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1 | /* | |
2 | * Copyright (C) 2001 Jens Axboe <axboe@kernel.dk> | |
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> | |
28 | #include <linux/blktrace_api.h> | |
29 | #include <trace/block.h> | |
30 | #include <scsi/sg.h> /* for struct sg_iovec */ | |
31 | ||
32 | static struct kmem_cache *bio_slab __read_mostly; | |
33 | ||
34 | static mempool_t *bio_split_pool __read_mostly; | |
35 | ||
36 | /* | |
37 | * if you change this list, also change bvec_alloc or things will | |
38 | * break badly! cannot be bigger than what you can fit into an | |
39 | * unsigned short | |
40 | */ | |
41 | ||
42 | #define BV(x) { .nr_vecs = x, .name = "biovec-"__stringify(x) } | |
43 | static struct biovec_slab bvec_slabs[BIOVEC_NR_POOLS] __read_mostly = { | |
44 | BV(1), BV(4), BV(16), BV(64), BV(128), BV(BIO_MAX_PAGES), | |
45 | }; | |
46 | #undef BV | |
47 | ||
48 | /* | |
49 | * fs_bio_set is the bio_set containing bio and iovec memory pools used by | |
50 | * IO code that does not need private memory pools. | |
51 | */ | |
52 | struct bio_set *fs_bio_set; | |
53 | ||
54 | unsigned int bvec_nr_vecs(unsigned short idx) | |
55 | { | |
56 | return bvec_slabs[idx].nr_vecs; | |
57 | } | |
58 | ||
59 | struct bio_vec *bvec_alloc_bs(gfp_t gfp_mask, int nr, unsigned long *idx, struct bio_set *bs) | |
60 | { | |
61 | struct bio_vec *bvl; | |
62 | ||
63 | /* | |
64 | * If 'bs' is given, lookup the pool and do the mempool alloc. | |
65 | * If not, this is a bio_kmalloc() allocation and just do a | |
66 | * kzalloc() for the exact number of vecs right away. | |
67 | */ | |
68 | if (bs) { | |
69 | /* | |
70 | * see comment near bvec_array define! | |
71 | */ | |
72 | switch (nr) { | |
73 | case 1: | |
74 | *idx = 0; | |
75 | break; | |
76 | case 2 ... 4: | |
77 | *idx = 1; | |
78 | break; | |
79 | case 5 ... 16: | |
80 | *idx = 2; | |
81 | break; | |
82 | case 17 ... 64: | |
83 | *idx = 3; | |
84 | break; | |
85 | case 65 ... 128: | |
86 | *idx = 4; | |
87 | break; | |
88 | case 129 ... BIO_MAX_PAGES: | |
89 | *idx = 5; | |
90 | break; | |
91 | default: | |
92 | return NULL; | |
93 | } | |
94 | ||
95 | /* | |
96 | * idx now points to the pool we want to allocate from | |
97 | */ | |
98 | bvl = mempool_alloc(bs->bvec_pools[*idx], gfp_mask); | |
99 | if (bvl) | |
100 | memset(bvl, 0, | |
101 | bvec_nr_vecs(*idx) * sizeof(struct bio_vec)); | |
102 | } else | |
103 | bvl = kzalloc(nr * sizeof(struct bio_vec), gfp_mask); | |
104 | ||
105 | return bvl; | |
106 | } | |
107 | ||
108 | void bio_free(struct bio *bio, struct bio_set *bio_set) | |
109 | { | |
110 | if (bio->bi_io_vec) { | |
111 | const int pool_idx = BIO_POOL_IDX(bio); | |
112 | ||
113 | BIO_BUG_ON(pool_idx >= BIOVEC_NR_POOLS); | |
114 | ||
115 | mempool_free(bio->bi_io_vec, bio_set->bvec_pools[pool_idx]); | |
116 | } | |
117 | ||
118 | if (bio_integrity(bio)) | |
119 | bio_integrity_free(bio, bio_set); | |
120 | ||
121 | mempool_free(bio, bio_set->bio_pool); | |
122 | } | |
123 | ||
124 | /* | |
125 | * default destructor for a bio allocated with bio_alloc_bioset() | |
126 | */ | |
127 | static void bio_fs_destructor(struct bio *bio) | |
128 | { | |
129 | bio_free(bio, fs_bio_set); | |
130 | } | |
131 | ||
132 | static void bio_kmalloc_destructor(struct bio *bio) | |
133 | { | |
134 | kfree(bio->bi_io_vec); | |
135 | kfree(bio); | |
136 | } | |
137 | ||
138 | void bio_init(struct bio *bio) | |
139 | { | |
140 | memset(bio, 0, sizeof(*bio)); | |
141 | bio->bi_flags = 1 << BIO_UPTODATE; | |
142 | bio->bi_comp_cpu = -1; | |
143 | atomic_set(&bio->bi_cnt, 1); | |
144 | } | |
145 | ||
146 | /** | |
147 | * bio_alloc_bioset - allocate a bio for I/O | |
148 | * @gfp_mask: the GFP_ mask given to the slab allocator | |
149 | * @nr_iovecs: number of iovecs to pre-allocate | |
150 | * @bs: the bio_set to allocate from. If %NULL, just use kmalloc | |
151 | * | |
152 | * Description: | |
153 | * bio_alloc_bioset will first try its own mempool to satisfy the allocation. | |
154 | * If %__GFP_WAIT is set then we will block on the internal pool waiting | |
155 | * for a &struct bio to become free. If a %NULL @bs is passed in, we will | |
156 | * fall back to just using @kmalloc to allocate the required memory. | |
157 | * | |
158 | * allocate bio and iovecs from the memory pools specified by the | |
159 | * bio_set structure, or @kmalloc if none given. | |
160 | **/ | |
161 | struct bio *bio_alloc_bioset(gfp_t gfp_mask, int nr_iovecs, struct bio_set *bs) | |
162 | { | |
163 | struct bio *bio; | |
164 | ||
165 | if (bs) | |
166 | bio = mempool_alloc(bs->bio_pool, gfp_mask); | |
167 | else | |
168 | bio = kmalloc(sizeof(*bio), gfp_mask); | |
169 | ||
170 | if (likely(bio)) { | |
171 | struct bio_vec *bvl = NULL; | |
172 | ||
173 | bio_init(bio); | |
174 | if (likely(nr_iovecs)) { | |
175 | unsigned long uninitialized_var(idx); | |
176 | ||
177 | bvl = bvec_alloc_bs(gfp_mask, nr_iovecs, &idx, bs); | |
178 | if (unlikely(!bvl)) { | |
179 | if (bs) | |
180 | mempool_free(bio, bs->bio_pool); | |
181 | else | |
182 | kfree(bio); | |
183 | bio = NULL; | |
184 | goto out; | |
185 | } | |
186 | bio->bi_flags |= idx << BIO_POOL_OFFSET; | |
187 | bio->bi_max_vecs = bvec_nr_vecs(idx); | |
188 | } | |
189 | bio->bi_io_vec = bvl; | |
190 | } | |
191 | out: | |
192 | return bio; | |
193 | } | |
194 | ||
195 | struct bio *bio_alloc(gfp_t gfp_mask, int nr_iovecs) | |
196 | { | |
197 | struct bio *bio = bio_alloc_bioset(gfp_mask, nr_iovecs, fs_bio_set); | |
198 | ||
199 | if (bio) | |
200 | bio->bi_destructor = bio_fs_destructor; | |
201 | ||
202 | return bio; | |
203 | } | |
204 | ||
205 | /* | |
206 | * Like bio_alloc(), but doesn't use a mempool backing. This means that | |
207 | * it CAN fail, but while bio_alloc() can only be used for allocations | |
