Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * Copyright (C) 2001 Jens Axboe <axboe@suse.de> | |
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> | |
f1970baf | 28 | #include <scsi/sg.h> /* for struct sg_iovec */ |
1da177e4 LT |
29 | |
30 | #define BIO_POOL_SIZE 256 | |
31 | ||
32 | static kmem_cache_t *bio_slab; | |
33 | ||
34 | #define BIOVEC_NR_POOLS 6 | |
35 | ||
36 | /* | |
37 | * a small number of entries is fine, not going to be performance critical. | |
38 | * basically we just need to survive | |
39 | */ | |
40 | #define BIO_SPLIT_ENTRIES 8 | |
41 | mempool_t *bio_split_pool; | |
42 | ||
43 | struct biovec_slab { | |
44 | int nr_vecs; | |
45 | char *name; | |
46 | kmem_cache_t *slab; | |
47 | }; | |
48 | ||
49 | /* | |
50 | * if you change this list, also change bvec_alloc or things will | |
51 | * break badly! cannot be bigger than what you can fit into an | |
52 | * unsigned short | |
53 | */ | |
54 | ||
55 | #define BV(x) { .nr_vecs = x, .name = "biovec-"__stringify(x) } | |
6c036527 | 56 | static struct biovec_slab bvec_slabs[BIOVEC_NR_POOLS] __read_mostly = { |
1da177e4 LT |
57 | BV(1), BV(4), BV(16), BV(64), BV(128), BV(BIO_MAX_PAGES), |
58 | }; | |
59 | #undef BV | |
60 | ||
61 | /* | |
62 | * bio_set is used to allow other portions of the IO system to | |
63 | * allocate their own private memory pools for bio and iovec structures. | |
64 | * These memory pools in turn all allocate from the bio_slab | |
65 | * and the bvec_slabs[]. | |
66 | */ | |
67 | struct bio_set { | |
68 | mempool_t *bio_pool; | |
69 | mempool_t *bvec_pools[BIOVEC_NR_POOLS]; | |
70 | }; | |
71 | ||
72 | /* | |
73 | * fs_bio_set is the bio_set containing bio and iovec memory pools used by | |
74 | * IO code that does not need private memory pools. | |
75 | */ | |
76 | static struct bio_set *fs_bio_set; | |
77 | ||
dd0fc66f | 78 | static inline struct bio_vec *bvec_alloc_bs(gfp_t gfp_mask, int nr, unsigned long *idx, struct bio_set *bs) |
1da177e4 LT |
79 | { |
80 | struct bio_vec *bvl; | |
81 | struct biovec_slab *bp; | |
82 | ||
83 | /* | |
84 | * see comment near bvec_array define! | |
85 | */ | |
86 | switch (nr) { | |
87 | case 1 : *idx = 0; break; | |
88 | case 2 ... 4: *idx = 1; break; | |
89 | case 5 ... 16: *idx = 2; break; | |
90 | case 17 ... 64: *idx = 3; break; | |
91 | case 65 ... 128: *idx = 4; break; | |
92 | case 129 ... BIO_MAX_PAGES: *idx = 5; break; | |
93 | default: | |
94 | return NULL; | |
95 | } | |
96 | /* | |
97 | * idx now points to the pool we want to allocate from | |
98 | */ | |
99 | ||
100 | bp = bvec_slabs + *idx; | |
101 | bvl = mempool_alloc(bs->bvec_pools[*idx], gfp_mask); | |
102 | if (bvl) | |
103 | memset(bvl, 0, bp->nr_vecs * sizeof(struct bio_vec)); | |
104 | ||
105 | return bvl; | |
106 | } | |
107 | ||
3676347a | 108 | void bio_free(struct bio *bio, struct bio_set *bio_set) |
1da177e4 LT |
109 | { |
110 | const int pool_idx = BIO_POOL_IDX(bio); | |
1da177e4 LT |
111 | |
112 | BIO_BUG_ON(pool_idx >= BIOVEC_NR_POOLS); | |
113 | ||
3676347a PO |
114 | mempool_free(bio->bi_io_vec, bio_set->bvec_pools[pool_idx]); |
115 | mempool_free(bio, bio_set->bio_pool); | |
116 | } | |
117 | ||
118 | /* | |
119 | * default destructor for a bio allocated with bio_alloc_bioset() | |
120 | */ | |
121 | static void bio_fs_destructor(struct bio *bio) | |
122 | { | |
123 | bio_free(bio, fs_bio_set); | |
1da177e4 LT |
124 | } |
125 | ||
858119e1 | 126 | void bio_init(struct bio *bio) |
1da177e4 LT |
127 | { |
128 | bio->bi_next = NULL; | |
0ea60b5a | 129 | bio->bi_bdev = NULL; |
1da177e4 LT |
130 | bio->bi_flags = 1 << BIO_UPTODATE; |
131 | bio->bi_rw = 0; | |
132 | bio->bi_vcnt = 0; | |
133 | bio->bi_idx = 0; | |
134 | bio->bi_phys_segments = 0; | |
135 | bio->bi_hw_segments = 0; | |
136 | bio->bi_hw_front_size = 0; | |
137 | bio->bi_hw_back_size = 0; | |
138 | bio->bi_size = 0; | |
139 | bio->bi_max_vecs = 0; | |
140 | bio->bi_end_io = NULL; | |
141 | atomic_set(&bio->bi_cnt, 1); | |
142 | bio->bi_private = NULL; | |
143 | } | |
144 | ||
145 | /** | |
146 | * bio_alloc_bioset - allocate a bio for I/O | |
147 | * @gfp_mask: the GFP_ mask given to the slab allocator | |
148 | * @nr_iovecs: number of iovecs to pre-allocate | |
67be2dd1 | 149 | * @bs: the bio_set to allocate from |
1da177e4 LT |
150 | * |
151 | * Description: | |
152 | * bio_alloc_bioset will first try it's on mempool to satisfy the allocation. | |
153 | * If %__GFP_WAIT is set then we will block on the internal pool waiting | |
154 | * for a &struct bio to become free. | |
155 | * | |
156 | * allocate bio and iovecs from the memory pools specified by the | |
157 | * bio_set structure. | |
158 | **/ | |
dd0fc66f | 159 | struct bio *bio_alloc_bioset(gfp_t gfp_mask, int nr_iovecs, struct bio_set *bs) |
1da177e4 LT |
160 | { |
161 | struct bio *bio = mempool_alloc(bs->bio_pool, gfp_mask); | |
162 | ||
163 | if (likely(bio)) { | |
164 | struct bio_vec *bvl = NULL; | |
165 | ||
166 | bio_init(bio); | |
167 | if (likely(nr_iovecs)) { | |
168 | unsigned long idx; | |
169 | ||
170 | bvl = bvec_alloc_bs(gfp_mask, nr_iovecs, &idx, bs); | |
171 | if (unlikely(!bvl)) { | |
172 | mempool_free(bio, bs->bio_pool); | |
173 | bio = NULL; | |
174 | goto out; | |
175 | } | |
