Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * Copyright (C) 2001-2003 Sistina Software (UK) Limited. | |
3 | * | |
4 | * This file is released under the GPL. | |
5 | */ | |
6 | ||
7fff5e8f | 7 | #include "dm.h" |
586e80e6 | 8 | #include <linux/device-mapper.h> |
1da177e4 LT |
9 | |
10 | #include <linux/module.h> | |
11 | #include <linux/init.h> | |
12 | #include <linux/blkdev.h> | |
13 | #include <linux/bio.h> | |
817bf402 | 14 | #include <linux/dax.h> |
1da177e4 | 15 | #include <linux/slab.h> |
6f3c3f0a | 16 | #include <linux/log2.h> |
1da177e4 | 17 | |
72d94861 | 18 | #define DM_MSG_PREFIX "striped" |
a25eb944 | 19 | #define DM_IO_ERROR_THRESHOLD 15 |
72d94861 | 20 | |
1da177e4 LT |
21 | struct stripe { |
22 | struct dm_dev *dev; | |
23 | sector_t physical_start; | |
a25eb944 BW |
24 | |
25 | atomic_t error_count; | |
1da177e4 LT |
26 | }; |
27 | ||
28 | struct stripe_c { | |
29 | uint32_t stripes; | |
c96053b7 | 30 | int stripes_shift; |
1da177e4 LT |
31 | |
32 | /* The size of this target / num. stripes */ | |
33 | sector_t stripe_width; | |
34 | ||
eb850de6 | 35 | uint32_t chunk_size; |
33d07c0d | 36 | int chunk_size_shift; |
1da177e4 | 37 | |
a25eb944 BW |
38 | /* Needed for handling events */ |
39 | struct dm_target *ti; | |
40 | ||
41 | /* Work struct used for triggering events*/ | |
f521f074 | 42 | struct work_struct trigger_event; |
a25eb944 | 43 | |
1da177e4 LT |
44 | struct stripe stripe[0]; |
45 | }; | |
46 | ||
a25eb944 BW |
47 | /* |
48 | * An event is triggered whenever a drive | |
49 | * drops out of a stripe volume. | |
50 | */ | |
51 | static void trigger_event(struct work_struct *work) | |
52 | { | |
f521f074 TH |
53 | struct stripe_c *sc = container_of(work, struct stripe_c, |
54 | trigger_event); | |
a25eb944 | 55 | dm_table_event(sc->ti->table); |
a25eb944 BW |
56 | } |
57 | ||
1da177e4 LT |
58 | static inline struct stripe_c *alloc_context(unsigned int stripes) |
59 | { | |
60 | size_t len; | |
61 | ||
d63a5ce3 MP |
62 | if (dm_array_too_big(sizeof(struct stripe_c), sizeof(struct stripe), |
63 | stripes)) | |
1da177e4 LT |
64 | return NULL; |
65 | ||
66 | len = sizeof(struct stripe_c) + (sizeof(struct stripe) * stripes); | |
67 | ||
68 | return kmalloc(len, GFP_KERNEL); | |
69 | } | |
70 | ||
71 | /* | |
72 | * Parse a single <dev> <sector> pair | |
73 | */ | |
74 | static int get_stripe(struct dm_target *ti, struct stripe_c *sc, | |
75 | unsigned int stripe, char **argv) | |
76 | { | |
4ee218cd | 77 | unsigned long long start; |
31998ef1 | 78 | char dummy; |
e80d1c80 | 79 | int ret; |
1da177e4 | 80 | |
31998ef1 | 81 | if (sscanf(argv[1], "%llu%c", &start, &dummy) != 1) |
1da177e4 LT |
82 | return -EINVAL; |
83 | ||
e80d1c80 VG |
84 | ret = dm_get_device(ti, argv[0], dm_table_get_mode(ti->table), |
85 | &sc->stripe[stripe].dev); | |
86 | if (ret) | |
87 | return ret; | |
1da177e4 LT |
88 | |
89 | sc->stripe[stripe].physical_start = start; | |
a25eb944 | 90 | |
1da177e4 LT |
