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Diffstat (limited to 'drivers/md/md.h')
| -rw-r--r-- | drivers/md/md.h | 1110 |
1 files changed, 1110 insertions, 0 deletions
diff --git a/drivers/md/md.h b/drivers/md/md.h new file mode 100644 index 000000000..b6d2e8929 --- /dev/null +++ b/drivers/md/md.h @@ -0,0 +1,1110 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + md.h : kernel internal structure of the Linux MD driver + Copyright (C) 1996-98 Ingo Molnar, Gadi Oxman + +*/ + +#ifndef _MD_MD_H +#define _MD_MD_H + +#include <linux/blkdev.h> +#include <linux/backing-dev.h> +#include <linux/badblocks.h> +#include <linux/kobject.h> +#include <linux/list.h> +#include <linux/mm.h> +#include <linux/mutex.h> +#include <linux/timer.h> +#include <linux/wait.h> +#include <linux/workqueue.h> +#include <linux/raid/md_u.h> +#include <trace/events/block.h> + +#define MaxSector (~(sector_t)0) +/* + * Number of guaranteed raid bios in case of extreme VM load: + */ +#define NR_RAID_BIOS 256 + +enum md_submodule_type { + MD_PERSONALITY = 0, + MD_CLUSTER, + MD_BITMAP, +}; + +enum md_submodule_id { + ID_LINEAR = LEVEL_LINEAR, + ID_RAID0 = 0, + ID_RAID1 = 1, + ID_RAID4 = 4, + ID_RAID5 = 5, + ID_RAID6 = 6, + ID_RAID10 = 10, + ID_CLUSTER, + ID_BITMAP, + ID_LLBITMAP, + ID_BITMAP_NONE, +}; + +struct md_submodule_head { + enum md_submodule_type type; + enum md_submodule_id id; + const char *name; + struct module *owner; +}; + +/* + * These flags should really be called "NO_RETRY" rather than + * "FAILFAST" because they don't make any promise about time lapse, + * only about the number of retries, which will be zero. + * REQ_FAILFAST_DRIVER is not included because + * Commit: 4a27446f3e39 ("[SCSI] modify scsi to handle new fail fast flags.") + * seems to suggest that the errors it avoids retrying should usually + * be retried. + */ +#define MD_FAILFAST (REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT) + +/* Status of sync thread. */ +enum sync_action { + /* + * Represent by MD_RECOVERY_SYNC, start when: + * 1) after assemble, sync data from first rdev to other copies, this + * must be done first before other sync actions and will only execute + * once; + * 2) resize the array(notice that this is not reshape), sync data for + * the new range; + */ + ACTION_RESYNC, + /* + * Represent by MD_RECOVERY_RECOVER, start when: + * 1) for new replacement, sync data based on the replace rdev or + * available copies from other rdev; + * 2) for new member disk while the array is degraded, sync data from + * other rdev; + * 3) reassemble after power failure or re-add a hot removed rdev, sync + * data from first rdev to other copies based on bitmap; + */ + ACTION_RECOVER, + /* + * Represent by MD_RECOVERY_SYNC | MD_RECOVERY_REQUESTED | + * MD_RECOVERY_CHECK, start when user echo "check" to sysfs api + * sync_action, used to check if data copies from differenct rdev are + * the same. The number of mismatch sectors will be exported to user + * by sysfs api mismatch_cnt; + */ + ACTION_CHECK, + /* + * Represent by MD_RECOVERY_SYNC | MD_RECOVERY_REQUESTED, start when + * user echo "repair" to sysfs api sync_action, usually paired with + * ACTION_CHECK, used to force syncing data once user found that there + * are inconsistent data, + */ + ACTION_REPAIR, + /* + * Represent by MD_RECOVERY_RESHAPE, start when new member disk is added + * to the conf, notice that this is different from spares or + * replacement; + */ + ACTION_RESHAPE, + /* + * Represent by MD_RECOVERY_FROZEN, can be set by sysfs api sync_action + * or internal usage like setting the array read-only, will forbid above + * actions. + */ + ACTION_FROZEN, + /* + * All above actions don't match. + */ + ACTION_IDLE, + NR_SYNC_ACTIONS, +}; + +/* + * The struct embedded in rdev is used to serialize IO. + */ +struct serial_in_rdev { + struct rb_root_cached serial_rb; + spinlock_t serial_lock; +}; + +/* + * MD's 'extended' device + */ +struct md_rdev { + struct list_head same_set; /* RAID devices within the same set */ + + sector_t sectors; /* Device size (in 512bytes sectors) */ + struct mddev *mddev; /* RAID array if running */ + unsigned long last_events; /* IO event timestamp */ + + /* + * If meta_bdev is non-NULL, it means that a separate device is + * being used to store the metadata (superblock/bitmap) which + * would otherwise be contained on the same device as the data (bdev). + */ + struct block_device *meta_bdev; + struct