Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * Copyright (C) 2003 Sistina Software | |
891ce207 | 3 | * Copyright (C) 2006 Red Hat GmbH |
1da177e4 LT |
4 | * |
5 | * This file is released under the GPL. | |
6 | */ | |
7 | ||
4cc96131 | 8 | #include "dm-core.h" |
952b3557 | 9 | |
586e80e6 | 10 | #include <linux/device-mapper.h> |
1da177e4 LT |
11 | |
12 | #include <linux/bio.h> | |
10f1d5d1 | 13 | #include <linux/completion.h> |
1da177e4 LT |
14 | #include <linux/mempool.h> |
15 | #include <linux/module.h> | |
16 | #include <linux/sched.h> | |
17 | #include <linux/slab.h> | |
a765e20e | 18 | #include <linux/dm-io.h> |
1da177e4 | 19 | |
f1e53987 MP |
20 | #define DM_MSG_PREFIX "io" |
21 | ||
22 | #define DM_IO_MAX_REGIONS BITS_PER_LONG | |
23 | ||
891ce207 HM |
24 | struct dm_io_client { |
25 | mempool_t *pool; | |
26 | struct bio_set *bios; | |
27 | }; | |
28 | ||
f1e53987 MP |
29 | /* |
30 | * Aligning 'struct io' reduces the number of bits required to store | |
31 | * its address. Refer to store_io_and_region_in_bio() below. | |
32 | */ | |
1da177e4 | 33 | struct io { |
e01fd7ee | 34 | unsigned long error_bits; |
1da177e4 | 35 | atomic_t count; |
891ce207 | 36 | struct dm_io_client *client; |
1da177e4 LT |
37 | io_notify_fn callback; |
38 | void *context; | |
bb91bc7b MP |
39 | void *vma_invalidate_address; |
40 | unsigned long vma_invalidate_size; | |
f1e53987 | 41 | } __attribute__((aligned(DM_IO_MAX_REGIONS))); |
1da177e4 | 42 | |
952b3557 MP |
43 | static struct kmem_cache *_dm_io_cache; |
44 | ||
c8b03afe HM |
45 | /* |
46 | * Create a client with mempool and bioset. | |
47 | */ | |
bda8efec | 48 | struct dm_io_client *dm_io_client_create(void) |
c8b03afe | 49 | { |
c8b03afe | 50 | struct dm_io_client *client; |
e8603136 | 51 | unsigned min_ios = dm_get_reserved_bio_based_ios(); |
c8b03afe HM |
52 | |
53 | client = kmalloc(sizeof(*client), GFP_KERNEL); | |
54 | if (!client) | |
55 | return ERR_PTR(-ENOMEM); | |
56 | ||
e8603136 | 57 | client->pool = mempool_create_slab_pool(min_ios, _dm_io_cache); |
c8b03afe HM |
58 | if (!client->pool) |
59 | goto bad; | |
60 | ||
e8603136 | 61 | client->bios = bioset_create(min_ios, 0); |
c8b03afe HM |
62 | if (!client->bios) |
63 | goto bad; | |
64 | ||
65 | return client; | |
66 | ||
67 | bad: | |
6f65985e | 68 | mempool_destroy(client->pool); |
c8b03afe HM |
69 | kfree(client); |
70 | return ERR_PTR(-ENOMEM); | |
71 | } | |
72 | EXPORT_SYMBOL(dm_io_client_create); | |
73 | ||
c8b03afe HM |
74 | void dm_io_client_destroy(struct dm_io_client *client) |
75 | { | |
76 | mempool_destroy(client->pool); | |
77 | bioset_free(client->bios); | |
78 | kfree(client); | |
79 | } | |
80 | EXPORT_SYMBOL(dm_io_client_destroy); | |
81 | ||
1da177e4 LT |
82 | /*----------------------------------------------------------------- |
83 | * We need to keep track of which region a bio is doing io for. | |
f1e53987 MP |
