Merge tag 'powerpc-5.15-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc...
[platform/kernel/linux-starfive.git] / drivers / md / dm-raid.c
1 /*
2  * Copyright (C) 2010-2011 Neil Brown
3  * Copyright (C) 2010-2018 Red Hat, Inc. All rights reserved.
4  *
5  * This file is released under the GPL.
6  */
7
8 #include <linux/slab.h>
9 #include <linux/module.h>
10
11 #include "md.h"
12 #include "raid1.h"
13 #include "raid5.h"
14 #include "raid10.h"
15 #include "md-bitmap.h"
16
17 #include <linux/device-mapper.h>
18
19 #define DM_MSG_PREFIX "raid"
20 #define MAX_RAID_DEVICES        253 /* md-raid kernel limit */
21
22 /*
23  * Minimum sectors of free reshape space per raid device
24  */
25 #define MIN_FREE_RESHAPE_SPACE to_sector(4*4096)
26
27 /*
28  * Minimum journal space 4 MiB in sectors.
29  */
30 #define MIN_RAID456_JOURNAL_SPACE (4*2048)
31
32 static bool devices_handle_discard_safely = false;
33
34 /*
35  * The following flags are used by dm-raid.c to set up the array state.
36  * They must be cleared before md_run is called.
37  */
38 #define FirstUse 10             /* rdev flag */
39
40 struct raid_dev {
41         /*
42          * Two DM devices, one to hold metadata and one to hold the
43          * actual data/parity.  The reason for this is to not confuse
44          * ti->len and give more flexibility in altering size and
45          * characteristics.
46          *
47          * While it is possible for this device to be associated
48          * with a different physical device than the data_dev, it
49          * is intended for it to be the same.
50          *    |--------- Physical Device ---------|
51          *    |- meta_dev -|------ data_dev ------|
52          */
53         struct dm_dev *meta_dev;
54         struct dm_dev *data_dev;
55         struct md_rdev rdev;
56 };
57
58 /*
59  * Bits for establishing rs->ctr_flags
60  *
61  * 1 = no flag value
62  * 2 = flag with value
63  */
64 #define __CTR_FLAG_SYNC                 0  /* 1 */ /* Not with raid0! */
65 #define __CTR_FLAG_NOSYNC               1  /* 1 */ /* Not with raid0! */
66 #define __CTR_FLAG_REBUILD              2  /* 2 */ /* Not with raid0! */
67 #define __CTR_FLAG_DAEMON_SLEEP         3  /* 2 */ /* Not with raid0! */
68 #define __CTR_FLAG_MIN_RECOVERY_RATE    4  /* 2 */ /* Not with raid0! */
69 #define __CTR_FLAG_MAX_RECOVERY_RATE    5  /* 2 */ /* Not with raid0! */
70 #define __CTR_FLAG_MAX_WRITE_BEHIND     6  /* 2 */ /* Only with raid1! */
71 #define __CTR_FLAG_WRITE_MOSTLY         7  /* 2 */ /* Only with raid1! */
72 #define __CTR_FLAG_STRIPE_CACHE         8  /* 2 */ /* Only with raid4/5/6! */
73 #define __CTR_FLAG_REGION_SIZE          9  /* 2 */ /* Not with raid0! */
74 #define __CTR_FLAG_RAID10_COPIES        10 /* 2 */ /* Only with raid10 */
75 #define __CTR_FLAG_RAID10_FORMAT        11 /* 2 */ /* Only with raid10 */
76 /* New for v1.9.0 */
77 #define __CTR_FLAG_DELTA_DISKS          12 /* 2 */ /* Only with reshapable raid1/4/5/6/10! */
78 #define __CTR_FLAG_DATA_OFFSET          13 /* 2 */ /* Only with reshapable raid4/5/6/10! */
79 #define __CTR_FLAG_RAID10_USE_NEAR_SETS 14 /* 2 */ /* Only with raid10! */
80
81 /* New for v1.10.0 */
82 #define __CTR_FLAG_JOURNAL_DEV          15 /* 2 */ /* Only with raid4/5/6 (journal device)! */
83
84 /* New for v1.11.1 */
85 #define __CTR_FLAG_JOURNAL_MODE         16 /* 2 */ /* Only with raid4/5/6 (journal mode)! */
86
87 /*
88  * Flags for rs->ctr_flags field.
89  */
90 #define CTR_FLAG_SYNC                   (1 << __CTR_FLAG_SYNC)
91 #define CTR_FLAG_NOSYNC                 (1 << __CTR_FLAG_NOSYNC)
92 #define CTR_FLAG_REBUILD                (1 << __CTR_FLAG_REBUILD)
93 #define CTR_FLAG_DAEMON_SLEEP           (1 << __CTR_FLAG_DAEMON_SLEEP)
94 #define CTR_FLAG_MIN_RECOVERY_RATE      (1 << __CTR_FLAG_MIN_RECOVERY_RATE)
95 #define CTR_FLAG_MAX_RECOVERY_RATE      (1 << __CTR_FLAG_MAX_RECOVERY_RATE)
96 #define CTR_FLAG_MAX_WRITE_BEHIND       (1 << __CTR_FLAG_MAX_WRITE_BEHIND)
97 #define CTR_FLAG_WRITE_MOSTLY           (1 << __CTR_FLAG_WRITE_MOSTLY)
98 #define CTR_FLAG_STRIPE_CACHE           (1 << __CTR_FLAG_STRIPE_CACHE)
99 #define CTR_FLAG_REGION_SIZE            (1 << __CTR_FLAG_REGION_SIZE)
100 #define CTR_FLAG_RAID10_COPIES          (1 << __CTR_FLAG_RAID10_COPIES)
101 #define CTR_FLAG_RAID10_FORMAT          (1 << __CTR_FLAG_RAID10_FORMAT)
102 #define CTR_FLAG_DELTA_DISKS            (1 << __CTR_FLAG_DELTA_DISKS)
103 #define CTR_FLAG_DATA_OFFSET            (1 << __CTR_FLAG_DATA_OFFSET)
104 #define CTR_FLAG_RAID10_USE_NEAR_SETS   (1 << __CTR_FLAG_RAID10_USE_NEAR_SETS)
105 #define CTR_FLAG_JOURNAL_DEV            (1 << __CTR_FLAG_JOURNAL_DEV)
106 #define CTR_FLAG_JOURNAL_MODE           (1 << __CTR_FLAG_JOURNAL_MODE)
107
108 /*
109  * Definitions of various constructor flags to
110  * be used in checks of valid / invalid flags
111  * per raid level.
112  */
113 /* Define all any sync flags */
114 #define CTR_FLAGS_ANY_SYNC              (CTR_FLAG_SYNC | CTR_FLAG_NOSYNC)
115
116 /* Define flags for options without argument (e.g. 'nosync') */
117 #define CTR_FLAG_OPTIONS_NO_ARGS        (CTR_FLAGS_ANY_SYNC | \
118                                          CTR_FLAG_RAID10_USE_NEAR_SETS)
119
120 /* Define flags for options with one argument (e.g. 'delta_disks +2') */
121 #define CTR_FLAG_OPTIONS_ONE_ARG (CTR_FLAG_REBUILD | \
122                                   CTR_FLAG_WRITE_MOSTLY | \
123                                   CTR_FLAG_DAEMON_SLEEP | \
124                                   CTR_FLAG_MIN_RECOVERY_RATE | \
125                                   CTR_FLAG_MAX_RECOVERY_RATE | \
126                                   CTR_FLAG_MAX_WRITE_BEHIND | \
127                                   CTR_FLAG_STRIPE_CACHE | \
128                                   CTR_FLAG_REGION_SIZE | \
129                                   CTR_FLAG_RAID10_COPIES | \
130                                   CTR_FLAG_RAID10_FORMAT | \
131                                   CTR_FLAG_DELTA_DISKS | \
132                                   CTR_FLAG_DATA_OFFSET | \
133                                   CTR_FLAG_JOURNAL_DEV | \
134                                   CTR_FLAG_JOURNAL_MODE)
135
136 /* Valid options definitions per raid level... */
137
138 /* "raid0" does only accept data offset */
139 #define RAID0_VALID_FLAGS       (CTR_FLAG_DATA_OFFSET)
140
141 /* "raid1" does not accept stripe cache, data offset, delta_disks or any raid10 options */
142 #define RAID1_VALID_FLAGS       (CTR_FLAGS_ANY_SYNC | \
143                                  CTR_FLAG_REBUILD | \
144                                  CTR_FLAG_WRITE_MOSTLY | \
145                                  CTR_FLAG_DAEMON_SLEEP | \
146                                  CTR_FLAG_MIN_RECOVERY_RATE | \
147                                  CTR_FLAG_MAX_RECOVERY_RATE | \
148                                  CTR_FLAG_MAX_WRITE_BEHIND | \
149                                  CTR_FLAG_REGION_SIZE | \
150                                  CTR_FLAG_DELTA_DISKS | \
151                                  CTR_FLAG_DATA_OFFSET)
152
153 /* "raid10" does not accept any raid1 or stripe cache options */
154 #define RAID10_VALID_FLAGS      (CTR_FLAGS_ANY_SYNC | \
155                                  CTR_FLAG_REBUILD | \
156                                  CTR_FLAG_DAEMON_SLEEP | \
157                                  CTR_FLAG_MIN_RECOVERY_RATE | \
158                                  CTR_FLAG_MAX_RECOVERY_RATE | \
159                                  CTR_FLAG_REGION_SIZE | \
160                                  CTR_FLAG_RAID10_COPIES | \
161                                  CTR_FLAG_RAID10_FORMAT | \
162                                  CTR_FLAG_DELTA_DISKS | \
163                                  CTR_FLAG_DATA_OFFSET | \
164                                  CTR_FLAG_RAID10_USE_NEAR_SETS)
165
166 /*
167  * "raid4/5/6" do not accept any raid1 or raid10 specific options
168  *
169  * "raid6" does not accept "nosync", because it is not guaranteed
170  * that both parity and q-syndrome are being written properly with
171  * any writes
172  */
173 #define RAID45_VALID_FLAGS      (CTR_FLAGS_ANY_SYNC | \
174                                  CTR_FLAG_REBUILD | \
175                                  CTR_FLAG_DAEMON_SLEEP | \
176                                  CTR_FLAG_MIN_RECOVERY_RATE | \
177                                  CTR_FLAG_MAX_RECOVERY_RATE | \
178                                  CTR_FLAG_STRIPE_CACHE | \
179                                  CTR_FLAG_REGION_SIZE | \
180                                  CTR_FLAG_DELTA_DISKS | \
181                                  CTR_FLAG_DATA_OFFSET | \
182                                  CTR_FLAG_JOURNAL_DEV | \
183                                  CTR_FLAG_JOURNAL_MODE)
184
185 #define RAID6_VALID_FLAGS       (CTR_FLAG_SYNC | \
186                                  CTR_FLAG_REBUILD | \
187                                  CTR_FLAG_DAEMON_SLEEP | \
188                                  CTR_FLAG_MIN_RECOVERY_RATE | \
189                                  CTR_FLAG_MAX_RECOVERY_RATE | \
190                                  CTR_FLAG_STRIPE_CACHE | \
191                                  CTR_FLAG_REGION_SIZE | \
192                                  CTR_FLAG_DELTA_DISKS | \
193                                  CTR_FLAG_DATA_OFFSET | \
194                                  CTR_FLAG_JOURNAL_DEV | \
195                                  CTR_FLAG_JOURNAL_MODE)
196 /* ...valid options definitions per raid level */
197
198 /*
199  * Flags for rs->runtime_flags field
200  * (RT_FLAG prefix meaning "runtime flag")
201  *
202  * These are all internal and used to define runtime state,
203  * e.g. to prevent another resume from preresume processing
204  * the raid set all over again.
205  */
206 #define RT_FLAG_RS_PRERESUMED           0
207 #define RT_FLAG_RS_RESUMED              1
208 #define RT_FLAG_RS_BITMAP_LOADED        2
209 #define RT_FLAG_UPDATE_SBS              3
210 #define RT_FLAG_RESHAPE_RS              4
211 #define RT_FLAG_RS_SUSPENDED            5
212 #define RT_FLAG_RS_IN_SYNC              6
213 #define RT_FLAG_RS_RESYNCING            7
214 #define RT_FLAG_RS_GROW                 8
215
216 /* Array elements of 64 bit needed for rebuild/failed disk bits */
217 #define DISKS_ARRAY_ELEMS ((MAX_RAID_DEVICES + (sizeof(uint64_t) * 8 - 1)) / sizeof(uint64_t) / 8)
218
219 /*
220  * raid set level, layout and chunk sectors backup/restore
221  */
222 struct rs_layout {
223         int new_level;
224         int new_layout;
225         int new_chunk_sectors;
226 };
227
228 struct raid_set {
229         struct dm_target *ti;
230
231         uint32_t stripe_cache_entries;
232         unsigned long ctr_flags;
233         unsigned long runtime_flags;
234
235         uint64_t rebuild_disks[DISKS_ARRAY_ELEMS];
236
237         int raid_disks;
238         int delta_disks;
239         int data_offset;
240         int raid10_copies;
241         int requested_bitmap_chunk_sectors;
242
243         struct mddev md;
244         struct raid_type *raid_type;
245
246         sector_t array_sectors;
247         sector_t dev_sectors;
248
249         /* Optional raid4/5/6 journal device */
250         struct journal_dev {
251                 struct dm_dev *dev;
252                 struct md_rdev rdev;
253                 int mode;
254         } journal_dev;
255
256         struct raid_dev dev[];
257 };
258
259 static void rs_config_backup(struct raid_set *rs, struct rs_layout *l)
260 {
261         struct mddev *mddev = &rs->md;
262
263         l->new_level = mddev->new_level;
264         l->new_layout = mddev->new_layout;
265         l->new_chunk_sectors = mddev->new_chunk_sectors;
266 }
267
268 static void rs_config_restore(struct raid_set *rs, struct rs_layout *l)
269 {
270         struct mddev *mddev = &rs->md;
271
272         mddev->new_level = l->new_level;
273         mddev->new_layout = l->new_layout;
274         mddev->new_chunk_sectors = l->new_chunk_sectors;
275 }
276
277 /* raid10 algorithms (i.e. formats) */
278 #define ALGORITHM_RAID10_DEFAULT        0
279 #define ALGORITHM_RAID10_NEAR           1
280 #define ALGORITHM_RAID10_OFFSET         2
281 #define ALGORITHM_RAID10_FAR            3
282
283 /* Supported raid types and properties. */
284 static struct raid_type {
285         const char *name;               /* RAID algorithm. */
286         const char *descr;              /* Descriptor text for logging. */
287         const unsigned int parity_devs; /* # of parity devices. */
288         const unsigned int minimal_devs;/* minimal # of devices in set. */
289         const unsigned int level;       /* RAID level. */
290         const unsigned int algorithm;   /* RAID algorithm. */
291 } raid_types[] = {
292         {"raid0",         "raid0 (striping)",                       0, 2, 0,  0 /* NONE */},
293         {"raid1",         "raid1 (mirroring)",                      0, 2, 1,  0 /* NONE */},
294         {"raid10_far",    "raid10 far (striped mirrors)",           0, 2, 10, ALGORITHM_RAID10_FAR},
295         {"raid10_offset", "raid10 offset (striped mirrors)",        0, 2, 10, ALGORITHM_RAID10_OFFSET},
296         {"raid10_near",   "raid10 near (striped mirrors)",          0, 2, 10, ALGORITHM_RAID10_NEAR},
297         {"raid10",        "raid10 (striped mirrors)",               0, 2, 10, ALGORITHM_RAID10_DEFAULT},
298         {"raid4",         "raid4 (dedicated first parity disk)",    1, 2, 5,  ALGORITHM_PARITY_0}, /* raid4 layout = raid5_0 */
299         {"raid5_n",       "raid5 (dedicated last parity disk)",     1, 2, 5,  ALGORITHM_PARITY_N},
300         {"raid5_ls",      "raid5 (left symmetric)",                 1, 2, 5,  ALGORITHM_LEFT_SYMMETRIC},
301         {"raid5_rs",      "raid5 (right symmetric)",                1, 2, 5,  ALGORITHM_RIGHT_SYMMETRIC},
302         {"raid5_la",      "raid5 (left asymmetric)",                1, 2, 5,  ALGORITHM_LEFT_ASYMMETRIC},
303         {"raid5_ra",      "raid5 (right asymmetric)",               1, 2, 5,  ALGORITHM_RIGHT_ASYMMETRIC},
304         {"raid6_zr",      "raid6 (zero restart)",                   2, 4, 6,  ALGORITHM_ROTATING_ZERO_RESTART},
305         {"raid6_nr",      "raid6 (N restart)",                      2, 4, 6,  ALGORITHM_ROTATING_N_RESTART},
306         {"raid6_nc",      "raid6 (N continue)",                     2, 4, 6,  ALGORITHM_ROTATING_N_CONTINUE},
307         {"raid6_n_6",     "raid6 (dedicated parity/Q n/6)",         2, 4, 6,  ALGORITHM_PARITY_N_6},
308         {"raid6_ls_6",    "raid6 (left symmetric dedicated Q 6)",   2, 4, 6,  ALGORITHM_LEFT_SYMMETRIC_6},
309         {"raid6_rs_6",    "raid6 (right symmetric dedicated Q 6)",  2, 4, 6,  ALGORITHM_RIGHT_SYMMETRIC_6},
310         {"raid6_la_6",    "raid6 (left asymmetric dedicated Q 6)",  2, 4, 6,  ALGORITHM_LEFT_ASYMMETRIC_6},
311         {"raid6_ra_6",    "raid6 (right asymmetric dedicated Q 6)", 2, 4, 6,  ALGORITHM_RIGHT_ASYMMETRIC_6}
312 };
313
314 /* True, if @v is in inclusive range [@min, @max] */
315 static bool __within_range(long v, long min, long max)
316 {
317         return v >= min && v <= max;
318 }
319
320 /* All table line arguments are defined here */
321 static struct arg_name_flag {
322         const unsigned long flag;
323         const char *name;
324 } __arg_name_flags[] = {
325         { CTR_FLAG_SYNC, "sync"},
326         { CTR_FLAG_NOSYNC, "nosync"},
327         { CTR_FLAG_REBUILD, "rebuild"},
328         { CTR_FLAG_DAEMON_SLEEP, "daemon_sleep"},
329         { CTR_FLAG_MIN_RECOVERY_RATE, "min_recovery_rate"},
330         { CTR_FLAG_MAX_RECOVERY_RATE, "max_recovery_rate"},
331         { CTR_FLAG_MAX_WRITE_BEHIND, "max_write_behind"},
332         { CTR_FLAG_WRITE_MOSTLY, "write_mostly"},
333         { CTR_FLAG_STRIPE_CACHE, "stripe_cache"},
334         { CTR_FLAG_REGION_SIZE, "region_size"},
335         { CTR_FLAG_RAID10_COPIES, "raid10_copies"},
336         { CTR_FLAG_RAID10_FORMAT, "raid10_format"},
337         { CTR_FLAG_DATA_OFFSET, "data_offset"},
338         { CTR_FLAG_DELTA_DISKS, "delta_disks"},
339         { CTR_FLAG_RAID10_USE_NEAR_SETS, "raid10_use_near_sets"},
340         { CTR_FLAG_JOURNAL_DEV, "journal_dev" },
341         { CTR_FLAG_JOURNAL_MODE, "journal_mode" },
342 };
343
344 /* Return argument name string for given @flag */
345 static const char *dm_raid_arg_name_by_flag(const uint32_t flag)
346 {
347         if (hweight32(flag) == 1) {
348                 struct arg_name_flag *anf = __arg_name_flags + ARRAY_SIZE(__arg_name_flags);
349
350                 while (anf-- > __arg_name_flags)
351                         if (flag & anf->flag)
352                                 return anf->name;
353
354         } else
355                 DMERR("%s called with more than one flag!", __func__);
356
357         return NULL;
358 }
359
360 /* Define correlation of raid456 journal cache modes and dm-raid target line parameters */
361 static struct {
362         const int mode;
363         const char *param;
364 } _raid456_journal_mode[] = {
365         { R5C_JOURNAL_MODE_WRITE_THROUGH , "writethrough" },
366         { R5C_JOURNAL_MODE_WRITE_BACK    , "writeback" }
367 };
368
369 /* Return MD raid4/5/6 journal mode for dm @journal_mode one */
370 static int dm_raid_journal_mode_to_md(const char *mode)
371 {
372         int m = ARRAY_SIZE(_raid456_journal_mode);
373
374         while (m--)
375                 if (!strcasecmp(mode, _raid456_journal_mode[m].param))
376                         return _raid456_journal_mode[m].mode;
377
378         return -EINVAL;
379 }
380
381 /* Return dm-raid raid4/5/6 journal mode string for @mode */
382 static const char *md_journal_mode_to_dm_raid(const int mode)
383 {
384         int m = ARRAY_SIZE(_raid456_journal_mode);
385
386         while (m--)
387                 if (mode == _raid456_journal_mode[m].mode)
388                         return _raid456_journal_mode[m].param;
389
390         return "unknown";
391 }
392
393 /*
394  * Bool helpers to test for various raid levels of a raid set.
395  * It's level as reported by the superblock rather than
396  * the requested raid_type passed to the constructor.