208 | * that have a short (finite) life span, bio_kmalloc() should be used | |
209 | * for more permanent bio allocations (like allocating some bio's for | |
210 | * initalization or setup purposes). | |
211 | */ | |
212 | struct bio *bio_kmalloc(gfp_t gfp_mask, int nr_iovecs) | |
213 | { | |
214 | struct bio *bio = bio_alloc_bioset(gfp_mask, nr_iovecs, NULL); | |
215 | ||
216 | if (bio) | |
217 | bio->bi_destructor = bio_kmalloc_destructor; | |
218 | ||
219 | return bio; | |
220 | } | |
221 | ||
222 | void zero_fill_bio(struct bio *bio) | |
223 | { | |
224 | unsigned long flags; | |
225 | struct bio_vec *bv; | |
226 | int i; | |
227 | ||
228 | bio_for_each_segment(bv, bio, i) { | |
229 | char *data = bvec_kmap_irq(bv, &flags); | |
230 | memset(data, 0, bv->bv_len); | |
231 | flush_dcache_page(bv->bv_page); | |
232 | bvec_kunmap_irq(data, &flags); | |
233 | } | |
234 | } | |
235 | EXPORT_SYMBOL(zero_fill_bio); | |
236 | ||
237 | /** | |
238 | * bio_put - release a reference to a bio | |
239 | * @bio: bio to release reference to | |
240 | * | |
241 | * Description: | |
242 | * Put a reference to a &struct bio, either one you have gotten with | |
243 | * bio_alloc or bio_get. The last put of a bio will free it. | |
244 | **/ | |
245 | void bio_put(struct bio *bio) | |
246 | { | |
247 | BIO_BUG_ON(!atomic_read(&bio->bi_cnt)); | |
248 | ||
249 | /* | |
250 | * last put frees it | |
251 | */ | |
252 | if (atomic_dec_and_test(&bio->bi_cnt)) { | |
253 | bio->bi_next = NULL; | |
254 | bio->bi_destructor(bio); | |
255 | } | |
256 | } | |
257 | ||
258 | inline int bio_phys_segments(struct request_queue *q, struct bio *bio) | |
259 | { | |
260 | if (unlikely(!bio_flagged(bio, BIO_SEG_VALID))) | |
261 | blk_recount_segments(q, bio); | |
262 | ||
263 | return bio->bi_phys_segments; | |
264 | } | |
265 | ||
266 | /** | |
267 | * __bio_clone - clone a bio | |
268 | * @bio: destination bio | |
269 | * @bio_src: bio to clone | |
270 | * | |
271 | * Clone a &bio. Caller will own the returned bio, but not | |
272 | * the actual data it points to. Reference count of returned | |
273 | * bio will be one. | |
274 | */ | |
275 | void __bio_clone(struct bio *bio, struct bio *bio_src) | |
276 | { | |
277 | memcpy(bio->bi_io_vec, bio_src->bi_io_vec, | |
278 | bio_src->bi_max_vecs * sizeof(struct bio_vec)); | |
279 | ||
280 | /* | |
281 | * most users will be overriding ->bi_bdev with a new target, | |
282 | * so we don't set nor calculate new physical/hw segment counts here | |
283 | */ | |
284 | bio->bi_sector = bio_src->bi_sector; | |
285 | bio->bi_bdev = bio_src->bi_bdev; | |
286 | bio->bi_flags |= 1 << BIO_CLONED; | |
287 | bio->bi_rw = bio_src->bi_rw; | |
288 | bio->bi_vcnt = bio_src->bi_vcnt; | |
289 | bio->bi_size = bio_src->bi_size; | |
290 | bio->bi_idx = bio_src->bi_idx; | |
291 | } | |
292 | ||
293 | /** | |
294 | * bio_clone - clone a bio | |
295 | * @bio: bio to clone | |
296 | * @gfp_mask: allocation priority | |
297 | * | |
298 | * Like __bio_clone, only also allocates the returned bio | |
299 | */ | |
300 | struct bio *bio_clone(struct bio *bio, gfp_t gfp_mask) | |
301 | { | |
302 | struct bio *b = bio_alloc_bioset(gfp_mask, bio->bi_max_vecs, fs_bio_set); | |
303 | ||
304 | if (!b) | |
305 | return NULL; | |
306 | ||
307 | b->bi_destructor = bio_fs_destructor; | |
308 | __bio_clone(b, bio); | |
309 | ||
310 | if (bio_integrity(bio)) { | |
311 | int ret; | |
312 | ||
313 | ret = bio_integrity_clone(b, bio, fs_bio_set); | |
314 | ||
315 | if (ret < 0) | |
316 | return NULL; | |
317 | } | |
318 | ||
319 | return b; | |
320 | } | |
321 | ||
322 | /** | |
323 | * bio_get_nr_vecs - return approx number of vecs | |
324 | * @bdev: I/O target | |
325 | * | |
326 | * Return the approximate number of pages we can send to this target. | |
327 | * There's no guarantee that you will be able to fit this number of pages | |
328 | * into a bio, it does not account for dynamic restrictions that vary | |
329 | * on offset. | |
330 | */ | |
331 | int bio_get_nr_vecs(struct block_device *bdev) | |
332 | { | |
333 | struct request_queue *q = bdev_get_queue(bdev); | |
334 | int nr_pages; | |
335 | ||
336 | nr_pages = ((q->max_sectors << 9) + PAGE_SIZE - 1) >> PAGE_SHIFT; | |
337 | if (nr_pages > q->max_phys_segments) | |
338 | nr_pages = q->max_phys_segments; | |
339 | if (nr_pages > q->max_hw_segments) | |
340 | nr_pages = q->max_hw_segments; | |
341 | ||
342 | return nr_pages; | |
343 | } | |
344 | ||
345 | static int __bio_add_page(struct request_queue *q, struct bio *bio, struct page | |
346 | *page, unsigned int len, unsigned int offset, | |
347 | unsigned short max_sectors) | |
348 | { | |
349 | int retried_segments = 0; | |
350 | struct bio_vec *bvec; | |
351 | ||
352 | /* | |
353 | * cloned bio must not modify vec list | |
354 | */ | |
355 | if (unlikely(bio_flagged(bio, BIO_CLONED))) | |
356 | return 0; | |
357 | ||
358 | if (((bio->bi_size + len) >> 9) > max_sectors) | |
359 | return 0; | |
360 | ||
361 | /* | |
362 | * For filesystems with a blocksize smaller than the pagesize | |
363 | * we will often be called with the same page as last time and | |
364 | * a consecutive offset. Optimize this special case. | |
365 | */ | |
366 | if (bio->bi_vcnt > 0) { | |
367 | struct bio_vec *prev = &bio->bi_io_vec[bio->bi_vcnt - 1]; | |
368 | ||
369 | if (page == prev->bv_page && | |
370 | offset == prev->bv_offset + prev->bv_len) { | |
371 | prev->bv_len += len; | |
372 | ||
373 | if (q->merge_bvec_fn) { | |
374 | struct bvec_merge_data bvm = { | |
375 | .bi_bdev = bio->bi_bdev, | |
376 | .bi_sector = bio->bi_sector, | |
377 | .bi_size = bio->bi_size, | |
378 | .bi_rw = bio->bi_rw, | |
379 | }; | |
380 | ||
381 | if (q->merge_bvec_fn(q, &bvm, prev) < len) { | |
382 | prev->bv_len -= len; | |
383 | return 0; | |
384 | } | |
385 | } | |
386 | ||
387 | goto done; | |
