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 | ||
586e80e6 | 7 | #include <linux/device-mapper.h> |
1da177e4 LT |
8 | |
9 | #include <linux/module.h> | |
10 | #include <linux/init.h> | |
11 | #include <linux/blkdev.h> | |
12 | #include <linux/bio.h> | |
13 | #include <linux/slab.h> | |
6f3c3f0a | 14 | #include <linux/log2.h> |
1da177e4 | 15 | |
72d94861 | 16 | #define DM_MSG_PREFIX "striped" |
a25eb944 | 17 | #define DM_IO_ERROR_THRESHOLD 15 |
72d94861 | 18 | |
1da177e4 LT |
19 | struct stripe { |
20 | struct dm_dev *dev; | |
21 | sector_t physical_start; | |
a25eb944 BW |
22 | |
23 | atomic_t error_count; | |
1da177e4 LT |
24 | }; |
25 | ||
26 | struct stripe_c { | |
27 | uint32_t stripes; | |
c96053b7 | 28 | int stripes_shift; |
1da177e4 LT |
29 | |
30 | /* The size of this target / num. stripes */ | |
31 | sector_t stripe_width; | |
32 | ||
eb850de6 | 33 | uint32_t chunk_size; |
33d07c0d | 34 | int chunk_size_shift; |
1da177e4 | 35 | |
a25eb944 BW |
36 | /* Needed for handling events */ |
37 | struct dm_target *ti; | |
38 | ||
39 | /* Work struct used for triggering events*/ | |
f521f074 | 40 | struct work_struct trigger_event; |
a25eb944 | 41 | |
1da177e4 LT |
42 | struct stripe stripe[0]; |
43 | }; | |
44 | ||
a25eb944 BW |
45 | /* |
46 | * An event is triggered whenever a drive | |
47 | * drops out of a stripe volume. | |
48 | */ | |
49 | static void trigger_event(struct work_struct *work) | |
50 | { | |
f521f074 TH |
51 | struct stripe_c *sc = container_of(work, struct stripe_c, |
52 | trigger_event); | |
a25eb944 | 53 | dm_table_event(sc->ti->table); |
a25eb944 BW |
54 | } |
55 | ||
1da177e4 LT |
56 | static inline struct stripe_c *alloc_context(unsigned int stripes) |
57 | { | |
58 | size_t len; | |
59 | ||
d63a5ce3 MP |
60 | if (dm_array_too_big(sizeof(struct stripe_c), sizeof(struct stripe), |
61 | stripes)) | |
1da177e4 LT |
62 | return NULL; |
63 | ||
64 | len = sizeof(struct stripe_c) + (sizeof(struct stripe) * stripes); | |
65 | ||
66 | return kmalloc(len, GFP_KERNEL); | |
67 | } | |
68 | ||
69 | /* | |
70 | * Parse a single <dev> <sector> pair | |
71 | */ | |
72 | static int get_stripe(struct dm_target *ti, struct stripe_c *sc, | |
73 | unsigned int stripe, char **argv) | |
74 | { | |
4ee218cd | 75 | unsigned long long start; |
31998ef1 | 76 | char dummy; |
1da177e4 | 77 | |
31998ef1 | 78 | if (sscanf(argv[1], "%llu%c", &start, &dummy) != 1) |
1da177e4 LT |
79 | return -EINVAL; |
80 | ||
8215d6ec | 81 | if (dm_get_device(ti, argv[0], dm_table_get_mode(ti->table), |
1da177e4 LT |
82 | &sc->stripe[stripe].dev)) |
83 | return -ENXIO; | |
84 | ||
85 | sc->stripe[stripe].physical_start = start; | |
a25eb944 | 86 | |
1da177e4 LT |
87 | return 0; |
88 | } | |
89 | ||
90 | /* | |
91 | * Construct a striped mapping. | |
eb850de6 | 92 | * <number of stripes> <chunk size> [<dev_path> <offset>]+ |
1da177e4 LT |
93 | */ |
94 | static int stripe_ctr(struct dm_target *ti, unsigned int argc, char **argv) | |
95 | { | |
96 | struct stripe_c *sc; | |
97 | sector_t width; | |
98 | uint32_t stripes; | |
99 | uint32_t chunk_size; | |
1da177e4 LT |
100 | int r; |
101 | unsigned int i; | |
102 | ||
