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>
9 #include <linux/module.h>
17 #include <linux/device-mapper.h>
19 #define DM_MSG_PREFIX "raid"
22 * The following flags are used by dm-raid.c to set up the array state.
23 * They must be cleared before md_run is called.
25 #define FirstUse 10 /* rdev flag */
29 * Two DM devices, one to hold metadata and one to hold the
30 * actual data/parity. The reason for this is to not confuse
31 * ti->len and give more flexibility in altering size and
34 * While it is possible for this device to be associated
35 * with a different physical device than the data_dev, it
36 * is intended for it to be the same.
37 * |--------- Physical Device ---------|
38 * |- meta_dev -|------ data_dev ------|
40 struct dm_dev
*meta_dev
;
41 struct dm_dev
*data_dev
;
46 * Flags for rs->print_flags field.
49 #define DMPF_NOSYNC 0x2
50 #define DMPF_REBUILD 0x4
51 #define DMPF_DAEMON_SLEEP 0x8
52 #define DMPF_MIN_RECOVERY_RATE 0x10
53 #define DMPF_MAX_RECOVERY_RATE 0x20
54 #define DMPF_MAX_WRITE_BEHIND 0x40
55 #define DMPF_STRIPE_CACHE 0x80
56 #define DMPF_REGION_SIZE 0x100
57 #define DMPF_RAID10_COPIES 0x200
58 #define DMPF_RAID10_FORMAT 0x400
63 uint32_t bitmap_loaded
;
67 struct raid_type
*raid_type
;
68 struct dm_target_callbacks callbacks
;
70 struct raid_dev dev
[0];
73 /* Supported raid types and properties. */
74 static struct raid_type
{
75 const char *name
; /* RAID algorithm. */
76 const char *descr
; /* Descriptor text for logging. */
77 const unsigned parity_devs
; /* # of parity devices. */
78 const unsigned minimal_devs
; /* minimal # of devices in set. */
79 const unsigned level
; /* RAID level. */
80 const unsigned algorithm
; /* RAID algorithm. */
82 {"raid1", "RAID1 (mirroring)", 0, 2, 1, 0 /* NONE */},
83 {"raid10", "RAID10 (striped mirrors)", 0, 2, 10, UINT_MAX
/* Varies */},
84 {"raid4", "RAID4 (dedicated parity disk)", 1, 2, 5, ALGORITHM_PARITY_0
},
85 {"raid5_la", "RAID5 (left asymmetric)", 1, 2, 5, ALGORITHM_LEFT_ASYMMETRIC
},
86 {"raid5_ra", "RAID5 (right asymmetric)", 1, 2, 5, ALGORITHM_RIGHT_ASYMMETRIC
},
87 {"raid5_ls", "RAID5 (left symmetric)", 1, 2, 5, ALGORITHM_LEFT_SYMMETRIC
},
88 {"raid5_rs", "RAID5 (right symmetric)", 1, 2, 5, ALGORITHM_RIGHT_SYMMETRIC
},
89 {"raid6_zr", "RAID6 (zero restart)", 2, 4, 6, ALGORITHM_ROTATING_ZERO_RESTART
},
90 {"raid6_nr", "RAID6 (N restart)", 2, 4, 6, ALGORITHM_ROTATING_N_RESTART
},
91 {"raid6_nc", "RAID6 (N continue)", 2, 4, 6, ALGORITHM_ROTATING_N_CONTINUE
}
94 static unsigned raid10_md_layout_to_copies(int layout
)
99 static int raid10_format_to_md_layout(char *format
, unsigned copies
)
101 /* 1 "far" copy, and 'copies' "near" copies */
102 return (1 << 8) | (copies
& 0xFF);
105 static struct raid_type
*get_raid_type(char *name
)
109 for (i
= 0; i
< ARRAY_SIZE(raid_types
); i
++)
110 if (!strcmp(raid_types
[i
].name
, name
))
111 return &raid_types
[i
];
116 static struct raid_set
*context_alloc(struct dm_target
*ti
, struct raid_type
*raid_type
, unsigned raid_devs
)
121 if (raid_devs
<= raid_type
->parity_devs
) {
122 ti
->error
= "Insufficient number of devices";
123 return ERR_PTR(-EINVAL
);
126 rs
= kzalloc(sizeof(*rs
) + raid_devs
* sizeof(rs
->dev
[0]), GFP_KERNEL
);
128 ti
->error
= "Cannot allocate raid context";
129 return ERR_PTR(-ENOMEM
);
135 rs
->raid_type
= raid_type
;
136 rs
->md
.raid_disks
= raid_devs
;
137 rs
->md
.level
= raid_type
->level
;
138 rs
->md
.new_level
= rs
->md
.level
;
139 rs
->md
.layout
= raid_type
->algorithm
;
140 rs
->md
.new_layout
= rs
->md
.layout
;
141 rs
->md
.delta_disks
= 0;
142 rs
->md
.recovery_cp
= 0;
144 for (i
= 0; i
< raid_devs
; i
++)
145 md_rdev_init(&rs
->dev
[i
].rdev
);
148 * Remaining items to be initialized by further RAID params:
151 * rs->md.chunk_sectors
152 * rs->md.new_chunk_sectors
159 static void context_free(struct raid_set
*rs
)
163 for (i
= 0; i
< rs
->md
.raid_disks
; i
++) {
164 if (rs
->dev
[i
].meta_dev
)
165 dm_put_device(rs
->ti
, rs
->dev
[i
].meta_dev
);
166 md_rdev_clear(&rs
->dev
[i
].rdev
);
167 if (rs
->dev
[i
].data_dev
)
168 dm_put_device(rs
->ti
, rs
->dev
[i
].data_dev
);
175 * For every device we have two words
176 * <meta_dev>: meta device name or '-' if missing
177 * <data_dev>: data device name or '-' if missing
179 * The following are permitted:
182 * <meta_dev> <data_dev>
184 * The following is not allowed:
187 * This code parses those words. If there is a failure,
188 * the caller must use context_free to unwind the operations.
