v4.19.13 snapshot.
diff --git a/drivers/md/md.h b/drivers/md/md.h
new file mode 100644
index 0000000..8afd6bf
--- /dev/null
+++ b/drivers/md/md.h
@@ -0,0 +1,761 @@
+/*
+ md.h : kernel internal structure of the Linux MD driver
+ Copyright (C) 1996-98 Ingo Molnar, Gadi Oxman
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 2, or (at your option)
+ any later version.
+
+ You should have received a copy of the GNU General Public License
+ (for example /usr/src/linux/COPYING); if not, write to the Free
+ Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+*/
+
+#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 "md-cluster.h"
+
+#define MaxSector (~(sector_t)0)
+
+/*
+ * 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)
+/*
+ * 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 */
+ int 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 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 work_struct del_work; /* used for delayed sysfs removal */
+
+ struct kernfs_node *sysfs_state; /* handle for 'state'
+ * sysfs entry */
+
+ 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,
+ RemoveSynchronized, /* synchronize_rcu() was called after
+ * this device was known to be faulty,
+ * so it is safe to remove without
+ * another synchronize_rcu() call.
+ */
+ 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
+ */
+};
+
+static inline int is_badblock(struct md_rdev *rdev, sector_t s, int sectors,
+ sector_t *first_bad, int *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;
+}
+extern int rdev_set_badblocks(struct md_rdev *rdev, sector_t s, int sectors,
+ int is_new);
+extern int rdev_clear_badblocks(struct md_rdev *rdev, sector_t s, int sectors,
+ int is_new);
+struct md_cluster_info;
+
+/* change UNSUPPORTED_MDDEV_FLAGS for each array type if new flag is added */
+enum mddev_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_ALLOW_SB_UPDATE, /* md_check_recovery is allowed to update
+ * the metadata without taking reconfig_mutex.
+ */
+ MD_UPDATING_SB, /* md_check_recovery is updating the metadata
+ * without explicitly holding reconfig_mutex.
+ */
+};
+
+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_FLUSH_INFOS 8
+#define NR_FLUSH_BIOS 64
+struct flush_info {
+ struct bio *bio;
+ struct mddev *mddev;
+ struct work_struct flush_work;
+ atomic_t flush_pending;
+};
+struct flush_bio {
+ struct flush_info *fi;
+ struct md_rdev *rdev;
+};
+
+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;
+ atomic_t active_io;
+ int ro;
+ int sysfs_active; /* set when sysfs deletes
+ * are happening, so run/
+ * takeover/stop are not safe
+ */
+ struct gendisk *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 */
+ __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 *thread; /* management thread */
+ struct md_thread *sync_thread; /* doing resync or reconstruct */
+
+ /* 'last_sync_action' is initialized to "none". It is set when a
+ * sync operation (i.e "data-check", "requested-resync", "resync",
+ * "recovery", or "reshape") 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.
+ */
+ char *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;
+
+ /* resync even though the same disks are shared among md-devices */
+ int parallel_resync;
+
+ int ok_start_degraded;
+
+ unsigned long 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 bdev->bd_mutex.
+ * Lock ordering is:
+ * reconfig_mutex -> bd_mutex : e.g. do_md_run -> revalidate_disk
+ * bd_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
+ */
+
+ atomic_t recovery_active; /* blocks scheduled, but not written */
+ wait_queue_head_t recovery_wait;
+ sector_t recovery_cp;
+ 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 work_struct del_work; /* used for delayed sysfs removal */
+
+ /* "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 */
+ struct request_queue *queue; /* for plugging ... */
+
+ struct bitmap *bitmap; /* the bitmap for the device */
+ 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;
+
+ struct attribute_group *to_remove;
+
+ struct bio_set bio_set;
+ struct bio_set sync_set; /* for sync operations like
+ * metadata and bitmap writes
+ */
+
+ mempool_t *flush_pool;
+ mempool_t *flush_bio_pool;
+ struct work_struct event_work; /* used by dm to report failure event */
+ void (*sync_super)(struct mddev *mddev, struct md_rdev *rdev);
+ struct md_cluster_info *cluster_info;
+ unsigned int good_device_nr; /* good device num within cluster raid */
+
+ bool has_superblocks:1;
+};
+
+enum recovery_flags {
+ /*
+ * If neither SYNC or RESHAPE are set, then it is a recovery.
+ */
+ MD_RECOVERY_RUNNING, /* a thread is running, or about to be started */
+ MD_RECOVERY_SYNC, /* actually doing a resync, not a recovery */
+ MD_RECOVERY_RECOVER, /* doing recovery, or need to try it. */
+ MD_RECOVERY_INTR, /* resync needs to be aborted for some reason */
+ MD_RECOVERY_DONE, /* thread is done and is waiting to be reaped */
+ MD_RECOVERY_NEEDED, /* we might need to start a resync/recover */
+ MD_RECOVERY_REQUESTED, /* user-space has requested a sync (used with SYNC) */
+ MD_RECOVERY_CHECK, /* user-space request for check-only, no repair */
+ MD_RECOVERY_RESHAPE, /* A reshape is happening */
+ MD_RECOVERY_FROZEN, /* User request to abort, and not restart, any action */
+ MD_RECOVERY_ERROR, /* sync-action interrupted because io-error */
+ MD_RECOVERY_WAIT, /* waiting for pers->start() to finish */
+ MD_RESYNCING_REMOTE, /* remote node is running resync thread */
+};
+
+static inline int __must_check mddev_lock(struct mddev *mddev)
+{
+ return mutex_lock_interruptible(&mddev->reconfig_mutex);
+}
+
+/* Sometimes we need to take the lock in a situation where
+ * failure due to interrupts is not acceptable.
