Commit | Line | Data |
---|---|---|
1da177e4 | 1 | /* |
0fe23479 | 2 | * Copyright (C) 2001 Jens Axboe <axboe@kernel.dk> |
1da177e4 LT |
3 | * |
4 | * This program is free software; you can redistribute it and/or modify | |
5 | * it under the terms of the GNU General Public License version 2 as | |
6 | * published by the Free Software Foundation. | |
7 | * | |
8 | * This program is distributed in the hope that it will be useful, | |
9 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
11 | * GNU General Public License for more details. | |
12 | * | |
13 | * You should have received a copy of the GNU General Public Licens | |
14 | * along with this program; if not, write to the Free Software | |
15 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111- | |
16 | * | |
17 | */ | |
18 | #include <linux/mm.h> | |
19 | #include <linux/swap.h> | |
20 | #include <linux/bio.h> | |
21 | #include <linux/blkdev.h> | |
22 | #include <linux/slab.h> | |
23 | #include <linux/init.h> | |
24 | #include <linux/kernel.h> | |
25 | #include <linux/module.h> | |
26 | #include <linux/mempool.h> | |
27 | #include <linux/workqueue.h> | |
2056a782 | 28 | #include <linux/blktrace_api.h> |
5f3ea37c | 29 | #include <trace/block.h> |
f1970baf | 30 | #include <scsi/sg.h> /* for struct sg_iovec */ |
1da177e4 | 31 | |
0bfc2455 IM |
32 | DEFINE_TRACE(block_split); |
33 | ||
392ddc32 JA |
34 | /* |
35 | * Test patch to inline a certain number of bi_io_vec's inside the bio | |
36 | * itself, to shrink a bio data allocation from two mempool calls to one | |
37 | */ | |
38 | #define BIO_INLINE_VECS 4 | |
39 | ||
6feef531 | 40 | static mempool_t *bio_split_pool __read_mostly; |
1da177e4 | 41 | |
1da177e4 LT |
42 | /* |
43 | * if you change this list, also change bvec_alloc or things will | |
44 | * break badly! cannot be bigger than what you can fit into an | |
45 | * unsigned short | |
46 | */ | |
1da177e4 | 47 | #define BV(x) { .nr_vecs = x, .name = "biovec-"__stringify(x) } |
bb799ca0 | 48 | struct biovec_slab bvec_slabs[BIOVEC_NR_POOLS] __read_mostly = { |
1da177e4 LT |
49 | BV(1), BV(4), BV(16), BV(64), BV(128), BV(BIO_MAX_PAGES), |
50 | }; | |
51 | #undef BV | |
52 | ||
1da177e4 LT |
53 | /* |
54 | * fs_bio_set is the bio_set containing bio and iovec memory pools used by | |
55 | * IO code that does not need private memory pools. | |
56 | */ | |
51d654e1 | 57 | struct bio_set *fs_bio_set; |
1da177e4 | 58 | |
bb799ca0 JA |
59 | /* |
60 | * Our slab pool management | |
61 | */ | |
62 | struct bio_slab { | |
63 | struct kmem_cache *slab; | |
64 | unsigned int slab_ref; | |
65 | unsigned int slab_size; | |
66 | char name[8]; | |
67 | }; | |
68 | static DEFINE_MUTEX(bio_slab_lock); | |
69 | static struct bio_slab *bio_slabs; | |
70 | static unsigned int bio_slab_nr, bio_slab_max; | |
71 | ||
72 | static struct kmem_cache *bio_find_or_create_slab(unsigned int extra_size) | |
73 | { | |
74 | unsigned int sz = sizeof(struct bio) + extra_size; | |
75 | struct kmem_cache *slab = NULL; | |
76 | struct bio_slab *bslab; | |
77 | unsigned int i, entry = -1; | |
78 | ||
79 | mutex_lock(&bio_slab_lock); | |
80 | ||
81 | i = 0; | |
82 | while (i < bio_slab_nr) { | |
83 | struct bio_slab *bslab = &bio_slabs[i]; | |
84 | ||
85 | if (!bslab->slab && entry == -1) | |
86 | entry = i; | |
87 | else if (bslab->slab_size == sz) { | |
88 | slab = bslab->slab; | |
89 | bslab->slab_ref++; | |
90 | break; | |
91 | } | |
92 | i++; | |
93 | } | |
94 | ||
95 | if (slab) | |
96 | goto out_unlock; | |
97 | ||
98 | if (bio_slab_nr == bio_slab_max && entry == -1) { | |
99 | bio_slab_max <<= 1; | |
100 | bio_slabs = krealloc(bio_slabs, | |
101 | bio_slab_max * sizeof(struct bio_slab), | |
102 | GFP_KERNEL); | |
103 | if (!bio_slabs) | |
104 | goto out_unlock; | |
105 | } | |
106 | if (entry == -1) | |
107 | entry = bio_slab_nr++; | |
108 | ||
109 | bslab = &bio_slabs[entry]; | |
110 | ||
111 | snprintf(bslab->name, sizeof(bslab->name), "bio-%d", entry); | |
112 | slab = kmem_cache_create(bslab->name, sz, 0, SLAB_HWCACHE_ALIGN, NULL); | |
113 | if (!slab) | |
114 | goto out_unlock; | |
115 | ||
116 | printk("bio: create slab <%s> at %d\n", bslab->name, entry); | |
117 | bslab->slab = slab; | |
118 | bslab->slab_ref = 1; | |
119 | bslab->slab_size = sz; | |
120 | out_unlock: | |
121 | mutex_unlock(&bio_slab_lock); | |
122 | return slab; | |
123 | } | |
124 | ||
125 | static void bio_put_slab(struct bio_set *bs) | |
126 | { | |
127 | struct bio_slab *bslab = NULL; | |
128 | unsigned int i; | |
129 | ||
130 | mutex_lock(&bio_slab_lock); | |
131 | ||
132 | for (i = 0; i < bio_slab_nr; i++) { | |
133 | if (bs->bio_slab == bio_slabs[i].slab) { | |
134 | bslab = &bio_slabs[i]; | |
135 | break; | |
136 | } | |
137 | } | |
138 | ||
139 | if (WARN(!bslab, KERN_ERR "bio: unable to find slab!\n")) | |
140 | goto out; | |
141 | ||
142 | WARN_ON(!bslab->slab_ref); | |
143 | ||
144 | if (--bslab->slab_ref) | |
145 | goto out; | |
146 | ||
147 | kmem_cache_destroy(bslab->slab); | |
148 | bslab->slab = NULL; | |
149 | ||
150 | out: | |
151 | mutex_unlock(&bio_slab_lock); | |
152 | } | |
153 | ||
7ba1ba12 MP |
154 | unsigned int bvec_nr_vecs(unsigned short idx) |
155 | { | |
156 | return bvec_slabs[idx].nr_vecs; | |
157 | } | |
158 | ||
bb799ca0 JA |
159 | void bvec_free_bs(struct bio_set *bs, struct bio_vec *bv, unsigned int idx) |
160 | { | |
161 | BIO_BUG_ON(idx >= BIOVEC_NR_POOLS); | |
162 | ||
163 | if (idx == BIOVEC_MAX_IDX) | |
164 | mempool_free(bv, bs->bvec_pool); | |
165 | else { | |
166 | struct biovec_slab *bvs = bvec_slabs + idx; | |
167 | ||
168 | kmem_cache_free(bvs->slab, bv); | |
169 | } | |
170 | } | |
171 | ||
7ff9345f JA |
172 | struct bio_vec *bvec_alloc_bs(gfp_t gfp_mask, int nr, unsigned long *idx, |
173 | struct bio_set *bs) | |
1da177e4 LT |
174 | { |
175 | struct bio_vec *bvl; | |
1da177e4 LT |
176 | |
177 | /* | |
0a0d96b0 JA |
178 | * If 'bs' is given, lookup the pool and do the mempool alloc. |
179 | * If not, this is a bio_kmalloc() allocation and just do a | |
180 | * kzalloc() for the exact number of vecs right away. | |
1da177e4 | 181 | */ |
7ff9345f | 182 | if (!bs) |
d3f76110 | 183 | bvl = kmalloc(nr * sizeof(struct bio_vec), gfp_mask); |
7ff9345f JA |
184 | |
185 | /* | |
186 | * see comment near bvec_array define! | |
187 | */ | |
188 | switch (nr) { | |
189 | case 1: | |
190 | *idx = 0; | |
191 | break; | |
192 | case 2 ... 4: | |
193 | *idx = 1; | |
194 | break; | |
195 | case 5 ... 16: | |
196 | *idx = 2; | |
197 | break; | |
198 | case 17 ... 64: | |
199 | *idx = 3; | |
200 | break; | |
201 | case 65 ... 128: | |
202 | *idx = 4; | |
203 | break; | |
204 | case 129 ... BIO_MAX_PAGES: | |
205 | *idx = 5; | |
206 | break; | |
207 | default: | |
208 | return NULL; | |
209 | } | |
210 | ||
211 | /* | |
212 | * idx now points to the pool we want to allocate from. only the | |
213 | * 1-vec entry pool is mempool backed. | |
214 | */ | |
215 | if (*idx == BIOVEC_MAX_IDX) { | |
216 | fallback: | |
217 | bvl = mempool_alloc(bs->bvec_pool, gfp_mask); | |
218 | } else { | |
219 | struct biovec_slab *bvs = bvec_slabs + *idx; | |
220 | gfp_t __gfp_mask = gfp_mask & ~(__GFP_WAIT | __GFP_IO); | |
221 | ||
0a0d96b0 | 222 | /* |
7ff9345f JA |
