blob: a299ed38fcd783d0f68b55f959d9f81b98c38581 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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>
Jens Axboe22e2c502005-06-27 10:55:12 +020025#include <linux/ioprio.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070026
David Howells02a5e0a2007-08-11 22:34:32 +020027#ifdef CONFIG_BLOCK
28
Linus Torvalds1da177e2005-04-16 15:20:36 -070029#include <asm/io.h>
30
Linus Torvalds1da177e2005-04-16 15:20:36 -070031#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
Alexey Dobriyand84a8472006-06-25 05:49:32 -070039#define BIO_MAX_PAGES 256
Linus Torvalds1da177e2005-04-16 15:20:36 -070040#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;
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +020054struct bio_integrity_payload;
NeilBrown6712ecf2007-09-27 12:47:43 +020055typedef void (bio_end_io_t) (struct bio *, int);
Linus Torvalds1da177e2005-04-16 15:20:36 -070056typedef 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 {
Roger Gammans2c2345c2006-10-04 13:37:45 +020063 sector_t bi_sector; /* device address in 512 byte
64 sectors */
Linus Torvalds1da177e2005-04-16 15:20:36 -070065 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 */
Jens Axboe5b99c2f2008-08-15 10:56:11 +020078 unsigned int bi_phys_segments;
Linus Torvalds1da177e2005-04-16 15:20:36 -070079
Linus Torvalds1da177e2005-04-16 15:20:36 -070080 unsigned int bi_size; /* residual I/O count */
81
FUJITA Tomonori86771422008-10-13 14:19:05 +020082 /*
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.
85 */
86 unsigned int bi_seg_front_size;
87 unsigned int bi_seg_back_size;
88
Linus Torvalds1da177e2005-04-16 15:20:36 -070089 unsigned int bi_max_vecs; /* max bvl_vecs we can hold */
90
Jens Axboec7c22e42008-09-13 20:26:01 +020091 unsigned int bi_comp_cpu; /* completion CPU */
92
Richard Kennedyba744d52008-12-03 12:41:40 +010093 atomic_t bi_cnt; /* pin count */
94
Linus Torvalds1da177e2005-04-16 15:20:36 -070095 struct bio_vec *bi_io_vec; /* the actual vec list */
96
97 bio_end_io_t *bi_end_io;
Linus Torvalds1da177e2005-04-16 15:20:36 -070098
99 void *bi_private;
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200100#if defined(CONFIG_BLK_DEV_INTEGRITY)
101 struct bio_integrity_payload *bi_integrity; /* data integrity */
102#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700103
104 bio_destructor_t *bi_destructor; /* destructor */
Jens Axboe392ddc32008-12-23 12:42:54 +0100105
106 /*
107 * We can inline a number of vecs at the end of the bio, to avoid
108 * double allocations for a small number of bio_vecs. This member
109 * MUST obviously be kept at the very end of the bio.
110 */
111 struct bio_vec bi_inline_vecs[0];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700112};
113
114/*
115 * bio flags
116 */
117#define BIO_UPTODATE 0 /* ok after I/O completion */
118#define BIO_RW_BLOCK 1 /* RW_AHEAD set, and read/write would block */
119#define BIO_EOF 2 /* out-out-bounds error */
Mikulas Patocka5df97b92008-08-15 10:20:02 +0200120#define BIO_SEG_VALID 3 /* bi_phys_segments valid */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700121#define BIO_CLONED 4 /* doesn't own data */
122#define BIO_BOUNCED 5 /* bio is a bounce bio */
123#define BIO_USER_MAPPED 6 /* contains user pages */
124#define BIO_EOPNOTSUPP 7 /* not supported */
Jens Axboec7c22e42008-09-13 20:26:01 +0200125#define BIO_CPU_AFFINE 8 /* complete bio on same CPU as submitted */
FUJITA Tomonori81882762008-09-02 16:20:19 +0900126#define BIO_NULL_MAPPED 9 /* contains invalid user pages */
Martin K. Petersen74aa8c22008-10-01 03:38:37 -0400127#define BIO_FS_INTEGRITY 10 /* fs owns integrity data, not block layer */
Keith Mannthey08bafc02008-11-25 10:24:35 +0100128#define BIO_QUIET 11 /* Make BIO Quiet */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700129#define bio_flagged(bio, flag) ((bio)->bi_flags & (1 << (flag)))
130
131/*
132 * top 4 bits of bio flags indicate the pool this bio came from
133 */
134#define BIO_POOL_BITS (4)
Tejun Heo451a9eb2009-04-15 19:50:51 +0200135#define BIO_POOL_NONE ((1UL << BIO_POOL_BITS) - 1)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700136#define BIO_POOL_OFFSET (BITS_PER_LONG - BIO_POOL_BITS)
137#define BIO_POOL_MASK (1UL << BIO_POOL_OFFSET)
138#define BIO_POOL_IDX(bio) ((bio)->bi_flags >> BIO_POOL_OFFSET)
139
140/*
141 * bio bi_rw flags
142 *
Jens Axboeaf563942008-10-09 09:01:10 +0200143 * bit 0 -- data direction
144 * If not set, bio is a read from device. If set, it's a write to device.
