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> | |
14 | #include <linux/slab.h> | |
6f3c3f0a | 15 | #include <linux/log2.h> |
1da177e4 | 16 | |
72d94861 | 17 | #define DM_MSG_PREFIX "striped" |
a25eb944 | 18 | #define DM_IO_ERROR_THRESHOLD 15 |
72d94861 | 19 | |
1da177e4 LT |
20 | struct stripe { |
21 | struct dm_dev *dev; | |
22 | sector_t physical_start; | |
a25eb944 BW |
23 | |
24 | atomic_t error_count; | |
1da177e4 LT |
25 | }; |
26 | ||
27 | struct stripe_c { | |
28 | uint32_t stripes; | |
c96053b7 | 29 | int stripes_shift; |
1da177e4 LT |
30 | |
31 | /* The size of this target / num. stripes */ | |
32 | sector_t stripe_width; | |
33 | ||
eb850de6 | 34 | uint32_t chunk_size; |
33d07c0d | 35 | int chunk_size_shift; |
1da177e4 | 36 | |
a25eb944 BW |
37 | /* Needed for handling events */ |
38 | struct dm_target *ti; | |
39 | ||
40 | /* Work struct used for triggering events*/ | |
f521f074 | 41 | struct work_struct trigger_event; |
a25eb944 | 42 | |
1da177e4 LT |
43 | struct stripe stripe[0]; |
44 | }; | |
45 | ||
a25eb944 BW |
46 | /* |
47 | * An event is triggered whenever a drive | |
48 | * drops out of a stripe volume. | |
49 | */ | |
50 | static void trigger_event(struct work_struct *work) | |
51 | { | |
f521f074 TH |
52 | struct stripe_c *sc = container_of(work, struct stripe_c, |
53 | trigger_event); | |
a25eb944 | 54 | dm_table_event(sc->ti->table); |
a25eb944 BW |
55 | } |
56 | ||
1da177e4 LT |
57 | static inline struct stripe_c *alloc_context(unsigned int stripes) |
58 | { | |
59 | size_t len; | |
60 | ||
d63a5ce3 MP |
61 | if (dm_array_too_big(sizeof(struct stripe_c), sizeof(struct stripe), |
62 | stripes)) | |
1da177e4 LT |
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 | */ | |
73 | static int get_stripe(struct dm_target *ti, struct stripe_c *sc, | |
74 | unsigned int stripe, char **argv) | |
75 | { | |
4ee218cd | 76 | unsigned long long start; |
31998ef1 | 77 | char dummy; |
e80d1c80 | 78 | int ret; |
1da177e4 | 79 | |
31998ef1 | 80 | if (sscanf(argv[1], "%llu%c", &start, &dummy) != 1) |
1da177e4 LT |
81 | return -EINVAL; |
82 | ||
e80d1c80 VG |
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; | |
1da177e4 LT |
87 | |
88 | sc->stripe[stripe].physical_start = start; | |
a25eb944 | 89 | |
1da177e4 LT |
90 | return 0; |
91 | } | |
92 | ||
93 | /* | |
94 | * Construct a striped mapping. | |
eb850de6 | 95 | * <number of stripes> <chunk size> [<dev_path> <offset>]+ |
1da177e4 LT |
96 | */ |
97 | static int stripe_ctr(struct dm_target *ti, unsigned int argc, char **argv) | |
98 | { | |
99 | struct stripe_c *sc; | |
d793e684 | 100 | sector_t width, tmp_len; |
1da177e4 LT |
101 | uint32_t stripes; |
102 | uint32_t chunk_size; | |
1da177e4 LT |
103 | int r; |
104 | unsigned int i; | |
105 | ||
106 | if (argc < 2) { | |
72d94861 | 107 | ti->error = "Not enough arguments"; |
1da177e4 LT |
108 | return -EINVAL; |
109 | } | |
110 | ||
1a66a08a | 111 | if (kstrtouint(argv[0], 10, &stripes) || !stripes) { |
72d94861 | 112 | ti->error = "Invalid stripe count"; |
1da177e4 LT |
113 | return -EINVAL; |
114 | } | |
115 | ||
8f069b41 | 116 | if (kstrtouint(argv[1], 10, &chunk_size) || !chunk_size) { |