84 | * To avoid a memory allocation to store just 5 or 6 bits, we |
85 | * ensure the 'struct io' pointer is aligned so enough low bits are | |
86 | * always zero and then combine it with the region number directly in | |
87 | * bi_private. | |
1da177e4 | 88 | *---------------------------------------------------------------*/ |
f1e53987 MP |
89 | static void store_io_and_region_in_bio(struct bio *bio, struct io *io, |
90 | unsigned region) | |
1da177e4 | 91 | { |
f1e53987 MP |
92 | if (unlikely(!IS_ALIGNED((unsigned long)io, DM_IO_MAX_REGIONS))) { |
93 | DMCRIT("Unaligned struct io pointer %p", io); | |
94 | BUG(); | |
95 | } | |
96 | ||
97 | bio->bi_private = (void *)((unsigned long)io | region); | |
1da177e4 LT |
98 | } |
99 | ||
f1e53987 MP |
100 | static void retrieve_io_and_region_from_bio(struct bio *bio, struct io **io, |
101 | unsigned *region) | |
1da177e4 | 102 | { |
f1e53987 MP |
103 | unsigned long val = (unsigned long)bio->bi_private; |
104 | ||
105 | *io = (void *)(val & -(unsigned long)DM_IO_MAX_REGIONS); | |
106 | *region = val & (DM_IO_MAX_REGIONS - 1); | |
1da177e4 LT |
107 | } |
108 | ||
109 | /*----------------------------------------------------------------- | |
110 | * We need an io object to keep track of the number of bios that | |
111 | * have been dispatched for a particular io. | |
112 | *---------------------------------------------------------------*/ | |
97e7cdf1 | 113 | static void complete_io(struct io *io) |
1da177e4 | 114 | { |
97e7cdf1 JT |
115 | unsigned long error_bits = io->error_bits; |
116 | io_notify_fn fn = io->callback; | |
117 | void *context = io->context; | |
1da177e4 | 118 | |
97e7cdf1 JT |
119 | if (io->vma_invalidate_size) |
120 | invalidate_kernel_vmap_range(io->vma_invalidate_address, | |
121 | io->vma_invalidate_size); | |
bb91bc7b | 122 | |
97e7cdf1 JT |
123 | mempool_free(io, io->client->pool); |
124 | fn(error_bits, context); | |
125 | } | |
1da177e4 | 126 | |
97e7cdf1 JT |
127 | static void dec_count(struct io *io, unsigned int region, int error) |
128 | { | |
129 | if (error) | |
130 | set_bit(region, &io->error_bits); | |
1da177e4 | 131 | |
97e7cdf1 JT |
132 | if (atomic_dec_and_test(&io->count)) |
133 | complete_io(io); | |
1da177e4 LT |
134 | } |
135 | ||
4246a0b6 | 136 | static void endio(struct bio *bio) |
1da177e4 | 137 | { |
c897feb3 HM |
138 | struct io *io; |
139 | unsigned region; | |
9b81c842 | 140 | int error; |
1da177e4 | 141 | |
4246a0b6 | 142 | if (bio->bi_error && bio_data_dir(bio) == READ) |
1da177e4 LT |
143 | zero_fill_bio(bio); |
144 | ||
c897feb3 HM |
145 | /* |
146 | * The bio destructor in bio_put() may use the io object. | |
147 | */ | |
f1e53987 | 148 | retrieve_io_and_region_from_bio(bio, &io, ®ion); |
c897feb3 | 149 | |
9b81c842 | 150 | error = bio->bi_error; |
1da177e4 LT |
151 | bio_put(bio); |
152 | ||
9b81c842 | 153 | dec_count(io, region, error); |
1da177e4 LT |
154 | } |
155 | ||
