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cfq-iosched: fix queue depth detection
[linux-block.git] / include / linux / bio.h
CommitLineData
1da177e4
LT		 1/*
2 * 2.5 block I/O model
3 *
4 * Copyright (C) 2001 Jens Axboe <axboe@suse.de>
5 *
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.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
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-
19 */
20#ifndef __LINUX_BIO_H
21#define __LINUX_BIO_H
22
23#include <linux/highmem.h>
24#include <linux/mempool.h>
22e2c507 25#include <linux/ioprio.h>
1da177e4 26
02a5e0ac
DH		 27#ifdef CONFIG_BLOCK
28
1da177e4
LT		 29#include <asm/io.h>
30
1da177e4
LT		 31#define BIO_DEBUG
32
33#ifdef BIO_DEBUG
34#define BIO_BUG_ON BUG_ON
35#else
36#define BIO_BUG_ON
37#endif
38
d84a8477 39#define BIO_MAX_PAGES 256
1da177e4
LT		 40#define BIO_MAX_SIZE (BIO_MAX_PAGES << PAGE_CACHE_SHIFT)
41#define BIO_MAX_SECTORS (BIO_MAX_SIZE >> 9)
42
43/*
44 * was unsigned short, but we might as well be ready for > 64kB I/O pages
45 */
46struct bio_vec {
47 struct page *bv_page;
48 unsigned int bv_len;
49 unsigned int bv_offset;
50};
51
52struct bio_set;
53struct bio;
7ba1ba12 54struct bio_integrity_payload;
6712ecf8 55typedef void (bio_end_io_t) (struct bio *, int);
1da177e4
LT		 56typedef void (bio_destructor_t) (struct bio *);
57
58/*
59 * main unit of I/O for the block layer and lower layers (ie drivers and
60 * stacking drivers)
61 */
62struct bio {
2c2345c2
RG		 63 sector_t bi_sector; /* device address in 512 byte
64 sectors */
1da177e4
LT		 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,
69 * top bits priority
70 */
71
72 unsigned short bi_vcnt; /* how many bio_vec's */
73 unsigned short bi_idx; /* current index into bvl_vec */
74
75 /* Number of segments in this BIO after
76 * physical address coalescing is performed.
77 */
5b99c2ff 78 unsigned int bi_phys_segments;
1da177e4 79
1da177e4
LT		 80 unsigned int bi_size; /* residual I/O count */
81
1da177e4
LT		 82 unsigned int bi_max_vecs; /* max bvl_vecs we can hold */
83
c7c22e4d
JA		 84 unsigned int bi_comp_cpu; /* completion CPU */
85
1da177e4
LT		 86 struct bio_vec *bi_io_vec; /* the actual vec list */
87
88 bio_end_io_t *bi_end_io;
89 atomic_t bi_cnt; /* pin count */
90
91 void *bi_private;
7ba1ba12
MP		 92#if defined(CONFIG_BLK_DEV_INTEGRITY)
93 struct bio_integrity_payload *bi_integrity; /* data integrity */
94#endif
1da177e4
LT		 95
96 bio_destructor_t *bi_destructor; /* destructor */
1da177e4
LT		 97};
98
99/*
100 * bio flags
101 */
102#define BIO_UPTODATE 0 /* ok after I/O completion */
103#define BIO_RW_BLOCK 1 /* RW_AHEAD set, and read/write would block */
104#define BIO_EOF 2 /* out-out-bounds error */
5df97b91 105#define BIO_SEG_VALID 3 /* bi_phys_segments valid */
1da177e4
LT		 106#define BIO_CLONED 4 /* doesn't own data */
