Merge branch 'omap-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
[linux-2.6/mini2440.git] / fs / bio.c
blob12da5db8682c24903d492798b365c010ba378c49
1 /*
2 * Copyright (C) 2001 Jens Axboe <axboe@kernel.dk>
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.
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.
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-
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>
28 #include <scsi/sg.h> /* for struct sg_iovec */
30 #include <trace/events/block.h>
33 * Test patch to inline a certain number of bi_io_vec's inside the bio
34 * itself, to shrink a bio data allocation from two mempool calls to one
36 #define BIO_INLINE_VECS 4
38 static mempool_t *bio_split_pool __read_mostly;
41 * if you change this list, also change bvec_alloc or things will
42 * break badly! cannot be bigger than what you can fit into an
43 * unsigned short
45 #define BV(x) { .nr_vecs = x, .name = "biovec-"__stringify(x) }
46 struct biovec_slab bvec_slabs[BIOVEC_NR_POOLS] __read_mostly = {
47 BV(1), BV(4), BV(16), BV(64), BV(128), BV(BIO_MAX_PAGES),
49 #undef BV
52 * fs_bio_set is the bio_set containing bio and iovec memory pools used by
53 * IO code that does not need private memory pools.
55 struct bio_set *fs_bio_set;
58 * Our slab pool management
60 struct bio_slab {
61 struct kmem_cache *slab;
62 unsigned int slab_ref;
63 unsigned int slab_size;
64 char name[8];
66 static DEFINE_MUTEX(bio_slab_lock);
67 static struct bio_slab *bio_slabs;
68 static unsigned int bio_slab_nr, bio_slab_max;
70 static struct kmem_cache *bio_find_or_create_slab(unsigned int extra_size)
72 unsigned int sz = sizeof(struct bio) + extra_size;
73 struct kmem_cache *slab = NULL;
74 struct bio_slab *bslab;
75 unsigned int i, entry = -1;
77 mutex_lock(&bio_slab_lock);
79 i = 0;
80 while (i < bio_slab_nr) {
81 struct bio_slab *bslab = &bio_slabs[i];
83 if (!bslab->slab && entry == -1)
84 entry = i;
85 else if (bslab->slab_size == sz) {
86 slab = bslab->slab;
87 bslab->slab_ref++;
88 break;
90 i++;
93 if (slab)
94 goto out_unlock;
96 if (bio_slab_nr == bio_slab_max && entry == -1) {
97 bio_slab_max <<= 1;
98 bio_slabs = krealloc(bio_slabs,
99 bio_slab_max * sizeof(struct bio_slab),
100 GFP_KERNEL);
101 if (!bio_slabs)
102 goto out_unlock;
104 if (entry == -1)
105 entry = bio_slab_nr++;
107 bslab = &bio_slabs[entry];
109 snprintf(bslab->name, sizeof(bslab->name), "bio-%d", entry);
110 slab = kmem_cache_create(bslab->name, sz, 0, SLAB_HWCACHE_ALIGN, NULL);
111 if (!slab)
112 goto out_unlock;
114 printk("bio: create slab <%s> at %d\n", bslab->name, entry);
115 bslab->slab = slab;
116 bslab->slab_ref = 1;
117 bslab->slab_size = sz;
118 out_unlock:
119 mutex_unlock(&bio_slab_lock);
120 return slab;
123 static void bio_put_slab(struct bio_set *bs)
125 struct bio_slab *bslab = NULL;
126 unsigned int i;
128 mutex_lock(&bio_slab_lock);
130 for (i = 0; i < bio_slab_nr; i++) {
131 if (bs->bio_slab == bio_slabs[i].slab) {
132 bslab = &bio_slabs[i];
133 break;
137 if (WARN(!bslab, KERN_ERR "bio: unable to find slab!\n"))
138 goto out;
140 WARN_ON(!bslab->slab_ref);
142 if (--bslab->slab_ref)
143 goto out;
145 kmem_cache_destroy(bslab->slab);
146 bslab->slab = NULL;
148 out:
149 mutex_unlock(&bio_slab_lock);
152 unsigned int bvec_nr_vecs(unsigned short idx)
154 return bvec_slabs[idx].nr_vecs;
157 void bvec_free_bs(struct bio_set *bs, struct bio_vec *bv, unsigned int idx)
159 BIO_BUG_ON(idx >= BIOVEC_NR_POOLS);
161 if (idx == BIOVEC_MAX_IDX)
162 mempool_free(bv, bs->bvec_pool);
163 else {
164 struct biovec_slab *bvs = bvec_slabs + idx;
166 kmem_cache_free(bvs->slab, bv);
170 struct bio_vec *bvec_alloc_bs(gfp_t gfp_mask, int nr, unsigned long *idx,
171 struct bio_set *bs)
173 struct bio_vec *bvl;
176 * see comment near bvec_array define!
178 switch (nr) {
179 case 1:
180 *idx = 0;
181 break;
182 case 2 ... 4:
183 *idx = 1;
184 break;
185 case 5 ... 16:
186 *idx = 2;
187 break;
188 case 17 ... 64:
189 *idx = 3;
190 break;
191 case 65 ... 128:
192 *idx = 4;
193 break;
194 case 129 ... BIO_MAX_PAGES:
195 *idx = 5;
196 break;
197 default:
198 return NULL;
202 * idx now points to the pool we want to allocate from. only the
203 * 1-vec entry pool is mempool backed.
205 if (*idx == BIOVEC_MAX_IDX) {
206 fallback:
207 bvl = mempool_alloc(bs->bvec_pool, gfp_mask);
208 } else {
209 struct biovec_slab *bvs = bvec_slabs + *idx;
210 gfp_t __gfp_mask = gfp_mask & ~(__GFP_WAIT | __GFP_IO);
213 * Make this allocation restricted and don't dump info on
214 * allocation failures, since we'll fallback to the mempool
215 * in case of failure.
