4 * Copyright (C) 2001 Jens Axboe <axboe@suse.de>
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public Licens
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-
23 #include <linux/highmem.h>
24 #include <linux/mempool.h>
25 #include <linux/ioprio.h>
26 #include <linux/bug.h>
32 /* struct bio, bio_vec and BIO_* flags are defined in blk_types.h */
33 #include <linux/blk_types.h>
38 #define BIO_BUG_ON BUG_ON
43 #define BIO_MAX_PAGES 256
44 #define BIO_MAX_SIZE (BIO_MAX_PAGES << PAGE_SHIFT)
45 #define BIO_MAX_SECTORS (BIO_MAX_SIZE >> 9)
47 #define bio_op(bio) (op_from_rq_bits((bio)->bi_rw))
48 #define bio_set_op_attrs(bio, op, flags) ((bio)->bi_rw |= (op | flags))
50 #define bio_prio(bio) (bio)->bi_ioprio
51 #define bio_set_prio(bio, prio) ((bio)->bi_ioprio = prio)
54 * various member access, note that bio_data should of course not be used
55 * on highmem page vectors
57 #define __bvec_iter_bvec(bvec, iter) (&(bvec)[(iter).bi_idx])
59 #define bvec_iter_page(bvec, iter) \
60 (__bvec_iter_bvec((bvec), (iter))->bv_page)
62 #define bvec_iter_len(bvec, iter) \
64 __bvec_iter_bvec((bvec), (iter))->bv_len - (iter).bi_bvec_done)
66 #define bvec_iter_offset(bvec, iter) \
67 (__bvec_iter_bvec((bvec), (iter))->bv_offset + (iter).bi_bvec_done)
69 #define bvec_iter_bvec(bvec, iter) \
71 .bv_page = bvec_iter_page((bvec), (iter)), \
72 .bv_len = bvec_iter_len((bvec), (iter)), \
73 .bv_offset = bvec_iter_offset((bvec), (iter)), \
76 #define bio_iter_iovec(bio, iter) \
77 bvec_iter_bvec((bio)->bi_io_vec, (iter))
79 #define bio_iter_page(bio, iter) \
80 bvec_iter_page((bio)->bi_io_vec, (iter))
81 #define bio_iter_len(bio, iter) \
82 bvec_iter_len((bio)->bi_io_vec, (iter))
83 #define bio_iter_offset(bio, iter) \
84 bvec_iter_offset((bio)->bi_io_vec, (iter))
86 #define bio_page(bio) bio_iter_page((bio), (bio)->bi_iter)
87 #define bio_offset(bio) bio_iter_offset((bio), (bio)->bi_iter)
88 #define bio_iovec(bio) bio_iter_iovec((bio), (bio)->bi_iter)
90 #define bio_multiple_segments(bio) \
91 ((bio)->bi_iter.bi_size != bio_iovec(bio).bv_len)
92 #define bio_sectors(bio) ((bio)->bi_iter.bi_size >> 9)
93 #define bio_end_sector(bio) ((bio)->bi_iter.bi_sector + bio_sectors((bio)))
96 * Check whether this bio carries any data or not. A NULL bio is allowed.