176 | bio->bi_flags |= idx << BIO_POOL_OFFSET; | |
177 | bio->bi_max_vecs = bvec_slabs[idx].nr_vecs; | |
178 | } | |
179 | bio->bi_io_vec = bvl; | |
1da177e4 LT |
180 | } |
181 | out: | |
182 | return bio; | |
183 | } | |
184 | ||
dd0fc66f | 185 | struct bio *bio_alloc(gfp_t gfp_mask, int nr_iovecs) |
1da177e4 | 186 | { |
3676347a PO |
187 | struct bio *bio = bio_alloc_bioset(gfp_mask, nr_iovecs, fs_bio_set); |
188 | ||
189 | if (bio) | |
190 | bio->bi_destructor = bio_fs_destructor; | |
191 | ||
192 | return bio; | |
1da177e4 LT |
193 | } |
194 | ||
195 | void zero_fill_bio(struct bio *bio) | |
196 | { | |
197 | unsigned long flags; | |
198 | struct bio_vec *bv; | |
199 | int i; | |
200 | ||
201 | bio_for_each_segment(bv, bio, i) { | |
202 | char *data = bvec_kmap_irq(bv, &flags); | |
203 | memset(data, 0, bv->bv_len); | |
204 | flush_dcache_page(bv->bv_page); | |
205 | bvec_kunmap_irq(data, &flags); | |
206 | } | |
207 | } | |
208 | EXPORT_SYMBOL(zero_fill_bio); | |
209 | ||
210 | /** | |
211 | * bio_put - release a reference to a bio | |
212 | * @bio: bio to release reference to | |
213 | * | |
214 | * Description: | |
215 | * Put a reference to a &struct bio, either one you have gotten with | |
216 | * bio_alloc or bio_get. The last put of a bio will free it. | |
217 | **/ | |
218 | void bio_put(struct bio *bio) | |
219 | { | |
220 | BIO_BUG_ON(!atomic_read(&bio->bi_cnt)); | |
221 | ||
222 | /* | |
223 | * last put frees it | |
224 | */ | |
225 | if (atomic_dec_and_test(&bio->bi_cnt)) { | |
226 | bio->bi_next = NULL; | |
227 | bio->bi_destructor(bio); | |
228 | } | |
229 | } | |
230 | ||
231 | inline int bio_phys_segments(request_queue_t *q, struct bio *bio) | |
232 | { | |
233 | if (unlikely(!bio_flagged(bio, BIO_SEG_VALID))) | |
234 | blk_recount_segments(q, bio); | |
235 | ||
236 | return bio->bi_phys_segments; | |
237 | } | |
238 | ||
239 | inline int bio_hw_segments(request_queue_t *q, struct bio *bio) | |
240 | { | |
241 | if (unlikely(!bio_flagged(bio, BIO_SEG_VALID))) | |
242 | blk_recount_segments(q, bio); | |
243 | ||
244 | return bio->bi_hw_segments; | |
245 | } | |
246 | ||
247 | /** | |
248 | * __bio_clone - clone a bio | |
249 | * @bio: destination bio | |
250 | * @bio_src: bio to clone | |
251 | * | |
252 | * Clone a &bio. Caller will own the returned bio, but not | |
253 | * the actual data it points to. Reference count of returned | |
254 | * bio will be one. | |
255 | */ | |
858119e1 | 256 | void __bio_clone(struct bio *bio, struct bio *bio_src) |
1da177e4 LT |
257 | { |
258 | request_queue_t *q = bdev_get_queue(bio_src->bi_bdev); | |
259 | ||
e525e153 AM |
260 | memcpy(bio->bi_io_vec, bio_src->bi_io_vec, |
261 | bio_src->bi_max_vecs * sizeof(struct bio_vec)); | |
1da177e4 LT |
262 | |
263 | bio->bi_sector = bio_src->bi_sector; | |
264 | bio->bi_bdev = bio_src->bi_bdev; | |
265 | bio->bi_flags |= 1 << BIO_CLONED; | |
266 | bio->bi_rw = bio_src->bi_rw; | |
1da177e4 LT |
267 | bio->bi_vcnt = bio_src->bi_vcnt; |
268 | bio->bi_size = bio_src->bi_size; | |
a5453be4 | 269 | bio->bi_idx = bio_src->bi_idx; |
1da177e4 LT |
270 | bio_phys_segments(q, bio); |
271 | bio_hw_segments(q, bio); | |
272 | } | |
273 | ||
274 | /** | |
275 | * bio_clone - clone a bio | |
276 | * @bio: bio to clone | |
277 | * @gfp_mask: allocation priority | |
278 | * | |
279 | * Like __bio_clone, only also allocates the returned bio | |
280 | */ | |
dd0fc66f | 281 | struct bio *bio_clone(struct bio *bio, gfp_t gfp_mask) |
1da177e4 LT |
282 | { |
283 | struct bio *b = bio_alloc_bioset(gfp_mask, bio->bi_max_vecs, fs_bio_set); | |
284 | ||
3676347a PO |
285 | if (b) { |
286 | b->bi_destructor = bio_fs_destructor; | |
1da177e4 | 287 | __bio_clone(b, bio); |
3676347a | 288 | } |
1da177e4 LT |
289 | |
290 | return b; | |
291 | } | |
292 | ||
293 | /** | |
294 | * bio_get_nr_vecs - return approx number of vecs | |
295 | * @bdev: I/O target | |
296 | * | |
297 | * Return the approximate number of pages we can send to this target. | |
298 | * There's no guarantee that you will be able to fit this number of pages | |
299 | * into a bio, it does not account for dynamic restrictions that vary | |
300 | * on offset. | |
301 | */ | |
302 | int bio_get_nr_vecs(struct block_device *bdev) | |
303 | { | |
304 | request_queue_t *q = bdev_get_queue(bdev); | |
305 | int nr_pages; | |
306 | ||
307 | nr_pages = ((q->max_sectors << 9) + PAGE_SIZE - 1) >> PAGE_SHIFT; | |
308 | if (nr_pages > q->max_phys_segments) | |
309 | nr_pages = q->max_phys_segments; | |
310 | if (nr_pages > q->max_hw_segments) | |
311 | nr_pages = q->max_hw_segments; | |
312 | ||
313 | return nr_pages; | |
314 | } | |
315 | ||
316 | static int __bio_add_page(request_queue_t *q, struct bio *bio, struct page | |
defd94b7 MC |
317 | *page, unsigned int len, unsigned int offset, |
318 | unsigned short max_sectors) | |
1da177e4 LT |
319 | { |
320 | int retried_segments = 0; | |
321 | struct bio_vec *bvec; | |
322 | ||
323 | /* | |
324 | * cloned bio must not modify vec list | |
325 | */ | |
326 | if (unlikely(bio_flagged(bio, BIO_CLONED))) | |
327 | return 0; | |
328 | ||
80cfd548 | 329 | if (((bio->bi_size + len) >> 9) > max_sectors) |
1da177e4 LT |
330 | return 0; |
331 | ||
80cfd548 JA |
332 | /* |
333 | * For filesystems with a blocksize smaller than the pagesize | |
