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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2001-2003 Sistina Software (UK) Limited.
4 *
5 * This file is released under the GPL.
6 */
7
8#include "dm.h"
9#include <linux/device-mapper.h>
10
11#include <linux/module.h>
12#include <linux/init.h>
13#include <linux/blkdev.h>
14#include <linux/bio.h>
15#include <linux/dax.h>
16#include <linux/slab.h>
17#include <linux/log2.h>
18
19static struct workqueue_struct *dm_stripe_wq;
20
21#define DM_MSG_PREFIX "striped"
22#define DM_IO_ERROR_THRESHOLD 15
23
24struct stripe {
25 struct dm_dev *dev;
26 sector_t physical_start;
27
28 atomic_t error_count;
29};
30
31struct stripe_c {
32 uint32_t stripes;
33 int stripes_shift;
34
35 /* The size of this target / num. stripes */
36 sector_t stripe_width;
37
38 uint32_t chunk_size;
39 int chunk_size_shift;
40
41 /* Needed for handling events */
42 struct dm_target *ti;
43
44 /* Work struct used for triggering events*/
45 struct work_struct trigger_event;
46
47 struct stripe stripe[] __counted_by(stripes);
48};
49
50/*
51 * An event is triggered whenever a drive
52 * drops out of a stripe volume.
53 */
54static void trigger_event(struct work_struct *work)
55{
56 struct stripe_c *sc = container_of(work, struct stripe_c,
57 trigger_event);
58 dm_table_event(sc->ti->table);
59}
60
61/*
62 * Parse a single <dev> <sector> pair
63 */
64static int get_stripe(struct dm_target *ti, struct stripe_c *sc,
65 unsigned int stripe, char **argv)
66{
67 unsigned long long start;
68 char dummy;
69 int ret;
70
71 if (sscanf(argv[1], "%llu%c", &start, &dummy) != 1)
72 return -EINVAL;
73
74 ret = dm_get_device(ti, argv[0], dm_table_get_mode(ti->table),
75 &sc->stripe[stripe].dev);
76 if (ret)
77 return ret;
78
79 sc->stripe[stripe].physical_start = start;
80
81 return 0;
82}
83
84/*
85 * Construct a striped mapping.
86 * <number of stripes> <chunk size> [<dev_path> <offset>]+
87 */
88static int stripe_ctr(struct dm_target *ti, unsigned int argc, char **argv)
89{
90 struct stripe_c *sc;
91 sector_t width, tmp_len;
92 uint32_t stripes;
93 uint32_t chunk_size;
94 int r;
95 unsigned int i;
96
97 if (argc < 2) {
98 ti->error = "Not enough arguments";
99 return -EINVAL;
100 }
101
102 if (kstrtouint(argv[0], 10, &stripes) || !stripes) {
103 ti->error = "Invalid stripe count";
104 return -EINVAL;
105 }
106
107 if (kstrtouint(argv[1], 10, &chunk_size) || !chunk_size) {
108 ti->error = "Invalid chunk_size";
109 return -EINVAL;
110 }
111
112 width = ti->len;
113 if (sector_div(width, stripes)) {
114 ti->error = "Target length not divisible by number of stripes";
115 return -EINVAL;
116 }
117
118 tmp_len = width;
119 if (sector_div(tmp_len, chunk_size)) {
120 ti->error = "Target length not divisible by chunk size";
121 return -EINVAL;
122 }
123
124 /*
125 * Do we have enough arguments for that many stripes ?
126 */
127 if (argc != (2 + 2 * stripes)) {
128 ti->error = "Not enough destinations specified";
129 return -EINVAL;
130 }
131
132 sc = kmalloc(struct_size(sc, stripe, stripes), GFP_KERNEL);
133 if (!sc) {
134 ti->error = "Memory allocation for striped context failed";
135 return -ENOMEM;
136 }
137
138 INIT_WORK(&sc->trigger_event, trigger_event);
139
140 /* Set pointer to dm target; used in trigger_event */
141 sc->ti = ti;
142 sc->stripes = stripes;
143 sc->stripe_width = width;
144
145 if (stripes & (stripes - 1))
146 sc->stripes_shift = -1;
147 else
148 sc->stripes_shift = __ffs(stripes);
149
150 r = dm_set_target_max_io_len(ti, chunk_size);
151 if (r) {
152 kfree(sc);
153 return r;
154 }
155
156 ti->num_flush_bios = stripes;
157 ti->num_discard_bios = stripes;
158 ti->num_secure_erase_bios = stripes;
159 ti->num_write_zeroes_bios = stripes;
160
161 sc->chunk_size = chunk_size;
162 if (chunk_size & (chunk_size - 1))
163 sc->chunk_size_shift = -1;
164 else
165 sc->chunk_size_shift = __ffs(chunk_size);
166
167 /*
168 * Get the stripe destinations.
