2 * Copyright (C) 2010-2011 Neil Brown
3 * Copyright (C) 2010-2011 Red Hat, Inc. All rights reserved.
5 * This file is released under the GPL.
8 #include <linux/slab.h>
15 #define DM_MSG_PREFIX "raid"
18 * If the MD doesn't support MD_SYNC_STATE_FORCED yet, then
19 * make it so the flag doesn't set anything.
21 #ifndef MD_SYNC_STATE_FORCED
22 #define MD_SYNC_STATE_FORCED 0
27 * Two DM devices, one to hold metadata and one to hold the
28 * actual data/parity. The reason for this is to not confuse
29 * ti->len and give more flexibility in altering size and
32 * While it is possible for this device to be associated
33 * with a different physical device than the data_dev, it
34 * is intended for it to be the same.
35 * |--------- Physical Device ---------|
36 * |- meta_dev -|------ data_dev ------|
38 struct dm_dev
*meta_dev
;
39 struct dm_dev
*data_dev
;
40 struct mdk_rdev_s rdev
;
44 * Flags for rs->print_flags field.
46 #define DMPF_DAEMON_SLEEP 0x1
47 #define DMPF_MAX_WRITE_BEHIND 0x2
49 #define DMPF_NOSYNC 0x8
50 #define DMPF_STRIPE_CACHE 0x10
51 #define DMPF_MIN_RECOVERY_RATE 0x20
52 #define DMPF_MAX_RECOVERY_RATE 0x40
60 struct raid_type
*raid_type
;
61 struct dm_target_callbacks callbacks
;
63 struct raid_dev dev
[0];
66 /* Supported raid types and properties. */
67 static struct raid_type
{
68 const char *name
; /* RAID algorithm. */
69 const char *descr
; /* Descriptor text for logging. */
70 const unsigned parity_devs
; /* # of parity devices. */
71 const unsigned minimal_devs
; /* minimal # of devices in set. */
72 const unsigned level
; /* RAID level. */
73 const unsigned algorithm
; /* RAID algorithm. */
75 {"raid4", "RAID4 (dedicated parity disk)", 1, 2, 5, ALGORITHM_PARITY_0
},
76 {"raid5_la", "RAID5 (left asymmetric)", 1, 2, 5, ALGORITHM_LEFT_ASYMMETRIC
},
77 {"raid5_ra", "RAID5 (right asymmetric)", 1, 2, 5, ALGORITHM_RIGHT_ASYMMETRIC
},
78 {"raid5_ls", "RAID5 (left symmetric)", 1, 2, 5, ALGORITHM_LEFT_SYMMETRIC
},
79 {"raid5_rs", "RAID5 (right symmetric)", 1, 2, 5, ALGORITHM_RIGHT_SYMMETRIC
},
80 {"raid6_zr", "RAID6 (zero restart)", 2, 4, 6, ALGORITHM_ROTATING_ZERO_RESTART
},
81 {"raid6_nr", "RAID6 (N restart)", 2, 4, 6, ALGORITHM_ROTATING_N_RESTART
},
82 {"raid6_nc", "RAID6 (N continue)", 2, 4, 6, ALGORITHM_ROTATING_N_CONTINUE
}
85 static struct raid_type
*get_raid_type(char *name
)
89 for (i
= 0; i
< ARRAY_SIZE(raid_types
); i
++)
90 if (!strcmp(raid_types
[i
].name
, name
))
91 return &raid_types
[i
];
96 static struct raid_set
*context_alloc(struct dm_target
*ti
, struct raid_type
*raid_type
, unsigned raid_devs
)
100 sector_t sectors_per_dev
;
102 if (raid_devs
<= raid_type
->parity_devs
) {
103 ti
->error
= "Insufficient number of devices";
104 return ERR_PTR(-EINVAL
);
107 sectors_per_dev
= ti
->len
;
108 if (sector_div(sectors_per_dev
, (raid_devs
- raid_type
->parity_devs
))) {
109 ti
->error
= "Target length not divisible by number of data devices";
110 return ERR_PTR(-EINVAL
);
113 rs
= kzalloc(sizeof(*rs
) + raid_devs
* sizeof(rs
->dev
[0]), GFP_KERNEL
);
115 ti
->error
= "Cannot allocate raid context";
116 return ERR_PTR(-ENOMEM
);
122 rs
->raid_type
= raid_type
;
123 rs
->md
.raid_disks
= raid_devs
;
124 rs
->md
.level
= raid_type
->level
;
125 rs
->md
.new_level
= rs
->md
.level
;
126 rs
->md
.dev_sectors
= sectors_per_dev
;
127 rs
->md
.layout
= raid_type
->algorithm
;
128 rs
->md
.new_layout
= rs
->md
.layout
;
129 rs
->md
.delta_disks
= 0;
130 rs
->md
.recovery_cp
= 0;
132 for (i
= 0; i
< raid_devs
; i
++)
133 md_rdev_init(&rs
->dev
[i
].rdev
);
136 * Remaining items to be initialized by further RAID params:
139 * rs->md.chunk_sectors
140 * rs->md.new_chunk_sectors
146 static void context_free(struct raid_set
*rs
)
150 for (i
= 0; i
< rs
->md
.raid_disks
; i
++)
151 if (rs
->dev
[i
].data_dev
)
152 dm_put_device(rs
->ti
, rs
->dev
[i
].data_dev
);
158 * For every device we have two words
159 * <meta_dev>: meta device name or '-' if missing
160 * <data_dev>: data device name or '-' if missing
162 * This code parses those words.
