source: src/linux/universal/linux-4.9/drivers/md/dm-raid.c @ 31859

Last change on this file since 31859 was 31859, checked in by brainslayer, 3 months ago

kernel update

File size: 104.9 KB
Line 
1/*
2 * Copyright (C) 2010-2011 Neil Brown
3 * Copyright (C) 2010-2016 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 "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
27static bool devices_handle_discard_safely = false;
28
29/*
30 * The following flags are used by dm-raid.c to set up the array state.
31 * They must be cleared before md_run is called.
32 */
33#define FirstUse 10             /* rdev flag */
34
35struct raid_dev {
36        /*
37         * Two DM devices, one to hold metadata and one to hold the
38         * actual data/parity.  The reason for this is to not confuse
39         * ti->len and give more flexibility in altering size and
40         * characteristics.
41         *
42         * While it is possible for this device to be associated
43         * with a different physical device than the data_dev, it
44         * is intended for it to be the same.
45         *    |--------- Physical Device ---------|
46         *    |- meta_dev -|------ data_dev ------|
47         */
48        struct dm_dev *meta_dev;
49        struct dm_dev *data_dev;
50        struct md_rdev rdev;
51};
52
53/*
54 * Bits for establishing rs->ctr_flags
55 *
56 * 1 = no flag value
57 * 2 = flag with value
58 */
59#define __CTR_FLAG_SYNC                 0  /* 1 */ /* Not with raid0! */
60#define __CTR_FLAG_NOSYNC               1  /* 1 */ /* Not with raid0! */
61#define __CTR_FLAG_REBUILD              2  /* 2 */ /* Not with raid0! */
62#define __CTR_FLAG_DAEMON_SLEEP         3  /* 2 */ /* Not with raid0! */
63#define __CTR_FLAG_MIN_RECOVERY_RATE    4  /* 2 */ /* Not with raid0! */
64#define __CTR_FLAG_MAX_RECOVERY_RATE    5  /* 2 */ /* Not with raid0! */
65#define __CTR_FLAG_MAX_WRITE_BEHIND     6  /* 2 */ /* Only with raid1! */
66#define __CTR_FLAG_WRITE_MOSTLY         7  /* 2 */ /* Only with raid1! */
67#define __CTR_FLAG_STRIPE_CACHE         8  /* 2 */ /* Only with raid4/5/6! */
68#define __CTR_FLAG_REGION_SIZE          9  /* 2 */ /* Not with raid0! */
69#define __CTR_FLAG_RAID10_COPIES        10 /* 2 */ /* Only with raid10 */
70#define __CTR_FLAG_RAID10_FORMAT        11 /* 2 */ /* Only with raid10 */
71/* New for v1.9.0 */
72#define __CTR_FLAG_DELTA_DISKS          12 /* 2 */ /* Only with reshapable raid1/4/5/6/10! */
73#define __CTR_FLAG_DATA_OFFSET          13 /* 2 */ /* Only with reshapable raid4/5/6/10! */
74#define __CTR_FLAG_RAID10_USE_NEAR_SETS 14 /* 2 */ /* Only with raid10! */
75
76/*
77 * Flags for rs->ctr_flags field.
78 */
79#define CTR_FLAG_SYNC                   (1 << __CTR_FLAG_SYNC)
80#define CTR_FLAG_NOSYNC                 (1 << __CTR_FLAG_NOSYNC)
81#define CTR_FLAG_REBUILD                (1 << __CTR_FLAG_REBUILD)
82#define CTR_FLAG_DAEMON_SLEEP           (1 << __CTR_FLAG_DAEMON_SLEEP)
83#define CTR_FLAG_MIN_RECOVERY_RATE      (1 << __CTR_FLAG_MIN_RECOVERY_RATE)
84#define CTR_FLAG_MAX_RECOVERY_RATE      (1 << __CTR_FLAG_MAX_RECOVERY_RATE)
85#define CTR_FLAG_MAX_WRITE_BEHIND       (1 << __CTR_FLAG_MAX_WRITE_BEHIND)
86#define CTR_FLAG_WRITE_MOSTLY           (1 << __CTR_FLAG_WRITE_MOSTLY)
87#define CTR_FLAG_STRIPE_CACHE           (1 << __CTR_FLAG_STRIPE_CACHE)
88#define CTR_FLAG_REGION_SIZE            (1 << __CTR_FLAG_REGION_SIZE)
89#define CTR_FLAG_RAID10_COPIES          (1 << __CTR_FLAG_RAID10_COPIES)
90#define CTR_FLAG_RAID10_FORMAT          (1 << __CTR_FLAG_RAID10_FORMAT)
91#define CTR_FLAG_DELTA_DISKS            (1 << __CTR_FLAG_DELTA_DISKS)
92#define CTR_FLAG_DATA_OFFSET            (1 << __CTR_FLAG_DATA_OFFSET)
93#define CTR_FLAG_RAID10_USE_NEAR_SETS   (1 << __CTR_FLAG_RAID10_USE_NEAR_SETS)
94
95/*
96 * Definitions of various constructor flags to
97 * be used in checks of valid / invalid flags
98 * per raid level.
99 */
100/* Define all any sync flags */
101#define CTR_FLAGS_ANY_SYNC              (CTR_FLAG_SYNC | CTR_FLAG_NOSYNC)
102
103/* Define flags for options without argument (e.g. 'nosync') */
104#define CTR_FLAG_OPTIONS_NO_ARGS        (CTR_FLAGS_ANY_SYNC | \
105                                         CTR_FLAG_RAID10_USE_NEAR_SETS)
106
107/* Define flags for options with one argument (e.g. 'delta_disks +2') */
108#define CTR_FLAG_OPTIONS_ONE_ARG (CTR_FLAG_REBUILD | \
109                                  CTR_FLAG_WRITE_MOSTLY | \
110                                  CTR_FLAG_DAEMON_SLEEP | \
111                                  CTR_FLAG_MIN_RECOVERY_RATE | \
112                                  CTR_FLAG_MAX_RECOVERY_RATE | \
113                                  CTR_FLAG_MAX_WRITE_BEHIND | \
114                                  CTR_FLAG_STRIPE_CACHE | \
115                                  CTR_FLAG_REGION_SIZE | \
116                                  CTR_FLAG_RAID10_COPIES | \
117                                  CTR_FLAG_RAID10_FORMAT | \
118                                  CTR_FLAG_DELTA_DISKS | \
119                                  CTR_FLAG_DATA_OFFSET)
120
121/* Valid options definitions per raid level... */
122
123/* "raid0" does only accept data offset */
124#define RAID0_VALID_FLAGS       (CTR_FLAG_DATA_OFFSET)
125
126/* "raid1" does not accept stripe cache, data offset, delta_disks or any raid10 options */
127#define RAID1_VALID_FLAGS       (CTR_FLAGS_ANY_SYNC | \
128                                 CTR_FLAG_REBUILD | \
129                                 CTR_FLAG_WRITE_MOSTLY | \
130                                 CTR_FLAG_DAEMON_SLEEP | \
131                                 CTR_FLAG_MIN_RECOVERY_RATE | \
132                                 CTR_FLAG_MAX_RECOVERY_RATE | \
133                                 CTR_FLAG_MAX_WRITE_BEHIND | \
134                                 CTR_FLAG_REGION_SIZE | \
135                                 CTR_FLAG_DELTA_DISKS | \
136                                 CTR_FLAG_DATA_OFFSET)
137
138/* "raid10" does not accept any raid1 or stripe cache options */
139#define RAID10_VALID_FLAGS      (CTR_FLAGS_ANY_SYNC | \
140                                 CTR_FLAG_REBUILD | \
141                                 CTR_FLAG_DAEMON_SLEEP | \
142                                 CTR_FLAG_MIN_RECOVERY_RATE | \
143                                 CTR_FLAG_MAX_RECOVERY_RATE | \
144                                 CTR_FLAG_REGION_SIZE | \
145                                 CTR_FLAG_RAID10_COPIES | \
146                                 CTR_FLAG_RAID10_FORMAT | \
147                                 CTR_FLAG_DELTA_DISKS | \
148                                 CTR_FLAG_DATA_OFFSET | \
149                                 CTR_FLAG_RAID10_USE_NEAR_SETS)
150
151/*
152 * "raid4/5/6" do not accept any raid1 or raid10 specific options
153 *
154 * "raid6" does not accept "nosync", because it is not guaranteed
155 * that both parity and q-syndrome are being written properly with
156 * any writes
157 */
158#define RAID45_VALID_FLAGS      (CTR_FLAGS_ANY_SYNC | \
159                                 CTR_FLAG_REBUILD | \
160                                 CTR_FLAG_DAEMON_SLEEP | \
161                                 CTR_FLAG_MIN_RECOVERY_RATE | \
162                                 CTR_FLAG_MAX_RECOVERY_RATE | \
163                                 CTR_FLAG_MAX_WRITE_BEHIND | \
164                                 CTR_FLAG_STRIPE_CACHE | \
165                                 CTR_FLAG_REGION_SIZE | \
166                                 CTR_FLAG_DELTA_DISKS | \
167                                 CTR_FLAG_DATA_OFFSET)
168
169#define RAID6_VALID_FLAGS       (CTR_FLAG_SYNC | \
170                                 CTR_FLAG_REBUILD | \
171                                 CTR_FLAG_DAEMON_SLEEP | \
172                                 CTR_FLAG_MIN_RECOVERY_RATE | \
173                                 CTR_FLAG_MAX_RECOVERY_RATE | \
174                                 CTR_FLAG_MAX_WRITE_BEHIND | \
175                                 CTR_FLAG_STRIPE_CACHE | \
176                                 CTR_FLAG_REGION_SIZE | \
177                                 CTR_FLAG_DELTA_DISKS | \
178                                 CTR_FLAG_DATA_OFFSET)
179/* ...valid options definitions per raid level */
180
181/*
182 * Flags for rs->runtime_flags field
183 * (RT_FLAG prefix meaning "runtime flag")
184 *
185 * These are all internal and used to define runtime state,
186 * e.g. to prevent another resume from preresume processing
187 * the raid set all over again.
188 */
189#define RT_FLAG_RS_PRERESUMED           0
190#define RT_FLAG_RS_RESUMED              1
191#define RT_FLAG_RS_BITMAP_LOADED        2
192#define RT_FLAG_UPDATE_SBS              3
193#define RT_FLAG_RESHAPE_RS              4
194
195/* Array elements of 64 bit needed for rebuild/failed disk bits */
196#define DISKS_ARRAY_ELEMS ((MAX_RAID_DEVICES + (sizeof(uint64_t) * 8 - 1)) / sizeof(uint64_t) / 8)
197
198/*
199 * raid set level, layout and chunk sectors backup/restore
200 */
201struct rs_layout {
202        int new_level;
203        int new_layout;
204        int new_chunk_sectors;
205};
206
207struct raid_set {
208        struct dm_target *ti;
209
210        uint32_t bitmap_loaded;
211        uint32_t stripe_cache_entries;
212        unsigned long ctr_flags;
213        unsigned long runtime_flags;
214
215        uint64_t rebuild_disks[DISKS_ARRAY_ELEMS];
216
217        int raid_disks;
218        int delta_disks;
219        int data_offset;
220        int raid10_copies;
221        int requested_bitmap_chunk_sectors;
222
223        struct mddev md;
224        struct raid_type *raid_type;
225        struct dm_target_callbacks callbacks;
226
227        struct raid_dev dev[0];
228};
229
230static void rs_config_backup(struct raid_set *rs, struct rs_layout *l)
231{
232        struct mddev *mddev = &rs->md;
233
234        l->new_level = mddev->new_level;
235        l->new_layout = mddev->new_layout;
236        l->new_chunk_sectors = mddev->new_chunk_sectors;
237}
238
239static void rs_config_restore(struct raid_set *rs, struct rs_layout *l)
240{
241        struct mddev *mddev = &rs->md;
242
243        mddev->new_level = l->new_level;
244        mddev->new_layout = l->new_layout;
245        mddev->new_chunk_sectors = l->new_chunk_sectors;
246}
247
248/* raid10 algorithms (i.e. formats) */
249#define ALGORITHM_RAID10_DEFAULT        0
250#define ALGORITHM_RAID10_NEAR           1
251#define ALGORITHM_RAID10_OFFSET         2
252#define ALGORITHM_RAID10_FAR            3
253
254/* Supported raid types and properties. */
255static struct raid_type {
256        const char *name;               /* RAID algorithm. */
257        const char *descr;              /* Descriptor text for logging. */
258        const unsigned int parity_devs; /* # of parity devices. */
259        const unsigned int minimal_devs;/* minimal # of devices in set. */
260        const unsigned int level;       /* RAID level. */
261        const unsigned int algorithm;   /* RAID algorithm. */
262} raid_types[] = {
263        {"raid0",         "raid0 (striping)",                       0, 2, 0,  0 /* NONE */},
264        {"raid1",         "raid1 (mirroring)",                      0, 2, 1,  0 /* NONE */},
265        {"raid10_far",    "raid10 far (striped mirrors)",           0, 2, 10, ALGORITHM_RAID10_FAR},
266        {"raid10_offset", "raid10 offset (striped mirrors)",        0, 2, 10, ALGORITHM_RAID10_OFFSET},
267        {"raid10_near",   "raid10 near (striped mirrors)",          0, 2, 10, ALGORITHM_RAID10_NEAR},
268        {"raid10",        "raid10 (striped mirrors)",               0, 2, 10, ALGORITHM_RAID10_DEFAULT},
269        {"raid4",         "raid4 (dedicated first parity disk)",    1, 2, 5,  ALGORITHM_PARITY_0}, /* raid4 layout = raid5_0 */
270        {"raid5_n",       "raid5 (dedicated last parity disk)",     1, 2, 5,  ALGORITHM_PARITY_N},
271        {"raid5_ls",      "raid5 (left symmetric)",                 1, 2, 5,  ALGORITHM_LEFT_SYMMETRIC},
272        {"raid5_rs",      "raid5 (right symmetric)",                1, 2, 5,  ALGORITHM_RIGHT_SYMMETRIC},
273        {"raid5_la",      "raid5 (left asymmetric)",                1, 2, 5,  ALGORITHM_LEFT_ASYMMETRIC},
274        {"raid5_ra",      "raid5 (right asymmetric)",               1, 2, 5,  ALGORITHM_RIGHT_ASYMMETRIC},
275        {"raid6_zr",      "raid6 (zero restart)",                   2, 4, 6,  ALGORITHM_ROTATING_ZERO_RESTART},
276        {"raid6_nr",      "raid6 (N restart)",                      2, 4, 6,  ALGORITHM_ROTATING_N_RESTART},
277        {"raid6_nc",      "raid6 (N continue)",                     2, 4, 6,  ALGORITHM_ROTATING_N_CONTINUE},
278        {"raid6_n_6",     "raid6 (dedicated parity/Q n/6)",         2, 4, 6,  ALGORITHM_PARITY_N_6},
279        {"raid6_ls_6",    "raid6 (left symmetric dedicated Q 6)",   2, 4, 6,  ALGORITHM_LEFT_SYMMETRIC_6},
280        {"raid6_rs_6",    "raid6 (right symmetric dedicated Q 6)",  2, 4, 6,  ALGORITHM_RIGHT_SYMMETRIC_6},
281        {"raid6_la_6",    "raid6 (left asymmetric dedicated Q 6)",  2, 4, 6,  ALGORITHM_LEFT_ASYMMETRIC_6},
282        {"raid6_ra_6",    "raid6 (right asymmetric dedicated Q 6)", 2, 4, 6,  ALGORITHM_RIGHT_ASYMMETRIC_6}
283};
284
285/* True, if @v is in inclusive range [@min, @max] */
286static bool __within_range(long v, long min, long max)
287{
288        return v >= min && v <= max;
289}
290
291/* All table line arguments are defined here */
292static struct arg_name_flag {
293        const unsigned long flag;
294        const char *name;
295} __arg_name_flags[] = {
296        { CTR_FLAG_SYNC, "sync"},
297        { CTR_FLAG_NOSYNC, "nosync"},
298        { CTR_FLAG_REBUILD, "rebuild"},
299        { CTR_FLAG_DAEMON_SLEEP, "daemon_sleep"},
300        { CTR_FLAG_MIN_RECOVERY_RATE, "min_recovery_rate"},
301        { CTR_FLAG_MAX_RECOVERY_RATE, "max_recovery_rate"},
302        { CTR_FLAG_MAX_WRITE_BEHIND, "max_write_behind"},
303        { CTR_FLAG_WRITE_MOSTLY, "write_mostly"},
304        { CTR_FLAG_STRIPE_CACHE, "stripe_cache"},
305        { CTR_FLAG_REGION_SIZE, "region_size"},
306        { CTR_FLAG_RAID10_COPIES, "raid10_copies"},
307        { CTR_FLAG_RAID10_FORMAT, "raid10_format"},
308        { CTR_FLAG_DATA_OFFSET, "data_offset"},
309        { CTR_FLAG_DELTA_DISKS, "delta_disks"},
310        { CTR_FLAG_RAID10_USE_NEAR_SETS, "raid10_use_near_sets"},
311};
312
313/* Return argument name string for given @flag */
314static const char *dm_raid_arg_name_by_flag(const uint32_t flag)
315{
316        if (hweight32(flag) == 1) {
317                struct arg_name_flag *anf = __arg_name_flags + ARRAY_SIZE(__arg_name_flags);
318
319                while (anf-- > __arg_name_flags)
320                        if (flag & anf->flag)
321                                return anf->name;
322
323        } else
324                DMERR("%s called with more than one flag!", __func__);
325
326        return NULL;
327}
328
329/*
330 * Bool helpers to test for various raid levels of a raid set.
331 * It's level as reported by the superblock rather than
332 * the requested raid_type passed to the constructor.