Tejun Heoa82afdf2009-07-03 17:48:16 +0900145 * bit 1 -- fail fast device errors
146 * bit 2 -- fail fast transport errors
147 * bit 3 -- fail fast driver errors
148 * bit 4 -- rw-ahead when set
149 * bit 5 -- barrier
Jens Axboeaf563942008-10-09 09:01:10 +0200150 * Insert a serialization point in the IO queue, forcing previously
Alberto Bertogli16642eb2009-01-05 10:18:53 +0100151 * submitted IO to be completed before this one is issued.
Tejun Heoa82afdf2009-07-03 17:48:16 +0900152 * bit 6 -- synchronous I/O hint.
153 * bit 7 -- Unplug the device immediately after submitting this bio.
154 * bit 8 -- metadata request
Jens Axboeaf563942008-10-09 09:01:10 +0200155 * Used for tracing to differentiate metadata and data IO. May also
156 * get some preferential treatment in the IO scheduler
Tejun Heoa82afdf2009-07-03 17:48:16 +0900157 * bit 9 -- discard sectors
Jens Axboeaf563942008-10-09 09:01:10 +0200158 * Informs the lower level device that this range of sectors is no longer
159 * used by the file system and may thus be freed by the device. Used
160 * for flash based storage.
Mike Christie6000a362008-08-19 18:45:30 -0500161 * Don't want driver retries for any fast fail whatever the reason.
Jens Axboeaeb6faf2009-04-06 14:48:07 +0200162 * bit 10 -- Tell the IO scheduler not to wait for more requests after this
163 one has been submitted, even if it is a SYNC request.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700164 */
Tejun Heoa82afdf2009-07-03 17:48:16 +0900165enum bio_rw_flags {
166 BIO_RW,
167 BIO_RW_FAILFAST_DEV,
168 BIO_RW_FAILFAST_TRANSPORT,
169 BIO_RW_FAILFAST_DRIVER,
170 /* above flags must match REQ_* */
171 BIO_RW_AHEAD,
172 BIO_RW_BARRIER,
173 BIO_RW_SYNCIO,
174 BIO_RW_UNPLUG,
175 BIO_RW_META,
176 BIO_RW_DISCARD,
177 BIO_RW_NOIDLE,
178};
Jens Axboe213d9412009-01-06 09:16:05 +0100179
Jens Axboe1dfa17f2009-01-06 09:21:49 +0100180#define bio_rw_flagged(bio, flag) ((bio)->bi_rw & (1 << (flag)))
181
182/*
183 * Old defines, these should eventually be replaced by direct usage of
184 * bio_rw_flagged()
185 */
186#define bio_barrier(bio) bio_rw_flagged(bio, BIO_RW_BARRIER)
187#define bio_sync(bio) bio_rw_flagged(bio, BIO_RW_SYNCIO)
188#define bio_unplug(bio) bio_rw_flagged(bio, BIO_RW_UNPLUG)
189#define bio_failfast_dev(bio) bio_rw_flagged(bio, BIO_RW_FAILFAST_DEV)
190#define bio_failfast_transport(bio) \
191 bio_rw_flagged(bio, BIO_RW_FAILFAST_TRANSPORT)
192#define bio_failfast_driver(bio) \
193 bio_rw_flagged(bio, BIO_RW_FAILFAST_DRIVER)
194#define bio_rw_ahead(bio) bio_rw_flagged(bio, BIO_RW_AHEAD)
195#define bio_rw_meta(bio) bio_rw_flagged(bio, BIO_RW_META)
196#define bio_discard(bio) bio_rw_flagged(bio, BIO_RW_DISCARD)