190 static int dev_parms(struct raid_set
*rs
, char **argv
)
194 int metadata_available
= 0;
197 for (i
= 0; i
< rs
->md
.raid_disks
; i
++, argv
+= 2) {
198 rs
->dev
[i
].rdev
.raid_disk
= i
;
200 rs
->dev
[i
].meta_dev
= NULL
;
201 rs
->dev
[i
].data_dev
= NULL
;
204 * There are no offsets, since there is a separate device
205 * for data and metadata.
207 rs
->dev
[i
].rdev
.data_offset
= 0;
208 rs
->dev
[i
].rdev
.mddev
= &rs
->md
;
210 if (strcmp(argv
[0], "-")) {
211 ret
= dm_get_device(rs
->ti
, argv
[0],
212 dm_table_get_mode(rs
->ti
->table
),
213 &rs
->dev
[i
].meta_dev
);
214 rs
->ti
->error
= "RAID metadata device lookup failure";
218 rs
->dev
[i
].rdev
.sb_page
= alloc_page(GFP_KERNEL
);
219 if (!rs
->dev
[i
].rdev
.sb_page
)
223 if (!strcmp(argv
[1], "-")) {
224 if (!test_bit(In_sync
, &rs
->dev
[i
].rdev
.flags
) &&
225 (!rs
->dev
[i
].rdev
.recovery_offset
)) {
226 rs
->ti
->error
= "Drive designated for rebuild not specified";
230 rs
->ti
->error
= "No data device supplied with metadata device";
231 if (rs
->dev
[i
].meta_dev
)
237 ret
= dm_get_device(rs
->ti
, argv
[1],
238 dm_table_get_mode(rs
->ti
->table
),
239 &rs
->dev
[i
].data_dev
);
241 rs
->ti
->error
= "RAID device lookup failure";
245 if (rs
->dev
[i
].meta_dev
) {
246 metadata_available
= 1;
247 rs
->dev
[i
].rdev
.meta_bdev
= rs
->dev
[i
].meta_dev
->bdev
;
249 rs
->dev
[i
].rdev
.bdev
= rs
->dev
[i
].data_dev
->bdev
;
250 list_add(&rs
->dev
[i
].rdev
.same_set
, &rs
->md
.disks
);
251 if (!test_bit(In_sync
, &rs
->dev
[i
].rdev
.flags
))
255 if (metadata_available
) {
257 rs
->md
.persistent
= 1;
258 rs
->md
.major_version
= 2;
259 } else if (rebuild
&& !rs
->md
.recovery_cp
) {
261 * Without metadata, we will not be able to tell if the array
262 * is in-sync or not - we must assume it is not. Therefore,
263 * it is impossible to rebuild a drive.
265 * Even if there is metadata, the on-disk information may
266 * indicate that the array is not in-sync and it will then
269 * User could specify 'nosync' option if desperate.
271 DMERR("Unable to rebuild drive while array is not in-sync");
272 rs
->ti
->error
= "RAID device lookup failure";
280 * validate_region_size
282 * @region_size: region size in sectors. If 0, pick a size (4MiB default).
284 * Set rs->md.bitmap_info.chunksize (which really refers to 'region size').
285 * Ensure that (ti->len/region_size < 2^21) - required by MD bitmap.
287 * Returns: 0 on success, -EINVAL on failure.
289 static int validate_region_size(struct raid_set
*rs
, unsigned long region_size
)
291 unsigned long min_region_size
= rs
->ti
->len
/ (1 << 21);
295 * Choose a reasonable default. All figures in sectors.
297 if (min_region_size
> (1 << 13)) {
298 /* If not a power of 2, make it the next power of 2 */
299 if (min_region_size
& (min_region_size
- 1))
300 region_size
= 1 << fls(region_size
);
301 DMINFO("Choosing default region size of %lu sectors",
304 DMINFO("Choosing default region size of 4MiB");
305 region_size
= 1 << 13; /* sectors */
309 * Validate user-supplied value.
311 if (region_size
> rs
->ti
->len
) {
312 rs
->ti
->error
= "Supplied region size is too large";
316 if (region_size
< min_region_size
) {
317 DMERR("Supplied region_size (%lu sectors) below minimum (%lu)",
318 region_size
, min_region_size
);
319 rs
->ti
->error
= "Supplied region size is too small";
323 if (!is_power_of_2(region_size
)) {
324 rs
->ti
->error
= "Region size is not a power of 2";
328 if (region_size
< rs
->md
.chunk_sectors
) {
329 rs
->ti
->error
= "Region size is smaller than the chunk size";
335 * Convert sectors to bytes.
337 rs
->md
.bitmap_info
.chunksize
= (region_size
<< 9);
343 * validate_raid_redundancy
346 * Determine if there are enough devices in the array that haven't
347 * failed (or are being rebuilt) to form a usable array.
349 * Returns: 0 on success, -EINVAL on failure.
351 static int validate_raid_redundancy(struct raid_set
*rs
)
353 unsigned i
, rebuild_cnt
= 0;
354 unsigned rebuilds_per_group
, copies
, d
;
356 for (i
= 0; i
< rs
->md
.raid_disks
; i
++)
357 if (!test_bit(In_sync
, &rs
->dev
[i
].rdev
.flags
) ||
358 !rs
->dev
[i
].rdev
.sb_page
)
361 switch (rs
->raid_type
->level
) {
363 if (rebuild_cnt
>= rs
->md
.raid_disks
)
369 if (rebuild_cnt
> rs
->raid_type
->parity_devs
)
373 copies
= raid10_md_layout_to_copies(rs
->md
.layout
);
374 if (rebuild_cnt
< copies
)
378 * It is possible to have a higher rebuild count for RAID10,
379 * as long as the failed devices occur in different mirror
380 * groups (i.e. different stripes).