223 | * Make this allocation restricted and don't dump info on |
224 | * allocation failures, since we'll fallback to the mempool | |
225 | * in case of failure. | |
0a0d96b0 | 226 | */ |
7ff9345f | 227 | __gfp_mask |= __GFP_NOMEMALLOC | __GFP_NORETRY | __GFP_NOWARN; |
1da177e4 | 228 | |
0a0d96b0 | 229 | /* |
7ff9345f JA |
230 | * Try a slab allocation. If this fails and __GFP_WAIT |
231 | * is set, retry with the 1-entry mempool | |
0a0d96b0 | 232 | */ |
7ff9345f JA |
233 | bvl = kmem_cache_alloc(bvs->slab, __gfp_mask); |
234 | if (unlikely(!bvl && (gfp_mask & __GFP_WAIT))) { | |
235 | *idx = BIOVEC_MAX_IDX; | |
236 | goto fallback; | |
237 | } | |
238 | } | |
239 | ||
1da177e4 LT |
240 | return bvl; |
241 | } | |
242 | ||
7ff9345f | 243 | void bio_free(struct bio *bio, struct bio_set *bs) |
1da177e4 | 244 | { |
bb799ca0 | 245 | void *p; |
1da177e4 | 246 | |
392ddc32 | 247 | if (bio_has_allocated_vec(bio)) |
bb799ca0 | 248 | bvec_free_bs(bs, bio->bi_io_vec, BIO_POOL_IDX(bio)); |
1da177e4 | 249 | |
7ba1ba12 | 250 | if (bio_integrity(bio)) |
7ff9345f | 251 | bio_integrity_free(bio, bs); |
7ba1ba12 | 252 | |
bb799ca0 JA |
253 | /* |
254 | * If we have front padding, adjust the bio pointer before freeing | |
255 | */ | |
256 | p = bio; | |
257 | if (bs->front_pad) | |
258 | p -= bs->front_pad; | |
259 | ||
260 | mempool_free(p, bs->bio_pool); | |
3676347a PO |
261 | } |
262 | ||
263 | /* | |
264 | * default destructor for a bio allocated with bio_alloc_bioset() | |
265 | */ | |
266 | static void bio_fs_destructor(struct bio *bio) | |
267 | { | |
268 | bio_free(bio, fs_bio_set); | |
1da177e4 LT |
269 | } |
270 | ||
0a0d96b0 JA |
271 | static void bio_kmalloc_destructor(struct bio *bio) |
272 | { | |
392ddc32 JA |
273 | if (bio_has_allocated_vec(bio)) |
274 | kfree(bio->bi_io_vec); | |
0a0d96b0 JA |
275 | kfree(bio); |
276 | } | |
277 | ||
858119e1 | 278 | void bio_init(struct bio *bio) |
1da177e4 | 279 | { |
2b94de55 | 280 | memset(bio, 0, sizeof(*bio)); |
1da177e4 | 281 | bio->bi_flags = 1 << BIO_UPTODATE; |
c7c22e4d | 282 | bio->bi_comp_cpu = -1; |
1da177e4 | 283 | atomic_set(&bio->bi_cnt, 1); |
1da177e4 LT |
284 | } |
285 | ||
286 | /** | |
287 | * bio_alloc_bioset - allocate a bio for I/O | |
288 | * @gfp_mask: the GFP_ mask given to the slab allocator | |
289 | * @nr_iovecs: number of iovecs to pre-allocate | |
0a0d96b0 | 290 | * @bs: the bio_set to allocate from. If %NULL, just use kmalloc |
1da177e4 LT |
291 | * |
292 | * Description: | |
0a0d96b0 | 293 | * bio_alloc_bioset will first try its own mempool to satisfy the allocation. |
1da177e4 | 294 | * If %__GFP_WAIT is set then we will block on the internal pool waiting |
0a0d96b0 JA |
295 | * for a &struct bio to become free. If a %NULL @bs is passed in, we will |
296 | * fall back to just using @kmalloc to allocate the required memory. | |
1da177e4 | 297 | * |
bb799ca0 JA |
298 | * Note that the caller must set ->bi_destructor on succesful return |
299 | * of a bio, to do the appropriate freeing of the bio once the reference | |
300 | * count drops to zero. | |
1da177e4 | 301 | **/ |
dd0fc66f | 302 | struct bio *bio_alloc_bioset(gfp_t gfp_mask, int nr_iovecs, struct bio_set *bs) |
1da177e4 | 303 | { |
bb799ca0 | 304 | struct bio *bio = NULL; |
a60e78e5 | 305 | void *p; |
bb799ca0 JA |
306 | |
307 | if (bs) { | |
a60e78e5 | 308 | p = mempool_alloc(bs->bio_pool, gfp_mask); |
0a0d96b0 | 309 | |
bb799ca0 JA |
310 | if (p) |
311 | bio = p + bs->front_pad; | |
312 | } else | |
0a0d96b0 | 313 | bio = kmalloc(sizeof(*bio), gfp_mask); |
1da177e4 LT |
314 | |
315 | if (likely(bio)) { | |
316 | struct bio_vec *bvl = NULL; | |
317 | ||
318 | bio_init(bio); | |
319 | if (likely(nr_iovecs)) { | |
eeae1d48 | 320 | unsigned long uninitialized_var(idx); |
1da177e4 | 321 | |
392ddc32 JA |
322 | if (nr_iovecs <= BIO_INLINE_VECS) { |
323 | idx = 0; | |
324 | bvl = bio->bi_inline_vecs; | |
325 | nr_iovecs = BIO_INLINE_VECS; | |
392ddc32 JA |
326 | } else { |
327 | bvl = bvec_alloc_bs(gfp_mask, nr_iovecs, &idx, | |
328 | bs); | |
329 | nr_iovecs = bvec_nr_vecs(idx); | |
330 | } | |
1da177e4 | 331 | if (unlikely(!bvl)) { |
0a0d96b0 | 332 | if (bs) |
a60e78e5 | 333 | mempool_free(p, bs->bio_pool); |
0a0d96b0 JA |
334 | else |
335 | kfree(bio); | |
1da177e4 LT |
336 | bio = NULL; |
337 | goto out; | |
338 | } | |
339 | bio->bi_flags |= idx << BIO_POOL_OFFSET; | |
392ddc32 | 340 | bio->bi_max_vecs = nr_iovecs; |
1da177e4 LT |
341 | } |
342 | bio->bi_io_vec = bvl; | |
1da177e4 LT |
343 | } |
344 | out: | |
345 | return bio; | |
346 | } | |
347 | ||
dd0fc66f | 348 | struct bio *bio_alloc(gfp_t gfp_mask, int nr_iovecs) |
1da177e4 | 349 | { |
3676347a PO |
350 | struct bio *bio = bio_alloc_bioset(gfp_mask, nr_iovecs, fs_bio_set); |
351 | ||
352 | if (bio) | |
353 | bio->bi_destructor = bio_fs_destructor; | |
354 | ||
355 | return bio; | |
1da177e4 LT |
356 | } |
357 | ||
0a0d96b0 JA |
358 | /* |
359 | * Like bio_alloc(), but doesn't use a mempool backing. This means that | |
360 | * it CAN fail, but while bio_alloc() can only be used for allocations | |
361 | * that have a short (finite) life span, bio_kmalloc() should be used | |
362 | * for more permanent bio allocations (like allocating some bio's for | |
363 | * initalization or setup purposes). | |
364 | */ | |
365 | struct bio *bio_kmalloc(gfp_t gfp_mask, int nr_iovecs) | |
366 | { | |
367 | struct bio *bio = bio_alloc_bioset(gfp_mask, nr_iovecs, NULL); | |
368 | ||
369 | if (bio) | |
370 | bio->bi_destructor = bio_kmalloc_destructor; | |
371 | ||
372 | return bio; | |
373 | } | |
374 | ||
1da177e4 LT |
375 | void zero_fill_bio(struct bio *bio) |
376 | { | |
377 | unsigned long flags; | |
378 | struct bio_vec *bv; | |
379 | int i; | |
380 | ||
381 | bio_for_each_segment(bv, bio, i) { | |
382 | char *data = bvec_kmap_irq(bv, &flags); | |
383 | memset(data, 0, bv->bv_len); | |
384 | flush_dcache_page(bv->bv_page); | |
385 | bvec_kunmap_irq(data, &flags); | |
386 | } | |
387 | } | |
388 | EXPORT_SYMBOL(zero_fill_bio); | |
389 | ||
390 | /** | |
391 | * bio_put - release a reference to a bio | |
392 | * @bio: bio to release reference to | |
393 | * | |
394 | * Description: | |
395 | * Put a reference to a &struct bio, either one you have gotten with | |
396 | * bio_alloc or bio_get. The last put of a bio will free it. | |
397 | **/ | |
398 | void bio_put(struct bio *bio) | |
399 | { | |
400 | BIO_BUG_ON(!atomic_read(&bio->bi_cnt)); | |
401 | ||
402 | /* | |
403 | * last put frees it | |
404 | */ | |
405 | if (atomic_dec_and_test(&bio->bi_cnt)) { | |
406 | bio->bi_next = NULL; | |
407 | bio->bi_destructor(bio); | |
408 | } | |
409 | } | |
410 | ||
165125e1 | 411 | inline int bio_phys_segments(struct request_queue *q, struct bio *bio) |
1da177e4 LT |
412 | { |
413 | if (unlikely(!bio_flagged(bio, BIO_SEG_VALID))) | |
414 | blk_recount_segments(q, bio); | |
415 | ||
416 | return bio->bi_phys_segments; | |
417 | } | |
418 | ||
1da177e4 LT |
419 | /** |
420 | * __bio_clone - clone a bio | |
421 | * @bio: destination bio | |
422 | * @bio_src: bio to clone | |
423 | * | |
424 | * Clone a &bio. Caller will own the returned bio, but not | |
425 | * the actual data it points to. Reference count of returned | |
426 | * bio will be one. | |
427 | */ | |