333 */
334/* Return true, if raid set in @rs is raid0 */
335static bool rs_is_raid0(struct raid_set *rs)
336{
337        return !rs->md.level;
338}
339
340/* Return true, if raid set in @rs is raid1 */
341static bool rs_is_raid1(struct raid_set *rs)
342{
343        return rs->md.level == 1;
344}
345
346/* Return true, if raid set in @rs is raid10 */
347static bool rs_is_raid10(struct raid_set *rs)
348{
349        return rs->md.level == 10;
350}
351
352/* Return true, if raid set in @rs is level 6 */
353static bool rs_is_raid6(struct raid_set *rs)
354{
355        return rs->md.level == 6;
356}
357
358/* Return true, if raid set in @rs is level 4, 5 or 6 */
359static bool rs_is_raid456(struct raid_set *rs)
360{
361        return __within_range(rs->md.level, 4, 6);
362}
363
364/* Return true, if raid set in @rs is reshapable */
365static bool __is_raid10_far(int layout);
366static bool rs_is_reshapable(struct raid_set *rs)
367{
368        return rs_is_raid456(rs) ||
369               (rs_is_raid10(rs) && !__is_raid10_far(rs->md.new_layout));
370}
371
372/* Return true, if raid set in @rs is recovering */
373static bool rs_is_recovering(struct raid_set *rs)
374{
375        return rs->md.recovery_cp < rs->dev[0].rdev.sectors;
376}
377
378/* Return true, if raid set in @rs is reshaping */
379static bool rs_is_reshaping(struct raid_set *rs)
380{
381        return rs->md.reshape_position != MaxSector;
382}
383
384/*
385 * bool helpers to test for various raid levels of a raid type @rt
386 */
387
388/* Return true, if raid type in @rt is raid0 */
389static bool rt_is_raid0(struct raid_type *rt)
390{
391        return !rt->level;
392}
393
394/* Return true, if raid type in @rt is raid1 */
395static bool rt_is_raid1(struct raid_type *rt)
396{
397        return rt->level == 1;
398}
399
400/* Return true, if raid type in @rt is raid10 */
401static bool rt_is_raid10(struct raid_type *rt)
402{
403        return rt->level == 10;
404}
405
406/* Return true, if raid type in @rt is raid4/5 */
407static bool rt_is_raid45(struct raid_type *rt)
408{
409        return __within_range(rt->level, 4, 5);
410}
411
412/* Return true, if raid type in @rt is raid6 */
413static bool rt_is_raid6(struct raid_type *rt)
414{
415        return rt->level == 6;
416}
417
418/* Return true, if raid type in @rt is raid4/5/6 */
419static bool rt_is_raid456(struct raid_type *rt)
420{
421        return __within_range(rt->level, 4, 6);
422}
423/* END: raid level bools */
424
425/* Return valid ctr flags for the raid level of @rs */
426static unsigned long __valid_flags(struct raid_set *rs)
427{
428        if (rt_is_raid0(rs->raid_type))
429                return RAID0_VALID_FLAGS;
430        else if (rt_is_raid1(rs->raid_type))
431                return RAID1_VALID_FLAGS;
432        else if (rt_is_raid10(rs->raid_type))
433                return RAID10_VALID_FLAGS;
434        else if (rt_is_raid45(rs->raid_type))
435                return RAID45_VALID_FLAGS;
436        else if (rt_is_raid6(rs->raid_type))
437                return RAID6_VALID_FLAGS;
438
439        return 0;
440}
441
442/*
443 * Check for valid flags set on @rs
444 *
445 * Has to be called after parsing of the ctr flags!
446 */
447static int rs_check_for_valid_flags(struct raid_set *rs)
448{
449        if (rs->ctr_flags & ~__valid_flags(rs)) {
450                rs->ti->error = "Invalid flags combination";
451                return -EINVAL;
452        }
453
454        return 0;
455}
456
457/* MD raid10 bit definitions and helpers */
458#define RAID10_OFFSET                   (1 << 16) /* stripes with data copies area adjacent on devices */
459#define RAID10_BROCKEN_USE_FAR_SETS     (1 << 17) /* Broken in raid10.c: use sets instead of whole stripe rotation */
460#define RAID10_USE_FAR_SETS             (1 << 18) /* Use sets instead of whole stripe rotation */
461#define RAID10_FAR_COPIES_SHIFT         8         /* raid10 # far copies shift (2nd byte of layout) */
462
463/* Return md raid10 near copies for @layout */
464static unsigned int __raid10_near_copies(int layout)
465{
466        return layout & 0xFF;
467}
468
469/* Return md raid10 far copies for @layout */
470static unsigned int __raid10_far_copies(int layout)
471{
472        return __raid10_near_copies(layout >> RAID10_FAR_COPIES_SHIFT);
473}
474
475/* Return true if md raid10 offset for @layout */
476static bool __is_raid10_offset(int layout)
477{
478        return !!(layout & RAID10_OFFSET);
479}
480
481/* Return true if md raid10 near for @layout */
482static bool __is_raid10_near(int layout)
483{
484        return !__is_raid10_offset(layout) && __raid10_near_copies(layout) > 1;
485}
486
487/* Return true if md raid10 far for @layout */
488static bool __is_raid10_far(int layout)
489{
490        return !__is_raid10_offset(layout) && __raid10_far_copies(layout) > 1;
491}
492
493/* Return md raid10 layout string for @layout */
494static const char *raid10_md_layout_to_format(int layout)
495{
496        /*
497         * Bit 16 stands for "offset"
498         * (i.e. adjacent stripes hold copies)
499         *
500         * Refer to MD's raid10.c for details
501         */
502        if (__is_raid10_offset(layout))
503                return "offset";
504
505        if (__raid10_near_copies(layout) > 1)
506                return "near";
507
508        WARN_ON(__raid10_far_copies(layout) < 2);
509
510        return "far";
511}
512
513/* Return md raid10 algorithm for @name */
514static int raid10_name_to_format(const char *name)
515{
516        if (!strcasecmp(name, "near"))
517                return ALGORITHM_RAID10_NEAR;
518        else if (!strcasecmp(name, "offset"))
519                return ALGORITHM_RAID10_OFFSET;
520        else if (!strcasecmp(name, "far"))
521                return ALGORITHM_RAID10_FAR;
522
523        return -EINVAL;
524}
525
526/* Return md raid10 copies for @layout */
527static unsigned int raid10_md_layout_to_copies(int layout)
528{
529        return max(__raid10_near_copies(layout), __raid10_far_copies(layout));
530}
531
532/* Return md raid10 format id for @format string */
533static int raid10_format_to_md_layout(struct raid_set *rs,
534                                      unsigned int algorithm,
535                                      unsigned int copies)
536{
537        unsigned int n = 1, f = 1, r = 0;
538
539        /*
540         * MD resilienece flaw:
541         *
542         * enabling use_far_sets for far/offset formats causes copies
543         * to be colocated on the same devs together with their origins!
544         *
545         * -> disable it for now in the definition above
546         */
547        if (algorithm == ALGORITHM_RAID10_DEFAULT ||
548            algorithm == ALGORITHM_RAID10_NEAR)
549                n = copies;
550
551        else if (algorithm == ALGORITHM_RAID10_OFFSET) {
552                f = copies;
553                r = RAID10_OFFSET;
554                if (!test_bit(__CTR_FLAG_RAID10_USE_NEAR_SETS, &rs->ctr_flags))
555                        r |= RAID10_USE_FAR_SETS;
556
557        } else if (algorithm == ALGORITHM_RAID10_FAR) {
558                f = copies;
559                r = !RAID10_OFFSET;
560                if (!test_bit(__CTR_FLAG_RAID10_USE_NEAR_SETS, &rs->ctr_flags))
561                        r |= RAID10_USE_FAR_SETS;
562
563        } else
564                return -EINVAL;
565
566        return r | (f << RAID10_FAR_COPIES_SHIFT) | n;
567}
568/* END: MD raid10 bit definitions and helpers */
569
570/* Check for any of the raid10 algorithms */
571static bool __got_raid10(struct raid_type *rtp, const int layout)
572{
573        if (rtp->level == 10) {
574                switch (rtp->algorithm) {
575                case ALGORITHM_RAID10_DEFAULT:
576                case ALGORITHM_RAID10_NEAR:
577                        return __is_raid10_near(layout);
578                case ALGORITHM_RAID10_OFFSET:
579                        return __is_raid10_offset(layout);
580                case ALGORITHM_RAID10_FAR:
581                        return __is_raid10_far(layout);
582                default:
583                        break;
584                }
585        }
586
587        return false;
588}
589
590/* Return raid_type for @name */
591static struct raid_type *get_raid_type(const char *name)
592{
593        struct raid_type *rtp = raid_types + ARRAY_SIZE(raid_types);
594
595        while (rtp-- > raid_types)
596                if (!strcasecmp(rtp->name, name))
597                        return rtp;
598
599        return NULL;
600}
601
602/* Return raid_type for @name based derived from @level and @layout */
603static struct raid_type *get_raid_type_by_ll(const int level, const int layout)
604{
605        struct raid_type *rtp = raid_types + ARRAY_SIZE(raid_types);
606
607        while (rtp-- > raid_types) {
608                /* RAID10 special checks based on @layout flags/properties */
609                if (rtp->level == level &&
610                    (__got_raid10(rtp, layout) || rtp->algorithm == layout))
611                        return rtp;
612        }
613
614        return NULL;
615}
616
617/*
618 * Conditionally change bdev capacity of @rs
619 * in case of a disk add/remove reshape
620 */
621static void rs_set_capacity(struct raid_set *rs)
622{
623        struct mddev *mddev = &rs->md;
624        struct md_rdev *rdev;
625        struct gendisk *gendisk = dm_disk(dm_table_get_md(rs->ti->table));
626
627        /*
628         * raid10 sets rdev->sector to the device size, which
629         * is unintended in case of out-of-place reshaping
630         */
631        rdev_for_each(rdev, mddev)
632                rdev->sectors = mddev->dev_sectors;
633
634        set_capacity(gendisk, mddev->array_sectors);
635        revalidate_disk(gendisk);
636}
637
638/*
639 * Set the mddev properties in @rs to the current
640 * ones retrieved from the freshest superblock
641 */
642static void rs_set_cur(struct raid_set *rs)
643{
644        struct mddev *mddev = &rs->md;
645
646        mddev->new_level = mddev->level;
647        mddev->new_layout = mddev->layout;
648        mddev->new_chunk_sectors = mddev->chunk_sectors;
649}
650
651/*
652 * Set the mddev properties in @rs to the new
653 * ones requested by the ctr
654 */
655static void rs_set_new(struct raid_set *rs)
656{
657        struct mddev *mddev = &rs->md;
658
659        mddev->level = mddev->new_level;
660        mddev->layout = mddev->new_layout;
661        mddev->chunk_sectors = mddev->new_chunk_sectors;
662        mddev->raid_disks = rs->raid_disks;
663        mddev->delta_disks = 0;
664}
665
666static struct raid_set *raid_set_alloc(struct dm_target *ti, struct raid_type *raid_type,
667                                       unsigned int raid_devs)
668{
669        unsigned int i;
670        struct raid_set *rs;
671
672        if (raid_devs <= raid_type->parity_devs) {
673                ti->error = "Insufficient number of devices";
674                return ERR_PTR(-EINVAL);
675        }
676
677        rs = kzalloc(sizeof(*rs) + raid_devs * sizeof(rs->dev[0]), GFP_KERNEL);
678        if (!rs) {
679                ti->error = "Cannot allocate raid context";
680                return ERR_PTR(-ENOMEM);
681        }
682
683        mddev_init(&rs->md);
684
685        rs->raid_disks = raid_devs;
686        rs->delta_disks = 0;
687
688        rs->ti = ti;
689        rs->raid_type = raid_type;
690        rs->stripe_cache_entries = 256;
691        rs->md.raid_disks = raid_devs;
692        rs->md.level = raid_type->level;
693        rs->md.new_level = rs->md.level;
694        rs->md.layout = raid_type->algorithm;
695        rs->md.new_layout = rs->md.layout;
696        rs->md.delta_disks = 0;
697        rs->md.recovery_cp = MaxSector;
698
699        for (i = 0; i < raid_devs; i++)
700                md_rdev_init(&rs->dev[i].rdev);
701
702        /*
703         * Remaining items to be initialized by further RAID params:
704         *  rs->md.persistent
705         *  rs->md.external
706         *  rs->md.chunk_sectors
707         *  rs->md.new_chunk_sectors
708         *  rs->md.dev_sectors
709         */
710
711        return rs;
712}
713
714static void raid_set_free(struct raid_set *rs)
715{
716        int i;
717
718        for (i = 0; i < rs->raid_disks; i++) {
719                if (rs->dev[i].meta_dev)
720                        dm_put_device(rs->ti, rs->dev[i].meta_dev);
721                md_rdev_clear(&rs->dev[i].rdev);
722                if (rs->dev[i].data_dev)
723                        dm_put_device(rs->ti, rs->dev[i].data_dev);
724        }
725
726        kfree(rs);
727}
728
729/*
730 * For every device we have two words
731 *  <meta_dev>: meta device name or '-' if missing
732 *  <data_dev>: data device name or '-' if missing
733 *
734 * The following are permitted:
735 *    - -
736 *    - <data_dev>
737 *    <meta_dev> <data_dev>
738 *
739 * The following is not allowed:
740 *    <meta_dev> -
741 *
742 * This code parses those words.  If there is a failure,
743 * the caller must use raid_set_free() to unwind the operations.
744 */
745static int parse_dev_params(struct raid_set *rs, struct dm_arg_set *as)
746{
747        int i;
748        int rebuild = 0;
749        int metadata_available = 0;
750        int r = 0;
751        const char *arg;
752
753        /* Put off the number of raid devices argument to get to dev pairs */
754        arg = dm_shift_arg(as);
755        if (!arg)
756                return -EINVAL;
757
758        for (i = 0; i < rs->raid_disks; i++) {
759                rs->dev[i].rdev.raid_disk = i;
760
761                rs->dev[i].meta_dev = NULL;
762                rs->dev[i].data_dev = NULL;
763
764                /*
765                 * There are no offsets, since there is a separate device
766                 * for data and metadata.
767                 */
768                rs->dev[i].rdev.data_offset = 0;
769                rs->dev[i].rdev.mddev = &rs->md;
770
771                arg = dm_shift_arg(as);
772                if (!arg)
773                        return -EINVAL;
774
775                if (strcmp(arg, "-")) {
776                        r = dm_get_device(rs->ti, arg, dm_table_get_mode(rs->ti->table),
777                                          &rs->dev[i].meta_dev);
778                        if (r) {
779                                rs->ti->error = "RAID metadata device lookup failure";
780                                return r;
781                        }
782
783                        rs->dev[i].rdev.sb_page = alloc_page(GFP_KERNEL);
784                        if (!rs->dev[i].rdev.sb_page) {
785                                rs->ti->error = "Failed to allocate superblock page";
786                                return -ENOMEM;
787                        }
788                }
789
790                arg = dm_shift_arg(as);
791                if (!arg)
792                        return -EINVAL;
793
794                if (!strcmp(arg, "-")) {
795                        if (!test_bit(In_sync, &rs->dev[i].rdev.flags) &&
796                            (!rs->dev[i].rdev.recovery_offset)) {
797                                rs->ti->error = "Drive designated for rebuild not specified";
798                                return -EINVAL;
799                        }
800
801                        if (rs->dev[i].meta_dev) {
802                                rs->ti->error = "No data device supplied with metadata device";
803                                return -EINVAL;
804                        }
805
806                        continue;
807                }
808
809                r = dm_get_device(rs->ti, arg, dm_table_get_mode(rs->ti->table),
810                                  &rs->dev[i].data_dev);
811                if (r) {
812                        rs->ti->error = "RAID device lookup failure";
813                        return r;
814                }
815
816                if (rs->dev[i].meta_dev) {
817                        metadata_available = 1;
818                        rs->dev[i].rdev.meta_bdev = rs->dev[i].meta_dev->bdev;
819                }
820                rs->dev[i].rdev.bdev = rs->dev[i].data_dev->bdev;
821                list_add_tail(&rs->dev[i].rdev.same_set, &rs->md.disks);
822                if (!test_bit(In_sync, &rs->dev[i].rdev.flags))
823                        rebuild++;
824        }
825
826        if (metadata_available) {
827                rs->md.external = 0;
828                rs->md.persistent = 1;
829                rs->md.major_version = 2;
830        } else if (rebuild && !rs->md.recovery_cp) {
831                /*
832                 * Without metadata, we will not be able to tell if the array
833                 * is in-sync or not - we must assume it is not.  Therefore,
834                 * it is impossible to rebuild a drive.
835                 *
836                 * Even if there is metadata, the on-disk information may
837                 * indicate that the array is not in-sync and it will then
838                 * fail at that time.
839                 *
840                 * User could specify 'nosync' option if desperate.
841                 */
842                rs->ti->error = "Unable to rebuild drive while array is not in-sync";
843                return -EINVAL;
844        }
845
846        return 0;
847}
848
849/*
850 * validate_region_size
851 * @rs
852 * @region_size:  region size in sectors.  If 0, pick a size (4MiB default).
853 *
854 * Set rs->md.bitmap_info.chunksize (which really refers to 'region size').
855 * Ensure that (ti->len/region_size < 2^21) - required by MD bitmap.
856 *
857 * Returns: 0 on success, -EINVAL on failure.
858 */
859static int validate_region_size(struct raid_set *rs, unsigned long region_size)
860{
861        unsigned long min_region_size = rs->ti->len / (1 << 21);
862
863        if (rs_is_raid0(rs))
864                return 0;
865
866        if (!region_size) {
867                /*
868                 * Choose a reasonable default.  All figures in sectors.
869                 */
870                if (min_region_size > (1 << 13)) {
871                        /* If not a power of 2, make it the next power of 2 */
872                        region_size = roundup_pow_of_two(min_region_size);
873                        DMINFO("Choosing default region size of %lu sectors",
874                               region_size);
875                } else {
876                        DMINFO("Choosing default region size of 4MiB");
877                        region_size = 1 << 13; /* sectors */
878                }
879        } else {
880                /*
881                 * Validate user-supplied value.
882                 */
883                if (region_size > rs->ti->len) {
884                        rs->ti->error = "Supplied region size is too large";
885                        return -EINVAL;
886                }
887
888                if (region_size < min_region_size) {
889                        DMERR("Supplied region_size (%lu sectors) below minimum (%lu)",
890                              region_size, min_region_size);
891                        rs->ti->error = "Supplied region size is too small";
892                        return -EINVAL;
893                }
894
895                if (!is_power_of_2(region_size)) {
896                        rs->ti->error = "Region size is not a power of 2";
897                        return -EINVAL;
898                }
899
900                if (region_size < rs->md.chunk_sectors) {
901                        rs->ti->error = "Region size is smaller than the chunk size";
902                        return -EINVAL;
903                }
904        }
905
906        /*
907         * Convert sectors to bytes.
908         */
909        rs->md.bitmap_info.chunksize = to_bytes(region_size);
910
911        return 0;
912}
913
914/*
915 * validate_raid_redundancy
916 * @rs
917 *
918 * Determine if there are enough devices in the array that haven't
919 * failed (or are being rebuilt) to form a usable array.
920 *
921 * Returns: 0 on success, -EINVAL on failure.
