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_CACHE_SHIFT)
45 #define BIO_MAX_SECTORS (BIO_MAX_SIZE >> 9)
48 * upper 16 bits of bi_rw define the io priority of this bio
50 #define BIO_PRIO_SHIFT (8 * sizeof(unsigned long) - IOPRIO_BITS)
51 #define bio_prio(bio) ((bio)->bi_rw >> BIO_PRIO_SHIFT)
52 #define bio_prio_valid(bio) ioprio_valid(bio_prio(bio))
54 #define bio_set_prio(bio, prio) do { \
55 WARN_ON(prio >= (1 << IOPRIO_BITS)); \
56 (bio)->bi_rw &= ((1UL << BIO_PRIO_SHIFT) - 1); \
57 (bio)->bi_rw |= ((unsigned long) (prio) << BIO_PRIO_SHIFT); \
61 * various member access, note that bio_data should of course not be used
62 * on highmem page vectors
64 #define bio_iovec_idx(bio, idx) (&((bio)->bi_io_vec[(idx)]))
65 #define bio_iovec(bio) bio_iovec_idx((bio), (bio)->bi_idx)
66 #define bio_page(bio) bio_iovec((bio))->bv_page
67 #define bio_offset(bio) bio_iovec((bio))->bv_offset
68 #define bio_segments(bio) ((bio)->bi_vcnt - (bio)->bi_idx)
69 #define bio_sectors(bio) ((bio)->bi_size >> 9)
70 #define bio_end_sector(bio) ((bio)->bi_sector + bio_sectors((bio)))
72 static inline unsigned int bio_cur_bytes(struct bio *bio)
75 return bio_iovec(bio)->bv_len;
76 else /* dataless requests such as discard */
80 static inline void *bio_data(struct bio *bio)
83 return page_address(bio_page(bio)) + bio_offset(bio);
91 #define bio_to_phys(bio) (page_to_phys(bio_page((bio))) + (unsigned long) bio_offset((bio)))
92 #define bvec_to_phys(bv) (page_to_phys((bv)->bv_page) + (unsigned long) (bv)->bv_offset)
95 * queues that have highmem support enabled may still need to revert to
96 * PIO transfers occasionally and thus map high pages temporarily. For
97 * permanent PIO fall back, user is probably better off disabling highmem
98 * I/O completely on that queue (see ide-dma for example)
100 #define __bio_kmap_atomic(bio, idx, kmtype) \
101 (kmap_atomic(bio_iovec_idx((bio), (idx))->bv_page) + \
102 bio_iovec_idx((bio), (idx))->bv_offset)
104 #define __bio_kunmap_atomic(addr, kmtype) kunmap_atomic(addr)
110 #define __BVEC_END(bio) bio_iovec_idx((bio), (bio)->bi_vcnt - 1)
111 #define __BVEC_START(bio) bio_iovec_idx((bio), (bio)->bi_idx)
113 /* Default implementation of BIOVEC_PHYS_MERGEABLE */
114 #define __BIOVEC_PHYS_MERGEABLE(vec1, vec2) \
115 ((bvec_to_phys((vec1)) + (vec1)->bv_len) == bvec_to_phys((vec2)))
118 * allow arch override, for eg virtualized architectures (put in asm/io.h)
120 #ifndef BIOVEC_PHYS_MERGEABLE
121 #define BIOVEC_PHYS_MERGEABLE(vec1, vec2) \
122 __BIOVEC_PHYS_MERGEABLE(vec1, vec2)
125 #define __BIO_SEG_BOUNDARY(addr1, addr2, mask) \
126 (((addr1) | (mask)) == (((addr2) - 1) | (mask)))
127 #define BIOVEC_SEG_BOUNDARY(q, b1, b2) \
128 __BIO_SEG_BOUNDARY(bvec_to_phys((b1)), bvec_to_phys((b2)) + (b2)->bv_len, queue_segment_boundary((q)))
129 #define BIO_SEG_BOUNDARY(q, b1, b2) \
130 BIOVEC_SEG_BOUNDARY((q), __BVEC_END((b1)), __BVEC_START((b2)))
132 #define bio_io_error(bio) bio_endio((bio), -EIO)
135 * drivers should not use the __ version unless they _really_ know what
138 #define __bio_for_each_segment(bvl, bio, i, start_idx) \
139 for (bvl = bio_iovec_idx((bio), (start_idx)), i = (start_idx); \
140 i < (bio)->bi_vcnt; \
144 * drivers should _never_ use the all version - the bio may have been split
145 * before it got to the driver and the driver won't own all of it
147 #define bio_for_each_segment_all(bvl, bio, i) \
149 bvl = bio_iovec_idx((bio), (i)), i < (bio)->bi_vcnt; \
152 #define bio_for_each_segment(bvl, bio, i) \
153 for (i = (bio)->bi_idx; \
154 bvl = bio_iovec_idx((bio), (i)), i < (bio)->bi_vcnt; \
158 * get a reference to a bio, so it won't disappear. the intended use is
162 * submit_bio(rw, bio);
163 * if (bio->bi_flags ...)
