diff options
Diffstat (limited to 'fs/btrfs/qgroup.c')
| -rw-r--r-- | fs/btrfs/qgroup.c | 4993 |
1 files changed, 4993 insertions, 0 deletions
diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c new file mode 100644 index 000000000..f68b696b4 --- /dev/null +++ b/fs/btrfs/qgroup.c @@ -0,0 +1,4993 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2011 STRATO. All rights reserved. + */ + +#include <linux/sched.h> +#include <linux/pagemap.h> +#include <linux/writeback.h> +#include <linux/blkdev.h> +#include <linux/rbtree.h> +#include <linux/slab.h> +#include <linux/workqueue.h> +#include <linux/btrfs.h> +#include <linux/sched/mm.h> + +#include "ctree.h" +#include "transaction.h" +#include "disk-io.h" +#include "locking.h" +#include "ulist.h" +#include "backref.h" +#include "extent_io.h" +#include "qgroup.h" +#include "block-group.h" +#include "sysfs.h" +#include "tree-mod-log.h" +#include "fs.h" +#include "accessors.h" +#include "extent-tree.h" +#include "root-tree.h" +#include "tree-checker.h" + +enum btrfs_qgroup_mode btrfs_qgroup_mode(const struct btrfs_fs_info *fs_info) +{ + if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags)) + return BTRFS_QGROUP_MODE_DISABLED; + if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_SIMPLE_MODE) + return BTRFS_QGROUP_MODE_SIMPLE; + return BTRFS_QGROUP_MODE_FULL; +} + +bool btrfs_qgroup_enabled(const struct btrfs_fs_info *fs_info) +{ + return btrfs_qgroup_mode(fs_info) != BTRFS_QGROUP_MODE_DISABLED; +} + +bool btrfs_qgroup_full_accounting(const struct btrfs_fs_info *fs_info) +{ + return btrfs_qgroup_mode(fs_info) == BTRFS_QGROUP_MODE_FULL; +} + +/* + * Helpers to access qgroup reservation + * + * Callers should ensure the lock context and type are valid + */ + +static u64 qgroup_rsv_total(const struct btrfs_qgroup *qgroup) +{ + u64 ret = 0; + int i; + + for (i = 0; i < BTRFS_QGROUP_RSV_LAST; i++) + ret += qgroup->rsv.values[i]; + + return ret; +} + +#ifdef CONFIG_BTRFS_DEBUG +static const char *qgroup_rsv_type_str(enum btrfs_qgroup_rsv_type type) +{ + if (type == BTRFS_QGROUP_RSV_DATA) + return "data"; + if (type == BTRFS_QGROUP_RSV_META_PERTRANS) + return "meta_pertrans"; + if (type == BTRFS_QGROUP_RSV_META_PREALLOC) + return "meta_prealloc"; + return NULL; +} +#endif + +static void qgroup_rsv_add(struct btrfs_fs_info *fs_info, + struct btrfs_qgroup *qgroup, u64 num_bytes, + enum btrfs_qgroup_rsv_type type) +{ + trace_btrfs_qgroup_update_reserve(fs_info, qgroup, num_bytes, type); + qgroup->rsv.values[type] += num_bytes; +} + +static void qgroup_rsv_release(struct btrfs_fs_info *fs_info, + struct btrfs_qgroup *qgroup, u64 num_bytes, + enum btrfs_qgroup_rsv_type type) +{ + trace_btrfs_qgroup_update_reserve(fs_info, qgroup, -(s64)num_bytes, type); + if (qgroup->rsv.values[type] >= num_bytes) { + qgroup->rsv.values[type] -= num_bytes; + return; + } +#ifdef CONFIG_BTRFS_DEBUG + WARN_RATELIMIT(1, + "qgroup %llu %s reserved space underflow, have %llu to free %llu", + qgroup->qgroupid, qgroup_rsv_type_str(type), + qgroup->rsv.values[type], num_bytes); +#endif + qgroup->rsv.values[type] = 0; +} + +static void qgroup_rsv_add_by_qgroup(struct btrfs_fs_info *fs_info, + struct btrfs_qgroup *dest, + const struct btrfs_qgroup *src) +{ + int i; + + for (i = 0; i < BTRFS_QGROUP_RSV_LAST; i++) + qgroup_rsv_add(fs_info, dest, src->rsv.values[i], i); +} + +static void qgroup_rsv_release_by_qgroup(struct btrfs_fs_info *fs_info, + struct btrfs_qgroup *dest, + const struct btrfs_qgroup *src) +{ + int i; + + for (i = 0; i < BTRFS_QGROUP_RSV_LAST; i++) + qgroup_rsv_release(fs_info, dest, src->rsv.values[i], i); +} + +static void btrfs_qgroup_update_old_refcnt(struct btrfs_qgroup *qg, u64 seq, + int mod) +{ + if (qg->old_refcnt < seq) + qg->old_refcnt = seq; + qg->old_refcnt += mod; +} + +static void btrfs_qgroup_update_new_refcnt(struct btrfs_qgroup *qg, u64 seq, + int mod) +{ + if (qg->new_refcnt < seq) + qg->new_refcnt = seq; + qg->new_refcnt += mod; +} + +static inline u64 btrfs_qgroup_get_old_refcnt(const struct btrfs_qgroup *qg, u64 seq) +{ + if (qg->old_refcnt < seq) + return 0; + return qg->old_refcnt - seq; +} + +static inline u64 btrfs_qgroup_get_new_refcnt(const struct btrfs_qgroup *qg, u64 seq) +{ + if (qg->new_refcnt < seq) + return 0; + return qg->new_refcnt - seq; +} + +static int +qgroup_rescan_init(struct btrfs_fs_info *fs_info, u64 progress_objectid, + int init_flags); +static void qgroup_rescan_zero_tracking(struct btrfs_fs_info *fs_info); + +static int btrfs_qgroup_qgroupid_key_cmp(const void *key, const struct rb_node *node) +{ + const u64 *qgroupid = key; + const struct btrfs_qgroup *qgroup = rb_entry(node, struct btrfs_qgroup, node); + + if (qgroup->qgroupid < *qgroupid) + return -1; + else if (qgroup->qgroupid > *qgroupid) + return 1; + + return 0; +} + +/* must be called with qgroup_ioctl_lock held */ +static struct btrfs_qgroup *find_qgroup_rb(const struct btrfs_fs_info *fs_info, + u64 qgroupid) +{ + struct rb_node *node; + + node = rb_find(&qgroupid, &fs_info->qgroup_tree, btrfs_qgroup_qgroupid_key_cmp); + return rb_entry_safe(node, struct btrfs_qgroup, node); +} + +static int btrfs_qgroup_qgroupid_cmp(struct rb_node *new, const struct rb_node *existing) +{ + const struct btrfs_qgroup *new_qgroup = rb_entry(new, struct btrfs_qgroup, node); + + return btrfs_qgroup_qgroupid_key_cmp(&new_qgroup->qgroupid, existing); +} + +/* + * Add qgroup to the filesystem's qgroup tree. + * + * Must be called with qgroup_lock held and @prealloc preallocated. + * + * The control on the lifespan of @prealloc would be transferred to this + * function, thus caller should no longer touch @prealloc. + */ +static struct btrfs_qgroup *add_qgroup_rb(struct btrfs_fs_info *fs_info, + struct btrfs_qgroup *prealloc, + u64 qgroupid) +{ + struct rb_node *node; + + /* Caller must have pre-allocated @prealloc. */ + ASSERT(prealloc); + + prealloc->qgroupid = qgroupid; + node = rb_find_add(&prealloc->node, &fs_info->qgroup_tree, btrfs_qgroup_qgroupid_cmp); + if (node) { + kfree(prealloc); + return rb_entry(node, struct btrfs_qgroup, node); + } + + INIT_LIST_HEAD(&prealloc->groups); + INIT_LIST_HEAD(&prealloc->members); + INIT_LIST_HEAD(&prealloc->dirty); + INIT_LIST_HEAD(&prealloc->iterator); + INIT_LIST_HEAD(&prealloc->nested_iterator); + + return prealloc; +} + +static void __del_qgroup_rb(struct btrfs_qgroup *qgroup) +{ + struct btrfs_qgroup_list *list; + + list_del(&qgroup->dirty); + while (!list_empty(&qgroup->groups)) { + list = list_first_entry(&qgroup->groups, + struct btrfs_qgroup_list, next_group); + list_del(&list->next_group); + list_del(&list->next_member); + kfree(list); + } + + while (!list_empty(&qgroup->members)) { + list = list_first_entry(&qgroup->members, + struct btrfs_qgroup_list, next_member); + list_del(&list->next_group); + list_del(&list->next_member); + kfree(list); + } +} + +/* must be called with qgroup_lock held */ +static int del_qgroup_rb(struct btrfs_fs_info *fs_info, u64 qgroupid) +{ + struct btrfs_qgroup *qgroup = find_qgroup_rb(fs_info, qgroupid); + + if (!qgroup) + return -ENOENT; + + rb_erase(&qgroup->node, &fs_info->qgroup_tree); + __del_qgroup_rb(qgroup); + return 0; +} + +/* + * Add relation specified by two qgroups. + * + * Must be called with qgroup_lock held, the ownership of @prealloc is + * transferred to this function and caller should not touch it anymore. + * + * Return: 0 on success + * -ENOENT if one of the qgroups is NULL + * <0 other errors + */ +static int __add_relation_rb(struct btrfs_qgroup_list *prealloc, + struct btrfs_qgroup *member, + struct btrfs_qgroup *parent) +{ + if (!member || !parent) { + kfree(prealloc); + return -ENOENT; + } + + prealloc->group = parent; + prealloc->member = member; + list_add_tail(&prealloc->next_group, &member->groups); + list_add_tail(&prealloc->next_member, &parent->members); + + return 0; +} + +/* + * Add relation specified by two qgroup ids. + * + * Must be called with qgroup_lock held. + * + * Return: 0 on success + * -ENOENT if one of the ids does not exist + * <0 other errors + */ +static int add_relation_rb(struct btrfs_fs_info *fs_info, + struct btrfs_qgroup_list *prealloc, + u64 memberid, u64 parentid) +{ + struct btrfs_qgroup *member; + struct btrfs_qgroup *parent; + + member = find_qgroup_rb(fs_info, memberid); + parent = find_qgroup_rb(fs_info, parentid); + + return __add_relation_rb(prealloc, member, parent); +} + +/* Must be called with qgroup_lock held */ +static int del_relation_rb(struct btrfs_fs_info *fs_info, + u64 memberid, u64 parentid) +{ + struct btrfs_qgroup *member; + struct btrfs_qgroup *parent; + struct btrfs_qgroup_list *list; + + member = find_qgroup_rb(fs_info, memberid); + parent = find_qgroup_rb(fs_info, parentid); + if (!member || !parent) + return -ENOENT; + + list_for_each_entry(list, &member->groups, next_group) { + if (list->group == parent) { + list_del(&list->next_group); + list_del(&list->next_member); + kfree(list); + return 0; + } + } + return -ENOENT; +} + +#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS +int btrfs_verify_qgroup_counts(const struct btrfs_fs_info *fs_info, u64 qgroupid, + u64 rfer, u64 excl) +{ + struct btrfs_qgroup *qgroup; + + qgroup = find_qgroup_rb(fs_info, qgroupid); + if (!qgroup) + return -EINVAL; + if (qgroup->rfer != rfer || qgroup->excl != excl) + return -EINVAL; + return 0; +} +#endif + +static bool squota_check_parent_usage(struct btrfs_fs_info *fs_info, struct btrfs_qgroup *parent) +{ + u64 excl_sum = 0; + u64 rfer_sum = 0; + u64 excl_cmpr_sum = 0; + u64 rfer_cmpr_sum = 0; + struct btrfs_qgroup_list *glist; + int nr_members = 0; + bool mismatch; + + if (btrfs_qgroup_mode(fs_info) != BTRFS_QGROUP_MODE_SIMPLE) + return false; + if (btrfs_qgroup_level(parent->qgroupid) == 0) + return false; + + /* Eligible parent qgroup. Squota; level > 0; empty members list. */ + list_for_each_entry(glist, &parent->members, next_member) { + excl_sum += glist->member->excl; + rfer_sum += glist->member->rfer; + excl_cmpr_sum += glist->member->excl_cmpr; + rfer_cmpr_sum += glist->member->rfer_cmpr; + nr_members++; + } + mismatch = (parent->excl != excl_sum || parent->rfer != rfer_sum || + parent->excl_cmpr != excl_cmpr_sum || parent->rfer_cmpr != rfer_cmpr_sum); + + WARN(mismatch, + "parent squota qgroup " BTRFS_QGROUP_FMT " has mismatched usage from its %d members. " + "%llu %llu %llu %llu vs %llu %llu %llu %llu\n", + BTRFS_QGROUP_FMT_VALUE(parent), nr_members, parent->excl, + parent->rfer, parent->excl_cmpr, parent->rfer_cmpr, excl_sum, + rfer_sum, excl_cmpr_sum, rfer_cmpr_sum); + return mismatch; +} + +__printf(2, 3) +static void qgroup_mark_inconsistent(struct btrfs_fs_info *fs_info, const char *fmt, ...) +{ + const u64 old_flags = fs_info->qgroup_flags; + + if (btrfs_qgroup_mode(fs_info) == BTRFS_QGROUP_MODE_SIMPLE) + return; + fs_info->qgroup_flags |= (BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT | + BTRFS_QGROUP_RUNTIME_FLAG_CANCEL_RESCAN | + BTRFS_QGROUP_RUNTIME_FLAG_NO_ACCOUNTING); + if (!(old_flags & BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT)) { + struct va_format vaf; + va_list args; + + va_start(args, fmt); + vaf.fmt = fmt; + vaf.va = &args; + + btrfs_warn_rl(fs_info, "qgroup marked inconsistent, %pV", &vaf); + va_end(args); + } +} + +static void qgroup_read_enable_gen(struct btrfs_fs_info *fs_info, + struct extent_buffer *leaf, int slot, + struct btrfs_qgroup_status_item *ptr) +{ + ASSERT(btrfs_fs_incompat(fs_info, SIMPLE_QUOTA)); + ASSERT(btrfs_item_size(leaf, slot) >= sizeof(*ptr)); + fs_info->qgroup_enable_gen = btrfs_qgroup_status_enable_gen(leaf, ptr); +} + +/* + * The full config is read in one go, only called from open_ctree() + * It doesn't use any locking, as at this point we're still single-threaded + */ +int btrfs_read_qgroup_config(struct btrfs_fs_info *fs_info) +{ + struct btrfs_key key; + struct btrfs_key found_key; + struct btrfs_root *quota_root = fs_info->quota_root; + struct btrfs_path *path = NULL; + struct extent_buffer *l; + int slot; + int ret = 0; + u64 flags = 0; + u64 rescan_progress = 0; + + if (!fs_info->quota_root) + return 0; + + path = btrfs_alloc_path(); + if (!path) { + ret = -ENOMEM; + goto out; + } + + ret = btrfs_sysfs_add_qgroups(fs_info); + if (ret < 0) + goto out; + /* default this to quota off, in case no status key is found */ + fs_info->qgroup_flags = 0; + + /* + * pass 1: read status, all qgroup infos and limits + */ + key.objectid = 0; + key.type = 0; + key.offset = 0; + ret = btrfs_search_slot_for_read(quota_root, &key, path, 1, 1); + if (ret) + goto out; + + while (1) { + struct btrfs_qgroup *qgroup; + + slot = path->slots[0]; + l = path->nodes[0]; + btrfs_item_key_to_cpu(l, &found_key, slot); + + if (found_key.type == BTRFS_QGROUP_STATUS_KEY) { + struct btrfs_qgroup_status_item *ptr; + + ptr = btrfs_item_ptr(l, slot, + struct btrfs_qgroup_status_item); + + if (btrfs_qgroup_status_version(l, ptr) != + BTRFS_QGROUP_STATUS_VERSION) { + btrfs_err(fs_info, + "old qgroup version, quota disabled"); + goto out; + } + fs_info->qgroup_flags = btrfs_qgroup_status_flags(l, ptr); + if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_SIMPLE_MODE) + qgroup_read_enable_gen(fs_info, l, slot, ptr); + else if (btrfs_qgroup_status_generation(l, ptr) != fs_info->generation) + qgroup_mark_inconsistent(fs_info, "qgroup generation mismatch"); + rescan_progress = btrfs_qgroup_status_rescan(l, ptr); + goto next1; + } + + if (found_key.type != BTRFS_QGROUP_INFO_KEY && + found_key.type != BTRFS_QGROUP_LIMIT_KEY) + goto next1; + + qgroup = find_qgroup_rb(fs_info, found_key.offset); + if ((qgroup && found_key.type == BTRFS_QGROUP_INFO_KEY) || + (!qgroup && found_key.type == BTRFS_QGROUP_LIMIT_KEY)) + qgroup_mark_inconsistent(fs_info, "inconsistent qgroup config"); + if (!qgroup) { + struct btrfs_qgroup *prealloc; + struct btrfs_root *tree_root = fs_info->tree_root; + + prealloc = kzalloc_obj(*prealloc); + if (!prealloc) { + ret = -ENOMEM; + goto out; + } + qgroup = add_qgroup_rb(fs_info, prealloc, found_key.offset); + /* + * If a qgroup exists for a subvolume ID, it is possible + * that subvolume has been deleted, in which case + * reusing that ID would lead to incorrect accounting. + * + * Ensure that we skip any such subvol ids. + * + * We don't need to lock because this is only called + * during mount before we start doing things like creating + * subvolumes. + */ + if (btrfs_is_fstree(qgroup->qgroupid) && + qgroup->qgroupid > tree_root->free_objectid) + /* + * Don't need to check against BTRFS_LAST_FREE_OBJECTID, + * as it will get checked on the next call to + * btrfs_get_free_objectid. + */ + tree_root->free_objectid = qgroup->qgroupid + 1; + } + ret = btrfs_sysfs_add_one_qgroup(fs_info, qgroup); + if (ret < 0) + goto out; + + switch (found_key.type) { + case BTRFS_QGROUP_INFO_KEY: { + struct btrfs_qgroup_info_item *ptr; + + ptr = btrfs_item_ptr(l, slot, + struct btrfs_qgroup_info_item); + qgroup->rfer = btrfs_qgroup_info_rfer(l, ptr); + qgroup->rfer_cmpr = btrfs_qgroup_info_rfer_cmpr(l, ptr); + qgroup->excl = btrfs_qgroup_info_excl(l, ptr); + qgroup->excl_cmpr = btrfs_qgroup_info_excl_cmpr(l, ptr); + /* generation currently unused */ + break; + } + case BTRFS_QGROUP_LIMIT_KEY: { + struct btrfs_qgroup_limit_item *ptr; + + ptr = btrfs_item_ptr(l, slot, + struct btrfs_qgroup_limit_item); + qgroup->lim_flags = btrfs_qgroup_limit_flags(l, ptr); + qgroup->max_rfer = btrfs_qgroup_limit_max_rfer(l, ptr); + qgroup->max_excl = btrfs_qgroup_limit_max_excl(l, ptr); + qgroup->rsv_rfer = btrfs_qgroup_limit_rsv_rfer(l, ptr); + qgroup->rsv_excl = btrfs_qgroup_limit_rsv_excl(l, ptr); + break; + } + } +next1: + ret = btrfs_next_item(quota_root, path); + if (ret < 0) + goto out; + if (ret) + break; + } + btrfs_release_path(path); + + /* + * pass 2: read all qgroup relations + */ + key.objectid = 0; + key.type = BTRFS_QGROUP_RELATION_KEY; + key.offset = 0; + ret = btrfs_search_slot_for_read(quota_root, &key, path, 1, 0); + if (ret) + goto out; + while (1) { + struct btrfs_qgroup_list *list = NULL; + + slot = path->slots[0]; + l = path->nodes[0]; + btrfs_item_key_to_cpu(l, &found_key, slot); + + if (found_key.type != BTRFS_QGROUP_RELATION_KEY) + goto next2; + + if (found_key.objectid > found_key.offset) { + /* parent <- member, not needed to build config */ + /* FIXME should we omit the key completely? */ + goto next2; + } + + list = kzalloc_obj(*list); + if (!list) { + ret = -ENOMEM; + goto out; + } + ret = add_relation_rb(fs_info, list, found_key.objectid, + found_key.offset); + list = NULL; + if (ret == -ENOENT) { + btrfs_warn(fs_info, + "orphan qgroup relation 0x%llx->0x%llx", + found_key.objectid, found_key.offset); + ret = 0; /* ignore the error */ + } + if (ret) + goto out; +next2: + ret = btrfs_next_item(quota_root, path); + if (ret < 0) + goto out; + if (ret) + break; + } +out: + btrfs_free_path(path); + fs_info->qgroup_flags |= flags; + if (ret >= 0) { + if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_ON) + set_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags); + if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) + ret = qgroup_rescan_init(fs_info, rescan_progress, 0); + } else { + fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_RESCAN; + btrfs_sysfs_del_qgroups(fs_info); + } + + return ret < 0 ? ret : 0; +} + +/* + * Called in close_ctree() when quota is still enabled. This verifies we don't + * leak some reserved space. + * + * Return false if no reserved space is left. + * Return true if some reserved space is