334 | * we will often be called with the same page as last time and | |
335 | * a consecutive offset. Optimize this special case. | |
336 | */ | |
337 | if (bio->bi_vcnt > 0) { | |
338 | struct bio_vec *prev = &bio->bi_io_vec[bio->bi_vcnt - 1]; | |
339 | ||
340 | if (page == prev->bv_page && | |
341 | offset == prev->bv_offset + prev->bv_len) { | |
342 | prev->bv_len += len; | |
343 | if (q->merge_bvec_fn && | |
344 | q->merge_bvec_fn(q, bio, prev) < len) { | |
345 | prev->bv_len -= len; | |
346 | return 0; | |
347 | } | |
348 | ||
349 | goto done; | |
350 | } | |
351 | } | |
352 | ||
353 | if (bio->bi_vcnt >= bio->bi_max_vecs) | |
1da177e4 LT |
354 | return 0; |
355 | ||
356 | /* | |
357 | * we might lose a segment or two here, but rather that than | |
358 | * make this too complex. | |
359 | */ | |
360 | ||
361 | while (bio->bi_phys_segments >= q->max_phys_segments | |
362 | || bio->bi_hw_segments >= q->max_hw_segments | |
363 | || BIOVEC_VIRT_OVERSIZE(bio->bi_size)) { | |
364 | ||
365 | if (retried_segments) | |
366 | return 0; | |
367 | ||
368 | retried_segments = 1; | |
369 | blk_recount_segments(q, bio); | |
370 | } | |
371 | ||
372 | /* | |
373 | * setup the new entry, we might clear it again later if we | |
374 | * cannot add the page | |
375 | */ | |
376 | bvec = &bio->bi_io_vec[bio->bi_vcnt]; | |
377 | bvec->bv_page = page; | |
378 | bvec->bv_len = len; | |
379 | bvec->bv_offset = offset; | |
380 | ||
381 | /* | |
382 | * if queue has other restrictions (eg varying max sector size | |
383 | * depending on offset), it can specify a merge_bvec_fn in the | |
384 | * queue to get further control | |
385 | */ | |
386 | if (q->merge_bvec_fn) { | |
387 | /* | |
388 | * merge_bvec_fn() returns number of bytes it can accept | |
389 | * at this offset | |
390 | */ | |
391 | if (q->merge_bvec_fn(q, bio, bvec) < len) { | |
392 | bvec->bv_page = NULL; | |
393 | bvec->bv_len = 0; | |
394 | bvec->bv_offset = 0; | |
395 | return 0; | |
396 | } | |
397 | } | |
398 | ||
399 | /* If we may be able to merge these biovecs, force a recount */ | |
400 | if (bio->bi_vcnt && (BIOVEC_PHYS_MERGEABLE(bvec-1, bvec) || | |
401 | BIOVEC_VIRT_MERGEABLE(bvec-1, bvec))) | |
402 | bio->bi_flags &= ~(1 << BIO_SEG_VALID); | |
403 | ||
404 | bio->bi_vcnt++; | |
405 | bio->bi_phys_segments++; | |
406 | bio->bi_hw_segments++; | |
80cfd548 | 407 | done: |
1da177e4 LT |
408 | bio->bi_size += len; |
409 | return len; | |
410 | } | |
411 | ||
6e68af66 MC |
412 | /** |
413 | * bio_add_pc_page - attempt to add page to bio | |
414 | * @bio: destination bio | |
415 | * @page: page to add | |
416 | * @len: vec entry length | |
417 | * @offset: vec entry offset | |
418 | * | |
419 | * Attempt to add a page to the bio_vec maplist. This can fail for a | |
420 | * number of reasons, such as the bio being full or target block | |
421 | * device limitations. The target block device must allow bio's | |
422 | * smaller than PAGE_SIZE, so it is always possible to add a single | |
423 | * page to an empty bio. This should only be used by REQ_PC bios. | |
424 | */ | |
425 | int bio_add_pc_page(request_queue_t *q, struct bio *bio, struct page *page, | |
426 | unsigned int len, unsigned int offset) | |
427 | { | |
defd94b7 | 428 | return __bio_add_page(q, bio, page, len, offset, q->max_hw_sectors); |
6e68af66 MC |
429 | } |
430 | ||
1da177e4 LT |
431 | /** |
432 | * bio_add_page - attempt to add page to bio | |
433 | * @bio: destination bio | |
434 | * @page: page to add | |
435 | * @len: vec entry length | |
436 | * @offset: vec entry offset | |
437 | * | |
438 | * Attempt to add a page to the bio_vec maplist. This can fail for a | |
439 | * number of reasons, such as the bio being full or target block | |
440 | * device limitations. The target block device must allow bio's | |
441 | * smaller than PAGE_SIZE, so it is always possible to add a single | |
442 | * page to an empty bio. | |
443 | */ | |
444 | int bio_add_page(struct bio *bio, struct page *page, unsigned int len, | |
445 | unsigned int offset) | |
446 | { | |
defd94b7 MC |
447 | struct request_queue *q = bdev_get_queue(bio->bi_bdev); |
448 | return __bio_add_page(q, bio, page, len, offset, q->max_sectors); | |
1da177e4 LT |
449 | } |
450 | ||
451 | struct bio_map_data { | |
452 | struct bio_vec *iovecs; | |
453 | void __user *userptr; | |
454 | }; | |
455 | ||
456 | static void bio_set_map_data(struct bio_map_data *bmd, struct bio *bio) | |
457 | { | |
458 | memcpy(bmd->iovecs, bio->bi_io_vec, sizeof(struct bio_vec) * bio->bi_vcnt); | |
459 | bio->bi_private = bmd; | |
460 | } | |
461 | ||
462 | static void bio_free_map_data(struct bio_map_data *bmd) | |
463 | { | |
464 | kfree(bmd->iovecs); | |
465 | kfree(bmd); | |
466 | } | |
467 | ||
468 | static struct bio_map_data *bio_alloc_map_data(int nr_segs) | |
469 | { | |
470 | struct bio_map_data *bmd = kmalloc(sizeof(*bmd), GFP_KERNEL); | |
471 | ||
472 | if (!bmd) | |
473 | return NULL; | |
474 | ||
475 | bmd->iovecs = kmalloc(sizeof(struct bio_vec) * nr_segs, GFP_KERNEL); | |
476 | if (bmd->iovecs) | |
477 | return bmd; | |
478 | ||
479 | kfree(bmd); | |
480 | return NULL; | |
481 | } | |
482 | ||
483 | /** | |
484 | * bio_uncopy_user - finish previously mapped bio | |