858119e1 | 428 | void __bio_clone(struct bio *bio, struct bio *bio_src) |
1da177e4 | 429 | { |
e525e153 AM |
430 | memcpy(bio->bi_io_vec, bio_src->bi_io_vec, |
431 | bio_src->bi_max_vecs * sizeof(struct bio_vec)); | |
1da177e4 | 432 | |
5d84070e JA |
433 | /* |
434 | * most users will be overriding ->bi_bdev with a new target, | |
435 | * so we don't set nor calculate new physical/hw segment counts here | |
436 | */ | |
1da177e4 LT |
437 | bio->bi_sector = bio_src->bi_sector; |
438 | bio->bi_bdev = bio_src->bi_bdev; | |
439 | bio->bi_flags |= 1 << BIO_CLONED; | |
440 | bio->bi_rw = bio_src->bi_rw; | |
1da177e4 LT |
441 | bio->bi_vcnt = bio_src->bi_vcnt; |
442 | bio->bi_size = bio_src->bi_size; | |
a5453be4 | 443 | bio->bi_idx = bio_src->bi_idx; |
1da177e4 LT |
444 | } |
445 | ||
446 | /** | |
447 | * bio_clone - clone a bio | |
448 | * @bio: bio to clone | |
449 | * @gfp_mask: allocation priority | |
450 | * | |
451 | * Like __bio_clone, only also allocates the returned bio | |
452 | */ | |
dd0fc66f | 453 | struct bio *bio_clone(struct bio *bio, gfp_t gfp_mask) |
1da177e4 LT |
454 | { |
455 | struct bio *b = bio_alloc_bioset(gfp_mask, bio->bi_max_vecs, fs_bio_set); | |
456 | ||
7ba1ba12 MP |
457 | if (!b) |
458 | return NULL; | |
459 | ||
460 | b->bi_destructor = bio_fs_destructor; | |
461 | __bio_clone(b, bio); | |
462 | ||
463 | if (bio_integrity(bio)) { | |
464 | int ret; | |
465 | ||
466 | ret = bio_integrity_clone(b, bio, fs_bio_set); | |
467 | ||
468 | if (ret < 0) | |
469 | return NULL; | |
3676347a | 470 | } |
1da177e4 LT |
471 | |
472 | return b; | |
473 | } | |
474 | ||
475 | /** | |
476 | * bio_get_nr_vecs - return approx number of vecs | |
477 | * @bdev: I/O target | |
478 | * | |
479 | * Return the approximate number of pages we can send to this target. | |
480 | * There's no guarantee that you will be able to fit this number of pages | |
481 | * into a bio, it does not account for dynamic restrictions that vary | |
482 | * on offset. | |
483 | */ | |
484 | int bio_get_nr_vecs(struct block_device *bdev) | |
485 | { | |
165125e1 | 486 | struct request_queue *q = bdev_get_queue(bdev); |
1da177e4 LT |
487 | int nr_pages; |
488 | ||
489 | nr_pages = ((q->max_sectors << 9) + PAGE_SIZE - 1) >> PAGE_SHIFT; | |
490 | if (nr_pages > q->max_phys_segments) | |
491 | nr_pages = q->max_phys_segments; | |
492 | if (nr_pages > q->max_hw_segments) | |
493 | nr_pages = q->max_hw_segments; | |
494 | ||
495 | return nr_pages; | |
496 | } | |
497 | ||
165125e1 | 498 | static int __bio_add_page(struct request_queue *q, struct bio *bio, struct page |
defd94b7 MC |
499 | *page, unsigned int len, unsigned int offset, |
500 | unsigned short max_sectors) | |
1da177e4 LT |
501 | { |
502 | int retried_segments = 0; | |
503 | struct bio_vec *bvec; | |
504 | ||
505 | /* | |
506 | * cloned bio must not modify vec list | |
507 | */ | |
508 | if (unlikely(bio_flagged(bio, BIO_CLONED))) | |
509 | return 0; | |
510 | ||
80cfd548 | 511 | if (((bio->bi_size + len) >> 9) > max_sectors) |
1da177e4 LT |
512 | return 0; |
513 | ||
80cfd548 JA |
514 | /* |
515 | * For filesystems with a blocksize smaller than the pagesize | |
516 | * we will often be called with the same page as last time and | |
517 | * a consecutive offset. Optimize this special case. | |
518 | */ | |
519 | if (bio->bi_vcnt > 0) { | |
520 | struct bio_vec *prev = &bio->bi_io_vec[bio->bi_vcnt - 1]; | |
521 | ||
522 | if (page == prev->bv_page && | |
523 | offset == prev->bv_offset + prev->bv_len) { | |
524 | prev->bv_len += len; | |
cc371e66 AK |
525 | |
526 | if (q->merge_bvec_fn) { | |
527 | struct bvec_merge_data bvm = { | |
528 | .bi_bdev = bio->bi_bdev, | |
529 | .bi_sector = bio->bi_sector, | |
530 | .bi_size = bio->bi_size, | |
531 | .bi_rw = bio->bi_rw, | |
532 | }; | |
533 | ||
534 | if (q->merge_bvec_fn(q, &bvm, prev) < len) { | |
535 | prev->bv_len -= len; | |
536 | return 0; | |
537 | } | |
80cfd548 JA |
538 | } |
539 | ||
540 | goto done; | |
541 | } | |
542 | } | |
543 | ||
544 | if (bio->bi_vcnt >= bio->bi_max_vecs) | |
1da177e4 LT |
545 | return 0; |
546 | ||
547 | /* | |
548 | * we might lose a segment or two here, but rather that than | |
549 | * make this too complex. | |
550 | */ | |
551 | ||
552 | while (bio->bi_phys_segments >= q->max_phys_segments | |
5df97b91 | 553 | || bio->bi_phys_segments >= q->max_hw_segments) { |
1da177e4 LT |
554 | |
555 | if (retried_segments) | |
556 | return 0; | |
557 | ||
558 | retried_segments = 1; | |
559 | blk_recount_segments(q, bio); | |
560 | } | |
561 | ||
562 | /* | |
563 | * setup the new entry, we might clear it again later if we | |
564 | * cannot add the page | |
565 | */ | |
566 | bvec = &bio->bi_io_vec[bio->bi_vcnt]; | |
567 | bvec->bv_page = page; | |
568 | bvec->bv_len = len; | |
569 | bvec->bv_offset = offset; | |
570 | ||
571 | /* | |
572 | * if queue has other restrictions (eg varying max sector size | |
573 | * depending on offset), it can specify a merge_bvec_fn in the | |
574 | * queue to get further control | |
575 | */ | |
576 | if (q->merge_bvec_fn) { | |
cc371e66 AK |
577 | struct bvec_merge_data bvm = { |
578 | .bi_bdev = bio->bi_bdev, | |
579 | .bi_sector = bio->bi_sector, | |
580 | .bi_size = bio->bi_size, | |
581 | .bi_rw = bio->bi_rw, | |
582 | }; | |
583 | ||
1da177e4 LT |
584 | /* |
585 | * merge_bvec_fn() returns number of bytes it can accept | |
586 | * at this offset | |
587 | */ | |
cc371e66 | 588 | if (q->merge_bvec_fn(q, &bvm, bvec) < len) { |
1da177e4 LT |
589 | bvec->bv_page = NULL; |
590 | bvec->bv_len = 0; | |
591 | bvec->bv_offset = 0; | |
592 | return 0; | |
593 | } | |
594 | } | |
595 | ||
596 | /* If we may be able to merge these biovecs, force a recount */ | |
b8b3e16c | 597 | if (bio->bi_vcnt && (BIOVEC_PHYS_MERGEABLE(bvec-1, bvec))) |
1da177e4 LT |
598 | bio->bi_flags &= ~(1 << BIO_SEG_VALID); |
599 | ||
600 | bio->bi_vcnt++; | |
601 | bio->bi_phys_segments++; | |
80cfd548 | 602 | done: |
1da177e4 LT |
603 | bio->bi_size += len; |
604 | return len; | |
605 | } | |
606 | ||
6e68af66 MC |
607 | /** |
608 | * bio_add_pc_page - attempt to add page to bio | |
fddfdeaf | 609 | * @q: the target queue |
6e68af66 MC |
610 | * @bio: destination bio |
611 | * @page: page to add | |
612 | * @len: vec entry length | |
613 | * @offset: vec entry offset | |
614 | * | |
615 | * Attempt to add a page to the bio_vec maplist. This can fail for a | |
616 | * number of reasons, such as the bio being full or target block | |
617 | * device limitations. The target block device must allow bio's | |
618 | * smaller than PAGE_SIZE, so it is always possible to add a single | |
619 | * page to an empty bio. This should only be used by REQ_PC bios. | |
620 | */ | |
165125e1 | 621 | int bio_add_pc_page(struct request_queue *q, struct bio *bio, struct page *page, |
6e68af66 MC |
622 | unsigned int len, unsigned int offset) |
623 | { | |
defd94b7 | 624 | return __bio_add_page(q, bio, page, len, offset, q->max_hw_sectors); |
6e68af66 MC |
625 | } |
626 | ||
1da177e4 LT |
627 | /** |
628 | * bio_add_page - attempt to add page to bio | |
629 | * @bio: destination bio | |
630 | * @page: page to add | |
631 | * @len: vec entry length | |
632 | * @offset: vec entry offset | |
633 | * | |
634 | * Attempt to add a page to the bio_vec maplist. This can fail for a | |