leaked. + */ +bool btrfs_check_quota_leak(const struct btrfs_fs_info *fs_info) +{ + struct rb_node *node; + bool ret = false; + + if (btrfs_qgroup_mode(fs_info) == BTRFS_QGROUP_MODE_DISABLED) + return ret; + /* + * Since we're unmounting, there is no race and no need to grab qgroup + * lock. And here we don't go post-order to provide a more user + * friendly sorted result. + */ + for (node = rb_first(&fs_info->qgroup_tree); node; node = rb_next(node)) { + struct btrfs_qgroup *qgroup; + int i; + + qgroup = rb_entry(node, struct btrfs_qgroup, node); + for (i = 0; i < BTRFS_QGROUP_RSV_LAST; i++) { + if (qgroup->rsv.values[i]) { + ret = true; + btrfs_warn(fs_info, + "qgroup " BTRFS_QGROUP_FMT " has unreleased space, type %d rsv %llu", + BTRFS_QGROUP_FMT_VALUE(qgroup), + i, qgroup->rsv.values[i]); + } + } + } + return ret; +} + +/* + * This is called from close_ctree() or open_ctree() or btrfs_quota_disable(), + * first two are in single-threaded paths. + */ +void btrfs_free_qgroup_config(struct btrfs_fs_info *fs_info) +{ + struct rb_node *n; + struct btrfs_qgroup *qgroup; + + /* + * btrfs_quota_disable() can be called concurrently with + * btrfs_qgroup_rescan() -> qgroup_rescan_zero_tracking(), so take the + * lock. + */ + spin_lock(&fs_info->qgroup_lock); + while ((n = rb_first(&fs_info->qgroup_tree))) { + qgroup = rb_entry(n, struct btrfs_qgroup, node); + rb_erase(n, &fs_info->qgroup_tree); + __del_qgroup_rb(qgroup); + spin_unlock(&fs_info->qgroup_lock); + btrfs_sysfs_del_one_qgroup(fs_info, qgroup); + kfree(qgroup); + spin_lock(&fs_info->qgroup_lock); + } + spin_unlock(&fs_info->qgroup_lock); + + btrfs_sysfs_del_qgroups(fs_info); +} + +static int add_qgroup_relation_item(struct btrfs_trans_handle *trans, u64 src, + u64 dst) +{ + struct btrfs_root *quota_root = trans->fs_info->quota_root; + BTRFS_PATH_AUTO_FREE(path); + struct btrfs_key key; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + key.objectid = src; + key.type = BTRFS_QGROUP_RELATION_KEY; + key.offset = dst; + + return btrfs_insert_empty_item(trans, quota_root, path, &key, 0); +} + +static int del_qgroup_relation_item(struct btrfs_trans_handle *trans, u64 src, + u64 dst) +{ + int ret; + struct btrfs_root *quota_root = trans->fs_info->quota_root; + BTRFS_PATH_AUTO_FREE(path); + struct btrfs_key key; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + key.objectid = src; + key.type = BTRFS_QGROUP_RELATION_KEY; + key.offset = dst; + + ret = btrfs_search_slot(trans, quota_root, &key, path, -1, 1); + if (ret < 0) + return ret; + + if (ret > 0) + return -ENOENT; + + return btrfs_del_item(trans, quota_root, path); +} + +static int add_qgroup_item(struct btrfs_trans_handle *trans, + struct btrfs_root *quota_root, u64 qgroupid) +{ + int ret; + BTRFS_PATH_AUTO_FREE(path); + struct btrfs_qgroup_info_item *qgroup_info; + struct btrfs_qgroup_limit_item *qgroup_limit; + struct extent_buffer *leaf; + struct btrfs_key key; + + if (btrfs_is_testing(quota_root->fs_info)) + return 0; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + key.objectid = 0; + key.type = BTRFS_QGROUP_INFO_KEY; + key.offset = qgroupid; + + /* + * Avoid a transaction abort by catching -EEXIST here. In that + * case, we proceed by re-initializing the existing structure + * on disk. + */ + + ret = btrfs_insert_empty_item(trans, quota_root, path, &key, + sizeof(*qgroup_info)); + if (ret && ret != -EEXIST) + return ret; + + leaf = path->nodes[0]; + qgroup_info = btrfs_item_ptr(leaf, path->slots[0], + struct btrfs_qgroup_info_item); + btrfs_set_qgroup_info_generation(leaf, qgroup_info, trans->transid); + btrfs_set_qgroup_info_rfer(leaf, qgroup_info, 0); + btrfs_set_qgroup_info_rfer_cmpr(leaf, qgroup_info, 0); + btrfs_set_qgroup_info_excl(leaf, qgroup_info, 0); + btrfs_set_qgroup_info_excl_cmpr(leaf, qgroup_info, 0); + + btrfs_release_path(path); + + key.type = BTRFS_QGROUP_LIMIT_KEY; + ret = btrfs_insert_empty_item(trans, quota_root, path, &key, + sizeof(*qgroup_limit)); + if (ret && ret != -EEXIST) + return ret; + + leaf = path->nodes[0]; + qgroup_limit = btrfs_item_ptr(leaf, path->slots[0], + struct btrfs_qgroup_limit_item); + btrfs_set_qgroup_limit_flags(leaf, qgroup_limit, 0); + btrfs_set_qgroup_limit_max_rfer(leaf, qgroup_limit, 0); + btrfs_set_qgroup_limit_max_excl(leaf, qgroup_limit, 0); + btrfs_set_qgroup_limit_rsv_rfer(leaf, qgroup_limit, 0); + btrfs_set_qgroup_limit_rsv_excl(leaf, qgroup_limit, 0); + + return 0; +} + +static int del_qgroup_item(struct btrfs_trans_handle *trans, u64 qgroupid) +{ + int ret; + struct btrfs_root *quota_root = trans->fs_info->quota_root; + BTRFS_PATH_AUTO_FREE(path); + struct btrfs_key key; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + key.objectid = 0; + key.type = BTRFS_QGROUP_INFO_KEY; + key.offset = qgroupid; + ret = btrfs_search_slot(trans, quota_root, &key, path, -1, 1); + if (ret < 0) + return ret; + + if (ret > 0) + return -ENOENT; + + ret = btrfs_del_item(trans, quota_root, path); + if (ret) + return ret; + + btrfs_release_path(path); + + key.type = BTRFS_QGROUP_LIMIT_KEY; + ret = btrfs_search_slot(trans, quota_root, &key, path, -1, 1); + if (ret < 0) + return ret; + + if (ret > 0) + return -ENOENT; + + return btrfs_del_item(trans, quota_root, path); +} + +static int update_qgroup_limit_item(struct btrfs_trans_handle *trans, + struct btrfs_qgroup *qgroup) +{ + struct btrfs_root *quota_root = trans->fs_info->quota_root; + BTRFS_PATH_AUTO_FREE(path); + struct btrfs_key key; + struct extent_buffer *l; + struct btrfs_qgroup_limit_item *qgroup_limit; + int ret; + int slot; + + key.objectid = 0; + key.type = BTRFS_QGROUP_LIMIT_KEY; + key.offset = qgroup->qgroupid; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + ret = btrfs_search_slot(trans, quota_root, &key, path, 0, 1); + if (ret > 0) + ret = -ENOENT; + + if (ret) + return ret; + + l = path->nodes[0]; + slot = path->slots[0]; + qgroup_limit = btrfs_item_ptr(l, slot, struct btrfs_qgroup_limit_item); + btrfs_set_qgroup_limit_flags(l, qgroup_limit, qgroup->lim_flags); + btrfs_set_qgroup_limit_max_rfer(l, qgroup_limit, qgroup->max_rfer); + btrfs_set_qgroup_limit_max_excl(l, qgroup_limit, qgroup->max_excl); + btrfs_set_qgroup_limit_rsv_rfer(l, qgroup_limit, qgroup->rsv_rfer); + btrfs_set_qgroup_limit_rsv_excl(l, qgroup_limit, qgroup->rsv_excl); + + return ret; +} + +static int update_qgroup_info_item(struct btrfs_trans_handle *trans, + struct btrfs_qgroup *qgroup) +{ + struct btrfs_fs_info *fs_info = trans->fs_info; + struct btrfs_root *quota_root = fs_info->quota_root; + BTRFS_PATH_AUTO_FREE(path); + struct btrfs_key key; + struct extent_buffer *l; + struct btrfs_qgroup_info_item *qgroup_info; + int ret; + int slot; + + if (btrfs_is_testing(fs_info)) + return 0; + + key.objectid = 0; + key.type = BTRFS_QGROUP_INFO_KEY; + key.offset = qgroup->qgroupid; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + ret = btrfs_search_slot(trans, quota_root, &key, path, 0, 1); + if (ret > 0) + ret = -ENOENT; + + if (ret) + return ret; + + l = path->nodes[0]; + slot = path->slots[0]; + qgroup_info = btrfs_item_ptr(l, slot, struct btrfs_qgroup_info_item); + btrfs_set_qgroup_info_generation(l, qgroup_info, trans->transid); + btrfs_set_qgroup_info_rfer(l, qgroup_info, qgroup->rfer); + btrfs_set_qgroup_info_rfer_cmpr(l, qgroup_info, qgroup->rfer_cmpr); + btrfs_set_qgroup_info_excl(l, qgroup_info, qgroup->excl); + btrfs_set_qgroup_info_excl_cmpr(l, qgroup_info, qgroup->excl_cmpr); + + return ret; +} + +static int update_qgroup_status_item(struct btrfs_trans_handle *trans) +{ + struct btrfs_fs_info *fs_info = trans->fs_info; + struct btrfs_root *quota_root = fs_info->quota_root; + BTRFS_PATH_AUTO_FREE(path); + struct btrfs_key key; + struct extent_buffer *l; + struct btrfs_qgroup_status_item *ptr; + int ret; + int slot; + + key.objectid = 0; + key.type = BTRFS_QGROUP_STATUS_KEY; + key.offset = 0; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + ret = btrfs_search_slot(trans, quota_root, &key, path, 0, 1); + if (ret > 0) + ret = -ENOENT; + + if (ret) + return ret; + + l = path->nodes[0]; + slot = path->slots[0]; + ptr = btrfs_item_ptr(l, slot, struct btrfs_qgroup_status_item); + btrfs_set_qgroup_status_flags(l, ptr, fs_info->qgroup_flags & + BTRFS_QGROUP_STATUS_FLAGS_MASK); + btrfs_set_qgroup_status_generation(l, ptr, trans->transid); + btrfs_set_qgroup_status_rescan(l, ptr, + fs_info->qgroup_rescan_progress.objectid); + + return ret; +} + +/* + * called with qgroup_lock held + */ +static int btrfs_clean_quota_tree(struct btrfs_trans_handle *trans, + struct btrfs_root *root) +{ + BTRFS_PATH_AUTO_FREE(path); + struct btrfs_key key; + struct extent_buffer *leaf = NULL; + int ret; + int nr = 0; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + key.objectid = 0; + key.type = 0; + key.offset = 0; + + while (1) { + ret = btrfs_search_slot(trans, root, &key, path, -1, 1); + if (ret < 0) + return ret; + leaf = path->nodes[0]; + nr = btrfs_header_nritems(leaf); + if (!nr) + break; + /* + * delete the leaf one by one + * since the whole tree is going + * to be deleted. + */ + path->slots[0] = 0; + ret = btrfs_del_items(trans, root, path, 0, nr); + if (ret) + return ret; + + btrfs_release_path(path); + } + + return 0; +} + +int btrfs_quota_enable(struct btrfs_fs_info *fs_info, + struct btrfs_ioctl_quota_ctl_args *quota_ctl_args) +{ + struct btrfs_root *quota_root; + struct btrfs_root *tree_root = fs_info->tree_root; + struct btrfs_path *path = NULL; + struct btrfs_qgroup_status_item *ptr; + struct extent_buffer *leaf; + struct btrfs_key key; + struct btrfs_key found_key; + struct btrfs_qgroup *qgroup = NULL; + struct btrfs_qgroup *prealloc = NULL; + struct btrfs_trans_handle *trans = NULL; + const bool simple = (quota_ctl_args->cmd == BTRFS_QUOTA_CTL_ENABLE_SIMPLE_QUOTA); + int ret = 0; + int slot; + + /* + * We need to have subvol_sem write locked, to prevent races between + * concurrent tasks trying to enable quotas, because we will unlock + * and relock qgroup_ioctl_lock before setting fs_info->quota_root + * and before setting BTRFS_FS_QUOTA_ENABLED. + */ + lockdep_assert_held_write(&fs_info->subvol_sem); + + if (btrfs_fs_incompat(fs_info, EXTENT_TREE_V2)) { + btrfs_err(fs_info, + "qgroups are currently unsupported in extent tree v2"); + return -EINVAL; + } + + mutex_lock(&fs_info->qgroup_ioctl_lock); + if (fs_info->quota_root) + goto out; + + ret = btrfs_sysfs_add_qgroups(fs_info); + if (ret < 0) + goto out; + + /* + * Unlock qgroup_ioctl_lock before starting the transaction. This is to + * avoid lock acquisition inversion problems (reported by lockdep) between + * qgroup_ioctl_lock and the vfs freeze semaphores, acquired when we + * start a transaction. + * After we started the transaction lock qgroup_ioctl_lock again and + * check if someone else created the quota root in the meanwhile. If so, + * just return success and release the transaction handle. + * + * Also we don't need to worry about someone else calling + * btrfs_sysfs_add_qgroups() after we unlock and getting an error because + * that function returns 0 (success) when the sysfs entries already exist. + */ + mutex_unlock(&fs_info->qgroup_ioctl_lock); + + /* + * 1 for quota root item + * 1 for BTRFS_QGROUP_STATUS item + * + * Yet we also need 2*n items for a QGROUP_INFO/QGROUP_LIMIT items + * per subvolume. However those are not currently reserved since it + * would be a lot of overkill. + */ + trans = btrfs_start_transaction(tree_root, 2); + + mutex_lock(&fs_info->qgroup_ioctl_lock); + if (IS_ERR(trans)) { + ret = PTR_ERR(trans); + trans = NULL; + goto out; + } + + if (fs_info->quota_root) + goto out; + + /* + * initially create the quota tree + */ + quota_root = btrfs_create_tree(trans, BTRFS_QUOTA_TREE_OBJECTID); + if (IS_ERR(quota_root)) { + ret = PTR_ERR(quota_root); + btrfs_abort_transaction(trans, ret); + goto out; + } + + path = btrfs_alloc_path(); + if (unlikely(!path)) { + ret = -ENOMEM; + btrfs_abort_transaction(trans, ret); + goto out_free_root; + } + + key.objectid = 0; + key.type = BTRFS_QGROUP_STATUS_KEY; + key.offset = 0; + + ret = btrfs_insert_empty_item(trans, quota_root, path, &key, + sizeof(*ptr)); + if (unlikely(ret)) { + btrfs_abort_transaction(trans, ret); + goto out_free_path; + } + + leaf = path->nodes[0]; + ptr = btrfs_item_ptr(leaf, path->slots[0], + struct btrfs_qgroup_status_item); + btrfs_set_qgroup_status_generation(leaf, ptr, trans->transid); + btrfs_set_qgroup_status_version(leaf, ptr, BTRFS_QGROUP_STATUS_VERSION); + fs_info->qgroup_flags = BTRFS_QGROUP_STATUS_FLAG_ON; + if (simple) { + fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_SIMPLE_MODE; + btrfs_set_fs_incompat(fs_info, SIMPLE_QUOTA); + /* + * Set the enable generation to the next transaction, as we cannot + * ensure that extents written during this transaction will see any + * state we have set here. So we should treat all extents of the + * transaction as coming in before squotas was enabled. + */ + btrfs_set_qgroup_status_enable_gen(leaf, ptr, trans->transid + 1); + } else { + fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT; + } + btrfs_set_qgroup_status_flags(leaf, ptr, fs_info->qgroup_flags & + BTRFS_QGROUP_STATUS_FLAGS_MASK); + btrfs_set_qgroup_status_rescan(leaf, ptr, 0); + + key.objectid = 0; + key.type = BTRFS_ROOT_REF_KEY; + key.offset = 0; + + btrfs_release_path(path); + ret = btrfs_search_slot_for_read(tree_root, &key, path, 1, 0); + if (ret > 0) + goto out_add_root; + if (unlikely(ret < 0)) { + btrfs_abort_transaction(trans, ret); + goto out_free_path; + } + + while (1) { + slot = path->slots[0]; + leaf = path->nodes[0]; + btrfs_item_key_to_cpu(leaf, &found_key, slot); + + if (found_key.type == BTRFS_ROOT_REF_KEY) { + + /* Release locks on tree_root before we access quota_root */ + btrfs_release_path(path); + + /* We should not have a stray @prealloc pointer. */ + ASSERT(prealloc == NULL); + prealloc = kzalloc_obj(*prealloc, GFP_NOFS); + if (unlikely(!prealloc)) { + ret = -ENOMEM; + btrfs_abort_transaction(trans, ret); + goto out_free_path; + } + + ret = add_qgroup_item(trans, quota_root, + found_key.offset); + if (unlikely(ret)) { + btrfs_abort_transaction(trans, ret); + goto out_free_path; + } + + qgroup = add_qgroup_rb(fs_info, prealloc, found_key.offset); + prealloc = NULL; + ret = btrfs_sysfs_add_one_qgroup(fs_info, qgroup); + if (unlikely(ret < 0)) { + btrfs_abort_transaction(trans, ret); + goto out_free_path; + } + ret = btrfs_search_slot_for_read(tree_root, &found_key, + path, 1, 0); + if (unlikely(ret < 0)) { + btrfs_abort_transaction(trans, ret); + goto out_free_path; + } + if (ret > 0) { + /* + * Shouldn't happen because the key should still + * be there (return 0), but in case it does it + * means we have reached the end of the tree - + * there are no more leaves with items that have + * a key greater than or equals to @found_key, + * so just stop the search loop. + */ + break; + } + } + ret = btrfs_next_item(tree_root, path); + if (unlikely(ret < 0)) { + btrfs_abort_transaction(trans, ret); + goto out_free_path; + } + if (ret) + break; + } + +out_add_root: + btrfs_release_path(path); + ret = add_qgroup_item(trans, quota_root, BTRFS_FS_TREE_OBJECTID); + if (unlikely(ret)) { + btrfs_abort_transaction(trans, ret); + goto out_free_path; + } + + ASSERT(prealloc == NULL); + prealloc = kzalloc_obj(*prealloc, GFP_NOFS); + if (!prealloc) { + ret = -ENOMEM; + goto out_free_path; + } + qgroup = add_qgroup_rb(fs_info, prealloc, BTRFS_FS_TREE_OBJECTID); + prealloc = NULL; + ret = btrfs_sysfs_add_one_qgroup(fs_info, qgroup); + if (unlikely(ret < 0)) { + btrfs_abort_transaction(trans, ret); + goto out_free_path; + } + + /* + * Set fs_info->qgroup_enable_gen and BTRFS_FS_SQUOTA_ENABLING + * under the transaction handle. We want to ensure that all extents in + * the next transaction definitely see them. + */ + if (simple) { + fs_info->qgroup_enable_gen = trans->transid + 1; + set_bit(BTRFS_FS_SQUOTA_ENABLING, &fs_info->flags); + } + + mutex_unlock(&fs_info->qgroup_ioctl_lock); + /* + * Commit the transaction while not holding qgroup_ioctl_lock, to avoid + * a deadlock with tasks concurrently doing other qgroup operations, such + * adding/removing qgroups or adding/deleting qgroup relations for example, + * because all qgroup operations first start or join a transaction and then + * lock the qgroup_ioctl_lock mutex. + * We are safe from a concurrent task trying to enable quotas, by calling + * this function, since we are serialized by fs_info->subvol_sem. + */ + ret = btrfs_commit_transaction(trans); + trans = NULL; + + mutex_lock(&fs_info->qgroup_ioctl_lock); + if (ret) { + if (simple) { + clear_bit(BTRFS_FS_SQUOTA_ENABLING, &fs_info->flags); + fs_info->qgroup_enable_gen = 0; + } + goto out_free_path; + } + + /* + * Set quota enabled flag after committing the transaction, to avoid + * deadlocks on fs_info->qgroup_ioctl_lock with concurrent snapshot + * creation. + */ + spin_lock(&fs_info->qgroup_lock); + fs_info->quota_root = quota_root; + set_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags); + if (simple) + clear_bit(BTRFS_FS_SQUOTA_ENABLING, &fs_info->flags); + spin_unlock(&fs_info->qgroup_lock); + + /* Skip rescan for simple qgroups. */ + if (btrfs_qgroup_mode(fs_info) == BTRFS_QGROUP_MODE_SIMPLE) + goto out_free_path; + + ret = qgroup_rescan_init(fs_info, 0, 1); + if (!ret) { + qgroup_rescan_zero_tracking(fs_info); + fs_info->qgroup_rescan_running = true; + btrfs_queue_work(fs_info->qgroup_rescan_workers, + &fs_info->qgroup_rescan_work); + } else { + /* + * We have set both