485 | * @bio: bio being terminated | |
486 | * | |
487 | * Free pages allocated from bio_copy_user() and write back data | |
488 | * to user space in case of a read. | |
489 | */ | |
490 | int bio_uncopy_user(struct bio *bio) | |
491 | { | |
492 | struct bio_map_data *bmd = bio->bi_private; | |
493 | const int read = bio_data_dir(bio) == READ; | |
494 | struct bio_vec *bvec; | |
495 | int i, ret = 0; | |
496 | ||
497 | __bio_for_each_segment(bvec, bio, i, 0) { | |
498 | char *addr = page_address(bvec->bv_page); | |
499 | unsigned int len = bmd->iovecs[i].bv_len; | |
500 | ||
501 | if (read && !ret && copy_to_user(bmd->userptr, addr, len)) | |
502 | ret = -EFAULT; | |
503 | ||
504 | __free_page(bvec->bv_page); | |
505 | bmd->userptr += len; | |
506 | } | |
507 | bio_free_map_data(bmd); | |
508 | bio_put(bio); | |
509 | return ret; | |
510 | } | |
511 | ||
512 | /** | |
513 | * bio_copy_user - copy user data to bio | |
514 | * @q: destination block queue | |
515 | * @uaddr: start of user address | |
516 | * @len: length in bytes | |
517 | * @write_to_vm: bool indicating writing to pages or not | |
518 | * | |
519 | * Prepares and returns a bio for indirect user io, bouncing data | |
520 | * to/from kernel pages as necessary. Must be paired with | |
521 | * call bio_uncopy_user() on io completion. | |
522 | */ | |
523 | struct bio *bio_copy_user(request_queue_t *q, unsigned long uaddr, | |
524 | unsigned int len, int write_to_vm) | |
525 | { | |
526 | unsigned long end = (uaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT; | |
527 | unsigned long start = uaddr >> PAGE_SHIFT; | |
528 | struct bio_map_data *bmd; | |
529 | struct bio_vec *bvec; | |
530 | struct page *page; | |
531 | struct bio *bio; | |
532 | int i, ret; | |
533 | ||
534 | bmd = bio_alloc_map_data(end - start); | |
535 | if (!bmd) | |
536 | return ERR_PTR(-ENOMEM); | |
537 | ||
538 | bmd->userptr = (void __user *) uaddr; | |
539 | ||
540 | ret = -ENOMEM; | |
541 | bio = bio_alloc(GFP_KERNEL, end - start); | |
542 | if (!bio) | |
543 | goto out_bmd; | |
544 | ||
545 | bio->bi_rw |= (!write_to_vm << BIO_RW); | |
546 | ||
547 | ret = 0; | |
548 | while (len) { | |
549 | unsigned int bytes = PAGE_SIZE; | |
550 | ||
551 | if (bytes > len) | |
552 | bytes = len; | |
553 | ||
554 | page = alloc_page(q->bounce_gfp | GFP_KERNEL); | |
555 | if (!page) { | |
556 | ret = -ENOMEM; | |
557 | break; | |
558 | } | |
559 | ||
defd94b7 | 560 | if (bio_add_pc_page(q, bio, page, bytes, 0) < bytes) { |
1da177e4 LT |
561 | ret = -EINVAL; |
562 | break; | |
563 | } | |
564 | ||
565 | len -= bytes; | |
566 | } | |
567 | ||
568 | if (ret) | |
569 | goto cleanup; | |
570 | ||
571 | /* | |
572 | * success | |
573 | */ | |
574 | if (!write_to_vm) { | |
575 | char __user *p = (char __user *) uaddr; | |
576 | ||
577 | /* | |
578 | * for a write, copy in data to kernel pages | |
579 | */ | |
580 | ret = -EFAULT; | |
581 | bio_for_each_segment(bvec, bio, i) { | |
582 | char *addr = page_address(bvec->bv_page); | |
583 | ||
584 | if (copy_from_user(addr, p, bvec->bv_len)) | |
585 | goto cleanup; | |
586 | p += bvec->bv_len; | |
587 | } | |
588 | } | |
589 | ||
590 | bio_set_map_data(bmd, bio); | |
591 | return bio; | |
592 | cleanup: | |
593 | bio_for_each_segment(bvec, bio, i) | |
594 | __free_page(bvec->bv_page); | |
595 | ||
596 | bio_put(bio); | |
597 | out_bmd: | |
598 | bio_free_map_data(bmd); | |
599 | return ERR_PTR(ret); | |
600 | } | |
601 | ||
f1970baf JB |
602 | static struct bio *__bio_map_user_iov(request_queue_t *q, |
603 | struct block_device *bdev, | |
604 | struct sg_iovec *iov, int iov_count, | |
605 | int write_to_vm) | |
1da177e4 | 606 | { |
f1970baf JB |
607 | int i, j; |
608 | int nr_pages = 0; | |
1da177e4 LT |
609 | struct page **pages; |
610 | struct bio *bio; | |
f1970baf JB |
611 | int cur_page = 0; |
612 | int ret, offset; | |
1da177e4 | 613 | |
f1970baf JB |
614 | for (i = 0; i < iov_count; i++) { |
615 | unsigned long uaddr = (unsigned long)iov[i].iov_base; | |
616 | unsigned long len = iov[i].iov_len; | |
617 | unsigned long end = (uaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT; | |
618 | unsigned long start = uaddr >> PAGE_SHIFT; | |
619 | ||
620 | nr_pages += end - start; | |
621 | /* | |
622 | * transfer and buffer must be aligned to at least hardsector | |
623 | * size for now, in the future we can relax this restriction | |
624 | */ | |
625 | if ((uaddr & queue_dma_alignment(q)) || (len & queue_dma_alignment(q))) | |
626 | return ERR_PTR(-EINVAL); | |
627 | } | |
628 | ||
629 | if (!nr_pages) | |
1da177e4 LT |
630 | return ERR_PTR(-EINVAL); |
631 | ||
632 | bio = bio_alloc(GFP_KERNEL, nr_pages); | |
633 | if (!bio) | |
634 | return ERR_PTR(-ENOMEM); | |
635 | ||
636 | ret = -ENOMEM; | |
637 | pages = kmalloc(nr_pages * sizeof(struct page *), GFP_KERNEL); | |
638 | if (!pages) | |
639 | goto out; | |
640 | ||
f1970baf JB |
641 | memset(pages, 0, nr_pages * sizeof(struct page *)); |
642 | ||
643 | for (i = 0; i < iov_count; i++) { | |
644 | unsigned long uaddr = (unsigned long)iov[i].iov_base; | |
645 | unsigned long len = iov[i].iov_len; | |
646 | unsigned long end = (uaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT; | |
647 | unsigned long start = uaddr >> PAGE_SHIFT; | |
