } + + if (!mount_arg_dev && btrfs_super_num_devices(disk_super) == 1 && + !(btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_SEEDING)) + return true; + + return false; +} + +/* + * Look for a btrfs signature on a device. This may be called out of the mount path + * and we are not allowed to call set_blocksize during the scan. The superblock + * is read via pagecache. + * + * With @mount_arg_dev it's a scan during mount time that will always register + * the device or return an error. Multi-device and seeding devices are registered + * in both cases. + */ +struct btrfs_device *btrfs_scan_one_device(const char *path, + bool mount_arg_dev) +{ + struct btrfs_super_block *disk_super; + bool new_device_added = false; + struct btrfs_device *device = NULL; + struct file *bdev_file; + dev_t devt; + + lockdep_assert_held(&uuid_mutex); + + /* + * Avoid an exclusive open here, as the systemd-udev may initiate the + * device scan which may race with the user's mount or mkfs command, + * resulting in failure. + * Since the device scan is solely for reading purposes, there is no + * need for an exclusive open. Additionally, the devices are read again + * during the mount process. It is ok to get some inconsistent + * values temporarily, as the device paths of the fsid are the only + * required information for assembling the volume. + */ + bdev_file = bdev_file_open_by_path(path, BLK_OPEN_READ, NULL, NULL); + if (IS_ERR(bdev_file)) + return ERR_CAST(bdev_file); + + disk_super = btrfs_read_disk_super(file_bdev(bdev_file), 0, false); + if (IS_ERR(disk_super)) { + device = ERR_CAST(disk_super); + goto error_bdev_put; + } + + devt = file_bdev(bdev_file)->bd_dev; + if (btrfs_skip_registration(disk_super, path, devt, mount_arg_dev)) { + btrfs_debug(NULL, "skip registering single non-seed device %s (%d:%d)", + path, MAJOR(devt), MINOR(devt)); + + btrfs_free_stale_devices(devt, NULL); + + device = NULL; + goto free_disk_super; + } + + device = device_list_add(path, disk_super, &new_device_added); + if (!IS_ERR(device) && new_device_added) + btrfs_free_stale_devices(device->devt, device); + +free_disk_super: + btrfs_release_disk_super(disk_super); + +error_bdev_put: + bdev_fput(bdev_file); + + return device; +} + +/* + * Find the first pending extent intersecting a range. + * + * @device: the device to search + * @start: start of the range to check + * @len: length of the range to check + * @pending_start: output pointer for the start of the found pending extent + * @pending_end: output pointer for the end of the found pending extent (inclusive) + * + * Search for a pending chunk allocation that intersects the half-open range + * [start, start + len). + * + * Return: true if a pending extent was found, false otherwise. + * If the return value is true, store the first pending extent in + * [*pending_start, *pending_end]. Otherwise, the two output variables + * may still be modified, to something outside the range and should not + * be used. + */ +bool btrfs_first_pending_extent(struct btrfs_device *device, u64 start, u64 len, + u64 *pending_start, u64 *pending_end) +{ + lockdep_assert_held(&device->fs_info->chunk_mutex); + + if (btrfs_find_first_extent_bit(&device->alloc_state, start, + pending_start, pending_end, + CHUNK_ALLOCATED, NULL)) { + + if (in_range(*pending_start, start, len) || + in_range(start, *pending_start, *pending_end + 1 - *pending_start)) { + return true; + } + } + return false; +} + +/* + * Find the first real hole accounting for pending extents. + * + * @device: the device containing the candidate hole + * @start: input/output pointer for the hole start position + * @len: input/output pointer for the hole length + * @min_hole_size: the size of hole we are looking for + * + * Given a potential hole specified by [*start, *start + *len), check for pending + * chunk allocations within that range. If pending extents are found, the hole is + * adjusted to represent the first true free space that is large enough when + * accounting for pending chunks. + * + * Note that this function must handle various cases involving non consecutive + * pending extents. + * + * Returns: true if a suitable hole was found and false otherwise. + * If the return value is true, then *start and *len are set to represent the hole. + * If the return value is false, then *start is set to the largest hole we + * found and *len is set to its length. + * If there are no holes at all, then *start is set to the end of the range and + * *len is set to 0. + */ +bool btrfs_find_hole_in_pending_extents(struct btrfs_device *device, u64 *start, + u64 *len, u64 min_hole_size) +{ + u64 pending_start, pending_end; + u64 end; + u64 max_hole_start = 0; + u64 max_hole_len = 0; + + lockdep_assert_held(&device->fs_info->chunk_mutex); + + if (*len == 0) + return false; + + end = *start + *len - 1; + + /* + * Loop until we either see a large enough hole or check every pending + * extent overlapping the candidate hole. + * At every hole that we observe, record it if it is the new max. + * At the end of the iteration, set the output variables to the max hole. + */ + while (true) { + if (btrfs_first_pending_extent(device, *start, *len, &pending_start, &pending_end)) { + /* + * Case 1: the pending extent overlaps the start of + * candidate hole. That means the true hole is after the + * pending extent, but we need to find the next pending + * extent to properly size the hole. In the next loop, + * we will reduce to case 2 or 3. + * e.g., + * + * |----pending A----| real hole |----pending B----| + * | candidate hole | + * *start end + */ + if (pending_start <= *start) { + *start = pending_end + 1; + goto next; + } + /* + * Case 2: The pending extent starts after *start (and overlaps + * [*start, end), so the first hole just goes up to the start + * of the pending extent. + * e.g., + * + * | real hole |----pending A----| + * | candidate hole | + * *start end + */ + *len = pending_start - *start; + if (*len > max_hole_len) { + max_hole_start = *start; + max_hole_len = *len; + } + if (*len >= min_hole_size) + break; + /* + * If the hole wasn't big enough, then we advance past + * the pending extent and keep looking. + */ + *start = pending_end + 1; + goto next; + } else { + /* + * Case 3: There is no pending extent overlapping the + * range [*start, *start + *len - 1], so the only remaining + * hole is the remaining range. + * e.g., + * + * | candidate hole | + * | real hole | + * *start end + */ + + if (*len > max_hole_len) { + max_hole_start = *start; + max_hole_len = *len; + } + break; + } +next: + if (*start > end) + break; + *len = end - *start + 1; + } + if (max_hole_len) { + *start = max_hole_start; + *len = max_hole_len; + } else { + *start = end + 1; + *len = 0; + } + return max_hole_len >= min_hole_size; +} + +static u64 dev_extent_search_start(struct btrfs_device *device) +{ + switch (device->fs_devices->chunk_alloc_policy) { + default: + btrfs_warn_unknown_chunk_allocation(device->fs_devices->chunk_alloc_policy); + fallthrough; + case BTRFS_CHUNK_ALLOC_REGULAR: + return BTRFS_DEVICE_RANGE_RESERVED; + case BTRFS_CHUNK_ALLOC_ZONED: + /* + * We don't care about the starting region like regular + * allocator, because we anyway use/reserve the first two zones + * for superblock logging. + */ + return 0; + } +} + +static bool dev_extent_hole_check_zoned(struct btrfs_device *device, + u64 *hole_start, u64 *hole_size, + u64 num_bytes) +{ + u64 zone_size = device->zone_info->zone_size; + u64 pos; + int ret; + bool changed = false; + + ASSERT(IS_ALIGNED(*hole_start, zone_size), + "hole_start=%llu zone_size=%llu", *hole_start, zone_size); + + while (*hole_size > 0) { + pos = btrfs_find_allocatable_zones(device, *hole_start, + *hole_start + *hole_size, + num_bytes); + if (pos != *hole_start) { + *hole_size = *hole_start + *hole_size - pos; + *hole_start = pos; + changed = true; + if (*hole_size < num_bytes) + break; + } + + ret = btrfs_ensure_empty_zones(device, pos, num_bytes); + + /* Range is ensured to be empty */ + if (!ret) + return changed; + + /* Given hole range was invalid (outside of device) */ + if (ret == -ERANGE) { + *hole_start += *hole_size; + *hole_size = 0; + return true; + } + + *hole_start += zone_size; + *hole_size -= zone_size; + changed = true; + } + + return changed; +} + +/* + * Validate and adjust a hole for chunk allocation + * + * @device: the device containing the candidate hole + * @hole_start: input/output pointer for the hole start position + * @hole_size: input/output pointer for the hole size + * @num_bytes: minimum allocation size required + * + * Check if the specified hole is suitable for allocation and adjust it if + * necessary. The hole may be modified to skip over pending chunk allocations + * and to satisfy stricter zoned requirements on zoned filesystems. + * + * For regular (non-zoned) allocation, if the hole after adjustment is smaller + * than @num_bytes, the search continues past additional pending extents until + * either a sufficiently large hole is found or no more pending extents exist. + * + * Return: true if a suitable hole was found and false otherwise. + * If the return value is true, then *hole_start and *hole_size are set to + * represent the hole we found. + * If the return value is false, then *hole_start is set to the largest + * hole we found and *hole_size is set to its length. + * If there are no holes at all, then *hole_start is set to the end of the range + * and *hole_size is set to 0. + */ +static bool dev_extent_hole_check(struct btrfs_device *device, u64 *hole_start, + u64 *hole_size, u64 num_bytes) +{ + bool found = false; + const u64 hole_end = *hole_start + *hole_size - 1; + + ASSERT(*hole_size > 0); + +again: + *hole_size = hole_end - *hole_start + 1; + found = btrfs_find_hole_in_pending_extents(device, hole_start, hole_size, num_bytes); + if (!found) + return found; + ASSERT(*hole_size >= num_bytes); + + switch (device->fs_devices->chunk_alloc_policy) { + default: + btrfs_warn_unknown_chunk_allocation(device->fs_devices->chunk_alloc_policy); + fallthrough; + case BTRFS_CHUNK_ALLOC_REGULAR: + return found; + case BTRFS_CHUNK_ALLOC_ZONED: + if (dev_extent_hole_check_zoned(device, hole_start, hole_size, num_bytes)) + goto again; + break; + } + + return found; +} + +/* + * Find free space in the specified device. + * + * @device: the device which we search the free space in + * @num_bytes: the size of the free space that we need + * @search_start: the position from which to begin the search + * @start: store the start of the free space. + * @len: the size of the free space. that we find, or the size + * of the max free space if we don't find suitable free space + * + * This does a pretty simple search, the expectation is that it is called very + * infrequently and that a given device has a small number of extents. + * + * @start is used to store the start of the free space if we find. But if we + * don't find suitable free space, it will be used to store the start position + * of the max free space. + * + * @len is used to store the size of the free space that we find. + * But if we don't find suitable free space, it is used to store the size of + * the max free space. + * + * NOTE: This function will search *commit* root of device tree, and does extra + * check to ensure dev extents are not double allocated. + * This makes the function safe to allocate dev extents but may not report + * correct usable device space, as device extent freed in current transaction + * is not reported as available. + */ +static int find_free_dev_extent(struct btrfs_device *device, u64 num_bytes, + u64 *start, u64 *len) +{ + struct btrfs_fs_info *fs_info = device->fs_info; + struct btrfs_root *root = fs_info->dev_root; + struct btrfs_key key; + struct btrfs_dev_extent *dev_extent; + BTRFS_PATH_AUTO_FREE(path); + u64 search_start; + u64 hole_size; + u64 max_hole_start; + u64 max_hole_size = 0; + u64 extent_end; + u64 search_end = device->total_bytes; + int ret; + int slot; + struct extent_buffer *l; + + search_start = dev_extent_search_start(device); + max_hole_start = search_start; + + WARN_ON(device->zone_info && + !IS_ALIGNED(num_bytes, device->zone_info->zone_size)); + + path = btrfs_alloc_path(); + if (!path) { + ret = -ENOMEM; + goto out; + } + + if (search_start >= search_end || + test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state)) { + ret = -ENOSPC; + goto out; + } + + path->reada = READA_FORWARD; + path->search_commit_root = true; + path->skip_locking = true; + + key.objectid = device->devid; + key.type = BTRFS_DEV_EXTENT_KEY; + key.offset = search_start; + + ret = btrfs_search_backwards(root, &key, path); + if (ret < 0) + goto out; + + while (search_start < search_end) { + l = path->nodes[0]; + slot = path->slots[0]; + if (slot >= btrfs_header_nritems(l)) { + ret = btrfs_next_leaf(root, path); + if (ret == 0) + continue; + if (ret < 0) + goto out; + + break; + } + btrfs_item_key_to_cpu(l, &key, slot); + + if (key.objectid < device->devid) + goto next; + + if (key.objectid > device->devid) + break; + + if (key.type != BTRFS_DEV_EXTENT_KEY) + goto next; + + if (key.offset > search_end) + break; + + if (key.offset > search_start) { + hole_size = key.offset - search_start; + dev_extent_hole_check(device, &search_start, &hole_size, + num_bytes); + + if (hole_size > max_hole_size) { + max_hole_start = search_start; + max_hole_size = hole_size; + } + + /* + * If this free space is greater than which we need, + * it must be the max free space that we have found + * until now, so max_hole_start must point to the start + * of this free space and the length of this free space + * is stored in max_hole_size. Thus, we return + * max_hole_start and max_hole_size and go back to the + * caller. + */ + if (hole_size >= num_bytes) { + ret = 0; + goto out; + } + } + + dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent); + extent_end = key.offset + btrfs_dev_extent_length(l, + dev_extent); + if (extent_end > search_start) + search_start = extent_end; +next: + path->slots[0]++; + cond_resched(); + } + + /* + * At this point, search_start should be the end of + * allocated dev extents, and when shrinking the device, + * search_end may be smaller than search_start. + */ + if (search_end > search_start) { + hole_size = search_end - search_start; + dev_extent_hole_check(device, &search_start, &hole_size, num_bytes); + + if (hole_size > max_hole_size) { + max_hole_start = search_start; + max_hole_size = hole_size; + } + } + + /* See above. */ + if (max_hole_size < num_bytes) + ret = -ENOSPC; + else + ret = 0; + + ASSERT(max_hole_start + max_hole_size <= search_end, + "max_hole_start=%llu max_hole_size=%llu search_end=%llu", + max_hole_start, max_hole_size, search_end); +out: + *start = max_hole_start; + if (len) + *len = max_hole_size; + return ret; +} + +static int btrfs_free_dev_extent(struct btrfs_trans_handle *trans, + struct btrfs_device *device, + u64 start, u64 *dev_extent_len) +{ + struct btrfs_fs_info *fs_info = device->fs_info; + struct btrfs_root *root = fs_info->dev_root; + int ret; + BTRFS_PATH_AUTO_FREE(path); + struct btrfs_key key; + struct btrfs_key found_key; + struct extent_buffer *leaf = NULL; + struct btrfs_dev_extent *extent = NULL; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + key.objectid = device->devid; + key.type = BTRFS_DEV_EXTENT_KEY; + key.offset = start; +again: + ret = btrfs_search_slot(trans, root, &key, path, -1, 1); + if (ret > 0) { + ret = btrfs_previous_item(root, path, key.objectid, + BTRFS_DEV_EXTENT_KEY); + if (ret) + return ret; + leaf = path->nodes[0]; + btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); + extent = btrfs_item_ptr(leaf, path->slots[0], + struct btrfs_dev_extent); + BUG_ON(found_key.offset > start || found_key.offset + + btrfs_dev_extent_length(leaf, extent) < start); + key = found_key; + btrfs_release_path(path); + goto again; + } else if (ret == 0) { + leaf = path->nodes[0]; + extent = btrfs_item_ptr(leaf, path->slots[0], + struct btrfs_dev_extent); + } else { + return ret; + } + + *dev_extent_len = btrfs_dev_extent_length(leaf, extent); + + ret = btrfs_del_item(trans, root, path); + if (ret == 0) + set_bit(BTRFS_TRANS_HAVE_FREE_BGS, &trans->transaction->flags); + return ret; +} + +static u64 find_next_chunk(struct btrfs_fs_info *fs_info) +{ + struct rb_node *n; + u64 ret = 0; + + read_lock(&fs_info->mapping_tree_lock); + n = rb_last(&fs_info->mapping_tree.rb_root); + if (n) { + struct btrfs_chunk_map *map; + + map = rb_entry(n, struct btrfs_chunk_map, rb_node); + ret = map->start + map->chunk_len; + } + read_unlock(&fs_info->mapping_tree_lock); + + return ret; +} + +static noinline int find_next_devid(struct btrfs_fs_info *fs_info, + u64 *devid_ret) +{ + int ret; + struct btrfs_key key; + struct btrfs_key found_key; + BTRFS_PATH_AUTO_FREE(path); + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + key.objectid = BTRFS_DEV_ITEMS_OBJECTID; + key.type = BTRFS_DEV_ITEM_KEY; + key.offset = (u64)-1; + + ret = btrfs_search_slot(NULL, fs_info->chunk_root, &key, path, 0, 0); + if (ret < 0) + return ret; + + if (unlikely(ret == 0)) { + /* Corruption */ + btrfs_err(fs_info, "corrupted chunk tree devid -1 matched"); + return -EUCLEAN; + } + + ret = btrfs_previous_item(fs_info->chunk_root, path, + BTRFS_DEV_ITEMS_OBJECTID, + BTRFS_DEV_ITEM_KEY); + if (ret) { + *devid_ret = 1; + } else { + btrfs_item_key_to_cpu(path->nodes[0], &found_key, + path->slots[0]); + *devid_ret = found_key.offset + 1; + } + return 0; +} + +/* + * the device information is stored in the chunk root + * the btrfs_device struct should be fully filled in + */ +static int btrfs_add_dev_item(struct btrfs_trans_handle *trans, + struct btrfs_device *device) +{ + int ret; + BTRFS_PATH_AUTO_FREE(path); + struct btrfs_dev_item *dev_item; + struct extent_buffer *leaf; + struct btrfs_key key; + unsigned long ptr; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + key.objectid = BTRFS_DEV_ITEMS_OBJECTID; + key.type = BTRFS_DEV_ITEM_KEY; + key.offset = device->devid; + + btrfs_reserve_chunk_metadata(trans, true); + ret = btrfs_insert_empty_item(trans, trans->fs_info->chunk_root, path, + &key, sizeof(*dev_item)); + btrfs_trans_release_chunk_metadata(trans); + if (ret) + return ret; + + leaf = path->nodes[0]; + dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item); + + btrfs_set_device_id(leaf, dev_item, device->devid); + btrfs_set_device_generation(leaf, dev_item, 0); + btrfs_set_device_type(leaf, dev_item, device->type); + btrfs_set_device_io_align(leaf, dev_item, device->io_align); + btrfs_set_device_io_width(leaf, dev_item, device->io_width); + btrfs_set_device_sector_size(leaf, dev_item, device->sector_size); + btrfs_set_device_total_bytes(leaf, dev_item, + btrfs_device_get_disk_total_bytes(device)); + btrfs_set_device_bytes_used(leaf, dev_item, + btrfs_device_get_bytes_used(device)); + btrfs_set_device_group(leaf, dev_item, 0); + btrfs_set_device_seek_speed(leaf, dev_item, 0); + btrfs_set_device_bandwidth(leaf, dev_item, 0); + btrfs_set_device_start_offset(leaf, dev_item, 0); + + ptr = btrfs_device_uuid(dev_item); + write_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE); + ptr = btrfs_device_fsid(dev_item); + write_extent_buffer(leaf, trans->fs_info->fs_devices->metadata_uuid, + ptr, BTRFS_FSID_SIZE); + + return 0; +} + +/* + * Function to update ctime/mtime for a given device path. + * Mainly used for ctime/mtime based probe like libblkid. + * + * We don't care about errors here, this is just to be kind to userspace. + */ +static void update_dev_time(const char *device_path) +{ + struct path path; + int err; + + if (tsk_is_kthread(current)) { + scoped_with_init_fs() + err = kern_path(device_path, LOOKUP_FOLLOW, &path); + } else { + err = kern_path(device_path, LOOKUP_FOLLOW, &path); + } + + if (!err) { + vfs_utimes(&path, NULL); + path_put(&path); + } +} + +static int btrfs_rm_dev_item(struct btrfs_trans_handle *trans, + struct btrfs_device *device) +{ + struct btrfs_root *root = device->fs_info->chunk_root; + int ret; + BTRFS_PATH_AUTO_FREE(path); + struct btrfs_key key; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + key.objectid = BTRFS_DEV_ITEMS_OBJECTID; + key.type = BTRFS_DEV_ITEM_KEY; + key.offset = device->devid; + + btrfs_reserve_chunk_metadata(trans, false); + ret = btrfs_search_slot(trans, root, &key, path, -1, 1); + btrfs_trans_release_chunk_metadata(trans); + if (ret > 0) + return -ENOENT; + if (ret < 0) + return ret; + + return btrfs_del_item(trans, root, path); +} + +/* + * Verify that @num_devices satisfies the RAID profile constraints in the whole + * filesystem. It's up to the caller to adjust that number regarding eg. device + * replace. + */ +static int btrfs_check_raid_min_devices(struct btrfs_fs_info *fs_info, + u64 num_devices) +{ + u64 all_avail; + unsigned seq; + int i; + + do { + seq = read_seqbegin(&fs_info->profiles_lock); + + all_avail = fs_info->avail_data_alloc_bits | + fs_info->avail_system_alloc_bits | + fs_info->avail_metadata_alloc_bits; + } while (read_seqretry(&fs_info->profiles_lock, seq)); + + for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) { + if (!(all_avail & btrfs_raid_array[i].bg_flag)) + continue; + + if (num_devices < btrfs_raid_array[i].devs_min) + return btrfs_raid_array[i].mindev_error; + } + + return 0; +} + +static struct btrfs_device * btrfs_find_next_active_device( + struct btrfs_fs_devices *fs_devs, struct btrfs_device *device) +{ + struct btrfs_device *next_device; + + list_for_each_entry(next_device, &fs_devs->devices, dev_list) { + if (next_device != device && + !test_bit(BTRFS_DEV_STATE_MISSING, &next_device->dev_state) + && next_device->bdev) + return next_device; + } + + return NULL; +} + +/* + * Helper function to check if the given device is part of s_bdev / latest_dev + * and replace it with the provided or the next active device, in the context + * where this function called, there should be always be another device (or + * this_dev) which is active. + */ +void __cold btrfs_assign_next_active_device(struct btrfs_device *device, + struct btrfs_device *next_device) +{ + struct btrfs_fs_info *fs_info = device->fs_info; + + if (!next_device) + next_device = btrfs_find_next_active_device(fs_info->fs_devices, + device); + ASSERT(next_device); + + if (fs_info->sb->s_bdev && + (fs_info->sb->s_bdev == device->bdev)) + fs_info->sb->s_bdev = next_device->bdev; + + if (fs_info->fs_devices->latest_dev->bdev == device->bdev) + fs_info->fs_devices->latest_dev = next_device; +} + +/* + * Return btrfs_fs_devices::num_devices excluding the device that's being + * currently replaced. + */ +static u64 btrfs_num_devices(struct btrfs_fs_info *fs_info) +{ + u64 num_devices = fs_info->fs_devices->num_devices; + + down_read(&fs_info->dev_replace.rwsem); + if (btrfs_dev_replace_is_ongoing(&fs_info->dev_replace)) { + ASSERT(num_devices > 1, "num_devices=%llu", num_devices); + num_devices--; + } + up_read(&fs_info->dev_replace.rwsem); + + return num_devices; +} + +static void btrfs_scratch_superblock(struct btrfs_fs_info *fs_info, + struct block_device *bdev, int copy_num) +{ + struct btrfs_super_block *disk_super; + const size_t len = sizeof(disk_super->magic); + const u64 bytenr = btrfs_sb_offset(copy_num); + int ret; + + disk_super = btrfs_read_disk_super(bdev, copy_num, false); + if (IS_ERR(disk_super)) + return; + + memset(&disk_super->magic, 0, len); + folio_mark_dirty(virt_to_folio(disk_super)); + btrfs_release_disk_super(disk_super); + + ret = sync_blockdev_range(bdev, bytenr, bytenr + len - 1); + if (ret) + btrfs_warn(fs_info, "error clearing superblock number %d (%d)", + copy_num, ret); +} + +void btrfs_scratch_superblocks(struct btrfs_fs_info *fs_info, struct btrfs_device *device) +{ + int copy_num; + struct block_device *bdev = device->bdev; + + if (!bdev) + return; + + for (copy_num = 0; copy_num < BTRFS_SUPER_MIRROR_MAX; copy_num++) { + if (bdev_is_zoned(bdev)) + btrfs_reset_sb_log_zones(bdev, copy_num); + else + btrfs_scratch_superblock(fs_info, bdev, copy_num); + } + + /* Notify udev that device has changed */ + btrfs_kobject_uevent(bdev, KOBJ_CHANGE); + + /* Update ctime/mtime for device path for libblkid */ + update_dev_time(rcu_dereference_raw(device->name)); +} + +int btrfs_remove_dev_stat_item(struct btrfs_trans_handle *trans, u64 devid) +{ + BTRFS_PATH_AUTO_RELEASE(path); + struct btrfs_fs_info *fs_info = trans->fs_info; + struct btrfs_root *dev_root = fs_info->dev_root; + struct btrfs_key key; + int ret; + + key.objectid = BTRFS_DEV_STATS_OBJECTID; + key.type = BTRFS_PERSISTENT_ITEM_KEY; + key.offset = devid; + + ret = btrfs_search_slot(trans, dev_root, &key, &path, -1, 1); + if (ret < 0) { + btrfs_warn(fs_info, + "error %d while searching for dev_stats item for devid %llu", + ret, devid); + return ret; + } + /* The dev stats item does not exist, nothing to bother. */ + if (ret > 0) + return 0; + ret = btrfs_del_item(trans, dev_root, &path); + if (ret < 0) { + btrfs_warn(fs_info, + "error %d while deleting dev_stats item for devid %llu", + ret, devid); + return ret; + } + return 0; +} + +int btrfs_rm_device(struct btrfs_fs_info *fs_info, + struct btrfs_dev_lookup_args *args, + struct file **bdev_file) +{ + struct btrfs_trans_handle *trans; + struct btrfs_device *device; + struct btrfs_fs_devices *cur_devices; + struct btrfs_fs_devices *fs_devices = fs_info->fs_devices; + u64 num_devices; + int ret = 0; + + if (btrfs_fs_incompat(fs_info, EXTENT_TREE_V2)) { + btrfs_err(fs_info, "device remove not supported on extent tree v2 yet"); + return -EINVAL; + } + + /* + * The device list in fs_devices is accessed without locks (neither + * uuid_mutex nor device_list_mutex) as it won't change on a mounted + * filesystem and another device rm cannot run. + */ + num_devices = btrfs_num_devices(fs_info); + + ret = btrfs_check_raid_min_devices(fs_info, num_devices - 1); + if (ret) + return ret; + + device = btrfs_find_device(fs_info->fs_devices, args); + if (!device) { + if (args->missing) + ret = BTRFS_ERROR_DEV_MISSING_NOT_FOUND; + else + ret = -ENOENT; + return ret; + } + + if (btrfs_pinned_by_swapfile(fs_info, device)) { + btrfs_warn(fs_info, + "cannot remove device %s (devid %llu) due to active swapfile", + btrfs_dev_name(device), device->devid); + return -ETXTBSY; + } + + if (test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state)) + return BTRFS_ERROR_DEV_TGT_REPLACE; + + if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state) && + fs_info->fs_devices->rw_devices == 1) + return BTRFS_ERROR_DEV_ONLY_WRITABLE; + + /* Removal and freezing are mutually exclusive; refuse if frozen now. */ + if (device->bdev) { + ret = bdev_deny_freeze(device->bdev); + if (ret) + return ret; + } + + if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state)) { + mutex_lock(&fs_info->chunk_mutex); + list_del_init(&device->dev_alloc_list); + device->fs_devices->rw_devices--; + btrfs_update_per_profile_avail(fs_info); + mutex_unlock(&fs_info->chunk_mutex); + } + + ret = btrfs_shrink_device(device, 0); + if (ret) + goto