91 | return 0; |
92 | } | |
93 | ||
94 | /* | |
95 | * Construct a striped mapping. | |
eb850de6 | 96 | * <number of stripes> <chunk size> [<dev_path> <offset>]+ |
1da177e4 LT |
97 | */ |
98 | static int stripe_ctr(struct dm_target *ti, unsigned int argc, char **argv) | |
99 | { | |
100 | struct stripe_c *sc; | |
d793e684 | 101 | sector_t width, tmp_len; |
1da177e4 LT |
102 | uint32_t stripes; |
103 | uint32_t chunk_size; | |
1da177e4 LT |
104 | int r; |
105 | unsigned int i; | |
106 | ||
107 | if (argc < 2) { | |
72d94861 | 108 | ti->error = "Not enough arguments"; |
1da177e4 LT |
109 | return -EINVAL; |
110 | } | |
111 | ||
1a66a08a | 112 | if (kstrtouint(argv[0], 10, &stripes) || !stripes) { |
72d94861 | 113 | ti->error = "Invalid stripe count"; |
1da177e4 LT |
114 | return -EINVAL; |
115 | } | |
116 | ||
8f069b41 | 117 | if (kstrtouint(argv[1], 10, &chunk_size) || !chunk_size) { |
eb850de6 | 118 | ti->error = "Invalid chunk_size"; |
1da177e4 LT |
119 | return -EINVAL; |
120 | } | |
121 | ||
eb850de6 | 122 | width = ti->len; |
d793e684 | 123 | if (sector_div(width, stripes)) { |
72d94861 | 124 | ti->error = "Target length not divisible by " |
d793e684 | 125 | "number of stripes"; |
8ba32fde KC |
126 | return -EINVAL; |
127 | } | |
128 | ||
d793e684 MS |
129 | tmp_len = width; |
130 | if (sector_div(tmp_len, chunk_size)) { | |
72d94861 | 131 | ti->error = "Target length not divisible by " |
d793e684 | 132 | "chunk size"; |
1da177e4 LT |
133 | return -EINVAL; |
134 | } | |
135 | ||
136 | /* | |
137 | * Do we have enough arguments for that many stripes ? | |
138 | */ | |
139 | if (argc != (2 + 2 * stripes)) { | |
72d94861 | 140 | ti->error = "Not enough destinations " |
1da177e4 LT |
141 | "specified"; |
142 | return -EINVAL; | |
143 | } | |
144 | ||
145 | sc = alloc_context(stripes); | |
146 | if (!sc) { | |
72d94861 | 147 | ti->error = "Memory allocation for striped context " |
1da177e4 LT |
148 | "failed"; |
149 | return -ENOMEM; | |
150 | } | |
151 | ||
f521f074 | 152 | INIT_WORK(&sc->trigger_event, trigger_event); |
a25eb944 BW |
153 | |
154 | /* Set pointer to dm target; used in trigger_event */ | |
155 | sc->ti = ti; | |
1da177e4 LT |
156 | sc->stripes = stripes; |
157 | sc->stripe_width = width; | |
c96053b7 MP |
158 | |
159 | if (stripes & (stripes - 1)) | |
160 | sc->stripes_shift = -1; | |
1df05483 MP |
161 | else |
162 | sc->stripes_shift = __ffs(stripes); | |
c96053b7 | 163 | |
542f9038 | 164 | r = dm_set_target_max_io_len(ti, chunk_size); |
a3f2af25 PK |
165 | if (r) { |
166 | kfree(sc); | |
542f9038 | 167 | return r; |
a3f2af25 | 168 | } |
542f9038 | 169 | |
55a62eef AK |
170 | ti->num_flush_bios = stripes; |
171 | ti->num_discard_bios = stripes; | |
172 | ti->num_write_same_bios = stripes; | |
ac62d620 | 173 | ti->num_write_zeroes_bios = stripes; |
1da177e4 | 174 | |
eb850de6 | 175 | sc->chunk_size = chunk_size; |
33d07c0d MP |
176 | if (chunk_size & (chunk_size - 1)) |
177 | sc->chunk_size_shift = -1; | |