635 | * number of reasons, such as the bio being full or target block | |
636 | * device limitations. The target block device must allow bio's | |
637 | * smaller than PAGE_SIZE, so it is always possible to add a single | |
638 | * page to an empty bio. | |
639 | */ | |
640 | int bio_add_page(struct bio *bio, struct page *page, unsigned int len, | |
641 | unsigned int offset) | |
642 | { | |
defd94b7 MC |
643 | struct request_queue *q = bdev_get_queue(bio->bi_bdev); |
644 | return __bio_add_page(q, bio, page, len, offset, q->max_sectors); | |
1da177e4 LT |
645 | } |
646 | ||
647 | struct bio_map_data { | |
648 | struct bio_vec *iovecs; | |
c5dec1c3 | 649 | struct sg_iovec *sgvecs; |
152e283f FT |
650 | int nr_sgvecs; |
651 | int is_our_pages; | |
1da177e4 LT |
652 | }; |
653 | ||
c5dec1c3 | 654 | static void bio_set_map_data(struct bio_map_data *bmd, struct bio *bio, |
152e283f FT |
655 | struct sg_iovec *iov, int iov_count, |
656 | int is_our_pages) | |
1da177e4 LT |
657 | { |
658 | memcpy(bmd->iovecs, bio->bi_io_vec, sizeof(struct bio_vec) * bio->bi_vcnt); | |
c5dec1c3 FT |
659 | memcpy(bmd->sgvecs, iov, sizeof(struct sg_iovec) * iov_count); |
660 | bmd->nr_sgvecs = iov_count; | |
152e283f | 661 | bmd->is_our_pages = is_our_pages; |
1da177e4 LT |
662 | bio->bi_private = bmd; |
663 | } | |
664 | ||
665 | static void bio_free_map_data(struct bio_map_data *bmd) | |
666 | { | |
667 | kfree(bmd->iovecs); | |
c5dec1c3 | 668 | kfree(bmd->sgvecs); |
1da177e4 LT |
669 | kfree(bmd); |
670 | } | |
671 | ||
76029ff3 FT |
672 | static struct bio_map_data *bio_alloc_map_data(int nr_segs, int iov_count, |
673 | gfp_t gfp_mask) | |
1da177e4 | 674 | { |
76029ff3 | 675 | struct bio_map_data *bmd = kmalloc(sizeof(*bmd), gfp_mask); |
1da177e4 LT |
676 | |
677 | if (!bmd) | |
678 | return NULL; | |
679 | ||
76029ff3 | 680 | bmd->iovecs = kmalloc(sizeof(struct bio_vec) * nr_segs, gfp_mask); |
c5dec1c3 FT |
681 | if (!bmd->iovecs) { |
682 | kfree(bmd); | |
683 | return NULL; | |
684 | } | |
685 | ||
76029ff3 | 686 | bmd->sgvecs = kmalloc(sizeof(struct sg_iovec) * iov_count, gfp_mask); |
c5dec1c3 | 687 | if (bmd->sgvecs) |
1da177e4 LT |
688 | return bmd; |
689 | ||
c5dec1c3 | 690 | kfree(bmd->iovecs); |
1da177e4 LT |
691 | kfree(bmd); |
692 | return NULL; | |
693 | } | |
694 | ||
aefcc28a | 695 | static int __bio_copy_iov(struct bio *bio, struct bio_vec *iovecs, |
152e283f FT |
696 | struct sg_iovec *iov, int iov_count, int uncopy, |
697 | int do_free_page) | |
c5dec1c3 FT |
698 | { |
699 | int ret = 0, i; | |
700 | struct bio_vec *bvec; | |
701 | int iov_idx = 0; | |
702 | unsigned int iov_off = 0; | |
703 | int read = bio_data_dir(bio) == READ; | |
704 | ||
705 | __bio_for_each_segment(bvec, bio, i, 0) { | |
706 | char *bv_addr = page_address(bvec->bv_page); | |
aefcc28a | 707 | unsigned int bv_len = iovecs[i].bv_len; |
c5dec1c3 FT |
708 | |
709 | while (bv_len && iov_idx < iov_count) { | |
710 | unsigned int bytes; | |
711 | char *iov_addr; | |
712 | ||
713 | bytes = min_t(unsigned int, | |
714 | iov[iov_idx].iov_len - iov_off, bv_len); | |
715 | iov_addr = iov[iov_idx].iov_base + iov_off; | |
716 | ||
717 | if (!ret) { | |
718 | if (!read && !uncopy) | |
719 | ret = copy_from_user(bv_addr, iov_addr, | |
720 | bytes); | |
721 | if (read && uncopy) | |
722 | ret = copy_to_user(iov_addr, bv_addr, | |
723 | bytes); | |
724 | ||
725 | if (ret) | |
726 | ret = -EFAULT; | |
727 | } | |
728 | ||
729 | bv_len -= bytes; | |
730 | bv_addr += bytes; | |
731 | iov_addr += bytes; | |
732 | iov_off += bytes; | |
733 | ||
734 | if (iov[iov_idx].iov_len == iov_off) { | |
735 | iov_idx++; | |
736 | iov_off = 0; | |
737 | } | |
738 | } | |
739 | ||
152e283f | 740 | if (do_free_page) |
c5dec1c3 FT |
741 | __free_page(bvec->bv_page); |
742 | } | |
743 | ||
744 | return ret; | |
745 | } | |
746 | ||
1da177e4 LT |
747 | /** |
748 | * bio_uncopy_user - finish previously mapped bio | |
749 | * @bio: bio being terminated | |
750 | * | |
751 | * Free pages allocated from bio_copy_user() and write back data | |
752 | * to user space in case of a read. | |
753 | */ | |
754 | int bio_uncopy_user(struct bio *bio) | |
755 | { | |
756 | struct bio_map_data *bmd = bio->bi_private; | |
81882766 | 757 | int ret = 0; |
1da177e4 | 758 | |
81882766 FT |
759 | if (!bio_flagged(bio, BIO_NULL_MAPPED)) |
760 | ret = __bio_copy_iov(bio, bmd->iovecs, bmd->sgvecs, | |
761 | bmd->nr_sgvecs, 1, bmd->is_our_pages); | |
1da177e4 LT |
762 | bio_free_map_data(bmd); |
763 | bio_put(bio); | |
764 | return ret; | |
765 | } | |
766 | ||
767 | /** | |
c5dec1c3 | 768 | * bio_copy_user_iov - copy user data to bio |
1da177e4 | 769 | * @q: destination block queue |
152e283f | 770 | * @map_data: pointer to the rq_map_data holding pages (if necessary) |
c5dec1c3 FT |
771 | * @iov: the iovec. |
772 | * @iov_count: number of elements in the iovec | |
1da177e4 | 773 | * @write_to_vm: bool indicating writing to pages or not |
a3bce90e | 774 | * @gfp_mask: memory allocation flags |
1da177e4 LT |
775 | * |
776 | * Prepares and returns a bio for indirect user io, bouncing data | |
777 | * to/from kernel pages as necessary. Must be paired with | |
778 | * call bio_uncopy_user() on io completion. | |
779 | */ | |
152e283f FT |
780 | struct bio *bio_copy_user_iov(struct request_queue *q, |
781 | struct rq_map_data *map_data, | |
782 | struct sg_iovec *iov, int iov_count, | |
783 | int write_to_vm, gfp_t gfp_mask) | |
1da177e4 | 784 | { |
1da177e4 LT |
785 | struct bio_map_data *bmd; |
786 | struct bio_vec *bvec; | |
787 | struct page *page; | |
788 | struct bio *bio; | |
789 | int i, ret; | |
c5dec1c3 FT |
790 | int nr_pages = 0; |
791 | unsigned int len = 0; | |
56c451f4 | 792 | unsigned int offset = map_data ? map_data->offset & ~PAGE_MASK : 0; |
1da177e4 | 793 | |
c5dec1c3 FT |
794 | for (i = 0; i < iov_count; i++) { |
795 | unsigned long uaddr; | |
796 | unsigned long end; | |
797 | unsigned long start; | |
798 | ||
799 | uaddr = (unsigned long)iov[i].iov_base; | |
800 | end = (uaddr + iov[i].iov_len + PAGE_SIZE - 1) >> PAGE_SHIFT; | |
801 | start = uaddr >> PAGE_SHIFT; | |
802 | ||
803 | nr_pages += end - start; | |
804 | len += iov[i].iov_len; | |
805 | } | |
806 | ||
a3bce90e | 807 | bmd = bio_alloc_map_data(nr_pages, iov_count, gfp_mask); |
1da177e4 LT |
808 | if (!bmd) |
809 | return ERR_PTR(-ENOMEM); | |
810 | ||
1da177e4 | 811 | ret = -ENOMEM; |
a3bce90e | 812 | bio = bio_alloc(gfp_mask, nr_pages); |
1da177e4 LT |
813 | if (!bio) |
814 | goto out_bmd; | |
815 | ||
816 | bio->bi_rw |= (!write_to_vm << BIO_RW); | |
817 | ||
818 | ret = 0; | |
56c451f4 FT |
819 | |
820 | if (map_data) { | |
e623ddb4 | 821 | nr_pages = 1 << map_data->page_order; |
56c451f4 FT |
822 | i = map_data->offset / PAGE_SIZE; |
823 | } | |
1da177e4 | 824 | while (len) { |
e623ddb4 | 825 | unsigned int bytes = PAGE_SIZE; |
1da177e4 | 826 | |
56c451f4 FT |
827 | bytes -= offset; |
828 | ||
1da177e4 LT |
829 | if (bytes > len) |
830 | bytes = len; | |
831 | ||
152e283f | 832 | if (map_data) { |
e623ddb4 | 833 | if (i == map_data->nr_entries * nr_pages) { |
152e283f FT |
834 | ret = -ENOMEM; |
835 | break; | |
836 | } | |
e623ddb4 FT |
837 | |
838 | page = map_data->pages[i / nr_pages]; | |