397  */
398 /* Return true, if raid set in @rs is raid0 */
399 static bool rs_is_raid0(struct raid_set *rs)
400 {
401         return !rs->md.level;
402 }
403
404 /* Return true, if raid set in @rs is raid1 */
405 static bool rs_is_raid1(struct raid_set *rs)
406 {
407         return rs->md.level == 1;
408 }
409
410 /* Return true, if raid set in @rs is raid10 */
411 static bool rs_is_raid10(struct raid_set *rs)
412 {
413         return rs->md.level == 10;
414 }
415
416 /* Return true, if raid set in @rs is level 6 */
417 static bool rs_is_raid6(struct raid_set *rs)
418 {
419         return rs->md.level == 6;
420 }
421
422 /* Return true, if raid set in @rs is level 4, 5 or 6 */
423 static bool rs_is_raid456(struct raid_set *rs)
424 {
425         return __within_range(rs->md.level, 4, 6);
426 }
427
428 /* Return true, if raid set in @rs is reshapable */
429 static bool __is_raid10_far(int layout);
430 static bool rs_is_reshapable(struct raid_set *rs)
431 {
432         return rs_is_raid456(rs) ||
433                (rs_is_raid10(rs) && !__is_raid10_far(rs->md.new_layout));
434 }
435
436 /* Return true, if raid set in @rs is recovering */
437 static bool rs_is_recovering(struct raid_set *rs)
438 {
439         return rs->md.recovery_cp < rs->md.dev_sectors;
440 }
441
442 /* Return true, if raid set in @rs is reshaping */
443 static bool rs_is_reshaping(struct raid_set *rs)
444 {
445         return rs->md.reshape_position != MaxSector;
446 }
447
448 /*
449  * bool helpers to test for various raid levels of a raid type @rt
450  */
451
452 /* Return true, if raid type in @rt is raid0 */
453 static bool rt_is_raid0(struct raid_type *rt)
454 {
455         return !rt->level;
456 }
457
458 /* Return true, if raid type in @rt is raid1 */
459 static bool rt_is_raid1(struct raid_type *rt)
460 {
461         return rt->level == 1;
462 }
463
464 /* Return true, if raid type in @rt is raid10 */
465 static bool rt_is_raid10(struct raid_type *rt)
466 {
467         return rt->level == 10;
468 }
469
470 /* Return true, if raid type in @rt is raid4/5 */
471 static bool rt_is_raid45(struct raid_type *rt)
472 {
473         return __within_range(rt->level, 4, 5);
474 }
475
476 /* Return true, if raid type in @rt is raid6 */
477 static bool rt_is_raid6(struct raid_type *rt)
478 {
479         return rt->level == 6;
480 }
481
482 /* Return true, if raid type in @rt is raid4/5/6 */
483 static bool rt_is_raid456(struct raid_type *rt)
484 {
485         return __within_range(rt->level, 4, 6);
486 }
487 /* END: raid level bools */
488
489 /* Return valid ctr flags for the raid level of @rs */
490 static unsigned long __valid_flags(struct raid_set *rs)
491 {
492         if (rt_is_raid0(rs->raid_type))
493                 return RAID0_VALID_FLAGS;
494         else if (rt_is_raid1(rs->raid_type))
495                 return RAID1_VALID_FLAGS;
496         else if (rt_is_raid10(rs->raid_type))
497                 return RAID10_VALID_FLAGS;
498         else if (rt_is_raid45(rs->raid_type))
499                 return RAID45_VALID_FLAGS;
500         else if (rt_is_raid6(rs->raid_type))
501                 return RAID6_VALID_FLAGS;
502
503         return 0;
504 }
505
506 /*
507  * Check for valid flags set on @rs
508  *
509  * Has to be called after parsing of the ctr flags!
510  */
511 static int rs_check_for_valid_flags(struct raid_set *rs)
512 {
513         if (rs->ctr_flags & ~__valid_flags(rs)) {
514                 rs->ti->error = "Invalid flags combination";
515                 return -EINVAL;
516         }
517
518         return 0;
519 }
520
521 /* MD raid10 bit definitions and helpers */
522 #define RAID10_OFFSET                   (1 << 16) /* stripes with data copies area adjacent on devices */
523 #define RAID10_BROCKEN_USE_FAR_SETS     (1 << 17) /* Broken in raid10.c: use sets instead of whole stripe rotation */
524 #define RAID10_USE_FAR_SETS             (1 << 18) /* Use sets instead of whole stripe rotation */
525 #define RAID10_FAR_COPIES_SHIFT         8         /* raid10 # far copies shift (2nd byte of layout) */
526
527 /* Return md raid10 near copies for @layout */
528 static unsigned int __raid10_near_copies(int layout)
529 {
530         return layout & 0xFF;
531 }
532
533 /* Return md raid10 far copies for @layout */
534 static unsigned int __raid10_far_copies(int layout)
535 {
536         return __raid10_near_copies(layout >> RAID10_FAR_COPIES_SHIFT);
537 }
538
539 /* Return true if md raid10 offset for @layout */
540 static bool __is_raid10_offset(int layout)
541 {
542         return !!(layout & RAID10_OFFSET);
543 }
544
545 /* Return true if md raid10 near for @layout */
546 static bool __is_raid10_near(int layout)
547 {
548         return !__is_raid10_offset(layout) && __raid10_near_copies(layout) > 1;
549 }
550
551 /* Return true if md raid10 far for @layout */
552 static bool __is_raid10_far(int layout)
553 {
554         return !__is_raid10_offset(layout) && __raid10_far_copies(layout) > 1;
555 }
556
557 /* Return md raid10 layout string for @layout */
558 static const char *raid10_md_layout_to_format(int layout)
559 {
560         /*
561          * Bit 16 stands for "offset"
562          * (i.e. adjacent stripes hold copies)
563          *
564          * Refer to MD's raid10.c for details
565          */
566         if (__is_raid10_offset(layout))
567                 return "offset";
568
569         if (__raid10_near_copies(layout) > 1)
570                 return "near";
571
572         if (__raid10_far_copies(layout) > 1)
573                 return "far";
574
575         return "unknown";
576 }
577
578 /* Return md raid10 algorithm for @name */
579 static int raid10_name_to_format(const char *name)
580 {
581         if (!strcasecmp(name, "near"))
582                 return ALGORITHM_RAID10_NEAR;
583         else if (!strcasecmp(name, "offset"))
584                 return ALGORITHM_RAID10_OFFSET;
585         else if (!strcasecmp(name, "far"))
586                 return ALGORITHM_RAID10_FAR;
587
588         return -EINVAL;
589 }
590
591 /* Return md raid10 copies for @layout */
592 static unsigned int raid10_md_layout_to_copies(int layout)
593 {
594         return max(__raid10_near_copies(layout), __raid10_far_copies(layout));
595 }
596
597 /* Return md raid10 format id for @format string */
598 static int raid10_format_to_md_layout(struct raid_set *rs,
599                                       unsigned int algorithm,
600                                       unsigned int copies)
601 {
602         unsigned int n = 1, f = 1, r = 0;
603
604         /*
605          * MD resilienece flaw:
606          *
607          * enabling use_far_sets for far/offset formats causes copies
608          * to be colocated on the same devs together with their origins!
609          *
610          * -> disable it for now in the definition above
611          */
612         if (algorithm == ALGORITHM_RAID10_DEFAULT ||
613             algorithm == ALGORITHM_RAID10_NEAR)
614                 n = copies;
615
616         else if (algorithm == ALGORITHM_RAID10_OFFSET) {
617                 f = copies;
618                 r = RAID10_OFFSET;
619                 if (!test_bit(__CTR_FLAG_RAID10_USE_NEAR_SETS, &rs->ctr_flags))
620                         r |= RAID10_USE_FAR_SETS;
621
622         } else if (algorithm == ALGORITHM_RAID10_FAR) {
623                 f = copies;
624                 if (!test_bit(__CTR_FLAG_RAID10_USE_NEAR_SETS, &rs->ctr_flags))
625                         r |= RAID10_USE_FAR_SETS;
626
627         } else
628                 return -EINVAL;
629
630         return r | (f << RAID10_FAR_COPIES_SHIFT) | n;
631 }
632 /* END: MD raid10 bit definitions and helpers */
633
634 /* Check for any of the raid10 algorithms */
635 static bool __got_raid10(struct raid_type *rtp, const int layout)
636 {
637         if (rtp->level == 10) {
638                 switch (rtp->algorithm) {
639                 case ALGORITHM_RAID10_DEFAULT:
640                 case ALGORITHM_RAID10_NEAR:
641                         return __is_raid10_near(layout);
642                 case ALGORITHM_RAID10_OFFSET:
643                         return __is_raid10_offset(layout);
644                 case ALGORITHM_RAID10_FAR:
645                         return __is_raid10_far(layout);
646                 default:
647                         break;
648                 }
649         }
650
651         return false;
652 }
653
654 /* Return raid_type for @name */
655 static struct raid_type *get_raid_type(const char *name)
656 {
657         struct raid_type *rtp = raid_types + ARRAY_SIZE(raid_types);
658
659         while (rtp-- > raid_types)
660                 if (!strcasecmp(rtp->name, name))
661                         return rtp;
662
663         return NULL;
664 }
665
666 /* Return raid_type for @name based derived from @level and @layout */
667 static struct raid_type *get_raid_type_by_ll(const int level, const int layout)
668 {
669         struct raid_type *rtp = raid_types + ARRAY_SIZE(raid_types);
670
671         while (rtp-- > raid_types) {
672                 /* RAID10 special checks based on @layout flags/properties */
673                 if (rtp->level == level &&
674                     (__got_raid10(rtp, layout) || rtp->algorithm == layout))
675                         return rtp;
676         }
677
678         return NULL;
679 }
680
681 /* Adjust rdev sectors */
682 static void rs_set_rdev_sectors(struct raid_set *rs)
683 {
684         struct mddev *mddev = &rs->md;
685         struct md_rdev *rdev;
686
687         /*
688          * raid10 sets rdev->sector to the device size, which
689          * is unintended in case of out-of-place reshaping
690          */
691         rdev_for_each(rdev, mddev)
692                 if (!test_bit(Journal, &rdev->flags))
693                         rdev->sectors = mddev->dev_sectors;
694 }
695
696 /*
697  * Change bdev capacity of @rs in case of a disk add/remove reshape
698  */
699 static void rs_set_capacity(struct raid_set *rs)
700 {
701         struct gendisk *gendisk = dm_disk(dm_table_get_md(rs->ti->table));
702
703         set_capacity_and_notify(gendisk, rs->md.array_sectors);
704 }
705
706 /*
707  * Set the mddev properties in @rs to the current
708  * ones retrieved from the freshest superblock
709  */
710 static void rs_set_cur(struct raid_set *rs)
711 {
712         struct mddev *mddev = &rs->md;
713
714         mddev->new_level = mddev->level;
715         mddev->new_layout = mddev->layout;
716         mddev->new_chunk_sectors = mddev->chunk_sectors;
717 }
718
719 /*
720  * Set the mddev properties in @rs to the new
721  * ones requested by the ctr
722  */
723 static void rs_set_new(struct raid_set *rs)
724 {
725         struct mddev *mddev = &rs->md;
726
727         mddev->level = mddev->new_level;
728         mddev->layout = mddev->new_layout;
729         mddev->chunk_sectors = mddev->new_chunk_sectors;
730         mddev->raid_disks = rs->raid_disks;
731         mddev->delta_disks = 0;
732 }
733
734 static struct raid_set *raid_set_alloc(struct dm_target *ti, struct raid_type *raid_type,
735                                        unsigned int raid_devs)
736 {
737         unsigned int i;
738         struct raid_set *rs;
739
740         if (raid_devs <= raid_type->parity_devs) {
741                 ti->error = "Insufficient number of devices";
742                 return ERR_PTR(-EINVAL);
743         }
744
745         rs = kzalloc(struct_size(rs, dev, raid_devs), GFP_KERNEL);
746         if (!rs) {
747                 ti->error = "Cannot allocate raid context";
748                 return ERR_PTR(-ENOMEM);
749         }
750
751         mddev_init(&rs->md);
752
753         rs->raid_disks = raid_devs;
754         rs->delta_disks = 0;
755
756         rs->ti = ti;
757         rs->raid_type = raid_type;
758         rs->stripe_cache_entries = 256;
759         rs->md.raid_disks = raid_devs;
760         rs->md.level = raid_type->level;
761         rs->md.new_level = rs->md.level;
762         rs->md.layout = raid_type->algorithm;
763         rs->md.new_layout = rs->md.layout;
764         rs->md.delta_disks = 0;
765         rs->md.recovery_cp = MaxSector;
766
767         for (i = 0; i < raid_devs; i++)
768                 md_rdev_init(&rs->dev[i].rdev);
769
770         /*
771          * Remaining items to be initialized by further RAID params:
772          *  rs->md.persistent
773          *  rs->md.external
774          *  rs->md.chunk_sectors
775          *  rs->md.new_chunk_sectors
776          *  rs->md.dev_sectors
777          */
778
779         return rs;
780 }
781
782 /* Free all @rs allocations */
783 static void raid_set_free(struct raid_set *rs)
784 {
785         int i;
786
787         if (rs->journal_dev.dev) {
788                 md_rdev_clear(&rs->journal_dev.rdev);
789                 dm_put_device(rs->ti, rs->journal_dev.dev);
790         }
791
792         for (i = 0; i < rs->raid_disks; i++) {
793                 if (rs->dev[i].meta_dev)
794                         dm_put_device(rs->ti, rs->dev[i].meta_dev);
795                 md_rdev_clear(&rs->dev[i].rdev);
796                 if (rs->dev[i].data_dev)
797                         dm_put_device(rs->ti, rs->dev[i].data_dev);
798         }
799
800         kfree(rs);
801 }
802
803 /*
804  * For every device we have two words
805  *  <meta_dev>: meta device name or '-' if missing
806  *  <data_dev>: data device name or '-' if missing
807  *
808  * The following are permitted:
809  *    - -
810  *    - <data_dev>
811  *    <meta_dev> <data_dev>
812  *
813  * The following is not allowed:
814  *    <meta_dev> -
815  *
816  * This code parses those words.  If there is a failure,
817  * the caller must use raid_set_free() to unwind the operations.
818  */
819 static int parse_dev_params(struct raid_set *rs, struct dm_arg_set *as)
820 {
821         int i;
822         int rebuild = 0;
823         int metadata_available = 0;
824         int r = 0;
825         const char *arg;
826
827         /* Put off the number of raid devices argument to get to dev pairs */
828         arg = dm_shift_arg(as);
829         if (!arg)
830                 return -EINVAL;
831
832         for (i = 0; i < rs->raid_disks; i++) {
833                 rs->dev[i].rdev.raid_disk = i;
834
835                 rs->dev[i].meta_dev = NULL;
836                 rs->dev[i].data_dev = NULL;
837
838                 /*
839                  * There are no offsets initially.
840                  * Out of place reshape will set them accordingly.
841                  */
842                 rs->dev[i].rdev.data_offset = 0;
843                 rs->dev[i].rdev.new_data_offset = 0;
844                 rs->dev[i].rdev.mddev = &rs->md;
845
846                 arg = dm_shift_arg(as);
847                 if (!arg)
848                         return -EINVAL;
849
850                 if (strcmp(arg, "-")) {
851                         r = dm_get_device(rs->ti, arg, dm_table_get_mode(rs->ti->table),
852                                           &rs->dev[i].meta_dev);
853                         if (r) {
854                                 rs->ti->error = "RAID metadata device lookup failure";
855                                 return r;
856                         }
857
858                         rs->dev[i].rdev.sb_page = alloc_page(GFP_KERNEL);
859                         if (!rs->dev[i].rdev.sb_page) {
860                                 rs->ti->error = "Failed to allocate superblock page";
861                                 return -ENOMEM;
862                         }
863                 }
864
865                 arg = dm_shift_arg(as);
866                 if (!arg)
867                         return -EINVAL;
868
869                 if (!strcmp(arg, "-")) {
870                         if (!test_bit(In_sync, &rs->dev[i].rdev.flags) &&
871                             (!rs->dev[i].rdev.recovery_offset)) {
872                                 rs->ti->error = "Drive designated for rebuild not specified";
873                                 return -EINVAL;
874                         }
875
876                         if (rs->dev[i].meta_dev) {
877                                 rs->ti->error = "No data device supplied with metadata device";
878                                 return -EINVAL;
879                         }
880
881                         continue;
882                 }
883
884                 r = dm_get_device(rs->ti, arg, dm_table_get_mode(rs->ti->table),
885                                   &rs->dev[i].data_dev);
886                 if (r) {
887                         rs->ti->error = "RAID device lookup failure";
888                         return r;
889                 }
890
891                 if (rs->dev[i].meta_dev) {
892                         metadata_available = 1;
893                         rs->dev[i].rdev.meta_bdev = rs->dev[i].meta_dev->bdev;
894                 }
895                 rs->dev[i].rdev.bdev = rs->dev[i].data_dev->bdev;
896                 list_add_tail(&rs->dev[i].rdev.same_set, &rs->md.disks);
897                 if (!test_bit(In_sync, &rs->dev[i].rdev.flags))
898                         rebuild++;
899         }
900
901         if (rs->journal_dev.dev)
902                 list_add_tail(&rs->journal_dev.rdev.same_set, &rs->md.disks);
903
904         if (metadata_available) {
905                 rs->md.external = 0;
906                 rs->md.persistent = 1;
907                 rs->md.major_version = 2;
908         } else if (rebuild && !rs->md.recovery_cp) {
909                 /*
910                  * Without metadata, we will not be able to tell if the array
911                  * is in-sync or not - we must assume it is not.  Therefore,
912                  * it is impossible to rebuild a drive.
913                  *
914                  * Even if there is metadata, the on-disk information may
915                  * indicate that the array is not in-sync and it will then
916                  * fail at that time.
917                  *
918                  * User could specify 'nosync' option if desperate.
919                  */
920                 rs->ti->error = "Unable to rebuild drive while array is not in-sync";
921                 return -EINVAL;
922         }
923
924         return 0;
925 }
926
927 /*
928  * validate_region_size
929  * @rs
930  * @region_size:  region size in sectors.  If 0, pick a size (4MiB default).
931  *
932  * Set rs->md.bitmap_info.chunksize (which really refers to 'region size').
933  * Ensure that (ti->len/region_size < 2^21) - required by MD bitmap.
934  *
935  * Returns: 0 on success, -EINVAL on failure.
936  */
937 static int validate_region_size(struct raid_set *rs, unsigned long region_size)
938 {
939         unsigned long min_region_size = rs->ti->len / (1 << 21);
940
941         if (rs_is_raid0(rs))
942                 return 0;
943
944         if (!region_size) {
945                 /*
946                  * Choose a reasonable default.  All figures in sectors.
947                  */
948                 if (min_region_size > (1 << 13)) {
949                         /* If not a power of 2, make it the next power of 2 */
950                         region_size = roundup_pow_of_two(min_region_size);
951                         DMINFO("Choosing default region size of %lu sectors",
952                                region_size);
953                 } else {
954                         DMINFO("Choosing default region size of 4MiB");
955                         region_size = 1 << 13; /* sectors */
956                 }
957         } else {
958                 /*
959                  * Validate user-supplied value.
960                  */
961                 if (region_size > rs->ti->len) {
962                         rs->ti->error = "Supplied region size is too large";
963                         return -EINVAL;
964                 }
965
966                 if (region_size < min_region_size) {
967                         DMERR("Supplied region_size (%lu sectors) below minimum (%lu)",
968                               region_size, min_region_size);
969                         rs->ti->error = "Supplied region size is too small";
970                         return -EINVAL;
971                 }
972
973                 if (!is_power_of_2(region_size)) {
974                         rs->ti->error = "Region size is not a power of 2";
975                         return -EINVAL;
976                 }
977
978                 if (region_size < rs->md.chunk_sectors) {
979                         rs->ti->error = "Region size is smaller than the chunk size";
980                         return -EINVAL;
981                 }
982         }
983
984         /*
985          * Convert sectors to bytes.
986          */
987         rs->md.bitmap_info.chunksize = to_bytes(region_size);
988
989         return 0;
990 }
991
992 /*
993  * validate_raid_redundancy
994  * @rs
995  *
996  * Determine if there are enough devices in the array that haven't
997  * failed (or are being rebuilt) to form a usable array.
998  *
999  * Returns: 0 on success, -EINVAL on failure.
1000  */
1001 static int validate_raid_redundancy(struct raid_set *rs)
1002 {
1003         unsigned int i, rebuild_cnt = 0;
1004         unsigned int rebuilds_per_group = 0, copies;
1005         unsigned int group_size, last_group_start;
1006
1007         for (i = 0; i < rs->md.raid_disks; i++)
1008                 if (!test_bit(In_sync, &rs->dev[i].rdev.flags) ||
1009                     !rs->dev[i].rdev.sb_page)
1010                         rebuild_cnt++;
1011
1012         switch (rs->md.level) {
1013         case 0:
1014                 break;
1015         case 1:
1016                 if (rebuild_cnt >= rs->md.raid_disks)
1017                         goto too_many;
1018                 break;
1019         case 4:
1020         case 5:
1021         case 6:
1022                 if (rebuild_cnt > rs->raid_type->parity_devs)
1023                         goto too_many;
1024                 break;
1025         case 10:
1026                 copies = raid10_md_layout_to_copies(rs->md.new_layout);
1027                 if (copies < 2) {
1028                         DMERR("Bogus raid10 data copies < 2!");
1029                         return -EINVAL;
1030                 }
1031
1032                 if (rebuild_cnt < copies)
1033                         break;
1034
1035                 /*
1036                  * It is possible to have a higher rebuild count for RAID10,
1037                  * as long as the failed devices occur in different mirror
1038                  * groups (i.e. different stripes).
1039                  *
1040                  * When checking "near" format, make sure no adjacent devices
1041                  * have failed beyond what can be handled.  In addition to the
1042                  * simple case where the number of devices is a multiple of the
1043                  * number of copies, we must also handle cases where the number
1044                  * of devices is not a multiple of the number of copies.