Jens Axboeaeb6faf2009-04-06 14:48:07 +0200197#define bio_noidle(bio) bio_rw_flagged(bio, BIO_RW_NOIDLE)
Jens Axboe1dfa17f2009-01-06 09:21:49 +0100198
Linus Torvalds1da177e2005-04-16 15:20:36 -0700199/*
Jens Axboe22e2c502005-06-27 10:55:12 +0200200 * upper 16 bits of bi_rw define the io priority of this bio
201 */
202#define BIO_PRIO_SHIFT (8 * sizeof(unsigned long) - IOPRIO_BITS)
203#define bio_prio(bio) ((bio)->bi_rw >> BIO_PRIO_SHIFT)
204#define bio_prio_valid(bio) ioprio_valid(bio_prio(bio))
205
206#define bio_set_prio(bio, prio) do { \
207 WARN_ON(prio >= (1 << IOPRIO_BITS)); \
208 (bio)->bi_rw &= ((1UL << BIO_PRIO_SHIFT) - 1); \
209 (bio)->bi_rw |= ((unsigned long) (prio) << BIO_PRIO_SHIFT); \
210} while (0)
211
212/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700213 * various member access, note that bio_data should of course not be used
214 * on highmem page vectors
215 */
216#define bio_iovec_idx(bio, idx) (&((bio)->bi_io_vec[(idx)]))
217#define bio_iovec(bio) bio_iovec_idx((bio), (bio)->bi_idx)
218#define bio_page(bio) bio_iovec((bio))->bv_page
219#define bio_offset(bio) bio_iovec((bio))->bv_offset
220#define bio_segments(bio) ((bio)->bi_vcnt - (bio)->bi_idx)
221#define bio_sectors(bio) ((bio)->bi_size >> 9)
David Woodhousee17fc0a2008-08-09 16:42:20 +0100222#define bio_empty_barrier(bio) (bio_barrier(bio) && !bio_has_data(bio) && !bio_discard(bio))
Jens Axboebf2de6f2007-09-27 13:01:25 +0200223
Tejun Heo2e46e8b2009-05-07 22:24:41 +0900224static inline unsigned int bio_cur_bytes(struct bio *bio)
Jens Axboebf2de6f2007-09-27 13:01:25 +0200225{
226 if (bio->bi_vcnt)
Tejun Heo2e46e8b2009-05-07 22:24:41 +0900227 return bio_iovec(bio)->bv_len;
David Woodhousefb2dce82008-08-05 18:01:53 +0100228 else /* dataless requests such as discard */
Tejun Heo2e46e8b2009-05-07 22:24:41 +0900229 return bio->bi_size;
Jens Axboebf2de6f2007-09-27 13:01:25 +0200230}
231
232static inline void *bio_data(struct bio *bio)
233{
234 if (bio->bi_vcnt)
235 return page_address(bio_page(bio)) + bio_offset(bio);
236
237 return NULL;
238}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700239
Jens Axboe392ddc32008-12-23 12:42:54 +0100240static inline int bio_has_allocated_vec(struct bio *bio)
241{
242 return bio->bi_io_vec && bio->bi_io_vec != bio->bi_inline_vecs;
243}
244
Linus Torvalds1da177e2005-04-16 15:20:36 -0700245/*
246 * will die
247 */
248#define bio_to_phys(bio) (page_to_phys(bio_page((bio))) + (unsigned long) bio_offset((bio)))
249#define bvec_to_phys(bv) (page_to_phys((bv)->bv_page) + (unsigned long) (bv)->bv_offset)
250
251/*
252 * queues that have highmem support enabled may still need to revert to
253 * PIO transfers occasionally and thus map high pages temporarily. For
