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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}
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/slab.h>
15#include <linux/log2.h>
16
17#define DM_MSG_PREFIX "striped"
18#define DM_IO_ERROR_THRESHOLD 15
19
20struct stripe {
21 struct dm_dev *dev;
22 sector_t physical_start;
23
24 atomic_t error_count;
25};
26
27struct stripe_c {
28 uint32_t stripes;
29 int stripes_shift;
30
31 /* The size of this target / num. stripes */
32 sector_t stripe_width;
33
34 uint32_t chunk_size;
35 int chunk_size_shift;
36
37 /* Needed for handling events */
38 struct dm_target *ti;
39
40 /* Work struct used for triggering events*/
41 struct work_struct trigger_event;
42
43 struct stripe stripe[0];
44};
45
46/*
47 * An event is triggered whenever a drive
48 * drops out of a stripe volume.
49 */
50static void trigger_event(struct work_struct *work)
51{
52 struct stripe_c *sc = container_of(work, struct stripe_c,
53 trigger_event);
54 dm_table_event(sc->ti->table);
55}
56
57static inline struct stripe_c *alloc_context(unsigned int stripes)
58{
59 size_t len;
60
61 if (dm_array_too_big(sizeof(struct stripe_c), sizeof(struct stripe),
62 stripes))
63 return NULL;
64
65 len = sizeof(struct stripe_c) + (sizeof(struct stripe) * stripes);
66
67 return kmalloc(len, GFP_KERNEL);
68}
69
70/*
71 * Parse a single <dev> <sector> pair
72 */
73static int get_stripe(struct dm_target *ti, struct stripe_c *sc,
74 unsigned int stripe, char **argv)
75{
76 unsigned long long start;
77 char dummy;
78 int ret;
79
80 if (sscanf(argv[1], "%llu%c", &start, &dummy) != 1)
81 return -EINVAL;
82
83 ret = dm_get_device(ti, argv[0], dm_table_get_mode(ti->table),
84 &sc->stripe[stripe].dev);
85 if (ret)
86 return ret;
87
88 sc->stripe[stripe].physical_start = start;
89
90 return 0;
91}
92
93/*
94 * Construct a striped mapping.
95 * <number of stripes> <chunk size> [<dev_path> <offset>]+
96 */
97static int stripe_ctr(struct dm_target *ti, unsigned int argc, char **argv)
98{
99 struct stripe_c *sc;
100 sector_t width, tmp_len;
101 uint32_t stripes;
102 uint32_t chunk_size;
103 int r;
104 unsigned int i;
105
106 if (argc < 2) {
107 ti->error = "Not enough arguments";
108 return -EINVAL;
109 }
110
111 if (kstrtouint(argv[0], 10, &stripes) || !stripes) {
112 ti->error = "Invalid stripe count";
113 return -EINVAL;
114 }
115
116 if (kstrtouint(argv[1], 10, &chunk_size) || !chunk_size) {
117 ti->error = "Invalid chunk_size";
118 return -EINVAL;
119 }
120
121 width = ti->len;
122 if (sector_div(width, stripes)) {
123 ti->error = "Target length not divisible by "
124 "number of stripes";
125 return -EINVAL;
126 }
127
128 tmp_len = width;
129 if (sector_div(tmp_len, chunk_size)) {
130 ti->error = "Target length not divisible by "
131 "chunk size";
132 return -EINVAL;
133 }
134
135 /*
136 * Do we have enough arguments for that many stripes ?
137 */
138 if (argc != (2 + 2 * stripes)) {
139 ti->error = "Not enough destinations "
140 "specified";
141 return -EINVAL;
142 }
143
144 sc = alloc_context(stripes);
145 if (!sc) {
146 ti->error = "Memory allocation for striped context "
147 "failed";
148 return -ENOMEM;
149 }
150
151 INIT_WORK(&sc->trigger_event, trigger_event);
152
153 /* Set pointer to dm target; used in trigger_event */
154 sc->ti = ti;
155 sc->stripes = stripes;
156 sc->stripe_width = width;
157
158 if (stripes & (stripes - 1))
159 sc->stripes_shift = -1;
160 else
161 sc->stripes_shift = __ffs(stripes);
162
163 r = dm_set_target_max_io_len(ti, chunk_size);
164 if (r) {
165 kfree(sc);
166 return r;
167 }
168
169 ti->num_flush_bios = stripes;
170 ti->num_discard_bios = stripes;
171 ti->num_write_same_bios = stripes;
172
173 sc->chunk_size = chunk_size;
174 if (chunk_size & (chunk_size - 1))
175 sc->chunk_size_shift = -1;
176 else
177 sc->chunk_size_shift = __ffs(chunk_size);
178
179 /*
180 * Get the stripe destinations.
