1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright (C) 2001 Jens Axboe <axboe@kernel.dk>
6 #include <linux/swap.h>
8 #include <linux/blkdev.h>
10 #include <linux/iocontext.h>
11 #include <linux/slab.h>
12 #include <linux/init.h>
13 #include <linux/kernel.h>
14 #include <linux/export.h>
15 #include <linux/mempool.h>
16 #include <linux/workqueue.h>
17 #include <linux/cgroup.h>
18 #include <linux/blk-cgroup.h>
19 #include <linux/highmem.h>
20 #include <linux/sched/sysctl.h>
21 #include <linux/blk-crypto.h>
22 #include <linux/xarray.h>
24 #include <trace/events/block.h>
26 #include "blk-rq-qos.h"
31 struct kmem_cache *slab;
35 * if you change this list, also change bvec_alloc or things will
36 * break badly! cannot be bigger than what you can fit into an
39 #define BV(x, n) { .nr_vecs = x, .name = "biovec-"#n }
40 static struct biovec_slab bvec_slabs[BVEC_POOL_NR] __read_mostly = {
41 BV(1, 1), BV(4, 4), BV(16, 16), BV(64, 64), BV(128, 128), BV(BIO_MAX_PAGES, max),
46 * fs_bio_set is the bio_set containing bio and iovec memory pools used by
47 * IO code that does not need private memory pools.
49 struct bio_set fs_bio_set;
50 EXPORT_SYMBOL(fs_bio_set);
53 * Our slab pool management
56 struct kmem_cache *slab;
57 unsigned int slab_ref;
58 unsigned int slab_size;
61 static DEFINE_MUTEX(bio_slab_lock);
62 static DEFINE_XARRAY(bio_slabs);
64 static struct bio_slab *create_bio_slab(unsigned int size)
66 struct bio_slab *bslab = kzalloc(sizeof(*bslab), GFP_KERNEL);
71 snprintf(bslab->name, sizeof(bslab->name), "bio-%d", size);
72 bslab->slab = kmem_cache_create(bslab->name, size,
73 ARCH_KMALLOC_MINALIGN, SLAB_HWCACHE_ALIGN, NULL);
78 bslab->slab_size = size;
80 if (!xa_err(xa_store(&bio_slabs, size, bslab, GFP_KERNEL)))
83 kmem_cache_destroy(bslab->slab);
90 static inline unsigned int bs_bio_slab_size(struct bio_set *bs)
92 return bs->front_pad + sizeof(struct bio) + bs->back_pad;
95 static struct kmem_cache *bio_find_or_create_slab(struct bio_set *bs)
97 unsigned int size = bs_bio_slab_size(bs);
98 struct bio_slab *bslab;
100 mutex_lock(&bio_slab_lock);
101 bslab = xa_load(&bio_slabs, size);
105 bslab = create_bio_slab(size);
106 mutex_unlock(&bio_slab_lock);
113 static void bio_put_slab(struct bio_set *bs)
115 struct bio_slab *bslab = NULL;
116 unsigned int slab_size = bs_bio_slab_size(bs);
118 mutex_lock(&bio_slab_lock);
120 bslab = xa_load(&bio_slabs, slab_size);
121 if (WARN(!bslab, KERN_ERR "bio: unable to find slab!\n"))
124 WARN_ON_ONCE(bslab->slab != bs->bio_slab);
126 WARN_ON(!bslab->slab_ref);
128 if (--bslab->slab_ref)
131 xa_erase(&bio_slabs, slab_size);
133 kmem_cache_destroy(bslab->slab);
137 mutex_unlock(&bio_slab_lock);
140 unsigned int bvec_nr_vecs(unsigned short idx)
142 return bvec_slabs[--idx].nr_vecs;
145 void bvec_free(mempool_t *pool, struct bio_vec *bv, unsigned int idx)
151 BIO_BUG_ON(idx >= BVEC_POOL_NR);
153 if (idx == BVEC_POOL_MAX) {
154 mempool_free(bv, pool);
156 struct biovec_slab *bvs = bvec_slabs + idx;
158 kmem_cache_free(bvs->slab, bv);
163 * Make the first allocation restricted and don't dump info on allocation
164 * failures, since we'll fall back to the mempool in case of failure.
166 static inline gfp_t bvec_alloc_gfp(gfp_t gfp)
168 return (gfp & ~(__GFP_DIRECT_RECLAIM | __GFP_IO)) |
169 __GFP_NOMEMALLOC | __GFP_NORETRY | __GFP_NOWARN;
172 struct bio_vec *bvec_alloc(gfp_t gfp_mask, int nr, unsigned long *idx,
176 * see comment near bvec_array define!
194 case 129 ... BIO_MAX_PAGES:
202 * Try a slab allocation first for all smaller allocations. If that
203 * fails and __GFP_DIRECT_RECLAIM is set retry with the mempool.
204 * The mempool is sized to handle up to BIO_MAX_PAGES entries.
206 if (*idx < BVEC_POOL_MAX) {
207 struct biovec_slab *bvs = bvec_slabs + *idx;
210 bvl = kmem_cache_alloc(bvs->slab, bvec_alloc_gfp(gfp_mask));
211 if (likely(bvl) || !(gfp_mask & __GFP_DIRECT_RECLAIM)) {
215 *idx = BVEC_POOL_MAX;
219 return mempool_alloc(pool, gfp_mask);
222 void bio_uninit(struct bio *bio)
224 #ifdef CONFIG_BLK_CGROUP
226 blkg_put(bio->bi_blkg);
230 if (bio_integrity(bio))
231 bio_integrity_free(bio);
233 bio_crypt_free_ctx(bio);
235 EXPORT_SYMBOL(bio_uninit);
237 static void bio_free(struct bio *bio)
239 struct bio_set *bs = bio->bi_pool;
245 bvec_free(&bs->bvec_pool, bio->bi_io_vec, BVEC_POOL_IDX(bio));
248 * If we have front padding, adjust the bio pointer before freeing
253 mempool_free(p, &bs->bio_pool);
255 /* Bio was allocated by bio_kmalloc() */
261 * Users of this function have their own bio allocation. Subsequently,
262 * they must remember to pair any call to bio_init() with bio_uninit()
263 * when IO has completed, or when the bio is released.
