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>
31 /* struct bio, bio_vec and BIO_* flags are defined in blk_types.h */
32 #include <linux/blk_types.h>
37 #define BIO_BUG_ON BUG_ON
42 #define BIO_MAX_PAGES 256
43 #define BIO_MAX_SIZE (BIO_MAX_PAGES << PAGE_CACHE_SHIFT)
44 #define BIO_MAX_SECTORS (BIO_MAX_SIZE >> 9)
47 * upper 16 bits of bi_rw define the io priority of this bio
49 #define BIO_PRIO_SHIFT (8 * sizeof(unsigned long) - IOPRIO_BITS)
50 #define bio_prio(bio) ((bio)->bi_rw >> BIO_PRIO_SHIFT)
51 #define bio_prio_valid(bio) ioprio_valid(bio_prio(bio))
53 #define bio_set_prio(bio, prio) do { \
54 WARN_ON(prio >= (1 << IOPRIO_BITS)); \
55 (bio)->bi_rw &= ((1UL << BIO_PRIO_SHIFT) - 1); \
56 (bio)->bi_rw |= ((unsigned long) (prio) << BIO_PRIO_SHIFT); \
60 * various member access, note that bio_data should of course not be used
61 * on highmem page vectors
63 #define bio_iovec_idx(bio, idx) (&((bio)->bi_io_vec[(idx)]))
64 #define bio_iovec(bio) bio_iovec_idx((bio), (bio)->bi_idx)
65 #define bio_page(bio) bio_iovec((bio))->bv_page
66 #define bio_offset(bio) bio_iovec((bio))->bv_offset
67 #define bio_segments(bio) ((bio)->bi_vcnt - (bio)->bi_idx)
68 #define bio_sectors(bio) ((bio)->bi_size >> 9)
70 static inline unsigned int bio_cur_bytes(struct bio *bio)
73 return bio_iovec(bio)->bv_len;
74 else /* dataless requests such as discard */
78 static inline void *bio_data(struct bio *bio)
81 return page_address(bio_page(bio)) + bio_offset(bio);
86 static inline int bio_has_allocated_vec(struct bio *bio)
88 return bio->bi_io_vec && bio->bi_io_vec != bio->bi_inline_vecs;
94 #define bio_to_phys(bio) (page_to_phys(bio_page((bio))) + (unsigned long) bio_offset((bio)))
95 #define bvec_to_phys(bv) (page_to_phys((bv)->bv_page) + (unsigned long) (bv)->bv_offset)
98 * queues that have highmem support enabled may still need to revert to
99 * PIO transfers occasionally and thus map high pages temporarily. For
100 * permanent PIO fall back, user is probably better off disabling highmem
101 * I/O completely on that queue (see ide-dma for example)
103 #define __bio_kmap_atomic(bio, idx, kmtype) \
104 (kmap_atomic(bio_iovec_idx((bio), (idx))->bv_page, kmtype) + \
105 bio_iovec_idx((bio), (idx))->bv_offset)
107 #define __bio_kunmap_atomic(addr, kmtype) kunmap_atomic(addr, kmtype)
113 #define __BVEC_END(bio) bio_iovec_idx((bio), (bio)->bi_vcnt - 1)
114 #define __BVEC_START(bio) bio_iovec_idx((bio), (bio)->bi_idx)
116 /* Default implementation of BIOVEC_PHYS_MERGEABLE */
117 #define __BIOVEC_PHYS_MERGEABLE(vec1, vec2) \
118 ((bvec_to_phys((vec1)) + (vec1)->bv_len) == bvec_to_phys((vec2)))
121 * allow arch override, for eg virtualized architectures (put in asm/io.h)
123 #ifndef BIOVEC_PHYS_MERGEABLE
124 #define BIOVEC_PHYS_MERGEABLE(vec1, vec2) \
125 __BIOVEC_PHYS_MERGEABLE(vec1, vec2)
128 #define __BIO_SEG_BOUNDARY(addr1, addr2, mask) \
129 (((addr1) | (mask)) == (((addr2) - 1) | (mask)))
130 #define BIOVEC_SEG_BOUNDARY(q, b1, b2) \
131 __BIO_SEG_BOUNDARY(bvec_to_phys((b1)), bvec_to_phys((b2)) + (b2)->bv_len, queue_segment_boundary((q)))