error_undo; + + trans = btrfs_start_transaction(fs_info->chunk_root, 0); + if (IS_ERR(trans)) { + ret = PTR_ERR(trans); + goto error_undo; + } + + ret = btrfs_rm_dev_item(trans, device); + if (unlikely(ret)) { + /* Any error in dev item removal is critical */ + btrfs_crit(fs_info, + "failed to remove device item for devid %llu: %d", + device->devid, ret); + btrfs_abort_transaction(trans, ret); + btrfs_end_transaction(trans); + if (device->bdev) + bdev_allow_freeze(device->bdev); + return ret; + } + + ret = btrfs_remove_dev_stat_item(trans, device->devid); + if (unlikely(ret)) { + btrfs_abort_transaction(trans, ret); + btrfs_end_transaction(trans); + return ret; + } + clear_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state); + btrfs_scrub_cancel_dev(device); + + /* + * the device list mutex makes sure that we don't change + * the device list while someone else is writing out all + * the device supers. Whoever is writing all supers, should + * lock the device list mutex before getting the number of + * devices in the super block (super_copy). Conversely, + * whoever updates the number of devices in the super block + * (super_copy) should hold the device list mutex. + */ + + /* + * In normal cases the cur_devices == fs_devices. But in case + * of deleting a seed device, the cur_devices should point to + * its own fs_devices listed under the fs_devices->seed_list. + */ + cur_devices = device->fs_devices; + mutex_lock(&fs_devices->device_list_mutex); + list_del_rcu(&device->dev_list); + + cur_devices->num_devices--; + cur_devices->total_devices--; + /* Update total_devices of the parent fs_devices if it's seed */ + if (cur_devices != fs_devices) + fs_devices->total_devices--; + + if (test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state)) + cur_devices->missing_devices--; + + btrfs_assign_next_active_device(device, NULL); + + if (device->bdev_file) { + cur_devices->open_devices--; + /* remove sysfs entry */ + btrfs_sysfs_remove_device(device); + } + + num_devices = btrfs_super_num_devices(fs_info->super_copy) - 1; + btrfs_set_super_num_devices(fs_info->super_copy, num_devices); + mutex_unlock(&fs_devices->device_list_mutex); + + /* + * At this point, the device is zero sized and detached from the + * devices list. All that's left is to zero out the old supers and + * free the device. + * + * We cannot call btrfs_close_bdev() here because we're holding the sb + * write lock, and bdev_fput() on the block device will pull in the + * ->open_mutex on the block device and it's dependencies. Instead + * just flush the device and let the caller do the final bdev_release. + */ + if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state)) { + btrfs_scratch_superblocks(fs_info, device); + if (device->bdev) { + sync_blockdev(device->bdev); + invalidate_bdev(device->bdev); + } + } + + *bdev_file = device->bdev_file; + synchronize_rcu(); + btrfs_free_device(device); + + /* + * This can happen if cur_devices is the private seed devices list. We + * cannot call close_fs_devices() here because it expects the uuid_mutex + * to be held, but in fact we don't need that for the private + * seed_devices, we can simply decrement cur_devices->opened and then + * remove it from our list and free the fs_devices. + */ + if (cur_devices->num_devices == 0) { + list_del_init(&cur_devices->seed_list); + ASSERT(cur_devices->opened == 1, "opened=%d", cur_devices->opened); + cur_devices->opened--; + free_fs_devices(cur_devices); + } + + return btrfs_commit_transaction(trans); + +error_undo: + if (device->bdev) + bdev_allow_freeze(device->bdev); + if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state)) { + mutex_lock(&fs_info->chunk_mutex); + list_add(&device->dev_alloc_list, + &fs_devices->alloc_list); + device->fs_devices->rw_devices++; + btrfs_update_per_profile_avail(fs_info); + mutex_unlock(&fs_info->chunk_mutex); + } + return ret; +} + +void btrfs_rm_dev_replace_remove_srcdev(struct btrfs_device *srcdev) +{ + struct btrfs_fs_devices *fs_devices; + + lockdep_assert_held(&srcdev->fs_info->fs_devices->device_list_mutex); + + /* + * in case of fs with no seed, srcdev->fs_devices will point + * to fs_devices of fs_info. However when the dev being replaced is + * a seed dev it will point to the seed's local fs_devices. In short + * srcdev will have its correct fs_devices in both the cases. + */ + fs_devices = srcdev->fs_devices; + + list_del_rcu(&srcdev->dev_list); + list_del(&srcdev->dev_alloc_list); + fs_devices->num_devices--; + if (test_bit(BTRFS_DEV_STATE_MISSING, &srcdev->dev_state)) + fs_devices->missing_devices--; + + if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &srcdev->dev_state)) + fs_devices->rw_devices--; + + if (srcdev->bdev) + fs_devices->open_devices--; +} + +void btrfs_rm_dev_replace_free_srcdev(struct btrfs_device *srcdev) +{ + struct btrfs_fs_devices *fs_devices = srcdev->fs_devices; + + mutex_lock(&uuid_mutex); + + /* The source was made unfreezable for the replace; undo it. */ + btrfs_close_bdev(srcdev, true); + synchronize_rcu(); + btrfs_free_device(srcdev); + + /* if this is no devs we rather delete the fs_devices */ + if (!fs_devices->num_devices) { + /* + * On a mounted FS, num_devices can't be zero unless it's a + * seed. In case of a seed device being replaced, the replace + * target added to the sprout FS, so there will be no more + * device left under the seed FS. + */ + ASSERT(fs_devices->seeding); + + list_del_init(&fs_devices->seed_list); + close_fs_devices(fs_devices); + free_fs_devices(fs_devices); + } + mutex_unlock(&uuid_mutex); +} + +void btrfs_destroy_dev_replace_tgtdev(struct btrfs_device *tgtdev, + bool allow_freeze) +{ + struct btrfs_fs_devices *fs_devices = tgtdev->fs_info->fs_devices; + + mutex_lock(&fs_devices->device_list_mutex); + + btrfs_sysfs_remove_device(tgtdev); + + if (tgtdev->bdev) + fs_devices->open_devices--; + + fs_devices->num_devices--; + + btrfs_assign_next_active_device(tgtdev, NULL); + + list_del_rcu(&tgtdev->dev_list); + + mutex_unlock(&fs_devices->device_list_mutex); + + btrfs_scratch_superblocks(tgtdev->fs_info, tgtdev); + + btrfs_close_bdev(tgtdev, allow_freeze); + synchronize_rcu(); + btrfs_free_device(tgtdev); +} + +/* + * Populate args from device at path. + * + * @fs_info: the filesystem + * @args: the args to populate + * @path: the path to the device + * + * This will read the super block of the device at @path and populate @args with + * the devid, fsid, and uuid. This is meant to be used for ioctls that need to + * lookup a device to operate on, but need to do it before we take any locks. + * This properly handles the special case of "missing" that a user may pass in, + * and does some basic sanity checks. The caller must make sure that @path is + * properly NUL terminated before calling in, and must call + * btrfs_put_dev_args_from_path() in order to free up the temporary fsid and + * uuid buffers. + * + * Return: 0 for success, -errno for failure + */ +int btrfs_get_dev_args_from_path(struct btrfs_fs_info *fs_info, + struct btrfs_dev_lookup_args *args, + const char *path) +{ + struct btrfs_super_block *disk_super; + struct file *bdev_file; + int ret; + + if (!path || !path[0]) + return -EINVAL; + if (!strcmp(path, "missing")) { + args->missing = true; + return 0; + } + + args->uuid = kzalloc(BTRFS_UUID_SIZE, GFP_KERNEL); + args->fsid = kzalloc(BTRFS_FSID_SIZE, GFP_KERNEL); + if (!args->uuid || !args->fsid) { + btrfs_put_dev_args_from_path(args); + return -ENOMEM; + } + + ret = btrfs_get_bdev_and_sb(path, BLK_OPEN_READ, NULL, 0, + &bdev_file, &disk_super); + if (ret) { + btrfs_put_dev_args_from_path(args); + return ret; + } + + args->devid = btrfs_stack_device_id(&disk_super->dev_item); + memcpy(args->uuid, disk_super->dev_item.uuid, BTRFS_UUID_SIZE); + if (btrfs_fs_incompat(fs_info, METADATA_UUID)) + memcpy(args->fsid, disk_super->metadata_uuid, BTRFS_FSID_SIZE); + else + memcpy(args->fsid, disk_super->fsid, BTRFS_FSID_SIZE); + btrfs_release_disk_super(disk_super); + bdev_fput(bdev_file); + return 0; +} + +/* + * Only use this jointly with btrfs_get_dev_args_from_path() because we will + * allocate our ->uuid and ->fsid pointers, everybody else uses local variables + * that don't need to be freed. + */ +void btrfs_put_dev_args_from_path(struct btrfs_dev_lookup_args *args) +{ + kfree(args->uuid); + kfree(args->fsid); + args->uuid = NULL; + args->fsid = NULL; +} + +struct btrfs_device *btrfs_find_device_by_devspec( + struct btrfs_fs_info *fs_info, u64 devid, + const char *device_path) +{ + BTRFS_DEV_LOOKUP_ARGS(args); + struct btrfs_device *device; + int ret; + + if (devid) { + args.devid = devid; + device = btrfs_find_device(fs_info->fs_devices, &args); + if (!device) + return ERR_PTR(-ENOENT); + return device; + } + + ret = btrfs_get_dev_args_from_path(fs_info, &args, device_path); + if (ret) + return ERR_PTR(ret); + device = btrfs_find_device(fs_info->fs_devices, &args); + btrfs_put_dev_args_from_path(&args); + if (!device) + return ERR_PTR(-ENOENT); + return device; +} + +static struct btrfs_fs_devices *btrfs_init_sprout(struct btrfs_fs_info *fs_info) +{ + struct btrfs_fs_devices *fs_devices = fs_info->fs_devices; + struct btrfs_fs_devices *old_devices; + struct btrfs_fs_devices *seed_devices; + + lockdep_assert_held(&uuid_mutex); + if (!fs_devices->seeding) + return ERR_PTR(-EINVAL); + + /* + * Private copy of the seed devices, anchored at + * fs_info->fs_devices->seed_list + */ + seed_devices = alloc_fs_devices(NULL); + if (IS_ERR(seed_devices)) + return seed_devices; + + /* + * It's necessary to retain a copy of the original seed fs_devices in + * fs_uuids so that filesystems which have been seeded can successfully + * reference the seed device from open_seed_devices. This also supports + * multiple fs seed. + */ + old_devices = clone_fs_devices(fs_devices); + if (IS_ERR(old_devices)) { + kfree(seed_devices); + return old_devices; + } + + list_add(&old_devices->fs_list, &fs_uuids); + + memcpy(seed_devices, fs_devices, sizeof(*seed_devices)); + seed_devices->opened = 1; + INIT_LIST_HEAD(&seed_devices->devices); + INIT_LIST_HEAD(&seed_devices->alloc_list); + mutex_init(&seed_devices->device_list_mutex); + + return seed_devices; +} + +/* + * Splice seed devices into the sprout fs_devices. + * Generate a new fsid for the sprouted read-write filesystem. + */ +static void btrfs_setup_sprout(struct btrfs_fs_info *fs_info, + struct btrfs_fs_devices *seed_devices) +{ + struct btrfs_fs_devices *fs_devices = fs_info->fs_devices; + struct btrfs_super_block *disk_super = fs_info->super_copy; + struct btrfs_device *device; + u64 super_flags; + + /* + * We are updating the fsid, the thread leading to device_list_add() + * could race, so uuid_mutex is needed. + */ + lockdep_assert_held(&uuid_mutex); + + /* + * The threads listed below may traverse dev_list but can do that without + * device_list_mutex: + * - All device ops and balance - as we are in btrfs_exclop_start. + * - Various dev_list readers - are using RCU. + * - btrfs_ioctl_fitrim() - is using RCU. + * + * For-read threads as below are using device_list_mutex: + * - Readonly scrub btrfs_scrub_dev() + * - Readonly scrub btrfs_scrub_progress() + * - btrfs_get_dev_stats() + */ + lockdep_assert_held(&fs_devices->device_list_mutex); + + list_splice_init_rcu(&fs_devices->devices, &seed_devices->devices, + synchronize_rcu); + list_for_each_entry(device, &seed_devices->devices, dev_list) + device->fs_devices = seed_devices; + + fs_devices->seeding = false; + fs_devices->num_devices = 0; + fs_devices->open_devices = 0; + fs_devices->missing_devices = 0; + fs_devices->rotating = false; + list_add(&seed_devices->seed_list, &fs_devices->seed_list); + + generate_random_uuid(fs_devices->fsid); + memcpy(fs_devices->metadata_uuid, fs_devices->fsid, BTRFS_FSID_SIZE); + memcpy(disk_super->fsid, fs_devices->fsid, BTRFS_FSID_SIZE); + + super_flags = btrfs_super_flags(disk_super) & + ~BTRFS_SUPER_FLAG_SEEDING; + btrfs_set_super_flags(disk_super, super_flags); +} + +/* + * Store the expected generation for seed devices in device items. + */ +static int btrfs_finish_sprout(struct btrfs_trans_handle *trans) +{ + BTRFS_DEV_LOOKUP_ARGS(args); + struct btrfs_fs_info *fs_info = trans->fs_info; + struct btrfs_root *root = fs_info->chunk_root; + BTRFS_PATH_AUTO_FREE(path); + struct extent_buffer *leaf; + struct btrfs_dev_item *dev_item; + struct btrfs_device *device; + struct btrfs_key key; + u8 fs_uuid[BTRFS_FSID_SIZE]; + u8 dev_uuid[BTRFS_UUID_SIZE]; + int ret; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + key.objectid = BTRFS_DEV_ITEMS_OBJECTID; + key.type = BTRFS_DEV_ITEM_KEY; + key.offset = 0; + + while (1) { + btrfs_reserve_chunk_metadata(trans, false); + ret = btrfs_search_slot(trans, root, &key, path, 0, 1); + btrfs_trans_release_chunk_metadata(trans); + if (ret < 0) + return ret; + + leaf = path->nodes[0]; +next_slot: + if (path->slots[0] >= btrfs_header_nritems(leaf)) { + ret = btrfs_next_leaf(root, path); + if (ret > 0) + break; + if (ret < 0) + return ret; + leaf = path->nodes[0]; + btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); + btrfs_release_path(path); + continue; + } + + btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); + if (key.objectid != BTRFS_DEV_ITEMS_OBJECTID || + key.type != BTRFS_DEV_ITEM_KEY) + break; + + dev_item = btrfs_item_ptr(leaf, path->slots[0], + struct btrfs_dev_item); + args.devid = btrfs_device_id(leaf, dev_item); + read_extent_buffer(leaf, dev_uuid, btrfs_device_uuid(dev_item), + BTRFS_UUID_SIZE); + read_extent_buffer(leaf, fs_uuid, btrfs_device_fsid(dev_item), + BTRFS_FSID_SIZE); + args.uuid = dev_uuid; + args.fsid = fs_uuid; + device = btrfs_find_device(fs_info->fs_devices, &args); + BUG_ON(!device); /* Logic error */ + + if (device->fs_devices->seeding) + btrfs_set_device_generation(leaf, dev_item, + device->generation); + + path->slots[0]++; + goto next_slot; + } + return 0; +} + +/* + * Open @path for @sb with freezing denied before the holder claim is published, + * so a racing bdev_freeze() can never reach a claim a device add or replace may + * still abort. The deny is taken on a throwaway non-holder probe open, then the + * holder is opened by the probe's dev_t. Balanced by the caller. + */ +struct file *btrfs_open_device_deny_freeze(const char *path, + struct super_block *sb) +{ + struct file *probe_file, *bdev_file; + int ret; + + /* WRITE so bdev_file_open_by_path() rejects a read-only device. */ + probe_file = bdev_file_open_by_path(path, BLK_OPEN_WRITE, NULL, NULL); + if (IS_ERR(probe_file)) + return probe_file; + + ret = bdev_deny_freeze(file_bdev(probe_file)); + if (ret) { + bdev_fput(probe_file); + return ERR_PTR(ret); + } + + bdev_file = fs_bdev_file_open_by_dev(file_bdev(probe_file)->bd_dev, + BLK_OPEN_WRITE, sb, sb); + if (IS_ERR(bdev_file)) + bdev_allow_freeze(file_bdev(probe_file)); + bdev_fput(probe_file); + return bdev_file; +} + +int btrfs_init_new_device(struct btrfs_fs_info *fs_info, const char *device_path) +{ + struct btrfs_root *root = fs_info->dev_root; + struct btrfs_trans_handle *trans; + struct btrfs_device *device; + struct file *bdev_file; + struct super_block *sb = fs_info->sb; + struct btrfs_fs_devices *fs_devices = fs_info->fs_devices; + struct btrfs_fs_devices *seed_devices = NULL; + u64 orig_super_total_bytes; + u64 orig_super_num_devices; + int ret = 0; + bool seeding_dev = false; + bool locked = false; + + if (sb_rdonly(sb) && !fs_devices->seeding) + return -EROFS; + + /* Forbid freezing until the device is a committed member (or unwound). */ + bdev_file = btrfs_open_device_deny_freeze(device_path, fs_info->sb); + if (IS_ERR(bdev_file)) + return PTR_ERR(bdev_file); + + if (!btrfs_check_device_zone_type(fs_info, file_bdev(bdev_file))) { + ret = -EINVAL; + goto error; + } + + if (bdev_nr_bytes(file_bdev(bdev_file)) <= BTRFS_DEVICE_RANGE_RESERVED) { + ret = -EINVAL; + goto error; + } + + if (fs_devices->seeding) { + seeding_dev = true; + down_write(&sb->s_umount); + mutex_lock(&uuid_mutex); + locked = true; + } + + sync_blockdev(file_bdev(bdev_file)); + + rcu_read_lock(); + list_for_each_entry_rcu(device, &fs_devices->devices, dev_list) { + if (device->bdev == file_bdev(bdev_file)) { + ret = -EEXIST; + rcu_read_unlock(); + goto error; + } + } + rcu_read_unlock(); + + device = btrfs_alloc_device(fs_info, NULL, NULL, device_path); + if (IS_ERR(device)) { + /* we can safely leave the fs_devices entry around */ + ret = PTR_ERR(device); + goto error; + } + + device->fs_info = fs_info; + device->bdev_file = bdev_file; + device->bdev = file_bdev(bdev_file); + ret = lookup_bdev(device_path, &device->devt); + if (ret) + goto error_free_device; + + ret = btrfs_get_dev_zone_info(device, false); + if (ret) + goto error_free_device; + + trans = btrfs_start_transaction(root, 0); + if (IS_ERR(trans)) { + ret = PTR_ERR(trans); + goto error_free_zone; + } + + set_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state); + device->generation = trans->transid; + device->io_width = fs_info->sectorsize; + device->io_align = fs_info->sectorsize; + device->sector_size = fs_info->sectorsize; + device->total_bytes = + round_down(bdev_nr_bytes(device->bdev), fs_info->sectorsize); + device->disk_total_bytes = device->total_bytes; + device->commit_total_bytes = device->total_bytes; + set_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state); + clear_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state); + + /* + * Increase dev_stats_ccnt so that corresponding DEV_STATS item can be + * created at the next transaction commit. + */ + atomic_inc(&device->dev_stats_ccnt); + device->dev_stats_valid = 1; + set_blocksize(device->bdev_file, BTRFS_BDEV_BLOCKSIZE); + + if (seeding_dev) { + /* GFP_KERNEL allocation must not be under device_list_mutex */ + seed_devices = btrfs_init_sprout(fs_info); + if (IS_ERR(seed_devices)) { + ret = PTR_ERR(seed_devices); + btrfs_abort_transaction(trans, ret); + goto error_trans; + } + } + + mutex_lock(&fs_devices->device_list_mutex); + if (seeding_dev) { + btrfs_setup_sprout(fs_info, seed_devices); + btrfs_assign_next_active_device(fs_info->fs_devices->latest_dev, + device); + } + + device->fs_devices = fs_devices; + + mutex_lock(&fs_info->chunk_mutex); + list_add_rcu(&device->dev_list, &fs_devices->devices); + list_add(&device->dev_alloc_list, &fs_devices->alloc_list); + fs_devices->num_devices++; + fs_devices->open_devices++; + fs_devices->rw_devices++; + fs_devices->total_devices++; + fs_devices->total_rw_bytes += device->total_bytes; + + atomic64_add(device->total_bytes, &fs_info->free_chunk_space); + + if (bdev_rot(device->bdev)) + fs_devices->rotating = true; + + orig_super_total_bytes = btrfs_super_total_bytes(fs_info->super_copy); + btrfs_set_super_total_bytes(fs_info->super_copy, + round_down(orig_super_total_bytes + device->total_bytes, + fs_info->sectorsize)); + + orig_super_num_devices = btrfs_super_num_devices(fs_info->super_copy); + btrfs_set_super_num_devices(fs_info->super_copy, + orig_super_num_devices + 1); + + /* + * we've got more storage, clear any full flags on the space + * infos + */ + btrfs_clear_space_info_full(fs_info); + + btrfs_update_per_profile_avail(fs_info); + mutex_unlock(&fs_info->chunk_mutex); + + /* Add sysfs device entry */ + btrfs_sysfs_add_device(device); + + mutex_unlock(&fs_devices->device_list_mutex); + + if (seeding_dev) { + mutex_lock(&fs_info->chunk_mutex); + ret = init_first_rw_device(trans); + btrfs_update_per_profile_avail(fs_info); + mutex_unlock(&fs_info->chunk_mutex); + if (unlikely(ret)) { + btrfs_abort_transaction(trans, ret); + goto error_sysfs; + } + } + + ret = btrfs_add_dev_item(trans, device); + if (unlikely(ret)) { + btrfs_abort_transaction(trans, ret); + goto error_sysfs; + } + + if (seeding_dev) { + ret = btrfs_finish_sprout(trans); + if (unlikely(ret)) { + btrfs_abort_transaction(trans, ret); + goto error_sysfs; + } + + /* + * fs_devices now represents the newly sprouted filesystem and + * its fsid has been changed by btrfs_sprout_splice(). + */ + btrfs_sysfs_update_sprout_fsid(fs_devices); + } + + ret = btrfs_commit_transaction(trans); + + if (seeding_dev) { + mutex_unlock(&uuid_mutex); + up_write(&sb->s_umount); + locked = false; + + if (ret) { /* transaction commit */ + bdev_allow_freeze(file_bdev(bdev_file)); + return ret; + } + + ret = btrfs_relocate_sys_chunks(fs_info); + if (ret < 0) + btrfs_handle_fs_error(fs_info, ret, + "Failed to relocate sys chunks after device initialization. This can be fixed using the \"btrfs balance\" command."); + trans = btrfs_attach_transaction(root); + if (IS_ERR(trans)) { + if (PTR_ERR(trans) == -ENOENT) { + bdev_allow_freeze(file_bdev(bdev_file)); + return 0; + } + ret = PTR_ERR(trans); + trans = NULL; + goto error_sysfs; + } + ret = btrfs_commit_transaction(trans); + } + + /* + * Now that we have written a new super block to this device, check all + * other fs_devices list if device_path alienates any other scanned + * device. + * We can ignore the return value as it typically returns -EINVAL and + * only succeeds if the device was an alien. + */ + btrfs_forget_devices(device->devt); + + /* Update ctime/mtime for blkid or udev */ + update_dev_time(device_path); + + bdev_allow_freeze(file_bdev(bdev_file)); + return ret; + +error_sysfs: + btrfs_sysfs_remove_device(device); + mutex_lock(&fs_info->fs_devices->device_list_mutex); + mutex_lock(&fs_info->chunk_mutex); + list_del_rcu(&device->dev_list); + list_del(&device->dev_alloc_list); + fs_info->fs_devices->num_devices--; + fs_info->fs_devices->open_devices--; + fs_info->fs_devices->rw_devices--; + fs_info->fs_devices->total_devices--; + fs_info->fs_devices->total_rw_bytes -= device->total_bytes; + atomic64_sub(device->total_bytes, &fs_info->free_chunk_space); + btrfs_set_super_total_bytes(fs_info->super_copy, + orig_super_total_bytes); + btrfs_set_super_num_devices(fs_info->super_copy, + orig_super_num_devices); + btrfs_update_per_profile_avail(fs_info); + mutex_unlock(&fs_info->chunk_mutex); + mutex_unlock(&fs_info->fs_devices->device_list_mutex); +error_trans: + if (trans) + btrfs_end_transaction(trans); +error_free_zone: + btrfs_destroy_dev_zone_info(device); +error_free_device: + btrfs_free_device(device); +error: + btrfs_release_device_allow_freeze(bdev_file); + if (locked) { + mutex_unlock(&uuid_mutex); + up_write(&sb->s_umount); + } + return ret; +} + +int btrfs_update_device(struct btrfs_trans_handle *trans, struct btrfs_device *device) +{ + int ret; + BTRFS_PATH_AUTO_FREE(path); + struct btrfs_root *root = device->fs_info->chunk_root; + struct btrfs_dev_item *dev_item; + struct extent_buffer *leaf; + struct btrfs_key key; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + key.objectid = BTRFS_DEV_ITEMS_OBJECTID; + key.type = BTRFS_DEV_ITEM_KEY; + key.offset = device->devid; + + ret = btrfs_search_slot(trans, root, &key, path, 0, 1); + if (ret < 0) + return ret; + + if (ret > 0) + return -ENOENT; + + leaf = path->nodes[0]; + dev_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dev_item); + + btrfs_set_device_id(leaf, dev_item, device->devid); + btrfs_set_device_type(leaf, dev_item, device->type); + btrfs_set_device_io_align(leaf, dev_item, device->io_align); + btrfs_set_device_io_width(leaf, dev_item, device->io_width); + btrfs_set_device_sector_size(leaf, dev_item, device->sector_size); + btrfs_set_device_total_bytes(leaf, dev_item, + btrfs_device_get_disk_total_bytes(device)); + btrfs_set_device_bytes_used(leaf, dev_item, + btrfs_device_get_bytes_used(device)); + return ret; +} + +int btrfs_grow_device(struct btrfs_trans_handle *trans, + struct btrfs_device *device, u64 new_size) +{ + struct btrfs_fs_info *fs_info = device->fs_info; + struct btrfs_super_block *super_copy = fs_info->super_copy; + u64 old_total; + u64 diff; + int ret; + + if (!test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state)) + return -EACCES; + + new_size = round_down(new_size, fs_info->sectorsize); + + mutex_lock(&fs_info->chunk_mutex); + old_total = btrfs_super_total_bytes(super_copy); + diff = round_down(new_size - device->total_bytes, fs_info->sectorsize); + + if (new_size <= device->total_bytes || + test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state)) { + mutex_unlock(&fs_info->chunk_mutex); + return -EINVAL; + } + + btrfs_set_super_total_bytes(super_copy, + round_down(old_total + diff, fs_info->sectorsize)); + device->fs_devices->total_rw_bytes += diff; + atomic64_add(diff, &fs_info->free_chunk_space); + + btrfs_device_set_total_bytes(device, new_size); + btrfs_device_set_disk_total_bytes(device, new_size); + btrfs_clear_space_info_full(device->fs_info); + if (list_empty(&device->post_commit_list)) + list_add_tail(&device->post_commit_list, + &trans->transaction->dev_update_list); + btrfs_update_per_profile_avail(fs_info); + mutex_unlock(&fs_info->chunk_mutex); + + btrfs_reserve_chunk_metadata(trans, false); + ret = btrfs_update_device(trans, device); + btrfs_trans_release_chunk_metadata(trans); + + return ret; +} + +static int btrfs_free_chunk(struct btrfs_trans_handle *trans, u64 chunk_offset) +{ + struct btrfs_fs_info *fs_info = trans->fs_info; + struct btrfs_root *root = fs_info->chunk_root; + int ret; + BTRFS_PATH_AUTO_FREE(path); + struct btrfs_key key; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID; + key.type = BTRFS_CHUNK_ITEM_KEY; + key.offset = chunk_offset; + + ret = btrfs_search_slot(trans, root, &key, path, -1, 1); + if (ret < 0) + return ret; + if (unlikely(ret > 0)) { + /* Logic error or corruption */ + btrfs_err(fs_info, "failed to lookup chunk %llu when freeing", + chunk_offset); + btrfs_abort_transaction(trans, -ENOENT); + return -EUCLEAN; + } + + ret = btrfs_del_item(trans, root, path); + if (unlikely(ret < 0)) { + btrfs_err(fs_info, "failed to delete chunk %llu item", chunk_offset); + btrfs_abort_transaction(trans, ret); + return ret; + } + return ret; +} + +static int btrfs_del_sys_chunk(struct btrfs_fs_info *fs_info, u64 chunk_offset) +{ + struct btrfs_super_block *super_copy = fs_info->super_copy; + struct btrfs_disk_key *disk_key; + struct btrfs_chunk *chunk; + u8 *ptr; + int ret = 0; + u32 num_stripes; + u32 array_size; + u32 len = 0; + u32 cur; + struct btrfs_key key; + + lockdep_assert_held(&fs_info->chunk_mutex); + array_size = btrfs_super_sys_array_size(super_copy); + + ptr = super_copy->sys_chunk_array; + cur = 0; + + while (cur < array_size) { + disk_key = (struct btrfs_disk_key *)ptr; + btrfs_disk_key_to_cpu(&key, disk_key); + + len = sizeof(*disk_key); + + if (key.type == BTRFS_CHUNK_ITEM_KEY) { + chunk = (struct btrfs_chunk *)(ptr + len); + num_stripes = btrfs_stack_chunk_num_stripes(chunk); + len += btrfs_chunk_item_size(num_stripes); + } else { + ret = -EIO; + break; + } + if (key.objectid == BTRFS_FIRST_CHUNK_TREE_OBJECTID && + key.offset == chunk_offset) { + memmove(ptr, ptr + len, array_size - (cur + len)); + array_size -= len; + btrfs_set_super_sys_array_size(super_copy, array_size); + } else { + ptr += len; + cur += len; + } + } + return ret; +} + +struct btrfs_chunk_map *btrfs_find_chunk_map_nolock(struct