1045                  * E.g.    dev1 dev2 dev3 dev4 dev5
1046                  *          A    A    B    B    C
1047                  *          C    D    D    E    E
1048                  */
1049                 if (__is_raid10_near(rs->md.new_layout)) {
1050                         for (i = 0; i < rs->md.raid_disks; i++) {
1051                                 if (!(i % copies))
1052                                         rebuilds_per_group = 0;
1053                                 if ((!rs->dev[i].rdev.sb_page ||
1054                                     !test_bit(In_sync, &rs->dev[i].rdev.flags)) &&
1055                                     (++rebuilds_per_group >= copies))
1056                                         goto too_many;
1057                         }
1058                         break;
1059                 }
1060
1061                 /*
1062                  * When checking "far" and "offset" formats, we need to ensure
1063                  * that the device that holds its copy is not also dead or
1064                  * being rebuilt.  (Note that "far" and "offset" formats only
1065                  * support two copies right now.  These formats also only ever
1066                  * use the 'use_far_sets' variant.)
1067                  *
1068                  * This check is somewhat complicated by the need to account
1069                  * for arrays that are not a multiple of (far) copies.  This
1070                  * results in the need to treat the last (potentially larger)
1071                  * set differently.
1072                  */
1073                 group_size = (rs->md.raid_disks / copies);
1074                 last_group_start = (rs->md.raid_disks / group_size) - 1;
1075                 last_group_start *= group_size;
1076                 for (i = 0; i < rs->md.raid_disks; i++) {
1077                         if (!(i % copies) && !(i > last_group_start))
1078                                 rebuilds_per_group = 0;
1079                         if ((!rs->dev[i].rdev.sb_page ||
1080                              !test_bit(In_sync, &rs->dev[i].rdev.flags)) &&
1081                             (++rebuilds_per_group >= copies))
1082                                         goto too_many;
1083                 }
1084                 break;
1085         default:
1086                 if (rebuild_cnt)
1087                         return -EINVAL;
1088         }
1089
1090         return 0;
1091
1092 too_many:
1093         return -EINVAL;
1094 }
1095
1096 /*
1097  * Possible arguments are...
1098  *      <chunk_size> [optional_args]
1099  *
1100  * Argument definitions
1101  *    <chunk_size>                      The number of sectors per disk that
1102  *                                      will form the "stripe"
1103  *    [[no]sync]                        Force or prevent recovery of the
1104  *                                      entire array
1105  *    [rebuild <idx>]                   Rebuild the drive indicated by the index
1106  *    [daemon_sleep <ms>]               Time between bitmap daemon work to
1107  *                                      clear bits
1108  *    [min_recovery_rate <kB/sec/disk>] Throttle RAID initialization
1109  *    [max_recovery_rate <kB/sec/disk>] Throttle RAID initialization
1110  *    [write_mostly <idx>]              Indicate a write mostly drive via index
1111  *    [max_write_behind <sectors>]      See '-write-behind=' (man mdadm)
1112  *    [stripe_cache <sectors>]          Stripe cache size for higher RAIDs
1113  *    [region_size <sectors>]           Defines granularity of bitmap
1114  *    [journal_dev <dev>]               raid4/5/6 journaling deviice
1115  *                                      (i.e. write hole closing log)
1116  *
1117  * RAID10-only options:
1118  *    [raid10_copies <# copies>]        Number of copies.  (Default: 2)
1119  *    [raid10_format <near|far|offset>] Layout algorithm.  (Default: near)
1120  */
1121 static int parse_raid_params(struct raid_set *rs, struct dm_arg_set *as,
1122                              unsigned int num_raid_params)
1123 {
1124         int value, raid10_format = ALGORITHM_RAID10_DEFAULT;
1125         unsigned int raid10_copies = 2;
1126         unsigned int i, write_mostly = 0;
1127         unsigned int region_size = 0;
1128         sector_t max_io_len;
1129         const char *arg, *key;
1130         struct raid_dev *rd;
1131         struct raid_type *rt = rs->raid_type;
1132
1133         arg = dm_shift_arg(as);
1134         num_raid_params--; /* Account for chunk_size argument */
1135
1136         if (kstrtoint(arg, 10, &value) < 0) {
1137                 rs->ti->error = "Bad numerical argument given for chunk_size";
1138                 return -EINVAL;
1139         }
1140
1141         /*
1142          * First, parse the in-order required arguments
1143          * "chunk_size" is the only argument of this type.
1144          */
1145         if (rt_is_raid1(rt)) {
1146                 if (value)
1147                         DMERR("Ignoring chunk size parameter for RAID 1");
1148                 value = 0;
1149         } else if (!is_power_of_2(value)) {
1150                 rs->ti->error = "Chunk size must be a power of 2";
1151                 return -EINVAL;
1152         } else if (value < 8) {
1153                 rs->ti->error = "Chunk size value is too small";
1154                 return -EINVAL;
1155         }
1156
1157         rs->md.new_chunk_sectors = rs->md.chunk_sectors = value;
1158
1159         /*
1160          * We set each individual device as In_sync with a completed
1161          * 'recovery_offset'.  If there has been a device failure or
1162          * replacement then one of the following cases applies:
1163          *
1164          *   1) User specifies 'rebuild'.
1165          *      - Device is reset when param is read.
1166          *   2) A new device is supplied.
1167          *      - No matching superblock found, resets device.
1168          *   3) Device failure was transient and returns on reload.
1169          *      - Failure noticed, resets device for bitmap replay.
1170          *   4) Device hadn't completed recovery after previous failure.
1171          *      - Superblock is read and overrides recovery_offset.
1172          *
1173          * What is found in the superblocks of the devices is always
1174          * authoritative, unless 'rebuild' or '[no]sync' was specified.
1175          */
1176         for (i = 0; i < rs->raid_disks; i++) {
1177                 set_bit(In_sync, &rs->dev[i].rdev.flags);
1178                 rs->dev[i].rdev.recovery_offset = MaxSector;
1179         }
1180
1181         /*
1182          * Second, parse the unordered optional arguments
1183          */
1184         for (i = 0; i < num_raid_params; i++) {
1185                 key = dm_shift_arg(as);
1186                 if (!key) {
1187                         rs->ti->error = "Not enough raid parameters given";
1188                         return -EINVAL;
1189                 }
1190
1191                 if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_NOSYNC))) {
1192                         if (test_and_set_bit(__CTR_FLAG_NOSYNC, &rs->ctr_flags)) {
1193                                 rs->ti->error = "Only one 'nosync' argument allowed";
1194                                 return -EINVAL;
1195                         }
1196                         continue;
1197                 }
1198                 if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_SYNC))) {
1199                         if (test_and_set_bit(__CTR_FLAG_SYNC, &rs->ctr_flags)) {
1200                                 rs->ti->error = "Only one 'sync' argument allowed";
1201                                 return -EINVAL;
1202                         }
1203                         continue;
1204                 }
1205                 if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_RAID10_USE_NEAR_SETS))) {
1206                         if (test_and_set_bit(__CTR_FLAG_RAID10_USE_NEAR_SETS, &rs->ctr_flags)) {
1207                                 rs->ti->error = "Only one 'raid10_use_new_sets' argument allowed";
1208                                 return -EINVAL;
1209                         }
1210                         continue;
1211                 }
1212
1213                 arg = dm_shift_arg(as);
1214                 i++; /* Account for the argument pairs */
1215                 if (!arg) {
1216                         rs->ti->error = "Wrong number of raid parameters given";
1217                         return -EINVAL;
1218                 }
1219
1220                 /*
1221                  * Parameters that take a string value are checked here.
1222                  */
1223                 /* "raid10_format {near|offset|far} */
1224                 if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_RAID10_FORMAT))) {
1225                         if (test_and_set_bit(__CTR_FLAG_RAID10_FORMAT, &rs->ctr_flags)) {
1226                                 rs->ti->error = "Only one 'raid10_format' argument pair allowed";
1227                                 return -EINVAL;
1228                         }
1229                         if (!rt_is_raid10(rt)) {
1230                                 rs->ti->error = "'raid10_format' is an invalid parameter for this RAID type";
1231                                 return -EINVAL;
1232                         }
1233                         raid10_format = raid10_name_to_format(arg);
1234                         if (raid10_format < 0) {
1235                                 rs->ti->error = "Invalid 'raid10_format' value given";
1236                                 return raid10_format;
1237                         }
1238                         continue;
1239                 }
1240
1241                 /* "journal_dev <dev>" */
1242                 if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_JOURNAL_DEV))) {
1243                         int r;
1244                         struct md_rdev *jdev;
1245
1246                         if (test_and_set_bit(__CTR_FLAG_JOURNAL_DEV, &rs->ctr_flags)) {
1247                                 rs->ti->error = "Only one raid4/5/6 set journaling device allowed";
1248                                 return -EINVAL;
1249                         }
1250                         if (!rt_is_raid456(rt)) {
1251                                 rs->ti->error = "'journal_dev' is an invalid parameter for this RAID type";
1252                                 return -EINVAL;
1253                         }
1254                         r = dm_get_device(rs->ti, arg, dm_table_get_mode(rs->ti->table),
1255                                           &rs->journal_dev.dev);
1256                         if (r) {
1257                                 rs->ti->error = "raid4/5/6 journal device lookup failure";
1258                                 return r;
1259                         }
1260                         jdev = &rs->journal_dev.rdev;
1261                         md_rdev_init(jdev);
1262                         jdev->mddev = &rs->md;
1263                         jdev->bdev = rs->journal_dev.dev->bdev;
1264                         jdev->sectors = to_sector(i_size_read(jdev->bdev->bd_inode));
1265                         if (jdev->sectors < MIN_RAID456_JOURNAL_SPACE) {
1266                                 rs->ti->error = "No space for raid4/5/6 journal";
1267                                 return -ENOSPC;
1268                         }
1269                         rs->journal_dev.mode = R5C_JOURNAL_MODE_WRITE_THROUGH;
1270                         set_bit(Journal, &jdev->flags);
1271                         continue;
1272                 }
1273
1274                 /* "journal_mode <mode>" ("journal_dev" mandatory!) */
1275                 if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_JOURNAL_MODE))) {
1276                         int r;
1277
1278                         if (!test_bit(__CTR_FLAG_JOURNAL_DEV, &rs->ctr_flags)) {
1279                                 rs->ti->error = "raid4/5/6 'journal_mode' is invalid without 'journal_dev'";
1280                                 return -EINVAL;
1281                         }
1282                         if (test_and_set_bit(__CTR_FLAG_JOURNAL_MODE, &rs->ctr_flags)) {
1283                                 rs->ti->error = "Only one raid4/5/6 'journal_mode' argument allowed";
1284                                 return -EINVAL;
1285                         }
1286                         r = dm_raid_journal_mode_to_md(arg);
1287                         if (r < 0) {
1288                                 rs->ti->error = "Invalid 'journal_mode' argument";
1289                                 return r;
1290                         }
1291                         rs->journal_dev.mode = r;
1292                         continue;
1293                 }
1294
1295                 /*
1296                  * Parameters with number values from here on.
1297                  */
1298                 if (kstrtoint(arg, 10, &value) < 0) {
1299                         rs->ti->error = "Bad numerical argument given in raid params";
1300                         return -EINVAL;
1301                 }
1302
1303                 if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_REBUILD))) {
1304                         /*
1305                          * "rebuild" is being passed in by userspace to provide
1306                          * indexes of replaced devices and to set up additional
1307                          * devices on raid level takeover.
1308                          */
1309                         if (!__within_range(value, 0, rs->raid_disks - 1)) {
1310                                 rs->ti->error = "Invalid rebuild index given";
1311                                 return -EINVAL;
1312                         }
1313
1314                         if (test_and_set_bit(value, (void *) rs->rebuild_disks)) {
1315                                 rs->ti->error = "rebuild for this index already given";
1316                                 return -EINVAL;
1317                         }
1318
1319                         rd = rs->dev + value;
1320                         clear_bit(In_sync, &rd->rdev.flags);
1321                         clear_bit(Faulty, &rd->rdev.flags);
1322                         rd->rdev.recovery_offset = 0;
1323                         set_bit(__CTR_FLAG_REBUILD, &rs->ctr_flags);
1324                 } else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_WRITE_MOSTLY))) {
1325                         if (!rt_is_raid1(rt)) {
1326                                 rs->ti->error = "write_mostly option is only valid for RAID1";
1327                                 return -EINVAL;
1328                         }
1329
1330                         if (!__within_range(value, 0, rs->md.raid_disks - 1)) {
1331                                 rs->ti->error = "Invalid write_mostly index given";
1332                                 return -EINVAL;
1333                         }
1334
1335                         write_mostly++;
1336                         set_bit(WriteMostly, &rs->dev[value].rdev.flags);
1337                         set_bit(__CTR_FLAG_WRITE_MOSTLY, &rs->ctr_flags);
1338                 } else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_MAX_WRITE_BEHIND))) {
1339                         if (!rt_is_raid1(rt)) {
1340                                 rs->ti->error = "max_write_behind option is only valid for RAID1";
1341                                 return -EINVAL;
1342                         }
1343
1344                         if (test_and_set_bit(__CTR_FLAG_MAX_WRITE_BEHIND, &rs->ctr_flags)) {
1345                                 rs->ti->error = "Only one max_write_behind argument pair allowed";
1346                                 return -EINVAL;
1347                         }
1348
1349                         /*
1350                          * In device-mapper, we specify things in sectors, but
1351                          * MD records this value in kB
1352                          */
1353                         if (value < 0 || value / 2 > COUNTER_MAX) {
1354                                 rs->ti->error = "Max write-behind limit out of range";
1355                                 return -EINVAL;
1356                         }
1357
1358                         rs->md.bitmap_info.max_write_behind = value / 2;
1359                 } else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_DAEMON_SLEEP))) {
1360                         if (test_and_set_bit(__CTR_FLAG_DAEMON_SLEEP, &rs->ctr_flags)) {
1361                                 rs->ti->error = "Only one daemon_sleep argument pair allowed";
1362                                 return -EINVAL;
1363                         }
1364                         if (value < 0) {
1365                                 rs->ti->error = "daemon sleep period out of range";
1366                                 return -EINVAL;
1367                         }
1368                         rs->md.bitmap_info.daemon_sleep = value;
1369                 } else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_DATA_OFFSET))) {
1370                         /* Userspace passes new data_offset after having extended the the data image LV */
1371                         if (test_and_set_bit(__CTR_FLAG_DATA_OFFSET, &rs->ctr_flags)) {
1372                                 rs->ti->error = "Only one data_offset argument pair allowed";
1373                                 return -EINVAL;
1374                         }
1375                         /* Ensure sensible data offset */
1376                         if (value < 0 ||
1377                             (value && (value < MIN_FREE_RESHAPE_SPACE || value % to_sector(PAGE_SIZE)))) {
1378                                 rs->ti->error = "Bogus data_offset value";
1379                                 return -EINVAL;
1380                         }
1381                         rs->data_offset = value;
1382                 } else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_DELTA_DISKS))) {
1383                         /* Define the +/-# of disks to add to/remove from the given raid set */
1384                         if (test_and_set_bit(__CTR_FLAG_DELTA_DISKS, &rs->ctr_flags)) {
1385                                 rs->ti->error = "Only one delta_disks argument pair allowed";
1386                                 return -EINVAL;
1387                         }
1388                         /* Ensure MAX_RAID_DEVICES and raid type minimal_devs! */
1389                         if (!__within_range(abs(value), 1, MAX_RAID_DEVICES - rt->minimal_devs)) {
1390                                 rs->ti->error = "Too many delta_disk requested";
1391                                 return -EINVAL;
1392                         }
1393
1394                         rs->delta_disks = value;
1395                 } else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_STRIPE_CACHE))) {
1396                         if (test_and_set_bit(__CTR_FLAG_STRIPE_CACHE, &rs->ctr_flags)) {
1397                                 rs->ti->error = "Only one stripe_cache argument pair allowed";
1398                                 return -EINVAL;
1399                         }
1400
1401                         if (!rt_is_raid456(rt)) {
1402                                 rs->ti->error = "Inappropriate argument: stripe_cache";
1403                                 return -EINVAL;
1404                         }
1405
1406                         if (value < 0) {
1407                                 rs->ti->error = "Bogus stripe cache entries value";
1408                                 return -EINVAL;
1409                         }
1410                         rs->stripe_cache_entries = value;
1411                 } else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_MIN_RECOVERY_RATE))) {
1412                         if (test_and_set_bit(__CTR_FLAG_MIN_RECOVERY_RATE, &rs->ctr_flags)) {
1413                                 rs->ti->error = "Only one min_recovery_rate argument pair allowed";
1414                                 return -EINVAL;
1415                         }
1416
1417                         if (value < 0) {
1418                                 rs->ti->error = "min_recovery_rate out of range";
1419                                 return -EINVAL;
1420                         }
1421                         rs->md.sync_speed_min = value;
1422                 } else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_MAX_RECOVERY_RATE))) {
1423                         if (test_and_set_bit(__CTR_FLAG_MAX_RECOVERY_RATE, &rs->ctr_flags)) {
1424                                 rs->ti->error = "Only one max_recovery_rate argument pair allowed";
1425                                 return -EINVAL;
1426                         }
1427
1428                         if (value < 0) {
1429                                 rs->ti->error = "max_recovery_rate out of range";
1430                                 return -EINVAL;
1431                         }
1432                         rs->md.sync_speed_max = value;
1433                 } else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_REGION_SIZE))) {
1434                         if (test_and_set_bit(__CTR_FLAG_REGION_SIZE, &rs->ctr_flags)) {
1435                                 rs->ti->error = "Only one region_size argument pair allowed";
1436                                 return -EINVAL;
1437                         }
1438
1439                         region_size = value;
1440                         rs->requested_bitmap_chunk_sectors = value;
1441                 } else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_RAID10_COPIES))) {
1442                         if (test_and_set_bit(__CTR_FLAG_RAID10_COPIES, &rs->ctr_flags)) {
1443                                 rs->ti->error = "Only one raid10_copies argument pair allowed";
1444                                 return -EINVAL;
1445                         }
1446
1447                         if (!__within_range(value, 2, rs->md.raid_disks)) {
1448                                 rs->ti->error = "Bad value for 'raid10_copies'";
1449                                 return -EINVAL;
1450                         }
1451
1452                         raid10_copies = value;
1453                 } else {
1454                         DMERR("Unable to parse RAID parameter: %s", key);
1455                         rs->ti->error = "Unable to parse RAID parameter";
1456                         return -EINVAL;
1457                 }
1458         }
1459
1460         if (test_bit(__CTR_FLAG_SYNC, &rs->ctr_flags) &&
1461             test_bit(__CTR_FLAG_NOSYNC, &rs->ctr_flags)) {
1462                 rs->ti->error = "sync and nosync are mutually exclusive";
1463                 return -EINVAL;
1464         }
1465
1466         if (test_bit(__CTR_FLAG_REBUILD, &rs->ctr_flags) &&
1467             (test_bit(__CTR_FLAG_SYNC, &rs->ctr_flags) ||
1468              test_bit(__CTR_FLAG_NOSYNC, &rs->ctr_flags))) {
1469                 rs->ti->error = "sync/nosync and rebuild are mutually exclusive";
1470                 return -EINVAL;
1471         }
1472
1473         if (write_mostly >= rs->md.raid_disks) {
1474                 rs->ti->error = "Can't set all raid1 devices to write_mostly";
1475                 return -EINVAL;
1476         }
1477
1478         if (rs->md.sync_speed_max &&
1479             rs->md.sync_speed_min > rs->md.sync_speed_max) {
1480                 rs->ti->error = "Bogus recovery rates";
1481                 return -EINVAL;
1482         }
1483
1484         if (validate_region_size(rs, region_size))
1485                 return -EINVAL;
1486
1487         if (rs->md.chunk_sectors)
1488                 max_io_len = rs->md.chunk_sectors;
1489         else
1490                 max_io_len = region_size;
1491
1492         if (dm_set_target_max_io_len(rs->ti, max_io_len))
1493                 return -EINVAL;
1494
1495         if (rt_is_raid10(rt)) {
1496                 if (raid10_copies > rs->md.raid_disks) {
1497                         rs->ti->error = "Not enough devices to satisfy specification";
1498                         return -EINVAL;
1499                 }
1500
1501                 rs->md.new_layout = raid10_format_to_md_layout(rs, raid10_format, raid10_copies);
1502                 if (rs->md.new_layout < 0) {
1503                         rs->ti->error = "Error getting raid10 format";
1504                         return rs->md.new_layout;
1505                 }
1506
1507                 rt = get_raid_type_by_ll(10, rs->md.new_layout);
1508                 if (!rt) {
1509                         rs->ti->error = "Failed to recognize new raid10 layout";
1510                         return -EINVAL;
1511                 }
1512
1513                 if ((rt->algorithm == ALGORITHM_RAID10_DEFAULT ||
1514                      rt->algorithm == ALGORITHM_RAID10_NEAR) &&
1515                     test_bit(__CTR_FLAG_RAID10_USE_NEAR_SETS, &rs->ctr_flags)) {
1516                         rs->ti->error = "RAID10 format 'near' and 'raid10_use_near_sets' are incompatible";
1517                         return -EINVAL;
1518                 }
1519         }
1520
1521         rs->raid10_copies = raid10_copies;
1522
1523         /* Assume there are no metadata devices until the drives are parsed */
1524         rs->md.persistent = 0;
1525         rs->md.external = 1;
1526
1527         /* Check, if any invalid ctr arguments have been passed in for the raid level */
1528         return rs_check_for_valid_flags(rs);
1529 }
1530
1531 /* Set raid4/5/6 cache size */
1532 static int rs_set_raid456_stripe_cache(struct raid_set *rs)
1533 {
1534         int r;
1535         struct r5conf *conf;
1536         struct mddev *mddev = &rs->md;
1537         uint32_t min_stripes = max(mddev->chunk_sectors, mddev->new_chunk_sectors) / 2;
1538         uint32_t nr_stripes = rs->stripe_cache_entries;
1539
1540         if (!rt_is_raid456(rs->raid_type)) {
1541                 rs->ti->error = "Inappropriate raid level; cannot change stripe_cache size";
1542                 return -EINVAL;
1543         }
1544
1545         if (nr_stripes < min_stripes) {
1546                 DMINFO("Adjusting requested %u stripe cache entries to %u to suit stripe size",
1547                        nr_stripes, min_stripes);
1548                 nr_stripes = min_stripes;
1549         }
1550
1551         conf = mddev->private;
1552         if (!conf) {
1553                 rs->ti->error = "Cannot change stripe_cache size on inactive RAID set";
1554                 return -EINVAL;
1555         }
1556
1557         /* Try setting number of stripes in raid456 stripe cache */
1558         if (conf->min_nr_stripes != nr_stripes) {
1559                 r = raid5_set_cache_size(mddev, nr_stripes);
1560                 if (r) {
1561                         rs->ti->error = "Failed to set raid4/5/6 stripe cache size";
1562                         return r;
1563                 }
1564
1565                 DMINFO("%u stripe cache entries", nr_stripes);
1566         }
1567
1568         return 0;
1569 }
1570
1571 /* Return # of data stripes as kept in mddev as of @rs (i.e. as of superblock) */
1572 static unsigned int mddev_data_stripes(struct raid_set *rs)
1573 {
1574         return rs->md.raid_disks - rs->raid_type->parity_devs;
1575 }
1576
1577 /* Return # of data stripes of @rs (i.e. as of ctr) */
1578 static unsigned int rs_data_stripes(struct raid_set *rs)
1579 {
1580         return rs->raid_disks - rs->raid_type->parity_devs;
1581 }
1582
1583 /*
1584  * Retrieve rdev->sectors from any valid raid device of @rs
1585  * to allow userpace to pass in arbitray "- -" device tupples.