103 | if (argc < 2) { | |
72d94861 | 104 | ti->error = "Not enough arguments"; |
1da177e4 LT |
105 | return -EINVAL; |
106 | } | |
107 | ||
1a66a08a | 108 | if (kstrtouint(argv[0], 10, &stripes) || !stripes) { |
72d94861 | 109 | ti->error = "Invalid stripe count"; |
1da177e4 LT |
110 | return -EINVAL; |
111 | } | |
112 | ||
8f069b41 | 113 | if (kstrtouint(argv[1], 10, &chunk_size) || !chunk_size) { |
eb850de6 | 114 | ti->error = "Invalid chunk_size"; |
1da177e4 LT |
115 | return -EINVAL; |
116 | } | |
117 | ||
eb850de6 MS |
118 | width = ti->len; |
119 | if (sector_div(width, chunk_size)) { | |
72d94861 | 120 | ti->error = "Target length not divisible by " |
8ba32fde KC |
121 | "chunk size"; |
122 | return -EINVAL; | |
123 | } | |
124 | ||
1da177e4 | 125 | if (sector_div(width, stripes)) { |
72d94861 | 126 | ti->error = "Target length not divisible by " |
1da177e4 LT |
127 | "number of stripes"; |
128 | return -EINVAL; | |
129 | } | |
130 | ||
131 | /* | |
132 | * Do we have enough arguments for that many stripes ? | |
133 | */ | |
134 | if (argc != (2 + 2 * stripes)) { | |
72d94861 | 135 | ti->error = "Not enough destinations " |
1da177e4 LT |
136 | "specified"; |
137 | return -EINVAL; | |
138 | } | |
139 | ||
140 | sc = alloc_context(stripes); | |
141 | if (!sc) { | |
72d94861 | 142 | ti->error = "Memory allocation for striped context " |
1da177e4 LT |
143 | "failed"; |
144 | return -ENOMEM; | |
145 | } | |
146 | ||
f521f074 | 147 | INIT_WORK(&sc->trigger_event, trigger_event); |
a25eb944 BW |
148 | |
149 | /* Set pointer to dm target; used in trigger_event */ | |
150 | sc->ti = ti; | |
1da177e4 LT |
151 | sc->stripes = stripes; |
152 | sc->stripe_width = width; | |
c96053b7 MP |
153 | |
154 | if (stripes & (stripes - 1)) | |
155 | sc->stripes_shift = -1; | |
1df05483 MP |
156 | else |
157 | sc->stripes_shift = __ffs(stripes); | |
c96053b7 | 158 | |
542f9038 MS |
159 | r = dm_set_target_max_io_len(ti, chunk_size); |
160 | if (r) | |
161 | return r; | |
162 | ||
55a62eef AK |
163 | ti->num_flush_bios = stripes; |
164 | ti->num_discard_bios = stripes; | |
165 | ti->num_write_same_bios = stripes; | |
1da177e4 | 166 | |
eb850de6 | 167 | sc->chunk_size = chunk_size; |
33d07c0d MP |
168 | if (chunk_size & (chunk_size - 1)) |
169 | sc->chunk_size_shift = -1; | |
170 | else | |
171 | sc->chunk_size_shift = __ffs(chunk_size); | |
1da177e4 LT |
172 | |
173 | /* | |
174 | * Get the stripe destinations. | |
175 | */ | |
176 | for (i = 0; i < stripes; i++) { | |
177 | argv += 2; | |
178 | ||
179 | r = get_stripe(ti, sc, i, argv); | |
180 | if (r < 0) { | |
72d94861 | 181 | ti->error = "Couldn't parse stripe destination"; |
1da177e4 LT |
182 | while (i--) |
183 | dm_put_device(ti, sc->stripe[i].dev); | |
184 | kfree(sc); | |
185 | return r; | |
186 | } | |
a25eb944 | 187 | atomic_set(&(sc->stripe[i].error_count), 0); |
1da177e4 LT |
188 | } |
189 | ||
190 | ti->private = sc; | |
a25eb944 | 191 | |
1da177e4 LT |
192 | return 0; |
193 | } | |
194 | ||
195 | static void stripe_dtr(struct dm_target *ti) | |
196 | { | |
197 | unsigned int i; | |
198 | struct stripe_c *sc = (struct stripe_c *) ti->private; | |