btrfs_fs_info *fs_info, + u64 logical, u64 length) +{ + struct rb_node *node = fs_info->mapping_tree.rb_root.rb_node; + struct rb_node *prev = NULL; + struct rb_node *orig_prev; + struct btrfs_chunk_map *map; + struct btrfs_chunk_map *prev_map = NULL; + + while (node) { + map = rb_entry(node, struct btrfs_chunk_map, rb_node); + prev = node; + prev_map = map; + + if (logical < map->start) { + node = node->rb_left; + } else if (logical >= map->start + map->chunk_len) { + node = node->rb_right; + } else { + refcount_inc(&map->refs); + return map; + } + } + + if (!prev) + return NULL; + + orig_prev = prev; + while (prev && logical >= prev_map->start + prev_map->chunk_len) { + prev = rb_next(prev); + prev_map = rb_entry(prev, struct btrfs_chunk_map, rb_node); + } + + if (!prev) { + prev = orig_prev; + prev_map = rb_entry(prev, struct btrfs_chunk_map, rb_node); + while (prev && logical < prev_map->start) { + prev = rb_prev(prev); + prev_map = rb_entry(prev, struct btrfs_chunk_map, rb_node); + } + } + + if (prev) { + u64 end = logical + length; + + /* + * Caller can pass a U64_MAX length when it wants to get any + * chunk starting at an offset of 'logical' or higher, so deal + * with underflow by resetting the end offset to U64_MAX. + */ + if (end < logical) + end = U64_MAX; + + if (end > prev_map->start && + logical < prev_map->start + prev_map->chunk_len) { + refcount_inc(&prev_map->refs); + return prev_map; + } + } + + return NULL; +} + +struct btrfs_chunk_map *btrfs_find_chunk_map(struct btrfs_fs_info *fs_info, + u64 logical, u64 length) +{ + struct btrfs_chunk_map *map; + + read_lock(&fs_info->mapping_tree_lock); + map = btrfs_find_chunk_map_nolock(fs_info, logical, length); + read_unlock(&fs_info->mapping_tree_lock); + + return map; +} + +/* + * Find the mapping containing the given logical extent. + * + * @logical: Logical block offset in bytes. + * @length: Length of extent in bytes. + * + * Return: Chunk mapping or ERR_PTR. + */ +struct btrfs_chunk_map *btrfs_get_chunk_map(struct btrfs_fs_info *fs_info, + u64 logical, u64 length) +{ + struct btrfs_chunk_map *map; + + map = btrfs_find_chunk_map(fs_info, logical, length); + + if (unlikely(!map)) { + btrfs_crit(fs_info, + "unable to find chunk map for logical %llu length %llu", + logical, length); + return ERR_PTR(-EINVAL); + } + + if (unlikely(map->start > logical || map->start + map->chunk_len <= logical)) { + btrfs_crit(fs_info, + "found a bad chunk map, wanted %llu-%llu, found %llu-%llu", + logical, logical + length, map->start, + map->start + map->chunk_len); + btrfs_free_chunk_map(map); + return ERR_PTR(-EINVAL); + } + + /* Callers are responsible for dropping the reference. */ + return map; +} + +static int remove_chunk_item(struct btrfs_trans_handle *trans, + struct btrfs_chunk_map *map, u64 chunk_offset) +{ + int i; + + /* + * Removing chunk items and updating the device items in the chunks btree + * requires holding the chunk_mutex. + * See the comment at btrfs_chunk_alloc() for the details. + */ + lockdep_assert_held(&trans->fs_info->chunk_mutex); + + for (i = 0; i < map->num_stripes; i++) { + int ret; + + ret = btrfs_update_device(trans, map->stripes[i].dev); + if (ret) + return ret; + } + + return btrfs_free_chunk(trans, chunk_offset); +} + +int btrfs_remove_dev_extents(struct btrfs_trans_handle *trans, struct btrfs_chunk_map *map) +{ + struct btrfs_fs_info *fs_info = trans->fs_info; + struct btrfs_fs_devices *fs_devices = fs_info->fs_devices; + u64 dev_extent_len = 0; + int i, ret = 0; + + /* + * First delete the device extent items from the devices btree. + * We take the device_list_mutex to avoid racing with the finishing phase + * of a device replace operation. See the comment below before acquiring + * fs_info->chunk_mutex. Note that here we do not acquire the chunk_mutex + * because that can result in a deadlock when deleting the device extent + * items from the devices btree - COWing an extent buffer from the btree + * may result in allocating a new metadata chunk, which would attempt to + * lock again fs_info->chunk_mutex. + */ + mutex_lock(&fs_devices->device_list_mutex); + for (i = 0; i < map->num_stripes; i++) { + struct btrfs_device *device = map->stripes[i].dev; + ret = btrfs_free_dev_extent(trans, device, + map->stripes[i].physical, + &dev_extent_len); + if (unlikely(ret)) { + mutex_unlock(&fs_devices->device_list_mutex); + btrfs_abort_transaction(trans, ret); + return ret; + } + + if (device->bytes_used > 0) { + mutex_lock(&fs_info->chunk_mutex); + btrfs_device_set_bytes_used(device, + device->bytes_used - dev_extent_len); + atomic64_add(dev_extent_len, &fs_info->free_chunk_space); + btrfs_clear_space_info_full(fs_info); + + if (list_empty(&device->post_commit_list)) { + list_add_tail(&device->post_commit_list, + &trans->transaction->dev_update_list); + } + + mutex_unlock(&fs_info->chunk_mutex); + } + } + mutex_unlock(&fs_devices->device_list_mutex); + + return 0; +} + +int btrfs_remove_chunk(struct btrfs_trans_handle *trans, u64 chunk_offset) +{ + struct btrfs_fs_info *fs_info = trans->fs_info; + struct btrfs_chunk_map *map; + int ret; + + map = btrfs_get_chunk_map(fs_info, chunk_offset, 1); + if (IS_ERR(map)) { + DEBUG_WARN("errr %ld reading chunk map at offset %llu", + PTR_ERR(map), chunk_offset); + return PTR_ERR(map); + } + + ret = btrfs_remove_dev_extents(trans, map); + if (ret) + goto out; + + /* + * We acquire fs_info->chunk_mutex for 2 reasons: + * + * 1) Just like with the first phase of the chunk allocation, we must + * reserve system space, do all chunk btree updates and deletions, and + * update the system chunk array in the superblock while holding this + * mutex. This is for similar reasons as explained on the comment at + * the top of btrfs_chunk_alloc(); + * + * 2) Prevent races with the final phase of a device replace operation + * that replaces the device object associated with the map's stripes, + * because the device object's id can change at any time during that + * final phase of the device replace operation + * (dev-replace.c:btrfs_dev_replace_finishing()), so we could grab the + * replaced device and then see it with an ID of + * BTRFS_DEV_REPLACE_DEVID, which would cause a failure when updating + * the device item, which does not exists on the chunk btree. + * The finishing phase of device replace acquires both the + * device_list_mutex and the chunk_mutex, in that order, so we are + * safe by just acquiring the chunk_mutex. + */ + trans->removing_chunk = true; + mutex_lock(&fs_info->chunk_mutex); + + check_system_chunk(trans, map->type); + + ret = remove_chunk_item(trans, map, chunk_offset); + /* + * Normally we should not get -ENOSPC since we reserved space before + * through the call to check_system_chunk(). + * + * Despite our system space_info having enough free space, we may not + * be able to allocate extents from its block groups, because all have + * an incompatible profile, which will force us to allocate a new system + * block group with the right profile, or right after we called + * check_system_space() above, a scrub turned the only system block group + * with enough free space into RO mode. + * This is explained with more detail at do_chunk_alloc(). + * + * So if we get -ENOSPC, allocate a new system chunk and retry once. + */ + if (ret == -ENOSPC) { + const u64 sys_flags = btrfs_system_alloc_profile(fs_info); + struct btrfs_block_group *sys_bg; + struct btrfs_space_info *space_info; + + space_info = btrfs_find_space_info(fs_info, sys_flags); + if (unlikely(!space_info)) { + ret = -EINVAL; + btrfs_abort_transaction(trans, ret); + goto out; + } + + sys_bg = btrfs_create_chunk(trans, space_info, sys_flags); + if (IS_ERR(sys_bg)) { + ret = PTR_ERR(sys_bg); + btrfs_abort_transaction(trans, ret); + goto out; + } + + ret = btrfs_chunk_alloc_add_chunk_item(trans, sys_bg); + if (unlikely(ret)) { + btrfs_abort_transaction(trans, ret); + goto out; + } + + ret = remove_chunk_item(trans, map, chunk_offset); + if (unlikely(ret)) { + btrfs_abort_transaction(trans, ret); + goto out; + } + } else if (unlikely(ret)) { + btrfs_abort_transaction(trans, ret); + goto out; + } + + trace_btrfs_chunk_free(fs_info, map, chunk_offset, map->chunk_len); + + if (map->type & BTRFS_BLOCK_GROUP_SYSTEM) { + ret = btrfs_del_sys_chunk(fs_info, chunk_offset); + if (unlikely(ret)) { + btrfs_abort_transaction(trans, ret); + goto out; + } + } + + btrfs_update_per_profile_avail(fs_info); + mutex_unlock(&fs_info->chunk_mutex); + trans->removing_chunk = false; + + /* + * We are done with chunk btree updates and deletions, so release the + * system space we previously reserved (with check_system_chunk()). + */ + btrfs_trans_release_chunk_metadata(trans); + + /* On error, btrfs_remove_block_group() aborts the transaction. */ + ret = btrfs_remove_block_group(trans, map); + if (unlikely(ret)) + ASSERT(BTRFS_FS_ERROR(fs_info) != 0); + +out: + if (trans->removing_chunk) { + mutex_unlock(&fs_info->chunk_mutex); + trans->removing_chunk = false; + } + /* once for us */ + btrfs_free_chunk_map(map); + return ret; +} + +static int btrfs_relocate_chunk_finish(struct btrfs_fs_info *fs_info, + struct btrfs_block_group *bg) +{ + struct btrfs_root *root = fs_info->chunk_root; + struct btrfs_trans_handle *trans; + u64 length; + int ret; + + btrfs_discard_cancel_work(&fs_info->discard_ctl, bg); + length = bg->length; + btrfs_put_block_group(bg); + + /* + * On a zoned file system, discard the whole block group, this will + * trigger a REQ_OP_ZONE_RESET operation on the device zone. If + * resetting the zone fails, don't treat it as a fatal problem from the + * filesystem's point of view. + */ + if (btrfs_is_zoned(fs_info)) { + ret = btrfs_discard_extent(fs_info, bg->start, length, NULL, true); + if (ret) + btrfs_info(fs_info, "failed to reset zone %llu after relocation", + bg->start); + } + + trans = btrfs_start_trans_remove_block_group(root->fs_info, bg->start); + if (IS_ERR(trans)) { + ret = PTR_ERR(trans); + btrfs_handle_fs_error(root->fs_info, ret, NULL); + return ret; + } + + /* Step two, delete the device extents and the chunk tree entries. */ + ret = btrfs_remove_chunk(trans, bg->start); + btrfs_end_transaction(trans); + + return ret; +} + +int btrfs_relocate_chunk(struct btrfs_fs_info *fs_info, u64 chunk_offset, bool verbose) +{ + struct btrfs_block_group *block_group; + int ret; + + if (btrfs_fs_incompat(fs_info, EXTENT_TREE_V2)) { + btrfs_err(fs_info, + "relocate: not supported on extent tree v2 yet"); + return -EINVAL; + } + + /* + * Prevent races with automatic removal of unused block groups. + * After we relocate and before we remove the chunk with offset + * chunk_offset, automatic removal of the block group can kick in, + * resulting in a failure when calling btrfs_remove_chunk() below. + * + * Make sure to acquire this mutex before doing a tree search (dev + * or chunk trees) to find chunks. Otherwise the cleaner kthread might + * call btrfs_remove_chunk() (through btrfs_delete_unused_bgs()) after + * we release the path used to search the chunk/dev tree and before + * the current task acquires this mutex and calls us. + */ + lockdep_assert_held(&fs_info->reclaim_bgs_lock); + + /* step one, relocate all the extents inside this chunk */ + btrfs_scrub_pause(fs_info); + ret = btrfs_relocate_block_group(fs_info, chunk_offset, verbose); + btrfs_scrub_continue(fs_info); + if (ret) { + /* + * If we had a transaction abort, stop all running scrubs. + * See transaction.c:cleanup_transaction() why we do it here. + */ + if (unlikely(BTRFS_FS_ERROR(fs_info))) + btrfs_scrub_cancel(fs_info); + return ret; + } + + block_group = btrfs_lookup_block_group(fs_info, chunk_offset); + if (!block_group) + return -ENOENT; + + if (should_relocate_using_remap_tree(block_group)) { + /* If we're relocating using the remap tree we're now done. */ + btrfs_put_block_group(block_group); + ret = 0; + } else { + ret = btrfs_relocate_chunk_finish(fs_info, block_group); + } + + return ret; +} + +static int btrfs_relocate_sys_chunks(struct btrfs_fs_info *fs_info) +{ + struct btrfs_root *chunk_root = fs_info->chunk_root; + BTRFS_PATH_AUTO_FREE(path); + struct extent_buffer *leaf; + struct btrfs_chunk *chunk; + struct btrfs_key key; + struct btrfs_key found_key; + u64 chunk_type; + bool retried = false; + int failed = 0; + int ret; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + +again: + key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID; + key.type = BTRFS_CHUNK_ITEM_KEY; + key.offset = (u64)-1; + + while (1) { + mutex_lock(&fs_info->reclaim_bgs_lock); + ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0); + if (ret < 0) { + mutex_unlock(&fs_info->reclaim_bgs_lock); + return ret; + } + if (unlikely(ret == 0)) { + /* + * On the first search we would find chunk tree with + * offset -1, which is not possible. On subsequent + * loops this would find an existing item on an invalid + * offset (one less than the previous one, wrong + * alignment and size). + */ + mutex_unlock(&fs_info->reclaim_bgs_lock); + return -EUCLEAN; + } + + ret = btrfs_previous_item(chunk_root, path, key.objectid, + key.type); + if (ret) + mutex_unlock(&fs_info->reclaim_bgs_lock); + if (ret < 0) + return ret; + if (ret > 0) + break; + + leaf = path->nodes[0]; + btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); + + chunk = btrfs_item_ptr(leaf, path->slots[0], + struct btrfs_chunk); + chunk_type = btrfs_chunk_type(leaf, chunk); + btrfs_release_path(path); + + if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM) { + ret = btrfs_relocate_chunk(fs_info, found_key.offset, + true); + if (ret == -ENOSPC) + failed++; + else + BUG_ON(ret); + } + mutex_unlock(&fs_info->reclaim_bgs_lock); + + if (found_key.offset == 0) + break; + key.offset = found_key.offset - 1; + } + ret = 0; + if (failed && !retried) { + failed = 0; + retried = true; + goto again; + } else if (WARN_ON(failed && retried)) { + ret = -ENOSPC; + } + return ret; +} + +/* + * return 1 : allocate a data chunk successfully, + * return <0: errors during allocating a data chunk, + * return 0 : no need to allocate a data chunk. + */ +static int btrfs_may_alloc_data_chunk(struct btrfs_fs_info *fs_info, + u64 chunk_offset) +{ + struct btrfs_block_group *cache; + u64 bytes_used; + u64 chunk_type; + + cache = btrfs_lookup_block_group(fs_info, chunk_offset); + if (unlikely(!cache)) { + btrfs_err(fs_info, "balance: chunk at bytenr %llu has no corresponding block group", + chunk_offset); + return -EUCLEAN; + } + chunk_type = cache->flags; + btrfs_put_block_group(cache); + + if (!(chunk_type & BTRFS_BLOCK_GROUP_DATA)) + return 0; + + spin_lock(&fs_info->data_sinfo->lock); + bytes_used = fs_info->data_sinfo->bytes_used; + spin_unlock(&fs_info->data_sinfo->lock); + + if (!bytes_used) { + struct btrfs_trans_handle *trans; + int ret; + + trans = btrfs_join_transaction(fs_info->tree_root); + if (IS_ERR(trans)) + return PTR_ERR(trans); + + ret = btrfs_force_chunk_alloc(trans, BTRFS_BLOCK_GROUP_DATA); + btrfs_end_transaction(trans); + if (ret < 0) + return ret; + return 1; + } + + return 0; +} + +static void btrfs_disk_balance_args_to_cpu(struct btrfs_balance_args *cpu, + const struct btrfs_disk_balance_args *disk) +{ + memset(cpu, 0, sizeof(*cpu)); + + cpu->profiles = le64_to_cpu(disk->profiles); + cpu->usage = le64_to_cpu(disk->usage); + cpu->devid = le64_to_cpu(disk->devid); + cpu->pstart = le64_to_cpu(disk->pstart); + cpu->pend = le64_to_cpu(disk->pend); + cpu->vstart = le64_to_cpu(disk->vstart); + cpu->vend = le64_to_cpu(disk->vend); + cpu->target = le64_to_cpu(disk->target); + cpu->flags = le64_to_cpu(disk->flags); + cpu->limit = le64_to_cpu(disk->limit); + cpu->stripes_min = le32_to_cpu(disk->stripes_min); + cpu->stripes_max = le32_to_cpu(disk->stripes_max); +} + +static void btrfs_cpu_balance_args_to_disk(struct btrfs_disk_balance_args *disk, + const struct btrfs_balance_args *cpu) +{ + memset(disk, 0, sizeof(*disk)); + + disk->profiles = cpu_to_le64(cpu->profiles); + disk->usage = cpu_to_le64(cpu->usage); + disk->devid = cpu_to_le64(cpu->devid); + disk->pstart = cpu_to_le64(cpu->pstart); + disk->pend = cpu_to_le64(cpu->pend); + disk->vstart = cpu_to_le64(cpu->vstart); + disk->vend = cpu_to_le64(cpu->vend); + disk->target = cpu_to_le64(cpu->target); + disk->flags = cpu_to_le64(cpu->flags); + disk->limit = cpu_to_le64(cpu->limit); + disk->stripes_min = cpu_to_le32(cpu->stripes_min); + disk->stripes_max = cpu_to_le32(cpu->stripes_max); +} + +static int insert_balance_item(struct btrfs_fs_info *fs_info, + struct btrfs_balance_control *bctl) +{ + struct btrfs_root *root = fs_info->tree_root; + struct btrfs_trans_handle *trans; + struct btrfs_balance_item *item; + struct btrfs_disk_balance_args disk_bargs; + struct btrfs_path *path; + struct extent_buffer *leaf; + struct btrfs_key key; + int ret; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + trans = btrfs_start_transaction(root, 0); + if (IS_ERR(trans)) { + btrfs_free_path(path); + return PTR_ERR(trans); + } + + key.objectid = BTRFS_BALANCE_OBJECTID; + key.type = BTRFS_TEMPORARY_ITEM_KEY; + key.offset = 0; + + ret = btrfs_insert_empty_item(trans, root, path, &key, + sizeof(*item)); + if (ret) + goto out; + + leaf = path->nodes[0]; + item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_balance_item); + + memzero_extent_buffer(leaf, (unsigned long)item, sizeof(*item)); + + btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->data); + btrfs_set_balance_data(leaf, item, &disk_bargs); + btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->meta); + btrfs_set_balance_meta(leaf, item, &disk_bargs); + btrfs_cpu_balance_args_to_disk(&disk_bargs, &bctl->sys); + btrfs_set_balance_sys(leaf, item, &disk_bargs); + btrfs_set_balance_flags(leaf, item, bctl->flags); +out: + btrfs_free_path(path); + if (ret == 0) + ret = btrfs_commit_transaction(trans); + else + btrfs_end_transaction(trans); + + return ret; +} + +static int del_balance_item(struct btrfs_fs_info *fs_info) +{ + struct btrfs_root *root = fs_info->tree_root; + struct btrfs_trans_handle *trans; + struct btrfs_path *path; + struct btrfs_key key; + int ret; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + trans = btrfs_start_transaction_fallback_global_rsv(root, 0); + if (IS_ERR(trans)) { + btrfs_free_path(path); + return PTR_ERR(trans); + } + + key.objectid = BTRFS_BALANCE_OBJECTID; + key.type = BTRFS_TEMPORARY_ITEM_KEY; + key.offset = 0; + + ret = btrfs_search_slot(trans, root, &key, path, -1, 1); + if (ret < 0) + goto out; + if (ret > 0) { + ret = -ENOENT; + goto out; + } + + ret = btrfs_del_item(trans, root, path); +out: + btrfs_free_path(path); + if (ret == 0) + ret = btrfs_commit_transaction(trans); + else + btrfs_end_transaction(trans); + + return ret; +} + +/* + * This is a heuristic used to reduce the number of chunks balanced on + * resume after balance was interrupted. + */ +static void update_balance_args(struct btrfs_balance_control *bctl) +{ + /* + * Turn on soft mode for chunk types that were being converted. + */ + if (bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT) + bctl->data.flags |= BTRFS_BALANCE_ARGS_SOFT; + if (bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) + bctl->sys.flags |= BTRFS_BALANCE_ARGS_SOFT; + if (bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) + bctl->meta.flags |= BTRFS_BALANCE_ARGS_SOFT; + + /* + * Turn on usage filter if is not already used. The idea is + * that chunks that we have already balanced should be + * reasonably full. Don't do it for chunks that are being + * converted - that will keep us from relocating unconverted + * (albeit full) chunks. + */ + if (!(bctl->data.flags & BTRFS_BALANCE_ARGS_USAGE) && + !(bctl->data.flags & BTRFS_BALANCE_ARGS_USAGE_RANGE) && + !(bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT)) { + bctl->data.flags |= BTRFS_BALANCE_ARGS_USAGE; + bctl->data.usage = 90; + } + if (!(bctl->sys.flags & BTRFS_BALANCE_ARGS_USAGE) && + !(bctl->sys.flags & BTRFS_BALANCE_ARGS_USAGE_RANGE) && + !(bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT)) { + bctl->sys.flags |= BTRFS_BALANCE_ARGS_USAGE; + bctl->sys.usage = 90; + } + if (!(bctl->meta.flags & BTRFS_BALANCE_ARGS_USAGE) && + !(bctl->meta.flags & BTRFS_BALANCE_ARGS_USAGE_RANGE) && + !(bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT)) { + bctl->meta.flags |= BTRFS_BALANCE_ARGS_USAGE; + bctl->meta.usage = 90; + } +} + +/* + * Clear the balance status in fs_info and delete the balance item from disk. + */ +static void reset_balance_state(struct btrfs_fs_info *fs_info) +{ + struct btrfs_balance_control *bctl = fs_info->balance_ctl; + int ret; + + ASSERT(fs_info->balance_ctl); + + spin_lock(&fs_info->balance_lock); + fs_info->balance_ctl = NULL; + spin_unlock(&fs_info->balance_lock); + + kfree(bctl); + ret = del_balance_item(fs_info); + if (ret) + btrfs_handle_fs_error(fs_info, ret, NULL); +} + +/* + * Balance filters. Return 1 if chunk should be filtered out + * (should not be balanced). + */ +static bool chunk_profiles_filter(u64 chunk_type, struct btrfs_balance_args *bargs) +{ + chunk_type = chunk_to_extended(chunk_type) & + BTRFS_EXTENDED_PROFILE_MASK; + + if (bargs->profiles & chunk_type) + return false; + + return true; +} + +static int chunk_usage_range_filter(struct btrfs_fs_info *fs_info, u64 chunk_offset, + struct btrfs_balance_args *bargs) +{ + struct btrfs_block_group *cache; + u64 chunk_used; + u64 user_thresh_min; + u64 user_thresh_max; + int ret = 1; + + cache = btrfs_lookup_block_group(fs_info, chunk_offset); + if (unlikely(!cache)) { + btrfs_err(fs_info, "balance: chunk at bytenr %llu has no corresponding block group", + chunk_offset); + return -EUCLEAN; + } + chunk_used = cache->used; + + if (bargs->usage_min == 0) + user_thresh_min = 0; + else + user_thresh_min = mult_perc(cache->length, bargs->usage_min); + + if (bargs->usage_max == 0) + user_thresh_max = 1; + else if (bargs->usage_max > 100) + user_thresh_max = cache->length; + else + user_thresh_max = mult_perc(cache->length, bargs->usage_max); + + if (user_thresh_min <= chunk_used && chunk_used < user_thresh_max) + ret = 0; + + btrfs_put_block_group(cache); + return ret; +} + +static int chunk_usage_filter(struct btrfs_fs_info *fs_info, u64 chunk_offset, + struct btrfs_balance_args *bargs) +{ + struct btrfs_block_group *cache; + u64 chunk_used, user_thresh; + int ret = 1; + + cache = btrfs_lookup_block_group(fs_info, chunk_offset); + if (unlikely(!cache)) { + btrfs_err(fs_info, "balance: chunk at bytenr %llu has no corresponding block group", + chunk_offset); + return -EUCLEAN; + } + chunk_used = cache->used; + + if (bargs->usage_min == 0) + user_thresh = 1; + else if (bargs->usage > 100) + user_thresh = cache->length; + else + user_thresh = mult_perc(cache->length, bargs->usage); + + if (chunk_used < user_thresh) + ret = 0; + + btrfs_put_block_group(cache); + return ret; +} + +static bool chunk_devid_filter(struct extent_buffer *leaf, struct btrfs_chunk *chunk, + struct btrfs_balance_args *bargs) +{ + struct btrfs_stripe *stripe; + int num_stripes = btrfs_chunk_num_stripes(leaf, chunk); + int i; + + for (i = 0; i < num_stripes; i++) { + stripe = btrfs_stripe_nr(chunk, i); + if (btrfs_stripe_devid(leaf, stripe) == bargs->devid) + return false; + } + + return true; +} + +static u64 calc_data_stripes(u64 type, int num_stripes) +{ + const int index = btrfs_bg_flags_to_raid_index(type); + const int ncopies = btrfs_raid_array[index].ncopies; + const int nparity = btrfs_raid_array[index].nparity; + + return (num_stripes - nparity) / ncopies; +} + +/* [pstart, pend) */ +static bool chunk_drange_filter(struct extent_buffer *leaf, struct btrfs_chunk *chunk, + struct btrfs_balance_args *bargs) +{ + struct btrfs_stripe *stripe; + int num_stripes = btrfs_chunk_num_stripes(leaf, chunk); + u64 stripe_offset; + u64 stripe_length; + u64 type; + int factor; + int i; + + if (!(bargs->flags & BTRFS_BALANCE_ARGS_DEVID)) + return false; + + type = btrfs_chunk_type(leaf, chunk); + factor = calc_data_stripes(type, num_stripes); + + for (i = 0; i < num_stripes; i++) { + stripe = btrfs_stripe_nr(chunk, i); + if (btrfs_stripe_devid(leaf, stripe) != bargs->devid) + continue; + + stripe_offset = btrfs_stripe_offset(leaf, stripe); + stripe_length = btrfs_chunk_length(leaf, chunk); + stripe_length = div_u64(stripe_length, factor); + + if (stripe_offset < bargs->pend && + stripe_offset + stripe_length > bargs->pstart) + return false; + } + + return true; +} + +/* [vstart, vend) */ +static bool chunk_vrange_filter(struct extent_buffer *leaf, struct btrfs_chunk *chunk, + u64 chunk_offset, struct btrfs_balance_args *bargs) +{ + if (chunk_offset < bargs->vend && + chunk_offset + btrfs_chunk_length(leaf, chunk) > bargs->vstart) + /* at least part of the chunk is inside this vrange */ + return false; + + return true; +} + +static bool chunk_stripes_range_filter(struct extent_buffer *leaf, + struct btrfs_chunk *chunk, + struct btrfs_balance_args *bargs) +{ + int num_stripes = btrfs_chunk_num_stripes(leaf, chunk); + + if (bargs->stripes_min <= num_stripes + && num_stripes <= bargs->stripes_max) + return false; + + return true; +} + +static bool chunk_soft_convert_filter(u64 chunk_type, struct btrfs_balance_args *bargs) +{ + if (!(bargs->flags & BTRFS_BALANCE_ARGS_CONVERT)) + return false; + + chunk_type = chunk_to_extended(chunk_type) & + BTRFS_EXTENDED_PROFILE_MASK; + + if (bargs->target == chunk_type) + return true; + + return false; +} + +static int should_balance_chunk(struct extent_buffer *leaf, struct btrfs_chunk *chunk, + u64 chunk_offset) +{ + struct btrfs_fs_info *fs_info = leaf->fs_info; + struct btrfs_balance_control *bctl = fs_info->balance_ctl; + struct btrfs_balance_args *bargs = NULL; + u64 chunk_type = btrfs_chunk_type(leaf, chunk); + + /* Treat METADATA_REMAP chunks as METADATA. */ + if (chunk_type & BTRFS_BLOCK_GROUP_METADATA_REMAP) { + chunk_type &= ~BTRFS_BLOCK_GROUP_METADATA_REMAP; + chunk_type |= BTRFS_BLOCK_GROUP_METADATA; + } + + /* type filter */ + if (!