Commit | Line | Data |
---|---|---|
1da177e4 | 1 | /* |
0fe23479 | 2 | * Copyright (C) 2001 Jens Axboe <axboe@kernel.dk> |
1da177e4 LT |
3 | * |
4 | * This program is free software; you can redistribute it and/or modify | |
5 | * it under the terms of the GNU General Public License version 2 as | |
6 | * published by the Free Software Foundation. | |
7 | * | |
8 | * This program is distributed in the hope that it will be useful, | |
9 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
11 | * GNU General Public License for more details. | |
12 | * | |
13 | * You should have received a copy of the GNU General Public Licens | |
14 | * along with this program; if not, write to the Free Software | |
15 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111- | |
16 | * | |
17 | */ | |
18 | #include <linux/mm.h> | |
19 | #include <linux/swap.h> | |
20 | #include <linux/bio.h> | |
21 | #include <linux/blkdev.h> | |
22 | #include <linux/slab.h> | |
23 | #include <linux/init.h> | |
24 | #include <linux/kernel.h> | |
25 | #include <linux/module.h> | |
26 | #include <linux/mempool.h> | |
27 | #include <linux/workqueue.h> | |
2056a782 | 28 | #include <linux/blktrace_api.h> |
f1970baf | 29 | #include <scsi/sg.h> /* for struct sg_iovec */ |
1da177e4 | 30 | |
e18b890b | 31 | static struct kmem_cache *bio_slab __read_mostly; |
1da177e4 | 32 | |
fa3536cc | 33 | mempool_t *bio_split_pool __read_mostly; |
1da177e4 | 34 | |
1da177e4 LT |
35 | /* |
36 | * if you change this list, also change bvec_alloc or things will | |
37 | * break badly! cannot be bigger than what you can fit into an | |
38 | * unsigned short | |
39 | */ | |
40 | ||
41 | #define BV(x) { .nr_vecs = x, .name = "biovec-"__stringify(x) } | |
6c036527 | 42 | static struct biovec_slab bvec_slabs[BIOVEC_NR_POOLS] __read_mostly = { |
1da177e4 LT |
43 | BV(1), BV(4), BV(16), BV(64), BV(128), BV(BIO_MAX_PAGES), |
44 | }; | |
45 | #undef BV | |
46 | ||
1da177e4 LT |
47 | /* |
48 | * fs_bio_set is the bio_set containing bio and iovec memory pools used by | |
49 | * IO code that does not need private memory pools. | |
50 | */ | |
51d654e1 | 51 | struct bio_set *fs_bio_set; |
1da177e4 | 52 | |
7ba1ba12 MP |
53 | unsigned int bvec_nr_vecs(unsigned short idx) |
54 | { | |
55 | return bvec_slabs[idx].nr_vecs; | |
56 | } | |
57 | ||
51d654e1 | 58 | struct bio_vec *bvec_alloc_bs(gfp_t gfp_mask, int nr, unsigned long *idx, struct bio_set *bs) |
1da177e4 LT |
59 | { |
60 | struct bio_vec *bvl; | |
1da177e4 LT |
61 | |
62 | /* | |
63 | * see comment near bvec_array define! | |
64 | */ | |
65 | switch (nr) { | |
66 | case 1 : *idx = 0; break; | |
67 | case 2 ... 4: *idx = 1; break; | |
68 | case 5 ... 16: *idx = 2; break; | |
69 | case 17 ... 64: *idx = 3; break; | |
70 | case 65 ... 128: *idx = 4; break; | |
71 | case 129 ... BIO_MAX_PAGES: *idx = 5; break; | |
72 | default: | |
73 | return NULL; | |
74 | } | |
75 | /* | |
76 | * idx now points to the pool we want to allocate from | |
77 | */ | |
78 | ||
1da177e4 | 79 | bvl = mempool_alloc(bs->bvec_pools[*idx], gfp_mask); |
1ac0ae06 DC |
80 | if (bvl) |
81 | memset(bvl, 0, bvec_nr_vecs(*idx) * sizeof(struct bio_vec)); | |
1da177e4 LT |
82 | |
83 | return bvl; | |
84 | } | |
85 | ||
3676347a | 86 | void bio_free(struct bio *bio, struct bio_set *bio_set) |
1da177e4 | 87 | { |
992c5dda JA |
88 | if (bio->bi_io_vec) { |
89 | const int pool_idx = BIO_POOL_IDX(bio); | |
1da177e4 | 90 | |
992c5dda JA |
91 | BIO_BUG_ON(pool_idx >= BIOVEC_NR_POOLS); |
92 | ||
93 | mempool_free(bio->bi_io_vec, bio_set->bvec_pools[pool_idx]); | |
94 | } | |
1da177e4 | 95 | |
7ba1ba12 MP |
96 | if (bio_integrity(bio)) |
97 | bio_integrity_free(bio, bio_set); | |
98 | ||
3676347a PO |
99 | mempool_free(bio, bio_set->bio_pool); |
100 | } | |
101 | ||
102 | /* | |
103 | * default destructor for a bio allocated with bio_alloc_bioset() | |
104 | */ | |
105 | static void bio_fs_destructor(struct bio *bio) | |
106 | { | |
107 | bio_free(bio, fs_bio_set); | |
1da177e4 LT |
108 | } |
109 | ||
858119e1 | 110 | void bio_init(struct bio *bio) |
1da177e4 | 111 | { |
2b94de55 | 112 | memset(bio, 0, sizeof(*bio)); |
1da177e4 | 113 | bio->bi_flags = 1 << BIO_UPTODATE; |
c7c22e4d | 114 | bio->bi_comp_cpu = -1; |
1da177e4 | 115 | atomic_set(&bio->bi_cnt, 1); |
1da177e4 LT |
116 | } |
117 | ||
118 | /** | |
119 | * bio_alloc_bioset - allocate a bio for I/O | |
120 | * @gfp_mask: the GFP_ mask given to the slab allocator | |
121 | * @nr_iovecs: number of iovecs to pre-allocate | |
67be2dd1 | 122 | * @bs: the bio_set to allocate from |
1da177e4 LT |
123 | * |
124 | * Description: | |
125 | * bio_alloc_bioset will first try it's on mempool to satisfy the allocation. | |
126 | * If %__GFP_WAIT is set then we will block on the internal pool waiting | |
127 | * for a &struct bio to become free. | |
128 | * | |
129 | * allocate bio and iovecs from the memory pools specified by the | |
130 | * bio_set structure. | |
131 | **/ | |
dd0fc66f | 132 | struct bio *bio_alloc_bioset(gfp_t gfp_mask, int nr_iovecs, struct bio_set *bs) |
1da177e4 LT |
133 | { |
134 | struct bio *bio = mempool_alloc(bs->bio_pool, gfp_mask); | |
135 | ||
136 | if (likely(bio)) { | |
137 | struct bio_vec *bvl = NULL; | |
138 | ||
139 | bio_init(bio); | |
140 | if (likely(nr_iovecs)) { | |
eeae1d48 | 141 | unsigned long uninitialized_var(idx); |
1da177e4 LT |
142 | |
143 | bvl = bvec_alloc_bs(gfp_mask, nr_iovecs, &idx, bs); | |
144 | if (unlikely(!bvl)) { | |
145 | mempool_free(bio, bs->bio_pool); | |
146 | bio = NULL; | |
147 | goto out; | |
148 | } | |
149 | bio->bi_flags |= idx << BIO_POOL_OFFSET; | |
1ac0ae06 | 150 | bio->bi_max_vecs = bvec_nr_vecs(idx); |
1da177e4 LT |
151 | } |
152 | bio->bi_io_vec = bvl; | |
1da177e4 LT |
153 | } |
154 | out: | |
155 | return bio; | |
156 | } | |
157 | ||
dd0fc66f | 158 | struct bio *bio_alloc(gfp_t gfp_mask, int nr_iovecs) |
1da177e4 | 159 | { |
3676347a PO |
160 | struct bio *bio = bio_alloc_bioset(gfp_mask, nr_iovecs, fs_bio_set); |
161 | ||
162 | if (bio) | |
163 | bio->bi_destructor = bio_fs_destructor; | |
164 | ||
165 | return bio; | |
