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