181 */
182 for (i = 0; i < stripes; i++) {
183 argv += 2;
184
185 r = get_stripe(ti, sc, i, argv);
186 if (r < 0) {
187 ti->error = "Couldn't parse stripe destination";
188 while (i--)
189 dm_put_device(ti, sc->stripe[i].dev);
190 kfree(sc);
191 return r;
192 }
193 atomic_set(&(sc->stripe[i].error_count), 0);
194 }
195
196 ti->private = sc;
197
198 return 0;
199}
200
201static void stripe_dtr(struct dm_target *ti)
202{
203 unsigned int i;
204 struct stripe_c *sc = (struct stripe_c *) ti->private;
205
206 for (i = 0; i < sc->stripes; i++)
207 dm_put_device(ti, sc->stripe[i].dev);
208
209 flush_work(&sc->trigger_event);
210 kfree(sc);
211}
212
213static void stripe_map_sector(struct stripe_c *sc, sector_t sector,
214 uint32_t *stripe, sector_t *result)
215{
216 sector_t chunk = dm_target_offset(sc->ti, sector);
217 sector_t chunk_offset;
218
219 if (sc->chunk_size_shift < 0)
220 chunk_offset = sector_div(chunk, sc->chunk_size);
221 else {
222 chunk_offset = chunk & (sc->chunk_size - 1);
223 chunk >>= sc->chunk_size_shift;
224 }
225
226 if (sc->stripes_shift < 0)
227 *stripe = sector_div(chunk, sc->stripes);
228 else {
229 *stripe = chunk & (sc->stripes - 1);
230 chunk >>= sc->stripes_shift;
231 }
232
233 if (sc->chunk_size_shift < 0)
234 chunk *= sc->chunk_size;
235 else
236 chunk <<= sc->chunk_size_shift;
237
238 *result = chunk + chunk_offset;
239}
240
241static void stripe_map_range_sector(struct stripe_c *sc, sector_t sector,
242 uint32_t target_stripe, sector_t *result)
243{
244 uint32_t stripe;
245
246 stripe_map_sector(sc, sector, &stripe, result);
247 if (stripe == target_stripe)
248 return;
249
250 /* round down */
251 sector = *result;
252 if (sc->chunk_size_shift < 0)
253 *result -= sector_div(sector, sc->chunk_size);
254 else
255 *result = sector & ~(sector_t)(sc->chunk_size - 1);
256
257 if (target_stripe < stripe)
258 *result += sc->chunk_size; /* next chunk */
259}
260
261static int stripe_map_range(struct stripe_c *sc, struct bio *bio,
262 uint32_t target_stripe)
263{
264 sector_t begin, end;
265
266 stripe_map_range_sector(sc, bio->bi_iter.bi_sector,
267 target_stripe, &begin);
268 stripe_map_range_sector(sc, bio_end_sector(bio),
269 target_stripe, &end);
270 if (begin < end) {
271 bio->bi_bdev = sc->stripe[target_stripe].dev->bdev;
272 bio->bi_iter.bi_sector = begin +
273 sc->stripe[target_stripe].physical_start;
274 bio->bi_iter.bi_size = to_bytes(end - begin);
275 return DM_MAPIO_REMAPPED;
276 } else {
277 /* The range doesn't map to the target stripe */
278 bio_endio(bio);
279 return DM_MAPIO_SUBMITTED;
280 }
281}
282
283static int stripe_map(struct dm_target *ti, struct bio *bio)
284{
285 struct stripe_c *sc = ti->private;
286 uint32_t stripe;
287 unsigned target_bio_nr;
288
289 if (bio->bi_rw & REQ_FLUSH) {
290 target_bio_nr = dm_bio_get_target_bio_nr(bio);
291 BUG_ON(target_bio_nr >= sc->stripes);
292 bio->bi_bdev = sc->stripe[target_bio_nr].dev->bdev;
293 return DM_MAPIO_REMAPPED;
294 }
295 if (unlikely(bio->bi_rw & REQ_DISCARD) ||
296 unlikely(bio->bi_rw & REQ_WRITE_SAME)) {
297 target_bio_nr = dm_bio_get_target_bio_nr(bio);
298 BUG_ON(target_bio_nr >= sc->stripes);
299 return stripe_map_range(sc, bio, target_bio_nr);
300 }
301
302 stripe_map_sector(sc, bio->bi_iter.bi_sector,
303 &stripe, &bio->bi_iter.bi_sector);
304
305 bio->bi_iter.bi_sector += sc->stripe[stripe].physical_start;
306 bio->bi_bdev = sc->stripe[stripe].dev->bdev;
307
308 return DM_MAPIO_REMAPPED;
309}
310
311/*
312 * Stripe status:
313 *
314 * INFO
315 * #stripes [stripe_name <stripe_name>] [group word count]
316 * [error count 'A|D' <error count 'A|D'>]
317 *
318 * TABLE
319 * #stripes [stripe chunk size]
320 * [stripe_name physical_start <stripe_name physical_start>]
321 *
322 */
323
324static void stripe_status(struct dm_target *ti, status_type_t type,
325 unsigned status_flags, char *result, unsigned maxlen)
326{
327 struct stripe_c *sc = (struct stripe_c *) ti->private;
328 char buffer[sc->stripes + 1];
329 unsigned int sz = 0;
330 unsigned int i;
331
332 switch (type) {
333 case STATUSTYPE_INFO:
334 DMEMIT("%d ", sc->stripes);
335 for (i = 0; i < sc->stripes; i++) {
336 DMEMIT("%s ", sc->stripe[i].dev->name);
337 buffer[i] = atomic_read(&(sc->stripe[i].error_count)) ?