178 | else | |
179 | sc->chunk_size_shift = __ffs(chunk_size); | |
1da177e4 LT |
180 | |
181 | /* | |
182 | * Get the stripe destinations. | |
183 | */ | |
184 | for (i = 0; i < stripes; i++) { | |
185 | argv += 2; | |
186 | ||
187 | r = get_stripe(ti, sc, i, argv); | |
188 | if (r < 0) { | |
72d94861 | 189 | ti->error = "Couldn't parse stripe destination"; |
1da177e4 LT |
190 | while (i--) |
191 | dm_put_device(ti, sc->stripe[i].dev); | |
192 | kfree(sc); | |
193 | return r; | |
194 | } | |
a25eb944 | 195 | atomic_set(&(sc->stripe[i].error_count), 0); |
1da177e4 LT |
196 | } |
197 | ||
198 | ti->private = sc; | |
a25eb944 | 199 | |
1da177e4 LT |
200 | return 0; |
201 | } | |
202 | ||
203 | static void stripe_dtr(struct dm_target *ti) | |
204 | { | |
205 | unsigned int i; | |
206 | struct stripe_c *sc = (struct stripe_c *) ti->private; | |
207 | ||
208 | for (i = 0; i < sc->stripes; i++) | |
209 | dm_put_device(ti, sc->stripe[i].dev); | |
210 | ||
43829731 | 211 | flush_work(&sc->trigger_event); |
1da177e4 LT |
212 | kfree(sc); |
213 | } | |
214 | ||
65988525 MP |
215 | static void stripe_map_sector(struct stripe_c *sc, sector_t sector, |
216 | uint32_t *stripe, sector_t *result) | |
217 | { | |
eb850de6 | 218 | sector_t chunk = dm_target_offset(sc->ti, sector); |
33d07c0d MP |
219 | sector_t chunk_offset; |
220 | ||
221 | if (sc->chunk_size_shift < 0) | |
222 | chunk_offset = sector_div(chunk, sc->chunk_size); | |
223 | else { | |
224 | chunk_offset = chunk & (sc->chunk_size - 1); | |
225 | chunk >>= sc->chunk_size_shift; | |
226 | } | |
65988525 | 227 | |
c96053b7 MP |
228 | if (sc->stripes_shift < 0) |
229 | *stripe = sector_div(chunk, sc->stripes); | |
230 | else { | |
1df05483 | 231 | *stripe = chunk & (sc->stripes - 1); |
c96053b7 MP |
232 | chunk >>= sc->stripes_shift; |
233 | } | |
234 | ||
33d07c0d MP |
235 | if (sc->chunk_size_shift < 0) |
236 | chunk *= sc->chunk_size; | |
237 | else | |
238 | chunk <<= sc->chunk_size_shift; | |
239 | ||
240 | *result = chunk + chunk_offset; | |
65988525 MP |
241 | } |
242 | ||
7b76ec11 MP |
243 | static void stripe_map_range_sector(struct stripe_c *sc, sector_t sector, |
244 | uint32_t target_stripe, sector_t *result) | |
245 | { | |
246 | uint32_t stripe; | |
247 | ||
248 | stripe_map_sector(sc, sector, &stripe, result); | |
249 | if (stripe == target_stripe) | |
250 | return; | |
eb850de6 MS |
251 | |
252 | /* round down */ | |
253 | sector = *result; | |
33d07c0d MP |
254 | if (sc->chunk_size_shift < 0) |
255 | *result -= sector_div(sector, sc->chunk_size); | |
256 | else | |
257 | *result = sector & ~(sector_t)(sc->chunk_size - 1); | |
eb850de6 | 258 | |
7b76ec11 | 259 | if (target_stripe < stripe) |
eb850de6 | 260 | *result += sc->chunk_size; /* next chunk */ |
7b76ec11 MP |
261 | } |
262 | ||
45e621d4 MS |
263 | static int stripe_map_range(struct stripe_c *sc, struct bio *bio, |
264 | uint32_t target_stripe) | |
7b76ec11 MP |
265 | { |
