2 md_k.h : kernel internal structure of the Linux MD driver
3 Copyright (C) 1996-98 Ingo Molnar, Gadi Oxman
5 This program is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 2, or (at your option)
10 You should have received a copy of the GNU General Public License
11 (for example /usr/src/linux/COPYING); if not, write to the Free
12 Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
18 /* and dm-bio-list.h is not under include/linux because.... ??? */
19 #include "../../../drivers/md/dm-bio-list.h"
23 #define LEVEL_MULTIPATH (-4)
24 #define LEVEL_LINEAR (-1)
25 #define LEVEL_FAULTY (-5)
27 /* we need a value for 'no level specified' and 0
28 * means 'raid0', so we need something else. This is
29 * for internal use only
31 #define LEVEL_NONE (-1000000)
33 #define MaxSector (~(sector_t)0)
35 typedef struct mddev_s mddev_t
;
36 typedef struct mdk_rdev_s mdk_rdev_t
;
39 * options passed in raidrun:
42 /* Currently this must fit in an 'int' */
43 #define MAX_CHUNK_SIZE (1<<30)
46 * MD's 'extended' device
50 struct list_head same_set
; /* RAID devices within the same set */
52 sector_t size
; /* Device size (in blocks) */
53 mddev_t
*mddev
; /* RAID array if running */
54 long last_events
; /* IO event timestamp */
56 struct block_device
*bdev
; /* block device handle */
61 sector_t data_offset
; /* start of data in array */
62 sector_t sb_start
; /* offset of the super block (in 512byte sectors) */
63 int sb_size
; /* bytes in the superblock */
64 int preferred_minor
; /* autorun support */
68 /* A device can be in one of three states based on two flags:
69 * Not working: faulty==1 in_sync==0
70 * Fully working: faulty==0 in_sync==1
73 * faulty==0 in_sync==0
75 * It can never have faulty==1, in_sync==1
76 * This reduces the burden of testing multiple flags in many cases
80 #define Faulty 1 /* device is known to have a fault */
81 #define In_sync 2 /* device is in_sync with rest of array */
82 #define WriteMostly 4 /* Avoid reading if at all possible */
83 #define BarriersNotsupp 5 /* BIO_RW_BARRIER is not supported */
84 #define AllReserved 6 /* If whole device is reserved for
86 #define AutoDetected 7 /* added by auto-detect */
87 #define Blocked 8 /* An error occured on an externally
88 * managed array, don't allow writes
89 * until it is cleared */
90 #define StateChanged 9 /* Faulty or Blocked has changed during
91 * interrupt, so it needs to be
92 * notified by the thread */
93 wait_queue_head_t blocked_wait
;
95 int desc_nr
; /* descriptor index in the superblock */
96 int raid_disk
; /* role of device in array */
97 int saved_raid_disk
; /* role that device used to have in the
98 * array and could again if we did a partial
99 * resync from the bitmap
101 sector_t recovery_offset
;/* If this device has been partially
102 * recovered, this is where we were
106 atomic_t nr_pending
; /* number of pending requests.
107 * only maintained for arrays that
108 * support hot removal
110 atomic_t read_errors
; /* number of consecutive read errors that
111 * we have tried to ignore.
113 atomic_t corrected_errors
; /* number of corrected read errors,
114 * for reporting to userspace and storing
117 struct work_struct del_work
; /* used for delayed sysfs removal */
123 struct mdk_personality
*pers
;
126 struct list_head disks
;
128 #define MD_CHANGE_DEVS 0 /* Some device status has changed */
129 #define MD_CHANGE_CLEAN 1 /* transition to or from 'clean' */
130 #define MD_CHANGE_PENDING 2 /* superblock update in progress */
131 #define MD_NOTIFY_ARRAY_STATE 3 /* atomic context wants to notify userspace */
135 struct gendisk
*gendisk
;
139 /* Superblock information */
144 int external
; /* metadata is
145 * managed externally */
146 char metadata_type
[17]; /* externally set*/
153 sector_t size
; /* used size of component devices */
154 sector_t array_sectors
; /* exported array size */
159 /* If the array is being reshaped, we need to record the
160 * new shape and an indication of where we are up to.