922 */
923static int validate_raid_redundancy(struct raid_set *rs)
924{
925        unsigned int i, rebuild_cnt = 0;
926        unsigned int rebuilds_per_group = 0, copies;
927        unsigned int group_size, last_group_start;
928
929        for (i = 0; i < rs->md.raid_disks; i++)
930                if (!test_bit(In_sync, &rs->dev[i].rdev.flags) ||
931                    !rs->dev[i].rdev.sb_page)
932                        rebuild_cnt++;
933
934        switch (rs->raid_type->level) {
935        case 0:
936                break;
937        case 1:
938                if (rebuild_cnt >= rs->md.raid_disks)
939                        goto too_many;
940                break;
941        case 4:
942        case 5:
943        case 6:
944                if (rebuild_cnt > rs->raid_type->parity_devs)
945                        goto too_many;
946                break;
947        case 10:
948                copies = raid10_md_layout_to_copies(rs->md.new_layout);
949                if (rebuild_cnt < copies)
950                        break;
951
952                /*
953                 * It is possible to have a higher rebuild count for RAID10,
954                 * as long as the failed devices occur in different mirror
955                 * groups (i.e. different stripes).
956                 *
957                 * When checking "near" format, make sure no adjacent devices
958                 * have failed beyond what can be handled.  In addition to the
959                 * simple case where the number of devices is a multiple of the
960                 * number of copies, we must also handle cases where the number
961                 * of devices is not a multiple of the number of copies.
962                 * E.g.    dev1 dev2 dev3 dev4 dev5
963                 *          A    A    B    B    C
964                 *          C    D    D    E    E
965                 */
966                if (__is_raid10_near(rs->md.new_layout)) {
967                        for (i = 0; i < rs->md.raid_disks; i++) {
968                                if (!(i % copies))
969                                        rebuilds_per_group = 0;
970                                if ((!rs->dev[i].rdev.sb_page ||
971                                    !test_bit(In_sync, &rs->dev[i].rdev.flags)) &&
972                                    (++rebuilds_per_group >= copies))
973                                        goto too_many;
974                        }
975                        break;
976                }
977
978                /*
979                 * When checking "far" and "offset" formats, we need to ensure
980                 * that the device that holds its copy is not also dead or
981                 * being rebuilt.  (Note that "far" and "offset" formats only
982                 * support two copies right now.  These formats also only ever
983                 * use the 'use_far_sets' variant.)
984                 *
985                 * This check is somewhat complicated by the need to account
986                 * for arrays that are not a multiple of (far) copies.  This
987                 * results in the need to treat the last (potentially larger)
988                 * set differently.
989                 */
990                group_size = (rs->md.raid_disks / copies);
991                last_group_start = (rs->md.raid_disks / group_size) - 1;
992                last_group_start *= group_size;
993                for (i = 0; i < rs->md.raid_disks; i++) {
994                        if (!(i % copies) && !(i > last_group_start))
995                                rebuilds_per_group = 0;
996                        if ((!rs->dev[i].rdev.sb_page ||
997                             !test_bit(In_sync, &rs->dev[i].rdev.flags)) &&
998                            (++rebuilds_per_group >= copies))
999                                        goto too_many;
1000                }
1001                break;
1002        default:
1003                if (rebuild_cnt)
1004                        return -EINVAL;
1005        }
1006
1007        return 0;
1008
1009too_many:
1010        return -EINVAL;
1011}
1012
1013/*
1014 * Possible arguments are...
1015 *      <chunk_size> [optional_args]
1016 *
1017 * Argument definitions
1018 *    <chunk_size>                      The number of sectors per disk that
1019 *                                      will form the "stripe"
1020 *    [[no]sync]                        Force or prevent recovery of the
1021 *                                      entire array
1022 *    [rebuild <idx>]                   Rebuild the drive indicated by the index
1023 *    [daemon_sleep <ms>]               Time between bitmap daemon work to
1024 *                                      clear bits
1025 *    [min_recovery_rate <kB/sec/disk>] Throttle RAID initialization
1026 *    [max_recovery_rate <kB/sec/disk>] Throttle RAID initialization
1027 *    [write_mostly <idx>]              Indicate a write mostly drive via index
1028 *    [max_write_behind <sectors>]      See '-write-behind=' (man mdadm)
1029 *    [stripe_cache <sectors>]          Stripe cache size for higher RAIDs
1030 *    [region_size <sectors>]           Defines granularity of bitmap
1031 *
1032 * RAID10-only options:
1033 *    [raid10_copies <# copies>]        Number of copies.  (Default: 2)
1034 *    [raid10_format <near|far|offset>] Layout algorithm.  (Default: near)
1035 */
1036static int parse_raid_params(struct raid_set *rs, struct dm_arg_set *as,
1037                             unsigned int num_raid_params)
1038{
1039        int value, raid10_format = ALGORITHM_RAID10_DEFAULT;
1040        unsigned int raid10_copies = 2;
1041        unsigned int i, write_mostly = 0;
1042        unsigned int region_size = 0;
1043        sector_t max_io_len;
1044        const char *arg, *key;
1045        struct raid_dev *rd;
1046        struct raid_type *rt = rs->raid_type;
1047
1048        arg = dm_shift_arg(as);
1049        num_raid_params--; /* Account for chunk_size argument */
1050
1051        if (kstrtoint(arg, 10, &value) < 0) {
1052                rs->ti->error = "Bad numerical argument given for chunk_size";
1053                return -EINVAL;
1054        }
1055
1056        /*
1057         * First, parse the in-order required arguments
1058         * "chunk_size" is the only argument of this type.
1059         */
1060        if (rt_is_raid1(rt)) {
1061                if (value)
1062                        DMERR("Ignoring chunk size parameter for RAID 1");
1063                value = 0;
1064        } else if (!is_power_of_2(value)) {
1065                rs->ti->error = "Chunk size must be a power of 2";
1066                return -EINVAL;
1067        } else if (value < 8) {
1068                rs->ti->error = "Chunk size value is too small";
1069                return -EINVAL;
1070        }
1071
1072        rs->md.new_chunk_sectors = rs->md.chunk_sectors = value;
1073
1074        /*
1075         * We set each individual device as In_sync with a completed
1076         * 'recovery_offset'.  If there has been a device failure or
1077         * replacement then one of the following cases applies:
1078         *
1079         *   1) User specifies 'rebuild'.
1080         *      - Device is reset when param is read.
1081         *   2) A new device is supplied.
1082         *      - No matching superblock found, resets device.
1083         *   3) Device failure was transient and returns on reload.
1084         *      - Failure noticed, resets device for bitmap replay.
1085         *   4) Device hadn't completed recovery after previous failure.
1086         *      - Superblock is read and overrides recovery_offset.
1087         *
1088         * What is found in the superblocks of the devices is always
1089         * authoritative, unless 'rebuild' or '[no]sync' was specified.
1090         */
1091        for (i = 0; i < rs->raid_disks; i++) {
1092                set_bit(In_sync, &rs->dev[i].rdev.flags);
1093                rs->dev[i].rdev.recovery_offset = MaxSector;
1094        }
1095
1096        /*
1097         * Second, parse the unordered optional arguments
1098         */
1099        for (i = 0; i < num_raid_params; i++) {
1100                key = dm_shift_arg(as);
1101                if (!key) {
1102                        rs->ti->error = "Not enough raid parameters given";
1103                        return -EINVAL;
1104                }
1105
1106                if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_NOSYNC))) {
1107                        if (test_and_set_bit(__CTR_FLAG_NOSYNC, &rs->ctr_flags)) {
1108                                rs->ti->error = "Only one 'nosync' argument allowed";
1109                                return -EINVAL;
1110                        }
1111                        continue;
1112                }
1113                if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_SYNC))) {
1114                        if (test_and_set_bit(__CTR_FLAG_SYNC, &rs->ctr_flags)) {
1115                                rs->ti->error = "Only one 'sync' argument allowed";
1116                                return -EINVAL;
1117                        }
1118                        continue;
1119                }
1120                if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_RAID10_USE_NEAR_SETS))) {
1121                        if (test_and_set_bit(__CTR_FLAG_RAID10_USE_NEAR_SETS, &rs->ctr_flags)) {
1122                                rs->ti->error = "Only one 'raid10_use_new_sets' argument allowed";
1123                                return -EINVAL;
1124                        }
1125                        continue;
1126                }
1127
1128                arg = dm_shift_arg(as);
1129                i++; /* Account for the argument pairs */
1130                if (!arg) {
1131                        rs->ti->error = "Wrong number of raid parameters given";
1132                        return -EINVAL;
1133                }
1134
1135                /*
1136                 * Parameters that take a string value are checked here.
1137                 */
1138
1139                if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_RAID10_FORMAT))) {
1140                        if (test_and_set_bit(__CTR_FLAG_RAID10_FORMAT, &rs->ctr_flags)) {
1141                                rs->ti->error = "Only one 'raid10_format' argument pair allowed";
1142                                return -EINVAL;
1143                        }
1144                        if (!rt_is_raid10(rt)) {
1145                                rs->ti->error = "'raid10_format' is an invalid parameter for this RAID type";
1146                                return -EINVAL;
1147                        }
1148                        raid10_format = raid10_name_to_format(arg);
1149                        if (raid10_format < 0) {
1150                                rs->ti->error = "Invalid 'raid10_format' value given";
1151                                return raid10_format;
1152                        }
1153                        continue;
1154                }
1155
1156                if (kstrtoint(arg, 10, &value) < 0) {
1157                        rs->ti->error = "Bad numerical argument given in raid params";
1158                        return -EINVAL;
1159                }
1160
1161                if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_REBUILD))) {
1162                        /*
1163                         * "rebuild" is being passed in by userspace to provide
1164                         * indexes of replaced devices and to set up additional
1165                         * devices on raid level takeover.
1166                         */
1167                        if (!__within_range(value, 0, rs->raid_disks - 1)) {
1168                                rs->ti->error = "Invalid rebuild index given";
1169                                return -EINVAL;
1170                        }
1171
1172                        if (test_and_set_bit(value, (void *) rs->rebuild_disks)) {
1173                                rs->ti->error = "rebuild for this index already given";
1174                                return -EINVAL;
1175                        }
1176
1177                        rd = rs->dev + value;
1178                        clear_bit(In_sync, &rd->rdev.flags);
1179                        clear_bit(Faulty, &rd->rdev.flags);
1180                        rd->rdev.recovery_offset = 0;
1181                        set_bit(__CTR_FLAG_REBUILD, &rs->ctr_flags);
1182                } else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_WRITE_MOSTLY))) {
1183                        if (!rt_is_raid1(rt)) {
1184                                rs->ti->error = "write_mostly option is only valid for RAID1";
1185                                return -EINVAL;
1186                        }
1187
1188                        if (!__within_range(value, 0, rs->md.raid_disks - 1)) {
1189                                rs->ti->error = "Invalid write_mostly index given";
1190                                return -EINVAL;
1191                        }
1192
1193                        write_mostly++;
1194                        set_bit(WriteMostly, &rs->dev[value].rdev.flags);
1195                        set_bit(__CTR_FLAG_WRITE_MOSTLY, &rs->ctr_flags);
1196                } else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_MAX_WRITE_BEHIND))) {
1197                        if (!rt_is_raid1(rt)) {
1198                                rs->ti->error = "max_write_behind option is only valid for RAID1";
1199                                return -EINVAL;
1200                        }
1201
1202                        if (test_and_set_bit(__CTR_FLAG_MAX_WRITE_BEHIND, &rs->ctr_flags)) {
1203                                rs->ti->error = "Only one max_write_behind argument pair allowed";
1204                                return -EINVAL;
1205                        }
1206
1207                        /*
1208                         * In device-mapper, we specify things in sectors, but
1209                         * MD records this value in kB
1210                         */
1211                        value /= 2;
1212                        if (value > COUNTER_MAX) {
1213                                rs->ti->error = "Max write-behind limit out of range";
1214                                return -EINVAL;
1215                        }
1216
1217                        rs->md.bitmap_info.max_write_behind = value;
1218                } else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_DAEMON_SLEEP))) {
1219                        if (test_and_set_bit(__CTR_FLAG_DAEMON_SLEEP, &rs->ctr_flags)) {
1220                                rs->ti->error = "Only one daemon_sleep argument pair allowed";
1221                                return -EINVAL;
1222                        }
1223                        if (!value || (value > MAX_SCHEDULE_TIMEOUT)) {
1224                                rs->ti->error = "daemon sleep period out of range";
1225                                return -EINVAL;
1226                        }
1227                        rs->md.bitmap_info.daemon_sleep = value;
1228                } else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_DATA_OFFSET))) {
1229                        /* Userspace passes new data_offset after having extended the the data image LV */
1230                        if (test_and_set_bit(__CTR_FLAG_DATA_OFFSET, &rs->ctr_flags)) {
1231                                rs->ti->error = "Only one data_offset argument pair allowed";
1232                                return -EINVAL;
1233                        }
1234                        /* Ensure sensible data offset */
1235                        if (value < 0 ||
1236                            (value && (value < MIN_FREE_RESHAPE_SPACE || value % to_sector(PAGE_SIZE)))) {
1237                                rs->ti->error = "Bogus data_offset value";
1238                                return -EINVAL;
1239                        }
1240                        rs->data_offset = value;
1241                } else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_DELTA_DISKS))) {
1242                        /* Define the +/-# of disks to add to/remove from the given raid set */
1243                        if (test_and_set_bit(__CTR_FLAG_DELTA_DISKS, &rs->ctr_flags)) {
1244                                rs->ti->error = "Only one delta_disks argument pair allowed";
1245                                return -EINVAL;
1246                        }
1247                        /* Ensure MAX_RAID_DEVICES and raid type minimal_devs! */
1248                        if (!__within_range(abs(value), 1, MAX_RAID_DEVICES - rt->minimal_devs)) {
1249                                rs->ti->error = "Too many delta_disk requested";
1250                                return -EINVAL;
1251                        }
1252
1253                        rs->delta_disks = value;
1254                } else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_STRIPE_CACHE))) {
1255                        if (test_and_set_bit(__CTR_FLAG_STRIPE_CACHE, &rs->ctr_flags)) {
1256                                rs->ti->error = "Only one stripe_cache argument pair allowed";
1257                                return -EINVAL;
1258                        }
1259
1260                        if (!rt_is_raid456(rt)) {
1261                                rs->ti->error = "Inappropriate argument: stripe_cache";
1262                                return -EINVAL;
1263                        }
1264
1265                        rs->stripe_cache_entries = value;
1266                } else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_MIN_RECOVERY_RATE))) {
1267                        if (test_and_set_bit(__CTR_FLAG_MIN_RECOVERY_RATE, &rs->ctr_flags)) {
1268                                rs->ti->error = "Only one min_recovery_rate argument pair allowed";
1269                                return -EINVAL;
1270                        }
1271                        if (value > INT_MAX) {
1272                                rs->ti->error = "min_recovery_rate out of range";
1273                                return -EINVAL;
1274                        }
1275                        rs->md.sync_speed_min = (int)value;
1276                } else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_MAX_RECOVERY_RATE))) {
1277                        if (test_and_set_bit(__CTR_FLAG_MAX_RECOVERY_RATE, &rs->ctr_flags)) {
1278                                rs->ti->error = "Only one max_recovery_rate argument pair allowed";
1279                                return -EINVAL;
1280                        }
1281                        if (value > INT_MAX) {
1282                                rs->ti->error = "max_recovery_rate out of range";
1283                                return -EINVAL;
1284                        }
1285                        rs->md.sync_speed_max = (int)value;
1286                } else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_REGION_SIZE))) {
1287                        if (test_and_set_bit(__CTR_FLAG_REGION_SIZE, &rs->ctr_flags)) {
1288                                rs->ti->error = "Only one region_size argument pair allowed";
1289                                return -EINVAL;
1290                        }
1291
1292                        region_size = value;
1293                        rs->requested_bitmap_chunk_sectors = value;
1294                } else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_RAID10_COPIES))) {
1295                        if (test_and_set_bit(__CTR_FLAG_RAID10_COPIES, &rs->ctr_flags)) {
1296                                rs->ti->error = "Only one raid10_copies argument pair allowed";
1297                                return -EINVAL;
1298                        }
1299
1300                        if (!__within_range(value, 2, rs->md.raid_disks)) {
1301                                rs->ti->error = "Bad value for 'raid10_copies'";
1302                                return -EINVAL;
1303                        }
1304
1305                        raid10_copies = value;
1306                } else {
1307                        DMERR("Unable to parse RAID parameter: %s", key);
1308                        rs->ti->error = "Unable to parse RAID parameter";
1309                        return -EINVAL;
1310                }
1311        }
1312
1313        if (test_bit(__CTR_FLAG_SYNC, &rs->ctr_flags) &&
1314            test_bit(__CTR_FLAG_NOSYNC, &rs->ctr_flags)) {
1315                rs->ti->error = "sync and nosync are mutually exclusive";
1316                return -EINVAL;
1317        }
1318
1319        if (test_bit(__CTR_FLAG_REBUILD, &rs->ctr_flags) &&
1320            (test_bit(__CTR_FLAG_SYNC, &rs->ctr_flags) ||
1321             test_bit(__CTR_FLAG_NOSYNC, &rs->ctr_flags))) {
1322                rs->ti->error = "sync/nosync and rebuild are mutually exclusive";
1323                return -EINVAL;
1324        }
1325
1326        if (write_mostly >= rs->md.raid_disks) {
1327                rs->ti->error = "Can't set all raid1 devices to write_mostly";
1328                return -EINVAL;
1329        }
1330
1331        if (validate_region_size(rs, region_size))
1332                return -EINVAL;
1333
1334        if (rs->md.chunk_sectors)
1335                max_io_len = rs->md.chunk_sectors;
1336        else
1337                max_io_len = region_size;
1338
1339        if (dm_set_target_max_io_len(rs->ti, max_io_len))
1340                return -EINVAL;
1341
1342        if (rt_is_raid10(rt)) {
1343                if (raid10_copies > rs->md.raid_disks) {
1344                        rs->ti->error = "Not enough devices to satisfy specification";
1345                        return -EINVAL;
1346                }
1347
1348                rs->md.new_layout = raid10_format_to_md_layout(rs, raid10_format, raid10_copies);
1349                if (rs->md.new_layout < 0) {
1350                        rs->ti->error = "Error getting raid10 format";
1351                        return rs->md.new_layout;
1352                }
1353
1354                rt = get_raid_type_by_ll(10, rs->md.new_layout);
1355                if (!rt) {
1356                        rs->ti->error = "Failed to recognize new raid10 layout";
1357                        return -EINVAL;
1358                }
1359
1360                if ((rt->algorithm == ALGORITHM_RAID10_DEFAULT ||
1361                     rt->algorithm == ALGORITHM_RAID10_NEAR) &&
1362                    test_bit(__CTR_FLAG_RAID10_USE_NEAR_SETS, &rs->ctr_flags)) {
1363                        rs->ti->error = "RAID10 format 'near' and 'raid10_use_near_sets' are incompatible";
1364                        return -EINVAL;
1365                }
1366        }
1367
1368        rs->raid10_copies = raid10_copies;
1369
1370        /* Assume there are no metadata devices until the drives are parsed */
1371        rs->md.persistent = 0;
1372        rs->md.external = 1;
1373
1374        /* Check, if any invalid ctr arguments have been passed in for the raid level */
1375        return rs_check_for_valid_flags(rs);
1376}
1377
1378/* Set raid4/5/6 cache size */
1379static int rs_set_raid456_stripe_cache(struct raid_set *rs)
1380{
1381        int r;
1382        struct r5conf *conf;
1383        struct mddev *mddev = &rs->md;
1384        uint32_t min_stripes = max(mddev->chunk_sectors, mddev->new_chunk_sectors) / 2;
1385        uint32_t nr_stripes = rs->stripe_cache_entries;
1386
1387        if (!rt_is_raid456(rs->raid_type)) {
1388                rs->ti->error = "Inappropriate raid level; cannot change stripe_cache size";
1389                return -EINVAL;
1390        }
1391
1392        if (nr_stripes < min_stripes) {
1393                DMINFO("Adjusting requested %u stripe cache entries to %u to suit stripe size",
1394                       nr_stripes, min_stripes);
1395                nr_stripes = min_stripes;
1396        }
1397
1398        conf = mddev->private;
1399        if (!conf) {
1400                rs->ti->error = "Cannot change stripe_cache size on inactive RAID set";
1401                return -EINVAL;
1402        }
1403
1404        /* Try setting number of stripes in raid456 stripe cache */
1405        if (conf->min_nr_stripes != nr_stripes) {
1406                r = raid5_set_cache_size(mddev, nr_stripes);
1407                if (r) {
1408                        rs->ti->error = "Failed to set raid4/5/6 stripe cache size";
1409                        return r;
1410                }
1411
1412                DMINFO("%u stripe cache entries", nr_stripes);
1413        }
1414
1415        return 0;
1416}
1417
1418/* Return # of data stripes as kept in mddev as of @rs (i.e. as of superblock) */
1419static unsigned int mddev_data_stripes(struct raid_set *rs)
1420{
1421        return rs->md.raid_disks - rs->raid_type->parity_devs;
1422}
1423
1424/* Return # of data stripes of @rs (i.e. as of ctr) */
1425static unsigned int rs_data_stripes(struct raid_set *rs)
1426{
1427        return rs->raid_disks - rs->raid_type->parity_devs;
1428}
1429
1430/* Calculate the sectors per device and per array used for @rs */
1431static int rs_set_dev_and_array_sectors(struct raid_set *rs, bool use_mddev)
1432{
1433        int delta_disks;
1434        unsigned int data_stripes;
1435        struct mddev *mddev = &rs->md;
1436        struct md_rdev *rdev;
1437        sector_t array_sectors = rs->ti->len, dev_sectors = rs->ti->len;
1438
1439        if (use_mddev) {
1440                delta_disks = mddev->delta_disks;
1441                data_stripes = mddev_data_stripes(rs);
1442        } else {
1443                delta_disks = rs->delta_disks;
1444                data_stripes = rs_data_stripes(rs);
1445        }
1446
1447        /* Special raid1 case w/o delta_disks support (yet) */
1448        if (rt_is_raid1(rs->raid_type))
1449                ;
1450        else if (rt_is_raid10(rs->raid_type)) {
1451                if (rs->raid10_copies < 2 ||
1452                    delta_disks < 0) {
1453                        rs->ti->error = "Bogus raid10 data copies or delta disks";
1454                        return -EINVAL;
1455                }
1456
1457                dev_sectors *= rs->raid10_copies;
1458                if (sector_div(dev_sectors, data_stripes))
1459                        goto bad;
1460
1461                array_sectors = (data_stripes + delta_disks) * dev_sectors;
1462                if (sector_div(array_sectors, rs->raid10_copies))
1463                        goto bad;
1464
1465        } else if (sector_div(dev_sectors, data_stripes))
1466                goto bad;
1467
1468        else
1469                /* Striped layouts */
1470                array_sectors = (data_stripes + delta_disks) * dev_sectors;
1471
1472        rdev_for_each(rdev, mddev)
1473                rdev->sectors = dev_sectors;
1474
1475        mddev->array_sectors = array_sectors;
1476        mddev->dev_sectors = dev_sectors;
1477
1478        return 0;
1479bad:
1480        rs->ti->error = "Target length not divisible by number of data devices";
1481        return -EINVAL;
1482}
1483
1484/* Setup recovery on @rs */
1485static void __rs_setup_recovery(struct raid_set *rs, sector_t dev_sectors)
1486{
1487        /* raid0 does not recover */
1488        if (rs_is_raid0(rs))
1489                rs->md.recovery_cp = MaxSector;
1490        /*
1491         * A raid6 set has to be recovered either
1492         * completely or for the grown part to
1493         * ensure proper parity and Q-Syndrome
1494         */
1495        else if (rs_is_raid6(rs))
1496                rs->md.recovery_cp = dev_sectors;
1497        /*
1498         * Other raid set types may skip recovery
1499         * depending on the 'nosync' flag.
