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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
Jens Axboe0fe23472006-09-04 15:41:16 +02002 * Copyright (C) 2001 Jens Axboe <axboe@kernel.dk>
Linus Torvalds1da177e2005-04-16 15:20:36 -07003 *
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>
Jens Axboe2056a782006-03-23 20:00:26 +010028#include <linux/blktrace_api.h>
Arnaldo Carvalho de Melo5f3ea372008-10-30 08:34:33 +010029#include <trace/block.h>
James Bottomley f1970ba2005-06-20 14:06:52 +020030#include <scsi/sg.h> /* for struct sg_iovec */
Linus Torvalds1da177e2005-04-16 15:20:36 -070031
Ingo Molnar0bfc2452008-11-26 11:59:56 +010032DEFINE_TRACE(block_split);
33
Christoph Lametere18b8902006-12-06 20:33:20 -080034static struct kmem_cache *bio_slab __read_mostly;
Linus Torvalds1da177e2005-04-16 15:20:36 -070035
Denis ChengRq6feef532008-10-09 08:57:05 +020036static mempool_t *bio_split_pool __read_mostly;
Linus Torvalds1da177e2005-04-16 15:20:36 -070037
Linus Torvalds1da177e2005-04-16 15:20:36 -070038/*
39 * if you change this list, also change bvec_alloc or things will
40 * break badly! cannot be bigger than what you can fit into an
41 * unsigned short
42 */
43
44#define BV(x) { .nr_vecs = x, .name = "biovec-"__stringify(x) }
Christoph Lameter6c036522005-07-07 17:56:59 -070045static struct biovec_slab bvec_slabs[BIOVEC_NR_POOLS] __read_mostly = {
Linus Torvalds1da177e2005-04-16 15:20:36 -070046 BV(1), BV(4), BV(16), BV(64), BV(128), BV(BIO_MAX_PAGES),
47};
48#undef BV
49
50/*
Linus Torvalds1da177e2005-04-16 15:20:36 -070051 * fs_bio_set is the bio_set containing bio and iovec memory pools used by
52 * IO code that does not need private memory pools.
53 */
Martin K. Petersen51d654e2008-06-17 18:59:56 +020054struct bio_set *fs_bio_set;
Linus Torvalds1da177e2005-04-16 15:20:36 -070055
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +020056unsigned int bvec_nr_vecs(unsigned short idx)
57{
58 return bvec_slabs[idx].nr_vecs;
59}
60
Jens Axboe7ff93452008-12-11 11:53:43 +010061struct bio_vec *bvec_alloc_bs(gfp_t gfp_mask, int nr, unsigned long *idx,
62 struct bio_set *bs)
Linus Torvalds1da177e2005-04-16 15:20:36 -070063{
64 struct bio_vec *bvl;
Linus Torvalds1da177e2005-04-16 15:20:36 -070065
66 /*
Jens Axboe0a0d96b2008-09-11 13:17:37 +020067 * If 'bs' is given, lookup the pool and do the mempool alloc.
68 * If not, this is a bio_kmalloc() allocation and just do a
69 * kzalloc() for the exact number of vecs right away.
Linus Torvalds1da177e2005-04-16 15:20:36 -070070 */
Jens Axboe7ff93452008-12-11 11:53:43 +010071 if (!bs)
72 bvl = kzalloc(nr * sizeof(struct bio_vec), gfp_mask);
73
74 /*
75 * see comment near bvec_array define!
76 */
77 switch (nr) {
78 case 1:
79 *idx = 0;
80 break;
81 case 2 ... 4:
82 *idx = 1;
83 break;
84 case 5 ... 16:
85 *idx = 2;
86 break;
87 case 17 ... 64:
88 *idx = 3;
89 break;
90 case 65 ... 128:
91 *idx = 4;
92 break;
93 case 129 ... BIO_MAX_PAGES:
94 *idx = 5;
95 break;
96 default:
97 return NULL;
98 }
99
100 /*
101 * idx now points to the pool we want to allocate from. only the
102 * 1-vec entry pool is mempool backed.
103 */
104 if (*idx == BIOVEC_MAX_IDX) {
105fallback:
106 bvl = mempool_alloc(bs->bvec_pool, gfp_mask);
107 } else {
108 struct biovec_slab *bvs = bvec_slabs + *idx;
109 gfp_t __gfp_mask = gfp_mask & ~(__GFP_WAIT | __GFP_IO);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700110
Jens Axboe0a0d96b2008-09-11 13:17:37 +0200111 /*
Jens Axboe7ff93452008-12-11 11:53:43 +0100112 * Make this allocation restricted and don't dump info on
113 * allocation failures, since we'll fallback to the mempool
114 * in case of failure.
Jens Axboe0a0d96b2008-09-11 13:17:37 +0200115 */
Jens Axboe7ff93452008-12-11 11:53:43 +0100116 __gfp_mask |= __GFP_NOMEMALLOC | __GFP_NORETRY | __GFP_NOWARN;
117
118 /*
119 * Try a slab allocation. If this fails and __GFP_WAIT
120 * is set, retry with the 1-entry mempool
121 */
122 bvl = kmem_cache_alloc(bvs->slab, __gfp_mask);
123 if (unlikely(!bvl && (gfp_mask & __GFP_WAIT))) {
124 *idx = BIOVEC_MAX_IDX;
125 goto fallback;
126 }
127 }
128
129 if (bvl)
130 memset(bvl, 0, bvec_nr_vecs(*idx) * sizeof(struct bio_vec));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700131
132 return bvl;
133}
134
Jens Axboe7ff93452008-12-11 11:53:43 +0100135void bio_free(struct bio *bio, struct bio_set *bs)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700136{
Jens Axboe992c5dd2007-07-18 13:18:08 +0200137 if (bio->bi_io_vec) {
138 const int pool_idx = BIO_POOL_IDX(bio);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700139
Jens Axboe992c5dd2007-07-18 13:18:08 +0200140 BIO_BUG_ON(pool_idx >= BIOVEC_NR_POOLS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700141
Jens Axboe7ff93452008-12-11 11:53:43 +0100142 if (pool_idx == BIOVEC_MAX_IDX)
143 mempool_free(bio->bi_io_vec, bs->bvec_pool);
144 else {
145 struct biovec_slab *bvs = bvec_slabs + pool_idx;
146
147 kmem_cache_free(bvs->slab, bio->bi_io_vec);
148 }
Jens Axboe992c5dd2007-07-18 13:18:08 +0200149 }
150
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200151 if (bio_integrity(bio))
Jens Axboe7ff93452008-12-11 11:53:43 +0100152 bio_integrity_free(bio, bs);
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200153
Jens Axboe7ff93452008-12-11 11:53:43 +0100154 mempool_free(bio, bs->bio_pool);
Peter Osterlund36763472005-09-06 15:16:42 -0700155}
156
157/*
158 * default destructor for a bio allocated with bio_alloc_bioset()
159 */
160static void bio_fs_destructor(struct bio *bio)
161{
162 bio_free(bio, fs_bio_set);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700163}
164
Jens Axboe0a0d96b2008-09-11 13:17:37 +0200165static void bio_kmalloc_destructor(struct bio *bio)
166{
167 kfree(bio->bi_io_vec);
168 kfree(bio);
169}
170
Arjan van de Ven858119e2006-01-14 13:20:43 -0800171void bio_init(struct bio *bio)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700172{
Jens Axboe2b94de52007-07-18 13:14:03 +0200173 memset(bio, 0, sizeof(*bio));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700174 bio->bi_flags = 1 << BIO_UPTODATE;
Jens Axboec7c22e42008-09-13 20:26:01 +0200175 bio->bi_comp_cpu = -1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700176 atomic_set(&bio->bi_cnt, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700177}
178
179/**
180 * bio_alloc_bioset - allocate a bio for I/O
181 * @gfp_mask: the GFP_ mask given to the slab allocator
182 * @nr_iovecs: number of iovecs to pre-allocate
Jens Axboe0a0d96b2008-09-11 13:17:37 +0200183 * @bs: the bio_set to allocate from. If %NULL, just use kmalloc
Linus Torvalds1da177e2005-04-16 15:20:36 -0700184 *
185 * Description:
Jens Axboe0a0d96b2008-09-11 13:17:37 +0200186 * bio_alloc_bioset will first try its own mempool to satisfy the allocation.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700187 * If %__GFP_WAIT is set then we will block on the internal pool waiting
Jens Axboe0a0d96b2008-09-11 13:17:37 +0200188 * for a &struct bio to become free. If a %NULL @bs is passed in, we will
189 * fall back to just using @kmalloc to allocate the required memory.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700190 *
191 * allocate bio and iovecs from the memory pools specified by the
Jens Axboe0a0d96b2008-09-11 13:17:37 +0200192 * bio_set structure, or @kmalloc if none given.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700193 **/