1da177e4 LT |
166 | } |
167 | ||
168 | void zero_fill_bio(struct bio *bio) | |
169 | { | |
170 | unsigned long flags; | |
171 | struct bio_vec *bv; | |
172 | int i; | |
173 | ||
174 | bio_for_each_segment(bv, bio, i) { | |
175 | char *data = bvec_kmap_irq(bv, &flags); | |
176 | memset(data, 0, bv->bv_len); | |
177 | flush_dcache_page(bv->bv_page); | |
178 | bvec_kunmap_irq(data, &flags); | |
179 | } | |
180 | } | |
181 | EXPORT_SYMBOL(zero_fill_bio); | |
182 | ||
183 | /** | |
184 | * bio_put - release a reference to a bio | |
185 | * @bio: bio to release reference to | |
186 | * | |
187 | * Description: | |
188 | * Put a reference to a &struct bio, either one you have gotten with | |
189 | * bio_alloc or bio_get. The last put of a bio will free it. | |
190 | **/ | |
191 | void bio_put(struct bio *bio) | |
192 | { | |
193 | BIO_BUG_ON(!atomic_read(&bio->bi_cnt)); | |
194 | ||
195 | /* | |
196 | * last put frees it | |
197 | */ | |
198 | if (atomic_dec_and_test(&bio->bi_cnt)) { | |
199 | bio->bi_next = NULL; | |
200 | bio->bi_destructor(bio); | |
201 | } | |
202 | } | |
203 | ||
165125e1 | 204 | inline int bio_phys_segments(struct request_queue *q, struct bio *bio) |
1da177e4 LT |
205 | { |
206 | if (unlikely(!bio_flagged(bio, BIO_SEG_VALID))) | |
207 | blk_recount_segments(q, bio); | |
208 | ||
209 | return bio->bi_phys_segments; | |
210 | } | |
211 | ||
1da177e4 LT |
212 | /** |
213 | * __bio_clone - clone a bio | |
214 | * @bio: destination bio | |
215 | * @bio_src: bio to clone | |
216 | * | |
217 | * Clone a &bio. Caller will own the returned bio, but not | |
218 | * the actual data it points to. Reference count of returned | |
219 | * bio will be one. | |
220 | */ | |
858119e1 | 221 | void __bio_clone(struct bio *bio, struct bio *bio_src) |
1da177e4 | 222 | { |
e525e153 AM |
223 | memcpy(bio->bi_io_vec, bio_src->bi_io_vec, |
224 | bio_src->bi_max_vecs * sizeof(struct bio_vec)); | |
1da177e4 | 225 | |
5d84070e JA |
226 | /* |
227 | * most users will be overriding ->bi_bdev with a new target, | |
228 | * so we don't set nor calculate new physical/hw segment counts here | |
229 | */ | |
1da177e4 LT |
230 | bio->bi_sector = bio_src->bi_sector; |
231 | bio->bi_bdev = bio_src->bi_bdev; | |
232 | bio->bi_flags |= 1 << BIO_CLONED; | |
233 | bio->bi_rw = bio_src->bi_rw; | |
1da177e4 LT |
234 | bio->bi_vcnt = bio_src->bi_vcnt; |
235 | bio->bi_size = bio_src->bi_size; | |
a5453be4 | 236 | bio->bi_idx = bio_src->bi_idx; |
1da177e4 LT |
237 | } |
238 | ||
239 | /** | |
240 | * bio_clone - clone a bio | |
241 | * @bio: bio to clone | |
242 | * @gfp_mask: allocation priority | |
243 | * | |
244 | * Like __bio_clone, only also allocates the returned bio | |
245 | */ | |
dd0fc66f | 246 | struct bio *bio_clone(struct bio *bio, gfp_t gfp_mask) |
1da177e4 LT |
247 | { |
248 | struct bio *b = bio_alloc_bioset(gfp_mask, bio->bi_max_vecs, fs_bio_set); | |
249 | ||
7ba1ba12 MP |
250 | if (!b) |
251 | return NULL; | |
252 | ||
253 | b->bi_destructor = bio_fs_destructor; | |
254 | __bio_clone(b, bio); | |
255 | ||
256 | if (bio_integrity(bio)) { | |
257 | int ret; | |
258 | ||
259 | ret = bio_integrity_clone(b, bio, fs_bio_set); | |
260 | ||
261 | if (ret < 0) | |
262 | return NULL; | |
3676347a | 263 | } |
1da177e4 LT |
264 | |
265 | return b; | |
266 | } | |
267 | ||
268 | /** | |
269 | * bio_get_nr_vecs - return approx number of vecs | |
270 | * @bdev: I/O target | |
271 | * | |
272 | * Return the approximate number of pages we can send to this target. | |
273 | * There's no guarantee that you will be able to fit this number of pages | |
274 | * into a bio, it does not account for dynamic restrictions that vary | |
275 | * on offset. | |
276 | */ | |
277 | int bio_get_nr_vecs(struct block_device *bdev) | |
278 | { | |
165125e1 | 279 | struct request_queue *q = bdev_get_queue(bdev); |
1da177e4 LT |
280 | int nr_pages; |
281 | ||
282 | nr_pages = ((q->max_sectors << 9) + PAGE_SIZE - 1) >> PAGE_SHIFT; | |
283 | if (nr_pages > q->max_phys_segments) | |
284 | nr_pages = q->max_phys_segments; | |
285 | if (nr_pages > q->max_hw_segments) | |
286 | nr_pages = q->max_hw_segments; | |
287 | ||
288 | return nr_pages; | |
289 | } | |
290 | ||
165125e1 | 291 | static int __bio_add_page(struct request_queue *q, struct bio *bio, struct page |
defd94b7 MC |
292 | *page, unsigned int len, unsigned int offset, |
293 | unsigned short max_sectors) | |
1da177e4 LT |
294 | { |
295 | int retried_segments = 0; | |
296 | struct bio_vec *bvec; | |
297 | ||
298 | /* | |
299 | * cloned bio must not modify vec list | |
300 | */ | |
301 | if (unlikely(bio_flagged(bio, BIO_CLONED))) | |
302 | return 0; | |
303 | ||
80cfd548 | 304 | if (((bio->bi_size + len) >> 9) > max_sectors) |
1da177e4 LT |
305 | return 0; |
306 | ||
80cfd548 JA |
307 | /* |
308 | * For filesystems with a blocksize smaller than the pagesize | |
309 | * we will often be called with the same page as last time and | |
310 | * a consecutive offset. Optimize this special case. | |
311 | */ | |
312 | if (bio->bi_vcnt > 0) { | |
313 | struct bio_vec *prev = &bio->bi_io_vec[bio->bi_vcnt - 1]; | |
314 | ||
315 | if (page == prev->bv_page && | |
316 | offset == prev->bv_offset + prev->bv_len) { | |
317 | prev->bv_len += len; | |
cc371e66 AK |
318 | |
319 | if (q->merge_bvec_fn) { | |
320 | struct bvec_merge_data bvm = { | |
321 | .bi_bdev = bio->bi_bdev, | |
322 | .bi_sector = bio->bi_sector, | |
323 | .bi_size = bio->bi_size, | |
324 | .bi_rw = bio->bi_rw, | |
325 | }; | |
326 | ||
327 | if (q->merge_bvec_fn(q, &bvm, prev) < len) { | |
328 | prev->bv_len -= len; | |
329 | return 0; | |
330 | } | |
80cfd548 JA |
331 | } |
332 | ||
333 | goto done; | |
334 | } | |
335 | } | |
336 | ||
337 | if (bio->bi_vcnt >= bio->bi_max_vecs) | |
1da177e4 LT |
338 | return 0; |
339 | ||
340 | /* | |
341 | * we might lose a segment or two here, but rather that than | |
342 | * make this too complex. | |
343 | */ | |
344 | ||
345 | while (bio->bi_phys_segments >= q->max_phys_segments | |
5df97b91 | 346 | || bio->bi_phys_segments >= q->max_hw_segments) { |
1da177e4 LT |
347 | |