265 void bio_init(struct bio *bio, struct bio_vec *table,
266 unsigned short max_vecs)
268 memset(bio, 0, sizeof(*bio));
269 atomic_set(&bio->__bi_remaining, 1);
270 atomic_set(&bio->__bi_cnt, 1);
272 bio->bi_io_vec = table;
273 bio->bi_max_vecs = max_vecs;
275 EXPORT_SYMBOL(bio_init);
278 * bio_reset - reinitialize a bio
282 * After calling bio_reset(), @bio will be in the same state as a freshly
283 * allocated bio returned bio bio_alloc_bioset() - the only fields that are
284 * preserved are the ones that are initialized by bio_alloc_bioset(). See
285 * comment in struct bio.
287 void bio_reset(struct bio *bio)
289 unsigned long flags = bio->bi_flags & (~0UL << BIO_RESET_BITS);
293 memset(bio, 0, BIO_RESET_BYTES);
294 bio->bi_flags = flags;
295 atomic_set(&bio->__bi_remaining, 1);
297 EXPORT_SYMBOL(bio_reset);
299 static struct bio *__bio_chain_endio(struct bio *bio)
301 struct bio *parent = bio->bi_private;
303 if (!parent->bi_status)
304 parent->bi_status = bio->bi_status;
309 static void bio_chain_endio(struct bio *bio)
311 bio_endio(__bio_chain_endio(bio));
315 * bio_chain - chain bio completions
316 * @bio: the target bio
317 * @parent: the parent bio of @bio
319 * The caller won't have a bi_end_io called when @bio completes - instead,
320 * @parent's bi_end_io won't be called until both @parent and @bio have
321 * completed; the chained bio will also be freed when it completes.
323 * The caller must not set bi_private or bi_end_io in @bio.
325 void bio_chain(struct bio *bio, struct bio *parent)
327 BUG_ON(bio->bi_private || bio->bi_end_io);
329 bio->bi_private = parent;
330 bio->bi_end_io = bio_chain_endio;
331 bio_inc_remaining(parent);
333 EXPORT_SYMBOL(bio_chain);
335 static void bio_alloc_rescue(struct work_struct *work)
337 struct bio_set *bs = container_of(work, struct bio_set, rescue_work);
341 spin_lock(&bs->rescue_lock);
342 bio = bio_list_pop(&bs->rescue_list);
343 spin_unlock(&bs->rescue_lock);
348 submit_bio_noacct(bio);
352 static void punt_bios_to_rescuer(struct bio_set *bs)
354 struct bio_list punt, nopunt;
357 if (WARN_ON_ONCE(!bs->rescue_workqueue))
360 * In order to guarantee forward progress we must punt only bios that
361 * were allocated from this bio_set; otherwise, if there was a bio on
362 * there for a stacking driver higher up in the stack, processing it
363 * could require allocating bios from this bio_set, and doing that from
364 * our own rescuer would be bad.
366 * Since bio lists are singly linked, pop them all instead of trying to
367 * remove from the middle of the list:
370 bio_list_init(&punt);
371 bio_list_init(&nopunt);
373 while ((bio = bio_list_pop(¤t->bio_list[0])))
374 bio_list_add(bio->bi_pool == bs ? &punt : &nopunt, bio);
375 current->bio_list[0] = nopunt;
377 bio_list_init(&nopunt);
378 while ((bio = bio_list_pop(¤t->bio_list[1])))
379 bio_list_add(bio->bi_pool == bs ? &punt : &nopunt, bio);
380 current->bio_list[1] = nopunt;
382 spin_lock(&bs->rescue_lock);
383 bio_list_merge(&bs->rescue_list, &punt);
384 spin_unlock(&bs->rescue_lock);
386 queue_work(bs->rescue_workqueue, &bs->rescue_work);
390 * bio_alloc_bioset - allocate a bio for I/O
391 * @gfp_mask: the GFP_* mask given to the slab allocator
392 * @nr_iovecs: number of iovecs to pre-allocate
393 * @bs: the bio_set to allocate from.
395 * Allocate a bio from the mempools in @bs.
397 * If %__GFP_DIRECT_RECLAIM is set then bio_alloc will always be able to
398 * allocate a bio. This is due to the mempool guarantees. To make this work,
399 * callers must never allocate more than 1 bio at a time from the general pool.
400 * Callers that need to allocate more than 1 bio must always submit the
401 * previously allocated bio for IO before attempting to allocate a new one.
402 * Failure to do so can cause deadlocks under memory pressure.
404 * Note that when running under submit_bio_noacct() (i.e. any block driver),
405 * bios are not submitted until after you return - see the code in
406 * submit_bio_noacct() that converts recursion into iteration, to prevent
409 * This would normally mean allocating multiple bios under submit_bio_noacct()
410 * would be susceptible to deadlocks, but we have
411 * deadlock avoidance code that resubmits any blocked bios from a rescuer
414 * However, we do not guarantee forward progress for allocations from other
415 * mempools. Doing multiple allocations from the same mempool under
416 * submit_bio_noacct() should be avoided - instead, use bio_set's front_pad
417 * for per bio allocations.
419 * Returns: Pointer to new bio on success, NULL on failure.
421 struct bio *bio_alloc_bioset(gfp_t gfp_mask, unsigned int nr_iovecs,
424 gfp_t saved_gfp = gfp_mask;
428 /* should not use nobvec bioset for nr_iovecs > 0 */
429 if (WARN_ON_ONCE(!mempool_initialized(&bs->bvec_pool) && nr_iovecs > 0))
433 * submit_bio_noacct() converts recursion to iteration; this means if
434 * we're running beneath it, any bios we allocate and submit will not be
435 * submitted (and thus freed) until after we return.
437 * This exposes us to a potential deadlock if we allocate multiple bios
438 * from the same bio_set() while running underneath submit_bio_noacct().