BTRFS_FS_QUOTA_ENABLED and + * BTRFS_QGROUP_STATUS_FLAG_ON, so we can only fail with + * -EINPROGRESS. That can happen because someone started the + * rescan worker by calling quota rescan ioctl before we + * attempted to initialize the rescan worker. Failure due to + * quotas disabled in the meanwhile is not possible, because + * we are holding a write lock on fs_info->subvol_sem, which + * is also acquired when disabling quotas. + * Ignore such error, and any other error would need to undo + * everything we did in the transaction we just committed. + */ + ASSERT(ret == -EINPROGRESS); + ret = 0; + } + +out_free_path: + btrfs_free_path(path); +out_free_root: + if (ret) + btrfs_put_root(quota_root); +out: + if (ret) + btrfs_sysfs_del_qgroups(fs_info); + mutex_unlock(&fs_info->qgroup_ioctl_lock); + if (ret && trans) + btrfs_end_transaction(trans); + else if (trans) + ret = btrfs_end_transaction(trans); + kfree(prealloc); + return ret; +} + +/* + * It is possible to have outstanding ordered extents which reserved bytes + * before we disabled. We need to fully flush delalloc, ordered extents, and a + * commit to ensure that we don't leak such reservations, only to have them + * come back if we re-enable. + * + * - enable simple quotas + * - reserve space + * - release it, store rsv_bytes in OE + * - disable quotas + * - enable simple quotas (qgroup rsv are all 0) + * - OE finishes + * - run delayed refs + * - free rsv_bytes, resulting in miscounting or even underflow + */ +static int flush_reservations(struct btrfs_fs_info *fs_info) +{ + int ret; + + ret = btrfs_start_delalloc_roots(fs_info, LONG_MAX, false); + if (ret) + return ret; + btrfs_wait_ordered_roots(fs_info, U64_MAX, NULL); + + return btrfs_commit_current_transaction(fs_info->tree_root); +} + +int btrfs_quota_disable(struct btrfs_fs_info *fs_info) +{ + struct btrfs_root *quota_root = NULL; + struct btrfs_trans_handle *trans = NULL; + int ret = 0; + + /* + * We need to have subvol_sem write locked to prevent races with + * snapshot creation. + */ + lockdep_assert_held_write(&fs_info->subvol_sem); + + /* + * Relocation will mess with backrefs, so make sure we have the + * cleaner_mutex held to protect us from relocate. + */ + lockdep_assert_held(&fs_info->cleaner_mutex); + + mutex_lock(&fs_info->qgroup_ioctl_lock); + if (!fs_info->quota_root) + goto out; + + /* + * Unlock the qgroup_ioctl_lock mutex before waiting for the rescan worker to + * complete. Otherwise we can deadlock because btrfs_remove_qgroup() needs + * to lock that mutex while holding a transaction handle and the rescan + * worker needs to commit a transaction. + */ + mutex_unlock(&fs_info->qgroup_ioctl_lock); + + /* + * Request qgroup rescan worker to complete and wait for it. This wait + * must be done before transaction start for quota disable since it may + * deadlock with transaction by the qgroup rescan worker. + */ + clear_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags); + btrfs_qgroup_wait_for_completion(fs_info, false); + + /* + * We have nothing held here and no trans handle, just return the error + * if there is one and set back the quota enabled bit since we didn't + * actually disable quotas. + */ + ret = flush_reservations(fs_info); + if (ret) { + set_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags); + return ret; + } + + /* + * 1 For the root item + * + * We should also reserve enough items for the quota tree deletion in + * btrfs_clean_quota_tree but this is not done. + * + * Also, we must always start a transaction without holding the mutex + * qgroup_ioctl_lock, see btrfs_quota_enable(). + */ + trans = btrfs_start_transaction(fs_info->tree_root, 1); + + mutex_lock(&fs_info->qgroup_ioctl_lock); + if (IS_ERR(trans)) { + ret = PTR_ERR(trans); + trans = NULL; + set_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags); + goto out; + } + + if (!fs_info->quota_root) + goto out; + + spin_lock(&fs_info->qgroup_lock); + quota_root = fs_info->quota_root; + fs_info->quota_root = NULL; + fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_ON; + fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_SIMPLE_MODE; + fs_info->qgroup_drop_subtree_thres = BTRFS_QGROUP_DROP_SUBTREE_THRES_DEFAULT; + spin_unlock(&fs_info->qgroup_lock); + + btrfs_free_qgroup_config(fs_info); + + ret = btrfs_clean_quota_tree(trans, quota_root); + if (unlikely(ret)) { + btrfs_abort_transaction(trans, ret); + goto out; + } + + ret = btrfs_del_root(trans, "a_root->root_key); + if (unlikely(ret)) { + btrfs_abort_transaction(trans, ret); + goto out; + } + + spin_lock(&fs_info->trans_lock); + list_del("a_root->dirty_list); + spin_unlock(&fs_info->trans_lock); + + btrfs_tree_lock(quota_root->node); + btrfs_clear_buffer_dirty(trans, quota_root->node); + btrfs_tree_unlock(quota_root->node); + ret = btrfs_free_tree_block(trans, btrfs_root_id(quota_root), + quota_root->node, 0, 1); + + if (ret < 0) + btrfs_abort_transaction(trans, ret); + +out: + btrfs_put_root(quota_root); + mutex_unlock(&fs_info->qgroup_ioctl_lock); + if (ret && trans) + btrfs_end_transaction(trans); + else if (trans) + ret = btrfs_commit_transaction(trans); + return ret; +} + +static void qgroup_dirty(struct btrfs_fs_info *fs_info, + struct btrfs_qgroup *qgroup) +{ + if (list_empty(&qgroup->dirty)) + list_add(&qgroup->dirty, &fs_info->dirty_qgroups); +} + +static void qgroup_iterator_add(struct list_head *head, struct btrfs_qgroup *qgroup) +{ + if (!list_empty(&qgroup->iterator)) + return; + + list_add_tail(&qgroup->iterator, head); +} + +static void qgroup_iterator_clean(struct list_head *head) +{ + while (!list_empty(head)) { + struct btrfs_qgroup *qgroup; + + qgroup = list_first_entry(head, struct btrfs_qgroup, iterator); + list_del_init(&qgroup->iterator); + } +} + +/* + * The easy accounting, we're updating qgroup relationship whose child qgroup + * only has exclusive extents. + * + * In this case, all exclusive extents will also be exclusive for parent, so + * excl/rfer just get added/removed. + * + * So is qgroup reservation space, which should also be added/removed to + * parent. + * Or when child tries to release reservation space, parent will underflow its + * reservation (for relationship adding case). + * + * Caller should hold fs_info->qgroup_lock. + */ +static int __qgroup_excl_accounting(struct btrfs_fs_info *fs_info, u64 ref_root, + struct btrfs_qgroup *src, int sign) +{ + struct btrfs_qgroup *qgroup; + LIST_HEAD(qgroup_list); + u64 num_bytes = src->excl; + u64 num_bytes_cmpr = src->excl_cmpr; + int ret = 0; + + qgroup = find_qgroup_rb(fs_info, ref_root); + if (!qgroup) + goto out; + + qgroup_iterator_add(&qgroup_list, qgroup); + list_for_each_entry(qgroup, &qgroup_list, iterator) { + struct btrfs_qgroup_list *glist; + + qgroup->rfer += sign * num_bytes; + qgroup->rfer_cmpr += sign * num_bytes_cmpr; + + WARN_ON(sign < 0 && qgroup->excl < num_bytes); + WARN_ON(sign < 0 && qgroup->excl_cmpr < num_bytes_cmpr); + qgroup->excl += sign * num_bytes; + qgroup->excl_cmpr += sign * num_bytes_cmpr; + + if (sign > 0) + qgroup_rsv_add_by_qgroup(fs_info, qgroup, src); + else + qgroup_rsv_release_by_qgroup(fs_info, qgroup, src); + qgroup_dirty(fs_info, qgroup); + + /* Append parent qgroups to @qgroup_list. */ + list_for_each_entry(glist, &qgroup->groups, next_group) + qgroup_iterator_add(&qgroup_list, glist->group); + } + ret = 0; +out: + qgroup_iterator_clean(&qgroup_list); + return ret; +} + + +/* + * Quick path for updating qgroup with only excl refs. + * + * In that case, just update all parent will be enough. + * Or we needs to do a full rescan. + * Caller should also hold fs_info->qgroup_lock. + * + * Return 0 for quick update, return >0 for need to full rescan + * and mark INCONSISTENT flag. + * Return < 0 for other error. + */ +static int quick_update_accounting(struct btrfs_fs_info *fs_info, + u64 src, u64 dst, int sign) +{ + struct btrfs_qgroup *qgroup; + int ret = 1; + + qgroup = find_qgroup_rb(fs_info, src); + if (!qgroup) + goto out; + if (qgroup->excl == qgroup->rfer) { + ret = __qgroup_excl_accounting(fs_info, dst, qgroup, sign); + if (ret < 0) + goto out; + ret = 0; + } +out: + if (ret) + fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT; + return ret; +} + +/* + * Add relation between @src and @dst qgroup. The @prealloc is allocated by the + * callers and transferred here (either used or freed on error). + */ +int btrfs_add_qgroup_relation(struct btrfs_trans_handle *trans, u64 src, u64 dst, + struct btrfs_qgroup_list *prealloc) +{ + struct btrfs_fs_info *fs_info = trans->fs_info; + struct btrfs_qgroup *parent; + struct btrfs_qgroup *member; + struct btrfs_qgroup_list *list; + int ret = 0; + + ASSERT(prealloc); + + /* Check the level of src and dst first */ + if (btrfs_qgroup_level(src) >= btrfs_qgroup_level(dst)) { + kfree(prealloc); + return -EINVAL; + } + + mutex_lock(&fs_info->qgroup_ioctl_lock); + if (!fs_info->quota_root) { + ret = -ENOTCONN; + goto out; + } + member = find_qgroup_rb(fs_info, src); + parent = find_qgroup_rb(fs_info, dst); + if (!member || !parent) { + ret = -EINVAL; + goto out; + } + + /* check if such qgroup relation exist firstly */ + list_for_each_entry(list, &member->groups, next_group) { + if (list->group == parent) { + ret = -EEXIST; + goto out; + } + } + + ret = add_qgroup_relation_item(trans, src, dst); + if (ret) + goto out; + + ret = add_qgroup_relation_item(trans, dst, src); + if (ret) { + del_qgroup_relation_item(trans, src, dst); + goto out; + } + + spin_lock(&fs_info->qgroup_lock); + ret = __add_relation_rb(prealloc, member, parent); + prealloc = NULL; + if (ret < 0) { + spin_unlock(&fs_info->qgroup_lock); + goto out; + } + ret = quick_update_accounting(fs_info, src, dst, 1); + squota_check_parent_usage(fs_info, parent); + spin_unlock(&fs_info->qgroup_lock); +out: + kfree(prealloc); + mutex_unlock(&fs_info->qgroup_ioctl_lock); + return ret; +} + +static int __del_qgroup_relation(struct btrfs_trans_handle *trans, u64 src, + u64 dst) +{ + struct btrfs_fs_info *fs_info = trans->fs_info; + struct btrfs_qgroup *parent; + struct btrfs_qgroup *member; + struct btrfs_qgroup_list *list; + bool found = false; + int ret = 0; + int ret2; + + if (!fs_info->quota_root) + return -ENOTCONN; + + member = find_qgroup_rb(fs_info, src); + parent = find_qgroup_rb(fs_info, dst); + /* + * The parent/member pair doesn't exist, then try to delete the dead + * relation items only. + */ + if (!member || !parent) + goto delete_item; + + /* check if such qgroup relation exist firstly */ + list_for_each_entry(list, &member->groups, next_group) { + if (list->group == parent) { + found = true; + break; + } + } + +delete_item: + ret = del_qgroup_relation_item(trans, src, dst); + if (ret < 0 && ret != -ENOENT) + return ret; + ret2 = del_qgroup_relation_item(trans, dst, src); + if (ret2 < 0 && ret2 != -ENOENT) + return ret2; + + /* At least one deletion succeeded, return 0 */ + if (!ret || !ret2) + ret = 0; + + if (found) { + spin_lock(&fs_info->qgroup_lock); + del_relation_rb(fs_info, src, dst); + ret = quick_update_accounting(fs_info, src, dst, -1); + ASSERT(parent); + squota_check_parent_usage(fs_info, parent); + spin_unlock(&fs_info->qgroup_lock); + } + + return ret; +} + +int btrfs_del_qgroup_relation(struct btrfs_trans_handle *trans, u64 src, + u64 dst) +{ + struct btrfs_fs_info *fs_info = trans->fs_info; + int ret = 0; + + mutex_lock(&fs_info->qgroup_ioctl_lock); + ret = __del_qgroup_relation(trans, src, dst); + mutex_unlock(&fs_info->qgroup_ioctl_lock); + + return ret; +} + +int btrfs_create_qgroup(struct btrfs_trans_handle *trans, u64 qgroupid) +{ + struct btrfs_fs_info *fs_info = trans->fs_info; + struct btrfs_root *quota_root; + struct btrfs_qgroup *qgroup; + struct btrfs_qgroup *prealloc = NULL; + int ret = 0; + + mutex_lock(&fs_info->qgroup_ioctl_lock); + if (!fs_info->quota_root) { + ret = -ENOTCONN; + goto out; + } + quota_root = fs_info->quota_root; + qgroup = find_qgroup_rb(fs_info, qgroupid); + if (qgroup) { + ret = -EEXIST; + goto out; + } + + prealloc = kzalloc_obj(*prealloc, GFP_NOFS); + if (!prealloc) { + ret = -ENOMEM; + goto out; + } + + ret = add_qgroup_item(trans, quota_root, qgroupid); + if (ret) + goto out; + + spin_lock(&fs_info->qgroup_lock); + qgroup = add_qgroup_rb(fs_info, prealloc, qgroupid); + spin_unlock(&fs_info->qgroup_lock); + prealloc = NULL; + + ret = btrfs_sysfs_add_one_qgroup(fs_info, qgroup); +out: + mutex_unlock(&fs_info->qgroup_ioctl_lock); + kfree(prealloc); + return ret; +} + +static bool can_delete_parent_qgroup(struct btrfs_fs_info *fs_info, struct btrfs_qgroup *qgroup) +{ + ASSERT(btrfs_qgroup_level(qgroup->qgroupid)); + if (btrfs_qgroup_mode(fs_info) == BTRFS_QGROUP_MODE_SIMPLE) + squota_check_parent_usage(fs_info, qgroup); + return list_empty(&qgroup->members); +} + +/* + * Because a shared extent can outlive its owning subvolume, we cannot delete a + * subvol squota qgroup until all of the extents it owns are gone, even if the + * subvolume itself has been deleted. + */ +static bool can_delete_squota_subvol_qgroup(struct btrfs_fs_info *fs_info, + struct btrfs_qgroup *qgroup) +{ + ASSERT(btrfs_qgroup_mode(fs_info) == BTRFS_QGROUP_MODE_SIMPLE); + ASSERT(btrfs_qgroup_level(qgroup->qgroupid) == 0); + + return !(qgroup->rfer || qgroup->excl || qgroup->rfer_cmpr || qgroup->excl_cmpr); +} + +/* + * Return 0 if we can not delete the qgroup (not empty or has children etc). + * Return >0 if we can delete the qgroup. + * Return <0 for other errors during tree search. + */ +static int can_delete_qgroup(struct btrfs_fs_info *fs_info, struct btrfs_qgroup *qgroup) +{ + struct btrfs_key key; + BTRFS_PATH_AUTO_FREE(path); + int ret; + + /* For higher level qgroup, we can only delete it if it has no child. */ + if (btrfs_qgroup_level(qgroup->qgroupid)) + return can_delete_parent_qgroup(fs_info, qgroup); + + /* + * For level-0 qgroups, we can only delete it if it has no subvolume + * for it. + * This means even a subvolume is unlinked but not yet fully dropped, + * we can not delete the qgroup. + */ + key.objectid = qgroup->qgroupid; + key.type = BTRFS_ROOT_ITEM_KEY; + key.offset = -1ULL; + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + /* + * Any subvol qgroup, regardless of mode, cannot be deleted if the + * subvol still exists. + */ + ret = btrfs_find_root(fs_info->tree_root, &key, path, NULL, NULL); + /* + * btrfs_find_root returns <0 on error, 0 if found, and >0 if not, + * so the "found" and "error" cases match our desired return values. + */ + if (ret <= 0) + return ret; + + /* Squotas require additional checks, even if the subvol is deleted. */ + if (btrfs_qgroup_mode(fs_info) == BTRFS_QGROUP_MODE_SIMPLE) + return can_delete_squota_subvol_qgroup(fs_info, qgroup); + return 1; +} + +int btrfs_remove_qgroup(struct btrfs_trans_handle *trans, u64 qgroupid) +{ + struct btrfs_fs_info *fs_info = trans->fs_info; + struct btrfs_qgroup *qgroup; + struct btrfs_qgroup_list *list; + int ret = 0; + + mutex_lock(&fs_info->qgroup_ioctl_lock); + if (!fs_info->quota_root) { + ret = -ENOTCONN; + goto out; + } + + qgroup = find_qgroup_rb(fs_info, qgroupid); + if (!qgroup) { + ret = -ENOENT; + goto out; + } + + ret = can_delete_qgroup(fs_info, qgroup); + if (ret < 0) + goto out; + if (ret == 0) { + ret = -EBUSY; + goto out; + } + + /* Check if there are no children of this qgroup */ + if (!list_empty(&qgroup->members)) { + ret = -EBUSY; + goto out; + } + + ret = del_qgroup_item(trans, qgroupid); + if (ret && ret != -ENOENT) + goto out; + + while (!list_empty(&qgroup->groups)) { + list = list_first_entry(&qgroup->groups, + struct btrfs_qgroup_list, next_group); + ret = __del_qgroup_relation(trans, qgroupid, + list->group->qgroupid); + if (ret) + goto out; + } + + spin_lock(&fs_info->qgroup_lock); + /* + * Warn on reserved space. The subvolume should has no child nor + * corresponding subvolume. + * Thus its reserved space should all be zero, no matter if qgroup + * is consistent or the mode. + */ + if (unlikely(qgroup->rsv.values[BTRFS_QGROUP_RSV_DATA] || + qgroup->rsv.values[BTRFS_QGROUP_RSV_META_PREALLOC] || + qgroup->rsv.values[BTRFS_QGROUP_RSV_META_PERTRANS])) { + DEBUG_WARN(); + btrfs_warn_rl(fs_info, +"to be deleted qgroup " BTRFS_QGROUP_FMT " has non-zero numbers, data %llu meta prealloc %llu meta pertrans %llu", + BTRFS_QGROUP_FMT_VALUE(qgroup), + qgroup->rsv.values[BTRFS_QGROUP_RSV_DATA], + qgroup->rsv.values[BTRFS_QGROUP_RSV_META_PREALLOC], + qgroup->rsv.values[BTRFS_QGROUP_RSV_META_PERTRANS]); + + } + /* + * The same for rfer/excl numbers, but that's only if our qgroup is + * consistent and if it's in regular qgroup mode. + * For simple mode it's not as accurate thus we can hit non-zero values + * very frequently. + */ + if (btrfs_qgroup_mode(fs_info) == BTRFS_QGROUP_MODE_FULL && + !(fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT)) { + if (unlikely(qgroup->rfer || qgroup->excl || + qgroup->rfer_cmpr || qgroup->excl_cmpr)) { + DEBUG_WARN(); + qgroup_mark_inconsistent(fs_info, +"to be deleted qgroup " BTRFS_QGROUP_FMT " has non-zero numbers, rfer %llu rfer_cmpr %llu excl %llu excl_cmpr %llu", + BTRFS_QGROUP_FMT_VALUE(qgroup), + qgroup->rfer, qgroup->rfer_cmpr, + qgroup->excl, qgroup->excl_cmpr); + } + } + del_qgroup_rb(fs_info, qgroupid); + spin_unlock(&fs_info->qgroup_lock); + + /* + * Remove the qgroup from sysfs now without holding the qgroup_lock + * spinlock, since the sysfs_remove_group() function needs to take + * the mutex kernfs_mutex through kernfs_remove_by_name_ns(). + */ + btrfs_sysfs_del_one_qgroup(fs_info, qgroup); + kfree(qgroup); +out: + mutex_unlock(&fs_info->qgroup_ioctl_lock); + return ret; +} + +int btrfs_qgroup_cleanup_dropped_subvolume(struct btrfs_fs_info *fs_info, u64 subvolid) +{ + struct btrfs_trans_handle *trans; + int ret; + + if (!btrfs_is_fstree(subvolid) || !btrfs_qgroup_enabled(fs_info) || + !fs_info->quota_root) + return 0; + + /* + * Commit current transaction to make sure all the rfer/excl numbers + * get updated. + */ + ret = btrfs_commit_current_transaction(fs_info->quota_root); + if (ret < 0) + return ret; + + /* Start new trans to delete the qgroup info and limit items. */ + trans = btrfs_start_transaction(fs_info->quota_root, 2); + if (IS_ERR(trans)) + return PTR_ERR(trans); + ret = btrfs_remove_qgroup(trans, subvolid); + btrfs_end_transaction(trans); + /* + * It's squota and the subvolume still has numbers needed for future + * accounting, in this case we can not delete it. Just skip it. + * + * Or the qgroup is already removed by a qgroup rescan. For both cases we're + * safe to ignore them. + */ + if (ret == -EBUSY || ret == -ENOENT) + ret = 0; + return ret; +} + +int btrfs_limit_qgroup(struct btrfs_trans_handle *trans, u64 qgroupid, + struct btrfs_qgroup_limit *limit) +{ + struct btrfs_fs_info *fs_info = trans->fs_info; + struct btrfs_qgroup *qgroup; + int ret = 0; + /* Sometimes we would want to clear the limit on this qgroup. + * To meet this requirement, we treat the -1 as a special value + * which tell kernel to clear the limit on this qgroup. + */ + const u64 CLEAR_VALUE = -1; + + mutex_lock(&fs_info->qgroup_ioctl_lock); + if (!fs_info->quota_root) { + ret = -ENOTCONN; + goto out; + } + + qgroup = find_qgroup_rb(fs_info, qgroupid); + if (!qgroup) { + ret = -ENOENT; + goto out; + } + + spin_lock(&fs_info->qgroup_lock); + if (limit->flags & BTRFS_QGROUP_LIMIT_MAX_RFER) { + if (limit->max_rfer == CLEAR_VALUE) { + qgroup->lim_flags &= ~BTRFS_QGROUP_LIMIT_MAX_RFER; + limit->flags &= ~BTRFS_QGROUP_LIMIT_MAX_RFER; + qgroup->max_rfer = 0; + } else { + qgroup->max_rfer = limit->max_rfer; + } + } + if (limit->flags & BTRFS_QGROUP_LIMIT_MAX_EXCL) { + if (limit->max_excl == CLEAR_VALUE) { + qgroup->lim_flags &= ~BTRFS_QGROUP_LIMIT_MAX_EXCL; + limit->flags &= ~BTRFS_QGROUP_LIMIT_MAX_EXCL; + qgroup->max_excl = 0; + } else { + qgroup->max_excl = limit->max_excl; + } + } + if (limit->flags & BTRFS_QGROUP_LIMIT_RSV_RFER) { + if (limit->rsv_rfer == CLEAR_VALUE) { + qgroup->lim_flags &= ~BTRFS_QGROUP_LIMIT_RSV_RFER; + limit->flags &= ~BTRFS_QGROUP_LIMIT_RSV_RFER; + qgroup->rsv_rfer = 0; + } else { + qgroup->rsv_rfer = limit->rsv_rfer; + } + } + if (limit->flags & BTRFS_QGROUP_LIMIT_RSV_EXCL) { + if (limit->rsv_excl == CLEAR_VALUE) { + qgroup->lim_flags &= ~BTRFS_QGROUP_LIMIT_RSV_EXCL; + limit->flags &= ~BTRFS_QGROUP_LIMIT_RSV_EXCL; + qgroup->rsv_excl = 0; + } else { + qgroup->rsv_excl = limit->rsv_excl; + } + } + qgroup->lim_flags |= limit->flags; + + spin_unlock(&fs_info->qgroup_lock); + + ret = update_qgroup_limit_item(trans, qgroup); + if (ret) + qgroup_mark_inconsistent(fs_info, "qgroup item update error %d", ret); + +out: + mutex_unlock(&fs_info->qgroup_ioctl_lock); + return ret; +} + +/* + * Inform qgroup to trace one dirty extent, its info is recorded in @record. + * So qgroup can account it at transaction committing time. + * + * No lock version, caller must acquire delayed ref lock and allocated memory, + * then call btrfs_qgroup_trace_extent_post() after exiting lock context. + * + * Return 0 for success insert + * Return >0 for existing record, caller can free @record safely. + * Return <0 for insertion failure, caller can free @record safely. + */ +int btrfs_qgroup_trace_extent_nolock(struct btrfs_fs_info *fs_info, + struct btrfs_delayed_ref_root *delayed_refs, + struct btrfs_qgroup_extent_record *record, + u64 bytenr) +{ + struct btrfs_qgroup_extent_record *existing, *ret; + const unsigned long index = (bytenr >> fs_info->sectorsize_bits); + + if (!btrfs_qgroup_full_accounting(fs_info)) + return 1; + +#if BITS_PER_LONG == 32 + if (bytenr >= MAX_LFS_FILESIZE) { + btrfs_err_rl(fs_info, +"qgroup record for extent at %llu is beyond 32bit page cache and xarray index limit", + bytenr); + btrfs_err_32bit_limit(fs_info); + return -EOVERFLOW; + } +#endif + + trace_btrfs_qgroup_trace_extent(fs_info, record, bytenr); + + xa_lock(&delayed_refs->dirty_extents); + existing = xa_load(&delayed_refs->dirty_extents, index); + if (existing) { + if (record->data_rsv && !existing->data_rsv) { + existing->data_rsv = record->data_rsv; + existing->data_rsv_refroot = record->data_rsv_refroot; + } + xa_unlock(&delayed_refs->dirty_extents); + return 1; + } + + ret = __xa_store(&delayed_refs->dirty_extents, index, record, GFP_ATOMIC); + xa_unlock(&delayed_refs->dirty_extents); + if (xa_is_err(ret)) { + qgroup_mark_inconsistent(fs_info, "xarray insert error: %d", xa_err(ret)); + return xa_err(ret); + } + + return 0; +} + +/* + * Post handler after qgroup_trace_extent_nolock(). + * + * NOTE: Current qgroup does the expensive backref walk at transaction + * committing time with TRANS_STATE_COMMIT_DOING, this blocks incoming + * new transaction. + * This is designed to allow btrfs_find_all_roots() to get correct new_roots + * result. + * + * However for old_roots there is no need to do backref walk at that time, + * since we search commit roots to walk backref and result will always be + * correct. + * + * Due to the nature of no lock version, we can't do backref there. + * So we must call btrfs_qgroup_trace_extent_post() after exiting + * spinlock context. + * + * TODO: If we can fix and prove btrfs_find_all_roots() can get correct result + * using current root, then we can move all expensive backref walk out of + * transaction committing, but not now as qgroup accounting will be wrong again. + */ +int btrfs_qgroup_trace_extent_post(struct btrfs_trans_handle *trans, + struct btrfs_qgroup_extent_record *qrecord, + u64 bytenr) +{ + struct btrfs_fs_info *fs_info = trans->fs_info; + struct btrfs_backref_walk_ctx ctx = { + .bytenr = bytenr, + .fs_info = fs_info, + }; + int ret; + + if (!btrfs_qgroup_full_accounting(fs_info)) + return 0; + /* + * We are always called in a context where we are already holding a + * transaction handle. Often we are called when adding a data delayed + * reference from btrfs_truncate_inode_items() (truncating or unlinking), + * in which case we will be holding a write lock on extent buffer from a + * subvolume tree. In this case we can't allow btrfs_find_all_roots() to + * acquire fs_info->commit_root_sem, because that is a higher level lock + * that must be acquired before locking any extent buffers. + * + * So we want btrfs_find_all_roots() to not acquire the commit_root_sem + * but we can't pass it a non-NULL transaction handle, because otherwise + * it would not use commit roots and would lock extent buffers, causing + * a deadlock if it ends up trying to read lock the same extent buffer + * that was previously write locked at btrfs_truncate_inode_items(). + * + * So pass a NULL transaction handle to btrfs_find_all_roots() and + * explicitly tell it to not acquire the commit_root_sem - if we are + * holding a transaction handle we don't need its protection. + */ + ASSERT(trans != NULL); + + if (fs_info->qgroup_flags & BTRFS_QGROUP_RUNTIME_FLAG_NO_ACCOUNTING) + return 0; + + ret = btrfs_find_all_roots(&ctx, true); + if (ret < 0) { + qgroup_mark_inconsistent(fs_info, + "error accounting new delayed refs extent: %d", ret); + return 0; + } + + /* + * Here we don't need to get the lock of + * trans->transaction->delayed_refs, since inserted qrecord won't + * be deleted, only qrecord->node may be modified (new qrecord insert) + * + * So modifying qrecord->old_roots is safe here + */ + qrecord->old_roots = ctx.roots; + return 0; +} + +/* + * Inform qgroup to trace one dirty extent, specified by @bytenr and + * @num_bytes. + * So qgroup can account it at commit trans time. + * + * Better encapsulated version, with memory allocation and backref walk for + * commit roots. + * So this can sleep. + * + * Return 0 if the operation is done. + * Return <0 for error, like memory allocation failure or invalid parameter + * (NULL trans) + */ +int btrfs_qgroup_trace_extent(struct btrfs_trans_handle *trans, u64 bytenr, + u64 num_bytes) +{ + struct btrfs_fs_info *fs_info = trans->fs_info; + struct btrfs_qgroup_extent_record *record; + struct btrfs_delayed_ref_root *delayed_refs = &trans->transaction->delayed_refs; + const unsigned long index = (bytenr >> fs_info->sectorsize_bits); + int ret; + + if (!btrfs_qgroup_full_accounting(fs_info) || bytenr == 0 || num_bytes == 0) + return 0; + record = kzalloc_obj(*record, GFP_NOFS); + if (!record) + return -ENOMEM; + + if (xa_reserve(&delayed_refs->dirty_extents, index, GFP_NOFS)) { + kfree(record); + return -ENOMEM; + } + + record->num_bytes = num_bytes; + + ret = btrfs_qgroup_trace_extent_nolock(fs_info, delayed_refs, record, bytenr); + if (ret) { + /* Clean up if insertion fails or item exists. */ + xa_release(&delayed_refs->dirty_extents, index); + kfree(record); + return 0; + } + return btrfs_qgroup_trace_extent_post(trans, record, bytenr); +} + +/* + * Inform qgroup to trace all leaf items of data + * + * Return 0 for success + * Return <0 for error(ENOMEM) + */ +int btrfs_qgroup_trace_leaf_items(struct btrfs_trans_handle *trans, + struct extent_buffer *eb) +{ + struct btrfs_fs_info *fs_info = trans->fs_info; + int nr = btrfs_header_nritems(eb); + int i, extent_type, ret; + struct btrfs_key key; + struct btrfs_file_extent_item *fi; + u64 bytenr, num_bytes; + + /* We can be called directly from walk_up_proc() */ + if (!btrfs_qgroup_full_accounting(fs_info)) + return 0; + + for (i = 0; i < nr; i++) { + btrfs_item_key_to_cpu(eb, &key, i); + + if (key.type != BTRFS_EXTENT_DATA_KEY) + continue; + + fi = btrfs_item_ptr(eb, i, struct btrfs_file_extent_item); + /* filter out non qgroup-accountable extents */ + extent_type = btrfs_file_extent_type(eb, fi); + + if (extent_type == BTRFS_FILE_EXTENT_INLINE) + continue; + + bytenr = btrfs_file_extent_disk_bytenr(eb, fi); + if (!bytenr) + continue; + + num_bytes = btrfs_file_extent_disk_num_bytes(eb, fi); + + ret = btrfs_qgroup_trace_extent(trans, bytenr, num_bytes); + if (ret) + return ret; + } + cond_resched(); + return 0; +} + +/* + * Walk up the tree from the bottom, freeing leaves and any interior + * nodes which have had all slots visited. If a node (leaf or + * interior) is freed, the node above it will have it's slot + * incremented. The root node will never be freed. + * + * At the end of this function, we should have a path which has all + * slots incremented to the next position for a search. If we need to + * read a new node it will be NULL and the node above it will have the + * correct slot selected for a later read. + * + * If we increment the root nodes slot counter past the number of + * elements, 1 is returned to signal completion of the search. + */ +static int adjust_slots_upwards(struct btrfs_path *path, int root_level) +{ + int level = 0; + int nr, slot; + struct extent_buffer *eb; + + if (root_level == 0) + return 1; + + while (level <= root_level) { + eb = path->nodes[level]; + nr = btrfs_header_nritems(eb); + path->slots[level]++; + slot = path->slots[level]; + if (slot >= nr || level == 0) { + /* + * Don't free the root - we will detect this + * condition after our loop and return a + * positive value for caller to stop walking the tree. + */ + if (level != root_level) { + btrfs_tree_unlock_rw(eb, path->locks[level]); + path->locks[level] = 0; + + free_extent_buffer(eb); + path->nodes[level] = NULL; + path->slots[level] = 0; + } + } else { + /* + * We have a valid slot to walk back down + * from. Stop here so caller can process these + * new nodes. + */ + break; + } + + level++; + } + + eb = path->nodes[root_level]; + if (path->slots[root_level] >= btrfs_header_nritems(eb)) + return 1; + + return 0; +} + +/* + * Helper function to trace a subtree tree block swap. + * + * The swap will happen in highest tree block, but there may be a lot of + * tree blocks involved. + * + * For example: + * OO = Old tree blocks + * NN = New tree blocks allocated during balance + * + * File tree (257) Reloc tree for 257 + * L2 OO NN + * / \ / \ + * L1 OO OO (a) OO NN (a) + * / \ / \ / \ / \ + * L0 OO OO OO OO OO OO NN NN + * (b) (c) (b) (c) + * + * When calling qgroup_trace_extent_swap(), we will pass: + * @src_eb = OO(a) + * @dst_path = [ nodes[1] = NN(a), nodes[0] = NN(c) ] + * @dst_level = 0 + * @root_level = 1 + * + * In that case, qgroup_trace_extent_swap() will search from OO(a) to + * reach OO(c), then mark both OO(c) and NN(c) as qgroup dirty. + * + * The main work of qgroup_trace_extent_swap() can be split into 3 parts: + * + * 1) Tree search from @src_eb + * It should acts as a simplified btrfs_search_slot(). + * The key for search can be extracted from @dst_path->nodes[dst_level] + * (first key). + * + * 2) Mark the final tree blocks in @src_path and @dst_path qgroup dirty + * NOTE: In above case, OO(a) and NN(a) won't be marked qgroup dirty. + * They should be marked during previous (@dst_level = 1) iteration. + * + * 3) Mark file extents in leaves dirty + * We don't have good way to pick out new file extents only. + * So we still follow the old method by scanning all file extents in + * the leave. + * + * This function can free us from keeping two paths, thus later we only need + * to care about how to iterate all new tree blocks in reloc tree. + */ +static int qgroup_trace_extent_swap(struct btrfs_trans_handle* trans, + struct extent_buffer *src_eb, + struct btrfs_path *dst_path, + int dst_level, int root_level, + bool trace_leaf) +{ + struct btrfs_key key; + BTRFS_PATH_AUTO_FREE(src_path); + struct btrfs_fs_info *fs_info = trans->fs_info; + u32 nodesize = fs_info->nodesize; + int cur_level = root_level; + int ret; + + BUG_ON(dst_level > root_level); + /* Level mismatch */ + if (btrfs_header_level(src_eb) != root_level) + return -EINVAL; + + src_path = btrfs_alloc_path(); + if (!src_path) + return -ENOMEM; + + if (dst_level) + btrfs_node_key_to_cpu(dst_path->nodes[dst_level], &key, 0); + else + btrfs_item_key_to_cpu(dst_path->nodes[dst_level], &key, 0); + + /* For src_path */ + refcount_inc(&src_eb->refs); + src_path->nodes[root_level] = src_eb; + src_path->slots[root_level] = dst_path->slots[root_level]; + src_path->locks[root_level] = 0; + + /* A simplified version of btrfs_search_slot() */ + while (cur_level >= dst_level) { + struct btrfs_key src_key; + struct btrfs_key dst_key; + + if (src_path->nodes[cur_level] == NULL) { + struct extent_buffer *eb; + int parent_slot; + + eb = src_path->nodes[cur_level + 1]; + parent_slot = src_path->slots[cur_level + 1]; + + eb = btrfs_read_node_slot(eb, parent_slot); + if (IS_ERR(eb)) + return PTR_ERR(eb); + + src_path->nodes[cur_level] = eb; + + btrfs_tree_read_lock(eb); + src_path->locks[cur_level] = BTRFS_READ_LOCK; + } + + src_path->slots[cur_level] = dst_path->slots[cur_level]; + if (cur_level) { + btrfs_node_key_to_cpu(dst_path->nodes[cur_level], + &dst_key, dst_path->slots[cur_level]); + btrfs_node_key_to_cpu(src_path->nodes[cur_level], + &src_key, src_path->slots[cur_level]); + } else { + btrfs_item_key_to_cpu(dst_path->nodes[cur_level], + &dst_key, dst_path->slots[cur_level]); + btrfs_item_key_to_cpu(src_path->nodes[cur_level], + &src_key, src_path->slots[cur_level]); + } + /* Content mismatch, something went wrong */ + if (btrfs_comp_cpu_keys(&dst_key, &src_key)) + return -ENOENT; + cur_level--; + } + + /* + * Now both @dst_path and @src_path have been populated, record the tree + * blocks for qgroup accounting. + */ + ret = btrfs_qgroup_trace_extent(trans, src_path->nodes[dst_level]->start, + nodesize); + if (ret < 0) + return ret; + ret = btrfs_qgroup_trace_extent(trans, dst_path->nodes[dst_level]->start, + nodesize); + if (ret < 0) + return ret; + + /* Record leaf file extents */ + if (dst_level == 0 && trace_leaf) { + ret = btrfs_qgroup_trace_leaf_items(trans, src_path->nodes[0]); + if (ret < 0) + return ret; + ret = btrfs_qgroup_trace_leaf_items(trans, dst_path->nodes[0]); + } + + return ret; +} + +/* + * Helper function to do recursive generation-aware depth-first search, to + * locate all new tree blocks in a subtree of reloc tree. + * + * E.g. (OO = Old tree blocks, NN = New tree blocks, whose gen == last_snapshot) + * reloc tree + * L2 NN (a) + * / \ + * L1 OO NN (b) + * / \ / \ + * L0 OO OO OO NN + * (c) (d) + * If we pass: + * @dst_path = [ nodes[1] = NN(b), nodes[0] = NULL ], + * @cur_level = 1 + * @root_level = 1 + * + * We will iterate through tree blocks NN(b), NN(d) and info qgroup to trace + * above tree blocks along with their counter parts in file tree. + * While during search, old tree blocks OO(c) will be skipped as tree block swap + * won't affect OO(c). + */ +static int qgroup_trace_new_subtree_blocks(struct btrfs_trans_handle* trans, + struct extent_buffer *src_eb, + struct btrfs_path *dst_path, + int cur_level, int root_level, + u64 last_snapshot, bool trace_leaf) +{ + struct btrfs_fs_info *fs_info = trans->fs_info; + struct extent_buffer *eb; + bool need_cleanup = false; + int ret = 0; + int i; + + /* Level sanity check */ + if (unlikely(cur_level < 0 || cur_level >= BTRFS_MAX_LEVEL - 1 || + root_level < 0 || root_level >= BTRFS_MAX_LEVEL - 1 || + root_level < cur_level)) { + btrfs_err_rl(fs_info, + "%s: bad levels, cur_level=%d root_level=%d", + __func__, cur_level, root_level); + return -EUCLEAN; + } + + /* Read the tree block if needed */ + if (dst_path->nodes[cur_level] == NULL) { + int parent_slot; + u64 child_gen; + + /* + * dst_path->nodes[root_level] must be initialized before + * calling this function. + */ + if (unlikely(cur_level == root_level)) { + btrfs_err_rl(fs_info, + "%s: dst_path->nodes[%d] not initialized, root_level=%d cur_level=%d", + __func__, root_level, root_level, cur_level); + return -EUCLEAN; + } + + /* + * We need to get child blockptr/gen from parent before we can + * read it. + */ + eb = dst_path->nodes[cur_level + 1]; + parent_slot = dst_path->slots[cur_level + 1]; + child_gen = btrfs_node_ptr_generation(eb, parent_slot); + + /* This node is old, no need to trace */ + if (child_gen < last_snapshot) + return ret; + + eb = btrfs_read_node_slot(eb, parent_slot); + if (IS_ERR(eb)) + return PTR_ERR(eb); + + dst_path->nodes[cur_level] = eb; + dst_path->slots[cur_level] = 0; + + btrfs_tree_read_lock(eb); + dst_path->locks[cur_level] = BTRFS_READ_LOCK; + need_cleanup = true; + } + + /* Now record this tree block and its counter part for qgroups */ + ret = qgroup_trace_extent_swap(trans, src_eb, dst_path, cur_level, + root_level, trace_leaf); + if (ret < 0) + goto cleanup; + + eb = dst_path->nodes[cur_level]; + + if (cur_level > 0) { + /* Iterate all child tree blocks */ + for (i = 0; i < btrfs_header_nritems(eb); i++) { + /* Skip old tree blocks as they won't be swapped */ + if (btrfs_node_ptr_generation(eb, i) < last_snapshot) + continue; + dst_path->slots[cur_level] = i; + + /* Recursive call (at most 7 times) */ + ret = qgroup_trace_new_subtree_blocks(trans, src_eb, + dst_path, cur_level - 1, root_level, + last_snapshot, trace_leaf); + if (ret < 0) + goto cleanup; + } + } + +cleanup: + if (need_cleanup) { + /* Clean up */ + btrfs_tree_unlock_rw(dst_path->nodes[cur_level], + dst_path->locks[cur_level]); + free_extent_buffer(dst_path->nodes[cur_level]); + dst_path->nodes[cur_level] = NULL; + dst_path->slots[cur_level] = 0; + dst_path->locks[cur_level] = 0; + } + + return ret; +} + +static int qgroup_trace_subtree_swap(struct btrfs_trans_handle *trans, + struct extent_buffer *src_eb, + struct extent_buffer *dst_eb, + u64 last_snapshot, bool trace_leaf) +{ + struct btrfs_fs_info *fs_info = trans->fs_info; + struct btrfs_path *dst_path = NULL; + int level; + int ret; + + if (!btrfs_qgroup_full_accounting(fs_info)) + return 0; + + /* Wrong parameter order */ + if (unlikely(btrfs_header_generation(src_eb) > btrfs_header_generation(dst_eb))) { + btrfs_err_rl(fs_info, + "%s: bad parameter order, src_gen=%llu dst_gen=%llu", __func__, + btrfs_header_generation(src_eb), + btrfs_header_generation(dst_eb)); + return -EUCLEAN; + } + + if (unlikely(!extent_buffer_uptodate(src_eb) || !extent_buffer_uptodate(dst_eb))) { + ret = -EIO; + goto out; + } + + level = btrfs_header_level(dst_eb); + dst_path = btrfs_alloc_path(); + if (!dst_path) { + ret = -ENOMEM; + goto out; + } + /* For dst_path */ + refcount_inc(&dst_eb->refs); + dst_path->nodes[level] = dst_eb; + dst_path->slots[level] = 0; + dst_path->locks[level] = 0; + + /* Do the generation aware breadth-first search */ + ret = qgroup_trace_new_subtree_blocks(trans, src_eb, dst_path, level, + level, last_snapshot, trace_leaf); + if (ret < 0) + goto out; + ret = 0; + +out: + btrfs_free_path(dst_path); + if (ret < 0) + qgroup_mark_inconsistent(fs_info, "%s error: %d", __func__, ret); + return ret; +} + +/* + * Inform qgroup to trace a whole subtree, including all its child tree + * blocks and data. + * The root tree block is specified by @root_eb. + * + * Normally used by relocation(tree block swap) and subvolume deletion. + * + * Return 0 for success + * Return <0 for error(ENOMEM or tree search error) + */ +int btrfs_qgroup_trace_subtree(struct btrfs_trans_handle *trans, + struct extent_buffer *root_eb, + u64 root_gen, int root_level) +{ + struct btrfs_fs_info *fs_info = trans->fs_info; + int ret = 0; + int level; + u8 drop_subptree_thres; + struct extent_buffer *eb = root_eb; + BTRFS_PATH_AUTO_FREE(path); + + ASSERT(0 <= root_level && root_level < BTRFS_MAX_LEVEL); + ASSERT(root_eb != NULL); + + if (!btrfs_qgroup_full_accounting(fs_info)) + return 0; + + spin_lock(&fs_info->qgroup_lock); + drop_subptree_thres = fs_info->qgroup_drop_subtree_thres; + spin_unlock(&fs_info->qgroup_lock); + + /* + * This function only gets called for snapshot drop, if we hit a high + * node here, it means we are going to change ownership for quite a lot + * of extents, which will greatly slow down btrfs_commit_transaction(). + * + * So here if we find a high tree here, we just skip the accounting and + * mark qgroup inconsistent. + */ + if (root_level >= drop_subptree_thres) { + qgroup_mark_inconsistent(fs_info, "subtree level reached threshold"); + return 0; + } + + if (!extent_buffer_uptodate(root_eb)) { + struct btrfs_tree_parent_check check = { + .transid = root_gen, + .level = root_level + }; + + ret = btrfs_read_extent_buffer(root_eb, &check); + if (ret) + return ret; + } + + if (root_level == 0) + return btrfs_qgroup_trace_leaf_items(trans, root_eb); + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + /* + * Walk down the tree. Missing extent blocks are filled in as + * we go. Metadata is accounted every time we read a new + * extent block. + * + * When we reach a leaf, we account for file extent items in it, + * walk back up the tree (adjusting slot pointers as we go) + * and restart the search process. + */ + refcount_inc(&root_eb->refs); /* For path */ + path->nodes[root_level] = root_eb; + path->slots[root_level] = 0; + path->locks[root_level] = 0; /* so release_path doesn't try to unlock */ +walk_down: + level = root_level; + while (level >= 0) { + if (path->nodes[level] == NULL) { + int parent_slot; + u64 child_bytenr; + + /* + * We need to get child blockptr from parent before we + * can read it. + */ + eb = path->nodes[level + 1]; + parent_slot = path->slots[level + 1]; + child_bytenr = btrfs_node_blockptr(eb, parent_slot); + + eb = btrfs_read_node_slot(eb, parent_slot); + if (IS_ERR(eb)) + return PTR_ERR(eb); + + path->nodes[level] = eb; + path->slots[level] = 0; + + btrfs_tree_read_lock(eb); + path->locks[level] = BTRFS_READ_LOCK; + + ret = btrfs_qgroup_trace_extent(trans, child_bytenr, + fs_info->nodesize); + if (ret) + return ret; + } + + if (level == 0) { + ret = btrfs_qgroup_trace_leaf_items(trans, + path->nodes[level]); + if (ret) + return ret; + + /* Nonzero return here means we completed our search */ + ret = adjust_slots_upwards(path, root_level); + if (ret) + break; + + /* Restart search with new slots */ + goto walk_down; + } + + level--; + } + + return 0; +} + +static void qgroup_iterator_nested_add(struct list_head *head, struct btrfs_qgroup *qgroup) +{ + if (!list_empty(&qgroup->nested_iterator)) + return; + + list_add_tail(&qgroup->nested_iterator, head); +} + +static void qgroup_iterator_nested_clean(struct list_head *head) +{ + while (!list_empty(head)) { + struct btrfs_qgroup *qgroup; + + qgroup = list_first_entry(head, struct btrfs_qgroup, nested_iterator); + list_del_init(&qgroup->nested_iterator); + } +} + +/* + * Walk all of the roots that points to the bytenr and adjust their refcnts. + */ +static void qgroup_update_refcnt(struct btrfs_fs_info *fs_info, + struct ulist *roots, struct list_head *qgroups, + u64 seq, bool update_old) +{ + struct ulist_node *unode; + struct ulist_iterator uiter; + struct btrfs_qgroup *qg; + + if (!roots) + return; + ULIST_ITER_INIT(&uiter); + while ((unode = ulist_next(roots, &uiter))) { + LIST_HEAD(tmp); + + qg = find_qgroup_rb(fs_info, unode->val); + if (!qg) + continue; + + qgroup_iterator_nested_add(qgroups, qg); + qgroup_iterator_add(&tmp, qg); + list_for_each_entry(qg, &tmp, iterator) { + struct btrfs_qgroup_list *glist; + + if (update_old) + btrfs_qgroup_update_old_refcnt(qg, seq, 1); + else + btrfs_qgroup_update_new_refcnt(qg, seq, 1); + + list_for_each_entry(glist, &qg->groups, next_group) { + qgroup_iterator_nested_add(qgroups, glist->group); + qgroup_iterator_add(&tmp, glist->group); + } + } + qgroup_iterator_clean(&tmp); + } +} + +/* + * Update qgroup rfer/excl counters. + * Rfer update is easy, codes can explain themselves. + * + * Excl update is tricky, the update is split into 2 parts. + * Part 1: Possible exclusive <-> sharing detect: + * | A | !A | + * ------------------------------------- + * B | * | - | + * ------------------------------------- + * !B | + | ** | + * ------------------------------------- + * + * Conditions: + * A: cur_old_roots < nr_old_roots (not exclusive before) + * !A: cur_old_roots == nr_old_roots (possible exclusive before) + * B: cur_new_roots < nr_new_roots (not exclusive now) + * !B: cur_new_roots == nr_new_roots (possible exclusive now) + * + * Results: + * +: Possible sharing -> exclusive -: Possible exclusive -> sharing + * *: Definitely not changed. **: Possible unchanged. + * + * For !A and !B condition, the exception is cur_old/new_roots == 0 case. + * + * To make the logic clear, we first use condition A and B to split + * combination into 4 results. + * + * Then, for result "+" and "-", check old/new_roots == 0 case, as in them + * only on variant maybe 0. + * + * Lastly, check result **, since there are 2 variants maybe 0, split them + * again(2x2). + * But this time we don't need to consider other things, the codes and logic + * is easy to understand now. + */ +static void qgroup_update_counters(struct btrfs_fs_info *fs_info, + struct list_head *qgroups, u64 nr_old_roots, + u64 nr_new_roots, u64 num_bytes, u64 seq) +{ + struct btrfs_qgroup *qg; + + list_for_each_entry(qg, qgroups, nested_iterator) { + u64 cur_new_count, cur_old_count; + bool dirty = false; + + cur_old_count = btrfs_qgroup_get_old_refcnt(qg, seq); + cur_new_count = btrfs_qgroup_get_new_refcnt(qg, seq); + + trace_btrfs_qgroup_update_counters(fs_info, qg, cur_old_count, + cur_new_count); + + /* Rfer update part */ + if (cur_old_count == 0 && cur_new_count > 0) { + qg->rfer += num_bytes; + qg->rfer_cmpr += num_bytes; + dirty = true; + } + if (cur_old_count > 0 && cur_new_count == 0) { + qg->rfer -= num_bytes; + qg->rfer_cmpr -= num_bytes; + dirty = true; + } + + /* Excl update part */ + /* Exclusive/none -> shared case */ + if (cur_old_count == nr_old_roots && + cur_new_count < nr_new_roots) { + /* Exclusive -> shared */ + if (cur_old_count != 0) { + qg->excl -= num_bytes; + qg->excl_cmpr -= num_bytes; + dirty = true; + } + } + + /* Shared -> exclusive/none case */ + if (cur_old_count < nr_old_roots && + cur_new_count == nr_new_roots) { + /* Shared->exclusive */ + if (cur_new_count != 0) { + qg->excl += num_bytes; + qg->excl_cmpr += num_bytes; + dirty = true; + } + } + + /* Exclusive/none -> exclusive/none case */ + if (cur_old_count == nr_old_roots && + cur_new_count == nr_new_roots) { + if (cur_old_count == 0) { + /* None -> exclusive/none */ + + if (cur_new_count != 0) { + /* None -> exclusive */ + qg->excl += num_bytes; + qg->excl_cmpr += num_bytes; + dirty = true; + } + /* None -> none, nothing changed */ + } else { + /* Exclusive -> exclusive/none */ + + if (cur_new_count == 0) { + /* Exclusive -> none */ + qg->excl -= num_bytes; + qg->excl_cmpr -= num_bytes; + dirty = true; + } + /* Exclusive -> exclusive, nothing changed */ + } + } + + if (dirty) + qgroup_dirty(fs_info, qg); + } +} + +/* + * Check if the @roots potentially is a list of fs tree roots + * + * Return 0 for definitely not a fs/subvol tree roots ulist + * Return 1 for possible fs/subvol tree roots in the list (considering an empty + * one as well) + */ +static int maybe_fs_roots(struct ulist *roots) +{ + struct ulist_node *unode; + struct ulist_iterator uiter; + + /* Empty one, still possible for fs roots */ + if (!roots || roots->nnodes == 0) + return 1; + + ULIST_ITER_INIT(&uiter); + unode = ulist_next(roots, &uiter); + if (!unode) + return 1; + + /* + * If it contains fs tree roots, then it must belong to fs/subvol + * trees. + * If it contains a non-fs tree, it won't be shared with fs/subvol trees. + */ + return btrfs_is_fstree(unode->val); +} + +int btrfs_qgroup_account_extent(struct btrfs_trans_handle *trans, u64 bytenr, + u64 num_bytes, struct ulist *old_roots, + struct ulist *new_roots) +{ + struct btrfs_fs_info *fs_info = trans->fs_info; + LIST_HEAD(qgroups); + u64 seq; + u64 nr_new_roots = 0; + u64 nr_old_roots = 0; + int ret = 0; + + /* + * If quotas get disabled meanwhile, the resources need to be freed and + * we can't just exit here. + */ + if (!btrfs_qgroup_full_accounting(fs_info) || + fs_info->qgroup_flags & BTRFS_QGROUP_RUNTIME_FLAG_NO_ACCOUNTING) + goto out_free; + + if (new_roots) { + if (!maybe_fs_roots(new_roots)) + goto out_free; + nr_new_roots = new_roots->nnodes; + } + if (old_roots) { + if (!maybe_fs_roots(old_roots)) + goto out_free; + nr_old_roots = old_roots->nnodes; + } + + /* Quick exit, either not fs tree roots, or won't affect any qgroup */ + if (nr_old_roots == 0 && nr_new_roots == 0) + goto out_free; + + trace_btrfs_qgroup_account_extent(fs_info, trans->transid, bytenr, + num_bytes, nr_old_roots, nr_new_roots); + + mutex_lock(&fs_info->qgroup_rescan_lock); + if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) { + if (fs_info->qgroup_rescan_progress.objectid <= bytenr) { + mutex_unlock(&fs_info->qgroup_rescan_lock); + ret = 0; + goto out_free; + } + } + mutex_unlock(&fs_info->qgroup_rescan_lock); + + spin_lock(&fs_info->qgroup_lock); + seq = fs_info->qgroup_seq; + + /* Update old refcnts using old_roots */ + qgroup_update_refcnt(fs_info, old_roots, &qgroups, seq, true); + + /* Update new refcnts using new_roots */ + qgroup_update_refcnt(fs_info, new_roots, &qgroups, seq, false); + + qgroup_update_counters(fs_info, &qgroups, nr_old_roots, nr_new_roots, + num_bytes, seq); + + /* + * We're done using the iterator, release all its qgroups while holding + * fs_info->qgroup_lock so that we don't race with btrfs_remove_qgroup() + * and trigger use-after-free accesses to qgroups. + */ + qgroup_iterator_nested_clean(&qgroups); + + /* + * Bump qgroup_seq to avoid seq overlap + */ + fs_info->qgroup_seq += max(nr_old_roots, nr_new_roots) + 1; + spin_unlock(&fs_info->qgroup_lock); +out_free: + ulist_free(old_roots); + ulist_free(new_roots); + return ret; +} + +int btrfs_qgroup_account_extents(struct btrfs_trans_handle *trans) +{ + struct btrfs_fs_info *fs_info = trans->fs_info; + struct btrfs_qgroup_extent_record *record; + struct btrfs_delayed_ref_root *delayed_refs; + struct ulist *new_roots = NULL; + unsigned long index; + u64 num_dirty_extents = 0; + u64 qgroup_to_skip; + int ret = 0; + + if (btrfs_qgroup_mode(fs_info) == BTRFS_QGROUP_MODE_SIMPLE) + return 0; + + delayed_refs = &trans->transaction->delayed_refs; + qgroup_to_skip = delayed_refs->qgroup_to_skip; + xa_for_each(&delayed_refs->dirty_extents, index, record) { + const u64 bytenr = (((u64)index) << fs_info->sectorsize_bits); + + num_dirty_extents++; + trace_btrfs_qgroup_account_extents(fs_info, record, bytenr); + + if (!ret && !