107#define BIO_BOUNCED 5 /* bio is a bounce bio */
108#define BIO_USER_MAPPED 6 /* contains user pages */
109#define BIO_EOPNOTSUPP 7 /* not supported */
c7c22e4d 110#define BIO_CPU_AFFINE 8 /* complete bio on same CPU as submitted */
1da177e4
LT		 111#define bio_flagged(bio, flag) ((bio)->bi_flags & (1 << (flag)))
112
113/*
114 * top 4 bits of bio flags indicate the pool this bio came from
115 */
116#define BIO_POOL_BITS (4)
117#define BIO_POOL_OFFSET (BITS_PER_LONG - BIO_POOL_BITS)
118#define BIO_POOL_MASK (1UL << BIO_POOL_OFFSET)
119#define BIO_POOL_IDX(bio) ((bio)->bi_flags >> BIO_POOL_OFFSET)
120
121/*
122 * bio bi_rw flags
123 *
124 * bit 0 -- read (not set) or write (set)
125 * bit 1 -- rw-ahead when set
126 * bit 2 -- barrier
127 * bit 3 -- fail fast, don't want low level driver retries
128 * bit 4 -- synchronous I/O hint: the block layer will unplug immediately
fb2dce86
DW		 129 * bit 5 -- metadata request
130 * bit 6 -- discard sectors
1da177e4 131 */
d628eaef
DW		 132#define BIO_RW 0 /* Must match RW in req flags (blkdev.h) */
133#define BIO_RW_AHEAD 1 /* Must match FAILFAST in req flags */
1da177e4
LT		 134#define BIO_RW_BARRIER 2
135#define BIO_RW_FAILFAST 3
136#define BIO_RW_SYNC 4
5404bc7a 137#define BIO_RW_META 5
fb2dce86 138#define BIO_RW_DISCARD 6
1da177e4 139
22e2c507
JA		 140/*
141 * upper 16 bits of bi_rw define the io priority of this bio
142 */
143#define BIO_PRIO_SHIFT (8 * sizeof(unsigned long) - IOPRIO_BITS)
144#define bio_prio(bio) ((bio)->bi_rw >> BIO_PRIO_SHIFT)
145#define bio_prio_valid(bio) ioprio_valid(bio_prio(bio))
146
147#define bio_set_prio(bio, prio) do { \
148 WARN_ON(prio >= (1 << IOPRIO_BITS)); \
149 (bio)->bi_rw &= ((1UL << BIO_PRIO_SHIFT) - 1); \
150 (bio)->bi_rw |= ((unsigned long) (prio) << BIO_PRIO_SHIFT); \
151} while (0)
152
1da177e4
LT		 153/*
154 * various member access, note that bio_data should of course not be used
155 * on highmem page vectors
156 */
157#define bio_iovec_idx(bio, idx) (&((bio)->bi_io_vec[(idx)]))
158#define bio_iovec(bio) bio_iovec_idx((bio), (bio)->bi_idx)
159#define bio_page(bio) bio_iovec((bio))->bv_page
160#define bio_offset(bio) bio_iovec((bio))->bv_offset
161#define bio_segments(bio) ((bio)->bi_vcnt - (bio)->bi_idx)
162#define bio_sectors(bio) ((bio)->bi_size >> 9)
1da177e4
LT		 163#define bio_barrier(bio) ((bio)->bi_rw & (1 << BIO_RW_BARRIER))
164#define bio_sync(bio) ((bio)->bi_rw & (1 << BIO_RW_SYNC))
165#define bio_failfast(bio) ((bio)->bi_rw & (1 << BIO_RW_FAILFAST))
166#define bio_rw_ahead(bio) ((bio)->bi_rw & (1 << BIO_RW_AHEAD))
5404bc7a 167#define bio_rw_meta(bio) ((bio)->bi_rw & (1 << BIO_RW_META))
fb2dce86 168#define bio_discard(bio) ((bio)->bi_rw & (1 << BIO_RW_DISCARD))
e17fc0a1 169#define bio_empty_barrier(bio) (bio_barrier(bio) && !bio_has_data(bio) && !bio_discard(bio))
bf2de6f5
JA		 170
171static inline unsigned int bio_cur_sectors(struct bio *bio)