98 static inline bool bio_has_data(struct bio *bio)
101 bio->bi_iter.bi_size &&
102 bio_op(bio) != REQ_OP_DISCARD)
108 static inline bool bio_no_advance_iter(struct bio *bio)
110 return bio_op(bio) == REQ_OP_DISCARD || bio_op(bio) == REQ_OP_WRITE_SAME;
113 static inline bool bio_is_rw(struct bio *bio)
115 if (!bio_has_data(bio))
118 if (bio_no_advance_iter(bio))
124 static inline bool bio_mergeable(struct bio *bio)
126 if (bio->bi_rw & REQ_NOMERGE_FLAGS)
132 static inline unsigned int bio_cur_bytes(struct bio *bio)
134 if (bio_has_data(bio))
135 return bio_iovec(bio).bv_len;
136 else /* dataless requests such as discard */
137 return bio->bi_iter.bi_size;
140 static inline void *bio_data(struct bio *bio)
142 if (bio_has_data(bio))
143 return page_address(bio_page(bio)) + bio_offset(bio);
151 #define bio_to_phys(bio) (page_to_phys(bio_page((bio))) + (unsigned long) bio_offset((bio)))
152 #define bvec_to_phys(bv) (page_to_phys((bv)->bv_page) + (unsigned long) (bv)->bv_offset)
155 * queues that have highmem support enabled may still need to revert to
156 * PIO transfers occasionally and thus map high pages temporarily. For
157 * permanent PIO fall back, user is probably better off disabling highmem
158 * I/O completely on that queue (see ide-dma for example)
160 #define __bio_kmap_atomic(bio, iter) \
161 (kmap_atomic(bio_iter_iovec((bio), (iter)).bv_page) + \
162 bio_iter_iovec((bio), (iter)).bv_offset)
164 #define __bio_kunmap_atomic(addr) kunmap_atomic(addr)
170 /* Default implementation of BIOVEC_PHYS_MERGEABLE */
171 #define __BIOVEC_PHYS_MERGEABLE(vec1, vec2) \
172 ((bvec_to_phys((vec1)) + (vec1)->bv_len) == bvec_to_phys((vec2)))
175 * allow arch override, for eg virtualized architectures (put in asm/io.h)
177 #ifndef BIOVEC_PHYS_MERGEABLE
178 #define BIOVEC_PHYS_MERGEABLE(vec1, vec2) \
179 __BIOVEC_PHYS_MERGEABLE(vec1, vec2)
182 #define __BIO_SEG_BOUNDARY(addr1, addr2, mask) \
183 (((addr1) | (mask)) == (((addr2) - 1) | (mask)))
184 #define BIOVEC_SEG_BOUNDARY(q, b1, b2) \
185 __BIO_SEG_BOUNDARY(bvec_to_phys((b1)), bvec_to_phys((b2)) + (b2)->bv_len, queue_segment_boundary((q)))
188 * drivers should _never_ use the all version - the bio may have been split
189 * before it got to the driver and the driver won't own all of it
191 #define bio_for_each_segment_all(bvl, bio, i) \
192 for (i = 0, bvl = (bio)->bi_io_vec; i < (bio)->bi_vcnt; i++, bvl++)
194 static inline void bvec_iter_advance(struct bio_vec *bv, struct bvec_iter *iter,
197 WARN_ONCE(bytes > iter->bi_size,
198 "Attempted to advance past end of bvec iter\n");
201 unsigned len = min(bytes, bvec_iter_len(bv, *iter));
204 iter->bi_size -= len;
205 iter->bi_bvec_done += len;
207 if (iter->bi_bvec_done == __bvec_iter_bvec(bv, *iter)->bv_len) {
208 iter->bi_bvec_done = 0;
214 #define for_each_bvec(bvl, bio_vec, iter, start) \
215 for (iter = (start); \
217 ((bvl = bvec_iter_bvec((bio_vec), (iter))), 1); \
218 bvec_iter_advance((bio_vec), &(iter), (bvl).bv_len))
221 static inline void bio_advance_iter(struct bio *bio, struct bvec_iter *iter,
224 iter->bi_sector += bytes >> 9;
226 if (bio_no_advance_iter(bio))
227 iter->bi_size -= bytes;
229 bvec_iter_advance(bio->bi_io_vec, iter, bytes);
232 #define __bio_for_each_segment(bvl, bio, iter, start) \
233 for (iter = (start); \
235 ((bvl = bio_iter_iovec((bio), (iter))), 1); \
236 bio_advance_iter((bio), &(iter), (bvl).bv_len))
238 #define bio_for_each_segment(bvl, bio, iter) \
239 __bio_for_each_segment(bvl, bio, iter, (bio)->bi_iter)
241 #define bio_iter_last(bvec, iter) ((iter).bi_size == (bvec).bv_len)
243 static inline unsigned bio_segments(struct bio *bio)
247 struct bvec_iter iter;
250 * We special case discard/write same, because they interpret bi_size
254 if (bio_op(bio) == REQ_OP_DISCARD)
257 if (bio_op(bio) == REQ_OP_WRITE_SAME)
260 bio_for_each_segment(bv, bio, iter)
267 * get a reference to a bio, so it won't disappear. the intended use is
271 * submit_bio(rw, bio);
272 * if (bio->bi_flags ...)