1586  */
1587 static sector_t __rdev_sectors(struct raid_set *rs)
1588 {
1589         int i;
1590
1591         for (i = 0; i < rs->md.raid_disks; i++) {
1592                 struct md_rdev *rdev = &rs->dev[i].rdev;
1593
1594                 if (!test_bit(Journal, &rdev->flags) &&
1595                     rdev->bdev && rdev->sectors)
1596                         return rdev->sectors;
1597         }
1598
1599         return 0;
1600 }
1601
1602 /* Check that calculated dev_sectors fits all component devices. */
1603 static int _check_data_dev_sectors(struct raid_set *rs)
1604 {
1605         sector_t ds = ~0;
1606         struct md_rdev *rdev;
1607
1608         rdev_for_each(rdev, &rs->md)
1609                 if (!test_bit(Journal, &rdev->flags) && rdev->bdev) {
1610                         ds = min(ds, to_sector(i_size_read(rdev->bdev->bd_inode)));
1611                         if (ds < rs->md.dev_sectors) {
1612                                 rs->ti->error = "Component device(s) too small";
1613                                 return -EINVAL;
1614                         }
1615                 }
1616
1617         return 0;
1618 }
1619
1620 /* Calculate the sectors per device and per array used for @rs */
1621 static int rs_set_dev_and_array_sectors(struct raid_set *rs, sector_t sectors, bool use_mddev)
1622 {
1623         int delta_disks;
1624         unsigned int data_stripes;
1625         sector_t array_sectors = sectors, dev_sectors = sectors;
1626         struct mddev *mddev = &rs->md;
1627
1628         if (use_mddev) {
1629                 delta_disks = mddev->delta_disks;
1630                 data_stripes = mddev_data_stripes(rs);
1631         } else {
1632                 delta_disks = rs->delta_disks;
1633                 data_stripes = rs_data_stripes(rs);
1634         }
1635
1636         /* Special raid1 case w/o delta_disks support (yet) */
1637         if (rt_is_raid1(rs->raid_type))
1638                 ;
1639         else if (rt_is_raid10(rs->raid_type)) {
1640                 if (rs->raid10_copies < 2 ||
1641                     delta_disks < 0) {
1642                         rs->ti->error = "Bogus raid10 data copies or delta disks";
1643                         return -EINVAL;
1644                 }
1645
1646                 dev_sectors *= rs->raid10_copies;
1647                 if (sector_div(dev_sectors, data_stripes))
1648                         goto bad;
1649
1650                 array_sectors = (data_stripes + delta_disks) * dev_sectors;
1651                 if (sector_div(array_sectors, rs->raid10_copies))
1652                         goto bad;
1653
1654         } else if (sector_div(dev_sectors, data_stripes))
1655                 goto bad;
1656
1657         else
1658                 /* Striped layouts */
1659                 array_sectors = (data_stripes + delta_disks) * dev_sectors;
1660
1661         mddev->array_sectors = array_sectors;
1662         mddev->dev_sectors = dev_sectors;
1663         rs_set_rdev_sectors(rs);
1664
1665         return _check_data_dev_sectors(rs);
1666 bad:
1667         rs->ti->error = "Target length not divisible by number of data devices";
1668         return -EINVAL;
1669 }
1670
1671 /* Setup recovery on @rs */
1672 static void rs_setup_recovery(struct raid_set *rs, sector_t dev_sectors)
1673 {
1674         /* raid0 does not recover */
1675         if (rs_is_raid0(rs))
1676                 rs->md.recovery_cp = MaxSector;
1677         /*
1678          * A raid6 set has to be recovered either
1679          * completely or for the grown part to
1680          * ensure proper parity and Q-Syndrome
1681          */
1682         else if (rs_is_raid6(rs))
1683                 rs->md.recovery_cp = dev_sectors;
1684         /*
1685          * Other raid set types may skip recovery
1686          * depending on the 'nosync' flag.
1687          */
1688         else
1689                 rs->md.recovery_cp = test_bit(__CTR_FLAG_NOSYNC, &rs->ctr_flags)
1690                                      ? MaxSector : dev_sectors;
1691 }
1692
1693 static void do_table_event(struct work_struct *ws)
1694 {
1695         struct raid_set *rs = container_of(ws, struct raid_set, md.event_work);
1696
1697         smp_rmb(); /* Make sure we access most actual mddev properties */
1698         if (!rs_is_reshaping(rs)) {
1699                 if (rs_is_raid10(rs))
1700                         rs_set_rdev_sectors(rs);
1701                 rs_set_capacity(rs);
1702         }
1703         dm_table_event(rs->ti->table);
1704 }
1705
1706 /*
1707  * Make sure a valid takover (level switch) is being requested on @rs
1708  *
1709  * Conversions of raid sets from one MD personality to another
1710  * have to conform to restrictions which are enforced here.
1711  */
1712 static int rs_check_takeover(struct raid_set *rs)
1713 {
1714         struct mddev *mddev = &rs->md;
1715         unsigned int near_copies;
1716
1717         if (rs->md.degraded) {
1718                 rs->ti->error = "Can't takeover degraded raid set";
1719                 return -EPERM;
1720         }
1721
1722         if (rs_is_reshaping(rs)) {
1723                 rs->ti->error = "Can't takeover reshaping raid set";
1724                 return -EPERM;
1725         }
1726
1727         switch (mddev->level) {
1728         case 0:
1729                 /* raid0 -> raid1/5 with one disk */
1730                 if ((mddev->new_level == 1 || mddev->new_level == 5) &&
1731                     mddev->raid_disks == 1)
1732                         return 0;
1733
1734                 /* raid0 -> raid10 */
1735                 if (mddev->new_level == 10 &&
1736                     !(rs->raid_disks % mddev->raid_disks))
1737                         return 0;
1738
1739                 /* raid0 with multiple disks -> raid4/5/6 */
1740                 if (__within_range(mddev->new_level, 4, 6) &&
1741                     mddev->new_layout == ALGORITHM_PARITY_N &&
1742                     mddev->raid_disks > 1)
1743                         return 0;
1744
1745                 break;
1746
1747         case 10:
1748                 /* Can't takeover raid10_offset! */
1749                 if (__is_raid10_offset(mddev->layout))
1750                         break;
1751
1752                 near_copies = __raid10_near_copies(mddev->layout);
1753
1754                 /* raid10* -> raid0 */
1755                 if (mddev->new_level == 0) {
1756                         /* Can takeover raid10_near with raid disks divisable by data copies! */
1757                         if (near_copies > 1 &&
1758                             !(mddev->raid_disks % near_copies)) {
1759                                 mddev->raid_disks /= near_copies;
1760                                 mddev->delta_disks = mddev->raid_disks;
1761                                 return 0;
1762                         }
1763
1764                         /* Can takeover raid10_far */
1765                         if (near_copies == 1 &&
1766                             __raid10_far_copies(mddev->layout) > 1)
1767                                 return 0;
1768
1769                         break;
1770                 }
1771
1772                 /* raid10_{near,far} -> raid1 */
1773                 if (mddev->new_level == 1 &&
1774                     max(near_copies, __raid10_far_copies(mddev->layout)) == mddev->raid_disks)
1775                         return 0;
1776
1777                 /* raid10_{near,far} with 2 disks -> raid4/5 */
1778                 if (__within_range(mddev->new_level, 4, 5) &&
1779                     mddev->raid_disks == 2)
1780                         return 0;
1781                 break;
1782
1783         case 1:
1784                 /* raid1 with 2 disks -> raid4/5 */
1785                 if (__within_range(mddev->new_level, 4, 5) &&
1786                     mddev->raid_disks == 2) {
1787                         mddev->degraded = 1;
1788                         return 0;
1789                 }
1790
1791                 /* raid1 -> raid0 */
1792                 if (mddev->new_level == 0 &&
1793                     mddev->raid_disks == 1)
1794                         return 0;
1795
1796                 /* raid1 -> raid10 */
1797                 if (mddev->new_level == 10)
1798                         return 0;
1799                 break;
1800
1801         case 4:
1802                 /* raid4 -> raid0 */
1803                 if (mddev->new_level == 0)
1804                         return 0;
1805
1806                 /* raid4 -> raid1/5 with 2 disks */
1807                 if ((mddev->new_level == 1 || mddev->new_level == 5) &&
1808                     mddev->raid_disks == 2)
1809                         return 0;
1810
1811                 /* raid4 -> raid5/6 with parity N */
1812                 if (__within_range(mddev->new_level, 5, 6) &&
1813                     mddev->layout == ALGORITHM_PARITY_N)
1814                         return 0;
1815                 break;
1816
1817         case 5:
1818                 /* raid5 with parity N -> raid0 */
1819                 if (mddev->new_level == 0 &&
1820                     mddev->layout == ALGORITHM_PARITY_N)
1821                         return 0;
1822
1823                 /* raid5 with parity N -> raid4 */
1824                 if (mddev->new_level == 4 &&
1825                     mddev->layout == ALGORITHM_PARITY_N)
1826                         return 0;
1827
1828                 /* raid5 with 2 disks -> raid1/4/10 */
1829                 if ((mddev->new_level == 1 || mddev->new_level == 4 || mddev->new_level == 10) &&
1830                     mddev->raid_disks == 2)
1831                         return 0;
1832
1833                 /* raid5_* ->  raid6_*_6 with Q-Syndrome N (e.g. raid5_ra -> raid6_ra_6 */
1834                 if (mddev->new_level == 6 &&
1835                     ((mddev->layout == ALGORITHM_PARITY_N && mddev->new_layout == ALGORITHM_PARITY_N) ||
1836                       __within_range(mddev->new_layout, ALGORITHM_LEFT_ASYMMETRIC_6, ALGORITHM_RIGHT_SYMMETRIC_6)))
1837                         return 0;
1838                 break;
1839
1840         case 6:
1841                 /* raid6 with parity N -> raid0 */
1842                 if (mddev->new_level == 0 &&
1843                     mddev->layout == ALGORITHM_PARITY_N)
1844                         return 0;
1845
1846                 /* raid6 with parity N -> raid4 */
1847                 if (mddev->new_level == 4 &&
1848                     mddev->layout == ALGORITHM_PARITY_N)
1849                         return 0;
1850
1851                 /* raid6_*_n with Q-Syndrome N -> raid5_* */
1852                 if (mddev->new_level == 5 &&
1853                     ((mddev->layout == ALGORITHM_PARITY_N && mddev->new_layout == ALGORITHM_PARITY_N) ||
1854                      __within_range(mddev->new_layout, ALGORITHM_LEFT_ASYMMETRIC, ALGORITHM_RIGHT_SYMMETRIC)))
1855                         return 0;
1856                 break;
1857
1858         default:
1859                 break;
1860         }
1861
1862         rs->ti->error = "takeover not possible";
1863         return -EINVAL;
1864 }
1865
1866 /* True if @rs requested to be taken over */
1867 static bool rs_takeover_requested(struct raid_set *rs)
1868 {
1869         return rs->md.new_level != rs->md.level;
1870 }
1871
1872 /* True if layout is set to reshape. */
1873 static bool rs_is_layout_change(struct raid_set *rs, bool use_mddev)
1874 {
1875         return (use_mddev ? rs->md.delta_disks : rs->delta_disks) ||
1876                rs->md.new_layout != rs->md.layout ||
1877                rs->md.new_chunk_sectors != rs->md.chunk_sectors;
1878 }
1879
1880 /* True if @rs is requested to reshape by ctr */
1881 static bool rs_reshape_requested(struct raid_set *rs)
1882 {
1883         bool change;
1884         struct mddev *mddev = &rs->md;
1885
1886         if (rs_takeover_requested(rs))
1887                 return false;
1888
1889         if (rs_is_raid0(rs))
1890                 return false;
1891
1892         change = rs_is_layout_change(rs, false);
1893
1894         /* Historical case to support raid1 reshape without delta disks */
1895         if (rs_is_raid1(rs)) {
1896                 if (rs->delta_disks)
1897                         return !!rs->delta_disks;
1898
1899                 return !change &&
1900                        mddev->raid_disks != rs->raid_disks;
1901         }
1902
1903         if (rs_is_raid10(rs))
1904                 return change &&
1905                        !__is_raid10_far(mddev->new_layout) &&
1906                        rs->delta_disks >= 0;
1907
1908         return change;
1909 }
1910
1911 /*  Features */
1912 #define FEATURE_FLAG_SUPPORTS_V190      0x1 /* Supports extended superblock */
1913
1914 /* State flags for sb->flags */
1915 #define SB_FLAG_RESHAPE_ACTIVE          0x1
1916 #define SB_FLAG_RESHAPE_BACKWARDS       0x2
1917
1918 /*
1919  * This structure is never routinely used by userspace, unlike md superblocks.
1920  * Devices with this superblock should only ever be accessed via device-mapper.
1921  */
1922 #define DM_RAID_MAGIC 0x64526D44
1923 struct dm_raid_superblock {
1924         __le32 magic;           /* "DmRd" */
1925         __le32 compat_features; /* Used to indicate compatible features (like 1.9.0 ondisk metadata extension) */
1926
1927         __le32 num_devices;     /* Number of devices in this raid set. (Max 64) */
1928         __le32 array_position;  /* The position of this drive in the raid set */
1929
1930         __le64 events;          /* Incremented by md when superblock updated */
1931         __le64 failed_devices;  /* Pre 1.9.0 part of bit field of devices to */
1932                                 /* indicate failures (see extension below) */
1933
1934         /*
1935          * This offset tracks the progress of the repair or replacement of
1936          * an individual drive.
1937          */
1938         __le64 disk_recovery_offset;
1939
1940         /*
1941          * This offset tracks the progress of the initial raid set
1942          * synchronisation/parity calculation.
1943          */
1944         __le64 array_resync_offset;
1945
1946         /*
1947          * raid characteristics
1948          */
1949         __le32 level;
1950         __le32 layout;
1951         __le32 stripe_sectors;
1952
1953         /********************************************************************
1954          * BELOW FOLLOW V1.9.0 EXTENSIONS TO THE PRISTINE SUPERBLOCK FORMAT!!!
1955          *
1956          * FEATURE_FLAG_SUPPORTS_V190 in the compat_features member indicates that those exist
1957          */
1958
1959         __le32 flags; /* Flags defining array states for reshaping */
1960
1961         /*
1962          * This offset tracks the progress of a raid
1963          * set reshape in order to be able to restart it
1964          */
1965         __le64 reshape_position;
1966
1967         /*
1968          * These define the properties of the array in case of an interrupted reshape
1969          */
1970         __le32 new_level;
1971         __le32 new_layout;
1972         __le32 new_stripe_sectors;
1973         __le32 delta_disks;
1974
1975         __le64 array_sectors; /* Array size in sectors */
1976
1977         /*
1978          * Sector offsets to data on devices (reshaping).
1979          * Needed to support out of place reshaping, thus
1980          * not writing over any stripes whilst converting
1981          * them from old to new layout
1982          */
1983         __le64 data_offset;
1984         __le64 new_data_offset;
1985
1986         __le64 sectors; /* Used device size in sectors */
1987
1988         /*
1989          * Additonal Bit field of devices indicating failures to support
1990          * up to 256 devices with the 1.9.0 on-disk metadata format
1991          */
1992         __le64 extended_failed_devices[DISKS_ARRAY_ELEMS - 1];
1993
1994         __le32 incompat_features;       /* Used to indicate any incompatible features */
1995
1996         /* Always set rest up to logical block size to 0 when writing (see get_metadata_device() below). */
1997 } __packed;
1998
1999 /*
2000  * Check for reshape constraints on raid set @rs:
2001  *
2002  * - reshape function non-existent
2003  * - degraded set
2004  * - ongoing recovery
2005  * - ongoing reshape
2006  *
2007  * Returns 0 if none or -EPERM if given constraint
2008  * and error message reference in @errmsg
2009  */
2010 static int rs_check_reshape(struct raid_set *rs)
2011 {
2012         struct mddev *mddev = &rs->md;
2013
2014         if (!mddev->pers || !mddev->pers->check_reshape)
2015                 rs->ti->error = "Reshape not supported";
2016         else if (mddev->degraded)
2017                 rs->ti->error = "Can't reshape degraded raid set";
2018         else if (rs_is_recovering(rs))
2019                 rs->ti->error = "Convert request on recovering raid set prohibited";
2020         else if (rs_is_reshaping(rs))
2021                 rs->ti->error = "raid set already reshaping!";
2022         else if (!(rs_is_raid1(rs) || rs_is_raid10(rs) || rs_is_raid456(rs)))
2023                 rs->ti->error = "Reshaping only supported for raid1/4/5/6/10";
2024         else
2025                 return 0;
2026
2027         return -EPERM;
2028 }
2029
2030 static int read_disk_sb(struct md_rdev *rdev, int size, bool force_reload)
2031 {
2032         BUG_ON(!rdev->sb_page);
2033
2034         if (rdev->sb_loaded && !force_reload)
2035                 return 0;
2036
2037         rdev->sb_loaded = 0;
2038
2039         if (!sync_page_io(rdev, 0, size, rdev->sb_page, REQ_OP_READ, 0, true)) {
2040                 DMERR("Failed to read superblock of device at position %d",
2041                       rdev->raid_disk);
2042                 md_error(rdev->mddev, rdev);
2043                 set_bit(Faulty, &rdev->flags);
2044                 return -EIO;
2045         }
2046
2047         rdev->sb_loaded = 1;
2048
2049         return 0;
2050 }
2051
2052 static void sb_retrieve_failed_devices(struct dm_raid_superblock *sb, uint64_t *failed_devices)
2053 {
2054         failed_devices[0] = le64_to_cpu(sb->failed_devices);
2055         memset(failed_devices + 1, 0, sizeof(sb->extended_failed_devices));
2056
2057         if (le32_to_cpu(sb->compat_features) & FEATURE_FLAG_SUPPORTS_V190) {
2058                 int i = ARRAY_SIZE(sb->extended_failed_devices);
2059
2060                 while (i--)
2061                         failed_devices[i+1] = le64_to_cpu(sb->extended_failed_devices[i]);
2062         }
2063 }
2064
2065 static void sb_update_failed_devices(struct dm_raid_superblock *sb, uint64_t *failed_devices)
2066 {
2067         int i = ARRAY_SIZE(sb->extended_failed_devices);
2068
2069         sb->failed_devices = cpu_to_le64(failed_devices[0]);
2070         while (i--)
2071                 sb->extended_failed_devices[i] = cpu_to_le64(failed_devices[i+1]);
2072 }
2073
2074 /*
2075  * Synchronize the superblock members with the raid set properties
2076  *
2077  * All superblock data is little endian.
