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_QUIET 11 /* Make BIO Quiet */
121 #define bio_flagged(bio, flag) ((bio)->bi_flags & (1 << (flag)))
124 * top 4 bits of bio flags indicate the pool this bio came from
126 #define BIO_POOL_BITS (4)
127 #define BIO_POOL_OFFSET (BITS_PER_LONG - BIO_POOL_BITS)
128 #define BIO_POOL_MASK (1UL << BIO_POOL_OFFSET)
129 #define BIO_POOL_IDX(bio) ((bio)->bi_flags >> BIO_POOL_OFFSET)
134 * bit 0 -- data direction
135 * If not set, bio is a read from device. If set, it's a write to device.
136 * bit 1 -- rw-ahead when set
138 * Insert a serialization point in the IO queue, forcing previously
139 * submitted IO to be completed before this oen is issued.
140 * bit 3 -- synchronous I/O hint: the block layer will unplug immediately
141 * Note that this does NOT indicate that the IO itself is sync, just
142 * that the block layer will not postpone issue of this IO by plugging.
143 * bit 4 -- metadata request
144 * Used for tracing to differentiate metadata and data IO. May also
145 * get some preferential treatment in the IO scheduler
146 * bit 5 -- discard sectors
147 * Informs the lower level device that this range of sectors is no longer
148 * used by the file system and may thus be freed by the device. Used
149 * for flash based storage.
150 * bit 6 -- fail fast device errors
151 * bit 7 -- fail fast transport errors
152 * bit 8 -- fail fast driver errors
153 * Don't want driver retries for any fast fail whatever the reason.
155 #define BIO_RW 0 /* Must match RW in req flags (blkdev.h) */
156 #define BIO_RW_AHEAD 1 /* Must match FAILFAST in req flags */
157 #define BIO_RW_BARRIER 2
158 #define BIO_RW_SYNC 3
159 #define BIO_RW_META 4
160 #define BIO_RW_DISCARD 5
161 #define BIO_RW_FAILFAST_DEV 6
162 #define BIO_RW_FAILFAST_TRANSPORT 7
163 #define BIO_RW_FAILFAST_DRIVER 8
166 * upper 16 bits of bi_rw define the io priority of this bio
168 #define BIO_PRIO_SHIFT (8 * sizeof(unsigned long) - IOPRIO_BITS)
169 #define bio_prio(bio) ((bio)->bi_rw >> BIO_PRIO_SHIFT)
170 #define bio_prio_valid(bio) ioprio_valid(bio_prio(bio))
172 #define bio_set_prio(bio, prio) do { \
173 WARN_ON(prio >= (1 << IOPRIO_BITS)); \
174 (bio)->bi_rw &= ((1UL << BIO_PRIO_SHIFT) - 1); \
175 (bio)->bi_rw |= ((unsigned long) (prio) << BIO_PRIO_SHIFT); \
179 * various member access, note that bio_data should of course not be used
180 * on highmem page vectors
182 #define bio_iovec_idx(bio, idx) (&((bio)->bi_io_vec[(idx)]))
183 #define bio_iovec(bio) bio_iovec_idx((bio), (bio)->bi_idx)
184 #define bio_page(bio) bio_iovec((bio))->bv_page
185 #define bio_offset(bio) bio_iovec((bio))->bv_offset
186 #define bio_segments(bio) ((bio)->bi_vcnt - (bio)->bi_idx)
187 #define bio_sectors(bio) ((bio)->bi_size >> 9)
188 #define bio_barrier(bio) ((bio)->bi_rw & (1 << BIO_RW_BARRIER))
189 #define bio_sync(bio) ((bio)->bi_rw & (1 << BIO_RW_SYNC))
190 #define bio_failfast_dev(bio) ((bio)->bi_rw & (1 << BIO_RW_FAILFAST_DEV))
191 #define bio_failfast_transport(bio) \
192 ((bio)->bi_rw & (1 << BIO_RW_FAILFAST_TRANSPORT))
193 #define bio_failfast_driver(bio) ((bio)->bi_rw & (1 << BIO_RW_FAILFAST_DRIVER))
194 #define bio_rw_ahead(bio) ((bio)->bi_rw & (1 << BIO_RW_AHEAD))
195 #define bio_rw_meta(bio) ((bio)->bi_rw & (1 << BIO_RW_META))
196 #define bio_discard(bio) ((bio)->bi_rw & (1 << BIO_RW_DISCARD))
197 #define bio_empty_barrier(bio) (bio_barrier(bio) && !bio_has_data(bio) && !bio_discard(bio))