388 | } | |
389 | } | |
390 | ||
391 | if (bio->bi_vcnt >= bio->bi_max_vecs) | |
392 | return 0; | |
393 | ||
394 | /* | |
395 | * we might lose a segment or two here, but rather that than | |
396 | * make this too complex. | |
397 | */ | |
398 | ||
399 | while (bio->bi_phys_segments >= q->max_phys_segments | |
400 | || bio->bi_phys_segments >= q->max_hw_segments) { | |
401 | ||
402 | if (retried_segments) | |
403 | return 0; | |
404 | ||
405 | retried_segments = 1; | |
406 | blk_recount_segments(q, bio); | |
407 | } | |
408 | ||
409 | /* | |
410 | * setup the new entry, we might clear it again later if we | |
411 | * cannot add the page | |
412 | */ | |
413 | bvec = &bio->bi_io_vec[bio->bi_vcnt]; | |
414 | bvec->bv_page = page; | |
415 | bvec->bv_len = len; | |
416 | bvec->bv_offset = offset; | |
417 | ||
418 | /* | |
419 | * if queue has other restrictions (eg varying max sector size | |
420 | * depending on offset), it can specify a merge_bvec_fn in the | |
421 | * queue to get further control | |
422 | */ | |
423 | if (q->merge_bvec_fn) { | |
424 | struct bvec_merge_data bvm = { | |
425 | .bi_bdev = bio->bi_bdev, | |
426 | .bi_sector = bio->bi_sector, | |
427 | .bi_size = bio->bi_size, | |
428 | .bi_rw = bio->bi_rw, | |
429 | }; | |
430 | ||
431 | /* | |
432 | * merge_bvec_fn() returns number of bytes it can accept | |
433 | * at this offset | |
434 | */ | |
435 | if (q->merge_bvec_fn(q, &bvm, bvec) < len) { | |
436 | bvec->bv_page = NULL; | |
437 | bvec->bv_len = 0; | |
438 | bvec->bv_offset = 0; | |
439 | return 0; | |
440 | } | |
441 | } | |
442 | ||
443 | /* If we may be able to merge these biovecs, force a recount */ | |
444 | if (bio->bi_vcnt && (BIOVEC_PHYS_MERGEABLE(bvec-1, bvec))) | |
445 | bio->bi_flags &= ~(1 << BIO_SEG_VALID); | |
446 | ||
447 | bio->bi_vcnt++; | |
448 | bio->bi_phys_segments++; | |
449 | done: | |
450 | bio->bi_size += len; | |
451 | return len; | |
452 | } | |
453 | ||
454 | /** | |
455 | * bio_add_pc_page - attempt to add page to bio | |
456 | * @q: the target queue | |
457 | * @bio: destination bio | |
458 | * @page: page to add | |
459 | * @len: vec entry length | |
460 | * @offset: vec entry offset | |
461 | * | |
462 | * Attempt to add a page to the bio_vec maplist. This can fail for a | |
463 | * number of reasons, such as the bio being full or target block | |
464 | * device limitations. The target block device must allow bio's | |
465 | * smaller than PAGE_SIZE, so it is always possible to add a single | |
466 | * page to an empty bio. This should only be used by REQ_PC bios. | |
467 | */ | |
468 | int bio_add_pc_page(struct request_queue *q, struct bio *bio, struct page *page, | |
469 | unsigned int len, unsigned int offset) | |
470 | { | |
471 | return __bio_add_page(q, bio, page, len, offset, q->max_hw_sectors); | |
472 | } | |
473 | ||
474 | /** | |
475 | * bio_add_page - attempt to add page to bio | |
476 | * @bio: destination bio | |
477 | * @page: page to add | |
478 | * @len: vec entry length | |
479 | * @offset: vec entry offset | |
480 | * | |
481 | * Attempt to add a page to the bio_vec maplist. This can fail for a | |
482 | * number of reasons, such as the bio being full or target block | |
483 | * device limitations. The target block device must allow bio's | |
484 | * smaller than PAGE_SIZE, so it is always possible to add a single | |
485 | * page to an empty bio. | |
486 | */ | |
487 | int bio_add_page(struct bio *bio, struct page *page, unsigned int len, | |
488 | unsigned int offset) | |
489 | { | |
490 | struct request_queue *q = bdev_get_queue(bio->bi_bdev); | |
491 | return __bio_add_page(q, bio, page, len, offset, q->max_sectors); | |
492 | } | |
493 | ||
494 | struct bio_map_data { | |
495 | struct bio_vec *iovecs; | |
496 | struct sg_iovec *sgvecs; | |
497 | int nr_sgvecs; | |
498 | int is_our_pages; | |
499 | }; | |
500 | ||
501 | static void bio_set_map_data(struct bio_map_data *bmd, struct bio *bio, | |
502 | struct sg_iovec *iov, int iov_count, | |
503 | int is_our_pages) | |
504 | { | |
505 | memcpy(bmd->iovecs, bio->bi_io_vec, sizeof(struct bio_vec) * bio->bi_vcnt); | |
506 | memcpy(bmd->sgvecs, iov, sizeof(struct sg_iovec) * iov_count); | |
507 | bmd->nr_sgvecs = iov_count; | |
508 | bmd->is_our_pages = is_our_pages; | |
509 | bio->bi_private = bmd; | |
510 | } | |
511 | ||
512 | static void bio_free_map_data(struct bio_map_data *bmd) | |
513 | { | |
514 | kfree(bmd->iovecs); | |
515 | kfree(bmd->sgvecs); | |
516 | kfree(bmd); | |
517 | } | |
518 | ||
519 | static struct bio_map_data *bio_alloc_map_data(int nr_segs, int iov_count, | |
520 | gfp_t gfp_mask) | |
521 | { | |
522 | struct bio_map_data *bmd = kmalloc(sizeof(*bmd), gfp_mask); | |
523 | ||
524 | if (!bmd) | |
525 | return NULL; | |
526 | ||
527 | bmd->iovecs = kmalloc(sizeof(struct bio_vec) * nr_segs, gfp_mask); | |
528 | if (!bmd->iovecs) { | |
529 | kfree(bmd); | |
530 | return NULL; | |
531 | } | |
532 | ||
533 | bmd->sgvecs = kmalloc(sizeof(struct sg_iovec) * iov_count, gfp_mask); | |
534 | if (bmd->sgvecs) | |
535 | return bmd; | |
536 | ||
537 | kfree(bmd->iovecs); | |
538 | kfree(bmd); | |
539 | return NULL; | |
540 | } | |
541 | ||
542 | static int __bio_copy_iov(struct bio *bio, struct bio_vec *iovecs, | |
543 | struct sg_iovec *iov, int iov_count, int uncopy, | |
544 | int do_free_page) | |
545 | { | |
546 | int ret = 0, i; | |
547 | struct bio_vec *bvec; | |
548 | int iov_idx = 0; | |
549 | unsigned int iov_off = 0; | |
550 | int read = bio_data_dir(bio) == READ; | |
551 | ||
552 | __bio_for_each_segment(bvec, bio, i, 0) { | |
553 | char *bv_addr = page_address(bvec->bv_page); | |
554 | unsigned int bv_len = iovecs[i].bv_len; | |
555 | ||
556 | while (bv_len && iov_idx < iov_count) { | |
557 | unsigned int bytes; | |
558 | char *iov_addr; | |
559 | ||