156 | /*----------------------------------------------------------------- | |
157 | * These little objects provide an abstraction for getting a new | |
158 | * destination page for io. | |
159 | *---------------------------------------------------------------*/ | |
160 | struct dpages { | |
161 | void (*get_page)(struct dpages *dp, | |
162 | struct page **p, unsigned long *len, unsigned *offset); | |
163 | void (*next_page)(struct dpages *dp); | |
164 | ||
165 | unsigned context_u; | |
166 | void *context_ptr; | |
bb91bc7b MP |
167 | |
168 | void *vma_invalidate_address; | |
169 | unsigned long vma_invalidate_size; | |
1da177e4 LT |
170 | }; |
171 | ||
172 | /* | |
173 | * Functions for getting the pages from a list. | |
174 | */ | |
175 | static void list_get_page(struct dpages *dp, | |
176 | struct page **p, unsigned long *len, unsigned *offset) | |
177 | { | |
178 | unsigned o = dp->context_u; | |
179 | struct page_list *pl = (struct page_list *) dp->context_ptr; | |
180 | ||
181 | *p = pl->page; | |
182 | *len = PAGE_SIZE - o; | |
183 | *offset = o; | |
184 | } | |
185 | ||
186 | static void list_next_page(struct dpages *dp) | |
187 | { | |
188 | struct page_list *pl = (struct page_list *) dp->context_ptr; | |
189 | dp->context_ptr = pl->next; | |
190 | dp->context_u = 0; | |
191 | } | |
192 | ||
193 | static void list_dp_init(struct dpages *dp, struct page_list *pl, unsigned offset) | |
194 | { | |
195 | dp->get_page = list_get_page; | |
196 | dp->next_page = list_next_page; | |
197 | dp->context_u = offset; | |
198 | dp->context_ptr = pl; | |
199 | } | |
200 | ||
201 | /* | |
202 | * Functions for getting the pages from a bvec. | |
203 | */ | |
d73f9907 MP |
204 | static void bio_get_page(struct dpages *dp, struct page **p, |
205 | unsigned long *len, unsigned *offset) | |
1da177e4 | 206 | { |
d73f9907 MP |
207 | struct bio_vec *bvec = dp->context_ptr; |
208 | *p = bvec->bv_page; | |
209 | *len = bvec->bv_len - dp->context_u; | |
210 | *offset = bvec->bv_offset + dp->context_u; | |
1da177e4 LT |
211 | } |
212 | ||
003b5c57 | 213 | static void bio_next_page(struct dpages *dp) |
1da177e4 | 214 | { |
d73f9907 MP |
215 | struct bio_vec *bvec = dp->context_ptr; |
216 | dp->context_ptr = bvec + 1; | |
217 | dp->context_u = 0; | |
1da177e4 LT |
218 | } |
219 | ||
003b5c57 | 220 | static void bio_dp_init(struct dpages *dp, struct bio *bio) |
1da177e4 | 221 | { |
003b5c57 KO |
222 | dp->get_page = bio_get_page; |
223 | dp->next_page = bio_next_page; | |
d73f9907 MP |
224 | dp->context_ptr = __bvec_iter_bvec(bio->bi_io_vec, bio->bi_iter); |
225 | dp->context_u = bio->bi_iter.bi_bvec_done; | |
1da177e4 LT |
226 | } |
227 | ||
c8b03afe HM |
228 | /* |
229 | * Functions for getting the pages from a VMA. | |
230 | */ | |
1da177e4 LT |
231 | static void vm_get_page(struct dpages *dp, |
232 | struct page **p, unsigned long *len, unsigned *offset) | |
233 | { | |
234 | *p = vmalloc_to_page(dp->context_ptr); | |