348 | if (retried_segments) | |
349 | return 0; | |
350 | ||
351 | retried_segments = 1; | |
352 | blk_recount_segments(q, bio); | |
353 | } | |
354 | ||
355 | /* | |
356 | * setup the new entry, we might clear it again later if we | |
357 | * cannot add the page | |
358 | */ | |
359 | bvec = &bio->bi_io_vec[bio->bi_vcnt]; | |
360 | bvec->bv_page = page; | |
361 | bvec->bv_len = len; | |
362 | bvec->bv_offset = offset; | |
363 | ||
364 | /* | |
365 | * if queue has other restrictions (eg varying max sector size | |
366 | * depending on offset), it can specify a merge_bvec_fn in the | |
367 | * queue to get further control | |
368 | */ | |
369 | if (q->merge_bvec_fn) { | |
cc371e66 AK |
370 | struct bvec_merge_data bvm = { |
371 | .bi_bdev = bio->bi_bdev, | |
372 | .bi_sector = bio->bi_sector, | |
373 | .bi_size = bio->bi_size, | |
374 | .bi_rw = bio->bi_rw, | |
375 | }; | |
376 | ||
1da177e4 LT |
377 | /* |
378 | * merge_bvec_fn() returns number of bytes it can accept | |
379 | * at this offset | |
380 | */ | |
cc371e66 | 381 | if (q->merge_bvec_fn(q, &bvm, bvec) < len) { |
1da177e4 LT |
382 | bvec->bv_page = NULL; |
383 | bvec->bv_len = 0; | |
384 | bvec->bv_offset = 0; | |
385 | return 0; | |
386 | } | |
387 | } | |
388 | ||
389 | /* If we may be able to merge these biovecs, force a recount */ | |
b8b3e16c | 390 | if (bio->bi_vcnt && (BIOVEC_PHYS_MERGEABLE(bvec-1, bvec))) |
1da177e4 LT |
391 | bio->bi_flags &= ~(1 << BIO_SEG_VALID); |
392 | ||
393 | bio->bi_vcnt++; | |
394 | bio->bi_phys_segments++; | |
80cfd548 | 395 | done: |
1da177e4 LT |
396 | bio->bi_size += len; |
397 | return len; | |
398 | } | |
399 | ||
6e68af66 MC |
400 | /** |
401 | * bio_add_pc_page - attempt to add page to bio | |
fddfdeaf | 402 | * @q: the target queue |
6e68af66 MC |
403 | * @bio: destination bio |
404 | * @page: page to add | |
405 | * @len: vec entry length | |
406 | * @offset: vec entry offset | |
407 | * | |
408 | * Attempt to add a page to the bio_vec maplist. This can fail for a | |
409 | * number of reasons, such as the bio being full or target block | |
410 | * device limitations. The target block device must allow bio's | |
411 | * smaller than PAGE_SIZE, so it is always possible to add a single | |
412 | * page to an empty bio. This should only be used by REQ_PC bios. | |
413 | */ | |
165125e1 | 414 | int bio_add_pc_page(struct request_queue *q, struct bio *bio, struct page *page, |
6e68af66 MC |
415 | unsigned int len, unsigned int offset) |
416 | { | |
defd94b7 | 417 | return __bio_add_page(q, bio, page, len, offset, q->max_hw_sectors); |
6e68af66 MC |
418 | } |
419 | ||
1da177e4 LT |
420 | /** |
421 | * bio_add_page - attempt to add page to bio | |
422 | * @bio: destination bio | |
423 | * @page: page to add | |
424 | * @len: vec entry length | |
425 | * @offset: vec entry offset | |
426 | * | |
427 | * Attempt to add a page to the bio_vec maplist. This can fail for a | |
428 | * number of reasons, such as the bio being full or target block | |
429 | * device limitations. The target block device must allow bio's | |
430 | * smaller than PAGE_SIZE, so it is always possible to add a single | |
431 | * page to an empty bio. | |
432 | */ | |
433 | int bio_add_page(struct bio *bio, struct page *page, unsigned int len, | |
434 | unsigned int offset) | |
435 | { | |
defd94b7 MC |
436 | struct request_queue *q = bdev_get_queue(bio->bi_bdev); |
437 | return __bio_add_page(q, bio, page, len, offset, q->max_sectors); | |
1da177e4 LT |
438 | } |
439 | ||
440 | struct bio_map_data { | |
441 | struct bio_vec *iovecs; | |
c5dec1c3 FT |
442 | int nr_sgvecs; |
443 | struct sg_iovec *sgvecs; | |
1da177e4 LT |
444 | }; |
445 | ||
c5dec1c3 FT |
446 | static void bio_set_map_data(struct bio_map_data *bmd, struct bio *bio, |
447 | struct sg_iovec *iov, int iov_count) | |
1da177e4 LT |
448 | { |
449 | memcpy(bmd->iovecs, bio->bi_io_vec, sizeof(struct bio_vec) * bio->bi_vcnt); | |
c5dec1c3 FT |
450 | memcpy(bmd->sgvecs, iov, sizeof(struct sg_iovec) * iov_count); |
451 | bmd->nr_sgvecs = iov_count; | |
1da177e4 LT |
452 | bio->bi_private = bmd; |
453 | } | |
454 | ||
455 | static void bio_free_map_data(struct bio_map_data *bmd) | |
456 | { | |
457 | kfree(bmd->iovecs); | |
c5dec1c3 | 458 | kfree(bmd->sgvecs); |
1da177e4 LT |
459 | kfree(bmd); |
460 | } | |
461 | ||
76029ff3 FT |
462 | static struct bio_map_data *bio_alloc_map_data(int nr_segs, int iov_count, |
463 | gfp_t gfp_mask) | |
1da177e4 | 464 | { |
76029ff3 | 465 | struct bio_map_data *bmd = kmalloc(sizeof(*bmd), gfp_mask); |
1da177e4 LT |
466 | |
467 | if (!bmd) | |
468 | return NULL; | |
469 | ||
76029ff3 | 470 | bmd->iovecs = kmalloc(sizeof(struct bio_vec) * nr_segs, gfp_mask); |
c5dec1c3 FT |
471 | if (!bmd->iovecs) { |
472 | kfree(bmd); | |
473 | return NULL; | |
474 | } | |
475 | ||
76029ff3 | 476 | bmd->sgvecs = kmalloc(sizeof(struct sg_iovec) * iov_count, gfp_mask); |
c5dec1c3 | 477 | if (bmd->sgvecs) |
1da177e4 LT |
478 | return bmd; |
479 | ||
c5dec1c3 | 480 | kfree(bmd->iovecs); |
1da177e4 LT |
481 | kfree(bmd); |
482 | return NULL; | |
483 | } | |
484 | ||
aefcc28a FT |
485 | static int __bio_copy_iov(struct bio *bio, struct bio_vec *iovecs, |
486 | struct sg_iovec *iov, int iov_count, int uncopy) | |
c5dec1c3 FT |
487 | { |
488 | int ret = 0, i; | |
489 | struct bio_vec *bvec; | |
490 | int iov_idx = 0; | |
491 | unsigned int iov_off = 0; | |
492 | int read = bio_data_dir(bio) == READ; | |
493 | ||
494 | __bio_for_each_segment(bvec, bio, i, 0) { | |
495 | char *bv_addr = page_address(bvec->bv_page); | |
aefcc28a | 496 | unsigned int bv_len = iovecs[i].bv_len; |
c5dec1c3 FT |
497 | |
498 | while (bv_len && iov_idx < iov_count) { | |
499 | unsigned int bytes; | |
500 | char *iov_addr; | |
501 | ||
502 | bytes = min_t(unsigned int, | |
503 | iov[iov_idx].iov_len - iov_off, bv_len); | |
504 | iov_addr = iov[iov_idx].iov_base + iov_off; | |
505 | ||
506 | if (!ret) { | |
507 | if (!read && !uncopy) | |
508 | ret = copy_from_user(bv_addr, iov_addr, | |
509 | bytes); | |
510 | if (read && uncopy) | |
511 | ret = copy_to_user(iov_addr, bv_addr, | |