560 | bytes = min_t(unsigned int, | |
561 | iov[iov_idx].iov_len - iov_off, bv_len); | |
562 | iov_addr = iov[iov_idx].iov_base + iov_off; | |
563 | ||
564 | if (!ret) { | |
565 | if (!read && !uncopy) | |
566 | ret = copy_from_user(bv_addr, iov_addr, | |
567 | bytes); | |
568 | if (read && uncopy) | |
569 | ret = copy_to_user(iov_addr, bv_addr, | |
570 | bytes); | |
571 | ||
572 | if (ret) | |
573 | ret = -EFAULT; | |
574 | } | |
575 | ||
576 | bv_len -= bytes; | |
577 | bv_addr += bytes; | |
578 | iov_addr += bytes; | |
579 | iov_off += bytes; | |
580 | ||
581 | if (iov[iov_idx].iov_len == iov_off) { | |
582 | iov_idx++; | |
583 | iov_off = 0; | |
584 | } | |
585 | } | |
586 | ||
587 | if (do_free_page) | |
588 | __free_page(bvec->bv_page); | |
589 | } | |
590 | ||
591 | return ret; | |
592 | } | |
593 | ||
594 | /** | |
595 | * bio_uncopy_user - finish previously mapped bio | |
596 | * @bio: bio being terminated | |
597 | * | |
598 | * Free pages allocated from bio_copy_user() and write back data | |
599 | * to user space in case of a read. | |
600 | */ | |
601 | int bio_uncopy_user(struct bio *bio) | |
602 | { | |
603 | struct bio_map_data *bmd = bio->bi_private; | |
604 | int ret = 0; | |
605 | ||
606 | if (!bio_flagged(bio, BIO_NULL_MAPPED)) | |
607 | ret = __bio_copy_iov(bio, bmd->iovecs, bmd->sgvecs, | |
608 | bmd->nr_sgvecs, 1, bmd->is_our_pages); | |
609 | bio_free_map_data(bmd); | |
610 | bio_put(bio); | |
611 | return ret; | |
612 | } | |
613 | ||
614 | /** | |
615 | * bio_copy_user_iov - copy user data to bio | |
616 | * @q: destination block queue | |
617 | * @map_data: pointer to the rq_map_data holding pages (if necessary) | |
618 | * @iov: the iovec. | |
619 | * @iov_count: number of elements in the iovec | |
620 | * @write_to_vm: bool indicating writing to pages or not | |
621 | * @gfp_mask: memory allocation flags | |
622 | * | |
623 | * Prepares and returns a bio for indirect user io, bouncing data | |
624 | * to/from kernel pages as necessary. Must be paired with | |
625 | * call bio_uncopy_user() on io completion. | |
626 | */ | |
627 | struct bio *bio_copy_user_iov(struct request_queue *q, | |
628 | struct rq_map_data *map_data, | |
629 | struct sg_iovec *iov, int iov_count, | |
630 | int write_to_vm, gfp_t gfp_mask) | |
631 | { | |
632 | struct bio_map_data *bmd; | |
633 | struct bio_vec *bvec; | |
634 | struct page *page; | |
635 | struct bio *bio; | |
636 | int i, ret; | |
637 | int nr_pages = 0; | |
638 | unsigned int len = 0; | |
639 | ||
640 | for (i = 0; i < iov_count; i++) { | |
641 | unsigned long uaddr; | |
642 | unsigned long end; | |
643 | unsigned long start; | |
644 | ||
645 | uaddr = (unsigned long)iov[i].iov_base; | |
646 | end = (uaddr + iov[i].iov_len + PAGE_SIZE - 1) >> PAGE_SHIFT; | |
647 | start = uaddr >> PAGE_SHIFT; | |
648 | ||
649 | nr_pages += end - start; | |
650 | len += iov[i].iov_len; | |
651 | } | |
652 | ||
653 | bmd = bio_alloc_map_data(nr_pages, iov_count, gfp_mask); | |
654 | if (!bmd) | |
655 | return ERR_PTR(-ENOMEM); | |
656 | ||
657 | ret = -ENOMEM; | |
658 | bio = bio_alloc(gfp_mask, nr_pages); | |
659 | if (!bio) | |
660 | goto out_bmd; | |
661 | ||
662 | bio->bi_rw |= (!write_to_vm << BIO_RW); | |
663 | ||
664 | ret = 0; | |
665 | i = 0; | |
666 | while (len) { | |
667 | unsigned int bytes; | |
668 | ||
669 | if (map_data) | |
670 | bytes = 1U << (PAGE_SHIFT + map_data->page_order); | |
671 | else | |
672 | bytes = PAGE_SIZE; | |
673 | ||
674 | if (bytes > len) | |
675 | bytes = len; | |
676 | ||
677 | if (map_data) { | |
678 | if (i == map_data->nr_entries) { | |
679 | ret = -ENOMEM; | |
680 | break; | |
681 | } | |
682 | page = map_data->pages[i++]; | |
683 | } else | |
684 | page = alloc_page(q->bounce_gfp | gfp_mask); | |
685 | if (!page) { | |
686 | ret = -ENOMEM; | |
687 | break; | |
688 | } | |
689 | ||
690 | if (bio_add_pc_page(q, bio, page, bytes, 0) < bytes) | |
691 | break; | |
692 | ||
693 | len -= bytes; | |
694 | } | |
695 | ||
696 | if (ret) | |
697 | goto cleanup; | |
698 | ||
699 | /* | |
700 | * success | |
701 | */ | |
702 | if (!write_to_vm) { | |
703 | ret = __bio_copy_iov(bio, bio->bi_io_vec, iov, iov_count, 0, 0); | |
704 | if (ret) | |
705 | goto cleanup; | |
706 | } | |
707 | ||
708 | bio_set_map_data(bmd, bio, iov, iov_count, map_data ? 0 : 1); | |
709 | return bio; | |
710 | cleanup: | |
711 | if (!map_data) | |
712 | bio_for_each_segment(bvec, bio, i) | |
713 | __free_page(bvec->bv_page); | |
714 | ||
715 | bio_put(bio); | |
716 | out_bmd: | |
717 | bio_free_map_data(bmd); | |
718 | return ERR_PTR(ret); | |
719 | } | |
720 | ||
721 | /** | |
722 | * bio_copy_user - copy user data to bio | |
723 | * @q: destination block queue | |
724 | * @map_data: pointer to the rq_map_data holding pages (if necessary) | |
725 | * @uaddr: start of user address | |
726 | * @len: length in bytes | |
727 | * @write_to_vm: bool indicating writing to pages or not | |
728 | * @gfp_mask: memory allocation flags | |
729 | * | |
730 | * Prepares and returns a bio for indirect user io, bouncing data | |
731 | * to/from kernel pages as necessary. Must be paired with | |
732 | * call bio_uncopy_user() on io completion. | |
733 | */ | |
734 | struct bio *bio_copy_user(struct request_queue *q, struct rq_map_data *map_data, | |
735 | unsigned long uaddr, unsigned int len, | |
736 | int write_to_vm, gfp_t gfp_mask) | |
737 | { | |
738 | struct sg_iovec iov; | |
739 | ||
740 | iov.iov_base = (void __user *)uaddr; | |
741 | iov.iov_len = len; | |
742 | ||
743 | return bio_copy_user_iov(q, map_data, &iov, 1, write_to_vm, gfp_mask); | |
744 | } | |
745 | ||
746 | static struct bio *__bio_map_user_iov(struct request_queue *q, | |
747 | struct block_device *bdev, | |
748 | struct sg_iovec *iov, int iov_count, | |
749 | int write_to_vm, gfp_t gfp_mask) | |
750 | { | |
