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-rw-r--r--drivers/md/md.h436
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diff --git a/drivers/md/md.h b/drivers/md/md.h
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+/*
+ md_k.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_K_H
+#define _MD_K_H
+
+#ifdef CONFIG_BLOCK
+
+#define MaxSector (~(sector_t)0)
+
+typedef struct mddev_s mddev_t;
+typedef struct mdk_rdev_s mdk_rdev_t;
+
+/*
+ * options passed in raidrun:
+ */
+
+/* Currently this must fit in an 'int' */
+#define MAX_CHUNK_SIZE (1<<30)
+
+/*
+ * MD's 'extended' device
+ */
+struct mdk_rdev_s
+{
+ struct list_head same_set; /* RAID devices within the same set */
+
+ sector_t sectors; /* Device size (in 512bytes sectors) */
+ mddev_t *mddev; /* RAID array if running */
+ int last_events; /* IO event timestamp */
+
+ struct block_device *bdev; /* block device handle */
+
+ struct page *sb_page;
+ int sb_loaded;
+ __u64 sb_events;
+ sector_t data_offset; /* start of data in array */
+ 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;
+#define Faulty 1 /* device is known to have a fault */
+#define In_sync 2 /* device is in_sync with rest of array */
+#define WriteMostly 4 /* Avoid reading if at all possible */
+#define BarriersNotsupp 5 /* BIO_RW_BARRIER is not supported */
+#define AllReserved 6 /* If whole device is reserved for
+ * one array */
+#define AutoDetected 7 /* added by auto-detect */
+#define Blocked 8 /* An error occured on an externally
+ * managed array, don't allow writes
+ * until it is cleared */
+#define StateChanged 9 /* Faulty or Blocked has changed during
+ * interrupt, so it needs to be
+ * notified by the thread */
+ wait_queue_head_t blocked_wait;
+
+ int desc_nr; /* descriptor index in the superblock */
+ int raid_disk; /* role of device in array */
+ 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
+ */
+ sector_t recovery_offset;/* If this device has been partially
+ * recovered, this is where we were
+ * up to.
+ */
+
+ 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.
+ */
+ 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 sysfs_dirent *sysfs_state; /* handle for 'state'
+ * sysfs entry */
+};
+
+struct mddev_s
+{
+ void *private;
+ struct mdk_personality *pers;
+ dev_t unit;
+ int md_minor;
+ struct list_head disks;
+ unsigned long flags;
+#define MD_CHANGE_DEVS 0 /* Some device status has changed */
+#define MD_CHANGE_CLEAN 1 /* transition to or from 'clean' */
+#define MD_CHANGE_PENDING 2 /* superblock update in progress */
+
+ int suspended;
+ atomic_t active_io;
+ int ro;
+
+ 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_size;
+ time_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;
+
+ 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, new_chunk;
+
+ struct mdk_thread_s *thread; /* management thread */
+ struct mdk_thread_s *sync_thread; /* doing resync or reconstruct */
+ 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 */
+
+ sector_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;
+ /* recovery/resync flags
+ * NEEDED: we might need to start a resync/recover
+ * RUNNING: a thread is running, or about to be started
+ * SYNC: actually doing a resync, not a recovery
+ * RECOVER: doing recovery, or need to try it.
+ * INTR: resync needs to be aborted for some reason
+ * DONE: thread is done and is waiting to be reaped
+ * REQUEST: user-space has requested a sync (used with SYNC)
+ * CHECK: user-space request for for check-only, no repair
+ * RESHAPE: A reshape is happening
+ *
+ * If neither SYNC or RESHAPE are set, then it is a recovery.
+ */
+#define MD_RECOVERY_RUNNING 0
+#define MD_RECOVERY_SYNC 1
+#define MD_RECOVERY_RECOVER 2
+#define MD_RECOVERY_INTR 3
+#define MD_RECOVERY_DONE 4
+#define MD_RECOVERY_NEEDED 5
+#define MD_RECOVERY_REQUESTED 6
+#define MD_RECOVERY_CHECK 7
+#define MD_RECOVERY_RESHAPE 8
+#define MD_RECOVERY_FROZEN 9
+
+ unsigned long recovery;
+ int recovery_disabled; /* if we detect that recovery
+ * will always fail, set this
+ * so we don't loop trying */
+
+ int in_sync; /* know to not need resync */
+ 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
+ */
+ int barriers_work; /* initialised to true, cleared as soon
+ * as a barrier request to slave
+ * fails. Only supported
+ */
+ struct bio *biolist; /* bios that need to be retried
+ * because BIO_RW_BARRIER is not supported
+ */
+
+ 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 sysfs_dirent *sysfs_state; /* handle for 'array_state'
+ * file in sysfs.
+ */
+ struct sysfs_dirent *sysfs_action; /* handle for 'sync_action' */
+
+ struct work_struct del_work; /* used for delayed sysfs removal */
+
+ spinlock_t write_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;
+ atomic_t writes_pending;
+ struct request_queue *queue; /* for plugging ... */
+
+ atomic_t write_behind; /* outstanding async IO */
+ unsigned int max_write_behind; /* 0 = sync */
+
+ struct bitmap *bitmap; /* the bitmap for the device */
+ struct file *bitmap_file; /* the bitmap file */
+ long bitmap_offset; /* offset from superblock of
+ * start of bitmap. May be
+ * negative, but not '0'
+ */
+ long default_bitmap_offset; /* this is the offset to use when
+ * hot-adding a bitmap. It should
+ * eventually be settable by sysfs.