439 * If we were to allocate multiple bios (say a stacking block driver
440 * that was splitting bios), we would deadlock if we exhausted the
443 * We solve this, and guarantee forward progress, with a rescuer
444 * workqueue per bio_set. If we go to allocate and there are bios on
445 * current->bio_list, we first try the allocation without
446 * __GFP_DIRECT_RECLAIM; if that fails, we punt those bios we would be
447 * blocking to the rescuer workqueue before we retry with the original
450 if (current->bio_list &&
451 (!bio_list_empty(¤t->bio_list[0]) ||
452 !bio_list_empty(¤t->bio_list[1])) &&
453 bs->rescue_workqueue)
454 gfp_mask &= ~__GFP_DIRECT_RECLAIM;
456 p = mempool_alloc(&bs->bio_pool, gfp_mask);
457 if (!p && gfp_mask != saved_gfp) {
458 punt_bios_to_rescuer(bs);
459 gfp_mask = saved_gfp;
460 p = mempool_alloc(&bs->bio_pool, gfp_mask);
465 bio = p + bs->front_pad;
466 if (nr_iovecs > BIO_INLINE_VECS) {
467 unsigned long idx = 0;
468 struct bio_vec *bvl = NULL;
470 bvl = bvec_alloc(gfp_mask, nr_iovecs, &idx, &bs->bvec_pool);
471 if (!bvl && gfp_mask != saved_gfp) {
472 punt_bios_to_rescuer(bs);
473 gfp_mask = saved_gfp;
474 bvl = bvec_alloc(gfp_mask, nr_iovecs, &idx,
481 bio_init(bio, bvl, bvec_nr_vecs(idx));
482 bio->bi_flags |= idx << BVEC_POOL_OFFSET;
483 } else if (nr_iovecs) {
484 bio_init(bio, bio->bi_inline_vecs, BIO_INLINE_VECS);
486 bio_init(bio, NULL, 0);
493 mempool_free(p, &bs->bio_pool);
496 EXPORT_SYMBOL(bio_alloc_bioset);
499 * bio_kmalloc - kmalloc a bio for I/O
500 * @gfp_mask: the GFP_* mask given to the slab allocator
501 * @nr_iovecs: number of iovecs to pre-allocate
503 * Use kmalloc to allocate and initialize a bio.
505 * Returns: Pointer to new bio on success, NULL on failure.
507 struct bio *bio_kmalloc(gfp_t gfp_mask, unsigned int nr_iovecs)
511 if (nr_iovecs > UIO_MAXIOV)
514 bio = kmalloc(struct_size(bio, bi_inline_vecs, nr_iovecs), gfp_mask);
517 bio_init(bio, nr_iovecs ? bio->bi_inline_vecs : NULL, nr_iovecs);
521 EXPORT_SYMBOL(bio_kmalloc);
523 void zero_fill_bio_iter(struct bio *bio, struct bvec_iter start)
527 struct bvec_iter iter;
529 __bio_for_each_segment(bv, bio, iter, start) {
530 char *data = bvec_kmap_irq(&bv, &flags);
531 memset(data, 0, bv.bv_len);
532 flush_dcache_page(bv.bv_page);
533 bvec_kunmap_irq(data, &flags);
536 EXPORT_SYMBOL(zero_fill_bio_iter);
539 * bio_truncate - truncate the bio to small size of @new_size
540 * @bio: the bio to be truncated
541 * @new_size: new size for truncating the bio
544 * Truncate the bio to new size of @new_size. If bio_op(bio) is
545 * REQ_OP_READ, zero the truncated part. This function should only
546 * be used for handling corner cases, such as bio eod.
548 void bio_truncate(struct bio *bio, unsigned new_size)
551 struct bvec_iter iter;
552 unsigned int done = 0;
553 bool truncated = false;
555 if (new_size >= bio->bi_iter.bi_size)
558 if (bio_op(bio) != REQ_OP_READ)
561 bio_for_each_segment(bv, bio, iter) {
562 if (done + bv.bv_len > new_size) {
566 offset = new_size - done;
569 zero_user(bv.bv_page, offset, bv.bv_len - offset);
577 * Don't touch bvec table here and make it really immutable, since
578 * fs bio user has to retrieve all pages via bio_for_each_segment_all
579 * in its .end_bio() callback.
581 * It is enough to truncate bio by updating .bi_size since we can make
582 * correct bvec with the updated .bi_size for drivers.
584 bio->bi_iter.bi_size = new_size;
588 * guard_bio_eod - truncate a BIO to fit the block device
589 * @bio: bio to truncate
591 * This allows us to do IO even on the odd last sectors of a device, even if the
592 * block size is some multiple of the physical sector size.
594 * We'll just truncate the bio to the size of the device, and clear the end of
595 * the buffer head manually. Truly out-of-range accesses will turn into actual
596 * I/O errors, this only handles the "we need to be able to do I/O at the final
599 void guard_bio_eod(struct bio *bio)
601 sector_t maxsector = bdev_nr_sectors(bio->bi_bdev);
607 * If the *whole* IO is past the end of the device,
608 * let it through, and the IO layer will turn it into
611 if (unlikely(bio->bi_iter.bi_sector >= maxsector))
614 maxsector -= bio->bi_iter.bi_sector;
615 if (likely((bio->bi_iter.bi_size >> 9) <= maxsector))
618 bio_truncate(bio, maxsector << 9);
622 * bio_put - release a reference to a bio
623 * @bio: bio to release reference to
626 * Put a reference to a &struct bio, either one you have gotten with
627 * bio_alloc, bio_get or bio_clone_*. The last put of a bio will free it.
629 void bio_put(struct bio *bio)
631 if (!bio_flagged(bio, BIO_REFFED))
634 BIO_BUG_ON(!atomic_read(&bio->__bi_cnt));
639 if (atomic_dec_and_test(&bio->__bi_cnt))
643 EXPORT_SYMBOL(bio_put);
646 * __bio_clone_fast - clone a bio that shares the original bio's biovec
647 * @bio: destination bio
648 * @bio_src: bio to clone
650 * Clone a &bio. Caller will own the returned bio, but not
651 * the actual data it points to. Reference count of returned
654 * Caller must ensure that @bio_src is not freed before @bio.