132 #define BIO_SEG_BOUNDARY(q, b1, b2) \
133 BIOVEC_SEG_BOUNDARY((q), __BVEC_END((b1)), __BVEC_START((b2)))
135 #define bio_io_error(bio) bio_endio((bio), -EIO)
138 * drivers should not use the __ version unless they _really_ know what
141 #define __bio_for_each_segment(bvl, bio, i, start_idx) \
142 for (bvl = bio_iovec_idx((bio), (start_idx)), i = (start_idx); \
143 i < (bio)->bi_vcnt; \
147 * drivers should _never_ use the all version - the bio may have been split
148 * before it got to the driver and the driver won't own all of it
150 #define bio_for_each_segment_all(bvl, bio, i) \
152 bvl = bio_iovec_idx((bio), (i)), i < (bio)->bi_vcnt; \
155 #define bio_for_each_segment(bvl, bio, i) \
156 for (i = (bio)->bi_idx; \
157 bvl = bio_iovec_idx((bio), (i)), i < (bio)->bi_vcnt; \
161 * get a reference to a bio, so it won't disappear. the intended use is
165 * submit_bio(rw, bio);
166 * if (bio->bi_flags ...)
170 * without the bio_get(), it could potentially complete I/O before submit_bio
171 * returns. and then bio would be freed memory when if (bio->bi_flags ...)
174 #define bio_get(bio) atomic_inc(&(bio)->bi_cnt)
176 #if defined(CONFIG_BLK_DEV_INTEGRITY)
178 * bio integrity payload
180 struct bio_integrity_payload {
181 struct bio *bip_bio; /* parent bio */
183 sector_t bip_sector; /* virtual start sector */
185 void *bip_buf; /* generated integrity data */
186 bio_end_io_t *bip_end_io; /* saved I/O completion fn */
188 unsigned int bip_size;
190 unsigned short bip_slab; /* slab the bip came from */
191 unsigned short bip_vcnt; /* # of integrity bio_vecs */
192 unsigned short bip_idx; /* current bip_vec index */
194 struct work_struct bip_work; /* I/O completion */
195 struct bio_vec bip_vec[0]; /* embedded bvec array */
197 #endif /* CONFIG_BLK_DEV_INTEGRITY */
200 * A bio_pair is used when we need to split a bio.
201 * This can only happen for a bio that refers to just one
202 * page of data, and in the unusual situation when the
203 * page crosses a chunk/device boundary
205 * The address of the master bio is stored in bio1.bi_private
206 * The address of the pool the pair was allocated from is stored
210 struct bio bio1, bio2;
211 struct bio_vec bv1, bv2;
212 #if defined(CONFIG_BLK_DEV_INTEGRITY)
213 struct bio_integrity_payload bip1, bip2;
214 struct bio_vec iv1, iv2;
219 extern struct bio_pair *bio_split(struct bio *bi, int first_sectors);
220 extern void bio_pair_release(struct bio_pair *dbio);
222 extern struct bio_set *bioset_create(unsigned int, unsigned int);
223 extern void bioset_free(struct bio_set *);
225 extern struct bio *bio_alloc(gfp_t, unsigned int);
226 extern struct bio *bio_kmalloc(gfp_t, unsigned int);
227 extern struct bio *bio_alloc_bioset(gfp_t, int, struct bio_set *);
228 extern void bio_put(struct bio *);
229 extern void bio_free(struct bio *, struct bio_set *);
231 extern void bio_endio(struct bio *, int);
232 struct request_queue;
233 extern int bio_phys_segments(struct request_queue *, struct bio *);
235 extern void __bio_clone(struct bio *, struct bio *);
236 extern struct bio *bio_clone(struct bio *, gfp_t);