161 * This is written to the superblock.
162 * If reshape_position is MaxSector, then no reshape is happening (yet).
164 sector_t reshape_position
;
165 int delta_disks
, new_level
, new_layout
, new_chunk
;
167 struct mdk_thread_s
*thread
; /* management thread */
168 struct mdk_thread_s
*sync_thread
; /* doing resync or reconstruct */
169 sector_t curr_resync
; /* last block scheduled */
170 unsigned long resync_mark
; /* a recent timestamp */
171 sector_t resync_mark_cnt
;/* blocks written at resync_mark */
172 sector_t curr_mark_cnt
; /* blocks scheduled now */
174 sector_t resync_max_sectors
; /* may be set by personality */
176 sector_t resync_mismatches
; /* count of sectors where
177 * parity/replica mismatch found
180 /* allow user-space to request suspension of IO to regions of the array */
183 /* if zero, use the system-wide default */
187 /* resync even though the same disks are shared among md-devices */
190 int ok_start_degraded
;
191 /* recovery/resync flags
192 * NEEDED: we might need to start a resync/recover
193 * RUNNING: a thread is running, or about to be started
194 * SYNC: actually doing a resync, not a recovery
195 * RECOVER: doing recovery, or need to try it.
196 * INTR: resync needs to be aborted for some reason
197 * DONE: thread is done and is waiting to be reaped
198 * REQUEST: user-space has requested a sync (used with SYNC)
199 * CHECK: user-space request for for check-only, no repair
200 * RESHAPE: A reshape is happening
202 * If neither SYNC or RESHAPE are set, then it is a recovery.
204 #define MD_RECOVERY_RUNNING 0
205 #define MD_RECOVERY_SYNC 1
206 #define MD_RECOVERY_RECOVER 2
207 #define MD_RECOVERY_INTR 3
208 #define MD_RECOVERY_DONE 4
209 #define MD_RECOVERY_NEEDED 5
210 #define MD_RECOVERY_REQUESTED 6
211 #define MD_RECOVERY_CHECK 7
212 #define MD_RECOVERY_RESHAPE 8
213 #define MD_RECOVERY_FROZEN 9
215 unsigned long recovery
;
217 int in_sync
; /* know to not need resync */
218 struct mutex reconfig_mutex
;
219 atomic_t active
; /* general refcount */
220 atomic_t openers
; /* number of active opens */
222 int changed
; /* true if we might need to reread partition info */
223 int degraded
; /* whether md should consider
226 int barriers_work
; /* initialised to true, cleared as soon
227 * as a barrier request to slave
228 * fails. Only supported
230 struct bio
*biolist
; /* bios that need to be retried
231 * because BIO_RW_BARRIER is not supported
234 atomic_t recovery_active
; /* blocks scheduled, but not written */
235 wait_queue_head_t recovery_wait
;
236 sector_t recovery_cp
;
237 sector_t resync_min
; /* user requested sync
239 sector_t resync_max
; /* resync should pause
240 * when it gets here */
242 spinlock_t write_lock
;
243 wait_queue_head_t sb_wait
; /* for waiting on superblock updates */
244 atomic_t pending_writes
; /* number of active superblock writes */
246 unsigned int safemode
; /* if set, update "clean" superblock
247 * when no writes pending.
249 unsigned int safemode_delay
;
250 struct timer_list safemode_timer
;
251 atomic_t writes_pending
;
252 struct request_queue
*queue
; /* for plugging ... */
254 atomic_t write_behind
; /* outstanding async IO */
255 unsigned int max_write_behind
; /* 0 = sync */
257 struct bitmap
*bitmap
; /* the bitmap for the device */
258 struct file
*bitmap_file
; /* the bitmap file */
259 long bitmap_offset
; /* offset from superblock of
260 * start of bitmap. May be
261 * negative, but not '0'
263 long default_bitmap_offset
; /* this is the offset to use when
264 * hot-adding a bitmap. It should
265 * eventually be settable by sysfs.