block_device *bdev; /* block device handle */ + struct file *bdev_file; /* Handle from open for bdev */ + + struct page *sb_page, *bb_page; + int sb_loaded; + __u64 sb_events; + sector_t data_offset; /* start of data in array */ + sector_t new_data_offset;/* only relevant while reshaping */ + sector_t sb_start; /* offset of the super block (in 512byte sectors) */ + int sb_size; /* bytes in the superblock */ + int preferred_minor; /* autorun support */ + + struct kobject kobj; + + /* A device can be in one of three states based on two flags: + * Not working: faulty==1 in_sync==0 + * Fully working: faulty==0 in_sync==1 + * Working, but not + * in sync with array + * faulty==0 in_sync==0 + * + * It can never have faulty==1, in_sync==1 + * This reduces the burden of testing multiple flags in many cases + */ + + unsigned long flags; /* bit set of 'enum flag_bits' bits. */ + wait_queue_head_t blocked_wait; + + int desc_nr; /* descriptor index in the superblock */ + int raid_disk; /* role of device in array */ + int new_raid_disk; /* role that the device will have in + * the array after a level-change completes. + */ + int saved_raid_disk; /* role that device used to have in the + * array and could again if we did a partial + * resync from the bitmap + */ + union { + sector_t recovery_offset;/* If this device has been partially + * recovered, this is where we were + * up to. + */ + sector_t journal_tail; /* If this device is a journal device, + * this is the journal tail (journal + * recovery start point) + */ + }; + + atomic_t nr_pending; /* number of pending requests. + * only maintained for arrays that + * support hot removal + */ + atomic_t read_errors; /* number of consecutive read errors that + * we have tried to ignore. + */ + time64_t last_read_error; /* monotonic time since our + * last read error + */ + atomic_t corrected_errors; /* number of corrected read errors, + * for reporting to userspace and storing + * in superblock. + */ + + struct serial_in_rdev *serial; /* used for raid1 io serialization */ + + struct kernfs_node *sysfs_state; /* handle for 'state' + * sysfs entry */ + /* handle for 'unacknowledged_bad_blocks' sysfs dentry */ + struct kernfs_node *sysfs_unack_badblocks; + /* handle for 'bad_blocks' sysfs dentry */ + struct kernfs_node *sysfs_badblocks; + struct badblocks badblocks; + + struct { + short offset; /* Offset from superblock to start of PPL. + * Not used by external metadata. */ + unsigned int size; /* Size in sectors of the PPL space */ + sector_t sector; /* First sector of the PPL space */ + } ppl; +}; +enum flag_bits { + Faulty, /* device is known to have a fault */ + In_sync, /* device is in_sync with rest of array */ + Bitmap_sync, /* ..actually, not quite In_sync. Need a + * bitmap-based recovery to get fully in sync. + * The bit is only meaningful before device + * has been passed to pers->hot_add_disk. + */ + WriteMostly, /* Avoid reading if at all possible */ + AutoDetected, /* added by auto-detect */ + Blocked, /* An error occurred but has not yet + * been acknowledged by the metadata + * handler, so don't allow writes + * until it is cleared */ + WriteErrorSeen, /* A write error has been seen on this + * device + */ + FaultRecorded, /* Intermediate state for clearing + * Blocked. The Fault is/will-be + * recorded in the metadata, but that + * metadata hasn't been stored safely + * on disk yet. + */ + BlockedBadBlocks, /* A writer is blocked because they + * found an unacknowledged bad-block. + * This can safely be cleared at any + * time, and the writer will re-check. + * It may be set at any time, and at + * worst the writer will timeout and + * re-check. So setting it as + * accurately as possible is good, but + * not absolutely critical. + */ + WantReplacement, /* This device is a candidate to be + * hot-replaced, either because it has + * reported some faults, or because + * of explicit request. + */ + Replacement, /* This device is a replacement for + * a want_replacement device with same + * raid_disk number. + */ + Candidate, /* For clustered environments only: + * This device is seen locally but not + * by the whole cluster + */ + Journal, /* This device is used as journal for + * raid-5/6. + * Usually, this device should be faster + * than other devices in the array + */ + ClusterRemove, + ExternalBbl, /* External metadata provides bad + * block management for a disk + */ + FailFast, /* Minimal retries should be