169 */
170 for (i = 0; i < stripes; i++) {
171 argv += 2;
172
173 r = get_stripe(ti, sc, i, argv);
174 if (r < 0) {
175 ti->error = "Couldn't parse stripe destination";
176 while (i--)
177 dm_put_device(ti, sc->stripe[i].dev);
178 kfree(sc);
179 return r;
180 }
181 atomic_set(&(sc->stripe[i].error_count), 0);
182 }
183
184 ti->private = sc;
185
186 return 0;
187}
188
189static void stripe_dtr(struct dm_target *ti)
190{
191 unsigned int i;
192 struct stripe_c *sc = ti->private;
193
194 for (i = 0; i < sc->stripes; i++)
195 dm_put_device(ti, sc->stripe[i].dev);
196
197 flush_work(&sc->trigger_event);
198 kfree(sc);
199}
200
201static void stripe_map_sector(struct stripe_c *sc, sector_t sector,
202 uint32_t *stripe, sector_t *result)
203{
204 sector_t chunk = dm_target_offset(sc->ti, sector);
205 sector_t chunk_offset;
206
207 if (sc->chunk_size_shift < 0)
208 chunk_offset = sector_div(chunk, sc->chunk_size);
209 else {
210 chunk_offset = chunk & (sc->chunk_size - 1);
211 chunk >>= sc->chunk_size_shift;
212 }
213
214 if (sc->stripes_shift < 0)
215 *stripe = sector_div(chunk, sc->stripes);
216 else {
217 *stripe = chunk & (sc->stripes - 1);
218 chunk >>= sc->stripes_shift;
219 }
220
221 if (sc->chunk_size_shift < 0)
222 chunk *= sc->chunk_size;
223 else
224 chunk <<= sc->chunk_size_shift;
225
226 *result = chunk + chunk_offset;
227}
228
229static void stripe_map_range_sector(struct stripe_c *sc, sector_t sector,
230 uint32_t target_stripe, sector_t *result)
231{
232 uint32_t stripe;
233
234 stripe_map_sector(sc, sector, &stripe, result);
235 if (stripe == target_stripe)
236 return;
237
238 /* round down */
239 sector = *result;
240 if (sc->chunk_size_shift < 0)
241 *result -= sector_div(sector, sc->chunk_size);
242 else
243 *result = sector & ~(sector_t)(sc->chunk_size - 1);
244
245 if (target_stripe < stripe)
246 *result += sc->chunk_size; /* next chunk */
247}
248
249static int stripe_map_range(struct stripe_c *sc, struct bio *bio,
250 uint32_t target_stripe)
251{
252 sector_t begin, end;
253
254 stripe_map_range_sector(sc, bio->bi_iter.bi_sector,
255 target_stripe, &begin);
256 stripe_map_range_sector(sc, bio_end_sector(bio),
257 target_stripe, &end);
258 if (begin < end) {
259 bio_set_dev(bio, sc->stripe[target_stripe].dev->bdev);
260 bio->bi_iter.bi_sector = begin +
261 sc->stripe[target_stripe].physical_start;
262 bio->bi_iter.bi_size = to_bytes(end - begin);
263 return DM_MAPIO_REMAPPED;
264 }
265
266 /* The range doesn't map to the target stripe */
267 bio_endio(bio);
268 return DM_MAPIO_SUBMITTED;
269}
270
271int stripe_map(struct dm_target *ti, struct bio *bio)
272{
273 struct stripe_c *sc = ti->private;
274 uint32_t stripe;
275 unsigned int target_bio_nr;
276
277 if (bio->bi_opf & REQ_PREFLUSH) {
278 target_bio_nr = dm_bio_get_target_bio_nr(bio);
279 BUG_ON(target_bio_nr >= sc->stripes);
280 bio_set_dev(bio, sc->stripe[target_bio_nr].dev->bdev);
281 return DM_MAPIO_REMAPPED;
282 }
283 if (unlikely(bio_op(bio) == REQ_OP_DISCARD) ||
284 unlikely(bio_op(bio) == REQ_OP_SECURE_ERASE) ||
285 unlikely(bio_op(bio) == REQ_OP_WRITE_ZEROES)) {
286 target_bio_nr = dm_bio_get_target_bio_nr(bio);
287 BUG_ON(target_bio_nr >= sc->stripes);
288 return stripe_map_range(sc, bio, target_bio_nr);
289 }
290
291 stripe_map_sector(sc, bio->bi_iter.bi_sector,
292 &stripe, &bio->bi_iter.bi_sector);
293
294 bio->bi_iter.bi_sector += sc->stripe[stripe].physical_start;
295 bio_set_dev(bio, sc->stripe[stripe].dev->bdev);
296
297 return DM_MAPIO_REMAPPED;
298}
299
300#if IS_ENABLED(CONFIG_FS_DAX)
301static struct dax_device *stripe_dax_pgoff(struct dm_target *ti, pgoff_t *pgoff)
302{