217 __gfp_mask |= __GFP_NOMEMALLOC | __GFP_NORETRY | __GFP_NOWARN;
220 * Try a slab allocation. If this fails and __GFP_WAIT
221 * is set, retry with the 1-entry mempool
223 bvl = kmem_cache_alloc(bvs->slab, __gfp_mask);
224 if (unlikely(!bvl && (gfp_mask & __GFP_WAIT))) {
225 *idx = BIOVEC_MAX_IDX;
226 goto fallback;
230 return bvl;
233 void bio_free(struct bio *bio, struct bio_set *bs)
235 void *p;
237 if (bio_has_allocated_vec(bio))
238 bvec_free_bs(bs, bio->bi_io_vec, BIO_POOL_IDX(bio));
240 if (bio_integrity(bio))
241 bio_integrity_free(bio, bs);
244 * If we have front padding, adjust the bio pointer before freeing
246 p = bio;
247 if (bs->front_pad)
248 p -= bs->front_pad;
250 mempool_free(p, bs->bio_pool);
252 EXPORT_SYMBOL(bio_free);
254 void bio_init(struct bio *bio)
256 memset(bio, 0, sizeof(*bio));
257 bio->bi_flags = 1 << BIO_UPTODATE;
258 bio->bi_comp_cpu = -1;
259 atomic_set(&bio->bi_cnt, 1);
261 EXPORT_SYMBOL(bio_init);
264 * bio_alloc_bioset - allocate a bio for I/O
265 * @gfp_mask: the GFP_ mask given to the slab allocator
266 * @nr_iovecs: number of iovecs to pre-allocate
267 * @bs: the bio_set to allocate from. If %NULL, just use kmalloc
269 * Description:
270 * bio_alloc_bioset will first try its own mempool to satisfy the allocation.
271 * If %__GFP_WAIT is set then we will block on the internal pool waiting
272 * for a &struct bio to become free. If a %NULL @bs is passed in, we will
273 * fall back to just using @kmalloc to allocate the required memory.
275 * Note that the caller must set ->bi_destructor on succesful return
276 * of a bio, to do the appropriate freeing of the bio once the reference
277 * count drops to zero.
279 struct bio *bio_alloc_bioset(gfp_t gfp_mask, int nr_iovecs, struct bio_set *bs)
281 unsigned long idx = BIO_POOL_NONE;
282 struct bio_vec *bvl = NULL;
283 struct bio *bio;
284 void *p;
286 p = mempool_alloc(bs->bio_pool, gfp_mask);
287 if (unlikely(!p))
288 return NULL;
289 bio = p + bs->front_pad;
291 bio_init(bio);
293 if (unlikely(!nr_iovecs))
294 goto out_set;
296 if (nr_iovecs <= BIO_INLINE_VECS) {
297 bvl = bio->bi_inline_vecs;
298 nr_iovecs = BIO_INLINE_VECS;
299 } else {
300 bvl = bvec_alloc_bs(gfp_mask, nr_iovecs, &idx, bs);
301 if (unlikely(!bvl))
302 goto err_free;
304 nr_iovecs = bvec_nr_vecs(idx);
306 out_set:
307 bio->bi_flags |= idx << BIO_POOL_OFFSET;
308 bio->bi_max_vecs = nr_iovecs;
309 bio->bi_io_vec = bvl;
310 return bio;
312 err_free:
313 mempool_free(p, bs->bio_pool);
314 return NULL;
316 EXPORT_SYMBOL(bio_alloc_bioset);
318 static void bio_fs_destructor(struct bio *bio)
320 bio_free(bio, fs_bio_set);
324 * bio_alloc - allocate a new bio, memory pool backed
325 * @gfp_mask: allocation mask to use
326 * @nr_iovecs: number of iovecs
328 * bio_alloc will allocate a bio and associated bio_vec array that can hold
329 * at least @nr_iovecs entries. Allocations will be done from the
330 * fs_bio_set. Also see @bio_alloc_bioset and @bio_kmalloc.
332 * If %__GFP_WAIT is set, then bio_alloc will always be able to allocate
333 * a bio. This is due to the mempool guarantees. To make this work, callers
334 * must never allocate more than 1 bio at a time from this pool. Callers
335 * that need to allocate more than 1 bio must always submit the previously
336 * allocated bio for IO before attempting to allocate a new one. Failure to
337 * do so can cause livelocks under memory pressure.
339 * RETURNS:
340 * Pointer to new bio on success, NULL on failure.
342 struct bio *bio_alloc(gfp_t gfp_mask, int nr_iovecs)
344 struct bio *bio = bio_alloc_bioset(gfp_mask, nr_iovecs, fs_bio_set);
346 if (bio)
347 bio->bi_destructor = bio_fs_destructor;
349 return bio;
351 EXPORT_SYMBOL(bio_alloc);
353 static void bio_kmalloc_destructor(struct bio *bio)
355 if (bio_integrity(bio))
356 bio_integrity_free(bio, fs_bio_set);
357 kfree(bio);
361 * bio_kmalloc - allocate a bio for I/O using kmalloc()
362 * @gfp_mask: the GFP_ mask given to the slab allocator
363 * @nr_iovecs: number of iovecs to pre-allocate
365 * Description:
366 * Allocate a new bio with @nr_iovecs bvecs. If @gfp_mask contains
367 * %__GFP_WAIT, the allocation is guaranteed to succeed.
370 struct bio *bio_kmalloc(gfp_t gfp_mask, int nr_iovecs)
372 struct bio *bio;
374 bio = kmalloc(sizeof(struct bio) + nr_iovecs * sizeof(struct bio_vec),
375 gfp_mask);
376 if (unlikely(!bio))
377 return NULL;
379 bio_init(bio);
380 bio->bi_flags |= BIO_POOL_NONE << BIO_POOL_OFFSET;
381 bio->bi_max_vecs = nr_iovecs;
382 bio->bi_io_vec = bio->bi_inline_vecs;
383 bio->bi_destructor = bio_kmalloc_destructor;
385 return bio;
387 EXPORT_SYMBOL(bio_kmalloc);
389 void zero_fill_bio(struct bio *bio)
391 unsigned long flags;
392 struct bio_vec *bv;
393 int i;
395 bio_for_each_segment(bv, bio, i) {
396 char *data = bvec_kmap_irq(bv, &flags);
397 memset(data, 0, bv->bv_len);
398 flush_dcache_page(bv->bv_page);
399 bvec_kunmap_irq(data, &flags);
402 EXPORT_SYMBOL(zero_fill_bio);
405 * bio_put - release a reference to a bio
406 * @bio: bio to release reference to
408 * Description:
409 * Put a reference to a &struct bio, either one you have gotten with
410 * bio_alloc, bio_get or bio_clone. The last put of a bio will free it.