382 * Right now, we only allow for "near" copies. When other
383 * formats are added, we will have to check those too.
385 * When checking "near" format, make sure no adjacent devices
386 * have failed beyond what can be handled. In addition to the
387 * simple case where the number of devices is a multiple of the
388 * number of copies, we must also handle cases where the number
389 * of devices is not a multiple of the number of copies.
390 * E.g. dev1 dev2 dev3 dev4 dev5
394 for (i
= 0; i
< rs
->md
.raid_disks
* copies
; i
++) {
396 rebuilds_per_group
= 0;
397 d
= i
% rs
->md
.raid_disks
;
398 if ((!rs
->dev
[d
].rdev
.sb_page
||
399 !test_bit(In_sync
, &rs
->dev
[d
].rdev
.flags
)) &&
400 (++rebuilds_per_group
>= copies
))
416 * Possible arguments are...
417 * <chunk_size> [optional_args]
419 * Argument definitions
420 * <chunk_size> The number of sectors per disk that
421 * will form the "stripe"
422 * [[no]sync] Force or prevent recovery of the
424 * [rebuild <idx>] Rebuild the drive indicated by the index
425 * [daemon_sleep <ms>] Time between bitmap daemon work to
427 * [min_recovery_rate <kB/sec/disk>] Throttle RAID initialization
428 * [max_recovery_rate <kB/sec/disk>] Throttle RAID initialization
429 * [write_mostly <idx>] Indicate a write mostly drive via index
430 * [max_write_behind <sectors>] See '-write-behind=' (man mdadm)
431 * [stripe_cache <sectors>] Stripe cache size for higher RAIDs
432 * [region_size <sectors>] Defines granularity of bitmap
434 * RAID10-only options:
435 * [raid10_copies <# copies>] Number of copies. (Default: 2)
436 * [raid10_format <near>] Layout algorithm. (Default: near)
438 static int parse_raid_params(struct raid_set
*rs
, char **argv
,
439 unsigned num_raid_params
)
441 char *raid10_format
= "near";
442 unsigned raid10_copies
= 2;
444 unsigned long value
, region_size
= 0;
445 sector_t sectors_per_dev
= rs
->ti
->len
;
450 * First, parse the in-order required arguments
451 * "chunk_size" is the only argument of this type.
453 if ((strict_strtoul(argv
[0], 10, &value
) < 0)) {
454 rs
->ti
->error
= "Bad chunk size";
456 } else if (rs
->raid_type
->level
== 1) {
458 DMERR("Ignoring chunk size parameter for RAID 1");
460 } else if (!is_power_of_2(value
)) {
461 rs
->ti
->error
= "Chunk size must be a power of 2";
463 } else if (value
< 8) {
464 rs
->ti
->error
= "Chunk size value is too small";
468 rs
->md
.new_chunk_sectors
= rs
->md
.chunk_sectors
= value
;
473 * We set each individual device as In_sync with a completed
474 * 'recovery_offset'. If there has been a device failure or
475 * replacement then one of the following cases applies:
477 * 1) User specifies 'rebuild'.
478 * - Device is reset when param is read.
479 * 2) A new device is supplied.
480 * - No matching superblock found, resets device.
481 * 3) Device failure was transient and returns on reload.
482 * - Failure noticed, resets device for bitmap replay.
483 * 4) Device hadn't completed recovery after previous failure.
484 * - Superblock is read and overrides recovery_offset.
486 * What is found in the superblocks of the devices is always
487 * authoritative, unless 'rebuild' or '[no]sync' was specified.
489 for (i
= 0; i
< rs
->md
.raid_disks
; i
++) {
490 set_bit(In_sync
, &rs
->dev
[i
].rdev
.flags
);
491 rs
->dev
[i
].rdev
.recovery_offset
= MaxSector
;
495 * Second, parse the unordered optional arguments
497 for (i
= 0; i
< num_raid_params
; i
++) {
498 if (!strcasecmp(argv
[i
], "nosync")) {
499 rs
->md
.recovery_cp
= MaxSector
;
500 rs
->print_flags
|= DMPF_NOSYNC
;
503 if (!strcasecmp(argv
[i
], "sync")) {
504 rs
->md
.recovery_cp
= 0;
505 rs
->print_flags
|= DMPF_SYNC
;
509 /* The rest of the optional arguments come in key/value pairs */
510 if ((i
+ 1) >= num_raid_params
) {
511 rs
->ti
->error
= "Wrong number of raid parameters given";
517 /* Parameters that take a string value are checked here. */
518 if (!strcasecmp(key
, "raid10_format")) {
519 if (rs
->raid_type
->level
!= 10) {
520 rs
->ti
->error
= "'raid10_format' is an invalid parameter for this RAID type";
523 if (strcmp("near", argv
[i
])) {
524 rs
->ti
->error
= "Invalid 'raid10_format' value given";
527 raid10_format
= argv
[i
];
528 rs
->print_flags
|= DMPF_RAID10_FORMAT
;
532 if (strict_strtoul(argv
[i
], 10, &value
) < 0) {
533 rs
->ti
->error
= "Bad numerical argument given in raid params";
537 /* Parameters that take a numeric value are checked here */
538 if (!strcasecmp(key
, "rebuild")) {
539 if (value
>= rs
->md
.raid_disks
) {
540 rs
->ti
->error
= "Invalid rebuild index given";
543 clear_bit(In_sync
, &rs
->dev
[value
].rdev
.flags
);
544 rs
->dev
[value
].rdev
.recovery_offset
= 0;
545 rs
->print_flags