+ */
+
+ struct list_head all_mddevs;
+};
+
+
+static inline void rdev_dec_pending(mdk_rdev_t *rdev, mddev_t *mddev)
+{
+ int faulty = test_bit(Faulty, &rdev->flags);
+ if (atomic_dec_and_test(&rdev->nr_pending) && faulty)
+ set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
+}
+
+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);
+}
+
+struct mdk_personality
+{
+ char *name;
+ int level;
+ struct list_head list;
+ struct module *owner;
+ int (*make_request)(struct request_queue *q, struct bio *bio);
+ int (*run)(mddev_t *mddev);
+ int (*stop)(mddev_t *mddev);
+ void (*status)(struct seq_file *seq, mddev_t *mddev);
+ /* error_handler must set ->faulty and clear ->in_sync
+ * if appropriate, and should abort recovery if needed
+ */
+ void (*error_handler)(mddev_t *mddev, mdk_rdev_t *rdev);
+ int (*hot_add_disk) (mddev_t *mddev, mdk_rdev_t *rdev);
+ int (*hot_remove_disk) (mddev_t *mddev, int number);
+ int (*spare_active) (mddev_t *mddev);
+ sector_t (*sync_request)(mddev_t *mddev, sector_t sector_nr, int *skipped, int go_faster);
+ int (*resize) (mddev_t *mddev, sector_t sectors);
+ sector_t (*size) (mddev_t *mddev, sector_t sectors, int raid_disks);
+ int (*check_reshape) (mddev_t *mddev);
+ int (*start_reshape) (mddev_t *mddev);
+ void (*finish_reshape) (mddev_t *mddev);
+ int (*reconfig) (mddev_t *mddev, int layout, int chunk_size);
+ /* quiesce moves between quiescence states
+ * 0 - fully active
+ * 1 - no new requests allowed
+ * others - reserved
+ */
+ void (*quiesce) (mddev_t *mddev, int state);
+ /* 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) (mddev_t *mddev);
+};
+
+
+struct md_sysfs_entry {
+ struct attribute attr;
+ ssize_t (*show)(mddev_t *, char *);
+ ssize_t (*store)(mddev_t *, const char *, size_t);
+};
+
+
+static inline char * mdname (mddev_t * mddev)
+{
+ return mddev->gendisk ? mddev->gendisk->disk_name : "mdX";
+}
+
+/*
+ * 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, 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)
+
+typedef struct mdk_thread_s {
+ void (*run) (mddev_t *mddev);
+ mddev_t *mddev;
+ wait_queue_head_t wqueue;
+ unsigned long flags;
+ struct task_struct *tsk;
+ unsigned long timeout;
+} mdk_thread_t;
+
+#define THREAD_WAKEUP 0
+
+#define __wait_event_lock_irq(wq, condition, lock, cmd) \
+do { \
+ wait_queue_t __wait; \
+ init_waitqueue_entry(&__wait, current); \
+ \
+ add_wait_queue(&wq, &__wait); \
+ for (;;) { \
+ set_current_state(TASK_UNINTERRUPTIBLE); \
+ if (condition) \
+ break; \
+ spin_unlock_irq(&lock); \
+ cmd; \
+ schedule(); \
+ spin_lock_irq(&lock); \
+ } \
+ current->state = TASK_RUNNING; \
+ remove_wait_queue(&wq, &__wait); \
+} while (0)
+
+#define wait_event_lock_irq(wq, condition, lock, cmd) \
+do { \
+ if (condition) \
+ break; \
+ __wait_event_lock_irq(wq, condition, lock, cmd); \
+} while (0)
+
+static inline void safe_put_page(struct page *p)
+{
+ if (p) put_page(p);
+}
+
+#endif /* CONFIG_BLOCK */
+#endif
+
+
+extern int register_md_personality(struct mdk_personality *p);
+extern int unregister_md_personality(struct mdk_personality *p);
+extern mdk_thread_t * md_register_thread(void (*run) (mddev_t *mddev),
+ mddev_t *mddev, const char *name);
+extern void md_unregister_thread(mdk_thread_t *thread);
+extern void md_wakeup_thread(mdk_thread_t *thread);
+extern void md_check_recovery(mddev_t *mddev);
+extern void md_write_start(mddev_t *mddev, struct bio *bi);
+extern void md_write_end(mddev_t *mddev);
+extern void md_done_sync(mddev_t *mddev, int blocks, int ok);
+extern void md_error(mddev_t *mddev, mdk_rdev_t *rdev);
+
+extern void md_super_write(mddev_t *mddev, mdk_rdev_t *rdev,
+ sector_t sector, int size, struct page *page);
+extern void md_super_wait(mddev_t *mddev);
+extern int sync_page_io(struct block_device *bdev, sector_t sector, int size,
+ struct page *page, int rw);
+extern void md_do_sync(mddev_t *mddev);
+extern void md_new_event(mddev_t *mddev);
+extern int md_allow_write(mddev_t *mddev);
+extern void md_wait_for_blocked_rdev(mdk_rdev_t *rdev, mddev_t *mddev);
+extern void md_set_array_sectors(mddev_t *mddev, sector_t array_sectors);