1500         */
1501        else
1502                rs->md.recovery_cp = test_bit(__CTR_FLAG_NOSYNC, &rs->ctr_flags)
1503                                     ? MaxSector : dev_sectors;
1504}
1505
1506/* Setup recovery on @rs based on raid type, device size and 'nosync' flag */
1507static void rs_setup_recovery(struct raid_set *rs, sector_t dev_sectors)
1508{
1509        if (!dev_sectors)
1510                /* New raid set or 'sync' flag provided */
1511                __rs_setup_recovery(rs, 0);
1512        else if (dev_sectors == MaxSector)
1513                /* Prevent recovery */
1514                __rs_setup_recovery(rs, MaxSector);
1515        else if (rs->dev[0].rdev.sectors < dev_sectors)
1516                /* Grown raid set */
1517                __rs_setup_recovery(rs, rs->dev[0].rdev.sectors);
1518        else
1519                __rs_setup_recovery(rs, MaxSector);
1520}
1521
1522static void do_table_event(struct work_struct *ws)
1523{
1524        struct raid_set *rs = container_of(ws, struct raid_set, md.event_work);
1525
1526        smp_rmb(); /* Make sure we access most actual mddev properties */
1527        if (!rs_is_reshaping(rs))
1528                rs_set_capacity(rs);
1529        dm_table_event(rs->ti->table);
1530}
1531
1532static int raid_is_congested(struct dm_target_callbacks *cb, int bits)
1533{
1534        struct raid_set *rs = container_of(cb, struct raid_set, callbacks);
1535
1536        return mddev_congested(&rs->md, bits);
1537}
1538
1539/*
1540 * Make sure a valid takover (level switch) is being requested on @rs
1541 *
1542 * Conversions of raid sets from one MD personality to another
1543 * have to conform to restrictions which are enforced here.
1544 */
1545static int rs_check_takeover(struct raid_set *rs)
1546{
1547        struct mddev *mddev = &rs->md;
1548        unsigned int near_copies;
1549
1550        if (rs->md.degraded) {
1551                rs->ti->error = "Can't takeover degraded raid set";
1552                return -EPERM;
1553        }
1554
1555        if (rs_is_reshaping(rs)) {
1556                rs->ti->error = "Can't takeover reshaping raid set";
1557                return -EPERM;
1558        }
1559
1560        switch (mddev->level) {
1561        case 0:
1562                /* raid0 -> raid1/5 with one disk */
1563                if ((mddev->new_level == 1 || mddev->new_level == 5) &&
1564                    mddev->raid_disks == 1)
1565                        return 0;
1566
1567                /* raid0 -> raid10 */
1568                if (mddev->new_level == 10 &&
1569                    !(rs->raid_disks % mddev->raid_disks))
1570                        return 0;
1571
1572                /* raid0 with multiple disks -> raid4/5/6 */
1573                if (__within_range(mddev->new_level, 4, 6) &&
1574                    mddev->new_layout == ALGORITHM_PARITY_N &&
1575                    mddev->raid_disks > 1)
1576                        return 0;
1577
1578                break;
1579
1580        case 10:
1581                /* Can't takeover raid10_offset! */
1582                if (__is_raid10_offset(mddev->layout))
1583                        break;
1584
1585                near_copies = __raid10_near_copies(mddev->layout);
1586
1587                /* raid10* -> raid0 */
1588                if (mddev->new_level == 0) {
1589                        /* Can takeover raid10_near with raid disks divisable by data copies! */
1590                        if (near_copies > 1 &&
1591                            !(mddev->raid_disks % near_copies)) {
1592                                mddev->raid_disks /= near_copies;
1593                                mddev->delta_disks = mddev->raid_disks;
1594                                return 0;
1595                        }
1596
1597                        /* Can takeover raid10_far */
1598                        if (near_copies == 1 &&
1599                            __raid10_far_copies(mddev->layout) > 1)
1600                                return 0;
1601
1602                        break;
1603                }
1604
1605                /* raid10_{near,far} -> raid1 */
1606                if (mddev->new_level == 1 &&
1607                    max(near_copies, __raid10_far_copies(mddev->layout)) == mddev->raid_disks)
1608                        return 0;
1609
1610                /* raid10_{near,far} with 2 disks -> raid4/5 */
1611                if (__within_range(mddev->new_level, 4, 5) &&
1612                    mddev->raid_disks == 2)
1613                        return 0;
1614                break;
1615
1616        case 1:
1617                /* raid1 with 2 disks -> raid4/5 */
1618                if (__within_range(mddev->new_level, 4, 5) &&
1619                    mddev->raid_disks == 2) {
1620                        mddev->degraded = 1;
1621                        return 0;
1622                }
1623
1624                /* raid1 -> raid0 */
1625                if (mddev->new_level == 0 &&
1626                    mddev->raid_disks == 1)
1627                        return 0;
1628
1629                /* raid1 -> raid10 */
1630                if (mddev->new_level == 10)
1631                        return 0;
1632                break;
1633
1634        case 4:
1635                /* raid4 -> raid0 */
1636                if (mddev->new_level == 0)
1637                        return 0;
1638
1639                /* raid4 -> raid1/5 with 2 disks */
1640                if ((mddev->new_level == 1 || mddev->new_level == 5) &&
1641                    mddev->raid_disks == 2)
1642                        return 0;
1643
1644                /* raid4 -> raid5/6 with parity N */
1645                if (__within_range(mddev->new_level, 5, 6) &&
1646                    mddev->layout == ALGORITHM_PARITY_N)
1647                        return 0;
1648                break;
1649
1650        case 5:
1651                /* raid5 with parity N -> raid0 */
1652                if (mddev->new_level == 0 &&
1653                    mddev->layout == ALGORITHM_PARITY_N)
1654                        return 0;
1655
1656                /* raid5 with parity N -> raid4 */
1657                if (mddev->new_level == 4 &&
1658                    mddev->layout == ALGORITHM_PARITY_N)
1659                        return 0;
1660
1661                /* raid5 with 2 disks -> raid1/4/10 */
1662                if ((mddev->new_level == 1 || mddev->new_level == 4 || mddev->new_level == 10) &&
1663                    mddev->raid_disks == 2)
1664                        return 0;
1665
1666                /* raid5_* ->  raid6_*_6 with Q-Syndrome N (e.g. raid5_ra -> raid6_ra_6 */
1667                if (mddev->new_level == 6 &&
1668                    ((mddev->layout == ALGORITHM_PARITY_N && mddev->new_layout == ALGORITHM_PARITY_N) ||
1669                      __within_range(mddev->new_layout, ALGORITHM_LEFT_ASYMMETRIC_6, ALGORITHM_RIGHT_SYMMETRIC_6)))
1670                        return 0;
1671                break;
1672
1673        case 6:
1674                /* raid6 with parity N -> raid0 */
1675                if (mddev->new_level == 0 &&
1676                    mddev->layout == ALGORITHM_PARITY_N)
1677                        return 0;
1678
1679                /* raid6 with parity N -> raid4 */
1680                if (mddev->new_level == 4 &&
1681                    mddev->layout == ALGORITHM_PARITY_N)
1682                        return 0;
1683
1684                /* raid6_*_n with Q-Syndrome N -> raid5_* */
1685                if (mddev->new_level == 5 &&
1686                    ((mddev->layout == ALGORITHM_PARITY_N && mddev->new_layout == ALGORITHM_PARITY_N) ||
1687                     __within_range(mddev->new_layout, ALGORITHM_LEFT_ASYMMETRIC, ALGORITHM_RIGHT_SYMMETRIC)))
1688                        return 0;
1689
1690        default:
1691                break;
1692        }
1693
1694        rs->ti->error = "takeover not possible";
1695        return -EINVAL;
1696}
1697
1698/* True if @rs requested to be taken over */
1699static bool rs_takeover_requested(struct raid_set *rs)
1700{
1701        return rs->md.new_level != rs->md.level;
1702}
1703
1704/* True if @rs is requested to reshape by ctr */
1705static bool rs_reshape_requested(struct raid_set *rs)
1706{
1707        bool change;
1708        struct mddev *mddev = &rs->md;
1709
1710        if (rs_takeover_requested(rs))
1711                return false;
1712
1713        if (!mddev->level)
1714                return false;
1715
1716        change = mddev->new_layout != mddev->layout ||
1717                 mddev->new_chunk_sectors != mddev->chunk_sectors ||
1718                 rs->delta_disks;
1719
1720        /* Historical case to support raid1 reshape without delta disks */
1721        if (mddev->level == 1) {
1722                if (rs->delta_disks)
1723                        return !!rs->delta_disks;
1724
1725                return !change &&
1726                       mddev->raid_disks != rs->raid_disks;
1727        }
1728
1729        if (mddev->level == 10)
1730                return change &&
1731                       !__is_raid10_far(mddev->new_layout) &&
1732                       rs->delta_disks >= 0;
1733
1734        return change;
1735}
1736
1737/*  Features */
1738#define FEATURE_FLAG_SUPPORTS_V190      0x1 /* Supports extended superblock */
1739
1740/* State flags for sb->flags */
1741#define SB_FLAG_RESHAPE_ACTIVE          0x1
1742#define SB_FLAG_RESHAPE_BACKWARDS       0x2
1743
1744/*
1745 * This structure is never routinely used by userspace, unlike md superblocks.
1746 * Devices with this superblock should only ever be accessed via device-mapper.
1747 */
1748#define DM_RAID_MAGIC 0x64526D44
1749struct dm_raid_superblock {
1750        __le32 magic;           /* "DmRd" */
1751        __le32 compat_features; /* Used to indicate compatible features (like 1.9.0 ondisk metadata extension) */
1752
1753        __le32 num_devices;     /* Number of devices in this raid set. (Max 64) */
1754        __le32 array_position;  /* The position of this drive in the raid set */
1755
1756        __le64 events;          /* Incremented by md when superblock updated */
1757        __le64 failed_devices;  /* Pre 1.9.0 part of bit field of devices to */
1758                                /* indicate failures (see extension below) */
1759
1760        /*
1761         * This offset tracks the progress of the repair or replacement of
1762         * an individual drive.
1763         */
1764        __le64 disk_recovery_offset;
1765
1766        /*
1767         * This offset tracks the progress of the initial raid set
1768         * synchronisation/parity calculation.
1769         */
1770        __le64 array_resync_offset;
1771
1772        /*
1773         * raid characteristics
1774         */
1775        __le32 level;
1776        __le32 layout;
1777        __le32 stripe_sectors;
1778
1779        /********************************************************************
1780         * BELOW FOLLOW V1.9.0 EXTENSIONS TO THE PRISTINE SUPERBLOCK FORMAT!!!
1781         *
1782         * FEATURE_FLAG_SUPPORTS_V190 in the features member indicates that those exist
1783         */
1784
1785        __le32 flags; /* Flags defining array states for reshaping */
1786
1787        /*
1788         * This offset tracks the progress of a raid
1789         * set reshape in order to be able to restart it
1790         */
1791        __le64 reshape_position;
1792
1793        /*
1794         * These define the properties of the array in case of an interrupted reshape
1795         */
1796        __le32 new_level;
1797        __le32 new_layout;
1798        __le32 new_stripe_sectors;
1799        __le32 delta_disks;
1800
1801        __le64 array_sectors; /* Array size in sectors */
1802
1803        /*
1804         * Sector offsets to data on devices (reshaping).
1805         * Needed to support out of place reshaping, thus
1806         * not writing over any stripes whilst converting
1807         * them from old to new layout
1808         */
1809        __le64 data_offset;
1810        __le64 new_data_offset;
1811
1812        __le64 sectors; /* Used device size in sectors */
1813
1814        /*
1815         * Additonal Bit field of devices indicating failures to support
1816         * up to 256 devices with the 1.9.0 on-disk metadata format
1817         */
1818        __le64 extended_failed_devices[DISKS_ARRAY_ELEMS - 1];
1819
1820        __le32 incompat_features;       /* Used to indicate any incompatible features */
1821
1822        /* Always set rest up to logical block size to 0 when writing (see get_metadata_device() below). */
1823} __packed;
1824
1825/*
1826 * Check for reshape constraints on raid set @rs:
1827 *
1828 * - reshape function non-existent
1829 * - degraded set
1830 * - ongoing recovery
1831 * - ongoing reshape
1832 *
1833 * Returns 0 if none or -EPERM if given constraint
1834 * and error message reference in @errmsg
1835 */
1836static int rs_check_reshape(struct raid_set *rs)
1837{
1838        struct mddev *mddev = &rs->md;
1839
1840        if (!mddev->pers || !mddev->pers->check_reshape)
1841                rs->ti->error = "Reshape not supported";
1842        else if (mddev->degraded)
1843                rs->ti->error = "Can't reshape degraded raid set";
1844        else if (rs_is_recovering(rs))
1845                rs->ti->error = "Convert request on recovering raid set prohibited";
1846        else if (rs_is_reshaping(rs))
1847                rs->ti->error = "raid set already reshaping!";
1848        else if (!(rs_is_raid1(rs) || rs_is_raid10(rs) || rs_is_raid456(rs)))
1849                rs->ti->error = "Reshaping only supported for raid1/4/5/6/10";
1850        else
1851                return 0;
1852
1853        return -EPERM;
1854}
1855
1856static int read_disk_sb(struct md_rdev *rdev, int size)
1857{
1858        BUG_ON(!rdev->sb_page);
1859
1860        if (rdev->sb_loaded)
1861                return 0;
1862
1863        if (!sync_page_io(rdev, 0, size, rdev->sb_page, REQ_OP_READ, 0, true)) {
1864                DMERR("Failed to read superblock of device at position %d",
1865                      rdev->raid_disk);
1866                md_error(rdev->mddev, rdev);
1867                return -EINVAL;
1868        }
1869
1870        rdev->sb_loaded = 1;
1871
1872        return 0;
1873}
1874
1875static void sb_retrieve_failed_devices(struct dm_raid_superblock *sb, uint64_t *failed_devices)
1876{
1877        failed_devices[0] = le64_to_cpu(sb->failed_devices);
1878        memset(failed_devices + 1, 0, sizeof(sb->extended_failed_devices));
1879
1880        if (le32_to_cpu(sb->compat_features) & FEATURE_FLAG_SUPPORTS_V190) {
1881                int i = ARRAY_SIZE(sb->extended_failed_devices);
1882
1883                while (i--)
1884                        failed_devices[i+1] = le64_to_cpu(sb->extended_failed_devices[i]);
1885        }
1886}
1887
1888static void sb_update_failed_devices(struct dm_raid_superblock *sb, uint64_t *failed_devices)
1889{
1890        int i = ARRAY_SIZE(sb->extended_failed_devices);
1891
1892        sb->failed_devices = cpu_to_le64(failed_devices[0]);
1893        while (i--)
1894                sb->extended_failed_devices[i] = cpu_to_le64(failed_devices[i+1]);
1895}
1896
1897/*
1898 * Synchronize the superblock members with the raid set properties
1899 *
1900 * All superblock data is little endian.
