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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> | |
852c788f | 22 | #include <linux/iocontext.h> |
1da177e4 LT |
23 | #include <linux/slab.h> |
24 | #include <linux/init.h> | |
25 | #include <linux/kernel.h> | |
630d9c47 | 26 | #include <linux/export.h> |
1da177e4 LT |
27 | #include <linux/mempool.h> |
28 | #include <linux/workqueue.h> | |
852c788f | 29 | #include <linux/cgroup.h> |
f1970baf | 30 | #include <scsi/sg.h> /* for struct sg_iovec */ |
1da177e4 | 31 | |
55782138 | 32 | #include <trace/events/block.h> |
0bfc2455 | 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) } |
df677140 | 48 | static 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; | |
389d7b26 | 76 | struct bio_slab *bslab, *new_bio_slabs; |
bb799ca0 JA |
77 | unsigned int i, entry = -1; |
78 | ||
79 | mutex_lock(&bio_slab_lock); | |
80 | ||
81 | i = 0; | |
82 | while (i < bio_slab_nr) { | |
f06f135d | 83 | bslab = &bio_slabs[i]; |
bb799ca0 JA |
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; | |
389d7b26 AK |
100 | new_bio_slabs = krealloc(bio_slabs, |
101 | bio_slab_max * sizeof(struct bio_slab), | |
102 | GFP_KERNEL); | |
103 | if (!new_bio_slabs) | |
bb799ca0 | 104 | goto out_unlock; |
389d7b26 | 105 | bio_slabs = new_bio_slabs; |
bb799ca0 JA |
106 | } |
107 | if (entry == -1) | |
108 | entry = bio_slab_nr++; | |
109 | ||
110 | bslab = &bio_slabs[entry]; | |
111 | ||
112 | snprintf(bslab->name, sizeof(bslab->name), "bio-%d", entry); | |
113 | slab = kmem_cache_create(bslab->name, sz, 0, SLAB_HWCACHE_ALIGN, NULL); | |
114 | if (!slab) | |
115 | goto out_unlock; | |
116 | ||
80cdc6da | 117 | printk(KERN_INFO "bio: create slab <%s> at %d\n", bslab->name, entry); |
bb799ca0 JA |
118 | bslab->slab = slab; |
119 | bslab->slab_ref = 1; | |
120 | bslab->slab_size = sz; | |
121 | out_unlock: | |
122 | mutex_unlock(&bio_slab_lock); | |
123 | return slab; | |
124 | } | |
125 | ||
126 | static void bio_put_slab(struct bio_set *bs) | |
127 | { | |
128 | struct bio_slab *bslab = NULL; | |
129 | unsigned int i; | |
130 | ||
131 | mutex_lock(&bio_slab_lock); | |
132 | ||
133 | for (i = 0; i < bio_slab_nr; i++) { | |
134 | if (bs->bio_slab == bio_slabs[i].slab) { | |
135 | bslab = &bio_slabs[i]; | |
136 | break; | |
137 | } | |
138 | } | |
139 | ||
140 | if (WARN(!bslab, KERN_ERR "bio: unable to find slab!\n")) | |
141 | goto out; | |
142 | ||
143 | WARN_ON(!bslab->slab_ref); | |
144 | ||
145 | if (--bslab->slab_ref) | |
146 | goto out; | |
147 | ||
148 | kmem_cache_destroy(bslab->slab); | |
149 | bslab->slab = NULL; | |
150 | ||
151 | out: | |
152 | mutex_unlock(&bio_slab_lock); | |
153 | } | |
154 | ||
7ba1ba12 MP |
155 | unsigned int bvec_nr_vecs(unsigned short idx) |
156 | { | |
157 | return bvec_slabs[idx].nr_vecs; | |
158 | } | |
159 | ||
bb799ca0 JA |
160 | void bvec_free_bs(struct bio_set *bs, struct bio_vec *bv, unsigned int idx) |
161 | { | |
162 | BIO_BUG_ON(idx >= BIOVEC_NR_POOLS); | |
163 | ||
164 | if (idx == BIOVEC_MAX_IDX) | |
165 | mempool_free(bv, bs->bvec_pool); | |
166 | else { | |
167 | struct biovec_slab *bvs = bvec_slabs + idx; | |
168 | ||
169 | kmem_cache_free(bvs->slab, bv); | |
170 | } | |
171 | } | |
172 | ||
7ff9345f JA |
173 | struct bio_vec *bvec_alloc_bs(gfp_t gfp_mask, int nr, unsigned long *idx, |
174 | struct bio_set *bs) | |
1da177e4 LT |
175 | { |
176 | struct bio_vec *bvl; | |
1da177e4 | 177 | |
7ff9345f JA |
178 | /* |
179 | * see comment near bvec_array define! | |
180 | */ | |
181 | switch (nr) { | |
182 | case 1: | |
183 | *idx = 0; | |
184 | break; | |
185 | case 2 ... 4: | |
186 | *idx = 1; | |
187 | break; | |
188 | case 5 ... 16: | |
189 | *idx = 2; | |
190 | break; | |
191 | case 17 ... 64: | |
192 | *idx = 3; | |
193 | break; | |
194 | case 65 ... 128: | |
195 | *idx = 4; | |
196 | break; | |
197 | case 129 ... BIO_MAX_PAGES: | |
198 | *idx = 5; | |
199 | break; | |
200 | default: | |
201 | return NULL; | |
202 | } | |
203 | ||
204 | /* | |
205 | * idx now points to the pool we want to allocate from. only the | |
206 | * 1-vec entry pool is mempool backed. | |
207 | */ | |
208 | if (*idx == BIOVEC_MAX_IDX) { | |
209 | fallback: | |
210 | bvl = mempool_alloc(bs->bvec_pool, gfp_mask); | |
211 | } else { | |
212 | struct biovec_slab *bvs = bvec_slabs + *idx; | |
213 | gfp_t __gfp_mask = gfp_mask & ~(__GFP_WAIT | __GFP_IO); | |
214 | ||
0a0d96b0 | 215 | /* |
7ff9345f JA |
216 | * Make this allocation restricted and don't dump info on |
217 | * allocation failures, since we'll fallback to the mempool | |
218 | * in case of failure. | |
0a0d96b0 | 219 | */ |
7ff9345f | 220 | __gfp_mask |= __GFP_NOMEMALLOC | __GFP_NORETRY | __GFP_NOWARN; |
1da177e4 | 221 | |
0a0d96b0 | 222 | /* |
7ff9345f JA |
223 | * Try a slab allocation. If this fails and __GFP_WAIT |
224 | * is set, retry with the 1-entry mempool | |
0a0d96b0 | 225 | */ |
7ff9345f JA |
226 | bvl = kmem_cache_alloc(bvs->slab, __gfp_mask); |
227 | if (unlikely(!bvl && (gfp_mask & __GFP_WAIT))) { | |
228 | *idx = BIOVEC_MAX_IDX; | |
229 | goto fallback; | |
230 | } | |
231 | } | |
232 | ||
1da177e4 LT |
233 | return bvl; |
234 | } | |
235 | ||
7ff9345f | 236 | void bio_free(struct bio *bio, struct bio_set *bs) |
1da177e4 | 237 | { |
bb799ca0 | 238 | void *p; |
1da177e4 | 239 | |
392ddc32 | 240 | if (bio_has_allocated_vec(bio)) |
bb799ca0 | 241 | bvec_free_bs(bs, bio->bi_io_vec, BIO_POOL_IDX(bio)); |
1da177e4 | 242 | |
7ba1ba12 | 243 | if (bio_integrity(bio)) |
7878cba9 | 244 | bio_integrity_free(bio, bs); |
7ba1ba12 | 245 | |
bb799ca0 JA |
246 | /* |
247 | * If we have front padding, adjust the bio pointer before freeing | |
248 | */ | |
249 | p = bio; | |
250 | if (bs->front_pad) | |
251 | p -= bs->front_pad; | |
252 | ||
253 | mempool_free(p, bs->bio_pool); | |
3676347a | 254 | } |
a112a71d | 255 | EXPORT_SYMBOL(bio_free); |
3676347a | 256 | |
858119e1 | 257 | void bio_init(struct bio *bio) |
1da177e4 | 258 | { |
2b94de55 | 259 | memset(bio, 0, sizeof(*bio)); |
1da177e4 | 260 | bio->bi_flags = 1 << BIO_UPTODATE; |
1da177e4 | 261 | atomic_set(&bio->bi_cnt, 1); |
1da177e4 | 262 | } |
a112a71d | 263 | EXPORT_SYMBOL(bio_init); |
1da177e4 LT |
264 | |
265 | /** | |
266 | * bio_alloc_bioset - allocate a bio for I/O | |
267 | * @gfp_mask: the GFP_ mask given to the slab allocator | |
268 | * @nr_iovecs: number of iovecs to pre-allocate | |
db18efac | 269 | * @bs: the bio_set to allocate from. |
1da177e4 LT |
270 | * |
271 | * Description: | |
db18efac | 272 | * bio_alloc_bioset will try its own mempool to satisfy the allocation. |
1da177e4 | 273 | * If %__GFP_WAIT is set then we will block on the internal pool waiting |
db18efac | 274 | * for a &struct bio to become free. |
1da177e4 | 275 | * |
af901ca1 | 276 | * Note that the caller must set ->bi_destructor on successful return |
bb799ca0 JA |
277 | * of a bio, to do the appropriate freeing of the bio once the reference |
278 | * count drops to zero. | |
1da177e4 | 279 | **/ |
dd0fc66f | 280 | struct bio *bio_alloc_bioset(gfp_t gfp_mask, int nr_iovecs, struct bio_set *bs) |
1da177e4 | 281 | { |
451a9ebf | 282 | unsigned long idx = BIO_POOL_NONE; |
34053979 | 283 | struct bio_vec *bvl = NULL; |
451a9ebf TH |
284 | struct bio *bio; |
285 | void *p; | |
286 | ||
287 | p = mempool_alloc(bs->bio_pool, gfp_mask); | |
288 | if (unlikely(!p)) | |
289 | return NULL; | |
290 | bio = p + bs->front_pad; | |
1da177e4 | 291 | |
34053979 IM |
292 | bio_init(bio); |
293 | ||
294 | if (unlikely(!nr_iovecs)) | |
295 | goto out_set; | |
296 | ||