199 | ||
200 | for (i = 0; i < sc->stripes; i++) | |
201 | dm_put_device(ti, sc->stripe[i].dev); | |
202 | ||
43829731 | 203 | flush_work(&sc->trigger_event); |
1da177e4 LT |
204 | kfree(sc); |
205 | } | |
206 | ||
65988525 MP |
207 | static void stripe_map_sector(struct stripe_c *sc, sector_t sector, |
208 | uint32_t *stripe, sector_t *result) | |
209 | { | |
eb850de6 | 210 | sector_t chunk = dm_target_offset(sc->ti, sector); |
33d07c0d MP |
211 | sector_t chunk_offset; |
212 | ||
213 | if (sc->chunk_size_shift < 0) | |
214 | chunk_offset = sector_div(chunk, sc->chunk_size); | |
215 | else { | |
216 | chunk_offset = chunk & (sc->chunk_size - 1); | |
217 | chunk >>= sc->chunk_size_shift; | |
218 | } | |
65988525 | 219 | |
c96053b7 MP |
220 | if (sc->stripes_shift < 0) |
221 | *stripe = sector_div(chunk, sc->stripes); | |
222 | else { | |
1df05483 | 223 | *stripe = chunk & (sc->stripes - 1); |
c96053b7 MP |
224 | chunk >>= sc->stripes_shift; |
225 | } | |
226 | ||
33d07c0d MP |
227 | if (sc->chunk_size_shift < 0) |
228 | chunk *= sc->chunk_size; | |
229 | else | |
230 | chunk <<= sc->chunk_size_shift; | |
231 | ||
232 | *result = chunk + chunk_offset; | |
65988525 MP |
233 | } |
234 | ||
7b76ec11 MP |
235 | static void stripe_map_range_sector(struct stripe_c *sc, sector_t sector, |
236 | uint32_t target_stripe, sector_t *result) | |
237 | { | |
238 | uint32_t stripe; | |
239 | ||
240 | stripe_map_sector(sc, sector, &stripe, result); | |
241 | if (stripe == target_stripe) | |
242 | return; | |
eb850de6 MS |
243 | |
244 | /* round down */ | |
245 | sector = *result; | |
33d07c0d MP |
246 | if (sc->chunk_size_shift < 0) |
247 | *result -= sector_div(sector, sc->chunk_size); | |
248 | else | |
249 | *result = sector & ~(sector_t)(sc->chunk_size - 1); | |
eb850de6 | 250 | |
7b76ec11 | 251 | if (target_stripe < stripe) |
eb850de6 | 252 | *result += sc->chunk_size; /* next chunk */ |
7b76ec11 MP |
253 | } |
254 | ||
45e621d4 MS |
255 | static int stripe_map_range(struct stripe_c *sc, struct bio *bio, |
256 | uint32_t target_stripe) | |
7b76ec11 MP |
257 | { |
258 | sector_t begin, end; | |
259 | ||
260 | stripe_map_range_sector(sc, bio->bi_sector, target_stripe, &begin); | |
261 | stripe_map_range_sector(sc, bio->bi_sector + bio_sectors(bio), | |
262 | target_stripe, &end); | |
263 | if (begin < end) { | |
264 | bio->bi_bdev = sc->stripe[target_stripe].dev->bdev; | |
265 | bio->bi_sector = begin + sc->stripe[target_stripe].physical_start; | |
266 | bio->bi_size = to_bytes(end - begin); | |
267 | return DM_MAPIO_REMAPPED; | |
268 | } else { | |
269 | /* The range doesn't map to the target stripe */ | |
270 | bio_endio(bio, 0); | |
271 | return DM_MAPIO_SUBMITTED; | |
272 | } | |
273 | } | |
274 | ||
7de3ee57 | 275 | static int stripe_map(struct dm_target *ti, struct bio *bio) |
1da177e4 | 276 | { |
65988525 | 277 | struct stripe_c *sc = ti->private; |
374bf7e7 | 278 | uint32_t stripe; |
55a62eef | 279 | unsigned target_bio_nr; |
1da177e4 | 280 | |
d87f4c14 | 281 | if (bio->bi_rw & REQ_FLUSH) { |
55a62eef AK |
282 | target_bio_nr = dm_bio_get_target_bio_nr(bio); |
283 | BUG_ON(target_bio_nr >= sc->stripes); | |
