/* 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_MD_H #define _MD_MD_H #include #include #include #include #include #include #include #include #define MaxSector (~(sector_t)0) typedef struct mddev_s mddev_t; typedef struct mdk_rdev_s mdk_rdev_t; /* generic plugging support - like that provided with request_queue, * but does not require a request_queue */ struct plug_handle { void (*unplug_fn)(struct plug_handle *); struct timer_list unplug_timer; struct work_struct unplug_work; unsigned long unplug_flag; }; #define PLUGGED_FLAG 1 void plugger_init(struct plug_handle *plug, void (*unplug_fn)(struct plug_handle *)); void plugger_set_plug(struct plug_handle *plug); int plugger_remove_plug(struct plug_handle *plug); static inline void plugger_flush(struct plug_handle *plug) { del_timer_sync(&plug->unplug_timer); cancel_work_sync(&plug->unplug_work); } /* * 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 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 */ 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 */ 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. */ struct timespec 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 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 /* switch from 'clean' to 'active' in progress */ 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; 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; /* 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; 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 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 */ /* '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 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 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 ... */ 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. */ loff_t default_offset; /* this is the offset to use when * hot-adding a bitmap. It should * eventually be settable by sysfs. */ /* When md is serving under dm, it might use a * dirty_log to store the bits. */ struct dm_dirty_log *log; 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; } bitmap_info; atomic_t max_corr_read_errors; /* max read retries */ struct list_head all_mddevs; struct attribute_group *to_remove; struct plug_handle *plug; /* if used by personality */ /* Generic flush handling. * The last to finish preflush schedules a worker to submit * the rest of the request (without the REQ_FLUSH flag). */ struct bio *flush_bio; atomic_t flush_pending; struct work_struct flush_work; struct work_struct event_work; /* used by dm to report failure event */ }; 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)(mddev_t *mddev, 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); /* 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); }; extern struct attribute_group md_bitmap_group; static inline struct sysfs_dirent *sysfs_get_dirent_safe(struct sysfs_dirent *sd, char *name) { if (sd) return sysfs_get_dirent(sd, NULL, name); return sd; } static inline void sysfs_notify_dirent_safe(struct sysfs_dirent *sd) { if (sd) sysfs_notify_dirent(sd); } 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); } 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 int mddev_congested(mddev_t *mddev, int bits); extern void md_flush_request(mddev_t *mddev, struct bio *bio); 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); extern int md_check_no_bitmap(mddev_t *mddev); extern int md_integrity_register(mddev_t *mddev); extern void md_integrity_add_rdev(mdk_rdev_t *rdev, mddev_t *mddev); extern int strict_strtoul_scaled(const char *cp, unsigned long *res, int scale); extern void restore_bitmap_write_access(struct file *file); extern void md_unplug(mddev_t *mddev); extern void mddev_init(mddev_t *mddev); extern int md_run(mddev_t *mddev); extern void md_stop(mddev_t *mddev); extern void md_stop_writes(mddev_t *mddev); extern void md_rdev_init(mdk_rdev_t *rdev); extern void mddev_suspend(mddev_t *mddev); extern void mddev_resume(mddev_t *mddev); #endif /* _MD_MD_H */