238 extern void bio_init(struct bio *);
240 extern int bio_add_page(struct bio *, struct page *, unsigned int,unsigned int);
241 extern int bio_add_pc_page(struct request_queue *, struct bio *, struct page *,
242 unsigned int, unsigned int);
243 extern int bio_get_nr_vecs(struct block_device *);
244 extern sector_t bio_sector_offset(struct bio *, unsigned short, unsigned int);
245 extern struct bio *bio_map_user(struct request_queue *, struct block_device *,
246 unsigned long, unsigned int, int, gfp_t);
249 extern struct bio *bio_map_user_iov(struct request_queue *,
250 struct block_device *,
251 struct sg_iovec *, int, int, gfp_t);
252 extern void bio_unmap_user(struct bio *);
253 extern struct bio *bio_map_kern(struct request_queue *, void *, unsigned int,
255 extern struct bio *bio_copy_kern(struct request_queue *, void *, unsigned int,
257 extern void bio_set_pages_dirty(struct bio *bio);
258 extern void bio_check_pages_dirty(struct bio *bio);
260 #ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
261 # error "You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform"
263 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
264 extern void bio_flush_dcache_pages(struct bio *bi);
266 static inline void bio_flush_dcache_pages(struct bio *bi)
271 extern struct bio *bio_copy_user(struct request_queue *, struct rq_map_data *,
272 unsigned long, unsigned int, int, gfp_t);
273 extern struct bio *bio_copy_user_iov(struct request_queue *,
274 struct rq_map_data *, struct sg_iovec *,
276 extern int bio_uncopy_user(struct bio *);
277 void zero_fill_bio(struct bio *bio);
278 extern struct bio_vec *bvec_alloc_bs(gfp_t, int, unsigned long *, struct bio_set *);
279 extern void bvec_free_bs(struct bio_set *, struct bio_vec *, unsigned int);
280 extern unsigned int bvec_nr_vecs(unsigned short idx);
283 * bio_set is used to allow other portions of the IO system to
284 * allocate their own private memory pools for bio and iovec structures.
285 * These memory pools in turn all allocate from the bio_slab
286 * and the bvec_slabs[].
288 #define BIO_POOL_SIZE 2
289 #define BIOVEC_NR_POOLS 6
290 #define BIOVEC_MAX_IDX (BIOVEC_NR_POOLS - 1)
293 struct kmem_cache *bio_slab;
294 unsigned int front_pad;
297 #if defined(CONFIG_BLK_DEV_INTEGRITY)
298 mempool_t *bio_integrity_pool;
300 mempool_t *bvec_pool;
306 struct kmem_cache *slab;
309 extern struct bio_set *fs_bio_set;
312 * a small number of entries is fine, not going to be performance critical.
313 * basically we just need to survive
315 #define BIO_SPLIT_ENTRIES 2
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, KM_BIO_SRC_IRQ);
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, KM_BIO_SRC_IRQ);
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 int bio_has_data(struct bio *bio)
374 return bio && bio->bi_io_vec != NULL;
378 * BIO list management for use by remapping drivers (e.g. DM or MD) and loop.
380 * A bio_list anchors a singly-linked list of bios chained through the bi_next
381 * member of the bio. The bio_list also caches the last list member to allow
382 * fast access to the tail.