(fs_info->qgroup_flags & + BTRFS_QGROUP_RUNTIME_FLAG_NO_ACCOUNTING)) { + struct btrfs_backref_walk_ctx ctx = { 0 }; + + ctx.bytenr = bytenr; + ctx.fs_info = fs_info; + + /* + * Old roots should be searched when inserting qgroup + * extent record. + * + * But for INCONSISTENT (NO_ACCOUNTING) -> rescan case, + * we may have some record inserted during + * NO_ACCOUNTING (thus no old_roots populated), but + * later we start rescan, which clears NO_ACCOUNTING, + * leaving some inserted records without old_roots + * populated. + * + * Those cases are rare and should not cause too much + * time spent during commit_transaction(). + */ + if (!record->old_roots) { + /* Search commit root to find old_roots */ + ret = btrfs_find_all_roots(&ctx, false); + if (ret < 0) + goto cleanup; + record->old_roots = ctx.roots; + ctx.roots = NULL; + } + + /* + * Use BTRFS_SEQ_LAST as time_seq to do special search, + * which doesn't lock tree or delayed_refs and search + * current root. It's safe inside commit_transaction(). + */ + ctx.trans = trans; + ctx.time_seq = BTRFS_SEQ_LAST; + ret = btrfs_find_all_roots(&ctx, false); + if (ret < 0) + goto cleanup; + new_roots = ctx.roots; + if (qgroup_to_skip) { + ulist_del(new_roots, qgroup_to_skip, 0); + ulist_del(record->old_roots, qgroup_to_skip, + 0); + } + ret = btrfs_qgroup_account_extent(trans, bytenr, + record->num_bytes, + record->old_roots, + new_roots); + record->old_roots = NULL; + new_roots = NULL; + } + /* Free the reserved data space */ + btrfs_qgroup_free_refroot(fs_info, + record->data_rsv_refroot, + record->data_rsv, + BTRFS_QGROUP_RSV_DATA); +cleanup: + ulist_free(record->old_roots); + ulist_free(new_roots); + new_roots = NULL; + xa_erase(&delayed_refs->dirty_extents, index); + kfree(record); + + } + trace_btrfs_qgroup_num_dirty_extents(fs_info, trans->transid, num_dirty_extents); + return ret; +} + +/* + * Writes all changed qgroups to disk. + * Called by the transaction commit path and the qgroup assign ioctl. + */ +int btrfs_run_qgroups(struct btrfs_trans_handle *trans) +{ + struct btrfs_fs_info *fs_info = trans->fs_info; + int ret = 0; + + /* + * In case we are called from the qgroup assign ioctl, assert that we + * are holding the qgroup_ioctl_lock, otherwise we can race with a quota + * disable operation (ioctl) and access a freed quota root. + */ + if (trans->transaction->state != TRANS_STATE_COMMIT_DOING) + lockdep_assert_held(&fs_info->qgroup_ioctl_lock); + + if (!fs_info->quota_root) + return ret; + + spin_lock(&fs_info->qgroup_lock); + while (!list_empty(&fs_info->dirty_qgroups)) { + struct btrfs_qgroup *qgroup; + qgroup = list_first_entry(&fs_info->dirty_qgroups, + struct btrfs_qgroup, dirty); + list_del_init(&qgroup->dirty); + spin_unlock(&fs_info->qgroup_lock); + ret = update_qgroup_info_item(trans, qgroup); + if (ret) + qgroup_mark_inconsistent(fs_info, + "qgroup info item update error %d", ret); + ret = update_qgroup_limit_item(trans, qgroup); + if (ret) + qgroup_mark_inconsistent(fs_info, + "qgroup limit item update error %d", ret); + spin_lock(&fs_info->qgroup_lock); + } + if (btrfs_qgroup_enabled(fs_info)) + fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_ON; + else + fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_ON; + spin_unlock(&fs_info->qgroup_lock); + + ret = update_qgroup_status_item(trans); + if (ret) + qgroup_mark_inconsistent(fs_info, + "qgroup status item update error %d", ret); + + return ret; +} + +int btrfs_qgroup_check_inherit(struct btrfs_fs_info *fs_info, + struct btrfs_qgroup_inherit *inherit, + size_t size) +{ + if (inherit->flags & ~BTRFS_QGROUP_INHERIT_FLAGS_SUPP) + return -EOPNOTSUPP; + if (size < sizeof(*inherit) || size > PAGE_SIZE) + return -EINVAL; + + /* + * In the past we allowed btrfs_qgroup_inherit to specify to copy + * rfer/excl numbers directly from other qgroups. This behavior has + * been disabled in userspace for a very long time, but here we should + * also disable it in kernel, as this behavior is known to mark qgroup + * inconsistent, and a rescan would wipe out the changes anyway. + * + * Reject any btrfs_qgroup_inherit with num_ref_copies or num_excl_copies. + */ + if (inherit->num_ref_copies > 0 || inherit->num_excl_copies > 0) + return -EINVAL; + + if (size != struct_size(inherit, qgroups, inherit->num_qgroups)) + return -EINVAL; + + /* + * Skip the inherit source qgroups check if qgroup is not enabled. + * Qgroup can still be later enabled causing problems, but in that case + * btrfs_qgroup_inherit() would just ignore those invalid ones. + */ + if (!btrfs_qgroup_enabled(fs_info)) + return 0; + + /* + * Now check all the remaining qgroups, they should all: + * + * - Exist + * - Be higher level qgroups. + */ + for (int i = 0; i < inherit->num_qgroups; i++) { + struct btrfs_qgroup *qgroup; + u64 qgroupid = inherit->qgroups[i]; + + if (btrfs_qgroup_level(qgroupid) == 0) + return -EINVAL; + + spin_lock(&fs_info->qgroup_lock); + qgroup = find_qgroup_rb(fs_info, qgroupid); + if (!qgroup) { + spin_unlock(&fs_info->qgroup_lock); + return -ENOENT; + } + spin_unlock(&fs_info->qgroup_lock); + } + return 0; +} + +static int qgroup_auto_inherit(struct btrfs_fs_info *fs_info, + u64 inode_rootid, + struct btrfs_qgroup_inherit **inherit) +{ + int i = 0; + u64 num_qgroups = 0; + struct btrfs_qgroup *inode_qg; + struct btrfs_qgroup_list *qg_list; + struct btrfs_qgroup_inherit *res; + size_t struct_sz; + u64 *qgids; + + if (*inherit) + return -EEXIST; + + inode_qg = find_qgroup_rb(fs_info, inode_rootid); + if (!inode_qg) + return -ENOENT; + + num_qgroups = list_count_nodes(&inode_qg->groups); + + if (!num_qgroups) + return 0; + + struct_sz = struct_size(res, qgroups, num_qgroups); + if (struct_sz == SIZE_MAX) + return -ERANGE; + + res = kzalloc(struct_sz, GFP_NOFS); + if (!res) + return -ENOMEM; + res->num_qgroups = num_qgroups; + qgids = res->qgroups; + + list_for_each_entry(qg_list, &inode_qg->groups, next_group) + qgids[i++] = qg_list->group->qgroupid; + + *inherit = res; + return 0; +} + +/* + * Check if we can skip rescan when inheriting qgroups. If @src has a single + * @parent, and that @parent is owning all its bytes exclusively, we can skip + * the full rescan, by just adding nodesize to the @parent's excl/rfer. + * + * Return <0 for fatal errors (like srcid/parentid has no qgroup). + * Return 0 if a quick inherit is done. + * Return >0 if a quick inherit is not possible, and a full rescan is needed. + */ +static int qgroup_snapshot_quick_inherit(struct btrfs_fs_info *fs_info, + u64 srcid, u64 parentid) +{ + struct btrfs_qgroup *src; + struct btrfs_qgroup *parent; + struct btrfs_qgroup *qgroup; + struct btrfs_qgroup_list *list; + LIST_HEAD(qgroup_list); + const u32 nodesize = fs_info->nodesize; + int nr_parents = 0; + + if (btrfs_qgroup_mode(fs_info) != BTRFS_QGROUP_MODE_FULL) + return 0; + + src = find_qgroup_rb(fs_info, srcid); + if (!src) + return -ENOENT; + parent = find_qgroup_rb(fs_info, parentid); + if (!parent) + return -ENOENT; + + /* + * Source has no parent qgroup, but our new qgroup would have one. + * Qgroup numbers would become inconsistent. + */ + if (list_empty(&src->groups)) + return 1; + + list_for_each_entry(list, &src->groups, next_group) { + /* The parent is not the same, quick update is not possible. */ + if (list->group->qgroupid != parentid) + return 1; + nr_parents++; + /* + * More than one parent qgroup, we can't be sure about accounting + * consistency. + */ + if (nr_parents > 1) + return 1; + } + + /* + * The parent is not exclusively owning all its bytes. We're not sure + * if the source has any bytes not fully owned by the parent. + */ + if (parent->excl != parent->rfer) + return 1; + + qgroup_iterator_add(&qgroup_list, parent); + list_for_each_entry(qgroup, &qgroup_list, iterator) { + qgroup->rfer += nodesize; + qgroup->rfer_cmpr += nodesize; + qgroup->excl += nodesize; + qgroup->excl_cmpr += nodesize; + qgroup_dirty(fs_info, qgroup); + + /* Append parent qgroups to @qgroup_list. */ + list_for_each_entry(list, &qgroup->groups, next_group) + qgroup_iterator_add(&qgroup_list, list->group); + } + qgroup_iterator_clean(&qgroup_list); + return 0; +} + +/* + * Copy the accounting information between qgroups. This is necessary + * when a snapshot or a subvolume is created. Throwing an error will + * cause a transaction abort so we take extra care here to only error + * when a readonly fs is a reasonable outcome. + */ +int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans, u64 srcid, + u64 objectid, u64 inode_rootid, + struct btrfs_qgroup_inherit *inherit) +{ + int ret = 0; + u64 *i_qgroups; + bool committing = false; + struct btrfs_fs_info *fs_info = trans->fs_info; + struct btrfs_root *quota_root; + struct btrfs_qgroup *srcgroup; + struct btrfs_qgroup *dstgroup; + struct btrfs_qgroup *prealloc; + struct btrfs_qgroup_list **qlist_prealloc = NULL; + bool free_inherit = false; + bool need_rescan = false; + u32 level_size = 0; + u64 nums; + + if (!btrfs_qgroup_enabled(fs_info)) + return 0; + + prealloc = kzalloc_obj(*prealloc, GFP_NOFS); + if (!prealloc) + return -ENOMEM; + + /* + * There are only two callers of this function. + * + * One in create_subvol() in the ioctl context, which needs to hold + * the qgroup_ioctl_lock. + * + * The other one in create_pending_snapshot() where no other qgroup + * code can modify the fs as they all need to either start a new trans + * or hold a trans handler, thus we don't need to hold + * qgroup_ioctl_lock. + * This would avoid long and complex lock chain and make lockdep happy. + */ + spin_lock(&fs_info->trans_lock); + if (trans->transaction->state == TRANS_STATE_COMMIT_DOING) + committing = true; + spin_unlock(&fs_info->trans_lock); + + if (!committing) + mutex_lock(&fs_info->qgroup_ioctl_lock); + + quota_root = fs_info->quota_root; + if (!quota_root) { + ret = -EINVAL; + goto out; + } + + if (btrfs_qgroup_mode(fs_info) == BTRFS_QGROUP_MODE_SIMPLE && !inherit) { + ret = qgroup_auto_inherit(fs_info, inode_rootid, &inherit); + if (ret) + goto out; + free_inherit = true; + } + + if (inherit) { + i_qgroups = (u64 *)(inherit + 1); + nums = inherit->num_qgroups + 2 * inherit->num_ref_copies + + 2 * inherit->num_excl_copies; + for (int i = 0; i < nums; i++) { + srcgroup = find_qgroup_rb(fs_info, *i_qgroups); + + /* + * Zero out invalid groups so we can ignore + * them later. + */ + if (!srcgroup || + ((srcgroup->qgroupid >> 48) <= (objectid >> 48))) + *i_qgroups = 0ULL; + + ++i_qgroups; + } + } + + /* + * create a tracking group for the subvol itself + */ + ret = add_qgroup_item(trans, quota_root, objectid); + if (ret) + goto out; + + /* + * add qgroup to all inherited groups + */ + if (inherit) { + i_qgroups = (u64 *)(inherit + 1); + for (int i = 0; i < inherit->num_qgroups; i++, i_qgroups++) { + if (*i_qgroups == 0) + continue; + ret = add_qgroup_relation_item(trans, objectid, + *i_qgroups); + if (ret && ret != -EEXIST) + goto out; + ret = add_qgroup_relation_item(trans, *i_qgroups, + objectid); + if (ret && ret != -EEXIST) + goto out; + } + ret = 0; + + qlist_prealloc = kzalloc_objs(struct btrfs_qgroup_list *, + inherit->num_qgroups, GFP_NOFS); + if (!qlist_prealloc) { + ret = -ENOMEM; + goto out; + } + for (int i = 0; i < inherit->num_qgroups; i++) { + qlist_prealloc[i] = kzalloc_obj(struct btrfs_qgroup_list, + GFP_NOFS); + if (!qlist_prealloc[i]) { + ret = -ENOMEM; + goto out; + } + } + } + + spin_lock(&fs_info->qgroup_lock); + + dstgroup = add_qgroup_rb(fs_info, prealloc, objectid); + prealloc = NULL; + + if (inherit && inherit->flags & BTRFS_QGROUP_INHERIT_SET_LIMITS) { + dstgroup->lim_flags = inherit->lim.flags; + dstgroup->max_rfer = inherit->lim.max_rfer; + dstgroup->max_excl = inherit->lim.max_excl; + dstgroup->rsv_rfer = inherit->lim.rsv_rfer; + dstgroup->rsv_excl = inherit->lim.rsv_excl; + + qgroup_dirty(fs_info, dstgroup); + } + + if (srcid && btrfs_qgroup_mode(fs_info) == BTRFS_QGROUP_MODE_FULL) { + srcgroup = find_qgroup_rb(fs_info, srcid); + if (!srcgroup) + goto unlock; + + /* + * We call inherit after we clone the root in order to make sure + * our counts don't go crazy, so at this point the only + * difference between the two roots should be the root node. + */ + level_size = fs_info->nodesize; + dstgroup->rfer = srcgroup->rfer; + dstgroup->rfer_cmpr = srcgroup->rfer_cmpr; + dstgroup->excl = level_size; + dstgroup->excl_cmpr = level_size; + srcgroup->excl = level_size; + srcgroup->excl_cmpr = level_size; + + /* inherit the limit info */ + dstgroup->lim_flags = srcgroup->lim_flags; + dstgroup->max_rfer = srcgroup->max_rfer; + dstgroup->max_excl = srcgroup->max_excl; + dstgroup->rsv_rfer = srcgroup->rsv_rfer; + dstgroup->rsv_excl = srcgroup->rsv_excl; + + qgroup_dirty(fs_info, dstgroup); + qgroup_dirty(fs_info, srcgroup); + + /* + * If the source qgroup has parent but the new one doesn't, + * we need a full rescan. + */ + if (!inherit && !list_empty(&srcgroup->groups)) + need_rescan = true; + } + + if (!inherit) + goto unlock; + + i_qgroups = (u64 *)(inherit + 1); + for (int i = 0; i < inherit->num_qgroups; i++) { + if (*i_qgroups) { + ret = add_relation_rb(fs_info, qlist_prealloc[i], objectid, + *i_qgroups); + qlist_prealloc[i] = NULL; + if (ret) + goto unlock; + } + if (srcid) { + /* Check if we can do a quick inherit. */ + ret = qgroup_snapshot_quick_inherit(fs_info, srcid, *i_qgroups); + if (ret < 0) + goto unlock; + if (ret > 0) + need_rescan = true; + ret = 0; + } + ++i_qgroups; + } + + for (int i = 0; i < inherit->num_ref_copies; i++, i_qgroups += 2) { + struct btrfs_qgroup *src; + struct btrfs_qgroup *dst; + + if (!i_qgroups[0] || !i_qgroups[1]) + continue; + + src = find_qgroup_rb(fs_info, i_qgroups[0]); + dst = find_qgroup_rb(fs_info, i_qgroups[1]); + + if (!src || !dst) { + ret = -EINVAL; + goto unlock; + } + + dst->rfer = src->rfer - level_size; + dst->rfer_cmpr = src->rfer_cmpr - level_size; + + /* Manually tweaking numbers certainly needs a rescan */ + need_rescan = true; + } + for (int i = 0; i < inherit->num_excl_copies; i++, i_qgroups += 2) { + struct btrfs_qgroup *src; + struct btrfs_qgroup *dst; + + if (!i_qgroups[0] || !i_qgroups[1]) + continue; + + src = find_qgroup_rb(fs_info, i_qgroups[0]); + dst = find_qgroup_rb(fs_info, i_qgroups[1]); + + if (!src || !dst) { + ret = -EINVAL; + goto unlock; + } + + dst->excl = src->excl + level_size; + dst->excl_cmpr = src->excl_cmpr + level_size; + need_rescan = true; + } + +unlock: + spin_unlock(&fs_info->qgroup_lock); + if (!ret) + ret = btrfs_sysfs_add_one_qgroup(fs_info, dstgroup); +out: + if (!committing) + mutex_unlock(&fs_info->qgroup_ioctl_lock); + if (need_rescan) + qgroup_mark_inconsistent(fs_info, "qgroup inherit needs a rescan"); + if (qlist_prealloc) { + for (int i = 0; i < inherit->num_qgroups; i++) + kfree(qlist_prealloc[i]); + kfree(qlist_prealloc); + } + if (free_inherit) + kfree(inherit); + kfree(prealloc); + return ret; +} + +static bool qgroup_check_limits(const struct btrfs_qgroup *qg, u64 num_bytes) +{ + if ((qg->lim_flags & BTRFS_QGROUP_LIMIT_MAX_RFER) && + qgroup_rsv_total(qg) + (s64)qg->rfer + num_bytes > qg->max_rfer) + return false; + + if ((qg->lim_flags & BTRFS_QGROUP_LIMIT_MAX_EXCL) && + qgroup_rsv_total(qg) + (s64)qg->excl + num_bytes > qg->max_excl) + return false; + + return true; +} + +static int qgroup_reserve(struct btrfs_root *root, u64 num_bytes, bool enforce, + enum btrfs_qgroup_rsv_type type) +{ + struct btrfs_qgroup *qgroup; + struct btrfs_fs_info *fs_info = root->fs_info; + u64 ref_root = btrfs_root_id(root); + int ret = 0; + LIST_HEAD(qgroup_list); + + if (!btrfs_is_fstree(ref_root)) + return 0; + + if (num_bytes == 0) + return 0; + + if (test_bit(BTRFS_FS_QUOTA_OVERRIDE, &fs_info->flags) && + capable(CAP_SYS_RESOURCE)) + enforce = false; + + spin_lock(&fs_info->qgroup_lock); + if (!fs_info->quota_root) + goto out; + + qgroup = find_qgroup_rb(fs_info, ref_root); + if (!qgroup) + goto out; + + qgroup_iterator_add(&qgroup_list, qgroup); + list_for_each_entry(qgroup, &qgroup_list, iterator) { + struct btrfs_qgroup_list *glist; + + if (enforce && !qgroup_check_limits(qgroup, num_bytes)) { + ret = -EDQUOT; + goto out; + } + + list_for_each_entry(glist, &qgroup->groups, next_group) + qgroup_iterator_add(&qgroup_list, glist->group); + } + + ret = 0; + /* + * no limits exceeded, now record the reservation into all qgroups + */ + list_for_each_entry(qgroup, &qgroup_list, iterator) + qgroup_rsv_add(fs_info, qgroup, num_bytes, type); + +out: + qgroup_iterator_clean(&qgroup_list); + spin_unlock(&fs_info->qgroup_lock); + return ret; +} + +/* + * Free @num_bytes of reserved space with @type for qgroup. (Normally level 0 + * qgroup). + * + * Will handle all higher level qgroup too. + * + * NOTE: If @num_bytes is (u64)-1, this means to free all bytes of this qgroup. + * This special case is only used for META_PERTRANS type. + */ +void btrfs_qgroup_free_refroot(struct btrfs_fs_info *fs_info, + u64 ref_root, u64 num_bytes, + enum btrfs_qgroup_rsv_type type) +{ + struct btrfs_qgroup *qgroup; + LIST_HEAD(qgroup_list); + + if (!btrfs_is_fstree(ref_root)) + return; + + if (num_bytes == 0) + return; + + if (num_bytes == (u64)-1 && type != BTRFS_QGROUP_RSV_META_PERTRANS) { + WARN(1, "%s: Invalid type to free", __func__); + return; + } + spin_lock(&fs_info->qgroup_lock); + + if (!fs_info->quota_root) + goto out; + + qgroup = find_qgroup_rb(fs_info, ref_root); + if (!qgroup) + goto out; + + if (num_bytes == (u64)-1) + /* + * We're freeing all pertrans rsv, get reserved value from + * level 0 qgroup as real num_bytes to free. + */ + num_bytes = qgroup->rsv.values[type]; + + qgroup_iterator_add(&qgroup_list, qgroup); + list_for_each_entry(qgroup, &qgroup_list, iterator) { + struct btrfs_qgroup_list *glist; + + qgroup_rsv_release(fs_info, qgroup, num_bytes, type); + list_for_each_entry(glist, &qgroup->groups, next_group) { + qgroup_iterator_add(&qgroup_list, glist->group); + } + } +out: + qgroup_iterator_clean(&qgroup_list); + spin_unlock(&fs_info->qgroup_lock); +} + +/* + * Check if the leaf is the last leaf. Which means all node pointers + * are at their last position. + */ +static bool is_last_leaf(struct btrfs_path *path) +{ + int i; + + for (i = 1; i < BTRFS_MAX_LEVEL && path->nodes[i]; i++) { + if (path->slots[i] != btrfs_header_nritems(path->nodes[i]) - 1) + return false; + } + return true; +} + +/* + * returns < 0 on error, 0 when more leafs are to be scanned. + * returns 1 when done. + */ +static int qgroup_rescan_leaf(struct btrfs_trans_handle *trans, + struct btrfs_path *path) +{ + struct btrfs_fs_info *fs_info = trans->fs_info; + struct btrfs_root *extent_root; + struct btrfs_key found; + struct extent_buffer *scratch_leaf = NULL; + u64 num_bytes; + bool done; + int slot; + int ret; + + if (!btrfs_qgroup_full_accounting(fs_info)) + return 1; + + mutex_lock(&fs_info->qgroup_rescan_lock); + extent_root = btrfs_extent_root(fs_info, + fs_info->qgroup_rescan_progress.objectid); + if (unlikely(!extent_root)) { + btrfs_err(fs_info, + "missing extent root for extent at bytenr %llu", + fs_info->qgroup_rescan_progress.objectid); + mutex_unlock(&fs_info->qgroup_rescan_lock); + return -EUCLEAN; + } + + ret = btrfs_search_slot_for_read(extent_root, + &fs_info->qgroup_rescan_progress, + path, 1, 0); + + btrfs_debug(fs_info, + "current progress key " BTRFS_KEY_FMT ", search_slot ret %d", + BTRFS_KEY_FMT_VALUE(&fs_info->qgroup_rescan_progress), ret); + + if (ret) { + /* + * The rescan is about to end, we will not be scanning any + * further blocks. We cannot unset the RESCAN flag here, because + * we want to commit the transaction if everything went well. + * To make the live accounting work in this phase, we set our + * scan progress pointer such that every real extent objectid + * will be smaller. + */ + fs_info->qgroup_rescan_progress.objectid = (u64)-1; + btrfs_release_path(path); + mutex_unlock(&fs_info->qgroup_rescan_lock); + return ret; + } + done = is_last_leaf(path); + + btrfs_item_key_to_cpu(path->nodes[0], &found, + btrfs_header_nritems(path->nodes[0]) - 1); + fs_info->qgroup_rescan_progress.objectid = found.objectid + 1; + + scratch_leaf = btrfs_clone_extent_buffer(path->nodes[0]); + if (!scratch_leaf) { + ret = -ENOMEM; + mutex_unlock(&fs_info->qgroup_rescan_lock); + goto out; + } + slot = path->slots[0]; + btrfs_release_path(path); + mutex_unlock(&fs_info->qgroup_rescan_lock); + + for (; slot < btrfs_header_nritems(scratch_leaf); ++slot) { + struct btrfs_backref_walk_ctx ctx = { 0 }; + + btrfs_item_key_to_cpu(scratch_leaf, &found, slot); + if (found.type != BTRFS_EXTENT_ITEM_KEY && + found.type != BTRFS_METADATA_ITEM_KEY) + continue; + if (found.type == BTRFS_METADATA_ITEM_KEY) + num_bytes = fs_info->nodesize; + else + num_bytes = found.offset; + + ctx.bytenr = found.objectid; + ctx.fs_info = fs_info; + + ret = btrfs_find_all_roots(&ctx, false); + if (ret < 0) + goto out; + /* For rescan, just pass old_roots as NULL */ + ret = btrfs_qgroup_account_extent(trans, found.objectid, + num_bytes, NULL, ctx.roots); + if (ret < 0) + goto out; + } +out: + if (scratch_leaf) + free_extent_buffer(scratch_leaf); + + if (done && !ret) { + ret = 1; + fs_info->qgroup_rescan_progress.objectid = (u64)-1; + } + return ret; +} + +static bool rescan_should_stop(struct btrfs_fs_info *fs_info) +{ + if (btrfs_fs_closing(fs_info)) + return true; + if (test_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state)) + return true; + if (!btrfs_qgroup_enabled(fs_info)) + return true; + if (fs_info->qgroup_flags & BTRFS_QGROUP_RUNTIME_FLAG_CANCEL_RESCAN) + return true; + return false; +} + +static void btrfs_qgroup_rescan_worker(struct btrfs_work *work) +{ + struct btrfs_fs_info *fs_info = container_of(work, struct btrfs_fs_info, + qgroup_rescan_work); + struct btrfs_path *path; + struct btrfs_trans_handle *trans = NULL; + int ret = 0; + bool stopped = false; + bool did_leaf_rescans = false; + + if (btrfs_qgroup_mode(fs_info) == BTRFS_QGROUP_MODE_SIMPLE) + return; + + path = btrfs_alloc_path(); + if (!path) { + ret = -ENOMEM; + goto out; + } + /* + * Rescan should only search for commit root, and any later difference + * should be recorded by qgroup + */ + path->search_commit_root = true; + path->skip_locking = true; + + while (!ret && !