|= DMPF_REBUILD
;
546 } else if (!strcasecmp(key
, "write_mostly")) {
547 if (rs
->raid_type
->level
!= 1) {
548 rs
->ti
->error
= "write_mostly option is only valid for RAID1";
551 if (value
>= rs
->md
.raid_disks
) {
552 rs
->ti
->error
= "Invalid write_mostly drive index given";
555 set_bit(WriteMostly
, &rs
->dev
[value
].rdev
.flags
);
556 } else if (!strcasecmp(key
, "max_write_behind")) {
557 if (rs
->raid_type
->level
!= 1) {
558 rs
->ti
->error
= "max_write_behind option is only valid for RAID1";
561 rs
->print_flags
|= DMPF_MAX_WRITE_BEHIND
;
564 * In device-mapper, we specify things in sectors, but
565 * MD records this value in kB
568 if (value
> COUNTER_MAX
) {
569 rs
->ti
->error
= "Max write-behind limit out of range";
572 rs
->md
.bitmap_info
.max_write_behind
= value
;
573 } else if (!strcasecmp(key
, "daemon_sleep")) {
574 rs
->print_flags
|= DMPF_DAEMON_SLEEP
;
575 if (!value
|| (value
> MAX_SCHEDULE_TIMEOUT
)) {
576 rs
->ti
->error
= "daemon sleep period out of range";
579 rs
->md
.bitmap_info
.daemon_sleep
= value
;
580 } else if (!strcasecmp(key
, "stripe_cache")) {
581 rs
->print_flags
|= DMPF_STRIPE_CACHE
;
584 * In device-mapper, we specify things in sectors, but
585 * MD records this value in kB
589 if ((rs
->raid_type
->level
!= 5) &&
590 (rs
->raid_type
->level
!= 6)) {
591 rs
->ti
->error
= "Inappropriate argument: stripe_cache";
594 if (raid5_set_cache_size(&rs
->md
, (int)value
)) {
595 rs
->ti
->error
= "Bad stripe_cache size";
598 } else if (!strcasecmp(key
, "min_recovery_rate")) {
599 rs
->print_flags
|= DMPF_MIN_RECOVERY_RATE
;
600 if (value
> INT_MAX
) {
601 rs
->ti
->error
= "min_recovery_rate out of range";
604 rs
->md
.sync_speed_min
= (int)value
;
605 } else if (!strcasecmp(key
, "max_recovery_rate")) {
606 rs
->print_flags
|= DMPF_MAX_RECOVERY_RATE
;
607 if (value
> INT_MAX
) {
608 rs
->ti
->error
= "max_recovery_rate out of range";
611 rs
->md
.sync_speed_max
= (int)value
;
612 } else if (!strcasecmp(key
, "region_size")) {
613 rs
->print_flags
|= DMPF_REGION_SIZE
;
615 } else if (!strcasecmp(key
, "raid10_copies") &&
616 (rs
->raid_type
->level
== 10)) {
617 if ((value
< 2) || (value
> 0xFF)) {
618 rs
->ti
->error
= "Bad value for 'raid10_copies'";
621 rs
->print_flags
|= DMPF_RAID10_COPIES
;
622 raid10_copies
= value
;
624 DMERR("Unable to parse RAID parameter: %s", key
);
625 rs
->ti
->error
= "Unable to parse RAID parameters";
630 if (validate_region_size(rs
, region_size
))
633 if (rs
->md
.chunk_sectors
)
634 max_io_len
= rs
->md
.chunk_sectors
;
636 max_io_len
= region_size
;
638 if (dm_set_target_max_io_len(rs
->ti
, max_io_len
))
641 if (rs
->raid_type
->level
== 10) {
642 if (raid10_copies
> rs
->md
.raid_disks
) {
643 rs
->ti
->error
= "Not enough devices to satisfy specification";
647 /* (Len * #mirrors) / #devices */
648 sectors_per_dev
= rs
->ti
->len
* raid10_copies
;
649 sector_div(sectors_per_dev
, rs
->md
.raid_disks
);
651 rs
->md
.layout
= raid10_format_to_md_layout(raid10_format
,
653 rs
->md
.new_layout
= rs
->md
.layout
;
654 } else if ((rs
->raid_type
->level
> 1) &&
655 sector_div(sectors_per_dev
,
656 (rs
->md
.raid_disks
- rs
->raid_type
->parity_devs
))) {
657 rs
->ti
->error
= "Target length not divisible by number of data devices";
660 rs
->md
.dev_sectors
= sectors_per_dev
;
662 /* Assume there are no metadata devices until the drives are parsed */
663 rs
->md
.persistent
= 0;
669 static void do_table_event(struct work_struct
*ws
)
671 struct raid_set
*rs
= container_of(ws
, struct raid_set
, md
.event_work
);
673 dm_table_event(rs
->ti
->table
);
676 static int raid_is_congested(struct dm_target_callbacks
*cb
, int bits
)
678 struct raid_set
*rs
= container_of(cb
, struct raid_set
, callbacks
);
680 if (rs
->raid_type
->level
== 1)
681 return md_raid1_congested(&rs
->md
, bits
);
683 if (rs
->raid_type
->level
== 10)
684 return md_raid10_congested(&rs
->md
, bits
);
686 return md_raid5_congested(&rs
->md
, bits
);
690 * This structure is never routinely used by userspace, unlike md superblocks.
691 * Devices with this superblock should only ever be accessed via device-mapper.
693 #define DM_RAID_MAGIC 0x64526D44
694 struct dm_raid_superblock
{
695 __le32 magic
; /* "DmRd" */
696 __le32 features
; /* Used to indicate possible future changes */
698 __le32 num_devices
; /* Number of devices in this array. (Max 64) */
699 __le32 array_position
; /* The position of this drive in the array */
701 __le64 events
; /* Incremented by md when superblock updated */
702 __le64 failed_devices
; /* Bit field of devices to indicate failures */
705 * This offset tracks the progress of the repair or replacement of
706 * an individual drive.