eb850de6 | 117 | ti->error = "Invalid chunk_size"; |
1da177e4 LT |
118 | return -EINVAL; |
119 | } | |
120 | ||
eb850de6 | 121 | width = ti->len; |
d793e684 | 122 | if (sector_div(width, stripes)) { |
72d94861 | 123 | ti->error = "Target length not divisible by " |
d793e684 | 124 | "number of stripes"; |
8ba32fde KC |
125 | return -EINVAL; |
126 | } | |
127 | ||
d793e684 MS |
128 | tmp_len = width; |
129 | if (sector_div(tmp_len, chunk_size)) { | |
72d94861 | 130 | ti->error = "Target length not divisible by " |
d793e684 | 131 | "chunk size"; |
1da177e4 LT |
132 | return -EINVAL; |
133 | } | |
134 | ||
135 | /* | |
136 | * Do we have enough arguments for that many stripes ? | |
137 | */ | |
138 | if (argc != (2 + 2 * stripes)) { | |
72d94861 | 139 | ti->error = "Not enough destinations " |
1da177e4 LT |
140 | "specified"; |
141 | return -EINVAL; | |
142 | } | |
143 | ||
144 | sc = alloc_context(stripes); | |
145 | if (!sc) { | |
72d94861 | 146 | ti->error = "Memory allocation for striped context " |
1da177e4 LT |
147 | "failed"; |
148 | return -ENOMEM; | |
149 | } | |
150 | ||
f521f074 | 151 | INIT_WORK(&sc->trigger_event, trigger_event); |
a25eb944 BW |
152 | |
153 | /* Set pointer to dm target; used in trigger_event */ | |
154 | sc->ti = ti; | |
1da177e4 LT |
155 | sc->stripes = stripes; |
156 | sc->stripe_width = width; | |
c96053b7 MP |
157 | |
158 | if (stripes & (stripes - 1)) | |
159 | sc->stripes_shift = -1; | |
1df05483 MP |
160 | else |
161 | sc->stripes_shift = __ffs(stripes); | |
c96053b7 | 162 | |
542f9038 | 163 | r = dm_set_target_max_io_len(ti, chunk_size); |
a3f2af25 PK |
164 | if (r) { |
165 | kfree(sc); | |
542f9038 | 166 | return r; |
a3f2af25 | 167 | } |
542f9038 | 168 | |
55a62eef AK |
169 | ti->num_flush_bios = stripes; |
170 | ti->num_discard_bios = stripes; | |
171 | ti->num_write_same_bios = stripes; | |
ac62d620 | 172 | ti->num_write_zeroes_bios = stripes; |
1da177e4 | 173 | |
eb850de6 | 174 | sc->chunk_size = chunk_size; |
33d07c0d MP |
175 | if (chunk_size & (chunk_size - 1)) |
176 | sc->chunk_size_shift = -1; | |
177 | else | |
178 | sc->chunk_size_shift = __ffs(chunk_size); | |
1da177e4 LT |
179 | |
180 | /* | |
181 | * Get the stripe destinations. | |
182 | */ | |
183 | for (i = 0; i < stripes; i++) { | |
184 | argv += 2; | |
185 | ||
186 | r = get_stripe(ti, sc, i, argv); | |
187 | if (r < 0) { | |
72d94861 | 188 | ti->error = "Couldn't parse stripe destination"; |
1da177e4 LT |
189 | while (i--) |
190 | dm_put_device(ti, sc->stripe[i].dev); | |
191 | kfree(sc); | |
192 | return r; | |
193 | } | |
a25eb944 | 194 | atomic_set(&(sc->stripe[i].error_count), 0); |
1da177e4 LT |
195 | } |
196 | ||
197 | ti->private = sc; | |
a25eb944 | 198 | |
1da177e4 LT |
199 | return 0; |
200 | } | |
201 | ||
202 | static void stripe_dtr(struct dm_target *ti) | |
203 | { | |
204 | unsigned int i; | |
205 | struct stripe_c *sc = (struct stripe_c *) ti->private; | |
206 | ||
207 | for (i = 0; i < sc->stripes; i++) | |
208 | dm_put_device(ti, sc->stripe[i].dev); | |
209 | ||
43829731 | 210 | flush_work(&sc->trigger_event); |
1da177e4 LT |
211 | kfree(sc); |
212 | } | |
213 | ||
65988525 MP |