412 void bio_put(struct bio *bio)
414 BIO_BUG_ON(!atomic_read(&bio->bi_cnt));
417 * last put frees it
419 if (atomic_dec_and_test(&bio->bi_cnt)) {
420 bio->bi_next = NULL;
421 bio->bi_destructor(bio);
424 EXPORT_SYMBOL(bio_put);
426 inline int bio_phys_segments(struct request_queue *q, struct bio *bio)
428 if (unlikely(!bio_flagged(bio, BIO_SEG_VALID)))
429 blk_recount_segments(q, bio);
431 return bio->bi_phys_segments;
433 EXPORT_SYMBOL(bio_phys_segments);
436 * __bio_clone - clone a bio
437 * @bio: destination bio
438 * @bio_src: bio to clone
440 * Clone a &bio. Caller will own the returned bio, but not
441 * the actual data it points to. Reference count of returned
442 * bio will be one.
444 void __bio_clone(struct bio *bio, struct bio *bio_src)
446 memcpy(bio->bi_io_vec, bio_src->bi_io_vec,
447 bio_src->bi_max_vecs * sizeof(struct bio_vec));
450 * most users will be overriding ->bi_bdev with a new target,
451 * so we don't set nor calculate new physical/hw segment counts here
453 bio->bi_sector = bio_src->bi_sector;
454 bio->bi_bdev = bio_src->bi_bdev;
455 bio->bi_flags |= 1 << BIO_CLONED;
456 bio->bi_rw = bio_src->bi_rw;
457 bio->bi_vcnt = bio_src->bi_vcnt;
458 bio->bi_size = bio_src->bi_size;
459 bio->bi_idx = bio_src->bi_idx;
461 EXPORT_SYMBOL(__bio_clone);
464 * bio_clone - clone a bio
465 * @bio: bio to clone
466 * @gfp_mask: allocation priority
468 * Like __bio_clone, only also allocates the returned bio
470 struct bio *bio_clone(struct bio *bio, gfp_t gfp_mask)
472 struct bio *b = bio_alloc_bioset(gfp_mask, bio->bi_max_vecs, fs_bio_set);
474 if (!b)
475 return NULL;
477 b->bi_destructor = bio_fs_destructor;
478 __bio_clone(b, bio);
480 if (bio_integrity(bio)) {
481 int ret;
483 ret = bio_integrity_clone(b, bio, gfp_mask, fs_bio_set);
485 if (ret < 0) {
486 bio_put(b);
487 return NULL;
491 return b;
493 EXPORT_SYMBOL(bio_clone);
496 * bio_get_nr_vecs - return approx number of vecs
497 * @bdev: I/O target
499 * Return the approximate number of pages we can send to this target.
500 * There's no guarantee that you will be able to fit this number of pages
501 * into a bio, it does not account for dynamic restrictions that vary
502 * on offset.
504 int bio_get_nr_vecs(struct block_device *bdev)
506 struct request_queue *q = bdev_get_queue(bdev);
507 int nr_pages;
509 nr_pages = ((queue_max_sectors(q) << 9) + PAGE_SIZE - 1) >> PAGE_SHIFT;
510 if (nr_pages > queue_max_phys_segments(q))
511 nr_pages = queue_max_phys_segments(q);
512 if (nr_pages > queue_max_hw_segments(q))
513 nr_pages = queue_max_hw_segments(q);
515 return nr_pages;
517 EXPORT_SYMBOL(bio_get_nr_vecs);
519 static int __bio_add_page(struct request_queue *q, struct bio *bio, struct page
520 *page, unsigned int len, unsigned int offset,
521 unsigned short max_sectors)
523 int retried_segments = 0;
524 struct bio_vec *bvec;
527 * cloned bio must not modify vec list
529 if (unlikely(bio_flagged(bio, BIO_CLONED)))
530 return 0;
532 if (((bio->bi_size + len) >> 9) > max_sectors)
533 return 0;
536 * For filesystems with a blocksize smaller than the pagesize
537 * we will often be called with the same page as last time and
538 * a consecutive offset. Optimize this special case.
540 if (bio->bi_vcnt > 0) {
541 struct bio_vec *prev = &bio->bi_io_vec[bio->bi_vcnt - 1];
543 if (page == prev->bv_page &&
544 offset == prev->bv_offset + prev->bv_len) {
545 prev->bv_len += len;
547 if (q->merge_bvec_fn) {
548 struct bvec_merge_data bvm = {
549 .bi_bdev = bio->bi_bdev,
550 .bi_sector = bio->bi_sector,
551 .bi_size = bio->bi_size,
552 .bi_rw = bio->bi_rw,
555 if (q->merge_bvec_fn(q, &bvm, prev) < len) {
556 prev->bv_len -= len;
557 return 0;
561 goto done;
565 if (bio->bi_vcnt >= bio->bi_max_vecs)
566 return 0;
569 * we might lose a segment or two here, but rather that than
570 * make this too complex.
573 while (bio->bi_phys_segments >= queue_max_phys_segments(q)
574 || bio->bi_phys_segments >= queue_max_hw_segments(q)) {
576 if (retried_segments)
577 return 0;
579 retried_segments = 1;
580 blk_recount_segments(q, bio);
584 * setup the new entry, we might clear it again later if we
585 * cannot add the page
587 bvec = &bio->bi_io_vec[bio->bi_vcnt];
588 bvec->bv_page = page;
589 bvec->bv_len = len;
590 bvec->bv_offset = offset;
593 * if queue has other restrictions (eg varying max sector size
594 * depending on offset), it can specify a merge_bvec_fn in the
595 * queue to get further control
597 if (q->merge_bvec_fn) {
598 struct bvec_merge_data bvm = {
599 .bi_bdev = bio->bi_bdev,
600 .bi_sector = bio->bi_sector,
601 .bi_size = bio->bi_size,
602 .bi_rw = bio->bi_rw,
606 * merge_bvec_fn() returns number of bytes it can accept
607 * at this offset
609 if (q->merge_bvec_fn(q, &bvm, bvec) < len) {
610 bvec->bv_page = NULL;
611 bvec->bv_len = 0;
612 bvec->bv_offset = 0;
613 return 0;
617 /* If we may be able to merge these biovecs, force a recount */
618 if (bio->bi_vcnt && (BIOVEC_PHYS_MERGEABLE(bvec-1, bvec)))
619 bio->bi_flags &= ~(1 << BIO_SEG_VALID);
621 bio->bi_vcnt++;
622 bio->bi_phys_segments++;
623 done:
624 bio->bi_size += len;
625 return len;
629 * bio_add_pc_page - attempt to add page to bio
630 * @q: the target queue
631 * @bio: destination bio
632 * @page: page to add
633 * @len: vec entry length
634 * @offset: vec entry offset
636 * Attempt to add a page to the bio_vec maplist. This can fail for a
637 * number of reasons, such as the bio being full or target block
638 * device limitations. The target block device must allow bio's
639 * smaller than PAGE_SIZE, so it is always possible to add a single
640 * page to an empty bio. This should only be used by REQ_PC bios.