199 static inline unsigned int bio_cur_sectors(struct bio *bio)
202 return bio_iovec(bio)->bv_len >> 9;
203 else /* dataless requests such as discard */
204 return bio->bi_size >> 9;
207 static inline void *bio_data(struct bio *bio)
210 return page_address(bio_page(bio)) + bio_offset(bio);
218 #define bio_to_phys(bio) (page_to_phys(bio_page((bio))) + (unsigned long) bio_offset((bio)))
219 #define bvec_to_phys(bv) (page_to_phys((bv)->bv_page) + (unsigned long) (bv)->bv_offset)
222 * queues that have highmem support enabled may still need to revert to
223 * PIO transfers occasionally and thus map high pages temporarily. For
224 * permanent PIO fall back, user is probably better off disabling highmem
225 * I/O completely on that queue (see ide-dma for example)
227 #define __bio_kmap_atomic(bio, idx, kmtype) \
228 (kmap_atomic(bio_iovec_idx((bio), (idx))->bv_page, kmtype) + \
229 bio_iovec_idx((bio), (idx))->bv_offset)
231 #define __bio_kunmap_atomic(addr, kmtype) kunmap_atomic(addr, kmtype)
237 #define __BVEC_END(bio) bio_iovec_idx((bio), (bio)->bi_vcnt - 1)
238 #define __BVEC_START(bio) bio_iovec_idx((bio), (bio)->bi_idx)
240 /* Default implementation of BIOVEC_PHYS_MERGEABLE */
241 #define __BIOVEC_PHYS_MERGEABLE(vec1, vec2) \
242 ((bvec_to_phys((vec1)) + (vec1)->bv_len) == bvec_to_phys((vec2)))
245 * allow arch override, for eg virtualized architectures (put in asm/io.h)
247 #ifndef BIOVEC_PHYS_MERGEABLE
248 #define BIOVEC_PHYS_MERGEABLE(vec1, vec2) \
249 __BIOVEC_PHYS_MERGEABLE(vec1, vec2)
252 #define __BIO_SEG_BOUNDARY(addr1, addr2, mask) \
253 (((addr1) | (mask)) == (((addr2) - 1) | (mask)))
254 #define BIOVEC_SEG_BOUNDARY(q, b1, b2) \
255 __BIO_SEG_BOUNDARY(bvec_to_phys((b1)), bvec_to_phys((b2)) + (b2)->bv_len, (q)->seg_boundary_mask)
256 #define BIO_SEG_BOUNDARY(q, b1, b2) \
257 BIOVEC_SEG_BOUNDARY((q), __BVEC_END((b1)), __BVEC_START((b2)))
259 #define bio_io_error(bio) bio_endio((bio), -EIO)
262 * drivers should not use the __ version unless they _really_ want to
263 * run through the entire bio and not just pending pieces
265 #define __bio_for_each_segment(bvl, bio, i, start_idx) \
266 for (bvl = bio_iovec_idx((bio), (start_idx)), i = (start_idx); \
267 i < (bio)->bi_vcnt; \
270 #define bio_for_each_segment(bvl, bio, i) \
271 __bio_for_each_segment(bvl, bio, i, (bio)->bi_idx)
274 * get a reference to a bio, so it won't disappear. the intended use is
278 * submit_bio(rw, bio);
279 * if (bio->bi_flags ...)
283 * without the bio_get(), it could potentially complete I/O before submit_bio
284 * returns. and then bio would be freed memory when if (bio->bi_flags ...)
287 #define bio_get(bio) atomic_inc(&(bio)->bi_cnt)
289 #if defined(CONFIG_BLK_DEV_INTEGRITY)
291 * bio integrity payload
293 struct bio_integrity_payload {
294 struct bio *bip_bio; /* parent bio */
295 struct bio_vec *bip_vec; /* integrity data vector */
297 sector_t bip_sector; /* virtual start sector */
299 void *bip_buf; /* generated integrity data */
300 bio_end_io_t *bip_end_io; /* saved I/O completion fn */
302 int bip_error; /* saved I/O error */
303 unsigned int bip_size;
305 unsigned short bip_pool; /* pool the ivec came from */
306 unsigned short bip_vcnt; /* # of integrity bio_vecs */
307 unsigned short bip_idx; /* current bip_vec index */
309 struct work_struct bip_work; /* I/O completion */
311 #endif /* CONFIG_BLK_DEV_INTEGRITY */
314 * A bio_pair is used when we need to split a bio.