167 * without the bio_get(), it could potentially complete I/O before submit_bio
168 * returns. and then bio would be freed memory when if (bio->bi_flags ...)
171 #define bio_get(bio) atomic_inc(&(bio)->bi_cnt)
173 #if defined(CONFIG_BLK_DEV_INTEGRITY)
175 * bio integrity payload
177 struct bio_integrity_payload {
178 struct bio *bip_bio; /* parent bio */
180 sector_t bip_sector; /* virtual start sector */
182 void *bip_buf; /* generated integrity data */
183 bio_end_io_t *bip_end_io; /* saved I/O completion fn */
185 unsigned int bip_size;
187 unsigned short bip_slab; /* slab the bip came from */
188 unsigned short bip_vcnt; /* # of integrity bio_vecs */
189 unsigned short bip_idx; /* current bip_vec index */
191 struct work_struct bip_work; /* I/O completion */
193 struct bio_vec *bip_vec;
194 struct bio_vec bip_inline_vecs[0];/* embedded bvec array */
196 #endif /* CONFIG_BLK_DEV_INTEGRITY */
199 * A bio_pair is used when we need to split a bio.
200 * This can only happen for a bio that refers to just one
201 * page of data, and in the unusual situation when the
202 * page crosses a chunk/device boundary
204 * The address of the master bio is stored in bio1.bi_private
205 * The address of the pool the pair was allocated from is stored
209 struct bio bio1, bio2;
210 struct bio_vec bv1, bv2;
211 #if defined(CONFIG_BLK_DEV_INTEGRITY)
212 struct bio_integrity_payload bip1, bip2;
213 struct bio_vec iv1, iv2;
218 extern struct bio_pair *bio_split(struct bio *bi, int first_sectors);
219 extern void bio_pair_release(struct bio_pair *dbio);
221 extern struct bio_set *bioset_create(unsigned int, unsigned int);
222 extern void bioset_free(struct bio_set *);
223 extern mempool_t *biovec_create_pool(struct bio_set *bs, int pool_entries);
225 extern struct bio *bio_alloc_bioset(gfp_t, int, struct bio_set *);
226 extern void bio_put(struct bio *);
228 extern void __bio_clone(struct bio *, struct bio *);
229 extern struct bio *bio_clone_bioset(struct bio *, gfp_t, struct bio_set *bs);
231 extern struct bio_set *fs_bio_set;
233 static inline struct bio *bio_alloc(gfp_t gfp_mask, unsigned int nr_iovecs)
235 return bio_alloc_bioset(gfp_mask, nr_iovecs, fs_bio_set);
238 static inline struct bio *bio_clone(struct bio *bio, gfp_t gfp_mask)
240 return bio_clone_bioset(bio, gfp_mask, fs_bio_set);
243 static inline struct bio *bio_kmalloc(gfp_t gfp_mask, unsigned int nr_iovecs)
245 return bio_alloc_bioset(gfp_mask, nr_iovecs, NULL);
248 static inline struct bio *bio_clone_kmalloc(struct bio *bio, gfp_t gfp_mask)
250 return bio_clone_bioset(bio, gfp_mask, NULL);
254 extern void bio_endio(struct bio *, int);
255 struct request_queue;
256 extern int bio_phys_segments(struct request_queue *, struct bio *);
258 extern int submit_bio_wait(int rw, struct bio *bio);
259 extern void bio_advance(struct bio *, unsigned);
261 extern void bio_init(struct bio *);
262 extern void bio_reset(struct bio *);
264 extern int bio_add_page(struct bio *, struct page *, unsigned int,unsigned int);
265 extern int bio_add_pc_page(struct request_queue *, struct bio *, struct page *,
266 unsigned int, unsigned int);
267 extern int bio_get_nr_vecs(struct block_device *);
268 extern sector_t bio_sector_offset(struct bio *, unsigned short, unsigned int);
269 extern struct bio *bio_map_user(struct request_queue *, struct block_device *,
270 unsigned long, unsigned int, int, gfp_t);
273 extern struct bio *bio_map_user_iov(struct request_queue *,
274 struct block_device *,
275 struct sg_iovec *, int, int, gfp_t);
276 extern void bio_unmap_user(struct bio *);
277 extern struct bio *bio_map_kern(struct request_queue *, void *, unsigned int,
279 extern struct bio *bio_copy_kern(struct request_queue *, void *, unsigned int,
281 extern void bio_set_pages_dirty(struct bio *bio);
282 extern void bio_check_pages_dirty(struct bio *bio);
284 #ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
285 # error "You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform"
287 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
288 extern void bio_flush_dcache_pages(struct bio *bi);
290 static inline void bio_flush_dcache_pages(struct bio *bi)
295 extern void bio_copy_data(struct bio *dst, struct bio *src);