((chunk_type & BTRFS_BLOCK_GROUP_TYPE_MASK) & + (bctl->flags & BTRFS_BALANCE_TYPE_MASK))) { + return false; + } + + if (chunk_type & BTRFS_BLOCK_GROUP_DATA) + bargs = &bctl->data; + else if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM) + bargs = &bctl->sys; + else if (chunk_type & BTRFS_BLOCK_GROUP_METADATA) + bargs = &bctl->meta; + + /* profiles filter */ + if ((bargs->flags & BTRFS_BALANCE_ARGS_PROFILES) && + chunk_profiles_filter(chunk_type, bargs)) { + return false; + } + + /* usage filter */ + if (bargs->flags & BTRFS_BALANCE_ARGS_USAGE) { + int ret2; + + ret2 = chunk_usage_filter(fs_info, chunk_offset, bargs); + if (ret2 < 0) + return ret2; + if (ret2) + return false; + } else if (bargs->flags & BTRFS_BALANCE_ARGS_USAGE_RANGE) { + int ret2; + + ret2 = chunk_usage_range_filter(fs_info, chunk_offset, bargs); + if (ret2 < 0) + return ret2; + if (ret2) + return false; + } + + /* devid filter */ + if ((bargs->flags & BTRFS_BALANCE_ARGS_DEVID) && + chunk_devid_filter(leaf, chunk, bargs)) { + return false; + } + + /* drange filter, makes sense only with devid filter */ + if ((bargs->flags & BTRFS_BALANCE_ARGS_DRANGE) && + chunk_drange_filter(leaf, chunk, bargs)) { + return false; + } + + /* vrange filter */ + if ((bargs->flags & BTRFS_BALANCE_ARGS_VRANGE) && + chunk_vrange_filter(leaf, chunk, chunk_offset, bargs)) { + return false; + } + + /* stripes filter */ + if ((bargs->flags & BTRFS_BALANCE_ARGS_STRIPES_RANGE) && + chunk_stripes_range_filter(leaf, chunk, bargs)) { + return false; + } + + /* soft profile changing mode */ + if ((bargs->flags & BTRFS_BALANCE_ARGS_SOFT) && + chunk_soft_convert_filter(chunk_type, bargs)) { + return false; + } + + /* + * limited by count, must be the last filter + */ + if ((bargs->flags & BTRFS_BALANCE_ARGS_LIMIT)) { + if (bargs->limit == 0) + return false; + else + bargs->limit--; + } else if ((bargs->flags & BTRFS_BALANCE_ARGS_LIMIT_RANGE)) { + /* + * Same logic as the 'limit' filter; the minimum cannot be + * determined here because we do not have the global information + * about the count of all chunks that satisfy the filters. + */ + if (bargs->limit_max == 0) + return false; + else + bargs->limit_max--; + } + + return true; +} + +struct remap_chunk_info { + struct list_head list; + u64 offset; + struct btrfs_block_group *bg; + bool made_ro; +}; + +static int cow_remap_tree(struct btrfs_trans_handle *trans, struct btrfs_path *path) +{ + struct btrfs_fs_info *fs_info = trans->fs_info; + struct btrfs_key key = { 0 }; + int ret; + + ret = btrfs_search_slot(trans, fs_info->remap_root, &key, path, 0, 1); + if (ret < 0) + return ret; + + while (true) { + ret = btrfs_next_leaf(fs_info->remap_root, path); + if (ret < 0) { + return ret; + } else if (ret > 0) { + ret = 0; + break; + } + + btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); + + btrfs_release_path(path); + + ret = btrfs_search_slot(trans, fs_info->remap_root, &key, path, 0, 1); + if (ret < 0) + break; + } + + return ret; +} + +static int balance_remap_chunks(struct btrfs_fs_info *fs_info, struct btrfs_path *path, + struct list_head *chunks) +{ + struct remap_chunk_info *rci, *tmp; + struct btrfs_trans_handle *trans; + int ret; + + list_for_each_entry_safe(rci, tmp, chunks, list) { + rci->bg = btrfs_lookup_block_group(fs_info, rci->offset); + if (!rci->bg) { + list_del(&rci->list); + kfree(rci); + continue; + } + + ret = btrfs_inc_block_group_ro(rci->bg, false); + if (ret) + goto end; + + rci->made_ro = true; + } + + if (list_empty(chunks)) + return 0; + + trans = btrfs_start_transaction(fs_info->remap_root, 0); + if (IS_ERR(trans)) { + ret = PTR_ERR(trans); + goto end; + } + + mutex_lock(&fs_info->remap_mutex); + ret = cow_remap_tree(trans, path); + mutex_unlock(&fs_info->remap_mutex); + + btrfs_release_path(path); + btrfs_commit_transaction(trans); + +end: + while (!list_empty(chunks)) { + bool is_unused; + struct btrfs_block_group *bg; + + rci = list_first_entry(chunks, struct remap_chunk_info, list); + + bg = rci->bg; + if (bg) { + /* + * This is a bit racy and the 'used' status can change + * but this is not a problem as later functions will + * verify it again. + */ + spin_lock(&bg->lock); + is_unused = !btrfs_is_block_group_used(bg); + spin_unlock(&bg->lock); + + if (is_unused) + btrfs_mark_bg_unused(bg); + + if (rci->made_ro) + btrfs_dec_block_group_ro(bg); + + btrfs_put_block_group(bg); + } + + list_del(&rci->list); + kfree(rci); + } + + return ret; +} + +static int __btrfs_balance(struct btrfs_fs_info *fs_info) +{ + struct btrfs_balance_control *bctl = fs_info->balance_ctl; + struct btrfs_root *chunk_root = fs_info->chunk_root; + u64 chunk_type; + struct btrfs_chunk *chunk; + BTRFS_PATH_AUTO_FREE(path); + struct btrfs_key key; + struct btrfs_key found_key; + struct extent_buffer *leaf; + int slot; + int ret; + int enospc_errors = 0; + bool counting = true; + /* The single value limit and min/max limits use the same bytes in the */ + u64 limit_data = bctl->data.limit; + u64 limit_meta = bctl->meta.limit; + u64 limit_sys = bctl->sys.limit; + u32 count_data = 0; + u32 count_meta = 0; + u32 count_sys = 0; + bool chunk_reserved = false; + struct remap_chunk_info *rci; + unsigned int num_remap_chunks = 0; + LIST_HEAD(remap_chunks); + + path = btrfs_alloc_path(); + if (!path) { + ret = -ENOMEM; + goto error; + } + + /* zero out stat counters */ + spin_lock(&fs_info->balance_lock); + memset(&bctl->stat, 0, sizeof(bctl->stat)); + spin_unlock(&fs_info->balance_lock); +again: + if (!counting) { + /* + * The single value limit and min/max limits use the same bytes + * in the + */ + bctl->data.limit = limit_data; + bctl->meta.limit = limit_meta; + bctl->sys.limit = limit_sys; + } + key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID; + key.type = BTRFS_CHUNK_ITEM_KEY; + key.offset = (u64)-1; + + while (1) { + if ((!counting && atomic_read(&fs_info->balance_pause_req)) || + atomic_read(&fs_info->balance_cancel_req)) { + ret = -ECANCELED; + goto error; + } + + mutex_lock(&fs_info->reclaim_bgs_lock); + ret = btrfs_search_slot(NULL, chunk_root, &key, path, 0, 0); + if (ret < 0) { + mutex_unlock(&fs_info->reclaim_bgs_lock); + goto error; + } + + /* + * this shouldn't happen, it means the last relocate + * failed + */ + if (unlikely(ret == 0)) { + btrfs_err(fs_info, + "unexpected exact match of CHUNK_ITEM in chunk tree, offset 0x%llx", + key.offset); + mutex_unlock(&fs_info->reclaim_bgs_lock); + ret = -EUCLEAN; + goto error; + } + + ret = btrfs_previous_item(chunk_root, path, 0, + BTRFS_CHUNK_ITEM_KEY); + if (ret) { + mutex_unlock(&fs_info->reclaim_bgs_lock); + ret = 0; + break; + } + + leaf = path->nodes[0]; + slot = path->slots[0]; + btrfs_item_key_to_cpu(leaf, &found_key, slot); + + if (found_key.objectid != key.objectid) { + mutex_unlock(&fs_info->reclaim_bgs_lock); + break; + } + + chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk); + chunk_type = btrfs_chunk_type(leaf, chunk); + + /* Check if chunk has already been fully relocated. */ + if (chunk_type & BTRFS_BLOCK_GROUP_REMAPPED && + btrfs_chunk_num_stripes(leaf, chunk) == 0) { + btrfs_release_path(path); + mutex_unlock(&fs_info->reclaim_bgs_lock); + goto loop; + } + + if (!counting) { + spin_lock(&fs_info->balance_lock); + bctl->stat.considered++; + spin_unlock(&fs_info->balance_lock); + } + + ret = should_balance_chunk(leaf, chunk, found_key.offset); + + btrfs_release_path(path); + if (ret < 0) { + mutex_unlock(&fs_info->reclaim_bgs_lock); + goto error; + } + if (!ret) { + mutex_unlock(&fs_info->reclaim_bgs_lock); + goto loop; + } + + if (counting) { + mutex_unlock(&fs_info->reclaim_bgs_lock); + spin_lock(&fs_info->balance_lock); + bctl->stat.expected++; + spin_unlock(&fs_info->balance_lock); + + if (chunk_type & BTRFS_BLOCK_GROUP_DATA) + count_data++; + else if (chunk_type & BTRFS_BLOCK_GROUP_SYSTEM) + count_sys++; + else if (chunk_type & (BTRFS_BLOCK_GROUP_METADATA | + BTRFS_BLOCK_GROUP_METADATA_REMAP)) + count_meta++; + + goto loop; + } + + /* + * Apply limit_min filter, no need to check if the LIMITS + * filter is used, limit_min is 0 by default + */ + if (((chunk_type & BTRFS_BLOCK_GROUP_DATA) && + count_data < bctl->data.limit_min) + || ((chunk_type & BTRFS_BLOCK_GROUP_METADATA) && + count_meta < bctl->meta.limit_min) + || ((chunk_type & BTRFS_BLOCK_GROUP_SYSTEM) && + count_sys < bctl->sys.limit_min)) { + mutex_unlock(&fs_info->reclaim_bgs_lock); + goto loop; + } + + /* + * Balancing METADATA_REMAP chunks takes place separately - add + * the details to a list so it can be processed later. + */ + if (chunk_type & BTRFS_BLOCK_GROUP_METADATA_REMAP) { + mutex_unlock(&fs_info->reclaim_bgs_lock); + + rci = kmalloc_obj(struct remap_chunk_info, GFP_NOFS); + if (!rci) { + ret = -ENOMEM; + goto error; + } + + rci->offset = found_key.offset; + rci->bg = NULL; + rci->made_ro = false; + list_add_tail(&rci->list, &remap_chunks); + + num_remap_chunks++; + + goto loop; + } + + if (!chunk_reserved) { + /* + * We may be relocating the only data chunk we have, + * which could potentially end up with losing data's + * raid profile, so lets allocate an empty one in + * advance. + */ + ret = btrfs_may_alloc_data_chunk(fs_info, + found_key.offset); + if (ret < 0) { + mutex_unlock(&fs_info->reclaim_bgs_lock); + goto error; + } else if (ret == 1) { + chunk_reserved = true; + } + } + + ret = btrfs_relocate_chunk(fs_info, found_key.offset, true); + mutex_unlock(&fs_info->reclaim_bgs_lock); + if (ret == -ENOSPC) { + enospc_errors++; + } else if (ret == -ETXTBSY) { + btrfs_warn(fs_info, + "skipping relocation of block group %llu due to active swapfile", + found_key.offset); + ret = 0; + } else if (ret) { + goto error; + } else { + spin_lock(&fs_info->balance_lock); + bctl->stat.completed++; + spin_unlock(&fs_info->balance_lock); + } +loop: + if (found_key.offset == 0) + break; + key.offset = found_key.offset - 1; + } + + btrfs_release_path(path); + + if (counting) { + counting = false; + goto again; + } + + if (!list_empty(&remap_chunks)) { + ret = balance_remap_chunks(fs_info, path, &remap_chunks); + if (ret == -ENOSPC) + enospc_errors++; + + if (!ret) { + spin_lock(&fs_info->balance_lock); + bctl->stat.completed += num_remap_chunks; + spin_unlock(&fs_info->balance_lock); + } + } +error: + if (enospc_errors) { + btrfs_info(fs_info, "%d enospc errors during balance", + enospc_errors); + if (!ret) + ret = -ENOSPC; + } + + return ret; +} + +/* + * See if a given profile is valid and reduced. + * + * @flags: profile to validate + * @extended: if true @flags is treated as an extended profile + */ +static int alloc_profile_is_valid(u64 flags, bool extended) +{ + u64 mask = (extended ? BTRFS_EXTENDED_PROFILE_MASK : + BTRFS_BLOCK_GROUP_PROFILE_MASK); + + flags &= ~BTRFS_BLOCK_GROUP_TYPE_MASK; + + /* 1) check that all other bits are zeroed */ + if (flags & ~mask) + return 0; + + /* 2) see if profile is reduced */ + if (flags == 0) + return !extended; /* "0" is valid for usual profiles */ + + return has_single_bit_set(flags); +} + +/* + * Validate target profile against allowed profiles and return true if it's OK. + * Otherwise print the error message and return false. + */ +static inline int validate_convert_profile(struct btrfs_fs_info *fs_info, + const struct btrfs_balance_args *bargs, + u64 allowed, const char *type) +{ + if (!(bargs->flags & BTRFS_BALANCE_ARGS_CONVERT)) + return true; + + /* Profile is valid and does not have bits outside of the allowed set */ + if (alloc_profile_is_valid(bargs->target, 1) && + (bargs->target & ~allowed) == 0) + return true; + + btrfs_err(fs_info, "balance: invalid convert %s profile %s", + type, btrfs_bg_type_to_raid_name(bargs->target)); + return false; +} + +/* + * Fill @buf with textual description of balance filter flags @bargs, up to + * @size_buf including the terminating null. The output may be trimmed if it + * does not fit into the provided buffer. + */ +static void describe_balance_args(struct btrfs_balance_args *bargs, char *buf, + u32 size_buf) +{ + int ret; + u32 size_bp = size_buf; + char *bp = buf; + u64 flags = bargs->flags; + char tmp_buf[128] = {'\0'}; + + if (!flags) + return; + +#define CHECK_APPEND_NOARG(a) \ + do { \ + ret = snprintf(bp, size_bp, (a)); \ + if (ret < 0 || ret >= size_bp) \ + goto out_overflow; \ + size_bp -= ret; \ + bp += ret; \ + } while (0) + +#define CHECK_APPEND_1ARG(a, v1) \ + do { \ + ret = snprintf(bp, size_bp, (a), (v1)); \ + if (ret < 0 || ret >= size_bp) \ + goto out_overflow; \ + size_bp -= ret; \ + bp += ret; \ + } while (0) + +#define CHECK_APPEND_2ARG(a, v1, v2) \ + do { \ + ret = snprintf(bp, size_bp, (a), (v1), (v2)); \ + if (ret < 0 || ret >= size_bp) \ + goto out_overflow; \ + size_bp -= ret; \ + bp += ret; \ + } while (0) + + if (flags & BTRFS_BALANCE_ARGS_CONVERT) + CHECK_APPEND_1ARG("convert=%s,", + btrfs_bg_type_to_raid_name(bargs->target)); + + if (flags & BTRFS_BALANCE_ARGS_SOFT) + CHECK_APPEND_NOARG("soft,"); + + if (flags & BTRFS_BALANCE_ARGS_PROFILES) { + btrfs_describe_block_groups(bargs->profiles, tmp_buf, + sizeof(tmp_buf)); + CHECK_APPEND_1ARG("profiles=%s,", tmp_buf); + } + + if (flags & BTRFS_BALANCE_ARGS_USAGE) + CHECK_APPEND_1ARG("usage=%llu,", bargs->usage); + + if (flags & BTRFS_BALANCE_ARGS_USAGE_RANGE) + CHECK_APPEND_2ARG("usage=%u..%u,", + bargs->usage_min, bargs->usage_max); + + if (flags & BTRFS_BALANCE_ARGS_DEVID) + CHECK_APPEND_1ARG("devid=%llu,", bargs->devid); + + if (flags & BTRFS_BALANCE_ARGS_DRANGE) + CHECK_APPEND_2ARG("drange=%llu..%llu,", + bargs->pstart, bargs->pend); + + if (flags & BTRFS_BALANCE_ARGS_VRANGE) + CHECK_APPEND_2ARG("vrange=%llu..%llu,", + bargs->vstart, bargs->vend); + + if (flags & BTRFS_BALANCE_ARGS_LIMIT) + CHECK_APPEND_1ARG("limit=%llu,", bargs->limit); + + if (flags & BTRFS_BALANCE_ARGS_LIMIT_RANGE) + CHECK_APPEND_2ARG("limit=%u..%u,", + bargs->limit_min, bargs->limit_max); + + if (flags & BTRFS_BALANCE_ARGS_STRIPES_RANGE) + CHECK_APPEND_2ARG("stripes=%u..%u,", + bargs->stripes_min, bargs->stripes_max); + +#undef CHECK_APPEND_2ARG +#undef CHECK_APPEND_1ARG +#undef CHECK_APPEND_NOARG + +out_overflow: + + if (size_bp < size_buf) + buf[size_buf - size_bp - 1] = '\0'; /* remove last , */ + else + buf[0] = '\0'; +} + +static void describe_balance_start_or_resume(struct btrfs_fs_info *fs_info) +{ + u32 size_buf = 1024; + char tmp_buf[192] = {'\0'}; + char AUTO_KFREE(buf); + char *bp; + u32 size_bp = size_buf; + int ret; + struct btrfs_balance_control *bctl = fs_info->balance_ctl; + + buf = kzalloc(size_buf, GFP_KERNEL); + if (!buf) + return; + + bp = buf; + +#define CHECK_APPEND_1ARG(a, v1) \ + do { \ + ret = snprintf(bp, size_bp, (a), (v1)); \ + if (ret < 0 || ret >= size_bp) \ + goto out_overflow; \ + size_bp -= ret; \ + bp += ret; \ + } while (0) + + if (bctl->flags & BTRFS_BALANCE_FORCE) + CHECK_APPEND_1ARG("%s", "-f "); + + if (bctl->flags & BTRFS_BALANCE_DATA) { + describe_balance_args(&bctl->data, tmp_buf, sizeof(tmp_buf)); + CHECK_APPEND_1ARG("-d%s ", tmp_buf); + } + + if (bctl->flags & BTRFS_BALANCE_METADATA) { + describe_balance_args(&bctl->meta, tmp_buf, sizeof(tmp_buf)); + CHECK_APPEND_1ARG("-m%s ", tmp_buf); + } + + if (bctl->flags & BTRFS_BALANCE_SYSTEM) { + describe_balance_args(&bctl->sys, tmp_buf, sizeof(tmp_buf)); + CHECK_APPEND_1ARG("-s%s ", tmp_buf); + } + +#undef CHECK_APPEND_1ARG + +out_overflow: + + if (size_bp < size_buf) + buf[size_buf - size_bp - 1] = '\0'; /* remove last " " */ + btrfs_info(fs_info, "balance: %s %s", + (bctl->flags & BTRFS_BALANCE_RESUME) ? + "resume" : "start", buf); +} + +/* + * Should be called with balance mutex held + */ +int btrfs_balance(struct btrfs_fs_info *fs_info, + struct btrfs_balance_control *bctl, + struct btrfs_ioctl_balance_args *bargs) +{ + u64 meta_target, data_target; + u64 allowed; + bool mixed = false; + int ret; + u64 num_devices; + unsigned seq; + bool reducing_redundancy; + bool paused = false; + int i; + + if (btrfs_fs_closing(fs_info) || + atomic_read(&fs_info->balance_pause_req) || + btrfs_should_cancel_balance(fs_info)) { + ret = -EINVAL; + goto out; + } + + allowed = btrfs_super_incompat_flags(fs_info->super_copy); + if (allowed & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS) + mixed = true; + + /* + * In case of mixed groups both data and meta should be picked, + * and identical options should be given for both of them. + */ + allowed = BTRFS_BALANCE_DATA | BTRFS_BALANCE_METADATA; + if (mixed && (bctl->flags & allowed)) { + if (!(bctl->flags & BTRFS_BALANCE_DATA) || + !(bctl->flags & BTRFS_BALANCE_METADATA) || + memcmp(&bctl->data, &bctl->meta, sizeof(bctl->data))) { + btrfs_err(fs_info, + "balance: mixed groups data and metadata options must be the same"); + ret = -EINVAL; + goto out; + } + } + + /* + * rw_devices will not change at the moment, device add/delete/replace + * are exclusive + */ + num_devices = fs_info->fs_devices->rw_devices; + + /* + * SINGLE profile on-disk has no profile bit, but in-memory we have a + * special bit for it, to make it easier to distinguish. Thus we need + * to set it manually, or balance would refuse the profile. + */ + allowed = BTRFS_AVAIL_ALLOC_BIT_SINGLE; + for (i = 0; i < ARRAY_SIZE(btrfs_raid_array); i++) + if (num_devices >= btrfs_raid_array[i].devs_min) + allowed |= btrfs_raid_array[i].bg_flag; + + if (!validate_convert_profile(fs_info, &bctl->data, allowed, "data") || + !validate_convert_profile(fs_info, &bctl->meta, allowed, "metadata") || + !validate_convert_profile(fs_info, &bctl->sys, allowed, "system")) { + ret = -EINVAL; + goto out; + } + + /* + * Allow to reduce metadata or system integrity only if force set for + * profiles with redundancy (copies, parity) + */ + allowed = 0; + for (i = 0; i < ARRAY_SIZE(btrfs_raid_array); i++) { + if (btrfs_raid_array[i].ncopies >= 2 || + btrfs_raid_array[i].tolerated_failures >= 1) + allowed |= btrfs_raid_array[i].bg_flag; + } + do { + seq = read_seqbegin(&fs_info->profiles_lock); + + if (((bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) && + (fs_info->avail_system_alloc_bits & allowed) && + !(bctl->sys.target & allowed)) || + ((bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) && + (fs_info->avail_metadata_alloc_bits & allowed) && + !(bctl->meta.target & allowed))) + reducing_redundancy = true; + else + reducing_redundancy = false; + + /* if we're not converting, the target field is uninitialized */ + meta_target = (bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) ? + bctl->meta.target : fs_info->avail_metadata_alloc_bits; + data_target = (bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT) ? + bctl->data.target : fs_info->avail_data_alloc_bits; + } while (read_seqretry(&fs_info->profiles_lock, seq)); + + if (reducing_redundancy) { + if (bctl->flags & BTRFS_BALANCE_FORCE) { + btrfs_info(fs_info, + "balance: force reducing metadata redundancy"); + } else { + btrfs_err(fs_info, + "balance: reduces metadata redundancy, use --force if you want this"); + ret = -EINVAL; + goto out; + } + } + + if (btrfs_get_num_tolerated_disk_barrier_failures(meta_target) < + btrfs_get_num_tolerated_disk_barrier_failures(data_target)) { + btrfs_warn(fs_info, + "balance: metadata profile %s has lower redundancy than data profile %s", + btrfs_bg_type_to_raid_name(meta_target), + btrfs_bg_type_to_raid_name(data_target)); + } + + ret = insert_balance_item(fs_info, bctl); + if (ret && ret != -EEXIST) + goto out; + + if (!(bctl->flags & BTRFS_BALANCE_RESUME)) { + BUG_ON(ret == -EEXIST); + BUG_ON(fs_info->balance_ctl); + spin_lock(&fs_info->balance_lock); + fs_info->balance_ctl = bctl; + spin_unlock(&fs_info->balance_lock); + } else { + BUG_ON(ret != -EEXIST); + spin_lock(&fs_info->balance_lock); + update_balance_args(bctl); + spin_unlock(&fs_info->balance_lock); + } + + ASSERT(!test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags)); + set_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags); + describe_balance_start_or_resume(fs_info); + mutex_unlock(&fs_info->balance_mutex); + + ret = __btrfs_balance(fs_info); + + mutex_lock(&fs_info->balance_mutex); + if (ret == -ECANCELED && atomic_read(&fs_info->balance_pause_req)) { + btrfs_info(fs_info, "balance: paused"); + btrfs_exclop_balance(fs_info, BTRFS_EXCLOP_BALANCE_PAUSED); + paused = true; + } + /* + * Balance can be canceled by: + * + * - Regular cancel request + * Then ret == -ECANCELED and balance_cancel_req > 0 + * + * - Fatal signal to "btrfs" process + * Either the signal caught by wait_reserve_ticket() and callers + * got -EINTR, or caught by btrfs_should_cancel_balance() and + * got -ECANCELED. + * Either way, in this case balance_cancel_req = 0, and + * ret == -EINTR or ret == -ECANCELED. + * + * So here we only check the return value to catch canceled balance. + */ + else if (ret == -ECANCELED || ret == -EINTR) + btrfs_info(fs_info, "balance: canceled"); + else + btrfs_info(fs_info, "balance: ended with status: %d", ret); + + clear_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags); + + if (bargs) { + memset(bargs, 0, sizeof(*bargs)); + btrfs_update_ioctl_balance_args(fs_info, bargs); + } + + /* We didn't pause, we can clean everything up. */ + if (!paused) { + reset_balance_state(fs_info); + btrfs_exclop_finish(fs_info); + } + + wake_up(&fs_info->balance_wait_q); + + return ret; +out: + if (bctl->flags & BTRFS_BALANCE_RESUME) + reset_balance_state(fs_info); + else + kfree(bctl); + btrfs_exclop_finish(fs_info); + + return ret; +} + +static int balance_kthread(void *data) +{ + struct btrfs_fs_info *fs_info = data; + int ret = 0; + + guard(super_write)(fs_info->sb); + + mutex_lock(&fs_info->balance_mutex); + if (fs_info->balance_ctl) + ret = btrfs_balance(fs_info, fs_info->balance_ctl, NULL); + mutex_unlock(&fs_info->balance_mutex); + + return ret; +} + +int btrfs_resume_balance_async(struct btrfs_fs_info *fs_info) +{ + struct task_struct *tsk; + + mutex_lock(&fs_info->balance_mutex); + if (!fs_info->balance_ctl) { + mutex_unlock(&fs_info->balance_mutex); + return 0; + } + mutex_unlock(&fs_info->balance_mutex); + + if (btrfs_test_opt(fs_info, SKIP_BALANCE)) { + btrfs_info(fs_info, "balance: resume skipped"); + return 0; + } + + spin_lock(&fs_info->super_lock); + ASSERT(fs_info->exclusive_operation == BTRFS_EXCLOP_BALANCE_PAUSED, + "exclusive_operation=%d", fs_info->exclusive_operation); + fs_info->exclusive_operation = BTRFS_EXCLOP_BALANCE; + spin_unlock(&fs_info->super_lock); + /* + * A ro->rw remount sequence should continue with the paused balance + * regardless of who pauses it, system or the user as of now, so set + * the resume flag. + */ + spin_lock(&fs_info->balance_lock); + fs_info->balance_ctl->flags |= BTRFS_BALANCE_RESUME; + spin_unlock(&fs_info->balance_lock); + + tsk = kthread_run(balance_kthread, fs_info, "btrfs-balance"); + return PTR_ERR_OR_ZERO(tsk); +} + +int btrfs_recover_balance(struct btrfs_fs_info *fs_info) +{ + struct btrfs_balance_control *bctl; + struct btrfs_balance_item *item; + struct btrfs_disk_balance_args disk_bargs; + BTRFS_PATH_AUTO_FREE(path); + struct extent_buffer *leaf; + struct btrfs_key key; + int ret; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + key.objectid = BTRFS_BALANCE_OBJECTID; + key.type = BTRFS_TEMPORARY_ITEM_KEY; + key.offset = 0; + + ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0); + if (ret < 0) + return ret; + if (ret > 0) { /* ret = -ENOENT; */ + return 0; + } + + bctl = kzalloc_obj(*bctl, GFP_NOFS); + if (!bctl) + return -ENOMEM; + + leaf = path->nodes[0]; + item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_balance_item); + + bctl->flags = btrfs_balance_flags(leaf, item); + bctl->flags |= BTRFS_BALANCE_RESUME; + + btrfs_balance_data(leaf, item, &disk_bargs); + btrfs_disk_balance_args_to_cpu(&bctl->data, &disk_bargs); + btrfs_balance_meta(leaf, item, &disk_bargs); + btrfs_disk_balance_args_to_cpu(&bctl->meta, &disk_bargs); + btrfs_balance_sys(leaf, item, &disk_bargs); + btrfs_disk_balance_args_to_cpu(&bctl->sys, &disk_bargs); + + /* + * This should never happen, as the paused balance state is recovered + * during mount without any chance of other exclusive ops to collide. + * + * This gives the exclusive op status to balance and keeps in paused + * state until user intervention (cancel or umount). If the ownership + * cannot be assigned, show a message but do not fail. The balance + * is in a paused state and must have fs_info::balance_ctl properly + * set up. + */ + if (!btrfs_exclop_start(fs_info, BTRFS_EXCLOP_BALANCE_PAUSED)) + btrfs_warn(fs_info, + "balance: cannot set exclusive op status, resume manually"); + + btrfs_release_path(path); + + mutex_lock(&fs_info->balance_mutex); + BUG_ON(fs_info->balance_ctl); + spin_lock(&fs_info->balance_lock); + fs_info->balance_ctl = bctl; + spin_unlock(&fs_info->balance_lock); + mutex_unlock(&fs_info->balance_mutex); + return ret; +} + +int btrfs_pause_balance(struct btrfs_fs_info *fs_info) +{ + int ret = 0; + + mutex_lock(&fs_info->balance_mutex); + if (!fs_info->balance_ctl) { + mutex_unlock(&fs_info->balance_mutex); + return -ENOTCONN; + } + + if (test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags)) { + atomic_inc(&fs_info->balance_pause_req); + mutex_unlock(&fs_info->balance_mutex); + + wait_event(fs_info->balance_wait_q, + !test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags)); + + mutex_lock(&fs_info->balance_mutex); + /* we are good with balance_ctl ripped off from under us */ + BUG_ON(test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags)); + atomic_dec(&fs_info->balance_pause_req); + } else { + ret = -ENOTCONN; + } + + mutex_unlock(&fs_info->balance_mutex); + return ret; +} + +int btrfs_cancel_balance(struct btrfs_fs_info *fs_info) +{ + mutex_lock(&fs_info->balance_mutex); + if (!fs_info->balance_ctl) { + mutex_unlock(&fs_info->balance_mutex); + return -ENOTCONN; + } + + /* + * A paused balance with the item stored on disk can be resumed at + * mount time if the mount is read-write. Otherwise it's still paused + * and we must not allow cancelling as it deletes the item. + */ + if (sb_rdonly(fs_info->sb)) { + mutex_unlock(&fs_info->balance_mutex); + return -EROFS; + } + + atomic_inc(&fs_info->balance_cancel_req); + /* + * if we are running just wait and return, balance item is + * deleted in btrfs_balance in this case + */ + if (test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags)) { + mutex_unlock(&fs_info->balance_mutex); + wait_event(fs_info->balance_wait_q, + !test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags)); + mutex_lock(&fs_info->balance_mutex); + } else { + mutex_unlock(&fs_info->balance_mutex); + /* + * Lock released to allow other waiters to continue, we'll + * reexamine the status again. + */ + mutex_lock(&fs_info->balance_mutex); + + if (fs_info->balance_ctl) { + reset_balance_state(fs_info); + btrfs_exclop_finish(fs_info); + btrfs_info(fs_info, "balance: canceled"); + } + } + + ASSERT(!test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags)); + atomic_dec(&fs_info->balance_cancel_req); + mutex_unlock(&fs_info->balance_mutex); + return 0; +} + +/* + * shrinking a device means finding all of the device extents past + * the new size, and then following the back refs to the chunks. + * The chunk relocation code actually frees the device extent + */ +int btrfs_shrink_device(struct btrfs_device *device, u64 new_size) +{ + struct btrfs_fs_info *fs_info = device->fs_info; + struct btrfs_root *root = fs_info->dev_root; + struct btrfs_trans_handle *trans; + struct btrfs_dev_extent *dev_extent = NULL; + struct btrfs_path *path; + u64 length; + u64 chunk_offset; + int ret; + int slot; + int failed = 0; + bool retried = false; + struct extent_buffer *l; + struct btrfs_key key; + struct btrfs_super_block *super_copy = fs_info->super_copy; + u64 old_total = btrfs_super_total_bytes(super_copy); + u64 old_size = btrfs_device_get_total_bytes(device); + u64 diff; + u64 start; + u64 free_diff = 0; + u64 pending_start, pending_end; + + new_size = round_down(new_size, fs_info->sectorsize); + start = new_size; + diff = round_down(old_size - new_size, fs_info->sectorsize); + + if (test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state)) + return -EINVAL; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + path->reada = READA_BACK; + + trans = btrfs_start_transaction(root, 0); + if (IS_ERR(trans)) { + btrfs_free_path(path); + return PTR_ERR(trans); + } + + mutex_lock(&fs_info->chunk_mutex); + + btrfs_device_set_total_bytes(device, new_size); + if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state)) { + device->fs_devices->total_rw_bytes -= diff; + + /* + * The new free_chunk_space is new_size - used, so we have to + * subtract the delta of the old free_chunk_space which included + * old_size - used. If used > new_size then just subtract this + * entire device's free space. + */ + if (device->bytes_used < new_size) + free_diff = (old_size - device->bytes_used) - + (new_size - device->bytes_used); + else + free_diff = old_size - device->bytes_used; + atomic64_sub(free_diff, &fs_info->free_chunk_space); + } + + btrfs_update_per_profile_avail(fs_info); + /* + * Once the device's size has been set to the new size, ensure all + * in-memory chunks are synced to disk so that the loop below sees them + * and relocates them accordingly. + */ + if (btrfs_first_pending_extent(device, start, diff, &pending_start, &pending_end)) { + mutex_unlock(&fs_info->chunk_mutex); + ret = btrfs_commit_transaction(trans); + if (ret) + goto done; + } else { + mutex_unlock(&fs_info->chunk_mutex); + btrfs_end_transaction(trans); + } + +again: + key.objectid = device->devid; + key.type = BTRFS_DEV_EXTENT_KEY; + key.offset = (u64)-1; + + do { + mutex_lock(&fs_info->reclaim_bgs_lock); + ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); + if (ret < 0) { + mutex_unlock(&fs_info->reclaim_bgs_lock); + goto done; + } + + ret = btrfs_previous_item(root, path, 0, key.type); + if (ret) { + mutex_unlock(&fs_info->reclaim_bgs_lock); + if (ret < 0) + goto done; + ret = 0; + btrfs_release_path(path); + break; + } + + l = path->nodes[0]; + slot = path->slots[0]; + btrfs_item_key_to_cpu(l, &key, path->slots[0]); + + if (key.objectid != device->devid) { + mutex_unlock(&fs_info->reclaim_bgs_lock); + btrfs_release_path(path); + break; + } + + dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent); + length = btrfs_dev_extent_length(l, dev_extent); + + if (key.offset + length <= new_size) { + mutex_unlock(&fs_info->reclaim_bgs_lock); + btrfs_release_path(path); + break; + } + + chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent); + btrfs_release_path(path); + + /* + * We may be relocating the only data chunk we have, + * which could potentially end up with losing data's + * raid profile, so lets allocate an empty one in + * advance. + */ + ret = btrfs_may_alloc_data_chunk(fs_info, chunk_offset); + if (ret < 0) { + mutex_unlock(&fs_info->reclaim_bgs_lock); + goto done; + } + + ret = btrfs_relocate_chunk(fs_info, chunk_offset, true); + mutex_unlock(&fs_info->reclaim_bgs_lock); + if (ret == -ENOSPC) { + failed++; + } else if (ret) { + if (ret == -ETXTBSY) { + btrfs_warn(fs_info, + "could not shrink block group %llu due to active swapfile", + chunk_offset); + } + goto done; + } + } while (key.offset-- > 0); + + if (failed && !retried) { + failed = 0; + retried = true; + goto again; + } else if (failed && retried) { + ret = -ENOSPC; + goto done; + } + + /* Shrinking succeeded, else we would be at "done". */ + trans = btrfs_start_transaction(root, 0); + if (IS_ERR(trans)) { + ret = PTR_ERR(trans); + goto done; + } + + mutex_lock(&fs_info->chunk_mutex); + /* Clear all state bits beyond the shrunk device size */ + btrfs_clear_extent_bit(&device->alloc_state, new_size, (u64)-1, + CHUNK_STATE_MASK, NULL); + + btrfs_device_set_disk_total_bytes(device, new_size); + if (list_empty(&device->post_commit_list)) + list_add_tail(&device->post_commit_list, + &trans->transaction->dev_update_list); + + WARN_ON(diff > old_total); + btrfs_set_super_total_bytes(super_copy, + round_down(old_total - diff, fs_info->sectorsize)); + btrfs_update_per_profile_avail(fs_info); + mutex_unlock(&fs_info->chunk_mutex); + + btrfs_reserve_chunk_metadata(trans, false); + /* Now btrfs_update_device() will change the on-disk size. */ + ret = btrfs_update_device(trans, device); + btrfs_trans_release_chunk_metadata(trans); + if (unlikely(ret < 0)) { + btrfs_abort_transaction(trans, ret); + btrfs_end_transaction(trans); + } else { + ret = btrfs_commit_transaction(trans); + } +done: + btrfs_free_path(path); + if (ret) { + mutex_lock(&fs_info->chunk_mutex); + btrfs_device_set_total_bytes(device, old_size); + if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state)) { + device->fs_devices->total_rw_bytes += diff; + atomic64_add(free_diff, &fs_info->free_chunk_space); + } + mutex_unlock(&fs_info->chunk_mutex); + } + return ret; +} + +static int btrfs_add_system_chunk(struct btrfs_fs_info *fs_info, + struct btrfs_key *key, + struct btrfs_chunk *chunk, int item_size) +{ + struct btrfs_super_block *super_copy = fs_info->super_copy; + struct btrfs_disk_key disk_key; + u32 array_size; + u8 *ptr; + + lockdep_assert_held(&fs_info->chunk_mutex); + + array_size = btrfs_super_sys_array_size(super_copy); + if (array_size + item_size + sizeof(disk_key) + > BTRFS_SYSTEM_CHUNK_ARRAY_SIZE) + return -EFBIG; + + ptr = super_copy->sys_chunk_array + array_size; + btrfs_cpu_key_to_disk(&disk_key, key); + memcpy(ptr, &disk_key, sizeof(disk_key)); + ptr += sizeof(disk_key); + memcpy(ptr, chunk, item_size); + item_size += sizeof(disk_key); + btrfs_set_super_sys_array_size(super_copy, array_size + item_size); + + return 0; +} + +/* + * sort the devices in descending order by max_avail, total_avail + */ +static int btrfs_cmp_device_info(const void *a, const void *b) +{ + const struct btrfs_device_info *di_a = a; + const struct btrfs_device_info *di_b = b; + + if (di_a->max_avail > di_b->max_avail) + return -1; + if (di_a->max_avail < di_b->max_avail) + return 1; + if (di_a->total_avail > di_b->total_avail) + return -1; + if (di_a->total_avail < di_b->total_avail) + return 1; + return 0; +} + +/* + * Return 0 if we allocated any virtual(*) chunk, and restore the size to + * @allocated. + * Return -ENOSPC if we have no more space to allocate virtual chunk + * + * *: A virtual chunk is a chunk that only exists during per-profile available + * estimation. + * Those numbers won't really take on-disk space, but only to emulate + * chunk allocator behavior to get accurate estimation on available space. + * + * Another difference is, a virtual chunk has no size limit and doesn't care + * about holes in the device tree, allowing us to exhaust device space + * much faster. + */ +static int alloc_virtual_chunk(struct btrfs_fs_info *fs_info, + struct btrfs_device_info *devices_info, + enum btrfs_raid_types type, + u64 *allocated) +{ + const struct btrfs_raid_attr *raid_attr = &btrfs_raid_array[type]; + struct btrfs_fs_devices *fs_devices = fs_info->fs_devices; + struct btrfs_device *device; + u64 stripe_size; + int ndevs = 0; + + lockdep_assert_held(&fs_info->chunk_mutex); + + /* Go through devices to collect their unallocated space. */ + list_for_each_entry(device, &fs_devices->alloc_list, dev_alloc_list) { + u64 avail; + + if (!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, + &device->dev_state) || + test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state)) + continue; + + if (device->total_bytes > device->bytes_used + + device->per_profile_allocated) + avail = device->total_bytes - device->bytes_used - + device->per_profile_allocated; + else + avail = 0; + + avail = round_down(avail, fs_info->sectorsize); + + /* And exclude the [0, 1M) reserved space. */ + if (avail > BTRFS_DEVICE_RANGE_RESERVED) + avail -= BTRFS_DEVICE_RANGE_RESERVED; + else + avail = 0; + + /* + * Not enough to support a single stripe, this device + * can not be utilized for chunk allocation. + */ + if (avail < BTRFS_STRIPE_LEN) + continue; + + /* + * Unlike chunk allocator, we don't care about stripe or hole + * size, so here we use @avail directly. + */ + devices_info[ndevs].dev_offset = 0; + devices_info[ndevs].total_avail = avail; + devices_info[ndevs].max_avail = avail; + devices_info[ndevs].dev = device; + ++ndevs; + } + sort(devices_info, ndevs, sizeof(struct btrfs_device_info), + btrfs_cmp_device_info, NULL); + ndevs = rounddown(ndevs, raid_attr->devs_increment); + if (ndevs < raid_attr->devs_min) + return -ENOSPC; + if (raid_attr->devs_max) + ndevs = min(ndevs, (int)raid_attr->devs_max); + else + ndevs = min(ndevs, (int)BTRFS_MAX_DEVS(fs_info)); + + /* + * Stripe size will be determined by the device with the least + * unallocated space. + */ + stripe_size = devices_info[ndevs - 1].total_avail; + + for (int i = 0; i < ndevs; i++) + devices_info[i].dev->per_profile_allocated += stripe_size; + *allocated = div_u64(stripe_size * (ndevs - raid_attr->nparity), + raid_attr->ncopies); + return 0; +} + +static int calc_one_profile_avail(struct btrfs_fs_info *fs_info, + enum btrfs_raid_types type, + u64 *result_ret) +{ + struct btrfs_device_info *devices_info = NULL; + struct btrfs_fs_devices *fs_devices = fs_info->fs_devices; + struct btrfs_device *device; + u64 allocated; + u64 result = 0; + int ret = 0; + + lockdep_assert_held(&fs_info->chunk_mutex); + ASSERT(type >= 0 && type < BTRFS_NR_RAID_TYPES); + + /* Not enough devices, quick exit, just update the result. */ + if (fs_devices->rw_devices < btrfs_raid_array[type].devs_min) { + ret = -ENOSPC; + goto out; + } + + devices_info = kzalloc_objs(*devices_info, fs_devices->rw_devices, GFP_NOFS); + if (!devices_info) { + ret = -ENOMEM; + goto out; + } + /* Clear virtual chunk used space for each device. */ + list_for_each_entry(device, &fs_devices->alloc_list, dev_alloc_list) + device->per_profile_allocated = 0; + + while (!alloc_virtual_chunk(fs_info, devices_info, type, &allocated)) + result += allocated; + +out: + kfree(devices_info); + if (ret < 0 && ret != -ENOSPC) + return ret; + *result_ret = result; + return 0; +} + +/* Update the per-profile available space array. */ +void btrfs_update_per_profile_avail(struct btrfs_fs_info *fs_info) +{ + u64 results[BTRFS_NR_RAID_TYPES]; + int ret; + + /* + * Zoned is more complex as we can not simply get the amount of + * available space for each device. + */ + if (btrfs_is_zoned(fs_info)) + goto error; + + for (int i = 0; i < BTRFS_NR_RAID_TYPES; i++) { + ret = calc_one_profile_avail(fs_info, i, &results[i]); + if (ret < 0) + goto error; + } + + spin_lock(&fs_info->fs_devices->per_profile_lock); + for (int i = 0; i < BTRFS_NR_RAID_TYPES; i++) + fs_info->fs_devices->per_profile_avail[i] = results[i]; + spin_unlock(&fs_info->fs_devices->per_profile_lock); + return; +error: + spin_lock(&fs_info->fs_devices->per_profile_lock); + for (int i = 0; i < BTRFS_NR_RAID_TYPES; i++) + fs_info->fs_devices->per_profile_avail[i] = U64_MAX; + spin_unlock(&fs_info->fs_devices->per_profile_lock); +} + +static void check_raid56_incompat_flag(struct btrfs_fs_info *info, u64 type) +{ + if (!(type & BTRFS_BLOCK_GROUP_RAID56_MASK)) + return; + + btrfs_set_fs_incompat(info, RAID56); +} + +static void check_raid1c34_incompat_flag(struct btrfs_fs_info *info, u64 type) +{ + if (!(type & (BTRFS_BLOCK_GROUP_RAID1C3 | BTRFS_BLOCK_GROUP_RAID1C4))) + return; + + btrfs_set_fs_incompat(info, RAID1C34); +} + +/* + * Structure used internally for btrfs_create_chunk() function. + * Wraps needed parameters. + */ +struct alloc_chunk_ctl { + u64 start; + u64 type; + /* Total number of stripes to allocate */ + int num_stripes; + /* sub_stripes info for map */ + int sub_stripes; + /* Stripes per device */ + int dev_stripes; + /* Maximum number of devices to use */ + int devs_max; + /* Minimum number of devices to use */ + int devs_min; + /* ndevs has to be a multiple of this */ + int devs_increment; + /* Number of copies */ + int ncopies; + /* Number of stripes worth of bytes to store parity information */ + int nparity; + u64 max_stripe_size; + u64 max_chunk_size; + u64 dev_extent_min; + u64 stripe_size; + u64 chunk_size; + int ndevs; + /* Space_info the block group is going to belong. */ + struct btrfs_space_info *space_info; +}; + +static void init_alloc_chunk_ctl_policy_regular( + struct btrfs_fs_devices *fs_devices, + struct alloc_chunk_ctl *ctl) +{ + struct btrfs_space_info *space_info; + + space_info = btrfs_find_space_info(fs_devices->fs_info, ctl->type); + ASSERT(space_info); + + ctl->max_chunk_size = READ_ONCE(space_info->chunk_size); + ctl->max_stripe_size = min_t(u64, ctl->max_chunk_size, SZ_1G); + + if (ctl->type & BTRFS_BLOCK_GROUP_SYSTEM) + ctl->devs_max = min_t(int, ctl->devs_max, BTRFS_MAX_DEVS_SYS_CHUNK); + + /* We don't want a chunk larger than 10% of writable space */ + ctl->max_chunk_size = min(mult_perc(fs_devices->total_rw_bytes, 10), + ctl->max_chunk_size); + ctl->dev_extent_min = btrfs_stripe_nr_to_offset(ctl->dev_stripes); +} + +static void init_alloc_chunk_ctl_policy_zoned( + struct btrfs_fs_devices *fs_devices, + struct alloc_chunk_ctl *ctl) +{ + u64 zone_size = fs_devices->fs_info->zone_size; + u64 limit; + int min_num_stripes = ctl->devs_min * ctl->dev_stripes; + int min_data_stripes = (min_num_stripes - ctl->nparity) / ctl->ncopies; + u64 min_chunk_size = min_data_stripes * zone_size; + u64 type = ctl->type; + + ctl->max_stripe_size = zone_size; + if (type & BTRFS_BLOCK_GROUP_DATA) { + ctl->max_chunk_size = round_down(BTRFS_MAX_DATA_CHUNK_SIZE, + zone_size); + } else if (type & BTRFS_BLOCK_GROUP_METADATA) { + ctl->max_chunk_size = ctl->max_stripe_size; + } else if (type & BTRFS_BLOCK_GROUP_SYSTEM) { + ctl->max_chunk_size = 2 * ctl->max_stripe_size; + ctl->devs_max = min_t(int, ctl->devs_max, + BTRFS_MAX_DEVS_SYS_CHUNK); + } else { + BUG(); + } + + /* We don't want a chunk larger than 10% of writable space */ + limit = max(round_down(mult_perc(fs_devices->total_rw_bytes, 10), + zone_size), + min_chunk_size); + ctl->max_chunk_size = min(limit, ctl->max_chunk_size); + ctl->dev_extent_min = zone_size * ctl->dev_stripes; +} + +static void init_alloc_chunk_ctl(struct btrfs_fs_devices *fs_devices, + struct alloc_chunk_ctl *ctl) +{ + int index = btrfs_bg_flags_to_raid_index(ctl->type); + + ctl->sub_stripes = btrfs_raid_array[index].sub_stripes; + ctl->dev_stripes = btrfs_raid_array[index].dev_stripes; + ctl->devs_max = btrfs_raid_array[index].devs_max; + if (!ctl->devs_max) + ctl->devs_max = BTRFS_MAX_DEVS(fs_devices->fs_info); + ctl->devs_min = btrfs_raid_array[index].devs_min; + ctl->devs_increment = btrfs_raid_array[index].devs_increment; + ctl->ncopies = btrfs_raid_array[index].ncopies; + ctl->nparity = btrfs_raid_array[index].nparity; + ctl->ndevs = 0; + + switch (fs_devices->chunk_alloc_policy) { + default: + btrfs_warn_unknown_chunk_allocation(fs_devices->chunk_alloc_policy); + fallthrough; + case BTRFS_CHUNK_ALLOC_REGULAR: + init_alloc_chunk_ctl_policy_regular(fs_devices, ctl); + break; + case BTRFS_CHUNK_ALLOC_ZONED: + init_alloc_chunk_ctl_policy_zoned(fs_devices, ctl); + break; + } +} + +static int gather_device_info(struct btrfs_fs_devices *fs_devices, + struct alloc_chunk_ctl *ctl, + struct btrfs_device_info *devices_info) +{ + struct btrfs_fs_info *info = fs_devices->fs_info; + struct btrfs_device *device; + u64 total_avail; + u64 dev_extent_want = ctl->max_stripe_size * ctl->dev_stripes; + int ret; + int ndevs = 0; + u64 max_avail; + u64 dev_offset; + + /* + * in the first pass through the devices list, we gather information + * about the available holes on each device. + */ + list_for_each_entry(device, &fs_devices->alloc_list, dev_alloc_list) { + if (!test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state)) { + WARN(1, KERN_ERR + "BTRFS: read-only device in alloc_list\n"); + continue; + } + + if (!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, + &device->dev_state) || + test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state)) + continue; + + if (device->total_bytes > device->bytes_used) + total_avail = device->total_bytes - device->bytes_used; + else + total_avail = 0; + + /* If there is no space on this device, skip it. */ + if (total_avail < ctl->dev_extent_min) + continue; + + ret = find_free_dev_extent(device, dev_extent_want, &dev_offset, + &max_avail); + if (ret && ret != -ENOSPC) + return ret; + + if (ret == 0) + max_avail = dev_extent_want; + + if (max_avail < ctl->dev_extent_min) { + if (btrfs_test_opt(info, ENOSPC_DEBUG)) + btrfs_debug(info, + "%s: devid %llu has no free space, have=%llu want=%llu", + __func__, device->devid, max_avail, + ctl->dev_extent_min); + continue; + } + + if (ndevs == fs_devices->rw_devices) { + WARN(1, "%s: found more than %llu devices\n", + __func__, fs_devices->rw_devices); + break; + } + devices_info[ndevs].dev_offset = dev_offset; + devices_info[ndevs].max_avail = max_avail; + devices_info[ndevs].total_avail = total_avail; + devices_info[ndevs].dev = device; + ++ndevs; + } + ctl->ndevs = ndevs; + + /* + * now sort the devices by hole size / available space + */ + sort(devices_info, ndevs, sizeof(struct btrfs_device_info), + btrfs_cmp_device_info, NULL); + + return 0; +} + +static int decide_stripe_size_regular(struct alloc_chunk_ctl *ctl, + struct btrfs_device_info *devices_info) +{ + /* Number of stripes that count for block group size */ + int data_stripes; + + /* + * The primary goal is to maximize the number of stripes, so use as + * many devices as possible, even if the stripes are not maximum sized. + * + * The DUP profile stores more than one stripe per device, the + * max_avail is the total size so we have to adjust. + */ + ctl->stripe_size = div_u64(devices_info[ctl->ndevs - 1].max_avail, + ctl->dev_stripes); + ctl->num_stripes = ctl->ndevs * ctl->dev_stripes; + + /* This will have to be fixed for RAID1 and RAID10 over more drives */ + data_stripes = (ctl->num_stripes - ctl->nparity) / ctl->ncopies; + + /* + * Use the number of data stripes to figure out how big this chunk is + * really going to be in terms of logical address space, and compare + * that answer with the max chunk size. If it's higher, we try to + * reduce stripe_size. + */ + if (ctl->stripe_size * data_stripes > ctl->max_chunk_size) { + /* + * Reduce stripe_size, round it up to a 16MB boundary again and + * then use it, unless it ends up being even bigger than the + * previous value we had already. + */ + ctl->stripe_size = min(round_up(div_u64(ctl->max_chunk_size, + data_stripes), SZ_16M), + ctl->stripe_size); + } + + /* Stripe size should not go beyond 1G. */ + ctl->stripe_size = min_t(u64, ctl->stripe_size, SZ_1G); + + /* Align to BTRFS_STRIPE_LEN */ + ctl->stripe_size = round_down(ctl->stripe_size, BTRFS_STRIPE_LEN); + ctl->chunk_size = ctl->stripe_size * data_stripes; + + return 0; +} + +static int decide_stripe_size_zoned(struct alloc_chunk_ctl *ctl, + struct btrfs_device_info *devices_info) +{ + u64 zone_size = devices_info[0].dev->zone_info->zone_size; + /* Number of stripes that count for block group size */ + int data_stripes; + + /* + * It should hold because: + * dev_extent_min == dev_extent_want == zone_size * dev_stripes + */ + ASSERT(devices_info[ctl->ndevs - 1].max_avail == ctl->dev_extent_min, + "ndevs=%d max_avail=%llu dev_extent_min=%llu", ctl->ndevs, + devices_info[ctl->ndevs - 1].max_avail, ctl->dev_extent_min); + + ctl->stripe_size = zone_size; + ctl->num_stripes = ctl->ndevs * ctl->dev_stripes; + data_stripes = (ctl->num_stripes - ctl->nparity) / ctl->ncopies; + + /* stripe_size is fixed in zoned filesystem. Reduce ndevs instead. */ + if (ctl->stripe_size * data_stripes > ctl->max_chunk_size) { + ctl->ndevs = div_u64(div_u64(ctl->max_chunk_size * ctl->ncopies, + ctl->stripe_size) + ctl->nparity, + ctl->dev_stripes); + ctl->num_stripes = ctl->ndevs * ctl->dev_stripes; + data_stripes = (ctl->num_stripes - ctl->nparity) / ctl->ncopies; + ASSERT(ctl->stripe_size * data_stripes <= ctl->max_chunk_size, + "stripe_size=%llu data_stripes=%d max_chunk_size=%llu", + ctl->stripe_size, data_stripes, ctl->max_chunk_size); + } + + ctl->chunk_size = ctl->stripe_size * data_stripes; + + return 0; +} + +static int decide_stripe_size(struct btrfs_fs_devices *fs_devices, + struct alloc_chunk_ctl *ctl, + struct btrfs_device_info *devices_info) +{ + struct btrfs_fs_info *info = fs_devices->fs_info; + + /* + * Round down to number of usable stripes, devs_increment can be any + * number so we can't use round_down() that requires power of 2, while + * rounddown is safe. + */ + ctl->ndevs = rounddown(ctl->ndevs, ctl->devs_increment); + + if (ctl->ndevs < ctl->devs_min) { + if (btrfs_test_opt(info, ENOSPC_DEBUG)) { + btrfs_debug(info, + "%s: not enough devices with free space: have=%d minimum required=%d", + __func__, ctl->ndevs, ctl->devs_min); + } + return -ENOSPC; + } + + ctl->ndevs = min(ctl->ndevs, ctl->devs_max); + + switch (fs_devices->chunk_alloc_policy) { + default: + btrfs_warn_unknown_chunk_allocation(fs_devices->chunk_alloc_policy); + fallthrough; + case BTRFS_CHUNK_ALLOC_REGULAR: + return decide_stripe_size_regular(ctl, devices_info); + case BTRFS_CHUNK_ALLOC_ZONED: + return decide_stripe_size_zoned(ctl, devices_info); + } +} + +static void chunk_map_device_set_bits(struct btrfs_chunk_map *map, unsigned int bits) +{ + for (int i = 0; i < map->num_stripes; i++) { + struct btrfs_io_stripe *stripe = &map->stripes[i]; + struct btrfs_device *device = stripe->dev; + + btrfs_set_extent_bit(&device->alloc_state, stripe->physical, + stripe->physical + map->stripe_size - 1, + bits | EXTENT_NOWAIT, NULL); + } +} + +void btrfs_chunk_map_device_clear_bits(struct btrfs_chunk_map *map, unsigned int bits) +{ + for (int i = 0; i < map->num_stripes; i++) { + struct btrfs_io_stripe *stripe = &map->stripes[i]; + struct btrfs_device *device = stripe->dev; + + btrfs_clear_extent_bit(&device->alloc_state, stripe->physical, + stripe->physical + map->stripe_size - 1, + bits | EXTENT_NOWAIT, NULL); + } +} + +void btrfs_remove_chunk_map(struct btrfs_fs_info *fs_info, struct btrfs_chunk_map *map) +{ + write_lock(&fs_info->mapping_tree_lock); + rb_erase_cached(&map->rb_node, &fs_info->mapping_tree); + RB_CLEAR_NODE(&map->rb_node); + btrfs_chunk_map_device_clear_bits(map, CHUNK_ALLOCATED); + write_unlock(&fs_info->mapping_tree_lock); + + /* Once for the tree reference. */ + btrfs_free_chunk_map(map); +} + +static int btrfs_chunk_map_cmp(const struct rb_node *new, + const struct rb_node *exist) +{ + const struct btrfs_chunk_map *new_map = + rb_entry(new, struct btrfs_chunk_map, rb_node); + const struct btrfs_chunk_map *exist_map = + rb_entry(exist, struct btrfs_chunk_map, rb_node); + + if (new_map->start == exist_map->start) + return 0; + if (new_map->start < exist_map->start) + return -1; + return 1; +} + +EXPORT_FOR_TESTS +int btrfs_add_chunk_map(struct btrfs_fs_info *fs_info, struct btrfs_chunk_map *map) +{ + struct rb_node *exist; + + write_lock(&fs_info->mapping_tree_lock); + exist = rb_find_add_cached(&map->rb_node, &fs_info->mapping_tree, + btrfs_chunk_map_cmp); + + if (exist) { + write_unlock(&fs_info->mapping_tree_lock); + return -EEXIST; + } + chunk_map_device_set_bits(map, CHUNK_ALLOCATED); + btrfs_chunk_map_device_clear_bits(map, CHUNK_TRIMMED); + write_unlock(&fs_info->mapping_tree_lock); + + return 0; +} + +EXPORT_FOR_TESTS +struct btrfs_chunk_map *btrfs_alloc_chunk_map(int num_stripes, gfp_t gfp) +{ + struct btrfs_chunk_map *map; + + map = kmalloc(btrfs_chunk_map_size(num_stripes), gfp); + if (!map) + return NULL; + + refcount_set(&map->refs, 1); + RB_CLEAR_NODE(&map->rb_node); + + return map; +} + +static void set_real_chunk_type(struct btrfs_chunk_map *map) +{ + map->type = map->on_disk_type; + if (likely((map->on_disk_type & BTRFS_BLOCK_GROUP_RAID56_MASK) == 0 || + nr_data_stripes(map) > 1)) + return; + if (map->on_disk_type & BTRFS_BLOCK_GROUP_RAID5) + map->type |= BTRFS_BLOCK_GROUP_RAID1; + else + map->type |= BTRFS_BLOCK_GROUP_RAID1C3; + map->type &= ~BTRFS_BLOCK_GROUP_RAID56_MASK; +} + +static struct btrfs_block_group *create_chunk(struct btrfs_trans_handle *trans, + struct alloc_chunk_ctl *ctl, + struct btrfs_device_info *devices_info) +{ + struct btrfs_fs_info *info = trans->fs_info; + struct btrfs_chunk_map *map; + struct btrfs_block_group *block_group; + u64 start = ctl->start; + u64 type = ctl->type; + int ret; + + map = btrfs_alloc_chunk_map(ctl->num_stripes, GFP_NOFS); + if (!map) + return ERR_PTR(-ENOMEM); + + map->start = start; + map->chunk_len = ctl->chunk_size; + map->stripe_size = ctl->stripe_size; + map->on_disk_type = type; + map->sub_stripes = ctl->sub_stripes; + map->num_stripes = ctl->num_stripes; + set_real_chunk_type(map); + + for (int i = 0; i < ctl->ndevs; i++) { + for (int j = 0; j < ctl->dev_stripes; j++) { + int s = i * ctl->dev_stripes + j; + map->stripes[s].dev = devices_info[i].dev; + map->stripes[s].physical = devices_info[i].dev_offset + + j * ctl->stripe_size; + } + } + + trace_btrfs_chunk_alloc(info, map, start, ctl->chunk_size); + + ret = btrfs_add_chunk_map(info, map); + if (ret) { + btrfs_free_chunk_map(map); + return ERR_PTR(ret); + } + + block_group = btrfs_make_block_group(trans, ctl->space_info, type, start, + ctl->chunk_size); + if (IS_ERR(block_group)) { + btrfs_remove_chunk_map(info, map); + return block_group; + } + + for (int i = 0; i < map->num_stripes; i++) { + struct btrfs_device *dev = map->stripes[i].dev; + + btrfs_device_set_bytes_used(dev, + dev->bytes_used + ctl->stripe_size); + if (list_empty(&dev->post_commit_list)) + list_add_tail(&dev->post_commit_list, + &trans->transaction->dev_update_list); + } + + atomic64_sub(ctl->stripe_size * map->num_stripes, + &info->free_chunk_space); + + check_raid56_incompat_flag(info, type); + check_raid1c34_incompat_flag(info, type); + + btrfs_update_per_profile_avail(info); + + return block_group; +} + +struct btrfs_block_group *btrfs_create_chunk(struct btrfs_trans_handle *trans, + struct btrfs_space_info *space_info, + u64 type) +{ + struct btrfs_fs_info *info = trans->fs_info; + struct btrfs_fs_devices *fs_devices = info->fs_devices; + struct btrfs_device_info AUTO_KFREE(devices_info); + struct alloc_chunk_ctl ctl; + int ret; + + lockdep_assert_held(&info->chunk_mutex); + + if (unlikely(!alloc_profile_is_valid(type, 0))) { + DEBUG_WARN("invalid alloc profile for type %llu", type); + return ERR_PTR(-EINVAL); + } + + if (list_empty(&fs_devices->alloc_list)) { + if (btrfs_test_opt(info, ENOSPC_DEBUG)) + btrfs_debug(info, "%s: no writable device", __func__); + return ERR_PTR(-ENOSPC); + } + + if (unlikely(!