(stopped = rescan_should_stop(fs_info))) { + trans = btrfs_start_transaction(fs_info->fs_root, 0); + if (IS_ERR(trans)) { + ret = PTR_ERR(trans); + break; + } + + ret = qgroup_rescan_leaf(trans, path); + did_leaf_rescans = true; + + if (ret > 0) + btrfs_commit_transaction(trans); + else + btrfs_end_transaction(trans); + } + +out: + btrfs_free_path(path); + + mutex_lock(&fs_info->qgroup_rescan_lock); + if (ret > 0 && + fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT) { + fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT; + } else if (ret < 0 || stopped) { + fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT; + } + mutex_unlock(&fs_info->qgroup_rescan_lock); + + /* + * Only update status, since the previous part has already updated the + * qgroup info, and only if we did any actual work. This also prevents + * race with a concurrent quota disable, which has already set + * fs_info->quota_root to NULL and cleared BTRFS_FS_QUOTA_ENABLED at + * btrfs_quota_disable(). + */ + if (did_leaf_rescans) { + trans = btrfs_start_transaction(fs_info->quota_root, 1); + if (IS_ERR(trans)) { + ret = PTR_ERR(trans); + trans = NULL; + btrfs_err(fs_info, + "fail to start transaction for status update: %pe", + ERR_PTR(ret)); + } + } else { + trans = NULL; + } + + mutex_lock(&fs_info->qgroup_rescan_lock); + if (!stopped || + fs_info->qgroup_flags & BTRFS_QGROUP_RUNTIME_FLAG_CANCEL_RESCAN) + fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_RESCAN; + if (trans) { + int ret2 = update_qgroup_status_item(trans); + + if (ret2 < 0) { + ret = ret2; + btrfs_err(fs_info, "fail to update qgroup status: %pe", ERR_PTR(ret)); + } + } + fs_info->qgroup_rescan_running = false; + fs_info->qgroup_flags &= ~BTRFS_QGROUP_RUNTIME_FLAG_CANCEL_RESCAN; + complete_all(&fs_info->qgroup_rescan_completion); + mutex_unlock(&fs_info->qgroup_rescan_lock); + + if (!trans) + return; + + btrfs_end_transaction(trans); + + if (stopped) { + btrfs_info(fs_info, "qgroup scan paused"); + } else if (fs_info->qgroup_flags & BTRFS_QGROUP_RUNTIME_FLAG_CANCEL_RESCAN) { + btrfs_info(fs_info, "qgroup scan cancelled"); + } else if (ret >= 0) { + btrfs_info(fs_info, "qgroup scan completed%s", + ret > 0 ? " (inconsistency flag cleared)" : ""); + } else { + btrfs_err(fs_info, "qgroup scan failed with %pe", ERR_PTR(ret)); + } +} + +/* + * Checks that (a) no rescan is running and (b) quota is enabled. Allocates all + * memory required for the rescan context. + */ +static int +qgroup_rescan_init(struct btrfs_fs_info *fs_info, u64 progress_objectid, + int init_flags) +{ + int ret = 0; + + if (btrfs_qgroup_mode(fs_info) == BTRFS_QGROUP_MODE_SIMPLE) { + btrfs_warn(fs_info, "qgroup rescan init failed, running in simple mode"); + return -EINVAL; + } + + if (!init_flags) { + /* we're resuming qgroup rescan at mount time */ + if (!(fs_info->qgroup_flags & + BTRFS_QGROUP_STATUS_FLAG_RESCAN)) { + btrfs_debug(fs_info, + "qgroup rescan init failed, qgroup rescan is not queued"); + ret = -EINVAL; + } else if (!(fs_info->qgroup_flags & + BTRFS_QGROUP_STATUS_FLAG_ON)) { + btrfs_debug(fs_info, + "qgroup rescan init failed, qgroup is not enabled"); + ret = -ENOTCONN; + } + + if (ret) + return ret; + } + + mutex_lock(&fs_info->qgroup_rescan_lock); + + if (init_flags) { + if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) { + ret = -EINPROGRESS; + } else if (!(fs_info->qgroup_flags & + BTRFS_QGROUP_STATUS_FLAG_ON)) { + btrfs_debug(fs_info, + "qgroup rescan init failed, qgroup is not enabled"); + ret = -ENOTCONN; + } else if (btrfs_qgroup_mode(fs_info) == BTRFS_QGROUP_MODE_DISABLED) { + /* Quota disable is in progress */ + ret = -EBUSY; + } + + if (ret) { + mutex_unlock(&fs_info->qgroup_rescan_lock); + return ret; + } + fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_RESCAN; + } + + memset(&fs_info->qgroup_rescan_progress, 0, + sizeof(fs_info->qgroup_rescan_progress)); + fs_info->qgroup_flags &= ~(BTRFS_QGROUP_RUNTIME_FLAG_CANCEL_RESCAN | + BTRFS_QGROUP_RUNTIME_FLAG_NO_ACCOUNTING); + fs_info->qgroup_rescan_progress.objectid = progress_objectid; + init_completion(&fs_info->qgroup_rescan_completion); + mutex_unlock(&fs_info->qgroup_rescan_lock); + + btrfs_init_work(&fs_info->qgroup_rescan_work, + btrfs_qgroup_rescan_worker, NULL); + return 0; +} + +static void +qgroup_rescan_zero_tracking(struct btrfs_fs_info *fs_info) +{ + struct rb_node *n; + struct btrfs_qgroup *qgroup; + + spin_lock(&fs_info->qgroup_lock); + /* clear all current qgroup tracking information */ + for (n = rb_first(&fs_info->qgroup_tree); n; n = rb_next(n)) { + qgroup = rb_entry(n, struct btrfs_qgroup, node); + qgroup->rfer = 0; + qgroup->rfer_cmpr = 0; + qgroup->excl = 0; + qgroup->excl_cmpr = 0; + qgroup_dirty(fs_info, qgroup); + } + spin_unlock(&fs_info->qgroup_lock); +} + +int +btrfs_qgroup_rescan(struct btrfs_fs_info *fs_info) +{ + int ret = 0; + + ret = qgroup_rescan_init(fs_info, 0, 1); + if (ret) + return ret; + + /* + * We have set the rescan_progress to 0, which means no more + * delayed refs will be accounted by btrfs_qgroup_account_ref. + * However, btrfs_qgroup_account_ref may be right after its call + * to btrfs_find_all_roots, in which case it would still do the + * accounting. + * To solve this, we're committing the transaction, which will + * ensure we run all delayed refs and only after that, we are + * going to clear all tracking information for a clean start. + */ + + ret = btrfs_commit_current_transaction(fs_info->fs_root); + if (ret) { + fs_info->qgroup_flags &= ~BTRFS_QGROUP_STATUS_FLAG_RESCAN; + return ret; + } + + qgroup_rescan_zero_tracking(fs_info); + + mutex_lock(&fs_info->qgroup_rescan_lock); + /* + * The rescan worker is only for full accounting qgroups, check if it's + * enabled as it is pointless to queue it otherwise. A concurrent quota + * disable may also have just cleared BTRFS_FS_QUOTA_ENABLED. + */ + if (btrfs_qgroup_full_accounting(fs_info)) { + fs_info->qgroup_rescan_running = true; + btrfs_queue_work(fs_info->qgroup_rescan_workers, + &fs_info->qgroup_rescan_work); + } else { + ret = -ENOTCONN; + } + mutex_unlock(&fs_info->qgroup_rescan_lock); + + return ret; +} + +int btrfs_qgroup_wait_for_completion(struct btrfs_fs_info *fs_info, + bool interruptible) +{ + int running; + int ret = 0; + + mutex_lock(&fs_info->qgroup_rescan_lock); + running = fs_info->qgroup_rescan_running; + mutex_unlock(&fs_info->qgroup_rescan_lock); + + if (!running) + return 0; + + if (interruptible) + ret = wait_for_completion_interruptible( + &fs_info->qgroup_rescan_completion); + else + wait_for_completion(&fs_info->qgroup_rescan_completion); + + return ret; +} + +/* + * this is only called from open_ctree where we're still single threaded, thus + * locking is omitted here. + */ +void +btrfs_qgroup_rescan_resume(struct btrfs_fs_info *fs_info) +{ + if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) { + mutex_lock(&fs_info->qgroup_rescan_lock); + fs_info->qgroup_rescan_running = true; + btrfs_queue_work(fs_info->qgroup_rescan_workers, + &fs_info->qgroup_rescan_work); + mutex_unlock(&fs_info->qgroup_rescan_lock); + } +} + +#define rbtree_iterate_from_safe(node, next, start) \ + for (node = start; node && ({ next = rb_next(node); 1;}); node = next) + +static int qgroup_unreserve_range(struct btrfs_inode *inode, + struct extent_changeset *reserved, u64 start, + u64 len) +{ + struct rb_node *node; + struct rb_node *next; + struct ulist_node *entry; + int ret = 0; + + node = reserved->range_changed.root.rb_node; + if (!node) + return 0; + while (node) { + entry = rb_entry(node, struct ulist_node, rb_node); + if (entry->val < start) + node = node->rb_right; + else + node = node->rb_left; + } + + if (entry->val > start && rb_prev(&entry->rb_node)) + entry = rb_entry(rb_prev(&entry->rb_node), struct ulist_node, + rb_node); + + rbtree_iterate_from_safe(node, next, &entry->rb_node) { + u64 entry_start; + u64 entry_end; + u64 entry_len; + int clear_ret; + + entry = rb_entry(node, struct ulist_node, rb_node); + entry_start = entry->val; + entry_end = entry->aux; + entry_len = entry_end - entry_start + 1; + + if (entry_start >= start + len) + break; + if (entry_start + entry_len <= start) + continue; + /* + * Now the entry is in [start, start + len), revert the + * EXTENT_QGROUP_RESERVED bit. + */ + clear_ret = btrfs_clear_extent_bit(&inode->io_tree, entry_start, entry_end, + EXTENT_QGROUP_RESERVED, NULL); + if (!ret && clear_ret < 0) + ret = clear_ret; + + ulist_del(&reserved->range_changed, entry->val, entry->aux); + if (likely(reserved->bytes_changed >= entry_len)) { + reserved->bytes_changed -= entry_len; + } else { + WARN_ON(1); + reserved->bytes_changed = 0; + } + } + + return ret; +} + +/* + * Try to free some space for qgroup. + * + * For qgroup, there are only 3 ways to free qgroup space: + * - Flush nodatacow write + * Any nodatacow write will free its reserved data space at run_delalloc_range(). + * In theory, we should only flush nodatacow inodes, but it's not yet + * possible, so we need to flush the whole root. + * + * - Wait for ordered extents + * When ordered extents are finished, their reserved metadata is finally + * converted to per_trans status, which can be freed by later commit + * transaction. + * + * - Commit transaction + * This would free the meta_per_trans space. + * In theory this shouldn't provide much space, but any more qgroup space + * is needed. + */ +static int try_flush_qgroup(struct btrfs_root *root) +{ + int ret; + + /* Can't hold an open transaction or we run the risk of deadlocking. */ + ASSERT(current->journal_info == NULL); + if (WARN_ON(current->journal_info)) + return 0; + + /* + * We don't want to run flush again and again, so if there is a running + * one, we won't try to start a new flush, but exit directly. + */ + if (test_and_set_bit(BTRFS_ROOT_QGROUP_FLUSHING, &root->state)) { + wait_event(root->qgroup_flush_wait, + !test_bit(BTRFS_ROOT_QGROUP_FLUSHING, &root->state)); + return 0; + } + + ret = btrfs_start_delalloc_snapshot(root, true); + if (ret < 0) + goto out; + btrfs_wait_ordered_extents(root, U64_MAX, NULL); + + /* + * After waiting for ordered extents run delayed iputs in order to free + * space from unlinked files before committing the current transaction, + * as ordered extents may have been holding the last reference of an + * inode and they add a delayed iput when they complete. + */ + btrfs_run_delayed_iputs(root->fs_info); + btrfs_wait_on_delayed_iputs(root->fs_info); + + ret = btrfs_commit_current_transaction(root); +out: + clear_bit(BTRFS_ROOT_QGROUP_FLUSHING, &root->state); + wake_up(&root->qgroup_flush_wait); + return ret; +} + +static int qgroup_reserve_data(struct btrfs_inode *inode, + struct extent_changeset **reserved_ret, u64 start, + u64 len) +{ + struct btrfs_root *root = inode->root; + struct extent_changeset *reserved; + bool new_reserved = false; + u64 orig_reserved; + u64 to_reserve; + int ret; + + if (btrfs_qgroup_mode(root->fs_info) == BTRFS_QGROUP_MODE_DISABLED || + !btrfs_is_fstree(btrfs_root_id(root)) || len == 0) + return 0; + + /* @reserved parameter is mandatory for qgroup */ + if (WARN_ON(!reserved_ret)) + return -EINVAL; + if (!*reserved_ret) { + new_reserved = true; + *reserved_ret = extent_changeset_alloc(); + if (!*reserved_ret) + return -ENOMEM; + } + reserved = *reserved_ret; + /* Record already reserved space */ + orig_reserved = reserved->bytes_changed; + ret = btrfs_set_record_extent_bits(&inode->io_tree, start, + start + len - 1, EXTENT_QGROUP_RESERVED, + reserved); + + /* Newly reserved space */ + to_reserve = reserved->bytes_changed - orig_reserved; + trace_btrfs_qgroup_reserve_data(&inode->vfs_inode, start, len, + to_reserve, QGROUP_RESERVE); + if (ret < 0) + goto out; + ret = qgroup_reserve(root, to_reserve, true, BTRFS_QGROUP_RSV_DATA); + if (ret < 0) + goto cleanup; + + return ret; + +cleanup: + qgroup_unreserve_range(inode, reserved, start, len); +out: + if (new_reserved) { + extent_changeset_free(reserved); + *reserved_ret = NULL; + } + return ret; +} + +/* + * Reserve qgroup space for range [start, start + len). + * + * This function will either reserve space from related qgroups or do nothing + * if the range is already reserved. + * + * Return 0 for successful reservation + * Return <0 for error (including -EQUOT) + * + * NOTE: This function may sleep for memory allocation, dirty page flushing and + * commit transaction. So caller should not hold any dirty page locked. + */ +int btrfs_qgroup_reserve_data(struct btrfs_inode *inode, + struct extent_changeset **reserved_ret, u64 start, + u64 len) +{ + int ret; + + ret = qgroup_reserve_data(inode, reserved_ret, start, len); + if (ret <= 0 && ret != -EDQUOT) + return ret; + + ret = try_flush_qgroup(inode->root); + if (ret < 0) + return ret; + return qgroup_reserve_data(inode, reserved_ret, start, len); +} + +/* Free ranges specified by @reserved, normally in error path */ +static int qgroup_free_reserved_data(struct btrfs_inode *inode, + struct extent_changeset *reserved, + u64 start, u64 len, u64 *freed_ret) +{ + struct btrfs_root *root = inode->root; + struct ulist_node *unode; + struct ulist_iterator uiter; + struct extent_changeset changeset; + const u32 sectorsize = root->fs_info->sectorsize; + const u64 aligned_start = round_down(start, sectorsize); + const u64 aligned_len = round_up(start + len, sectorsize) - aligned_start; + u64 freed = 0; + int ret; + + extent_changeset_init_bytes_only(&changeset); + + ULIST_ITER_INIT(&uiter); + while ((unode = ulist_next(&reserved->range_changed, &uiter))) { + u64 range_start = unode->val; + /* unode->aux is the inclusive end */ + u64 range_len = unode->aux - range_start + 1; + u64 free_start; + u64 free_len; + + extent_changeset_release(&changeset); + + /* + * Only free the range within + * [aligned_start, aligned_start + aligned_len). + */ + if (range_start >= aligned_start + aligned_len || + range_start + range_len <= aligned_start) + continue; + free_start = max(range_start, aligned_start); + free_len = min(aligned_start + aligned_len, range_start + range_len) - + free_start; + /* + * TODO: To also modify reserved->ranges_reserved to reflect + * the modification. + * + * However as long as we free qgroup reserved according to + * EXTENT_QGROUP_RESERVED, we won't double free. + * So not need to rush. + */ + ret = btrfs_clear_record_extent_bits(&inode->io_tree, free_start, + free_start + free_len - 1, + EXTENT_QGROUP_RESERVED, + &changeset); + if (ret < 0) + goto out; + freed += changeset.bytes_changed; + } + btrfs_qgroup_free_refroot(root->fs_info, btrfs_root_id(root), freed, + BTRFS_QGROUP_RSV_DATA); + if (freed_ret) + *freed_ret = freed; + ret = 0; +out: + extent_changeset_release(&changeset); + return ret; +} + +static int __btrfs_qgroup_release_data(struct btrfs_inode *inode, + struct extent_changeset *reserved, u64 start, u64 len, + u64 *released, int free) +{ + struct extent_changeset changeset; + int trace_op = QGROUP_RELEASE; + int ret; + + if (btrfs_qgroup_mode(inode->root->fs_info) == BTRFS_QGROUP_MODE_DISABLED) { + return btrfs_clear_record_extent_bits(&inode->io_tree, start, + start + len - 1, + EXTENT_QGROUP_RESERVED, NULL); + } + + /* In release case, we shouldn't have @reserved */ + WARN_ON(!free && reserved); + if (free && reserved) + return