648 | const int local_nr_pages = end - start; | |
649 | const int page_limit = cur_page + local_nr_pages; | |
650 | ||
651 | down_read(¤t->mm->mmap_sem); | |
652 | ret = get_user_pages(current, current->mm, uaddr, | |
653 | local_nr_pages, | |
654 | write_to_vm, 0, &pages[cur_page], NULL); | |
655 | up_read(¤t->mm->mmap_sem); | |
656 | ||
657 | if (ret < local_nr_pages) | |
658 | goto out_unmap; | |
659 | ||
660 | ||
661 | offset = uaddr & ~PAGE_MASK; | |
662 | for (j = cur_page; j < page_limit; j++) { | |
663 | unsigned int bytes = PAGE_SIZE - offset; | |
664 | ||
665 | if (len <= 0) | |
666 | break; | |
667 | ||
668 | if (bytes > len) | |
669 | bytes = len; | |
670 | ||
671 | /* | |
672 | * sorry... | |
673 | */ | |
defd94b7 MC |
674 | if (bio_add_pc_page(q, bio, pages[j], bytes, offset) < |
675 | bytes) | |
f1970baf JB |
676 | break; |
677 | ||
678 | len -= bytes; | |
679 | offset = 0; | |
680 | } | |
1da177e4 | 681 | |
f1970baf | 682 | cur_page = j; |
1da177e4 | 683 | /* |
f1970baf | 684 | * release the pages we didn't map into the bio, if any |
1da177e4 | 685 | */ |
f1970baf JB |
686 | while (j < page_limit) |
687 | page_cache_release(pages[j++]); | |
1da177e4 LT |
688 | } |
689 | ||
1da177e4 LT |
690 | kfree(pages); |
691 | ||
692 | /* | |
693 | * set data direction, and check if mapped pages need bouncing | |
694 | */ | |
695 | if (!write_to_vm) | |
696 | bio->bi_rw |= (1 << BIO_RW); | |
697 | ||
f1970baf | 698 | bio->bi_bdev = bdev; |
1da177e4 LT |
699 | bio->bi_flags |= (1 << BIO_USER_MAPPED); |
700 | return bio; | |
f1970baf JB |
701 | |
702 | out_unmap: | |
703 | for (i = 0; i < nr_pages; i++) { | |
704 | if(!pages[i]) | |
705 | break; | |
706 | page_cache_release(pages[i]); | |
707 | } | |
708 | out: | |
1da177e4 LT |
709 | kfree(pages); |
710 | bio_put(bio); | |
711 | return ERR_PTR(ret); | |
712 | } | |
713 | ||
714 | /** | |
715 | * bio_map_user - map user address into bio | |
67be2dd1 | 716 | * @q: the request_queue_t for the bio |
1da177e4 LT |
717 | * @bdev: destination block device |
718 | * @uaddr: start of user address | |
719 | * @len: length in bytes | |
720 | * @write_to_vm: bool indicating writing to pages or not | |
721 | * | |
722 | * Map the user space address into a bio suitable for io to a block | |
723 | * device. Returns an error pointer in case of error. | |
724 | */ | |
725 | struct bio *bio_map_user(request_queue_t *q, struct block_device *bdev, | |
726 | unsigned long uaddr, unsigned int len, int write_to_vm) | |
f1970baf JB |
727 | { |
728 | struct sg_iovec iov; | |
729 | ||
3f70353e | 730 | iov.iov_base = (void __user *)uaddr; |
f1970baf JB |
731 | iov.iov_len = len; |
732 | ||
733 | return bio_map_user_iov(q, bdev, &iov, 1, write_to_vm); | |
734 | } | |
735 | ||
736 | /** | |
737 | * bio_map_user_iov - map user sg_iovec table into bio | |
738 | * @q: the request_queue_t for the bio | |
739 | * @bdev: destination block device | |
740 | * @iov: the iovec. | |
741 | * @iov_count: number of elements in the iovec | |
742 | * @write_to_vm: bool indicating writing to pages or not | |
743 | * | |
744 | * Map the user space address into a bio suitable for io to a block | |
745 | * device. Returns an error pointer in case of error. | |
746 | */ | |
747 | struct bio *bio_map_user_iov(request_queue_t *q, struct block_device *bdev, | |
748 | struct sg_iovec *iov, int iov_count, | |
749 | int write_to_vm) | |
1da177e4 LT |
750 | { |
751 | struct bio *bio; | |
f1970baf | 752 | int len = 0, i; |
1da177e4 | 753 | |
f1970baf | 754 | bio = __bio_map_user_iov(q, bdev, iov, iov_count, write_to_vm); |
1da177e4 LT |
755 | |
756 | if (IS_ERR(bio)) | |
757 | return bio; | |
758 | ||
759 | /* | |
760 | * subtle -- if __bio_map_user() ended up bouncing a bio, | |
761 | * it would normally disappear when its bi_end_io is run. | |
762 | * however, we need it for the unmap, so grab an extra | |
763 | * reference to it | |
764 | */ | |
765 | bio_get(bio); | |
766 | ||
f1970baf JB |
767 | for (i = 0; i < iov_count; i++) |
768 | len += iov[i].iov_len; | |
769 | ||
1da177e4 LT |
770 | if (bio->bi_size == len) |
771 | return bio; | |
772 | ||
773 | /* | |
774 | * don't support partial mappings | |
775 | */ | |
776 | bio_endio(bio, bio->bi_size, 0); | |
777 | bio_unmap_user(bio); | |
778 | return ERR_PTR(-EINVAL); | |
779 | } | |
780 | ||
781 | static void __bio_unmap_user(struct bio *bio) | |
782 | { | |
783 | struct bio_vec *bvec; | |
784 | int i; | |
785 | ||
786 | /* | |
787 | * make sure we dirty pages we wrote to | |
788 | */ | |
789 | __bio_for_each_segment(bvec, bio, i, 0) { | |
790 | if (bio_data_dir(bio) == READ) | |
791 | set_page_dirty_lock(bvec->bv_page); | |
792 | ||
793 | page_cache_release(bvec->bv_page); | |
794 | } | |
795 | ||
796 | bio_put(bio); | |
797 | } | |
798 | ||
799 | /** | |
800 | * bio_unmap_user - unmap a bio | |
801 | * @bio: the bio being unmapped | |
802 | * | |
803 | * Unmap a bio previously mapped by bio_map_user(). Must be called with | |
804 | * a process context. | |
805 | * | |
806 | * bio_unmap_user() may sleep. | |
807 | */ | |
808 | void bio_unmap_user(struct bio *bio) | |
809 | { | |
810 | __bio_unmap_user(bio); | |
811 | bio_put(bio); | |
812 | } | |
813 | ||
b823825e JA |