303 struct stripe_c *sc = ti->private;
304 struct block_device *bdev;
305 sector_t dev_sector;
306 uint32_t stripe;
307
308 stripe_map_sector(sc, *pgoff * PAGE_SECTORS, &stripe, &dev_sector);
309 dev_sector += sc->stripe[stripe].physical_start;
310 bdev = sc->stripe[stripe].dev->bdev;
311
312 *pgoff = (get_start_sect(bdev) + dev_sector) >> PAGE_SECTORS_SHIFT;
313 return sc->stripe[stripe].dev->dax_dev;
314}
315
316static long stripe_dax_direct_access(struct dm_target *ti, pgoff_t pgoff,
317 long nr_pages, enum dax_access_mode mode, void **kaddr,
318 pfn_t *pfn)
319{
320 struct dax_device *dax_dev = stripe_dax_pgoff(ti, &pgoff);
321
322 return dax_direct_access(dax_dev, pgoff, nr_pages, mode, kaddr, pfn);
323}
324
325static int stripe_dax_zero_page_range(struct dm_target *ti, pgoff_t pgoff,
326 size_t nr_pages)
327{
328 struct dax_device *dax_dev = stripe_dax_pgoff(ti, &pgoff);
329
330 return dax_zero_page_range(dax_dev, pgoff, nr_pages);
331}
332
333static size_t stripe_dax_recovery_write(struct dm_target *ti, pgoff_t pgoff,
334 void *addr, size_t bytes, struct iov_iter *i)
335{
336 struct dax_device *dax_dev = stripe_dax_pgoff(ti, &pgoff);
337
338 return dax_recovery_write(dax_dev, pgoff, addr, bytes, i);
339}
340
341#else
342#define stripe_dax_direct_access NULL
343#define stripe_dax_zero_page_range NULL
344#define stripe_dax_recovery_write NULL
345#endif
346
347/*
348 * Stripe status:
349 *
350 * INFO
351 * #stripes [stripe_name <stripe_name>] [group word count]
352 * [error count 'A|D' <error count 'A|D'>]
353 *
354 * TABLE
355 * #stripes [stripe chunk size]
356 * [stripe_name physical_start <stripe_name physical_start>]
357 *
358 */
359
360static void stripe_status(struct dm_target *ti, status_type_t type,
361 unsigned int status_flags, char *result, unsigned int maxlen)
362{
363 struct stripe_c *sc = ti->private;
364 unsigned int sz = 0;
365 unsigned int i;
366
367 switch (type) {
368 case STATUSTYPE_INFO:
369 DMEMIT("%d ", sc->stripes);
370 for (i = 0; i < sc->stripes; i++)
371 DMEMIT("%s ", sc->stripe[i].dev->name);
372
373 DMEMIT("1 ");
374 for (i = 0; i < sc->stripes; i++)
375 DMEMIT("%c", atomic_read(&(sc->stripe[i].error_count)) ? 'D' : 'A');
376 break;
377
378 case STATUSTYPE_TABLE:
379 DMEMIT("%d %llu", sc->stripes,
380 (unsigned long long)sc->chunk_size);
381 for (i = 0; i < sc->stripes; i++)
382 DMEMIT(" %s %llu", sc->stripe[i].dev->name,
383 (unsigned long long)sc->stripe[i].physical_start);
384 break;
385
386 case STATUSTYPE_IMA:
387 DMEMIT_TARGET_NAME_VERSION(ti->type);
388 DMEMIT(",stripes=%d,chunk_size=%llu", sc->stripes,
389 (unsigned long long)sc->chunk_size);
390
391 for (i = 0; i < sc->stripes; i++) {
392 DMEMIT(",stripe_%d_device_name=%s", i, sc->stripe[i].dev->name);
393 DMEMIT(",stripe_%d_physical_start=%llu", i,
394 (unsigned long long)sc->stripe[i].physical_start);
395 DMEMIT(",stripe_%d_status=%c", i,
396 atomic_read(&(sc->stripe[i].error_count)) ? 'D' : 'A');
397 }
398 DMEMIT(";");
399 break;
400 }
401}
402
403static int stripe_end_io(struct dm_target *ti, struct bio *bio,
404 blk_status_t *error)
405{
406 unsigned int i;
407 char major_minor[16];
408 struct stripe_c *sc = ti->private;
409
410 if (!*error)
411 return DM_ENDIO_DONE; /* I/O complete */
412
413 if (bio->bi_opf & REQ_RAHEAD)
414 return DM_ENDIO_DONE;
415
416 if (*error == BLK_STS_NOTSUPP)
417 return DM_ENDIO_DONE;
418
419 memset(major_minor, 0, sizeof(major_minor));
420 sprintf(major_minor, "%d:%d", MAJOR(bio_dev(bio)), MINOR(bio_dev(bio)));
421
422 /*
423 * Test to see which stripe drive triggered the event
424 * and increment error count for all stripes on that device.