2078  */
2079 static void super_sync(struct mddev *mddev, struct md_rdev *rdev)
2080 {
2081         bool update_failed_devices = false;
2082         unsigned int i;
2083         uint64_t failed_devices[DISKS_ARRAY_ELEMS];
2084         struct dm_raid_superblock *sb;
2085         struct raid_set *rs = container_of(mddev, struct raid_set, md);
2086
2087         /* No metadata device, no superblock */
2088         if (!rdev->meta_bdev)
2089                 return;
2090
2091         BUG_ON(!rdev->sb_page);
2092
2093         sb = page_address(rdev->sb_page);
2094
2095         sb_retrieve_failed_devices(sb, failed_devices);
2096
2097         for (i = 0; i < rs->raid_disks; i++)
2098                 if (!rs->dev[i].data_dev || test_bit(Faulty, &rs->dev[i].rdev.flags)) {
2099                         update_failed_devices = true;
2100                         set_bit(i, (void *) failed_devices);
2101                 }
2102
2103         if (update_failed_devices)
2104                 sb_update_failed_devices(sb, failed_devices);
2105
2106         sb->magic = cpu_to_le32(DM_RAID_MAGIC);
2107         sb->compat_features = cpu_to_le32(FEATURE_FLAG_SUPPORTS_V190);
2108
2109         sb->num_devices = cpu_to_le32(mddev->raid_disks);
2110         sb->array_position = cpu_to_le32(rdev->raid_disk);
2111
2112         sb->events = cpu_to_le64(mddev->events);
2113
2114         sb->disk_recovery_offset = cpu_to_le64(rdev->recovery_offset);
2115         sb->array_resync_offset = cpu_to_le64(mddev->recovery_cp);
2116
2117         sb->level = cpu_to_le32(mddev->level);
2118         sb->layout = cpu_to_le32(mddev->layout);
2119         sb->stripe_sectors = cpu_to_le32(mddev->chunk_sectors);
2120
2121         /********************************************************************
2122          * BELOW FOLLOW V1.9.0 EXTENSIONS TO THE PRISTINE SUPERBLOCK FORMAT!!!
2123          *
2124          * FEATURE_FLAG_SUPPORTS_V190 in the compat_features member indicates that those exist
2125          */
2126         sb->new_level = cpu_to_le32(mddev->new_level);
2127         sb->new_layout = cpu_to_le32(mddev->new_layout);
2128         sb->new_stripe_sectors = cpu_to_le32(mddev->new_chunk_sectors);
2129
2130         sb->delta_disks = cpu_to_le32(mddev->delta_disks);
2131
2132         smp_rmb(); /* Make sure we access most recent reshape position */
2133         sb->reshape_position = cpu_to_le64(mddev->reshape_position);
2134         if (le64_to_cpu(sb->reshape_position) != MaxSector) {
2135                 /* Flag ongoing reshape */
2136                 sb->flags |= cpu_to_le32(SB_FLAG_RESHAPE_ACTIVE);
2137
2138                 if (mddev->delta_disks < 0 || mddev->reshape_backwards)
2139                         sb->flags |= cpu_to_le32(SB_FLAG_RESHAPE_BACKWARDS);
2140         } else {
2141                 /* Clear reshape flags */
2142                 sb->flags &= ~(cpu_to_le32(SB_FLAG_RESHAPE_ACTIVE|SB_FLAG_RESHAPE_BACKWARDS));
2143         }
2144
2145         sb->array_sectors = cpu_to_le64(mddev->array_sectors);
2146         sb->data_offset = cpu_to_le64(rdev->data_offset);
2147         sb->new_data_offset = cpu_to_le64(rdev->new_data_offset);
2148         sb->sectors = cpu_to_le64(rdev->sectors);
2149         sb->incompat_features = cpu_to_le32(0);
2150
2151         /* Zero out the rest of the payload after the size of the superblock */
2152         memset(sb + 1, 0, rdev->sb_size - sizeof(*sb));
2153 }
2154
2155 /*
2156  * super_load
2157  *
2158  * This function creates a superblock if one is not found on the device
2159  * and will decide which superblock to use if there's a choice.
2160  *
2161  * Return: 1 if use rdev, 0 if use refdev, -Exxx otherwise
2162  */
2163 static int super_load(struct md_rdev *rdev, struct md_rdev *refdev)
2164 {
2165         int r;
2166         struct dm_raid_superblock *sb;
2167         struct dm_raid_superblock *refsb;
2168         uint64_t events_sb, events_refsb;
2169
2170         r = read_disk_sb(rdev, rdev->sb_size, false);
2171         if (r)
2172                 return r;
2173
2174         sb = page_address(rdev->sb_page);
2175
2176         /*
2177          * Two cases that we want to write new superblocks and rebuild:
2178          * 1) New device (no matching magic number)
2179          * 2) Device specified for rebuild (!In_sync w/ offset == 0)
2180          */
2181         if ((sb->magic != cpu_to_le32(DM_RAID_MAGIC)) ||
2182             (!test_bit(In_sync, &rdev->flags) && !rdev->recovery_offset)) {
2183                 super_sync(rdev->mddev, rdev);
2184
2185                 set_bit(FirstUse, &rdev->flags);
2186                 sb->compat_features = cpu_to_le32(FEATURE_FLAG_SUPPORTS_V190);
2187
2188                 /* Force writing of superblocks to disk */
2189                 set_bit(MD_SB_CHANGE_DEVS, &rdev->mddev->sb_flags);
2190
2191                 /* Any superblock is better than none, choose that if given */
2192                 return refdev ? 0 : 1;
2193         }
2194
2195         if (!refdev)
2196                 return 1;
2197
2198         events_sb = le64_to_cpu(sb->events);
2199
2200         refsb = page_address(refdev->sb_page);
2201         events_refsb = le64_to_cpu(refsb->events);
2202
2203         return (events_sb > events_refsb) ? 1 : 0;
2204 }
2205
2206 static int super_init_validation(struct raid_set *rs, struct md_rdev *rdev)
2207 {
2208         int role;
2209         unsigned int d;
2210         struct mddev *mddev = &rs->md;
2211         uint64_t events_sb;
2212         uint64_t failed_devices[DISKS_ARRAY_ELEMS];
2213         struct dm_raid_superblock *sb;
2214         uint32_t new_devs = 0, rebuild_and_new = 0, rebuilds = 0;
2215         struct md_rdev *r;
2216         struct dm_raid_superblock *sb2;
2217
2218         sb = page_address(rdev->sb_page);
2219         events_sb = le64_to_cpu(sb->events);
2220
2221         /*
2222          * Initialise to 1 if this is a new superblock.
2223          */
2224         mddev->events = events_sb ? : 1;
2225
2226         mddev->reshape_position = MaxSector;
2227
2228         mddev->raid_disks = le32_to_cpu(sb->num_devices);
2229         mddev->level = le32_to_cpu(sb->level);
2230         mddev->layout = le32_to_cpu(sb->layout);
2231         mddev->chunk_sectors = le32_to_cpu(sb->stripe_sectors);
2232
2233         /*
2234          * Reshaping is supported, e.g. reshape_position is valid
2235          * in superblock and superblock content is authoritative.
2236          */
2237         if (le32_to_cpu(sb->compat_features) & FEATURE_FLAG_SUPPORTS_V190) {
2238                 /* Superblock is authoritative wrt given raid set layout! */
2239                 mddev->new_level = le32_to_cpu(sb->new_level);
2240                 mddev->new_layout = le32_to_cpu(sb->new_layout);
2241                 mddev->new_chunk_sectors = le32_to_cpu(sb->new_stripe_sectors);
2242                 mddev->delta_disks = le32_to_cpu(sb->delta_disks);
2243                 mddev->array_sectors = le64_to_cpu(sb->array_sectors);
2244
2245                 /* raid was reshaping and got interrupted */
2246                 if (le32_to_cpu(sb->flags) & SB_FLAG_RESHAPE_ACTIVE) {
2247                         if (test_bit(__CTR_FLAG_DELTA_DISKS, &rs->ctr_flags)) {
2248                                 DMERR("Reshape requested but raid set is still reshaping");
2249                                 return -EINVAL;
2250                         }
2251
2252                         if (mddev->delta_disks < 0 ||
2253                             (!mddev->delta_disks && (le32_to_cpu(sb->flags) & SB_FLAG_RESHAPE_BACKWARDS)))
2254                                 mddev->reshape_backwards = 1;
2255                         else
2256                                 mddev->reshape_backwards = 0;
2257
2258                         mddev->reshape_position = le64_to_cpu(sb->reshape_position);
2259                         rs->raid_type = get_raid_type_by_ll(mddev->level, mddev->layout);
2260                 }
2261
2262         } else {
2263                 /*
2264                  * No takeover/reshaping, because we don't have the extended v1.9.0 metadata
2265                  */
2266                 struct raid_type *rt_cur = get_raid_type_by_ll(mddev->level, mddev->layout);
2267                 struct raid_type *rt_new = get_raid_type_by_ll(mddev->new_level, mddev->new_layout);
2268
2269                 if (rs_takeover_requested(rs)) {
2270                         if (rt_cur && rt_new)
2271                                 DMERR("Takeover raid sets from %s to %s not yet supported by metadata. (raid level change)",
2272                                       rt_cur->name, rt_new->name);
2273                         else
2274                                 DMERR("Takeover raid sets not yet supported by metadata. (raid level change)");
2275                         return -EINVAL;
2276                 } else if (rs_reshape_requested(rs)) {
2277                         DMERR("Reshaping raid sets not yet supported by metadata. (raid layout change keeping level)");
2278                         if (mddev->layout != mddev->new_layout) {
2279                                 if (rt_cur && rt_new)
2280                                         DMERR("  current layout %s vs new layout %s",
2281                                               rt_cur->name, rt_new->name);
2282                                 else
2283                                         DMERR("  current layout 0x%X vs new layout 0x%X",
2284                                               le32_to_cpu(sb->layout), mddev->new_layout);
2285                         }
2286                         if (mddev->chunk_sectors != mddev->new_chunk_sectors)
2287                                 DMERR("  current stripe sectors %u vs new stripe sectors %u",
2288                                       mddev->chunk_sectors, mddev->new_chunk_sectors);
2289                         if (rs->delta_disks)
2290                                 DMERR("  current %u disks vs new %u disks",
2291                                       mddev->raid_disks, mddev->raid_disks + rs->delta_disks);
2292                         if (rs_is_raid10(rs)) {
2293                                 DMERR("  Old layout: %s w/ %u copies",
2294                                       raid10_md_layout_to_format(mddev->layout),
2295                                       raid10_md_layout_to_copies(mddev->layout));
2296                                 DMERR("  New layout: %s w/ %u copies",
2297                                       raid10_md_layout_to_format(mddev->new_layout),
2298                                       raid10_md_layout_to_copies(mddev->new_layout));
2299                         }
2300                         return -EINVAL;
2301                 }
2302
2303                 DMINFO("Discovered old metadata format; upgrading to extended metadata format");
2304         }
2305
2306         if (!test_bit(__CTR_FLAG_NOSYNC, &rs->ctr_flags))
2307                 mddev->recovery_cp = le64_to_cpu(sb->array_resync_offset);
2308
2309         /*
2310          * During load, we set FirstUse if a new superblock was written.
2311          * There are two reasons we might not have a superblock:
2312          * 1) The raid set is brand new - in which case, all of the
2313          *    devices must have their In_sync bit set.  Also,
2314          *    recovery_cp must be 0, unless forced.
2315          * 2) This is a new device being added to an old raid set
2316          *    and the new device needs to be rebuilt - in which
2317          *    case the In_sync bit will /not/ be set and
2318          *    recovery_cp must be MaxSector.
2319          * 3) This is/are a new device(s) being added to an old
2320          *    raid set during takeover to a higher raid level
2321          *    to provide capacity for redundancy or during reshape
2322          *    to add capacity to grow the raid set.
2323          */
2324         d = 0;
2325         rdev_for_each(r, mddev) {
2326                 if (test_bit(Journal, &rdev->flags))
2327                         continue;
2328
2329                 if (test_bit(FirstUse, &r->flags))
2330                         new_devs++;
2331
2332                 if (!test_bit(In_sync, &r->flags)) {
2333                         DMINFO("Device %d specified for rebuild; clearing superblock",
2334                                 r->raid_disk);
2335                         rebuilds++;
2336
2337                         if (test_bit(FirstUse, &r->flags))
2338                                 rebuild_and_new++;
2339                 }
2340
2341                 d++;
2342         }
2343
2344         if (new_devs == rs->raid_disks || !rebuilds) {
2345                 /* Replace a broken device */
2346                 if (new_devs == rs->raid_disks) {
2347                         DMINFO("Superblocks created for new raid set");
2348                         set_bit(MD_ARRAY_FIRST_USE, &mddev->flags);
2349                 } else if (new_devs != rebuilds &&
2350                            new_devs != rs->delta_disks) {
2351                         DMERR("New device injected into existing raid set without "
2352                               "'delta_disks' or 'rebuild' parameter specified");
2353                         return -EINVAL;
2354                 }
2355         } else if (new_devs && new_devs != rebuilds) {
2356                 DMERR("%u 'rebuild' devices cannot be injected into"
2357                       " a raid set with %u other first-time devices",
2358                       rebuilds, new_devs);
2359                 return -EINVAL;
2360         } else if (rebuilds) {
2361                 if (rebuild_and_new && rebuilds != rebuild_and_new) {
2362                         DMERR("new device%s provided without 'rebuild'",
2363                               new_devs > 1 ? "s" : "");
2364                         return -EINVAL;
2365                 } else if (!test_bit(__CTR_FLAG_REBUILD, &rs->ctr_flags) && rs_is_recovering(rs)) {
2366                         DMERR("'rebuild' specified while raid set is not in-sync (recovery_cp=%llu)",
2367                               (unsigned long long) mddev->recovery_cp);
2368                         return -EINVAL;
2369                 } else if (rs_is_reshaping(rs)) {
2370                         DMERR("'rebuild' specified while raid set is being reshaped (reshape_position=%llu)",
2371                               (unsigned long long) mddev->reshape_position);
2372                         return -EINVAL;
2373                 }
2374         }
2375
2376         /*
2377          * Now we set the Faulty bit for those devices that are
2378          * recorded in the superblock as failed.
2379          */
2380         sb_retrieve_failed_devices(sb, failed_devices);
2381         rdev_for_each(r, mddev) {
2382                 if (test_bit(Journal, &rdev->flags) ||
2383                     !r->sb_page)
2384                         continue;
2385                 sb2 = page_address(r->sb_page);
2386                 sb2->failed_devices = 0;
2387                 memset(sb2->extended_failed_devices, 0, sizeof(sb2->extended_failed_devices));
2388
2389                 /*
2390                  * Check for any device re-ordering.
2391                  */
2392                 if (!test_bit(FirstUse, &r->flags) && (r->raid_disk >= 0)) {
2393                         role = le32_to_cpu(sb2->array_position);
2394                         if (role < 0)
2395                                 continue;
2396
2397                         if (role != r->raid_disk) {
2398                                 if (rs_is_raid10(rs) && __is_raid10_near(mddev->layout)) {
2399                                         if (mddev->raid_disks % __raid10_near_copies(mddev->layout) ||
2400                                             rs->raid_disks % rs->raid10_copies) {
2401                                                 rs->ti->error =
2402                                                         "Cannot change raid10 near set to odd # of devices!";
2403                                                 return -EINVAL;
2404                                         }
2405
2406                                         sb2->array_position = cpu_to_le32(r->raid_disk);
2407
2408                                 } else if (!(rs_is_raid10(rs) && rt_is_raid0(rs->raid_type)) &&
2409                                            !(rs_is_raid0(rs) && rt_is_raid10(rs->raid_type)) &&
2410                                            !rt_is_raid1(rs->raid_type)) {
2411                                         rs->ti->error = "Cannot change device positions in raid set";
2412                                         return -EINVAL;
2413                                 }
2414
2415                                 DMINFO("raid device #%d now at position #%d", role, r->raid_disk);
2416                         }
2417
2418                         /*
2419                          * Partial recovery is performed on
2420                          * returning failed devices.
2421                          */
2422                         if (test_bit(role, (void *) failed_devices))
2423                                 set_bit(Faulty, &r->flags);
2424                 }
2425         }
2426
2427         return 0;
2428 }
2429
2430 static int super_validate(struct raid_set *rs, struct md_rdev *rdev)
2431 {
2432         struct mddev *mddev = &rs->md;
2433         struct dm_raid_superblock *sb;
2434
2435         if (rs_is_raid0(rs) || !rdev->sb_page || rdev->raid_disk < 0)
2436                 return 0;
2437
2438         sb = page_address(rdev->sb_page);
2439
2440         /*
2441          * If mddev->events is not set, we know we have not yet initialized
2442          * the array.
2443          */
2444         if (!mddev->events && super_init_validation(rs, rdev))
2445                 return -EINVAL;
2446
2447         if (le32_to_cpu(sb->compat_features) &&
2448             le32_to_cpu(sb->compat_features) != FEATURE_FLAG_SUPPORTS_V190) {
2449                 rs->ti->error = "Unable to assemble array: Unknown flag(s) in compatible feature flags";
2450                 return -EINVAL;
2451         }
2452
2453         if (sb->incompat_features) {
2454                 rs->ti->error = "Unable to assemble array: No incompatible feature flags supported yet";
2455                 return -EINVAL;
2456         }
2457
2458         /* Enable bitmap creation on @rs unless no metadevs or raid0 or journaled raid4/5/6 set. */
2459         mddev->bitmap_info.offset = (rt_is_raid0(rs->raid_type) || rs->journal_dev.dev) ? 0 : to_sector(4096);
2460         mddev->bitmap_info.default_offset = mddev->bitmap_info.offset;
2461
2462         if (!test_and_clear_bit(FirstUse, &rdev->flags)) {
2463                 /*
2464                  * Retrieve rdev size stored in superblock to be prepared for shrink.
2465                  * Check extended superblock members are present otherwise the size
2466                  * will not be set!
2467                  */
2468                 if (le32_to_cpu(sb->compat_features) & FEATURE_FLAG_SUPPORTS_V190)
2469                         rdev->sectors = le64_to_cpu(sb->sectors);
2470
2471                 rdev->recovery_offset = le64_to_cpu(sb->disk_recovery_offset);
2472                 if (rdev->recovery_offset == MaxSector)
2473                         set_bit(In_sync, &rdev->flags);
2474                 /*
2475                  * If no reshape in progress -> we're recovering single
2476                  * disk(s) and have to set the device(s) to out-of-sync
2477                  */
2478                 else if (!rs_is_reshaping(rs))
2479                         clear_bit(In_sync, &rdev->flags); /* Mandatory for recovery */
2480         }
2481
2482         /*
2483          * If a device comes back, set it as not In_sync and no longer faulty.
2484          */
2485         if (test_and_clear_bit(Faulty, &rdev->flags)) {
2486                 rdev->recovery_offset = 0;
2487                 clear_bit(In_sync, &rdev->flags);
2488                 rdev->saved_raid_disk = rdev->raid_disk;
2489         }
2490
2491         /* Reshape support -> restore repective data offsets */
2492         rdev->data_offset = le64_to_cpu(sb->data_offset);
2493         rdev->new_data_offset = le64_to_cpu(sb->new_data_offset);
2494
2495         return 0;
2496 }
2497
2498 /*
2499  * Analyse superblocks and select the freshest.
2500  */
2501 static int analyse_superblocks(struct dm_target *ti, struct raid_set *rs)
2502 {
2503         int r;
2504         struct md_rdev *rdev, *freshest;
2505         struct mddev *mddev = &rs->md;
2506
2507         freshest = NULL;
2508         rdev_for_each(rdev, mddev) {
2509                 if (test_bit(Journal, &rdev->flags))
2510                         continue;
2511
2512                 if (!rdev->meta_bdev)
2513                         continue;
2514
2515                 /* Set superblock offset/size for metadata device. */
2516                 rdev->sb_start = 0;
2517                 rdev->sb_size = bdev_logical_block_size(rdev->meta_bdev);
2518                 if (rdev->sb_size < sizeof(struct dm_raid_superblock) || rdev->sb_size > PAGE_SIZE) {
2519                         DMERR("superblock size of a logical block is no longer valid");
2520                         return -EINVAL;
2521                 }
2522
2523                 /*
2524                  * Skipping super_load due to CTR_FLAG_SYNC will cause
2525                  * the array to undergo initialization again as
2526                  * though it were new.  This is the intended effect
2527                  * of the "sync" directive.
2528                  *
2529                  * With reshaping capability added, we must ensure that
2530                  * that the "sync" directive is disallowed during the reshape.
2531                  */
2532                 if (test_bit(__CTR_FLAG_SYNC, &rs->ctr_flags))
2533                         continue;
2534
2535                 r = super_load(rdev, freshest);
2536
2537                 switch (r) {
2538                 case 1:
2539                         freshest = rdev;
2540                         break;
2541                 case 0:
2542                         break;
2543                 default:
2544                         /* This is a failure to read the superblock from the metadata device. */
2545                         /*
2546                          * We have to keep any raid0 data/metadata device pairs or
2547                          * the MD raid0 personality will fail to start the array.
2548                          */
2549                         if (rs_is_raid0(rs))
2550                                 continue;
2551
2552                         /*
2553                          * We keep the dm_devs to be able to emit the device tuple
2554                          * properly on the table line in raid_status() (rather than
2555                          * mistakenly acting as if '- -' got passed into the constructor).
2556                          *
2557                          * The rdev has to stay on the same_set list to allow for
2558                          * the attempt to restore faulty devices on second resume.
2559                          */
2560                         rdev->raid_disk = rdev->saved_raid_disk = -1;
2561                         break;
2562                 }
2563         }
2564
2565         if (!freshest)
2566                 return 0;
2567
2568         /*
2569          * Validation of the freshest device provides the source of
2570          * validation for the remaining devices.
2571          */
2572         rs->ti->error = "Unable to assemble array: Invalid superblocks";
2573         if (super_validate(rs, freshest))
2574                 return -EINVAL;
2575
2576         if (validate_raid_redundancy(rs)) {
2577                 rs->ti->error = "Insufficient redundancy to activate array";
2578                 return -EINVAL;
2579         }
2580
2581         rdev_for_each(rdev, mddev)
2582                 if (!test_bit(Journal, &rdev->flags) &&
2583                     rdev != freshest &&
2584                     super_validate(rs, rdev))
2585                         return -EINVAL;
2586         return 0;
2587 }
2588
2589 /*
2590  * Adjust data_offset and new_data_offset on all disk members of @rs
2591  * for out of place reshaping if requested by contructor
2592  *
2593  * We need free space at the beginning of each raid disk for forward
2594  * and at the end for backward reshapes which userspace has to provide
2595  * via remapping/reordering of space.