297 | if (nr_iovecs <= BIO_INLINE_VECS) { | |
298 | bvl = bio->bi_inline_vecs; | |
299 | nr_iovecs = BIO_INLINE_VECS; | |
300 | } else { | |
301 | bvl = bvec_alloc_bs(gfp_mask, nr_iovecs, &idx, bs); | |
302 | if (unlikely(!bvl)) | |
303 | goto err_free; | |
304 | ||
305 | nr_iovecs = bvec_nr_vecs(idx); | |
1da177e4 | 306 | } |
451a9ebf | 307 | out_set: |
34053979 IM |
308 | bio->bi_flags |= idx << BIO_POOL_OFFSET; |
309 | bio->bi_max_vecs = nr_iovecs; | |
34053979 | 310 | bio->bi_io_vec = bvl; |
1da177e4 | 311 | return bio; |
34053979 IM |
312 | |
313 | err_free: | |
451a9ebf | 314 | mempool_free(p, bs->bio_pool); |
34053979 | 315 | return NULL; |
1da177e4 | 316 | } |
a112a71d | 317 | EXPORT_SYMBOL(bio_alloc_bioset); |
1da177e4 | 318 | |
451a9ebf TH |
319 | static void bio_fs_destructor(struct bio *bio) |
320 | { | |
321 | bio_free(bio, fs_bio_set); | |
322 | } | |
323 | ||
324 | /** | |
325 | * bio_alloc - allocate a new bio, memory pool backed | |
326 | * @gfp_mask: allocation mask to use | |
327 | * @nr_iovecs: number of iovecs | |
328 | * | |
5f04eeb8 AB |
329 | * bio_alloc will allocate a bio and associated bio_vec array that can hold |
330 | * at least @nr_iovecs entries. Allocations will be done from the | |
331 | * fs_bio_set. Also see @bio_alloc_bioset and @bio_kmalloc. | |
332 | * | |
333 | * If %__GFP_WAIT is set, then bio_alloc will always be able to allocate | |
334 | * a bio. This is due to the mempool guarantees. To make this work, callers | |
335 | * must never allocate more than 1 bio at a time from this pool. Callers | |
336 | * that need to allocate more than 1 bio must always submit the previously | |
337 | * allocated bio for IO before attempting to allocate a new one. Failure to | |
338 | * do so can cause livelocks under memory pressure. | |
451a9ebf TH |
339 | * |
340 | * RETURNS: | |
341 | * Pointer to new bio on success, NULL on failure. | |
342 | */ | |
121f0994 | 343 | struct bio *bio_alloc(gfp_t gfp_mask, unsigned int nr_iovecs) |
451a9ebf TH |
344 | { |
345 | struct bio *bio = bio_alloc_bioset(gfp_mask, nr_iovecs, fs_bio_set); | |
346 | ||
347 | if (bio) | |
348 | bio->bi_destructor = bio_fs_destructor; | |
349 | ||
350 | return bio; | |
351 | } | |
a112a71d | 352 | EXPORT_SYMBOL(bio_alloc); |
451a9ebf TH |
353 | |
354 | static void bio_kmalloc_destructor(struct bio *bio) | |
355 | { | |
356 | if (bio_integrity(bio)) | |
7878cba9 | 357 | bio_integrity_free(bio, fs_bio_set); |
451a9ebf TH |
358 | kfree(bio); |
359 | } | |
360 | ||
86c824b9 | 361 | /** |
5f04eeb8 | 362 | * bio_kmalloc - allocate a bio for I/O using kmalloc() |
86c824b9 JA |
363 | * @gfp_mask: the GFP_ mask given to the slab allocator |
364 | * @nr_iovecs: number of iovecs to pre-allocate | |
365 | * | |
366 | * Description: | |
5f04eeb8 AB |
367 | * Allocate a new bio with @nr_iovecs bvecs. If @gfp_mask contains |
368 | * %__GFP_WAIT, the allocation is guaranteed to succeed. | |
86c824b9 JA |
369 | * |
370 | **/ | |
121f0994 | 371 | struct bio *bio_kmalloc(gfp_t gfp_mask, unsigned int nr_iovecs) |
0a0d96b0 | 372 | { |
451a9ebf | 373 | struct bio *bio; |
0a0d96b0 | 374 | |
f3f63c1c JA |
375 | if (nr_iovecs > UIO_MAXIOV) |
376 | return NULL; | |
377 | ||
451a9ebf TH |
378 | bio = kmalloc(sizeof(struct bio) + nr_iovecs * sizeof(struct bio_vec), |
379 | gfp_mask); | |
380 | if (unlikely(!bio)) | |
381 | return NULL; | |
382 | ||
383 | bio_init(bio); | |
384 | bio->bi_flags |= BIO_POOL_NONE << BIO_POOL_OFFSET; | |
385 | bio->bi_max_vecs = nr_iovecs; | |
386 | bio->bi_io_vec = bio->bi_inline_vecs; | |
387 | bio->bi_destructor = bio_kmalloc_destructor; | |
0a0d96b0 JA |
388 | |
389 | return bio; | |
390 | } | |
a112a71d | 391 | EXPORT_SYMBOL(bio_kmalloc); |
0a0d96b0 | 392 | |
1da177e4 LT |
393 | void zero_fill_bio(struct bio *bio) |
394 | { | |
395 | unsigned long flags; | |
396 | struct bio_vec *bv; | |
397 | int i; | |
398 | ||
399 | bio_for_each_segment(bv, bio, i) { | |
400 | char *data = bvec_kmap_irq(bv, &flags); | |
401 | memset(data, 0, bv->bv_len); | |
402 | flush_dcache_page(bv->bv_page); | |
403 | bvec_kunmap_irq(data, &flags); | |
404 | } | |
405 | } | |
406 | EXPORT_SYMBOL(zero_fill_bio); | |
407 | ||
408 | /** | |
409 | * bio_put - release a reference to a bio | |
410 | * @bio: bio to release reference to | |
411 | * | |
412 | * Description: | |
413 | * Put a reference to a &struct bio, either one you have gotten with | |
ad0bf110 | 414 | * bio_alloc, bio_get or bio_clone. The last put of a bio will free it. |
1da177e4 LT |
415 | **/ |
416 | void bio_put(struct bio *bio) | |
417 | { | |
418 | BIO_BUG_ON(!atomic_read(&bio->bi_cnt)); | |
419 | ||
420 | /* | |
421 | * last put frees it | |
422 | */ | |
423 | if (atomic_dec_and_test(&bio->bi_cnt)) { | |
852c788f | 424 | bio_disassociate_task(bio); |
1da177e4 LT |
425 | bio->bi_next = NULL; |
426 | bio->bi_destructor(bio); | |
427 | } | |
428 | } | |
a112a71d | 429 | EXPORT_SYMBOL(bio_put); |
1da177e4 | 430 | |
165125e1 | 431 | inline int bio_phys_segments(struct request_queue *q, struct bio *bio) |
1da177e4 LT |
432 | { |
433 | if (unlikely(!bio_flagged(bio, BIO_SEG_VALID))) | |
434 | blk_recount_segments(q, bio); | |
435 | ||
436 | return bio->bi_phys_segments; | |
437 | } | |
a112a71d | 438 | EXPORT_SYMBOL(bio_phys_segments); |
1da177e4 | 439 | |
1da177e4 LT |
440 | /** |
441 | * __bio_clone - clone a bio | |
442 | * @bio: destination bio | |
443 | * @bio_src: bio to clone | |
444 | * | |
445 | * Clone a &bio. Caller will own the returned bio, but not | |
446 | * the actual data it points to. Reference count of returned | |
447 | * bio will be one. | |
448 | */ | |
858119e1 | 449 | void __bio_clone(struct bio *bio, struct bio *bio_src) |
1da177e4 | 450 | { |
e525e153 AM |
451 | memcpy(bio->bi_io_vec, bio_src->bi_io_vec, |
452 | bio_src->bi_max_vecs * sizeof(struct bio_vec)); | |
1da177e4 | 453 | |
5d84070e JA |
454 | /* |
455 | * most users will be overriding ->bi_bdev with a new target, | |
456 | * so we don't set nor calculate new physical/hw segment counts here | |
457 | */ | |
1da177e4 LT |
458 | bio->bi_sector = bio_src->bi_sector; |
459 | bio->bi_bdev = bio_src->bi_bdev; | |
460 | bio->bi_flags |= 1 << BIO_CLONED; | |
461 | bio->bi_rw = bio_src->bi_rw; | |
1da177e4 LT |
462 | bio->bi_vcnt = bio_src->bi_vcnt; |
463 | bio->bi_size = bio_src->bi_size; | |
a5453be4 | 464 | bio->bi_idx = bio_src->bi_idx; |
1da177e4 | 465 | } |
a112a71d | 466 | EXPORT_SYMBOL(__bio_clone); |
1da177e4 LT |
467 | |
468 | /** | |
469 | * bio_clone - clone a bio | |
470 | * @bio: bio to clone | |
471 | * @gfp_mask: allocation priority | |
472 | * | |
473 | * Like __bio_clone, only also allocates the returned bio | |
474 | */ | |
dd0fc66f | 475 | struct bio *bio_clone(struct bio *bio, gfp_t gfp_mask) |
1da177e4 LT |
476 | { |
477 | struct bio *b = bio_alloc_bioset(gfp_mask, bio->bi_max_vecs, fs_bio_set); | |
478 | ||
7ba1ba12 MP |
479 | if (!b) |
480 | return NULL; | |
481 | ||
482 | b->bi_destructor = bio_fs_destructor; | |
483 | __bio_clone(b, bio); | |
484 | ||
485 | if (bio_integrity(bio)) { | |
486 | int ret; | |
487 | ||
7878cba9 | 488 | ret = bio_integrity_clone(b, bio, gfp_mask, fs_bio_set); |
7ba1ba12 | 489 | |
059ea331 LZ |
490 | if (ret < 0) { |
491 | bio_put(b); | |
7ba1ba12 | 492 | return NULL; |
059ea331 | 493 | } |
3676347a | 494 | } |
1da177e4 LT |
495 | |
496 | return b; | |
497 | } | |
a112a71d | 498 | EXPORT_SYMBOL(bio_clone); |
1da177e4 LT |
499 | |
500 | /** | |
501 | * bio_get_nr_vecs - return approx number of vecs | |
502 | * @bdev: I/O target | |
503 | * | |
