/* * 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;
wait_queue_head_t serial_io_wait;
};
/* * MD's 'extended' device
*/ struct md_rdev { struct list_head same_set; /* RAID devices within the same set */
/* * 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
*/
unsignedlong 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 { short offset; /* Offset from superblock to start of PPL.
* Not used by external metadata. */ unsignedint 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) */
};
externbool rdev_set_badblocks(struct md_rdev *rdev, sector_t s, int sectors, int is_new); externvoid rdev_clear_badblocks(struct md_rdev *rdev, sector_t s, int 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 * * 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_DELETED,
};
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 _subtree_last; /* highest sector in subtree of rb node */
};
/* * 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,
};
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 */
/* 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 */
__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;
/* * 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; unsignedlong 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;
unsignedlong recovery; /* If a RAID personality determines that recovery (of a particular * device) will fail due to a read error on the source device, it * takes a copy of this number and does not attempt recovery again * until this number changes.
*/ int recovery_disabled;
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
*/
unsignedlong 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 */
unsignedint safemode; /* if set, update "clean" superblock * when no writes pending.
*/ unsignedint safemode_delay; struct timer_list safemode_timer; struct percpu_ref writes_pending; int sync_checkers; /* # of threads checking writes_pending */
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.
*/ unsignedlong 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.
*/ unsignedlong default_space; /* space available at
* default offset */ struct mutex mutex; unsignedlong chunksize; unsignedlong daemon_sleep; /* how many jiffies between updates? */ unsignedlong 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;
conststruct 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; unsignedint good_device_nr; /* good device num within cluster raid */ unsignedint noio_flag; /* for memalloc scope API */
/* * 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, /* interrupted because io-error */
MD_RECOVERY_ERROR,
/* 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,
};
staticinlinebool reshape_interrupted(struct mddev *mddev)
{ /* reshape never start */ if (mddev->reshape_position == MaxSector) returnfalse;
/* interrupted */ if (!test_bit(MD_RECOVERY_RUNNING, &mddev->recovery)) returntrue;
/* 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)) returntrue;
returnfalse;
}
staticinlineint __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.
*/ staticinlinevoid mddev_lock_nointr(struct mddev *mddev)
{
mutex_lock(&mddev->reconfig_mutex);
}
staticinlineint mddev_trylock(struct mddev *mddev)
{ int ret;
ret = mutex_trylock(&mddev->reconfig_mutex); if (!ret && test_bit(MD_DELETED, &mddev->flags)) {
ret = -ENODEV;
mutex_unlock(&mddev->reconfig_mutex);
} return ret;
} externvoid mddev_unlock(struct mddev *mddev);
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, constchar *buf); /* convert io ranges from array to bitmap */ void (*bitmap_sector)(struct mddev *mddev, sector_t *offset, unsignedlong *sectors);
};
/* * 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)
/* * MD devices can be used undeneath by DM, in which case ->gendisk is NULL.
*/ staticinlinebool mddev_is_dm(struct mddev *mddev)
{ return !mddev->gendisk;
}
staticinlinevoid 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);
}
staticinlinebool 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)) returntrue;
/* * 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)) returnfalse;
/* rdev is blocked by badblocks. */ if (test_bit(BlockedBadBlocks, &rdev->flags)) returntrue;
returnfalse;
}
#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 */
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