751 | int i, j; | |
752 | int nr_pages = 0; | |
753 | struct page **pages; | |
754 | struct bio *bio; | |
755 | int cur_page = 0; | |
756 | int ret, offset; | |
757 | ||
758 | for (i = 0; i < iov_count; i++) { | |
759 | unsigned long uaddr = (unsigned long)iov[i].iov_base; | |
760 | unsigned long len = iov[i].iov_len; | |
761 | unsigned long end = (uaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT; | |
762 | unsigned long start = uaddr >> PAGE_SHIFT; | |
763 | ||
764 | nr_pages += end - start; | |
765 | /* | |
766 | * buffer must be aligned to at least hardsector size for now | |
767 | */ | |
768 | if (uaddr & queue_dma_alignment(q)) | |
769 | return ERR_PTR(-EINVAL); | |
770 | } | |
771 | ||
772 | if (!nr_pages) | |
773 | return ERR_PTR(-EINVAL); | |
774 | ||
775 | bio = bio_alloc(gfp_mask, nr_pages); | |
776 | if (!bio) | |
777 | return ERR_PTR(-ENOMEM); | |
778 | ||
779 | ret = -ENOMEM; | |
780 | pages = kcalloc(nr_pages, sizeof(struct page *), gfp_mask); | |
781 | if (!pages) | |
782 | goto out; | |
783 | ||
784 | for (i = 0; i < iov_count; i++) { | |
785 | unsigned long uaddr = (unsigned long)iov[i].iov_base; | |
786 | unsigned long len = iov[i].iov_len; | |
787 | unsigned long end = (uaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT; | |
788 | unsigned long start = uaddr >> PAGE_SHIFT; | |
789 | const int local_nr_pages = end - start; | |
790 | const int page_limit = cur_page + local_nr_pages; | |
791 | ||
792 | ret = get_user_pages_fast(uaddr, local_nr_pages, | |
793 | write_to_vm, &pages[cur_page]); | |
794 | if (ret < local_nr_pages) { | |
795 | ret = -EFAULT; | |
796 | goto out_unmap; | |
797 | } | |
798 | ||
799 | offset = uaddr & ~PAGE_MASK; | |
800 | for (j = cur_page; j < page_limit; j++) { | |
801 | unsigned int bytes = PAGE_SIZE - offset; | |
802 | ||
803 | if (len <= 0) | |
804 | break; | |
805 | ||
806 | if (bytes > len) | |
807 | bytes = len; | |
808 | ||
809 | /* | |
810 | * sorry... | |
811 | */ | |
812 | if (bio_add_pc_page(q, bio, pages[j], bytes, offset) < | |
813 | bytes) | |
814 | break; | |
815 | ||
816 | len -= bytes; | |
817 | offset = 0; | |
818 | } | |
819 | ||
820 | cur_page = j; | |
821 | /* | |
822 | * release the pages we didn't map into the bio, if any | |
823 | */ | |
824 | while (j < page_limit) | |
825 | page_cache_release(pages[j++]); | |
826 | } | |
827 | ||
828 | kfree(pages); | |
829 | ||
830 | /* | |
831 | * set data direction, and check if mapped pages need bouncing | |
832 | */ | |
833 | if (!write_to_vm) | |
834 | bio->bi_rw |= (1 << BIO_RW); | |
835 | ||
836 | bio->bi_bdev = bdev; | |
837 | bio->bi_flags |= (1 << BIO_USER_MAPPED); | |
838 | return bio; | |
839 | ||
840 | out_unmap: | |
841 | for (i = 0; i < nr_pages; i++) { | |
842 | if(!pages[i]) | |
843 | break; | |
844 | page_cache_release(pages[i]); | |
845 | } | |
846 | out: | |
847 | kfree(pages); | |
848 | bio_put(bio); | |
849 | return ERR_PTR(ret); | |
850 | } | |
851 | ||
852 | /** | |
853 | * bio_map_user - map user address into bio | |
854 | * @q: the struct request_queue for the bio | |
855 | * @bdev: destination block device | |
856 | * @uaddr: start of user address | |
857 | * @len: length in bytes | |
858 | * @write_to_vm: bool indicating writing to pages or not | |
859 | * @gfp_mask: memory allocation flags | |
860 | * | |
861 | * Map the user space address into a bio suitable for io to a block | |
862 | * device. Returns an error pointer in case of error. | |
863 | */ | |
864 | struct bio *bio_map_user(struct request_queue *q, struct block_device *bdev, | |
865 | unsigned long uaddr, unsigned int len, int write_to_vm, | |
866 | gfp_t gfp_mask) | |
867 | { | |
868 | struct sg_iovec iov; | |
869 | ||
870 | iov.iov_base = (void __user *)uaddr; | |
871 | iov.iov_len = len; | |
872 | ||
873 | return bio_map_user_iov(q, bdev, &iov, 1, write_to_vm, gfp_mask); | |
874 | } | |
875 | ||
876 | /** | |
877 | * bio_map_user_iov - map user sg_iovec table into bio | |
878 | * @q: the struct request_queue for the bio | |
879 | * @bdev: destination block device | |
880 | * @iov: the iovec. | |
881 | * @iov_count: number of elements in the iovec | |
882 | * @write_to_vm: bool indicating writing to pages or not | |
883 | * @gfp_mask: memory allocation flags | |
884 | * | |
885 | * Map the user space address into a bio suitable for io to a block | |
886 | * device. Returns an error pointer in case of error. | |
887 | */ | |
888 | struct bio *bio_map_user_iov(struct request_queue *q, struct block_device *bdev, | |
889 | struct sg_iovec *iov, int iov_count, | |
890 | int write_to_vm, gfp_t gfp_mask) | |
891 | { | |
892 | struct bio *bio; | |
893 | ||
894 | bio = __bio_map_user_iov(q, bdev, iov, iov_count, write_to_vm, | |
895 | gfp_mask); | |
896 | if (IS_ERR(bio)) | |
897 | return bio; | |
898 | ||
899 | /* | |
900 | * subtle -- if __bio_map_user() ended up bouncing a bio, | |
901 | * it would normally disappear when its bi_end_io is run. | |
902 | * however, we need it for the unmap, so grab an extra | |
903 | * reference to it | |
904 | */ | |
905 | bio_get(bio); | |
906 | ||
907 | return bio; | |
908 | } | |
909 | ||
910 | static void __bio_unmap_user(struct bio *bio) | |
911 | { | |
912 | struct bio_vec *bvec; | |
913 | int i; | |
914 | ||
915 | /* | |
916 | * make sure we dirty pages we wrote to | |
917 | */ | |
918 | __bio_for_each_segment(bvec, bio, i, 0) { | |
919 | if (bio_data_dir(bio) == READ) | |
920 | set_page_dirty_lock(bvec->bv_page); | |
921 | ||
922 | page_cache_release(bvec->bv_page); | |
923 | } | |
924 | ||
925 | bio_put(bio); | |
926 | } | |
927 | ||
928 | /** | |
929 | * bio_unmap_user - unmap a bio | |
930 | * @bio: the bio being unmapped | |
931 | * | |
932 | * Unmap a bio previously mapped by bio_map_user(). Must be called with | |
933 | * a process context. | |
934 | * | |