656 void __bio_clone_fast(struct bio *bio, struct bio *bio_src)
658 BUG_ON(bio->bi_pool && BVEC_POOL_IDX(bio));
661 * most users will be overriding ->bi_bdev with a new target,
662 * so we don't set nor calculate new physical/hw segment counts here
664 bio->bi_bdev = bio_src->bi_bdev;
665 bio_set_flag(bio, BIO_CLONED);
666 if (bio_flagged(bio_src, BIO_THROTTLED))
667 bio_set_flag(bio, BIO_THROTTLED);
668 if (bio_flagged(bio_src, BIO_REMAPPED))
669 bio_set_flag(bio, BIO_REMAPPED);
670 bio->bi_opf = bio_src->bi_opf;
671 bio->bi_ioprio = bio_src->bi_ioprio;
672 bio->bi_write_hint = bio_src->bi_write_hint;
673 bio->bi_iter = bio_src->bi_iter;
674 bio->bi_io_vec = bio_src->bi_io_vec;
676 bio_clone_blkg_association(bio, bio_src);
677 blkcg_bio_issue_init(bio);
679 EXPORT_SYMBOL(__bio_clone_fast);
682 * bio_clone_fast - clone a bio that shares the original bio's biovec
684 * @gfp_mask: allocation priority
685 * @bs: bio_set to allocate from
687 * Like __bio_clone_fast, only also allocates the returned bio
689 struct bio *bio_clone_fast(struct bio *bio, gfp_t gfp_mask, struct bio_set *bs)
693 b = bio_alloc_bioset(gfp_mask, 0, bs);
697 __bio_clone_fast(b, bio);
699 if (bio_crypt_clone(b, bio, gfp_mask) < 0)
702 if (bio_integrity(bio) &&
703 bio_integrity_clone(b, bio, gfp_mask) < 0)
712 EXPORT_SYMBOL(bio_clone_fast);
714 const char *bio_devname(struct bio *bio, char *buf)
716 return bdevname(bio->bi_bdev, buf);
718 EXPORT_SYMBOL(bio_devname);
720 static inline bool page_is_mergeable(const struct bio_vec *bv,
721 struct page *page, unsigned int len, unsigned int off,
724 size_t bv_end = bv->bv_offset + bv->bv_len;
725 phys_addr_t vec_end_addr = page_to_phys(bv->bv_page) + bv_end - 1;
726 phys_addr_t page_addr = page_to_phys(page);
728 if (vec_end_addr + 1 != page_addr + off)
730 if (xen_domain() && !xen_biovec_phys_mergeable(bv, page))
733 *same_page = ((vec_end_addr & PAGE_MASK) == page_addr);
736 return (bv->bv_page + bv_end / PAGE_SIZE) == (page + off / PAGE_SIZE);
740 * Try to merge a page into a segment, while obeying the hardware segment
741 * size limit. This is not for normal read/write bios, but for passthrough
742 * or Zone Append operations that we can't split.
744 static bool bio_try_merge_hw_seg(struct request_queue *q, struct bio *bio,
745 struct page *page, unsigned len,
746 unsigned offset, bool *same_page)
748 struct bio_vec *bv = &bio->bi_io_vec[bio->bi_vcnt - 1];
749 unsigned long mask = queue_segment_boundary(q);
750 phys_addr_t addr1 = page_to_phys(bv->bv_page) + bv->bv_offset;
751 phys_addr_t addr2 = page_to_phys(page) + offset + len - 1;
753 if ((addr1 | mask) != (addr2 | mask))
755 if (bv->bv_len + len > queue_max_segment_size(q))
757 return __bio_try_merge_page(bio, page, len, offset, same_page);
761 * bio_add_hw_page - attempt to add a page to a bio with hw constraints
762 * @q: the target queue
763 * @bio: destination bio
765 * @len: vec entry length
766 * @offset: vec entry offset
767 * @max_sectors: maximum number of sectors that can be added
768 * @same_page: return if the segment has been merged inside the same page
770 * Add a page to a bio while respecting the hardware max_sectors, max_segment
771 * and gap limitations.
773 int bio_add_hw_page(struct request_queue *q, struct bio *bio,
774 struct page *page, unsigned int len, unsigned int offset,
775 unsigned int max_sectors, bool *same_page)
777 struct bio_vec *bvec;
779 if (WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED)))
782 if (((bio->bi_iter.bi_size + len) >> 9) > max_sectors)
785 if (bio->bi_vcnt > 0) {
786 if (bio_try_merge_hw_seg(q, bio, page, len, offset, same_page))
790 * If the queue doesn't support SG gaps and adding this segment
791 * would create a gap, disallow it.
793 bvec = &bio->bi_io_vec[bio->bi_vcnt - 1];
794 if (bvec_gap_to_prev(q, bvec, offset))
798 if (bio_full(bio, len))
801 if (bio->bi_vcnt >= queue_max_segments(q))
804 bvec = &bio->bi_io_vec[bio->bi_vcnt];
805 bvec->bv_page = page;
807 bvec->bv_offset = offset;
809 bio->bi_iter.bi_size += len;
814 * bio_add_pc_page - attempt to add page to passthrough bio
815 * @q: the target queue
816 * @bio: destination bio
818 * @len: vec entry length
819 * @offset: vec entry offset
821 * Attempt to add a page to the bio_vec maplist. This can fail for a
822 * number of reasons, such as the bio being full or target block device
823 * limitations. The target block device must allow bio's up to PAGE_SIZE,
824 * so it is always possible to add a single page to an empty bio.
826 * This should only be used by passthrough bios.
828 int bio_add_pc_page(struct request_queue *q, struct bio *bio,
829 struct page *page, unsigned int len, unsigned int offset)
831 bool same_page = false;
832 return bio_add_hw_page(q, bio, page, len, offset,
833 queue_max_hw_sectors(q), &same_page);
835 EXPORT_SYMBOL(bio_add_pc_page);
838 * __bio_try_merge_page - try appending data to an existing bvec.
839 * @bio: destination bio
840 * @page: start page to add
841 * @len: length of the data to add
842 * @off: offset of the data relative to @page
843 * @same_page: return if the segment has been merged inside the same page
845 * Try to add the data at @page + @off to the last bvec of @bio. This is a
846 * useful optimisation for file systems with a block size smaller than the
849 * Warn if (@len, @off) crosses pages in case that @same_page is true.
851 * Return %true on success or %false on failure.
853 bool __bio_try_merge_page(struct bio *bio, struct page *page,
854 unsigned int len, unsigned int off, bool *same_page)
856 if (WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED)))
859 if (bio->bi_vcnt > 0) {
860 struct bio_vec *bv = &bio->bi_io_vec[bio->bi_vcnt - 1];
862 if (page_is_mergeable(bv, page, len, off, same_page)) {
863 if (bio->bi_iter.bi_size > UINT_MAX - len) {
868 bio->bi_iter.bi_size += len;
874 EXPORT_SYMBOL_GPL(__bio_try_merge_page);
877 * __bio_add_page - add page(s) to a bio in a new segment
878 * @bio: destination bio
879 * @page: start page to add
880 * @len: length of the data to add, may cross pages
881 * @off: offset of the data relative to @page, may cross pages
883 * Add the data at @page + @off to @bio as a new bvec. The caller must ensure
884 * that @bio has space for another bvec.