642 int bio_add_pc_page(struct request_queue *q, struct bio *bio, struct page *page,
643 unsigned int len, unsigned int offset)
645 return __bio_add_page(q, bio, page, len, offset,
646 queue_max_hw_sectors(q));
648 EXPORT_SYMBOL(bio_add_pc_page);
651 * bio_add_page - attempt to add page to bio
652 * @bio: destination bio
653 * @page: page to add
654 * @len: vec entry length
655 * @offset: vec entry offset
657 * Attempt to add a page to the bio_vec maplist. This can fail for a
658 * number of reasons, such as the bio being full or target block
659 * device limitations. The target block device must allow bio's
660 * smaller than PAGE_SIZE, so it is always possible to add a single
661 * page to an empty bio.
663 int bio_add_page(struct bio *bio, struct page *page, unsigned int len,
664 unsigned int offset)
666 struct request_queue *q = bdev_get_queue(bio->bi_bdev);
667 return __bio_add_page(q, bio, page, len, offset, queue_max_sectors(q));
669 EXPORT_SYMBOL(bio_add_page);
671 struct bio_map_data {
672 struct bio_vec *iovecs;
673 struct sg_iovec *sgvecs;
674 int nr_sgvecs;
675 int is_our_pages;
678 static void bio_set_map_data(struct bio_map_data *bmd, struct bio *bio,
679 struct sg_iovec *iov, int iov_count,
680 int is_our_pages)
682 memcpy(bmd->iovecs, bio->bi_io_vec, sizeof(struct bio_vec) * bio->bi_vcnt);
683 memcpy(bmd->sgvecs, iov, sizeof(struct sg_iovec) * iov_count);
684 bmd->nr_sgvecs = iov_count;
685 bmd->is_our_pages = is_our_pages;
686 bio->bi_private = bmd;
689 static void bio_free_map_data(struct bio_map_data *bmd)
691 kfree(bmd->iovecs);
692 kfree(bmd->sgvecs);
693 kfree(bmd);
696 static struct bio_map_data *bio_alloc_map_data(int nr_segs, int iov_count,
697 gfp_t gfp_mask)
699 struct bio_map_data *bmd = kmalloc(sizeof(*bmd), gfp_mask);
701 if (!bmd)
702 return NULL;
704 bmd->iovecs = kmalloc(sizeof(struct bio_vec) * nr_segs, gfp_mask);
705 if (!bmd->iovecs) {
706 kfree(bmd);
707 return NULL;
710 bmd->sgvecs = kmalloc(sizeof(struct sg_iovec) * iov_count, gfp_mask);
711 if (bmd->sgvecs)
712 return bmd;
714 kfree(bmd->iovecs);
715 kfree(bmd);
716 return NULL;
719 static int __bio_copy_iov(struct bio *bio, struct bio_vec *iovecs,
720 struct sg_iovec *iov, int iov_count,
721 int to_user, int from_user, int do_free_page)
723 int ret = 0, i;
724 struct bio_vec *bvec;
725 int iov_idx = 0;
726 unsigned int iov_off = 0;
728 __bio_for_each_segment(bvec, bio, i, 0) {
729 char *bv_addr = page_address(bvec->bv_page);
730 unsigned int bv_len = iovecs[i].bv_len;
732 while (bv_len && iov_idx < iov_count) {
733 unsigned int bytes;
734 char __user *iov_addr;
736 bytes = min_t(unsigned int,
737 iov[iov_idx].iov_len - iov_off, bv_len);
738 iov_addr = iov[iov_idx].iov_base + iov_off;
740 if (!ret) {
741 if (to_user)
742 ret = copy_to_user(iov_addr, bv_addr,
743 bytes);
745 if (from_user)
746 ret = copy_from_user(bv_addr, iov_addr,
747 bytes);
749 if (ret)
750 ret = -EFAULT;
753 bv_len -= bytes;
754 bv_addr += bytes;
755 iov_addr += bytes;
756 iov_off += bytes;
758 if (iov[iov_idx].iov_len == iov_off) {
759 iov_idx++;
760 iov_off = 0;
764 if (do_free_page)
765 __free_page(bvec->bv_page);
768 return ret;
772 * bio_uncopy_user - finish previously mapped bio
773 * @bio: bio being terminated
775 * Free pages allocated from bio_copy_user() and write back data
776 * to user space in case of a read.
778 int bio_uncopy_user(struct bio *bio)
780 struct bio_map_data *bmd = bio->bi_private;
781 int ret = 0;
783 if (!bio_flagged(bio, BIO_NULL_MAPPED))
784 ret = __bio_copy_iov(bio, bmd->iovecs, bmd->sgvecs,
785 bmd->nr_sgvecs, bio_data_dir(bio) == READ,
786 0, bmd->is_our_pages);
787 bio_free_map_data(bmd);
788 bio_put(bio);
789 return ret;
791 EXPORT_SYMBOL(bio_uncopy_user);
794 * bio_copy_user_iov - copy user data to bio
795 * @q: destination block queue
796 * @map_data: pointer to the rq_map_data holding pages (if necessary)
797 * @iov: the iovec.
798 * @iov_count: number of elements in the iovec
799 * @write_to_vm: bool indicating writing to pages or not
800 * @gfp_mask: memory allocation flags
802 * Prepares and returns a bio for indirect user io, bouncing data
803 * to/from kernel pages as necessary. Must be paired with
804 * call bio_uncopy_user() on io completion.