839 | page += (i % nr_pages); | |
840 | ||
841 | i++; | |
842 | } else { | |
152e283f | 843 | page = alloc_page(q->bounce_gfp | gfp_mask); |
e623ddb4 FT |
844 | if (!page) { |
845 | ret = -ENOMEM; | |
846 | break; | |
847 | } | |
1da177e4 LT |
848 | } |
849 | ||
56c451f4 | 850 | if (bio_add_pc_page(q, bio, page, bytes, offset) < bytes) |
1da177e4 | 851 | break; |
1da177e4 LT |
852 | |
853 | len -= bytes; | |
56c451f4 | 854 | offset = 0; |
1da177e4 LT |
855 | } |
856 | ||
857 | if (ret) | |
858 | goto cleanup; | |
859 | ||
860 | /* | |
861 | * success | |
862 | */ | |
97ae77a1 | 863 | if (!write_to_vm && (!map_data || !map_data->null_mapped)) { |
152e283f | 864 | ret = __bio_copy_iov(bio, bio->bi_io_vec, iov, iov_count, 0, 0); |
c5dec1c3 FT |
865 | if (ret) |
866 | goto cleanup; | |
1da177e4 LT |
867 | } |
868 | ||
152e283f | 869 | bio_set_map_data(bmd, bio, iov, iov_count, map_data ? 0 : 1); |
1da177e4 LT |
870 | return bio; |
871 | cleanup: | |
152e283f FT |
872 | if (!map_data) |
873 | bio_for_each_segment(bvec, bio, i) | |
874 | __free_page(bvec->bv_page); | |
1da177e4 LT |
875 | |
876 | bio_put(bio); | |
877 | out_bmd: | |
878 | bio_free_map_data(bmd); | |
879 | return ERR_PTR(ret); | |
880 | } | |
881 | ||
c5dec1c3 FT |
882 | /** |
883 | * bio_copy_user - copy user data to bio | |
884 | * @q: destination block queue | |
152e283f | 885 | * @map_data: pointer to the rq_map_data holding pages (if necessary) |
c5dec1c3 FT |
886 | * @uaddr: start of user address |
887 | * @len: length in bytes | |
888 | * @write_to_vm: bool indicating writing to pages or not | |
a3bce90e | 889 | * @gfp_mask: memory allocation flags |
c5dec1c3 FT |
890 | * |
891 | * Prepares and returns a bio for indirect user io, bouncing data | |
892 | * to/from kernel pages as necessary. Must be paired with | |
893 | * call bio_uncopy_user() on io completion. | |
894 | */ | |
152e283f FT |
895 | struct bio *bio_copy_user(struct request_queue *q, struct rq_map_data *map_data, |
896 | unsigned long uaddr, unsigned int len, | |
897 | int write_to_vm, gfp_t gfp_mask) | |
c5dec1c3 FT |
898 | { |
899 | struct sg_iovec iov; | |
900 | ||
901 | iov.iov_base = (void __user *)uaddr; | |
902 | iov.iov_len = len; | |
903 | ||
152e283f | 904 | return bio_copy_user_iov(q, map_data, &iov, 1, write_to_vm, gfp_mask); |
c5dec1c3 FT |
905 | } |
906 | ||
165125e1 | 907 | static struct bio *__bio_map_user_iov(struct request_queue *q, |
f1970baf JB |
908 | struct block_device *bdev, |
909 | struct sg_iovec *iov, int iov_count, | |
a3bce90e | 910 | int write_to_vm, gfp_t gfp_mask) |
1da177e4 | 911 | { |
f1970baf JB |
912 | int i, j; |
913 | int nr_pages = 0; | |
1da177e4 LT |
914 | struct page **pages; |
915 | struct bio *bio; | |
f1970baf JB |
916 | int cur_page = 0; |
917 | int ret, offset; | |
1da177e4 | 918 | |
f1970baf JB |
919 | for (i = 0; i < iov_count; i++) { |
920 | unsigned long uaddr = (unsigned long)iov[i].iov_base; | |
921 | unsigned long len = iov[i].iov_len; | |
922 | unsigned long end = (uaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT; | |
923 | unsigned long start = uaddr >> PAGE_SHIFT; | |
924 | ||
925 | nr_pages += end - start; | |
926 | /* | |
ad2d7225 | 927 | * buffer must be aligned to at least hardsector size for now |
f1970baf | 928 | */ |
ad2d7225 | 929 | if (uaddr & queue_dma_alignment(q)) |
f1970baf JB |
930 | return ERR_PTR(-EINVAL); |
931 | } | |
932 | ||
933 | if (!nr_pages) | |
1da177e4 LT |
934 | return ERR_PTR(-EINVAL); |
935 | ||
a3bce90e | 936 | bio = bio_alloc(gfp_mask, nr_pages); |
1da177e4 LT |
937 | if (!bio) |
938 | return ERR_PTR(-ENOMEM); | |
939 | ||
940 | ret = -ENOMEM; | |
a3bce90e | 941 | pages = kcalloc(nr_pages, sizeof(struct page *), gfp_mask); |
1da177e4 LT |
942 | if (!pages) |
943 | goto out; | |
944 | ||
f1970baf JB |
945 | for (i = 0; i < iov_count; i++) { |
946 | unsigned long uaddr = (unsigned long)iov[i].iov_base; | |
947 | unsigned long len = iov[i].iov_len; | |
948 | unsigned long end = (uaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT; | |
949 | unsigned long start = uaddr >> PAGE_SHIFT; | |
950 | const int local_nr_pages = end - start; | |
951 | const int page_limit = cur_page + local_nr_pages; | |
952 | ||
f5dd33c4 NP |
953 | ret = get_user_pages_fast(uaddr, local_nr_pages, |
954 | write_to_vm, &pages[cur_page]); | |
99172157 JA |
955 | if (ret < local_nr_pages) { |
956 | ret = -EFAULT; | |
f1970baf | 957 | goto out_unmap; |
99172157 | 958 | } |
f1970baf JB |
959 | |
960 | offset = uaddr & ~PAGE_MASK; | |
961 | for (j = cur_page; j < page_limit; j++) { | |
962 | unsigned int bytes = PAGE_SIZE - offset; | |
963 | ||
964 | if (len <= 0) | |
965 | break; | |
966 | ||
967 | if (bytes > len) | |
968 | bytes = len; | |
969 | ||
970 | /* | |
971 | * sorry... | |
972 | */ | |
defd94b7 MC |
973 | if (bio_add_pc_page(q, bio, pages[j], bytes, offset) < |
974 | bytes) | |
f1970baf JB |
975 | break; |
976 | ||
977 | len -= bytes; | |
978 | offset = 0; | |
979 | } | |
1da177e4 | 980 | |
f1970baf | 981 | cur_page = j; |
1da177e4 | 982 | /* |
f1970baf | 983 | * release the pages we didn't map into the bio, if any |
1da177e4 | 984 | */ |
f1970baf JB |
985 | while (j < page_limit) |
986 | page_cache_release(pages[j++]); | |
1da177e4 LT |
987 | } |
988 | ||
1da177e4 LT |
989 | kfree(pages); |
990 | ||
991 | /* | |
992 | * set data direction, and check if mapped pages need bouncing | |
993 | */ | |
994 | if (!write_to_vm) | |
995 | bio->bi_rw |= (1 << BIO_RW); | |
996 | ||
f1970baf | 997 | bio->bi_bdev = bdev; |
1da177e4 LT |
998 | bio->bi_flags |= (1 << BIO_USER_MAPPED); |
999 | return bio; | |
f1970baf JB |
1000 | |
1001 | out_unmap: | |
1002 | for (i = 0; i < nr_pages; i++) { | |
1003 | if(!pages[i]) | |
1004 | break; | |
1005 | page_cache_release(pages[i]); | |
1006 | } | |
1007 | out: | |
1da177e4 LT |
1008 | kfree(pages); |
1009 | bio_put(bio); | |
1010 | return ERR_PTR(ret); | |
1011 | } | |
1012 | ||
1013 | /** | |
1014 | * bio_map_user - map user address into bio | |
165125e1 | 1015 | * @q: the struct request_queue for the bio |
1da177e4 LT |
1016 | * @bdev: destination block device |
1017 | * @uaddr: start of user address | |
1018 | * @len: length in bytes | |
1019 | * @write_to_vm: bool indicating writing to pages or not | |
a3bce90e | 1020 | * @gfp_mask: memory allocation flags |
1da177e4 LT |
1021 | * |
1022 | * Map the user space address into a bio suitable for io to a block | |
1023 | * device. Returns an error pointer in case of error. | |
1024 | */ | |
165125e1 | 1025 | struct bio *bio_map_user(struct request_queue *q, struct block_device *bdev, |
a3bce90e FT |
1026 | unsigned long uaddr, unsigned int len, int write_to_vm, |
1027 | gfp_t gfp_mask) | |
f1970baf JB |
1028 | { |
1029 | struct sg_iovec iov; | |
1030 | ||
3f70353e | 1031 | iov.iov_base = (void __user *)uaddr; |
f1970baf JB |
1032 | iov.iov_len = len; |
1033 | ||
a3bce90e | 1034 | return bio_map_user_iov(q, bdev, &iov, 1, write_to_vm, gfp_mask); |
f1970baf JB |
1035 | } |
1036 | ||
1037 | /** | |
1038 | * bio_map_user_iov - map user sg_iovec table into bio | |
165125e1 | 1039 | * @q: the struct request_queue for the bio |
f1970baf JB |
1040 | * @bdev: destination block device |
1041 | * @iov: the iovec. | |
1042 | * @iov_count: number of elements in the iovec | |