Al Virodd0fc662005-10-07 07:46:04 +0100194struct bio *bio_alloc_bioset(gfp_t gfp_mask, int nr_iovecs, struct bio_set *bs)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700195{
Jens Axboe0a0d96b2008-09-11 13:17:37 +0200196 struct bio *bio;
197
198 if (bs)
199 bio = mempool_alloc(bs->bio_pool, gfp_mask);
200 else
201 bio = kmalloc(sizeof(*bio), gfp_mask);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700202
203 if (likely(bio)) {
204 struct bio_vec *bvl = NULL;
205
206 bio_init(bio);
207 if (likely(nr_iovecs)) {
Jens Axboeeeae1d42008-05-07 13:26:27 +0200208 unsigned long uninitialized_var(idx);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700209
210 bvl = bvec_alloc_bs(gfp_mask, nr_iovecs, &idx, bs);
211 if (unlikely(!bvl)) {
Jens Axboe0a0d96b2008-09-11 13:17:37 +0200212 if (bs)
213 mempool_free(bio, bs->bio_pool);
214 else
215 kfree(bio);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700216 bio = NULL;
217 goto out;
218 }
219 bio->bi_flags |= idx << BIO_POOL_OFFSET;
Denis ChengRq1ac0ae02008-08-04 11:56:30 +0200220 bio->bi_max_vecs = bvec_nr_vecs(idx);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700221 }
222 bio->bi_io_vec = bvl;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700223 }
224out:
225 return bio;
226}
227
Al Virodd0fc662005-10-07 07:46:04 +0100228struct bio *bio_alloc(gfp_t gfp_mask, int nr_iovecs)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700229{
Peter Osterlund36763472005-09-06 15:16:42 -0700230 struct bio *bio = bio_alloc_bioset(gfp_mask, nr_iovecs, fs_bio_set);
231
232 if (bio)
233 bio->bi_destructor = bio_fs_destructor;
234
235 return bio;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700236}
237
Jens Axboe0a0d96b2008-09-11 13:17:37 +0200238/*
239 * Like bio_alloc(), but doesn't use a mempool backing. This means that
240 * it CAN fail, but while bio_alloc() can only be used for allocations
241 * that have a short (finite) life span, bio_kmalloc() should be used
242 * for more permanent bio allocations (like allocating some bio's for
243 * initalization or setup purposes).
244 */
245struct bio *bio_kmalloc(gfp_t gfp_mask, int nr_iovecs)
246{
247 struct bio *bio = bio_alloc_bioset(gfp_mask, nr_iovecs, NULL);
248
249 if (bio)
250 bio->bi_destructor = bio_kmalloc_destructor;
251
252 return bio;
253}
254
Linus Torvalds1da177e2005-04-16 15:20:36 -0700255void zero_fill_bio(struct bio *bio)
256{
257 unsigned long flags;
258 struct bio_vec *bv;
259 int i;
260
261 bio_for_each_segment(bv, bio, i) {
262 char *data = bvec_kmap_irq(bv, &flags);
263 memset(data, 0, bv->bv_len);
264 flush_dcache_page(bv->bv_page);
265 bvec_kunmap_irq(data, &flags);
266 }
267}
268EXPORT_SYMBOL(zero_fill_bio);
269
270/**
271 * bio_put - release a reference to a bio
272 * @bio: bio to release reference to
273 *
274 * Description:
275 * Put a reference to a &struct bio, either one you have gotten with
276 * bio_alloc or bio_get. The last put of a bio will free it.
277 **/
278void bio_put(struct bio *bio)
279{
280 BIO_BUG_ON(!atomic_read(&bio->bi_cnt));
281
282 /*
283 * last put frees it
284 */
285 if (atomic_dec_and_test(&bio->bi_cnt)) {
286 bio->bi_next = NULL;
287 bio->bi_destructor(bio);
288 }
289}
290
Jens Axboe165125e2007-07-24 09:28:11 +0200291inline int bio_phys_segments(struct request_queue *q, struct bio *bio)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700292{
293 if (unlikely(!bio_flagged(bio, BIO_SEG_VALID)))
294 blk_recount_segments(q, bio);
295
296 return bio->bi_phys_segments;
297}
298
Linus Torvalds1da177e2005-04-16 15:20:36 -0700299/**
300 * __bio_clone - clone a bio
301 * @bio: destination bio
302 * @bio_src: bio to clone
303 *
304 * Clone a &bio. Caller will own the returned bio, but not
305 * the actual data it points to. Reference count of returned
306 * bio will be one.
307 */
Arjan van de Ven858119e2006-01-14 13:20:43 -0800308void __bio_clone(struct bio *bio, struct bio *bio_src)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700309{
Andrew Mortone525e152005-08-07 09:42:12 -0700310 memcpy(bio->bi_io_vec, bio_src->bi_io_vec,
311 bio_src->bi_max_vecs * sizeof(struct bio_vec));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700312
Jens Axboe5d840702008-01-25 12:44:44 +0100313 /*
314 * most users will be overriding ->bi_bdev with a new target,
315 * so we don't set nor calculate new physical/hw segment counts here
316 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700317 bio->bi_sector = bio_src->bi_sector;
318 bio->bi_bdev = bio_src->bi_bdev;
319 bio->bi_flags |= 1 << BIO_CLONED;
320 bio->bi_rw = bio_src->bi_rw;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700321 bio->bi_vcnt = bio_src->bi_vcnt;
322 bio->bi_size = bio_src->bi_size;
Andrew Mortona5453be2005-07-28 01:07:18 -0700323 bio->bi_idx = bio_src->bi_idx;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700324}
325
326/**
327 * bio_clone - clone a bio
328 * @bio: bio to clone
329 * @gfp_mask: allocation priority
330 *
331 * Like __bio_clone, only also allocates the returned bio
332 */
Al Virodd0fc662005-10-07 07:46:04 +0100333struct bio *bio_clone(struct bio *bio, gfp_t gfp_mask)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700334{
335 struct bio *b = bio_alloc_bioset(gfp_mask, bio->bi_max_vecs, fs_bio_set);
336
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200337 if (!b)
338 return NULL;
339
340 b->bi_destructor = bio_fs_destructor;
341 __bio_clone(b, bio);
342
343 if (bio_integrity(bio)) {
344 int ret;
345
346 ret = bio_integrity_clone(b, bio, fs_bio_set);
347
348 if (ret < 0)
349 return NULL;
Peter Osterlund36763472005-09-06 15:16:42 -0700350 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700351
352 return b;
353}
354
355/**
356 * bio_get_nr_vecs - return approx number of vecs
357 * @bdev: I/O target
358 *
359 * Return the approximate number of pages we can send to this target.
360 * There's no guarantee that you will be able to fit this number of pages
361 * into a bio, it does not account for dynamic restrictions that vary
362 * on offset.
363 */
364int bio_get_nr_vecs(struct block_device *bdev)
365{
Jens Axboe165125e2007-07-24 09:28:11 +0200366 struct request_queue *q = bdev_get_queue(bdev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700367 int nr_pages;
368
369 nr_pages = ((q->max_sectors << 9) + PAGE_SIZE - 1) >> PAGE_SHIFT;
370 if (nr_pages > q->max_phys_segments)
371 nr_pages = q->max_phys_segments;
372 if (nr_pages > q->max_hw_segments)
373 nr_pages = q->max_hw_segments;
374
375 return nr_pages;
376}
377
Jens Axboe165125e2007-07-24 09:28:11 +0200378static int __bio_add_page(struct request_queue *q, struct bio *bio, struct page
Mike Christiedefd94b2005-12-05 02:37:06 -0600379 *page, unsigned int len, unsigned int offset,
380 unsigned short max_sectors)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700381{
382 int retried_segments = 0;
383 struct bio_vec *bvec;
384
385 /*
386 * cloned bio must not modify vec list
387 */
388 if (unlikely(bio_flagged(bio, BIO_CLONED)))
389 return 0;
390
Jens Axboe80cfd542006-01-06 09:43:28 +0100391 if (((bio->bi_size + len) >> 9) > max_sectors)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700392 return 0;
393
Jens Axboe80cfd542006-01-06 09:43:28 +0100394 /*
395 * For filesystems with a blocksize smaller than the pagesize
396 * we will often be called with the same page as last time and
397 * a consecutive offset. Optimize this special case.