276 * without the bio_get(), it could potentially complete I/O before submit_bio
277 * returns. and then bio would be freed memory when if (bio->bi_flags ...)
280 static inline void bio_get(struct bio *bio)
282 bio->bi_flags |= (1 << BIO_REFFED);
283 smp_mb__before_atomic();
284 atomic_inc(&bio->__bi_cnt);
287 static inline void bio_cnt_set(struct bio *bio, unsigned int count)
290 bio->bi_flags |= (1 << BIO_REFFED);
291 smp_mb__before_atomic();
293 atomic_set(&bio->__bi_cnt, count);
296 static inline bool bio_flagged(struct bio *bio, unsigned int bit)
298 return (bio->bi_flags & (1U << bit)) != 0;
301 static inline void bio_set_flag(struct bio *bio, unsigned int bit)
303 bio->bi_flags |= (1U << bit);
306 static inline void bio_clear_flag(struct bio *bio, unsigned int bit)
308 bio->bi_flags &= ~(1U << bit);
311 static inline void bio_get_first_bvec(struct bio *bio, struct bio_vec *bv)
313 *bv = bio_iovec(bio);
316 static inline void bio_get_last_bvec(struct bio *bio, struct bio_vec *bv)
318 struct bvec_iter iter = bio->bi_iter;
321 if (unlikely(!bio_multiple_segments(bio))) {
322 *bv = bio_iovec(bio);
326 bio_advance_iter(bio, &iter, iter.bi_size);
328 if (!iter.bi_bvec_done)
329 idx = iter.bi_idx - 1;
330 else /* in the middle of bvec */
333 *bv = bio->bi_io_vec[idx];
336 * iter.bi_bvec_done records actual length of the last bvec
337 * if this bio ends in the middle of one io vector
339 if (iter.bi_bvec_done)
340 bv->bv_len = iter.bi_bvec_done;
344 BIP_BLOCK_INTEGRITY = 1 << 0, /* block layer owns integrity data */
345 BIP_MAPPED_INTEGRITY = 1 << 1, /* ref tag has been remapped */
346 BIP_CTRL_NOCHECK = 1 << 2, /* disable HBA integrity checking */
347 BIP_DISK_NOCHECK = 1 << 3, /* disable disk integrity checking */
348 BIP_IP_CHECKSUM = 1 << 4, /* IP checksum */
352 * bio integrity payload
354 struct bio_integrity_payload {
355 struct bio *bip_bio; /* parent bio */
357 struct bvec_iter bip_iter;
359 bio_end_io_t *bip_end_io; /* saved I/O completion fn */
361 unsigned short bip_slab; /* slab the bip came from */
362 unsigned short bip_vcnt; /* # of integrity bio_vecs */
363 unsigned short bip_max_vcnt; /* integrity bio_vec slots */
364 unsigned short bip_flags; /* control flags */
366 struct work_struct bip_work; /* I/O completion */
368 struct bio_vec *bip_vec;
369 struct bio_vec bip_inline_vecs[0];/* embedded bvec array */
372 #if defined(CONFIG_BLK_DEV_INTEGRITY)
374 static inline struct bio_integrity_payload *bio_integrity(struct bio *bio)
376 if (bio->bi_rw & REQ_INTEGRITY)
377 return bio->bi_integrity;
382 static inline bool bio_integrity_flagged(struct bio *bio, enum bip_flags flag)
384 struct bio_integrity_payload *bip = bio_integrity(bio);
387 return bip->bip_flags & flag;
392 static inline sector_t bip_get_seed(struct bio_integrity_payload *bip)
394 return bip->bip_iter.bi_sector;
397 static inline void bip_set_seed(struct bio_integrity_payload *bip,
400 bip->bip_iter.bi_sector = seed;
403 #endif /* CONFIG_BLK_DEV_INTEGRITY */
405 extern void bio_trim(struct bio *bio, int offset, int size);
406 extern struct bio *bio_split(struct bio *bio, int sectors,
407 gfp_t gfp, struct bio_set *bs);
410 * bio_next_split - get next @sectors from a bio, splitting if necessary
412 * @sectors: number of sectors to split from the front of @bio
414 * @bs: bio set to allocate from
416 * Returns a bio representing the next @sectors of @bio - if the bio is smaller
417 * than @sectors, returns the original bio unchanged.