1043 | * @write_to_vm: bool indicating writing to pages or not | |
a3bce90e | 1044 | * @gfp_mask: memory allocation flags |
f1970baf JB |
1045 | * |
1046 | * Map the user space address into a bio suitable for io to a block | |
1047 | * device. Returns an error pointer in case of error. | |
1048 | */ | |
165125e1 | 1049 | struct bio *bio_map_user_iov(struct request_queue *q, struct block_device *bdev, |
f1970baf | 1050 | struct sg_iovec *iov, int iov_count, |
a3bce90e | 1051 | int write_to_vm, gfp_t gfp_mask) |
1da177e4 LT |
1052 | { |
1053 | struct bio *bio; | |
1054 | ||
a3bce90e FT |
1055 | bio = __bio_map_user_iov(q, bdev, iov, iov_count, write_to_vm, |
1056 | gfp_mask); | |
1da177e4 LT |
1057 | if (IS_ERR(bio)) |
1058 | return bio; | |
1059 | ||
1060 | /* | |
1061 | * subtle -- if __bio_map_user() ended up bouncing a bio, | |
1062 | * it would normally disappear when its bi_end_io is run. | |
1063 | * however, we need it for the unmap, so grab an extra | |
1064 | * reference to it | |
1065 | */ | |
1066 | bio_get(bio); | |
1067 | ||
0e75f906 | 1068 | return bio; |
1da177e4 LT |
1069 | } |
1070 | ||
1071 | static void __bio_unmap_user(struct bio *bio) | |
1072 | { | |
1073 | struct bio_vec *bvec; | |
1074 | int i; | |
1075 | ||
1076 | /* | |
1077 | * make sure we dirty pages we wrote to | |
1078 | */ | |
1079 | __bio_for_each_segment(bvec, bio, i, 0) { | |
1080 | if (bio_data_dir(bio) == READ) | |
1081 | set_page_dirty_lock(bvec->bv_page); | |
1082 | ||
1083 | page_cache_release(bvec->bv_page); | |
1084 | } | |
1085 | ||
1086 | bio_put(bio); | |
1087 | } | |
1088 | ||
1089 | /** | |
1090 | * bio_unmap_user - unmap a bio | |
1091 | * @bio: the bio being unmapped | |
1092 | * | |
1093 | * Unmap a bio previously mapped by bio_map_user(). Must be called with | |
1094 | * a process context. | |
1095 | * | |
1096 | * bio_unmap_user() may sleep. | |
1097 | */ | |
1098 | void bio_unmap_user(struct bio *bio) | |
1099 | { | |
1100 | __bio_unmap_user(bio); | |
1101 | bio_put(bio); | |
1102 | } | |
1103 | ||
6712ecf8 | 1104 | static void bio_map_kern_endio(struct bio *bio, int err) |
b823825e | 1105 | { |
b823825e | 1106 | bio_put(bio); |
b823825e JA |
1107 | } |
1108 | ||
1109 | ||
165125e1 | 1110 | static struct bio *__bio_map_kern(struct request_queue *q, void *data, |
27496a8c | 1111 | unsigned int len, gfp_t gfp_mask) |
df46b9a4 MC |
1112 | { |
1113 | unsigned long kaddr = (unsigned long)data; | |
1114 | unsigned long end = (kaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT; | |
1115 | unsigned long start = kaddr >> PAGE_SHIFT; | |
1116 | const int nr_pages = end - start; | |
1117 | int offset, i; | |
1118 | struct bio *bio; | |
1119 | ||
1120 | bio = bio_alloc(gfp_mask, nr_pages); | |
1121 | if (!bio) | |
1122 | return ERR_PTR(-ENOMEM); | |
1123 | ||
1124 | offset = offset_in_page(kaddr); | |
1125 | for (i = 0; i < nr_pages; i++) { | |
1126 | unsigned int bytes = PAGE_SIZE - offset; | |
1127 | ||
1128 | if (len <= 0) | |
1129 | break; | |
1130 | ||
1131 | if (bytes > len) | |
1132 | bytes = len; | |
1133 | ||
defd94b7 MC |
1134 | if (bio_add_pc_page(q, bio, virt_to_page(data), bytes, |
1135 | offset) < bytes) | |
df46b9a4 MC |
1136 | break; |
1137 | ||
1138 | data += bytes; | |
1139 | len -= bytes; | |
1140 | offset = 0; | |
1141 | } | |
1142 | ||
b823825e | 1143 | bio->bi_end_io = bio_map_kern_endio; |
df46b9a4 MC |
1144 | return bio; |
1145 | } | |
1146 | ||
1147 | /** | |
1148 | * bio_map_kern - map kernel address into bio | |
165125e1 | 1149 | * @q: the struct request_queue for the bio |
df46b9a4 MC |
1150 | * @data: pointer to buffer to map |
1151 | * @len: length in bytes | |
1152 | * @gfp_mask: allocation flags for bio allocation | |
1153 | * | |
1154 | * Map the kernel address into a bio suitable for io to a block | |
1155 | * device. Returns an error pointer in case of error. | |
1156 | */ | |
165125e1 | 1157 | struct bio *bio_map_kern(struct request_queue *q, void *data, unsigned int len, |
27496a8c | 1158 | gfp_t gfp_mask) |
df46b9a4 MC |
1159 | { |
1160 | struct bio *bio; | |
1161 | ||
1162 | bio = __bio_map_kern(q, data, len, gfp_mask); | |
1163 | if (IS_ERR(bio)) | |
1164 | return bio; | |
1165 | ||
1166 | if (bio->bi_size == len) | |
1167 | return bio; | |
1168 | ||
1169 | /* | |
1170 | * Don't support partial mappings. | |
1171 | */ | |
1172 | bio_put(bio); | |
1173 | return ERR_PTR(-EINVAL); | |
1174 | } | |
1175 | ||
68154e90 FT |
1176 | static void bio_copy_kern_endio(struct bio *bio, int err) |
1177 | { | |
1178 | struct bio_vec *bvec; | |
1179 | const int read = bio_data_dir(bio) == READ; | |
76029ff3 | 1180 | struct bio_map_data *bmd = bio->bi_private; |
68154e90 | 1181 | int i; |
76029ff3 | 1182 | char *p = bmd->sgvecs[0].iov_base; |
68154e90 FT |
1183 | |
1184 | __bio_for_each_segment(bvec, bio, i, 0) { | |
1185 | char *addr = page_address(bvec->bv_page); | |
76029ff3 | 1186 | int len = bmd->iovecs[i].bv_len; |
68154e90 FT |
1187 | |
1188 | if (read && !err) | |
76029ff3 | 1189 | memcpy(p, addr, len); |
68154e90 FT |
1190 | |
1191 | __free_page(bvec->bv_page); | |
76029ff3 | 1192 | p += len; |
68154e90 FT |
1193 | } |
1194 | ||
76029ff3 | 1195 | bio_free_map_data(bmd); |
68154e90 FT |
1196 | bio_put(bio); |
1197 | } | |
1198 | ||
1199 | /** | |
1200 | * bio_copy_kern - copy kernel address into bio | |
1201 | * @q: the struct request_queue for the bio | |
1202 | * @data: pointer to buffer to copy | |
1203 | * @len: length in bytes | |
1204 | * @gfp_mask: allocation flags for bio and page allocation | |
ffee0259 | 1205 | * @reading: data direction is READ |
68154e90 FT |
1206 | * |
1207 | * copy the kernel address into a bio suitable for io to a block | |
1208 | * device. Returns an error pointer in case of error. | |
1209 | */ | |
1210 | struct bio *bio_copy_kern(struct request_queue *q, void *data, unsigned int len, | |
1211 | gfp_t gfp_mask, int reading) | |
1212 | { | |
68154e90 FT |
1213 | struct bio *bio; |
1214 | struct bio_vec *bvec; | |
4d8ab62e | 1215 | int i; |
68154e90 | 1216 | |
4d8ab62e FT |
1217 | bio = bio_copy_user(q, NULL, (unsigned long)data, len, 1, gfp_mask); |
1218 | if (IS_ERR(bio)) | |
1219 | return bio; | |
68154e90 FT |
1220 | |
1221 | if (!reading) { | |
1222 | void *p = data; | |
1223 | ||
1224 | bio_for_each_segment(bvec, bio, i) { | |
1225 | char *addr = page_address(bvec->bv_page); | |
1226 | ||
1227 | memcpy(addr, p, bvec->bv_len); | |
1228 | p += bvec->bv_len; | |
1229 | } | |
1230 | } | |
1231 | ||
68154e90 | 1232 | bio->bi_end_io = bio_copy_kern_endio; |
76029ff3 | 1233 | |
68154e90 | 1234 | return bio; |
68154e90 FT |
1235 | } |
1236 | ||
1da177e4 LT |
1237 | /* |
1238 | * bio_set_pages_dirty() and bio_check_pages_dirty() are support functions | |
1239 | * for performing direct-IO in BIOs. | |
1240 | * | |
1241 | * The problem is that we cannot run set_page_dirty() from interrupt context | |
1242 | * because the required locks are not interrupt-safe. So what we can do is to | |
1243 | * mark the pages dirty _before_ performing IO. And in interrupt context, | |
1244 | * check that the pages are still dirty. If so, fine. If not, redirty them | |
1245 | * in process context. | |
1246 | * | |
1247 | * We special-case compound pages here: normally this means reads into hugetlb | |