attempted on + * this device, so use REQ_FAILFAST_DEV. + * Also don't try to repair failed reads. + * It is expects that no bad block log + * is present. + */ + LastDev, /* Seems to be the last working dev as + * it didn't fail, so don't use FailFast + * any more for metadata + */ + CollisionCheck, /* + * check if there is collision between raid1 + * serial bios. + */ + Nonrot, /* non-rotational device (SSD) */ +}; + +static inline int is_badblock(struct md_rdev *rdev, sector_t s, sector_t sectors, + sector_t *first_bad, sector_t *bad_sectors) +{ + if (unlikely(rdev->badblocks.count)) { + int rv = badblocks_check(&rdev->badblocks, rdev->data_offset + s, + sectors, + first_bad, bad_sectors); + if (rv) + *first_bad -= rdev->data_offset; + return rv; + } + return 0; +} + +static inline int rdev_has_badblock(struct md_rdev *rdev, sector_t s, + sector_t sectors) +{ + sector_t first_bad; + sector_t bad_sectors; + + return is_badblock(rdev, s, sectors, &first_bad, &bad_sectors); +} + +extern bool rdev_set_badblocks(struct md_rdev *rdev, sector_t s, sector_t sectors, + int is_new); +extern void rdev_clear_badblocks(struct md_rdev *rdev, sector_t s, sector_t sectors, + int is_new); +struct md_cluster_info; +struct md_cluster_operations; + +/** + * enum mddev_flags - md device flags. + * @MD_ARRAY_FIRST_USE: First use of array, needs initialization. + * @MD_CLOSING: If set, we are closing the array, do not open it then. + * @MD_JOURNAL_CLEAN: A raid with journal is already clean. + * @MD_HAS_JOURNAL: The raid array has journal feature set. + * @MD_CLUSTER_RESYNC_LOCKED: cluster raid only, which means node, already took + * resync lock, need to release the lock. + * @MD_FAILFAST_SUPPORTED: Using MD_FAILFAST on metadata writes is supported as + * calls to md_error() will never cause the array to + * become failed. + * @MD_HAS_PPL: The raid array has PPL feature set. + * @MD_HAS_MULTIPLE_PPLS: The raid array has multiple PPLs feature set. + * @MD_NOT_READY: do_md_run() is active, so 'array_state', ust not report that + * array is ready yet. + * @MD_BROKEN: This is used to stop writes and mark array as failed. + * @MD_DELETED: This device is being deleted + * @MD_HAS_SUPERBLOCK: There is persistence sb in member disks. + * @MD_FAILLAST_DEV: Allow last rdev to be removed. + * @MD_SERIALIZE_POLICY: Enforce write IO is not reordered, just used by raid1. + * @MD_DM_SUSPENDING: This DM raid device is suspending. + * + * change UNSUPPORTED_MDDEV_FLAGS for each array type if new flag is added + */ +enum mddev_flags { + MD_ARRAY_FIRST_USE, + MD_CLOSING, + MD_JOURNAL_CLEAN, + MD_HAS_JOURNAL, + MD_CLUSTER_RESYNC_LOCKED, + MD_FAILFAST_SUPPORTED, + MD_HAS_PPL, + MD_HAS_MULTIPLE_PPLS, + MD_NOT_READY, + MD_BROKEN, + MD_DO_DELETE, + MD_DELETED, + MD_HAS_SUPERBLOCK, + MD_FAILLAST_DEV, + MD_SERIALIZE_POLICY, + MD_DM_SUSPENDING, +}; + +enum mddev_sb_flags { + MD_SB_CHANGE_DEVS, /* Some device status has changed */ + MD_SB_CHANGE_CLEAN, /* transition to or from 'clean' */ + MD_SB_CHANGE_PENDING, /* switch from 'clean' to 'active' in progress */ + MD_SB_NEED_REWRITE, /* metadata write needs to be repeated */ +}; + +#define NR_SERIAL_INFOS 8 +/* record current range of serialize IOs */ +struct serial_info { + struct rb_node node; + sector_t start; /* start sector of rb node */ + sector_t last; /* end sector of rb node */ + sector_t wnode_start; /* address of waiting nodes on the same list */ + sector_t _subtree_last; /* highest sector in subtree of rb node */ + struct list_head list_node; + struct list_head waiters; + struct completion ready; +}; + +/* + * mddev->curr_resync stores the current sector of the resync but + * also has some overloaded values. + */ +enum { + /* No resync in progress */ + MD_RESYNC_NONE = 0, + /* Yielded to allow another conflicting resync to commence */ + MD_RESYNC_YIELDED = 1, + /* Delayed to check that there is no conflict with another sync */ + MD_RESYNC_DELAYED = 2, + /* Any value greater than or equal to this is in an active resync */ + MD_RESYNC_ACTIVE = 3, +}; + +struct mddev { + void *private; + struct md_personality *pers; + dev_t unit; + int md_minor; + struct list_head disks; + unsigned long flags; + unsigned long sb_flags; + + int suspended; + struct mutex suspend_mutex; + struct percpu_ref active_io; + int ro; + int sysfs_active; /* set when sysfs deletes + * are happening, so run/ + * takeover/stop are not safe + */ + struct gendisk *gendisk; /* mdraid