419 static inline struct bio *bio_next_split(struct bio *bio, int sectors,
420 gfp_t gfp, struct bio_set *bs)
422 if (sectors >= bio_sectors(bio))
425 return bio_split(bio, sectors, gfp, bs);
428 extern struct bio_set *bioset_create(unsigned int, unsigned int);
429 extern struct bio_set *bioset_create_nobvec(unsigned int, unsigned int);
430 extern void bioset_free(struct bio_set *);
431 extern mempool_t *biovec_create_pool(int pool_entries);
433 extern struct bio *bio_alloc_bioset(gfp_t, int, struct bio_set *);
434 extern void bio_put(struct bio *);
436 extern void __bio_clone_fast(struct bio *, struct bio *);
437 extern struct bio *bio_clone_fast(struct bio *, gfp_t, struct bio_set *);
438 extern struct bio *bio_clone_bioset(struct bio *, gfp_t, struct bio_set *bs);
440 extern struct bio_set *fs_bio_set;
442 static inline struct bio *bio_alloc(gfp_t gfp_mask, unsigned int nr_iovecs)
444 return bio_alloc_bioset(gfp_mask, nr_iovecs, fs_bio_set);
447 static inline struct bio *bio_clone(struct bio *bio, gfp_t gfp_mask)
449 return bio_clone_bioset(bio, gfp_mask, fs_bio_set);
452 static inline struct bio *bio_kmalloc(gfp_t gfp_mask, unsigned int nr_iovecs)
454 return bio_alloc_bioset(gfp_mask, nr_iovecs, NULL);
457 static inline struct bio *bio_clone_kmalloc(struct bio *bio, gfp_t gfp_mask)
459 return bio_clone_bioset(bio, gfp_mask, NULL);
463 extern void bio_endio(struct bio *);
465 static inline void bio_io_error(struct bio *bio)
467 bio->bi_error = -EIO;
471 struct request_queue;
472 extern int bio_phys_segments(struct request_queue *, struct bio *);
474 extern int submit_bio_wait(struct bio *bio);
475 extern void bio_advance(struct bio *, unsigned);
477 extern void bio_init(struct bio *);
478 extern void bio_reset(struct bio *);
479 void bio_chain(struct bio *, struct bio *);
481 extern int bio_add_page(struct bio *, struct page *, unsigned int,unsigned int);
482 extern int bio_add_pc_page(struct request_queue *, struct bio *, struct page *,
483 unsigned int, unsigned int);
485 extern struct bio *bio_map_user_iov(struct request_queue *,
486 const struct iov_iter *, gfp_t);
487 extern void bio_unmap_user(struct bio *);
488 extern struct bio *bio_map_kern(struct request_queue *, void *, unsigned int,
490 extern struct bio *bio_copy_kern(struct request_queue *, void *, unsigned int,
492 extern void bio_set_pages_dirty(struct bio *bio);
493 extern void bio_check_pages_dirty(struct bio *bio);
495 void generic_start_io_acct(int rw, unsigned long sectors,
496 struct hd_struct *part);
497 void generic_end_io_acct(int rw, struct hd_struct *part,
498 unsigned long start_time);
500 #ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
501 # error "You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform"
503 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
504 extern void bio_flush_dcache_pages(struct bio *bi);
506 static inline void bio_flush_dcache_pages(struct bio *bi)
511 extern void bio_copy_data(struct bio *dst, struct bio *src);
512 extern int bio_alloc_pages(struct bio *bio, gfp_t gfp);
514 extern struct bio *bio_copy_user_iov(struct request_queue *,
515 struct rq_map_data *,
516 const struct iov_iter *,
518 extern int bio_uncopy_user(struct bio *);
519 void zero_fill_bio(struct bio *bio);
520 extern struct bio_vec *bvec_alloc(gfp_t, int, unsigned long *, mempool_t *);
521 extern void bvec_free(mempool_t *, struct bio_vec *, unsigned int);
522 extern unsigned int bvec_nr_vecs(unsigned short idx);