266 | sector_t begin, end; | |
267 | ||
4f024f37 KO |
268 | stripe_map_range_sector(sc, bio->bi_iter.bi_sector, |
269 | target_stripe, &begin); | |
f73a1c7d | 270 | stripe_map_range_sector(sc, bio_end_sector(bio), |
7b76ec11 MP |
271 | target_stripe, &end); |
272 | if (begin < end) { | |
74d46992 | 273 | bio_set_dev(bio, sc->stripe[target_stripe].dev->bdev); |
4f024f37 KO |
274 | bio->bi_iter.bi_sector = begin + |
275 | sc->stripe[target_stripe].physical_start; | |
276 | bio->bi_iter.bi_size = to_bytes(end - begin); | |
7b76ec11 MP |
277 | return DM_MAPIO_REMAPPED; |
278 | } else { | |
279 | /* The range doesn't map to the target stripe */ | |
4246a0b6 | 280 | bio_endio(bio); |
7b76ec11 MP |
281 | return DM_MAPIO_SUBMITTED; |
282 | } | |
283 | } | |
284 | ||
7de3ee57 | 285 | static int stripe_map(struct dm_target *ti, struct bio *bio) |
1da177e4 | 286 | { |
65988525 | 287 | struct stripe_c *sc = ti->private; |
374bf7e7 | 288 | uint32_t stripe; |
55a62eef | 289 | unsigned target_bio_nr; |
1da177e4 | 290 | |
1eff9d32 | 291 | if (bio->bi_opf & REQ_PREFLUSH) { |
55a62eef AK |
292 | target_bio_nr = dm_bio_get_target_bio_nr(bio); |
293 | BUG_ON(target_bio_nr >= sc->stripes); | |
74d46992 | 294 | bio_set_dev(bio, sc->stripe[target_bio_nr].dev->bdev); |
374bf7e7 MP |
295 | return DM_MAPIO_REMAPPED; |
296 | } | |
e6047149 | 297 | if (unlikely(bio_op(bio) == REQ_OP_DISCARD) || |
ac62d620 | 298 | unlikely(bio_op(bio) == REQ_OP_WRITE_ZEROES) || |
e6047149 | 299 | unlikely(bio_op(bio) == REQ_OP_WRITE_SAME)) { |
55a62eef AK |
300 | target_bio_nr = dm_bio_get_target_bio_nr(bio); |
301 | BUG_ON(target_bio_nr >= sc->stripes); | |
302 | return stripe_map_range(sc, bio, target_bio_nr); | |
7b76ec11 | 303 | } |
374bf7e7 | 304 | |
4f024f37 KO |
305 | stripe_map_sector(sc, bio->bi_iter.bi_sector, |
306 | &stripe, &bio->bi_iter.bi_sector); | |
1da177e4 | 307 | |
4f024f37 | 308 | bio->bi_iter.bi_sector += sc->stripe[stripe].physical_start; |
74d46992 | 309 | bio_set_dev(bio, sc->stripe[stripe].dev->bdev); |
65988525 | 310 | |
d2a7ad29 | 311 | return DM_MAPIO_REMAPPED; |
1da177e4 LT |
312 | } |
313 | ||
817bf402 DW |
314 | static long stripe_dax_direct_access(struct dm_target *ti, pgoff_t pgoff, |
315 | long nr_pages, void **kaddr, pfn_t *pfn) | |
beec25b4 | 316 | { |
817bf402 | 317 | sector_t dev_sector, sector = pgoff * PAGE_SECTORS; |
beec25b4 | 318 | struct stripe_c *sc = ti->private; |
817bf402 | 319 | struct dax_device *dax_dev; |
beec25b4 | 320 | struct block_device *bdev; |
817bf402 | 321 | uint32_t stripe; |
beec25b4 TK |
322 | long ret; |
323 | ||
817bf402 DW |
324 | stripe_map_sector(sc, sector, &stripe, &dev_sector); |
325 | dev_sector += sc->stripe[stripe].physical_start; | |
326 | dax_dev = sc->stripe[stripe].dev->dax_dev; | |
beec25b4 TK |
327 | bdev = sc->stripe[stripe].dev->bdev; |
328 | ||
817bf402 DW |
329 | ret = bdev_dax_pgoff(bdev, dev_sector, nr_pages * PAGE_SIZE, &pgoff); |
330 | if (ret) | |
331 | return ret; | |
