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>
34 #define BIO_BUG_ON BUG_ON
39 #define BIO_MAX_PAGES 256
40 #define BIO_MAX_SIZE (BIO_MAX_PAGES << PAGE_CACHE_SHIFT)
41 #define BIO_MAX_SECTORS (BIO_MAX_SIZE >> 9)
44 * was unsigned short, but we might as well be ready for > 64kB I/O pages
49 unsigned int bv_offset
;
54 struct bio_integrity_payload
;
55 typedef void (bio_end_io_t
) (struct bio
*, int);
56 typedef void (bio_destructor_t
) (struct bio
*);
59 * main unit of I/O for the block layer and lower layers (ie drivers and
63 sector_t bi_sector
; /* device address in 512 byte
65 struct bio
*bi_next
; /* request queue link */
66 struct block_device
*bi_bdev
;
67 unsigned long bi_flags
; /* status, command, etc */
68 unsigned long bi_rw
; /* bottom bits READ/WRITE,
72 unsigned short bi_vcnt
; /* how many bio_vec's */
73 unsigned short bi_idx
; /* current index into bvl_vec */
75 /* Number of segments in this BIO after
76 * physical address coalescing is performed.
78 unsigned int bi_phys_segments
;
80 unsigned int bi_size
; /* residual I/O count */
83 * To keep track of the max segment size, we account for the
84 * sizes of the first and last mergeable segments in this bio.
86 unsigned int bi_seg_front_size
;
87 unsigned int bi_seg_back_size
;
89 unsigned int bi_max_vecs
; /* max bvl_vecs we can hold */
91 unsigned int bi_comp_cpu
; /* completion CPU */
93 struct bio_vec
*bi_io_vec
; /* the actual vec list */
95 bio_end_io_t
*bi_end_io
;
96 atomic_t bi_cnt
; /* pin count */
99 #if defined(CONFIG_BLK_DEV_INTEGRITY)
100 struct bio_integrity_payload
*bi_integrity
; /* data integrity */
103 bio_destructor_t
*bi_destructor
; /* destructor */
109 #define BIO_UPTODATE 0 /* ok after I/O completion */
110 #define BIO_RW_BLOCK 1 /* RW_AHEAD set, and read/write would block */
111 #define BIO_EOF 2 /* out-out-bounds error */
112 #define BIO_SEG_VALID 3 /* bi_phys_segments valid */
113 #define BIO_CLONED 4 /* doesn't own data */
114 #define BIO_BOUNCED 5 /* bio is a bounce bio */
115 #define BIO_USER_MAPPED 6 /* contains user pages */
116 #define BIO_EOPNOTSUPP 7 /* not supported */
117 #define BIO_CPU_AFFINE 8 /* complete bio on same CPU as submitted */
118 #define BIO_NULL_MAPPED 9 /* contains invalid user pages */
119 #define BIO_FS_INTEGRITY 10 /* fs owns integrity data, not block layer */
120 #define bio_flagged(bio, flag) ((bio)->bi_flags & (1 << (flag)))
123 * top 4 bits of bio flags indicate the pool this bio came from
125 #define BIO_POOL_BITS (4)
126 #define BIO_POOL_OFFSET (BITS_PER_LONG - BIO_POOL_BITS)
127 #define BIO_POOL_MASK (1UL << BIO_POOL_OFFSET)
128 #define BIO_POOL_IDX(bio) ((bio)->bi_flags >> BIO_POOL_OFFSET)
133 * bit 0 -- data direction
134 * If not set, bio is a read from device. If set, it's a write to device.
135 * bit 1 -- rw-ahead when set
137 * Insert a serialization point in the IO queue, forcing previously
138 * submitted IO to be completed before this oen is issued.
139 * bit 3 -- synchronous I/O hint: the block layer will unplug immediately
140 * Note that this does NOT indicate that the IO itself is sync, just
141 * that the block layer will not postpone issue of this IO by plugging.
142 * bit 4 -- metadata request
143 * Used for tracing to differentiate metadata and data IO. May also
144 * get some preferential treatment in the IO scheduler
145 * bit 5 -- discard sectors
146 * Informs the lower level device that this range of sectors is no longer
147 * used by the file system and may thus be freed by the device. Used
148 * for flash based storage.