935 | * bio_unmap_user() may sleep. | |
936 | */ | |
937 | void bio_unmap_user(struct bio *bio) | |
938 | { | |
939 | __bio_unmap_user(bio); | |
940 | bio_put(bio); | |
941 | } | |
942 | ||
943 | static void bio_map_kern_endio(struct bio *bio, int err) | |
944 | { | |
945 | bio_put(bio); | |
946 | } | |
947 | ||
948 | ||
949 | static struct bio *__bio_map_kern(struct request_queue *q, void *data, | |
950 | unsigned int len, gfp_t gfp_mask) | |
951 | { | |
952 | unsigned long kaddr = (unsigned long)data; | |
953 | unsigned long end = (kaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT; | |
954 | unsigned long start = kaddr >> PAGE_SHIFT; | |
955 | const int nr_pages = end - start; | |
956 | int offset, i; | |
957 | struct bio *bio; | |
958 | ||
959 | bio = bio_alloc(gfp_mask, nr_pages); | |
960 | if (!bio) | |
961 | return ERR_PTR(-ENOMEM); | |
962 | ||
963 | offset = offset_in_page(kaddr); | |
964 | for (i = 0; i < nr_pages; i++) { | |
965 | unsigned int bytes = PAGE_SIZE - offset; | |
966 | ||
967 | if (len <= 0) | |
968 | break; | |
969 | ||
970 | if (bytes > len) | |
971 | bytes = len; | |
972 | ||
973 | if (bio_add_pc_page(q, bio, virt_to_page(data), bytes, | |
974 | offset) < bytes) | |
975 | break; | |
976 | ||
977 | data += bytes; | |
978 | len -= bytes; | |
979 | offset = 0; | |
980 | } | |
981 | ||
982 | bio->bi_end_io = bio_map_kern_endio; | |
983 | return bio; | |
984 | } | |
985 | ||
986 | /** | |
987 | * bio_map_kern - map kernel address into bio | |
988 | * @q: the struct request_queue for the bio | |
989 | * @data: pointer to buffer to map | |
990 | * @len: length in bytes | |
991 | * @gfp_mask: allocation flags for bio allocation | |
992 | * | |
993 | * Map the kernel address into a bio suitable for io to a block | |
994 | * device. Returns an error pointer in case of error. | |
995 | */ | |
996 | struct bio *bio_map_kern(struct request_queue *q, void *data, unsigned int len, | |
997 | gfp_t gfp_mask) | |
998 | { | |
999 | struct bio *bio; | |
1000 | ||
1001 | bio = __bio_map_kern(q, data, len, gfp_mask); | |
1002 | if (IS_ERR(bio)) | |
1003 | return bio; | |
1004 | ||
1005 | if (bio->bi_size == len) | |
1006 | return bio; | |
1007 | ||
1008 | /* | |
1009 | * Don't support partial mappings. | |
1010 | */ | |
1011 | bio_put(bio); | |
1012 | return ERR_PTR(-EINVAL); | |
1013 | } | |
1014 | ||
1015 | static void bio_copy_kern_endio(struct bio *bio, int err) | |
1016 | { | |
1017 | struct bio_vec *bvec; | |
1018 | const int read = bio_data_dir(bio) == READ; | |
1019 | struct bio_map_data *bmd = bio->bi_private; | |
1020 | int i; | |
1021 | char *p = bmd->sgvecs[0].iov_base; | |
1022 | ||
1023 | __bio_for_each_segment(bvec, bio, i, 0) { | |
1024 | char *addr = page_address(bvec->bv_page); | |
1025 | int len = bmd->iovecs[i].bv_len; | |
1026 | ||
1027 | if (read && !err) | |
1028 | memcpy(p, addr, len); | |
1029 | ||
1030 | __free_page(bvec->bv_page); | |
1031 | p += len; | |
1032 | } | |
1033 | ||
1034 | bio_free_map_data(bmd); | |
1035 | bio_put(bio); | |
1036 | } | |
1037 | ||
1038 | /** | |
1039 | * bio_copy_kern - copy kernel address into bio | |
1040 | * @q: the struct request_queue for the bio | |
1041 | * @data: pointer to buffer to copy | |
1042 | * @len: length in bytes | |
1043 | * @gfp_mask: allocation flags for bio and page allocation | |
1044 | * @reading: data direction is READ | |
1045 | * | |
1046 | * copy the kernel address into a bio suitable for io to a block | |
1047 | * device. Returns an error pointer in case of error. | |
1048 | */ | |
1049 | struct bio *bio_copy_kern(struct request_queue *q, void *data, unsigned int len, | |
1050 | gfp_t gfp_mask, int reading) | |
1051 | { | |
1052 | struct bio *bio; | |
1053 | struct bio_vec *bvec; | |
1054 | int i; | |
1055 | ||
1056 | bio = bio_copy_user(q, NULL, (unsigned long)data, len, 1, gfp_mask); | |
1057 | if (IS_ERR(bio)) | |
1058 | return bio; | |
1059 | ||
1060 | if (!reading) { | |
1061 | void *p = data; | |
1062 | ||
1063 | bio_for_each_segment(bvec, bio, i) { | |
1064 | char *addr = page_address(bvec->bv_page); | |
1065 | ||
1066 | memcpy(addr, p, bvec->bv_len); | |
1067 | p += bvec->bv_len; | |
1068 | } | |
1069 | } | |
1070 | ||
1071 | bio->bi_end_io = bio_copy_kern_endio; | |
1072 | ||
1073 | return bio; | |
1074 | } | |
1075 | ||
1076 | /* | |
1077 | * bio_set_pages_dirty() and bio_check_pages_dirty() are support functions | |
1078 | * for performing direct-IO in BIOs. | |
1079 | * | |
1080 | * The problem is that we cannot run set_page_dirty() from interrupt context | |
1081 | * because the required locks are not interrupt-safe. So what we can do is to | |
1082 | * mark the pages dirty _before_ performing IO. And in interrupt context, | |
1083 | * check that the pages are still dirty. If so, fine. If not, redirty them | |
1084 | * in process context. | |
1085 | * | |
1086 | * We special-case compound pages here: normally this means reads into hugetlb | |
1087 | * pages. The logic in here doesn't really work right for compound pages | |
1088 | * because the VM does not uniformly chase down the head page in all cases. | |
1089 | * But dirtiness of compound pages is pretty meaningless anyway: the VM doesn't | |
1090 | * handle them at all. So we skip compound pages here at an early stage. | |
1091 | * | |
1092 | * Note that this code is very hard to test under normal circumstances because | |
1093 | * direct-io pins the pages with get_user_pages(). This makes | |
1094 | * is_page_cache_freeable return false, and the VM will not clean the pages. | |
1095 | * But other code (eg, pdflush) could clean the pages if they are mapped | |
1096 | * pagecache. | |
1097 | * | |
1098 | * Simply disabling the call to bio_set_pages_dirty() is a good way to test the | |
1099 | * deferred bio dirtying paths. | |
1100 | */ | |
1101 | ||
1102 | /* | |