214 | static void stripe_map_sector(struct stripe_c *sc, sector_t sector, |
215 | uint32_t *stripe, sector_t *result) | |
216 | { | |
eb850de6 | 217 | sector_t chunk = dm_target_offset(sc->ti, sector); |
33d07c0d MP |
218 | sector_t chunk_offset; |
219 | ||
220 | if (sc->chunk_size_shift < 0) | |
221 | chunk_offset = sector_div(chunk, sc->chunk_size); | |
222 | else { | |
223 | chunk_offset = chunk & (sc->chunk_size - 1); | |
224 | chunk >>= sc->chunk_size_shift; | |
225 | } | |
65988525 | 226 | |
c96053b7 MP |
227 | if (sc->stripes_shift < 0) |
228 | *stripe = sector_div(chunk, sc->stripes); | |
229 | else { | |
1df05483 | 230 | *stripe = chunk & (sc->stripes - 1); |
c96053b7 MP |
231 | chunk >>= sc->stripes_shift; |
232 | } | |
233 | ||
33d07c0d MP |
234 | if (sc->chunk_size_shift < 0) |
235 | chunk *= sc->chunk_size; | |
236 | else | |
237 | chunk <<= sc->chunk_size_shift; | |
238 | ||
239 | *result = chunk + chunk_offset; | |
65988525 MP |
240 | } |
241 | ||
7b76ec11 MP |
242 | static void stripe_map_range_sector(struct stripe_c *sc, sector_t sector, |
243 | uint32_t target_stripe, sector_t *result) | |
244 | { | |
245 | uint32_t stripe; | |
246 | ||
247 | stripe_map_sector(sc, sector, &stripe, result); | |
248 | if (stripe == target_stripe) | |
249 | return; | |
eb850de6 MS |
250 | |
251 | /* round down */ | |
252 | sector = *result; | |
33d07c0d MP |
253 | if (sc->chunk_size_shift < 0) |
254 | *result -= sector_div(sector, sc->chunk_size); | |
255 | else | |
256 | *result = sector & ~(sector_t)(sc->chunk_size - 1); | |
eb850de6 | 257 | |
7b76ec11 | 258 | if (target_stripe < stripe) |
eb850de6 | 259 | *result += sc->chunk_size; /* next chunk */ |
7b76ec11 MP |
260 | } |
261 | ||
45e621d4 MS |
262 | static int stripe_map_range(struct stripe_c *sc, struct bio *bio, |
263 | uint32_t target_stripe) | |
7b76ec11 MP |
264 | { |
265 | sector_t begin, end; | |
266 | ||
4f024f37 KO |
267 | stripe_map_range_sector(sc, bio->bi_iter.bi_sector, |
268 | target_stripe, &begin); | |
f73a1c7d | 269 | stripe_map_range_sector(sc, bio_end_sector(bio), |
7b76ec11 MP |
270 | target_stripe, &end); |
271 | if (begin < end) { | |
272 | bio->bi_bdev = sc->stripe[target_stripe].dev->bdev; | |
4f024f37 KO |
273 | bio->bi_iter.bi_sector = begin + |
274 | sc->stripe[target_stripe].physical_start; | |
275 | bio->bi_iter.bi_size = to_bytes(end - begin); | |
7b76ec11 MP |
276 | return DM_MAPIO_REMAPPED; |
277 | } else { | |
278 | /* The range doesn't map to the target stripe */ | |
4246a0b6 | 279 | bio_endio(bio); |
7b76ec11 MP |
280 | return DM_MAPIO_SUBMITTED; |
281 | } | |
282 | } | |
283 | ||
7de3ee57 | 284 | static int stripe_map(struct dm_target *ti, struct bio *bio) |
1da177e4 | 285 | { |
65988525 | 286 | struct stripe_c *sc = ti->private; |
374bf7e7 | 287 | uint32_t stripe; |
55a62eef | 288 | unsigned target_bio_nr; |
1da177e4 | 289 | |
1eff9d32 | 290 | if (bio->bi_opf & REQ_PREFLUSH) { |
55a62eef AK |
291 | target_bio_nr = dm_bio_get_target_bio_nr(bio); |
292 | BUG_ON(target_bio_nr >= sc->stripes); | |
293 | bio->bi_bdev = sc->stripe[target_bio_nr].dev->bdev; | |
374bf7e7 MP |
294 | return DM_MAPIO_REMAPPED; |
295 | } | |
e6047149 | 296 | if (unlikely(bio_op(bio) == REQ_OP_DISCARD) || |