332 | return dax_direct_access(dax_dev, pgoff, nr_pages, kaddr, pfn); | |
beec25b4 TK |
333 | } |
334 | ||
7e026c8c DW |
335 | static size_t stripe_dax_copy_from_iter(struct dm_target *ti, pgoff_t pgoff, |
336 | void *addr, size_t bytes, struct iov_iter *i) | |
337 | { | |
338 | sector_t dev_sector, sector = pgoff * PAGE_SECTORS; | |
339 | struct stripe_c *sc = ti->private; | |
340 | struct dax_device *dax_dev; | |
341 | struct block_device *bdev; | |
342 | uint32_t stripe; | |
343 | ||
344 | stripe_map_sector(sc, sector, &stripe, &dev_sector); | |
345 | dev_sector += sc->stripe[stripe].physical_start; | |
346 | dax_dev = sc->stripe[stripe].dev->dax_dev; | |
347 | bdev = sc->stripe[stripe].dev->bdev; | |
348 | ||
349 | if (bdev_dax_pgoff(bdev, dev_sector, ALIGN(bytes, PAGE_SIZE), &pgoff)) | |
350 | return 0; | |
351 | return dax_copy_from_iter(dax_dev, pgoff, addr, bytes, i); | |
352 | } | |
353 | ||
4f7f5c67 BW |
354 | /* |
355 | * Stripe status: | |
356 | * | |
357 | * INFO | |
358 | * #stripes [stripe_name <stripe_name>] [group word count] | |
359 | * [error count 'A|D' <error count 'A|D'>] | |
360 | * | |
361 | * TABLE | |
362 | * #stripes [stripe chunk size] | |
363 | * [stripe_name physical_start <stripe_name physical_start>] | |
364 | * | |
365 | */ | |
366 | ||
fd7c092e MP |
367 | static void stripe_status(struct dm_target *ti, status_type_t type, |
368 | unsigned status_flags, char *result, unsigned maxlen) | |
1da177e4 LT |
369 | { |
370 | struct stripe_c *sc = (struct stripe_c *) ti->private; | |
4f7f5c67 | 371 | char buffer[sc->stripes + 1]; |
1da177e4 LT |
372 | unsigned int sz = 0; |
373 | unsigned int i; | |
374 | ||
375 | switch (type) { | |
376 | case STATUSTYPE_INFO: | |
4f7f5c67 BW |
377 | DMEMIT("%d ", sc->stripes); |
378 | for (i = 0; i < sc->stripes; i++) { | |
379 | DMEMIT("%s ", sc->stripe[i].dev->name); | |
380 | buffer[i] = atomic_read(&(sc->stripe[i].error_count)) ? | |
381 | 'D' : 'A'; | |
382 | } | |
383 | buffer[i] = '\0'; | |
384 | DMEMIT("1 %s", buffer); | |
1da177e4 LT |
385 | break; |
386 | ||
387 | case STATUSTYPE_TABLE: | |
4ee218cd | 388 | DMEMIT("%d %llu", sc->stripes, |
eb850de6 | 389 | (unsigned long long)sc->chunk_size); |
1da177e4 | 390 | for (i = 0; i < sc->stripes; i++) |
4ee218cd AM |
391 | DMEMIT(" %s %llu", sc->stripe[i].dev->name, |
392 | (unsigned long long)sc->stripe[i].physical_start); | |
1da177e4 LT |
393 | break; |
394 | } | |
1da177e4 LT |
395 | } |
396 | ||
4e4cbee9 CH |
397 | static int stripe_end_io(struct dm_target *ti, struct bio *bio, |
398 | blk_status_t *error) | |
a25eb944 BW |
399 | { |
400 | unsigned i; | |
401 | char major_minor[16]; | |
402 | struct stripe_c *sc = ti->private; | |
403 | ||
1be56909 CH |
404 | if (!*error) |
405 | return DM_ENDIO_DONE; /* I/O complete */ | |
a25eb944 | 406 | |
9966afaf | 407 | if (bio->bi_opf & REQ_RAHEAD) |
1be56909 | 408 | return DM_ENDIO_DONE; |
a25eb944 | 409 | |
4e4cbee9 | 410 | if (*error == BLK_STS_NOTSUPP) |