398 */
399 if (bio->bi_vcnt > 0) {
400 struct bio_vec *prev = &bio->bi_io_vec[bio->bi_vcnt - 1];
401
402 if (page == prev->bv_page &&
403 offset == prev->bv_offset + prev->bv_len) {
404 prev->bv_len += len;
Alasdair G Kergoncc371e62008-07-03 09:53:43 +0200405
406 if (q->merge_bvec_fn) {
407 struct bvec_merge_data bvm = {
408 .bi_bdev = bio->bi_bdev,
409 .bi_sector = bio->bi_sector,
410 .bi_size = bio->bi_size,
411 .bi_rw = bio->bi_rw,
412 };
413
414 if (q->merge_bvec_fn(q, &bvm, prev) < len) {
415 prev->bv_len -= len;
416 return 0;
417 }
Jens Axboe80cfd542006-01-06 09:43:28 +0100418 }
419
420 goto done;
421 }
422 }
423
424 if (bio->bi_vcnt >= bio->bi_max_vecs)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700425 return 0;
426
427 /*
428 * we might lose a segment or two here, but rather that than
429 * make this too complex.
430 */
431
432 while (bio->bi_phys_segments >= q->max_phys_segments
Mikulas Patocka5df97b92008-08-15 10:20:02 +0200433 || bio->bi_phys_segments >= q->max_hw_segments) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700434
435 if (retried_segments)
436 return 0;
437
438 retried_segments = 1;
439 blk_recount_segments(q, bio);
440 }
441
442 /*
443 * setup the new entry, we might clear it again later if we
444 * cannot add the page
445 */
446 bvec = &bio->bi_io_vec[bio->bi_vcnt];
447 bvec->bv_page = page;
448 bvec->bv_len = len;
449 bvec->bv_offset = offset;
450
451 /*
452 * if queue has other restrictions (eg varying max sector size
453 * depending on offset), it can specify a merge_bvec_fn in the
454 * queue to get further control
455 */
456 if (q->merge_bvec_fn) {
Alasdair G Kergoncc371e62008-07-03 09:53:43 +0200457 struct bvec_merge_data bvm = {
458 .bi_bdev = bio->bi_bdev,
459 .bi_sector = bio->bi_sector,
460 .bi_size = bio->bi_size,
461 .bi_rw = bio->bi_rw,
462 };
463
Linus Torvalds1da177e2005-04-16 15:20:36 -0700464 /*
465 * merge_bvec_fn() returns number of bytes it can accept
466 * at this offset
467 */
Alasdair G Kergoncc371e62008-07-03 09:53:43 +0200468 if (q->merge_bvec_fn(q, &bvm, bvec) < len) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700469 bvec->bv_page = NULL;
470 bvec->bv_len = 0;
471 bvec->bv_offset = 0;
472 return 0;
473 }
474 }
475
476 /* If we may be able to merge these biovecs, force a recount */
Mikulas Patockab8b3e162008-08-15 10:15:19 +0200477 if (bio->bi_vcnt && (BIOVEC_PHYS_MERGEABLE(bvec-1, bvec)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700478 bio->bi_flags &= ~(1 << BIO_SEG_VALID);
479
480 bio->bi_vcnt++;
481 bio->bi_phys_segments++;
Jens Axboe80cfd542006-01-06 09:43:28 +0100482 done:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700483 bio->bi_size += len;
484 return len;
485}
486
487/**
Mike Christie6e68af62005-11-11 05:30:27 -0600488 * bio_add_pc_page - attempt to add page to bio
Jens Axboefddfdea2006-01-31 15:24:34 +0100489 * @q: the target queue
Mike Christie6e68af62005-11-11 05:30:27 -0600490 * @bio: destination bio
491 * @page: page to add
492 * @len: vec entry length
493 * @offset: vec entry offset
494 *
495 * Attempt to add a page to the bio_vec maplist. This can fail for a
496 * number of reasons, such as the bio being full or target block
497 * device limitations. The target block device must allow bio's
498 * smaller than PAGE_SIZE, so it is always possible to add a single
499 * page to an empty bio. This should only be used by REQ_PC bios.
500 */
Jens Axboe165125e2007-07-24 09:28:11 +0200501int bio_add_pc_page(struct request_queue *q, struct bio *bio, struct page *page,
Mike Christie6e68af62005-11-11 05:30:27 -0600502 unsigned int len, unsigned int offset)
503{
Mike Christiedefd94b2005-12-05 02:37:06 -0600504 return __bio_add_page(q, bio, page, len, offset, q->max_hw_sectors);
Mike Christie6e68af62005-11-11 05:30:27 -0600505}
506
507/**
Linus Torvalds1da177e2005-04-16 15:20:36 -0700508 * bio_add_page - attempt to add page to bio
509 * @bio: destination bio
510 * @page: page to add
511 * @len: vec entry length
512 * @offset: vec entry offset
513 *
514 * Attempt to add a page to the bio_vec maplist. This can fail for a
515 * number of reasons, such as the bio being full or target block
516 * device limitations. The target block device must allow bio's
517 * smaller than PAGE_SIZE, so it is always possible to add a single
518 * page to an empty bio.
519 */
520int bio_add_page(struct bio *bio, struct page *page, unsigned int len,
521 unsigned int offset)
522{
Mike Christiedefd94b2005-12-05 02:37:06 -0600523 struct request_queue *q = bdev_get_queue(bio->bi_bdev);
524 return __bio_add_page(q, bio, page, len, offset, q->max_sectors);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700525}
526
527struct bio_map_data {
528 struct bio_vec *iovecs;
FUJITA Tomonoric5dec1c2008-04-11 12:56:49 +0200529 struct sg_iovec *sgvecs;
FUJITA Tomonori152e2832008-08-28 16:17:06 +0900530 int nr_sgvecs;
531 int is_our_pages;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700532};
533
FUJITA Tomonoric5dec1c2008-04-11 12:56:49 +0200534static void bio_set_map_data(struct bio_map_data *bmd, struct bio *bio,
FUJITA Tomonori152e2832008-08-28 16:17:06 +0900535 struct sg_iovec *iov, int iov_count,
536 int is_our_pages)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700537{
538 memcpy(bmd->iovecs, bio->bi_io_vec, sizeof(struct bio_vec) * bio->bi_vcnt);
FUJITA Tomonoric5dec1c2008-04-11 12:56:49 +0200539 memcpy(bmd->sgvecs, iov, sizeof(struct sg_iovec) * iov_count);
540 bmd->nr_sgvecs = iov_count;
FUJITA Tomonori152e2832008-08-28 16:17:06 +0900541 bmd->is_our_pages = is_our_pages;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700542 bio->bi_private = bmd;
543}
544
545static void bio_free_map_data(struct bio_map_data *bmd)
546{
547 kfree(bmd->iovecs);
FUJITA Tomonoric5dec1c2008-04-11 12:56:49 +0200548 kfree(bmd->sgvecs);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700549 kfree(bmd);
550}
551
FUJITA Tomonori76029ff2008-08-25 20:36:08 +0200552static struct bio_map_data *bio_alloc_map_data(int nr_segs, int iov_count,
553 gfp_t gfp_mask)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700554{
FUJITA Tomonori76029ff2008-08-25 20:36:08 +0200555 struct bio_map_data *bmd = kmalloc(sizeof(*bmd), gfp_mask);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700556
557 if (!bmd)
558 return NULL;
559
FUJITA Tomonori76029ff2008-08-25 20:36:08 +0200560 bmd->iovecs = kmalloc(sizeof(struct bio_vec) * nr_segs, gfp_mask);
FUJITA Tomonoric5dec1c2008-04-11 12:56:49 +0200561 if (!bmd->iovecs) {
562 kfree(bmd);
563 return NULL;
564 }
565
FUJITA Tomonori76029ff2008-08-25 20:36:08 +0200566 bmd->sgvecs = kmalloc(sizeof(struct sg_iovec) * iov_count, gfp_mask);
FUJITA Tomonoric5dec1c2008-04-11 12:56:49 +0200567 if (bmd->sgvecs)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700568 return bmd;
569
FUJITA Tomonoric5dec1c2008-04-11 12:56:49 +0200570 kfree(bmd->iovecs);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700571 kfree(bmd);
572 return NULL;
573}
574
FUJITA Tomonoriaefcc282008-08-25 20:36:08 +0200575static int __bio_copy_iov(struct bio *bio, struct bio_vec *iovecs,
FUJITA Tomonori152e2832008-08-28 16:17:06 +0900576 struct sg_iovec *iov, int iov_count, int uncopy,
577 int do_free_page)
FUJITA Tomonoric5dec1c2008-04-11 12:56:49 +0200578{
579 int ret = 0, i;
580 struct bio_vec *bvec;
581 int iov_idx = 0;
582 unsigned int iov_off = 0;
583 int read = bio_data_dir(bio) == READ;
584
585 __bio_for_each_segment(bvec, bio, i, 0) {
586 char *bv_addr = page_address(bvec->bv_page);
FUJITA Tomonoriaefcc282008-08-25 20:36:08 +0200587 unsigned int bv_len = iovecs[i].bv_len;
FUJITA Tomonoric5dec1c2008-04-11 12:56:49 +0200588
589 while (bv_len && iov_idx < iov_count) {
590 unsigned int bytes;
591 char *iov_addr;
592
593 bytes = min_t(unsigned int,
594 iov[iov_idx].iov_len - iov_off, bv_len);
595 iov_addr = iov[iov_idx].iov_base + iov_off;
596
597 if (!ret) {
598 if (!read && !uncopy)
599 ret = copy_from_user(bv_addr, iov_addr,
600 bytes);
601 if (read && uncopy)
602 ret = copy_to_user(iov_addr, bv_addr,
603 bytes);
604
605 if (ret)
606 ret = -EFAULT;
607 }
608
609 bv_len -= bytes;
610 bv_addr += bytes;
611 iov_addr += bytes;
612 iov_off += bytes;
613
614 if (iov[iov_idx].iov_len == iov_off) {
615 iov_idx++;
616 iov_off = 0;
617 }
618 }
619
FUJITA Tomonori152e2832008-08-28 16:17:06 +0900620 if (do_free_page)
FUJITA Tomonoric5dec1c2008-04-11 12:56:49 +0200621 __free_page(bvec->bv_page);
622 }
623
624 return ret;
625}
626
Linus Torvalds1da177e2005-04-16 15:20:36 -0700627/**
628 * bio_uncopy_user - finish previously mapped bio
629 * @bio: bio being terminated
630 *
631 * Free pages allocated from bio_copy_user() and write back data
632 * to user space in case of a read.