gendisk */ + struct gendisk *dm_gendisk; /* dm-raid gendisk */ + + struct kobject kobj; + int hold_active; +#define UNTIL_IOCTL 1 +#define UNTIL_STOP 2 + + /* Superblock information */ + int major_version, + minor_version, + patch_version; + int persistent; + int external; /* metadata is + * managed externally */ + char metadata_type[17]; /* externally set*/ + int chunk_sectors; + time64_t ctime, utime; + int level, layout; + char clevel[16]; + int raid_disks; + int max_disks; + sector_t dev_sectors; /* used size of + * component devices */ + sector_t array_sectors; /* exported array size */ + int external_size; /* size managed + * externally */ + unsigned int logical_block_size; + __u64 events; + /* If the last 'event' was simply a clean->dirty transition, and + * we didn't write it to the spares, then it is safe and simple + * to just decrement the event count on a dirty->clean transition. + * So we record that possibility here. + */ + int can_decrease_events; + + char uuid[16]; + + /* If the array is being reshaped, we need to record the + * new shape and an indication of where we are up to. + * This is written to the superblock. + * If reshape_position is MaxSector, then no reshape is happening (yet). + */ + sector_t reshape_position; + int delta_disks, new_level, new_layout; + int new_chunk_sectors; + int reshape_backwards; + + struct md_thread __rcu *thread; /* management thread */ + struct md_thread __rcu *sync_thread; /* doing resync or reconstruct */ + + /* + * Set when a sync operation is started. It holds this value even + * when the sync thread is "frozen" (interrupted) or "idle" (stopped + * or finished). It is overwritten when a new sync operation is begun. + */ + enum sync_action last_sync_action; + sector_t curr_resync; /* last block scheduled */ + /* As resync requests can complete out of order, we cannot easily track + * how much resync has been completed. So we occasionally pause until + * everything completes, then set curr_resync_completed to curr_resync. + * As such it may be well behind the real resync mark, but it is a value + * we are certain of. + */ + sector_t curr_resync_completed; + unsigned long resync_mark; /* a recent timestamp */ + sector_t resync_mark_cnt;/* blocks written at resync_mark */ + sector_t curr_mark_cnt; /* blocks scheduled now */ + + sector_t resync_max_sectors; /* may be set by personality */ + + atomic64_t resync_mismatches; /* count of sectors where + * parity/replica mismatch found + */ + + /* allow user-space to request suspension of IO to regions of the array */ + sector_t suspend_lo; + sector_t suspend_hi; + /* if zero, use the system-wide default */ + int sync_speed_min; + int sync_speed_max; + int sync_io_depth; + + /* resync even though the same disks are shared among md-devices */ + int parallel_resync; + + int ok_start_degraded; + + unsigned long recovery; + + int in_sync; /* know to not need resync */ + /* 'open_mutex' avoids races between 'md_open' and 'do_md_stop', so + * that we are never stopping an array while it is open. + * 'reconfig_mutex' protects all other reconfiguration. + * These locks are separate due to conflicting interactions + * with disk->open_mutex. + * Lock ordering is: + * reconfig_mutex -> disk->open_mutex + * disk->open_mutex -> open_mutex: e.g. __blkdev_get -> md_open + */ + struct mutex open_mutex; + struct mutex reconfig_mutex; + atomic_t active; /* general refcount */ + atomic_t openers; /* number of active opens */ + + int changed; /* True if we might need to + * reread partition info */ + int degraded; /* whether md should consider + * adding a spare + */ + + unsigned long normal_io_events; /* IO event timestamp */ + atomic_t recovery_active; /* blocks scheduled, but not written */ + wait_queue_head_t recovery_wait; + sector_t resync_offset; + sector_t resync_min; /* user requested sync + * starts here */ + sector_t resync_max; /* resync should pause + * when it gets here */ + + struct kernfs_node *sysfs_state; /* handle for 'array_state' + * file in sysfs. + */ + struct kernfs_node *sysfs_action; /* handle for 'sync_action' */ + struct kernfs_node *sysfs_completed; /*handle for 'sync_completed' */ + struct kernfs_node *sysfs_degraded; /*handle for 'degraded' */ + struct kernfs_node *sysfs_level; /*handle for 'level' */ + + /* used for delayed sysfs removal */ + struct work_struct del_work; + /* used for register new sync thread */ + struct work_struct