296 extern int bio_alloc_pages(struct bio *bio, gfp_t gfp);
298 extern struct bio *bio_copy_user(struct request_queue *, struct rq_map_data *,
299 unsigned long, unsigned int, int, gfp_t);
300 extern struct bio *bio_copy_user_iov(struct request_queue *,
301 struct rq_map_data *, struct sg_iovec *,
303 extern int bio_uncopy_user(struct bio *);
304 void zero_fill_bio(struct bio *bio);
305 extern struct bio_vec *bvec_alloc(gfp_t, int, unsigned long *, mempool_t *);
306 extern void bvec_free(mempool_t *, struct bio_vec *, unsigned int);
307 extern unsigned int bvec_nr_vecs(unsigned short idx);
309 #ifdef CONFIG_BLK_CGROUP
310 int bio_associate_current(struct bio *bio);
311 void bio_disassociate_task(struct bio *bio);
312 #else /* CONFIG_BLK_CGROUP */
313 static inline int bio_associate_current(struct bio *bio) { return -ENOENT; }
314 static inline void bio_disassociate_task(struct bio *bio) { }
315 #endif /* CONFIG_BLK_CGROUP */
317 #ifdef CONFIG_HIGHMEM
319 * remember never ever reenable interrupts between a bvec_kmap_irq and
322 static inline char *bvec_kmap_irq(struct bio_vec *bvec, unsigned long *flags)
327 * might not be a highmem page, but the preempt/irq count
328 * balancing is a lot nicer this way
330 local_irq_save(*flags);
331 addr = (unsigned long) kmap_atomic(bvec->bv_page);
333 BUG_ON(addr & ~PAGE_MASK);
335 return (char *) addr + bvec->bv_offset;
338 static inline void bvec_kunmap_irq(char *buffer, unsigned long *flags)
340 unsigned long ptr = (unsigned long) buffer & PAGE_MASK;
342 kunmap_atomic((void *) ptr);
343 local_irq_restore(*flags);
347 static inline char *bvec_kmap_irq(struct bio_vec *bvec, unsigned long *flags)
349 return page_address(bvec->bv_page) + bvec->bv_offset;
352 static inline void bvec_kunmap_irq(char *buffer, unsigned long *flags)
358 static inline char *__bio_kmap_irq(struct bio *bio, unsigned short idx,
359 unsigned long *flags)
361 return bvec_kmap_irq(bio_iovec_idx(bio, idx), flags);
363 #define __bio_kunmap_irq(buf, flags) bvec_kunmap_irq(buf, flags)
365 #define bio_kmap_irq(bio, flags) \
366 __bio_kmap_irq((bio), (bio)->bi_idx, (flags))
367 #define bio_kunmap_irq(buf,flags) __bio_kunmap_irq(buf, flags)
370 * Check whether this bio carries any data or not. A NULL bio is allowed.
372 static inline bool bio_has_data(struct bio *bio)
374 if (bio && bio->bi_vcnt)
380 static inline bool bio_is_rw(struct bio *bio)
382 if (!bio_has_data(bio))
385 if (bio->bi_rw & REQ_WRITE_SAME)
391 static inline bool bio_mergeable(struct bio *bio)
393 if (bio->bi_rw & REQ_NOMERGE_FLAGS)
400 * BIO list management for use by remapping drivers (e.g. DM or MD) and loop.
402 * A bio_list anchors a singly-linked list of bios chained through the bi_next
403 * member of the bio. The bio_list also caches the last list member to allow
404 * fast access to the tail.
411 static inline int bio_list_empty(const struct bio_list *bl)
413 return bl->head == NULL;
416 static inline void bio_list_init(struct bio_list *bl)
418 bl->head = bl->tail = NULL;
421 #define bio_list_for_each(bio, bl) \
422 for (bio = (bl)->head; bio; bio = bio->bi_next)
424 static inline unsigned bio_list_size(const struct bio_list *bl)
429 bio_list_for_each(bio, bl)
435 static inline void bio_list_add(struct bio_list *bl, struct bio *bio)
440 bl->tail->bi_next = bio;
447 static inline void bio_list_add_head(struct bio_list *bl, struct bio *bio)
449 bio->bi_next = bl->head;
457 static inline void bio_list_merge(struct bio_list *bl, struct bio_list *bl2)
463 bl->tail->bi_next = bl2->head;
465 bl->head = bl2->head;
467 bl->tail = bl2->tail;
470 static inline void bio_list_merge_head(struct bio_list *bl,
471 struct bio_list *bl2)
477 bl2->tail->bi_next = bl->head;
479 bl->tail = bl2->tail;
481 bl->head = bl2->head;
484 static inline struct bio *bio_list_peek(struct bio_list *bl)
489 static inline struct bio *bio_list_pop(struct bio_list *bl)
491 struct bio *bio = bl->head;
494 bl->head = bl->head->bi_next;
504 static inline struct bio *bio_list_get(struct bio_list *bl)
506 struct bio *bio = bl->head;
508 bl->head = bl->tail = NULL;
514 * bio_set is used to allow other portions of the IO system to
515 * allocate their own private memory pools for bio and iovec structures.