886 void __bio_add_page(struct bio *bio, struct page *page,
887 unsigned int len, unsigned int off)
889 struct bio_vec *bv = &bio->bi_io_vec[bio->bi_vcnt];
891 WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED));
892 WARN_ON_ONCE(bio_full(bio, len));
898 bio->bi_iter.bi_size += len;
901 if (!bio_flagged(bio, BIO_WORKINGSET) && unlikely(PageWorkingset(page)))
902 bio_set_flag(bio, BIO_WORKINGSET);
904 EXPORT_SYMBOL_GPL(__bio_add_page);
907 * bio_add_page - attempt to add page(s) to bio
908 * @bio: destination bio
909 * @page: start page to add
910 * @len: vec entry length, may cross pages
911 * @offset: vec entry offset relative to @page, may cross pages
913 * Attempt to add page(s) to the bio_vec maplist. This will only fail
914 * if either bio->bi_vcnt == bio->bi_max_vecs or it's a cloned bio.
916 int bio_add_page(struct bio *bio, struct page *page,
917 unsigned int len, unsigned int offset)
919 bool same_page = false;
921 if (!__bio_try_merge_page(bio, page, len, offset, &same_page)) {
922 if (bio_full(bio, len))
924 __bio_add_page(bio, page, len, offset);
928 EXPORT_SYMBOL(bio_add_page);
930 void bio_release_pages(struct bio *bio, bool mark_dirty)
932 struct bvec_iter_all iter_all;
933 struct bio_vec *bvec;
935 if (bio_flagged(bio, BIO_NO_PAGE_REF))
938 bio_for_each_segment_all(bvec, bio, iter_all) {
939 if (mark_dirty && !PageCompound(bvec->bv_page))
940 set_page_dirty_lock(bvec->bv_page);
941 put_page(bvec->bv_page);
944 EXPORT_SYMBOL_GPL(bio_release_pages);
946 static int bio_iov_bvec_set(struct bio *bio, struct iov_iter *iter)
948 WARN_ON_ONCE(BVEC_POOL_IDX(bio) != 0);
950 bio->bi_vcnt = iter->nr_segs;
951 bio->bi_max_vecs = iter->nr_segs;
952 bio->bi_io_vec = (struct bio_vec *)iter->bvec;
953 bio->bi_iter.bi_bvec_done = iter->iov_offset;
954 bio->bi_iter.bi_size = iter->count;
956 iov_iter_advance(iter, iter->count);
960 #define PAGE_PTRS_PER_BVEC (sizeof(struct bio_vec) / sizeof(struct page *))
963 * __bio_iov_iter_get_pages - pin user or kernel pages and add them to a bio
964 * @bio: bio to add pages to
965 * @iter: iov iterator describing the region to be mapped
967 * Pins pages from *iter and appends them to @bio's bvec array. The
968 * pages will have to be released using put_page() when done.
969 * For multi-segment *iter, this function only adds pages from the
970 * next non-empty segment of the iov iterator.
972 static int __bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter)
974 unsigned short nr_pages = bio->bi_max_vecs - bio->bi_vcnt;
975 unsigned short entries_left = bio->bi_max_vecs - bio->bi_vcnt;
976 struct bio_vec *bv = bio->bi_io_vec + bio->bi_vcnt;
977 struct page **pages = (struct page **)bv;
978 bool same_page = false;
984 * Move page array up in the allocated memory for the bio vecs as far as
985 * possible so that we can start filling biovecs from the beginning
986 * without overwriting the temporary page array.
988 BUILD_BUG_ON(PAGE_PTRS_PER_BVEC < 2);
989 pages += entries_left * (PAGE_PTRS_PER_BVEC - 1);
991 size = iov_iter_get_pages(iter, pages, LONG_MAX, nr_pages, &offset);
992 if (unlikely(size <= 0))
993 return size ? size : -EFAULT;
995 for (left = size, i = 0; left > 0; left -= len, i++) {
996 struct page *page = pages[i];
998 len = min_t(size_t, PAGE_SIZE - offset, left);
1000 if (__bio_try_merge_page(bio, page, len, offset, &same_page)) {
1004 if (WARN_ON_ONCE(bio_full(bio, len)))
1006 __bio_add_page(bio, page, len, offset);
1011 iov_iter_advance(iter, size);
1015 static int __bio_iov_append_get_pages(struct bio *bio, struct iov_iter *iter)
1017 unsigned short nr_pages = bio->bi_max_vecs - bio->bi_vcnt;
1018 unsigned short entries_left = bio->bi_max_vecs - bio->bi_vcnt;
1019 struct request_queue *q = bio->bi_bdev->bd_disk->queue;
1020 unsigned int max_append_sectors = queue_max_zone_append_sectors(q);
1021 struct bio_vec *bv = bio->bi_io_vec + bio->bi_vcnt;
1022 struct page **pages = (struct page **)bv;
1028 if (WARN_ON_ONCE(!max_append_sectors))
1032 * Move page array up in the allocated memory for the bio vecs as far as
1033 * possible so that we can start filling biovecs from the beginning
1034 * without overwriting the temporary page array.
1036 BUILD_BUG_ON(PAGE_PTRS_PER_BVEC < 2);
1037 pages += entries_left * (PAGE_PTRS_PER_BVEC - 1);
1039 size = iov_iter_get_pages(iter, pages, LONG_MAX, nr_pages, &offset);
1040 if (unlikely(size <= 0))
1041 return size ? size : -EFAULT;
1043 for (left = size, i = 0; left > 0; left -= len, i++) {
1044 struct page *page = pages[i];
1045 bool same_page = false;
1047 len = min_t(size_t, PAGE_SIZE - offset, left);
1048 if (bio_add_hw_page(q, bio, page, len, offset,
1049 max_append_sectors, &same_page) != len) {
1058 iov_iter_advance(iter, size - left);
1063 * bio_iov_iter_get_pages - add user or kernel pages to a bio
1064 * @bio: bio to add pages to
1065 * @iter: iov iterator describing the region to be added
1067 * This takes either an iterator pointing to user memory, or one pointing to
1068 * kernel pages (BVEC iterator). If we're adding user pages, we pin them and
1069 * map them into the kernel. On IO completion, the caller should put those
1070 * pages. For bvec based iterators bio_iov_iter_get_pages() uses the provided
1071 * bvecs rather than copying them. Hence anyone issuing kiocb based IO needs
1072 * to ensure the bvecs and pages stay referenced until the submitted I/O is
1073 * completed by a call to ->ki_complete() or returns with an error other than
1074 * -EIOCBQUEUED. The caller needs to check if the bio is flagged BIO_NO_PAGE_REF
1075 * on IO completion. If it isn't, then pages should be released.