806 struct bio *bio_copy_user_iov(struct request_queue *q,
807 struct rq_map_data *map_data,
808 struct sg_iovec *iov, int iov_count,
809 int write_to_vm, gfp_t gfp_mask)
811 struct bio_map_data *bmd;
812 struct bio_vec *bvec;
813 struct page *page;
814 struct bio *bio;
815 int i, ret;
816 int nr_pages = 0;
817 unsigned int len = 0;
818 unsigned int offset = map_data ? map_data->offset & ~PAGE_MASK : 0;
820 for (i = 0; i < iov_count; i++) {
821 unsigned long uaddr;
822 unsigned long end;
823 unsigned long start;
825 uaddr = (unsigned long)iov[i].iov_base;
826 end = (uaddr + iov[i].iov_len + PAGE_SIZE - 1) >> PAGE_SHIFT;
827 start = uaddr >> PAGE_SHIFT;
829 nr_pages += end - start;
830 len += iov[i].iov_len;
833 if (offset)
834 nr_pages++;
836 bmd = bio_alloc_map_data(nr_pages, iov_count, gfp_mask);
837 if (!bmd)
838 return ERR_PTR(-ENOMEM);
840 ret = -ENOMEM;
841 bio = bio_kmalloc(gfp_mask, nr_pages);
842 if (!bio)
843 goto out_bmd;
845 bio->bi_rw |= (!write_to_vm << BIO_RW);
847 ret = 0;
849 if (map_data) {
850 nr_pages = 1 << map_data->page_order;
851 i = map_data->offset / PAGE_SIZE;
853 while (len) {
854 unsigned int bytes = PAGE_SIZE;
856 bytes -= offset;
858 if (bytes > len)
859 bytes = len;
861 if (map_data) {
862 if (i == map_data->nr_entries * nr_pages) {
863 ret = -ENOMEM;
864 break;
867 page = map_data->pages[i / nr_pages];
868 page += (i % nr_pages);
870 i++;
871 } else {
872 page = alloc_page(q->bounce_gfp | gfp_mask);
873 if (!page) {
874 ret = -ENOMEM;
875 break;
879 if (bio_add_pc_page(q, bio, page, bytes, offset) < bytes)
880 break;
882 len -= bytes;
883 offset = 0;
886 if (ret)
887 goto cleanup;
890 * success
892 if ((!write_to_vm && (!map_data || !map_data->null_mapped)) ||
893 (map_data && map_data->from_user)) {
894 ret = __bio_copy_iov(bio, bio->bi_io_vec, iov, iov_count, 0, 1, 0);
895 if (ret)
896 goto cleanup;
899 bio_set_map_data(bmd, bio, iov, iov_count, map_data ? 0 : 1);
900 return bio;
901 cleanup:
902 if (!map_data)
903 bio_for_each_segment(bvec, bio, i)
904 __free_page(bvec->bv_page);
906 bio_put(bio);
907 out_bmd:
908 bio_free_map_data(bmd);
909 return ERR_PTR(ret);
913 * bio_copy_user - copy user data to bio
914 * @q: destination block queue
915 * @map_data: pointer to the rq_map_data holding pages (if necessary)
916 * @uaddr: start of user address
917 * @len: length in bytes
918 * @write_to_vm: bool indicating writing to pages or not
919 * @gfp_mask: memory allocation flags
921 * Prepares and returns a bio for indirect user io, bouncing data
922 * to/from kernel pages as necessary. Must be paired with
923 * call bio_uncopy_user() on io completion.
925 struct bio *bio_copy_user(struct request_queue *q, struct rq_map_data *map_data,
926 unsigned long uaddr, unsigned int len,
927 int write_to_vm, gfp_t gfp_mask)
929 struct sg_iovec iov;
931 iov.iov_base = (void __user *)uaddr;
932 iov.iov_len = len;
934 return bio_copy_user_iov(q, map_data, &iov, 1, write_to_vm, gfp_mask);
936 EXPORT_SYMBOL(bio_copy_user);
938 static struct bio *__bio_map_user_iov(struct request_queue *q,
939 struct block_device *bdev,
940 struct sg_iovec *iov, int iov_count,
941 int write_to_vm, gfp_t gfp_mask)
943 int i, j;
944 int nr_pages = 0;
945 struct page **pages;
946 struct bio *bio;
947 int cur_page = 0;
948 int ret, offset;
950 for (i = 0; i < iov_count; i++) {
951 unsigned long uaddr = (unsigned long)iov[i].iov_base;
952 unsigned long len = iov[i].iov_len;
953 unsigned long end = (uaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
954 unsigned long start = uaddr >> PAGE_SHIFT;
956 nr_pages += end - start;
958 * buffer must be aligned to at least hardsector size for now
960 if (uaddr & queue_dma_alignment(q))
961 return ERR_PTR(-EINVAL);
964 if (!nr_pages)
965 return ERR_PTR(-EINVAL);
967 bio = bio_kmalloc(gfp_mask, nr_pages);
968 if (!bio)
969 return ERR_PTR(-ENOMEM);
971 ret = -ENOMEM;
972 pages = kcalloc(nr_pages, sizeof(struct page *), gfp_mask);
973 if (!pages)
974 goto out;
976 for (i = 0; i < iov_count; i++) {
977 unsigned long uaddr = (unsigned long)iov[i].iov_base;
978 unsigned long len = iov[i].iov_len;
979 unsigned long end = (uaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
980 unsigned long start = uaddr >> PAGE_SHIFT;
981 const int local_nr_pages = end - start;
982 const int page_limit = cur_page + local_nr_pages;
984 ret = get_user_pages_fast(uaddr, local_nr_pages,
985 write_to_vm, &pages[cur_page]);
986 if (ret < local_nr_pages) {
987 ret = -EFAULT;
988 goto out_unmap;
991 offset = uaddr & ~PAGE_MASK;
992 for (j = cur_page; j < page_limit; j++) {
993 unsigned int bytes = PAGE_SIZE - offset;
995 if (len <= 0)
996 break;
998 if (bytes > len)
999 bytes = len;
1002 * sorry...
1004 if (bio_add_pc_page(q, bio, pages[j], bytes, offset) <
1005 bytes)
1006 break;
1008 len -= bytes;
1009 offset = 0;
1012 cur_page = j;
1014 * release the pages we didn't map into the bio, if any
1016 while (j < page_limit)
1017 page_cache_release(pages[j++]);
1020 kfree(pages);
1023 * set data direction, and check if mapped pages need bouncing
1025 if (!write_to_vm)
1026 bio->bi_rw |= (1 << BIO_RW);
1028 bio->bi_bdev = bdev;
1029 bio->bi_flags |= (1 << BIO_USER_MAPPED);
1030 return bio;
1032 out_unmap:
1033 for (i = 0; i < nr_pages; i++) {
1034 if(!pages[i])
1035 break;
1036 page_cache_release(pages[i]);
1038 out:
1039 kfree(pages);
1040 bio_put(bio);
1041 return ERR_PTR(ret);
1045 * bio_map_user - map user address into bio
1046 * @q: the struct request_queue for the bio
1047 * @bdev: destination block device
1048 * @uaddr: start of user address
1049 * @len: length in bytes
1050 * @write_to_vm: bool indicating writing to pages or not
1051 * @gfp_mask: memory allocation flags
1053 * Map the user space address into a bio suitable for io to a block
1054 * device. Returns an error pointer in case of error.