524 #ifdef CONFIG_BLK_CGROUP
525 int bio_associate_blkcg(struct bio *bio, struct cgroup_subsys_state *blkcg_css);
526 int bio_associate_current(struct bio *bio);
527 void bio_disassociate_task(struct bio *bio);
528 #else /* CONFIG_BLK_CGROUP */
529 static inline int bio_associate_blkcg(struct bio *bio,
530 struct cgroup_subsys_state *blkcg_css) { return 0; }
531 static inline int bio_associate_current(struct bio *bio) { return -ENOENT; }
532 static inline void bio_disassociate_task(struct bio *bio) { }
533 #endif /* CONFIG_BLK_CGROUP */
535 #ifdef CONFIG_HIGHMEM
537 * remember never ever reenable interrupts between a bvec_kmap_irq and
540 static inline char *bvec_kmap_irq(struct bio_vec *bvec, unsigned long *flags)
545 * might not be a highmem page, but the preempt/irq count
546 * balancing is a lot nicer this way
548 local_irq_save(*flags);
549 addr = (unsigned long) kmap_atomic(bvec->bv_page);
551 BUG_ON(addr & ~PAGE_MASK);
553 return (char *) addr + bvec->bv_offset;
556 static inline void bvec_kunmap_irq(char *buffer, unsigned long *flags)
558 unsigned long ptr = (unsigned long) buffer & PAGE_MASK;
560 kunmap_atomic((void *) ptr);
561 local_irq_restore(*flags);
565 static inline char *bvec_kmap_irq(struct bio_vec *bvec, unsigned long *flags)
567 return page_address(bvec->bv_page) + bvec->bv_offset;
570 static inline void bvec_kunmap_irq(char *buffer, unsigned long *flags)
576 static inline char *__bio_kmap_irq(struct bio *bio, struct bvec_iter iter,
577 unsigned long *flags)
579 return bvec_kmap_irq(&bio_iter_iovec(bio, iter), flags);
581 #define __bio_kunmap_irq(buf, flags) bvec_kunmap_irq(buf, flags)
583 #define bio_kmap_irq(bio, flags) \
584 __bio_kmap_irq((bio), (bio)->bi_iter, (flags))
585 #define bio_kunmap_irq(buf,flags) __bio_kunmap_irq(buf, flags)
588 * BIO list management for use by remapping drivers (e.g. DM or MD) and loop.
590 * A bio_list anchors a singly-linked list of bios chained through the bi_next
591 * member of the bio. The bio_list also caches the last list member to allow
592 * fast access to the tail.
599 static inline int bio_list_empty(const struct bio_list *bl)
601 return bl->head == NULL;
604 static inline void bio_list_init(struct bio_list *bl)
606 bl->head = bl->tail = NULL;
609 #define BIO_EMPTY_LIST { NULL, NULL }
611 #define bio_list_for_each(bio, bl) \
612 for (bio = (bl)->head; bio; bio = bio->bi_next)
614 static inline unsigned bio_list_size(const struct bio_list *bl)
619 bio_list_for_each(bio, bl)
625 static inline void bio_list_add(struct bio_list *bl, struct bio *bio)
630 bl->tail->bi_next = bio;
637 static inline void bio_list_add_head(struct bio_list *bl, struct bio *bio)
639 bio->bi_next = bl->head;
647 static inline void bio_list_merge(struct bio_list *bl, struct bio_list *bl2)
653 bl->tail->bi_next = bl2->head;
655 bl->head = bl2->head;
657 bl->tail = bl2->tail;
660 static inline void bio_list_merge_head(struct bio_list *bl,
661 struct bio_list *bl2)
667 bl2->tail->bi_next = bl->head;
669 bl->tail = bl2->tail;
671 bl->head = bl2->head;
674 static inline struct bio *bio_list_peek(struct bio_list *bl)
679 static inline struct bio *bio_list_pop(struct bio_list *bl)
681 struct bio *bio = bl->head;
684 bl->head = bl->head->bi_next;
694 static inline struct bio *bio_list_get(struct bio_list *bl)
696 struct bio *bio = bl->head;
698 bl->head = bl->tail = NULL;
704 * Increment chain count for the bio. Make sure the CHAIN flag update
705 * is visible before the raised count.