504 | * Return the approximate number of pages we can send to this target. | |
505 | * There's no guarantee that you will be able to fit this number of pages | |
506 | * into a bio, it does not account for dynamic restrictions that vary | |
507 | * on offset. | |
508 | */ | |
509 | int bio_get_nr_vecs(struct block_device *bdev) | |
510 | { | |
165125e1 | 511 | struct request_queue *q = bdev_get_queue(bdev); |
f908ee94 BS |
512 | int nr_pages; |
513 | ||
514 | nr_pages = min_t(unsigned, | |
5abebfdd KO |
515 | queue_max_segments(q), |
516 | queue_max_sectors(q) / (PAGE_SIZE >> 9) + 1); | |
f908ee94 BS |
517 | |
518 | return min_t(unsigned, nr_pages, BIO_MAX_PAGES); | |
519 | ||
1da177e4 | 520 | } |
a112a71d | 521 | EXPORT_SYMBOL(bio_get_nr_vecs); |
1da177e4 | 522 | |
165125e1 | 523 | static int __bio_add_page(struct request_queue *q, struct bio *bio, struct page |
defd94b7 MC |
524 | *page, unsigned int len, unsigned int offset, |
525 | unsigned short max_sectors) | |
1da177e4 LT |
526 | { |
527 | int retried_segments = 0; | |
528 | struct bio_vec *bvec; | |
529 | ||
530 | /* | |
531 | * cloned bio must not modify vec list | |
532 | */ | |
533 | if (unlikely(bio_flagged(bio, BIO_CLONED))) | |
534 | return 0; | |
535 | ||
80cfd548 | 536 | if (((bio->bi_size + len) >> 9) > max_sectors) |
1da177e4 LT |
537 | return 0; |
538 | ||
80cfd548 JA |
539 | /* |
540 | * For filesystems with a blocksize smaller than the pagesize | |
541 | * we will often be called with the same page as last time and | |
542 | * a consecutive offset. Optimize this special case. | |
543 | */ | |
544 | if (bio->bi_vcnt > 0) { | |
545 | struct bio_vec *prev = &bio->bi_io_vec[bio->bi_vcnt - 1]; | |
546 | ||
547 | if (page == prev->bv_page && | |
548 | offset == prev->bv_offset + prev->bv_len) { | |
1d616585 | 549 | unsigned int prev_bv_len = prev->bv_len; |
80cfd548 | 550 | prev->bv_len += len; |
cc371e66 AK |
551 | |
552 | if (q->merge_bvec_fn) { | |
553 | struct bvec_merge_data bvm = { | |
1d616585 DM |
554 | /* prev_bvec is already charged in |
555 | bi_size, discharge it in order to | |
556 | simulate merging updated prev_bvec | |
557 | as new bvec. */ | |
cc371e66 AK |
558 | .bi_bdev = bio->bi_bdev, |
559 | .bi_sector = bio->bi_sector, | |
1d616585 | 560 | .bi_size = bio->bi_size - prev_bv_len, |
cc371e66 AK |
561 | .bi_rw = bio->bi_rw, |
562 | }; | |
563 | ||
8bf8c376 | 564 | if (q->merge_bvec_fn(q, &bvm, prev) < prev->bv_len) { |
cc371e66 AK |
565 | prev->bv_len -= len; |
566 | return 0; | |
567 | } | |
80cfd548 JA |
568 | } |
569 | ||
570 | goto done; | |
571 | } | |
572 | } | |
573 | ||
574 | if (bio->bi_vcnt >= bio->bi_max_vecs) | |
1da177e4 LT |
575 | return 0; |
576 | ||
577 | /* | |
578 | * we might lose a segment or two here, but rather that than | |
579 | * make this too complex. | |
580 | */ | |
581 | ||
8a78362c | 582 | while (bio->bi_phys_segments >= queue_max_segments(q)) { |
1da177e4 LT |
583 | |
584 | if (retried_segments) | |
585 | return 0; | |
586 | ||
587 | retried_segments = 1; | |
588 | blk_recount_segments(q, bio); | |
589 | } | |
590 | ||
591 | /* | |
592 | * setup the new entry, we might clear it again later if we | |
593 | * cannot add the page | |
594 | */ | |
595 | bvec = &bio->bi_io_vec[bio->bi_vcnt]; | |
596 | bvec->bv_page = page; | |
597 | bvec->bv_len = len; | |
598 | bvec->bv_offset = offset; | |
599 | ||
600 | /* | |
601 | * if queue has other restrictions (eg varying max sector size | |
602 | * depending on offset), it can specify a merge_bvec_fn in the | |
603 | * queue to get further control | |
604 | */ | |
605 | if (q->merge_bvec_fn) { | |
cc371e66 AK |
606 | struct bvec_merge_data bvm = { |
607 | .bi_bdev = bio->bi_bdev, | |
608 | .bi_sector = bio->bi_sector, | |
609 | .bi_size = bio->bi_size, | |
610 | .bi_rw = bio->bi_rw, | |
611 | }; | |
612 | ||
1da177e4 LT |
613 | /* |
614 | * merge_bvec_fn() returns number of bytes it can accept | |
615 | * at this offset | |
616 | */ | |
8bf8c376 | 617 | if (q->merge_bvec_fn(q, &bvm, bvec) < bvec->bv_len) { |
1da177e4 LT |
618 | bvec->bv_page = NULL; |
619 | bvec->bv_len = 0; | |
620 | bvec->bv_offset = 0; | |
621 | return 0; | |
622 | } | |
623 | } | |
624 | ||
625 | /* If we may be able to merge these biovecs, force a recount */ | |
b8b3e16c | 626 | if (bio->bi_vcnt && (BIOVEC_PHYS_MERGEABLE(bvec-1, bvec))) |
1da177e4 LT |
627 | bio->bi_flags &= ~(1 << BIO_SEG_VALID); |
628 | ||
629 | bio->bi_vcnt++; | |
630 | bio->bi_phys_segments++; | |
80cfd548 | 631 | done: |
1da177e4 LT |
632 | bio->bi_size += len; |
633 | return len; | |
634 | } | |
635 | ||
6e68af66 MC |
636 | /** |
637 | * bio_add_pc_page - attempt to add page to bio | |
fddfdeaf | 638 | * @q: the target queue |
6e68af66 MC |
639 | * @bio: destination bio |
640 | * @page: page to add | |
641 | * @len: vec entry length | |
642 | * @offset: vec entry offset | |
643 | * | |
644 | * Attempt to add a page to the bio_vec maplist. This can fail for a | |
c6428084 AG |
645 | * number of reasons, such as the bio being full or target block device |
646 | * limitations. The target block device must allow bio's up to PAGE_SIZE, | |
647 | * so it is always possible to add a single page to an empty bio. | |
648 | * | |
649 | * This should only be used by REQ_PC bios. | |
6e68af66 | 650 | */ |
165125e1 | 651 | int bio_add_pc_page(struct request_queue *q, struct bio *bio, struct page *page, |
6e68af66 MC |
652 | unsigned int len, unsigned int offset) |
653 | { | |
ae03bf63 MP |
654 | return __bio_add_page(q, bio, page, len, offset, |
655 | queue_max_hw_sectors(q)); | |
6e68af66 | 656 | } |
a112a71d | 657 | EXPORT_SYMBOL(bio_add_pc_page); |
6e68af66 | 658 | |
1da177e4 LT |
659 | /** |
660 | * bio_add_page - attempt to add page to bio | |
661 | * @bio: destination bio | |
662 | * @page: page to add | |
663 | * @len: vec entry length | |
664 | * @offset: vec entry offset | |
665 | * | |
666 | * Attempt to add a page to the bio_vec maplist. This can fail for a | |
c6428084 AG |
667 | * number of reasons, such as the bio being full or target block device |
668 | * limitations. The target block device must allow bio's up to PAGE_SIZE, | |
669 | * so it is always possible to add a single page to an empty bio. | |
1da177e4 LT |
670 | */ |
671 | int bio_add_page(struct bio *bio, struct page *page, unsigned int len, | |
672 | unsigned int offset) | |
673 | { | |
defd94b7 | 674 | struct request_queue *q = bdev_get_queue(bio->bi_bdev); |
ae03bf63 | 675 | return __bio_add_page(q, bio, page, len, offset, queue_max_sectors(q)); |
1da177e4 | 676 | } |
a112a71d | 677 | EXPORT_SYMBOL(bio_add_page); |
1da177e4 LT |
678 | |
679 | struct bio_map_data { | |
680 | struct bio_vec *iovecs; | |
c5dec1c3 | 681 | struct sg_iovec *sgvecs; |
152e283f FT |
682 | int nr_sgvecs; |
683 | int is_our_pages; | |
1da177e4 LT |
684 | }; |
685 | ||
c5dec1c3 | 686 | static void bio_set_map_data(struct bio_map_data *bmd, struct bio *bio, |
152e283f FT |
687 | struct sg_iovec *iov, int iov_count, |
688 | int is_our_pages) | |
1da177e4 LT |
689 | { |
690 | memcpy(bmd->iovecs, bio->bi_io_vec, sizeof(struct bio_vec) * bio->bi_vcnt); | |
c5dec1c3 FT |
691 | memcpy(bmd->sgvecs, iov, sizeof(struct sg_iovec) * iov_count); |
692 | bmd->nr_sgvecs = iov_count; | |
152e283f | 693 | bmd->is_our_pages = is_our_pages; |
1da177e4 LT |
694 | bio->bi_private = bmd; |
695 | } | |
696 | ||
697 | static void bio_free_map_data(struct bio_map_data *bmd) | |
698 | { | |
699 | kfree(bmd->iovecs); | |
c5dec1c3 | 700 | kfree(bmd->sgvecs); |
1da177e4 LT |
701 | kfree(bmd); |
702 | } | |