164 static int dev_parms(struct raid_set
*rs
, char **argv
)
168 int metadata_available
= 0;
171 for (i
= 0; i
< rs
->md
.raid_disks
; i
++, argv
+= 2) {
172 rs
->dev
[i
].rdev
.raid_disk
= i
;
174 rs
->dev
[i
].meta_dev
= NULL
;
175 rs
->dev
[i
].data_dev
= NULL
;
178 * There are no offsets, since there is a separate device
179 * for data and metadata.
181 rs
->dev
[i
].rdev
.data_offset
= 0;
182 rs
->dev
[i
].rdev
.mddev
= &rs
->md
;
184 if (strcmp(argv
[0], "-")) {
185 rs
->ti
->error
= "Metadata devices not supported";
189 if (!strcmp(argv
[1], "-")) {
190 if (!test_bit(In_sync
, &rs
->dev
[i
].rdev
.flags
) &&
191 (!rs
->dev
[i
].rdev
.recovery_offset
)) {
192 rs
->ti
->error
= "Drive designated for rebuild not specified";
199 ret
= dm_get_device(rs
->ti
, argv
[1],
200 dm_table_get_mode(rs
->ti
->table
),
201 &rs
->dev
[i
].data_dev
);
203 rs
->ti
->error
= "RAID device lookup failure";
207 rs
->dev
[i
].rdev
.bdev
= rs
->dev
[i
].data_dev
->bdev
;
208 list_add(&rs
->dev
[i
].rdev
.same_set
, &rs
->md
.disks
);
209 if (!test_bit(In_sync
, &rs
->dev
[i
].rdev
.flags
))
213 if (metadata_available
) {
215 rs
->md
.persistent
= 1;
216 rs
->md
.major_version
= 2;
217 } else if (rebuild
&& !rs
->md
.recovery_cp
) {
219 * Without metadata, we will not be able to tell if the array
220 * is in-sync or not - we must assume it is not. Therefore,
221 * it is impossible to rebuild a drive.
223 * Even if there is metadata, the on-disk information may
224 * indicate that the array is not in-sync and it will then
227 * User could specify 'nosync' option if desperate.
229 DMERR("Unable to rebuild drive while array is not in-sync");
230 rs
->ti
->error
= "RAID device lookup failure";
238 * Possible arguments are...