sync_work; + + /* "lock" protects: + * flush_bio transition from NULL to !NULL + * rdev superblocks, events + * clearing MD_CHANGE_* + * in_sync - and related safemode and MD_CHANGE changes + * pers (also protected by reconfig_mutex and pending IO). + * clearing ->bitmap + * clearing ->bitmap_info.file + * changing ->resync_{min,max} + * setting MD_RECOVERY_RUNNING (which interacts with resync_{min,max}) + */ + spinlock_t lock; + wait_queue_head_t sb_wait; /* for waiting on superblock updates */ + atomic_t pending_writes; /* number of active superblock writes */ + + unsigned int safemode; /* if set, update "clean" superblock + * when no writes pending. + */ + unsigned int safemode_delay; + struct timer_list safemode_timer; + struct percpu_ref writes_pending; + int sync_checkers; /* # of threads checking writes_pending */ + + enum md_submodule_id bitmap_id; + void *bitmap; /* the bitmap for the device */ + struct bitmap_operations *bitmap_ops; + struct { + struct file *file; /* the bitmap file */ + loff_t offset; /* offset from superblock of + * start of bitmap. May be + * negative, but not '0' + * For external metadata, offset + * from start of device. + */ + unsigned long space; /* space available at this offset */ + loff_t default_offset; /* this is the offset to use when + * hot-adding a bitmap. It should + * eventually be settable by sysfs. + */ + unsigned long default_space; /* space available at + * default offset */ + struct mutex mutex; + unsigned long chunksize; + unsigned long daemon_sleep; /* how many jiffies between updates? */ + unsigned long max_write_behind; /* write-behind mode */ + int external; + int nodes; /* Maximum number of nodes in the cluster */ + char cluster_name[64]; /* Name of the cluster */ + } bitmap_info; + + atomic_t max_corr_read_errors; /* max read retries */ + struct list_head all_mddevs; + + const struct attribute_group *to_remove; + + struct bio_set bio_set; + struct bio_set sync_set; /* for sync operations like + * metadata and bitmap writes + */ + struct bio_set io_clone_set; + + struct work_struct event_work; /* used by dm to report failure event */ + mempool_t *serial_info_pool; + void (*sync_super)(struct mddev *mddev, struct md_rdev *rdev); + struct md_cluster_info *cluster_info; + struct md_cluster_operations *cluster_ops; + unsigned int good_device_nr; /* good device num within cluster raid */ + + /* + * Temporarily store rdev that will be finally removed when + * reconfig_mutex is unlocked, protected by reconfig_mutex. + */ + struct list_head deleting; + + /* The sequence number for sync thread */ + atomic_t sync_seq; +}; + +enum recovery_flags { + /* flags for sync thread running status */ + + /* + * set when one of sync action is set and new sync thread need to be + * registered, or just add/remove spares from conf. + */ + MD_RECOVERY_NEEDED, + /* sync thread is running, or about to be started */ + MD_RECOVERY_RUNNING, + /* sync thread needs to be aborted for some reason */ + MD_RECOVERY_INTR, + /* sync thread is done and is waiting to be unregistered */ + MD_RECOVERY_DONE, + /* running sync thread must abort immediately, and not restart */ + MD_RECOVERY_FROZEN, + /* waiting for pers->start() to finish */ + MD_RECOVERY_WAIT, + + /* flags determines sync action, see details in enum sync_action */ + + /* if just this flag is set, action is resync. */ + MD_RECOVERY_SYNC, + /* + * paired with MD_RECOVERY_SYNC, if MD_RECOVERY_CHECK is not set, + * action is repair, means user requested resync. + */ + MD_RECOVERY_REQUESTED, + /* + * paired with MD_RECOVERY_SYNC and MD_RECOVERY_REQUESTED, action is + * check. + */ + MD_RECOVERY_CHECK, + /* recovery, or need to try it */ + MD_RECOVERY_RECOVER, + /* reshape */ + MD_RECOVERY_RESHAPE, + /* remote node is running resync thread */ + MD_RESYNCING_REMOTE, + /* raid456 lazy initial recover */ + MD_RECOVERY_LAZY_RECOVER, +}; + +enum md_ro_state { + MD_RDWR, + MD_RDONLY, + MD_AUTO_READ, + MD_MAX_STATE +}; + +static inline bool md_is_rdwr(struct mddev *mddev) +{ + return (mddev->ro == MD_RDWR); +} + +static inline bool reshape_interrupted(struct mddev *mddev) +{ + /* reshape never start */ + if (mddev->reshape_position == MaxSector) + return false; + + /* interrupted */ + if (!test_bit(MD_RECOVERY_RUNNING, &mddev->recovery)) + return true; + + /* running reshape will be interrupted soon. */ + if (test_bit(MD_RECOVERY_WAIT, &mddev->recovery) || + test_bit(MD_RECOVERY_INTR, &mddev->recovery) || + test_bit(MD_RECOVERY_FROZEN, &mddev->recovery)) + return