425 * If the error count for a given device exceeds the threshold
426 * value we will no longer trigger any further events.
427 */
428 for (i = 0; i < sc->stripes; i++)
429 if (!strcmp(sc->stripe[i].dev->name, major_minor)) {
430 atomic_inc(&(sc->stripe[i].error_count));
431 if (atomic_read(&(sc->stripe[i].error_count)) <
432 DM_IO_ERROR_THRESHOLD)
433 queue_work(dm_stripe_wq, &sc->trigger_event);
434 }
435
436 return DM_ENDIO_DONE;
437}
438
439static int stripe_iterate_devices(struct dm_target *ti,
440 iterate_devices_callout_fn fn, void *data)
441{
442 struct stripe_c *sc = ti->private;
443 int ret = 0;
444 unsigned int i = 0;
445
446 do {
447 ret = fn(ti, sc->stripe[i].dev,
448 sc->stripe[i].physical_start,
449 sc->stripe_width, data);
450 } while (!ret && ++i < sc->stripes);
451
452 return ret;
453}
454
455static void stripe_io_hints(struct dm_target *ti,
456 struct queue_limits *limits)
457{
458 struct stripe_c *sc = ti->private;
459 unsigned int chunk_size = sc->chunk_size << SECTOR_SHIFT;
460
461 blk_limits_io_min(limits, chunk_size);
462 blk_limits_io_opt(limits, chunk_size * sc->stripes);
463}
464
465static struct target_type stripe_target = {
466 .name = "striped",
467 .version = {1, 6, 0},
468 .features = DM_TARGET_PASSES_INTEGRITY | DM_TARGET_NOWAIT,
469 .module = THIS_MODULE,
470 .ctr = stripe_ctr,
471 .dtr = stripe_dtr,
472 .map = stripe_map,
473 .end_io = stripe_end_io,
474 .status = stripe_status,
475 .iterate_devices = stripe_iterate_devices,
476 .io_hints = stripe_io_hints,
477 .direct_access = stripe_dax_direct_access,
478 .dax_zero_page_range = stripe_dax_zero_page_range,
479 .dax_recovery_write = stripe_dax_recovery_write,
480};
481
482int __init dm_stripe_init(void)
483{
484 int r;
485
486 dm_stripe_wq = alloc_workqueue("dm_stripe_wq", 0, 0);
487 if (!dm_stripe_wq)
488 return -ENOMEM;
489 r = dm_register_target(&stripe_target);
490 if (r < 0) {
491 destroy_workqueue(dm_stripe_wq);
492 DMWARN("target registration failed");
493 }
494
495 return r;
496}
497
498void dm_stripe_exit(void)
499{
500 dm_unregister_target(&stripe_target);
501 destroy_workqueue(dm_stripe_wq);
502}
1/*
2 * Copyright (C) 2001-2003 Sistina Software (UK) Limited.
3 *
4 * This file is released under the GPL.