814 | static int bio_map_kern_endio(struct bio *bio, unsigned int bytes_done, int err) |
815 | { | |
816 | if (bio->bi_size) | |
817 | return 1; | |
818 | ||
819 | bio_put(bio); | |
820 | return 0; | |
821 | } | |
822 | ||
823 | ||
df46b9a4 | 824 | static struct bio *__bio_map_kern(request_queue_t *q, void *data, |
27496a8c | 825 | unsigned int len, gfp_t gfp_mask) |
df46b9a4 MC |
826 | { |
827 | unsigned long kaddr = (unsigned long)data; | |
828 | unsigned long end = (kaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT; | |
829 | unsigned long start = kaddr >> PAGE_SHIFT; | |
830 | const int nr_pages = end - start; | |
831 | int offset, i; | |
832 | struct bio *bio; | |
833 | ||
834 | bio = bio_alloc(gfp_mask, nr_pages); | |
835 | if (!bio) | |
836 | return ERR_PTR(-ENOMEM); | |
837 | ||
838 | offset = offset_in_page(kaddr); | |
839 | for (i = 0; i < nr_pages; i++) { | |
840 | unsigned int bytes = PAGE_SIZE - offset; | |
841 | ||
842 | if (len <= 0) | |
843 | break; | |
844 | ||
845 | if (bytes > len) | |
846 | bytes = len; | |
847 | ||
defd94b7 MC |
848 | if (bio_add_pc_page(q, bio, virt_to_page(data), bytes, |
849 | offset) < bytes) | |
df46b9a4 MC |
850 | break; |
851 | ||
852 | data += bytes; | |
853 | len -= bytes; | |
854 | offset = 0; | |
855 | } | |
856 | ||
b823825e | 857 | bio->bi_end_io = bio_map_kern_endio; |
df46b9a4 MC |
858 | return bio; |
859 | } | |
860 | ||
861 | /** | |
862 | * bio_map_kern - map kernel address into bio | |
863 | * @q: the request_queue_t for the bio | |
864 | * @data: pointer to buffer to map | |
865 | * @len: length in bytes | |
866 | * @gfp_mask: allocation flags for bio allocation | |
867 | * | |
868 | * Map the kernel address into a bio suitable for io to a block | |
869 | * device. Returns an error pointer in case of error. | |
870 | */ | |
871 | struct bio *bio_map_kern(request_queue_t *q, void *data, unsigned int len, | |
27496a8c | 872 | gfp_t gfp_mask) |
df46b9a4 MC |
873 | { |
874 | struct bio *bio; | |
875 | ||
876 | bio = __bio_map_kern(q, data, len, gfp_mask); | |
877 | if (IS_ERR(bio)) | |
878 | return bio; | |
879 | ||
880 | if (bio->bi_size == len) | |
881 | return bio; | |
882 | ||
883 | /* | |
884 | * Don't support partial mappings. | |
885 | */ | |
886 | bio_put(bio); | |
887 | return ERR_PTR(-EINVAL); | |
888 | } | |
889 | ||
1da177e4 LT |
890 | /* |
891 | * bio_set_pages_dirty() and bio_check_pages_dirty() are support functions | |
892 | * for performing direct-IO in BIOs. | |
893 | * | |
894 | * The problem is that we cannot run set_page_dirty() from interrupt context | |
895 | * because the required locks are not interrupt-safe. So what we can do is to | |
896 | * mark the pages dirty _before_ performing IO. And in interrupt context, | |
897 | * check that the pages are still dirty. If so, fine. If not, redirty them | |
898 | * in process context. | |
899 | * | |
900 | * We special-case compound pages here: normally this means reads into hugetlb | |
901 | * pages. The logic in here doesn't really work right for compound pages | |
902 | * because the VM does not uniformly chase down the head page in all cases. | |
903 | * But dirtiness of compound pages is pretty meaningless anyway: the VM doesn't | |
904 | * handle them at all. So we skip compound pages here at an early stage. | |
905 | * | |
906 | * Note that this code is very hard to test under normal circumstances because | |
907 | * direct-io pins the pages with get_user_pages(). This makes | |
908 | * is_page_cache_freeable return false, and the VM will not clean the pages. | |
909 | * But other code (eg, pdflush) could clean the pages if they are mapped | |
910 | * pagecache. | |
911 | * | |
912 | * Simply disabling the call to bio_set_pages_dirty() is a good way to test the | |
913 | * deferred bio dirtying paths. | |
914 | */ | |
915 | ||
916 | /* | |
917 | * bio_set_pages_dirty() will mark all the bio's pages as dirty. | |
918 | */ | |
919 | void bio_set_pages_dirty(struct bio *bio) | |
920 | { | |
921 | struct bio_vec *bvec = bio->bi_io_vec; | |
922 | int i; | |
923 | ||
924 | for (i = 0; i < bio->bi_vcnt; i++) { | |
925 | struct page *page = bvec[i].bv_page; | |
926 | ||
927 | if (page && !PageCompound(page)) | |
928 | set_page_dirty_lock(page); | |
929 | } | |
930 | } | |
931 | ||
932 | static void bio_release_pages(struct bio *bio) | |
933 | { | |
934 | struct bio_vec *bvec = bio->bi_io_vec; | |
935 | int i; | |
936 | ||
937 | for (i = 0; i < bio->bi_vcnt; i++) { | |
938 | struct page *page = bvec[i].bv_page; | |
939 | ||
940 | if (page) | |
941 | put_page(page); | |
942 | } | |
943 | } | |
944 | ||
945 | /* | |
946 | * bio_check_pages_dirty() will check that all the BIO's pages are still dirty. | |
947 | * If they are, then fine. If, however, some pages are clean then they must | |
948 | * have been written out during the direct-IO read. So we take another ref on | |
949 | * the BIO and the offending pages and re-dirty the pages in process context. | |
950 | * | |
951 | * It is expected that bio_check_pages_dirty() will wholly own the BIO from | |
952 | * here on. It will run one page_cache_release() against each page and will | |
953 | * run one bio_put() against the BIO. | |
954 | */ | |
955 | ||
956 | static void bio_dirty_fn(void *data); | |
957 | ||