284 | bio->bi_bdev = sc->stripe[target_bio_nr].dev->bdev; | |
374bf7e7 MP |
285 | return DM_MAPIO_REMAPPED; |
286 | } | |
45e621d4 MS |
287 | if (unlikely(bio->bi_rw & REQ_DISCARD) || |
288 | unlikely(bio->bi_rw & REQ_WRITE_SAME)) { | |
55a62eef AK |
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); | |
7b76ec11 | 292 | } |
374bf7e7 | 293 | |
65988525 | 294 | stripe_map_sector(sc, bio->bi_sector, &stripe, &bio->bi_sector); |
1da177e4 | 295 | |
65988525 | 296 | bio->bi_sector += sc->stripe[stripe].physical_start; |
1da177e4 | 297 | bio->bi_bdev = sc->stripe[stripe].dev->bdev; |
65988525 | 298 | |
d2a7ad29 | 299 | return DM_MAPIO_REMAPPED; |
1da177e4 LT |
300 | } |
301 | ||
4f7f5c67 BW |
302 | /* |
303 | * Stripe status: | |
304 | * | |
305 | * INFO | |
306 | * #stripes [stripe_name <stripe_name>] [group word count] | |
307 | * [error count 'A|D' <error count 'A|D'>] | |
308 | * | |
309 | * TABLE | |
310 | * #stripes [stripe chunk size] | |
311 | * [stripe_name physical_start <stripe_name physical_start>] | |
312 | * | |
313 | */ | |
314 | ||
fd7c092e MP |
315 | static void stripe_status(struct dm_target *ti, status_type_t type, |
316 | unsigned status_flags, char *result, unsigned maxlen) | |
1da177e4 LT |
317 | { |
318 | struct stripe_c *sc = (struct stripe_c *) ti->private; | |
4f7f5c67 | 319 | char buffer[sc->stripes + 1]; |
1da177e4 LT |
320 | unsigned int sz = 0; |
321 | unsigned int i; | |
322 | ||
323 | switch (type) { | |
324 | case STATUSTYPE_INFO: | |
4f7f5c67 BW |
325 | DMEMIT("%d ", sc->stripes); |
326 | for (i = 0; i < sc->stripes; i++) { | |
327 | DMEMIT("%s ", sc->stripe[i].dev->name); | |
328 | buffer[i] = atomic_read(&(sc->stripe[i].error_count)) ? | |
329 | 'D' : 'A'; | |
330 | } | |
331 | buffer[i] = '\0'; | |
332 | DMEMIT("1 %s", buffer); | |
1da177e4 LT |
333 | break; |
334 | ||
335 | case STATUSTYPE_TABLE: | |
4ee218cd | 336 | DMEMIT("%d %llu", sc->stripes, |
eb850de6 | 337 | (unsigned long long)sc->chunk_size); |
1da177e4 | 338 | for (i = 0; i < sc->stripes; i++) |
4ee218cd AM |
339 | DMEMIT(" %s %llu", sc->stripe[i].dev->name, |
340 | (unsigned long long)sc->stripe[i].physical_start); | |
1da177e4 LT |
341 | break; |
342 | } | |
1da177e4 LT |
343 | } |
344 | ||
7de3ee57 | 345 | static int stripe_end_io(struct dm_target *ti, struct bio *bio, int error) |
a25eb944 BW |
346 | { |
347 | unsigned i; | |
348 | char major_minor[16]; | |
349 | struct stripe_c *sc = ti->private; | |
350 | ||
351 | if (!error) | |
352 | return 0; /* I/O complete */ | |
353 | ||
7b6d91da | 354 | if ((error == -EWOULDBLOCK) && (bio->bi_rw & REQ_RAHEAD)) |
a25eb944 BW |
355 | return error; |
356 | ||
357 | if (error == -EOPNOTSUPP) | |
358 | return error; | |
359 | ||
360 | memset(major_minor, 0, sizeof(major_minor)); | |
361 | sprintf(major_minor, "%d:%d", | |
f331c029 TH |
362 | MAJOR(disk_devt(bio->bi_bdev->bd_disk)), |
363 | MINOR(disk_devt(bio->bi_bdev->bd_disk))); | |
a25eb944 BW |
364 | |
365 | /* | |
366 | * Test to see which stripe drive triggered the event | |
367 | * and increment error count for all stripes on that device. | |
368 | * If the error count for a given device exceeds the threshold | |