5 */
6
7#include "dm.h"
8#include <linux/device-mapper.h>
9
10#include <linux/module.h>
11#include <linux/init.h>
12#include <linux/blkdev.h>
13#include <linux/bio.h>
14#include <linux/dax.h>
15#include <linux/slab.h>
16#include <linux/log2.h>
17
18#define DM_MSG_PREFIX "striped"
19#define DM_IO_ERROR_THRESHOLD 15
20
21struct stripe {
22 struct dm_dev *dev;
23 sector_t physical_start;
24
25 atomic_t error_count;
26};
27
28struct stripe_c {
29 uint32_t stripes;
30 int stripes_shift;
31
32 /* The size of this target / num. stripes */
33 sector_t stripe_width;
34
35 uint32_t chunk_size;
36 int chunk_size_shift;
37
38 /* Needed for handling events */
39 struct dm_target *ti;
40
41 /* Work struct used for triggering events*/
42 struct work_struct trigger_event;
43
44 struct stripe stripe[];
45};
46
47/*
48 * An event is triggered whenever a drive
49 * drops out of a stripe volume.
50 */
51static void trigger_event(struct work_struct *work)
52{
53 struct stripe_c *sc = container_of(work, struct stripe_c,
54 trigger_event);
55 dm_table_event(sc->ti->table);
56}
57
58/*
59 * Parse a single <dev> <sector> pair
60 */
61static int get_stripe(struct dm_target *ti, struct stripe_c *sc,
62 unsigned int stripe, char **argv)
63{
64 unsigned long long start;
65 char dummy;
66 int ret;
67
68 if (sscanf(argv[1], "%llu%c", &start, &dummy) != 1)
69 return -EINVAL;
70
71 ret = dm_get_device(ti, argv[0], dm_table_get_mode(ti->table),
72 &sc->stripe[stripe].dev);
73 if (ret)
74 return ret;
75
76 sc->stripe[stripe].physical_start = start;
77
78 return 0;
79}
80
81/*
82 * Construct a striped mapping.
83 * <number of stripes> <chunk size> [<dev_path> <offset>]+
84 */
85static int stripe_ctr(struct dm_target *ti, unsigned int argc, char **argv)
86{
87 struct stripe_c *sc;
88 sector_t width, tmp_len;
89 uint32_t stripes;
90 uint32_t chunk_size;
91 int r;
92 unsigned int i;
93
94 if (argc < 2) {
95 ti->error = "Not enough arguments";
96 return -EINVAL;
97 }
98
99 if (kstrtouint(argv[0], 10, &stripes) || !stripes) {
100 ti->error = "Invalid stripe count";
101 return -EINVAL;
102 }
103
104 if (kstrtouint(argv[1], 10, &chunk_size) || !chunk_size) {
105 ti->error = "Invalid chunk_size";
106 return -EINVAL;
107 }
108
109 width = ti->len;
110 if (sector_div(width, stripes)) {
111 ti->error = "Target length not divisible by "
112 "number of stripes";
113 return -EINVAL;
114 }
115
116 tmp_len = width;
117 if (sector_div(tmp_len, chunk_size)) {
118 ti->error = "Target length not divisible by "
119 "chunk size";
120 return -EINVAL;
121 }
122
123 /*
124 * Do we have enough arguments for that many stripes ?
125 */
126 if (argc != (2 + 2 * stripes)) {
127 ti->error = "Not enough destinations "
128 "specified";
129 return -EINVAL;
130 }
131
132 sc = kmalloc(struct_size(sc, stripe, stripes), GFP_KERNEL);
133 if (!sc) {
134 ti->error = "Memory allocation for striped context "
135 "failed";
136 return -ENOMEM;
137 }
138
139 INIT_WORK(&sc->trigger_event, trigger_event);
140
141 /* Set pointer to dm target; used in trigger_event */
142 sc->ti = ti;
143 sc->stripes = stripes;
144 sc->stripe_width = width;
145
146 if (stripes & (stripes - 1))
147 sc->stripes_shift = -1;
148 else
149 sc->stripes_shift = __ffs(stripes);
150
151 r = dm_set_target_max_io_len(ti, chunk_size);
152 if (r) {
153 kfree(sc);
154 return r;
155 }
156
157 ti->num_flush_bios = stripes;
158 ti->num_discard_bios = stripes;
159 ti->num_secure_erase_bios = stripes;
160 ti->num_write_same_bios = stripes;
161 ti->num_write_zeroes_bios = stripes;
162
163 sc->chunk_size = chunk_size;
164 if (chunk_size & (chunk_size - 1))
165 sc->chunk_size_shift = -1;
166 else
167 sc->chunk_size_shift = __ffs(chunk_size);
168
169 /*
170 * Get the stripe destinations.