315 * This can only happen for a bio that refers to just one
316 * page of data, and in the unusual situation when the
317 * page crosses a chunk/device boundary
319 * The address of the master bio is stored in bio1.bi_private
320 * The address of the pool the pair was allocated from is stored
324 struct bio bio1, bio2;
325 struct bio_vec bv1, bv2;
326 #if defined(CONFIG_BLK_DEV_INTEGRITY)
327 struct bio_integrity_payload bip1, bip2;
328 struct bio_vec iv1, iv2;
333 extern struct bio_pair *bio_split(struct bio *bi, int first_sectors);
334 extern void bio_pair_release(struct bio_pair *dbio);
336 extern struct bio_set *bioset_create(int, int);
337 extern void bioset_free(struct bio_set *);
339 extern struct bio *bio_alloc(gfp_t, int);
340 extern struct bio *bio_kmalloc(gfp_t, int);
341 extern struct bio *bio_alloc_bioset(gfp_t, int, struct bio_set *);
342 extern void bio_put(struct bio *);
343 extern void bio_free(struct bio *, struct bio_set *);
345 extern void bio_endio(struct bio *, int);
346 struct request_queue;
347 extern int bio_phys_segments(struct request_queue *, struct bio *);
349 extern void __bio_clone(struct bio *, struct bio *);
350 extern struct bio *bio_clone(struct bio *, gfp_t);
352 extern void bio_init(struct bio *);
354 extern int bio_add_page(struct bio *, struct page *, unsigned int,unsigned int);
355 extern int bio_add_pc_page(struct request_queue *, struct bio *, struct page *,
356 unsigned int, unsigned int);
357 extern int bio_get_nr_vecs(struct block_device *);
358 extern sector_t bio_sector_offset(struct bio *, unsigned short, unsigned int);
359 extern struct bio *bio_map_user(struct request_queue *, struct block_device *,
360 unsigned long, unsigned int, int, gfp_t);
363 extern struct bio *bio_map_user_iov(struct request_queue *,
364 struct block_device *,
365 struct sg_iovec *, int, int, gfp_t);
366 extern void bio_unmap_user(struct bio *);
367 extern struct bio *bio_map_kern(struct request_queue *, void *, unsigned int,
369 extern struct bio *bio_copy_kern(struct request_queue *, void *, unsigned int,
371 extern void bio_set_pages_dirty(struct bio *bio);
372 extern void bio_check_pages_dirty(struct bio *bio);
373 extern struct bio *bio_copy_user(struct request_queue *, struct rq_map_data *,
374 unsigned long, unsigned int, int, gfp_t);
375 extern struct bio *bio_copy_user_iov(struct request_queue *,
376 struct rq_map_data *, struct sg_iovec *,
378 extern int bio_uncopy_user(struct bio *);
379 void zero_fill_bio(struct bio *bio);
380 extern struct bio_vec *bvec_alloc_bs(gfp_t, int, unsigned long *, struct bio_set *);
381 extern unsigned int bvec_nr_vecs(unsigned short idx);
384 * Allow queuer to specify a completion CPU for this bio
386 static inline void bio_set_completion_cpu(struct bio *bio, unsigned int cpu)
388 bio->bi_comp_cpu = cpu;
392 * bio_set is used to allow other portions of the IO system to
393 * allocate their own private memory pools for bio and iovec structures.
394 * These memory pools in turn all allocate from the bio_slab
395 * and the bvec_slabs[].
397 #define BIO_POOL_SIZE 2
398 #define BIOVEC_NR_POOLS 6
402 #if defined(CONFIG_BLK_DEV_INTEGRITY)
403 mempool_t *bio_integrity_pool;
405 mempool_t *bvec_pools[BIOVEC_NR_POOLS];
411 struct kmem_cache *slab;
414 extern struct bio_set *fs_bio_set;
417 * a small number of entries is fine, not going to be performance critical.
418 * basically we just need to survive
420 #define BIO_SPLIT_ENTRIES 2
422 #ifdef CONFIG_HIGHMEM
424 * remember to add offset! and never ever reenable interrupts between a
425 * bvec_kmap_irq and bvec_kunmap_irq!!
427 * This function MUST be inlined - it plays with the CPU interrupt flags.