1901 */
1902static void super_sync(struct mddev *mddev, struct md_rdev *rdev)
1903{
1904        bool update_failed_devices = false;
1905        unsigned int i;
1906        uint64_t failed_devices[DISKS_ARRAY_ELEMS];
1907        struct dm_raid_superblock *sb;
1908        struct raid_set *rs = container_of(mddev, struct raid_set, md);
1909
1910        /* No metadata device, no superblock */
1911        if (!rdev->meta_bdev)
1912                return;
1913
1914        BUG_ON(!rdev->sb_page);
1915
1916        sb = page_address(rdev->sb_page);
1917
1918        sb_retrieve_failed_devices(sb, failed_devices);
1919
1920        for (i = 0; i < rs->raid_disks; i++)
1921                if (!rs->dev[i].data_dev || test_bit(Faulty, &rs->dev[i].rdev.flags)) {
1922                        update_failed_devices = true;
1923                        set_bit(i, (void *) failed_devices);
1924                }
1925
1926        if (update_failed_devices)
1927                sb_update_failed_devices(sb, failed_devices);
1928
1929        sb->magic = cpu_to_le32(DM_RAID_MAGIC);
1930        sb->compat_features = cpu_to_le32(FEATURE_FLAG_SUPPORTS_V190);
1931
1932        sb->num_devices = cpu_to_le32(mddev->raid_disks);
1933        sb->array_position = cpu_to_le32(rdev->raid_disk);
1934
1935        sb->events = cpu_to_le64(mddev->events);
1936
1937        sb->disk_recovery_offset = cpu_to_le64(rdev->recovery_offset);
1938        sb->array_resync_offset = cpu_to_le64(mddev->recovery_cp);
1939
1940        sb->level = cpu_to_le32(mddev->level);
1941        sb->layout = cpu_to_le32(mddev->layout);
1942        sb->stripe_sectors = cpu_to_le32(mddev->chunk_sectors);
1943
1944        sb->new_level = cpu_to_le32(mddev->new_level);
1945        sb->new_layout = cpu_to_le32(mddev->new_layout);
1946        sb->new_stripe_sectors = cpu_to_le32(mddev->new_chunk_sectors);
1947
1948        sb->delta_disks = cpu_to_le32(mddev->delta_disks);
1949
1950        smp_rmb(); /* Make sure we access most recent reshape position */
1951        sb->reshape_position = cpu_to_le64(mddev->reshape_position);
1952        if (le64_to_cpu(sb->reshape_position) != MaxSector) {
1953                /* Flag ongoing reshape */
1954                sb->flags |= cpu_to_le32(SB_FLAG_RESHAPE_ACTIVE);
1955
1956                if (mddev->delta_disks < 0 || mddev->reshape_backwards)
1957                        sb->flags |= cpu_to_le32(SB_FLAG_RESHAPE_BACKWARDS);
1958        } else {
1959                /* Clear reshape flags */
1960                sb->flags &= ~(cpu_to_le32(SB_FLAG_RESHAPE_ACTIVE|SB_FLAG_RESHAPE_BACKWARDS));
1961        }
1962
1963        sb->array_sectors = cpu_to_le64(mddev->array_sectors);
1964        sb->data_offset = cpu_to_le64(rdev->data_offset);
1965        sb->new_data_offset = cpu_to_le64(rdev->new_data_offset);
1966        sb->sectors = cpu_to_le64(rdev->sectors);
1967        sb->incompat_features = cpu_to_le32(0);
1968
1969        /* Zero out the rest of the payload after the size of the superblock */
1970        memset(sb + 1, 0, rdev->sb_size - sizeof(*sb));
1971}
1972
1973/*
1974 * super_load
1975 *
1976 * This function creates a superblock if one is not found on the device
1977 * and will decide which superblock to use if there's a choice.
1978 *
1979 * Return: 1 if use rdev, 0 if use refdev, -Exxx otherwise
1980 */
1981static int super_load(struct md_rdev *rdev, struct md_rdev *refdev)
1982{
1983        int r;
1984        struct dm_raid_superblock *sb;
1985        struct dm_raid_superblock *refsb;
1986        uint64_t events_sb, events_refsb;
1987
1988        rdev->sb_start = 0;
1989        rdev->sb_size = bdev_logical_block_size(rdev->meta_bdev);
1990        if (rdev->sb_size < sizeof(*sb) || rdev->sb_size > PAGE_SIZE) {
1991                DMERR("superblock size of a logical block is no longer valid");
1992                return -EINVAL;
1993        }
1994
1995        r = read_disk_sb(rdev, rdev->sb_size);
1996        if (r)
1997                return r;
1998
1999        sb = page_address(rdev->sb_page);
2000
2001        /*
2002         * Two cases that we want to write new superblocks and rebuild:
2003         * 1) New device (no matching magic number)
2004         * 2) Device specified for rebuild (!In_sync w/ offset == 0)
2005         */
2006        if ((sb->magic != cpu_to_le32(DM_RAID_MAGIC)) ||
2007            (!test_bit(In_sync, &rdev->flags) && !rdev->recovery_offset)) {
2008                super_sync(rdev->mddev, rdev);
2009
2010                set_bit(FirstUse, &rdev->flags);
2011                sb->compat_features = cpu_to_le32(FEATURE_FLAG_SUPPORTS_V190);
2012
2013                /* Force writing of superblocks to disk */
2014                set_bit(MD_CHANGE_DEVS, &rdev->mddev->flags);
2015
2016                /* Any superblock is better than none, choose that if given */
2017                return refdev ? 0 : 1;
2018        }
2019
2020        if (!refdev)
2021                return 1;
2022
2023        events_sb = le64_to_cpu(sb->events);
2024
2025        refsb = page_address(refdev->sb_page);
2026        events_refsb = le64_to_cpu(refsb->events);
2027
2028        return (events_sb > events_refsb) ? 1 : 0;
2029}
2030
2031static int super_init_validation(struct raid_set *rs, struct md_rdev *rdev)
2032{
2033        int role;
2034        unsigned int d;
2035        struct mddev *mddev = &rs->md;
2036        uint64_t events_sb;
2037        uint64_t failed_devices[DISKS_ARRAY_ELEMS];
2038        struct dm_raid_superblock *sb;
2039        uint32_t new_devs = 0, rebuild_and_new = 0, rebuilds = 0;
2040        struct md_rdev *r;
2041        struct dm_raid_superblock *sb2;
2042
2043        sb = page_address(rdev->sb_page);
2044        events_sb = le64_to_cpu(sb->events);
2045
2046        /*
2047         * Initialise to 1 if this is a new superblock.
2048         */
2049        mddev->events = events_sb ? : 1;
2050
2051        mddev->reshape_position = MaxSector;
2052
2053        /*
2054         * Reshaping is supported, e.g. reshape_position is valid
2055         * in superblock and superblock content is authoritative.
2056         */
2057        if (le32_to_cpu(sb->compat_features) & FEATURE_FLAG_SUPPORTS_V190) {
2058                /* Superblock is authoritative wrt given raid set layout! */
2059                mddev->raid_disks = le32_to_cpu(sb->num_devices);
2060                mddev->level = le32_to_cpu(sb->level);
2061                mddev->layout = le32_to_cpu(sb->layout);
2062                mddev->chunk_sectors = le32_to_cpu(sb->stripe_sectors);
2063                mddev->new_level = le32_to_cpu(sb->new_level);
2064                mddev->new_layout = le32_to_cpu(sb->new_layout);
2065                mddev->new_chunk_sectors = le32_to_cpu(sb->new_stripe_sectors);
2066                mddev->delta_disks = le32_to_cpu(sb->delta_disks);
2067                mddev->array_sectors = le64_to_cpu(sb->array_sectors);
2068
2069                /* raid was reshaping and got interrupted */
2070                if (le32_to_cpu(sb->flags) & SB_FLAG_RESHAPE_ACTIVE) {
2071                        if (test_bit(__CTR_FLAG_DELTA_DISKS, &rs->ctr_flags)) {
2072                                DMERR("Reshape requested but raid set is still reshaping");
2073                                return -EINVAL;
2074                        }
2075
2076                        if (mddev->delta_disks < 0 ||
2077                            (!mddev->delta_disks && (le32_to_cpu(sb->flags) & SB_FLAG_RESHAPE_BACKWARDS)))
2078                                mddev->reshape_backwards = 1;
2079                        else
2080                                mddev->reshape_backwards = 0;
2081
2082                        mddev->reshape_position = le64_to_cpu(sb->reshape_position);
2083                        rs->raid_type = get_raid_type_by_ll(mddev->level, mddev->layout);
2084                }
2085
2086        } else {
2087                /*
2088                 * No takeover/reshaping, because we don't have the extended v1.9.0 metadata
2089                 */
2090                if (le32_to_cpu(sb->level) != mddev->new_level) {
2091                        DMERR("Reshaping/takeover raid sets not yet supported. (raid level/stripes/size change)");
2092                        return -EINVAL;
2093                }
2094                if (le32_to_cpu(sb->layout) != mddev->new_layout) {
2095                        DMERR("Reshaping raid sets not yet supported. (raid layout change)");
2096                        DMERR("  0x%X vs 0x%X", le32_to_cpu(sb->layout), mddev->layout);
2097                        DMERR("  Old layout: %s w/ %d copies",
2098                              raid10_md_layout_to_format(le32_to_cpu(sb->layout)),
2099                              raid10_md_layout_to_copies(le32_to_cpu(sb->layout)));
2100                        DMERR("  New layout: %s w/ %d copies",
2101                              raid10_md_layout_to_format(mddev->layout),
2102                              raid10_md_layout_to_copies(mddev->layout));
2103                        return -EINVAL;
2104                }
2105                if (le32_to_cpu(sb->stripe_sectors) != mddev->new_chunk_sectors) {
2106                        DMERR("Reshaping raid sets not yet supported. (stripe sectors change)");
2107                        return -EINVAL;
2108                }
2109
2110                /* We can only change the number of devices in raid1 with old (i.e. pre 1.0.7) metadata */
2111                if (!rt_is_raid1(rs->raid_type) &&
2112                    (le32_to_cpu(sb->num_devices) != mddev->raid_disks)) {
2113                        DMERR("Reshaping raid sets not yet supported. (device count change from %u to %u)",
2114                              sb->num_devices, mddev->raid_disks);
2115                        return -EINVAL;
2116                }
2117
2118                DMINFO("Discovered old metadata format; upgrading to extended metadata format");
2119
2120                /* Table line is checked vs. authoritative superblock */
2121                rs_set_new(rs);
2122        }
2123
2124        if (!test_bit(__CTR_FLAG_NOSYNC, &rs->ctr_flags))
2125                mddev->recovery_cp = le64_to_cpu(sb->array_resync_offset);
2126
2127        /*
2128         * During load, we set FirstUse if a new superblock was written.
2129         * There are two reasons we might not have a superblock:
2130         * 1) The raid set is brand new - in which case, all of the
2131         *    devices must have their In_sync bit set.  Also,
2132         *    recovery_cp must be 0, unless forced.
2133         * 2) This is a new device being added to an old raid set
2134         *    and the new device needs to be rebuilt - in which
2135         *    case the In_sync bit will /not/ be set and
2136         *    recovery_cp must be MaxSector.
2137         * 3) This is/are a new device(s) being added to an old
2138         *    raid set during takeover to a higher raid level
2139         *    to provide capacity for redundancy or during reshape
2140         *    to add capacity to grow the raid set.
2141         */
2142        d = 0;
2143        rdev_for_each(r, mddev) {
2144                if (test_bit(FirstUse, &r->flags))
2145                        new_devs++;
2146
2147                if (!test_bit(In_sync, &r->flags)) {
2148                        DMINFO("Device %d specified for rebuild; clearing superblock",
2149                                r->raid_disk);
2150                        rebuilds++;
2151
2152                        if (test_bit(FirstUse, &r->flags))
2153                                rebuild_and_new++;
2154                }
2155
2156                d++;
2157        }
2158
2159        if (new_devs == rs->raid_disks || !rebuilds) {
2160                /* Replace a broken device */
2161                if (new_devs == 1 && !rs->delta_disks)
2162                        ;
2163                if (new_devs == rs->raid_disks) {
2164                        DMINFO("Superblocks created for new raid set");
2165                        set_bit(MD_ARRAY_FIRST_USE, &mddev->flags);
2166                } else if (new_devs != rebuilds &&
2167                           new_devs != rs->delta_disks) {
2168                        DMERR("New device injected into existing raid set without "
2169                              "'delta_disks' or 'rebuild' parameter specified");
2170                        return -EINVAL;
2171                }
2172        } else if (new_devs && new_devs != rebuilds) {
2173                DMERR("%u 'rebuild' devices cannot be injected into"
2174                      " a raid set with %u other first-time devices",
2175                      rebuilds, new_devs);
2176                return -EINVAL;
2177        } else if (rebuilds) {
2178                if (rebuild_and_new && rebuilds != rebuild_and_new) {
2179                        DMERR("new device%s provided without 'rebuild'",
2180                              new_devs > 1 ? "s" : "");
2181                        return -EINVAL;
2182                } else if (rs_is_recovering(rs)) {
2183                        DMERR("'rebuild' specified while raid set is not in-sync (recovery_cp=%llu)",
2184                              (unsigned long long) mddev->recovery_cp);
2185                        return -EINVAL;
2186                } else if (rs_is_reshaping(rs)) {
2187                        DMERR("'rebuild' specified while raid set is being reshaped (reshape_position=%llu)",
2188                              (unsigned long long) mddev->reshape_position);
2189                        return -EINVAL;
2190                }
2191        }
2192
2193        /*
2194         * Now we set the Faulty bit for those devices that are
2195         * recorded in the superblock as failed.
2196         */
2197        sb_retrieve_failed_devices(sb, failed_devices);
2198        rdev_for_each(r, mddev) {
2199                if (!r->sb_page)
2200                        continue;
2201                sb2 = page_address(r->sb_page);
2202                sb2->failed_devices = 0;
2203                memset(sb2->extended_failed_devices, 0, sizeof(sb2->extended_failed_devices));
2204
2205                /*
2206                 * Check for any device re-ordering.
2207                 */
2208                if (!test_bit(FirstUse, &r->flags) && (r->raid_disk >= 0)) {
2209                        role = le32_to_cpu(sb2->array_position);
2210                        if (role < 0)
2211                                continue;
2212
2213                        if (role != r->raid_disk) {
2214                                if (__is_raid10_near(mddev->layout)) {
2215                                        if (mddev->raid_disks % __raid10_near_copies(mddev->layout) ||
2216                                            rs->raid_disks % rs->raid10_copies) {
2217                                                rs->ti->error =
2218                                                        "Cannot change raid10 near set to odd # of devices!";
2219                                                return -EINVAL;
2220                                        }
2221
2222                                        sb2->array_position = cpu_to_le32(r->raid_disk);
2223
2224                                } else if (!(rs_is_raid10(rs) && rt_is_raid0(rs->raid_type)) &&
2225                                           !(rs_is_raid0(rs) && rt_is_raid10(rs->raid_type)) &&
2226                                           !rt_is_raid1(rs->raid_type)) {
2227                                        rs->ti->error = "Cannot change device positions in raid set";
2228                                        return -EINVAL;
2229                                }
2230
2231                                DMINFO("raid device #%d now at position #%d", role, r->raid_disk);
2232                        }
2233
2234                        /*
2235                         * Partial recovery is performed on
2236                         * returning failed devices.
2237                         */
2238                        if (test_bit(role, (void *) failed_devices))
2239                                set_bit(Faulty, &r->flags);
2240                }
2241        }
2242
2243        return 0;
2244}
2245
2246static int super_validate(struct raid_set *rs, struct md_rdev *rdev)
2247{
2248        struct mddev *mddev = &rs->md;
2249        struct dm_raid_superblock *sb;
2250
2251        if (rs_is_raid0(rs) || !rdev->sb_page)
2252                return 0;
2253
2254        sb = page_address(rdev->sb_page);
2255
2256        /*
2257         * If mddev->events is not set, we know we have not yet initialized
2258         * the array.
2259         */
2260        if (!mddev->events && super_init_validation(rs, rdev))
2261                return -EINVAL;
2262
2263        if (le32_to_cpu(sb->compat_features) &&
2264            le32_to_cpu(sb->compat_features) != FEATURE_FLAG_SUPPORTS_V190) {
2265                rs->ti->error = "Unable to assemble array: Unknown flag(s) in compatible feature flags";
2266                return -EINVAL;
2267        }
2268
2269        if (sb->incompat_features) {
2270                rs->ti->error = "Unable to assemble array: No incompatible feature flags supported yet";
2271                return -EINVAL;
2272        }
2273
2274        /* Enable bitmap creation for RAID levels != 0 */
2275        mddev->bitmap_info.offset = rt_is_raid0(rs->raid_type) ? 0 : to_sector(4096);
2276        rdev->mddev->bitmap_info.default_offset = mddev->bitmap_info.offset;
2277
2278        if (!test_and_clear_bit(FirstUse, &rdev->flags)) {
2279                /* Retrieve device size stored in superblock to be prepared for shrink */
2280                rdev->sectors = le64_to_cpu(sb->sectors);
2281                rdev->recovery_offset = le64_to_cpu(sb->disk_recovery_offset);
2282                if (rdev->recovery_offset == MaxSector)
2283                        set_bit(In_sync, &rdev->flags);
2284                /*
2285                 * If no reshape in progress -> we're recovering single
2286                 * disk(s) and have to set the device(s) to out-of-sync
2287                 */
2288                else if (!rs_is_reshaping(rs))
2289                        clear_bit(In_sync, &rdev->flags); /* Mandatory for recovery */
2290        }
2291
2292        /*
2293         * If a device comes back, set it as not In_sync and no longer faulty.