true; + + return false; +} + +static inline int __must_check mddev_lock(struct mddev *mddev) +{ + int ret; + + ret = mutex_lock_interruptible(&mddev->reconfig_mutex); + + /* MD_DELETED is set in do_md_stop with reconfig_mutex. + * So check it here. + */ + if (!ret && test_bit(MD_DELETED, &mddev->flags)) { + ret = -ENODEV; + mutex_unlock(&mddev->reconfig_mutex); + } + + return ret; +} + +/* Sometimes we need to take the lock in a situation where + * failure due to interrupts is not acceptable. + * It doesn't need to check MD_DELETED here, the owner which + * holds the lock here can't be stopped. And all paths can't + * call this function after do_md_stop. + */ +static inline void mddev_lock_nointr(struct mddev *mddev) +{ + mutex_lock(&mddev->reconfig_mutex); +} + +static inline int mddev_trylock(struct mddev *mddev) +{ + int ret; + + ret = mutex_trylock(&mddev->reconfig_mutex); + if (ret && test_bit(MD_DELETED, &mddev->flags)) { + ret = 0; + mutex_unlock(&mddev->reconfig_mutex); + } + return ret; +} +extern void mddev_unlock(struct mddev *mddev); + +struct md_personality +{ + struct md_submodule_head head; + + bool __must_check (*make_request)(struct mddev *mddev, struct bio *bio); + /* + * start up works that do NOT require md_thread. tasks that + * requires md_thread should go into start() + */ + int (*run)(struct mddev *mddev); + /* start up works that require md threads */ + int (*start)(struct mddev *mddev); + void (*free)(struct mddev *mddev, void *priv); + void (*status)(struct seq_file *seq, struct mddev *mddev); + /* error_handler must set ->faulty and clear ->in_sync + * if appropriate, and should abort recovery if needed + */ + void (*error_handler)(struct mddev *mddev, struct md_rdev *rdev); + int (*hot_add_disk) (struct mddev *mddev, struct md_rdev *rdev); + int (*hot_remove_disk) (struct mddev *mddev, struct md_rdev *rdev); + int (*spare_active) (struct mddev *mddev); + sector_t (*sync_request)(struct mddev *mddev, sector_t sector_nr, + sector_t max_sector, int *skipped); + int (*resize) (struct mddev *mddev, sector_t sectors); + sector_t (*size) (struct mddev *mddev, sector_t sectors, int raid_disks); + int (*check_reshape) (struct mddev *mddev); + int (*start_reshape) (struct mddev *mddev); + void (*finish_reshape) (struct mddev *mddev); + void (*update_reshape_pos) (struct mddev *mddev); + void (*prepare_suspend) (struct mddev *mddev); + /* quiesce suspends or resumes internal processing. + * 1 - stop new actions and wait for action io to complete + * 0 - return to normal behaviour + */ + void (*quiesce) (struct mddev *mddev, int quiesce); + /* takeover is used to transition an array from one + * personality to another. The new personality must be able + * to handle the data in the current layout. + * e.g. 2drive raid1 -> 2drive raid5 + * ndrive raid5 -> degraded n+1drive raid6 with special layout + * If the takeover succeeds, a new 'private' structure is returned. + * This needs to be installed and then ->run used to activate the + * array. + */ + void *(*takeover) (struct mddev *mddev); + /* Changes the consistency policy of an active array. */ + int (*change_consistency_policy)(struct mddev *mddev, const char *buf); + /* convert io ranges from array to bitmap */ + void (*bitmap_sector)(struct mddev *mddev, sector_t *offset, + unsigned long *sectors); + void (*bitmap_sector_map)(struct mddev *mddev, sector_t *offset, + unsigned long *sectors, bool previous); + sector_t (*bitmap_sync_size)(struct mddev *mddev, bool previous); + sector_t (*bitmap_array_sectors)(struct mddev *mddev, bool previous); +}; + +struct md_sysfs_entry { + struct attribute attr; + ssize_t (*show)(struct mddev *, char *); + ssize_t (*store)(struct mddev *, const char *, size_t); +}; + +static inline struct kernfs_node *sysfs_get_dirent_safe(struct kernfs_node *sd, char *name) +{ + if (sd) + return sysfs_get_dirent(sd, name); + return sd; +} +static inline void sysfs_notify_dirent_safe(struct kernfs_node *sd) +{ + if (sd) + sysfs_notify_dirent(sd); +} + +static inline char * mdname (struct mddev * mddev) +{ + return mddev->gendisk ? mddev->gendisk->disk_name : "mdX"; +} + +static inline int sysfs_link_rdev(struct mddev *mddev, struct md_rdev *rdev) +{ + char nm[20]; + if (!test_bit(Replacement, &rdev->flags) && + !test_bit(Journal, &rdev->flags) && + mddev->kobj.sd) { + sprintf(nm, "rd%d", rdev->raid_disk); + return