703 | ||
121f0994 DC |
704 | static struct bio_map_data *bio_alloc_map_data(int nr_segs, |
705 | unsigned int iov_count, | |
76029ff3 | 706 | gfp_t gfp_mask) |
1da177e4 | 707 | { |
f3f63c1c JA |
708 | struct bio_map_data *bmd; |
709 | ||
710 | if (iov_count > UIO_MAXIOV) | |
711 | return NULL; | |
1da177e4 | 712 | |
f3f63c1c | 713 | bmd = kmalloc(sizeof(*bmd), gfp_mask); |
1da177e4 LT |
714 | if (!bmd) |
715 | return NULL; | |
716 | ||
76029ff3 | 717 | bmd->iovecs = kmalloc(sizeof(struct bio_vec) * nr_segs, gfp_mask); |
c5dec1c3 FT |
718 | if (!bmd->iovecs) { |
719 | kfree(bmd); | |
720 | return NULL; | |
721 | } | |
722 | ||
76029ff3 | 723 | bmd->sgvecs = kmalloc(sizeof(struct sg_iovec) * iov_count, gfp_mask); |
c5dec1c3 | 724 | if (bmd->sgvecs) |
1da177e4 LT |
725 | return bmd; |
726 | ||
c5dec1c3 | 727 | kfree(bmd->iovecs); |
1da177e4 LT |
728 | kfree(bmd); |
729 | return NULL; | |
730 | } | |
731 | ||
aefcc28a | 732 | static int __bio_copy_iov(struct bio *bio, struct bio_vec *iovecs, |
ecb554a8 FT |
733 | struct sg_iovec *iov, int iov_count, |
734 | int to_user, int from_user, int do_free_page) | |
c5dec1c3 FT |
735 | { |
736 | int ret = 0, i; | |
737 | struct bio_vec *bvec; | |
738 | int iov_idx = 0; | |
739 | unsigned int iov_off = 0; | |
c5dec1c3 FT |
740 | |
741 | __bio_for_each_segment(bvec, bio, i, 0) { | |
742 | char *bv_addr = page_address(bvec->bv_page); | |
aefcc28a | 743 | unsigned int bv_len = iovecs[i].bv_len; |
c5dec1c3 FT |
744 | |
745 | while (bv_len && iov_idx < iov_count) { | |
746 | unsigned int bytes; | |
0e0c6212 | 747 | char __user *iov_addr; |
c5dec1c3 FT |
748 | |
749 | bytes = min_t(unsigned int, | |
750 | iov[iov_idx].iov_len - iov_off, bv_len); | |
751 | iov_addr = iov[iov_idx].iov_base + iov_off; | |
752 | ||
753 | if (!ret) { | |
ecb554a8 | 754 | if (to_user) |
c5dec1c3 FT |
755 | ret = copy_to_user(iov_addr, bv_addr, |
756 | bytes); | |
757 | ||
ecb554a8 FT |
758 | if (from_user) |
759 | ret = copy_from_user(bv_addr, iov_addr, | |
760 | bytes); | |
761 | ||
c5dec1c3 FT |
762 | if (ret) |
763 | ret = -EFAULT; | |
764 | } | |
765 | ||
766 | bv_len -= bytes; | |
767 | bv_addr += bytes; | |
768 | iov_addr += bytes; | |
769 | iov_off += bytes; | |
770 | ||
771 | if (iov[iov_idx].iov_len == iov_off) { | |
772 | iov_idx++; | |
773 | iov_off = 0; | |
774 | } | |
775 | } | |
776 | ||
152e283f | 777 | if (do_free_page) |
c5dec1c3 FT |
778 | __free_page(bvec->bv_page); |
779 | } | |
780 | ||
781 | return ret; | |
782 | } | |
783 | ||
1da177e4 LT |
784 | /** |
785 | * bio_uncopy_user - finish previously mapped bio | |
786 | * @bio: bio being terminated | |
787 | * | |
788 | * Free pages allocated from bio_copy_user() and write back data | |
789 | * to user space in case of a read. | |
790 | */ | |
791 | int bio_uncopy_user(struct bio *bio) | |
792 | { | |
793 | struct bio_map_data *bmd = bio->bi_private; | |
81882766 | 794 | int ret = 0; |
1da177e4 | 795 | |
81882766 FT |
796 | if (!bio_flagged(bio, BIO_NULL_MAPPED)) |
797 | ret = __bio_copy_iov(bio, bmd->iovecs, bmd->sgvecs, | |
ecb554a8 FT |
798 | bmd->nr_sgvecs, bio_data_dir(bio) == READ, |
799 | 0, bmd->is_our_pages); | |
1da177e4 LT |
800 | bio_free_map_data(bmd); |
801 | bio_put(bio); | |
802 | return ret; | |
803 | } | |
a112a71d | 804 | EXPORT_SYMBOL(bio_uncopy_user); |
1da177e4 LT |
805 | |
806 | /** | |
c5dec1c3 | 807 | * bio_copy_user_iov - copy user data to bio |
1da177e4 | 808 | * @q: destination block queue |
152e283f | 809 | * @map_data: pointer to the rq_map_data holding pages (if necessary) |
c5dec1c3 FT |
810 | * @iov: the iovec. |
811 | * @iov_count: number of elements in the iovec | |
1da177e4 | 812 | * @write_to_vm: bool indicating writing to pages or not |
a3bce90e | 813 | * @gfp_mask: memory allocation flags |
1da177e4 LT |
814 | * |
815 | * Prepares and returns a bio for indirect user io, bouncing data | |
816 | * to/from kernel pages as necessary. Must be paired with | |
817 | * call bio_uncopy_user() on io completion. | |
818 | */ | |
152e283f FT |
819 | struct bio *bio_copy_user_iov(struct request_queue *q, |
820 | struct rq_map_data *map_data, | |
821 | struct sg_iovec *iov, int iov_count, | |
822 | int write_to_vm, gfp_t gfp_mask) | |
1da177e4 | 823 | { |
1da177e4 LT |
824 | struct bio_map_data *bmd; |
825 | struct bio_vec *bvec; | |
826 | struct page *page; | |
827 | struct bio *bio; | |
828 | int i, ret; | |
c5dec1c3 FT |
829 | int nr_pages = 0; |
830 | unsigned int len = 0; | |
56c451f4 | 831 | unsigned int offset = map_data ? map_data->offset & ~PAGE_MASK : 0; |
1da177e4 | 832 | |
c5dec1c3 FT |
833 | for (i = 0; i < iov_count; i++) { |
834 | unsigned long uaddr; | |
835 | unsigned long end; | |
836 | unsigned long start; | |
837 | ||
838 | uaddr = (unsigned long)iov[i].iov_base; | |
839 | end = (uaddr + iov[i].iov_len + PAGE_SIZE - 1) >> PAGE_SHIFT; | |
840 | start = uaddr >> PAGE_SHIFT; | |
841 | ||
cb4644ca JA |
842 | /* |
843 | * Overflow, abort | |
844 | */ | |
845 | if (end < start) | |
846 | return ERR_PTR(-EINVAL); | |
847 | ||
c5dec1c3 FT |
848 | nr_pages += end - start; |
849 | len += iov[i].iov_len; | |
850 | } | |
851 | ||
69838727 FT |
852 | if (offset) |
853 | nr_pages++; | |
854 | ||
a3bce90e | 855 | bmd = bio_alloc_map_data(nr_pages, iov_count, gfp_mask); |
1da177e4 LT |
856 | if (!bmd) |
857 | return ERR_PTR(-ENOMEM); | |
858 | ||
1da177e4 | 859 | ret = -ENOMEM; |
a9e9dc24 | 860 | bio = bio_kmalloc(gfp_mask, nr_pages); |
1da177e4 LT |
861 | if (!bio) |
862 | goto out_bmd; | |
863 | ||
7b6d91da CH |
864 | if (!write_to_vm) |
865 | bio->bi_rw |= REQ_WRITE; | |
1da177e4 LT |
866 | |
867 | ret = 0; | |
56c451f4 FT |
868 | |
869 | if (map_data) { | |
e623ddb4 | 870 | nr_pages = 1 << map_data->page_order; |
56c451f4 FT |
871 | i = map_data->offset / PAGE_SIZE; |
872 | } | |
1da177e4 | 873 | while (len) { |
e623ddb4 | 874 | unsigned int bytes = PAGE_SIZE; |
1da177e4 | 875 | |
56c451f4 FT |
876 | bytes -= offset; |
877 | ||
1da177e4 LT |
878 | if (bytes > len) |
879 | bytes = len; | |
880 | ||
152e283f | 881 | if (map_data) { |
e623ddb4 | 882 | if (i == map_data->nr_entries * nr_pages) { |
152e283f FT |
883 | ret = -ENOMEM; |
884 | break; | |
885 | } | |
e623ddb4 FT |
886 | |
887 | page = map_data->pages[i / nr_pages]; | |
888 | page += (i % nr_pages); | |
889 | ||
890 | i++; | |
891 | } else { | |
152e283f | 892 | page = alloc_page(q->bounce_gfp | gfp_mask); |
e623ddb4 FT |
893 | if (!page) { |
894 | ret = -ENOMEM; | |
895 | break; | |
896 | } | |
1da177e4 LT |
897 | } |
898 | ||
56c451f4 | 899 | if (bio_add_pc_page(q, bio, page, bytes, offset) < bytes) |
1da177e4 | 900 | break; |
1da177e4 LT |
901 | |
902 | len -= bytes; | |
56c451f4 | 903 | offset = 0; |
1da177e4 LT |
904 | } |
905 | ||
906 | if (ret) | |
907 | goto cleanup; | |
908 | ||
909 | /* | |
910 | * success | |
911 | */ | |
ecb554a8 FT |
912 | if ((!write_to_vm && (!map_data || !map_data->null_mapped)) || |
913 | (map_data && map_data->from_user)) { | |
914 | ret = __bio_copy_iov(bio, bio->bi_io_vec, iov, iov_count, 0, 1, 0); | |
c5dec1c3 FT |
915 | if (ret) |
916 | goto cleanup; | |
1da177e4 LT |
917 | } |
918 | ||
152e283f | 919 | bio_set_map_data(bmd, bio, iov, iov_count, map_data ? 0 : 1); |
1da177e4 LT |
920 | return bio; |
921 | cleanup: | |
152e283f FT |
922 | if (!map_data) |
923 | bio_for_each_segment(bvec, bio, i) | |
924 | __free_page(bvec->bv_page); | |
1da177e4 LT |
925 | |
926 | bio_put(bio); | |
927 | out_bmd: | |
928 | bio_free_map_data(bmd); | |
929 | return ERR_PTR(ret); | |
930 | } | |
931 | ||
c5dec1c3 FT |