qgroup_free_reserved_data(inode, reserved, start, len, released); + extent_changeset_init_bytes_only(&changeset); + ret = btrfs_clear_record_extent_bits(&inode->io_tree, start, start + len - 1, + EXTENT_QGROUP_RESERVED, &changeset); + if (ret < 0) + goto out; + + if (free) + trace_op = QGROUP_FREE; + trace_btrfs_qgroup_release_data(&inode->vfs_inode, start, len, + changeset.bytes_changed, trace_op); + if (free) + btrfs_qgroup_free_refroot(inode->root->fs_info, + btrfs_root_id(inode->root), + changeset.bytes_changed, BTRFS_QGROUP_RSV_DATA); + if (released) + *released = changeset.bytes_changed; +out: + extent_changeset_release(&changeset); + return ret; +} + +/* + * Free a reserved space range from io_tree and related qgroups + * + * Should be called when a range of pages get invalidated before reaching disk. + * Or for error cleanup case. + * if @reserved is given, only reserved range in [@start, @start + @len) will + * be freed. + * + * For data written to disk, use btrfs_qgroup_release_data(). + * + * NOTE: This function may sleep for memory allocation. + */ +int btrfs_qgroup_free_data(struct btrfs_inode *inode, + struct extent_changeset *reserved, + u64 start, u64 len, u64 *freed) +{ + return __btrfs_qgroup_release_data(inode, reserved, start, len, freed, 1); +} + +/* + * Release a reserved space range from io_tree only. + * + * Should be called when a range of pages get written to disk and corresponding + * FILE_EXTENT is inserted into corresponding root. + * + * Since new qgroup accounting framework will only update qgroup numbers at + * commit_transaction() time, its reserved space shouldn't be freed from + * related qgroups. + * + * But we should release the range from io_tree, to allow further write to be + * COWed. + * + * NOTE: This function may sleep for memory allocation. + */ +int btrfs_qgroup_release_data(struct btrfs_inode *inode, u64 start, u64 len, u64 *released) +{ + return __btrfs_qgroup_release_data(inode, NULL, start, len, released, 0); +} + +static void add_root_meta_rsv(struct btrfs_root *root, int num_bytes, + enum btrfs_qgroup_rsv_type type) +{ + if (type != BTRFS_QGROUP_RSV_META_PREALLOC && + type != BTRFS_QGROUP_RSV_META_PERTRANS) + return; + if (num_bytes == 0) + return; + + spin_lock(&root->qgroup_meta_rsv_lock); + if (type == BTRFS_QGROUP_RSV_META_PREALLOC) + root->qgroup_meta_rsv_prealloc += num_bytes; + else + root->qgroup_meta_rsv_pertrans += num_bytes; + spin_unlock(&root->qgroup_meta_rsv_lock); +} + +static int sub_root_meta_rsv(struct btrfs_root *root, int num_bytes, + enum btrfs_qgroup_rsv_type type) +{ + if (type != BTRFS_QGROUP_RSV_META_PREALLOC && + type != BTRFS_QGROUP_RSV_META_PERTRANS) + return 0; + if (num_bytes == 0) + return 0; + + spin_lock(&root->qgroup_meta_rsv_lock); + if (type == BTRFS_QGROUP_RSV_META_PREALLOC) { + num_bytes = min_t(u64, root->qgroup_meta_rsv_prealloc, + num_bytes); + root->qgroup_meta_rsv_prealloc -= num_bytes; + } else { + num_bytes = min_t(u64, root->qgroup_meta_rsv_pertrans, + num_bytes); + root->qgroup_meta_rsv_pertrans -= num_bytes; + } + spin_unlock(&root->qgroup_meta_rsv_lock); + return num_bytes; +} + +static int btrfs_qgroup_reserve_meta(struct btrfs_root *root, int num_bytes, + enum btrfs_qgroup_rsv_type type, bool enforce) +{ + struct btrfs_fs_info *fs_info = root->fs_info; + int ret; + + if (btrfs_qgroup_mode(fs_info) == BTRFS_QGROUP_MODE_DISABLED || + !btrfs_is_fstree(btrfs_root_id(root)) || num_bytes == 0) + return 0; + + BUG_ON(num_bytes != round_down(num_bytes, fs_info->nodesize)); + trace_btrfs_qgroup_meta_reserve(root, (s64)num_bytes, type); + ret = qgroup_reserve(root, num_bytes, enforce, type); + if (ret < 0) + return ret; + /* + * Record what we have reserved into root. + * + * To avoid quota disabled->enabled underflow. + * In that case, we may try to free space we haven't reserved + * (since quota was disabled), so record what we reserved into root. + * And ensure later release won't underflow this number. + */ + add_root_meta_rsv(root, num_bytes, type); + return ret; +} + +int btrfs_qgroup_reserve_meta_prealloc(struct btrfs_root *root, int num_bytes, + bool enforce, bool noflush) +{ + int ret; + + ret = btrfs_qgroup_reserve_meta(root, num_bytes, + BTRFS_QGROUP_RSV_META_PREALLOC, enforce); + if ((ret <= 0 && ret != -EDQUOT) || noflush) + return ret; + + ret = try_flush_qgroup(root); + if (ret < 0) + return ret; + return btrfs_qgroup_reserve_meta(root, num_bytes, + BTRFS_QGROUP_RSV_META_PREALLOC, enforce); +} + +/* + * Per-transaction meta reservation should be all freed at transaction commit + * time + */ +void btrfs_qgroup_free_meta_all_pertrans(struct btrfs_root *root) +{ + struct btrfs_fs_info *fs_info = root->fs_info; + + if (btrfs_qgroup_mode(fs_info) == BTRFS_QGROUP_MODE_DISABLED || + !btrfs_is_fstree(btrfs_root_id(root))) + return; + + /* TODO: Update trace point to handle such free */ + trace_btrfs_qgroup_meta_free_all_pertrans(root); + /* Special value -1 means to free all reserved space */ + btrfs_qgroup_free_refroot(fs_info, btrfs_root_id(root), (u64)-1, + BTRFS_QGROUP_RSV_META_PERTRANS); +} + +void btrfs_qgroup_free_meta_prealloc(struct btrfs_root *root, int num_bytes) +{ + struct btrfs_fs_info *fs_info = root->fs_info; + + if (btrfs_qgroup_mode(fs_info) == BTRFS_QGROUP_MODE_DISABLED || + !btrfs_is_fstree(btrfs_root_id(root))) + return; + + /* + * reservation for META_PREALLOC can happen before quota is enabled, + * which can lead to underflow. + * Here ensure we will only free what we really have reserved. + */ + num_bytes = sub_root_meta_rsv(root, num_bytes, + BTRFS_QGROUP_RSV_META_PREALLOC); + BUG_ON(num_bytes != round_down(num_bytes, fs_info->nodesize)); + trace_btrfs_qgroup_meta_reserve(root, -(s64)num_bytes, + BTRFS_QGROUP_RSV_META_PREALLOC); + btrfs_qgroup_free_refroot(fs_info, btrfs_root_id(root), num_bytes, + BTRFS_QGROUP_RSV_META_PREALLOC); +} + +static void qgroup_convert_meta(struct btrfs_fs_info *fs_info, u64 ref_root, + int num_bytes) +{ + struct btrfs_qgroup *qgroup; + LIST_HEAD(qgroup_list); + + if (num_bytes == 0) + return; + if (!fs_info->quota_root) + return; + + spin_lock(&fs_info->qgroup_lock); + qgroup = find_qgroup_rb(fs_info, ref_root); + if (!qgroup) + goto out; + + qgroup_iterator_add(&qgroup_list, qgroup); + list_for_each_entry(qgroup, &qgroup_list, iterator) { + struct btrfs_qgroup_list *glist; + + qgroup_rsv_release(fs_info, qgroup, num_bytes, + BTRFS_QGROUP_RSV_META_PREALLOC); + if (!sb_rdonly(fs_info->sb)) + qgroup_rsv_add(fs_info, qgroup, num_bytes, + BTRFS_QGROUP_RSV_META_PERTRANS); + + list_for_each_entry(glist, &qgroup->groups, next_group) + qgroup_iterator_add(&qgroup_list, glist->group); + } +out: + qgroup_iterator_clean(&qgroup_list); + spin_unlock(&fs_info->qgroup_lock); +} + +/* + * Convert @num_bytes of META_PREALLOCATED reservation to META_PERTRANS. + * + * This is called when preallocated meta reservation needs to be used. + * Normally after btrfs_join_transaction() call. + */ +void btrfs_qgroup_convert_reserved_meta(struct btrfs_root *root, int num_bytes) +{ + struct btrfs_fs_info *fs_info = root->fs_info; + + if (btrfs_qgroup_mode(fs_info) == BTRFS_QGROUP_MODE_DISABLED || + !btrfs_is_fstree(btrfs_root_id(root))) + return; + /* Same as btrfs_qgroup_free_meta_prealloc() */ + num_bytes = sub_root_meta_rsv(root, num_bytes, + BTRFS_QGROUP_RSV_META_PREALLOC); + trace_btrfs_qgroup_meta_convert(root, num_bytes); + qgroup_convert_meta(fs_info, btrfs_root_id(root), num_bytes); + if (!sb_rdonly(fs_info->sb)) + add_root_meta_rsv(root, num_bytes, BTRFS_QGROUP_RSV_META_PERTRANS); +} + +/* + * Check qgroup reserved space leaking, normally at destroy inode + * time + */ +void btrfs_qgroup_check_reserved_leak(struct btrfs_inode *inode) +{ + struct extent_changeset changeset; + struct ulist_node *unode; + struct ulist_iterator iter; + int ret; + + extent_changeset_init(&changeset); + ret = btrfs_clear_record_extent_bits(&inode->io_tree, 0, (u64)-1, + EXTENT_QGROUP_RESERVED, &changeset); + + WARN_ON(ret < 0); + if (WARN_ON(changeset.bytes_changed)) { + ASSERT(extent_changeset_tracks_ranges(&changeset)); + ULIST_ITER_INIT(&iter); + while ((unode = ulist_next(&changeset.range_changed, &iter))) { + btrfs_warn(inode->root->fs_info, + "leaking qgroup reserved space, ino: %llu, start: %llu, end: %llu", + btrfs_ino(inode), unode->val, unode->aux); + } + btrfs_qgroup_free_refroot(inode->root->fs_info, + btrfs_root_id(inode->root), + changeset.bytes_changed, BTRFS_QGROUP_RSV_DATA); + + } + extent_changeset_release(&changeset); +} + +void btrfs_qgroup_init_swapped_blocks( + struct btrfs_qgroup_swapped_blocks *swapped_blocks) +{ + int i; + + spin_lock_init(&swapped_blocks->lock); + for (i = 0; i < BTRFS_MAX_LEVEL; i++) + swapped_blocks->blocks[i] = RB_ROOT; + swapped_blocks->swapped = false; +} + +/* + * Delete all swapped blocks record of @root. + * Every record here means we skipped a full subtree scan for qgroup. + * + * Gets called when committing one transaction. + */ +void btrfs_qgroup_clean_swapped_blocks(struct btrfs_root *root) +{ + struct btrfs_qgroup_swapped_blocks *swapped_blocks; + int i; + + swapped_blocks = &root->swapped_blocks; + + spin_lock(&swapped_blocks->lock); + if (!swapped_blocks->swapped) + goto out; + for (i = 0; i < BTRFS_MAX_LEVEL; i++) { + struct rb_root *cur_root = &swapped_blocks->blocks[i]; + struct btrfs_qgroup_swapped_block *entry; + struct btrfs_qgroup_swapped_block *next; + + rbtree_postorder_for_each_entry_safe(entry, next, cur_root, + node) + kfree(entry); + swapped_blocks->blocks[i] = RB_ROOT; + } + swapped_blocks->swapped = false; +out: + spin_unlock(&swapped_blocks->lock); +} + +static int qgroup_swapped_block_bytenr_key_cmp(const void *key, const struct rb_node *node) +{ + const u64 *bytenr = key; + const struct btrfs_qgroup_swapped_block *block = rb_entry(node, + struct btrfs_qgroup_swapped_block, node); + + if (block->subvol_bytenr < *bytenr) + return -1; + else if (block->subvol_bytenr > *bytenr) + return 1; + + return 0; +} + +static int qgroup_swapped_block_bytenr_cmp(struct rb_node *new, const struct rb_node *existing) +{ + const struct btrfs_qgroup_swapped_block *new_block = rb_entry(new, + struct btrfs_qgroup_swapped_block, node); + + return qgroup_swapped_block_bytenr_key_cmp(&new_block->subvol_bytenr, existing); +} + +/* + * Add subtree roots record into @subvol_root. + * + * @subvol_root: tree root of the subvolume tree get swapped + * @bg: block group under balance + * @subvol_parent/slot: pointer to the subtree root in subvolume tree + * @reloc_parent/slot: pointer to the subtree root in reloc tree + * BOTH POINTERS ARE BEFORE TREE SWAP + * @last_snapshot: last snapshot generation of the subvolume tree + */ +int btrfs_qgroup_add_swapped_blocks(struct btrfs_root *subvol_root, + struct btrfs_block_group *bg, + struct extent_buffer *subvol_parent, int subvol_slot, + struct extent_buffer *reloc_parent, int reloc_slot, + u64 last_snapshot) +{ + struct btrfs_fs_info *fs_info = subvol_root->fs_info; + struct btrfs_qgroup_swapped_blocks *blocks = &subvol_root->swapped_blocks; + struct btrfs_qgroup_swapped_block *block; + struct rb_node *node; + int level = btrfs_header_level(subvol_parent) - 1; + int ret = 0; + + if (!btrfs_qgroup_full_accounting(fs_info)) + return 0; + + if (unlikely(btrfs_node_ptr_generation(subvol_parent, subvol_slot) > + btrfs_node_ptr_generation(reloc_parent, reloc_slot))) { + btrfs_err_rl(fs_info, + "%s: bad parameter order, subvol_gen=%llu reloc_gen=%llu", + __func__, + btrfs_node_ptr_generation(subvol_parent, subvol_slot), + btrfs_node_ptr_generation(reloc_parent, reloc_slot)); + return -EUCLEAN; + } + + block = kmalloc_obj(*block, GFP_NOFS); + if (!block) { + ret = -ENOMEM; + goto out; + } + + /* + * @reloc_parent/slot is still before swap, while @block is going to + * record the bytenr after swap, so we do the swap here. + */ + block->subvol_bytenr = btrfs_node_blockptr(reloc_parent, reloc_slot); + block->subvol_generation = btrfs_node_ptr_generation(reloc_parent, + reloc_slot); + block->reloc_bytenr = btrfs_node_blockptr(subvol_parent, subvol_slot); + block->reloc_generation = btrfs_node_ptr_generation(subvol_parent, + subvol_slot); + block->last_snapshot = last_snapshot; + block->level = level; + + /* + * If we have bg == NULL, we're called from btrfs_recover_relocation(), + * no one else can modify tree blocks thus we qgroup will not change + * no matter the value of trace_leaf. + */ + if (bg && bg->flags & BTRFS_BLOCK_GROUP_DATA) + block->trace_leaf = true; + else + block->trace_leaf = false; + btrfs_node_key_to_cpu(reloc_parent, &block->first_key, reloc_slot); + + /* Insert @block into @blocks */ + spin_lock(&blocks->lock); + node = rb_find_add(&block->node, &blocks->blocks[level], qgroup_swapped_block_bytenr_cmp); + if (node) { + struct btrfs_qgroup_swapped_block *entry; + + entry = rb_entry(node, struct btrfs_qgroup_swapped_block, node); + + if (unlikely(entry->subvol_generation != block->subvol_generation || + entry->reloc_bytenr != block->reloc_bytenr || + entry->reloc_generation != block->reloc_generation)) { + /* + * Duplicated but mismatch entry found. Shouldn't happen. + * Marking qgroup inconsistent should be enough for end + * users. + */ + DEBUG_WARN("duplicated but mismatched entry found"); + ret = -EEXIST; + } + kfree(block); + goto out_unlock; + } + blocks->swapped = true; +out_unlock: + spin_unlock(&blocks->lock); +out: + if (ret < 0) + qgroup_mark_inconsistent(fs_info, "%s error: %d", __func__, ret); + return ret; +} + +/* + * Check if the tree block is a subtree root, and if so do the needed + * delayed subtree trace for qgroup. + * + * This is called during btrfs_cow_block(). + */ +int btrfs_qgroup_trace_subtree_after_cow(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct extent_buffer *subvol_eb) +{ + struct btrfs_fs_info *fs_info = root->fs_info; + struct btrfs_tree_parent_check check = { 0 }; + struct btrfs_qgroup_swapped_blocks *blocks = &root->swapped_blocks; + struct btrfs_qgroup_swapped_block AUTO_KFREE(block); + struct extent_buffer *reloc_eb = NULL; + struct rb_node *node; + bool swapped = false; + int level = btrfs_header_level(subvol_eb); + int ret = 0; + int i; + + if (!btrfs_qgroup_full_accounting(fs_info)) + return 0; + if (!btrfs_is_fstree(btrfs_root_id(root)) || !root->reloc_root) + return 0; + + spin_lock(&blocks->lock); + if (!blocks->swapped) { + spin_unlock(&blocks->lock); + return 0; + } + node = rb_find(&subvol_eb->start, &blocks->blocks[level], + qgroup_swapped_block_bytenr_key_cmp); + if (!node) { + spin_unlock(&blocks->lock); + goto out; + } + block = rb_entry(node, struct btrfs_qgroup_swapped_block, node); + + /* Found one, remove it from @blocks first and update blocks->swapped */ + rb_erase(&block->node, &blocks->blocks[level]); + for (i = 0; i < BTRFS_MAX_LEVEL; i++) { + if (RB_EMPTY_ROOT(&blocks->blocks[i])) { + swapped = true; + break; + } + } + blocks->swapped = swapped; + spin_unlock(&blocks->lock); + + check.level = block->level; + check.transid = block->reloc_generation; + check.has_first_key = true; + memcpy(&check.first_key, &block->first_key, sizeof(check.first_key)); + + /* Read out reloc subtree root */ + reloc_eb = read_tree_block(fs_info, block->reloc_bytenr, &check); + if (IS_ERR(reloc_eb)) { + ret = PTR_ERR(reloc_eb); + reloc_eb = NULL; + goto free_out; + } + + ret = qgroup_trace_subtree_swap(trans, reloc_eb, subvol_eb, + block->last_snapshot, block->trace_leaf); +free_out: + free_extent_buffer(reloc_eb); +out: + if (ret < 0) { + qgroup_mark_inconsistent(fs_info, + "failed to account subtree at bytenr %llu: %d", + subvol_eb->start, ret); + } + return ret; +} + +void btrfs_qgroup_destroy_extent_records(struct btrfs_transaction *trans) +{ + struct btrfs_qgroup_extent_record *entry; + unsigned long index; + + xa_for_each(&trans->delayed_refs.dirty_extents, index, entry) { + ulist_free(entry->old_roots); + kfree(entry); + } + xa_destroy(&trans->delayed_refs.dirty_extents); +} + +int btrfs_record_squota_delta(struct btrfs_fs_info *fs_info, + const struct btrfs_squota_delta *delta) +{ + int ret; + struct btrfs_qgroup *qgroup; + struct btrfs_qgroup *qg; + LIST_HEAD(qgroup_list); + u64 root = delta->root; + u64 num_bytes = delta->num_bytes; + const int sign = (delta->is_inc ? 1 : -1); + + if (btrfs_qgroup_mode(fs_info) != BTRFS_QGROUP_MODE_SIMPLE && + !test_bit(BTRFS_FS_SQUOTA_ENABLING, &fs_info->flags)) + return 0; + + if (!btrfs_is_fstree(root)) + return 0; + + /* If the extent predates enabling quotas, don't count it. */ + if (delta->generation < fs_info->qgroup_enable_gen) + return 0; + + spin_lock(&fs_info->qgroup_lock); + qgroup = find_qgroup_rb(fs_info, root); + if (WARN_ON_ONCE(!qgroup)) { + btrfs_warn(fs_info, "squota failed to find qgroup for root %llu", root); + ret = 0; + goto out; + } + + ret = 0; + qgroup_iterator_add(&qgroup_list, qgroup); + list_for_each_entry(qg, &qgroup_list, iterator) { + struct btrfs_qgroup_list *glist; + + ASSERT(qg->excl == qg->rfer); + if (WARN_ON_ONCE(sign < 0 && qg->excl < num_bytes)) { + btrfs_warn(fs_info, + "squota underflow qg " BTRFS_QGROUP_FMT " excl %llu num_bytes %llu", + BTRFS_QGROUP_FMT_VALUE(qg), + qg->excl, num_bytes); + qg->excl = 0; + qg->rfer = 0; + } else { + qg->excl += num_bytes * sign; + qg->rfer += num_bytes * sign; + } + qgroup_dirty(fs_info, qg); + + list_for_each_entry(glist, &qg->groups, next_group) + qgroup_iterator_add(&qgroup_list, glist->group); + } + qgroup_iterator_clean(&qgroup_list); + +out: + spin_unlock(&fs_info->qgroup_lock); + return ret; +} |