369 | * value we will no longer trigger any further events. | |
370 | */ | |
371 | for (i = 0; i < sc->stripes; i++) | |
372 | if (!strcmp(sc->stripe[i].dev->name, major_minor)) { | |
373 | atomic_inc(&(sc->stripe[i].error_count)); | |
374 | if (atomic_read(&(sc->stripe[i].error_count)) < | |
375 | DM_IO_ERROR_THRESHOLD) | |
f521f074 | 376 | schedule_work(&sc->trigger_event); |
a25eb944 BW |
377 | } |
378 | ||
379 | return error; | |
380 | } | |
381 | ||
af4874e0 MS |
382 | static int stripe_iterate_devices(struct dm_target *ti, |
383 | iterate_devices_callout_fn fn, void *data) | |
384 | { | |
385 | struct stripe_c *sc = ti->private; | |
386 | int ret = 0; | |
387 | unsigned i = 0; | |
388 | ||
5dea271b | 389 | do { |
af4874e0 | 390 | ret = fn(ti, sc->stripe[i].dev, |
5dea271b MS |
391 | sc->stripe[i].physical_start, |
392 | sc->stripe_width, data); | |
393 | } while (!ret && ++i < sc->stripes); | |
af4874e0 MS |
394 | |
395 | return ret; | |
396 | } | |
397 | ||
40bea431 MS |
398 | static void stripe_io_hints(struct dm_target *ti, |
399 | struct queue_limits *limits) | |
400 | { | |
401 | struct stripe_c *sc = ti->private; | |
eb850de6 | 402 | unsigned chunk_size = sc->chunk_size << SECTOR_SHIFT; |
40bea431 MS |
403 | |
404 | blk_limits_io_min(limits, chunk_size); | |
3c5820c7 | 405 | blk_limits_io_opt(limits, chunk_size * sc->stripes); |
40bea431 MS |
406 | } |
407 | ||
29915202 MM |
408 | static int stripe_merge(struct dm_target *ti, struct bvec_merge_data *bvm, |
409 | struct bio_vec *biovec, int max_size) | |
410 | { | |
411 | struct stripe_c *sc = ti->private; | |
412 | sector_t bvm_sector = bvm->bi_sector; | |
413 | uint32_t stripe; | |
414 | struct request_queue *q; | |
415 | ||
416 | stripe_map_sector(sc, bvm_sector, &stripe, &bvm_sector); | |
417 | ||
418 | q = bdev_get_queue(sc->stripe[stripe].dev->bdev); | |
419 | if (!q->merge_bvec_fn) | |
420 | return max_size; | |
421 | ||
422 | bvm->bi_bdev = sc->stripe[stripe].dev->bdev; | |
423 | bvm->bi_sector = sc->stripe[stripe].physical_start + bvm_sector; | |
424 | ||
425 | return min(max_size, q->merge_bvec_fn(q, bvm, biovec)); | |
426 | } | |
427 | ||
1da177e4 LT |
428 | static struct target_type stripe_target = { |
429 | .name = "striped", | |
fd7c092e | 430 | .version = {1, 5, 1}, |
1da177e4 LT |
431 | .module = THIS_MODULE, |
432 | .ctr = stripe_ctr, | |
433 | .dtr = stripe_dtr, | |
434 | .map = stripe_map, | |
a25eb944 | 435 | .end_io = stripe_end_io, |
1da177e4 | 436 | .status = stripe_status, |
af4874e0 | 437 | .iterate_devices = stripe_iterate_devices, |
40bea431 | 438 | .io_hints = stripe_io_hints, |
29915202 | 439 | .merge = stripe_merge, |
1da177e4 LT |
440 | }; |
441 | ||
442 | int __init dm_stripe_init(void) | |
443 | { | |
444 | int r; | |
445 | ||
446 | r = dm_register_target(&stripe_target); | |
6edebdee | 447 | if (r < 0) { |
72d94861 | 448 | DMWARN("target registration failed"); |
6edebdee HM |
449 | return r; |
450 | } | |
1da177e4 LT |
451 | |
452 | return r; | |
453 | } | |
454 | ||
455 | void dm_stripe_exit(void) | |
456 | { | |
10d3bd09 | 457 | dm_unregister_target(&stripe_target); |
1da177e4 | 458 | } |