254 * permanent PIO fall back, user is probably better off disabling highmem
255 * I/O completely on that queue (see ide-dma for example)
256 */
257#define __bio_kmap_atomic(bio, idx, kmtype) \
258 (kmap_atomic(bio_iovec_idx((bio), (idx))->bv_page, kmtype) + \
259 bio_iovec_idx((bio), (idx))->bv_offset)
260
261#define __bio_kunmap_atomic(addr, kmtype) kunmap_atomic(addr, kmtype)
262
263/*
264 * merge helpers etc
265 */
266
267#define __BVEC_END(bio) bio_iovec_idx((bio), (bio)->bi_vcnt - 1)
268#define __BVEC_START(bio) bio_iovec_idx((bio), (bio)->bi_idx)
269
Jeremy Fitzhardingef92131c2008-10-29 14:10:51 +0100270/* Default implementation of BIOVEC_PHYS_MERGEABLE */
271#define __BIOVEC_PHYS_MERGEABLE(vec1, vec2) \
272 ((bvec_to_phys((vec1)) + (vec1)->bv_len) == bvec_to_phys((vec2)))
273
Linus Torvalds1da177e2005-04-16 15:20:36 -0700274/*
275 * allow arch override, for eg virtualized architectures (put in asm/io.h)
276 */
277#ifndef BIOVEC_PHYS_MERGEABLE
278#define BIOVEC_PHYS_MERGEABLE(vec1, vec2) \
Jeremy Fitzhardingef92131c2008-10-29 14:10:51 +0100279 __BIOVEC_PHYS_MERGEABLE(vec1, vec2)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700280#endif
281
Linus Torvalds1da177e2005-04-16 15:20:36 -0700282#define __BIO_SEG_BOUNDARY(addr1, addr2, mask) \
283 (((addr1) | (mask)) == (((addr2) - 1) | (mask)))
284#define BIOVEC_SEG_BOUNDARY(q, b1, b2) \
Martin K. Petersenae03bf62009-05-22 17:17:50 -0400285 __BIO_SEG_BOUNDARY(bvec_to_phys((b1)), bvec_to_phys((b2)) + (b2)->bv_len, queue_segment_boundary((q)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700286#define BIO_SEG_BOUNDARY(q, b1, b2) \
287 BIOVEC_SEG_BOUNDARY((q), __BVEC_END((b1)), __BVEC_START((b2)))
288
NeilBrown6712ecf2007-09-27 12:47:43 +0200289#define bio_io_error(bio) bio_endio((bio), -EIO)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700290
291/*
292 * drivers should not use the __ version unless they _really_ want to
293 * run through the entire bio and not just pending pieces
294 */
295#define __bio_for_each_segment(bvl, bio, i, start_idx) \
296 for (bvl = bio_iovec_idx((bio), (start_idx)), i = (start_idx); \
297 i < (bio)->bi_vcnt; \
298 bvl++, i++)
299
300#define bio_for_each_segment(bvl, bio, i) \
301 __bio_for_each_segment(bvl, bio, i, (bio)->bi_idx)
302
303/*
304 * get a reference to a bio, so it won't disappear. the intended use is
305 * something like:
306 *
307 * bio_get(bio);
308 * submit_bio(rw, bio);
309 * if (bio->bi_flags ...)
310 * do_something
311 * bio_put(bio);
312 *
313 * without the bio_get(), it could potentially complete I/O before submit_bio
314 * returns. and then bio would be freed memory when if (bio->bi_flags ...)