932 | /** |
933 | * bio_copy_user - copy user data to bio | |
934 | * @q: destination block queue | |
152e283f | 935 | * @map_data: pointer to the rq_map_data holding pages (if necessary) |
c5dec1c3 FT |
936 | * @uaddr: start of user address |
937 | * @len: length in bytes | |
938 | * @write_to_vm: bool indicating writing to pages or not | |
a3bce90e | 939 | * @gfp_mask: memory allocation flags |
c5dec1c3 FT |
940 | * |
941 | * Prepares and returns a bio for indirect user io, bouncing data | |
942 | * to/from kernel pages as necessary. Must be paired with | |
943 | * call bio_uncopy_user() on io completion. | |
944 | */ | |
152e283f FT |
945 | struct bio *bio_copy_user(struct request_queue *q, struct rq_map_data *map_data, |
946 | unsigned long uaddr, unsigned int len, | |
947 | int write_to_vm, gfp_t gfp_mask) | |
c5dec1c3 FT |
948 | { |
949 | struct sg_iovec iov; | |
950 | ||
951 | iov.iov_base = (void __user *)uaddr; | |
952 | iov.iov_len = len; | |
953 | ||
152e283f | 954 | return bio_copy_user_iov(q, map_data, &iov, 1, write_to_vm, gfp_mask); |
c5dec1c3 | 955 | } |
a112a71d | 956 | EXPORT_SYMBOL(bio_copy_user); |
c5dec1c3 | 957 | |
165125e1 | 958 | static struct bio *__bio_map_user_iov(struct request_queue *q, |
f1970baf JB |
959 | struct block_device *bdev, |
960 | struct sg_iovec *iov, int iov_count, | |
a3bce90e | 961 | int write_to_vm, gfp_t gfp_mask) |
1da177e4 | 962 | { |
f1970baf JB |
963 | int i, j; |
964 | int nr_pages = 0; | |
1da177e4 LT |
965 | struct page **pages; |
966 | struct bio *bio; | |
f1970baf JB |
967 | int cur_page = 0; |
968 | int ret, offset; | |
1da177e4 | 969 | |
f1970baf JB |
970 | for (i = 0; i < iov_count; i++) { |
971 | unsigned long uaddr = (unsigned long)iov[i].iov_base; | |
972 | unsigned long len = iov[i].iov_len; | |
973 | unsigned long end = (uaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT; | |
974 | unsigned long start = uaddr >> PAGE_SHIFT; | |
975 | ||
cb4644ca JA |
976 | /* |
977 | * Overflow, abort | |
978 | */ | |
979 | if (end < start) | |
980 | return ERR_PTR(-EINVAL); | |
981 | ||
f1970baf JB |
982 | nr_pages += end - start; |
983 | /* | |
ad2d7225 | 984 | * buffer must be aligned to at least hardsector size for now |
f1970baf | 985 | */ |
ad2d7225 | 986 | if (uaddr & queue_dma_alignment(q)) |
f1970baf JB |
987 | return ERR_PTR(-EINVAL); |
988 | } | |
989 | ||
990 | if (!nr_pages) | |
1da177e4 LT |
991 | return ERR_PTR(-EINVAL); |
992 | ||
a9e9dc24 | 993 | bio = bio_kmalloc(gfp_mask, nr_pages); |
1da177e4 LT |
994 | if (!bio) |
995 | return ERR_PTR(-ENOMEM); | |
996 | ||
997 | ret = -ENOMEM; | |
a3bce90e | 998 | pages = kcalloc(nr_pages, sizeof(struct page *), gfp_mask); |
1da177e4 LT |
999 | if (!pages) |
1000 | goto out; | |
1001 | ||
f1970baf JB |
1002 | for (i = 0; i < iov_count; i++) { |
1003 | unsigned long uaddr = (unsigned long)iov[i].iov_base; | |
1004 | unsigned long len = iov[i].iov_len; | |
1005 | unsigned long end = (uaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT; | |
1006 | unsigned long start = uaddr >> PAGE_SHIFT; | |
1007 | const int local_nr_pages = end - start; | |
1008 | const int page_limit = cur_page + local_nr_pages; | |
cb4644ca | 1009 | |
f5dd33c4 NP |
1010 | ret = get_user_pages_fast(uaddr, local_nr_pages, |
1011 | write_to_vm, &pages[cur_page]); | |
99172157 JA |
1012 | if (ret < local_nr_pages) { |
1013 | ret = -EFAULT; | |
f1970baf | 1014 | goto out_unmap; |
99172157 | 1015 | } |
f1970baf JB |
1016 | |
1017 | offset = uaddr & ~PAGE_MASK; | |
1018 | for (j = cur_page; j < page_limit; j++) { | |
1019 | unsigned int bytes = PAGE_SIZE - offset; | |
1020 | ||
1021 | if (len <= 0) | |
1022 | break; | |
1023 | ||
1024 | if (bytes > len) | |
1025 | bytes = len; | |
1026 | ||
1027 | /* | |
1028 | * sorry... | |
1029 | */ | |
defd94b7 MC |
1030 | if (bio_add_pc_page(q, bio, pages[j], bytes, offset) < |
1031 | bytes) | |
f1970baf JB |
1032 | break; |
1033 | ||
1034 | len -= bytes; | |
1035 | offset = 0; | |
1036 | } | |
1da177e4 | 1037 | |
f1970baf | 1038 | cur_page = j; |
1da177e4 | 1039 | /* |
f1970baf | 1040 | * release the pages we didn't map into the bio, if any |
1da177e4 | 1041 | */ |
f1970baf JB |
1042 | while (j < page_limit) |
1043 | page_cache_release(pages[j++]); | |
1da177e4 LT |
1044 | } |
1045 | ||
1da177e4 LT |
1046 | kfree(pages); |
1047 | ||
1048 | /* | |
1049 | * set data direction, and check if mapped pages need bouncing | |
1050 | */ | |
1051 | if (!write_to_vm) | |
7b6d91da | 1052 | bio->bi_rw |= REQ_WRITE; |
1da177e4 | 1053 | |
f1970baf | 1054 | bio->bi_bdev = bdev; |
1da177e4 LT |
1055 | bio->bi_flags |= (1 << BIO_USER_MAPPED); |
1056 | return bio; | |
f1970baf JB |
1057 | |
1058 | out_unmap: | |
1059 | for (i = 0; i < nr_pages; i++) { | |
1060 | if(!pages[i]) | |
1061 | break; | |
1062 | page_cache_release(pages[i]); | |
1063 | } | |
1064 | out: | |
1da177e4 LT |
1065 | kfree(pages); |
1066 | bio_put(bio); | |
1067 | return ERR_PTR(ret); | |
1068 | } | |
1069 | ||
1070 | /** | |
1071 | * bio_map_user - map user address into bio | |
165125e1 | 1072 | * @q: the struct request_queue for the bio |
1da177e4 LT |
1073 | * @bdev: destination block device |
1074 | * @uaddr: start of user address | |
1075 | * @len: length in bytes | |
1076 | * @write_to_vm: bool indicating writing to pages or not | |
a3bce90e | 1077 | * @gfp_mask: memory allocation flags |
1da177e4 LT |
1078 | * |
1079 | * Map the user space address into a bio suitable for io to a block | |
1080 | * device. Returns an error pointer in case of error. | |
1081 | */ | |
165125e1 | 1082 | struct bio *bio_map_user(struct request_queue *q, struct block_device *bdev, |
a3bce90e FT |
1083 | unsigned long uaddr, unsigned int len, int write_to_vm, |
1084 | gfp_t gfp_mask) | |
f1970baf JB |
1085 | { |
1086 | struct sg_iovec iov; | |
1087 | ||
3f70353e | 1088 | iov.iov_base = (void __user *)uaddr; |
f1970baf JB |
1089 | iov.iov_len = len; |
1090 | ||
a3bce90e | 1091 | return bio_map_user_iov(q, bdev, &iov, 1, write_to_vm, gfp_mask); |
f1970baf | 1092 | } |
a112a71d | 1093 | EXPORT_SYMBOL(bio_map_user); |
f1970baf JB |
1094 | |
1095 | /** | |
1096 | * bio_map_user_iov - map user sg_iovec table into bio | |
165125e1 | 1097 | * @q: the struct request_queue for the bio |
f1970baf JB |
1098 | * @bdev: destination block device |
1099 | * @iov: the iovec. | |
1100 | * @iov_count: number of elements in the iovec | |
1101 | * @write_to_vm: bool indicating writing to pages or not | |
a3bce90e | 1102 | * @gfp_mask: memory allocation flags |
f1970baf JB |
1103 | * |
1104 | * Map the user space address into a bio suitable for io to a block | |
1105 | * device. Returns an error pointer in case of error. | |
1106 | */ | |
165125e1 | 1107 | struct bio *bio_map_user_iov(struct request_queue *q, struct block_device *bdev, |
f1970baf | 1108 | struct sg_iovec *iov, int iov_count, |
a3bce90e | 1109 | int write_to_vm, gfp_t gfp_mask) |
1da177e4 LT |
1110 | { |
1111 | struct bio *bio; | |
1112 | ||
a3bce90e FT |
1113 | bio = __bio_map_user_iov(q, bdev, iov, iov_count, write_to_vm, |
1114 | gfp_mask); | |
1da177e4 LT |
1115 | if (IS_ERR(bio)) |
1116 | return bio; | |
1117 | ||
1118 | /* | |
1119 | * subtle -- if __bio_map_user() ended up bouncing a bio, | |
1120 | * it would normally disappear when its bi_end_io is run. | |
1121 | * however, we need it for the unmap, so grab an extra | |
1122 | * reference to it | |
1123 | */ | |
1124 | bio_get(bio); | |
1125 | ||
0e75f906 | 1126 | return bio; |
1da177e4 LT |
1127 | } |
1128 | ||
1129 | static void __bio_unmap_user(struct bio *bio) | |