1056 struct bio *bio_map_user(struct request_queue *q, struct block_device *bdev,
1057 unsigned long uaddr, unsigned int len, int write_to_vm,
1058 gfp_t gfp_mask)
1060 struct sg_iovec iov;
1062 iov.iov_base = (void __user *)uaddr;
1063 iov.iov_len = len;
1065 return bio_map_user_iov(q, bdev, &iov, 1, write_to_vm, gfp_mask);
1067 EXPORT_SYMBOL(bio_map_user);
1070 * bio_map_user_iov - map user sg_iovec table into bio
1071 * @q: the struct request_queue for the bio
1072 * @bdev: destination block device
1073 * @iov: the iovec.
1074 * @iov_count: number of elements in the iovec
1075 * @write_to_vm: bool indicating writing to pages or not
1076 * @gfp_mask: memory allocation flags
1078 * Map the user space address into a bio suitable for io to a block
1079 * device. Returns an error pointer in case of error.
1081 struct bio *bio_map_user_iov(struct request_queue *q, struct block_device *bdev,
1082 struct sg_iovec *iov, int iov_count,
1083 int write_to_vm, gfp_t gfp_mask)
1085 struct bio *bio;
1087 bio = __bio_map_user_iov(q, bdev, iov, iov_count, write_to_vm,
1088 gfp_mask);
1089 if (IS_ERR(bio))
1090 return bio;
1093 * subtle -- if __bio_map_user() ended up bouncing a bio,
1094 * it would normally disappear when its bi_end_io is run.
1095 * however, we need it for the unmap, so grab an extra
1096 * reference to it
1098 bio_get(bio);
1100 return bio;
1103 static void __bio_unmap_user(struct bio *bio)
1105 struct bio_vec *bvec;
1106 int i;
1109 * make sure we dirty pages we wrote to
1111 __bio_for_each_segment(bvec, bio, i, 0) {
1112 if (bio_data_dir(bio) == READ)
1113 set_page_dirty_lock(bvec->bv_page);
1115 page_cache_release(bvec->bv_page);
1118 bio_put(bio);
1122 * bio_unmap_user - unmap a bio
1123 * @bio: the bio being unmapped
1125 * Unmap a bio previously mapped by bio_map_user(). Must be called with
1126 * a process context.
1128 * bio_unmap_user() may sleep.
1130 void bio_unmap_user(struct bio *bio)
1132 __bio_unmap_user(bio);
1133 bio_put(bio);
1135 EXPORT_SYMBOL(bio_unmap_user);
1137 static void bio_map_kern_endio(struct bio *bio, int err)
1139 bio_put(bio);
1142 static struct bio *__bio_map_kern(struct request_queue *q, void *data,
1143 unsigned int len, gfp_t gfp_mask)
1145 unsigned long kaddr = (unsigned long)data;
1146 unsigned long end = (kaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
1147 unsigned long start = kaddr >> PAGE_SHIFT;
1148 const int nr_pages = end - start;
1149 int offset, i;
1150 struct bio *bio;
1152 bio = bio_kmalloc(gfp_mask, nr_pages);
1153 if (!bio)
1154 return ERR_PTR(-ENOMEM);
1156 offset = offset_in_page(kaddr);
1157 for (i = 0; i < nr_pages; i++) {
1158 unsigned int bytes = PAGE_SIZE - offset;
1160 if (len <= 0)
1161 break;
1163 if (bytes > len)
1164 bytes = len;
1166 if (bio_add_pc_page(q, bio, virt_to_page(data), bytes,
1167 offset) < bytes)
1168 break;
1170 data += bytes;
1171 len -= bytes;
1172 offset = 0;
1175 bio->bi_end_io = bio_map_kern_endio;
1176 return bio;
1180 * bio_map_kern - map kernel address into bio
1181 * @q: the struct request_queue for the bio
1182 * @data: pointer to buffer to map
1183 * @len: length in bytes
1184 * @gfp_mask: allocation flags for bio allocation
1186 * Map the kernel address into a bio suitable for io to a block
1187 * device. Returns an error pointer in case of error.
1189 struct bio *bio_map_kern(struct request_queue *q, void *data, unsigned int len,
1190 gfp_t gfp_mask)
1192 struct bio *bio;
1194 bio = __bio_map_kern(q, data, len, gfp_mask);
1195 if (IS_ERR(bio))
1196 return bio;
1198 if (bio->bi_size == len)
1199 return bio;
1202 * Don't support partial mappings.
1204 bio_put(bio);
1205 return ERR_PTR(-EINVAL);
1207 EXPORT_SYMBOL(bio_map_kern);
1209 static void bio_copy_kern_endio(struct bio *bio, int err)
1211 struct bio_vec *bvec;
1212 const int read = bio_data_dir(bio) == READ;
1213 struct bio_map_data *bmd = bio->bi_private;
1214 int i;
1215 char *p = bmd->sgvecs[0].iov_base;
1217 __bio_for_each_segment(bvec, bio, i, 0) {
1218 char *addr = page_address(bvec->bv_page);
1219 int len = bmd->iovecs[i].bv_len;
1221 if (read)
1222 memcpy(p, addr, len);
1224 __free_page(bvec->bv_page);
1225 p += len;
1228 bio_free_map_data(bmd);
1229 bio_put(bio);
1233 * bio_copy_kern - copy kernel address into bio
1234 * @q: the struct request_queue for the bio
1235 * @data: pointer to buffer to copy
1236 * @len: length in bytes
1237 * @gfp_mask: allocation flags for bio and page allocation
1238 * @reading: data direction is READ
1240 * copy the kernel address into a bio suitable for io to a block
1241 * device. Returns an error pointer in case of error.
1243 struct bio *bio_copy_kern(struct request_queue *q, void *data, unsigned int len,
1244 gfp_t gfp_mask, int reading)
1246 struct bio *bio;
1247 struct bio_vec *bvec;
1248 int i;
1250 bio = bio_copy_user(q, NULL, (unsigned long)data, len, 1, gfp_mask);
1251 if (IS_ERR(bio))
1252 return bio;
1254 if (!reading) {
1255 void *p = data;
1257 bio_for_each_segment(bvec, bio, i) {
1258 char *addr = page_address(bvec->bv_page);
1260 memcpy(addr, p, bvec->bv_len);
1261 p += bvec->bv_len;
1265 bio->bi_end_io = bio_copy_kern_endio;
1267 return bio;
1269 EXPORT_SYMBOL(bio_copy_kern);
1272 * bio_set_pages_dirty() and bio_check_pages_dirty() are support functions
1273 * for performing direct-IO in BIOs.
