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"
21 #define MD_RESERVED 0UL
26 #define TRANSLUCENT 5UL
32 #define MAX_PERSONALITY 11UL
34 #define LEVEL_MULTIPATH (-4)
35 #define LEVEL_LINEAR (-1)
36 #define LEVEL_FAULTY (-5)
38 #define MaxSector (~(sector_t)0)
39 #define MD_THREAD_NAME_MAX 14
41 static inline int pers_to_level (int pers
)
44 case FAULTY
: return LEVEL_FAULTY
;
45 case MULTIPATH
: return LEVEL_MULTIPATH
;
47 case TRANSLUCENT
: return -2;
48 case LINEAR
: return LEVEL_LINEAR
;
53 case RAID10
: return 10;
59 static inline int level_to_pers (int level
)
62 case LEVEL_FAULTY
: return FAULTY
;
63 case LEVEL_MULTIPATH
: return MULTIPATH
;
65 case -2: return TRANSLUCENT
;
66 case LEVEL_LINEAR
: return LINEAR
;
72 case 10: return RAID10
;
77 typedef struct mddev_s mddev_t
;
78 typedef struct mdk_rdev_s mdk_rdev_t
;
80 #define MAX_MD_DEVS 256 /* Max number of md dev */
83 * options passed in raidrun:
86 #define MAX_CHUNK_SIZE (4096*1024)
89 * MD's 'extended' device
93 struct list_head same_set
; /* RAID devices within the same set */
95 sector_t size
; /* Device size (in blocks) */
96 mddev_t
*mddev
; /* RAID array if running */
97 unsigned long last_events
; /* IO event timestamp */
99 struct block_device
*bdev
; /* block device handle */
101 struct page
*sb_page
;
103 sector_t data_offset
; /* start of data in array */
105 int sb_size
; /* bytes in the superblock */
106 int preferred_minor
; /* autorun support */
110 /* A device can be in one of three states based on two flags:
111 * Not working: faulty==1 in_sync==0
112 * Fully working: faulty==0 in_sync==1
115 * faulty==0 in_sync==0
117 * It can never have faulty==1, in_sync==1
118 * This reduces the burden of testing multiple flags in many cases
120 int faulty
; /* if faulty do not issue IO requests */
121 int in_sync
; /* device is a full member of the array */
123 unsigned long flags
; /* Should include faulty and in_sync here. */
124 #define WriteMostly 4 /* Avoid reading if at all possible */
126 int desc_nr
; /* descriptor index in the superblock */
127 int raid_disk
; /* role of device in array */
128 int saved_raid_disk
; /* role that device used to have in the
129 * array and could again if we did a partial
130 * resync from the bitmap
133 atomic_t nr_pending
; /* number of pending requests.
134 * only maintained for arrays that
135 * support hot removal
139 typedef struct mdk_personality_s mdk_personality_t
;
144 mdk_personality_t
*pers
;
147 struct list_head disks
;
151 struct gendisk
*gendisk
;
155 /* Superblock information */
165 sector_t size
; /* used size of component devices */
166 sector_t array_size
; /* exported array size */
171 struct mdk_thread_s
*thread
; /* management thread */
172 struct mdk_thread_s
*sync_thread
; /* doing resync or reconstruct */
173 sector_t curr_resync
; /* blocks scheduled */
174 unsigned long resync_mark
; /* a recent timestamp */
175 sector_t resync_mark_cnt
;/* blocks written at resync_mark */
177 sector_t resync_max_sectors
; /* may be set by personality */
179 sector_t resync_mismatches
; /* count of sectors where
180 * parity/replica mismatch found
182 /* recovery/resync flags
183 * NEEDED: we might need to start a resync/recover
184 * RUNNING: a thread is running, or about to be started
185 * SYNC: actually doing a resync, not a recovery
186 * ERR: and IO error was detected - abort the resync/recovery
187 * INTR: someone requested a (clean) early abort.
188 * DONE: thread is done and is waiting to be reaped
189 * REQUEST: user-space has requested a sync (used with SYNC)
190 * CHECK: user-space request for for check-only, no repair
192 #define MD_RECOVERY_RUNNING 0
193 #define MD_RECOVERY_SYNC 1
194 #define MD_RECOVERY_ERR 2
195 #define MD_RECOVERY_INTR 3
196 #define MD_RECOVERY_DONE 4
197 #define MD_RECOVERY_NEEDED 5
198 #define MD_RECOVERY_REQUESTED 6
199 #define MD_RECOVERY_CHECK 7
200 unsigned long recovery
;
202 int in_sync
; /* know to not need resync */
203 struct semaphore reconfig_sem
;
206 int changed
; /* true if we might need to reread partition info */
207 int degraded
; /* whether md should consider
211 atomic_t recovery_active
; /* blocks scheduled, but not written */
212 wait_queue_head_t recovery_wait
;
213 sector_t recovery_cp
;
215 spinlock_t write_lock
;
216 wait_queue_head_t sb_wait
; /* for waiting on superblock updates */
217 atomic_t pending_writes
; /* number of active superblock writes */
219 unsigned int safemode
; /* if set, update "clean" superblock
220 * when no writes pending.
