| /* |
| 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 <linux/blkdev.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> |
| |
| #define MaxSector (~(sector_t)0) |
| |
| typedef struct mddev_s mddev_t; |
| typedef struct mdk_rdev_s mdk_rdev_t; |
| |
| /* |
| * 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 */ |
| 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 /* superblock update 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 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 ... */ |
| |
| 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. |
| */ |
| struct mutex mutex; |
| unsigned long chunksize; |
| unsigned long daemon_sleep; /* how many seconds 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; |
| /* Generic barrier handling. |
| * If there is a pending barrier request, all other |
| * writes are blocked while the devices are flushed. |
| * The last to finish a flush schedules a worker to |
| * submit the barrier request (without the barrier flag), |
| * then submit more flush requests. |
| */ |
| struct bio *barrier; |
| atomic_t flush_pending; |
| struct work_struct barrier_work; |
| }; |
| |
| |
| 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 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_barrier_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); |
| |
| #endif /* _MD_MD_H */ |