235 | *offset = dp->context_u; | |
236 | *len = PAGE_SIZE - dp->context_u; | |
237 | } | |
238 | ||
239 | static void vm_next_page(struct dpages *dp) | |
240 | { | |
241 | dp->context_ptr += PAGE_SIZE - dp->context_u; | |
242 | dp->context_u = 0; | |
243 | } | |
244 | ||
245 | static void vm_dp_init(struct dpages *dp, void *data) | |
246 | { | |
247 | dp->get_page = vm_get_page; | |
248 | dp->next_page = vm_next_page; | |
93bbf583 | 249 | dp->context_u = offset_in_page(data); |
1da177e4 LT |
250 | dp->context_ptr = data; |
251 | } | |
252 | ||
c8b03afe HM |
253 | /* |
254 | * Functions for getting the pages from kernel memory. | |
255 | */ | |
256 | static void km_get_page(struct dpages *dp, struct page **p, unsigned long *len, | |
257 | unsigned *offset) | |
258 | { | |
259 | *p = virt_to_page(dp->context_ptr); | |
260 | *offset = dp->context_u; | |
261 | *len = PAGE_SIZE - dp->context_u; | |
262 | } | |
263 | ||
264 | static void km_next_page(struct dpages *dp) | |
265 | { | |
266 | dp->context_ptr += PAGE_SIZE - dp->context_u; | |
267 | dp->context_u = 0; | |
268 | } | |
269 | ||
270 | static void km_dp_init(struct dpages *dp, void *data) | |
271 | { | |
272 | dp->get_page = km_get_page; | |
273 | dp->next_page = km_next_page; | |
93bbf583 | 274 | dp->context_u = offset_in_page(data); |
c8b03afe HM |
275 | dp->context_ptr = data; |
276 | } | |
277 | ||
1da177e4 LT |
278 | /*----------------------------------------------------------------- |
279 | * IO routines that accept a list of pages. | |
280 | *---------------------------------------------------------------*/ | |
e6047149 MC |
281 | static void do_region(int op, int op_flags, unsigned region, |
282 | struct dm_io_region *where, struct dpages *dp, | |
283 | struct io *io) | |
1da177e4 LT |
284 | { |
285 | struct bio *bio; | |
286 | struct page *page; | |
287 | unsigned long len; | |
288 | unsigned offset; | |
289 | unsigned num_bvecs; | |
290 | sector_t remaining = where->count; | |
0c535e0d | 291 | struct request_queue *q = bdev_get_queue(where->bdev); |
70d6c400 MS |
292 | unsigned short logical_block_size = queue_logical_block_size(q); |
293 | sector_t num_sectors; | |
e5db2980 | 294 | unsigned int uninitialized_var(special_cmd_max_sectors); |
1da177e4 | 295 | |
e5db2980 DW |
296 | /* |
297 | * Reject unsupported discard and write same requests. | |
298 | */ | |
e6047149 | 299 | if (op == REQ_OP_DISCARD) |
e5db2980 | 300 | special_cmd_max_sectors = q->limits.max_discard_sectors; |
e6047149 | 301 | else if (op == REQ_OP_WRITE_SAME) |
e5db2980 | 302 | special_cmd_max_sectors = q->limits.max_write_same_sectors; |
e6047149 MC |
303 | if ((op == REQ_OP_DISCARD || op == REQ_OP_WRITE_SAME) && |
304 | special_cmd_max_sectors == 0) { | |
37527b86 DW |
305 | dec_count(io, region, -EOPNOTSUPP); |
306 | return; | |
307 | } | |
308 | ||
12fc0f49 | 309 | /* |
e6047149 | 310 | * where->count may be zero if op holds a flush and we need to |