512 | bytes); | |
513 | ||
514 | if (ret) | |
515 | ret = -EFAULT; | |
516 | } | |
517 | ||
518 | bv_len -= bytes; | |
519 | bv_addr += bytes; | |
520 | iov_addr += bytes; | |
521 | iov_off += bytes; | |
522 | ||
523 | if (iov[iov_idx].iov_len == iov_off) { | |
524 | iov_idx++; | |
525 | iov_off = 0; | |
526 | } | |
527 | } | |
528 | ||
529 | if (uncopy) | |
530 | __free_page(bvec->bv_page); | |
531 | } | |
532 | ||
533 | return ret; | |
534 | } | |
535 | ||
1da177e4 LT |
536 | /** |
537 | * bio_uncopy_user - finish previously mapped bio | |
538 | * @bio: bio being terminated | |
539 | * | |
540 | * Free pages allocated from bio_copy_user() and write back data | |
541 | * to user space in case of a read. | |
542 | */ | |
543 | int bio_uncopy_user(struct bio *bio) | |
544 | { | |
545 | struct bio_map_data *bmd = bio->bi_private; | |
c5dec1c3 | 546 | int ret; |
1da177e4 | 547 | |
aefcc28a | 548 | ret = __bio_copy_iov(bio, bmd->iovecs, bmd->sgvecs, bmd->nr_sgvecs, 1); |
1da177e4 | 549 | |
1da177e4 LT |
550 | bio_free_map_data(bmd); |
551 | bio_put(bio); | |
552 | return ret; | |
553 | } | |
554 | ||
555 | /** | |
c5dec1c3 | 556 | * bio_copy_user_iov - copy user data to bio |
1da177e4 | 557 | * @q: destination block queue |
c5dec1c3 FT |
558 | * @iov: the iovec. |
559 | * @iov_count: number of elements in the iovec | |
1da177e4 | 560 | * @write_to_vm: bool indicating writing to pages or not |
a3bce90e | 561 | * @gfp_mask: memory allocation flags |
1da177e4 LT |
562 | * |
563 | * Prepares and returns a bio for indirect user io, bouncing data | |
564 | * to/from kernel pages as necessary. Must be paired with | |
565 | * call bio_uncopy_user() on io completion. | |
566 | */ | |
c5dec1c3 | 567 | struct bio *bio_copy_user_iov(struct request_queue *q, struct sg_iovec *iov, |
a3bce90e | 568 | int iov_count, int write_to_vm, gfp_t gfp_mask) |
1da177e4 | 569 | { |
1da177e4 LT |
570 | struct bio_map_data *bmd; |
571 | struct bio_vec *bvec; | |
572 | struct page *page; | |
573 | struct bio *bio; | |
574 | int i, ret; | |
c5dec1c3 FT |
575 | int nr_pages = 0; |
576 | unsigned int len = 0; | |
1da177e4 | 577 | |
c5dec1c3 FT |
578 | for (i = 0; i < iov_count; i++) { |
579 | unsigned long uaddr; | |
580 | unsigned long end; | |
581 | unsigned long start; | |
582 | ||
583 | uaddr = (unsigned long)iov[i].iov_base; | |
584 | end = (uaddr + iov[i].iov_len + PAGE_SIZE - 1) >> PAGE_SHIFT; | |
585 | start = uaddr >> PAGE_SHIFT; | |
586 | ||
587 | nr_pages += end - start; | |
588 | len += iov[i].iov_len; | |
589 | } | |
590 | ||
a3bce90e | 591 | bmd = bio_alloc_map_data(nr_pages, iov_count, gfp_mask); |
1da177e4 LT |
592 | if (!bmd) |
593 | return ERR_PTR(-ENOMEM); | |
594 | ||
1da177e4 | 595 | ret = -ENOMEM; |
a3bce90e | 596 | bio = bio_alloc(gfp_mask, nr_pages); |
1da177e4 LT |
597 | if (!bio) |
598 | goto out_bmd; | |
599 | ||
600 | bio->bi_rw |= (!write_to_vm << BIO_RW); | |
601 | ||
602 | ret = 0; | |
603 | while (len) { | |
604 | unsigned int bytes = PAGE_SIZE; | |
605 | ||
606 | if (bytes > len) | |
607 | bytes = len; | |
608 | ||
a3bce90e | 609 | page = alloc_page(q->bounce_gfp | gfp_mask); |
1da177e4 LT |
610 | if (!page) { |
611 | ret = -ENOMEM; | |
612 | break; | |
613 | } | |
614 | ||
0e75f906 | 615 | if (bio_add_pc_page(q, bio, page, bytes, 0) < bytes) |
1da177e4 | 616 | break; |
1da177e4 LT |
617 | |
618 | len -= bytes; | |
619 | } | |
620 | ||
621 | if (ret) | |
622 | goto cleanup; | |
623 | ||
624 | /* | |
625 | * success | |
626 | */ | |
627 | if (!write_to_vm) { | |
aefcc28a | 628 | ret = __bio_copy_iov(bio, bio->bi_io_vec, iov, iov_count, 0); |
c5dec1c3 FT |
629 | if (ret) |
630 | goto cleanup; | |
1da177e4 LT |
631 | } |
632 | ||
c5dec1c3 | 633 | bio_set_map_data(bmd, bio, iov, iov_count); |
1da177e4 LT |
634 | return bio; |
635 | cleanup: | |
636 | bio_for_each_segment(bvec, bio, i) | |
637 | __free_page(bvec->bv_page); | |
638 | ||
639 | bio_put(bio); | |
640 | out_bmd: | |
641 | bio_free_map_data(bmd); | |
642 | return ERR_PTR(ret); | |
643 | } | |
644 | ||
c5dec1c3 FT |
645 | /** |
646 | * bio_copy_user - copy user data to bio | |
647 | * @q: destination block queue | |
648 | * @uaddr: start of user address | |
649 | * @len: length in bytes | |
650 | * @write_to_vm: bool indicating writing to pages or not | |
a3bce90e | 651 | * @gfp_mask: memory allocation flags |
c5dec1c3 FT |
652 | * |
653 | * Prepares and returns a bio for indirect user io, bouncing data | |
654 | * to/from kernel pages as necessary. Must be paired with | |
655 | * call bio_uncopy_user() on io completion. | |
656 | */ | |
657 | struct bio *bio_copy_user(struct request_queue *q, unsigned long uaddr, | |
a3bce90e | 658 | unsigned int len, int write_to_vm, gfp_t gfp_mask) |
c5dec1c3 FT |
659 | { |
660 | struct sg_iovec iov; | |
661 | ||
662 | iov.iov_base = (void __user *)uaddr; | |
663 | iov.iov_len = len; | |
664 | ||
a3bce90e | 665 | return bio_copy_user_iov(q, &iov, 1, write_to_vm, gfp_mask); |
c5dec1c3 FT |
666 | } |
667 | ||
165125e1 | 668 | static struct bio *__bio_map_user_iov(struct request_queue *q, |
f1970baf JB |
669 | struct block_device *bdev, |
670 | struct sg_iovec *iov, int iov_count, | |
a3bce90e | 671 | int write_to_vm, gfp_t gfp_mask) |
1da177e4 | 672 | { |
f1970baf JB |
673 | int i, j; |
674 | int nr_pages = 0; | |
1da177e4 LT |
675 | struct page **pages; |
676 | struct bio *bio; | |
f1970baf JB |
677 | int cur_page = 0; |
678 | int ret, offset; | |
1da177e4 | 679 | |
f1970baf JB |
680 | for (i = 0; i < iov_count; i++) { |
681 | unsigned long uaddr = (unsigned long)iov[i].iov_base; | |
682 | unsigned long len = iov[i].iov_len; | |
683 | unsigned long end = (uaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT; | |
684 | unsigned long start = uaddr >> PAGE_SHIFT; | |
685 | ||
686 | nr_pages += end - start; | |
687 | /* | |
ad2d7225 | 688 | * buffer must be aligned to at least hardsector size for now |
f1970baf | 689 | */ |
ad2d7225 | 690 | if (uaddr & queue_dma_alignment(q)) |
f1970baf JB |
691 | return ERR_PTR(-EINVAL); |
692 | } | |
693 | ||
694 | if (!nr_pages) | |
1da177e4 LT |