268 struct list_head all_mddevs
;
272 static inline void rdev_dec_pending(mdk_rdev_t
*rdev
, mddev_t
*mddev
)
274 int faulty
= test_bit(Faulty
, &rdev
->flags
);
275 if (atomic_dec_and_test(&rdev
->nr_pending
) && faulty
)
276 set_bit(MD_RECOVERY_NEEDED
, &mddev
->recovery
);
279 static inline void md_sync_acct(struct block_device
*bdev
, unsigned long nr_sectors
)
281 atomic_add(nr_sectors
, &bdev
->bd_contains
->bd_disk
->sync_io
);
284 struct mdk_personality
288 struct list_head list
;
289 struct module
*owner
;
290 int (*make_request
)(struct request_queue
*q
, struct bio
*bio
);
291 int (*run
)(mddev_t
*mddev
);
292 int (*stop
)(mddev_t
*mddev
);
293 void (*status
)(struct seq_file
*seq
, mddev_t
*mddev
);
294 /* error_handler must set ->faulty and clear ->in_sync
295 * if appropriate, and should abort recovery if needed
297 void (*error_handler
)(mddev_t
*mddev
, mdk_rdev_t
*rdev
);
298 int (*hot_add_disk
) (mddev_t
*mddev
, mdk_rdev_t
*rdev
);
299 int (*hot_remove_disk
) (mddev_t
*mddev
, int number
);
300 int (*spare_active
) (mddev_t
*mddev
);
301 sector_t (*sync_request
)(mddev_t
*mddev
, sector_t sector_nr
, int *skipped
, int go_faster
);
302 int (*resize
) (mddev_t
*mddev
, sector_t sectors
);
303 int (*check_reshape
) (mddev_t
*mddev
);
304 int (*start_reshape
) (mddev_t
*mddev
);
305 int (*reconfig
) (mddev_t
*mddev
, int layout
, int chunk_size
);
306 /* quiesce moves between quiescence states
308 * 1 - no new requests allowed
311 void (*quiesce
) (mddev_t
*mddev
, int state
);
315 struct md_sysfs_entry
{
316 struct attribute attr
;
317 ssize_t (*show
)(mddev_t
*, char *);
318 ssize_t (*store
)(mddev_t
*, const char *, size_t);
322 static inline char * mdname (mddev_t
* mddev
)
324 return mddev
->gendisk
? mddev
->gendisk
->disk_name
: "mdX";
328 * iterates through some rdev ringlist. It's safe to remove the
329 * current 'rdev'. Dont touch 'tmp' though.
331 #define rdev_for_each_list(rdev, tmp, list) \
333 for ((tmp) = (list).next; \
334 (rdev) = (list_entry((tmp), mdk_rdev_t, same_set)), \
335 (tmp) = (tmp)->next, (tmp)->prev != &(list) \
338 * iterates through the 'same array disks' ringlist
340 #define rdev_for_each(rdev, tmp, mddev) \
341 rdev_for_each_list(rdev, tmp, (mddev)->disks)
343 #define rdev_for_each_rcu(rdev, mddev) \
344 list_for_each_entry_rcu(rdev, &((mddev)->disks), same_set)
346 typedef struct mdk_thread_s
{
347 void (*run
) (mddev_t
*mddev
);
349 wait_queue_head_t wqueue
;
351 struct task_struct
*tsk
;
352 unsigned long timeout
;
355 #define THREAD_WAKEUP 0
357 #define __wait_event_lock_irq(wq, condition, lock, cmd) \
359 wait_queue_t __wait; \
360 init_waitqueue_entry(&__wait, current); \
362 add_wait_queue(&wq, &__wait); \
364 set_current_state(TASK_UNINTERRUPTIBLE); \
367 spin_unlock_irq(&lock); \
370 spin_lock_irq(&lock); \
372 current->state = TASK_RUNNING; \
373 remove_wait_queue(&wq, &__wait); \
376 #define wait_event_lock_irq(wq, condition, lock, cmd) \
380 __wait_event_lock_irq(wq, condition, lock, cmd); \
383 static inline void safe_put_page(struct page
*p
)
388 #endif /* CONFIG_BLOCK */