171 */
172 for (i = 0; i < stripes; i++) {
173 argv += 2;
174
175 r = get_stripe(ti, sc, i, argv);
176 if (r < 0) {
177 ti->error = "Couldn't parse stripe destination";
178 while (i--)
179 dm_put_device(ti, sc->stripe[i].dev);
180 kfree(sc);
181 return r;
182 }
183 atomic_set(&(sc->stripe[i].error_count), 0);
184 }
185
186 ti->private = sc;
187
188 return 0;
189}
190
191static void stripe_dtr(struct dm_target *ti)
192{
193 unsigned int i;
194 struct stripe_c *sc = (struct stripe_c *) ti->private;
195
196 for (i = 0; i < sc->stripes; i++)
197 dm_put_device(ti, sc->stripe[i].dev);
198
199 flush_work(&sc->trigger_event);
200 kfree(sc);
201}
202
203static void stripe_map_sector(struct stripe_c *sc, sector_t sector,
204 uint32_t *stripe, sector_t *result)
205{
206 sector_t chunk = dm_target_offset(sc->ti, sector);
207 sector_t chunk_offset;
208
209 if (sc->chunk_size_shift < 0)
210 chunk_offset = sector_div(chunk, sc->chunk_size);
211 else {
212 chunk_offset = chunk & (sc->chunk_size - 1);
213 chunk >>= sc->chunk_size_shift;
214 }
215
216 if (sc->stripes_shift < 0)
217 *stripe = sector_div(chunk, sc->stripes);
218 else {
219 *stripe = chunk & (sc->stripes - 1);
220 chunk >>= sc->stripes_shift;
221 }
222
223 if (sc->chunk_size_shift < 0)
224 chunk *= sc->chunk_size;
225 else
226 chunk <<= sc->chunk_size_shift;
227
228 *result = chunk + chunk_offset;
229}
230
231static void stripe_map_range_sector(struct stripe_c *sc, sector_t sector,
232 uint32_t target_stripe, sector_t *result)
233{
234 uint32_t stripe;
235
236 stripe_map_sector(sc, sector, &stripe, result);
237 if (stripe == target_stripe)
238 return;
239
240 /* round down */
241 sector = *result;
242 if (sc->chunk_size_shift < 0)
243 *result -= sector_div(sector, sc->chunk_size);
244 else
245 *result = sector & ~(sector_t)(sc->chunk_size - 1);
246
247 if (target_stripe < stripe)
248 *result += sc->chunk_size; /* next chunk */
249}
250
251static int stripe_map_range(struct stripe_c *sc, struct bio *bio,
252 uint32_t target_stripe)
253{
254 sector_t begin, end;
255
256 stripe_map_range_sector(sc, bio->bi_iter.bi_sector,
257 target_stripe, &begin);
258 stripe_map_range_sector(sc, bio_end_sector(bio),
259 target_stripe, &end);
260 if (begin < end) {
261 bio_set_dev(bio, sc->stripe[target_stripe].dev->bdev);
262 bio->bi_iter.bi_sector = begin +
263 sc->stripe[target_stripe].physical_start;
264 bio->bi_iter.bi_size = to_bytes(end - begin);
265 return DM_MAPIO_REMAPPED;
266 } else {
267 /* The range doesn't map to the target stripe */
268 bio_endio(bio);
269 return DM_MAPIO_SUBMITTED;
270 }
271}
272
273static int stripe_map(struct dm_target *ti, struct bio *bio)
274{
275 struct stripe_c *sc = ti->private;
276 uint32_t stripe;
277 unsigned target_bio_nr;
278
279 if (bio->bi_opf & REQ_PREFLUSH) {
280 target_bio_nr = dm_bio_get_target_bio_nr(bio);
281 BUG_ON(target_bio_nr >= sc->stripes);
282 bio_set_dev(bio, sc->stripe[target_bio_nr].dev->bdev);
283 return DM_MAPIO_REMAPPED;
284 }
285 if (unlikely(bio_op(bio) == REQ_OP_DISCARD) ||
286 unlikely(bio_op(bio) == REQ_OP_SECURE_ERASE) ||
287 unlikely(bio_op(bio) == REQ_OP_WRITE_ZEROES) ||
288 unlikely(bio_op(bio) == REQ_OP_WRITE_SAME)) {
289 target_bio_nr = dm_bio_get_target_bio_nr(bio);
290 BUG_ON(target_bio_nr >= sc->stripes);
291 return stripe_map_range(sc, bio, target_bio_nr);
292 }
293
294 stripe_map_sector(sc, bio->bi_iter.bi_sector,
295 &stripe, &bio->bi_iter.bi_sector);
296
297 bio->bi_iter.bi_sector += sc->stripe[stripe].physical_start;
298 bio_set_dev(bio, sc->stripe[stripe].dev->bdev);
299