1130 | { | |
1131 | struct bio_vec *bvec; | |
1132 | int i; | |
1133 | ||
1134 | /* | |
1135 | * make sure we dirty pages we wrote to | |
1136 | */ | |
1137 | __bio_for_each_segment(bvec, bio, i, 0) { | |
1138 | if (bio_data_dir(bio) == READ) | |
1139 | set_page_dirty_lock(bvec->bv_page); | |
1140 | ||
1141 | page_cache_release(bvec->bv_page); | |
1142 | } | |
1143 | ||
1144 | bio_put(bio); | |
1145 | } | |
1146 | ||
1147 | /** | |
1148 | * bio_unmap_user - unmap a bio | |
1149 | * @bio: the bio being unmapped | |
1150 | * | |
1151 | * Unmap a bio previously mapped by bio_map_user(). Must be called with | |
1152 | * a process context. | |
1153 | * | |
1154 | * bio_unmap_user() may sleep. | |
1155 | */ | |
1156 | void bio_unmap_user(struct bio *bio) | |
1157 | { | |
1158 | __bio_unmap_user(bio); | |
1159 | bio_put(bio); | |
1160 | } | |
a112a71d | 1161 | EXPORT_SYMBOL(bio_unmap_user); |
1da177e4 | 1162 | |
6712ecf8 | 1163 | static void bio_map_kern_endio(struct bio *bio, int err) |
b823825e | 1164 | { |
b823825e | 1165 | bio_put(bio); |
b823825e JA |
1166 | } |
1167 | ||
165125e1 | 1168 | static struct bio *__bio_map_kern(struct request_queue *q, void *data, |
27496a8c | 1169 | unsigned int len, gfp_t gfp_mask) |
df46b9a4 MC |
1170 | { |
1171 | unsigned long kaddr = (unsigned long)data; | |
1172 | unsigned long end = (kaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT; | |
1173 | unsigned long start = kaddr >> PAGE_SHIFT; | |
1174 | const int nr_pages = end - start; | |
1175 | int offset, i; | |
1176 | struct bio *bio; | |
1177 | ||
a9e9dc24 | 1178 | bio = bio_kmalloc(gfp_mask, nr_pages); |
df46b9a4 MC |
1179 | if (!bio) |
1180 | return ERR_PTR(-ENOMEM); | |
1181 | ||
1182 | offset = offset_in_page(kaddr); | |
1183 | for (i = 0; i < nr_pages; i++) { | |
1184 | unsigned int bytes = PAGE_SIZE - offset; | |
1185 | ||
1186 | if (len <= 0) | |
1187 | break; | |
1188 | ||
1189 | if (bytes > len) | |
1190 | bytes = len; | |
1191 | ||
defd94b7 MC |
1192 | if (bio_add_pc_page(q, bio, virt_to_page(data), bytes, |
1193 | offset) < bytes) | |
df46b9a4 MC |
1194 | break; |
1195 | ||
1196 | data += bytes; | |
1197 | len -= bytes; | |
1198 | offset = 0; | |
1199 | } | |
1200 | ||
b823825e | 1201 | bio->bi_end_io = bio_map_kern_endio; |
df46b9a4 MC |
1202 | return bio; |
1203 | } | |
1204 | ||
1205 | /** | |
1206 | * bio_map_kern - map kernel address into bio | |
165125e1 | 1207 | * @q: the struct request_queue for the bio |
df46b9a4 MC |
1208 | * @data: pointer to buffer to map |
1209 | * @len: length in bytes | |
1210 | * @gfp_mask: allocation flags for bio allocation | |
1211 | * | |
1212 | * Map the kernel address into a bio suitable for io to a block | |
1213 | * device. Returns an error pointer in case of error. | |
1214 | */ | |
165125e1 | 1215 | struct bio *bio_map_kern(struct request_queue *q, void *data, unsigned int len, |
27496a8c | 1216 | gfp_t gfp_mask) |
df46b9a4 MC |
1217 | { |
1218 | struct bio *bio; | |
1219 | ||
1220 | bio = __bio_map_kern(q, data, len, gfp_mask); | |
1221 | if (IS_ERR(bio)) | |
1222 | return bio; | |
1223 | ||
1224 | if (bio->bi_size == len) | |
1225 | return bio; | |
1226 | ||
1227 | /* | |
1228 | * Don't support partial mappings. | |
1229 | */ | |
1230 | bio_put(bio); | |
1231 | return ERR_PTR(-EINVAL); | |
1232 | } | |
a112a71d | 1233 | EXPORT_SYMBOL(bio_map_kern); |
df46b9a4 | 1234 | |
68154e90 FT |
1235 | static void bio_copy_kern_endio(struct bio *bio, int err) |
1236 | { | |
1237 | struct bio_vec *bvec; | |
1238 | const int read = bio_data_dir(bio) == READ; | |
76029ff3 | 1239 | struct bio_map_data *bmd = bio->bi_private; |
68154e90 | 1240 | int i; |
76029ff3 | 1241 | char *p = bmd->sgvecs[0].iov_base; |
68154e90 FT |
1242 | |
1243 | __bio_for_each_segment(bvec, bio, i, 0) { | |
1244 | char *addr = page_address(bvec->bv_page); | |
76029ff3 | 1245 | int len = bmd->iovecs[i].bv_len; |
68154e90 | 1246 | |
4fc981ef | 1247 | if (read) |
76029ff3 | 1248 | memcpy(p, addr, len); |
68154e90 FT |
1249 | |
1250 | __free_page(bvec->bv_page); | |
76029ff3 | 1251 | p += len; |
68154e90 FT |
1252 | } |
1253 | ||
76029ff3 | 1254 | bio_free_map_data(bmd); |
68154e90 FT |
1255 | bio_put(bio); |
1256 | } | |
1257 | ||
1258 | /** | |
1259 | * bio_copy_kern - copy kernel address into bio | |
1260 | * @q: the struct request_queue for the bio | |
1261 | * @data: pointer to buffer to copy | |
1262 | * @len: length in bytes | |
1263 | * @gfp_mask: allocation flags for bio and page allocation | |
ffee0259 | 1264 | * @reading: data direction is READ |
68154e90 FT |
1265 | * |
1266 | * copy the kernel address into a bio suitable for io to a block | |
1267 | * device. Returns an error pointer in case of error. | |
1268 | */ | |
1269 | struct bio *bio_copy_kern(struct request_queue *q, void *data, unsigned int len, | |
1270 | gfp_t gfp_mask, int reading) | |
1271 | { | |
68154e90 FT |
1272 | struct bio *bio; |
1273 | struct bio_vec *bvec; | |
4d8ab62e | 1274 | int i; |
68154e90 | 1275 | |
4d8ab62e FT |
1276 | bio = bio_copy_user(q, NULL, (unsigned long)data, len, 1, gfp_mask); |
1277 | if (IS_ERR(bio)) | |
1278 | return bio; | |
68154e90 FT |
1279 | |
1280 | if (!reading) { | |
1281 | void *p = data; | |
1282 | ||
1283 | bio_for_each_segment(bvec, bio, i) { | |
1284 | char *addr = page_address(bvec->bv_page); | |
1285 | ||
1286 | memcpy(addr, p, bvec->bv_len); | |
1287 | p += bvec->bv_len; | |
1288 | } | |
1289 | } | |
1290 | ||
68154e90 | 1291 | bio->bi_end_io = bio_copy_kern_endio; |
76029ff3 | 1292 | |
68154e90 | 1293 | return bio; |
68154e90 | 1294 | } |
a112a71d | 1295 | EXPORT_SYMBOL(bio_copy_kern); |
68154e90 | 1296 | |
1da177e4 LT |
1297 | /* |
1298 | * bio_set_pages_dirty() and bio_check_pages_dirty() are support functions | |
1299 | * for performing direct-IO in BIOs. | |
1300 | * | |
1301 | * The problem is that we cannot run set_page_dirty() from interrupt context | |
1302 | * because the required locks are not interrupt-safe. So what we can do is to | |
1303 | * mark the pages dirty _before_ performing IO. And in interrupt context, | |
1304 | * check that the pages are still dirty. If so, fine. If not, redirty them | |
1305 | * in process context. | |
1306 | * | |
1307 | * We special-case compound pages here: normally this means reads into hugetlb | |
1308 | * pages. The logic in here doesn't really work right for compound pages | |
1309 | * because the VM does not uniformly chase down the head page in all cases. | |
1310 | * But dirtiness of compound pages is pretty meaningless anyway: the VM doesn't | |
1311 | * handle them at all. So we skip compound pages here at an early stage. | |
1312 | * | |
1313 | * Note that this code is very hard to test under normal circumstances because | |
1314 | * direct-io pins the pages with get_user_pages(). This makes | |
1315 | * is_page_cache_freeable return false, and the VM will not clean the pages. | |
0d5c3eba | 1316 | * But other code (eg, flusher threads) could clean the pages if they are mapped |
1da177e4 LT |
1317 | * pagecache. |
1318 | * | |
1319 | * Simply disabling the call to bio_set_pages_dirty() is a good way to test the | |
1320 | * deferred bio dirtying paths. | |
1321 | */ | |
1322 | ||
1323 | /* | |
1324 | * bio_set_pages_dirty() will mark all the bio's pages as dirty. | |
1325 | */ | |
1326 | void bio_set_pages_dirty(struct bio *bio) | |
1327 | { | |
1328 | struct bio_vec *bvec = bio->bi_io_vec; | |
1329 | int i; | |
1330 | ||
1331 | for (i = 0; i < bio->bi_vcnt; i++) { | |
1332 | struct page *page = bvec[i].bv_page; | |