1077 * The function tries, but does not guarantee, to pin as many pages as
1078 * fit into the bio, or are requested in @iter, whatever is smaller. If
1079 * MM encounters an error pinning the requested pages, it stops. Error
1080 * is returned only if 0 pages could be pinned.
1082 * It's intended for direct IO, so doesn't do PSI tracking, the caller is
1083 * responsible for setting BIO_WORKINGSET if necessary.
1085 int bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter)
1089 if (iov_iter_is_bvec(iter)) {
1090 if (WARN_ON_ONCE(bio_op(bio) == REQ_OP_ZONE_APPEND))
1092 bio_iov_bvec_set(bio, iter);
1093 bio_set_flag(bio, BIO_NO_PAGE_REF);
1097 if (bio_op(bio) == REQ_OP_ZONE_APPEND)
1098 ret = __bio_iov_append_get_pages(bio, iter);
1100 ret = __bio_iov_iter_get_pages(bio, iter);
1101 } while (!ret && iov_iter_count(iter) && !bio_full(bio, 0));
1104 /* don't account direct I/O as memory stall */
1105 bio_clear_flag(bio, BIO_WORKINGSET);
1106 return bio->bi_vcnt ? 0 : ret;
1108 EXPORT_SYMBOL_GPL(bio_iov_iter_get_pages);
1110 static void submit_bio_wait_endio(struct bio *bio)
1112 complete(bio->bi_private);
1116 * submit_bio_wait - submit a bio, and wait until it completes
1117 * @bio: The &struct bio which describes the I/O
1119 * Simple wrapper around submit_bio(). Returns 0 on success, or the error from
1120 * bio_endio() on failure.
1122 * WARNING: Unlike to how submit_bio() is usually used, this function does not
1123 * result in bio reference to be consumed. The caller must drop the reference
1126 int submit_bio_wait(struct bio *bio)
1128 DECLARE_COMPLETION_ONSTACK_MAP(done,
1129 bio->bi_bdev->bd_disk->lockdep_map);
1130 unsigned long hang_check;
1132 bio->bi_private = &done;
1133 bio->bi_end_io = submit_bio_wait_endio;
1134 bio->bi_opf |= REQ_SYNC;
1137 /* Prevent hang_check timer from firing at us during very long I/O */
1138 hang_check = sysctl_hung_task_timeout_secs;
1140 while (!wait_for_completion_io_timeout(&done,
1141 hang_check * (HZ/2)))
1144 wait_for_completion_io(&done);
1146 return blk_status_to_errno(bio->bi_status);
1148 EXPORT_SYMBOL(submit_bio_wait);
1151 * bio_advance - increment/complete a bio by some number of bytes
1152 * @bio: bio to advance
1153 * @bytes: number of bytes to complete
1155 * This updates bi_sector, bi_size and bi_idx; if the number of bytes to
1156 * complete doesn't align with a bvec boundary, then bv_len and bv_offset will
1157 * be updated on the last bvec as well.
1159 * @bio will then represent the remaining, uncompleted portion of the io.
1161 void bio_advance(struct bio *bio, unsigned bytes)
1163 if (bio_integrity(bio))
1164 bio_integrity_advance(bio, bytes);
1166 bio_crypt_advance(bio, bytes);
1167 bio_advance_iter(bio, &bio->bi_iter, bytes);
1169 EXPORT_SYMBOL(bio_advance);
1171 void bio_copy_data_iter(struct bio *dst, struct bvec_iter *dst_iter,
1172 struct bio *src, struct bvec_iter *src_iter)
1174 struct bio_vec src_bv, dst_bv;
1175 void *src_p, *dst_p;
1178 while (src_iter->bi_size && dst_iter->bi_size) {
1179 src_bv = bio_iter_iovec(src, *src_iter);
1180 dst_bv = bio_iter_iovec(dst, *dst_iter);
1182 bytes = min(src_bv.bv_len, dst_bv.bv_len);
1184 src_p = kmap_atomic(src_bv.bv_page);
1185 dst_p = kmap_atomic(dst_bv.bv_page);
1187 memcpy(dst_p + dst_bv.bv_offset,
1188 src_p + src_bv.bv_offset,
1191 kunmap_atomic(dst_p);
1192 kunmap_atomic(src_p);
1194 flush_dcache_page(dst_bv.bv_page);
1196 bio_advance_iter_single(src, src_iter, bytes);
1197 bio_advance_iter_single(dst, dst_iter, bytes);
1200 EXPORT_SYMBOL(bio_copy_data_iter);
1203 * bio_copy_data - copy contents of data buffers from one bio to another
1205 * @dst: destination bio
1207 * Stops when it reaches the end of either @src or @dst - that is, copies
1208 * min(src->bi_size, dst->bi_size) bytes (or the equivalent for lists of bios).
1210 void bio_copy_data(struct bio *dst, struct bio *src)
1212 struct bvec_iter src_iter = src->bi_iter;
1213 struct bvec_iter dst_iter = dst->bi_iter;
1215 bio_copy_data_iter(dst, &dst_iter, src, &src_iter);
1217 EXPORT_SYMBOL(bio_copy_data);
1220 * bio_list_copy_data - copy contents of data buffers from one chain of bios to
1222 * @src: source bio list
1223 * @dst: destination bio list
1225 * Stops when it reaches the end of either the @src list or @dst list - that is,
1226 * copies min(src->bi_size, dst->bi_size) bytes (or the equivalent for lists of
1229 void bio_list_copy_data(struct bio *dst, struct bio *src)
1231 struct bvec_iter src_iter = src->bi_iter;
1232 struct bvec_iter dst_iter = dst->bi_iter;
1235 if (!src_iter.bi_size) {
1240 src_iter = src->bi_iter;
1243 if (!dst_iter.bi_size) {
1248 dst_iter = dst->bi_iter;
1251 bio_copy_data_iter(dst, &dst_iter, src, &src_iter);
1254 EXPORT_SYMBOL(bio_list_copy_data);
1256 void bio_free_pages(struct bio *bio)
1258 struct bio_vec *bvec;
1259 struct bvec_iter_all iter_all;
1261 bio_for_each_segment_all(bvec, bio, iter_all)
1262 __free_page(bvec->bv_page);
1264 EXPORT_SYMBOL(bio_free_pages);
1267 * bio_set_pages_dirty() and bio_check_pages_dirty() are support functions
1268 * for performing direct-IO in BIOs.