2294         */
2295        if (test_and_clear_bit(Faulty, &rdev->flags)) {
2296                rdev->recovery_offset = 0;
2297                clear_bit(In_sync, &rdev->flags);
2298                rdev->saved_raid_disk = rdev->raid_disk;
2299        }
2300
2301        /* Reshape support -> restore repective data offsets */
2302        rdev->data_offset = le64_to_cpu(sb->data_offset);
2303        rdev->new_data_offset = le64_to_cpu(sb->new_data_offset);
2304
2305        return 0;
2306}
2307
2308/*
2309 * Analyse superblocks and select the freshest.
2310 */
2311static int analyse_superblocks(struct dm_target *ti, struct raid_set *rs)
2312{
2313        int r;
2314        struct raid_dev *dev;
2315        struct md_rdev *rdev, *tmp, *freshest;
2316        struct mddev *mddev = &rs->md;
2317
2318        freshest = NULL;
2319        rdev_for_each_safe(rdev, tmp, mddev) {
2320                /*
2321                 * Skipping super_load due to CTR_FLAG_SYNC will cause
2322                 * the array to undergo initialization again as
2323                 * though it were new.  This is the intended effect
2324                 * of the "sync" directive.
2325                 *
2326                 * When reshaping capability is added, we must ensure
2327                 * that the "sync" directive is disallowed during the
2328                 * reshape.
2329                 */
2330                if (test_bit(__CTR_FLAG_SYNC, &rs->ctr_flags))
2331                        continue;
2332
2333                if (!rdev->meta_bdev)
2334                        continue;
2335
2336                r = super_load(rdev, freshest);
2337
2338                switch (r) {
2339                case 1:
2340                        freshest = rdev;
2341                        break;
2342                case 0:
2343                        break;
2344                default:
2345                        /*
2346                         * We have to keep any raid0 data/metadata device pairs or
2347                         * the MD raid0 personality will fail to start the array.
2348                         */
2349                        if (rs_is_raid0(rs))
2350                                continue;
2351
2352                        dev = container_of(rdev, struct raid_dev, rdev);
2353                        if (dev->meta_dev)
2354                                dm_put_device(ti, dev->meta_dev);
2355
2356                        dev->meta_dev = NULL;
2357                        rdev->meta_bdev = NULL;
2358
2359                        if (rdev->sb_page)
2360                                put_page(rdev->sb_page);
2361
2362                        rdev->sb_page = NULL;
2363
2364                        rdev->sb_loaded = 0;
2365
2366                        /*
2367                         * We might be able to salvage the data device
2368                         * even though the meta device has failed.  For
2369                         * now, we behave as though '- -' had been
2370                         * set for this device in the table.
2371                         */
2372                        if (dev->data_dev)
2373                                dm_put_device(ti, dev->data_dev);
2374
2375                        dev->data_dev = NULL;
2376                        rdev->bdev = NULL;
2377
2378                        list_del(&rdev->same_set);
2379                }
2380        }
2381
2382        if (!freshest)
2383                return 0;
2384
2385        if (validate_raid_redundancy(rs)) {
2386                rs->ti->error = "Insufficient redundancy to activate array";
2387                return -EINVAL;
2388        }
2389
2390        /*
2391         * Validation of the freshest device provides the source of
2392         * validation for the remaining devices.
2393         */
2394        rs->ti->error = "Unable to assemble array: Invalid superblocks";
2395        if (super_validate(rs, freshest))
2396                return -EINVAL;
2397
2398        rdev_for_each(rdev, mddev)
2399                if ((rdev != freshest) && super_validate(rs, rdev))
2400                        return -EINVAL;
2401        return 0;
2402}
2403
2404/*
2405 * Adjust data_offset and new_data_offset on all disk members of @rs
2406 * for out of place reshaping if requested by contructor
2407 *
2408 * We need free space at the beginning of each raid disk for forward
2409 * and at the end for backward reshapes which userspace has to provide
2410 * via remapping/reordering of space.
2411 */
2412static int rs_adjust_data_offsets(struct raid_set *rs)
2413{
2414        sector_t data_offset = 0, new_data_offset = 0;
2415        struct md_rdev *rdev;
2416
2417        /* Constructor did not request data offset change */
2418        if (!test_bit(__CTR_FLAG_DATA_OFFSET, &rs->ctr_flags)) {
2419                if (!rs_is_reshapable(rs))
2420                        goto out;
2421
2422                return 0;
2423        }
2424
2425        /* HM FIXME: get InSync raid_dev? */
2426        rdev = &rs->dev[0].rdev;
2427
2428        if (rs->delta_disks < 0) {
2429                /*
2430                 * Removing disks (reshaping backwards):
2431                 *
2432                 * - before reshape: data is at offset 0 and free space
2433                 *                   is at end of each component LV
2434                 *
2435                 * - after reshape: data is at offset rs->data_offset != 0 on each component LV
2436                 */
2437                data_offset = 0;
2438                new_data_offset = rs->data_offset;
2439
2440        } else if (rs->delta_disks > 0) {
2441                /*
2442                 * Adding disks (reshaping forwards):
2443                 *
2444                 * - before reshape: data is at offset rs->data_offset != 0 and
2445                 *                   free space is at begin of each component LV
2446                 *
2447                 * - after reshape: data is at offset 0 on each component LV
2448                 */
2449                data_offset = rs->data_offset;
2450                new_data_offset = 0;
2451
2452        } else {
2453                /*
2454                 * User space passes in 0 for data offset after having removed reshape space
2455                 *
2456                 * - or - (data offset != 0)
2457                 *
2458                 * Changing RAID layout or chunk size -> toggle offsets
2459                 *
2460                 * - before reshape: data is at offset rs->data_offset 0 and
2461                 *                   free space is at end of each component LV
2462                 *                   -or-
2463                 *                   data is at offset rs->data_offset != 0 and
2464                 *                   free space is at begin of each component LV
2465                 *
2466                 * - after reshape: data is at offset 0 if it was at offset != 0
2467                 *                  or at offset != 0 if it was at offset 0
2468                 *                  on each component LV
2469                 *
2470                 */
2471                data_offset = rs->data_offset ? rdev->data_offset : 0;
2472                new_data_offset = data_offset ? 0 : rs->data_offset;
2473                set_bit(RT_FLAG_UPDATE_SBS, &rs->runtime_flags);
2474        }
2475
2476        /*
2477         * Make sure we got a minimum amount of free sectors per device
2478         */
2479        if (rs->data_offset &&
2480            to_sector(i_size_read(rdev->bdev->bd_inode)) - rdev->sectors < MIN_FREE_RESHAPE_SPACE) {
2481                rs->ti->error = data_offset ? "No space for forward reshape" :
2482                                              "No space for backward reshape";
2483                return -ENOSPC;
2484        }
2485out:
2486        /* Adjust data offsets on all rdevs */
2487        rdev_for_each(rdev, &rs->md) {
2488                rdev->data_offset = data_offset;
2489                rdev->new_data_offset = new_data_offset;
2490        }
2491
2492        return 0;
2493}
2494
2495/* Userpace reordered disks -> adjust raid_disk indexes in @rs */
2496static void __reorder_raid_disk_indexes(struct raid_set *rs)
2497{
2498        int i = 0;
2499        struct md_rdev *rdev;
2500
2501        rdev_for_each(rdev, &rs->md) {
2502                rdev->raid_disk = i++;
2503                rdev->saved_raid_disk = rdev->new_raid_disk = -1;
2504        }
2505}
2506
2507/*
2508 * Setup @rs for takeover by a different raid level
2509 */
2510static int rs_setup_takeover(struct raid_set *rs)
2511{
2512        struct mddev *mddev = &rs->md;
2513        struct md_rdev *rdev;
2514        unsigned int d = mddev->raid_disks = rs->raid_disks;
2515        sector_t new_data_offset = rs->dev[0].rdev.data_offset ? 0 : rs->data_offset;
2516
2517        if (rt_is_raid10(rs->raid_type)) {
2518                if (mddev->level == 0) {
2519                        /* Userpace reordered disks -> adjust raid_disk indexes */
2520                        __reorder_raid_disk_indexes(rs);
2521
2522                        /* raid0 -> raid10_far layout */
2523                        mddev->layout = raid10_format_to_md_layout(rs, ALGORITHM_RAID10_FAR,
2524                                                                   rs->raid10_copies);
2525                } else if (mddev->level == 1)
2526                        /* raid1 -> raid10_near layout */
2527                        mddev->layout = raid10_format_to_md_layout(rs, ALGORITHM_RAID10_NEAR,
2528                                                                   rs->raid_disks);
2529                else
2530                        return -EINVAL;
2531
2532        }
2533
2534        clear_bit(MD_ARRAY_FIRST_USE, &mddev->flags);
2535        mddev->recovery_cp = MaxSector;
2536
2537        while (d--) {
2538                rdev = &rs->dev[d].rdev;
2539
2540                if (test_bit(d, (void *) rs->rebuild_disks)) {
2541                        clear_bit(In_sync, &rdev->flags);
2542                        clear_bit(Faulty, &rdev->flags);
2543                        mddev->recovery_cp = rdev->recovery_offset = 0;
2544                        /* Bitmap has to be created when we do an "up" takeover */
2545                        set_bit(MD_ARRAY_FIRST_USE, &mddev->flags);
2546                }
2547
2548                rdev->new_data_offset = new_data_offset;
2549        }
2550
2551        return 0;
2552}
2553
2554/* Prepare @rs for reshape */
2555static int rs_prepare_reshape(struct raid_set *rs)
2556{
2557        bool reshape;
2558        struct mddev *mddev = &rs->md;
2559
2560        if (rs_is_raid10(rs)) {
2561                if (rs->raid_disks != mddev->raid_disks &&
2562                    __is_raid10_near(mddev->layout) &&
2563                    rs->raid10_copies &&
2564                    rs->raid10_copies != __raid10_near_copies(mddev->layout)) {
2565                        /*
2566                         * raid disk have to be multiple of data copies to allow this conversion,
2567                         *
2568                         * This is actually not a reshape it is a
2569                         * rebuild of any additional mirrors per group
2570                         */
2571                        if (rs->raid_disks % rs->raid10_copies) {
2572                                rs->ti->error = "Can't reshape raid10 mirror groups";
2573                                return -EINVAL;
2574                        }
2575
2576                        /* Userpace reordered disks to add/remove mirrors -> adjust raid_disk indexes */
2577                        __reorder_raid_disk_indexes(rs);
2578                        mddev->layout = raid10_format_to_md_layout(rs, ALGORITHM_RAID10_NEAR,
2579                                                                   rs->raid10_copies);
2580                        mddev->new_layout = mddev->layout;
2581                        reshape = false;
2582                } else
2583                        reshape = true;
2584
2585        } else if (rs_is_raid456(rs))
2586                reshape = true;
2587
2588        else if (rs_is_raid1(rs)) {
2589                if (rs->delta_disks) {
2590                        /* Process raid1 via delta_disks */
2591                        mddev->degraded = rs->delta_disks < 0 ? -rs->delta_disks : rs->delta_disks;
2592                        reshape = true;
2593                } else {
2594                        /* Process raid1 without delta_disks */
2595                        mddev->raid_disks = rs->raid_disks;
2596                        reshape = false;
2597                }
2598        } else {
2599                rs->ti->error = "Called with bogus raid type";
2600                return -EINVAL;
2601        }
2602
2603        if (reshape) {
2604                set_bit(RT_FLAG_RESHAPE_RS, &rs->runtime_flags);
2605                set_bit(RT_FLAG_UPDATE_SBS, &rs->runtime_flags);
2606        } else if (mddev->raid_disks < rs->raid_disks)
2607                /* Create new superblocks and bitmaps, if any new disks */
2608                set_bit(RT_FLAG_UPDATE_SBS, &rs->runtime_flags);
2609
2610        return 0;
2611}
2612
2613/*
2614 *
2615 * - change raid layout
2616 * - change chunk size
2617 * - add disks
2618 * - remove disks
2619 */
2620static int rs_setup_reshape(struct raid_set *rs)
2621{
2622        int r = 0;
2623        unsigned int cur_raid_devs, d;
2624        struct mddev *mddev = &rs->md;
2625        struct md_rdev *rdev;
2626
2627        mddev->delta_disks = rs->delta_disks;
2628        cur_raid_devs = mddev->raid_disks;
2629
2630        /* Ignore impossible layout change whilst adding/removing disks */
2631        if (mddev->delta_disks &&
2632            mddev->layout != mddev->new_layout) {
2633                DMINFO("Ignoring invalid layout change with delta_disks=%d", rs->delta_disks);
2634                mddev->new_layout = mddev->layout;
2635        }
2636
2637        /*
2638         * Adjust array size:
2639         *
2640         * - in case of adding disks, array size has
2641         *   to grow after the disk adding reshape,
2642         *   which'll hapen in the event handler;
2643         *   reshape will happen forward, so space has to
2644         *   be available at the beginning of each disk
2645         *
2646         * - in case of removing disks, array size
2647         *   has to shrink before starting the reshape,
2648         *   which'll happen here;
2649         *   reshape will happen backward, so space has to
2650         *   be available at the end of each disk
2651         *
2652         * - data_offset and new_data_offset are
2653         *   adjusted for aforementioned out of place
2654         *   reshaping based on userspace passing in
2655         *   the "data_offset <sectors>" key/value
2656         *   pair via the constructor
2657         */
2658
2659        /* Add disk(s) */
2660        if (rs->delta_disks > 0) {
2661                /* Prepare disks for check in raid4/5/6/10 {check|start}_reshape */
2662                for (d = cur_raid_devs; d < rs->raid_disks; d++) {
2663                        rdev = &rs->dev[d].rdev;
2664                        clear_bit(In_sync, &rdev->flags);
2665
2666                        /*
2667                         * save_raid_disk needs to be -1, or recovery_offset will be set to 0
2668                         * by md, which'll store that erroneously in the superblock on reshape
2669                         */
2670                        rdev->saved_raid_disk = -1;
2671                        rdev->raid_disk = d;
2672
2673                        rdev->sectors = mddev->dev_sectors;
2674                        rdev->recovery_offset = rs_is_raid1(rs) ? 0 : MaxSector;
2675                }
2676
2677                mddev->reshape_backwards = 0; /* adding disks -> forward reshape */
2678
2679        /* Remove disk(s) */
2680        } else if (rs->delta_disks < 0) {
2681                r = rs_set_dev_and_array_sectors(rs, true);
2682                mddev->reshape_backwards = 1; /* removing disk(s) -> backward reshape */
2683
2684        /* Change layout and/or chunk size */
2685        } else {
2686                /*
2687                 * Reshape layout (e.g. raid5_ls -> raid5_n) and/or chunk size:
2688                 *
2689                 * keeping number of disks and do layout change ->
2690                 *
2691                 * toggle reshape_backward depending on data_offset:
2692                 *
2693                 * - free space upfront -> reshape forward
2694                 *
2695                 * - free space at the end -> reshape backward
2696                 *
2697                 *
2698                 * This utilizes free reshape space avoiding the need
2699                 * for userspace to move (parts of) LV segments in
2700                 * case of layout/chunksize change  (for disk
2701                 * adding/removing reshape space has to be at
2702                 * the proper address (see above with delta_disks):
2703                 *
2704                 * add disk(s)   -> begin
2705                 * remove disk(s)-> end
2706                 */
2707                mddev->reshape_backwards = rs->dev[0].rdev.data_offset ? 0 : 1;
2708        }
2709
2710        return r;
2711}
2712
2713/*
2714 * Enable/disable discard support on RAID set depending on
2715 * RAID level and discard properties of underlying RAID members.
2716 */
2717static void configure_discard_support(struct raid_set *rs)
2718{
2719        int i;
2720        bool raid456;
2721        struct dm_target *ti = rs->ti;
2722
2723        /* Assume discards not supported until after checks below. */
2724        ti->discards_supported = false;
2725
2726        /* RAID level 4,5,6 require discard_zeroes_data for data integrity! */
2727        raid456 = (rs->md.level == 4 || rs->md.level == 5 || rs->md.level == 6);
2728
2729        for (i = 0; i < rs->raid_disks; i++) {
2730                struct request_queue *q;
2731
2732                if (!rs->dev[i].rdev.bdev)
2733                        continue;
2734
2735                q = bdev_get_queue(rs->dev[i].rdev.bdev);
2736                if (!q || !blk_queue_discard(q))
2737                        return;
2738
2739                if (raid456) {
2740                        if (!q->limits.discard_zeroes_data)
2741                                return;
2742                        if (!devices_handle_discard_safely) {
2743                                DMERR("raid456 discard support disabled due to discard_zeroes_data uncertainty.");
2744                                DMERR("Set dm-raid.devices_handle_discard_safely=Y to override.");
2745                                return;
2746                        }
2747                }
2748        }
2749
2750        /* All RAID members properly support discards */
2751        ti->discards_supported = true;
2752
2753        /*
2754         * RAID1 and RAID10 personalities require bio splitting,
2755         * RAID0/4/5/6 don't and process large discard bios properly.
2756         */
2757        ti->split_discard_bios = !!(rs->md.level == 1 || rs->md.level == 10);
2758        ti->num_discard_bios = 1;
2759}
2760
2761/*
2762 * Construct a RAID0/1/10/4/5/6 mapping:
2763 * Args:
2764 *      <raid_type> <#raid_params> <raid_params>{0,}    \
2765 *      <#raid_devs> [<meta_dev1> <dev1>]{1,}
2766 *
2767 * <raid_params> varies by <raid_type>.  See 'parse_raid_params' for
2768 * details on possible <raid_params>.
2769 *
2770 * Userspace is free to initialize the metadata devices, hence the superblocks to
2771 * enforce recreation based on the passed in table parameters.