240 * <chunk_size> [optional_args]
243 * [[no]sync] Force or prevent recovery of the entire array
244 * [rebuild <idx>] Rebuild the drive indicated by the index
245 * [daemon_sleep <ms>] Time between bitmap daemon work to clear bits
246 * [min_recovery_rate <kB/sec/disk>] Throttle RAID initialization
247 * [max_recovery_rate <kB/sec/disk>] Throttle RAID initialization
248 * [max_write_behind <sectors>] See '-write-behind=' (man mdadm)
249 * [stripe_cache <sectors>] Stripe cache size for higher RAIDs
251 static int parse_raid_params(struct raid_set
*rs
, char **argv
,
252 unsigned num_raid_params
)
254 unsigned i
, rebuild_cnt
= 0;
259 * First, parse the in-order required arguments
261 if ((strict_strtoul(argv
[0], 10, &value
) < 0) ||
262 !is_power_of_2(value
) || (value
< 8)) {
263 rs
->ti
->error
= "Bad chunk size";
267 rs
->md
.new_chunk_sectors
= rs
->md
.chunk_sectors
= value
;
272 * Second, parse the unordered optional arguments
274 for (i
= 0; i
< rs
->md
.raid_disks
; i
++)
275 set_bit(In_sync
, &rs
->dev
[i
].rdev
.flags
);
277 for (i
= 0; i
< num_raid_params
; i
++) {
278 if (!strcmp(argv
[i
], "nosync")) {
279 rs
->md
.recovery_cp
= MaxSector
;
280 rs
->print_flags
|= DMPF_NOSYNC
;
281 rs
->md
.flags
|= MD_SYNC_STATE_FORCED
;
284 if (!strcmp(argv
[i
], "sync")) {
285 rs
->md
.recovery_cp
= 0;
286 rs
->print_flags
|= DMPF_SYNC
;
287 rs
->md
.flags
|= MD_SYNC_STATE_FORCED
;
291 /* The rest of the optional arguments come in key/value pairs */
292 if ((i
+ 1) >= num_raid_params
) {
293 rs
->ti
->error
= "Wrong number of raid parameters given";
298 if (strict_strtoul(argv
[i
], 10, &value
) < 0) {
299 rs
->ti
->error
= "Bad numerical argument given in raid params";
303 if (!strcmp(key
, "rebuild")) {
304 if (++rebuild_cnt
> rs
->raid_type
->parity_devs
) {
305 rs
->ti
->error
= "Too many rebuild drives given";
308 if (value
> rs
->md
.raid_disks
) {
309 rs
->ti
->error
= "Invalid rebuild index given";
312 clear_bit(In_sync
, &rs
->dev
[value
].rdev
.flags
);
313 rs
->dev
[value
].rdev
.recovery_offset
= 0;
314 } else if (!strcmp(key
, "max_write_behind")) {
315 rs
->print_flags
|= DMPF_MAX_WRITE_BEHIND
;
318 * In device-mapper, we specify things in sectors, but
319 * MD records this value in kB
322 if (value
> COUNTER_MAX
) {
323 rs
->ti
->error
= "Max write-behind limit out of range";
326 rs
->md
.bitmap_info
.max_write_behind
= value
;
327 } else if (!strcmp(key
, "daemon_sleep")) {
328 rs
->print_flags
|= DMPF_DAEMON_SLEEP
;
329 if (!value
|| (value
> MAX_SCHEDULE_TIMEOUT
)) {
330 rs
->ti
->error
= "daemon sleep period out of range";
333 rs
->md
.bitmap_info
.daemon_sleep
= value
;
334 } else if (!strcmp(key
, "stripe_cache")) {
335 rs
->print_flags
|= DMPF_STRIPE_CACHE
;
338 * In device-mapper, we specify things in sectors, but
339 * MD records this value in kB
343 if (rs
->raid_type
->level
< 5) {
344 rs
->ti
->error
= "Inappropriate argument: stripe_cache";
347 if (raid5_set_cache_size(&rs
->md
, (int)value
)) {
348 rs
->ti
->error
= "Bad stripe_cache size";
351 } else if (!strcmp(key
, "min_recovery_rate")) {
352 rs
->print_flags
|= DMPF_MIN_RECOVERY_RATE
;
353 if (value
> INT_MAX
) {
354 rs
->ti
->error
= "min_recovery_rate out of range";
357 rs
->md
.sync_speed_min
= (int)value
;
358 } else if (!strcmp(key
, "max_recovery_rate")) {
359 rs
->print_flags
|= DMPF_MAX_RECOVERY_RATE
;
360 if (value
> INT_MAX
) {
361 rs
->ti
->error
= "max_recovery_rate out of range";
364 rs
->md
.sync_speed_max
= (int)value
;
366 DMERR("Unable to parse RAID parameter: %s", key
);
367 rs
->ti
->error
= "Unable to parse RAID parameters";
372 /* Assume there are no metadata devices until the drives are parsed */
373 rs
->md
.persistent
= 0;
379 static void do_table_event(struct work_struct
*ws
)
381 struct raid_set
*rs
= container_of(ws
, struct raid_set
, md
.event_work
);
383 dm_table_event(rs
->ti
->table
);
386 static int raid_is_congested(struct dm_target_callbacks
*cb
, int bits
)
388 struct raid_set
*rs
= container_of(cb
, struct raid_set
, callbacks
);
390 return md_raid5_congested(&rs
->md
, bits
);
393 static void raid_unplug(struct dm_target_callbacks
*cb
)
395 struct raid_set
*rs
= container_of(cb
, struct raid_set
, callbacks
);
397 md_raid5_kick_device(rs
->md
.private);
401 * Construct a RAID4/5/6 mapping:
403 * <raid_type> <#raid_params> <raid_params> \
404 * <#raid_devs> { <meta_dev1> <dev1> .. <meta_devN> <devN> }
406 * ** metadata devices are not supported yet, use '-' instead **
408 * <raid_params> varies by <raid_type>. See 'parse_raid_params' for
409 * details on possible <raid_params>.