958 | static DECLARE_WORK(bio_dirty_work, bio_dirty_fn, NULL); | |
959 | static DEFINE_SPINLOCK(bio_dirty_lock); | |
960 | static struct bio *bio_dirty_list; | |
961 | ||
962 | /* | |
963 | * This runs in process context | |
964 | */ | |
965 | static void bio_dirty_fn(void *data) | |
966 | { | |
967 | unsigned long flags; | |
968 | struct bio *bio; | |
969 | ||
970 | spin_lock_irqsave(&bio_dirty_lock, flags); | |
971 | bio = bio_dirty_list; | |
972 | bio_dirty_list = NULL; | |
973 | spin_unlock_irqrestore(&bio_dirty_lock, flags); | |
974 | ||
975 | while (bio) { | |
976 | struct bio *next = bio->bi_private; | |
977 | ||
978 | bio_set_pages_dirty(bio); | |
979 | bio_release_pages(bio); | |
980 | bio_put(bio); | |
981 | bio = next; | |
982 | } | |
983 | } | |
984 | ||
985 | void bio_check_pages_dirty(struct bio *bio) | |
986 | { | |
987 | struct bio_vec *bvec = bio->bi_io_vec; | |
988 | int nr_clean_pages = 0; | |
989 | int i; | |
990 | ||
991 | for (i = 0; i < bio->bi_vcnt; i++) { | |
992 | struct page *page = bvec[i].bv_page; | |
993 | ||
994 | if (PageDirty(page) || PageCompound(page)) { | |
995 | page_cache_release(page); | |
996 | bvec[i].bv_page = NULL; | |
997 | } else { | |
998 | nr_clean_pages++; | |
999 | } | |
1000 | } | |
1001 | ||
1002 | if (nr_clean_pages) { | |
1003 | unsigned long flags; | |
1004 | ||
1005 | spin_lock_irqsave(&bio_dirty_lock, flags); | |
1006 | bio->bi_private = bio_dirty_list; | |
1007 | bio_dirty_list = bio; | |
1008 | spin_unlock_irqrestore(&bio_dirty_lock, flags); | |
1009 | schedule_work(&bio_dirty_work); | |
1010 | } else { | |
1011 | bio_put(bio); | |
1012 | } | |
1013 | } | |
1014 | ||
1015 | /** | |
1016 | * bio_endio - end I/O on a bio | |
1017 | * @bio: bio | |
1018 | * @bytes_done: number of bytes completed | |
1019 | * @error: error, if any | |
1020 | * | |
1021 | * Description: | |
1022 | * bio_endio() will end I/O on @bytes_done number of bytes. This may be | |
1023 | * just a partial part of the bio, or it may be the whole bio. bio_endio() | |
1024 | * is the preferred way to end I/O on a bio, it takes care of decrementing | |
1025 | * bi_size and clearing BIO_UPTODATE on error. @error is 0 on success, and | |
1026 | * and one of the established -Exxxx (-EIO, for instance) error values in | |
1027 | * case something went wrong. Noone should call bi_end_io() directly on | |
1028 | * a bio unless they own it and thus know that it has an end_io function. | |
1029 | **/ | |
1030 | void bio_endio(struct bio *bio, unsigned int bytes_done, int error) | |
1031 | { | |
1032 | if (error) | |
1033 | clear_bit(BIO_UPTODATE, &bio->bi_flags); | |
1034 | ||
1035 | if (unlikely(bytes_done > bio->bi_size)) { | |
1036 | printk("%s: want %u bytes done, only %u left\n", __FUNCTION__, | |
1037 | bytes_done, bio->bi_size); | |
1038 | bytes_done = bio->bi_size; | |
1039 | } | |
1040 | ||
1041 | bio->bi_size -= bytes_done; | |
1042 | bio->bi_sector += (bytes_done >> 9); | |
1043 | ||
1044 | if (bio->bi_end_io) | |
1045 | bio->bi_end_io(bio, bytes_done, error); | |
1046 | } | |
1047 | ||
1048 | void bio_pair_release(struct bio_pair *bp) | |
1049 | { | |
1050 | if (atomic_dec_and_test(&bp->cnt)) { | |
1051 | struct bio *master = bp->bio1.bi_private; | |
1052 | ||
1053 | bio_endio(master, master->bi_size, bp->error); | |
1054 | mempool_free(bp, bp->bio2.bi_private); | |
1055 | } | |
1056 | } | |
1057 | ||
1058 | static int bio_pair_end_1(struct bio * bi, unsigned int done, int err) | |
1059 | { | |
1060 | struct bio_pair *bp = container_of(bi, struct bio_pair, bio1); | |
1061 | ||
1062 | if (err) | |
1063 | bp->error = err; | |
1064 | ||
1065 | if (bi->bi_size) | |
1066 | return 1; | |
1067 | ||
1068 | bio_pair_release(bp); | |
1069 | return 0; | |
1070 | } | |
1071 | ||
1072 | static int bio_pair_end_2(struct bio * bi, unsigned int done, int err) | |
1073 | { | |
1074 | struct bio_pair *bp = container_of(bi, struct bio_pair, bio2); | |
1075 | ||
1076 | if (err) | |
1077 | bp->error = err; | |
1078 | ||
1079 | if (bi->bi_size) | |
1080 | return 1; | |
1081 | ||
1082 | bio_pair_release(bp); | |
1083 | return 0; | |
1084 | } | |
1085 | ||
1086 | /* | |
1087 | * split a bio - only worry about a bio with a single page | |
1088 | * in it's iovec | |
1089 | */ | |
1090 | struct bio_pair *bio_split(struct bio *bi, mempool_t *pool, int first_sectors) | |
1091 | { | |
1092 | struct bio_pair *bp = mempool_alloc(pool, GFP_NOIO); | |
1093 | ||
1094 | if (!bp) | |
1095 | return bp; | |
1096 | ||
1097 | BUG_ON(bi->bi_vcnt != 1); | |
1098 | BUG_ON(bi->bi_idx != 0); | |
1099 | atomic_set(&bp->cnt, 3); | |
1100 | bp->error = 0; | |
1101 | bp->bio1 = *bi; | |
1102 | bp->bio2 = *bi; | |
1103 | bp->bio2.bi_sector += first_sectors; | |
1104 | bp->bio2.bi_size -= first_sectors << 9; | |
1105 | bp->bio1.bi_size = first_sectors << 9; | |
1106 | ||
1107 | bp->bv1 = bi->bi_io_vec[0]; | |
1108 | bp->bv2 = bi->bi_io_vec[0]; | |
1109 | bp->bv2.bv_offset += first_sectors << 9; | |
1110 | bp->bv2.bv_len -= first_sectors << 9; | |
1111 | bp->bv1.bv_len = first_sectors << 9; | |
1112 | ||
1113 | bp->bio1.bi_io_vec = &bp->bv1; | |
1114 | bp->bio2.bi_io_vec = &bp->bv2; | |
1115 | ||
1116 | bp->bio1.bi_end_io = bio_pair_end_1; | |
1117 | bp->bio2.bi_end_io = bio_pair_end_2; | |
1118 | ||