389 static inline int bio_list_empty(const struct bio_list *bl)
391 return bl->head == NULL;
394 static inline void bio_list_init(struct bio_list *bl)
396 bl->head = bl->tail = NULL;
399 #define bio_list_for_each(bio, bl) \
400 for (bio = (bl)->head; bio; bio = bio->bi_next)
402 static inline unsigned bio_list_size(const struct bio_list *bl)
407 bio_list_for_each(bio, bl)
413 static inline void bio_list_add(struct bio_list *bl, struct bio *bio)
418 bl->tail->bi_next = bio;
425 static inline void bio_list_add_head(struct bio_list *bl, struct bio *bio)
427 bio->bi_next = bl->head;
435 static inline void bio_list_merge(struct bio_list *bl, struct bio_list *bl2)
441 bl->tail->bi_next = bl2->head;
443 bl->head = bl2->head;
445 bl->tail = bl2->tail;
448 static inline void bio_list_merge_head(struct bio_list *bl,
449 struct bio_list *bl2)
455 bl2->tail->bi_next = bl->head;
457 bl->tail = bl2->tail;
459 bl->head = bl2->head;
462 static inline struct bio *bio_list_peek(struct bio_list *bl)
467 static inline struct bio *bio_list_pop(struct bio_list *bl)
469 struct bio *bio = bl->head;
472 bl->head = bl->head->bi_next;
482 static inline struct bio *bio_list_get(struct bio_list *bl)
484 struct bio *bio = bl->head;
486 bl->head = bl->tail = NULL;
491 #if defined(CONFIG_BLK_DEV_INTEGRITY)
493 #define bip_vec_idx(bip, idx) (&(bip->bip_vec[(idx)]))
494 #define bip_vec(bip) bip_vec_idx(bip, 0)
496 #define __bip_for_each_vec(bvl, bip, i, start_idx) \
497 for (bvl = bip_vec_idx((bip), (start_idx)), i = (start_idx); \
498 i < (bip)->bip_vcnt; \
501 #define bip_for_each_vec(bvl, bip, i) \
502 __bip_for_each_vec(bvl, bip, i, (bip)->bip_idx)
504 #define bio_for_each_integrity_vec(_bvl, _bio, _iter) \
506 bip_for_each_vec(_bvl, _bio->bi_integrity, _iter)
508 #define bio_integrity(bio) (bio->bi_integrity != NULL)
510 extern struct bio_integrity_payload *bio_integrity_alloc_bioset(struct bio *, gfp_t, unsigned int, struct bio_set *);
511 extern struct bio_integrity_payload *bio_integrity_alloc(struct bio *, gfp_t, unsigned int);
512 extern void bio_integrity_free(struct bio *, struct bio_set *);
513 extern int bio_integrity_add_page(struct bio *, struct page *, unsigned int, unsigned int);
514 extern int bio_integrity_enabled(struct bio *bio);
515 extern int bio_integrity_set_tag(struct bio *, void *, unsigned int);
516 extern int bio_integrity_get_tag(struct bio *, void *, unsigned int);
517 extern int bio_integrity_prep(struct bio *);
518 extern void bio_integrity_endio(struct bio *, int);
519 extern void bio_integrity_advance(struct bio *, unsigned int);
520 extern void bio_integrity_trim(struct bio *, unsigned int, unsigned int);
521 extern void bio_integrity_split(struct bio *, struct bio_pair *, int);
522 extern int bio_integrity_clone(struct bio *, struct bio *, gfp_t, struct bio_set *);
523 extern int bioset_integrity_create(struct bio_set *, int);
524 extern void bioset_integrity_free(struct bio_set *);
525 extern void bio_integrity_init(void);
527 #else /* CONFIG_BLK_DEV_INTEGRITY */
529 #define bio_integrity(a) (0)
530 #define bioset_integrity_create(a, b) (0)
531 #define bio_integrity_prep(a) (0)
532 #define bio_integrity_enabled(a) (0)
533 static inline int bio_integrity_clone(struct bio *bio, struct bio *bio_src,
534 gfp_t gfp_mask, struct bio_set *bs)
538 #define bioset_integrity_free(a) do { } while (0)
539 #define bio_integrity_free(a, b) do { } while (0)
540 #define bio_integrity_endio(a, b) do { } while (0)
541 #define bio_integrity_advance(a, b) do { } while (0)
542 #define bio_integrity_trim(a, b, c) do { } while (0)
543 #define bio_integrity_split(a, b, c) do { } while (0)
544 #define bio_integrity_set_tag(a, b, c) do { } while (0)
545 #define bio_integrity_get_tag(a, b, c) do { } while (0)
546 #define bio_integrity_init(a) do { } while (0)
548 #endif /* CONFIG_BLK_DEV_INTEGRITY */
550 #endif /* CONFIG_BLOCK */
551 #endif /* __LINUX_BIO_H */