708 __le64 disk_recovery_offset
;
711 * This offset tracks the progress of the initial array
712 * synchronisation/parity calculation.
714 __le64 array_resync_offset
;
717 * RAID characteristics
721 __le32 stripe_sectors
;
723 __u8 pad
[452]; /* Round struct to 512 bytes. */
724 /* Always set to 0 when writing. */
727 static int read_disk_sb(struct md_rdev
*rdev
, int size
)
729 BUG_ON(!rdev
->sb_page
);
734 if (!sync_page_io(rdev
, 0, size
, rdev
->sb_page
, READ
, 1)) {
735 DMERR("Failed to read superblock of device at position %d",
737 md_error(rdev
->mddev
, rdev
);
746 static void super_sync(struct mddev
*mddev
, struct md_rdev
*rdev
)
749 uint64_t failed_devices
;
750 struct dm_raid_superblock
*sb
;
751 struct raid_set
*rs
= container_of(mddev
, struct raid_set
, md
);
753 sb
= page_address(rdev
->sb_page
);
754 failed_devices
= le64_to_cpu(sb
->failed_devices
);
756 for (i
= 0; i
< mddev
->raid_disks
; i
++)
757 if (!rs
->dev
[i
].data_dev
||
758 test_bit(Faulty
, &(rs
->dev
[i
].rdev
.flags
)))
759 failed_devices
|= (1ULL << i
);
761 memset(sb
, 0, sizeof(*sb
));
763 sb
->magic
= cpu_to_le32(DM_RAID_MAGIC
);
764 sb
->features
= cpu_to_le32(0); /* No features yet */
766 sb
->num_devices
= cpu_to_le32(mddev
->raid_disks
);
767 sb
->array_position
= cpu_to_le32(rdev
->raid_disk
);
769 sb
->events
= cpu_to_le64(mddev
->events
);
770 sb
->failed_devices
= cpu_to_le64(failed_devices
);
772 sb
->disk_recovery_offset
= cpu_to_le64(rdev
->recovery_offset
);
773 sb
->array_resync_offset
= cpu_to_le64(mddev
->recovery_cp
);
775 sb
->level
= cpu_to_le32(mddev
->level
);
776 sb
->layout
= cpu_to_le32(mddev
->layout
);
777 sb
->stripe_sectors
= cpu_to_le32(mddev
->chunk_sectors
);
783 * This function creates a superblock if one is not found on the device
784 * and will decide which superblock to use if there's a choice.
786 * Return: 1 if use rdev, 0 if use refdev, -Exxx otherwise
788 static int super_load(struct md_rdev
*rdev
, struct md_rdev
*refdev
)
791 struct dm_raid_superblock
*sb
;
792 struct dm_raid_superblock
*refsb
;
793 uint64_t events_sb
, events_refsb
;
796 rdev
->sb_size
= sizeof(*sb
);
798 ret
= read_disk_sb(rdev
, rdev
->sb_size
);
802 sb
= page_address(rdev
->sb_page
);
805 * Two cases that we want to write new superblocks and rebuild:
806 * 1) New device (no matching magic number)
807 * 2) Device specified for rebuild (!In_sync w/ offset == 0)
809 if ((sb
->magic
!= cpu_to_le32(DM_RAID_MAGIC
)) ||
810 (!test_bit(In_sync
, &rdev
->flags
) && !rdev
->recovery_offset
)) {
811 super_sync(rdev
->mddev
, rdev
);
813 set_bit(FirstUse
, &rdev
->flags
);
815 /* Force writing of superblocks to disk */
816 set_bit(MD_CHANGE_DEVS
, &rdev
->mddev
->flags
);
818 /* Any superblock is better than none, choose that if given */
819 return refdev
? 0 : 1;
825 events_sb
= le64_to_cpu(sb
->events
);
827 refsb
= page_address(refdev
->sb_page
);
828 events_refsb
= le64_to_cpu(refsb
->events
);
830 return (events_sb
> events_refsb
) ? 1 : 0;
833 static int super_init_validation(struct mddev
*mddev
, struct md_rdev
*rdev
)
836 struct raid_set
*rs
= container_of(mddev
, struct raid_set
, md
);
838 uint64_t failed_devices
;
839 struct dm_raid_superblock
*sb
;
840 uint32_t new_devs
= 0;
841 uint32_t rebuilds
= 0;
843 struct dm_raid_superblock
*sb2
;
845 sb
= page_address(rdev
->sb_page
);
846 events_sb
= le64_to_cpu(sb
->events
);
847 failed_devices
= le64_to_cpu(sb
->failed_devices
);
850 * Initialise to 1 if this is a new superblock.
852 mddev
->events
= events_sb
? : 1;
855 * Reshaping is not currently allowed
857 if ((le32_to_cpu(sb
->level
) != mddev
->level
) ||
858 (le32_to_cpu(sb
->layout
) != mddev
->layout
) ||
859 (le32_to_cpu(sb
->stripe_sectors
) != mddev
->chunk_sectors
)) {
860 DMERR("Reshaping arrays not yet supported.");
864 /* We can only change the number of devices in RAID1 right now */
865 if ((rs
->raid_type
->level
!= 1) &&
866 (le32_to_cpu(sb
->num_devices
) != mddev
->raid_disks
)) {
867 DMERR("Reshaping arrays not yet supported.");
871 if (!(rs
->print_flags
& (DMPF_SYNC
| DMPF_NOSYNC
)))
872 mddev
->recovery_cp
= le64_to_cpu(sb
->array_resync_offset
);
875 * During load, we set FirstUse if a new superblock was written.
876 * There are two reasons we might not have a superblock:
877 * 1) The array is brand new - in which case, all of the
878 * devices must have their In_sync bit set. Also,
879 * recovery_cp must be 0, unless forced.
880 * 2) This is a new device being added to an old array
881 * and the new device needs to be rebuilt - in which
882 * case the In_sync bit will /not/ be set and
883 * recovery_cp must be MaxSector.