2772 *
2773 */
2774static int raid_ctr(struct dm_target *ti, unsigned int argc, char **argv)
2775{
2776        int r;
2777        bool resize;
2778        struct raid_type *rt;
2779        unsigned int num_raid_params, num_raid_devs;
2780        sector_t calculated_dev_sectors;
2781        struct raid_set *rs = NULL;
2782        const char *arg;
2783        struct rs_layout rs_layout;
2784        struct dm_arg_set as = { argc, argv }, as_nrd;
2785        struct dm_arg _args[] = {
2786                { 0, as.argc, "Cannot understand number of raid parameters" },
2787                { 1, 254, "Cannot understand number of raid devices parameters" }
2788        };
2789
2790        /* Must have <raid_type> */
2791        arg = dm_shift_arg(&as);
2792        if (!arg) {
2793                ti->error = "No arguments";
2794                return -EINVAL;
2795        }
2796
2797        rt = get_raid_type(arg);
2798        if (!rt) {
2799                ti->error = "Unrecognised raid_type";
2800                return -EINVAL;
2801        }
2802
2803        /* Must have <#raid_params> */
2804        if (dm_read_arg_group(_args, &as, &num_raid_params, &ti->error))
2805                return -EINVAL;
2806
2807        /* number of raid device tupples <meta_dev data_dev> */
2808        as_nrd = as;
2809        dm_consume_args(&as_nrd, num_raid_params);
2810        _args[1].max = (as_nrd.argc - 1) / 2;
2811        if (dm_read_arg(_args + 1, &as_nrd, &num_raid_devs, &ti->error))
2812                return -EINVAL;
2813
2814        if (!__within_range(num_raid_devs, 1, MAX_RAID_DEVICES)) {
2815                ti->error = "Invalid number of supplied raid devices";
2816                return -EINVAL;
2817        }
2818
2819        rs = raid_set_alloc(ti, rt, num_raid_devs);
2820        if (IS_ERR(rs))
2821                return PTR_ERR(rs);
2822
2823        r = parse_raid_params(rs, &as, num_raid_params);
2824        if (r)
2825                goto bad;
2826
2827        r = parse_dev_params(rs, &as);
2828        if (r)
2829                goto bad;
2830
2831        rs->md.sync_super = super_sync;
2832
2833        /*
2834         * Calculate ctr requested array and device sizes to allow
2835         * for superblock analysis needing device sizes defined.
2836         *
2837         * Any existing superblock will overwrite the array and device sizes
2838         */
2839        r = rs_set_dev_and_array_sectors(rs, false);
2840        if (r)
2841                goto bad;
2842
2843        calculated_dev_sectors = rs->dev[0].rdev.sectors;
2844
2845        /*
2846         * Backup any new raid set level, layout, ...
2847         * requested to be able to compare to superblock
2848         * members for conversion decisions.
2849         */
2850        rs_config_backup(rs, &rs_layout);
2851
2852        r = analyse_superblocks(ti, rs);
2853        if (r)
2854                goto bad;
2855
2856        resize = calculated_dev_sectors != rs->dev[0].rdev.sectors;
2857
2858        INIT_WORK(&rs->md.event_work, do_table_event);
2859        ti->private = rs;
2860        ti->num_flush_bios = 1;
2861
2862        /* Restore any requested new layout for conversion decision */
2863        rs_config_restore(rs, &rs_layout);
2864
2865        /*
2866         * Now that we have any superblock metadata available,
2867         * check for new, recovering, reshaping, to be taken over,
2868         * to be reshaped or an existing, unchanged raid set to
2869         * run in sequence.
2870         */
2871        if (test_bit(MD_ARRAY_FIRST_USE, &rs->md.flags)) {
2872                /* A new raid6 set has to be recovered to ensure proper parity and Q-Syndrome */
2873                if (rs_is_raid6(rs) &&
2874                    test_bit(__CTR_FLAG_NOSYNC, &rs->ctr_flags)) {
2875                        ti->error = "'nosync' not allowed for new raid6 set";
2876                        r = -EINVAL;
2877                        goto bad;
2878                }
2879                rs_setup_recovery(rs, 0);
2880                set_bit(RT_FLAG_UPDATE_SBS, &rs->runtime_flags);
2881                rs_set_new(rs);
2882        } else if (rs_is_recovering(rs)) {
2883                /* A recovering raid set may be resized */
2884                ; /* skip setup rs */
2885        } else if (rs_is_reshaping(rs)) {
2886                /* Have to reject size change request during reshape */
2887                if (resize) {
2888                        ti->error = "Can't resize a reshaping raid set";
2889                        r = -EPERM;
2890                        goto bad;
2891                }
2892                /* skip setup rs */
2893        } else if (rs_takeover_requested(rs)) {
2894                if (rs_is_reshaping(rs)) {
2895                        ti->error = "Can't takeover a reshaping raid set";
2896                        r = -EPERM;
2897                        goto bad;
2898                }
2899
2900                /*
2901                 * If a takeover is needed, userspace sets any additional
2902                 * devices to rebuild and we can check for a valid request here.
2903                 *
2904                 * If acceptible, set the level to the new requested
2905                 * one, prohibit requesting recovery, allow the raid
2906                 * set to run and store superblocks during resume.
2907                 */
2908                r = rs_check_takeover(rs);
2909                if (r)
2910                        goto bad;
2911
2912                r = rs_setup_takeover(rs);
2913                if (r)
2914                        goto bad;
2915
2916                set_bit(RT_FLAG_UPDATE_SBS, &rs->runtime_flags);
2917                /* Takeover ain't recovery, so disable recovery */
2918                rs_setup_recovery(rs, MaxSector);
2919                rs_set_new(rs);
2920        } else if (rs_reshape_requested(rs)) {
2921                /*
2922                  * We can only prepare for a reshape here, because the
2923                  * raid set needs to run to provide the repective reshape
2924                  * check functions via its MD personality instance.
2925                  *
2926                  * So do the reshape check after md_run() succeeded.
2927                  */
2928                r = rs_prepare_reshape(rs);
2929                if (r)
2930                        return r;
2931
2932                /* Reshaping ain't recovery, so disable recovery */
2933                rs_setup_recovery(rs, MaxSector);
2934                rs_set_cur(rs);
2935        } else {
2936                /* May not set recovery when a device rebuild is requested */
2937                if (test_bit(__CTR_FLAG_REBUILD, &rs->ctr_flags)) {
2938                        rs_setup_recovery(rs, MaxSector);
2939                        set_bit(RT_FLAG_UPDATE_SBS, &rs->runtime_flags);
2940                } else
2941                        rs_setup_recovery(rs, test_bit(__CTR_FLAG_SYNC, &rs->ctr_flags) ?
2942                                              0 : (resize ? calculated_dev_sectors : MaxSector));
2943                rs_set_cur(rs);
2944        }
2945
2946        /* If constructor requested it, change data and new_data offsets */
2947        r = rs_adjust_data_offsets(rs);
2948        if (r)
2949                goto bad;
2950
2951        /* Start raid set read-only and assumed clean to change in raid_resume() */
2952        rs->md.ro = 1;
2953        rs->md.in_sync = 1;
2954        set_bit(MD_RECOVERY_FROZEN, &rs->md.recovery);
2955
2956        /* Has to be held on running the array */
2957        mddev_lock_nointr(&rs->md);
2958        r = md_run(&rs->md);
2959        rs->md.in_sync = 0; /* Assume already marked dirty */
2960
2961        if (r) {
2962                ti->error = "Failed to run raid array";
2963                mddev_unlock(&rs->md);
2964                goto bad;
2965        }
2966
2967        rs->callbacks.congested_fn = raid_is_congested;
2968        dm_table_add_target_callbacks(ti->table, &rs->callbacks);
2969
2970        mddev_suspend(&rs->md);
2971
2972        /* Try to adjust the raid4/5/6 stripe cache size to the stripe size */
2973        if (rs_is_raid456(rs)) {
2974                r = rs_set_raid456_stripe_cache(rs);
2975                if (r)
2976                        goto bad_stripe_cache;
2977        }
2978
2979        /* Now do an early reshape check */
2980        if (test_bit(RT_FLAG_RESHAPE_RS, &rs->runtime_flags)) {
2981                r = rs_check_reshape(rs);
2982                if (r)
2983                        goto bad_check_reshape;
2984
2985                /* Restore new, ctr requested layout to perform check */
2986                rs_config_restore(rs, &rs_layout);
2987
2988                if (rs->md.pers->start_reshape) {
2989                        r = rs->md.pers->check_reshape(&rs->md);
2990                        if (r) {
2991                                ti->error = "Reshape check failed";
2992                                goto bad_check_reshape;
2993                        }
2994                }
2995        }
2996
2997        /* Disable/enable discard support on raid set. */
2998        configure_discard_support(rs);
2999
3000        mddev_unlock(&rs->md);
3001        return 0;
3002
3003bad_stripe_cache:
3004bad_check_reshape:
3005        md_stop(&rs->md);
3006bad:
3007        raid_set_free(rs);
3008
3009        return r;
3010}
3011
3012static void raid_dtr(struct dm_target *ti)
3013{
3014        struct raid_set *rs = ti->private;
3015
3016        list_del_init(&rs->callbacks.list);
3017        md_stop(&rs->md);
3018        raid_set_free(rs);
3019}
3020
3021static int raid_map(struct dm_target *ti, struct bio *bio)
3022{
3023        struct raid_set *rs = ti->private;
3024        struct mddev *mddev = &rs->md;
3025
3026        /*
3027         * If we're reshaping to add disk(s)), ti->len and
3028         * mddev->array_sectors will differ during the process
3029         * (ti->len > mddev->array_sectors), so we have to requeue
3030         * bios with addresses > mddev->array_sectors here or
3031         * there will occur accesses past EOD of the component
3032         * data images thus erroring the raid set.
3033         */
3034        if (unlikely(bio_end_sector(bio) > mddev->array_sectors))
3035                return DM_MAPIO_REQUEUE;
3036
3037        mddev->pers->make_request(mddev, bio);
3038
3039        return DM_MAPIO_SUBMITTED;
3040}
3041
3042/* Return string describing the current sync action of @mddev */
3043static const char *decipher_sync_action(struct mddev *mddev)
3044{
3045        if (test_bit(MD_RECOVERY_FROZEN, &mddev->recovery))
3046                return "frozen";
3047
3048        if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
3049            (!mddev->ro && test_bit(MD_RECOVERY_NEEDED, &mddev->recovery))) {
3050                if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
3051                        return "reshape";
3052
3053                if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
3054                        if (!test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
3055                                return "resync";
3056                        else if (test_bit(MD_RECOVERY_CHECK, &mddev->recovery))
3057                                return "check";
3058                        return "repair";
3059                }
3060
3061                if (test_bit(MD_RECOVERY_RECOVER, &mddev->recovery))
3062                        return "recover";
3063        }
3064
3065        return "idle";
3066}
3067
3068/*
3069 * Return status string @rdev
3070 *
3071 * Status characters:
3072 *
3073 *  'D' = Dead/Failed device
3074 *  'a' = Alive but not in-sync
3075 *  'A' = Alive and in-sync
3076 */
3077static const char *__raid_dev_status(struct md_rdev *rdev, bool array_in_sync)
3078{
3079        if (test_bit(Faulty, &rdev->flags))
3080                return "D";
3081        else if (!array_in_sync || !test_bit(In_sync, &rdev->flags))
3082                return "a";
3083        else
3084                return "A";
3085}
3086
3087/* Helper to return resync/reshape progress for @rs and @array_in_sync */
3088static sector_t rs_get_progress(struct raid_set *rs,
3089                                sector_t resync_max_sectors, bool *array_in_sync)
3090{
3091        sector_t r, recovery_cp, curr_resync_completed;
3092        struct mddev *mddev = &rs->md;
3093
3094        curr_resync_completed = mddev->curr_resync_completed ?: mddev->recovery_cp;
3095        recovery_cp = mddev->recovery_cp;
3096        *array_in_sync = false;
3097
3098        if (rs_is_raid0(rs)) {
3099                r = resync_max_sectors;
3100                *array_in_sync = true;
3101
3102        } else {
3103                r = mddev->reshape_position;
3104
3105                /* Reshape is relative to the array size */
3106                if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) ||
3107                    r != MaxSector) {
3108                        if (r == MaxSector) {
3109                                *array_in_sync = true;
3110                                r = resync_max_sectors;
3111                        } else {
3112                                /* Got to reverse on backward reshape */
3113                                if (mddev->reshape_backwards)
3114                                        r = mddev->array_sectors - r;
3115
3116                                /* Devide by # of data stripes */
3117                                sector_div(r, mddev_data_stripes(rs));
3118                        }
3119
3120                /* Sync is relative to the component device size */
3121                } else if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
3122                        r = curr_resync_completed;
3123                else
3124                        r = recovery_cp;
3125
3126                if (r == MaxSector) {
3127                        /*
3128                         * Sync complete.
3129                         */
3130                        *array_in_sync = true;
3131                        r = resync_max_sectors;
3132                } else if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
3133                        /*
3134                         * If "check" or "repair" is occurring, the raid set has
3135                         * undergone an initial sync and the health characters
3136                         * should not be 'a' anymore.
3137                         */
3138                        *array_in_sync = true;
3139                } else {
3140                        struct md_rdev *rdev;
3141
3142                        /*
3143                         * The raid set may be doing an initial sync, or it may
3144                         * be rebuilding individual components.  If all the
3145                         * devices are In_sync, then it is the raid set that is
3146                         * being initialized.
3147                         */
3148                        rdev_for_each(rdev, mddev)
3149                                if (!test_bit(In_sync, &rdev->flags))
3150                                        *array_in_sync = true;
3151#if 0
3152                        r = 0; /* HM FIXME: TESTME: https://bugzilla.redhat.com/show_bug.cgi?id=1210637 ? */
3153#endif
3154                }
3155        }
3156
3157        return r;
3158}
3159
3160/* Helper to return @dev name or "-" if !@dev */
3161static const char *__get_dev_name(struct dm_dev *dev)
3162{
3163        return dev ? dev->name : "-";
3164}
3165
3166static void raid_status(struct dm_target *ti, status_type_t type,
3167                        unsigned int status_flags, char *result, unsigned int maxlen)
3168{
3169        struct raid_set *rs = ti->private;
3170        struct mddev *mddev = &rs->md;
3171        struct r5conf *conf = mddev->private;
3172        int i, max_nr_stripes = conf ? conf->max_nr_stripes : 0;
3173        bool array_in_sync;
3174        unsigned int raid_param_cnt = 1; /* at least 1 for chunksize */
3175        unsigned int sz = 0;
3176        unsigned int rebuild_disks;
3177        unsigned int write_mostly_params = 0;
3178        sector_t progress, resync_max_sectors, resync_mismatches;
3179        const char *sync_action;
3180        struct raid_type *rt;
3181        struct md_rdev *rdev;
3182
3183        switch (type) {
3184        case STATUSTYPE_INFO:
3185                /* *Should* always succeed */
3186                rt = get_raid_type_by_ll(mddev->new_level, mddev->new_layout);
3187                if (!rt)
3188                        return;
3189
3190                DMEMIT("%s %d ", rt->name, mddev->raid_disks);
3191
3192                /* Access most recent mddev properties for status output */
3193                smp_rmb();
3194                /* Get sensible max sectors even if raid set not yet started */
3195                resync_max_sectors = test_bit(RT_FLAG_RS_PRERESUMED, &rs->runtime_flags) ?
3196                                      mddev->resync_max_sectors : mddev->dev_sectors;
3197                progress = rs_get_progress(rs, resync_max_sectors, &array_in_sync);
3198                resync_mismatches = (mddev->last_sync_action && !strcasecmp(mddev->last_sync_action, "check")) ?
3199                                    atomic64_read(&mddev->resync_mismatches) : 0;
3200                sync_action = decipher_sync_action(&rs->md);
3201
3202                /* HM FIXME: do we want another state char for raid0? It shows 'D' or 'A' now */
3203                rdev_for_each(rdev, mddev)
3204                        DMEMIT(__raid_dev_status(rdev, array_in_sync));
3205
3206                /*
3207                 * In-sync/Reshape ratio:
3208                 *  The in-sync ratio shows the progress of:
3209                 *   - Initializing the raid set
3210                 *   - Rebuilding a subset of devices of the raid set
3211                 *  The user can distinguish between the two by referring
3212                 *  to the status characters.
3213                 *
3214                 *  The reshape ratio shows the progress of
3215                 *  changing the raid layout or the number of
3216                 *  disks of a raid set
3217                 */
3218                DMEMIT(" %llu/%llu", (unsigned long long) progress,
3219                                     (unsigned long long) resync_max_sectors);
3220
3221                /*
3222                 * v1.5.0+:
3223                 *
3224                 * Sync action:
3225                 *   See Documentation/device-mapper/dm-raid.txt for
3226                 *   information on each of these states.
3227                 */
3228                DMEMIT(" %s", sync_action);
3229
3230                /*
3231                 * v1.5.0+:
3232                 *
3233                 * resync_mismatches/mismatch_cnt
3234                 *   This field shows the number of discrepancies found when
3235                 *   performing a "check" of the raid set.
3236                 */
3237                DMEMIT(" %llu", (unsigned long long) resync_mismatches);
3238
3239                /*
3240                 * v1.9.0+:
3241                 *
3242                 * data_offset (needed for out of space reshaping)
3243                 *   This field shows the data offset into the data
3244                 *   image LV where the first stripes data starts.
3245                 *
3246                 * We keep data_offset equal on all raid disks of the set,
3247                 * so retrieving it from the first raid disk is sufficient.