411 static int raid_ctr(struct dm_target
*ti
, unsigned argc
, char **argv
)
414 struct raid_type
*rt
;
415 unsigned long num_raid_params
, num_raid_devs
;
416 struct raid_set
*rs
= NULL
;
418 /* Must have at least <raid_type> <#raid_params> */
420 ti
->error
= "Too few arguments";
425 rt
= get_raid_type(argv
[0]);
427 ti
->error
= "Unrecognised raid_type";
433 /* number of RAID parameters */
434 if (strict_strtoul(argv
[0], 10, &num_raid_params
) < 0) {
435 ti
->error
= "Cannot understand number of RAID parameters";
441 /* Skip over RAID params for now and find out # of devices */
442 if (num_raid_params
+ 1 > argc
) {
443 ti
->error
= "Arguments do not agree with counts given";
447 if ((strict_strtoul(argv
[num_raid_params
], 10, &num_raid_devs
) < 0) ||
448 (num_raid_devs
>= INT_MAX
)) {
449 ti
->error
= "Cannot understand number of raid devices";
453 rs
= context_alloc(ti
, rt
, (unsigned)num_raid_devs
);
457 ret
= parse_raid_params(rs
, argv
, (unsigned)num_raid_params
);
463 argc
-= num_raid_params
+ 1; /* +1: we already have num_raid_devs */
464 argv
+= num_raid_params
+ 1;
466 if (argc
!= (num_raid_devs
* 2)) {
467 ti
->error
= "Supplied RAID devices does not match the count given";
471 ret
= dev_parms(rs
, argv
);
475 INIT_WORK(&rs
->md
.event_work
, do_table_event
);
476 ti
->split_io
= rs
->md
.chunk_sectors
;
479 mutex_lock(&rs
->md
.reconfig_mutex
);
480 ret
= md_run(&rs
->md
);
481 rs
->md
.in_sync
= 0; /* Assume already marked dirty */
482 mutex_unlock(&rs
->md
.reconfig_mutex
);
485 ti
->error
= "Fail to run raid array";
489 rs
->callbacks
.congested_fn
= raid_is_congested
;
490 rs
->callbacks
.unplug_fn
= raid_unplug
;
491 dm_table_add_target_callbacks(ti
->table
, &rs
->callbacks
);
501 static void raid_dtr(struct dm_target
*ti
)
503 struct raid_set
*rs
= ti
->private;
505 list_del_init(&rs
->callbacks
.list
);
510 static int raid_map(struct dm_target
*ti
, struct bio
*bio
, union map_info
*map_context
)
512 struct raid_set
*rs
= ti
->private;
513 mddev_t
*mddev
= &rs
->md
;
515 mddev
->pers
->make_request(mddev
, bio
);
517 return DM_MAPIO_SUBMITTED
;
520 static int raid_status(struct dm_target
*ti
, status_type_t type
,
521 char *result
, unsigned maxlen
)
523 struct raid_set
*rs
= ti
->private;
524 unsigned raid_param_cnt
= 1; /* at least 1 for chunksize */
530 case STATUSTYPE_INFO
:
531 DMEMIT("%s %d ", rs
->raid_type
->name
, rs
->md
.raid_disks
);
533 for (i
= 0; i
< rs
->md
.raid_disks
; i
++) {
534 if (test_bit(Faulty
, &rs
->dev
[i
].rdev
.flags
))
536 else if (test_bit(In_sync
, &rs
->dev
[i
].rdev
.flags
))
542 if (test_bit(MD_RECOVERY_RUNNING
, &rs
->md
.recovery
))
543 sync
= rs
->md
.curr_resync_completed
;
545 sync
= rs
->md
.recovery_cp
;
547 if (sync
> rs
->md
.resync_max_sectors
)
548 sync
= rs
->md
.resync_max_sectors
;
551 (unsigned long long) sync
,
552 (unsigned long long) rs
->md
.resync_max_sectors
);
555 case STATUSTYPE_TABLE
:
556 /* The string you would use to construct this array */
557 for (i
= 0; i
< rs
->md
.raid_disks
; i
++)
558 if (rs
->dev
[i
].data_dev
&&
559 !test_bit(In_sync
, &rs
->dev
[i
].rdev
.flags
))
560 raid_param_cnt
++; /* for rebuilds */