172{
173 if (bio->bi_vcnt)
174 return bio_iovec(bio)->bv_len >> 9;
fb2dce86
DW		 175 else /* dataless requests such as discard */
176 return bio->bi_size >> 9;
bf2de6f5
JA		 177}
178
179static inline void *bio_data(struct bio *bio)
180{
181 if (bio->bi_vcnt)
182 return page_address(bio_page(bio)) + bio_offset(bio);
183
184 return NULL;
185}
1da177e4
LT		 186
187/*
188 * will die
189 */
190#define bio_to_phys(bio) (page_to_phys(bio_page((bio))) + (unsigned long) bio_offset((bio)))
191#define bvec_to_phys(bv) (page_to_phys((bv)->bv_page) + (unsigned long) (bv)->bv_offset)
192
193/*
194 * queues that have highmem support enabled may still need to revert to
195 * PIO transfers occasionally and thus map high pages temporarily. For
196 * permanent PIO fall back, user is probably better off disabling highmem
197 * I/O completely on that queue (see ide-dma for example)
198 */
199#define __bio_kmap_atomic(bio, idx, kmtype) \
200 (kmap_atomic(bio_iovec_idx((bio), (idx))->bv_page, kmtype) + \
201 bio_iovec_idx((bio), (idx))->bv_offset)
202
203#define __bio_kunmap_atomic(addr, kmtype) kunmap_atomic(addr, kmtype)
204
205/*
206 * merge helpers etc
207 */
208
209#define __BVEC_END(bio) bio_iovec_idx((bio), (bio)->bi_vcnt - 1)
210#define __BVEC_START(bio) bio_iovec_idx((bio), (bio)->bi_idx)
211
212/*
213 * allow arch override, for eg virtualized architectures (put in asm/io.h)
214 */
215#ifndef BIOVEC_PHYS_MERGEABLE
216#define BIOVEC_PHYS_MERGEABLE(vec1, vec2) \
217 ((bvec_to_phys((vec1)) + (vec1)->bv_len) == bvec_to_phys((vec2)))
218#endif
219
1da177e4
LT		 220#define __BIO_SEG_BOUNDARY(addr1, addr2, mask) \
221 (((addr1) | (mask)) == (((addr2) - 1) | (mask)))
222#define BIOVEC_SEG_BOUNDARY(q, b1, b2) \
223 __BIO_SEG_BOUNDARY(bvec_to_phys((b1)), bvec_to_phys((b2)) + (b2)->bv_len, (q)->seg_boundary_mask)
224#define BIO_SEG_BOUNDARY(q, b1, b2) \
225 BIOVEC_SEG_BOUNDARY((q), __BVEC_END((b1)), __BVEC_START((b2)))
226
6712ecf8 227#define bio_io_error(bio) bio_endio((bio), -EIO)
1da177e4
LT		 228
229/*
230 * drivers should not use the __ version unless they _really_ want to
231 * run through the entire bio and not just pending pieces
232 */
233#define __bio_for_each_segment(bvl, bio, i, start_idx) \
234 for (bvl = bio_iovec_idx((bio), (start_idx)), i = (start_idx); \
235 i < (bio)->bi_vcnt; \
236 bvl++, i++)
237
238#define bio_for_each_segment(bvl, bio, i) \
239 __bio_for_each_segment(bvl, bio, i, (bio)->bi_idx)
240
241/*
242 * get a reference to a bio, so it won't disappear. the intended use is
243 * something like:
244 *
245 * bio_get(bio);
246 * submit_bio(rw, bio);
247 * if (bio->bi_flags ...)
248 * do_something
249 * bio_put(bio);
250 *
251 * without the bio_get(), it could potentially complete I/O before submit_bio
252 * returns. and then bio would be freed memory when if (bio->bi_flags ...)