695 | return ERR_PTR(-EINVAL); |
696 | ||
a3bce90e | 697 | bio = bio_alloc(gfp_mask, nr_pages); |
1da177e4 LT |
698 | if (!bio) |
699 | return ERR_PTR(-ENOMEM); | |
700 | ||
701 | ret = -ENOMEM; | |
a3bce90e | 702 | pages = kcalloc(nr_pages, sizeof(struct page *), gfp_mask); |
1da177e4 LT |
703 | if (!pages) |
704 | goto out; | |
705 | ||
f1970baf JB |
706 | for (i = 0; i < iov_count; i++) { |
707 | unsigned long uaddr = (unsigned long)iov[i].iov_base; | |
708 | unsigned long len = iov[i].iov_len; | |
709 | unsigned long end = (uaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT; | |
710 | unsigned long start = uaddr >> PAGE_SHIFT; | |
711 | const int local_nr_pages = end - start; | |
712 | const int page_limit = cur_page + local_nr_pages; | |
713 | ||
f5dd33c4 NP |
714 | ret = get_user_pages_fast(uaddr, local_nr_pages, |
715 | write_to_vm, &pages[cur_page]); | |
99172157 JA |
716 | if (ret < local_nr_pages) { |
717 | ret = -EFAULT; | |
f1970baf | 718 | goto out_unmap; |
99172157 | 719 | } |
f1970baf JB |
720 | |
721 | offset = uaddr & ~PAGE_MASK; | |
722 | for (j = cur_page; j < page_limit; j++) { | |
723 | unsigned int bytes = PAGE_SIZE - offset; | |
724 | ||
725 | if (len <= 0) | |
726 | break; | |
727 | ||
728 | if (bytes > len) | |
729 | bytes = len; | |
730 | ||
731 | /* | |
732 | * sorry... | |
733 | */ | |
defd94b7 MC |
734 | if (bio_add_pc_page(q, bio, pages[j], bytes, offset) < |
735 | bytes) | |
f1970baf JB |
736 | break; |
737 | ||
738 | len -= bytes; | |
739 | offset = 0; | |
740 | } | |
1da177e4 | 741 | |
f1970baf | 742 | cur_page = j; |
1da177e4 | 743 | /* |
f1970baf | 744 | * release the pages we didn't map into the bio, if any |
1da177e4 | 745 | */ |
f1970baf JB |
746 | while (j < page_limit) |
747 | page_cache_release(pages[j++]); | |
1da177e4 LT |
748 | } |
749 | ||
1da177e4 LT |
750 | kfree(pages); |
751 | ||
752 | /* | |
753 | * set data direction, and check if mapped pages need bouncing | |
754 | */ | |
755 | if (!write_to_vm) | |
756 | bio->bi_rw |= (1 << BIO_RW); | |
757 | ||
f1970baf | 758 | bio->bi_bdev = bdev; |
1da177e4 LT |
759 | bio->bi_flags |= (1 << BIO_USER_MAPPED); |
760 | return bio; | |
f1970baf JB |
761 | |
762 | out_unmap: | |
763 | for (i = 0; i < nr_pages; i++) { | |
764 | if(!pages[i]) | |
765 | break; | |
766 | page_cache_release(pages[i]); | |
767 | } | |
768 | out: | |
1da177e4 LT |
769 | kfree(pages); |
770 | bio_put(bio); | |
771 | return ERR_PTR(ret); | |
772 | } | |
773 | ||
774 | /** | |
775 | * bio_map_user - map user address into bio | |
165125e1 | 776 | * @q: the struct request_queue for the bio |
1da177e4 LT |
777 | * @bdev: destination block device |
778 | * @uaddr: start of user address | |
779 | * @len: length in bytes | |
780 | * @write_to_vm: bool indicating writing to pages or not | |
a3bce90e | 781 | * @gfp_mask: memory allocation flags |
1da177e4 LT |
782 | * |
783 | * Map the user space address into a bio suitable for io to a block | |
784 | * device. Returns an error pointer in case of error. | |
785 | */ | |
165125e1 | 786 | struct bio *bio_map_user(struct request_queue *q, struct block_device *bdev, |
a3bce90e FT |
787 | unsigned long uaddr, unsigned int len, int write_to_vm, |
788 | gfp_t gfp_mask) | |
f1970baf JB |
789 | { |
790 | struct sg_iovec iov; | |
791 | ||
3f70353e | 792 | iov.iov_base = (void __user *)uaddr; |
f1970baf JB |
793 | iov.iov_len = len; |
794 | ||
a3bce90e | 795 | return bio_map_user_iov(q, bdev, &iov, 1, write_to_vm, gfp_mask); |
f1970baf JB |
796 | } |
797 | ||
798 | /** | |
799 | * bio_map_user_iov - map user sg_iovec table into bio | |
165125e1 | 800 | * @q: the struct request_queue for the bio |
f1970baf JB |
801 | * @bdev: destination block device |
802 | * @iov: the iovec. | |
803 | * @iov_count: number of elements in the iovec | |
804 | * @write_to_vm: bool indicating writing to pages or not | |
a3bce90e | 805 | * @gfp_mask: memory allocation flags |
f1970baf JB |
806 | * |
807 | * Map the user space address into a bio suitable for io to a block | |
808 | * device. Returns an error pointer in case of error. | |
809 | */ | |
165125e1 | 810 | struct bio *bio_map_user_iov(struct request_queue *q, struct block_device *bdev, |
f1970baf | 811 | struct sg_iovec *iov, int iov_count, |
a3bce90e | 812 | int write_to_vm, gfp_t gfp_mask) |
1da177e4 LT |
813 | { |
814 | struct bio *bio; | |
815 | ||
a3bce90e FT |
816 | bio = __bio_map_user_iov(q, bdev, iov, iov_count, write_to_vm, |
817 | gfp_mask); | |
1da177e4 LT |
818 | if (IS_ERR(bio)) |
819 | return bio; | |
820 | ||
821 | /* | |
822 | * subtle -- if __bio_map_user() ended up bouncing a bio, | |
823 | * it would normally disappear when its bi_end_io is run. | |
824 | * however, we need it for the unmap, so grab an extra | |
825 | * reference to it | |
826 | */ | |
827 | bio_get(bio); | |
828 | ||
0e75f906 | 829 | return bio; |
1da177e4 LT |
830 | } |
831 | ||
832 | static void __bio_unmap_user(struct bio *bio) | |
833 | { | |
834 | struct bio_vec *bvec; | |
835 | int i; | |
836 | ||
837 | /* | |
838 | * make sure we dirty pages we wrote to | |
839 | */ | |
840 | __bio_for_each_segment(bvec, bio, i, 0) { | |
841 | if (bio_data_dir(bio) == READ) | |
842 | set_page_dirty_lock(bvec->bv_page); | |
843 | ||
844 | page_cache_release(bvec->bv_page); | |
845 | } | |
846 | ||
847 | bio_put(bio); | |
848 | } | |
849 | ||
850 | /** | |
851 | * bio_unmap_user - unmap a bio | |
852 | * @bio: the bio being unmapped | |
853 | * | |
854 | * Unmap a bio previously mapped by bio_map_user(). Must be called with | |
855 | * a process context. | |
856 | * | |
857 | * bio_unmap_user() may sleep. | |
858 | */ | |
859 | void bio_unmap_user(struct bio *bio) | |
860 | { | |
861 | __bio_unmap_user(bio); | |
862 | bio_put(bio); | |
863 | } | |
864 | ||
6712ecf8 | 865 | static void bio_map_kern_endio(struct bio *bio, int err) |
b823825e | 866 | { |
b823825e | 867 | bio_put(bio); |
b823825e JA |
868 | } |
869 | ||
870 | ||
165125e1 | 871 | static struct bio *__bio_map_kern(struct request_queue *q, void *data, |
27496a8c | 872 | unsigned int len, gfp_t gfp_mask) |