ac62d620 | 297 | unlikely(bio_op(bio) == REQ_OP_WRITE_ZEROES) || |
e6047149 | 298 | unlikely(bio_op(bio) == REQ_OP_WRITE_SAME)) { |
55a62eef AK |
299 | target_bio_nr = dm_bio_get_target_bio_nr(bio); |
300 | BUG_ON(target_bio_nr >= sc->stripes); | |
301 | return stripe_map_range(sc, bio, target_bio_nr); | |
7b76ec11 | 302 | } |
374bf7e7 | 303 | |
4f024f37 KO |
304 | stripe_map_sector(sc, bio->bi_iter.bi_sector, |
305 | &stripe, &bio->bi_iter.bi_sector); | |
1da177e4 | 306 | |
4f024f37 | 307 | bio->bi_iter.bi_sector += sc->stripe[stripe].physical_start; |
1da177e4 | 308 | bio->bi_bdev = sc->stripe[stripe].dev->bdev; |
65988525 | 309 | |
d2a7ad29 | 310 | return DM_MAPIO_REMAPPED; |
1da177e4 LT |
311 | } |
312 | ||
beec25b4 | 313 | static long stripe_direct_access(struct dm_target *ti, sector_t sector, |
f0c98ebc | 314 | void **kaddr, pfn_t *pfn, long size) |
beec25b4 TK |
315 | { |
316 | struct stripe_c *sc = ti->private; | |
317 | uint32_t stripe; | |
318 | struct block_device *bdev; | |
319 | struct blk_dax_ctl dax = { | |
320 | .size = size, | |
321 | }; | |
322 | long ret; | |
323 | ||
324 | stripe_map_sector(sc, sector, &stripe, &dax.sector); | |
325 | ||
326 | dax.sector += sc->stripe[stripe].physical_start; | |
327 | bdev = sc->stripe[stripe].dev->bdev; | |
328 | ||
329 | ret = bdev_direct_access(bdev, &dax); | |
330 | *kaddr = dax.addr; | |
331 | *pfn = dax.pfn; | |
332 | ||
333 | return ret; | |
334 | } | |
335 | ||
4f7f5c67 BW |
336 | /* |
337 | * Stripe status: | |
338 | * | |
339 | * INFO | |
340 | * #stripes [stripe_name <stripe_name>] [group word count] | |
341 | * [error count 'A|D' <error count 'A|D'>] | |
342 | * | |
343 | * TABLE | |
344 | * #stripes [stripe chunk size] | |
345 | * [stripe_name physical_start <stripe_name physical_start>] | |
346 | * | |
347 | */ | |
348 | ||
fd7c092e MP |
349 | static void stripe_status(struct dm_target *ti, status_type_t type, |
350 | unsigned status_flags, char *result, unsigned maxlen) | |
1da177e4 LT |
351 | { |
352 | struct stripe_c *sc = (struct stripe_c *) ti->private; | |
4f7f5c67 | 353 | char buffer[sc->stripes + 1]; |
1da177e4 LT |
354 | unsigned int sz = 0; |
355 | unsigned int i; | |
356 | ||
357 | switch (type) { | |
358 | case STATUSTYPE_INFO: | |
4f7f5c67 BW |
359 | DMEMIT("%d ", sc->stripes); |
360 | for (i = 0; i < sc->stripes; i++) { | |
361 | DMEMIT("%s ", sc->stripe[i].dev->name); | |
362 | buffer[i] = atomic_read(&(sc->stripe[i].error_count)) ? | |
363 | 'D' : 'A'; | |
364 | } | |
365 | buffer[i] = '\0'; | |
366 | DMEMIT("1 %s", buffer); | |
1da177e4 LT |
367 | break; |
368 | ||
369 | case STATUSTYPE_TABLE: | |
4ee218cd | 370 | DMEMIT("%d %llu", sc->stripes, |
eb850de6 | 371 | (unsigned long long)sc->chunk_size); |
1da177e4 | 372 | for (i = 0; i < sc->stripes; i++) |
4ee218cd AM |
373 | DMEMIT(" %s %llu", sc->stripe[i].dev->name, |
374 | (unsigned long long)sc->stripe[i].physical_start); | |
1da177e4 LT |
375 | break; |
376 | } | |
1da177e4 LT |
377 | } |
378 | ||
7de3ee57 | 379 | static int stripe_end_io(struct dm_target *ti, struct bio *bio, int error) |
a25eb944 BW |
380 | { |
381 | unsigned i; | |
382 | char major_minor[16]; | |