885 rdev_for_each(r
, mddev
) {
886 if (!test_bit(In_sync
, &r
->flags
)) {
887 DMINFO("Device %d specified for rebuild: "
888 "Clearing superblock", r
->raid_disk
);
890 } else if (test_bit(FirstUse
, &r
->flags
))
895 if (new_devs
== mddev
->raid_disks
) {
896 DMINFO("Superblocks created for new array");
897 set_bit(MD_ARRAY_FIRST_USE
, &mddev
->flags
);
898 } else if (new_devs
) {
899 DMERR("New device injected "
900 "into existing array without 'rebuild' "
901 "parameter specified");
904 } else if (new_devs
) {
905 DMERR("'rebuild' devices cannot be "
906 "injected into an array with other first-time devices");
908 } else if (mddev
->recovery_cp
!= MaxSector
) {
909 DMERR("'rebuild' specified while array is not in-sync");
914 * Now we set the Faulty bit for those devices that are
915 * recorded in the superblock as failed.
917 rdev_for_each(r
, mddev
) {
920 sb2
= page_address(r
->sb_page
);
921 sb2
->failed_devices
= 0;
924 * Check for any device re-ordering.
926 if (!test_bit(FirstUse
, &r
->flags
) && (r
->raid_disk
>= 0)) {
927 role
= le32_to_cpu(sb2
->array_position
);
928 if (role
!= r
->raid_disk
) {
929 if (rs
->raid_type
->level
!= 1) {
930 rs
->ti
->error
= "Cannot change device "
931 "positions in RAID array";
934 DMINFO("RAID1 device #%d now at position #%d",
939 * Partial recovery is performed on
940 * returning failed devices.
942 if (failed_devices
& (1 << role
))
943 set_bit(Faulty
, &r
->flags
);
950 static int super_validate(struct mddev
*mddev
, struct md_rdev
*rdev
)
952 struct dm_raid_superblock
*sb
= page_address(rdev
->sb_page
);
955 * If mddev->events is not set, we know we have not yet initialized
958 if (!mddev
->events
&& super_init_validation(mddev
, rdev
))
961 mddev
->bitmap_info
.offset
= 4096 >> 9; /* Enable bitmap creation */
962 rdev
->mddev
->bitmap_info
.default_offset
= 4096 >> 9;
963 if (!test_bit(FirstUse
, &rdev
->flags
)) {
964 rdev
->recovery_offset
= le64_to_cpu(sb
->disk_recovery_offset
);
965 if (rdev
->recovery_offset
!= MaxSector
)
966 clear_bit(In_sync
, &rdev
->flags
);
970 * If a device comes back, set it as not In_sync and no longer faulty.
972 if (test_bit(Faulty
, &rdev
->flags
)) {
973 clear_bit(Faulty
, &rdev
->flags
);
974 clear_bit(In_sync
, &rdev
->flags
);
975 rdev
->saved_raid_disk
= rdev
->raid_disk
;
976 rdev
->recovery_offset
= 0;
979 clear_bit(FirstUse
, &rdev
->flags
);
985 * Analyse superblocks and select the freshest.
987 static int analyse_superblocks(struct dm_target
*ti
, struct raid_set
*rs
)
990 struct raid_dev
*dev
;
991 struct md_rdev
*rdev
, *tmp
, *freshest
;
992 struct mddev
*mddev
= &rs
->md
;
995 rdev_for_each_safe(rdev
, tmp
, mddev
) {
997 * Skipping super_load due to DMPF_SYNC will cause
998 * the array to undergo initialization again as
999 * though it were new. This is the intended effect
1000 * of the "sync" directive.
1002 * When reshaping capability is added, we must ensure
1003 * that the "sync" directive is disallowed during the
1006 if (rs
->print_flags
& DMPF_SYNC
)
1009 if (!rdev
->meta_bdev
)
1012 ret
= super_load(rdev
, freshest
);
1021 dev
= container_of(rdev
, struct raid_dev
, rdev
);
1023 dm_put_device(ti
, dev
->meta_dev
);
1025 dev
->meta_dev
= NULL
;
1026 rdev
->meta_bdev
= NULL
;
1029 put_page(rdev
->sb_page
);
1031 rdev
->sb_page
= NULL
;
1033 rdev
->sb_loaded
= 0;
1036 * We might be able to salvage the data device
1037 * even though the meta device has failed. For
1038 * now, we behave as though '- -' had been
1039 * set for this device in the table.
1042 dm_put_device(ti
, dev
->data_dev
);
1044 dev
->data_dev
= NULL
;
1047 list_del(&rdev
->same_set
);
1054 if (validate_raid_redundancy(rs
)) {
1055 rs
->ti
->error
= "Insufficient redundancy to activate array";
1060 * Validation of the freshest device provides the source of
1061 * validation for the remaining devices.
1063 ti
->error
= "Unable to assemble array: Invalid superblocks";
1064 if (super_validate(mddev
, freshest
))
1067 rdev_for_each(rdev
, mddev
)
1068 if ((rdev
!= freshest
) && super_validate(mddev
, rdev
))
1075 * Construct a RAID4/5/6 mapping:
1077 * <raid_type> <#raid_params> <raid_params> \
1078 * <#raid_devs> { <meta_dev1> <dev1> .. <meta_devN> <devN> }
1080 * <raid_params> varies by <raid_type>. See 'parse_raid_params' for
1081 * details on possible <raid_params>.