1333 | ||
1334 | if (page && !PageCompound(page)) | |
1335 | set_page_dirty_lock(page); | |
1336 | } | |
1337 | } | |
1338 | ||
86b6c7a7 | 1339 | static void bio_release_pages(struct bio *bio) |
1da177e4 LT |
1340 | { |
1341 | struct bio_vec *bvec = bio->bi_io_vec; | |
1342 | int i; | |
1343 | ||
1344 | for (i = 0; i < bio->bi_vcnt; i++) { | |
1345 | struct page *page = bvec[i].bv_page; | |
1346 | ||
1347 | if (page) | |
1348 | put_page(page); | |
1349 | } | |
1350 | } | |
1351 | ||
1352 | /* | |
1353 | * bio_check_pages_dirty() will check that all the BIO's pages are still dirty. | |
1354 | * If they are, then fine. If, however, some pages are clean then they must | |
1355 | * have been written out during the direct-IO read. So we take another ref on | |
1356 | * the BIO and the offending pages and re-dirty the pages in process context. | |
1357 | * | |
1358 | * It is expected that bio_check_pages_dirty() will wholly own the BIO from | |
1359 | * here on. It will run one page_cache_release() against each page and will | |
1360 | * run one bio_put() against the BIO. | |
1361 | */ | |
1362 | ||
65f27f38 | 1363 | static void bio_dirty_fn(struct work_struct *work); |
1da177e4 | 1364 | |
65f27f38 | 1365 | static DECLARE_WORK(bio_dirty_work, bio_dirty_fn); |
1da177e4 LT |
1366 | static DEFINE_SPINLOCK(bio_dirty_lock); |
1367 | static struct bio *bio_dirty_list; | |
1368 | ||
1369 | /* | |
1370 | * This runs in process context | |
1371 | */ | |
65f27f38 | 1372 | static void bio_dirty_fn(struct work_struct *work) |
1da177e4 LT |
1373 | { |
1374 | unsigned long flags; | |
1375 | struct bio *bio; | |
1376 | ||
1377 | spin_lock_irqsave(&bio_dirty_lock, flags); | |
1378 | bio = bio_dirty_list; | |
1379 | bio_dirty_list = NULL; | |
1380 | spin_unlock_irqrestore(&bio_dirty_lock, flags); | |
1381 | ||
1382 | while (bio) { | |
1383 | struct bio *next = bio->bi_private; | |
1384 | ||
1385 | bio_set_pages_dirty(bio); | |
1386 | bio_release_pages(bio); | |
1387 | bio_put(bio); | |
1388 | bio = next; | |
1389 | } | |
1390 | } | |
1391 | ||
1392 | void bio_check_pages_dirty(struct bio *bio) | |
1393 | { | |
1394 | struct bio_vec *bvec = bio->bi_io_vec; | |
1395 | int nr_clean_pages = 0; | |
1396 | int i; | |
1397 | ||
1398 | for (i = 0; i < bio->bi_vcnt; i++) { | |
1399 | struct page *page = bvec[i].bv_page; | |
1400 | ||
1401 | if (PageDirty(page) || PageCompound(page)) { | |
1402 | page_cache_release(page); | |
1403 | bvec[i].bv_page = NULL; | |
1404 | } else { | |
1405 | nr_clean_pages++; | |
1406 | } | |
1407 | } | |
1408 | ||
1409 | if (nr_clean_pages) { | |
1410 | unsigned long flags; | |
1411 | ||
1412 | spin_lock_irqsave(&bio_dirty_lock, flags); | |
1413 | bio->bi_private = bio_dirty_list; | |
1414 | bio_dirty_list = bio; | |
1415 | spin_unlock_irqrestore(&bio_dirty_lock, flags); | |
1416 | schedule_work(&bio_dirty_work); | |
1417 | } else { | |
1418 | bio_put(bio); | |
1419 | } | |
1420 | } | |
1421 | ||
2d4dc890 IL |
1422 | #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE |
1423 | void bio_flush_dcache_pages(struct bio *bi) | |
1424 | { | |
1425 | int i; | |
1426 | struct bio_vec *bvec; | |
1427 | ||
1428 | bio_for_each_segment(bvec, bi, i) | |
1429 | flush_dcache_page(bvec->bv_page); | |
1430 | } | |
1431 | EXPORT_SYMBOL(bio_flush_dcache_pages); | |
1432 | #endif | |
1433 | ||
1da177e4 LT |
1434 | /** |
1435 | * bio_endio - end I/O on a bio | |
1436 | * @bio: bio | |
1da177e4 LT |
1437 | * @error: error, if any |
1438 | * | |
1439 | * Description: | |
6712ecf8 | 1440 | * bio_endio() will end I/O on the whole bio. bio_endio() is the |
5bb23a68 N |
1441 | * preferred way to end I/O on a bio, it takes care of clearing |
1442 | * BIO_UPTODATE on error. @error is 0 on success, and and one of the | |
1443 | * established -Exxxx (-EIO, for instance) error values in case | |
25985edc | 1444 | * something went wrong. No one should call bi_end_io() directly on a |
5bb23a68 N |
1445 | * bio unless they own it and thus know that it has an end_io |
1446 | * function. | |
1da177e4 | 1447 | **/ |
6712ecf8 | 1448 | void bio_endio(struct bio *bio, int error) |
1da177e4 LT |
1449 | { |
1450 | if (error) | |
1451 | clear_bit(BIO_UPTODATE, &bio->bi_flags); | |
9cc54d40 N |
1452 | else if (!test_bit(BIO_UPTODATE, &bio->bi_flags)) |
1453 | error = -EIO; | |
1da177e4 | 1454 | |
5bb23a68 | 1455 | if (bio->bi_end_io) |
6712ecf8 | 1456 | bio->bi_end_io(bio, error); |
1da177e4 | 1457 | } |
a112a71d | 1458 | EXPORT_SYMBOL(bio_endio); |
1da177e4 LT |
1459 | |
1460 | void bio_pair_release(struct bio_pair *bp) | |
1461 | { | |
1462 | if (atomic_dec_and_test(&bp->cnt)) { | |
1463 | struct bio *master = bp->bio1.bi_private; | |
1464 | ||
6712ecf8 | 1465 | bio_endio(master, bp->error); |
1da177e4 LT |
1466 | mempool_free(bp, bp->bio2.bi_private); |
1467 | } | |
1468 | } | |
a112a71d | 1469 | EXPORT_SYMBOL(bio_pair_release); |
1da177e4 | 1470 | |
6712ecf8 | 1471 | static void bio_pair_end_1(struct bio *bi, int err) |
1da177e4 LT |
1472 | { |
1473 | struct bio_pair *bp = container_of(bi, struct bio_pair, bio1); | |
1474 | ||
1475 | if (err) | |
1476 | bp->error = err; | |
1477 | ||
1da177e4 | 1478 | bio_pair_release(bp); |
1da177e4 LT |
1479 | } |
1480 | ||
6712ecf8 | 1481 | static void bio_pair_end_2(struct bio *bi, int err) |
1da177e4 LT |
1482 | { |
1483 | struct bio_pair *bp = container_of(bi, struct bio_pair, bio2); | |
1484 | ||
1485 | if (err) | |
1486 | bp->error = err; | |
1487 | ||
1da177e4 | 1488 | bio_pair_release(bp); |
1da177e4 LT |
1489 | } |
1490 | ||
1491 | /* | |
c7eee1b8 | 1492 | * split a bio - only worry about a bio with a single page in its iovec |
1da177e4 | 1493 | */ |
6feef531 | 1494 | struct bio_pair *bio_split(struct bio *bi, int first_sectors) |
1da177e4 | 1495 | { |
6feef531 | 1496 | struct bio_pair *bp = mempool_alloc(bio_split_pool, GFP_NOIO); |
1da177e4 LT |
1497 | |
1498 | if (!bp) | |
1499 | return bp; | |
1500 | ||
5f3ea37c | 1501 | trace_block_split(bdev_get_queue(bi->bi_bdev), bi, |
2056a782 JA |
1502 | bi->bi_sector + first_sectors); |
1503 | ||
1da177e4 LT |
1504 | BUG_ON(bi->bi_vcnt != 1); |
1505 | BUG_ON(bi->bi_idx != 0); | |
1506 | atomic_set(&bp->cnt, 3); | |
1507 | bp->error = 0; | |
1508 | bp->bio1 = *bi; | |
1509 | bp->bio2 = *bi; | |
1510 | bp->bio2.bi_sector += first_sectors; | |
1511 | bp->bio2.bi_size -= first_sectors << 9; | |
1512 | bp->bio1.bi_size = first_sectors << 9; | |
1513 | ||
1514 | bp->bv1 = bi->bi_io_vec[0]; | |
1515 | bp->bv2 = bi->bi_io_vec[0]; | |
1516 | bp->bv2.bv_offset += first_sectors << 9; | |
1517 | bp->bv2.bv_len -= first_sectors << 9; | |
1518 | bp->bv1.bv_len = first_sectors << 9; | |
1519 | ||
1520 | bp->bio1.bi_io_vec = &bp->bv1; | |
1521 | bp->bio2.bi_io_vec = &bp->bv2; | |
1522 | ||
a2eb0c10 N |
1523 | bp->bio1.bi_max_vecs = 1; |
1524 | bp->bio2.bi_max_vecs = 1; | |
1525 | ||
1da177e4 LT |
1526 | bp->bio1.bi_end_io = bio_pair_end_1; |
1527 | bp->bio2.bi_end_io = bio_pair_end_2; | |
1528 | ||
1529 | bp->bio1.bi_private = bi; | |
6feef531 | 1530 | bp->bio2.bi_private = bio_split_pool; |
1da177e4 | 1531 | |
7ba1ba12 MP |
1532 | if (bio_integrity(bi)) |
1533 | bio_integrity_split(bi, bp, first_sectors); | |
1534 | ||
1da177e4 LT |
1535 | return bp; |
1536 | } | |
a112a71d | 1537 | EXPORT_SYMBOL(bio_split); |
1da177e4 | 1538 | |
ad3316bf MP |
1539 | /** |
1540 | * bio_sector_offset - Find hardware sector offset in bio | |
1541 | * @bio: bio to inspect | |
1542 | * @index: bio_vec index | |
1543 | * @offset: offset in bv_page | |
1544 | * | |