1be56909 | 411 | return DM_ENDIO_DONE; |
a25eb944 BW |
412 | |
413 | memset(major_minor, 0, sizeof(major_minor)); | |
74d46992 | 414 | sprintf(major_minor, "%d:%d", MAJOR(bio_dev(bio)), MINOR(bio_dev(bio))); |
a25eb944 BW |
415 | |
416 | /* | |
417 | * Test to see which stripe drive triggered the event | |
418 | * and increment error count for all stripes on that device. | |
419 | * If the error count for a given device exceeds the threshold | |
420 | * value we will no longer trigger any further events. | |
421 | */ | |
422 | for (i = 0; i < sc->stripes; i++) | |
423 | if (!strcmp(sc->stripe[i].dev->name, major_minor)) { | |
424 | atomic_inc(&(sc->stripe[i].error_count)); | |
425 | if (atomic_read(&(sc->stripe[i].error_count)) < | |
426 | DM_IO_ERROR_THRESHOLD) | |
f521f074 | 427 | schedule_work(&sc->trigger_event); |
a25eb944 BW |
428 | } |
429 | ||
1be56909 | 430 | return DM_ENDIO_DONE; |
a25eb944 BW |
431 | } |
432 | ||
af4874e0 MS |
433 | static int stripe_iterate_devices(struct dm_target *ti, |
434 | iterate_devices_callout_fn fn, void *data) | |
435 | { | |
436 | struct stripe_c *sc = ti->private; | |
437 | int ret = 0; | |
438 | unsigned i = 0; | |
439 | ||
5dea271b | 440 | do { |
af4874e0 | 441 | ret = fn(ti, sc->stripe[i].dev, |
5dea271b MS |
442 | sc->stripe[i].physical_start, |
443 | sc->stripe_width, data); | |
444 | } while (!ret && ++i < sc->stripes); | |
af4874e0 MS |
445 | |
446 | return ret; | |
447 | } | |
448 | ||
40bea431 MS |
449 | static void stripe_io_hints(struct dm_target *ti, |
450 | struct queue_limits *limits) | |
451 | { | |
452 | struct stripe_c *sc = ti->private; | |
eb850de6 | 453 | unsigned chunk_size = sc->chunk_size << SECTOR_SHIFT; |
40bea431 MS |
454 | |
455 | blk_limits_io_min(limits, chunk_size); | |
3c5820c7 | 456 | blk_limits_io_opt(limits, chunk_size * sc->stripes); |
40bea431 MS |
457 | } |
458 | ||
1da177e4 LT |
459 | static struct target_type stripe_target = { |
460 | .name = "striped", | |
beec25b4 | 461 | .version = {1, 6, 0}, |
e2460f2a | 462 | .features = DM_TARGET_PASSES_INTEGRITY, |
1da177e4 LT |
463 | .module = THIS_MODULE, |
464 | .ctr = stripe_ctr, | |
465 | .dtr = stripe_dtr, | |
466 | .map = stripe_map, | |
a25eb944 | 467 | .end_io = stripe_end_io, |
1da177e4 | 468 | .status = stripe_status, |
af4874e0 | 469 | .iterate_devices = stripe_iterate_devices, |
40bea431 | 470 | .io_hints = stripe_io_hints, |
817bf402 | 471 | .direct_access = stripe_dax_direct_access, |
7e026c8c | 472 | .dax_copy_from_iter = stripe_dax_copy_from_iter, |
1da177e4 LT |
473 | }; |
474 | ||
475 | int __init dm_stripe_init(void) | |
476 | { | |
477 | int r; | |
478 | ||
479 | r = dm_register_target(&stripe_target); | |
e223e1de | 480 | if (r < 0) |
72d94861 | 481 | DMWARN("target registration failed"); |
1da177e4 LT |
482 | |
483 | return r; | |
484 | } | |
485 | ||
486 | void dm_stripe_exit(void) | |
487 | { | |
10d3bd09 | 488 | dm_unregister_target(&stripe_target); |
1da177e4 | 489 | } |