1270 * The problem is that we cannot run set_page_dirty() from interrupt context
1271 * because the required locks are not interrupt-safe. So what we can do is to
1272 * mark the pages dirty _before_ performing IO. And in interrupt context,
1273 * check that the pages are still dirty. If so, fine. If not, redirty them
1274 * in process context.
1276 * We special-case compound pages here: normally this means reads into hugetlb
1277 * pages. The logic in here doesn't really work right for compound pages
1278 * because the VM does not uniformly chase down the head page in all cases.
1279 * But dirtiness of compound pages is pretty meaningless anyway: the VM doesn't
1280 * handle them at all. So we skip compound pages here at an early stage.
1282 * Note that this code is very hard to test under normal circumstances because
1283 * direct-io pins the pages with get_user_pages(). This makes
1284 * is_page_cache_freeable return false, and the VM will not clean the pages.
1285 * But other code (eg, flusher threads) could clean the pages if they are mapped
1288 * Simply disabling the call to bio_set_pages_dirty() is a good way to test the
1289 * deferred bio dirtying paths.
1293 * bio_set_pages_dirty() will mark all the bio's pages as dirty.
1295 void bio_set_pages_dirty(struct bio *bio)
1297 struct bio_vec *bvec;
1298 struct bvec_iter_all iter_all;
1300 bio_for_each_segment_all(bvec, bio, iter_all) {
1301 if (!PageCompound(bvec->bv_page))
1302 set_page_dirty_lock(bvec->bv_page);
1307 * bio_check_pages_dirty() will check that all the BIO's pages are still dirty.
1308 * If they are, then fine. If, however, some pages are clean then they must
1309 * have been written out during the direct-IO read. So we take another ref on
1310 * the BIO and re-dirty the pages in process context.
1312 * It is expected that bio_check_pages_dirty() will wholly own the BIO from
1313 * here on. It will run one put_page() against each page and will run one
1314 * bio_put() against the BIO.
1317 static void bio_dirty_fn(struct work_struct *work);
1319 static DECLARE_WORK(bio_dirty_work, bio_dirty_fn);
1320 static DEFINE_SPINLOCK(bio_dirty_lock);
1321 static struct bio *bio_dirty_list;
1324 * This runs in process context
1326 static void bio_dirty_fn(struct work_struct *work)
1328 struct bio *bio, *next;
1330 spin_lock_irq(&bio_dirty_lock);
1331 next = bio_dirty_list;
1332 bio_dirty_list = NULL;
1333 spin_unlock_irq(&bio_dirty_lock);
1335 while ((bio = next) != NULL) {
1336 next = bio->bi_private;
1338 bio_release_pages(bio, true);
1343 void bio_check_pages_dirty(struct bio *bio)
1345 struct bio_vec *bvec;
1346 unsigned long flags;
1347 struct bvec_iter_all iter_all;
1349 bio_for_each_segment_all(bvec, bio, iter_all) {
1350 if (!PageDirty(bvec->bv_page) && !PageCompound(bvec->bv_page))
1354 bio_release_pages(bio, false);
1358 spin_lock_irqsave(&bio_dirty_lock, flags);
1359 bio->bi_private = bio_dirty_list;
1360 bio_dirty_list = bio;
1361 spin_unlock_irqrestore(&bio_dirty_lock, flags);
1362 schedule_work(&bio_dirty_work);
1365 static inline bool bio_remaining_done(struct bio *bio)
1368 * If we're not chaining, then ->__bi_remaining is always 1 and
1369 * we always end io on the first invocation.
1371 if (!bio_flagged(bio, BIO_CHAIN))
1374 BUG_ON(atomic_read(&bio->__bi_remaining) <= 0);
1376 if (atomic_dec_and_test(&bio->__bi_remaining)) {
1377 bio_clear_flag(bio, BIO_CHAIN);
1385 * bio_endio - end I/O on a bio
1389 * bio_endio() will end I/O on the whole bio. bio_endio() is the preferred
1390 * way to end I/O on a bio. No one should call bi_end_io() directly on a
1391 * bio unless they own it and thus know that it has an end_io function.
1393 * bio_endio() can be called several times on a bio that has been chained
1394 * using bio_chain(). The ->bi_end_io() function will only be called the
1395 * last time. At this point the BLK_TA_COMPLETE tracing event will be
1396 * generated if BIO_TRACE_COMPLETION is set.
1398 void bio_endio(struct bio *bio)
1401 if (!bio_remaining_done(bio))
1403 if (!bio_integrity_endio(bio))
1407 rq_qos_done_bio(bio->bi_bdev->bd_disk->queue, bio);
1410 * Need to have a real endio function for chained bios, otherwise
1411 * various corner cases will break (like stacking block devices that
1412 * save/restore bi_end_io) - however, we want to avoid unbounded
1413 * recursion and blowing the stack. Tail call optimization would
1414 * handle this, but compiling with frame pointers also disables
1415 * gcc's sibling call optimization.
1417 if (bio->bi_end_io == bio_chain_endio) {
1418 bio = __bio_chain_endio(bio);
1422 if (bio->bi_bdev && bio_flagged(bio, BIO_TRACE_COMPLETION)) {
1423 trace_block_bio_complete(bio->bi_bdev->bd_disk->queue, bio);
1424 bio_clear_flag(bio, BIO_TRACE_COMPLETION);
1427 blk_throtl_bio_endio(bio);
1428 /* release cgroup info */
1431 bio->bi_end_io(bio);
1433 EXPORT_SYMBOL(bio_endio);
1436 * bio_split - split a bio
1437 * @bio: bio to split
1438 * @sectors: number of sectors to split from the front of @bio
1440 * @bs: bio set to allocate from
1442 * Allocates and returns a new bio which represents @sectors from the start of
1443 * @bio, and updates @bio to represent the remaining sectors.