149 * bit 6 -- fail fast device errors
150 * bit 7 -- fail fast transport errors
151 * bit 8 -- fail fast driver errors
152 * Don't want driver retries for any fast fail whatever the reason.
154 #define BIO_RW 0 /* Must match RW in req flags (blkdev.h) */
155 #define BIO_RW_AHEAD 1 /* Must match FAILFAST in req flags */
156 #define BIO_RW_BARRIER 2
157 #define BIO_RW_SYNC 3
158 #define BIO_RW_META 4
159 #define BIO_RW_DISCARD 5
160 #define BIO_RW_FAILFAST_DEV 6
161 #define BIO_RW_FAILFAST_TRANSPORT 7
162 #define BIO_RW_FAILFAST_DRIVER 8
165 * upper 16 bits of bi_rw define the io priority of this bio
167 #define BIO_PRIO_SHIFT (8 * sizeof(unsigned long) - IOPRIO_BITS)
168 #define bio_prio(bio) ((bio)->bi_rw >> BIO_PRIO_SHIFT)
169 #define bio_prio_valid(bio) ioprio_valid(bio_prio(bio))
171 #define bio_set_prio(bio, prio) do { \
172 WARN_ON(prio >= (1 << IOPRIO_BITS)); \
173 (bio)->bi_rw &= ((1UL << BIO_PRIO_SHIFT) - 1); \
174 (bio)->bi_rw |= ((unsigned long) (prio) << BIO_PRIO_SHIFT); \
178 * various member access, note that bio_data should of course not be used
179 * on highmem page vectors
181 #define bio_iovec_idx(bio, idx) (&((bio)->bi_io_vec[(idx)]))
182 #define bio_iovec(bio) bio_iovec_idx((bio), (bio)->bi_idx)
183 #define bio_page(bio) bio_iovec((bio))->bv_page
184 #define bio_offset(bio) bio_iovec((bio))->bv_offset
185 #define bio_segments(bio) ((bio)->bi_vcnt - (bio)->bi_idx)
186 #define bio_sectors(bio) ((bio)->bi_size >> 9)
187 #define bio_barrier(bio) ((bio)->bi_rw & (1 << BIO_RW_BARRIER))
188 #define bio_sync(bio) ((bio)->bi_rw & (1 << BIO_RW_SYNC))
189 #define bio_failfast_dev(bio) ((bio)->bi_rw & (1 << BIO_RW_FAILFAST_DEV))
190 #define bio_failfast_transport(bio) \
191 ((bio)->bi_rw & (1 << BIO_RW_FAILFAST_TRANSPORT))
192 #define bio_failfast_driver(bio) ((bio)->bi_rw & (1 << BIO_RW_FAILFAST_DRIVER))
193 #define bio_rw_ahead(bio) ((bio)->bi_rw & (1 << BIO_RW_AHEAD))
194 #define bio_rw_meta(bio) ((bio)->bi_rw & (1 << BIO_RW_META))
195 #define bio_discard(bio) ((bio)->bi_rw & (1 << BIO_RW_DISCARD))
196 #define bio_empty_barrier(bio) (bio_barrier(bio) && !bio_has_data(bio) && !bio_discard(bio))
198 static inline unsigned int bio_cur_sectors(struct bio
*bio
)
201 return bio_iovec(bio
)->bv_len
>> 9;
202 else /* dataless requests such as discard */
203 return bio
->bi_size
>> 9;
206 static inline void *bio_data(struct bio
*bio
)
209 return page_address(bio_page(bio
)) + bio_offset(bio
);
217 #define bio_to_phys(bio) (page_to_phys(bio_page((bio))) + (unsigned long) bio_offset((bio)))
218 #define bvec_to_phys(bv) (page_to_phys((bv)->bv_page) + (unsigned long) (bv)->bv_offset)
221 * queues that have highmem support enabled may still need to revert to
