treewide: remove redundant IS_ERR() before error code check
[linux/fpc-iii.git] / drivers / md / dm-stripe.c
blob63bbcc20f49aa1a69a72b6fa2fa2901a3207abde
1 /*
2 * Copyright (C) 2001-2003 Sistina Software (UK) Limited.
4 * This file is released under the GPL.
5 */
7 #include "dm.h"
8 #include <linux/device-mapper.h>
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>
18 #define DM_MSG_PREFIX "striped"
19 #define DM_IO_ERROR_THRESHOLD 15
21 struct stripe {
22 struct dm_dev *dev;
23 sector_t physical_start;
25 atomic_t error_count;
28 struct stripe_c {
29 uint32_t stripes;
30 int stripes_shift;
32 /* The size of this target / num. stripes */
33 sector_t stripe_width;
35 uint32_t chunk_size;
36 int chunk_size_shift;
38 /* Needed for handling events */
39 struct dm_target *ti;
41 /* Work struct used for triggering events*/
42 struct work_struct trigger_event;
44 struct stripe stripe[0];
48 * An event is triggered whenever a drive
49 * drops out of a stripe volume.
51 static void trigger_event(struct work_struct *work)
53 struct stripe_c *sc = container_of(work, struct stripe_c,
54 trigger_event);
55 dm_table_event(sc->ti->table);
59 * Parse a single <dev> <sector> pair
61 static int get_stripe(struct dm_target *ti, struct stripe_c *sc,
62 unsigned int stripe, char **argv)
64 unsigned long long start;
65 char dummy;
66 int ret;
68 if (sscanf(argv[1], "%llu%c", &start, &dummy) != 1)
69 return -EINVAL;
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;
76 sc->stripe[stripe].physical_start = start;
78 return 0;
82 * Construct a striped mapping.
83 * <number of stripes> <chunk size> [<dev_path> <offset>]+
85 static int stripe_ctr(struct dm_target *ti, unsigned int argc, char **argv)
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;
94 if (argc < 2) {
95 ti->error = "Not enough arguments";
96 return -EINVAL;
99 if (kstrtouint(argv[0], 10, &stripes) || !stripes) {
100 ti->error = "Invalid stripe count";
101 return -EINVAL;
104 if (kstrtouint(argv[1], 10, &chunk_size) || !chunk_size) {
105 ti->error = "Invalid chunk_size";
106 return -EINVAL;
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;
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;
124 * Do we have enough arguments for that many stripes ?
126 if (argc != (2 + 2 * stripes)) {
127 ti->error = "Not enough destinations "
128 "specified";
129 return -EINVAL;
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;
139 INIT_WORK(&sc->trigger_event, trigger_event);
141 /* Set pointer to dm target; used in trigger_event */
142 sc->ti = ti;
143 sc->stripes = stripes;
144 sc->stripe_width = width;
146 if (stripes & (stripes - 1))
147 sc->stripes_shift = -1;
148 else
149 sc->stripes_shift = __ffs(stripes);
151 r = dm_set_target_max_io_len(ti, chunk_size);
152 if (r) {
153 kfree(sc);
154 return r;
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;
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);
170 * Get the stripe destinations.
172 for (i = 0; i < stripes; i++) {
173 argv += 2;
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;
183 atomic_set(&(sc->stripe[i].error_count), 0);
186 ti->private = sc;
188 return 0;
191 static void stripe_dtr(struct dm_target *ti)
193 unsigned int i;
194 struct stripe_c *sc = (struct stripe_c *) ti->private;
196 for (i = 0; i < sc->stripes; i++)
197 dm_put_device(ti, sc->stripe[i].dev);
199 flush_work(&sc->trigger_event);
200 kfree(sc);
203 static void stripe_map_sector(struct stripe_c *sc, sector_t sector,
204 uint32_t *stripe, sector_t *result)
206 sector_t chunk = dm_target_offset(sc->ti, sector);
207 sector_t chunk_offset;
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;
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;
223 if (sc->chunk_size_shift < 0)
224 chunk *= sc->chunk_size;
225 else
226 chunk <<= sc->chunk_size_shift;
228 *result = chunk + chunk_offset;
231 static void stripe_map_range_sector(struct stripe_c *sc, sector_t sector,
232 uint32_t target_stripe, sector_t *result)
234 uint32_t stripe;
236 stripe_map_sector(sc, sector, &stripe, result);
237 if (stripe == target_stripe)
238 return;
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);
247 if (target_stripe < stripe)
248 *result += sc->chunk_size; /* next chunk */
251 static int stripe_map_range(struct stripe_c *sc, struct bio *bio,
252 uint32_t target_stripe)
254 sector_t begin, end;
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;
273 static int stripe_map(struct dm_target *ti, struct bio *bio)
275 struct stripe_c *sc = ti->private;
276 uint32_t stripe;
277 unsigned target_bio_nr;
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;
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);
294 stripe_map_sector(sc, bio->bi_iter.bi_sector,