3248                 */
3249                DMEMIT(" %llu", (unsigned long long) rs->dev[0].rdev.data_offset);
3250                break;
3251
3252        case STATUSTYPE_TABLE:
3253                /* Report the table line string you would use to construct this raid set */
3254
3255                /* Calculate raid parameter count */
3256                for (i = 0; i < rs->raid_disks; i++)
3257                        if (test_bit(WriteMostly, &rs->dev[i].rdev.flags))
3258                                write_mostly_params += 2;
3259                rebuild_disks = memweight(rs->rebuild_disks, DISKS_ARRAY_ELEMS * sizeof(*rs->rebuild_disks));
3260                raid_param_cnt += rebuild_disks * 2 +
3261                                  write_mostly_params +
3262                                  hweight32(rs->ctr_flags & CTR_FLAG_OPTIONS_NO_ARGS) +
3263                                  hweight32(rs->ctr_flags & CTR_FLAG_OPTIONS_ONE_ARG) * 2;
3264                /* Emit table line */
3265                DMEMIT("%s %u %u", rs->raid_type->name, raid_param_cnt, mddev->new_chunk_sectors);
3266                if (test_bit(__CTR_FLAG_RAID10_FORMAT, &rs->ctr_flags))
3267                        DMEMIT(" %s %s", dm_raid_arg_name_by_flag(CTR_FLAG_RAID10_FORMAT),
3268                                         raid10_md_layout_to_format(mddev->layout));
3269                if (test_bit(__CTR_FLAG_RAID10_COPIES, &rs->ctr_flags))
3270                        DMEMIT(" %s %d", dm_raid_arg_name_by_flag(CTR_FLAG_RAID10_COPIES),
3271                                         raid10_md_layout_to_copies(mddev->layout));
3272                if (test_bit(__CTR_FLAG_NOSYNC, &rs->ctr_flags))
3273                        DMEMIT(" %s", dm_raid_arg_name_by_flag(CTR_FLAG_NOSYNC));
3274                if (test_bit(__CTR_FLAG_SYNC, &rs->ctr_flags))
3275                        DMEMIT(" %s", dm_raid_arg_name_by_flag(CTR_FLAG_SYNC));
3276                if (test_bit(__CTR_FLAG_REGION_SIZE, &rs->ctr_flags))
3277                        DMEMIT(" %s %llu", dm_raid_arg_name_by_flag(CTR_FLAG_REGION_SIZE),
3278                                           (unsigned long long) to_sector(mddev->bitmap_info.chunksize));
3279                if (test_bit(__CTR_FLAG_DATA_OFFSET, &rs->ctr_flags))
3280                        DMEMIT(" %s %llu", dm_raid_arg_name_by_flag(CTR_FLAG_DATA_OFFSET),
3281                                           (unsigned long long) rs->data_offset);
3282                if (test_bit(__CTR_FLAG_DAEMON_SLEEP, &rs->ctr_flags))
3283                        DMEMIT(" %s %lu", dm_raid_arg_name_by_flag(CTR_FLAG_DAEMON_SLEEP),
3284                                          mddev->bitmap_info.daemon_sleep);
3285                if (test_bit(__CTR_FLAG_DELTA_DISKS, &rs->ctr_flags))
3286                        DMEMIT(" %s %d", dm_raid_arg_name_by_flag(CTR_FLAG_DELTA_DISKS),
3287                                         max(rs->delta_disks, mddev->delta_disks));
3288                if (test_bit(__CTR_FLAG_STRIPE_CACHE, &rs->ctr_flags))
3289                        DMEMIT(" %s %d", dm_raid_arg_name_by_flag(CTR_FLAG_STRIPE_CACHE),
3290                                         max_nr_stripes);
3291                if (rebuild_disks)
3292                        for (i = 0; i < rs->raid_disks; i++)
3293                                if (test_bit(rs->dev[i].rdev.raid_disk, (void *) rs->rebuild_disks))
3294                                        DMEMIT(" %s %u", dm_raid_arg_name_by_flag(CTR_FLAG_REBUILD),
3295                                                         rs->dev[i].rdev.raid_disk);
3296                if (write_mostly_params)
3297                        for (i = 0; i < rs->raid_disks; i++)
3298                                if (test_bit(WriteMostly, &rs->dev[i].rdev.flags))
3299                                        DMEMIT(" %s %d", dm_raid_arg_name_by_flag(CTR_FLAG_WRITE_MOSTLY),
3300                                               rs->dev[i].rdev.raid_disk);
3301                if (test_bit(__CTR_FLAG_MAX_WRITE_BEHIND, &rs->ctr_flags))
3302                        DMEMIT(" %s %lu", dm_raid_arg_name_by_flag(CTR_FLAG_MAX_WRITE_BEHIND),
3303                                          mddev->bitmap_info.max_write_behind);
3304                if (test_bit(__CTR_FLAG_MAX_RECOVERY_RATE, &rs->ctr_flags))
3305                        DMEMIT(" %s %d", dm_raid_arg_name_by_flag(CTR_FLAG_MAX_RECOVERY_RATE),
3306                                         mddev->sync_speed_max);
3307                if (test_bit(__CTR_FLAG_MIN_RECOVERY_RATE, &rs->ctr_flags))
3308                        DMEMIT(" %s %d", dm_raid_arg_name_by_flag(CTR_FLAG_MIN_RECOVERY_RATE),
3309                                         mddev->sync_speed_min);
3310                DMEMIT(" %d", rs->raid_disks);
3311                for (i = 0; i < rs->raid_disks; i++)
3312                        DMEMIT(" %s %s", __get_dev_name(rs->dev[i].meta_dev),
3313                                         __get_dev_name(rs->dev[i].data_dev));
3314        }
3315}
3316
3317static int raid_message(struct dm_target *ti, unsigned int argc, char **argv)
3318{
3319        struct raid_set *rs = ti->private;
3320        struct mddev *mddev = &rs->md;
3321
3322        if (!mddev->pers || !mddev->pers->sync_request)
3323                return -EINVAL;
3324
3325        if (!strcasecmp(argv[0], "frozen"))
3326                set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
3327        else
3328                clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
3329
3330        if (!strcasecmp(argv[0], "idle") || !strcasecmp(argv[0], "frozen")) {
3331                if (mddev->sync_thread) {
3332                        set_bit(MD_RECOVERY_INTR, &mddev->recovery);
3333                        md_reap_sync_thread(mddev);
3334                }
3335        } else if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
3336                   test_bit(MD_RECOVERY_NEEDED, &mddev->recovery))
3337                return -EBUSY;
3338        else if (!strcasecmp(argv[0], "resync"))
3339                ; /* MD_RECOVERY_NEEDED set below */
3340        else if (!strcasecmp(argv[0], "recover"))
3341                set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
3342        else {
3343                if (!strcasecmp(argv[0], "check"))
3344                        set_bit(MD_RECOVERY_CHECK, &mddev->recovery);
3345                else if (!!strcasecmp(argv[0], "repair"))
3346                        return -EINVAL;
3347                set_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
3348                set_bit(MD_RECOVERY_SYNC, &mddev->recovery);
3349        }
3350        if (mddev->ro == 2) {
3351                /* A write to sync_action is enough to justify
3352                 * canceling read-auto mode
3353                 */
3354                mddev->ro = 0;
3355                if (!mddev->suspended && mddev->sync_thread)
3356                        md_wakeup_thread(mddev->sync_thread);
3357        }
3358        set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
3359        if (!mddev->suspended && mddev->thread)
3360                md_wakeup_thread(mddev->thread);
3361
3362        return 0;
3363}
3364
3365static int raid_iterate_devices(struct dm_target *ti,
3366                                iterate_devices_callout_fn fn, void *data)
3367{
3368        struct raid_set *rs = ti->private;
3369        unsigned int i;
3370        int r = 0;
3371
3372        for (i = 0; !r && i < rs->md.raid_disks; i++)
3373                if (rs->dev[i].data_dev)
3374                        r = fn(ti,
3375                                 rs->dev[i].data_dev,
3376                                 0, /* No offset on data devs */
3377                                 rs->md.dev_sectors,
3378                                 data);
3379
3380        return r;
3381}
3382
3383static void raid_io_hints(struct dm_target *ti, struct queue_limits *limits)
3384{
3385        struct raid_set *rs = ti->private;
3386        unsigned int chunk_size = to_bytes(rs->md.chunk_sectors);
3387
3388        blk_limits_io_min(limits, chunk_size);
3389        blk_limits_io_opt(limits, chunk_size * mddev_data_stripes(rs));
3390}
3391
3392static void raid_presuspend(struct dm_target *ti)
3393{
3394        struct raid_set *rs = ti->private;
3395
3396        md_stop_writes(&rs->md);
3397}
3398
3399static void raid_postsuspend(struct dm_target *ti)
3400{
3401        struct raid_set *rs = ti->private;
3402
3403        if (!rs->md.suspended)
3404                mddev_suspend(&rs->md);
3405
3406        rs->md.ro = 1;
3407}
3408
3409static void attempt_restore_of_faulty_devices(struct raid_set *rs)
3410{
3411        int i;
3412        uint64_t cleared_failed_devices[DISKS_ARRAY_ELEMS];
3413        unsigned long flags;
3414        bool cleared = false;
3415        struct dm_raid_superblock *sb;
3416        struct mddev *mddev = &rs->md;
3417        struct md_rdev *r;
3418
3419        /* RAID personalities have to provide hot add/remove methods or we need to bail out. */
3420        if (!mddev->pers || !mddev->pers->hot_add_disk || !mddev->pers->hot_remove_disk)
3421                return;
3422
3423        memset(cleared_failed_devices, 0, sizeof(cleared_failed_devices));
3424
3425        for (i = 0; i < rs->md.raid_disks; i++) {
3426                r = &rs->dev[i].rdev;
3427                if (test_bit(Faulty, &r->flags) && r->sb_page &&
3428                    sync_page_io(r, 0, r->sb_size, r->sb_page,
3429                                 REQ_OP_READ, 0, true)) {
3430                        DMINFO("Faulty %s device #%d has readable super block."
3431                               "  Attempting to revive it.",
3432                               rs->raid_type->name, i);
3433
3434                        /*
3435                         * Faulty bit may be set, but sometimes the array can
3436                         * be suspended before the personalities can respond
3437                         * by removing the device from the array (i.e. calling
3438                         * 'hot_remove_disk').  If they haven't yet removed
3439                         * the failed device, its 'raid_disk' number will be
3440                         * '>= 0' - meaning we must call this function
3441                         * ourselves.
3442                         */
3443                        if ((r->raid_disk >= 0) &&
3444                            (mddev->pers->hot_remove_disk(mddev, r) != 0))
3445                                /* Failed to revive this device, try next */
3446                                continue;
3447
3448                        r->raid_disk = i;
3449                        r->saved_raid_disk = i;
3450                        flags = r->flags;
3451                        clear_bit(Faulty, &r->flags);
3452                        clear_bit(WriteErrorSeen, &r->flags);
3453                        clear_bit(In_sync, &r->flags);
3454                        if (mddev->pers->hot_add_disk(mddev, r)) {
3455                                r->raid_disk = -1;
3456                                r->saved_raid_disk = -1;
3457                                r->flags = flags;
3458                        } else {
3459                                r->recovery_offset = 0;
3460                                set_bit(i, (void *) cleared_failed_devices);
3461                                cleared = true;
3462                        }
3463                }
3464        }
3465
3466        /* If any failed devices could be cleared, update all sbs failed_devices bits */
3467        if (cleared) {
3468                uint64_t failed_devices[DISKS_ARRAY_ELEMS];
3469
3470                rdev_for_each(r, &rs->md) {
3471                        sb = page_address(r->sb_page);
3472                        sb_retrieve_failed_devices(sb, failed_devices);
3473
3474                        for (i = 0; i < DISKS_ARRAY_ELEMS; i++)
3475                                failed_devices[i] &= ~cleared_failed_devices[i];
3476
3477                        sb_update_failed_devices(sb, failed_devices);
3478                }
3479        }
3480}
3481
3482static int __load_dirty_region_bitmap(struct raid_set *rs)
3483{
3484        int r = 0;
3485
3486        /* Try loading the bitmap unless "raid0", which does not have one */
3487        if (!rs_is_raid0(rs) &&
3488            !test_and_set_bit(RT_FLAG_RS_BITMAP_LOADED, &rs->runtime_flags)) {
3489                r = bitmap_load(&rs->md);
3490                if (r)
3491                        DMERR("Failed to load bitmap");
3492        }
3493
3494        return r;
3495}
3496
3497/* Enforce updating all superblocks */
3498static void rs_update_sbs(struct raid_set *rs)
3499{
3500        struct mddev *mddev = &rs->md;
3501        int ro = mddev->ro;
3502
3503        set_bit(MD_CHANGE_DEVS, &mddev->flags);
3504        mddev->ro = 0;
3505        md_update_sb(mddev, 1);
3506        mddev->ro = ro;
3507}
3508
3509/*
3510 * Reshape changes raid algorithm of @rs to new one within personality
3511 * (e.g. raid6_zr -> raid6_nc), changes stripe size, adds/removes
3512 * disks from a raid set thus growing/shrinking it or resizes the set
3513 *
3514 * Call mddev_lock_nointr() before!
3515 */
3516static int rs_start_reshape(struct raid_set *rs)
3517{
3518        int r;
3519        struct mddev *mddev = &rs->md;
3520        struct md_personality *pers = mddev->pers;
3521
3522        r = rs_setup_reshape(rs);
3523        if (r)
3524                return r;
3525
3526        /* Need to be resumed to be able to start reshape, recovery is frozen until raid_resume() though */
3527        if (mddev->suspended)
3528                mddev_resume(mddev);
3529
3530        /*
3531         * Check any reshape constraints enforced by the personalility
3532         *
3533         * May as well already kick the reshape off so that * pers->start_reshape() becomes optional.
3534         */
3535        r = pers->check_reshape(mddev);
3536        if (r) {
3537                rs->ti->error = "pers->check_reshape() failed";
3538                return r;
3539        }
3540
3541        /*
3542         * Personality may not provide start reshape method in which
3543         * case check_reshape above has already covered everything
3544         */
3545        if (pers->start_reshape) {
3546                r = pers->start_reshape(mddev);
3547                if (r) {
3548                        rs->ti->error = "pers->start_reshape() failed";
3549                        return r;
3550                }
3551        }
3552
3553        /* Suspend because a resume will happen in raid_resume() */
3554        if (!mddev->suspended)
3555                mddev_suspend(mddev);
3556
3557        /*
3558         * Now reshape got set up, update superblocks to
3559         * reflect the fact so that a table reload will
3560         * access proper superblock content in the ctr.
3561         */
3562        rs_update_sbs(rs);
3563
3564        return 0;
3565}
3566
3567static int raid_preresume(struct dm_target *ti)
3568{
3569        int r;
3570        struct raid_set *rs = ti->private;
3571        struct mddev *mddev = &rs->md;
3572
3573        /* This is a resume after a suspend of the set -> it's already started */
3574        if (test_and_set_bit(RT_FLAG_RS_PRERESUMED, &rs->runtime_flags))
3575                return 0;
3576
3577        /*
3578         * The superblocks need to be updated on disk if the
3579         * array is new or new devices got added (thus zeroed
3580         * out by userspace) or __load_dirty_region_bitmap
3581         * will overwrite them in core with old data or fail.
3582         */
3583        if (test_bit(RT_FLAG_UPDATE_SBS, &rs->runtime_flags))
3584                rs_update_sbs(rs);
3585
3586        /* Load the bitmap from disk unless raid0 */
3587        r = __load_dirty_region_bitmap(rs);
3588        if (r)
3589                return r;
3590
3591        /* Resize bitmap to adjust to changed region size (aka MD bitmap chunksize) */
3592        if (test_bit(RT_FLAG_RS_BITMAP_LOADED, &rs->runtime_flags) && mddev->bitmap &&
3593            mddev->bitmap_info.chunksize != to_bytes(rs->requested_bitmap_chunk_sectors)) {
3594                r = bitmap_resize(mddev->bitmap, mddev->dev_sectors,
3595                                  to_bytes(rs->requested_bitmap_chunk_sectors), 0);
3596                if (r)
3597                        DMERR("Failed to resize bitmap");
3598        }
3599
3600        /* Check for any resize/reshape on @rs and adjust/initiate */
3601        /* Be prepared for mddev_resume() in raid_resume() */
3602        set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
3603        if (mddev->recovery_cp && mddev->recovery_cp < MaxSector) {
3604                set_bit(MD_RECOVERY_SYNC, &mddev->recovery);
3605                mddev->resync_min = mddev->recovery_cp;
3606        }
3607
3608        rs_set_capacity(rs);
3609
3610        /* Check for any reshape request unless new raid set */
3611        if (test_and_clear_bit(RT_FLAG_RESHAPE_RS, &rs->runtime_flags)) {
3612                /* Initiate a reshape. */
3613                mddev_lock_nointr(mddev);
3614                r = rs_start_reshape(rs);
3615                mddev_unlock(mddev);
3616                if (r)
3617                        DMWARN("Failed to check/start reshape, continuing without change");
3618                r = 0;
3619        }
3620
3621        return r;
3622}
3623
3624#define RESUME_STAY_FROZEN_FLAGS (CTR_FLAG_DELTA_DISKS | CTR_FLAG_DATA_OFFSET)
3625
3626static void raid_resume(struct dm_target *ti)
3627{
3628        struct raid_set *rs = ti->private;
3629        struct mddev *mddev = &rs->md;
3630
3631        if (test_and_set_bit(RT_FLAG_RS_RESUMED, &rs->runtime_flags)) {
3632                /*
3633                 * A secondary resume while the device is active.
3634                 * Take this opportunity to check whether any failed
3635                 * devices are reachable again.
3636                 */
3637                attempt_restore_of_faulty_devices(rs);
3638        }
3639
3640        mddev->ro = 0;
3641        mddev->in_sync = 0;
3642
3643        /*
3644         * Keep the RAID set frozen if reshape/rebuild flags are set.
3645         * The RAID set is unfrozen once the next table load/resume,
3646         * which clears the reshape/rebuild flags, occurs.
3647         * This ensures that the constructor for the inactive table
3648         * retrieves an up-to-date reshape_position.
3649         */
3650        if (!(rs->ctr_flags & RESUME_STAY_FROZEN_FLAGS))
3651                clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
3652
3653        if (mddev->suspended)
3654                mddev_resume(mddev);
3655}
3656
3657static struct target_type raid_target = {
3658        .name = "raid",
3659        .version = {1, 9, 1},
3660        .module = THIS_MODULE,
3661        .ctr = raid_ctr,
3662        .dtr = raid_dtr,
3663        .map = raid_map,
3664        .status = raid_status,
3665        .message = raid_message,
3666        .iterate_devices = raid_iterate_devices,
3667        .io_hints = raid_io_hints,
3668        .presuspend = raid_presuspend,
3669        .postsuspend = raid_postsuspend,
3670        .preresume = raid_preresume,
3671        .resume = raid_resume,
3672};
3673
3674static int __init dm_raid_init(void)
3675{
3676        DMINFO("Loading target version %u.%u.%u",
3677               raid_target.version[0],
3678               raid_target.version[1],
3679               raid_target.version[2]);
3680        return dm_register_target(&raid_target);
3681}
3682
3683static void __exit dm_raid_exit(void)
3684{
3685        dm_unregister_target(&raid_target);
3686}
3687
3688module_init(dm_raid_init);
3689module_exit(dm_raid_exit);
3690
3691module_param(devices_handle_discard_safely, bool, 0644);
3692MODULE_PARM_DESC(devices_handle_discard_safely,
3693                 "Set to Y if all devices in each array reliably return zeroes on reads from discarded regions");
3694
3695MODULE_DESCRIPTION(DM_NAME " raid0/1/10/4/5/6 target");
3696MODULE_ALIAS("dm-raid0");
3697MODULE_ALIAS("dm-raid1");
3698MODULE_ALIAS("dm-raid10");
3699MODULE_ALIAS("dm-raid4");
3700MODULE_ALIAS("dm-raid5");
3701MODULE_ALIAS("dm-raid6");
3702MODULE_AUTHOR("Neil Brown <dm-devel@redhat.com>");
3703MODULE_AUTHOR("Heinz Mauelshagen <dm-devel@redhat.com>");
3704MODULE_LICENSE("GPL");
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