sysfs_create_link(&mddev->kobj, &rdev->kobj, nm); + } else + return 0; +} + +static inline void sysfs_unlink_rdev(struct mddev *mddev, struct md_rdev *rdev) +{ + char nm[20]; + if (!test_bit(Replacement, &rdev->flags) && + !test_bit(Journal, &rdev->flags) && + mddev->kobj.sd) { + sprintf(nm, "rd%d", rdev->raid_disk); + sysfs_remove_link(&mddev->kobj, nm); + } +} + +/* + * iterates through some rdev ringlist. It's safe to remove the + * current 'rdev'. Dont touch 'tmp' though. + */ +#define rdev_for_each_list(rdev, tmp, head) \ + list_for_each_entry_safe(rdev, tmp, head, same_set) + +/* + * iterates through the 'same array disks' ringlist + */ +#define rdev_for_each(rdev, mddev) \ + list_for_each_entry(rdev, &((mddev)->disks), same_set) + +#define rdev_for_each_safe(rdev, tmp, mddev) \ + list_for_each_entry_safe(rdev, tmp, &((mddev)->disks), same_set) + +#define rdev_for_each_rcu(rdev, mddev) \ + list_for_each_entry_rcu(rdev, &((mddev)->disks), same_set) + +struct md_thread { + void (*run) (struct md_thread *thread); + struct mddev *mddev; + wait_queue_head_t wqueue; + unsigned long flags; + struct task_struct *tsk; + unsigned long timeout; + void *private; +}; + +struct md_io_clone { + struct mddev *mddev; + struct bio *orig_bio; + unsigned long start_time; + sector_t offset; + unsigned long sectors; + enum stat_group rw; + struct bio bio_clone; +}; + +#define THREAD_WAKEUP 0 + +#define md_wakeup_thread(thread) do { \ + rcu_read_lock(); \ + __md_wakeup_thread(thread); \ + rcu_read_unlock(); \ +} while (0) + +static inline void safe_put_page(struct page *p) +{ + if (p) put_page(p); +} + +int register_md_submodule(struct md_submodule_head *msh); +void unregister_md_submodule(struct md_submodule_head *msh); + +extern struct md_thread *md_register_thread( + void (*run)(struct md_thread *thread), + struct mddev *mddev, + const char *name); +extern void md_unregister_thread(struct mddev *mddev, struct md_thread __rcu **threadp); +extern void __md_wakeup_thread(struct md_thread __rcu *thread); +extern void md_check_recovery(struct mddev *mddev); +extern void md_reap_sync_thread(struct mddev *mddev); +extern enum sync_action md_sync_action(struct mddev *mddev); +extern enum sync_action md_sync_action_by_name(const char *page); +extern const char *md_sync_action_name(enum sync_action action); +extern void md_write_start(struct mddev *mddev, struct bio *bi); +extern void md_write_inc(struct mddev *mddev, struct bio *bi); +extern void md_write_end(struct mddev *mddev); +extern void md_done_sync(struct mddev *mddev, int blocks); +extern void md_sync_error(struct mddev *mddev); +extern void md_error(struct mddev *mddev, struct md_rdev *rdev); +extern void md_finish_reshape(struct mddev *mddev); +void md_submit_discard_bio(struct mddev *mddev, struct md_rdev *rdev, + struct bio *bio, sector_t start, sector_t size); +struct bio *mddev_bio_split_at_reshape_offset(struct mddev *mddev, + struct bio *bio, + unsigned int *max_sectors, + struct bio_set *bs); +void md_account_bio(struct mddev *mddev, struct bio **bio); + +extern bool __must_check md_flush_request(struct mddev *mddev, struct bio *bio); +void md_write_metadata(struct mddev *mddev, struct md_rdev *rdev, + sector_t sector, int size, struct page *page, + unsigned int offset); +extern int md_super_wait(struct mddev *mddev); +extern int sync_page_io(struct md_rdev *rdev, sector_t sector, int size, + struct page *page, blk_opf_t opf, bool metadata_op); +extern void md_do_sync(struct md_thread *thread); +extern void md_new_event(void); +extern void md_allow_write(struct mddev *mddev); +extern void md_wait_for_blocked_rdev(struct md_rdev *rdev, struct mddev *mddev); +extern void md_set_array_sectors(struct mddev *mddev, sector_t array_sectors); +extern int md_check_no_bitmap(struct mddev *mddev); +bool mddev_set_bitmap_ops_nosysfs(struct mddev *mddev); +int md_bitmap_create_nosysfs(struct mddev *mddev); +void md_bitmap_destroy_nosysfs(struct mddev *mddev); +extern int md_integrity_register(struct mddev *mddev); +extern int strict_strtoul_scaled(const char *cp, unsigned long *res, int scale); + +extern int mddev_init(struct mddev *mddev); +extern void mddev_destroy(struct mddev *mddev); +void md_init_stacking_limits(struct queue_limits *lim); +struct mddev *md_alloc(dev_t dev, char *name); +void mddev_put(struct mddev *mddev); +extern int md_run(struct mddev *mddev); +extern int md_start(struct mddev *mddev); +extern void