1275 * The problem is that we cannot run set_page_dirty() from interrupt context
1276 * because the required locks are not interrupt-safe. So what we can do is to
1277 * mark the pages dirty _before_ performing IO. And in interrupt context,
1278 * check that the pages are still dirty. If so, fine. If not, redirty them
1279 * in process context.
1281 * We special-case compound pages here: normally this means reads into hugetlb
1282 * pages. The logic in here doesn't really work right for compound pages
1283 * because the VM does not uniformly chase down the head page in all cases.
1284 * But dirtiness of compound pages is pretty meaningless anyway: the VM doesn't
1285 * handle them at all. So we skip compound pages here at an early stage.
1287 * Note that this code is very hard to test under normal circumstances because
1288 * direct-io pins the pages with get_user_pages(). This makes
1289 * is_page_cache_freeable return false, and the VM will not clean the pages.
1290 * But other code (eg, pdflush) could clean the pages if they are mapped
1291 * pagecache.
1293 * Simply disabling the call to bio_set_pages_dirty() is a good way to test the
1294 * deferred bio dirtying paths.
1298 * bio_set_pages_dirty() will mark all the bio's pages as dirty.
1300 void bio_set_pages_dirty(struct bio *bio)
1302 struct bio_vec *bvec = bio->bi_io_vec;
1303 int i;
1305 for (i = 0; i < bio->bi_vcnt; i++) {
1306 struct page *page = bvec[i].bv_page;
1308 if (page && !PageCompound(page))
1309 set_page_dirty_lock(page);
1313 static void bio_release_pages(struct bio *bio)
1315 struct bio_vec *bvec = bio->bi_io_vec;
1316 int i;
1318 for (i = 0; i < bio->bi_vcnt; i++) {
1319 struct page *page = bvec[i].bv_page;
1321 if (page)
1322 put_page(page);
1327 * bio_check_pages_dirty() will check that all the BIO's pages are still dirty.
1328 * If they are, then fine. If, however, some pages are clean then they must
1329 * have been written out during the direct-IO read. So we take another ref on
1330 * the BIO and the offending pages and re-dirty the pages in process context.
1332 * It is expected that bio_check_pages_dirty() will wholly own the BIO from
1333 * here on. It will run one page_cache_release() against each page and will
1334 * run one bio_put() against the BIO.
1337 static void bio_dirty_fn(struct work_struct *work);
1339 static DECLARE_WORK(bio_dirty_work, bio_dirty_fn);
1340 static DEFINE_SPINLOCK(bio_dirty_lock);
1341 static struct bio *bio_dirty_list;
1344 * This runs in process context
1346 static void bio_dirty_fn(struct work_struct *work)
1348 unsigned long flags;
1349 struct bio *bio;
1351 spin_lock_irqsave(&bio_dirty_lock, flags);
1352 bio = bio_dirty_list;
1353 bio_dirty_list = NULL;
1354 spin_unlock_irqrestore(&bio_dirty_lock, flags);
1356 while (bio) {
1357 struct bio *next = bio->bi_private;
1359 bio_set_pages_dirty(bio);
1360 bio_release_pages(bio);
1361 bio_put(bio);
1362 bio = next;
1366 void bio_check_pages_dirty(struct bio *bio)
1368 struct bio_vec *bvec = bio->bi_io_vec;
1369 int nr_clean_pages = 0;
1370 int i;
1372 for (i = 0; i < bio->bi_vcnt; i++) {
1373 struct page *page = bvec[i].bv_page;
1375 if (PageDirty(page) || PageCompound(page)) {
1376 page_cache_release(page);
1377 bvec[i].bv_page = NULL;
1378 } else {
1379 nr_clean_pages++;
1383 if (nr_clean_pages) {
1384 unsigned long flags;
1386 spin_lock_irqsave(&bio_dirty_lock, flags);
1387 bio->bi_private = bio_dirty_list;
1388 bio_dirty_list = bio;
1389 spin_unlock_irqrestore(&bio_dirty_lock, flags);
1390 schedule_work(&bio_dirty_work);
1391 } else {
1392 bio_put(bio);
1397 * bio_endio - end I/O on a bio
1398 * @bio: bio
1399 * @error: error, if any
1401 * Description:
1402 * bio_endio() will end I/O on the whole bio. bio_endio() is the
1403 * preferred way to end I/O on a bio, it takes care of clearing
1404 * BIO_UPTODATE on error. @error is 0 on success, and and one of the
1405 * established -Exxxx (-EIO, for instance) error values in case
1406 * something went wrong. Noone should call bi_end_io() directly on a
1407 * bio unless they own it and thus know that it has an end_io
1408 * function.
1410 void bio_endio(struct bio *bio, int error)
1412 if (error)
1413 clear_bit(BIO_UPTODATE, &bio->bi_flags);
1414 else if (!test_bit(BIO_UPTODATE, &bio->bi_flags))
1415 error = -EIO;
1417 if (bio->bi_end_io)
1418 bio->bi_end_io(bio, error);
1420 EXPORT_SYMBOL(bio_endio);
1422 void bio_pair_release(struct bio_pair *bp)
1424 if (atomic_dec_and_test(&bp->cnt)) {
1425 struct bio *master = bp->bio1.bi_private;
1427 bio_endio(master, bp->error);
1428 mempool_free(bp, bp->bio2.bi_private);
1431 EXPORT_SYMBOL(bio_pair_release);
1433 static void bio_pair_end_1(struct bio *bi, int err)
1435 struct bio_pair *bp = container_of(bi, struct bio_pair, bio1);
1437 if (err)
1438 bp->error = err;
1440 bio_pair_release(bp);
1443 static void bio_pair_end_2(struct bio *bi, int err)
1445 struct bio_pair *bp = container_of(bi, struct bio_pair, bio2);
1447 if (err)
1448 bp->error = err;
1450 bio_pair_release(bp);
1454 * split a bio - only worry about a bio with a single page in its iovec
1456 struct bio_pair *bio_split(struct bio *bi, int first_sectors)
1458 struct bio_pair *bp = mempool_alloc(bio_split_pool, GFP_NOIO);
1460 if (!bp)
1461 return bp;
1463 trace_block_split(bdev_get_queue(bi->bi_bdev), bi,
1464 bi->bi_sector + first_sectors);
1466 BUG_ON(bi->bi_vcnt != 1);
1467 BUG_ON(bi->bi_idx != 0);
1468 atomic_set(&bp->cnt, 3);
1469 bp->error = 0;
1470 bp->bio1 = *bi;
1471 bp->bio2 = *bi;
1472 bp->bio2.bi_sector += first_sectors;
1473 bp->bio2.bi_size -= first_sectors << 9;
1474 bp->bio1.bi_size = first_sectors << 9;
1476 bp->bv1 = bi->bi_io_vec[0];
1477 bp->bv2 = bi->bi_io_vec[0];
1478 bp->bv2.bv_offset += first_sectors << 9;
1479 bp->bv2.bv_len -= first_sectors << 9;
1480 bp->bv1.bv_len = first_sectors << 9;
1482 bp->bio1.bi_io_vec = &bp->bv1;
1483 bp->bio2.bi_io_vec = &bp->bv2;
1485 bp->bio1.bi_max_vecs = 1;
1486 bp->bio2.bi_max_vecs = 1;
1488 bp->bio1.bi_end_io = bio_pair_end_1;
1489 bp->bio2.bi_end_io = bio_pair_end_2;
1491 bp->bio1.bi_private = bi;
1492 bp->bio2.bi_private = bio_split_pool;
1494 if (bio_integrity(bi))
1495 bio_integrity_split(bi, bp, first_sectors);
1497 return bp;
1499 EXPORT_SYMBOL(bio_split);
1502 * bio_sector_offset - Find hardware sector offset in bio
1503 * @bio: bio to inspect
1504 * @index: bio_vec index
1505 * @offset: offset in bv_page
1507 * Return the number of hardware sectors between beginning of bio
1508 * and an end point indicated by a bio_vec index and an offset
1509 * within that vector's page.