1545 | * Return the number of hardware sectors between beginning of bio | |
1546 | * and an end point indicated by a bio_vec index and an offset | |
1547 | * within that vector's page. | |
1548 | */ | |
1549 | sector_t bio_sector_offset(struct bio *bio, unsigned short index, | |
1550 | unsigned int offset) | |
1551 | { | |
e1defc4f | 1552 | unsigned int sector_sz; |
ad3316bf MP |
1553 | struct bio_vec *bv; |
1554 | sector_t sectors; | |
1555 | int i; | |
1556 | ||
e1defc4f | 1557 | sector_sz = queue_logical_block_size(bio->bi_bdev->bd_disk->queue); |
ad3316bf MP |
1558 | sectors = 0; |
1559 | ||
1560 | if (index >= bio->bi_idx) | |
1561 | index = bio->bi_vcnt - 1; | |
1562 | ||
1563 | __bio_for_each_segment(bv, bio, i, 0) { | |
1564 | if (i == index) { | |
1565 | if (offset > bv->bv_offset) | |
1566 | sectors += (offset - bv->bv_offset) / sector_sz; | |
1567 | break; | |
1568 | } | |
1569 | ||
1570 | sectors += bv->bv_len / sector_sz; | |
1571 | } | |
1572 | ||
1573 | return sectors; | |
1574 | } | |
1575 | EXPORT_SYMBOL(bio_sector_offset); | |
1da177e4 LT |
1576 | |
1577 | /* | |
1578 | * create memory pools for biovec's in a bio_set. | |
1579 | * use the global biovec slabs created for general use. | |
1580 | */ | |
5972511b | 1581 | static int biovec_create_pools(struct bio_set *bs, int pool_entries) |
1da177e4 | 1582 | { |
7ff9345f | 1583 | struct biovec_slab *bp = bvec_slabs + BIOVEC_MAX_IDX; |
1da177e4 | 1584 | |
7ff9345f JA |
1585 | bs->bvec_pool = mempool_create_slab_pool(pool_entries, bp->slab); |
1586 | if (!bs->bvec_pool) | |
1587 | return -ENOMEM; | |
1da177e4 | 1588 | |
1da177e4 LT |
1589 | return 0; |
1590 | } | |
1591 | ||
1592 | static void biovec_free_pools(struct bio_set *bs) | |
1593 | { | |
7ff9345f | 1594 | mempool_destroy(bs->bvec_pool); |
1da177e4 LT |
1595 | } |
1596 | ||
1597 | void bioset_free(struct bio_set *bs) | |
1598 | { | |
1599 | if (bs->bio_pool) | |
1600 | mempool_destroy(bs->bio_pool); | |
1601 | ||
7878cba9 | 1602 | bioset_integrity_free(bs); |
1da177e4 | 1603 | biovec_free_pools(bs); |
bb799ca0 | 1604 | bio_put_slab(bs); |
1da177e4 LT |
1605 | |
1606 | kfree(bs); | |
1607 | } | |
a112a71d | 1608 | EXPORT_SYMBOL(bioset_free); |
1da177e4 | 1609 | |
bb799ca0 JA |
1610 | /** |
1611 | * bioset_create - Create a bio_set | |
1612 | * @pool_size: Number of bio and bio_vecs to cache in the mempool | |
1613 | * @front_pad: Number of bytes to allocate in front of the returned bio | |
1614 | * | |
1615 | * Description: | |
1616 | * Set up a bio_set to be used with @bio_alloc_bioset. Allows the caller | |
1617 | * to ask for a number of bytes to be allocated in front of the bio. | |
1618 | * Front pad allocation is useful for embedding the bio inside | |
1619 | * another structure, to avoid allocating extra data to go with the bio. | |
1620 | * Note that the bio must be embedded at the END of that structure always, | |
1621 | * or things will break badly. | |
1622 | */ | |
1623 | struct bio_set *bioset_create(unsigned int pool_size, unsigned int front_pad) | |
1da177e4 | 1624 | { |
392ddc32 | 1625 | unsigned int back_pad = BIO_INLINE_VECS * sizeof(struct bio_vec); |
1b434498 | 1626 | struct bio_set *bs; |
1da177e4 | 1627 | |
1b434498 | 1628 | bs = kzalloc(sizeof(*bs), GFP_KERNEL); |
1da177e4 LT |
1629 | if (!bs) |
1630 | return NULL; | |
1631 | ||
bb799ca0 | 1632 | bs->front_pad = front_pad; |
1b434498 | 1633 | |
392ddc32 | 1634 | bs->bio_slab = bio_find_or_create_slab(front_pad + back_pad); |
bb799ca0 JA |
1635 | if (!bs->bio_slab) { |
1636 | kfree(bs); | |
1637 | return NULL; | |
1638 | } | |
1639 | ||
1640 | bs->bio_pool = mempool_create_slab_pool(pool_size, bs->bio_slab); | |
1da177e4 LT |
1641 | if (!bs->bio_pool) |
1642 | goto bad; | |
1643 | ||
bb799ca0 | 1644 | if (!biovec_create_pools(bs, pool_size)) |
1da177e4 LT |
1645 | return bs; |
1646 | ||
1647 | bad: | |
1648 | bioset_free(bs); | |
1649 | return NULL; | |
1650 | } | |
a112a71d | 1651 | EXPORT_SYMBOL(bioset_create); |
1da177e4 | 1652 | |
852c788f TH |
1653 | #ifdef CONFIG_BLK_CGROUP |
1654 | /** | |
1655 | * bio_associate_current - associate a bio with %current | |
1656 | * @bio: target bio | |
1657 | * | |
1658 | * Associate @bio with %current if it hasn't been associated yet. Block | |
1659 | * layer will treat @bio as if it were issued by %current no matter which | |
1660 | * task actually issues it. | |
1661 | * | |
1662 | * This function takes an extra reference of @task's io_context and blkcg | |
1663 | * which will be put when @bio is released. The caller must own @bio, | |
1664 | * ensure %current->io_context exists, and is responsible for synchronizing | |
1665 | * calls to this function. | |
1666 | */ | |
1667 | int bio_associate_current(struct bio *bio) | |
1668 | { | |
1669 | struct io_context *ioc; | |
1670 | struct cgroup_subsys_state *css; | |
1671 | ||
1672 | if (bio->bi_ioc) | |
1673 | return -EBUSY; | |
1674 | ||
1675 | ioc = current->io_context; | |
1676 | if (!ioc) | |
1677 | return -ENOENT; | |
1678 | ||
1679 | /* acquire active ref on @ioc and associate */ | |
1680 | get_io_context_active(ioc); | |
1681 | bio->bi_ioc = ioc; | |
1682 | ||
1683 | /* associate blkcg if exists */ | |
1684 | rcu_read_lock(); | |
1685 | css = task_subsys_state(current, blkio_subsys_id); | |
1686 | if (css && css_tryget(css)) | |
1687 | bio->bi_css = css; | |
1688 | rcu_read_unlock(); | |
1689 | ||
1690 | return 0; | |
1691 | } | |
1692 | ||
1693 | /** | |
1694 | * bio_disassociate_task - undo bio_associate_current() | |
1695 | * @bio: target bio | |
1696 | */ | |
1697 | void bio_disassociate_task(struct bio *bio) | |
1698 | { | |
1699 | if (bio->bi_ioc) { | |
1700 | put_io_context(bio->bi_ioc); | |
1701 | bio->bi_ioc = NULL; | |
1702 | } | |
1703 | if (bio->bi_css) { | |
1704 | css_put(bio->bi_css); | |
1705 | bio->bi_css = NULL; | |
1706 | } | |
1707 | } | |
1708 | ||
1709 | #endif /* CONFIG_BLK_CGROUP */ | |
1710 | ||
1da177e4 LT |
1711 | static void __init biovec_init_slabs(void) |
1712 | { | |
1713 | int i; | |
1714 | ||
1715 | for (i = 0; i < BIOVEC_NR_POOLS; i++) { | |
1716 | int size; | |
1717 | struct biovec_slab *bvs = bvec_slabs + i; | |
1718 | ||
a7fcd37c JA |
1719 | if (bvs->nr_vecs <= BIO_INLINE_VECS) { |
1720 | bvs->slab = NULL; | |
1721 | continue; | |
1722 | } | |
a7fcd37c | 1723 | |
1da177e4 LT |
1724 | size = bvs->nr_vecs * sizeof(struct bio_vec); |
1725 | bvs->slab = kmem_cache_create(bvs->name, size, 0, | |
20c2df83 | 1726 | SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); |
1da177e4 LT |
1727 | } |
1728 | } | |
1729 | ||
1730 | static int __init init_bio(void) | |
1731 | { | |
bb799ca0 JA |
1732 | bio_slab_max = 2; |
1733 | bio_slab_nr = 0; | |
1734 | bio_slabs = kzalloc(bio_slab_max * sizeof(struct bio_slab), GFP_KERNEL); | |
1735 | if (!bio_slabs) | |
1736 | panic("bio: can't allocate bios\n"); | |
1da177e4 | 1737 | |
7878cba9 | 1738 | bio_integrity_init(); |
1da177e4 LT |
1739 | biovec_init_slabs(); |
1740 | ||
bb799ca0 | 1741 | fs_bio_set = bioset_create(BIO_POOL_SIZE, 0); |
1da177e4 LT |
1742 | if (!fs_bio_set) |
1743 | panic("bio: can't allocate bios\n"); | |
1744 | ||
a91a2785 MP |
1745 | if (bioset_integrity_create(fs_bio_set, BIO_POOL_SIZE)) |
1746 | panic("bio: can't create integrity pool\n"); | |
1747 | ||
0eaae62a MD |
1748 | bio_split_pool = mempool_create_kmalloc_pool(BIO_SPLIT_ENTRIES, |
1749 | sizeof(struct bio_pair)); | |
1da177e4 LT |
1750 | if (!bio_split_pool) |
1751 | panic("bio: can't create split pool\n"); | |
1752 | ||
1753 | return 0; | |
1754 | } | |
1da177e4 | 1755 | subsys_initcall(init_bio); |