1083 static int raid_ctr(struct dm_target
*ti
, unsigned argc
, char **argv
)
1086 struct raid_type
*rt
;
1087 unsigned long num_raid_params
, num_raid_devs
;
1088 struct raid_set
*rs
= NULL
;
1090 /* Must have at least <raid_type> <#raid_params> */
1092 ti
->error
= "Too few arguments";
1097 rt
= get_raid_type(argv
[0]);
1099 ti
->error
= "Unrecognised raid_type";
1105 /* number of RAID parameters */
1106 if (strict_strtoul(argv
[0], 10, &num_raid_params
) < 0) {
1107 ti
->error
= "Cannot understand number of RAID parameters";
1113 /* Skip over RAID params for now and find out # of devices */
1114 if (num_raid_params
+ 1 > argc
) {
1115 ti
->error
= "Arguments do not agree with counts given";
1119 if ((strict_strtoul(argv
[num_raid_params
], 10, &num_raid_devs
) < 0) ||
1120 (num_raid_devs
>= INT_MAX
)) {
1121 ti
->error
= "Cannot understand number of raid devices";
1125 rs
= context_alloc(ti
, rt
, (unsigned)num_raid_devs
);
1129 ret
= parse_raid_params(rs
, argv
, (unsigned)num_raid_params
);
1135 argc
-= num_raid_params
+ 1; /* +1: we already have num_raid_devs */
1136 argv
+= num_raid_params
+ 1;
1138 if (argc
!= (num_raid_devs
* 2)) {
1139 ti
->error
= "Supplied RAID devices does not match the count given";
1143 ret
= dev_parms(rs
, argv
);
1147 rs
->md
.sync_super
= super_sync
;
1148 ret
= analyse_superblocks(ti
, rs
);
1152 INIT_WORK(&rs
->md
.event_work
, do_table_event
);
1154 ti
->num_flush_bios
= 1;
1156 mutex_lock(&rs
->md
.reconfig_mutex
);
1157 ret
= md_run(&rs
->md
);
1158 rs
->md
.in_sync
= 0; /* Assume already marked dirty */
1159 mutex_unlock(&rs
->md
.reconfig_mutex
);
1162 ti
->error
= "Fail to run raid array";
1166 if (ti
->len
!= rs
->md
.array_sectors
) {
1167 ti
->error
= "Array size does not match requested target length";
1171 rs
->callbacks
.congested_fn
= raid_is_congested
;
1172 dm_table_add_target_callbacks(ti
->table
, &rs
->callbacks
);
1174 mddev_suspend(&rs
->md
);
1185 static void raid_dtr(struct dm_target
*ti
)
1187 struct raid_set
*rs
= ti
->private;
1189 list_del_init(&rs
->callbacks
.list
);
1194 static int raid_map(struct dm_target
*ti
, struct bio
*bio
)
1196 struct raid_set
*rs
= ti
->private;
1197 struct mddev
*mddev
= &rs
->md
;
1199 mddev
->pers
->make_request(mddev
, bio
);
1201 return DM_MAPIO_SUBMITTED
;
1204 static void raid_status(struct dm_target
*ti
, status_type_t type
,
1205 unsigned status_flags
, char *result
, unsigned maxlen
)
1207 struct raid_set
*rs
= ti
->private;
1208 unsigned raid_param_cnt
= 1; /* at least 1 for chunksize */
1210 int i
, array_in_sync
= 0;
1214 case STATUSTYPE_INFO
:
1215 DMEMIT("%s %d ", rs
->raid_type
->name
, rs
->md
.raid_disks
);
1217 if (test_bit(MD_RECOVERY_RUNNING
, &rs
->md
.recovery
))
1218 sync
= rs
->md
.curr_resync_completed
;
1220 sync
= rs
->md
.recovery_cp
;
1222 if (sync
>= rs
->md
.resync_max_sectors
) {
1224 sync
= rs
->md
.resync_max_sectors
;
1227 * The array may be doing an initial sync, or it may
1228 * be rebuilding individual components. If all the
1229 * devices are In_sync, then it is the array that is
1230 * being initialized.
1232 for (i
= 0; i
< rs
->md
.raid_disks
; i
++)
1233 if (!test_bit(In_sync
, &rs
->dev
[i
].rdev
.flags
))
1237 * Status characters:
1238 * 'D' = Dead/Failed device
1239 * 'a' = Alive but not in-sync
1240 * 'A' = Alive and in-sync
1242 for (i
= 0; i
< rs
->md
.raid_disks
; i
++) {
1243 if (test_bit(Faulty
, &rs
->dev
[i
].rdev
.flags
))
1245 else if (!array_in_sync
||
1246 !test_bit(In_sync
, &rs
->dev
[i
].rdev
.flags
))
1254 * The in-sync ratio shows the progress of:
1255 * - Initializing the array
1256 * - Rebuilding a subset of devices of the array
1257 * The user can distinguish between the two by referring
1258 * to the status characters.