2596  */
2597 static int rs_adjust_data_offsets(struct raid_set *rs)
2598 {
2599         sector_t data_offset = 0, new_data_offset = 0;
2600         struct md_rdev *rdev;
2601
2602         /* Constructor did not request data offset change */
2603         if (!test_bit(__CTR_FLAG_DATA_OFFSET, &rs->ctr_flags)) {
2604                 if (!rs_is_reshapable(rs))
2605                         goto out;
2606
2607                 return 0;
2608         }
2609
2610         /* HM FIXME: get In_Sync raid_dev? */
2611         rdev = &rs->dev[0].rdev;
2612
2613         if (rs->delta_disks < 0) {
2614                 /*
2615                  * Removing disks (reshaping backwards):
2616                  *
2617                  * - before reshape: data is at offset 0 and free space
2618                  *                   is at end of each component LV
2619                  *
2620                  * - after reshape: data is at offset rs->data_offset != 0 on each component LV
2621                  */
2622                 data_offset = 0;
2623                 new_data_offset = rs->data_offset;
2624
2625         } else if (rs->delta_disks > 0) {
2626                 /*
2627                  * Adding disks (reshaping forwards):
2628                  *
2629                  * - before reshape: data is at offset rs->data_offset != 0 and
2630                  *                   free space is at begin of each component LV
2631                  *
2632                  * - after reshape: data is at offset 0 on each component LV
2633                  */
2634                 data_offset = rs->data_offset;
2635                 new_data_offset = 0;
2636
2637         } else {
2638                 /*
2639                  * User space passes in 0 for data offset after having removed reshape space
2640                  *
2641                  * - or - (data offset != 0)
2642                  *
2643                  * Changing RAID layout or chunk size -> toggle offsets
2644                  *
2645                  * - before reshape: data is at offset rs->data_offset 0 and
2646                  *                   free space is at end of each component LV
2647                  *                   -or-
2648                  *                   data is at offset rs->data_offset != 0 and
2649                  *                   free space is at begin of each component LV
2650                  *
2651                  * - after reshape: data is at offset 0 if it was at offset != 0
2652                  *                  or at offset != 0 if it was at offset 0
2653                  *                  on each component LV
2654                  *
2655                  */
2656                 data_offset = rs->data_offset ? rdev->data_offset : 0;
2657                 new_data_offset = data_offset ? 0 : rs->data_offset;
2658                 set_bit(RT_FLAG_UPDATE_SBS, &rs->runtime_flags);
2659         }
2660
2661         /*
2662          * Make sure we got a minimum amount of free sectors per device
2663          */
2664         if (rs->data_offset &&
2665             to_sector(i_size_read(rdev->bdev->bd_inode)) - rs->md.dev_sectors < MIN_FREE_RESHAPE_SPACE) {
2666                 rs->ti->error = data_offset ? "No space for forward reshape" :
2667                                               "No space for backward reshape";
2668                 return -ENOSPC;
2669         }
2670 out:
2671         /*
2672          * Raise recovery_cp in case data_offset != 0 to
2673          * avoid false recovery positives in the constructor.
2674          */
2675         if (rs->md.recovery_cp < rs->md.dev_sectors)
2676                 rs->md.recovery_cp += rs->dev[0].rdev.data_offset;
2677
2678         /* Adjust data offsets on all rdevs but on any raid4/5/6 journal device */
2679         rdev_for_each(rdev, &rs->md) {
2680                 if (!test_bit(Journal, &rdev->flags)) {
2681                         rdev->data_offset = data_offset;
2682                         rdev->new_data_offset = new_data_offset;
2683                 }
2684         }
2685
2686         return 0;
2687 }
2688
2689 /* Userpace reordered disks -> adjust raid_disk indexes in @rs */
2690 static void __reorder_raid_disk_indexes(struct raid_set *rs)
2691 {
2692         int i = 0;
2693         struct md_rdev *rdev;
2694
2695         rdev_for_each(rdev, &rs->md) {
2696                 if (!test_bit(Journal, &rdev->flags)) {
2697                         rdev->raid_disk = i++;
2698                         rdev->saved_raid_disk = rdev->new_raid_disk = -1;
2699                 }
2700         }
2701 }
2702
2703 /*
2704  * Setup @rs for takeover by a different raid level
2705  */
2706 static int rs_setup_takeover(struct raid_set *rs)
2707 {
2708         struct mddev *mddev = &rs->md;
2709         struct md_rdev *rdev;
2710         unsigned int d = mddev->raid_disks = rs->raid_disks;
2711         sector_t new_data_offset = rs->dev[0].rdev.data_offset ? 0 : rs->data_offset;
2712
2713         if (rt_is_raid10(rs->raid_type)) {
2714                 if (rs_is_raid0(rs)) {
2715                         /* Userpace reordered disks -> adjust raid_disk indexes */
2716                         __reorder_raid_disk_indexes(rs);
2717
2718                         /* raid0 -> raid10_far layout */
2719                         mddev->layout = raid10_format_to_md_layout(rs, ALGORITHM_RAID10_FAR,
2720                                                                    rs->raid10_copies);
2721                 } else if (rs_is_raid1(rs))
2722                         /* raid1 -> raid10_near layout */
2723                         mddev->layout = raid10_format_to_md_layout(rs, ALGORITHM_RAID10_NEAR,
2724                                                                    rs->raid_disks);
2725                 else
2726                         return -EINVAL;
2727
2728         }
2729
2730         clear_bit(MD_ARRAY_FIRST_USE, &mddev->flags);
2731         mddev->recovery_cp = MaxSector;
2732
2733         while (d--) {
2734                 rdev = &rs->dev[d].rdev;
2735
2736                 if (test_bit(d, (void *) rs->rebuild_disks)) {
2737                         clear_bit(In_sync, &rdev->flags);
2738                         clear_bit(Faulty, &rdev->flags);
2739                         mddev->recovery_cp = rdev->recovery_offset = 0;
2740                         /* Bitmap has to be created when we do an "up" takeover */
2741                         set_bit(MD_ARRAY_FIRST_USE, &mddev->flags);
2742                 }
2743
2744                 rdev->new_data_offset = new_data_offset;
2745         }
2746
2747         return 0;
2748 }
2749
2750 /* Prepare @rs for reshape */
2751 static int rs_prepare_reshape(struct raid_set *rs)
2752 {
2753         bool reshape;
2754         struct mddev *mddev = &rs->md;
2755
2756         if (rs_is_raid10(rs)) {
2757                 if (rs->raid_disks != mddev->raid_disks &&
2758                     __is_raid10_near(mddev->layout) &&
2759                     rs->raid10_copies &&
2760                     rs->raid10_copies != __raid10_near_copies(mddev->layout)) {
2761                         /*
2762                          * raid disk have to be multiple of data copies to allow this conversion,
2763                          *
2764                          * This is actually not a reshape it is a
2765                          * rebuild of any additional mirrors per group
2766                          */
2767                         if (rs->raid_disks % rs->raid10_copies) {
2768                                 rs->ti->error = "Can't reshape raid10 mirror groups";
2769                                 return -EINVAL;
2770                         }
2771
2772                         /* Userpace reordered disks to add/remove mirrors -> adjust raid_disk indexes */
2773                         __reorder_raid_disk_indexes(rs);
2774                         mddev->layout = raid10_format_to_md_layout(rs, ALGORITHM_RAID10_NEAR,
2775                                                                    rs->raid10_copies);
2776                         mddev->new_layout = mddev->layout;
2777                         reshape = false;
2778                 } else
2779                         reshape = true;
2780
2781         } else if (rs_is_raid456(rs))
2782                 reshape = true;
2783
2784         else if (rs_is_raid1(rs)) {
2785                 if (rs->delta_disks) {
2786                         /* Process raid1 via delta_disks */
2787                         mddev->degraded = rs->delta_disks < 0 ? -rs->delta_disks : rs->delta_disks;
2788                         reshape = true;
2789                 } else {
2790                         /* Process raid1 without delta_disks */
2791                         mddev->raid_disks = rs->raid_disks;
2792                         reshape = false;
2793                 }
2794         } else {
2795                 rs->ti->error = "Called with bogus raid type";
2796                 return -EINVAL;
2797         }
2798
2799         if (reshape) {
2800                 set_bit(RT_FLAG_RESHAPE_RS, &rs->runtime_flags);
2801                 set_bit(RT_FLAG_UPDATE_SBS, &rs->runtime_flags);
2802         } else if (mddev->raid_disks < rs->raid_disks)
2803                 /* Create new superblocks and bitmaps, if any new disks */
2804                 set_bit(RT_FLAG_UPDATE_SBS, &rs->runtime_flags);
2805
2806         return 0;
2807 }
2808
2809 /* Get reshape sectors from data_offsets or raid set */
2810 static sector_t _get_reshape_sectors(struct raid_set *rs)
2811 {
2812         struct md_rdev *rdev;
2813         sector_t reshape_sectors = 0;
2814
2815         rdev_for_each(rdev, &rs->md)
2816                 if (!test_bit(Journal, &rdev->flags)) {
2817                         reshape_sectors = (rdev->data_offset > rdev->new_data_offset) ?
2818                                         rdev->data_offset - rdev->new_data_offset :
2819                                         rdev->new_data_offset - rdev->data_offset;
2820                         break;
2821                 }
2822
2823         return max(reshape_sectors, (sector_t) rs->data_offset);
2824 }
2825
2826 /*
2827  * Reshape:
2828  * - change raid layout
2829  * - change chunk size
2830  * - add disks
2831  * - remove disks
2832  */
2833 static int rs_setup_reshape(struct raid_set *rs)
2834 {
2835         int r = 0;
2836         unsigned int cur_raid_devs, d;
2837         sector_t reshape_sectors = _get_reshape_sectors(rs);
2838         struct mddev *mddev = &rs->md;
2839         struct md_rdev *rdev;
2840
2841         mddev->delta_disks = rs->delta_disks;
2842         cur_raid_devs = mddev->raid_disks;
2843
2844         /* Ignore impossible layout change whilst adding/removing disks */
2845         if (mddev->delta_disks &&
2846             mddev->layout != mddev->new_layout) {
2847                 DMINFO("Ignoring invalid layout change with delta_disks=%d", rs->delta_disks);
2848                 mddev->new_layout = mddev->layout;
2849         }
2850
2851         /*
2852          * Adjust array size:
2853          *
2854          * - in case of adding disk(s), array size has
2855          *   to grow after the disk adding reshape,
2856          *   which'll hapen in the event handler;
2857          *   reshape will happen forward, so space has to
2858          *   be available at the beginning of each disk
2859          *
2860          * - in case of removing disk(s), array size
2861          *   has to shrink before starting the reshape,
2862          *   which'll happen here;
2863          *   reshape will happen backward, so space has to
2864          *   be available at the end of each disk
2865          *
2866          * - data_offset and new_data_offset are
2867          *   adjusted for aforementioned out of place
2868          *   reshaping based on userspace passing in
2869          *   the "data_offset <sectors>" key/value
2870          *   pair via the constructor
2871          */
2872
2873         /* Add disk(s) */
2874         if (rs->delta_disks > 0) {
2875                 /* Prepare disks for check in raid4/5/6/10 {check|start}_reshape */
2876                 for (d = cur_raid_devs; d < rs->raid_disks; d++) {
2877                         rdev = &rs->dev[d].rdev;
2878                         clear_bit(In_sync, &rdev->flags);
2879
2880                         /*
2881                          * save_raid_disk needs to be -1, or recovery_offset will be set to 0
2882                          * by md, which'll store that erroneously in the superblock on reshape
2883                          */
2884                         rdev->saved_raid_disk = -1;
2885                         rdev->raid_disk = d;
2886
2887                         rdev->sectors = mddev->dev_sectors;
2888                         rdev->recovery_offset = rs_is_raid1(rs) ? 0 : MaxSector;
2889                 }
2890
2891                 mddev->reshape_backwards = 0; /* adding disk(s) -> forward reshape */
2892
2893         /* Remove disk(s) */
2894         } else if (rs->delta_disks < 0) {
2895                 r = rs_set_dev_and_array_sectors(rs, rs->ti->len, true);
2896                 mddev->reshape_backwards = 1; /* removing disk(s) -> backward reshape */
2897
2898         /* Change layout and/or chunk size */
2899         } else {
2900                 /*
2901                  * Reshape layout (e.g. raid5_ls -> raid5_n) and/or chunk size:
2902                  *
2903                  * keeping number of disks and do layout change ->
2904                  *
2905                  * toggle reshape_backward depending on data_offset:
2906                  *
2907                  * - free space upfront -> reshape forward
2908                  *
2909                  * - free space at the end -> reshape backward
2910                  *
2911                  *
2912                  * This utilizes free reshape space avoiding the need
2913                  * for userspace to move (parts of) LV segments in
2914                  * case of layout/chunksize change  (for disk
2915                  * adding/removing reshape space has to be at
2916                  * the proper address (see above with delta_disks):
2917                  *
2918                  * add disk(s)   -> begin
2919                  * remove disk(s)-> end
2920                  */
2921                 mddev->reshape_backwards = rs->dev[0].rdev.data_offset ? 0 : 1;
2922         }
2923
2924         /*
2925          * Adjust device size for forward reshape
2926          * because md_finish_reshape() reduces it.
2927          */
2928         if (!mddev->reshape_backwards)
2929                 rdev_for_each(rdev, &rs->md)
2930                         if (!test_bit(Journal, &rdev->flags))
2931                                 rdev->sectors += reshape_sectors;
2932
2933         return r;
2934 }
2935
2936 /*
2937  * If the md resync thread has updated superblock with max reshape position
2938  * at the end of a reshape but not (yet) reset the layout configuration
2939  * changes -> reset the latter.
2940  */
2941 static void rs_reset_inconclusive_reshape(struct raid_set *rs)
2942 {
2943         if (!rs_is_reshaping(rs) && rs_is_layout_change(rs, true)) {
2944                 rs_set_cur(rs);
2945                 rs->md.delta_disks = 0;
2946                 rs->md.reshape_backwards = 0;
2947         }
2948 }
2949
2950 /*
2951  * Enable/disable discard support on RAID set depending on
2952  * RAID level and discard properties of underlying RAID members.
2953  */
2954 static void configure_discard_support(struct raid_set *rs)
2955 {
2956         int i;
2957         bool raid456;
2958         struct dm_target *ti = rs->ti;
2959
2960         /*
2961          * XXX: RAID level 4,5,6 require zeroing for safety.
2962          */
2963         raid456 = rs_is_raid456(rs);
2964
2965         for (i = 0; i < rs->raid_disks; i++) {
2966                 struct request_queue *q;
2967
2968                 if (!rs->dev[i].rdev.bdev)
2969                         continue;
2970
2971                 q = bdev_get_queue(rs->dev[i].rdev.bdev);
2972                 if (!q || !blk_queue_discard(q))
2973                         return;
2974
2975                 if (raid456) {
2976                         if (!devices_handle_discard_safely) {
2977                                 DMERR("raid456 discard support disabled due to discard_zeroes_data uncertainty.");
2978                                 DMERR("Set dm-raid.devices_handle_discard_safely=Y to override.");
2979                                 return;
2980                         }
2981                 }
2982         }
2983
2984         ti->num_discard_bios = 1;
2985 }
2986
2987 /*
2988  * Construct a RAID0/1/10/4/5/6 mapping:
2989  * Args:
2990  *      <raid_type> <#raid_params> <raid_params>{0,}    \
2991  *      <#raid_devs> [<meta_dev1> <dev1>]{1,}
2992  *
2993  * <raid_params> varies by <raid_type>.  See 'parse_raid_params' for
2994  * details on possible <raid_params>.
2995  *
2996  * Userspace is free to initialize the metadata devices, hence the superblocks to
2997  * enforce recreation based on the passed in table parameters.
2998  *
2999  */
3000 static int raid_ctr(struct dm_target *ti, unsigned int argc, char **argv)
3001 {
3002         int r;
3003         bool resize = false;
3004         struct raid_type *rt;
3005         unsigned int num_raid_params, num_raid_devs;
3006         sector_t sb_array_sectors, rdev_sectors, reshape_sectors;
3007         struct raid_set *rs = NULL;
3008         const char *arg;
3009         struct rs_layout rs_layout;
3010         struct dm_arg_set as = { argc, argv }, as_nrd;
3011         struct dm_arg _args[] = {
3012                 { 0, as.argc, "Cannot understand number of raid parameters" },
3013                 { 1, 254, "Cannot understand number of raid devices parameters" }
3014         };
3015
3016         arg = dm_shift_arg(&as);
3017         if (!arg) {
3018                 ti->error = "No arguments";
3019                 return -EINVAL;
3020         }
3021
3022         rt = get_raid_type(arg);
3023         if (!rt) {
3024                 ti->error = "Unrecognised raid_type";
3025                 return -EINVAL;
3026         }
3027
3028         /* Must have <#raid_params> */
3029         if (dm_read_arg_group(_args, &as, &num_raid_params, &ti->error))
3030                 return -EINVAL;
3031
3032         /* number of raid device tupples <meta_dev data_dev> */
3033         as_nrd = as;
3034         dm_consume_args(&as_nrd, num_raid_params);
3035         _args[1].max = (as_nrd.argc - 1) / 2;
3036         if (dm_read_arg(_args + 1, &as_nrd, &num_raid_devs, &ti->error))
3037                 return -EINVAL;
3038
3039         if (!__within_range(num_raid_devs, 1, MAX_RAID_DEVICES)) {
3040                 ti->error = "Invalid number of supplied raid devices";
3041                 return -EINVAL;
3042         }
3043
3044         rs = raid_set_alloc(ti, rt, num_raid_devs);
3045         if (IS_ERR(rs))
3046                 return PTR_ERR(rs);
3047
3048         r = parse_raid_params(rs, &as, num_raid_params);
3049         if (r)
3050                 goto bad;
3051
3052         r = parse_dev_params(rs, &as);
3053         if (r)
3054                 goto bad;
3055
3056         rs->md.sync_super = super_sync;
3057
3058         /*
3059          * Calculate ctr requested array and device sizes to allow
3060          * for superblock analysis needing device sizes defined.
3061          *
3062          * Any existing superblock will overwrite the array and device sizes
3063          */
3064         r = rs_set_dev_and_array_sectors(rs, rs->ti->len, false);
3065         if (r)
3066                 goto bad;
3067
3068         /* Memorize just calculated, potentially larger sizes to grow the raid set in preresume */
3069         rs->array_sectors = rs->md.array_sectors;
3070         rs->dev_sectors = rs->md.dev_sectors;
3071
3072         /*
3073          * Backup any new raid set level, layout, ...
3074          * requested to be able to compare to superblock
3075          * members for conversion decisions.
3076          */
3077         rs_config_backup(rs, &rs_layout);
3078
3079         r = analyse_superblocks(ti, rs);
3080         if (r)
3081                 goto bad;
3082
3083         /* All in-core metadata now as of current superblocks after calling analyse_superblocks() */
3084         sb_array_sectors = rs->md.array_sectors;
3085         rdev_sectors = __rdev_sectors(rs);
3086         if (!rdev_sectors) {
3087                 ti->error = "Invalid rdev size";
3088                 r = -EINVAL;
3089                 goto bad;
3090         }
3091
3092
3093         reshape_sectors = _get_reshape_sectors(rs);
3094         if (rs->dev_sectors != rdev_sectors) {
3095                 resize = (rs->dev_sectors != rdev_sectors - reshape_sectors);
3096                 if (rs->dev_sectors > rdev_sectors - reshape_sectors)
3097                         set_bit(RT_FLAG_RS_GROW, &rs->runtime_flags);
3098         }
3099
3100         INIT_WORK(&rs->md.event_work, do_table_event);
3101         ti->private = rs;
3102         ti->num_flush_bios = 1;
3103
3104         /* Restore any requested new layout for conversion decision */
3105         rs_config_restore(rs, &rs_layout);
3106
3107         /*
3108          * Now that we have any superblock metadata available,
3109          * check for new, recovering, reshaping, to be taken over,
3110          * to be reshaped or an existing, unchanged raid set to
3111          * run in sequence.
3112          */
3113         if (test_bit(MD_ARRAY_FIRST_USE, &rs->md.flags)) {
3114                 /* A new raid6 set has to be recovered to ensure proper parity and Q-Syndrome */
3115                 if (rs_is_raid6(rs) &&
3116                     test_bit(__CTR_FLAG_NOSYNC, &rs->ctr_flags)) {
3117                         ti->error = "'nosync' not allowed for new raid6 set";
3118                         r = -EINVAL;
3119                         goto bad;
3120                 }
3121                 rs_setup_recovery(rs, 0);
3122                 set_bit(RT_FLAG_UPDATE_SBS, &rs->runtime_flags);
3123                 rs_set_new(rs);
3124         } else if (rs_is_recovering(rs)) {
3125                 /* A recovering raid set may be resized */
3126                 goto size_check;
3127         } else if (rs_is_reshaping(rs)) {
3128                 /* Have to reject size change request during reshape */
3129                 if (resize) {
3130                         ti->error = "Can't resize a reshaping raid set";
3131                         r = -EPERM;
3132                         goto bad;
3133                 }
3134                 /* skip setup rs */
3135         } else if (rs_takeover_requested(rs)) {
3136                 if (rs_is_reshaping(rs)) {
3137                         ti->error = "Can't takeover a reshaping raid set";
3138                         r = -EPERM;
3139                         goto bad;
3140                 }
3141
3142                 /* We can't takeover a journaled raid4/5/6 */
3143                 if (test_bit(__CTR_FLAG_JOURNAL_DEV, &rs->ctr_flags)) {
3144                         ti->error = "Can't takeover a journaled raid4/5/6 set";
3145                         r = -EPERM;
3146                         goto bad;
3147                 }
3148
3149                 /*
3150                  * If a takeover is needed, userspace sets any additional
3151                  * devices to rebuild and we can check for a valid request here.