1511 sector_t bio_sector_offset(struct bio *bio, unsigned short index,
1512 unsigned int offset)
1514 unsigned int sector_sz;
1515 struct bio_vec *bv;
1516 sector_t sectors;
1517 int i;
1519 sector_sz = queue_logical_block_size(bio->bi_bdev->bd_disk->queue);
1520 sectors = 0;
1522 if (index >= bio->bi_idx)
1523 index = bio->bi_vcnt - 1;
1525 __bio_for_each_segment(bv, bio, i, 0) {
1526 if (i == index) {
1527 if (offset > bv->bv_offset)
1528 sectors += (offset - bv->bv_offset) / sector_sz;
1529 break;
1532 sectors += bv->bv_len / sector_sz;
1535 return sectors;
1537 EXPORT_SYMBOL(bio_sector_offset);
1540 * create memory pools for biovec's in a bio_set.
1541 * use the global biovec slabs created for general use.
1543 static int biovec_create_pools(struct bio_set *bs, int pool_entries)
1545 struct biovec_slab *bp = bvec_slabs + BIOVEC_MAX_IDX;
1547 bs->bvec_pool = mempool_create_slab_pool(pool_entries, bp->slab);
1548 if (!bs->bvec_pool)
1549 return -ENOMEM;
1551 return 0;
1554 static void biovec_free_pools(struct bio_set *bs)
1556 mempool_destroy(bs->bvec_pool);
1559 void bioset_free(struct bio_set *bs)
1561 if (bs->bio_pool)
1562 mempool_destroy(bs->bio_pool);
1564 bioset_integrity_free(bs);
1565 biovec_free_pools(bs);
1566 bio_put_slab(bs);
1568 kfree(bs);
1570 EXPORT_SYMBOL(bioset_free);
1573 * bioset_create - Create a bio_set
1574 * @pool_size: Number of bio and bio_vecs to cache in the mempool
1575 * @front_pad: Number of bytes to allocate in front of the returned bio
1577 * Description:
1578 * Set up a bio_set to be used with @bio_alloc_bioset. Allows the caller
1579 * to ask for a number of bytes to be allocated in front of the bio.
1580 * Front pad allocation is useful for embedding the bio inside
1581 * another structure, to avoid allocating extra data to go with the bio.
1582 * Note that the bio must be embedded at the END of that structure always,
1583 * or things will break badly.
1585 struct bio_set *bioset_create(unsigned int pool_size, unsigned int front_pad)
1587 unsigned int back_pad = BIO_INLINE_VECS * sizeof(struct bio_vec);
1588 struct bio_set *bs;
1590 bs = kzalloc(sizeof(*bs), GFP_KERNEL);
1591 if (!bs)
1592 return NULL;
1594 bs->front_pad = front_pad;
1596 bs->bio_slab = bio_find_or_create_slab(front_pad + back_pad);
1597 if (!bs->bio_slab) {
1598 kfree(bs);
1599 return NULL;
1602 bs->bio_pool = mempool_create_slab_pool(pool_size, bs->bio_slab);
1603 if (!bs->bio_pool)
1604 goto bad;
1606 if (bioset_integrity_create(bs, pool_size))
1607 goto bad;
1609 if (!biovec_create_pools(bs, pool_size))
1610 return bs;
1612 bad:
1613 bioset_free(bs);
1614 return NULL;
1616 EXPORT_SYMBOL(bioset_create);
1618 static void __init biovec_init_slabs(void)
1620 int i;
1622 for (i = 0; i < BIOVEC_NR_POOLS; i++) {
1623 int size;
1624 struct biovec_slab *bvs = bvec_slabs + i;
1626 #ifndef CONFIG_BLK_DEV_INTEGRITY
1627 if (bvs->nr_vecs <= BIO_INLINE_VECS) {
1628 bvs->slab = NULL;
1629 continue;
1631 #endif
1633 size = bvs->nr_vecs * sizeof(struct bio_vec);
1634 bvs->slab = kmem_cache_create(bvs->name, size, 0,
1635 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
1639 static int __init init_bio(void)
1641 bio_slab_max = 2;
1642 bio_slab_nr = 0;
1643 bio_slabs = kzalloc(bio_slab_max * sizeof(struct bio_slab), GFP_KERNEL);
1644 if (!bio_slabs)
1645 panic("bio: can't allocate bios\n");
1647 bio_integrity_init();
1648 biovec_init_slabs();
1650 fs_bio_set = bioset_create(BIO_POOL_SIZE, 0);
1651 if (!fs_bio_set)
1652 panic("bio: can't allocate bios\n");
1654 bio_split_pool = mempool_create_kmalloc_pool(BIO_SPLIT_ENTRIES,
1655 sizeof(struct bio_pair));
1656 if (!bio_split_pool)
1657 panic("bio: can't create split pool\n");
1659 return 0;
1661 subsys_initcall(init_bio);