253 * runs
254 */
255#define bio_get(bio) atomic_inc(&(bio)->bi_cnt)
256
7ba1ba12
MP		 257#if defined(CONFIG_BLK_DEV_INTEGRITY)
258/*
259 * bio integrity payload
260 */
261struct bio_integrity_payload {
262 struct bio *bip_bio; /* parent bio */
263 struct bio_vec *bip_vec; /* integrity data vector */
264
265 sector_t bip_sector; /* virtual start sector */
266
267 void *bip_buf; /* generated integrity data */
268 bio_end_io_t *bip_end_io; /* saved I/O completion fn */
269
270 int bip_error; /* saved I/O error */
271 unsigned int bip_size;
272
273 unsigned short bip_pool; /* pool the ivec came from */
274 unsigned short bip_vcnt; /* # of integrity bio_vecs */
275 unsigned short bip_idx; /* current bip_vec index */
276
277 struct work_struct bip_work; /* I/O completion */
278};
279#endif /* CONFIG_BLK_DEV_INTEGRITY */
1da177e4
LT		 280
281/*
282 * A bio_pair is used when we need to split a bio.
283 * This can only happen for a bio that refers to just one
284 * page of data, and in the unusual situation when the
285 * page crosses a chunk/device boundary
286 *
287 * The address of the master bio is stored in bio1.bi_private
288 * The address of the pool the pair was allocated from is stored
289 * in bio2.bi_private
290 */
291struct bio_pair {
7ba1ba12
MP		 292 struct bio bio1, bio2;
293 struct bio_vec bv1, bv2;
294#if defined(CONFIG_BLK_DEV_INTEGRITY)
295 struct bio_integrity_payload bip1, bip2;
296 struct bio_vec iv1, iv2;
297#endif
298 atomic_t cnt;
299 int error;
1da177e4
LT		 300};
301extern struct bio_pair *bio_split(struct bio *bi, mempool_t *pool,
302 int first_sectors);
303extern mempool_t *bio_split_pool;
304extern void bio_pair_release(struct bio_pair *dbio);
305
5972511b 306extern struct bio_set *bioset_create(int, int);
1da177e4
LT		 307extern void bioset_free(struct bio_set *);
308
dd0fc66f
AV		 309extern struct bio *bio_alloc(gfp_t, int);
310extern struct bio *bio_alloc_bioset(gfp_t, int, struct bio_set *);
1da177e4 311extern void bio_put(struct bio *);
3676347a 312extern void bio_free(struct bio *, struct bio_set *);
1da177e4 313
6712ecf8 314extern void bio_endio(struct bio *, int);
1da177e4
LT		 315struct request_queue;
316extern int bio_phys_segments(struct request_queue *, struct bio *);
1da177e4
LT		 317
318extern void __bio_clone(struct bio *, struct bio *);
dd0fc66f 319extern struct bio *bio_clone(struct bio *, gfp_t);
1da177e4
LT		 320
321extern void bio_init(struct bio *);
322
323extern int bio_add_page(struct bio *, struct page *, unsigned int,unsigned int);
6e68af66
MC		 324extern int bio_add_pc_page(struct request_queue *, struct bio *, struct page *,
325 unsigned int, unsigned int);
1da177e4
LT		 326extern int bio_get_nr_vecs(struct block_device *);
327extern struct bio *bio_map_user(struct request_queue *, struct block_device *,
328 unsigned long, unsigned int, int);
f1970baf
JB		 329struct sg_iovec;
330extern struct bio *bio_map_user_iov(struct request_queue *,
331 struct block_device *,
332 struct sg_iovec *, int, int);
1da177e4 333extern void bio_unmap_user(struct bio *);
df46b9a4 334extern struct bio *bio_map_kern(struct request_queue *, void *, unsigned int,
27496a8c 335 gfp_t);
68154e90
FT		 336extern struct bio *bio_copy_kern(struct request_queue *, void *, unsigned int,
337 gfp_t, int);
1da177e4
LT		 338extern void bio_set_pages_dirty(struct bio *bio);
339extern void bio_check_pages_dirty(struct bio *bio);
340extern struct bio *bio_copy_user(struct request_queue *, unsigned long, unsigned int, int);
c5dec1c3
FT		 341extern struct bio *bio_copy_user_iov(struct request_queue *, struct sg_iovec *,
342 int, int);
1da177e4
LT		 343extern int bio_uncopy_user(struct bio *);
344void zero_fill_bio(struct bio *bio);
51d654e1 345extern struct bio_vec *bvec_alloc_bs(gfp_t, int, unsigned long *, struct bio_set *);
7ba1ba12 346extern unsigned int bvec_nr_vecs(unsigned short idx);
51d654e1 347
c7c22e4d
JA		 348/*
349 * Allow queuer to specify a completion CPU for this bio
350 */
351static inline void bio_set_completion_cpu(struct bio *bio, unsigned int cpu)
352{
353 bio->bi_comp_cpu = cpu;
354}
355
51d654e1
MP		 356/*
357 * bio_set is used to allow other portions of the IO system to
358 * allocate their own private memory pools for bio and iovec structures.