1248 | * pages. The logic in here doesn't really work right for compound pages | |
1249 | * because the VM does not uniformly chase down the head page in all cases. | |
1250 | * But dirtiness of compound pages is pretty meaningless anyway: the VM doesn't | |
1251 | * handle them at all. So we skip compound pages here at an early stage. | |
1252 | * | |
1253 | * Note that this code is very hard to test under normal circumstances because | |
1254 | * direct-io pins the pages with get_user_pages(). This makes | |
1255 | * is_page_cache_freeable return false, and the VM will not clean the pages. | |
1256 | * But other code (eg, pdflush) could clean the pages if they are mapped | |
1257 | * pagecache. | |
1258 | * | |
1259 | * Simply disabling the call to bio_set_pages_dirty() is a good way to test the | |
1260 | * deferred bio dirtying paths. | |
1261 | */ | |
1262 | ||
1263 | /* | |
1264 | * bio_set_pages_dirty() will mark all the bio's pages as dirty. | |
1265 | */ | |
1266 | void bio_set_pages_dirty(struct bio *bio) | |
1267 | { | |
1268 | struct bio_vec *bvec = bio->bi_io_vec; | |
1269 | int i; | |
1270 | ||
1271 | for (i = 0; i < bio->bi_vcnt; i++) { | |
1272 | struct page *page = bvec[i].bv_page; | |
1273 | ||
1274 | if (page && !PageCompound(page)) | |
1275 | set_page_dirty_lock(page); | |
1276 | } | |
1277 | } | |
1278 | ||
86b6c7a7 | 1279 | static void bio_release_pages(struct bio *bio) |
1da177e4 LT |
1280 | { |
1281 | struct bio_vec *bvec = bio->bi_io_vec; | |
1282 | int i; | |
1283 | ||
1284 | for (i = 0; i < bio->bi_vcnt; i++) { | |
1285 | struct page *page = bvec[i].bv_page; | |
1286 | ||
1287 | if (page) | |
1288 | put_page(page); | |
1289 | } | |
1290 | } | |
1291 | ||
1292 | /* | |
1293 | * bio_check_pages_dirty() will check that all the BIO's pages are still dirty. | |
1294 | * If they are, then fine. If, however, some pages are clean then they must | |
1295 | * have been written out during the direct-IO read. So we take another ref on | |
1296 | * the BIO and the offending pages and re-dirty the pages in process context. | |
1297 | * | |
1298 | * It is expected that bio_check_pages_dirty() will wholly own the BIO from | |
1299 | * here on. It will run one page_cache_release() against each page and will | |
1300 | * run one bio_put() against the BIO. | |
1301 | */ | |
1302 | ||
65f27f38 | 1303 | static void bio_dirty_fn(struct work_struct *work); |
1da177e4 | 1304 | |
65f27f38 | 1305 | static DECLARE_WORK(bio_dirty_work, bio_dirty_fn); |
1da177e4 LT |
1306 | static DEFINE_SPINLOCK(bio_dirty_lock); |
1307 | static struct bio *bio_dirty_list; | |
1308 | ||
1309 | /* | |
1310 | * This runs in process context | |
1311 | */ | |
65f27f38 | 1312 | static void bio_dirty_fn(struct work_struct *work) |
1da177e4 LT |
1313 | { |
1314 | unsigned long flags; | |
1315 | struct bio *bio; | |
1316 | ||
1317 | spin_lock_irqsave(&bio_dirty_lock, flags); | |
1318 | bio = bio_dirty_list; | |
1319 | bio_dirty_list = NULL; | |
1320 | spin_unlock_irqrestore(&bio_dirty_lock, flags); | |
1321 | ||
1322 | while (bio) { | |
1323 | struct bio *next = bio->bi_private; | |
1324 | ||
1325 | bio_set_pages_dirty(bio); | |
1326 | bio_release_pages(bio); | |
1327 | bio_put(bio); | |
1328 | bio = next; | |
1329 | } | |
1330 | } | |
1331 | ||
1332 | void bio_check_pages_dirty(struct bio *bio) | |
1333 | { | |
1334 | struct bio_vec *bvec = bio->bi_io_vec; | |
1335 | int nr_clean_pages = 0; | |
1336 | int i; | |
1337 | ||
1338 | for (i = 0; i < bio->bi_vcnt; i++) { | |
1339 | struct page *page = bvec[i].bv_page; | |
1340 | ||
1341 | if (PageDirty(page) || PageCompound(page)) { | |
1342 | page_cache_release(page); | |
1343 | bvec[i].bv_page = NULL; | |
1344 | } else { | |
1345 | nr_clean_pages++; | |
1346 | } | |
1347 | } | |
1348 | ||
1349 | if (nr_clean_pages) { | |
1350 | unsigned long flags; | |
1351 | ||
1352 | spin_lock_irqsave(&bio_dirty_lock, flags); | |
1353 | bio->bi_private = bio_dirty_list; | |
1354 | bio_dirty_list = bio; | |
1355 | spin_unlock_irqrestore(&bio_dirty_lock, flags); | |
1356 | schedule_work(&bio_dirty_work); | |
1357 | } else { | |
1358 | bio_put(bio); | |
1359 | } | |
1360 | } | |
1361 | ||
1362 | /** | |
1363 | * bio_endio - end I/O on a bio | |
1364 | * @bio: bio | |
1da177e4 LT |
1365 | * @error: error, if any |
1366 | * | |
1367 | * Description: | |
6712ecf8 | 1368 | * bio_endio() will end I/O on the whole bio. bio_endio() is the |
5bb23a68 N |
1369 | * preferred way to end I/O on a bio, it takes care of clearing |
1370 | * BIO_UPTODATE on error. @error is 0 on success, and and one of the | |
1371 | * established -Exxxx (-EIO, for instance) error values in case | |
1372 | * something went wrong. Noone should call bi_end_io() directly on a | |
1373 | * bio unless they own it and thus know that it has an end_io | |
1374 | * function. | |
1da177e4 | 1375 | **/ |
6712ecf8 | 1376 | void bio_endio(struct bio *bio, int error) |
1da177e4 LT |
1377 | { |
1378 | if (error) | |
1379 | clear_bit(BIO_UPTODATE, &bio->bi_flags); | |
9cc54d40 N |
1380 | else if (!test_bit(BIO_UPTODATE, &bio->bi_flags)) |
1381 | error = -EIO; | |
1da177e4 | 1382 | |
5bb23a68 | 1383 | if (bio->bi_end_io) |
6712ecf8 | 1384 | bio->bi_end_io(bio, error); |
1da177e4 LT |
1385 | } |
1386 | ||
1387 | void bio_pair_release(struct bio_pair *bp) | |
1388 | { | |
1389 | if (atomic_dec_and_test(&bp->cnt)) { | |
1390 | struct bio *master = bp->bio1.bi_private; | |
1391 | ||
6712ecf8 | 1392 | bio_endio(master, bp->error); |
1da177e4 LT |
1393 | mempool_free(bp, bp->bio2.bi_private); |
1394 | } | |
1395 | } | |
1396 | ||
6712ecf8 | 1397 | static void bio_pair_end_1(struct bio *bi, int err) |
1da177e4 LT |
1398 | { |
1399 | struct bio_pair *bp = container_of(bi, struct bio_pair, bio1); | |
1400 | ||
1401 | if (err) | |
1402 | bp->error = err; | |
1403 | ||
1da177e4 | 1404 | bio_pair_release(bp); |
1da177e4 LT |
1405 | } |
1406 | ||
6712ecf8 | 1407 | static void bio_pair_end_2(struct bio *bi, int err) |
1da177e4 LT |
1408 | { |
1409 | struct bio_pair *bp = container_of(bi, struct bio_pair, bio2); | |
1410 | ||
1411 | if (err) | |
1412 | bp->error = err; | |
1413 | ||
1da177e4 | 1414 | bio_pair_release(bp); |
1da177e4 LT |
1415 | } |
1416 | ||
1417 | /* | |
1418 | * split a bio - only worry about a bio with a single page | |
1419 | * in it's iovec | |
1420 | */ | |
6feef531 | 1421 | struct bio_pair *bio_split(struct bio *bi, int first_sectors) |
1da177e4 | 1422 | { |
6feef531 | 1423 | struct bio_pair *bp = mempool_alloc(bio_split_pool, GFP_NOIO); |
1da177e4 LT |
1424 | |
1425 | if (!bp) | |
1426 | return bp; | |
1427 | ||
5f3ea37c | 1428 | trace_block_split(bdev_get_queue(bi->bi_bdev), bi, |
2056a782 JA |
1429 | bi->bi_sector + first_sectors); |
1430 | ||
1da177e4 LT |
1431 | BUG_ON(bi->bi_vcnt != 1); |
1432 | BUG_ON(bi->bi_idx != 0); | |
1433 | atomic_set(&bp->cnt, 3); | |
1434 | bp->error = 0; | |
1435 | bp->bio1 = *bi; | |
1436 | bp->bio2 = *bi; | |
1437 | bp->bio2.bi_sector += first_sectors; | |
1438 | bp->bio2.bi_size -= first_sectors << 9; | |
1439 | bp->bio1.bi_size = first_sectors << 9; | |
1440 | ||
1441 | bp->bv1 = bi->bi_io_vec[0]; | |
1442 | bp->bv2 = bi->bi_io_vec[0]; | |
1443 | bp->bv2.bv_offset += first_sectors << 9; | |