222 * PIO transfers occasionally and thus map high pages temporarily. For
223 * permanent PIO fall back, user is probably better off disabling highmem
224 * I/O completely on that queue (see ide-dma for example)
226 #define __bio_kmap_atomic(bio, idx, kmtype) \
227 (kmap_atomic(bio_iovec_idx((bio), (idx))->bv_page, kmtype) + \
228 bio_iovec_idx((bio), (idx))->bv_offset)
230 #define __bio_kunmap_atomic(addr, kmtype) kunmap_atomic(addr, kmtype)
236 #define __BVEC_END(bio) bio_iovec_idx((bio), (bio)->bi_vcnt - 1)
237 #define __BVEC_START(bio) bio_iovec_idx((bio), (bio)->bi_idx)
240 * allow arch override, for eg virtualized architectures (put in asm/io.h)
242 #ifndef BIOVEC_PHYS_MERGEABLE
243 #define BIOVEC_PHYS_MERGEABLE(vec1, vec2) \
244 ((bvec_to_phys((vec1)) + (vec1)->bv_len) == bvec_to_phys((vec2)))
247 #define __BIO_SEG_BOUNDARY(addr1, addr2, mask) \
248 (((addr1) | (mask)) == (((addr2) - 1) | (mask)))
249 #define BIOVEC_SEG_BOUNDARY(q, b1, b2) \
250 __BIO_SEG_BOUNDARY(bvec_to_phys((b1)), bvec_to_phys((b2)) + (b2)->bv_len, (q)->seg_boundary_mask)
251 #define BIO_SEG_BOUNDARY(q, b1, b2) \
252 BIOVEC_SEG_BOUNDARY((q), __BVEC_END((b1)), __BVEC_START((b2)))
254 #define bio_io_error(bio) bio_endio((bio), -EIO)
257 * drivers should not use the __ version unless they _really_ want to
258 * run through the entire bio and not just pending pieces
260 #define __bio_for_each_segment(bvl, bio, i, start_idx) \
261 for (bvl = bio_iovec_idx((bio), (start_idx)), i = (start_idx); \
262 i < (bio)->bi_vcnt; \
265 #define bio_for_each_segment(bvl, bio, i) \
266 __bio_for_each_segment(bvl, bio, i, (bio)->bi_idx)
269 * get a reference to a bio, so it won't disappear. the intended use is
273 * submit_bio(rw, bio);
274 * if (bio->bi_flags ...)
278 * without the bio_get(), it could potentially complete I/O before submit_bio
279 * returns. and then bio would be freed memory when if (bio->bi_flags ...)
282 #define bio_get(bio) atomic_inc(&(bio)->bi_cnt)
284 #if defined(CONFIG_BLK_DEV_INTEGRITY)
286 * bio integrity payload
288 struct bio_integrity_payload
{
289 struct bio
*bip_bio
; /* parent bio */
290 struct bio_vec
*bip_vec
; /* integrity data vector */
292 sector_t bip_sector
; /* virtual start sector */
294 void *bip_buf
; /* generated integrity data */
295 bio_end_io_t
*bip_end_io
; /* saved I/O completion fn */
297 int bip_error
; /* saved I/O error */
298 unsigned int bip_size
;
300 unsigned short bip_pool
; /* pool the ivec came from */
301 unsigned short bip_vcnt
; /* # of integrity bio_vecs */
302 unsigned short bip_idx
; /* current bip_vec index */
304 struct work_struct bip_work
; /* I/O completion */
306 #endif /* CONFIG_BLK_DEV_INTEGRITY */
309 * A bio_pair is used when we need to split a bio.