633 */
634int bio_uncopy_user(struct bio *bio)
635{
636 struct bio_map_data *bmd = bio->bi_private;
FUJITA Tomonori81882762008-09-02 16:20:19 +0900637 int ret = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700638
FUJITA Tomonori81882762008-09-02 16:20:19 +0900639 if (!bio_flagged(bio, BIO_NULL_MAPPED))
640 ret = __bio_copy_iov(bio, bmd->iovecs, bmd->sgvecs,
641 bmd->nr_sgvecs, 1, bmd->is_our_pages);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700642 bio_free_map_data(bmd);
643 bio_put(bio);
644 return ret;
645}
646
647/**
FUJITA Tomonoric5dec1c2008-04-11 12:56:49 +0200648 * bio_copy_user_iov - copy user data to bio
Linus Torvalds1da177e2005-04-16 15:20:36 -0700649 * @q: destination block queue
FUJITA Tomonori152e2832008-08-28 16:17:06 +0900650 * @map_data: pointer to the rq_map_data holding pages (if necessary)
FUJITA Tomonoric5dec1c2008-04-11 12:56:49 +0200651 * @iov: the iovec.
652 * @iov_count: number of elements in the iovec
Linus Torvalds1da177e2005-04-16 15:20:36 -0700653 * @write_to_vm: bool indicating writing to pages or not
FUJITA Tomonoria3bce902008-08-28 16:17:05 +0900654 * @gfp_mask: memory allocation flags
Linus Torvalds1da177e2005-04-16 15:20:36 -0700655 *
656 * Prepares and returns a bio for indirect user io, bouncing data
657 * to/from kernel pages as necessary. Must be paired with
658 * call bio_uncopy_user() on io completion.
659 */
FUJITA Tomonori152e2832008-08-28 16:17:06 +0900660struct bio *bio_copy_user_iov(struct request_queue *q,
661 struct rq_map_data *map_data,
662 struct sg_iovec *iov, int iov_count,
663 int write_to_vm, gfp_t gfp_mask)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700664{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700665 struct bio_map_data *bmd;
666 struct bio_vec *bvec;
667 struct page *page;
668 struct bio *bio;
669 int i, ret;
FUJITA Tomonoric5dec1c2008-04-11 12:56:49 +0200670 int nr_pages = 0;
671 unsigned int len = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700672
FUJITA Tomonoric5dec1c2008-04-11 12:56:49 +0200673 for (i = 0; i < iov_count; i++) {
674 unsigned long uaddr;
675 unsigned long end;
676 unsigned long start;
677
678 uaddr = (unsigned long)iov[i].iov_base;
679 end = (uaddr + iov[i].iov_len + PAGE_SIZE - 1) >> PAGE_SHIFT;
680 start = uaddr >> PAGE_SHIFT;
681
682 nr_pages += end - start;
683 len += iov[i].iov_len;
684 }
685
FUJITA Tomonoria3bce902008-08-28 16:17:05 +0900686 bmd = bio_alloc_map_data(nr_pages, iov_count, gfp_mask);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700687 if (!bmd)
688 return ERR_PTR(-ENOMEM);
689
Linus Torvalds1da177e2005-04-16 15:20:36 -0700690 ret = -ENOMEM;
FUJITA Tomonoria3bce902008-08-28 16:17:05 +0900691 bio = bio_alloc(gfp_mask, nr_pages);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700692 if (!bio)
693 goto out_bmd;
694
695 bio->bi_rw |= (!write_to_vm << BIO_RW);
696
697 ret = 0;
FUJITA Tomonori152e2832008-08-28 16:17:06 +0900698 i = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700699 while (len) {
FUJITA Tomonori152e2832008-08-28 16:17:06 +0900700 unsigned int bytes;
701
702 if (map_data)
703 bytes = 1U << (PAGE_SHIFT + map_data->page_order);
704 else
705 bytes = PAGE_SIZE;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700706
707 if (bytes > len)
708 bytes = len;
709
FUJITA Tomonori152e2832008-08-28 16:17:06 +0900710 if (map_data) {
711 if (i == map_data->nr_entries) {
712 ret = -ENOMEM;
713 break;
714 }
715 page = map_data->pages[i++];
716 } else
717 page = alloc_page(q->bounce_gfp | gfp_mask);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700718 if (!page) {
719 ret = -ENOMEM;
720 break;
721 }
722
Mike Christie0e75f902006-12-01 10:40:55 +0100723 if (bio_add_pc_page(q, bio, page, bytes, 0) < bytes)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700724 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700725
726 len -= bytes;
727 }
728
729 if (ret)
730 goto cleanup;
731
732 /*
733 * success
734 */
735 if (!write_to_vm) {
FUJITA Tomonori152e2832008-08-28 16:17:06 +0900736 ret = __bio_copy_iov(bio, bio->bi_io_vec, iov, iov_count, 0, 0);
FUJITA Tomonoric5dec1c2008-04-11 12:56:49 +0200737 if (ret)
738 goto cleanup;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700739 }
740
FUJITA Tomonori152e2832008-08-28 16:17:06 +0900741 bio_set_map_data(bmd, bio, iov, iov_count, map_data ? 0 : 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700742 return bio;
743cleanup:
FUJITA Tomonori152e2832008-08-28 16:17:06 +0900744 if (!map_data)
745 bio_for_each_segment(bvec, bio, i)
746 __free_page(bvec->bv_page);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700747
748 bio_put(bio);
749out_bmd:
750 bio_free_map_data(bmd);
751 return ERR_PTR(ret);
752}
753
FUJITA Tomonoric5dec1c2008-04-11 12:56:49 +0200754/**
755 * bio_copy_user - copy user data to bio
756 * @q: destination block queue
FUJITA Tomonori152e2832008-08-28 16:17:06 +0900757 * @map_data: pointer to the rq_map_data holding pages (if necessary)
FUJITA Tomonoric5dec1c2008-04-11 12:56:49 +0200758 * @uaddr: start of user address
759 * @len: length in bytes
760 * @write_to_vm: bool indicating writing to pages or not
FUJITA Tomonoria3bce902008-08-28 16:17:05 +0900761 * @gfp_mask: memory allocation flags
FUJITA Tomonoric5dec1c2008-04-11 12:56:49 +0200762 *
763 * Prepares and returns a bio for indirect user io, bouncing data
764 * to/from kernel pages as necessary. Must be paired with
765 * call bio_uncopy_user() on io completion.