315 * runs
316 */
317#define bio_get(bio) atomic_inc(&(bio)->bi_cnt)
318
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200319#if defined(CONFIG_BLK_DEV_INTEGRITY)
320/*
321 * bio integrity payload
322 */
323struct bio_integrity_payload {
324 struct bio *bip_bio; /* parent bio */
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200325
326 sector_t bip_sector; /* virtual start sector */
327
328 void *bip_buf; /* generated integrity data */
329 bio_end_io_t *bip_end_io; /* saved I/O completion fn */
330
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200331 unsigned int bip_size;
332
Martin K. Petersen7878cba2009-06-26 15:37:49 +0200333 unsigned short bip_slab; /* slab the bip came from */
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200334 unsigned short bip_vcnt; /* # of integrity bio_vecs */
335 unsigned short bip_idx; /* current bip_vec index */
336
337 struct work_struct bip_work; /* I/O completion */
Martin K. Petersen7878cba2009-06-26 15:37:49 +0200338 struct bio_vec bip_vec[0]; /* embedded bvec array */
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200339};
340#endif /* CONFIG_BLK_DEV_INTEGRITY */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700341
342/*
343 * A bio_pair is used when we need to split a bio.
344 * This can only happen for a bio that refers to just one
345 * page of data, and in the unusual situation when the
346 * page crosses a chunk/device boundary
347 *
348 * The address of the master bio is stored in bio1.bi_private
349 * The address of the pool the pair was allocated from is stored
350 * in bio2.bi_private
351 */
352struct bio_pair {
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200353 struct bio bio1, bio2;
354 struct bio_vec bv1, bv2;
355#if defined(CONFIG_BLK_DEV_INTEGRITY)
356 struct bio_integrity_payload bip1, bip2;
357 struct bio_vec iv1, iv2;
358#endif
359 atomic_t cnt;
360 int error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700361};
Denis ChengRq6feef532008-10-09 08:57:05 +0200362extern struct bio_pair *bio_split(struct bio *bi, int first_sectors);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700363extern void bio_pair_release(struct bio_pair *dbio);
364
Jens Axboebb799ca2008-12-10 15:35:05 +0100365extern struct bio_set *bioset_create(unsigned int, unsigned int);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700366extern void bioset_free(struct bio_set *);
367
Al Virodd0fc662005-10-07 07:46:04 +0100368extern struct bio *bio_alloc(gfp_t, int);
Jens Axboe0a0d96b2008-09-11 13:17:37 +0200369extern struct bio *bio_kmalloc(gfp_t, int);
Al Virodd0fc662005-10-07 07:46:04 +0100370extern struct bio *bio_alloc_bioset(gfp_t, int, struct bio_set *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700371extern void bio_put(struct bio *);
Peter Osterlund36763472005-09-06 15:16:42 -0700372extern void bio_free(struct bio *, struct bio_set *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700373
NeilBrown6712ecf2007-09-27 12:47:43 +0200374extern void bio_endio(struct bio *, int);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700375struct request_queue;
376extern int bio_phys_segments(struct request_queue *, struct bio *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700377
378extern void __bio_clone(struct bio *, struct bio *);
Al Virodd0fc662005-10-07 07:46:04 +0100379extern struct bio *bio_clone(struct bio *, gfp_t);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700380
381extern void bio_init(struct bio *);
382
383extern int bio_add_page(struct bio *, struct page *, unsigned int,unsigned int);
Mike Christie6e68af62005-11-11 05:30:27 -0600384extern int bio_add_pc_page(struct request_queue *, struct bio *, struct page *,
385 unsigned int, unsigned int);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700386extern int bio_get_nr_vecs(struct block_device *);