310 * This can only happen for a bio that refers to just one
311 * page of data, and in the unusual situation when the
312 * page crosses a chunk/device boundary
314 * The address of the master bio is stored in bio1.bi_private
315 * The address of the pool the pair was allocated from is stored
319 struct bio bio1
, bio2
;
320 struct bio_vec bv1
, bv2
;
321 #if defined(CONFIG_BLK_DEV_INTEGRITY)
322 struct bio_integrity_payload bip1
, bip2
;
323 struct bio_vec iv1
, iv2
;
328 extern struct bio_pair
*bio_split(struct bio
*bi
, int first_sectors
);
329 extern void bio_pair_release(struct bio_pair
*dbio
);
331 extern struct bio_set
*bioset_create(int, int);
332 extern void bioset_free(struct bio_set
*);
334 extern struct bio
*bio_alloc(gfp_t
, int);
335 extern struct bio
*bio_kmalloc(gfp_t
, int);
336 extern struct bio
*bio_alloc_bioset(gfp_t
, int, struct bio_set
*);
337 extern void bio_put(struct bio
*);
338 extern void bio_free(struct bio
*, struct bio_set
*);
340 extern void bio_endio(struct bio
*, int);
341 struct request_queue
;
342 extern int bio_phys_segments(struct request_queue
*, struct bio
*);
344 extern void __bio_clone(struct bio
*, struct bio
*);
345 extern struct bio
*bio_clone(struct bio
*, gfp_t
);
347 extern void bio_init(struct bio
*);
349 extern int bio_add_page(struct bio
*, struct page
*, unsigned int,unsigned int);
350 extern int bio_add_pc_page(struct request_queue
*, struct bio
*, struct page
*,
351 unsigned int, unsigned int);
352 extern int bio_get_nr_vecs(struct block_device
*);
353 extern sector_t
bio_sector_offset(struct bio
*, unsigned short, unsigned int);
354 extern struct bio
*bio_map_user(struct request_queue
*, struct block_device
*,
355 unsigned long, unsigned int, int, gfp_t
);
358 extern struct bio
*bio_map_user_iov(struct request_queue
*,
359 struct block_device
*,
360 struct sg_iovec
*, int, int, gfp_t
);
361 extern void bio_unmap_user(struct bio
*);
362 extern struct bio
*bio_map_kern(struct request_queue
*, void *, unsigned int,
364 extern struct bio
*bio_copy_kern(struct request_queue
*, void *, unsigned int,
366 extern void bio_set_pages_dirty(struct bio
*bio
);
367 extern void bio_check_pages_dirty(struct bio
*bio
);
368 extern struct bio
*bio_copy_user(struct request_queue
*, struct rq_map_data
*,
369 unsigned long, unsigned int, int, gfp_t
);
370 extern struct bio
*bio_copy_user_iov(struct request_queue
*,
371 struct rq_map_data
*, struct sg_iovec
*,
373 extern int bio_uncopy_user(struct bio
*);
374 void zero_fill_bio(struct bio
*bio
);
375 extern struct bio_vec
*bvec_alloc_bs(gfp_t
, int, unsigned long *, struct bio_set
*);
376 extern unsigned int bvec_nr_vecs(unsigned short idx
);
379 * Allow queuer to specify a completion CPU for this bio
381 static inline void bio_set_completion_cpu(struct bio
*bio
, unsigned int cpu
)
383 bio
->bi_comp_cpu
= cpu
;
387 * bio_set is used to allow other portions of the IO system to
388 * allocate their own private memory pools for bio and iovec structures.
389 * These memory pools in turn all allocate from the bio_slab
390 * and the bvec_slabs[].
392 #define BIO_POOL_SIZE 2
393 #define BIOVEC_NR_POOLS 6
397 #if defined(CONFIG_BLK_DEV_INTEGRITY)
398 mempool_t
*bio_integrity_pool
;
400 mempool_t
*bvec_pools
[BIOVEC_NR_POOLS
];
406 struct kmem_cache
*slab
;
409 extern struct bio_set
*fs_bio_set
;
412 * a small number of entries is fine, not going to be performance critical.
413 * basically we just need to survive
415 #define BIO_SPLIT_ENTRIES 2
417 #ifdef CONFIG_HIGHMEM
419 * remember to add offset! and never ever reenable interrupts between a
420 * bvec_kmap_irq and bvec_kunmap_irq!!
422 * This function MUST be inlined - it plays with the CPU interrupt flags.