1444 | bp->bv2.bv_len -= first_sectors << 9; | |
1445 | bp->bv1.bv_len = first_sectors << 9; | |
1446 | ||
1447 | bp->bio1.bi_io_vec = &bp->bv1; | |
1448 | bp->bio2.bi_io_vec = &bp->bv2; | |
1449 | ||
a2eb0c10 N |
1450 | bp->bio1.bi_max_vecs = 1; |
1451 | bp->bio2.bi_max_vecs = 1; | |
1452 | ||
1da177e4 LT |
1453 | bp->bio1.bi_end_io = bio_pair_end_1; |
1454 | bp->bio2.bi_end_io = bio_pair_end_2; | |
1455 | ||
1456 | bp->bio1.bi_private = bi; | |
6feef531 | 1457 | bp->bio2.bi_private = bio_split_pool; |
1da177e4 | 1458 | |
7ba1ba12 MP |
1459 | if (bio_integrity(bi)) |
1460 | bio_integrity_split(bi, bp, first_sectors); | |
1461 | ||
1da177e4 LT |
1462 | return bp; |
1463 | } | |
1464 | ||
ad3316bf MP |
1465 | /** |
1466 | * bio_sector_offset - Find hardware sector offset in bio | |
1467 | * @bio: bio to inspect | |
1468 | * @index: bio_vec index | |
1469 | * @offset: offset in bv_page | |
1470 | * | |
1471 | * Return the number of hardware sectors between beginning of bio | |
1472 | * and an end point indicated by a bio_vec index and an offset | |
1473 | * within that vector's page. | |
1474 | */ | |
1475 | sector_t bio_sector_offset(struct bio *bio, unsigned short index, | |
1476 | unsigned int offset) | |
1477 | { | |
1478 | unsigned int sector_sz = queue_hardsect_size(bio->bi_bdev->bd_disk->queue); | |
1479 | struct bio_vec *bv; | |
1480 | sector_t sectors; | |
1481 | int i; | |
1482 | ||
1483 | sectors = 0; | |
1484 | ||
1485 | if (index >= bio->bi_idx) | |
1486 | index = bio->bi_vcnt - 1; | |
1487 | ||
1488 | __bio_for_each_segment(bv, bio, i, 0) { | |
1489 | if (i == index) { | |
1490 | if (offset > bv->bv_offset) | |
1491 | sectors += (offset - bv->bv_offset) / sector_sz; | |
1492 | break; | |
1493 | } | |
1494 | ||
1495 | sectors += bv->bv_len / sector_sz; | |
1496 | } | |
1497 | ||
1498 | return sectors; | |
1499 | } | |
1500 | EXPORT_SYMBOL(bio_sector_offset); | |
1da177e4 LT |
1501 | |
1502 | /* | |
1503 | * create memory pools for biovec's in a bio_set. | |
1504 | * use the global biovec slabs created for general use. | |
1505 | */ | |
5972511b | 1506 | static int biovec_create_pools(struct bio_set *bs, int pool_entries) |
1da177e4 | 1507 | { |
7ff9345f | 1508 | struct biovec_slab *bp = bvec_slabs + BIOVEC_MAX_IDX; |
1da177e4 | 1509 | |
7ff9345f JA |
1510 | bs->bvec_pool = mempool_create_slab_pool(pool_entries, bp->slab); |
1511 | if (!bs->bvec_pool) | |
1512 | return -ENOMEM; | |
1da177e4 | 1513 | |
1da177e4 LT |
1514 | return 0; |
1515 | } | |
1516 | ||
1517 | static void biovec_free_pools(struct bio_set *bs) | |
1518 | { | |
7ff9345f | 1519 | mempool_destroy(bs->bvec_pool); |
1da177e4 LT |
1520 | } |
1521 | ||
1522 | void bioset_free(struct bio_set *bs) | |
1523 | { | |
1524 | if (bs->bio_pool) | |
1525 | mempool_destroy(bs->bio_pool); | |
1526 | ||
7ba1ba12 | 1527 | bioset_integrity_free(bs); |
1da177e4 | 1528 | biovec_free_pools(bs); |
bb799ca0 | 1529 | bio_put_slab(bs); |
1da177e4 LT |
1530 | |
1531 | kfree(bs); | |
1532 | } | |
1533 | ||
bb799ca0 JA |
1534 | /** |
1535 | * bioset_create - Create a bio_set | |
1536 | * @pool_size: Number of bio and bio_vecs to cache in the mempool | |
1537 | * @front_pad: Number of bytes to allocate in front of the returned bio | |
1538 | * | |
1539 | * Description: | |
1540 | * Set up a bio_set to be used with @bio_alloc_bioset. Allows the caller | |
1541 | * to ask for a number of bytes to be allocated in front of the bio. | |
1542 | * Front pad allocation is useful for embedding the bio inside | |
1543 | * another structure, to avoid allocating extra data to go with the bio. | |
1544 | * Note that the bio must be embedded at the END of that structure always, | |
1545 | * or things will break badly. | |
1546 | */ | |
1547 | struct bio_set *bioset_create(unsigned int pool_size, unsigned int front_pad) | |
1da177e4 | 1548 | { |
392ddc32 | 1549 | unsigned int back_pad = BIO_INLINE_VECS * sizeof(struct bio_vec); |
1b434498 | 1550 | struct bio_set *bs; |
1da177e4 | 1551 | |
1b434498 | 1552 | bs = kzalloc(sizeof(*bs), GFP_KERNEL); |
1da177e4 LT |
1553 | if (!bs) |
1554 | return NULL; | |
1555 | ||
bb799ca0 | 1556 | bs->front_pad = front_pad; |
1b434498 | 1557 | |
392ddc32 | 1558 | bs->bio_slab = bio_find_or_create_slab(front_pad + back_pad); |
bb799ca0 JA |
1559 | if (!bs->bio_slab) { |
1560 | kfree(bs); | |
1561 | return NULL; | |
1562 | } | |
1563 | ||
1564 | bs->bio_pool = mempool_create_slab_pool(pool_size, bs->bio_slab); | |
1da177e4 LT |
1565 | if (!bs->bio_pool) |
1566 | goto bad; | |
1567 | ||
bb799ca0 | 1568 | if (bioset_integrity_create(bs, pool_size)) |
7ba1ba12 MP |
1569 | goto bad; |
1570 | ||
bb799ca0 | 1571 | if (!biovec_create_pools(bs, pool_size)) |
1da177e4 LT |
1572 | return bs; |
1573 | ||
1574 | bad: | |
1575 | bioset_free(bs); | |
1576 | return NULL; | |
1577 | } | |
1578 | ||
1579 | static void __init biovec_init_slabs(void) | |
1580 | { | |
1581 | int i; | |
1582 | ||
1583 | for (i = 0; i < BIOVEC_NR_POOLS; i++) { | |
1584 | int size; | |
1585 | struct biovec_slab *bvs = bvec_slabs + i; | |
1586 | ||
1587 | size = bvs->nr_vecs * sizeof(struct bio_vec); | |
1588 | bvs->slab = kmem_cache_create(bvs->name, size, 0, | |
20c2df83 | 1589 | SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); |
1da177e4 LT |
1590 | } |
1591 | } | |
1592 | ||
1593 | static int __init init_bio(void) | |
1594 | { | |
bb799ca0 JA |
1595 | bio_slab_max = 2; |
1596 | bio_slab_nr = 0; | |
1597 | bio_slabs = kzalloc(bio_slab_max * sizeof(struct bio_slab), GFP_KERNEL); | |
1598 | if (!bio_slabs) | |
1599 | panic("bio: can't allocate bios\n"); | |
1da177e4 | 1600 | |
7ba1ba12 | 1601 | bio_integrity_init_slab(); |
1da177e4 LT |
1602 | biovec_init_slabs(); |
1603 | ||
bb799ca0 | 1604 | fs_bio_set = bioset_create(BIO_POOL_SIZE, 0); |
1da177e4 LT |
1605 | if (!fs_bio_set) |
1606 | panic("bio: can't allocate bios\n"); | |
1607 | ||
0eaae62a MD |
1608 | bio_split_pool = mempool_create_kmalloc_pool(BIO_SPLIT_ENTRIES, |
1609 | sizeof(struct bio_pair)); | |
1da177e4 LT |
1610 | if (!bio_split_pool) |
1611 | panic("bio: can't create split pool\n"); | |
1612 | ||
1613 | return 0; | |
1614 | } | |
1615 | ||
1616 | subsys_initcall(init_bio); | |
1617 | ||
1618 | EXPORT_SYMBOL(bio_alloc); | |
0a0d96b0 | 1619 | EXPORT_SYMBOL(bio_kmalloc); |
1da177e4 | 1620 | EXPORT_SYMBOL(bio_put); |
3676347a | 1621 | EXPORT_SYMBOL(bio_free); |
1da177e4 LT |
1622 | EXPORT_SYMBOL(bio_endio); |
1623 | EXPORT_SYMBOL(bio_init); | |
1624 | EXPORT_SYMBOL(__bio_clone); | |
1625 | EXPORT_SYMBOL(bio_clone); | |
1626 | EXPORT_SYMBOL(bio_phys_segments); | |
1da177e4 | 1627 | EXPORT_SYMBOL(bio_add_page); |
6e68af66 | 1628 | EXPORT_SYMBOL(bio_add_pc_page); |
1da177e4 | 1629 | EXPORT_SYMBOL(bio_get_nr_vecs); |
40044ce0 JA |
1630 | EXPORT_SYMBOL(bio_map_user); |
1631 | EXPORT_SYMBOL(bio_unmap_user); | |
df46b9a4 | 1632 | EXPORT_SYMBOL(bio_map_kern); |
68154e90 | 1633 | EXPORT_SYMBOL(bio_copy_kern); |
1da177e4 LT |
1634 | EXPORT_SYMBOL(bio_pair_release); |
1635 | EXPORT_SYMBOL(bio_split); | |
1da177e4 LT |
1636 | EXPORT_SYMBOL(bio_copy_user); |
1637 | EXPORT_SYMBOL(bio_uncopy_user); | |
1638 | EXPORT_SYMBOL(bioset_create); | |
1639 | EXPORT_SYMBOL(bioset_free); | |
1640 | EXPORT_SYMBOL(bio_alloc_bioset); |