222 unsigned int safemode_delay
;
223 struct timer_list safemode_timer
;
224 atomic_t writes_pending
;
225 request_queue_t
*queue
; /* for plugging ... */
227 atomic_t write_behind
; /* outstanding async IO */
228 unsigned int max_write_behind
; /* 0 = sync */
230 struct bitmap
*bitmap
; /* the bitmap for the device */
231 struct file
*bitmap_file
; /* the bitmap file */
232 long bitmap_offset
; /* offset from superblock of
233 * start of bitmap. May be
234 * negative, but not '0'
236 long default_bitmap_offset
; /* this is the offset to use when
237 * hot-adding a bitmap. It should
238 * eventually be settable by sysfs.
241 struct list_head all_mddevs
;
245 static inline void rdev_dec_pending(mdk_rdev_t
*rdev
, mddev_t
*mddev
)
247 int faulty
= rdev
->faulty
;
248 if (atomic_dec_and_test(&rdev
->nr_pending
) && faulty
)
249 set_bit(MD_RECOVERY_NEEDED
, &mddev
->recovery
);
252 static inline void md_sync_acct(struct block_device
*bdev
, unsigned long nr_sectors
)
254 atomic_add(nr_sectors
, &bdev
->bd_contains
->bd_disk
->sync_io
);
257 struct mdk_personality_s
260 struct module
*owner
;
261 int (*make_request
)(request_queue_t
*q
, struct bio
*bio
);
262 int (*run
)(mddev_t
*mddev
);
263 int (*stop
)(mddev_t
*mddev
);
264 void (*status
)(struct seq_file
*seq
, mddev_t
*mddev
);
265 /* error_handler must set ->faulty and clear ->in_sync
266 * if appropriate, and should abort recovery if needed
268 void (*error_handler
)(mddev_t
*mddev
, mdk_rdev_t
*rdev
);
269 int (*hot_add_disk
) (mddev_t
*mddev
, mdk_rdev_t
*rdev
);
270 int (*hot_remove_disk
) (mddev_t
*mddev
, int number
);
271 int (*spare_active
) (mddev_t
*mddev
);
272 sector_t (*sync_request
)(mddev_t
*mddev
, sector_t sector_nr
, int *skipped
, int go_faster
);
273 int (*resize
) (mddev_t
*mddev
, sector_t sectors
);
274 int (*reshape
) (mddev_t
*mddev
, int raid_disks
);
275 int (*reconfig
) (mddev_t
*mddev
, int layout
, int chunk_size
);
276 /* quiesce moves between quiescence states
278 * 1 - no new requests allowed
281 void (*quiesce
) (mddev_t
*mddev
, int state
);
285 static inline char * mdname (mddev_t
* mddev
)
287 return mddev
->gendisk
? mddev
->gendisk
->disk_name
: "mdX";
290 extern mdk_rdev_t
* find_rdev_nr(mddev_t
*mddev
, int nr
);
293 * iterates through some rdev ringlist. It's safe to remove the
294 * current 'rdev'. Dont touch 'tmp' though.
296 #define ITERATE_RDEV_GENERIC(head,rdev,tmp) \
298 for ((tmp) = (head).next; \
299 (rdev) = (list_entry((tmp), mdk_rdev_t, same_set)), \
300 (tmp) = (tmp)->next, (tmp)->prev != &(head) \
303 * iterates through the 'same array disks' ringlist
305 #define ITERATE_RDEV(mddev,rdev,tmp) \
306 ITERATE_RDEV_GENERIC((mddev)->disks,rdev,tmp)
309 * Iterates through 'pending RAID disks'
311 #define ITERATE_RDEV_PENDING(rdev,tmp) \
312 ITERATE_RDEV_GENERIC(pending_raid_disks,rdev,tmp)
314 typedef struct mdk_thread_s
{
315 void (*run
) (mddev_t
*mddev
);
317 wait_queue_head_t wqueue
;
319 struct completion
*event
;
320 struct task_struct
*tsk
;
321 unsigned long timeout
;
325 #define THREAD_WAKEUP 0
327 #define __wait_event_lock_irq(wq, condition, lock, cmd) \
329 wait_queue_t __wait; \
330 init_waitqueue_entry(&__wait, current); \
332 add_wait_queue(&wq, &__wait); \
334 set_current_state(TASK_UNINTERRUPTIBLE); \
337 spin_unlock_irq(&lock); \
340 spin_lock_irq(&lock); \
342 current->state = TASK_RUNNING; \
343 remove_wait_queue(&wq, &__wait); \
346 #define wait_event_lock_irq(wq, condition, lock, cmd) \
350 __wait_event_lock_irq(wq, condition, lock, cmd); \