766 */
FUJITA Tomonori152e2832008-08-28 16:17:06 +0900767struct bio *bio_copy_user(struct request_queue *q, struct rq_map_data *map_data,
768 unsigned long uaddr, unsigned int len,
769 int write_to_vm, gfp_t gfp_mask)
FUJITA Tomonoric5dec1c2008-04-11 12:56:49 +0200770{
771 struct sg_iovec iov;
772
773 iov.iov_base = (void __user *)uaddr;
774 iov.iov_len = len;
775
FUJITA Tomonori152e2832008-08-28 16:17:06 +0900776 return bio_copy_user_iov(q, map_data, &iov, 1, write_to_vm, gfp_mask);
FUJITA Tomonoric5dec1c2008-04-11 12:56:49 +0200777}
778
Jens Axboe165125e2007-07-24 09:28:11 +0200779static struct bio *__bio_map_user_iov(struct request_queue *q,
James Bottomley f1970ba2005-06-20 14:06:52 +0200780 struct block_device *bdev,
781 struct sg_iovec *iov, int iov_count,
FUJITA Tomonoria3bce902008-08-28 16:17:05 +0900782 int write_to_vm, gfp_t gfp_mask)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700783{
James Bottomley f1970ba2005-06-20 14:06:52 +0200784 int i, j;
785 int nr_pages = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700786 struct page **pages;
787 struct bio *bio;
James Bottomley f1970ba2005-06-20 14:06:52 +0200788 int cur_page = 0;
789 int ret, offset;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700790
James Bottomley f1970ba2005-06-20 14:06:52 +0200791 for (i = 0; i < iov_count; i++) {
792 unsigned long uaddr = (unsigned long)iov[i].iov_base;
793 unsigned long len = iov[i].iov_len;
794 unsigned long end = (uaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
795 unsigned long start = uaddr >> PAGE_SHIFT;
796
797 nr_pages += end - start;
798 /*
Mike Christiead2d7222006-12-01 10:40:20 +0100799 * buffer must be aligned to at least hardsector size for now
James Bottomley f1970ba2005-06-20 14:06:52 +0200800 */
Mike Christiead2d7222006-12-01 10:40:20 +0100801 if (uaddr & queue_dma_alignment(q))
James Bottomley f1970ba2005-06-20 14:06:52 +0200802 return ERR_PTR(-EINVAL);
803 }
804
805 if (!nr_pages)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700806 return ERR_PTR(-EINVAL);
807
FUJITA Tomonoria3bce902008-08-28 16:17:05 +0900808 bio = bio_alloc(gfp_mask, nr_pages);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700809 if (!bio)
810 return ERR_PTR(-ENOMEM);
811
812 ret = -ENOMEM;
FUJITA Tomonoria3bce902008-08-28 16:17:05 +0900813 pages = kcalloc(nr_pages, sizeof(struct page *), gfp_mask);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700814 if (!pages)
815 goto out;
816
James Bottomley f1970ba2005-06-20 14:06:52 +0200817 for (i = 0; i < iov_count; i++) {
818 unsigned long uaddr = (unsigned long)iov[i].iov_base;
819 unsigned long len = iov[i].iov_len;
820 unsigned long end = (uaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
821 unsigned long start = uaddr >> PAGE_SHIFT;
822 const int local_nr_pages = end - start;
823 const int page_limit = cur_page + local_nr_pages;
824
Nick Pigginf5dd33c2008-07-25 19:45:25 -0700825 ret = get_user_pages_fast(uaddr, local_nr_pages,
826 write_to_vm, &pages[cur_page]);
Jens Axboe99172152006-06-16 13:02:29 +0200827 if (ret < local_nr_pages) {
828 ret = -EFAULT;
James Bottomley f1970ba2005-06-20 14:06:52 +0200829 goto out_unmap;
Jens Axboe99172152006-06-16 13:02:29 +0200830 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700831
James Bottomley f1970ba2005-06-20 14:06:52 +0200832 offset = uaddr & ~PAGE_MASK;
833 for (j = cur_page; j < page_limit; j++) {
834 unsigned int bytes = PAGE_SIZE - offset;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700835
James Bottomley f1970ba2005-06-20 14:06:52 +0200836 if (len <= 0)
837 break;
838
839 if (bytes > len)
840 bytes = len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700841
James Bottomley f1970ba2005-06-20 14:06:52 +0200842 /*
843 * sorry...
844 */
Mike Christiedefd94b2005-12-05 02:37:06 -0600845 if (bio_add_pc_page(q, bio, pages[j], bytes, offset) <
846 bytes)
James Bottomley f1970ba2005-06-20 14:06:52 +0200847 break;
848
849 len -= bytes;
850 offset = 0;
851 }
852
853 cur_page = j;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700854 /*
James Bottomley f1970ba2005-06-20 14:06:52 +0200855 * release the pages we didn't map into the bio, if any
Linus Torvalds1da177e2005-04-16 15:20:36 -0700856 */
James Bottomley f1970ba2005-06-20 14:06:52 +0200857 while (j < page_limit)
858 page_cache_release(pages[j++]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700859 }
860
Linus Torvalds1da177e2005-04-16 15:20:36 -0700861 kfree(pages);
862
863 /*
864 * set data direction, and check if mapped pages need bouncing
865 */
866 if (!write_to_vm)
867 bio->bi_rw |= (1 << BIO_RW);
868
James Bottomley f1970ba2005-06-20 14:06:52 +0200869 bio->bi_bdev = bdev;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700870 bio->bi_flags |= (1 << BIO_USER_MAPPED);
871 return bio;
James Bottomley f1970ba2005-06-20 14:06:52 +0200872
873 out_unmap:
874 for (i = 0; i < nr_pages; i++) {
875 if(!pages[i])
876 break;
877 page_cache_release(pages[i]);
878 }
879 out:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700880 kfree(pages);
881 bio_put(bio);
882 return ERR_PTR(ret);
883}
884
885/**
886 * bio_map_user - map user address into bio
Jens Axboe165125e2007-07-24 09:28:11 +0200887 * @q: the struct request_queue for the bio
Linus Torvalds1da177e2005-04-16 15:20:36 -0700888 * @bdev: destination block device
889 * @uaddr: start of user address
890 * @len: length in bytes
891 * @write_to_vm: bool indicating writing to pages or not
FUJITA Tomonoria3bce902008-08-28 16:17:05 +0900892 * @gfp_mask: memory allocation flags
Linus Torvalds1da177e2005-04-16 15:20:36 -0700893 *
894 * Map the user space address into a bio suitable for io to a block
895 * device. Returns an error pointer in case of error.
896 */
Jens Axboe165125e2007-07-24 09:28:11 +0200897struct bio *bio_map_user(struct request_queue *q, struct block_device *bdev,
FUJITA Tomonoria3bce902008-08-28 16:17:05 +0900898 unsigned long uaddr, unsigned int len, int write_to_vm,
899 gfp_t gfp_mask)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700900{
James Bottomley f1970ba2005-06-20 14:06:52 +0200901 struct sg_iovec iov;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700902
viro@ZenIV.linux.org.uk3f703532005-09-09 16:53:56 +0100903 iov.iov_base = (void __user *)uaddr;
James Bottomley f1970ba2005-06-20 14:06:52 +0200904 iov.iov_len = len;
905
FUJITA Tomonoria3bce902008-08-28 16:17:05 +0900906 return bio_map_user_iov(q, bdev, &iov, 1, write_to_vm, gfp_mask);
James Bottomley f1970ba2005-06-20 14:06:52 +0200907}
908
909/**
910 * bio_map_user_iov - map user sg_iovec table into bio
Jens Axboe165125e2007-07-24 09:28:11 +0200911 * @q: the struct request_queue for the bio
James Bottomley f1970ba2005-06-20 14:06:52 +0200912 * @bdev: destination block device
913 * @iov: the iovec.
914 * @iov_count: number of elements in the iovec
915 * @write_to_vm: bool indicating writing to pages or not
FUJITA Tomonoria3bce902008-08-28 16:17:05 +0900916 * @gfp_mask: memory allocation flags
James Bottomley f1970ba2005-06-20 14:06:52 +0200917 *
918 * Map the user space address into a bio suitable for io to a block
919 * device. Returns an error pointer in case of error.