md_stop(struct mddev *mddev); +extern void md_stop_writes(struct mddev *mddev); +extern int md_rdev_init(struct md_rdev *rdev); +extern void md_rdev_clear(struct md_rdev *rdev); + +extern bool md_handle_request(struct mddev *mddev, struct bio *bio); +extern int mddev_suspend(struct mddev *mddev, bool interruptible); +extern void mddev_resume(struct mddev *mddev); +extern void md_idle_sync_thread(struct mddev *mddev); +extern void md_frozen_sync_thread(struct mddev *mddev); +extern void md_unfrozen_sync_thread(struct mddev *mddev); + +extern void md_update_sb(struct mddev *mddev, int force); +extern void mddev_create_serial_pool(struct mddev *mddev, struct md_rdev *rdev); +extern void mddev_destroy_serial_pool(struct mddev *mddev, + struct md_rdev *rdev); +struct md_rdev *md_find_rdev_nr_rcu(struct mddev *mddev, int nr); +struct md_rdev *md_find_rdev_rcu(struct mddev *mddev, dev_t dev); + +static inline bool is_rdev_broken(struct md_rdev *rdev) +{ + return !disk_live(rdev->bdev->bd_disk); +} + +static inline void rdev_dec_pending(struct md_rdev *rdev, struct mddev *mddev) +{ + int faulty = test_bit(Faulty, &rdev->flags); + if (atomic_dec_and_test(&rdev->nr_pending) && faulty) { + set_bit(MD_RECOVERY_NEEDED, &mddev->recovery); + md_wakeup_thread(mddev->thread); + } +} + +static inline int mddev_is_clustered(struct mddev *mddev) +{ + return mddev->cluster_info && mddev->bitmap_info.nodes > 1; +} + +/* clear unsupported mddev_flags */ +static inline void mddev_clear_unsupported_flags(struct mddev *mddev, + unsigned long unsupported_flags) +{ + mddev->flags &= ~unsupported_flags; +} + +static inline void mddev_check_write_zeroes(struct mddev *mddev, struct bio *bio) +{ + if (bio_op(bio) == REQ_OP_WRITE_ZEROES && + !bio->bi_bdev->bd_disk->queue->limits.max_write_zeroes_sectors) + mddev->gendisk->queue->limits.max_write_zeroes_sectors = 0; +} + +static inline int mddev_suspend_and_lock(struct mddev *mddev) +{ + int ret; + + ret = mddev_suspend(mddev, true); + if (ret) + return ret; + + ret = mddev_lock(mddev); + if (ret) + mddev_resume(mddev); + + return ret; +} + +static inline void mddev_suspend_and_lock_nointr(struct mddev *mddev) +{ + mddev_suspend(mddev, false); + mddev_lock_nointr(mddev); +} + +static inline void mddev_unlock_and_resume(struct mddev *mddev) +{ + mddev_unlock(mddev); + mddev_resume(mddev); +} + +struct mdu_array_info_s; +struct mdu_disk_info_s; + +extern int mdp_major; +void md_autostart_arrays(int part); +int md_set_array_info(struct mddev *mddev, struct mdu_array_info_s *info); +int md_add_new_disk(struct mddev *mddev, struct mdu_disk_info_s *info); +int do_md_run(struct mddev *mddev); +#define MDDEV_STACK_INTEGRITY (1u << 0) +int mddev_stack_rdev_limits(struct mddev *mddev, struct queue_limits *lim, + unsigned int flags); +int mddev_stack_new_rdev(struct mddev *mddev, struct md_rdev *rdev); +void mddev_update_io_opt(struct mddev *mddev, unsigned int nr_stripes); + +extern const struct block_device_operations md_fops; + +static inline bool md_cloned_bio(struct mddev *mddev, struct bio *bio) +{ + return bio->bi_pool == &mddev->io_clone_set; +} + +/* + * MD devices can be used undeneath by DM, in which case ->gendisk is NULL. + */ +static inline bool mddev_is_dm(struct mddev *mddev) +{ + return !mddev->gendisk; +} + +static inline bool raid_is_456(struct mddev *mddev) +{ + return mddev->level == ID_RAID4 || mddev->level == ID_RAID5 || + mddev->level == ID_RAID6; +} + +static inline void mddev_trace_remap(struct mddev *mddev, struct bio *bio, + sector_t sector) +{ + if (!mddev_is_dm(mddev)) + trace_block_bio_remap(bio, disk_devt(mddev->gendisk), sector); +} + +static inline bool rdev_blocked(struct md_rdev *rdev) +{ + /* + * Blocked will be set by error handler and cleared by daemon after + * updating superblock, meanwhile write IO should be blocked to prevent + * reading old data after power failure. + */ + if (test_bit(Blocked, &rdev->flags)) + return true; + + /* + * Faulty device should not be accessed anymore, there is no need to + * wait for bad block to be acknowledged. + */ + if (test_bit(Faulty, &rdev->flags)) + return false; + + /* rdev is blocked by badblocks. */ + if (test_bit(BlockedBadBlocks, &rdev->flags)) + return true; + + return false; +} + +#define mddev_add_trace_msg(mddev, fmt, args...) \ +do { \ + if (!mddev_is_dm(mddev)) \ + blk_add_trace_msg((mddev)->gendisk->queue, fmt, ##args); \ +} while (0) + +#endif /* _MD_MD_H */ |