Martin K. Petersenad3316b2008-10-01 22:42:53 -0400387extern sector_t bio_sector_offset(struct bio *, unsigned short, unsigned int);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700388extern struct bio *bio_map_user(struct request_queue *, struct block_device *,
FUJITA Tomonoria3bce902008-08-28 16:17:05 +0900389 unsigned long, unsigned int, int, gfp_t);
James Bottomley f1970ba2005-06-20 14:06:52 +0200390struct sg_iovec;
FUJITA Tomonori152e2832008-08-28 16:17:06 +0900391struct rq_map_data;
James Bottomley f1970ba2005-06-20 14:06:52 +0200392extern struct bio *bio_map_user_iov(struct request_queue *,
393 struct block_device *,
FUJITA Tomonoria3bce902008-08-28 16:17:05 +0900394 struct sg_iovec *, int, int, gfp_t);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700395extern void bio_unmap_user(struct bio *);
Mike Christie df46b9a2005-06-20 14:04:44 +0200396extern struct bio *bio_map_kern(struct request_queue *, void *, unsigned int,
Al Viro27496a82005-10-21 03:20:48 -0400397 gfp_t);
FUJITA Tomonori68154e92008-04-25 12:47:50 +0200398extern struct bio *bio_copy_kern(struct request_queue *, void *, unsigned int,
399 gfp_t, int);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700400extern void bio_set_pages_dirty(struct bio *bio);
401extern void bio_check_pages_dirty(struct bio *bio);
FUJITA Tomonori152e2832008-08-28 16:17:06 +0900402extern struct bio *bio_copy_user(struct request_queue *, struct rq_map_data *,
403 unsigned long, unsigned int, int, gfp_t);
404extern struct bio *bio_copy_user_iov(struct request_queue *,
405 struct rq_map_data *, struct sg_iovec *,
FUJITA Tomonoria3bce902008-08-28 16:17:05 +0900406 int, int, gfp_t);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700407extern int bio_uncopy_user(struct bio *);
408void zero_fill_bio(struct bio *bio);
Martin K. Petersen51d654e2008-06-17 18:59:56 +0200409extern struct bio_vec *bvec_alloc_bs(gfp_t, int, unsigned long *, struct bio_set *);
Jens Axboebb799ca2008-12-10 15:35:05 +0100410extern void bvec_free_bs(struct bio_set *, struct bio_vec *, unsigned int);
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200411extern unsigned int bvec_nr_vecs(unsigned short idx);
Martin K. Petersen51d654e2008-06-17 18:59:56 +0200412
413/*
Jens Axboec7c22e42008-09-13 20:26:01 +0200414 * Allow queuer to specify a completion CPU for this bio
415 */
416static inline void bio_set_completion_cpu(struct bio *bio, unsigned int cpu)
417{
418 bio->bi_comp_cpu = cpu;
419}
420
421/*
Martin K. Petersen51d654e2008-06-17 18:59:56 +0200422 * bio_set is used to allow other portions of the IO system to
423 * allocate their own private memory pools for bio and iovec structures.
424 * These memory pools in turn all allocate from the bio_slab
425 * and the bvec_slabs[].
426 */
427#define BIO_POOL_SIZE 2
428#define BIOVEC_NR_POOLS 6
Jens Axboe7ff93452008-12-11 11:53:43 +0100429#define BIOVEC_MAX_IDX (BIOVEC_NR_POOLS - 1)
Martin K. Petersen51d654e2008-06-17 18:59:56 +0200430
431struct bio_set {
Jens Axboe1b434492008-10-22 20:32:58 +0200432 struct kmem_cache *bio_slab;
Jens Axboebb799ca2008-12-10 15:35:05 +0100433 unsigned int front_pad;
434
Martin K. Petersen51d654e2008-06-17 18:59:56 +0200435 mempool_t *bio_pool;
Martin K. Petersen7878cba2009-06-26 15:37:49 +0200436#if defined(CONFIG_BLK_DEV_INTEGRITY)
437 mempool_t *bio_integrity_pool;
438#endif
Jens Axboe7ff93452008-12-11 11:53:43 +0100439 mempool_t *bvec_pool;
Martin K. Petersen51d654e2008-06-17 18:59:56 +0200440};
441
442struct biovec_slab {
443 int nr_vecs;
444 char *name;
445 struct kmem_cache *slab;
446};
447
448extern struct bio_set *fs_bio_set;
Jens Axboebb799ca2008-12-10 15:35:05 +0100449extern struct biovec_slab bvec_slabs[BIOVEC_NR_POOLS] __read_mostly;
Martin K. Petersen51d654e2008-06-17 18:59:56 +0200450
451/*
452 * a small number of entries is fine, not going to be performance critical.