920 */
Jens Axboe165125e2007-07-24 09:28:11 +0200921struct bio *bio_map_user_iov(struct request_queue *q, struct block_device *bdev,
James Bottomley f1970ba2005-06-20 14:06:52 +0200922 struct sg_iovec *iov, int iov_count,
FUJITA Tomonoria3bce902008-08-28 16:17:05 +0900923 int write_to_vm, gfp_t gfp_mask)
James Bottomley f1970ba2005-06-20 14:06:52 +0200924{
925 struct bio *bio;
James Bottomley f1970ba2005-06-20 14:06:52 +0200926
FUJITA Tomonoria3bce902008-08-28 16:17:05 +0900927 bio = __bio_map_user_iov(q, bdev, iov, iov_count, write_to_vm,
928 gfp_mask);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700929 if (IS_ERR(bio))
930 return bio;
931
932 /*
933 * subtle -- if __bio_map_user() ended up bouncing a bio,
934 * it would normally disappear when its bi_end_io is run.
935 * however, we need it for the unmap, so grab an extra
936 * reference to it
937 */
938 bio_get(bio);
939
Mike Christie0e75f902006-12-01 10:40:55 +0100940 return bio;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700941}
942
943static void __bio_unmap_user(struct bio *bio)
944{
945 struct bio_vec *bvec;
946 int i;
947
948 /*
949 * make sure we dirty pages we wrote to
950 */
951 __bio_for_each_segment(bvec, bio, i, 0) {
952 if (bio_data_dir(bio) == READ)
953 set_page_dirty_lock(bvec->bv_page);
954
955 page_cache_release(bvec->bv_page);
956 }
957
958 bio_put(bio);
959}
960
961/**
962 * bio_unmap_user - unmap a bio
963 * @bio: the bio being unmapped
964 *
965 * Unmap a bio previously mapped by bio_map_user(). Must be called with
966 * a process context.
967 *
968 * bio_unmap_user() may sleep.
969 */
970void bio_unmap_user(struct bio *bio)
971{
972 __bio_unmap_user(bio);
973 bio_put(bio);
974}
975
NeilBrown6712ecf2007-09-27 12:47:43 +0200976static void bio_map_kern_endio(struct bio *bio, int err)
Jens Axboeb8238252005-06-20 14:05:27 +0200977{
Jens Axboeb8238252005-06-20 14:05:27 +0200978 bio_put(bio);
Jens Axboeb8238252005-06-20 14:05:27 +0200979}
980
981
Jens Axboe165125e2007-07-24 09:28:11 +0200982static struct bio *__bio_map_kern(struct request_queue *q, void *data,
Al Viro27496a82005-10-21 03:20:48 -0400983 unsigned int len, gfp_t gfp_mask)
Mike Christie df46b9a2005-06-20 14:04:44 +0200984{
985 unsigned long kaddr = (unsigned long)data;
986 unsigned long end = (kaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
987 unsigned long start = kaddr >> PAGE_SHIFT;
988 const int nr_pages = end - start;
989 int offset, i;
990 struct bio *bio;
991
992 bio = bio_alloc(gfp_mask, nr_pages);
993 if (!bio)
994 return ERR_PTR(-ENOMEM);
995
996 offset = offset_in_page(kaddr);
997 for (i = 0; i < nr_pages; i++) {
998 unsigned int bytes = PAGE_SIZE - offset;
999
1000 if (len <= 0)
1001 break;
1002
1003 if (bytes > len)
1004 bytes = len;
1005
Mike Christiedefd94b2005-12-05 02:37:06 -06001006 if (bio_add_pc_page(q, bio, virt_to_page(data), bytes,
1007 offset) < bytes)
Mike Christie df46b9a2005-06-20 14:04:44 +02001008 break;
1009
1010 data += bytes;
1011 len -= bytes;
1012 offset = 0;
1013 }
1014
Jens Axboeb8238252005-06-20 14:05:27 +02001015 bio->bi_end_io = bio_map_kern_endio;
Mike Christie df46b9a2005-06-20 14:04:44 +02001016 return bio;
1017}
1018
1019/**
1020 * bio_map_kern - map kernel address into bio
Jens Axboe165125e2007-07-24 09:28:11 +02001021 * @q: the struct request_queue for the bio
Mike Christie df46b9a2005-06-20 14:04:44 +02001022 * @data: pointer to buffer to map
1023 * @len: length in bytes
1024 * @gfp_mask: allocation flags for bio allocation
1025 *
1026 * Map the kernel address into a bio suitable for io to a block
1027 * device. Returns an error pointer in case of error.
1028 */
Jens Axboe165125e2007-07-24 09:28:11 +02001029struct bio *bio_map_kern(struct request_queue *q, void *data, unsigned int len,
Al Viro27496a82005-10-21 03:20:48 -04001030 gfp_t gfp_mask)
Mike Christie df46b9a2005-06-20 14:04:44 +02001031{
1032 struct bio *bio;
1033
1034 bio = __bio_map_kern(q, data, len, gfp_mask);
1035 if (IS_ERR(bio))
1036 return bio;
1037
1038 if (bio->bi_size == len)
1039 return bio;
1040
1041 /*
1042 * Don't support partial mappings.
1043 */
1044 bio_put(bio);
1045 return ERR_PTR(-EINVAL);
1046}
1047
FUJITA Tomonori68154e92008-04-25 12:47:50 +02001048static void bio_copy_kern_endio(struct bio *bio, int err)
1049{
1050 struct bio_vec *bvec;
1051 const int read = bio_data_dir(bio) == READ;
FUJITA Tomonori76029ff2008-08-25 20:36:08 +02001052 struct bio_map_data *bmd = bio->bi_private;
FUJITA Tomonori68154e92008-04-25 12:47:50 +02001053 int i;
FUJITA Tomonori76029ff2008-08-25 20:36:08 +02001054 char *p = bmd->sgvecs[0].iov_base;
FUJITA Tomonori68154e92008-04-25 12:47:50 +02001055
1056 __bio_for_each_segment(bvec, bio, i, 0) {
1057 char *addr = page_address(bvec->bv_page);
FUJITA Tomonori76029ff2008-08-25 20:36:08 +02001058 int len = bmd->iovecs[i].bv_len;
FUJITA Tomonori68154e92008-04-25 12:47:50 +02001059
1060 if (read && !err)
FUJITA Tomonori76029ff2008-08-25 20:36:08 +02001061 memcpy(p, addr, len);
FUJITA Tomonori68154e92008-04-25 12:47:50 +02001062
1063 __free_page(bvec->bv_page);
FUJITA Tomonori76029ff2008-08-25 20:36:08 +02001064 p += len;
FUJITA Tomonori68154e92008-04-25 12:47:50 +02001065 }
1066
FUJITA Tomonori76029ff2008-08-25 20:36:08 +02001067 bio_free_map_data(bmd);
FUJITA Tomonori68154e92008-04-25 12:47:50 +02001068 bio_put(bio);
1069}
1070
1071/**
1072 * bio_copy_kern - copy kernel address into bio
1073 * @q: the struct request_queue for the bio
1074 * @data: pointer to buffer to copy
1075 * @len: length in bytes
1076 * @gfp_mask: allocation flags for bio and page allocation
Randy Dunlapffee0252008-04-30 09:08:54 +02001077 * @reading: data direction is READ
FUJITA Tomonori68154e92008-04-25 12:47:50 +02001078 *
1079 * copy the kernel address into a bio suitable for io to a block
1080 * device. Returns an error pointer in case of error.
1081 */
1082struct bio *bio_copy_kern(struct request_queue *q, void *data, unsigned int len,
1083 gfp_t gfp_mask, int reading)
1084{
FUJITA Tomonori68154e92008-04-25 12:47:50 +02001085 struct bio *bio;
1086 struct bio_vec *bvec;
FUJITA Tomonori4d8ab622008-08-28 15:05:57 +09001087 int i;
FUJITA Tomonori68154e92008-04-25 12:47:50 +02001088
FUJITA Tomonori4d8ab622008-08-28 15:05:57 +09001089 bio = bio_copy_user(q, NULL, (unsigned long)data, len, 1, gfp_mask);
1090 if (IS_ERR(bio))
1091 return bio;
FUJITA Tomonori68154e92008-04-25 12:47:50 +02001092
1093 if (!reading) {
1094 void *p = data;
1095
1096 bio_for_each_segment(bvec, bio, i) {
1097 char *addr = page_address(bvec->bv_page);
1098
1099 memcpy(addr, p, bvec->bv_len);
1100 p += bvec->bv_len;
1101 }
1102 }
1103
FUJITA Tomonori68154e92008-04-25 12:47:50 +02001104 bio->bi_end_io = bio_copy_kern_endio;
FUJITA Tomonori76029ff2008-08-25 20:36:08 +02001105
FUJITA Tomonori68154e92008-04-25 12:47:50 +02001106 return bio;
FUJITA Tomonori68154e92008-04-25 12:47:50 +02001107}
1108
Linus Torvalds1da177e2005-04-16 15:20:36 -07001109/*
1110 * bio_set_pages_dirty() and bio_check_pages_dirty() are support functions
1111 * for performing direct-IO in BIOs.