359 * These memory pools in turn all allocate from the bio_slab
360 * and the bvec_slabs[].
361 */
362#define BIO_POOL_SIZE 2
363#define BIOVEC_NR_POOLS 6
364
365struct bio_set {
366 mempool_t *bio_pool;
7ba1ba12
MP		 367#if defined(CONFIG_BLK_DEV_INTEGRITY)
368 mempool_t *bio_integrity_pool;
369#endif
51d654e1
MP		 370 mempool_t *bvec_pools[BIOVEC_NR_POOLS];
371};
372
373struct biovec_slab {
374 int nr_vecs;
375 char *name;
376 struct kmem_cache *slab;
377};
378
379extern struct bio_set *fs_bio_set;
380
381/*
382 * a small number of entries is fine, not going to be performance critical.
383 * basically we just need to survive
384 */
385#define BIO_SPLIT_ENTRIES 2
1da177e4
LT		 386
387#ifdef CONFIG_HIGHMEM
388/*
389 * remember to add offset! and never ever reenable interrupts between a
390 * bvec_kmap_irq and bvec_kunmap_irq!!
391 *
392 * This function MUST be inlined - it plays with the CPU interrupt flags.
1da177e4 393 */
c2d08dad 394static inline char *bvec_kmap_irq(struct bio_vec *bvec, unsigned long *flags)
1da177e4
LT		 395{
396 unsigned long addr;
397
398 /*
399 * might not be a highmem page, but the preempt/irq count
400 * balancing is a lot nicer this way
401 */
402 local_irq_save(*flags);
403 addr = (unsigned long) kmap_atomic(bvec->bv_page, KM_BIO_SRC_IRQ);
404
405 BUG_ON(addr & ~PAGE_MASK);
406
407 return (char *) addr + bvec->bv_offset;
408}
409
c2d08dad 410static inline void bvec_kunmap_irq(char *buffer, unsigned long *flags)
1da177e4
LT		 411{
412 unsigned long ptr = (unsigned long) buffer & PAGE_MASK;
413
414 kunmap_atomic((void *) ptr, KM_BIO_SRC_IRQ);
415 local_irq_restore(*flags);
416}
417
418#else
419#define bvec_kmap_irq(bvec, flags) (page_address((bvec)->bv_page) + (bvec)->bv_offset)
420#define bvec_kunmap_irq(buf, flags) do { *(flags) = 0; } while (0)
421#endif
422
c2d08dad 423static inline char *__bio_kmap_irq(struct bio *bio, unsigned short idx,
1da177e4
LT		 424 unsigned long *flags)
425{
426 return bvec_kmap_irq(bio_iovec_idx(bio, idx), flags);
427}
428#define __bio_kunmap_irq(buf, flags) bvec_kunmap_irq(buf, flags)
429
430#define bio_kmap_irq(bio, flags) \
431 __bio_kmap_irq((bio), (bio)->bi_idx, (flags))
432#define bio_kunmap_irq(buf,flags) __bio_kunmap_irq(buf, flags)
433
7a67f63b
JA		 434/*
435 * Check whether this bio carries any data or not. A NULL bio is allowed.