383 | struct stripe_c *sc = ti->private; | |
384 | ||
385 | if (!error) | |
386 | return 0; /* I/O complete */ | |
387 | ||
1eff9d32 | 388 | if ((error == -EWOULDBLOCK) && (bio->bi_opf & REQ_RAHEAD)) |
a25eb944 BW |
389 | return error; |
390 | ||
391 | if (error == -EOPNOTSUPP) | |
392 | return error; | |
393 | ||
394 | memset(major_minor, 0, sizeof(major_minor)); | |
395 | sprintf(major_minor, "%d:%d", | |
f331c029 TH |
396 | MAJOR(disk_devt(bio->bi_bdev->bd_disk)), |
397 | MINOR(disk_devt(bio->bi_bdev->bd_disk))); | |
a25eb944 BW |
398 | |
399 | /* | |
400 | * Test to see which stripe drive triggered the event | |
401 | * and increment error count for all stripes on that device. | |
402 | * If the error count for a given device exceeds the threshold | |
403 | * value we will no longer trigger any further events. | |
404 | */ | |
405 | for (i = 0; i < sc->stripes; i++) | |
406 | if (!strcmp(sc->stripe[i].dev->name, major_minor)) { | |
407 | atomic_inc(&(sc->stripe[i].error_count)); | |
408 | if (atomic_read(&(sc->stripe[i].error_count)) < | |
409 | DM_IO_ERROR_THRESHOLD) | |
f521f074 | 410 | schedule_work(&sc->trigger_event); |
a25eb944 BW |
411 | } |
412 | ||
413 | return error; | |
414 | } | |
415 | ||
af4874e0 MS |
416 | static int stripe_iterate_devices(struct dm_target *ti, |
417 | iterate_devices_callout_fn fn, void *data) | |
418 | { | |
419 | struct stripe_c *sc = ti->private; | |
420 | int ret = 0; | |
421 | unsigned i = 0; | |
422 | ||
5dea271b | 423 | do { |
af4874e0 | 424 | ret = fn(ti, sc->stripe[i].dev, |
5dea271b MS |
425 | sc->stripe[i].physical_start, |
426 | sc->stripe_width, data); | |
427 | } while (!ret && ++i < sc->stripes); | |
af4874e0 MS |
428 | |
429 | return ret; | |
430 | } | |
431 | ||
40bea431 MS |
432 | static void stripe_io_hints(struct dm_target *ti, |
433 | struct queue_limits *limits) | |
434 | { | |
435 | struct stripe_c *sc = ti->private; | |
eb850de6 | 436 | unsigned chunk_size = sc->chunk_size << SECTOR_SHIFT; |
40bea431 MS |
437 | |
438 | blk_limits_io_min(limits, chunk_size); | |
3c5820c7 | 439 | blk_limits_io_opt(limits, chunk_size * sc->stripes); |
40bea431 MS |
440 | } |
441 | ||
1da177e4 LT |
442 | static struct target_type stripe_target = { |
443 | .name = "striped", | |
beec25b4 | 444 | .version = {1, 6, 0}, |
e2460f2a | 445 | .features = DM_TARGET_PASSES_INTEGRITY, |
1da177e4 LT |
446 | .module = THIS_MODULE, |
447 | .ctr = stripe_ctr, | |
448 | .dtr = stripe_dtr, | |
449 | .map = stripe_map, | |
a25eb944 | 450 | .end_io = stripe_end_io, |
1da177e4 | 451 | .status = stripe_status, |
af4874e0 | 452 | .iterate_devices = stripe_iterate_devices, |
40bea431 | 453 | .io_hints = stripe_io_hints, |
beec25b4 | 454 | .direct_access = stripe_direct_access, |
1da177e4 LT |
455 | }; |
456 | ||
457 | int __init dm_stripe_init(void) | |
458 | { | |
459 | int r; | |
460 | ||
461 | r = dm_register_target(&stripe_target); | |
e223e1de | 462 | if (r < 0) |
72d94861 | 463 | DMWARN("target registration failed"); |
1da177e4 LT |
464 | |
465 | return r; | |
466 | } | |
467 | ||
468 | void dm_stripe_exit(void) | |
469 | { | |
10d3bd09 | 470 | dm_unregister_target(&stripe_target); |
1da177e4 | 471 | } |