1119 | bp->bio1.bi_private = bi; | |
1120 | bp->bio2.bi_private = pool; | |
1121 | ||
1122 | return bp; | |
1123 | } | |
1124 | ||
dd0fc66f | 1125 | static void *bio_pair_alloc(gfp_t gfp_flags, void *data) |
1da177e4 LT |
1126 | { |
1127 | return kmalloc(sizeof(struct bio_pair), gfp_flags); | |
1128 | } | |
1129 | ||
1130 | static void bio_pair_free(void *bp, void *data) | |
1131 | { | |
1132 | kfree(bp); | |
1133 | } | |
1134 | ||
1135 | ||
1136 | /* | |
1137 | * create memory pools for biovec's in a bio_set. | |
1138 | * use the global biovec slabs created for general use. | |
1139 | */ | |
1140 | static int biovec_create_pools(struct bio_set *bs, int pool_entries, int scale) | |
1141 | { | |
1142 | int i; | |
1143 | ||
1144 | for (i = 0; i < BIOVEC_NR_POOLS; i++) { | |
1145 | struct biovec_slab *bp = bvec_slabs + i; | |
1146 | mempool_t **bvp = bs->bvec_pools + i; | |
1147 | ||
1148 | if (i >= scale) | |
1149 | pool_entries >>= 1; | |
1150 | ||
1151 | *bvp = mempool_create(pool_entries, mempool_alloc_slab, | |
1152 | mempool_free_slab, bp->slab); | |
1153 | if (!*bvp) | |
1154 | return -ENOMEM; | |
1155 | } | |
1156 | return 0; | |
1157 | } | |
1158 | ||
1159 | static void biovec_free_pools(struct bio_set *bs) | |
1160 | { | |
1161 | int i; | |
1162 | ||
1163 | for (i = 0; i < BIOVEC_NR_POOLS; i++) { | |
1164 | mempool_t *bvp = bs->bvec_pools[i]; | |
1165 | ||
1166 | if (bvp) | |
1167 | mempool_destroy(bvp); | |
1168 | } | |
1169 | ||
1170 | } | |
1171 | ||
1172 | void bioset_free(struct bio_set *bs) | |
1173 | { | |
1174 | if (bs->bio_pool) | |
1175 | mempool_destroy(bs->bio_pool); | |
1176 | ||
1177 | biovec_free_pools(bs); | |
1178 | ||
1179 | kfree(bs); | |
1180 | } | |
1181 | ||
1182 | struct bio_set *bioset_create(int bio_pool_size, int bvec_pool_size, int scale) | |
1183 | { | |
1184 | struct bio_set *bs = kmalloc(sizeof(*bs), GFP_KERNEL); | |
1185 | ||
1186 | if (!bs) | |
1187 | return NULL; | |
1188 | ||
1189 | memset(bs, 0, sizeof(*bs)); | |
1190 | bs->bio_pool = mempool_create(bio_pool_size, mempool_alloc_slab, | |
1191 | mempool_free_slab, bio_slab); | |
1192 | ||
1193 | if (!bs->bio_pool) | |
1194 | goto bad; | |
1195 | ||
1196 | if (!biovec_create_pools(bs, bvec_pool_size, scale)) | |
1197 | return bs; | |
1198 | ||
1199 | bad: | |
1200 | bioset_free(bs); | |
1201 | return NULL; | |
1202 | } | |
1203 | ||
1204 | static void __init biovec_init_slabs(void) | |
1205 | { | |
1206 | int i; | |
1207 | ||
1208 | for (i = 0; i < BIOVEC_NR_POOLS; i++) { | |
1209 | int size; | |
1210 | struct biovec_slab *bvs = bvec_slabs + i; | |
1211 | ||
1212 | size = bvs->nr_vecs * sizeof(struct bio_vec); | |
1213 | bvs->slab = kmem_cache_create(bvs->name, size, 0, | |
1214 | SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL, NULL); | |
1215 | } | |
1216 | } | |
1217 | ||
1218 | static int __init init_bio(void) | |
1219 | { | |
1220 | int megabytes, bvec_pool_entries; | |
1221 | int scale = BIOVEC_NR_POOLS; | |
1222 | ||
1223 | bio_slab = kmem_cache_create("bio", sizeof(struct bio), 0, | |
1224 | SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL, NULL); | |
1225 | ||
1226 | biovec_init_slabs(); | |
1227 | ||
1228 | megabytes = nr_free_pages() >> (20 - PAGE_SHIFT); | |
1229 | ||
1230 | /* | |
1231 | * find out where to start scaling | |
1232 | */ | |
1233 | if (megabytes <= 16) | |
1234 | scale = 0; | |
1235 | else if (megabytes <= 32) | |
1236 | scale = 1; | |
1237 | else if (megabytes <= 64) | |
1238 | scale = 2; | |
1239 | else if (megabytes <= 96) | |
1240 | scale = 3; | |
1241 | else if (megabytes <= 128) | |
1242 | scale = 4; | |
1243 | ||
1244 | /* | |
1245 | * scale number of entries | |
1246 | */ | |
1247 | bvec_pool_entries = megabytes * 2; | |
1248 | if (bvec_pool_entries > 256) | |
1249 | bvec_pool_entries = 256; | |
1250 | ||
1251 | fs_bio_set = bioset_create(BIO_POOL_SIZE, bvec_pool_entries, scale); | |
1252 | if (!fs_bio_set) | |
1253 | panic("bio: can't allocate bios\n"); | |
1254 | ||
1255 | bio_split_pool = mempool_create(BIO_SPLIT_ENTRIES, | |
1256 | bio_pair_alloc, bio_pair_free, NULL); | |
1257 | if (!bio_split_pool) | |
1258 | panic("bio: can't create split pool\n"); | |
1259 | ||
1260 | return 0; | |
1261 | } | |
1262 | ||
1263 | subsys_initcall(init_bio); | |
1264 | ||
1265 | EXPORT_SYMBOL(bio_alloc); | |
1266 | EXPORT_SYMBOL(bio_put); | |
3676347a | 1267 | EXPORT_SYMBOL(bio_free); |
1da177e4 LT |
1268 | EXPORT_SYMBOL(bio_endio); |
1269 | EXPORT_SYMBOL(bio_init); | |
1270 | EXPORT_SYMBOL(__bio_clone); | |
1271 | EXPORT_SYMBOL(bio_clone); | |
1272 | EXPORT_SYMBOL(bio_phys_segments); | |
1273 | EXPORT_SYMBOL(bio_hw_segments); | |
1274 | EXPORT_SYMBOL(bio_add_page); | |
6e68af66 | 1275 | EXPORT_SYMBOL(bio_add_pc_page); |
1da177e4 LT |
1276 | EXPORT_SYMBOL(bio_get_nr_vecs); |
1277 | EXPORT_SYMBOL(bio_map_user); | |
1278 | EXPORT_SYMBOL(bio_unmap_user); | |
df46b9a4 | 1279 | EXPORT_SYMBOL(bio_map_kern); |
1da177e4 LT |
1280 | EXPORT_SYMBOL(bio_pair_release); |
1281 | EXPORT_SYMBOL(bio_split); | |
1282 | EXPORT_SYMBOL(bio_split_pool); | |
1283 | EXPORT_SYMBOL(bio_copy_user); | |
1284 | EXPORT_SYMBOL(bio_uncopy_user); | |
1285 | EXPORT_SYMBOL(bioset_create); | |
1286 | EXPORT_SYMBOL(bioset_free); | |
1287 | EXPORT_SYMBOL(bio_alloc_bioset); |