df46b9a4 MC |
873 | { |
874 | unsigned long kaddr = (unsigned long)data; | |
875 | unsigned long end = (kaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT; | |
876 | unsigned long start = kaddr >> PAGE_SHIFT; | |
877 | const int nr_pages = end - start; | |
878 | int offset, i; | |
879 | struct bio *bio; | |
880 | ||
881 | bio = bio_alloc(gfp_mask, nr_pages); | |
882 | if (!bio) | |
883 | return ERR_PTR(-ENOMEM); | |
884 | ||
885 | offset = offset_in_page(kaddr); | |
886 | for (i = 0; i < nr_pages; i++) { | |
887 | unsigned int bytes = PAGE_SIZE - offset; | |
888 | ||
889 | if (len <= 0) | |
890 | break; | |
891 | ||
892 | if (bytes > len) | |
893 | bytes = len; | |
894 | ||
defd94b7 MC |
895 | if (bio_add_pc_page(q, bio, virt_to_page(data), bytes, |
896 | offset) < bytes) | |
df46b9a4 MC |
897 | break; |
898 | ||
899 | data += bytes; | |
900 | len -= bytes; | |
901 | offset = 0; | |
902 | } | |
903 | ||
b823825e | 904 | bio->bi_end_io = bio_map_kern_endio; |
df46b9a4 MC |
905 | return bio; |
906 | } | |
907 | ||
908 | /** | |
909 | * bio_map_kern - map kernel address into bio | |
165125e1 | 910 | * @q: the struct request_queue for the bio |
df46b9a4 MC |
911 | * @data: pointer to buffer to map |
912 | * @len: length in bytes | |
913 | * @gfp_mask: allocation flags for bio allocation | |
914 | * | |
915 | * Map the kernel address into a bio suitable for io to a block | |
916 | * device. Returns an error pointer in case of error. | |
917 | */ | |
165125e1 | 918 | struct bio *bio_map_kern(struct request_queue *q, void *data, unsigned int len, |
27496a8c | 919 | gfp_t gfp_mask) |
df46b9a4 MC |
920 | { |
921 | struct bio *bio; | |
922 | ||
923 | bio = __bio_map_kern(q, data, len, gfp_mask); | |
924 | if (IS_ERR(bio)) | |
925 | return bio; | |
926 | ||
927 | if (bio->bi_size == len) | |
928 | return bio; | |
929 | ||
930 | /* | |
931 | * Don't support partial mappings. | |
932 | */ | |
933 | bio_put(bio); | |
934 | return ERR_PTR(-EINVAL); | |
935 | } | |
936 | ||
68154e90 FT |
937 | static void bio_copy_kern_endio(struct bio *bio, int err) |
938 | { | |
939 | struct bio_vec *bvec; | |
940 | const int read = bio_data_dir(bio) == READ; | |
76029ff3 | 941 | struct bio_map_data *bmd = bio->bi_private; |
68154e90 | 942 | int i; |
76029ff3 | 943 | char *p = bmd->sgvecs[0].iov_base; |
68154e90 FT |
944 | |
945 | __bio_for_each_segment(bvec, bio, i, 0) { | |
946 | char *addr = page_address(bvec->bv_page); | |
76029ff3 | 947 | int len = bmd->iovecs[i].bv_len; |
68154e90 FT |
948 | |
949 | if (read && !err) | |
76029ff3 | 950 | memcpy(p, addr, len); |
68154e90 FT |
951 | |
952 | __free_page(bvec->bv_page); | |
76029ff3 | 953 | p += len; |
68154e90 FT |
954 | } |
955 | ||
76029ff3 | 956 | bio_free_map_data(bmd); |
68154e90 FT |
957 | bio_put(bio); |
958 | } | |
959 | ||
960 | /** | |
961 | * bio_copy_kern - copy kernel address into bio | |
962 | * @q: the struct request_queue for the bio | |
963 | * @data: pointer to buffer to copy | |
964 | * @len: length in bytes | |
965 | * @gfp_mask: allocation flags for bio and page allocation | |
ffee0259 | 966 | * @reading: data direction is READ |
68154e90 FT |
967 | * |
968 | * copy the kernel address into a bio suitable for io to a block | |
969 | * device. Returns an error pointer in case of error. | |
970 | */ | |
971 | struct bio *bio_copy_kern(struct request_queue *q, void *data, unsigned int len, | |
972 | gfp_t gfp_mask, int reading) | |
973 | { | |
974 | unsigned long kaddr = (unsigned long)data; | |
975 | unsigned long end = (kaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT; | |
976 | unsigned long start = kaddr >> PAGE_SHIFT; | |
977 | const int nr_pages = end - start; | |
978 | struct bio *bio; | |
979 | struct bio_vec *bvec; | |
76029ff3 | 980 | struct bio_map_data *bmd; |
68154e90 | 981 | int i, ret; |
76029ff3 FT |
982 | struct sg_iovec iov; |
983 | ||
984 | iov.iov_base = data; | |
985 | iov.iov_len = len; | |
986 | ||
987 | bmd = bio_alloc_map_data(nr_pages, 1, gfp_mask); | |
988 | if (!bmd) | |
989 | return ERR_PTR(-ENOMEM); | |
68154e90 | 990 | |
76029ff3 | 991 | ret = -ENOMEM; |
68154e90 FT |
992 | bio = bio_alloc(gfp_mask, nr_pages); |
993 | if (!bio) | |
76029ff3 | 994 | goto out_bmd; |
68154e90 FT |
995 | |
996 | while (len) { | |
997 | struct page *page; | |
998 | unsigned int bytes = PAGE_SIZE; | |
999 | ||
1000 | if (bytes > len) | |
1001 | bytes = len; | |
1002 | ||
1003 | page = alloc_page(q->bounce_gfp | gfp_mask); | |
1004 | if (!page) { | |
1005 | ret = -ENOMEM; | |
1006 | goto cleanup; | |
1007 | } | |
1008 | ||
1009 | if (bio_add_pc_page(q, bio, page, bytes, 0) < bytes) { | |
1010 | ret = -EINVAL; | |
1011 | goto cleanup; | |
1012 | } | |
1013 | ||
1014 | len -= bytes; | |
1015 | } | |
1016 | ||
1017 | if (!reading) { | |
1018 | void *p = data; | |
1019 | ||
1020 | bio_for_each_segment(bvec, bio, i) { | |
1021 | char *addr = page_address(bvec->bv_page); | |
1022 | ||
1023 | memcpy(addr, p, bvec->bv_len); | |
1024 | p += bvec->bv_len; | |
1025 | } | |
1026 | } | |
1027 | ||
76029ff3 | 1028 | bio->bi_private = bmd; |
68154e90 | 1029 | bio->bi_end_io = bio_copy_kern_endio; |
76029ff3 FT |
1030 | |
1031 | bio_set_map_data(bmd, bio, &iov, 1); | |
68154e90 FT |
1032 | return bio; |
1033 | cleanup: | |
1034 | bio_for_each_segment(bvec, bio, i) | |
1035 | __free_page(bvec->bv_page); | |
1036 | ||
1037 | bio_put(bio); | |
76029ff3 FT |
1038 | out_bmd: |
1039 | bio_free_map_data(bmd); | |
68154e90 FT |
1040 | |
1041 | return ERR_PTR(ret); | |
1042 | } | |
1043 | ||
1da177e4 LT |
1044 | /* |
1045 | * bio_set_pages_dirty() and bio_check_pages_dirty() are support functions | |
1046 | * for performing direct-IO in BIOs. | |
1047 | * | |
1048 | * The problem is that we cannot run set_page_dirty() from interrupt context | |
1049 | * because the required locks are not interrupt-safe. So what we can do is to | |
1050 | * mark the pages dirty _before_ performing IO. And in interrupt context, | |
1051 | * check that the pages are still dirty. If so, fine. If not, redirty them | |
1052 | * in process context. | |
1053 | * | |