295 &stripe, &bio->bi_iter.bi_sector);
297 bio->bi_iter.bi_sector += sc->stripe[stripe].physical_start;
298 bio_set_dev(bio, sc->stripe[stripe].dev->bdev);
300 return DM_MAPIO_REMAPPED;
303 #if IS_ENABLED(CONFIG_DAX_DRIVER)
304 static long stripe_dax_direct_access(struct dm_target *ti, pgoff_t pgoff,
305 long nr_pages, void **kaddr, pfn_t *pfn)
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;
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;
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);
325 static size_t stripe_dax_copy_from_iter(struct dm_target *ti, pgoff_t pgoff,
326 void *addr, size_t bytes, struct iov_iter *i)
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;
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;
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);
344 static size_t stripe_dax_copy_to_iter(struct dm_target *ti, pgoff_t pgoff,
345 void *addr, size_t bytes, struct iov_iter *i)
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;
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;
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);
363 #else
364 #define stripe_dax_direct_access NULL
365 #define stripe_dax_copy_from_iter NULL
366 #define stripe_dax_copy_to_iter NULL
367 #endif
370 * Stripe status:
372 * INFO
373 * #stripes [stripe_name <stripe_name>] [group word count]
374 * [error count 'A|D' <error count 'A|D'>]
376 * TABLE
377 * #stripes [stripe chunk size]
378 * [stripe_name physical_start <stripe_name physical_start>]
382 static void stripe_status(struct dm_target *ti, status_type_t type,
383 unsigned status_flags, char *result, unsigned maxlen)
385 struct stripe_c *sc = (struct stripe_c *) ti->private;
386 unsigned int sz = 0;
387 unsigned int i;
389 switch (type) {
390 case STATUSTYPE_INFO:
391 DMEMIT("%d ", sc->stripes);
392 for (i = 0; i < sc->stripes; i++) {
393 DMEMIT("%s ", sc->stripe[i].dev->name);
395 DMEMIT("1 ");
396 for (i = 0; i < sc->stripes; i++) {
397 DMEMIT("%c", atomic_read(&(sc->stripe[i].error_count)) ?
398 'D' : 'A');
400 break;
402 case STATUSTYPE_TABLE:
403 DMEMIT("%d %llu", sc->stripes,
404 (unsigned long long)sc->chunk_size);
405 for (i = 0; i < sc->stripes; i++)
406 DMEMIT(" %s %llu", sc->stripe[i].dev->name,
407 (unsigned long long)sc->stripe[i].physical_start);
408 break;
412 static int stripe_end_io(struct dm_target *ti, struct bio *bio,
413 blk_status_t *error)
415 unsigned i;
416 char major_minor[16];
417 struct stripe_c *sc = ti->private;
419 if (!*error)
420 return DM_ENDIO_DONE; /* I/O complete */
422 if (bio->bi_opf & REQ_RAHEAD)
423 return DM_ENDIO_DONE;
425 if (*error == BLK_STS_NOTSUPP)
426 return DM_ENDIO_DONE;
428 memset(major_minor, 0, sizeof(major_minor));
429 sprintf(major_minor, "%d:%d", MAJOR(bio_dev(bio)), MINOR(bio_dev(bio)));
432 * Test to see which stripe drive triggered the event
433 * and increment error count for all stripes on that device.
434 * If the error count for a given device exceeds the threshold
435 * value we will no longer trigger any further events.
437 for (i = 0; i < sc->stripes; i++)
438 if (!strcmp(sc->stripe[i].dev->name, major_minor)) {
439 atomic_inc(&(sc->stripe[i].error_count));
440 if (atomic_read(&(sc->stripe[i].error_count)) <
441 DM_IO_ERROR_THRESHOLD)
442 schedule_work(&sc->trigger_event);
445 return DM_ENDIO_DONE;
448 static int stripe_iterate_devices(struct dm_target *ti,
449 iterate_devices_callout_fn fn, void *data)
451 struct stripe_c *sc = ti->private;
452 int ret = 0;
453 unsigned i = 0;
455 do {
456 ret = fn(ti, sc->stripe[i].dev,
457 sc->stripe[i].physical_start,
458 sc->stripe_width, data);
459 } while (!ret && ++i < sc->stripes);
461 return ret;
464 static void stripe_io_hints(struct dm_target *ti,
465 struct queue_limits *limits)
467 struct stripe_c *sc = ti->private;
468 unsigned chunk_size = sc->chunk_size << SECTOR_SHIFT;
470 blk_limits_io_min(limits, chunk_size);
471 blk_limits_io_opt(limits, chunk_size * sc->stripes);
474 static struct target_type stripe_target = {
475 .name = "striped",
476 .version = {1, 6, 0},
477 .features = DM_TARGET_PASSES_INTEGRITY,
478 .module = THIS_MODULE,
479 .ctr = stripe_ctr,
480 .dtr = stripe_dtr,
481 .map = stripe_map,
482 .end_io = stripe_end_io,
483 .status = stripe_status,
484 .iterate_devices = stripe_iterate_devices,
485 .io_hints = stripe_io_hints,
486 .direct_access = stripe_dax_direct_access,
487 .dax_copy_from_iter = stripe_dax_copy_from_iter,
488 .dax_copy_to_iter = stripe_dax_copy_to_iter,
491 int __init dm_stripe_init(void)
493 int r;
495 r = dm_register_target(&stripe_target);
496 if (r < 0)
497 DMWARN("target registration failed");
499 return r;
502 void dm_stripe_exit(void)
504 dm_unregister_target(&stripe_target);