(type & BTRFS_BLOCK_GROUP_TYPE_MASK))) { + btrfs_err(info, "invalid chunk type 0x%llx requested", type); + DEBUG_WARN(); + return ERR_PTR(-EINVAL); + } + + ctl.start = find_next_chunk(info); + ctl.type = type; + ctl.space_info = space_info; + init_alloc_chunk_ctl(fs_devices, &ctl); + + devices_info = kzalloc_objs(*devices_info, fs_devices->rw_devices, GFP_NOFS); + if (!devices_info) + return ERR_PTR(-ENOMEM); + + ret = gather_device_info(fs_devices, &ctl, devices_info); + if (ret < 0) + return ERR_PTR(ret); + + ret = decide_stripe_size(fs_devices, &ctl, devices_info); + if (ret < 0) + return ERR_PTR(ret); + + return create_chunk(trans, &ctl, devices_info); +} + +/* + * This function, btrfs_chunk_alloc_add_chunk_item(), typically belongs to the + * phase 1 of chunk allocation. It belongs to phase 2 only when allocating system + * chunks. + * + * See the comment at btrfs_chunk_alloc() for details about the chunk allocation + * phases. + */ +int btrfs_chunk_alloc_add_chunk_item(struct btrfs_trans_handle *trans, + struct btrfs_block_group *bg) +{ + struct btrfs_fs_info *fs_info = trans->fs_info; + struct btrfs_root *chunk_root = fs_info->chunk_root; + struct btrfs_key key; + struct btrfs_chunk *chunk; + struct btrfs_stripe *stripe; + struct btrfs_chunk_map *map; + size_t item_size; + int i; + int ret; + + /* + * We take the chunk_mutex for 2 reasons: + * + * 1) Updates and insertions in the chunk btree must be done while holding + * the chunk_mutex, as well as updating the system chunk array in the + * superblock. See the comment on top of btrfs_chunk_alloc() for the + * details; + * + * 2) To prevent races with the final phase of a device replace operation + * that replaces the device object associated with the map's stripes, + * because the device object's id can change at any time during that + * final phase of the device replace operation + * (dev-replace.c:btrfs_dev_replace_finishing()), so we could grab the + * replaced device and then see it with an ID of BTRFS_DEV_REPLACE_DEVID, + * which would cause a failure when updating the device item, which does + * not exists, or persisting a stripe of the chunk item with such ID. + * Here we can't use the device_list_mutex because our caller already + * has locked the chunk_mutex, and the final phase of device replace + * acquires both mutexes - first the device_list_mutex and then the + * chunk_mutex. Using any of those two mutexes protects us from a + * concurrent device replace. + */ + lockdep_assert_held(&fs_info->chunk_mutex); + + map = btrfs_get_chunk_map(fs_info, bg->start, bg->length); + if (IS_ERR(map)) { + ret = PTR_ERR(map); + btrfs_abort_transaction(trans, ret); + return ret; + } + + item_size = btrfs_chunk_item_size(map->num_stripes); + + chunk = kzalloc(item_size, GFP_NOFS); + if (unlikely(!chunk)) { + ret = -ENOMEM; + btrfs_abort_transaction(trans, ret); + goto out; + } + + for (i = 0; i < map->num_stripes; i++) { + struct btrfs_device *device = map->stripes[i].dev; + + ret = btrfs_update_device(trans, device); + if (ret) + goto out; + } + + stripe = &chunk->stripe; + for (i = 0; i < map->num_stripes; i++) { + struct btrfs_device *device = map->stripes[i].dev; + const u64 dev_offset = map->stripes[i].physical; + + btrfs_set_stack_stripe_devid(stripe, device->devid); + btrfs_set_stack_stripe_offset(stripe, dev_offset); + memcpy(stripe->dev_uuid, device->uuid, BTRFS_UUID_SIZE); + stripe++; + } + + btrfs_set_stack_chunk_length(chunk, bg->length); + btrfs_set_stack_chunk_owner(chunk, BTRFS_EXTENT_TREE_OBJECTID); + btrfs_set_stack_chunk_stripe_len(chunk, BTRFS_STRIPE_LEN); + btrfs_set_stack_chunk_type(chunk, map->on_disk_type); + btrfs_set_stack_chunk_num_stripes(chunk, map->num_stripes); + btrfs_set_stack_chunk_io_align(chunk, BTRFS_STRIPE_LEN); + btrfs_set_stack_chunk_io_width(chunk, BTRFS_STRIPE_LEN); + btrfs_set_stack_chunk_sector_size(chunk, fs_info->sectorsize); + btrfs_set_stack_chunk_sub_stripes(chunk, map->sub_stripes); + + key.objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID; + key.type = BTRFS_CHUNK_ITEM_KEY; + key.offset = bg->start; + + ret = btrfs_insert_item(trans, chunk_root, &key, chunk, item_size); + if (ret) + goto out; + + set_bit(BLOCK_GROUP_FLAG_CHUNK_ITEM_INSERTED, &bg->runtime_flags); + + if (map->type & BTRFS_BLOCK_GROUP_SYSTEM) { + ret = btrfs_add_system_chunk(fs_info, &key, chunk, item_size); + if (ret) + goto out; + } + +out: + kfree(chunk); + btrfs_free_chunk_map(map); + return ret; +} + +static noinline int init_first_rw_device(struct btrfs_trans_handle *trans) +{ + struct btrfs_fs_info *fs_info = trans->fs_info; + u64 alloc_profile; + struct btrfs_block_group *meta_bg; + struct btrfs_space_info *meta_space_info; + struct btrfs_block_group *sys_bg; + struct btrfs_space_info *sys_space_info; + + /* + * When adding a new device for sprouting, the seed device is read-only + * so we must first allocate a metadata and a system chunk. But before + * adding the block group items to the extent, device and chunk btrees, + * we must first: + * + * 1) Create both chunks without doing any changes to the btrees, as + * otherwise we would get -ENOSPC since the block groups from the + * seed device are read-only; + * + * 2) Add the device item for the new sprout device - finishing the setup + * of a new block group requires updating the device item in the chunk + * btree, so it must exist when we attempt to do it. The previous step + * ensures this does not fail with -ENOSPC. + * + * After that we can add the block group items to their btrees: + * update existing device item in the chunk btree, add a new block group + * item to the extent btree, add a new chunk item to the chunk btree and + * finally add the new device extent items to the devices btree. + */ + + alloc_profile = btrfs_metadata_alloc_profile(fs_info); + meta_space_info = btrfs_find_space_info(fs_info, alloc_profile); + if (unlikely(!meta_space_info)) { + DEBUG_WARN(); + return -EINVAL; + } + meta_bg = btrfs_create_chunk(trans, meta_space_info, alloc_profile); + if (IS_ERR(meta_bg)) + return PTR_ERR(meta_bg); + + alloc_profile = btrfs_system_alloc_profile(fs_info); + sys_space_info = btrfs_find_space_info(fs_info, alloc_profile); + if (unlikely(!sys_space_info)) { + DEBUG_WARN(); + return -EINVAL; + } + sys_bg = btrfs_create_chunk(trans, sys_space_info, alloc_profile); + if (IS_ERR(sys_bg)) + return PTR_ERR(sys_bg); + + return 0; +} + +static inline int btrfs_chunk_max_errors(struct btrfs_chunk_map *map) +{ + const int index = btrfs_bg_flags_to_raid_index(map->type); + + return btrfs_raid_array[index].tolerated_failures; +} + +bool btrfs_chunk_writeable(struct btrfs_fs_info *fs_info, u64 chunk_offset) +{ + struct btrfs_chunk_map *map; + int miss_ndevs = 0; + int i; + bool ret = true; + + map = btrfs_get_chunk_map(fs_info, chunk_offset, 1); + if (IS_ERR(map)) + return false; + + for (i = 0; i < map->num_stripes; i++) { + if (test_bit(BTRFS_DEV_STATE_MISSING, + &map->stripes[i].dev->dev_state)) { + miss_ndevs++; + continue; + } + if (!test_bit(BTRFS_DEV_STATE_WRITEABLE, + &map->stripes[i].dev->dev_state)) { + ret = false; + goto end; + } + } + + /* + * If the number of missing devices is larger than max errors, we can + * not write the data into that chunk successfully. + */ + if (miss_ndevs > btrfs_chunk_max_errors(map)) + ret = false; +end: + btrfs_free_chunk_map(map); + return ret; +} + +void btrfs_mapping_tree_free(struct btrfs_fs_info *fs_info) +{ + write_lock(&fs_info->mapping_tree_lock); + while (!RB_EMPTY_ROOT(&fs_info->mapping_tree.rb_root)) { + struct btrfs_chunk_map *map; + struct rb_node *node; + + node = rb_first_cached(&fs_info->mapping_tree); + map = rb_entry(node, struct btrfs_chunk_map, rb_node); + rb_erase_cached(&map->rb_node, &fs_info->mapping_tree); + RB_CLEAR_NODE(&map->rb_node); + btrfs_chunk_map_device_clear_bits(map, CHUNK_ALLOCATED); + /* Once for the tree ref. */ + btrfs_free_chunk_map(map); + cond_resched_rwlock_write(&fs_info->mapping_tree_lock); + } + write_unlock(&fs_info->mapping_tree_lock); +} + +static int btrfs_chunk_map_num_copies(const struct btrfs_chunk_map *map) +{ + enum btrfs_raid_types index = btrfs_bg_flags_to_raid_index(map->type); + + if (map->type & BTRFS_BLOCK_GROUP_RAID5) + return 2; + + /* + * There could be two corrupted data stripes, we need to loop retry in + * order to rebuild the correct data. + * + * Fail a stripe at a time on every retry except the stripe under + * reconstruction. + */ + if (map->type & BTRFS_BLOCK_GROUP_RAID6) + return map->num_stripes; + + /* Non-RAID56, use their ncopies from btrfs_raid_array. */ + return btrfs_raid_array[index].ncopies; +} + +int btrfs_num_copies(struct btrfs_fs_info *fs_info, u64 logical, u64 len) +{ + struct btrfs_chunk_map *map; + int ret; + + map = btrfs_get_chunk_map(fs_info, logical, len); + if (IS_ERR(map)) + /* + * We could return errors for these cases, but that could get + * ugly and we'd probably do the same thing which is just not do + * anything else and exit, so return 1 so the callers don't try + * to use other copies. + */ + return 1; + + ret = btrfs_chunk_map_num_copies(map); + btrfs_free_chunk_map(map); + return ret; +} + +unsigned long btrfs_full_stripe_len(struct btrfs_fs_info *fs_info, + u64 logical) +{ + struct btrfs_chunk_map *map; + unsigned long len = fs_info->sectorsize; + + if (!btrfs_fs_incompat(fs_info, RAID56)) + return len; + + map = btrfs_get_chunk_map(fs_info, logical, len); + + if (!WARN_ON(IS_ERR(map))) { + if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) + len = btrfs_stripe_nr_to_offset(nr_data_stripes(map)); + btrfs_free_chunk_map(map); + } + return len; +} + +#ifdef CONFIG_BTRFS_EXPERIMENTAL +static int btrfs_read_preferred(struct btrfs_chunk_map *map, int first, int num_stripes) +{ + for (int index = first; index < first + num_stripes; index++) { + const struct btrfs_device *device = map->stripes[index].dev; + + if (device->devid == READ_ONCE(device->fs_devices->read_devid)) + return index; + } + + /* If no read-preferred device is set use the first stripe. */ + return first; +} + +struct stripe_mirror { + u64 devid; + int num; +}; + +static int btrfs_cmp_devid(const void *a, const void *b) +{ + const struct stripe_mirror *s1 = (const struct stripe_mirror *)a; + const struct stripe_mirror *s2 = (const struct stripe_mirror *)b; + + if (s1->devid < s2->devid) + return -1; + if (s1->devid > s2->devid) + return 1; + return 0; +} + +/* + * Select a stripe for reading using the round-robin algorithm. + * + * 1. Compute the read cycle as the total sectors read divided by the minimum + * sectors per device. + * 2. Determine the stripe number for the current read by taking the modulus + * of the read cycle with the total number of stripes: + * + * stripe index = (total sectors / min sectors per dev) % num stripes + * + * The calculated stripe index is then used to select the corresponding device + * from the list of devices, which is ordered by devid. + */ +static int btrfs_read_rr(const struct btrfs_chunk_map *map, int first, int num_stripes) +{ + struct stripe_mirror stripes[BTRFS_RAID1_MAX_MIRRORS] = { 0 }; + struct btrfs_device *device = map->stripes[first].dev; + struct btrfs_fs_info *fs_info = device->fs_devices->fs_info; + unsigned int read_cycle; + unsigned int total_reads; + unsigned int min_reads_per_dev; + + total_reads = percpu_counter_sum(&fs_info->stats_read_blocks); + min_reads_per_dev = READ_ONCE(fs_info->fs_devices->rr_min_contig_read) >> + fs_info->sectorsize_bits; + + for (int index = 0, i = first; i < first + num_stripes; i++) { + stripes[index].devid = map->stripes[i].dev->devid; + stripes[index].num = i; + index++; + } + sort(stripes, num_stripes, sizeof(struct stripe_mirror), + btrfs_cmp_devid, NULL); + + read_cycle = total_reads / min_reads_per_dev; + return stripes[read_cycle % num_stripes].num; +} +#endif + +static int find_live_mirror(struct btrfs_fs_info *fs_info, + struct btrfs_chunk_map *map, int first, + bool dev_replace_is_ongoing) +{ + const enum btrfs_read_policy policy = READ_ONCE(fs_info->fs_devices->read_policy); + int i; + int num_stripes; + int preferred_mirror; + int tolerance; + struct btrfs_device *srcdev; + + ASSERT((map->type & (BTRFS_BLOCK_GROUP_RAID1_MASK | BTRFS_BLOCK_GROUP_RAID10)), + "type=%llu", map->type); + + if (map->type & BTRFS_BLOCK_GROUP_RAID10) + num_stripes = map->sub_stripes; + else + num_stripes = map->num_stripes; + + switch (policy) { + default: + /* Shouldn't happen, just warn and use pid instead of failing */ + btrfs_warn_rl(fs_info, "unknown read_policy type %u, reset to pid", + policy); + WRITE_ONCE(fs_info->fs_devices->read_policy, BTRFS_READ_POLICY_PID); + fallthrough; + case BTRFS_READ_POLICY_PID: + preferred_mirror = first + (current->pid % num_stripes); + break; +#ifdef CONFIG_BTRFS_EXPERIMENTAL + case BTRFS_READ_POLICY_RR: + preferred_mirror = btrfs_read_rr(map, first, num_stripes); + break; + case BTRFS_READ_POLICY_DEVID: + preferred_mirror = btrfs_read_preferred(map, first, num_stripes); + break; +#endif + } + + if (dev_replace_is_ongoing && + fs_info->dev_replace.cont_reading_from_srcdev_mode == + BTRFS_DEV_REPLACE_ITEM_CONT_READING_FROM_SRCDEV_MODE_AVOID) + srcdev = fs_info->dev_replace.srcdev; + else + srcdev = NULL; + + /* + * try to avoid the drive that is the source drive for a + * dev-replace procedure, only choose it if no other non-missing + * mirror is available + */ + for (tolerance = 0; tolerance < 2; tolerance++) { + if (map->stripes[preferred_mirror].dev->bdev && + (tolerance || map->stripes[preferred_mirror].dev != srcdev)) + return preferred_mirror; + for (i = first; i < first + num_stripes; i++) { + if (map->stripes[i].dev->bdev && + (tolerance || map->stripes[i].dev != srcdev)) + return i; + } + } + + /* we couldn't find one that doesn't fail. Just return something + * and the io error handling code will clean up eventually + */ + return preferred_mirror; +} + +EXPORT_FOR_TESTS +struct btrfs_io_context *alloc_btrfs_io_context(struct btrfs_fs_info *fs_info, + u64 logical, u16 total_stripes) +{ + struct btrfs_io_context *bioc; + + bioc = kzalloc_flex(*bioc, stripes, total_stripes, GFP_NOFS); + + if (!bioc) + return NULL; + + refcount_set(&bioc->refs, 1); + + bioc->fs_info = fs_info; + bioc->replace_stripe_src = -1; + bioc->full_stripe_logical = (u64)-1; + bioc->logical = logical; + + return bioc; +} + +void btrfs_get_bioc(struct btrfs_io_context *bioc) +{ + WARN_ON(!refcount_read(&bioc->refs)); + refcount_inc(&bioc->refs); +} + +void btrfs_put_bioc(struct btrfs_io_context *bioc) +{ + if (!bioc) + return; + if (refcount_dec_and_test(&bioc->refs)) + kfree(bioc); +} + +/* + * Please note that, discard won't be sent to target device of device + * replace. + */ +struct btrfs_discard_stripe *btrfs_map_discard(struct btrfs_fs_info *fs_info, + u64 logical, u64 *length_ret, + u32 *num_stripes, bool do_remap) +{ + struct btrfs_chunk_map *map; + struct btrfs_discard_stripe *stripes; + u64 length = *length_ret; + u64 offset; + u32 stripe_nr; + u32 stripe_nr_end; + u32 stripe_cnt; + u64 stripe_end_offset; + u64 stripe_offset; + u32 stripe_index; + u32 factor = 0; + u32 sub_stripes = 0; + u32 stripes_per_dev = 0; + u32 remaining_stripes = 0; + u32 last_stripe = 0; + int ret; + int i; + + map = btrfs_get_chunk_map(fs_info, logical, length); + if (IS_ERR(map)) + return ERR_CAST(map); + + if (do_remap && (map->type & BTRFS_BLOCK_GROUP_REMAPPED)) { + u64 new_logical = logical; + + ret = btrfs_translate_remap(fs_info, &new_logical, &length); + if (ret) + goto out_free_map; + + if (new_logical != logical) { + btrfs_free_chunk_map(map); + + map = btrfs_get_chunk_map(fs_info, new_logical, length); + if (IS_ERR(map)) + return ERR_CAST(map); + + logical = new_logical; + } + } + + /* we don't discard raid56 yet */ + if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) { + ret = -EOPNOTSUPP; + goto out_free_map; + } + + offset = logical - map->start; + length = min_t(u64, map->start + map->chunk_len - logical, length); + *length_ret = length; + + /* + * stripe_nr counts the total number of stripes we have to stride + * to get to this block + */ + stripe_nr = offset >> BTRFS_STRIPE_LEN_SHIFT; + + /* stripe_offset is the offset of this block in its stripe */ + stripe_offset = offset - btrfs_stripe_nr_to_offset(stripe_nr); + + stripe_nr_end = round_up(offset + length, BTRFS_STRIPE_LEN) >> + BTRFS_STRIPE_LEN_SHIFT; + stripe_cnt = stripe_nr_end - stripe_nr; + stripe_end_offset = btrfs_stripe_nr_to_offset(stripe_nr_end) - + (offset + length); + /* + * after this, stripe_nr is the number of stripes on this + * device we have to walk to find the data, and stripe_index is + * the number of our device in the stripe array + */ + *num_stripes = 1; + stripe_index = 0; + if (map->type & (BTRFS_BLOCK_GROUP_RAID0 | + BTRFS_BLOCK_GROUP_RAID10)) { + if (map->type & BTRFS_BLOCK_GROUP_RAID0) + sub_stripes = 1; + else + sub_stripes = map->sub_stripes; + + factor = map->num_stripes / sub_stripes; + *num_stripes = min_t(u64, map->num_stripes, + sub_stripes * stripe_cnt); + stripe_index = stripe_nr % factor; + stripe_nr /= factor; + stripe_index *= sub_stripes; + + remaining_stripes = stripe_cnt % factor; + stripes_per_dev = stripe_cnt / factor; + last_stripe = ((stripe_nr_end - 1) % factor) * sub_stripes; + } else if (map->type & (BTRFS_BLOCK_GROUP_RAID1_MASK | + BTRFS_BLOCK_GROUP_DUP)) { + *num_stripes = map->num_stripes; + } else { + stripe_index = stripe_nr % map->num_stripes; + stripe_nr /= map->num_stripes; + } + + stripes = kzalloc_objs(*stripes, *num_stripes, GFP_NOFS); + if (!stripes) { + ret = -ENOMEM; + goto out_free_map; + } + + for (i = 0; i < *num_stripes; i++) { + stripes[i].physical = + map->stripes[stripe_index].physical + + stripe_offset + btrfs_stripe_nr_to_offset(stripe_nr); + stripes[i].dev = map->stripes[stripe_index].dev; + + if (map->type & (BTRFS_BLOCK_GROUP_RAID0 | + BTRFS_BLOCK_GROUP_RAID10)) { + stripes[i].length = btrfs_stripe_nr_to_offset(stripes_per_dev); + + if (i / sub_stripes < remaining_stripes) + stripes[i].length += BTRFS_STRIPE_LEN; + + /* + * Special for the first stripe and + * the last stripe: + * + * |-------|...|-------| + * |----------| + * off end_off + */ + if (i < sub_stripes) + stripes[i].length -= stripe_offset; + + if (stripe_index >= last_stripe && + stripe_index <= (last_stripe + + sub_stripes - 1)) + stripes[i].length -= stripe_end_offset; + + if (i == sub_stripes - 1) + stripe_offset = 0; + } else { + stripes[i].length = length; + } + + stripe_index++; + if (stripe_index == map->num_stripes) { + stripe_index = 0; + stripe_nr++; + } + } + + btrfs_free_chunk_map(map); + return stripes; +out_free_map: + btrfs_free_chunk_map(map); + return ERR_PTR(ret); +} + +static bool is_block_group_to_copy(struct btrfs_fs_info *fs_info, u64 logical) +{ + struct btrfs_block_group *cache; + bool ret; + + /* Non zoned filesystem does not use "to_copy" flag */ + if (!btrfs_is_zoned(fs_info)) + return false; + + cache = btrfs_lookup_block_group(fs_info, logical); + + ret = test_bit(BLOCK_GROUP_FLAG_TO_COPY, &cache->runtime_flags); + + btrfs_put_block_group(cache); + return ret; +} + +static void handle_ops_on_dev_replace(struct btrfs_io_context *bioc, + struct btrfs_dev_replace *dev_replace, + u64 logical, + struct btrfs_io_geometry *io_geom) +{ + u64 srcdev_devid = dev_replace->srcdev->devid; + /* + * At this stage, num_stripes is still the real number of stripes, + * excluding the duplicated stripes. + */ + int num_stripes = io_geom->num_stripes; + int max_errors = io_geom->max_errors; + int nr_extra_stripes = 0; + int i; + + /* + * A block group which has "to_copy" set will eventually be copied by + * the dev-replace process. We can avoid cloning IO here. + */ + if (is_block_group_to_copy(dev_replace->srcdev->fs_info, logical)) + return; + + /* + * Duplicate the write operations while the dev-replace procedure is + * running. Since the copying of the old disk to the new disk takes + * place at run time while the filesystem is mounted writable, the + * regular write operations to the old disk have to be duplicated to go + * to the new disk as well. + * + * Note that device->missing is handled by the caller, and that the + * write to the old disk is already set up in the stripes array. + */ + for (i = 0; i < num_stripes; i++) { + struct btrfs_io_stripe *old = &bioc->stripes[i]; + struct btrfs_io_stripe *new = &bioc->stripes[num_stripes + nr_extra_stripes]; + + if (old->dev->devid != srcdev_devid) + continue; + + new->physical = old->physical; + new->dev = dev_replace->tgtdev; + if (bioc->map_type & BTRFS_BLOCK_GROUP_RAID56_MASK) + bioc->replace_stripe_src = i; + nr_extra_stripes++; + } + + /* We can only have at most 2 extra nr_stripes (for DUP). */ + ASSERT(nr_extra_stripes <= 2, "nr_extra_stripes=%d", nr_extra_stripes); + /* + * For GET_READ_MIRRORS, we can only return at most 1 extra stripe for + * replace. + * If we have 2 extra stripes, only choose the one with smaller physical. + */ + if (io_geom->op == BTRFS_MAP_GET_READ_MIRRORS && nr_extra_stripes == 2) { + struct btrfs_io_stripe *first = &bioc->stripes[num_stripes]; + struct btrfs_io_stripe *second = &bioc->stripes[num_stripes + 1]; + + /* Only DUP can have two extra stripes. */ + ASSERT(bioc->map_type & BTRFS_BLOCK_GROUP_DUP, + "map_type=%llu", bioc->map_type); + + /* + * Swap the last stripe stripes and reduce @nr_extra_stripes. + * The extra stripe would still be there, but won't be accessed. + */ + if (first->physical > second->physical) { + swap(second->physical, first->physical); + swap(second->dev, first->dev); + nr_extra_stripes--; + } + } + + io_geom->num_stripes = num_stripes + nr_extra_stripes; + io_geom->max_errors = max_errors + nr_extra_stripes; + bioc->replace_nr_stripes = nr_extra_stripes; +} + +static u64 btrfs_max_io_len(struct btrfs_chunk_map *map, u64 offset, + struct btrfs_io_geometry *io_geom) +{ + /* + * Stripe_nr is the stripe where this block falls. stripe_offset is + * the offset of this block in its stripe. + */ + io_geom->stripe_offset = offset & BTRFS_STRIPE_LEN_MASK; + io_geom->stripe_nr = offset >> BTRFS_STRIPE_LEN_SHIFT; + ASSERT(io_geom->stripe_offset < U32_MAX, + "stripe_offset=%llu", io_geom->stripe_offset); + + if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) { + unsigned long full_stripe_len = + btrfs_stripe_nr_to_offset(nr_data_stripes(map)); + + /* + * For full stripe start, we use previously calculated + * @stripe_nr. Align it to nr_data_stripes, then multiply with + * STRIPE_LEN. + * + * By this we can avoid u64 division completely. And we have + * to go rounddown(), not round_down(), as nr_data_stripes is + * not ensured to be power of 2. + */ + io_geom->raid56_full_stripe_start = btrfs_stripe_nr_to_offset( + rounddown(io_geom->stripe_nr, nr_data_stripes(map))); + + ASSERT(io_geom->raid56_full_stripe_start + full_stripe_len > offset, + "raid56_full_stripe_start=%llu full_stripe_len=%lu offset=%llu", + io_geom->raid56_full_stripe_start, full_stripe_len, offset); + ASSERT(io_geom->raid56_full_stripe_start <= offset, + "raid56_full_stripe_start=%llu offset=%llu", + io_geom->raid56_full_stripe_start, offset); + /* + * For writes to RAID56, allow to write a full stripe set, but + * no straddling of stripe sets. + */ + if (io_geom->op == BTRFS_MAP_WRITE) + return full_stripe_len - (offset - io_geom->raid56_full_stripe_start); + } + + /* + * For other RAID types and for RAID56 reads, allow a single stripe (on + * a single disk). + */ + if (map->type & BTRFS_BLOCK_GROUP_STRIPE_MASK) + return BTRFS_STRIPE_LEN - io_geom->stripe_offset; + return U64_MAX; +} + +static int set_io_stripe(struct btrfs_fs_info *fs_info, u64 logical, + u64 *length, struct btrfs_io_stripe *dst, + struct btrfs_chunk_map *map, + struct btrfs_io_geometry *io_geom) +{ + dst->dev = map->stripes[io_geom->stripe_index].dev; + + if (io_geom->op == BTRFS_MAP_READ && io_geom->use_rst) + return btrfs_get_raid_extent_offset(fs_info, logical, length, + map->type, + io_geom->stripe_index, dst); + + dst->physical = map->stripes[io_geom->stripe_index].physical + + io_geom->stripe_offset + + btrfs_stripe_nr_to_offset(io_geom->stripe_nr); + return 0; +} + +static bool is_single_device_io(struct btrfs_fs_info *fs_info, + const struct btrfs_io_stripe *smap, + const struct btrfs_chunk_map *map, + int num_alloc_stripes, + struct btrfs_io_geometry *io_geom) +{ + if (!smap) + return false; + + if (num_alloc_stripes != 1) + return false; + + if (io_geom->use_rst && io_geom->op != BTRFS_MAP_READ) + return false; + + if ((map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) && io_geom->mirror_num > 1) + return false; + + return true; +} + +static void map_blocks_raid0(const struct btrfs_chunk_map *map, + struct btrfs_io_geometry *io_geom) +{ + io_geom->stripe_index = io_geom->stripe_nr % map->num_stripes; + io_geom->stripe_nr /= map->num_stripes; + if (io_geom->op == BTRFS_MAP_READ) + io_geom->mirror_num = 1; +} + +static void map_blocks_raid1(struct btrfs_fs_info *fs_info, + struct btrfs_chunk_map *map, + struct btrfs_io_geometry *io_geom, + bool dev_replace_is_ongoing) +{ + if (io_geom->op != BTRFS_MAP_READ) { + io_geom->num_stripes = map->num_stripes; + return; + } + + if (io_geom->mirror_num) { + io_geom->stripe_index = io_geom->mirror_num - 1; + return; + } + + io_geom->stripe_index = find_live_mirror(fs_info, map, 0, + dev_replace_is_ongoing); + io_geom->mirror_num = io_geom->stripe_index + 1; +} + +static void map_blocks_dup(const struct btrfs_chunk_map *map, + struct btrfs_io_geometry *io_geom) +{ + if (io_geom->op != BTRFS_MAP_READ) { + io_geom->num_stripes = map->num_stripes; + return; + } + + if (io_geom->mirror_num) { + io_geom->stripe_index = io_geom->mirror_num - 1; + return; + } + + io_geom->mirror_num = 1; +} + +static void map_blocks_raid10(struct btrfs_fs_info *fs_info, + struct btrfs_chunk_map *map, + struct btrfs_io_geometry *io_geom, + bool dev_replace_is_ongoing) +{ + u32 factor = map->num_stripes / map->sub_stripes; + int old_stripe_index; + + io_geom->stripe_index = (io_geom->stripe_nr % factor) * map->sub_stripes; + io_geom->stripe_nr /= factor; + + if (io_geom->op != BTRFS_MAP_READ) { + io_geom->num_stripes = map->sub_stripes; + return; + } + + if (io_geom->mirror_num) { + io_geom->stripe_index += io_geom->mirror_num - 1; + return; + } + + old_stripe_index = io_geom->stripe_index; + io_geom->stripe_index = find_live_mirror(fs_info, map, + io_geom->stripe_index, + dev_replace_is_ongoing); + io_geom->mirror_num = io_geom->stripe_index - old_stripe_index + 1; +} + +static void map_blocks_raid56_write(struct btrfs_chunk_map *map, + struct btrfs_io_geometry *io_geom, + u64 logical, u64 *length) +{ + int data_stripes = nr_data_stripes(map); + + /* + * Needs full stripe mapping. + * + * Push stripe_nr back to the start of the full stripe For those cases + * needing a full stripe, @stripe_nr is the full stripe number. + * + * Originally we go raid56_full_stripe_start / full_stripe_len, but + * that can be expensive. Here we just divide @stripe_nr with + * @data_stripes. + */ + io_geom->stripe_nr /= data_stripes; + + /* RAID[56] write or recovery. Return all stripes */ + io_geom->num_stripes = map->num_stripes; + io_geom->max_errors = btrfs_chunk_max_errors(map); + + /* Return the length to the full stripe end. */ + *length = min(logical + *length, + io_geom->raid56_full_stripe_start + map->start + + btrfs_stripe_nr_to_offset(data_stripes)) - + logical; + io_geom->stripe_index = 0; + io_geom->stripe_offset = 0; +} + +static void map_blocks_raid56_read(struct btrfs_chunk_map *map, + struct btrfs_io_geometry *io_geom) +{ + int data_stripes = nr_data_stripes(map); + + ASSERT(io_geom->mirror_num <= 1, "mirror_num=%d", io_geom->mirror_num); + /* Just grab the data stripe directly. */ + io_geom->stripe_index = io_geom->stripe_nr % data_stripes; + io_geom->stripe_nr /= data_stripes; + + /* We distribute the parity blocks across stripes. */ + io_geom->stripe_index = + (io_geom->stripe_nr + io_geom->stripe_index) % map->num_stripes; + + if (io_geom->op == BTRFS_MAP_READ && io_geom->mirror_num < 1) + io_geom->mirror_num = 1; +} + +static void map_blocks_single(const struct btrfs_chunk_map *map, + struct btrfs_io_geometry *io_geom) +{ + io_geom->stripe_index = io_geom->stripe_nr % map->num_stripes; + io_geom->stripe_nr /= map->num_stripes; + io_geom->mirror_num = io_geom->stripe_index + 1; +} + +/* + * Map one logical range to one or more physical ranges. + * + * @length: (Mandatory) mapped length of this run. + * One logical range can be split into different segments + * due to factors like zones and RAID0/5/6/10 stripe + * boundaries. + * + * @bioc_ret: (Mandatory) returned btrfs_io_context structure. + * which has one or more physical ranges (btrfs_io_stripe) + * recorded inside. + * Caller should call btrfs_put_bioc() to free it after use. + * + * @smap: (Optional) single physical range optimization. + * If the map request can be fulfilled by one single + * physical range, and this is parameter is not NULL, + * then @bioc_ret would be NULL, and @smap would be + * updated. + * + * @mirror_num_ret: (Mandatory) returned mirror number if the original + * value is 0. + * + * Mirror number 0 means to choose any live mirrors. + * + * For non-RAID56 profiles, non-zero mirror_num means + * the Nth mirror. (e.g. mirror_num 1 means the first + * copy). + * + * For RAID56 profile, mirror 1 means rebuild from P and + * the remaining data stripes. + * + * For RAID6 profile, mirror > 2 means mark another + * data/P stripe error and rebuild from the remaining + * stripes.. + */ +int btrfs_map_block(struct btrfs_fs_info *fs_info, enum btrfs_map_op op, + u64 logical, u64 *length, + struct btrfs_io_context **bioc_ret, + struct btrfs_io_stripe *smap, int *mirror_num_ret) +{ + struct btrfs_chunk_map *map; + struct btrfs_io_geometry io_geom = { 0 }; + u64 map_offset; + int ret = 0; + int num_copies; + struct btrfs_io_context *bioc = NULL; + struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; + bool dev_replace_is_ongoing = false; + u16 num_alloc_stripes; + u64 max_len; + + ASSERT(bioc_ret); + + io_geom.mirror_num = (mirror_num_ret ? *mirror_num_ret : 0); + io_geom.num_stripes = 1; + io_geom.stripe_index = 0; + io_geom.op = op; + + map = btrfs_get_chunk_map(fs_info, logical, *length); + if (IS_ERR(map)) + return PTR_ERR(map); + + if (map->type & BTRFS_BLOCK_GROUP_REMAPPED) { + u64 new_logical = logical; + + ret = btrfs_translate_remap(fs_info, &new_logical, length); + if (ret) + goto out; + + if (new_logical != logical) { + btrfs_free_chunk_map(map); + + map = btrfs_get_chunk_map(fs_info, new_logical, *length); + if (IS_ERR(map)) + return PTR_ERR(map); + + logical = new_logical; + } + } + + num_copies = btrfs_chunk_map_num_copies(map); + if (io_geom.mirror_num > num_copies) { + ret = -EINVAL; + goto out; + } + + map_offset = logical - map->start; + io_geom.raid56_full_stripe_start = (u64)-1; + max_len = btrfs_max_io_len(map, map_offset, &io_geom); + *length = min_t(u64, map->chunk_len - map_offset, max_len); + io_geom.use_rst = btrfs_need_stripe_tree_update(fs_info, map->type); + + if (dev_replace->replace_task != current) + down_read(&dev_replace->rwsem); + + dev_replace_is_ongoing = btrfs_dev_replace_is_ongoing(dev_replace); + /* + * Hold the semaphore for read during the whole operation, write is + * requested at commit time but must wait. + */ + if (!dev_replace_is_ongoing && dev_replace->replace_task != current) + up_read(&dev_replace->rwsem); + + switch (map->type & BTRFS_BLOCK_GROUP_PROFILE_MASK) { + case BTRFS_BLOCK_GROUP_RAID0: + map_blocks_raid0(map, &io_geom); + break; + case BTRFS_BLOCK_GROUP_RAID1: + case BTRFS_BLOCK_GROUP_RAID1C3: + case BTRFS_BLOCK_GROUP_RAID1C4: + map_blocks_raid1(fs_info, map, &io_geom, dev_replace_is_ongoing); + break; + case BTRFS_BLOCK_GROUP_DUP: + map_blocks_dup(map, &io_geom); + break; + case BTRFS_BLOCK_GROUP_RAID10: + map_blocks_raid10(fs_info, map, &io_geom, dev_replace_is_ongoing); + break; + case BTRFS_BLOCK_GROUP_RAID5: + case BTRFS_BLOCK_GROUP_RAID6: + if (op != BTRFS_MAP_READ || io_geom.mirror_num > 1) + map_blocks_raid56_write(map, &io_geom, logical, length); + else + map_blocks_raid56_read(map, &io_geom); + break; + default: + /* + * After this, stripe_nr is the number of stripes on this + * device we have to walk to find the data, and stripe_index is + * the number of our device in the stripe array + */ + map_blocks_single(map, &io_geom); + break; + } + if (io_geom.stripe_index >= map->num_stripes) { + btrfs_crit(fs_info, + "stripe index math went horribly wrong, got stripe_index=%u, num_stripes=%u", + io_geom.stripe_index, map->num_stripes); + ret = -EINVAL; + goto out; + } + + num_alloc_stripes = io_geom.num_stripes; + if (dev_replace_is_ongoing && dev_replace->tgtdev != NULL && + op != BTRFS_MAP_READ) + /* + * For replace case, we need to add extra stripes for extra + * duplicated stripes. + * + * For both WRITE and GET_READ_MIRRORS, we may have at most + * 2 more stripes (DUP types, otherwise 1). + */ + num_alloc_stripes += 2; + + /* + * If this I/O maps to a single device, try to return the device and + * physical block information on the stack instead of allocating an + * I/O context structure. + */ + if (is_single_device_io(fs_info, smap, map, num_alloc_stripes, &io_geom)) { + ret = set_io_stripe(fs_info, logical, length, smap, map, &io_geom); + if (mirror_num_ret) + *mirror_num_ret = io_geom.mirror_num; + *bioc_ret = NULL; + goto out; + } + + bioc = alloc_btrfs_io_context(fs_info, logical, num_alloc_stripes); + if (!bioc) { + ret = -ENOMEM; + goto out; + } + bioc->map_type = map->type; + bioc->use_rst = io_geom.use_rst; + + /* + * For RAID56 full map, we need to make sure the stripes[] follows the + * rule that data stripes are all ordered, then followed with P and Q + * (if we have). + * + * It's still mostly the same as other profiles, just with extra rotation. + */ + if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK && + (op != BTRFS_MAP_READ || io_geom.mirror_num > 1)) { + /* + * For RAID56 @stripe_nr is already the number of full stripes + * before us, which is also the rotation value (needs to modulo + * with num_stripes). + * + * In this case, we just add @stripe_nr with @i, then do the + * modulo, to reduce one modulo call. + */ + bioc->full_stripe_logical = map->start + + btrfs_stripe_nr_to_offset(io_geom.stripe_nr * + nr_data_stripes(map)); + for (int i = 0; i < io_geom.num_stripes; i++) { + struct btrfs_io_stripe *dst = &bioc->stripes[i]; + u32 stripe_index; + + stripe_index = (i + io_geom.stripe_nr) % io_geom.num_stripes; + dst->dev = map->stripes[stripe_index].dev; + dst->physical = + map->stripes[stripe_index].physical + + io_geom.stripe_offset + + btrfs_stripe_nr_to_offset(io_geom.stripe_nr); + } + } else { + /* + * For all other non-RAID56 profiles, just copy the target + * stripe into the bioc. + */ + for (int i = 0; i < io_geom.num_stripes; i++) { + ret = set_io_stripe(fs_info, logical, length, + &bioc->stripes[i], map, &io_geom); + if (ret < 0) + break; + io_geom.stripe_index++; + } + } + + if (ret) { + *bioc_ret = NULL; + btrfs_put_bioc(bioc); + goto out; + } + + if (op != BTRFS_MAP_READ) + io_geom.max_errors = btrfs_chunk_max_errors(map); + + if (dev_replace_is_ongoing && dev_replace->tgtdev != NULL && + op != BTRFS_MAP_READ) { + handle_ops_on_dev_replace(bioc, dev_replace, logical, &io_geom); + } + + *bioc_ret = bioc; + bioc->num_stripes = io_geom.num_stripes; + bioc->max_errors = io_geom.max_errors; + bioc->mirror_num = io_geom.mirror_num; + +out: + if (dev_replace_is_ongoing && dev_replace->replace_task != current) { + lockdep_assert_held(&dev_replace->rwsem); + /* Unlock and let waiting writers proceed */ + up_read(&dev_replace->rwsem); + } + btrfs_free_chunk_map(map); + return ret; +} + +static bool dev_args_match_fs_devices(const struct btrfs_dev_lookup_args *args, + const struct btrfs_fs_devices *fs_devices) +{ + if (args->fsid == NULL) + return true; + if (memcmp(fs_devices->metadata_uuid, args->fsid, BTRFS_FSID_SIZE) == 0) + return true; + return false; +} + +static bool dev_args_match_device(const struct btrfs_dev_lookup_args *args, + const struct btrfs_device *device) +{ + if (args->devt) + return device->devt == args->devt; + if (args->missing) { + if (test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state) && + !device->bdev) + return true; + return false; + } + + if (device->devid != args->devid) + return false; + if (args->uuid && memcmp(device->uuid, args->uuid, BTRFS_UUID_SIZE) != 0) + return false; + return true; +} + +/* + * Find a device specified by @devid or @uuid in the list of @fs_devices, or + * return NULL. + * + * If devid and uuid are both specified, the match must be exact, otherwise + * only devid is used. + */ +struct btrfs_device *btrfs_find_device(const struct btrfs_fs_devices *fs_devices, + const struct btrfs_dev_lookup_args *args) +{ + struct btrfs_device *device; + struct btrfs_fs_devices *seed_devs; + + if (dev_args_match_fs_devices(args, fs_devices)) { + list_for_each_entry(device, &fs_devices->devices, dev_list) { + if (dev_args_match_device(args, device)) + return device; + } + } + + list_for_each_entry(seed_devs, &fs_devices->seed_list, seed_list) { + if (!dev_args_match_fs_devices(args, seed_devs)) + continue; + list_for_each_entry(device, &seed_devs->devices, dev_list) { + if (dev_args_match_device(args, device)) + return device; + } + } + + return NULL; +} + +static struct btrfs_device *add_missing_dev(struct btrfs_fs_devices *fs_devices, + u64 devid, u8 *dev_uuid) +{ + struct btrfs_device *device; + unsigned int nofs_flag; + + /* + * We call this under the chunk_mutex, so we want to use NOFS for this + * allocation, however we don't want to change btrfs_alloc_device() to + * always do NOFS because we use it in a lot of other GFP_KERNEL safe + * places. + */ + + nofs_flag = memalloc_nofs_save(); + device = btrfs_alloc_device(NULL, &devid, dev_uuid, NULL); + memalloc_nofs_restore(nofs_flag); + if (IS_ERR(device)) + return device; + + list_add(&device->dev_list, &fs_devices->devices); + device->fs_devices = fs_devices; + fs_devices->num_devices++; + + set_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state); + fs_devices->missing_devices++; + + return device; +} + +/* + * Allocate new device struct, set up devid and UUID. + * + * @fs_info: used only for generating a new devid, can be NULL if + * devid is provided (i.e. @devid != NULL). + * @devid: a pointer to devid for this device. If NULL a new devid + * is generated. + * @uuid: a pointer to UUID for this device. If NULL a new UUID + * is generated. + * @path: a pointer to device path if available, NULL otherwise. + * + * Return: a pointer to a new &struct btrfs_device on success; ERR_PTR() + * on error. Returned struct is not linked onto any lists and must be + * destroyed with btrfs_free_device. + */ +struct btrfs_device *btrfs_alloc_device(struct btrfs_fs_info *fs_info, + const u64 *devid, const u8 *uuid, + const char *path) +{ + struct btrfs_device *dev; + u64 tmp; + + if (WARN_ON(!devid && !fs_info)) + return ERR_PTR(-EINVAL); + + dev = kzalloc_obj(*dev); + if (!dev) + return ERR_PTR(-ENOMEM); + + INIT_LIST_HEAD(&dev->dev_list); + INIT_LIST_HEAD(&dev->dev_alloc_list); + INIT_LIST_HEAD(&dev->post_commit_list); + + atomic_set(&dev->dev_stats_ccnt, 0); + btrfs_device_data_ordered_init(dev); + btrfs_extent_io_tree_init(fs_info, &dev->alloc_state, IO_TREE_DEVICE_ALLOC_STATE); + + if (devid) + tmp = *devid; + else { + int ret; + + ret = find_next_devid(fs_info, &tmp); + if (ret) { + btrfs_free_device(dev); + return ERR_PTR(ret); + } + } + dev->devid = tmp; + + if (uuid) + memcpy(dev->uuid, uuid, BTRFS_UUID_SIZE); + else + generate_random_uuid(dev->uuid); + + if (path) { + const char *name; + + name = kstrdup(path, GFP_KERNEL); + if (!name) { + btrfs_free_device(dev); + return ERR_PTR(-ENOMEM); + } + rcu_assign_pointer(dev->name, name); + } + + return dev; +} + +static void btrfs_report_missing_device(struct btrfs_fs_info *fs_info, + u64 devid, u8 *uuid, bool error) +{ + if (error) + btrfs_err_rl(fs_info, "devid %llu uuid %pU is missing", + devid, uuid); + else + btrfs_warn_rl(fs_info, "devid %llu uuid %pU is missing", + devid, uuid); +} + +u64 btrfs_calc_stripe_length(const struct btrfs_chunk_map *map) +{ + const int data_stripes = calc_data_stripes(map->type, map->num_stripes); + + return div_u64(map->chunk_len, data_stripes); +} + +#if BITS_PER_LONG == 32 +/* + * Due to page cache limit, metadata beyond BTRFS_32BIT_MAX_FILE_SIZE + * can't be accessed on 32bit systems. + * + * This function do mount time check to reject the fs if it already has + * metadata chunk beyond that limit. + */ +static int check_32bit_meta_chunk(struct btrfs_fs_info *fs_info, + u64 logical, u64 length, u64 type) +{ + if (!(type & BTRFS_BLOCK_GROUP_METADATA)) + return 0; + + if (logical + length < MAX_LFS_FILESIZE) + return 0; + + btrfs_err_32bit_limit(fs_info); + return -EOVERFLOW; +} + +/* + * This is to give early warning for any metadata chunk reaching + * BTRFS_32BIT_EARLY_WARN_THRESHOLD. + * Although we can still access the metadata, it's not going to be possible + * once the limit is reached. + */ +static void warn_32bit_meta_chunk(struct btrfs_fs_info *fs_info, + u64 logical, u64 length, u64 type) +{ + if (!(type & BTRFS_BLOCK_GROUP_METADATA)) + return; + + if (logical + length < BTRFS_32BIT_EARLY_WARN_THRESHOLD) + return; + + btrfs_warn_32bit_limit(fs_info); +} +#endif + +static struct btrfs_device *handle_missing_device(struct btrfs_fs_info *fs_info, + u64 devid, u8 *uuid) +{ + struct btrfs_device *dev; + + if (!btrfs_test_opt(fs_info, DEGRADED)) { + btrfs_report_missing_device(fs_info, devid, uuid, true); + return ERR_PTR(-ENOENT); + } + + dev = add_missing_dev(fs_info->fs_devices, devid, uuid); + if (IS_ERR(dev)) { + btrfs_err(fs_info, "failed to init missing device %llu: %ld", + devid, PTR_ERR(dev)); + return dev; + } + btrfs_report_missing_device(fs_info, devid, uuid, false); + + return dev; +} + +static int read_one_chunk(struct btrfs_key *key, struct extent_buffer *leaf, + struct btrfs_chunk *chunk) +{ + BTRFS_DEV_LOOKUP_ARGS(args); + struct btrfs_fs_info *fs_info = leaf->fs_info; + struct btrfs_chunk_map *map; + u64 logical; + u64 length; + u64 devid; + u64 type; + u8 uuid[BTRFS_UUID_SIZE]; + int index; + int num_stripes; + int ret; + int i; + + logical = key->offset; + length = btrfs_chunk_length(leaf, chunk); + type = btrfs_chunk_type(leaf, chunk); + index = btrfs_bg_flags_to_raid_index(type); + num_stripes = btrfs_chunk_num_stripes(leaf, chunk); + +#if BITS_PER_LONG == 32 + ret = check_32bit_meta_chunk(fs_info, logical, length, type); + if (ret < 0) + return ret; + warn_32bit_meta_chunk(fs_info, logical, length, type); +#endif + + map = btrfs_find_chunk_map(fs_info, logical, 1); + + /* already mapped? */ + if (map && map->start <= logical && map->start + map->chunk_len > logical) { + btrfs_free_chunk_map(map); + return 0; + } else if (map) { + btrfs_free_chunk_map(map); + } + + map = btrfs_alloc_chunk_map(num_stripes, GFP_NOFS); + if (!map) + return -ENOMEM; + + map->start = logical; + map->chunk_len = length; + map->num_stripes = num_stripes; + map->on_disk_type = type; + /* + * We can't use the sub_stripes value, as for profiles other than + * RAID10, they may have 0 as sub_stripes for filesystems created by + * older mkfs (<v5.4). + * In that case, it can cause divide-by-zero errors later. + * Since currently sub_stripes is fixed for each profile, let's + * use the trusted value instead. + */ + map->sub_stripes = btrfs_raid_array[index].sub_stripes; + map->verified_stripes = 0; + set_real_chunk_type(map); + + if (num_stripes > 0) + map->stripe_size = btrfs_calc_stripe_length(map); + else + map->stripe_size = 0; + + for (i = 0; i < num_stripes; i++) { + map->stripes[i].physical = + btrfs_stripe_offset_nr(leaf, chunk, i); + devid = btrfs_stripe_devid_nr(leaf, chunk, i); + args.devid = devid; + read_extent_buffer(leaf, uuid, (unsigned long) + btrfs_stripe_dev_uuid_nr(chunk, i), + BTRFS_UUID_SIZE); + args.uuid = uuid; + map->stripes[i].dev = btrfs_find_device(fs_info->fs_devices, &args); + if (!map->stripes[i].dev) { + map->stripes[i].dev = handle_missing_device(fs_info, + devid, uuid); + if (IS_ERR(map->stripes[i].dev)) { + ret = PTR_ERR(map->stripes[i].dev); + btrfs_free_chunk_map(map); + return ret; + } + } + + set_bit(BTRFS_DEV_STATE_IN_FS_METADATA, + &(map->stripes[i].dev->dev_state)); + } + + ret = btrfs_add_chunk_map(fs_info, map); + if (ret < 0) { + btrfs_err(fs_info, + "failed to add chunk map, start=%llu len=%llu: %d", + map->start, map->chunk_len, ret); + btrfs_free_chunk_map(map); + } + + return ret; +} + +static void fill_device_from_item(struct extent_buffer *leaf, + struct btrfs_dev_item *dev_item, + struct btrfs_device *device) +{ + unsigned long ptr; + + device->devid = btrfs_device_id(leaf, dev_item); + device->disk_total_bytes = btrfs_device_total_bytes(leaf, dev_item); + device->total_bytes = device->disk_total_bytes; + device->commit_total_bytes = device->disk_total_bytes; + device->bytes_used = btrfs_device_bytes_used(leaf, dev_item); + device->commit_bytes_used = device->bytes_used; + device->type = btrfs_device_type(leaf, dev_item); + device->io_align = btrfs_device_io_align(leaf, dev_item); + device->io_width = btrfs_device_io_width(leaf, dev_item); + device->sector_size = btrfs_device_sector_size(leaf, dev_item); + WARN_ON(device->devid == BTRFS_DEV_REPLACE_DEVID); + clear_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state); + + ptr = btrfs_device_uuid(dev_item); + read_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE); +} + +static struct btrfs_fs_devices *open_seed_devices(struct btrfs_fs_info *fs_info, + u8 *fsid) +{ + struct btrfs_fs_devices *fs_devices; + int ret; + + lockdep_assert_held(&uuid_mutex); + ASSERT(fsid); + + /* This will match only for multi-device seed fs */ + list_for_each_entry(fs_devices, &fs_info->fs_devices->seed_list, seed_list) + if (!memcmp(fs_devices->fsid, fsid, BTRFS_FSID_SIZE)) + return fs_devices; + + + fs_devices = find_fsid(fsid, NULL); + if (!fs_devices) { + if (!btrfs_test_opt(fs_info, DEGRADED)) { + btrfs_err(fs_info, + "failed to find fsid %pU when attempting to open seed devices", + fsid); + return ERR_PTR(-ENOENT); + } + + fs_devices = alloc_fs_devices(fsid); + if (IS_ERR(fs_devices)) + return fs_devices; + + fs_devices->seeding = true; + fs_devices->opened = 1; + list_add(&fs_devices->seed_list, &fs_info->fs_devices->seed_list); + return fs_devices; + } + + /* + * Upon first call for a seed fs fsid, just create a private copy of the + * respective fs_devices and anchor it at fs_info->fs_devices->seed_list + */ + fs_devices = clone_fs_devices(fs_devices); + if (IS_ERR(fs_devices)) + return fs_devices; + + ret = open_fs_devices(fs_devices, BLK_OPEN_READ, fs_info->sb); + if (ret) { + free_fs_devices(fs_devices); + return ERR_PTR(ret); + } + + if (!fs_devices->seeding) { + close_fs_devices(fs_devices); + free_fs_devices(fs_devices); + return ERR_PTR(-EINVAL); + } + + list_add(&fs_devices->seed_list, &fs_info->fs_devices->seed_list); + + return fs_devices; +} + +static int read_one_dev(struct extent_buffer *leaf, + struct btrfs_dev_item *dev_item) +{ + BTRFS_DEV_LOOKUP_ARGS(args); + struct btrfs_fs_info *fs_info = leaf->fs_info; + struct btrfs_fs_devices *fs_devices = fs_info->fs_devices; + struct btrfs_device *device; + u64 devid; + u8 fs_uuid[BTRFS_FSID_SIZE]; + u8 dev_uuid[BTRFS_UUID_SIZE]; + + devid = btrfs_device_id(leaf, dev_item); + args.devid = devid; + read_extent_buffer(leaf, dev_uuid, btrfs_device_uuid(dev_item), + BTRFS_UUID_SIZE); + read_extent_buffer(leaf, fs_uuid, btrfs_device_fsid(dev_item), + BTRFS_FSID_SIZE); + args.uuid = dev_uuid; + args.fsid = fs_uuid; + + if (memcmp(fs_uuid, fs_devices->metadata_uuid, BTRFS_FSID_SIZE)) { + fs_devices = open_seed_devices(fs_info, fs_uuid); + if (IS_ERR(fs_devices)) + return PTR_ERR(fs_devices); + } + + device = btrfs_find_device(fs_info->fs_devices, &args); + if (!device) { + if (!btrfs_test_opt(fs_info, DEGRADED)) { + btrfs_report_missing_device(fs_info, devid, + dev_uuid, true); + return -ENOENT; + } + + device = add_missing_dev(fs_devices, devid, dev_uuid); + if (IS_ERR(device)) { + btrfs_err(fs_info, + "failed to add missing dev %llu: %ld", + devid, PTR_ERR(device)); + return PTR_ERR(device); + } + btrfs_report_missing_device(fs_info, devid, dev_uuid, false); + } else { + if (!device->bdev) { + if (!btrfs_test_opt(fs_info, DEGRADED)) { + btrfs_report_missing_device(fs_info, + devid, dev_uuid, true); + return -ENOENT; + } + btrfs_report_missing_device(fs_info, devid, + dev_uuid, false); + } + + if (!device->bdev && + !test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state)) { + /* + * this happens when a device that was properly setup + * in the device info lists suddenly goes bad. + * device->bdev is NULL, and so we have to set + * device->missing to one here + */ + device->fs_devices->missing_devices++; + set_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state); + } + + /* Move the device to its own fs_devices */ + if (device->fs_devices != fs_devices) { + ASSERT(test_bit(BTRFS_DEV_STATE_MISSING, + &device->dev_state)); + + list_move(&device->dev_list, &fs_devices->devices); + device->fs_devices->num_devices--; + fs_devices->num_devices++; + + device->fs_devices->missing_devices--; + fs_devices->missing_devices++; + + device->fs_devices = fs_devices; + } + } + + if (device->fs_devices != fs_info->fs_devices) { + BUG_ON(test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state)); + if (device->generation != + btrfs_device_generation(leaf, dev_item)) + return -EINVAL; + } + + fill_device_from_item(leaf, dev_item, device); + if (device->bdev) { + u64 max_total_bytes = bdev_nr_bytes(device->bdev); + + if (device->total_bytes > max_total_bytes) { + btrfs_err(fs_info, + "device total_bytes should be at most %llu but found %llu", + max_total_bytes, device->total_bytes); + return -EINVAL; + } + } + set_bit(BTRFS_DEV_STATE_ITEM_FOUND, &device->dev_state); + set_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state); + if (test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state) && + !test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state)) { + device->fs_devices->total_rw_bytes += device->total_bytes; + atomic64_add(device->total_bytes - device->bytes_used, + &fs_info->free_chunk_space); + } + + return 0; +} + +int btrfs_read_sys_array(struct btrfs_fs_info *fs_info) +{ + struct btrfs_super_block *super_copy = fs_info->super_copy; + struct extent_buffer *sb; + u8 *array_ptr; + unsigned long sb_array_offset; + int ret = 0; + u32 array_size; + u32 cur_offset; + struct btrfs_key key; + + ASSERT(BTRFS_SUPER_INFO_SIZE <= fs_info->nodesize); + + /* + * We allocated a dummy extent, just to use extent buffer accessors. + * There will be unused space after BTRFS_SUPER_INFO_SIZE, but + * that's fine, we will not go beyond system chunk array anyway. + */ + sb = alloc_dummy_extent_buffer(fs_info, BTRFS_SUPER_INFO_OFFSET); + if (!sb) + return -ENOMEM; + set_extent_buffer_uptodate(sb); + + write_extent_buffer(sb, super_copy, 0, BTRFS_SUPER_INFO_SIZE); + array_size = btrfs_super_sys_array_size(super_copy); + + array_ptr = super_copy->sys_chunk_array; + sb_array_offset = offsetof(struct btrfs_super_block, sys_chunk_array); + cur_offset = 0; + + while (cur_offset < array_size) { + struct btrfs_chunk *chunk; + struct btrfs_disk_key *disk_key = (struct btrfs_disk_key *)array_ptr; + u32 len = sizeof(*disk_key); + + /* + * The sys_chunk_array has been already verified at super block + * read time. Only do ASSERT()s for basic checks. + */ + ASSERT(cur_offset + len <= array_size); + + btrfs_disk_key_to_cpu(&key, disk_key); + + array_ptr += len; + sb_array_offset += len; + cur_offset += len; + + ASSERT(key.type == BTRFS_CHUNK_ITEM_KEY); + + chunk = (struct btrfs_chunk *)sb_array_offset; + ASSERT(btrfs_chunk_type(sb, chunk) & BTRFS_BLOCK_GROUP_SYSTEM); + + len = btrfs_chunk_item_size(btrfs_chunk_num_stripes(sb, chunk)); + + ASSERT(cur_offset + len <= array_size); + + ret = read_one_chunk(&key, sb, chunk); + if (ret) + break; + + array_ptr += len; + sb_array_offset += len; + cur_offset += len; + } + clear_extent_buffer_uptodate(sb); + free_extent_buffer_stale(sb); + return ret; +} + +/* + * Check if all chunks in the fs are OK for read-write degraded mount + * + * If the @failing_dev is specified, it's accounted as missing. + * + * Return true if all chunks meet the minimal RW mount requirements. + * Return false if any chunk doesn't meet the minimal RW mount requirements. + */ +bool btrfs_check_rw_degradable(struct btrfs_fs_info *fs_info, + struct btrfs_device *failing_dev) +{ + struct btrfs_chunk_map *map; + u64 next_start; + bool ret = true; + + map = btrfs_find_chunk_map(fs_info, 0, U64_MAX); + /* No chunk at all? Return false anyway */ + if (!map) + return false; + + while (map) { + int missing = 0; + int max_tolerated; + int i; + + max_tolerated = + btrfs_get_num_tolerated_disk_barrier_failures( + map->type); + for (i = 0; i < map->num_stripes; i++) { + struct btrfs_device *dev = map->stripes[i].dev; + + if (!dev || !dev->bdev || + test_bit(BTRFS_DEV_STATE_MISSING, &dev->dev_state) || + test_bit(BTRFS_DEV_STATE_FLUSH_FAILED, &dev->dev_state)) + missing++; + else if (failing_dev && failing_dev == dev) + missing++; + } + if (missing > max_tolerated) { + if (!failing_dev) + btrfs_warn(fs_info, + "chunk %llu missing %d devices, max tolerance is %d for writable mount", + map->start, missing, max_tolerated); + btrfs_free_chunk_map(map); + return false; + } + next_start = map->start + map->chunk_len; + btrfs_free_chunk_map(map); + + map = btrfs_find_chunk_map(fs_info, next_start, U64_MAX - next_start); + } + + return ret; +} + +static void readahead_tree_node_children(struct extent_buffer *node) +{ + int i; + const int nr_items = btrfs_header_nritems(node); + + for (i = 0; i < nr_items; i++) + btrfs_readahead_node_child(node, i); +} + +int btrfs_read_chunk_tree(struct btrfs_fs_info *fs_info) +{ + struct btrfs_root *root = fs_info->chunk_root; + BTRFS_PATH_AUTO_FREE(path); + struct extent_buffer *leaf; + struct btrfs_key key; + struct btrfs_key found_key; + int ret; + int slot; + int iter_ret = 0; + u64 total_dev = 0; + u64 last_ra_node = 0; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + /* + * uuid_mutex is needed only if we are mounting a sprout FS + * otherwise we don't need it. + */ + mutex_lock(&uuid_mutex); + + /* + * It is possible for mount and umount to race in such a way that + * we execute this code path, but open_fs_devices failed to clear + * total_rw_bytes. We certainly want it cleared before reading the + * device items, so clear it here. + */ + fs_info->fs_devices->total_rw_bytes = 0; + + /* + * Lockdep