1054 | * We special-case compound pages here: normally this means reads into hugetlb | |
1055 | * pages. The logic in here doesn't really work right for compound pages | |
1056 | * because the VM does not uniformly chase down the head page in all cases. | |
1057 | * But dirtiness of compound pages is pretty meaningless anyway: the VM doesn't | |
1058 | * handle them at all. So we skip compound pages here at an early stage. | |
1059 | * | |
1060 | * Note that this code is very hard to test under normal circumstances because | |
1061 | * direct-io pins the pages with get_user_pages(). This makes | |
1062 | * is_page_cache_freeable return false, and the VM will not clean the pages. | |
1063 | * But other code (eg, pdflush) could clean the pages if they are mapped | |
1064 | * pagecache. | |
1065 | * | |
1066 | * Simply disabling the call to bio_set_pages_dirty() is a good way to test the | |
1067 | * deferred bio dirtying paths. | |
1068 | */ | |
1069 | ||
1070 | /* | |
1071 | * bio_set_pages_dirty() will mark all the bio's pages as dirty. | |
1072 | */ | |
1073 | void bio_set_pages_dirty(struct bio *bio) | |
1074 | { | |
1075 | struct bio_vec *bvec = bio->bi_io_vec; | |
1076 | int i; | |
1077 | ||
1078 | for (i = 0; i < bio->bi_vcnt; i++) { | |
1079 | struct page *page = bvec[i].bv_page; | |
1080 | ||
1081 | if (page && !PageCompound(page)) | |
1082 | set_page_dirty_lock(page); | |
1083 | } | |
1084 | } | |
1085 | ||
86b6c7a7 | 1086 | static void bio_release_pages(struct bio *bio) |
1da177e4 LT |
1087 | { |
1088 | struct bio_vec *bvec = bio->bi_io_vec; | |
1089 | int i; | |
1090 | ||
1091 | for (i = 0; i < bio->bi_vcnt; i++) { | |
1092 | struct page *page = bvec[i].bv_page; | |
1093 | ||
1094 | if (page) | |
1095 | put_page(page); | |
1096 | } | |
1097 | } | |
1098 | ||
1099 | /* | |
1100 | * bio_check_pages_dirty() will check that all the BIO's pages are still dirty. | |
1101 | * If they are, then fine. If, however, some pages are clean then they must | |
1102 | * have been written out during the direct-IO read. So we take another ref on | |
1103 | * the BIO and the offending pages and re-dirty the pages in process context. | |
1104 | * | |
1105 | * It is expected that bio_check_pages_dirty() will wholly own the BIO from | |
1106 | * here on. It will run one page_cache_release() against each page and will | |
1107 | * run one bio_put() against the BIO. | |
1108 | */ | |
1109 | ||
65f27f38 | 1110 | static void bio_dirty_fn(struct work_struct *work); |
1da177e4 | 1111 | |
65f27f38 | 1112 | static DECLARE_WORK(bio_dirty_work, bio_dirty_fn); |
1da177e4 LT |
1113 | static DEFINE_SPINLOCK(bio_dirty_lock); |
1114 | static struct bio *bio_dirty_list; | |
1115 | ||
1116 | /* | |
1117 | * This runs in process context | |
1118 | */ | |
65f27f38 | 1119 | static void bio_dirty_fn(struct work_struct *work) |
1da177e4 LT |
1120 | { |
1121 | unsigned long flags; | |
1122 | struct bio *bio; | |
1123 | ||
1124 | spin_lock_irqsave(&bio_dirty_lock, flags); | |
1125 | bio = bio_dirty_list; | |
1126 | bio_dirty_list = NULL; | |
1127 | spin_unlock_irqrestore(&bio_dirty_lock, flags); | |
1128 | ||
1129 | while (bio) { | |
1130 | struct bio *next = bio->bi_private; | |
1131 | ||
1132 | bio_set_pages_dirty(bio); | |
1133 | bio_release_pages(bio); | |
1134 | bio_put(bio); | |
1135 | bio = next; | |
1136 | } | |
1137 | } | |
1138 | ||
1139 | void bio_check_pages_dirty(struct bio *bio) | |
1140 | { | |
1141 | struct bio_vec *bvec = bio->bi_io_vec; | |
1142 | int nr_clean_pages = 0; | |
1143 | int i; | |
1144 | ||
1145 | for (i = 0; i < bio->bi_vcnt; i++) { | |
1146 | struct page *page = bvec[i].bv_page; | |
1147 | ||
1148 | if (PageDirty(page) || PageCompound(page)) { | |
1149 | page_cache_release(page); | |
1150 | bvec[i].bv_page = NULL; | |
1151 | } else { | |
1152 | nr_clean_pages++; | |
1153 | } | |
1154 | } | |
1155 | ||
1156 | if (nr_clean_pages) { | |
1157 | unsigned long flags; | |
1158 | ||
1159 | spin_lock_irqsave(&bio_dirty_lock, flags); | |
1160 | bio->bi_private = bio_dirty_list; | |
1161 | bio_dirty_list = bio; | |
1162 | spin_unlock_irqrestore(&bio_dirty_lock, flags); | |
1163 | schedule_work(&bio_dirty_work); | |
1164 | } else { | |
1165 | bio_put(bio); | |
1166 | } | |
1167 | } | |
1168 | ||
1169 | /** | |
1170 | * bio_endio - end I/O on a bio | |
1171 | * @bio: bio | |
1da177e4 LT |
1172 | * @error: error, if any |
1173 | * | |
1174 | * Description: | |
6712ecf8 | 1175 | * bio_endio() will end I/O on the whole bio. bio_endio() is the |
5bb23a68 N |
1176 | * preferred way to end I/O on a bio, it takes care of clearing |
1177 | * BIO_UPTODATE on error. @error is 0 on success, and and one of the | |
1178 | * established -Exxxx (-EIO, for instance) error values in case | |
1179 | * something went wrong. Noone should call bi_end_io() directly on a | |
1180 | * bio unless they own it and thus know that it has an end_io | |
1181 | * function. | |
1da177e4 | 1182 | **/ |
6712ecf8 | 1183 | void bio_endio(struct bio *bio, int error) |
1da177e4 LT |
1184 | { |
1185 | if (error) | |
1186 | clear_bit(BIO_UPTODATE, &bio->bi_flags); | |
9cc54d40 N |
1187 | else if (!test_bit(BIO_UPTODATE, &bio->bi_flags)) |
1188 | error = -EIO; | |
1da177e4 | 1189 | |
5bb23a68 | 1190 | if (bio->bi_end_io) |
6712ecf8 | 1191 | bio->bi_end_io(bio, error); |
1da177e4 LT |
1192 | } |
1193 | ||
1194 | void bio_pair_release(struct bio_pair *bp) | |
1195 | { | |
1196 | if (atomic_dec_and_test(&bp->cnt)) { | |
1197 | struct bio *master = bp->bio1.bi_private; | |
1198 | ||
6712ecf8 | 1199 | bio_endio(master, bp->error); |
1da177e4 LT |
1200 | mempool_free(bp, bp->bio2.bi_private); |
1201 | } | |
1202 | } | |
1203 | ||
6712ecf8 | 1204 | static void bio_pair_end_1(struct bio *bi, int err) |
1da177e4 LT |
1205 | { |
1206 | struct bio_pair *bp = container_of(bi, struct bio_pair, bio1); | |
1207 | ||
1208 | if (err) | |
1209 | bp->error = err; | |
1210 | ||
1da177e4 | 1211 | bio_pair_release(bp); |
1da177e4 LT |
1212 | } |
1213 | ||
6712ecf8 | 1214 | static void bio_pair_end_2(struct bio *bi, int err) |
1da177e4 LT |
1215 | { |