1103 | * bio_set_pages_dirty() will mark all the bio's pages as dirty. | |
1104 | */ | |
1105 | void bio_set_pages_dirty(struct bio *bio) | |
1106 | { | |
1107 | struct bio_vec *bvec = bio->bi_io_vec; | |
1108 | int i; | |
1109 | ||
1110 | for (i = 0; i < bio->bi_vcnt; i++) { | |
1111 | struct page *page = bvec[i].bv_page; | |
1112 | ||
1113 | if (page && !PageCompound(page)) | |
1114 | set_page_dirty_lock(page); | |
1115 | } | |
1116 | } | |
1117 | ||
1118 | static void bio_release_pages(struct bio *bio) | |
1119 | { | |
1120 | struct bio_vec *bvec = bio->bi_io_vec; | |
1121 | int i; | |
1122 | ||
1123 | for (i = 0; i < bio->bi_vcnt; i++) { | |
1124 | struct page *page = bvec[i].bv_page; | |
1125 | ||
1126 | if (page) | |
1127 | put_page(page); | |
1128 | } | |
1129 | } | |
1130 | ||
1131 | /* | |
1132 | * bio_check_pages_dirty() will check that all the BIO's pages are still dirty. | |
1133 | * If they are, then fine. If, however, some pages are clean then they must | |
1134 | * have been written out during the direct-IO read. So we take another ref on | |
1135 | * the BIO and the offending pages and re-dirty the pages in process context. | |
1136 | * | |
1137 | * It is expected that bio_check_pages_dirty() will wholly own the BIO from | |
1138 | * here on. It will run one page_cache_release() against each page and will | |
1139 | * run one bio_put() against the BIO. | |
1140 | */ | |
1141 | ||
1142 | static void bio_dirty_fn(struct work_struct *work); | |
1143 | ||
1144 | static DECLARE_WORK(bio_dirty_work, bio_dirty_fn); | |
1145 | static DEFINE_SPINLOCK(bio_dirty_lock); | |
1146 | static struct bio *bio_dirty_list; | |
1147 | ||
1148 | /* | |
1149 | * This runs in process context | |
1150 | */ | |
1151 | static void bio_dirty_fn(struct work_struct *work) | |
1152 | { | |
1153 | unsigned long flags; | |
1154 | struct bio *bio; | |
1155 | ||
1156 | spin_lock_irqsave(&bio_dirty_lock, flags); | |
1157 | bio = bio_dirty_list; | |
1158 | bio_dirty_list = NULL; | |
1159 | spin_unlock_irqrestore(&bio_dirty_lock, flags); | |
1160 | ||
1161 | while (bio) { | |
1162 | struct bio *next = bio->bi_private; | |
1163 | ||
1164 | bio_set_pages_dirty(bio); | |
1165 | bio_release_pages(bio); | |
1166 | bio_put(bio); | |
1167 | bio = next; | |
1168 | } | |
1169 | } | |
1170 | ||
1171 | void bio_check_pages_dirty(struct bio *bio) | |
1172 | { | |
1173 | struct bio_vec *bvec = bio->bi_io_vec; | |
1174 | int nr_clean_pages = 0; | |
1175 | int i; | |
1176 | ||
1177 | for (i = 0; i < bio->bi_vcnt; i++) { | |
1178 | struct page *page = bvec[i].bv_page; | |
1179 | ||
1180 | if (PageDirty(page) || PageCompound(page)) { | |
1181 | page_cache_release(page); | |
1182 | bvec[i].bv_page = NULL; | |
1183 | } else { | |
1184 | nr_clean_pages++; | |
1185 | } | |
1186 | } | |
1187 | ||
1188 | if (nr_clean_pages) { | |
1189 | unsigned long flags; | |
1190 | ||
1191 | spin_lock_irqsave(&bio_dirty_lock, flags); | |
1192 | bio->bi_private = bio_dirty_list; | |
1193 | bio_dirty_list = bio; | |
1194 | spin_unlock_irqrestore(&bio_dirty_lock, flags); | |
1195 | schedule_work(&bio_dirty_work); | |
1196 | } else { | |
1197 | bio_put(bio); | |
1198 | } | |
1199 | } | |
1200 | ||
1201 | /** | |
1202 | * bio_endio - end I/O on a bio | |
1203 | * @bio: bio | |
1204 | * @error: error, if any | |
1205 | * | |
1206 | * Description: | |
1207 | * bio_endio() will end I/O on the whole bio. bio_endio() is the | |
1208 | * preferred way to end I/O on a bio, it takes care of clearing | |
1209 | * BIO_UPTODATE on error. @error is 0 on success, and and one of the | |
1210 | * established -Exxxx (-EIO, for instance) error values in case | |
1211 | * something went wrong. Noone should call bi_end_io() directly on a | |
1212 | * bio unless they own it and thus know that it has an end_io | |
1213 | * function. | |
1214 | **/ | |
1215 | void bio_endio(struct bio *bio, int error) | |
1216 | { | |
1217 | if (error) | |
1218 | clear_bit(BIO_UPTODATE, &bio->bi_flags); | |
1219 | else if (!test_bit(BIO_UPTODATE, &bio->bi_flags)) | |
1220 | error = -EIO; | |
1221 | ||
1222 | if (bio->bi_end_io) | |
1223 | bio->bi_end_io(bio, error); | |
1224 | } | |
1225 | ||
1226 | void bio_pair_release(struct bio_pair *bp) | |
1227 | { | |
1228 | if (atomic_dec_and_test(&bp->cnt)) { | |
1229 | struct bio *master = bp->bio1.bi_private; | |
1230 | ||
1231 | bio_endio(master, bp->error); | |
1232 | mempool_free(bp, bp->bio2.bi_private); | |
1233 | } | |
1234 | } | |
1235 | ||
1236 | static void bio_pair_end_1(struct bio *bi, int err) | |
1237 | { | |
1238 | struct bio_pair *bp = container_of(bi, struct bio_pair, bio1); | |
1239 | ||
1240 | if (err) | |
1241 | bp->error = err; | |
1242 | ||
1243 | bio_pair_release(bp); | |
1244 | } | |
1245 | ||
1246 | static void bio_pair_end_2(struct bio *bi, int err) | |
1247 | { | |
1248 | struct bio_pair *bp = container_of(bi, struct bio_pair, bio2); | |
1249 | ||
1250 | if (err) | |
1251 | bp->error = err; | |
1252 | ||
1253 | bio_pair_release(bp); | |
1254 | } | |
1255 | ||
1256 | /* | |
1257 | * split a bio - only worry about a bio with a single page | |
1258 | * in it's iovec | |
1259 | */ | |
1260 | struct bio_pair *bio_split(struct bio *bi, int first_sectors) | |
1261 | { | |
1262 | struct bio_pair *bp = mempool_alloc(bio_split_pool, GFP_NOIO); | |
1263 | ||
1264 | if (!bp) | |
1265 | return bp; | |
1266 | ||
1267 | trace_block_split(bdev_get_queue(bi->bi_bdev), bi, | |
1268 | bi->bi_sector + first_sectors); | |
1269 | ||
1270 | BUG_ON(bi->bi_vcnt != 1); | |
1271 | BUG_ON(bi->bi_idx != 0); | |
1272 | atomic_set(&bp->cnt, 3); | |
1273 | bp->error = 0; | |
1274 | bp->bio1 = *bi; | |
1275 | bp->bio2 = *bi; | |
1276 | bp->bio2.bi_sector += first_sectors; | |
1277 | bp->bio2.bi_size -= first_sectors << 9; | |
1278 | bp->bio1.bi_size = first_sectors << 9; | |