300 return DM_MAPIO_REMAPPED;
301}
302
303#if IS_ENABLED(CONFIG_DAX_DRIVER)
304static long stripe_dax_direct_access(struct dm_target *ti, pgoff_t pgoff,
305 long nr_pages, void **kaddr, pfn_t *pfn)
306{
307 sector_t dev_sector, sector = pgoff * PAGE_SECTORS;
308 struct stripe_c *sc = ti->private;
309 struct dax_device *dax_dev;
310 struct block_device *bdev;
311 uint32_t stripe;
312 long ret;
313
314 stripe_map_sector(sc, sector, &stripe, &dev_sector);
315 dev_sector += sc->stripe[stripe].physical_start;
316 dax_dev = sc->stripe[stripe].dev->dax_dev;
317 bdev = sc->stripe[stripe].dev->bdev;
318
319 ret = bdev_dax_pgoff(bdev, dev_sector, nr_pages * PAGE_SIZE, &pgoff);
320 if (ret)
321 return ret;
322 return dax_direct_access(dax_dev, pgoff, nr_pages, kaddr, pfn);
323}
324
325static size_t stripe_dax_copy_from_iter(struct dm_target *ti, pgoff_t pgoff,
326 void *addr, size_t bytes, struct iov_iter *i)
327{
328 sector_t dev_sector, sector = pgoff * PAGE_SECTORS;
329 struct stripe_c *sc = ti->private;
330 struct dax_device *dax_dev;
331 struct block_device *bdev;
332 uint32_t stripe;
333
334 stripe_map_sector(sc, sector, &stripe, &dev_sector);
335 dev_sector += sc->stripe[stripe].physical_start;
336 dax_dev = sc->stripe[stripe].dev->dax_dev;
337 bdev = sc->stripe[stripe].dev->bdev;
338
339 if (bdev_dax_pgoff(bdev, dev_sector, ALIGN(bytes, PAGE_SIZE), &pgoff))
340 return 0;
341 return dax_copy_from_iter(dax_dev, pgoff, addr, bytes, i);
342}
343
344static size_t stripe_dax_copy_to_iter(struct dm_target *ti, pgoff_t pgoff,
345 void *addr, size_t bytes, struct iov_iter *i)
346{
347 sector_t dev_sector, sector = pgoff * PAGE_SECTORS;
348 struct stripe_c *sc = ti->private;
349 struct dax_device *dax_dev;
350 struct block_device *bdev;
351 uint32_t stripe;
352
353 stripe_map_sector(sc, sector, &stripe, &dev_sector);
354 dev_sector += sc->stripe[stripe].physical_start;
355 dax_dev = sc->stripe[stripe].dev->dax_dev;
356 bdev = sc->stripe[stripe].dev->bdev;
357
358 if (bdev_dax_pgoff(bdev, dev_sector, ALIGN(bytes, PAGE_SIZE), &pgoff))
359 return 0;
360 return dax_copy_to_iter(dax_dev, pgoff, addr, bytes, i);
361}
362
363static int stripe_dax_zero_page_range(struct dm_target *ti, pgoff_t pgoff,
364 size_t nr_pages)
365{
366 int ret;
367 sector_t dev_sector, sector = pgoff * PAGE_SECTORS;
368 struct stripe_c *sc = ti->private;
369 struct dax_device *dax_dev;
370 struct block_device *bdev;
371 uint32_t stripe;
372
373 stripe_map_sector(sc, sector, &stripe, &dev_sector);
374 dev_sector += sc->stripe[stripe].physical_start;
375 dax_dev = sc->stripe[stripe].dev->dax_dev;
376 bdev = sc->stripe[stripe].dev->bdev;
377
378 ret = bdev_dax_pgoff(bdev, dev_sector, nr_pages << PAGE_SHIFT, &pgoff);
379 if (ret)
380 return ret;
381 return dax_zero_page_range(dax_dev, pgoff, nr_pages);
382}
383
384#else
385#define stripe_dax_direct_access NULL
386#define stripe_dax_copy_from_iter NULL
387#define stripe_dax_copy_to_iter NULL
388#define stripe_dax_zero_page_range NULL
389#endif
390
391/*
392 * Stripe status:
393 *
394 * INFO
395 * #stripes [stripe_name <stripe_name>] [group word count]
396 * [error count 'A|D' <error count 'A|D'>]
397 *
398 * TABLE
399 * #stripes [stripe chunk size]
400 * [stripe_name physical_start <stripe_name physical_start>]
401 *
402 */
403
404static void stripe_status(struct dm_target *ti, status_type_t type,
405 unsigned status_flags, char *result, unsigned maxlen)
406{
407 struct stripe_c *sc = (struct stripe_c *) ti->private;
408 unsigned int sz = 0;
409 unsigned int i;
410
411 switch (type) {
412 case STATUSTYPE_INFO:
413 DMEMIT("%d ", sc->stripes);
414 for (i = 0; i < sc->stripes; i++) {
415 DMEMIT("%s ", sc->stripe[i].dev->name);
416 }
417 DMEMIT("1 ");
418 for (i = 0; i < sc->stripes; i++) {
419 DMEMIT("%c", atomic_read(&(sc->stripe[i].error_count)) ?
420 'D' : 'A');
421 }
422 break;
423
424 case STATUSTYPE_TABLE:
425 DMEMIT("%d %llu", sc->stripes,
426 (unsigned long long)sc->chunk_size);
427 for (i = 0; i < sc->stripes; i++)
428 DMEMIT(" %s %llu", sc->stripe[i].dev->name,
429 (unsigned long long)sc->stripe[i].physical_start);
430 break;
431 }
432}
433
434static int stripe_end_io(struct dm_target *ti, struct bio *bio,
435 blk_status_t *error)
436{
437 unsigned i;
438 char major_minor[16];
439 struct stripe_c *sc = ti->private;
440
441 if (!*error)
442 return DM_ENDIO_DONE; /* I/O complete */
443
444 if (bio->bi_opf & REQ_RAHEAD)
445 return DM_ENDIO_DONE;
446
447 if (*error == BLK_STS_NOTSUPP)
448 return DM_ENDIO_DONE;
449
450 memset(major_minor, 0, sizeof(major_minor));
451 sprintf(major_minor, "%d:%d", MAJOR(bio_dev(bio)), MINOR(bio_dev(bio)));
452
453 /*
454 * Test to see which stripe drive triggered the event
455 * and increment error count for all stripes on that device.
456 * If the error count for a given device exceeds the threshold
457 * value we will no longer trigger any further events.
458 */
459 for (i = 0; i < sc->stripes; i++)
460 if (!strcmp(sc->stripe[i].dev->name, major_minor)) {
461 atomic_inc(&(sc->stripe[i].error_count));
462 if (atomic_read(&(sc->stripe[i].error_count)) <
463 DM_IO_ERROR_THRESHOLD)
464 schedule_work(&sc->trigger_event);
465 }
466
467 return DM_ENDIO_DONE;
468}
469
470static int stripe_iterate_devices(struct dm_target *ti,
471 iterate_devices_callout_fn fn, void *data)
472{
473 struct stripe_c *sc = ti->private;
474 int ret = 0;
475 unsigned i = 0;
476
477 do {
478 ret = fn(ti, sc->stripe[i].dev,
479 sc->stripe[i].physical_start,
480 sc->stripe_width, data);
481 } while (!ret && ++i < sc->stripes);
482
483 return ret;
484}
485
486static void stripe_io_hints(struct dm_target *ti,
487 struct queue_limits *limits)
488{
489 struct stripe_c *sc = ti->private;
490 unsigned chunk_size = sc->chunk_size << SECTOR_SHIFT;
491
492 blk_limits_io_min(limits, chunk_size);
493 blk_limits_io_opt(limits, chunk_size * sc->stripes);
494}
495
496static struct target_type stripe_target = {
497 .name = "striped",
498 .version = {1, 6, 0},
499 .features = DM_TARGET_PASSES_INTEGRITY,
500 .module = THIS_MODULE,
501 .ctr = stripe_ctr,
502 .dtr = stripe_dtr,
503 .map = stripe_map,
504 .end_io = stripe_end_io,
505 .status = stripe_status,
506 .iterate_devices = stripe_iterate_devices,
507 .io_hints = stripe_io_hints,
508 .direct_access = stripe_dax_direct_access,
509 .dax_copy_from_iter = stripe_dax_copy_from_iter,
510 .dax_copy_to_iter = stripe_dax_copy_to_iter,
511 .dax_zero_page_range = stripe_dax_zero_page_range,
512};
513
514int __init dm_stripe_init(void)
515{
516 int r;
517
518 r = dm_register_target(&stripe_target);
519 if (r < 0)
520 DMWARN("target registration failed");
521
522 return r;
523}
524
525void dm_stripe_exit(void)
526{
527 dm_unregister_target(&stripe_target);
528}