1445 * Unless this is a discard request the newly allocated bio will point
1446 * to @bio's bi_io_vec. It is the caller's responsibility to ensure that
1447 * neither @bio nor @bs are freed before the split bio.
1449 struct bio *bio_split(struct bio *bio, int sectors,
1450 gfp_t gfp, struct bio_set *bs)
1454 BUG_ON(sectors <= 0);
1455 BUG_ON(sectors >= bio_sectors(bio));
1457 /* Zone append commands cannot be split */
1458 if (WARN_ON_ONCE(bio_op(bio) == REQ_OP_ZONE_APPEND))
1461 split = bio_clone_fast(bio, gfp, bs);
1465 split->bi_iter.bi_size = sectors << 9;
1467 if (bio_integrity(split))
1468 bio_integrity_trim(split);
1470 bio_advance(bio, split->bi_iter.bi_size);
1472 if (bio_flagged(bio, BIO_TRACE_COMPLETION))
1473 bio_set_flag(split, BIO_TRACE_COMPLETION);
1477 EXPORT_SYMBOL(bio_split);
1480 * bio_trim - trim a bio
1482 * @offset: number of sectors to trim from the front of @bio
1483 * @size: size we want to trim @bio to, in sectors
1485 void bio_trim(struct bio *bio, int offset, int size)
1487 /* 'bio' is a cloned bio which we need to trim to match
1488 * the given offset and size.
1492 if (offset == 0 && size == bio->bi_iter.bi_size)
1495 bio_advance(bio, offset << 9);
1496 bio->bi_iter.bi_size = size;
1498 if (bio_integrity(bio))
1499 bio_integrity_trim(bio);
1502 EXPORT_SYMBOL_GPL(bio_trim);
1505 * create memory pools for biovec's in a bio_set.
1506 * use the global biovec slabs created for general use.
1508 int biovec_init_pool(mempool_t *pool, int pool_entries)
1510 struct biovec_slab *bp = bvec_slabs + BVEC_POOL_MAX;
1512 return mempool_init_slab_pool(pool, pool_entries, bp->slab);
1516 * bioset_exit - exit a bioset initialized with bioset_init()
1518 * May be called on a zeroed but uninitialized bioset (i.e. allocated with
1521 void bioset_exit(struct bio_set *bs)
1523 if (bs->rescue_workqueue)
1524 destroy_workqueue(bs->rescue_workqueue);
1525 bs->rescue_workqueue = NULL;
1527 mempool_exit(&bs->bio_pool);
1528 mempool_exit(&bs->bvec_pool);
1530 bioset_integrity_free(bs);
1533 bs->bio_slab = NULL;
1535 EXPORT_SYMBOL(bioset_exit);
1538 * bioset_init - Initialize a bio_set
1539 * @bs: pool to initialize
1540 * @pool_size: Number of bio and bio_vecs to cache in the mempool
1541 * @front_pad: Number of bytes to allocate in front of the returned bio
1542 * @flags: Flags to modify behavior, currently %BIOSET_NEED_BVECS
1543 * and %BIOSET_NEED_RESCUER
1546 * Set up a bio_set to be used with @bio_alloc_bioset. Allows the caller
1547 * to ask for a number of bytes to be allocated in front of the bio.
1548 * Front pad allocation is useful for embedding the bio inside
1549 * another structure, to avoid allocating extra data to go with the bio.
1550 * Note that the bio must be embedded at the END of that structure always,
1551 * or things will break badly.
1552 * If %BIOSET_NEED_BVECS is set in @flags, a separate pool will be allocated
1553 * for allocating iovecs. This pool is not needed e.g. for bio_clone_fast().
1554 * If %BIOSET_NEED_RESCUER is set, a workqueue is created which can be used to
1555 * dispatch queued requests when the mempool runs out of space.
1558 int bioset_init(struct bio_set *bs,
1559 unsigned int pool_size,
1560 unsigned int front_pad,
1563 bs->front_pad = front_pad;
1564 if (flags & BIOSET_NEED_BVECS)
1565 bs->back_pad = BIO_INLINE_VECS * sizeof(struct bio_vec);
1569 spin_lock_init(&bs->rescue_lock);
1570 bio_list_init(&bs->rescue_list);
1571 INIT_WORK(&bs->rescue_work, bio_alloc_rescue);
1573 bs->bio_slab = bio_find_or_create_slab(bs);
1577 if (mempool_init_slab_pool(&bs->bio_pool, pool_size, bs->bio_slab))
1580 if ((flags & BIOSET_NEED_BVECS) &&
1581 biovec_init_pool(&bs->bvec_pool, pool_size))
1584 if (!(flags & BIOSET_NEED_RESCUER))
1587 bs->rescue_workqueue = alloc_workqueue("bioset", WQ_MEM_RECLAIM, 0);
1588 if (!bs->rescue_workqueue)
1596 EXPORT_SYMBOL(bioset_init);
1599 * Initialize and setup a new bio_set, based on the settings from
1602 int bioset_init_from_src(struct bio_set *bs, struct bio_set *src)
1607 if (src->bvec_pool.min_nr)
1608 flags |= BIOSET_NEED_BVECS;
1609 if (src->rescue_workqueue)
1610 flags |= BIOSET_NEED_RESCUER;
1612 return bioset_init(bs, src->bio_pool.min_nr, src->front_pad, flags);
1614 EXPORT_SYMBOL(bioset_init_from_src);
1616 static void __init biovec_init_slabs(void)
1620 for (i = 0; i < BVEC_POOL_NR; i++) {
1622 struct biovec_slab *bvs = bvec_slabs + i;
1624 if (bvs->nr_vecs <= BIO_INLINE_VECS) {
1629 size = bvs->nr_vecs * sizeof(struct bio_vec);
1630 bvs->slab = kmem_cache_create(bvs->name, size, 0,
1631 SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
1635 static int __init init_bio(void)
1637 BUILD_BUG_ON(BIO_FLAG_LAST > BVEC_POOL_OFFSET);
1639 bio_integrity_init();
1640 biovec_init_slabs();
1642 if (bioset_init(&fs_bio_set, BIO_POOL_SIZE, 0, BIOSET_NEED_BVECS))
1643 panic("bio: can't allocate bios\n");
1645 if (bioset_integrity_create(&fs_bio_set, BIO_POOL_SIZE))
1646 panic("bio: can't create integrity pool\n");
1650 subsys_initcall(init_bio);