d87f4c14 | 311 | * send a zero-sized flush. |
12fc0f49 MP |
312 | */ |
313 | do { | |
1da177e4 | 314 | /* |
f1e53987 | 315 | * Allocate a suitably sized-bio. |
1da177e4 | 316 | */ |
e6047149 | 317 | if ((op == REQ_OP_DISCARD) || (op == REQ_OP_WRITE_SAME)) |
0c535e0d MB |
318 | num_bvecs = 1; |
319 | else | |
b54ffb73 | 320 | num_bvecs = min_t(int, BIO_MAX_PAGES, |
0c535e0d MB |
321 | dm_sector_div_up(remaining, (PAGE_SIZE >> SECTOR_SHIFT))); |
322 | ||
bf17ce3a | 323 | bio = bio_alloc_bioset(GFP_NOIO, num_bvecs, io->client->bios); |
4f024f37 | 324 | bio->bi_iter.bi_sector = where->sector + (where->count - remaining); |
1da177e4 LT |
325 | bio->bi_bdev = where->bdev; |
326 | bio->bi_end_io = endio; | |
e6047149 | 327 | bio_set_op_attrs(bio, op, op_flags); |
f1e53987 | 328 | store_io_and_region_in_bio(bio, io, region); |
1da177e4 | 329 | |
e6047149 | 330 | if (op == REQ_OP_DISCARD) { |
e5db2980 | 331 | num_sectors = min_t(sector_t, special_cmd_max_sectors, remaining); |
4f024f37 | 332 | bio->bi_iter.bi_size = num_sectors << SECTOR_SHIFT; |
70d6c400 | 333 | remaining -= num_sectors; |
e6047149 | 334 | } else if (op == REQ_OP_WRITE_SAME) { |
70d6c400 MS |
335 | /* |
336 | * WRITE SAME only uses a single page. | |
337 | */ | |
338 | dp->get_page(dp, &page, &len, &offset); | |
339 | bio_add_page(bio, page, logical_block_size, offset); | |
e5db2980 | 340 | num_sectors = min_t(sector_t, special_cmd_max_sectors, remaining); |
4f024f37 | 341 | bio->bi_iter.bi_size = num_sectors << SECTOR_SHIFT; |
70d6c400 MS |
342 | |
343 | offset = 0; | |
344 | remaining -= num_sectors; | |
345 | dp->next_page(dp); | |
0c535e0d MB |
346 | } else while (remaining) { |
347 | /* | |
348 | * Try and add as many pages as possible. | |
349 | */ | |
1da177e4 LT |
350 | dp->get_page(dp, &page, &len, &offset); |
351 | len = min(len, to_bytes(remaining)); | |
352 | if (!bio_add_page(bio, page, len, offset)) | |
353 | break; | |
354 | ||
355 | offset = 0; | |
356 | remaining -= to_sector(len); | |
357 | dp->next_page(dp); | |
358 | } | |
359 | ||
360 | atomic_inc(&io->count); | |
4e49ea4a | 361 | submit_bio(bio); |
12fc0f49 | 362 | } while (remaining); |
1da177e4 LT |
363 | } |
364 | ||
e6047149 | 365 | static void dispatch_io(int op, int op_flags, unsigned int num_regions, |
22a1ceb1 | 366 | struct dm_io_region *where, struct dpages *dp, |
1da177e4 LT |
367 | struct io *io, int sync) |
368 | { | |
369 | int i; | |
370 | struct dpages old_pages = *dp; | |
371 | ||
f1e53987 MP |
372 | BUG_ON(num_regions > DM_IO_MAX_REGIONS); |
373 | ||
1da177e4 | 374 | if (sync) |
e6047149 | 375 | op_flags |= REQ_SYNC; |
1da177e4 LT |
376 | |
377 | /* | |
378 | * For multiple regions we need to be careful to rewind | |
379 | * the dp object for each call to do_region. | |
380 | */ | |
381 | for (i = 0; i < num_regions; i++) { | |
382 | *dp = old_pages; | |
28a8f0d3 | 383 | if (where[i].count || (op_flags & REQ_PREFLUSH)) |