3152                  *
3153                  * If acceptible, set the level to the new requested
3154                  * one, prohibit requesting recovery, allow the raid
3155                  * set to run and store superblocks during resume.
3156                  */
3157                 r = rs_check_takeover(rs);
3158                 if (r)
3159                         goto bad;
3160
3161                 r = rs_setup_takeover(rs);
3162                 if (r)
3163                         goto bad;
3164
3165                 set_bit(RT_FLAG_UPDATE_SBS, &rs->runtime_flags);
3166                 /* Takeover ain't recovery, so disable recovery */
3167                 rs_setup_recovery(rs, MaxSector);
3168                 rs_set_new(rs);
3169         } else if (rs_reshape_requested(rs)) {
3170                 /* Only request grow on raid set size extensions, not on reshapes. */
3171                 clear_bit(RT_FLAG_RS_GROW, &rs->runtime_flags);
3172
3173                 /*
3174                  * No need to check for 'ongoing' takeover here, because takeover
3175                  * is an instant operation as oposed to an ongoing reshape.
3176                  */
3177
3178                 /* We can't reshape a journaled raid4/5/6 */
3179                 if (test_bit(__CTR_FLAG_JOURNAL_DEV, &rs->ctr_flags)) {
3180                         ti->error = "Can't reshape a journaled raid4/5/6 set";
3181                         r = -EPERM;
3182                         goto bad;
3183                 }
3184
3185                 /* Out-of-place space has to be available to allow for a reshape unless raid1! */
3186                 if (reshape_sectors || rs_is_raid1(rs)) {
3187                         /*
3188                           * We can only prepare for a reshape here, because the
3189                           * raid set needs to run to provide the repective reshape
3190                           * check functions via its MD personality instance.
3191                           *
3192                           * So do the reshape check after md_run() succeeded.
3193                           */
3194                         r = rs_prepare_reshape(rs);
3195                         if (r)
3196                                 goto bad;
3197
3198                         /* Reshaping ain't recovery, so disable recovery */
3199                         rs_setup_recovery(rs, MaxSector);
3200                 }
3201                 rs_set_cur(rs);
3202         } else {
3203 size_check:
3204                 /* May not set recovery when a device rebuild is requested */
3205                 if (test_bit(__CTR_FLAG_REBUILD, &rs->ctr_flags)) {
3206                         clear_bit(RT_FLAG_RS_GROW, &rs->runtime_flags);
3207                         set_bit(RT_FLAG_UPDATE_SBS, &rs->runtime_flags);
3208                         rs_setup_recovery(rs, MaxSector);
3209                 } else if (test_bit(RT_FLAG_RS_GROW, &rs->runtime_flags)) {
3210                         /*
3211                          * Set raid set to current size, i.e. size as of
3212                          * superblocks to grow to larger size in preresume.
3213                          */
3214                         r = rs_set_dev_and_array_sectors(rs, sb_array_sectors, false);
3215                         if (r)
3216                                 goto bad;
3217
3218                         rs_setup_recovery(rs, rs->md.recovery_cp < rs->md.dev_sectors ? rs->md.recovery_cp : rs->md.dev_sectors);
3219                 } else {
3220                         /* This is no size change or it is shrinking, update size and record in superblocks */
3221                         r = rs_set_dev_and_array_sectors(rs, rs->ti->len, false);
3222                         if (r)
3223                                 goto bad;
3224
3225                         if (sb_array_sectors > rs->array_sectors)
3226                                 set_bit(RT_FLAG_UPDATE_SBS, &rs->runtime_flags);
3227                 }
3228                 rs_set_cur(rs);
3229         }
3230
3231         /* If constructor requested it, change data and new_data offsets */
3232         r = rs_adjust_data_offsets(rs);
3233         if (r)
3234                 goto bad;
3235
3236         /* Catch any inconclusive reshape superblock content. */
3237         rs_reset_inconclusive_reshape(rs);
3238
3239         /* Start raid set read-only and assumed clean to change in raid_resume() */
3240         rs->md.ro = 1;
3241         rs->md.in_sync = 1;
3242
3243         /* Keep array frozen until resume. */
3244         set_bit(MD_RECOVERY_FROZEN, &rs->md.recovery);
3245
3246         /* Has to be held on running the array */
3247         mddev_lock_nointr(&rs->md);
3248         r = md_run(&rs->md);
3249         rs->md.in_sync = 0; /* Assume already marked dirty */
3250         if (r) {
3251                 ti->error = "Failed to run raid array";
3252                 mddev_unlock(&rs->md);
3253                 goto bad;
3254         }
3255
3256         r = md_start(&rs->md);
3257         if (r) {
3258                 ti->error = "Failed to start raid array";
3259                 mddev_unlock(&rs->md);
3260                 goto bad_md_start;
3261         }
3262
3263         /* If raid4/5/6 journal mode explicitly requested (only possible with journal dev) -> set it */
3264         if (test_bit(__CTR_FLAG_JOURNAL_MODE, &rs->ctr_flags)) {
3265                 r = r5c_journal_mode_set(&rs->md, rs->journal_dev.mode);
3266                 if (r) {
3267                         ti->error = "Failed to set raid4/5/6 journal mode";
3268                         mddev_unlock(&rs->md);
3269                         goto bad_journal_mode_set;
3270                 }
3271         }
3272
3273         mddev_suspend(&rs->md);
3274         set_bit(RT_FLAG_RS_SUSPENDED, &rs->runtime_flags);
3275
3276         /* Try to adjust the raid4/5/6 stripe cache size to the stripe size */
3277         if (rs_is_raid456(rs)) {
3278                 r = rs_set_raid456_stripe_cache(rs);
3279                 if (r)
3280                         goto bad_stripe_cache;
3281         }
3282
3283         /* Now do an early reshape check */
3284         if (test_bit(RT_FLAG_RESHAPE_RS, &rs->runtime_flags)) {
3285                 r = rs_check_reshape(rs);
3286                 if (r)
3287                         goto bad_check_reshape;
3288
3289                 /* Restore new, ctr requested layout to perform check */
3290                 rs_config_restore(rs, &rs_layout);
3291
3292                 if (rs->md.pers->start_reshape) {
3293                         r = rs->md.pers->check_reshape(&rs->md);
3294                         if (r) {
3295                                 ti->error = "Reshape check failed";
3296                                 goto bad_check_reshape;
3297                         }
3298                 }
3299         }
3300
3301         /* Disable/enable discard support on raid set. */
3302         configure_discard_support(rs);
3303
3304         mddev_unlock(&rs->md);
3305         return 0;
3306
3307 bad_md_start:
3308 bad_journal_mode_set:
3309 bad_stripe_cache:
3310 bad_check_reshape:
3311         md_stop(&rs->md);
3312 bad:
3313         raid_set_free(rs);
3314
3315         return r;
3316 }
3317
3318 static void raid_dtr(struct dm_target *ti)
3319 {
3320         struct raid_set *rs = ti->private;
3321
3322         md_stop(&rs->md);
3323         raid_set_free(rs);
3324 }
3325
3326 static int raid_map(struct dm_target *ti, struct bio *bio)
3327 {
3328         struct raid_set *rs = ti->private;
3329         struct mddev *mddev = &rs->md;
3330
3331         /*
3332          * If we're reshaping to add disk(s)), ti->len and
3333          * mddev->array_sectors will differ during the process
3334          * (ti->len > mddev->array_sectors), so we have to requeue
3335          * bios with addresses > mddev->array_sectors here or
3336          * there will occur accesses past EOD of the component
3337          * data images thus erroring the raid set.
3338          */
3339         if (unlikely(bio_end_sector(bio) > mddev->array_sectors))
3340                 return DM_MAPIO_REQUEUE;
3341
3342         md_handle_request(mddev, bio);
3343
3344         return DM_MAPIO_SUBMITTED;
3345 }
3346
3347 /* Return sync state string for @state */
3348 enum sync_state { st_frozen, st_reshape, st_resync, st_check, st_repair, st_recover, st_idle };
3349 static const char *sync_str(enum sync_state state)
3350 {
3351         /* Has to be in above sync_state order! */
3352         static const char *sync_strs[] = {
3353                 "frozen",
3354                 "reshape",
3355                 "resync",
3356                 "check",
3357                 "repair",
3358                 "recover",
3359                 "idle"
3360         };
3361
3362         return __within_range(state, 0, ARRAY_SIZE(sync_strs) - 1) ? sync_strs[state] : "undef";
3363 };
3364
3365 /* Return enum sync_state for @mddev derived from @recovery flags */
3366 static enum sync_state decipher_sync_action(struct mddev *mddev, unsigned long recovery)
3367 {
3368         if (test_bit(MD_RECOVERY_FROZEN, &recovery))
3369                 return st_frozen;
3370
3371         /* The MD sync thread can be done with io or be interrupted but still be running */
3372         if (!test_bit(MD_RECOVERY_DONE, &recovery) &&
3373             (test_bit(MD_RECOVERY_RUNNING, &recovery) ||
3374              (!mddev->ro && test_bit(MD_RECOVERY_NEEDED, &recovery)))) {
3375                 if (test_bit(MD_RECOVERY_RESHAPE, &recovery))
3376                         return st_reshape;
3377
3378                 if (test_bit(MD_RECOVERY_SYNC, &recovery)) {
3379                         if (!test_bit(MD_RECOVERY_REQUESTED, &recovery))
3380                                 return st_resync;
3381                         if (test_bit(MD_RECOVERY_CHECK, &recovery))
3382                                 return st_check;
3383                         return st_repair;
3384                 }
3385
3386                 if (test_bit(MD_RECOVERY_RECOVER, &recovery))
3387                         return st_recover;
3388
3389                 if (mddev->reshape_position != MaxSector)
3390                         return st_reshape;
3391         }
3392
3393         return st_idle;
3394 }
3395
3396 /*
3397  * Return status string for @rdev
3398  *
3399  * Status characters:
3400  *
3401  *  'D' = Dead/Failed raid set component or raid4/5/6 journal device
3402  *  'a' = Alive but not in-sync raid set component _or_ alive raid4/5/6 'write_back' journal device
3403  *  'A' = Alive and in-sync raid set component _or_ alive raid4/5/6 'write_through' journal device
3404  *  '-' = Non-existing device (i.e. uspace passed '- -' into the ctr)
3405  */
3406 static const char *__raid_dev_status(struct raid_set *rs, struct md_rdev *rdev)
3407 {
3408         if (!rdev->bdev)
3409                 return "-";
3410         else if (test_bit(Faulty, &rdev->flags))
3411                 return "D";
3412         else if (test_bit(Journal, &rdev->flags))
3413                 return (rs->journal_dev.mode == R5C_JOURNAL_MODE_WRITE_THROUGH) ? "A" : "a";
3414         else if (test_bit(RT_FLAG_RS_RESYNCING, &rs->runtime_flags) ||
3415                  (!test_bit(RT_FLAG_RS_IN_SYNC, &rs->runtime_flags) &&
3416                   !test_bit(In_sync, &rdev->flags)))
3417                 return "a";
3418         else
3419                 return "A";
3420 }
3421
3422 /* Helper to return resync/reshape progress for @rs and runtime flags for raid set in sync / resynching */
3423 static sector_t rs_get_progress(struct raid_set *rs, unsigned long recovery,
3424                                 enum sync_state state, sector_t resync_max_sectors)
3425 {
3426         sector_t r;
3427         struct mddev *mddev = &rs->md;
3428
3429         clear_bit(RT_FLAG_RS_IN_SYNC, &rs->runtime_flags);
3430         clear_bit(RT_FLAG_RS_RESYNCING, &rs->runtime_flags);
3431
3432         if (rs_is_raid0(rs)) {
3433                 r = resync_max_sectors;
3434                 set_bit(RT_FLAG_RS_IN_SYNC, &rs->runtime_flags);
3435
3436         } else {
3437                 if (state == st_idle && !test_bit(MD_RECOVERY_INTR, &recovery))
3438                         r = mddev->recovery_cp;
3439                 else
3440                         r = mddev->curr_resync_completed;
3441
3442                 if (state == st_idle && r >= resync_max_sectors) {
3443                         /*
3444                          * Sync complete.
3445                          */
3446                         /* In case we have finished recovering, the array is in sync. */
3447                         if (test_bit(MD_RECOVERY_RECOVER, &recovery))
3448                                 set_bit(RT_FLAG_RS_IN_SYNC, &rs->runtime_flags);
3449
3450                 } else if (state == st_recover)
3451                         /*
3452                          * In case we are recovering, the array is not in sync
3453                          * and health chars should show the recovering legs.
3454                          *
3455                          * Already retrieved recovery offset from curr_resync_completed above.
3456                          */
3457                         ;
3458
3459                 else if (state == st_resync || state == st_reshape)
3460                         /*
3461                          * If "resync/reshape" is occurring, the raid set
3462                          * is or may be out of sync hence the health
3463                          * characters shall be 'a'.
3464                          */
3465                         set_bit(RT_FLAG_RS_RESYNCING, &rs->runtime_flags);
3466
3467                 else if (state == st_check || state == st_repair)
3468                         /*
3469                          * If "check" or "repair" is occurring, the raid set has
3470                          * undergone an initial sync and the health characters
3471                          * should not be 'a' anymore.
3472                          */
3473                         set_bit(RT_FLAG_RS_IN_SYNC, &rs->runtime_flags);
3474
3475                 else if (test_bit(MD_RECOVERY_NEEDED, &recovery))
3476                         /*
3477                          * We are idle and recovery is needed, prevent 'A' chars race
3478                          * caused by components still set to in-sync by constructor.
3479                          */
3480                         set_bit(RT_FLAG_RS_RESYNCING, &rs->runtime_flags);
3481
3482                 else {
3483                         /*
3484                          * We are idle and the raid set may be doing an initial
3485                          * sync, or it may be rebuilding individual components.
3486                          * If all the devices are In_sync, then it is the raid set
3487                          * that is being initialized.
3488                          */
3489                         struct md_rdev *rdev;
3490
3491                         set_bit(RT_FLAG_RS_IN_SYNC, &rs->runtime_flags);
3492                         rdev_for_each(rdev, mddev)
3493                                 if (!test_bit(Journal, &rdev->flags) &&
3494                                     !test_bit(In_sync, &rdev->flags)) {
3495                                         clear_bit(RT_FLAG_RS_IN_SYNC, &rs->runtime_flags);
3496                                         break;
3497                                 }
3498                 }
3499         }
3500
3501         return min(r, resync_max_sectors);
3502 }
3503
3504 /* Helper to return @dev name or "-" if !@dev */
3505 static const char *__get_dev_name(struct dm_dev *dev)
3506 {
3507         return dev ? dev->name : "-";
3508 }
3509
3510 static void raid_status(struct dm_target *ti, status_type_t type,
3511                         unsigned int status_flags, char *result, unsigned int maxlen)
3512 {
3513         struct raid_set *rs = ti->private;
3514         struct mddev *mddev = &rs->md;
3515         struct r5conf *conf = mddev->private;
3516         int i, max_nr_stripes = conf ? conf->max_nr_stripes : 0;
3517         unsigned long recovery;
3518         unsigned int raid_param_cnt = 1; /* at least 1 for chunksize */
3519         unsigned int sz = 0;
3520         unsigned int rebuild_writemostly_count = 0;
3521         sector_t progress, resync_max_sectors, resync_mismatches;
3522         enum sync_state state;
3523         struct raid_type *rt;
3524
3525         switch (type) {
3526         case STATUSTYPE_INFO:
3527                 /* *Should* always succeed */
3528                 rt = get_raid_type_by_ll(mddev->new_level, mddev->new_layout);
3529                 if (!rt)
3530                         return;
3531
3532                 DMEMIT("%s %d ", rt->name, mddev->raid_disks);
3533
3534                 /* Access most recent mddev properties for status output */
3535                 smp_rmb();
3536                 /* Get sensible max sectors even if raid set not yet started */
3537                 resync_max_sectors = test_bit(RT_FLAG_RS_PRERESUMED, &rs->runtime_flags) ?
3538                                       mddev->resync_max_sectors : mddev->dev_sectors;
3539                 recovery = rs->md.recovery;
3540                 state = decipher_sync_action(mddev, recovery);
3541                 progress = rs_get_progress(rs, recovery, state, resync_max_sectors);
3542                 resync_mismatches = (mddev->last_sync_action && !strcasecmp(mddev->last_sync_action, "check")) ?
3543                                     atomic64_read(&mddev->resync_mismatches) : 0;
3544
3545                 /* HM FIXME: do we want another state char for raid0? It shows 'D'/'A'/'-' now */
3546                 for (i = 0; i < rs->raid_disks; i++)
3547                         DMEMIT(__raid_dev_status(rs, &rs->dev[i].rdev));
3548
3549                 /*
3550                  * In-sync/Reshape ratio:
3551                  *  The in-sync ratio shows the progress of:
3552                  *   - Initializing the raid set
3553                  *   - Rebuilding a subset of devices of the raid set
3554                  *  The user can distinguish between the two by referring
3555                  *  to the status characters.
3556                  *
3557                  *  The reshape ratio shows the progress of
3558                  *  changing the raid layout or the number of
3559                  *  disks of a raid set
3560                  */
3561                 DMEMIT(" %llu/%llu", (unsigned long long) progress,
3562                                      (unsigned long long) resync_max_sectors);
3563
3564                 /*
3565                  * v1.5.0+:
3566                  *
3567                  * Sync action:
3568                  *   See Documentation/admin-guide/device-mapper/dm-raid.rst for
3569                  *   information on each of these states.
3570                  */
3571                 DMEMIT(" %s", sync_str(state));
3572
3573                 /*
3574                  * v1.5.0+:
3575                  *
3576                  * resync_mismatches/mismatch_cnt
3577                  *   This field shows the number of discrepancies found when
3578                  *   performing a "check" of the raid set.
3579                  */
3580                 DMEMIT(" %llu", (unsigned long long) resync_mismatches);
3581
3582                 /*
3583                  * v1.9.0+:
3584                  *
3585                  * data_offset (needed for out of space reshaping)
3586                  *   This field shows the data offset into the data
3587                  *   image LV where the first stripes data starts.
3588                  *
3589                  * We keep data_offset equal on all raid disks of the set,
3590                  * so retrieving it from the first raid disk is sufficient.
3591                  */
3592                 DMEMIT(" %llu", (unsigned long long) rs->dev[0].rdev.data_offset);
3593
3594                 /*
3595                  * v1.10.0+:
3596                  */
3597                 DMEMIT(" %s", test_bit(__CTR_FLAG_JOURNAL_DEV, &rs->ctr_flags) ?
3598                               __raid_dev_status(rs, &rs->journal_dev.rdev) : "-");
3599                 break;
3600
3601         case STATUSTYPE_TABLE:
3602                 /* Report the table line string you would use to construct this raid set */
3603
3604                 /*
3605                  * Count any rebuild or writemostly argument pairs and subtract the
3606                  * hweight count being added below of any rebuild and writemostly ctr flags.