+ */
+static inline void mddev_lock_nointr(struct mddev *mddev)
+{
+ mutex_lock(&mddev->reconfig_mutex);
+}
+
+static inline int mddev_trylock(struct mddev *mddev)
+{
+ return mutex_trylock(&mddev->reconfig_mutex);
+}
+extern void mddev_unlock(struct mddev *mddev);
+
+static inline void md_sync_acct(struct block_device *bdev, unsigned long nr_sectors)
+{
+ atomic_add(nr_sectors, &bdev->bd_contains->bd_disk->sync_io);
+}
+
+static inline void md_sync_acct_bio(struct bio *bio, unsigned long nr_sectors)
+{
+ atomic_add(nr_sectors, &bio->bi_disk->sync_io);
+}
+
+struct md_personality
+{
+ char *name;
+ int level;
+ struct list_head list;
+ struct module *owner;
+ bool (*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, 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);
+ /* 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);
+ /* congested implements bdi.congested_fn().
+ * Will not be called while array is 'suspended' */
+ int (*congested)(struct mddev *mddev, int bits);
+ /* Changes the consistency policy of an active array. */
+ int (*change_consistency_policy)(struct mddev *mddev, const char *buf);
+};
+
+struct md_sysfs_entry {
+ struct attribute attr;
+ ssize_t (*show)(struct mddev *, char *);
+ ssize_t (*store)(struct mddev *, const char *, size_t);
+};
+extern struct attribute_group md_bitmap_group;
+
+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;
+};
+
+#define THREAD_WAKEUP 0
+
+static inline void safe_put_page(struct page *p)
+{
+ if (p) put_page(p);
+}
+
+extern int register_md_personality(struct md_personality *p);
+extern int unregister_md_personality(struct md_personality *p);
+extern int register_md_cluster_operations(struct md_cluster_operations *ops,
+ struct module *module);
+extern int unregister_md_cluster_operations(void);
+extern int md_setup_cluster(struct mddev *mddev, int nodes);
+extern void md_cluster_stop(struct mddev *mddev);
+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 md_thread **threadp);
+extern void md_wakeup_thread(struct md_thread *thread);
+extern void md_check_recovery(struct mddev *mddev);
+extern void md_reap_sync_thread(struct mddev *mddev);
+extern int mddev_init_writes_pending(struct mddev *mddev);
+extern bool 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, int ok);
+extern void md_error(struct mddev *mddev, struct md_rdev *rdev);
+extern void md_finish_reshape(struct mddev *mddev);
+
+extern int mddev_congested(struct mddev *mddev, int bits);
+extern void md_flush_request(struct mddev *mddev, struct bio *bio);
+extern void md_super_write(struct mddev *mddev, struct md_rdev *rdev,
+ sector_t sector, int size, struct page *page);
+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, int op, int op_flags,
+ bool metadata_op);
+extern void md_do_sync(struct md_thread *thread);
+extern void md_new_event(struct mddev *mddev);
+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);
+extern int md_integrity_register(struct mddev *mddev);
+extern int md_integrity_add_rdev(struct md_rdev *rdev, struct mddev *mddev);
+extern int strict_strtoul_scaled(const char *cp, unsigned long *res, int scale);
+
+extern void mddev_init(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 void md_handle_request(struct mddev *mddev, struct bio *bio);
+extern void mddev_suspend(struct mddev *mddev);
+extern void mddev_resume(struct mddev *mddev);
+extern struct bio *bio_alloc_mddev(gfp_t gfp_mask, int nr_iovecs,
+ struct mddev *mddev);
+
+extern void md_reload_sb(struct mddev *mddev, int raid_disk);
+extern void md_update_sb(struct mddev *mddev, int force);
+extern void md_kick_rdev_from_array(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 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);
+ }
+}
+
+extern struct md_cluster_operations *md_cluster_ops;
+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_writesame(struct mddev *mddev, struct bio *bio)
+{
+ if (bio_op(bio) == REQ_OP_WRITE_SAME &&
+ !bio->bi_disk->queue->limits.max_write_same_sectors)
+ mddev->queue->limits.max_write_same_sectors = 0;
+}
+
+static inline void mddev_check_write_zeroes(struct mddev *mddev, struct bio *bio)
+{
+ if (bio_op(bio) == REQ_OP_WRITE_ZEROES &&
+ !bio->bi_disk->queue->limits.max_write_zeroes_sectors)
+ mddev->queue->limits.max_write_zeroes_sectors = 0;
+}
+#endif /* _MD_MD_H */