338 'D' : 'A';
339 }
340 buffer[i] = '\0';
341 DMEMIT("1 %s", buffer);
342 break;
343
344 case STATUSTYPE_TABLE:
345 DMEMIT("%d %llu", sc->stripes,
346 (unsigned long long)sc->chunk_size);
347 for (i = 0; i < sc->stripes; i++)
348 DMEMIT(" %s %llu", sc->stripe[i].dev->name,
349 (unsigned long long)sc->stripe[i].physical_start);
350 break;
351 }
352}
353
354static int stripe_end_io(struct dm_target *ti, struct bio *bio, int error)
355{
356 unsigned i;
357 char major_minor[16];
358 struct stripe_c *sc = ti->private;
359
360 if (!error)
361 return 0; /* I/O complete */
362
363 if ((error == -EWOULDBLOCK) && (bio->bi_rw & REQ_RAHEAD))
364 return error;
365
366 if (error == -EOPNOTSUPP)
367 return error;
368
369 memset(major_minor, 0, sizeof(major_minor));
370 sprintf(major_minor, "%d:%d",
371 MAJOR(disk_devt(bio->bi_bdev->bd_disk)),
372 MINOR(disk_devt(bio->bi_bdev->bd_disk)));
373
374 /*
375 * Test to see which stripe drive triggered the event
376 * and increment error count for all stripes on that device.
377 * If the error count for a given device exceeds the threshold
378 * value we will no longer trigger any further events.
379 */
380 for (i = 0; i < sc->stripes; i++)
381 if (!strcmp(sc->stripe[i].dev->name, major_minor)) {
382 atomic_inc(&(sc->stripe[i].error_count));
383 if (atomic_read(&(sc->stripe[i].error_count)) <
384 DM_IO_ERROR_THRESHOLD)
385 schedule_work(&sc->trigger_event);
386 }
387
388 return error;
389}
390
391static int stripe_iterate_devices(struct dm_target *ti,
392 iterate_devices_callout_fn fn, void *data)
393{
394 struct stripe_c *sc = ti->private;
395 int ret = 0;
396 unsigned i = 0;
397
398 do {
399 ret = fn(ti, sc->stripe[i].dev,
400 sc->stripe[i].physical_start,
401 sc->stripe_width, data);
402 } while (!ret && ++i < sc->stripes);
403
404 return ret;
405}
406
407static void stripe_io_hints(struct dm_target *ti,
408 struct queue_limits *limits)
409{
410 struct stripe_c *sc = ti->private;
411 unsigned chunk_size = sc->chunk_size << SECTOR_SHIFT;
412
413 blk_limits_io_min(limits, chunk_size);
414 blk_limits_io_opt(limits, chunk_size * sc->stripes);
415}
416
417static struct target_type stripe_target = {
418 .name = "striped",
419 .version = {1, 5, 1},
420 .module = THIS_MODULE,
421 .ctr = stripe_ctr,
422 .dtr = stripe_dtr,
423 .map = stripe_map,
424 .end_io = stripe_end_io,
425 .status = stripe_status,
426 .iterate_devices = stripe_iterate_devices,
427 .io_hints = stripe_io_hints,
428};
429
430int __init dm_stripe_init(void)
431{
432 int r;
433
434 r = dm_register_target(&stripe_target);
435 if (r < 0)
436 DMWARN("target registration failed");
437
438 return r;
439}
440
441void dm_stripe_exit(void)
442{
443 dm_unregister_target(&stripe_target);
444}