429 static inline char *bvec_kmap_irq(struct bio_vec *bvec, unsigned long *flags)
434 * might not be a highmem page, but the preempt/irq count
435 * balancing is a lot nicer this way
437 local_irq_save(*flags);
438 addr = (unsigned long) kmap_atomic(bvec->bv_page, KM_BIO_SRC_IRQ);
440 BUG_ON(addr & ~PAGE_MASK);
442 return (char *) addr + bvec->bv_offset;
445 static inline void bvec_kunmap_irq(char *buffer, unsigned long *flags)
447 unsigned long ptr = (unsigned long) buffer & PAGE_MASK;
449 kunmap_atomic((void *) ptr, KM_BIO_SRC_IRQ);
450 local_irq_restore(*flags);
454 #define bvec_kmap_irq(bvec, flags) (page_address((bvec)->bv_page) + (bvec)->bv_offset)
455 #define bvec_kunmap_irq(buf, flags) do { *(flags) = 0; } while (0)
458 static inline char *__bio_kmap_irq(struct bio *bio, unsigned short idx,
459 unsigned long *flags)
461 return bvec_kmap_irq(bio_iovec_idx(bio, idx), flags);
463 #define __bio_kunmap_irq(buf, flags) bvec_kunmap_irq(buf, flags)
465 #define bio_kmap_irq(bio, flags) \
466 __bio_kmap_irq((bio), (bio)->bi_idx, (flags))
467 #define bio_kunmap_irq(buf,flags) __bio_kunmap_irq(buf, flags)
470 * Check whether this bio carries any data or not. A NULL bio is allowed.
472 static inline int bio_has_data(struct bio *bio)
474 return bio && bio->bi_io_vec != NULL;
477 #if defined(CONFIG_BLK_DEV_INTEGRITY)
479 #define bip_vec_idx(bip, idx) (&(bip->bip_vec[(idx)]))
480 #define bip_vec(bip) bip_vec_idx(bip, 0)
482 #define __bip_for_each_vec(bvl, bip, i, start_idx) \
483 for (bvl = bip_vec_idx((bip), (start_idx)), i = (start_idx); \
484 i < (bip)->bip_vcnt; \
487 #define bip_for_each_vec(bvl, bip, i) \
488 __bip_for_each_vec(bvl, bip, i, (bip)->bip_idx)
490 #define bio_integrity(bio) (bio->bi_integrity != NULL)
492 extern struct bio_integrity_payload *bio_integrity_alloc_bioset(struct bio *, gfp_t, unsigned int, struct bio_set *);
493 extern struct bio_integrity_payload *bio_integrity_alloc(struct bio *, gfp_t, unsigned int);
494 extern void bio_integrity_free(struct bio *, struct bio_set *);
495 extern int bio_integrity_add_page(struct bio *, struct page *, unsigned int, unsigned int);
496 extern int bio_integrity_enabled(struct bio *bio);
497 extern int bio_integrity_set_tag(struct bio *, void *, unsigned int);
498 extern int bio_integrity_get_tag(struct bio *, void *, unsigned int);
499 extern int bio_integrity_prep(struct bio *);
500 extern void bio_integrity_endio(struct bio *, int);
501 extern void bio_integrity_advance(struct bio *, unsigned int);
502 extern void bio_integrity_trim(struct bio *, unsigned int, unsigned int);
503 extern void bio_integrity_split(struct bio *, struct bio_pair *, int);
504 extern int bio_integrity_clone(struct bio *, struct bio *, struct bio_set *);
505 extern int bioset_integrity_create(struct bio_set *, int);
506 extern void bioset_integrity_free(struct bio_set *);
507 extern void bio_integrity_init_slab(void);
509 #else /* CONFIG_BLK_DEV_INTEGRITY */
511 #define bio_integrity(a) (0)
512 #define bioset_integrity_create(a, b) (0)
513 #define bio_integrity_prep(a) (0)
514 #define bio_integrity_enabled(a) (0)
515 #define bio_integrity_clone(a, b, c) (0)
516 #define bioset_integrity_free(a) do { } while (0)
517 #define bio_integrity_free(a, b) do { } while (0)
518 #define bio_integrity_endio(a, b) do { } while (0)
519 #define bio_integrity_advance(a, b) do { } while (0)
520 #define bio_integrity_trim(a, b, c) do { } while (0)
521 #define bio_integrity_split(a, b, c) do { } while (0)
522 #define bio_integrity_set_tag(a, b, c) do { } while (0)
523 #define bio_integrity_get_tag(a, b, c) do { } while (0)
524 #define bio_integrity_init_slab(a) do { } while (0)
526 #endif /* CONFIG_BLK_DEV_INTEGRITY */
528 #endif /* CONFIG_BLOCK */
529 #endif /* __LINUX_BIO_H */