424 static inline char *bvec_kmap_irq(struct bio_vec
*bvec
, unsigned long *flags
)
429 * might not be a highmem page, but the preempt/irq count
430 * balancing is a lot nicer this way
432 local_irq_save(*flags
);
433 addr
= (unsigned long) kmap_atomic(bvec
->bv_page
, KM_BIO_SRC_IRQ
);
435 BUG_ON(addr
& ~PAGE_MASK
);
437 return (char *) addr
+ bvec
->bv_offset
;
440 static inline void bvec_kunmap_irq(char *buffer
, unsigned long *flags
)
442 unsigned long ptr
= (unsigned long) buffer
& PAGE_MASK
;
444 kunmap_atomic((void *) ptr
, KM_BIO_SRC_IRQ
);
445 local_irq_restore(*flags
);
449 #define bvec_kmap_irq(bvec, flags) (page_address((bvec)->bv_page) + (bvec)->bv_offset)
450 #define bvec_kunmap_irq(buf, flags) do { *(flags) = 0; } while (0)
453 static inline char *__bio_kmap_irq(struct bio
*bio
, unsigned short idx
,
454 unsigned long *flags
)
456 return bvec_kmap_irq(bio_iovec_idx(bio
, idx
), flags
);
458 #define __bio_kunmap_irq(buf, flags) bvec_kunmap_irq(buf, flags)
460 #define bio_kmap_irq(bio, flags) \
461 __bio_kmap_irq((bio), (bio)->bi_idx, (flags))
462 #define bio_kunmap_irq(buf,flags) __bio_kunmap_irq(buf, flags)
465 * Check whether this bio carries any data or not. A NULL bio is allowed.
467 static inline int bio_has_data(struct bio
*bio
)
469 return bio
&& bio
->bi_io_vec
!= NULL
;
472 #if defined(CONFIG_BLK_DEV_INTEGRITY)
474 #define bip_vec_idx(bip, idx) (&(bip->bip_vec[(idx)]))
475 #define bip_vec(bip) bip_vec_idx(bip, 0)
477 #define __bip_for_each_vec(bvl, bip, i, start_idx) \
478 for (bvl = bip_vec_idx((bip), (start_idx)), i = (start_idx); \
479 i < (bip)->bip_vcnt; \
482 #define bip_for_each_vec(bvl, bip, i) \
483 __bip_for_each_vec(bvl, bip, i, (bip)->bip_idx)
485 #define bio_integrity(bio) (bio->bi_integrity != NULL)
487 extern struct bio_integrity_payload
*bio_integrity_alloc_bioset(struct bio
*, gfp_t
, unsigned int, struct bio_set
*);
488 extern struct bio_integrity_payload
*bio_integrity_alloc(struct bio
*, gfp_t
, unsigned int);
489 extern void bio_integrity_free(struct bio
*, struct bio_set
*);
490 extern int bio_integrity_add_page(struct bio
*, struct page
*, unsigned int, unsigned int);
491 extern int bio_integrity_enabled(struct bio
*bio
);
492 extern int bio_integrity_set_tag(struct bio
*, void *, unsigned int);
493 extern int bio_integrity_get_tag(struct bio
*, void *, unsigned int);
494 extern int bio_integrity_prep(struct bio
*);
495 extern void bio_integrity_endio(struct bio
*, int);
496 extern void bio_integrity_advance(struct bio
*, unsigned int);
497 extern void bio_integrity_trim(struct bio
*, unsigned int, unsigned int);
498 extern void bio_integrity_split(struct bio
*, struct bio_pair
*, int);
499 extern int bio_integrity_clone(struct bio
*, struct bio
*, struct bio_set
*);
500 extern int bioset_integrity_create(struct bio_set
*, int);
501 extern void bioset_integrity_free(struct bio_set
*);
502 extern void bio_integrity_init_slab(void);
504 #else /* CONFIG_BLK_DEV_INTEGRITY */
506 #define bio_integrity(a) (0)
507 #define bioset_integrity_create(a, b) (0)
508 #define bio_integrity_prep(a) (0)
509 #define bio_integrity_enabled(a) (0)
510 #define bio_integrity_clone(a, b, c) (0)
511 #define bioset_integrity_free(a) do { } while (0)
512 #define bio_integrity_free(a, b) do { } while (0)
513 #define bio_integrity_endio(a, b) do { } while (0)
514 #define bio_integrity_advance(a, b) do { } while (0)
515 #define bio_integrity_trim(a, b, c) do { } while (0)
516 #define bio_integrity_split(a, b, c) do { } while (0)
517 #define bio_integrity_set_tag(a, b, c) do { } while (0)
518 #define bio_integrity_get_tag(a, b, c) do { } while (0)
519 #define bio_integrity_init_slab(a) do { } while (0)
521 #endif /* CONFIG_BLK_DEV_INTEGRITY */
523 #endif /* CONFIG_BLOCK */
524 #endif /* __LINUX_BIO_H */