e6047149 | 384 | do_region(op, op_flags, i, where + i, dp, io); |
1da177e4 LT |
385 | } |
386 | ||
387 | /* | |
f00b16ad | 388 | * Drop the extra reference that we were holding to avoid |
1da177e4 LT |
389 | * the io being completed too early. |
390 | */ | |
391 | dec_count(io, 0, 0); | |
392 | } | |
393 | ||
97e7cdf1 JT |
394 | struct sync_io { |
395 | unsigned long error_bits; | |
396 | struct completion wait; | |
397 | }; | |
398 | ||
399 | static void sync_io_complete(unsigned long error, void *context) | |
400 | { | |
401 | struct sync_io *sio = context; | |
402 | ||
403 | sio->error_bits = error; | |
404 | complete(&sio->wait); | |
405 | } | |
406 | ||
891ce207 | 407 | static int sync_io(struct dm_io_client *client, unsigned int num_regions, |
e6047149 MC |
408 | struct dm_io_region *where, int op, int op_flags, |
409 | struct dpages *dp, unsigned long *error_bits) | |
1da177e4 | 410 | { |
97e7cdf1 JT |
411 | struct io *io; |
412 | struct sync_io sio; | |
1da177e4 | 413 | |
e6047149 | 414 | if (num_regions > 1 && !op_is_write(op)) { |
1da177e4 LT |
415 | WARN_ON(1); |
416 | return -EIO; | |
417 | } | |
418 | ||
97e7cdf1 JT |
419 | init_completion(&sio.wait); |
420 | ||
421 | io = mempool_alloc(client->pool, GFP_NOIO); | |
f1e53987 | 422 | io->error_bits = 0; |
f1e53987 | 423 | atomic_set(&io->count, 1); /* see dispatch_io() */ |
f1e53987 | 424 | io->client = client; |
97e7cdf1 JT |
425 | io->callback = sync_io_complete; |
426 | io->context = &sio; | |
1da177e4 | 427 | |
bb91bc7b MP |
428 | io->vma_invalidate_address = dp->vma_invalidate_address; |
429 | io->vma_invalidate_size = dp->vma_invalidate_size; | |
430 | ||
e6047149 | 431 | dispatch_io(op, op_flags, num_regions, where, dp, io, 1); |
1da177e4 | 432 | |
97e7cdf1 | 433 | wait_for_completion_io(&sio.wait); |
1da177e4 | 434 | |
891ce207 | 435 | if (error_bits) |
97e7cdf1 | 436 | *error_bits = sio.error_bits; |
891ce207 | 437 | |
97e7cdf1 | 438 | return sio.error_bits ? -EIO : 0; |
1da177e4 LT |
439 | } |
440 | ||
891ce207 | 441 | static int async_io(struct dm_io_client *client, unsigned int num_regions, |
e6047149 MC |
442 | struct dm_io_region *where, int op, int op_flags, |
443 | struct dpages *dp, io_notify_fn fn, void *context) | |
1da177e4 LT |
444 | { |
445 | struct io *io; | |
446 | ||
e6047149 | 447 | if (num_regions > 1 && !op_is_write(op)) { |
1da177e4 LT |
448 | WARN_ON(1); |
449 | fn(1, context); | |
450 | return -EIO; | |
451 | } | |
452 | ||
bf17ce3a | 453 | io = mempool_alloc(client->pool, GFP_NOIO); |
e01fd7ee | 454 | io->error_bits = 0; |
1da177e4 | 455 | atomic_set(&io->count, 1); /* see dispatch_io() */ |
891ce207 | 456 | io->client = client; |
1da177e4 LT |
457 | io->callback = fn; |
458 | io->context = context; | |
459 | ||
bb91bc7b MP |
460 | io->vma_invalidate_address = dp->vma_invalidate_address; |
461 | io->vma_invalidate_size = dp->vma_invalidate_size; | |
462 | ||