1279 | ||
1280 | bp->bv1 = bi->bi_io_vec[0]; | |
1281 | bp->bv2 = bi->bi_io_vec[0]; | |
1282 | bp->bv2.bv_offset += first_sectors << 9; | |
1283 | bp->bv2.bv_len -= first_sectors << 9; | |
1284 | bp->bv1.bv_len = first_sectors << 9; | |
1285 | ||
1286 | bp->bio1.bi_io_vec = &bp->bv1; | |
1287 | bp->bio2.bi_io_vec = &bp->bv2; | |
1288 | ||
1289 | bp->bio1.bi_max_vecs = 1; | |
1290 | bp->bio2.bi_max_vecs = 1; | |
1291 | ||
1292 | bp->bio1.bi_end_io = bio_pair_end_1; | |
1293 | bp->bio2.bi_end_io = bio_pair_end_2; | |
1294 | ||
1295 | bp->bio1.bi_private = bi; | |
1296 | bp->bio2.bi_private = bio_split_pool; | |
1297 | ||
1298 | if (bio_integrity(bi)) | |
1299 | bio_integrity_split(bi, bp, first_sectors); | |
1300 | ||
1301 | return bp; | |
1302 | } | |
1303 | ||
1304 | /** | |
1305 | * bio_sector_offset - Find hardware sector offset in bio | |
1306 | * @bio: bio to inspect | |
1307 | * @index: bio_vec index | |
1308 | * @offset: offset in bv_page | |
1309 | * | |
1310 | * Return the number of hardware sectors between beginning of bio | |
1311 | * and an end point indicated by a bio_vec index and an offset | |
1312 | * within that vector's page. | |
1313 | */ | |
1314 | sector_t bio_sector_offset(struct bio *bio, unsigned short index, | |
1315 | unsigned int offset) | |
1316 | { | |
1317 | unsigned int sector_sz = queue_hardsect_size(bio->bi_bdev->bd_disk->queue); | |
1318 | struct bio_vec *bv; | |
1319 | sector_t sectors; | |
1320 | int i; | |
1321 | ||
1322 | sectors = 0; | |
1323 | ||
1324 | if (index >= bio->bi_idx) | |
1325 | index = bio->bi_vcnt - 1; | |
1326 | ||
1327 | __bio_for_each_segment(bv, bio, i, 0) { | |
1328 | if (i == index) { | |
1329 | if (offset > bv->bv_offset) | |
1330 | sectors += (offset - bv->bv_offset) / sector_sz; | |
1331 | break; | |
1332 | } | |
1333 | ||
1334 | sectors += bv->bv_len / sector_sz; | |
1335 | } | |
1336 | ||
1337 | return sectors; | |
1338 | } | |
1339 | EXPORT_SYMBOL(bio_sector_offset); | |
1340 | ||
1341 | /* | |
1342 | * create memory pools for biovec's in a bio_set. | |
1343 | * use the global biovec slabs created for general use. | |
1344 | */ | |
1345 | static int biovec_create_pools(struct bio_set *bs, int pool_entries) | |
1346 | { | |
1347 | int i; | |
1348 | ||
1349 | for (i = 0; i < BIOVEC_NR_POOLS; i++) { | |
1350 | struct biovec_slab *bp = bvec_slabs + i; | |
1351 | mempool_t **bvp = bs->bvec_pools + i; | |
1352 | ||
1353 | *bvp = mempool_create_slab_pool(pool_entries, bp->slab); | |
1354 | if (!*bvp) | |
1355 | return -ENOMEM; | |
1356 | } | |
1357 | return 0; | |
1358 | } | |
1359 | ||
1360 | static void biovec_free_pools(struct bio_set *bs) | |
1361 | { | |
1362 | int i; | |
1363 | ||
1364 | for (i = 0; i < BIOVEC_NR_POOLS; i++) { | |
1365 | mempool_t *bvp = bs->bvec_pools[i]; | |
1366 | ||
1367 | if (bvp) | |
1368 | mempool_destroy(bvp); | |
1369 | } | |
1370 | ||
1371 | } | |
1372 | ||
1373 | void bioset_free(struct bio_set *bs) | |
1374 | { | |
1375 | if (bs->bio_pool) | |
1376 | mempool_destroy(bs->bio_pool); | |
1377 | ||
1378 | bioset_integrity_free(bs); | |
1379 | biovec_free_pools(bs); | |
1380 | ||
1381 | kfree(bs); | |
1382 | } | |
1383 | ||
1384 | struct bio_set *bioset_create(int bio_pool_size, int bvec_pool_size) | |
1385 | { | |
1386 | struct bio_set *bs = kzalloc(sizeof(*bs), GFP_KERNEL); | |
1387 | ||
1388 | if (!bs) | |
1389 | return NULL; | |
1390 | ||
1391 | bs->bio_pool = mempool_create_slab_pool(bio_pool_size, bio_slab); | |
1392 | if (!bs->bio_pool) | |
1393 | goto bad; | |
1394 | ||
1395 | if (bioset_integrity_create(bs, bio_pool_size)) | |
1396 | goto bad; | |
1397 | ||
1398 | if (!biovec_create_pools(bs, bvec_pool_size)) | |
1399 | return bs; | |
1400 | ||
1401 | bad: | |
1402 | bioset_free(bs); | |
1403 | return NULL; | |
1404 | } | |
1405 | ||
1406 | static void __init biovec_init_slabs(void) | |
1407 | { | |
1408 | int i; | |
1409 | ||
1410 | for (i = 0; i < BIOVEC_NR_POOLS; i++) { | |
1411 | int size; | |
1412 | struct biovec_slab *bvs = bvec_slabs + i; | |
1413 | ||
1414 | size = bvs->nr_vecs * sizeof(struct bio_vec); | |
1415 | bvs->slab = kmem_cache_create(bvs->name, size, 0, | |
1416 | SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); | |
1417 | } | |
1418 | } | |
1419 | ||
1420 | static int __init init_bio(void) | |
1421 | { | |
1422 | bio_slab = KMEM_CACHE(bio, SLAB_HWCACHE_ALIGN|SLAB_PANIC); | |
1423 | ||
1424 | bio_integrity_init_slab(); | |
1425 | biovec_init_slabs(); | |
1426 | ||
1427 | fs_bio_set = bioset_create(BIO_POOL_SIZE, 2); | |
1428 | if (!fs_bio_set) | |
1429 | panic("bio: can't allocate bios\n"); | |
1430 | ||
1431 | bio_split_pool = mempool_create_kmalloc_pool(BIO_SPLIT_ENTRIES, | |
1432 | sizeof(struct bio_pair)); | |
1433 | if (!bio_split_pool) | |
1434 | panic("bio: can't create split pool\n"); | |
1435 | ||
1436 | return 0; | |
1437 | } | |
1438 | ||
1439 | subsys_initcall(init_bio); | |
1440 | ||
1441 | EXPORT_SYMBOL(bio_alloc); | |
1442 | EXPORT_SYMBOL(bio_kmalloc); | |
1443 | EXPORT_SYMBOL(bio_put); | |
1444 | EXPORT_SYMBOL(bio_free); | |
1445 | EXPORT_SYMBOL(bio_endio); | |
1446 | EXPORT_SYMBOL(bio_init); | |
1447 | EXPORT_SYMBOL(__bio_clone); | |
1448 | EXPORT_SYMBOL(bio_clone); | |
1449 | EXPORT_SYMBOL(bio_phys_segments); | |
1450 | EXPORT_SYMBOL(bio_add_page); | |
1451 | EXPORT_SYMBOL(bio_add_pc_page); | |
1452 | EXPORT_SYMBOL(bio_get_nr_vecs); | |
1453 | EXPORT_SYMBOL(bio_map_user); | |
1454 | EXPORT_SYMBOL(bio_unmap_user); | |
1455 | EXPORT_SYMBOL(bio_map_kern); | |
1456 | EXPORT_SYMBOL(bio_copy_kern); | |
1457 | EXPORT_SYMBOL(bio_pair_release); | |
1458 | EXPORT_SYMBOL(bio_split); | |
1459 | EXPORT_SYMBOL(bio_copy_user); | |
1460 | EXPORT_SYMBOL(bio_uncopy_user); | |
1461 | EXPORT_SYMBOL(bioset_create); | |
1462 | EXPORT_SYMBOL(bioset_free); | |
1463 | EXPORT_SYMBOL(bio_alloc_bioset); |