516 * These memory pools in turn all allocate from the bio_slab
517 * and the bvec_slabs[].
519 #define BIO_POOL_SIZE 2
520 #define BIOVEC_NR_POOLS 6
521 #define BIOVEC_MAX_IDX (BIOVEC_NR_POOLS - 1)
524 struct kmem_cache *bio_slab;
525 unsigned int front_pad;
528 mempool_t *bvec_pool;
529 #if defined(CONFIG_BLK_DEV_INTEGRITY)
530 mempool_t *bio_integrity_pool;
531 mempool_t *bvec_integrity_pool;
535 * Deadlock avoidance for stacking block drivers: see comments in
536 * bio_alloc_bioset() for details
538 spinlock_t rescue_lock;
539 struct bio_list rescue_list;
540 struct work_struct rescue_work;
541 struct workqueue_struct *rescue_workqueue;
547 struct kmem_cache *slab;
551 * a small number of entries is fine, not going to be performance critical.
552 * basically we just need to survive
554 #define BIO_SPLIT_ENTRIES 2
556 #if defined(CONFIG_BLK_DEV_INTEGRITY)
558 #define bip_vec_idx(bip, idx) (&(bip->bip_vec[(idx)]))
559 #define bip_vec(bip) bip_vec_idx(bip, 0)
561 #define __bip_for_each_vec(bvl, bip, i, start_idx) \
562 for (bvl = bip_vec_idx((bip), (start_idx)), i = (start_idx); \
563 i < (bip)->bip_vcnt; \
566 #define bip_for_each_vec(bvl, bip, i) \
567 __bip_for_each_vec(bvl, bip, i, (bip)->bip_idx)
569 #define bio_for_each_integrity_vec(_bvl, _bio, _iter) \
571 bip_for_each_vec(_bvl, _bio->bi_integrity, _iter)
573 #define bio_integrity(bio) (bio->bi_integrity != NULL)
575 extern struct bio_integrity_payload *bio_integrity_alloc(struct bio *, gfp_t, unsigned int);
576 extern void bio_integrity_free(struct bio *);
577 extern int bio_integrity_add_page(struct bio *, struct page *, unsigned int, unsigned int);
578 extern int bio_integrity_enabled(struct bio *bio);
579 extern int bio_integrity_set_tag(struct bio *, void *, unsigned int);
580 extern int bio_integrity_get_tag(struct bio *, void *, unsigned int);
581 extern int bio_integrity_prep(struct bio *);
582 extern void bio_integrity_endio(struct bio *, int);
583 extern void bio_integrity_advance(struct bio *, unsigned int);
584 extern void bio_integrity_trim(struct bio *, unsigned int, unsigned int);
585 extern void bio_integrity_split(struct bio *, struct bio_pair *, int);
586 extern int bio_integrity_clone(struct bio *, struct bio *, gfp_t);
587 extern int bioset_integrity_create(struct bio_set *, int);
588 extern void bioset_integrity_free(struct bio_set *);
589 extern void bio_integrity_init(void);
591 #else /* CONFIG_BLK_DEV_INTEGRITY */
593 static inline int bio_integrity(struct bio *bio)
598 static inline int bio_integrity_enabled(struct bio *bio)
603 static inline int bioset_integrity_create(struct bio_set *bs, int pool_size)
608 static inline void bioset_integrity_free (struct bio_set *bs)
613 static inline int bio_integrity_prep(struct bio *bio)
618 static inline void bio_integrity_free(struct bio *bio)
623 static inline int bio_integrity_clone(struct bio *bio, struct bio *bio_src,
629 static inline void bio_integrity_split(struct bio *bio, struct bio_pair *bp,
635 static inline void bio_integrity_advance(struct bio *bio,
636 unsigned int bytes_done)
641 static inline void bio_integrity_trim(struct bio *bio, unsigned int offset,
642 unsigned int sectors)
647 static inline void bio_integrity_init(void)
652 #endif /* CONFIG_BLK_DEV_INTEGRITY */
654 #endif /* CONFIG_BLOCK */
655 #endif /* __LINUX_BIO_H */