1112 *
1113 * The problem is that we cannot run set_page_dirty() from interrupt context
1114 * because the required locks are not interrupt-safe. So what we can do is to
1115 * mark the pages dirty _before_ performing IO. And in interrupt context,
1116 * check that the pages are still dirty. If so, fine. If not, redirty them
1117 * in process context.
1118 *
1119 * We special-case compound pages here: normally this means reads into hugetlb
1120 * pages. The logic in here doesn't really work right for compound pages
1121 * because the VM does not uniformly chase down the head page in all cases.
1122 * But dirtiness of compound pages is pretty meaningless anyway: the VM doesn't
1123 * handle them at all. So we skip compound pages here at an early stage.
1124 *
1125 * Note that this code is very hard to test under normal circumstances because
1126 * direct-io pins the pages with get_user_pages(). This makes
1127 * is_page_cache_freeable return false, and the VM will not clean the pages.
1128 * But other code (eg, pdflush) could clean the pages if they are mapped
1129 * pagecache.
1130 *
1131 * Simply disabling the call to bio_set_pages_dirty() is a good way to test the
1132 * deferred bio dirtying paths.
1133 */
1134
1135/*
1136 * bio_set_pages_dirty() will mark all the bio's pages as dirty.
1137 */
1138void bio_set_pages_dirty(struct bio *bio)
1139{
1140 struct bio_vec *bvec = bio->bi_io_vec;
1141 int i;
1142
1143 for (i = 0; i < bio->bi_vcnt; i++) {
1144 struct page *page = bvec[i].bv_page;
1145
1146 if (page && !PageCompound(page))
1147 set_page_dirty_lock(page);
1148 }
1149}
1150
Adrian Bunk86b6c7a2008-02-18 13:48:32 +01001151static void bio_release_pages(struct bio *bio)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001152{
1153 struct bio_vec *bvec = bio->bi_io_vec;
1154 int i;
1155
1156 for (i = 0; i < bio->bi_vcnt; i++) {
1157 struct page *page = bvec[i].bv_page;
1158
1159 if (page)
1160 put_page(page);
1161 }
1162}
1163
1164/*
1165 * bio_check_pages_dirty() will check that all the BIO's pages are still dirty.
1166 * If they are, then fine. If, however, some pages are clean then they must
1167 * have been written out during the direct-IO read. So we take another ref on
1168 * the BIO and the offending pages and re-dirty the pages in process context.
1169 *
1170 * It is expected that bio_check_pages_dirty() will wholly own the BIO from
1171 * here on. It will run one page_cache_release() against each page and will
1172 * run one bio_put() against the BIO.
1173 */
1174
David Howells65f27f32006-11-22 14:55:48 +00001175static void bio_dirty_fn(struct work_struct *work);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001176
David Howells65f27f32006-11-22 14:55:48 +00001177static DECLARE_WORK(bio_dirty_work, bio_dirty_fn);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001178static DEFINE_SPINLOCK(bio_dirty_lock);
1179static struct bio *bio_dirty_list;
1180
1181/*
1182 * This runs in process context
1183 */
David Howells65f27f32006-11-22 14:55:48 +00001184static void bio_dirty_fn(struct work_struct *work)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001185{
1186 unsigned long flags;
1187 struct bio *bio;
1188
1189 spin_lock_irqsave(&bio_dirty_lock, flags);
1190 bio = bio_dirty_list;
1191 bio_dirty_list = NULL;
1192 spin_unlock_irqrestore(&bio_dirty_lock, flags);
1193
1194 while (bio) {
1195 struct bio *next = bio->bi_private;
1196
1197 bio_set_pages_dirty(bio);
1198 bio_release_pages(bio);
1199 bio_put(bio);
1200 bio = next;
1201 }
1202}
1203
1204void bio_check_pages_dirty(struct bio *bio)
1205{
1206 struct bio_vec *bvec = bio->bi_io_vec;
1207 int nr_clean_pages = 0;
1208 int i;
1209
1210 for (i = 0; i < bio->bi_vcnt; i++) {
1211 struct page *page = bvec[i].bv_page;
1212
1213 if (PageDirty(page) || PageCompound(page)) {
1214 page_cache_release(page);
1215 bvec[i].bv_page = NULL;
1216 } else {
1217 nr_clean_pages++;
1218 }
1219 }
1220
1221 if (nr_clean_pages) {
1222 unsigned long flags;
1223
1224 spin_lock_irqsave(&bio_dirty_lock, flags);
1225 bio->bi_private = bio_dirty_list;
1226 bio_dirty_list = bio;
1227 spin_unlock_irqrestore(&bio_dirty_lock, flags);
1228 schedule_work(&bio_dirty_work);
1229 } else {
1230 bio_put(bio);
1231 }
1232}
1233
1234/**
1235 * bio_endio - end I/O on a bio
1236 * @bio: bio
Linus Torvalds1da177e2005-04-16 15:20:36 -07001237 * @error: error, if any
1238 *
1239 * Description:
NeilBrown6712ecf2007-09-27 12:47:43 +02001240 * bio_endio() will end I/O on the whole bio. bio_endio() is the
NeilBrown5bb23a62007-09-27 12:46:13 +02001241 * preferred way to end I/O on a bio, it takes care of clearing
1242 * BIO_UPTODATE on error. @error is 0 on success, and and one of the
1243 * established -Exxxx (-EIO, for instance) error values in case
1244 * something went wrong. Noone should call bi_end_io() directly on a
1245 * bio unless they own it and thus know that it has an end_io
1246 * function.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001247 **/
NeilBrown6712ecf2007-09-27 12:47:43 +02001248void bio_endio(struct bio *bio, int error)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001249{
1250 if (error)
1251 clear_bit(BIO_UPTODATE, &bio->bi_flags);
NeilBrown9cc54d42007-09-27 12:46:12 +02001252 else if (!test_bit(BIO_UPTODATE, &bio->bi_flags))
1253 error = -EIO;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001254
NeilBrown5bb23a62007-09-27 12:46:13 +02001255 if (bio->bi_end_io)
NeilBrown6712ecf2007-09-27 12:47:43 +02001256 bio->bi_end_io(bio, error);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001257}
1258
1259void bio_pair_release(struct bio_pair *bp)
1260{
1261 if (atomic_dec_and_test(&bp->cnt)) {
1262 struct bio *master = bp->bio1.bi_private;
1263
NeilBrown6712ecf2007-09-27 12:47:43 +02001264 bio_endio(master, bp->error);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001265 mempool_free(bp, bp->bio2.bi_private);
1266 }
1267}
1268
NeilBrown6712ecf2007-09-27 12:47:43 +02001269static void bio_pair_end_1(struct bio *bi, int err)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001270{
1271 struct bio_pair *bp = container_of(bi, struct bio_pair, bio1);
1272
1273 if (err)
1274 bp->error = err;
1275
Linus Torvalds1da177e2005-04-16 15:20:36 -07001276 bio_pair_release(bp);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001277}
1278
NeilBrown6712ecf2007-09-27 12:47:43 +02001279static void bio_pair_end_2(struct bio *bi, int err)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001280{
1281 struct bio_pair *bp = container_of(bi, struct bio_pair, bio2);
1282
1283 if (err)
1284 bp->error = err;
1285
Linus Torvalds1da177e2005-04-16 15:20:36 -07001286 bio_pair_release(bp);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001287}
1288
1289/*
1290 * split a bio - only worry about a bio with a single page
1291 * in it's iovec
1292 */
Denis ChengRq6feef532008-10-09 08:57:05 +02001293struct bio_pair *bio_split(struct bio *bi, int first_sectors)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001294{
Denis ChengRq6feef532008-10-09 08:57:05 +02001295 struct bio_pair *bp = mempool_alloc(bio_split_pool, GFP_NOIO);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001296
1297 if (!bp)
1298 return bp;
1299
Arnaldo Carvalho de Melo5f3ea372008-10-30 08:34:33 +01001300 trace_block_split(bdev_get_queue(bi->bi_bdev), bi,
Jens Axboe2056a782006-03-23 20:00:26 +01001301 bi->bi_sector + first_sectors);
1302
Linus Torvalds1da177e2005-04-16 15:20:36 -07001303 BUG_ON(bi->bi_vcnt != 1);
1304 BUG_ON(bi->bi_idx != 0);
1305 atomic_set(&bp->cnt, 3);
1306 bp->error = 0;
1307 bp->bio1 = *bi;
1308 bp->bio2 = *bi;
1309 bp->bio2.bi_sector += first_sectors;
1310 bp->bio2.bi_size -= first_sectors << 9;
1311 bp->bio1.bi_size = first_sectors << 9;
1312
1313 bp->bv1 = bi->bi_io_vec[0];
1314 bp->bv2 = bi->bi_io_vec[0];
1315 bp->bv2.bv_offset += first_sectors << 9;
1316 bp->bv2.bv_len -= first_sectors << 9;
1317 bp->bv1.bv_len = first_sectors << 9;
1318
1319 bp->bio1.bi_io_vec = &bp->bv1;
1320 bp->bio2.bi_io_vec = &bp->bv2;
1321
NeilBrowna2eb0c12006-05-22 22:35:27 -07001322 bp->bio1.bi_max_vecs = 1;
1323 bp->bio2.bi_max_vecs = 1;
1324
Linus Torvalds1da177e2005-04-16 15:20:36 -07001325 bp->bio1.bi_end_io = bio_pair_end_1;
1326 bp->bio2.bi_end_io = bio_pair_end_2;
1327
1328 bp->bio1.bi_private = bi;
Denis ChengRq6feef532008-10-09 08:57:05 +02001329 bp->bio2.bi_private = bio_split_pool;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001330
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +02001331 if (bio_integrity(bi))
1332 bio_integrity_split(bi, bp, first_sectors);
1333
Linus Torvalds1da177e2005-04-16 15:20:36 -07001334 return bp;
1335}
1336
Martin K. Petersenad3316b2008-10-01 22:42:53 -04001337/**
1338 * bio_sector_offset - Find hardware sector offset in bio
1339 * @bio: bio to inspect
1340 * @index: bio_vec index
1341 * @offset: offset in bv_page
1342 *
1343 * Return the number of hardware sectors between beginning of bio
1344 * and an end point indicated by a bio_vec index and an offset
1345 * within that vector's page.