562 raid_param_cnt
+= (hweight64(rs
->print_flags
) * 2);
563 if (rs
->print_flags
& (DMPF_SYNC
| DMPF_NOSYNC
))
566 DMEMIT("%s %u %u", rs
->raid_type
->name
,
567 raid_param_cnt
, rs
->md
.chunk_sectors
);
569 if ((rs
->print_flags
& DMPF_SYNC
) &&
570 (rs
->md
.recovery_cp
== MaxSector
))
572 if (rs
->print_flags
& DMPF_NOSYNC
)
575 for (i
= 0; i
< rs
->md
.raid_disks
; i
++)
576 if (rs
->dev
[i
].data_dev
&&
577 !test_bit(In_sync
, &rs
->dev
[i
].rdev
.flags
))
578 DMEMIT(" rebuild %u", i
);
580 if (rs
->print_flags
& DMPF_DAEMON_SLEEP
)
581 DMEMIT(" daemon_sleep %lu",
582 rs
->md
.bitmap_info
.daemon_sleep
);
584 if (rs
->print_flags
& DMPF_MIN_RECOVERY_RATE
)
585 DMEMIT(" min_recovery_rate %d", rs
->md
.sync_speed_min
);
587 if (rs
->print_flags
& DMPF_MAX_RECOVERY_RATE
)
588 DMEMIT(" max_recovery_rate %d", rs
->md
.sync_speed_max
);
590 if (rs
->print_flags
& DMPF_MAX_WRITE_BEHIND
)
591 DMEMIT(" max_write_behind %lu",
592 rs
->md
.bitmap_info
.max_write_behind
);
594 if (rs
->print_flags
& DMPF_STRIPE_CACHE
) {
595 raid5_conf_t
*conf
= rs
->md
.private;
597 /* convert from kiB to sectors */
598 DMEMIT(" stripe_cache %d",
599 conf
? conf
->max_nr_stripes
* 2 : 0);
602 DMEMIT(" %d", rs
->md
.raid_disks
);
603 for (i
= 0; i
< rs
->md
.raid_disks
; i
++) {
604 DMEMIT(" -"); /* metadata device */
606 if (rs
->dev
[i
].data_dev
)
607 DMEMIT(" %s", rs
->dev
[i
].data_dev
->name
);
616 static int raid_iterate_devices(struct dm_target
*ti
, iterate_devices_callout_fn fn
, void *data
)
618 struct raid_set
*rs
= ti
->private;
622 for (i
= 0; !ret
&& i
< rs
->md
.raid_disks
; i
++)
623 if (rs
->dev
[i
].data_dev
)
626 0, /* No offset on data devs */
633 static void raid_io_hints(struct dm_target
*ti
, struct queue_limits
*limits
)
635 struct raid_set
*rs
= ti
->private;
636 unsigned chunk_size
= rs
->md
.chunk_sectors
<< 9;
637 raid5_conf_t
*conf
= rs
->md
.private;
639 blk_limits_io_min(limits
, chunk_size
);
640 blk_limits_io_opt(limits
, chunk_size
* (conf
->raid_disks
- conf
->max_degraded
));
643 static void raid_presuspend(struct dm_target
*ti
)
645 struct raid_set
*rs
= ti
->private;
647 md_stop_writes(&rs
->md
);
650 static void raid_postsuspend(struct dm_target
*ti
)
652 struct raid_set
*rs
= ti
->private;
654 mddev_suspend(&rs
->md
);
657 static void raid_resume(struct dm_target
*ti
)
659 struct raid_set
*rs
= ti
->private;
661 mddev_resume(&rs
->md
);
664 static struct target_type raid_target
= {
666 .version
= {1, 0, 0},
667 .module
= THIS_MODULE
,
671 .status
= raid_status
,
672 .iterate_devices
= raid_iterate_devices
,
673 .io_hints
= raid_io_hints
,
674 .presuspend
= raid_presuspend
,
675 .postsuspend
= raid_postsuspend
,
676 .resume
= raid_resume
,
679 static int __init
dm_raid_init(void)
681 return dm_register_target(&raid_target
);
684 static void __exit
dm_raid_exit(void)
686 dm_unregister_target(&raid_target
);
689 module_init(dm_raid_init
);
690 module_exit(dm_raid_exit
);
692 MODULE_DESCRIPTION(DM_NAME
" raid4/5/6 target");
693 MODULE_ALIAS("dm-raid4");
694 MODULE_ALIAS("dm-raid5");
695 MODULE_ALIAS("dm-raid6");
696 MODULE_AUTHOR("Neil Brown <dm-devel@redhat.com>");
697 MODULE_LICENSE("GPL");