436 */
437static inline int bio_has_data(struct bio *bio)
438{
439 return bio && bio->bi_io_vec != NULL;
440}
441
7ba1ba12
MP		 442#if defined(CONFIG_BLK_DEV_INTEGRITY)
443
444#define bip_vec_idx(bip, idx) (&(bip->bip_vec[(idx)]))
445#define bip_vec(bip) bip_vec_idx(bip, 0)
446
447#define __bip_for_each_vec(bvl, bip, i, start_idx) \
448 for (bvl = bip_vec_idx((bip), (start_idx)), i = (start_idx); \
449 i < (bip)->bip_vcnt; \
450 bvl++, i++)
451
452#define bip_for_each_vec(bvl, bip, i) \
453 __bip_for_each_vec(bvl, bip, i, (bip)->bip_idx)
454
6e2401ad
JA		 455static inline int bio_integrity(struct bio *bio)
456{
457#if defined(CONFIG_BLK_DEV_INTEGRITY)
458 return bio->bi_integrity != NULL;
459#else
460 return 0;
461#endif
462}
7ba1ba12
MP		 463
464extern struct bio_integrity_payload *bio_integrity_alloc_bioset(struct bio *, gfp_t, unsigned int, struct bio_set *);
465extern struct bio_integrity_payload *bio_integrity_alloc(struct bio *, gfp_t, unsigned int);
466extern void bio_integrity_free(struct bio *, struct bio_set *);
467extern int bio_integrity_add_page(struct bio *, struct page *, unsigned int, unsigned int);
468extern int bio_integrity_enabled(struct bio *bio);
469extern int bio_integrity_set_tag(struct bio *, void *, unsigned int);
470extern int bio_integrity_get_tag(struct bio *, void *, unsigned int);
471extern int bio_integrity_prep(struct bio *);
472extern void bio_integrity_endio(struct bio *, int);
473extern void bio_integrity_advance(struct bio *, unsigned int);
474extern void bio_integrity_trim(struct bio *, unsigned int, unsigned int);
475extern void bio_integrity_split(struct bio *, struct bio_pair *, int);
476extern int bio_integrity_clone(struct bio *, struct bio *, struct bio_set *);
477extern int bioset_integrity_create(struct bio_set *, int);
478extern void bioset_integrity_free(struct bio_set *);
479extern void bio_integrity_init_slab(void);
480
481#else /* CONFIG_BLK_DEV_INTEGRITY */
482
483#define bio_integrity(a) (0)
484#define bioset_integrity_create(a, b) (0)
485#define bio_integrity_prep(a) (0)
486#define bio_integrity_enabled(a) (0)
487#define bio_integrity_clone(a, b, c) (0)
488#define bioset_integrity_free(a) do { } while (0)
489#define bio_integrity_free(a, b) do { } while (0)
490#define bio_integrity_endio(a, b) do { } while (0)
491#define bio_integrity_advance(a, b) do { } while (0)
492#define bio_integrity_trim(a, b, c) do { } while (0)
493#define bio_integrity_split(a, b, c) do { } while (0)
494#define bio_integrity_set_tag(a, b, c) do { } while (0)
495#define bio_integrity_get_tag(a, b, c) do { } while (0)
496#define bio_integrity_init_slab(a) do { } while (0)
497
498#endif /* CONFIG_BLK_DEV_INTEGRITY */
499
02a5e0ac 500#endif /* CONFIG_BLOCK */
1da177e4 501#endif /* __LINUX_BIO_H */
Linux 6.x block layer and io_uring tree(s)