1346 */
1347sector_t bio_sector_offset(struct bio *bio, unsigned short index,
1348 unsigned int offset)
1349{
1350 unsigned int sector_sz = queue_hardsect_size(bio->bi_bdev->bd_disk->queue);
1351 struct bio_vec *bv;
1352 sector_t sectors;
1353 int i;
1354
1355 sectors = 0;
1356
1357 if (index >= bio->bi_idx)
1358 index = bio->bi_vcnt - 1;
1359
1360 __bio_for_each_segment(bv, bio, i, 0) {
1361 if (i == index) {
1362 if (offset > bv->bv_offset)
1363 sectors += (offset - bv->bv_offset) / sector_sz;
1364 break;
1365 }
1366
1367 sectors += bv->bv_len / sector_sz;
1368 }
1369
1370 return sectors;
1371}
1372EXPORT_SYMBOL(bio_sector_offset);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001373
1374/*
1375 * create memory pools for biovec's in a bio_set.
1376 * use the global biovec slabs created for general use.
1377 */
Jens Axboe59725112007-04-02 10:06:42 +02001378static int biovec_create_pools(struct bio_set *bs, int pool_entries)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001379{
Jens Axboe7ff93452008-12-11 11:53:43 +01001380 struct biovec_slab *bp = bvec_slabs + BIOVEC_MAX_IDX;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001381
Jens Axboe7ff93452008-12-11 11:53:43 +01001382 bs->bvec_pool = mempool_create_slab_pool(pool_entries, bp->slab);
1383 if (!bs->bvec_pool)
1384 return -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001385
Linus Torvalds1da177e2005-04-16 15:20:36 -07001386 return 0;
1387}
1388
1389static void biovec_free_pools(struct bio_set *bs)
1390{
Jens Axboe7ff93452008-12-11 11:53:43 +01001391 mempool_destroy(bs->bvec_pool);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001392}
1393
1394void bioset_free(struct bio_set *bs)
1395{
1396 if (bs->bio_pool)
1397 mempool_destroy(bs->bio_pool);
1398
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +02001399 bioset_integrity_free(bs);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001400 biovec_free_pools(bs);
1401
1402 kfree(bs);
1403}
1404
Jens Axboe59725112007-04-02 10:06:42 +02001405struct bio_set *bioset_create(int bio_pool_size, int bvec_pool_size)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001406{
Oliver Neukum11b0b5a2006-03-25 03:08:13 -08001407 struct bio_set *bs = kzalloc(sizeof(*bs), GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001408
1409 if (!bs)
1410 return NULL;
1411
Matthew Dobson93d23412006-03-26 01:37:50 -08001412 bs->bio_pool = mempool_create_slab_pool(bio_pool_size, bio_slab);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001413 if (!bs->bio_pool)
1414 goto bad;
1415
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +02001416 if (bioset_integrity_create(bs, bio_pool_size))
1417 goto bad;
1418
Jens Axboe59725112007-04-02 10:06:42 +02001419 if (!biovec_create_pools(bs, bvec_pool_size))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001420 return bs;
1421
1422bad:
1423 bioset_free(bs);
1424 return NULL;
1425}
1426
1427static void __init biovec_init_slabs(void)
1428{
1429 int i;
1430
1431 for (i = 0; i < BIOVEC_NR_POOLS; i++) {
1432 int size;
1433 struct biovec_slab *bvs = bvec_slabs + i;
1434
1435 size = bvs->nr_vecs * sizeof(struct bio_vec);
1436 bvs->slab = kmem_cache_create(bvs->name, size, 0,
Paul Mundt20c2df82007-07-20 10:11:58 +09001437 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001438 }
1439}
1440
1441static int __init init_bio(void)
1442{
Christoph Lameter0a31bd52007-05-06 14:49:57 -07001443 bio_slab = KMEM_CACHE(bio, SLAB_HWCACHE_ALIGN|SLAB_PANIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001444
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +02001445 bio_integrity_init_slab();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001446 biovec_init_slabs();
1447
Jens Axboe59725112007-04-02 10:06:42 +02001448 fs_bio_set = bioset_create(BIO_POOL_SIZE, 2);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001449 if (!fs_bio_set)
1450 panic("bio: can't allocate bios\n");
1451
Matthew Dobson0eaae62a2006-03-26 01:37:47 -08001452 bio_split_pool = mempool_create_kmalloc_pool(BIO_SPLIT_ENTRIES,
1453 sizeof(struct bio_pair));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001454 if (!bio_split_pool)
1455 panic("bio: can't create split pool\n");
1456
1457 return 0;
1458}
1459
1460subsys_initcall(init_bio);
1461
1462EXPORT_SYMBOL(bio_alloc);
Jens Axboe0a0d96b2008-09-11 13:17:37 +02001463EXPORT_SYMBOL(bio_kmalloc);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001464EXPORT_SYMBOL(bio_put);
Peter Osterlund36763472005-09-06 15:16:42 -07001465EXPORT_SYMBOL(bio_free);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001466EXPORT_SYMBOL(bio_endio);
1467EXPORT_SYMBOL(bio_init);
1468EXPORT_SYMBOL(__bio_clone);
1469EXPORT_SYMBOL(bio_clone);
1470EXPORT_SYMBOL(bio_phys_segments);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001471EXPORT_SYMBOL(bio_add_page);
Mike Christie6e68af62005-11-11 05:30:27 -06001472EXPORT_SYMBOL(bio_add_pc_page);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001473EXPORT_SYMBOL(bio_get_nr_vecs);
Jens Axboe40044ce2008-03-17 21:14:40 +01001474EXPORT_SYMBOL(bio_map_user);
1475EXPORT_SYMBOL(bio_unmap_user);
Mike Christie df46b9a2005-06-20 14:04:44 +02001476EXPORT_SYMBOL(bio_map_kern);
FUJITA Tomonori68154e92008-04-25 12:47:50 +02001477EXPORT_SYMBOL(bio_copy_kern);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001478EXPORT_SYMBOL(bio_pair_release);
1479EXPORT_SYMBOL(bio_split);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001480EXPORT_SYMBOL(bio_copy_user);
1481EXPORT_SYMBOL(bio_uncopy_user);
1482EXPORT_SYMBOL(bioset_create);
1483EXPORT_SYMBOL(bioset_free);
1484EXPORT_SYMBOL(bio_alloc_bioset);