e6047149 | 463 | dispatch_io(op, op_flags, num_regions, where, dp, io, 0); |
1da177e4 LT |
464 | return 0; |
465 | } | |
466 | ||
bb91bc7b MP |
467 | static int dp_init(struct dm_io_request *io_req, struct dpages *dp, |
468 | unsigned long size) | |
c8b03afe HM |
469 | { |
470 | /* Set up dpages based on memory type */ | |
bb91bc7b MP |
471 | |
472 | dp->vma_invalidate_address = NULL; | |
473 | dp->vma_invalidate_size = 0; | |
474 | ||
c8b03afe HM |
475 | switch (io_req->mem.type) { |
476 | case DM_IO_PAGE_LIST: | |
477 | list_dp_init(dp, io_req->mem.ptr.pl, io_req->mem.offset); | |
478 | break; | |
479 | ||
003b5c57 KO |
480 | case DM_IO_BIO: |
481 | bio_dp_init(dp, io_req->mem.ptr.bio); | |
c8b03afe HM |
482 | break; |
483 | ||
484 | case DM_IO_VMA: | |
bb91bc7b | 485 | flush_kernel_vmap_range(io_req->mem.ptr.vma, size); |
e6047149 | 486 | if (io_req->bi_op == REQ_OP_READ) { |
bb91bc7b MP |
487 | dp->vma_invalidate_address = io_req->mem.ptr.vma; |
488 | dp->vma_invalidate_size = size; | |
489 | } | |
c8b03afe HM |
490 | vm_dp_init(dp, io_req->mem.ptr.vma); |
491 | break; | |
492 | ||
493 | case DM_IO_KMEM: | |
494 | km_dp_init(dp, io_req->mem.ptr.addr); | |
495 | break; | |
496 | ||
497 | default: | |
498 | return -EINVAL; | |
499 | } | |
500 | ||
501 | return 0; | |
502 | } | |
503 | ||
504 | /* | |
7ff14a36 MP |
505 | * New collapsed (a)synchronous interface. |
506 | * | |
507 | * If the IO is asynchronous (i.e. it has notify.fn), you must either unplug | |
1eff9d32 JA |
508 | * the queue with blk_unplug() some time later or set REQ_SYNC in |
509 | * io_req->bi_opf. If you fail to do one of these, the IO will be submitted to | |
510 | * the disk after q->unplug_delay, which defaults to 3ms in blk-settings.c. | |
c8b03afe HM |
511 | */ |
512 | int dm_io(struct dm_io_request *io_req, unsigned num_regions, | |
22a1ceb1 | 513 | struct dm_io_region *where, unsigned long *sync_error_bits) |
c8b03afe HM |
514 | { |
515 | int r; | |
516 | struct dpages dp; | |
517 | ||
bb91bc7b | 518 | r = dp_init(io_req, &dp, (unsigned long)where->count << SECTOR_SHIFT); |
c8b03afe HM |
519 | if (r) |
520 | return r; | |
521 | ||
522 | if (!io_req->notify.fn) | |
523 | return sync_io(io_req->client, num_regions, where, | |
e6047149 MC |
524 | io_req->bi_op, io_req->bi_op_flags, &dp, |
525 | sync_error_bits); | |
c8b03afe | 526 | |
e6047149 MC |
527 | return async_io(io_req->client, num_regions, where, io_req->bi_op, |
528 | io_req->bi_op_flags, &dp, io_req->notify.fn, | |
529 | io_req->notify.context); | |
c8b03afe HM |
530 | } |
531 | EXPORT_SYMBOL(dm_io); | |
952b3557 MP |
532 | |
533 | int __init dm_io_init(void) | |
534 | { | |
535 | _dm_io_cache = KMEM_CACHE(io, 0); | |
536 | if (!_dm_io_cache) | |
537 | return -ENOMEM; | |
538 | ||
539 | return 0; | |
540 | } | |
541 | ||
542 | void dm_io_exit(void) | |
543 | { | |
544 | kmem_cache_destroy(_dm_io_cache); | |
545 | _dm_io_cache = NULL; | |
546 | } |