complains about possible circular locking dependency between + * a disk's open_mutex (struct gendisk.open_mutex), the rw semaphores + * used for freeze protection of a fs (struct super_block.s_writers), + * which we take when starting a transaction, and extent buffers of the + * chunk tree if we call read_one_dev() while holding a lock on an + * extent buffer of the chunk tree. Since we are mounting the filesystem + * and at this point there can't be any concurrent task modifying the + * chunk tree, to keep it simple, just skip locking on the chunk tree. + */ + ASSERT(!test_bit(BTRFS_FS_OPEN, &fs_info->flags)); + path->skip_locking = true; + + /* + * Read all device items, and then all the chunk items. All + * device items are found before any chunk item (their object id + * is smaller than the lowest possible object id for a chunk + * item - BTRFS_FIRST_CHUNK_TREE_OBJECTID). + */ + key.objectid = BTRFS_DEV_ITEMS_OBJECTID; + key.type = 0; + key.offset = 0; + btrfs_for_each_slot(root, &key, &found_key, path, iter_ret) { + struct extent_buffer *node = path->nodes[1]; + + leaf = path->nodes[0]; + slot = path->slots[0]; + + if (node) { + if (last_ra_node != node->start) { + readahead_tree_node_children(node); + last_ra_node = node->start; + } + } + if (found_key.type == BTRFS_DEV_ITEM_KEY) { + struct btrfs_dev_item *dev_item; + dev_item = btrfs_item_ptr(leaf, slot, + struct btrfs_dev_item); + ret = read_one_dev(leaf, dev_item); + if (ret) + goto error; + total_dev++; + } else if (found_key.type == BTRFS_CHUNK_ITEM_KEY) { + struct btrfs_chunk *chunk; + + /* + * We are only called at mount time, so no need to take + * fs_info->chunk_mutex. Plus, to avoid lockdep warnings, + * we always lock first fs_info->chunk_mutex before + * acquiring any locks on the chunk tree. This is a + * requirement for chunk allocation, see the comment on + * top of btrfs_chunk_alloc() for details. + */ + chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk); + ret = read_one_chunk(&found_key, leaf, chunk); + if (ret) + goto error; + } + } + /* Catch error found during iteration */ + if (iter_ret < 0) { + ret = iter_ret; + goto error; + } + + /* + * After loading chunk tree, we've got all device information, + * do another round of validation checks. + */ + if (total_dev != fs_info->fs_devices->total_devices) { + btrfs_warn(fs_info, +"super block num_devices %llu mismatch with DEV_ITEM count %llu, will be repaired on next transaction commit", + btrfs_super_num_devices(fs_info->super_copy), + total_dev); + fs_info->fs_devices->total_devices = total_dev; + btrfs_set_super_num_devices(fs_info->super_copy, total_dev); + } + if (btrfs_super_total_bytes(fs_info->super_copy) < + fs_info->fs_devices->total_rw_bytes) { + btrfs_err(fs_info, + "super_total_bytes %llu mismatch with fs_devices total_rw_bytes %llu", + btrfs_super_total_bytes(fs_info->super_copy), + fs_info->fs_devices->total_rw_bytes); + ret = -EINVAL; + goto error; + } + ret = 0; +error: + mutex_unlock(&uuid_mutex); + return ret; +} + +int btrfs_init_devices_late(struct btrfs_fs_info *fs_info) +{ + struct btrfs_fs_devices *fs_devices = fs_info->fs_devices, *seed_devs; + struct btrfs_device *device; + int ret = 0; + + mutex_lock(&fs_devices->device_list_mutex); + list_for_each_entry(device, &fs_devices->devices, dev_list) + device->fs_info = fs_info; + + list_for_each_entry(seed_devs, &fs_devices->seed_list, seed_list) { + list_for_each_entry(device, &seed_devs->devices, dev_list) { + device->fs_info = fs_info; + ret = btrfs_get_dev_zone_info(device, false); + if (ret) + break; + } + + seed_devs->fs_info = fs_info; + } + mutex_unlock(&fs_devices->device_list_mutex); + + return ret; +} + +static u64 btrfs_dev_stats_value(const struct extent_buffer *eb, + const struct btrfs_dev_stats_item *ptr, + int index) +{ + u64 val; + + read_extent_buffer(eb, &val, + offsetof(struct btrfs_dev_stats_item, values) + + ((unsigned long)ptr) + (index * sizeof(u64)), + sizeof(val)); + return val; +} + +static void btrfs_set_dev_stats_value(struct extent_buffer *eb, + struct btrfs_dev_stats_item *ptr, + int index, u64 val) +{ + write_extent_buffer(eb, &val, + offsetof(struct btrfs_dev_stats_item, values) + + ((unsigned long)ptr) + (index * sizeof(u64)), + sizeof(val)); +} + +static int btrfs_device_init_dev_stats(struct btrfs_device *device, + struct btrfs_path *path) +{ + struct btrfs_dev_stats_item *ptr; + struct extent_buffer *eb; + struct btrfs_key key; + int item_size; + int i, ret, slot; + + if (!device->fs_info->dev_root) + return 0; + + key.objectid = BTRFS_DEV_STATS_OBJECTID; + key.type = BTRFS_PERSISTENT_ITEM_KEY; + key.offset = device->devid; + ret = btrfs_search_slot(NULL, device->fs_info->dev_root, &key, path, 0, 0); + if (ret) { + for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++) + btrfs_dev_stat_set(device, i, 0); + device->dev_stats_valid = 1; + btrfs_release_path(path); + return ret < 0 ? ret : 0; + } + slot = path->slots[0]; + eb = path->nodes[0]; + item_size = btrfs_item_size(eb, slot); + + ptr = btrfs_item_ptr(eb, slot, struct btrfs_dev_stats_item); + + for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++) { + if (item_size >= (1 + i) * sizeof(__le64)) + atomic_set(device->dev_stat_values + i, + btrfs_dev_stats_value(eb, ptr, i)); + else + btrfs_dev_stat_set(device, i, 0); + } + + device->dev_stats_valid = 1; + btrfs_dev_stat_print_on_load(device); + btrfs_release_path(path); + + return 0; +} + +int btrfs_init_dev_stats(struct btrfs_fs_info *fs_info) +{ + struct btrfs_fs_devices *fs_devices = fs_info->fs_devices, *seed_devs; + struct btrfs_device *device; + BTRFS_PATH_AUTO_FREE(path); + int ret = 0; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + mutex_lock(&fs_devices->device_list_mutex); + list_for_each_entry(device, &fs_devices->devices, dev_list) { + ret = btrfs_device_init_dev_stats(device, path); + if (ret) + goto out; + } + list_for_each_entry(seed_devs, &fs_devices->seed_list, seed_list) { + list_for_each_entry(device, &seed_devs->devices, dev_list) { + ret = btrfs_device_init_dev_stats(device, path); + if (ret) + goto out; + } + } +out: + mutex_unlock(&fs_devices->device_list_mutex); + return ret; +} + +int btrfs_init_writeback_bio_size(struct btrfs_fs_info *fs_info) +{ + struct btrfs_fs_devices *fs_devices = fs_info->fs_devices; + struct btrfs_device *device; + u32 writeback_bio_size = fs_info->sectorsize; + + mutex_lock(&fs_devices->device_list_mutex); + /* + * Let's take maximum over optimal request sizes for all devices. For + * RAID profiles writeback will submit stripe (64k) sized bios anyway + * so our value doesn't matter and for simple profiles this is a good + * approximation of sensible IO chunking. + */ + list_for_each_entry(device, &fs_devices->devices, dev_list) { + struct request_queue *queue; + unsigned int io_opt; + + if (!device->bdev || test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state)) + continue; + queue = bdev_get_queue(device->bdev); + io_opt = queue_io_opt(queue) ? : + queue_max_sectors(queue) << SECTOR_SHIFT; + writeback_bio_size = max(writeback_bio_size, io_opt); + } + mutex_unlock(&fs_devices->device_list_mutex); + + fs_info->writeback_bio_size = writeback_bio_size; + + return 0; +} + +static int update_dev_stat_item(struct btrfs_trans_handle *trans, + struct btrfs_device *device) +{ + struct btrfs_fs_info *fs_info = trans->fs_info; + struct btrfs_root *dev_root = fs_info->dev_root; + BTRFS_PATH_AUTO_FREE(path); + struct btrfs_key key; + struct extent_buffer *eb; + struct btrfs_dev_stats_item *ptr; + int ret; + int i; + + key.objectid = BTRFS_DEV_STATS_OBJECTID; + key.type = BTRFS_PERSISTENT_ITEM_KEY; + key.offset = device->devid; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + ret = btrfs_search_slot(trans, dev_root, &key, path, -1, 1); + if (ret < 0) { + btrfs_warn(fs_info, + "error %d while searching for dev_stats item for device %s", + ret, btrfs_dev_name(device)); + return ret; + } + + if (ret == 0 && + btrfs_item_size(path->nodes[0], path->slots[0]) < sizeof(*ptr)) { + /* need to delete old one and insert a new one */ + ret = btrfs_del_item(trans, dev_root, path); + if (ret != 0) { + btrfs_warn(fs_info, + "delete too small dev_stats item for device %s failed %d", + btrfs_dev_name(device), ret); + return ret; + } + ret = 1; + } + + if (ret == 1) { + /* need to insert a new item */ + btrfs_release_path(path); + ret = btrfs_insert_empty_item(trans, dev_root, path, + &key, sizeof(*ptr)); + if (ret < 0) { + btrfs_warn(fs_info, + "insert dev_stats item for device %s failed %d", + btrfs_dev_name(device), ret); + return ret; + } + } + + eb = path->nodes[0]; + ptr = btrfs_item_ptr(eb, path->slots[0], struct btrfs_dev_stats_item); + for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++) + btrfs_set_dev_stats_value(eb, ptr, i, + btrfs_dev_stat_read(device, i)); + return ret; +} + +/* + * called from commit_transaction. Writes all changed device stats to disk. + */ +int btrfs_run_dev_stats(struct btrfs_trans_handle *trans) +{ + struct btrfs_fs_info *fs_info = trans->fs_info; + struct btrfs_fs_devices *fs_devices = fs_info->fs_devices; + struct btrfs_device *device; + int stats_cnt; + int ret = 0; + bool need_update_dev_stats = false; + + /* + * Do an initial pass using RCU to see if we need to update any dev + * stats item. This is to avoid taking the device_list_mutex which is + * acquired by the fitrim operation and can take a while since it does + * discard operations while holding that mutex. Most of the time, if + * we are on a healthy filesystem, we don't have new stat updates, so + * this avoids blocking on that mutex, which is specially important + * because we are called during the critical section of a transaction + * commit, therefore blocking new transactions from starting while + * discard is running. + * + * Also note that adding/removing devices also requires starting a + * transaction, and since we are called from the critical section of a + * transaction commit, no one can be concurrently adding or removing a + * device. + */ + rcu_read_lock(); + list_for_each_entry_rcu(device, &fs_devices->devices, dev_list) { + if (device->dev_stats_valid && + atomic_read(&device->dev_stats_ccnt) != 0) { + need_update_dev_stats = true; + break; + } + } + rcu_read_unlock(); + + if (!need_update_dev_stats) + return 0; + + mutex_lock(&fs_devices->device_list_mutex); + list_for_each_entry(device, &fs_devices->devices, dev_list) { + stats_cnt = atomic_read(&device->dev_stats_ccnt); + if (!device->dev_stats_valid || stats_cnt == 0) + continue; + + + /* + * There is a LOAD-LOAD control dependency between the value of + * dev_stats_ccnt and updating the on-disk values which requires + * reading the in-memory counters. Such control dependencies + * require explicit read memory barriers. + * + * This memory barriers pairs with smp_mb__before_atomic in + * btrfs_dev_stat_inc/btrfs_dev_stat_set and with the full + * barrier implied by atomic_xchg in + * btrfs_dev_stats_read_and_reset + */ + smp_rmb(); + + ret = update_dev_stat_item(trans, device); + if (ret) + break; + atomic_sub(stats_cnt, &device->dev_stats_ccnt); + } + mutex_unlock(&fs_devices->device_list_mutex); + + return ret; +} + +void btrfs_dev_stat_inc_and_print(struct btrfs_device *dev, int index) +{ + btrfs_dev_stat_inc(dev, index); + + if (!dev->dev_stats_valid) + return; + btrfs_err_rl(dev->fs_info, + "bdev %s errs: wr %u, rd %u, flush %u, corrupt %u, gen %u", + btrfs_dev_name(dev), + btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_WRITE_ERRS), + btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_READ_ERRS), + btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_FLUSH_ERRS), + btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_CORRUPTION_ERRS), + btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_GENERATION_ERRS)); +} + +static void btrfs_dev_stat_print_on_load(struct btrfs_device *dev) +{ + int i; + + for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++) + if (btrfs_dev_stat_read(dev, i) != 0) + break; + if (i == BTRFS_DEV_STAT_VALUES_MAX) + return; /* all values == 0, suppress message */ + + btrfs_info(dev->fs_info, + "bdev %s errs: wr %u, rd %u, flush %u, corrupt %u, gen %u", + btrfs_dev_name(dev), + btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_WRITE_ERRS), + btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_READ_ERRS), + btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_FLUSH_ERRS), + btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_CORRUPTION_ERRS), + btrfs_dev_stat_read(dev, BTRFS_DEV_STAT_GENERATION_ERRS)); +} + +int btrfs_get_dev_stats(struct btrfs_fs_info *fs_info, + struct btrfs_ioctl_get_dev_stats *stats) +{ + BTRFS_DEV_LOOKUP_ARGS(args); + struct btrfs_device *dev; + struct btrfs_fs_devices *fs_devices = fs_info->fs_devices; + int i; + + mutex_lock(&fs_devices->device_list_mutex); + args.devid = stats->devid; + dev = btrfs_find_device(fs_info->fs_devices, &args); + mutex_unlock(&fs_devices->device_list_mutex); + + if (!dev) { + btrfs_warn(fs_info, "get dev_stats failed, device not found"); + return -ENODEV; + } else if (!dev->dev_stats_valid) { + btrfs_warn(fs_info, "get dev_stats failed, not yet valid"); + return -ENODEV; + } else if (stats->flags & BTRFS_DEV_STATS_RESET) { + for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++) { + if (stats->nr_items > i) + stats->values[i] = + btrfs_dev_stat_read_and_reset(dev, i); + else + btrfs_dev_stat_set(dev, i, 0); + } + btrfs_info(fs_info, "device stats zeroed by %s (%d)", + current->comm, task_pid_nr(current)); + } else { + for (i = 0; i < BTRFS_DEV_STAT_VALUES_MAX; i++) + if (stats->nr_items > i) + stats->values[i] = btrfs_dev_stat_read(dev, i); + } + if (stats->nr_items > BTRFS_DEV_STAT_VALUES_MAX) + stats->nr_items = BTRFS_DEV_STAT_VALUES_MAX; + return 0; +} + +/* + * Update the size and bytes used for each device where it changed. This is + * delayed since we would otherwise get errors while writing out the + * superblocks. + * + * Must be invoked during transaction commit. + */ +void btrfs_commit_device_sizes(struct btrfs_transaction *trans) +{ + struct btrfs_device *curr, *next; + + ASSERT(trans->state == TRANS_STATE_COMMIT_DOING, "state=%d" , trans->state); + + if (list_empty(&trans->dev_update_list)) + return; + + /* + * We don't need the device_list_mutex here. This list is owned by the + * transaction and the transaction must complete before the device is + * released. + */ + mutex_lock(&trans->fs_info->chunk_mutex); + list_for_each_entry_safe(curr, next, &trans->dev_update_list, + post_commit_list) { + list_del_init(&curr->post_commit_list); + curr->commit_total_bytes = curr->disk_total_bytes; + curr->commit_bytes_used = curr->bytes_used; + } + mutex_unlock(&trans->fs_info->chunk_mutex); +} + +/* + * Multiplicity factor for simple profiles: DUP, RAID1-like and RAID10. + */ +int btrfs_bg_type_to_factor(u64 flags) +{ + const int index = btrfs_bg_flags_to_raid_index(flags); + + return btrfs_raid_array[index].ncopies; +} + +static int verify_one_dev_extent(struct btrfs_fs_info *fs_info, + u64 chunk_offset, u64 devid, + u64 physical_offset, u64 physical_len) +{ + struct btrfs_dev_lookup_args args = { .devid = devid }; + struct btrfs_chunk_map *map; + struct btrfs_device *dev; + u64 stripe_len; + bool found = false; + int ret = 0; + int i; + + map = btrfs_find_chunk_map(fs_info, chunk_offset, 1); + if (unlikely(!map)) { + btrfs_err(fs_info, +"dev extent physical offset %llu on devid %llu doesn't have corresponding chunk", + physical_offset, devid); + ret = -EUCLEAN; + goto out; + } + + stripe_len = btrfs_calc_stripe_length(map); + if (unlikely(physical_len != stripe_len)) { + btrfs_err(fs_info, +"dev extent physical offset %llu on devid %llu length doesn't match chunk %llu, have %llu expect %llu", + physical_offset, devid, map->start, physical_len, + stripe_len); + ret = -EUCLEAN; + goto out; + } + + /* + * Very old mkfs.btrfs (before v4.15) will not respect the reserved + * space. Although kernel can handle it without problem, better to warn + * the users. + */ + if (physical_offset < BTRFS_DEVICE_RANGE_RESERVED) + btrfs_warn(fs_info, + "devid %llu physical %llu len %llu inside the reserved space", + devid, physical_offset, physical_len); + + for (i = 0; i < map->num_stripes; i++) { + if (unlikely(map->stripes[i].dev->devid == devid && + map->stripes[i].physical == physical_offset)) { + found = true; + if (map->verified_stripes >= map->num_stripes) { + btrfs_err(fs_info, + "too many dev extents for chunk %llu found", + map->start); + ret = -EUCLEAN; + goto out; + } + map->verified_stripes++; + break; + } + } + if (unlikely(!found)) { + btrfs_err(fs_info, + "dev extent physical offset %llu devid %llu has no corresponding chunk", + physical_offset, devid); + ret = -EUCLEAN; + } + + /* Make sure no dev extent is beyond device boundary */ + dev = btrfs_find_device(fs_info->fs_devices, &args); + if (unlikely(!dev)) { + btrfs_err(fs_info, "failed to find devid %llu", devid); + ret = -EUCLEAN; + goto out; + } + + if (unlikely(physical_offset + physical_len > dev->disk_total_bytes)) { + btrfs_err(fs_info, +"dev extent devid %llu physical offset %llu len %llu is beyond device boundary %llu", + devid, physical_offset, physical_len, + dev->disk_total_bytes); + ret = -EUCLEAN; + goto out; + } + + if (dev->zone_info) { + u64 zone_size = dev->zone_info->zone_size; + + if (unlikely(!IS_ALIGNED(physical_offset, zone_size) || + !IS_ALIGNED(physical_len, zone_size))) { + btrfs_err(fs_info, +"zoned: dev extent devid %llu physical offset %llu len %llu is not aligned to device zone", + devid, physical_offset, physical_len); + ret = -EUCLEAN; + goto out; + } + } + +out: + btrfs_free_chunk_map(map); + return ret; +} + +static int verify_chunk_dev_extent_mapping(struct btrfs_fs_info *fs_info) +{ + struct rb_node *node; + int ret = 0; + + read_lock(&fs_info->mapping_tree_lock); + for (node = rb_first_cached(&fs_info->mapping_tree); node; node = rb_next(node)) { + struct btrfs_chunk_map *map; + + map = rb_entry(node, struct btrfs_chunk_map, rb_node); + if (unlikely(map->num_stripes != map->verified_stripes)) { + btrfs_err(fs_info, + "chunk %llu has missing dev extent, have %d expect %d", + map->start, map->verified_stripes, map->num_stripes); + ret = -EUCLEAN; + goto out; + } + } +out: + read_unlock(&fs_info->mapping_tree_lock); + return ret; +} + +/* + * Ensure that all dev extents are mapped to correct chunk, otherwise + * later chunk allocation/free would cause unexpected behavior. + * + * NOTE: This will iterate through the whole device tree, which should be of + * the same size level as the chunk tree. This slightly increases mount time. + */ +int btrfs_verify_dev_extents(struct btrfs_fs_info *fs_info) +{ + BTRFS_PATH_AUTO_FREE(path); + struct btrfs_root *root = fs_info->dev_root; + struct btrfs_key key; + u64 prev_devid = 0; + u64 prev_dev_ext_end = 0; + int ret = 0; + + /* + * We don't have a dev_root because we mounted with ignorebadroots and + * failed to load the root, so we want to skip the verification in this + * case for sure. + * + * However if the dev root is fine, but the tree itself is corrupted + * we'd still fail to mount. This verification is only to make sure + * writes can happen safely, so instead just bypass this check + * completely in the case of IGNOREBADROOTS. + */ + if (btrfs_test_opt(fs_info, IGNOREBADROOTS)) + return 0; + + key.objectid = 1; + key.type = BTRFS_DEV_EXTENT_KEY; + key.offset = 0; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + path->reada = READA_FORWARD_ALWAYS; + ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); + if (ret < 0) + return ret; + + if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) { + ret = btrfs_next_leaf(root, path); + if (ret < 0) + return ret; + /* No dev extents at all? Not good */ + if (unlikely(ret > 0)) + return -EUCLEAN; + } + while (1) { + struct extent_buffer *leaf = path->nodes[0]; + struct btrfs_dev_extent *dext; + int slot = path->slots[0]; + u64 chunk_offset; + u64 physical_offset; + u64 physical_len; + u64 devid; + + btrfs_item_key_to_cpu(leaf, &key, slot); + if (key.type != BTRFS_DEV_EXTENT_KEY) + break; + devid = key.objectid; + physical_offset = key.offset; + + dext = btrfs_item_ptr(leaf, slot, struct btrfs_dev_extent); + chunk_offset = btrfs_dev_extent_chunk_offset(leaf, dext); + physical_len = btrfs_dev_extent_length(leaf, dext); + + /* Check if this dev extent overlaps with the previous one */ + if (unlikely(devid == prev_devid && physical_offset < prev_dev_ext_end)) { + btrfs_err(fs_info, +"dev extent devid %llu physical offset %llu overlap with previous dev extent end %llu", + devid, physical_offset, prev_dev_ext_end); + return -EUCLEAN; + } + + ret = verify_one_dev_extent(fs_info, chunk_offset, devid, + physical_offset, physical_len); + if (ret < 0) + return ret; + prev_devid = devid; + prev_dev_ext_end = physical_offset + physical_len; + + ret = btrfs_next_item(root, path); + if (ret < 0) + return ret; + if (ret > 0) { + ret = 0; + break; + } + } + + /* Ensure all chunks have corresponding dev extents */ + ret = verify_chunk_dev_extent_mapping(fs_info); + if (ret < 0) + return ret; + + mutex_lock(&fs_info->chunk_mutex); + btrfs_update_per_profile_avail(fs_info); + mutex_unlock(&fs_info->chunk_mutex); + return 0; +} + +/* + * Ensure that all devices registered in the fs have their device items in the + * chunk tree. + * + * Return true if unexpected device is found. + * Return false otherwise. + */ +bool btrfs_verify_dev_items(const struct btrfs_fs_info *fs_info) +{ + struct btrfs_fs_devices *seed_devs; + struct btrfs_device *dev; + bool ret = false; + + mutex_lock(&uuid_mutex); + list_for_each_entry(dev, &fs_info->fs_devices->devices, dev_list) { + /* + * Replace target dev item (devid 0) is not inserted into chunk tree. + * So skip the DEV_STATE_ITEM check. + */ + if (dev->devid != BTRFS_DEV_REPLACE_DEVID && + !test_bit(BTRFS_DEV_STATE_ITEM_FOUND, &dev->dev_state)) { + btrfs_err(fs_info, + "devid %llu path %s is registered but not found in chunk tree", + dev->devid, btrfs_dev_name(dev)); + ret = true; + } + } + list_for_each_entry(seed_devs, &fs_info->fs_devices->seed_list, seed_list) { + list_for_each_entry(dev, &seed_devs->devices, dev_list) { + if (!test_bit(BTRFS_DEV_STATE_ITEM_FOUND, &dev->dev_state)) { + btrfs_err(fs_info, + "devid %llu path %s is registered but not found in chunk tree", + dev->devid, btrfs_dev_name(dev)); + ret = true; + } + } + } + mutex_unlock(&uuid_mutex); + if (ret) + btrfs_err(fs_info, +"remove the above devices or use 'btrfs device scan --forget <dev>' to unregister them before mount"); + return ret; +} + +/* + * Check whether the given block group or device is pinned by any inode being + * used as a swapfile. + */ +bool btrfs_pinned_by_swapfile(struct btrfs_fs_info *fs_info, void *ptr) +{ + struct btrfs_swapfile_pin *sp; + struct rb_node *node; + + spin_lock(&fs_info->swapfile_pins_lock); + node = fs_info->swapfile_pins.rb_node; + while (node) { + sp = rb_entry(node, struct btrfs_swapfile_pin, node); + if (ptr < sp->ptr) + node = node->rb_left; + else if (ptr > sp->ptr) + node = node->rb_right; + else + break; + } + spin_unlock(&fs_info->swapfile_pins_lock); + return node != NULL; +} + +static int relocating_repair_kthread(void *data) +{ + struct btrfs_block_group *cache = data; + struct btrfs_fs_info *fs_info = cache->fs_info; + u64 target; + int ret = 0; + + target = cache->start; + btrfs_put_block_group(cache); + + guard(super_write)(fs_info->sb); + + if (!btrfs_exclop_start(fs_info, BTRFS_EXCLOP_BALANCE)) { + btrfs_info(fs_info, + "zoned: skip relocating block group %llu to repair: EBUSY", + target); + return -EBUSY; + } + + mutex_lock(&fs_info->reclaim_bgs_lock); + + /* Ensure block group still exists */ + cache = btrfs_lookup_block_group(fs_info, target); + if (!cache) + goto out; + + if (!test_bit(BLOCK_GROUP_FLAG_RELOCATING_REPAIR, &cache->runtime_flags)) + goto out; + + ret = btrfs_may_alloc_data_chunk(fs_info, target); + if (ret < 0) + goto out; + + btrfs_info(fs_info, + "zoned: relocating block group %llu to repair IO failure", + target); + ret = btrfs_relocate_chunk(fs_info, target, true); + +out: + if (cache) + btrfs_put_block_group(cache); + mutex_unlock(&fs_info->reclaim_bgs_lock); + btrfs_exclop_finish(fs_info); + + return ret; +} + +bool btrfs_repair_one_zone(struct btrfs_fs_info *fs_info, u64 logical) +{ + struct btrfs_block_group *cache; + + if (!btrfs_is_zoned(fs_info)) + return false; + + /* Do not attempt to repair in degraded state */ + if (btrfs_test_opt(fs_info, DEGRADED)) + return true; + + cache = btrfs_lookup_block_group(fs_info, logical); + if (!cache) + return true; + + if (test_and_set_bit(BLOCK_GROUP_FLAG_RELOCATING_REPAIR, &cache->runtime_flags)) { + btrfs_put_block_group(cache); + return true; + } + + kthread_run(relocating_repair_kthread, cache, + "btrfs-relocating-repair"); + + return true; +} + +static void map_raid56_repair_block(struct btrfs_io_context *bioc, + struct btrfs_io_stripe *smap, + u64 logical) +{ + int data_stripes = nr_bioc_data_stripes(bioc); + int i; + + for (i = 0; i < data_stripes; i++) { + u64 stripe_start = bioc->full_stripe_logical + + btrfs_stripe_nr_to_offset(i); + + if (logical >= stripe_start && + logical < stripe_start + BTRFS_STRIPE_LEN) + break; + } + ASSERT(i < data_stripes, "i=%d data_stripes=%d", i, data_stripes); + smap->dev = bioc->stripes[i].dev; + smap->physical = bioc->stripes[i].physical + + ((logical - bioc->full_stripe_logical) & + BTRFS_STRIPE_LEN_MASK); +} + +/* + * Map a repair write into a single device. + * + * A repair write is triggered by read time repair or scrub, which would only + * update the contents of a single device. + * Not update any other mirrors nor go through RMW path. + * + * Callers should ensure: + * + * - Call btrfs_bio_counter_inc_blocked() first + * - The range does not cross stripe boundary + * - Has a valid @mirror_num passed in. + */ +int btrfs_map_repair_block(struct btrfs_fs_info *fs_info, + struct btrfs_io_stripe *smap, u64 logical, + u32 length, int mirror_num) +{ + struct btrfs_io_context *bioc = NULL; + u64 map_length = length; + int mirror_ret = mirror_num; + int ret; + + ASSERT(mirror_num > 0, "mirror_num=%d", mirror_num); + + ret = btrfs_map_block(fs_info, BTRFS_MAP_WRITE, logical, &map_length, + &bioc, smap, &mirror_ret); + if (ret < 0) + return ret; + + /* The map range should not cross stripe boundary. */ + ASSERT(map_length >= length, "map_length=%llu length=%u", map_length, length); + + /* Already mapped to single stripe. */ + if (!bioc) + goto out; + + /* Map the RAID56 multi-stripe writes to a single one. */ + if (bioc->map_type & BTRFS_BLOCK_GROUP_RAID56_MASK) { + map_raid56_repair_block(bioc, smap, logical); + goto out; + } + + ASSERT(mirror_num <= bioc->num_stripes, + "mirror_num=%d num_stripes=%d", mirror_num, bioc->num_stripes); + smap->dev = bioc->stripes[mirror_num - 1].dev; + smap->physical = bioc->stripes[mirror_num - 1].physical; +out: + btrfs_put_bioc(bioc); + ASSERT(smap->dev); + return 0; +} |