1216 | struct bio_pair *bp = container_of(bi, struct bio_pair, bio2); | |
1217 | ||
1218 | if (err) | |
1219 | bp->error = err; | |
1220 | ||
1da177e4 | 1221 | bio_pair_release(bp); |
1da177e4 LT |
1222 | } |
1223 | ||
1224 | /* | |
1225 | * split a bio - only worry about a bio with a single page | |
1226 | * in it's iovec | |
1227 | */ | |
1228 | struct bio_pair *bio_split(struct bio *bi, mempool_t *pool, int first_sectors) | |
1229 | { | |
1230 | struct bio_pair *bp = mempool_alloc(pool, GFP_NOIO); | |
1231 | ||
1232 | if (!bp) | |
1233 | return bp; | |
1234 | ||
2056a782 JA |
1235 | blk_add_trace_pdu_int(bdev_get_queue(bi->bi_bdev), BLK_TA_SPLIT, bi, |
1236 | bi->bi_sector + first_sectors); | |
1237 | ||
1da177e4 LT |
1238 | BUG_ON(bi->bi_vcnt != 1); |
1239 | BUG_ON(bi->bi_idx != 0); | |
1240 | atomic_set(&bp->cnt, 3); | |
1241 | bp->error = 0; | |
1242 | bp->bio1 = *bi; | |
1243 | bp->bio2 = *bi; | |
1244 | bp->bio2.bi_sector += first_sectors; | |
1245 | bp->bio2.bi_size -= first_sectors << 9; | |
1246 | bp->bio1.bi_size = first_sectors << 9; | |
1247 | ||
1248 | bp->bv1 = bi->bi_io_vec[0]; | |
1249 | bp->bv2 = bi->bi_io_vec[0]; | |
1250 | bp->bv2.bv_offset += first_sectors << 9; | |
1251 | bp->bv2.bv_len -= first_sectors << 9; | |
1252 | bp->bv1.bv_len = first_sectors << 9; | |
1253 | ||
1254 | bp->bio1.bi_io_vec = &bp->bv1; | |
1255 | bp->bio2.bi_io_vec = &bp->bv2; | |
1256 | ||
a2eb0c10 N |
1257 | bp->bio1.bi_max_vecs = 1; |
1258 | bp->bio2.bi_max_vecs = 1; | |
1259 | ||
1da177e4 LT |
1260 | bp->bio1.bi_end_io = bio_pair_end_1; |
1261 | bp->bio2.bi_end_io = bio_pair_end_2; | |
1262 | ||
1263 | bp->bio1.bi_private = bi; | |
1264 | bp->bio2.bi_private = pool; | |
1265 | ||
7ba1ba12 MP |
1266 | if (bio_integrity(bi)) |
1267 | bio_integrity_split(bi, bp, first_sectors); | |
1268 | ||
1da177e4 LT |
1269 | return bp; |
1270 | } | |
1271 | ||
1da177e4 LT |
1272 | |
1273 | /* | |
1274 | * create memory pools for biovec's in a bio_set. | |
1275 | * use the global biovec slabs created for general use. | |
1276 | */ | |
5972511b | 1277 | static int biovec_create_pools(struct bio_set *bs, int pool_entries) |
1da177e4 LT |
1278 | { |
1279 | int i; | |
1280 | ||
1281 | for (i = 0; i < BIOVEC_NR_POOLS; i++) { | |
1282 | struct biovec_slab *bp = bvec_slabs + i; | |
1283 | mempool_t **bvp = bs->bvec_pools + i; | |
1284 | ||
93d2341c | 1285 | *bvp = mempool_create_slab_pool(pool_entries, bp->slab); |
1da177e4 LT |
1286 | if (!*bvp) |
1287 | return -ENOMEM; | |
1288 | } | |
1289 | return 0; | |
1290 | } | |
1291 | ||
1292 | static void biovec_free_pools(struct bio_set *bs) | |
1293 | { | |
1294 | int i; | |
1295 | ||
1296 | for (i = 0; i < BIOVEC_NR_POOLS; i++) { | |
1297 | mempool_t *bvp = bs->bvec_pools[i]; | |
1298 | ||
1299 | if (bvp) | |
1300 | mempool_destroy(bvp); | |
1301 | } | |
1302 | ||
1303 | } | |
1304 | ||
1305 | void bioset_free(struct bio_set *bs) | |
1306 | { | |
1307 | if (bs->bio_pool) | |
1308 | mempool_destroy(bs->bio_pool); | |
1309 | ||
7ba1ba12 | 1310 | bioset_integrity_free(bs); |
1da177e4 LT |
1311 | biovec_free_pools(bs); |
1312 | ||
1313 | kfree(bs); | |
1314 | } | |
1315 | ||
5972511b | 1316 | struct bio_set *bioset_create(int bio_pool_size, int bvec_pool_size) |
1da177e4 | 1317 | { |
11b0b5ab | 1318 | struct bio_set *bs = kzalloc(sizeof(*bs), GFP_KERNEL); |
1da177e4 LT |
1319 | |
1320 | if (!bs) | |
1321 | return NULL; | |
1322 | ||
93d2341c | 1323 | bs->bio_pool = mempool_create_slab_pool(bio_pool_size, bio_slab); |
1da177e4 LT |
1324 | if (!bs->bio_pool) |
1325 | goto bad; | |
1326 | ||
7ba1ba12 MP |
1327 | if (bioset_integrity_create(bs, bio_pool_size)) |
1328 | goto bad; | |
1329 | ||
5972511b | 1330 | if (!biovec_create_pools(bs, bvec_pool_size)) |
1da177e4 LT |
1331 | return bs; |
1332 | ||
1333 | bad: | |
1334 | bioset_free(bs); | |
1335 | return NULL; | |
1336 | } | |
1337 | ||
1338 | static void __init biovec_init_slabs(void) | |
1339 | { | |
1340 | int i; | |
1341 | ||
1342 | for (i = 0; i < BIOVEC_NR_POOLS; i++) { | |
1343 | int size; | |
1344 | struct biovec_slab *bvs = bvec_slabs + i; | |
1345 | ||
1346 | size = bvs->nr_vecs * sizeof(struct bio_vec); | |
1347 | bvs->slab = kmem_cache_create(bvs->name, size, 0, | |
20c2df83 | 1348 | SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); |
1da177e4 LT |
1349 | } |
1350 | } | |
1351 | ||
1352 | static int __init init_bio(void) | |
1353 | { | |
0a31bd5f | 1354 | bio_slab = KMEM_CACHE(bio, SLAB_HWCACHE_ALIGN|SLAB_PANIC); |
1da177e4 | 1355 | |
7ba1ba12 | 1356 | bio_integrity_init_slab(); |
1da177e4 LT |
1357 | biovec_init_slabs(); |
1358 | ||
5972511b | 1359 | fs_bio_set = bioset_create(BIO_POOL_SIZE, 2); |
1da177e4 LT |
1360 | if (!fs_bio_set) |
1361 | panic("bio: can't allocate bios\n"); | |
1362 | ||
0eaae62a MD |
1363 | bio_split_pool = mempool_create_kmalloc_pool(BIO_SPLIT_ENTRIES, |
1364 | sizeof(struct bio_pair)); | |
1da177e4 LT |
1365 | if (!bio_split_pool) |
1366 | panic("bio: can't create split pool\n"); | |
1367 | ||
1368 | return 0; | |
1369 | } | |
1370 | ||
1371 | subsys_initcall(init_bio); | |
1372 | ||
1373 | EXPORT_SYMBOL(bio_alloc); | |
1374 | EXPORT_SYMBOL(bio_put); | |
3676347a | 1375 | EXPORT_SYMBOL(bio_free); |
1da177e4 LT |
1376 | EXPORT_SYMBOL(bio_endio); |
1377 | EXPORT_SYMBOL(bio_init); | |
1378 | EXPORT_SYMBOL(__bio_clone); | |
1379 | EXPORT_SYMBOL(bio_clone); | |
1380 | EXPORT_SYMBOL(bio_phys_segments); | |
1da177e4 | 1381 | EXPORT_SYMBOL(bio_add_page); |
6e68af66 | 1382 | EXPORT_SYMBOL(bio_add_pc_page); |
1da177e4 | 1383 | EXPORT_SYMBOL(bio_get_nr_vecs); |
40044ce0 JA |
1384 | EXPORT_SYMBOL(bio_map_user); |
1385 | EXPORT_SYMBOL(bio_unmap_user); | |
df46b9a4 | 1386 | EXPORT_SYMBOL(bio_map_kern); |
68154e90 | 1387 | EXPORT_SYMBOL(bio_copy_kern); |
1da177e4 LT |
1388 | EXPORT_SYMBOL(bio_pair_release); |
1389 | EXPORT_SYMBOL(bio_split); | |
1390 | EXPORT_SYMBOL(bio_split_pool); | |
1391 | EXPORT_SYMBOL(bio_copy_user); | |
1392 | EXPORT_SYMBOL(bio_uncopy_user); | |
1393 | EXPORT_SYMBOL(bioset_create); | |
1394 | EXPORT_SYMBOL(bioset_free); | |
1395 | EXPORT_SYMBOL(bio_alloc_bioset); |