1260 DMEMIT(" %llu/%llu",
1261 (unsigned long long) sync
,
1262 (unsigned long long) rs
->md
.resync_max_sectors
);
1265 case STATUSTYPE_TABLE
:
1266 /* The string you would use to construct this array */
1267 for (i
= 0; i
< rs
->md
.raid_disks
; i
++) {
1268 if ((rs
->print_flags
& DMPF_REBUILD
) &&
1269 rs
->dev
[i
].data_dev
&&
1270 !test_bit(In_sync
, &rs
->dev
[i
].rdev
.flags
))
1271 raid_param_cnt
+= 2; /* for rebuilds */
1272 if (rs
->dev
[i
].data_dev
&&
1273 test_bit(WriteMostly
, &rs
->dev
[i
].rdev
.flags
))
1274 raid_param_cnt
+= 2;
1277 raid_param_cnt
+= (hweight32(rs
->print_flags
& ~DMPF_REBUILD
) * 2);
1278 if (rs
->print_flags
& (DMPF_SYNC
| DMPF_NOSYNC
))
1281 DMEMIT("%s %u %u", rs
->raid_type
->name
,
1282 raid_param_cnt
, rs
->md
.chunk_sectors
);
1284 if ((rs
->print_flags
& DMPF_SYNC
) &&
1285 (rs
->md
.recovery_cp
== MaxSector
))
1287 if (rs
->print_flags
& DMPF_NOSYNC
)
1290 for (i
= 0; i
< rs
->md
.raid_disks
; i
++)
1291 if ((rs
->print_flags
& DMPF_REBUILD
) &&
1292 rs
->dev
[i
].data_dev
&&
1293 !test_bit(In_sync
, &rs
->dev
[i
].rdev
.flags
))
1294 DMEMIT(" rebuild %u", i
);
1296 if (rs
->print_flags
& DMPF_DAEMON_SLEEP
)
1297 DMEMIT(" daemon_sleep %lu",
1298 rs
->md
.bitmap_info
.daemon_sleep
);
1300 if (rs
->print_flags
& DMPF_MIN_RECOVERY_RATE
)
1301 DMEMIT(" min_recovery_rate %d", rs
->md
.sync_speed_min
);
1303 if (rs
->print_flags
& DMPF_MAX_RECOVERY_RATE
)
1304 DMEMIT(" max_recovery_rate %d", rs
->md
.sync_speed_max
);
1306 for (i
= 0; i
< rs
->md
.raid_disks
; i
++)
1307 if (rs
->dev
[i
].data_dev
&&
1308 test_bit(WriteMostly
, &rs
->dev
[i
].rdev
.flags
))
1309 DMEMIT(" write_mostly %u", i
);
1311 if (rs
->print_flags
& DMPF_MAX_WRITE_BEHIND
)
1312 DMEMIT(" max_write_behind %lu",
1313 rs
->md
.bitmap_info
.max_write_behind
);
1315 if (rs
->print_flags
& DMPF_STRIPE_CACHE
) {
1316 struct r5conf
*conf
= rs
->md
.private;
1318 /* convert from kiB to sectors */
1319 DMEMIT(" stripe_cache %d",
1320 conf
? conf
->max_nr_stripes
* 2 : 0);
1323 if (rs
->print_flags
& DMPF_REGION_SIZE
)
1324 DMEMIT(" region_size %lu",
1325 rs
->md
.bitmap_info
.chunksize
>> 9);
1327 if (rs
->print_flags
& DMPF_RAID10_COPIES
)
1328 DMEMIT(" raid10_copies %u",
1329 raid10_md_layout_to_copies(rs
->md
.layout
));
1331 if (rs
->print_flags
& DMPF_RAID10_FORMAT
)
1332 DMEMIT(" raid10_format near");
1334 DMEMIT(" %d", rs
->md
.raid_disks
);
1335 for (i
= 0; i
< rs
->md
.raid_disks
; i
++) {
1336 if (rs
->dev
[i
].meta_dev
)
1337 DMEMIT(" %s", rs
->dev
[i
].meta_dev
->name
);
1341 if (rs
->dev
[i
].data_dev
)
1342 DMEMIT(" %s", rs
->dev
[i
].data_dev
->name
);
1349 static int raid_iterate_devices(struct dm_target
*ti
, iterate_devices_callout_fn fn
, void *data
)
1351 struct raid_set
*rs
= ti
->private;
1355 for (i
= 0; !ret
&& i
< rs
->md
.raid_disks
; i
++)
1356 if (rs
->dev
[i
].data_dev
)
1358 rs
->dev
[i
].data_dev
,
1359 0, /* No offset on data devs */
1366 static void raid_io_hints(struct dm_target
*ti
, struct queue_limits
*limits
)
1368 struct raid_set
*rs
= ti
->private;
1369 unsigned chunk_size
= rs
->md
.chunk_sectors
<< 9;
1370 struct r5conf
*conf
= rs
->md
.private;
1372 blk_limits_io_min(limits
, chunk_size
);
1373 blk_limits_io_opt(limits
, chunk_size
* (conf
->raid_disks
- conf
->max_degraded
));
1376 static void raid_presuspend(struct dm_target
*ti
)
1378 struct raid_set
*rs
= ti
->private;
1380 md_stop_writes(&rs
->md
);
1383 static void raid_postsuspend(struct dm_target
*ti
)
1385 struct raid_set
*rs
= ti
->private;
1387 mddev_suspend(&rs
->md
);
1390 static void raid_resume(struct dm_target
*ti
)
1392 struct raid_set
*rs
= ti
->private;
1394 set_bit(MD_CHANGE_DEVS
, &rs
->md
.flags
);
1395 if (!rs
->bitmap_loaded
) {
1396 bitmap_load(&rs
->md
);
1397 rs
->bitmap_loaded
= 1;
1400 clear_bit(MD_RECOVERY_FROZEN
, &rs
->md
.recovery
);
1401 mddev_resume(&rs
->md
);
1404 static struct target_type raid_target
= {
1406 .version
= {1, 4, 2},
1407 .module
= THIS_MODULE
,
1411 .status
= raid_status
,
1412 .iterate_devices
= raid_iterate_devices
,
1413 .io_hints
= raid_io_hints
,
1414 .presuspend
= raid_presuspend
,
1415 .postsuspend
= raid_postsuspend
,
1416 .resume
= raid_resume
,
1419 static int __init
dm_raid_init(void)
1421 return dm_register_target(&raid_target
);
1424 static void __exit
dm_raid_exit(void)
1426 dm_unregister_target(&raid_target
);
1429 module_init(dm_raid_init
);
1430 module_exit(dm_raid_exit
);
1432 MODULE_DESCRIPTION(DM_NAME
" raid4/5/6 target");
1433 MODULE_ALIAS("dm-raid1");
1434 MODULE_ALIAS("dm-raid10");
1435 MODULE_ALIAS("dm-raid4");
1436 MODULE_ALIAS("dm-raid5");
1437 MODULE_ALIAS("dm-raid6");
1438 MODULE_AUTHOR("Neil Brown <dm-devel@redhat.com>");
1439 MODULE_LICENSE("GPL");