3607                  */
3608                 for (i = 0; i < rs->raid_disks; i++) {
3609                         rebuild_writemostly_count += (test_bit(i, (void *) rs->rebuild_disks) ? 2 : 0) +
3610                                                      (test_bit(WriteMostly, &rs->dev[i].rdev.flags) ? 2 : 0);
3611                 }
3612                 rebuild_writemostly_count -= (test_bit(__CTR_FLAG_REBUILD, &rs->ctr_flags) ? 2 : 0) +
3613                                              (test_bit(__CTR_FLAG_WRITE_MOSTLY, &rs->ctr_flags) ? 2 : 0);
3614                 /* Calculate raid parameter count based on ^ rebuild/writemostly argument counts and ctr flags set. */
3615                 raid_param_cnt += rebuild_writemostly_count +
3616                                   hweight32(rs->ctr_flags & CTR_FLAG_OPTIONS_NO_ARGS) +
3617                                   hweight32(rs->ctr_flags & CTR_FLAG_OPTIONS_ONE_ARG) * 2;
3618                 /* Emit table line */
3619                 /* This has to be in the documented order for userspace! */
3620                 DMEMIT("%s %u %u", rs->raid_type->name, raid_param_cnt, mddev->new_chunk_sectors);
3621                 if (test_bit(__CTR_FLAG_SYNC, &rs->ctr_flags))
3622                         DMEMIT(" %s", dm_raid_arg_name_by_flag(CTR_FLAG_SYNC));
3623                 if (test_bit(__CTR_FLAG_NOSYNC, &rs->ctr_flags))
3624                         DMEMIT(" %s", dm_raid_arg_name_by_flag(CTR_FLAG_NOSYNC));
3625                 if (test_bit(__CTR_FLAG_REBUILD, &rs->ctr_flags))
3626                         for (i = 0; i < rs->raid_disks; i++)
3627                                 if (test_bit(i, (void *) rs->rebuild_disks))
3628                                         DMEMIT(" %s %u", dm_raid_arg_name_by_flag(CTR_FLAG_REBUILD), i);
3629                 if (test_bit(__CTR_FLAG_DAEMON_SLEEP, &rs->ctr_flags))
3630                         DMEMIT(" %s %lu", dm_raid_arg_name_by_flag(CTR_FLAG_DAEMON_SLEEP),
3631                                           mddev->bitmap_info.daemon_sleep);
3632                 if (test_bit(__CTR_FLAG_MIN_RECOVERY_RATE, &rs->ctr_flags))
3633                         DMEMIT(" %s %d", dm_raid_arg_name_by_flag(CTR_FLAG_MIN_RECOVERY_RATE),
3634                                          mddev->sync_speed_min);
3635                 if (test_bit(__CTR_FLAG_MAX_RECOVERY_RATE, &rs->ctr_flags))
3636                         DMEMIT(" %s %d", dm_raid_arg_name_by_flag(CTR_FLAG_MAX_RECOVERY_RATE),
3637                                          mddev->sync_speed_max);
3638                 if (test_bit(__CTR_FLAG_WRITE_MOSTLY, &rs->ctr_flags))
3639                         for (i = 0; i < rs->raid_disks; i++)
3640                                 if (test_bit(WriteMostly, &rs->dev[i].rdev.flags))
3641                                         DMEMIT(" %s %d", dm_raid_arg_name_by_flag(CTR_FLAG_WRITE_MOSTLY),
3642                                                rs->dev[i].rdev.raid_disk);
3643                 if (test_bit(__CTR_FLAG_MAX_WRITE_BEHIND, &rs->ctr_flags))
3644                         DMEMIT(" %s %lu", dm_raid_arg_name_by_flag(CTR_FLAG_MAX_WRITE_BEHIND),
3645                                           mddev->bitmap_info.max_write_behind);
3646                 if (test_bit(__CTR_FLAG_STRIPE_CACHE, &rs->ctr_flags))
3647                         DMEMIT(" %s %d", dm_raid_arg_name_by_flag(CTR_FLAG_STRIPE_CACHE),
3648                                          max_nr_stripes);
3649                 if (test_bit(__CTR_FLAG_REGION_SIZE, &rs->ctr_flags))
3650                         DMEMIT(" %s %llu", dm_raid_arg_name_by_flag(CTR_FLAG_REGION_SIZE),
3651                                            (unsigned long long) to_sector(mddev->bitmap_info.chunksize));
3652                 if (test_bit(__CTR_FLAG_RAID10_COPIES, &rs->ctr_flags))
3653                         DMEMIT(" %s %d", dm_raid_arg_name_by_flag(CTR_FLAG_RAID10_COPIES),
3654                                          raid10_md_layout_to_copies(mddev->layout));
3655                 if (test_bit(__CTR_FLAG_RAID10_FORMAT, &rs->ctr_flags))
3656                         DMEMIT(" %s %s", dm_raid_arg_name_by_flag(CTR_FLAG_RAID10_FORMAT),
3657                                          raid10_md_layout_to_format(mddev->layout));
3658                 if (test_bit(__CTR_FLAG_DELTA_DISKS, &rs->ctr_flags))
3659                         DMEMIT(" %s %d", dm_raid_arg_name_by_flag(CTR_FLAG_DELTA_DISKS),
3660                                          max(rs->delta_disks, mddev->delta_disks));
3661                 if (test_bit(__CTR_FLAG_DATA_OFFSET, &rs->ctr_flags))
3662                         DMEMIT(" %s %llu", dm_raid_arg_name_by_flag(CTR_FLAG_DATA_OFFSET),
3663                                            (unsigned long long) rs->data_offset);
3664                 if (test_bit(__CTR_FLAG_JOURNAL_DEV, &rs->ctr_flags))
3665                         DMEMIT(" %s %s", dm_raid_arg_name_by_flag(CTR_FLAG_JOURNAL_DEV),
3666                                         __get_dev_name(rs->journal_dev.dev));
3667                 if (test_bit(__CTR_FLAG_JOURNAL_MODE, &rs->ctr_flags))
3668                         DMEMIT(" %s %s", dm_raid_arg_name_by_flag(CTR_FLAG_JOURNAL_MODE),
3669                                          md_journal_mode_to_dm_raid(rs->journal_dev.mode));
3670                 DMEMIT(" %d", rs->raid_disks);
3671                 for (i = 0; i < rs->raid_disks; i++)
3672                         DMEMIT(" %s %s", __get_dev_name(rs->dev[i].meta_dev),
3673                                          __get_dev_name(rs->dev[i].data_dev));
3674                 break;
3675
3676         case STATUSTYPE_IMA:
3677                 rt = get_raid_type_by_ll(mddev->new_level, mddev->new_layout);
3678                 if (!rt)
3679                         return;
3680
3681                 DMEMIT_TARGET_NAME_VERSION(ti->type);
3682                 DMEMIT(",raid_type=%s,raid_disks=%d", rt->name, mddev->raid_disks);
3683
3684                 /* Access most recent mddev properties for status output */
3685                 smp_rmb();
3686                 recovery = rs->md.recovery;
3687                 state = decipher_sync_action(mddev, recovery);
3688                 DMEMIT(",raid_state=%s", sync_str(state));
3689
3690                 for (i = 0; i < rs->raid_disks; i++) {
3691                         DMEMIT(",raid_device_%d_status=", i);
3692                         DMEMIT(__raid_dev_status(rs, &rs->dev[i].rdev));
3693                 }
3694
3695                 if (rt_is_raid456(rt)) {
3696                         DMEMIT(",journal_dev_mode=");
3697                         switch (rs->journal_dev.mode) {
3698                         case R5C_JOURNAL_MODE_WRITE_THROUGH:
3699                                 DMEMIT("%s",
3700                                        _raid456_journal_mode[R5C_JOURNAL_MODE_WRITE_THROUGH].param);
3701                                 break;
3702                         case R5C_JOURNAL_MODE_WRITE_BACK:
3703                                 DMEMIT("%s",
3704                                        _raid456_journal_mode[R5C_JOURNAL_MODE_WRITE_BACK].param);
3705                                 break;
3706                         default:
3707                                 DMEMIT("invalid");
3708                                 break;
3709                         }
3710                 }
3711                 DMEMIT(";");
3712                 break;
3713         }
3714 }
3715
3716 static int raid_message(struct dm_target *ti, unsigned int argc, char **argv,
3717                         char *result, unsigned maxlen)
3718 {
3719         struct raid_set *rs = ti->private;
3720         struct mddev *mddev = &rs->md;
3721
3722         if (!mddev->pers || !mddev->pers->sync_request)
3723                 return -EINVAL;
3724
3725         if (!strcasecmp(argv[0], "frozen"))
3726                 set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
3727         else
3728                 clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
3729
3730         if (!strcasecmp(argv[0], "idle") || !strcasecmp(argv[0], "frozen")) {
3731                 if (mddev->sync_thread) {
3732                         set_bit(MD_RECOVERY_INTR, &mddev->recovery);
3733                         md_reap_sync_thread(mddev);
3734                 }
3735         } else if (decipher_sync_action(mddev, mddev->recovery) != st_idle)
3736                 return -EBUSY;
3737         else if (!strcasecmp(argv[0], "resync"))
3738                 ; /* MD_RECOVERY_NEEDED set below */
3739         else if (!strcasecmp(argv[0], "recover"))
3740                 set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
3741         else {
3742                 if (!strcasecmp(argv[0], "check")) {
3743                         set_bit(MD_RECOVERY_CHECK, &mddev->recovery);
3744                         set_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
3745                         set_bit(MD_RECOVERY_SYNC, &mddev->recovery);
3746                 } else if (!strcasecmp(argv[0], "repair")) {
3747                         set_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
3748                         set_bit(MD_RECOVERY_SYNC, &mddev->recovery);
3749                 } else
3750                         return -EINVAL;
3751         }
3752         if (mddev->ro == 2) {
3753                 /* A write to sync_action is enough to justify
3754                  * canceling read-auto mode
3755                  */
3756                 mddev->ro = 0;
3757                 if (!mddev->suspended && mddev->sync_thread)
3758                         md_wakeup_thread(mddev->sync_thread);
3759         }
3760         set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
3761         if (!mddev->suspended && mddev->thread)
3762                 md_wakeup_thread(mddev->thread);
3763
3764         return 0;
3765 }
3766
3767 static int raid_iterate_devices(struct dm_target *ti,
3768                                 iterate_devices_callout_fn fn, void *data)
3769 {
3770         struct raid_set *rs = ti->private;
3771         unsigned int i;
3772         int r = 0;
3773
3774         for (i = 0; !r && i < rs->md.raid_disks; i++)
3775                 if (rs->dev[i].data_dev)
3776                         r = fn(ti,
3777                                  rs->dev[i].data_dev,
3778                                  0, /* No offset on data devs */
3779                                  rs->md.dev_sectors,
3780                                  data);
3781
3782         return r;
3783 }
3784
3785 static void raid_io_hints(struct dm_target *ti, struct queue_limits *limits)
3786 {
3787         struct raid_set *rs = ti->private;
3788         unsigned int chunk_size_bytes = to_bytes(rs->md.chunk_sectors);
3789
3790         blk_limits_io_min(limits, chunk_size_bytes);
3791         blk_limits_io_opt(limits, chunk_size_bytes * mddev_data_stripes(rs));
3792 }
3793
3794 static void raid_postsuspend(struct dm_target *ti)
3795 {
3796         struct raid_set *rs = ti->private;
3797
3798         if (!test_and_set_bit(RT_FLAG_RS_SUSPENDED, &rs->runtime_flags)) {
3799                 /* Writes have to be stopped before suspending to avoid deadlocks. */
3800                 if (!test_bit(MD_RECOVERY_FROZEN, &rs->md.recovery))
3801                         md_stop_writes(&rs->md);
3802
3803                 mddev_lock_nointr(&rs->md);
3804                 mddev_suspend(&rs->md);
3805                 mddev_unlock(&rs->md);
3806         }
3807 }
3808
3809 static void attempt_restore_of_faulty_devices(struct raid_set *rs)
3810 {
3811         int i;
3812         uint64_t cleared_failed_devices[DISKS_ARRAY_ELEMS];
3813         unsigned long flags;
3814         bool cleared = false;
3815         struct dm_raid_superblock *sb;
3816         struct mddev *mddev = &rs->md;
3817         struct md_rdev *r;
3818
3819         /* RAID personalities have to provide hot add/remove methods or we need to bail out. */
3820         if (!mddev->pers || !mddev->pers->hot_add_disk || !mddev->pers->hot_remove_disk)
3821                 return;
3822
3823         memset(cleared_failed_devices, 0, sizeof(cleared_failed_devices));
3824
3825         for (i = 0; i < mddev->raid_disks; i++) {
3826                 r = &rs->dev[i].rdev;
3827                 /* HM FIXME: enhance journal device recovery processing */
3828                 if (test_bit(Journal, &r->flags))
3829                         continue;
3830
3831                 if (test_bit(Faulty, &r->flags) &&
3832                     r->meta_bdev && !read_disk_sb(r, r->sb_size, true)) {
3833                         DMINFO("Faulty %s device #%d has readable super block."
3834                                "  Attempting to revive it.",
3835                                rs->raid_type->name, i);
3836
3837                         /*
3838                          * Faulty bit may be set, but sometimes the array can
3839                          * be suspended before the personalities can respond
3840                          * by removing the device from the array (i.e. calling
3841                          * 'hot_remove_disk').  If they haven't yet removed
3842                          * the failed device, its 'raid_disk' number will be
3843                          * '>= 0' - meaning we must call this function
3844                          * ourselves.
3845                          */
3846                         flags = r->flags;
3847                         clear_bit(In_sync, &r->flags); /* Mandatory for hot remove. */
3848                         if (r->raid_disk >= 0) {
3849                                 if (mddev->pers->hot_remove_disk(mddev, r)) {
3850                                         /* Failed to revive this device, try next */
3851                                         r->flags = flags;
3852                                         continue;
3853                                 }
3854                         } else
3855                                 r->raid_disk = r->saved_raid_disk = i;
3856
3857                         clear_bit(Faulty, &r->flags);
3858                         clear_bit(WriteErrorSeen, &r->flags);
3859
3860                         if (mddev->pers->hot_add_disk(mddev, r)) {
3861                                 /* Failed to revive this device, try next */
3862                                 r->raid_disk = r->saved_raid_disk = -1;
3863                                 r->flags = flags;
3864                         } else {
3865                                 clear_bit(In_sync, &r->flags);
3866                                 r->recovery_offset = 0;
3867                                 set_bit(i, (void *) cleared_failed_devices);
3868                                 cleared = true;
3869                         }
3870                 }
3871         }
3872
3873         /* If any failed devices could be cleared, update all sbs failed_devices bits */
3874         if (cleared) {
3875                 uint64_t failed_devices[DISKS_ARRAY_ELEMS];
3876
3877                 rdev_for_each(r, &rs->md) {
3878                         if (test_bit(Journal, &r->flags))
3879                                 continue;
3880
3881                         sb = page_address(r->sb_page);
3882                         sb_retrieve_failed_devices(sb, failed_devices);
3883
3884                         for (i = 0; i < DISKS_ARRAY_ELEMS; i++)
3885                                 failed_devices[i] &= ~cleared_failed_devices[i];
3886
3887                         sb_update_failed_devices(sb, failed_devices);
3888                 }
3889         }
3890 }
3891
3892 static int __load_dirty_region_bitmap(struct raid_set *rs)
3893 {
3894         int r = 0;
3895
3896         /* Try loading the bitmap unless "raid0", which does not have one */
3897         if (!rs_is_raid0(rs) &&
3898             !test_and_set_bit(RT_FLAG_RS_BITMAP_LOADED, &rs->runtime_flags)) {
3899                 r = md_bitmap_load(&rs->md);
3900                 if (r)
3901                         DMERR("Failed to load bitmap");
3902         }
3903
3904         return r;
3905 }
3906
3907 /* Enforce updating all superblocks */
3908 static void rs_update_sbs(struct raid_set *rs)
3909 {
3910         struct mddev *mddev = &rs->md;
3911         int ro = mddev->ro;
3912
3913         set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags);
3914         mddev->ro = 0;
3915         md_update_sb(mddev, 1);
3916         mddev->ro = ro;
3917 }
3918
3919 /*
3920  * Reshape changes raid algorithm of @rs to new one within personality
3921  * (e.g. raid6_zr -> raid6_nc), changes stripe size, adds/removes
3922  * disks from a raid set thus growing/shrinking it or resizes the set
3923  *
3924  * Call mddev_lock_nointr() before!
3925  */
3926 static int rs_start_reshape(struct raid_set *rs)
3927 {
3928         int r;
3929         struct mddev *mddev = &rs->md;
3930         struct md_personality *pers = mddev->pers;
3931
3932         /* Don't allow the sync thread to work until the table gets reloaded. */
3933         set_bit(MD_RECOVERY_WAIT, &mddev->recovery);
3934
3935         r = rs_setup_reshape(rs);
3936         if (r)
3937                 return r;
3938
3939         /*
3940          * Check any reshape constraints enforced by the personalility
3941          *
3942          * May as well already kick the reshape off so that * pers->start_reshape() becomes optional.
3943          */
3944         r = pers->check_reshape(mddev);
3945         if (r) {
3946                 rs->ti->error = "pers->check_reshape() failed";
3947                 return r;
3948         }
3949
3950         /*
3951          * Personality may not provide start reshape method in which
3952          * case check_reshape above has already covered everything
3953          */
3954         if (pers->start_reshape) {
3955                 r = pers->start_reshape(mddev);
3956                 if (r) {
3957                         rs->ti->error = "pers->start_reshape() failed";
3958                         return r;
3959                 }
3960         }
3961
3962         /*
3963          * Now reshape got set up, update superblocks to
3964          * reflect the fact so that a table reload will
3965          * access proper superblock content in the ctr.
3966          */
3967         rs_update_sbs(rs);
3968
3969         return 0;
3970 }
3971
3972 static int raid_preresume(struct dm_target *ti)
3973 {
3974         int r;
3975         struct raid_set *rs = ti->private;
3976         struct mddev *mddev = &rs->md;
3977
3978         /* This is a resume after a suspend of the set -> it's already started. */
3979         if (test_and_set_bit(RT_FLAG_RS_PRERESUMED, &rs->runtime_flags))
3980                 return 0;
3981
3982         /*
3983          * The superblocks need to be updated on disk if the
3984          * array is new or new devices got added (thus zeroed
3985          * out by userspace) or __load_dirty_region_bitmap
3986          * will overwrite them in core with old data or fail.
3987          */
3988         if (test_bit(RT_FLAG_UPDATE_SBS, &rs->runtime_flags))
3989                 rs_update_sbs(rs);
3990
3991         /* Load the bitmap from disk unless raid0 */
3992         r = __load_dirty_region_bitmap(rs);
3993         if (r)
3994                 return r;
3995
3996         /* We are extending the raid set size, adjust mddev/md_rdev sizes and set capacity. */
3997         if (test_bit(RT_FLAG_RS_GROW, &rs->runtime_flags)) {
3998                 mddev->array_sectors = rs->array_sectors;
3999                 mddev->dev_sectors = rs->dev_sectors;
4000                 rs_set_rdev_sectors(rs);
4001                 rs_set_capacity(rs);
4002         }
4003
4004         /* Resize bitmap to adjust to changed region size (aka MD bitmap chunksize) or grown device size */
4005         if (test_bit(RT_FLAG_RS_BITMAP_LOADED, &rs->runtime_flags) && mddev->bitmap &&
4006             (test_bit(RT_FLAG_RS_GROW, &rs->runtime_flags) ||
4007              (rs->requested_bitmap_chunk_sectors &&
4008                mddev->bitmap_info.chunksize != to_bytes(rs->requested_bitmap_chunk_sectors)))) {
4009                 int chunksize = to_bytes(rs->requested_bitmap_chunk_sectors) ?: mddev->bitmap_info.chunksize;
4010
4011                 r = md_bitmap_resize(mddev->bitmap, mddev->dev_sectors, chunksize, 0);
4012                 if (r)
4013                         DMERR("Failed to resize bitmap");
4014         }
4015
4016         /* Check for any resize/reshape on @rs and adjust/initiate */
4017         /* Be prepared for mddev_resume() in raid_resume() */
4018         set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
4019         if (mddev->recovery_cp && mddev->recovery_cp < MaxSector) {
4020                 set_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
4021                 mddev->resync_min = mddev->recovery_cp;
4022                 if (test_bit(RT_FLAG_RS_GROW, &rs->runtime_flags))
4023                         mddev->resync_max_sectors = mddev->dev_sectors;
4024         }
4025
4026         /* Check for any reshape request unless new raid set */
4027         if (test_bit(RT_FLAG_RESHAPE_RS, &rs->runtime_flags)) {
4028                 /* Initiate a reshape. */
4029                 rs_set_rdev_sectors(rs);
4030                 mddev_lock_nointr(mddev);
4031                 r = rs_start_reshape(rs);
4032                 mddev_unlock(mddev);
4033                 if (r)
4034                         DMWARN("Failed to check/start reshape, continuing without change");
4035                 r = 0;
4036         }
4037
4038         return r;
4039 }
4040
4041 static void raid_resume(struct dm_target *ti)
4042 {
4043         struct raid_set *rs = ti->private;
4044         struct mddev *mddev = &rs->md;
4045
4046         if (test_and_set_bit(RT_FLAG_RS_RESUMED, &rs->runtime_flags)) {
4047                 /*
4048                  * A secondary resume while the device is active.
4049                  * Take this opportunity to check whether any failed
4050                  * devices are reachable again.
4051                  */
4052                 attempt_restore_of_faulty_devices(rs);
4053         }
4054
4055         if (test_and_clear_bit(RT_FLAG_RS_SUSPENDED, &rs->runtime_flags)) {
4056                 /* Only reduce raid set size before running a disk removing reshape. */
4057                 if (mddev->delta_disks < 0)
4058                         rs_set_capacity(rs);
4059
4060                 mddev_lock_nointr(mddev);
4061                 clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
4062                 mddev->ro = 0;
4063                 mddev->in_sync = 0;
4064                 mddev_resume(mddev);
4065                 mddev_unlock(mddev);
4066         }
4067 }
4068
4069 static struct target_type raid_target = {
4070         .name = "raid",
4071         .version = {1, 15, 1},
4072         .module = THIS_MODULE,
4073         .ctr = raid_ctr,
4074         .dtr = raid_dtr,
4075         .map = raid_map,
4076         .status = raid_status,
4077         .message = raid_message,
4078         .iterate_devices = raid_iterate_devices,
4079         .io_hints = raid_io_hints,
4080         .postsuspend = raid_postsuspend,
4081         .preresume = raid_preresume,
4082         .resume = raid_resume,
4083 };
4084
4085 static int __init dm_raid_init(void)
4086 {
4087         DMINFO("Loading target version %u.%u.%u",
4088                raid_target.version[0],
4089                raid_target.version[1],
4090                raid_target.version[2]);
4091         return dm_register_target(&raid_target);
4092 }
4093
4094 static void __exit dm_raid_exit(void)
4095 {
4096         dm_unregister_target(&raid_target);
4097 }
4098
4099 module_init(dm_raid_init);
4100 module_exit(dm_raid_exit);
4101
4102 module_param(devices_handle_discard_safely, bool, 0644);
4103 MODULE_PARM_DESC(devices_handle_discard_safely,
4104                  "Set to Y if all devices in each array reliably return zeroes on reads from discarded regions");
4105
4106 MODULE_DESCRIPTION(DM_NAME " raid0/1/10/4/5/6 target");
4107 MODULE_ALIAS("dm-raid0");
4108 MODULE_ALIAS("dm-raid1");
4109 MODULE_ALIAS("dm-raid10");
4110 MODULE_ALIAS("dm-raid4");
4111 MODULE_ALIAS("dm-raid5");
4112 MODULE_ALIAS("dm-raid6");
4113 MODULE_AUTHOR("Neil Brown <dm-devel@redhat.com>");
4114 MODULE_AUTHOR("Heinz Mauelshagen <dm-devel@redhat.com>");
4115 MODULE_LICENSE("GPL");