707 static inline void bio_inc_remaining(struct bio *bio)
709 bio_set_flag(bio, BIO_CHAIN);
710 smp_mb__before_atomic();
711 atomic_inc(&bio->__bi_remaining);
715 * bio_set is used to allow other portions of the IO system to
716 * allocate their own private memory pools for bio and iovec structures.
717 * These memory pools in turn all allocate from the bio_slab
718 * and the bvec_slabs[].
720 #define BIO_POOL_SIZE 2
721 #define BIOVEC_NR_POOLS 6
722 #define BIOVEC_MAX_IDX (BIOVEC_NR_POOLS - 1)
725 struct kmem_cache *bio_slab;
726 unsigned int front_pad;
729 mempool_t *bvec_pool;
730 #if defined(CONFIG_BLK_DEV_INTEGRITY)
731 mempool_t *bio_integrity_pool;
732 mempool_t *bvec_integrity_pool;
736 * Deadlock avoidance for stacking block drivers: see comments in
737 * bio_alloc_bioset() for details
739 spinlock_t rescue_lock;
740 struct bio_list rescue_list;
741 struct work_struct rescue_work;
742 struct workqueue_struct *rescue_workqueue;
748 struct kmem_cache *slab;
752 * a small number of entries is fine, not going to be performance critical.
753 * basically we just need to survive
755 #define BIO_SPLIT_ENTRIES 2
757 #if defined(CONFIG_BLK_DEV_INTEGRITY)
759 #define bip_for_each_vec(bvl, bip, iter) \
760 for_each_bvec(bvl, (bip)->bip_vec, iter, (bip)->bip_iter)
762 #define bio_for_each_integrity_vec(_bvl, _bio, _iter) \
764 bip_for_each_vec(_bvl, _bio->bi_integrity, _iter)
766 extern struct bio_integrity_payload *bio_integrity_alloc(struct bio *, gfp_t, unsigned int);
767 extern void bio_integrity_free(struct bio *);
768 extern int bio_integrity_add_page(struct bio *, struct page *, unsigned int, unsigned int);
769 extern bool bio_integrity_enabled(struct bio *bio);
770 extern int bio_integrity_prep(struct bio *);
771 extern void bio_integrity_endio(struct bio *);
772 extern void bio_integrity_advance(struct bio *, unsigned int);
773 extern void bio_integrity_trim(struct bio *, unsigned int, unsigned int);
774 extern int bio_integrity_clone(struct bio *, struct bio *, gfp_t);
775 extern int bioset_integrity_create(struct bio_set *, int);
776 extern void bioset_integrity_free(struct bio_set *);
777 extern void bio_integrity_init(void);
779 #else /* CONFIG_BLK_DEV_INTEGRITY */
781 static inline void *bio_integrity(struct bio *bio)
786 static inline bool bio_integrity_enabled(struct bio *bio)
791 static inline int bioset_integrity_create(struct bio_set *bs, int pool_size)
796 static inline void bioset_integrity_free (struct bio_set *bs)
801 static inline int bio_integrity_prep(struct bio *bio)
806 static inline void bio_integrity_free(struct bio *bio)
811 static inline int bio_integrity_clone(struct bio *bio, struct bio *bio_src,
817 static inline void bio_integrity_advance(struct bio *bio,
818 unsigned int bytes_done)
823 static inline void bio_integrity_trim(struct bio *bio, unsigned int offset,
824 unsigned int sectors)
829 static inline void bio_integrity_init(void)
834 static inline bool bio_integrity_flagged(struct bio *bio, enum bip_flags flag)
839 static inline void *bio_integrity_alloc(struct bio * bio, gfp_t gfp,
842 return ERR_PTR(-EINVAL);
845 static inline int bio_integrity_add_page(struct bio *bio, struct page *page,
846 unsigned int len, unsigned int offset)
851 #endif /* CONFIG_BLK_DEV_INTEGRITY */
853 #endif /* CONFIG_BLOCK */
854 #endif /* __LINUX_BIO_H */