453 * basically we just need to survive
454 */
455#define BIO_SPLIT_ENTRIES 2
Linus Torvalds1da177e2005-04-16 15:20:36 -0700456
457#ifdef CONFIG_HIGHMEM
458/*
Alberto Bertogli20b636b2009-02-02 12:41:07 +0100459 * remember never ever reenable interrupts between a bvec_kmap_irq and
460 * bvec_kunmap_irq!
Linus Torvalds1da177e2005-04-16 15:20:36 -0700461 *
462 * This function MUST be inlined - it plays with the CPU interrupt flags.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700463 */
Alberto Bertoglic52440a2009-02-02 12:41:07 +0100464static __always_inline char *bvec_kmap_irq(struct bio_vec *bvec,
465 unsigned long *flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700466{
467 unsigned long addr;
468
469 /*
470 * might not be a highmem page, but the preempt/irq count
471 * balancing is a lot nicer this way
472 */
473 local_irq_save(*flags);
474 addr = (unsigned long) kmap_atomic(bvec->bv_page, KM_BIO_SRC_IRQ);
475
476 BUG_ON(addr & ~PAGE_MASK);
477
478 return (char *) addr + bvec->bv_offset;
479}
480
Alberto Bertoglic52440a2009-02-02 12:41:07 +0100481static __always_inline void bvec_kunmap_irq(char *buffer,
482 unsigned long *flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700483{
484 unsigned long ptr = (unsigned long) buffer & PAGE_MASK;
485
486 kunmap_atomic((void *) ptr, KM_BIO_SRC_IRQ);
487 local_irq_restore(*flags);
488}
489
490#else
491#define bvec_kmap_irq(bvec, flags) (page_address((bvec)->bv_page) + (bvec)->bv_offset)
492#define bvec_kunmap_irq(buf, flags) do { *(flags) = 0; } while (0)
493#endif
494
Adrian Bunkc2d08da2005-09-10 00:27:18 -0700495static inline char *__bio_kmap_irq(struct bio *bio, unsigned short idx,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700496 unsigned long *flags)
497{
498 return bvec_kmap_irq(bio_iovec_idx(bio, idx), flags);
499}
500#define __bio_kunmap_irq(buf, flags) bvec_kunmap_irq(buf, flags)
501
502#define bio_kmap_irq(bio, flags) \
503 __bio_kmap_irq((bio), (bio)->bi_idx, (flags))
504#define bio_kunmap_irq(buf,flags) __bio_kunmap_irq(buf, flags)
505
Jens Axboe7a67f632008-08-08 11:17:12 +0200506/*
507 * Check whether this bio carries any data or not. A NULL bio is allowed.
508 */
509static inline int bio_has_data(struct bio *bio)
510{
511 return bio && bio->bi_io_vec != NULL;
512}
513
Christoph Hellwig8f3d8ba2009-04-07 19:55:13 +0200514/*
Akinobu Mitae6863072009-04-17 08:41:21 +0200515 * BIO list management for use by remapping drivers (e.g. DM or MD) and loop.
Christoph Hellwig8f3d8ba2009-04-07 19:55:13 +0200516 *
517 * A bio_list anchors a singly-linked list of bios chained through the bi_next
518 * member of the bio. The bio_list also caches the last list member to allow
519 * fast access to the tail.
520 */
521struct bio_list {
522 struct bio *head;
523 struct bio *tail;
524};
525
526static inline int bio_list_empty(const struct bio_list *bl)
527{
528 return bl->head == NULL;
529}
530
531static inline void bio_list_init(struct bio_list *bl)
532{
533 bl->head = bl->tail = NULL;
534}
535
536#define bio_list_for_each(bio, bl) \
537 for (bio = (bl)->head; bio; bio = bio->bi_next)
538
539static inline unsigned bio_list_size(const struct bio_list *bl)
540{
541 unsigned sz = 0;
542 struct bio *bio;
543
544 bio_list_for_each(bio, bl)
545 sz++;
546
547 return sz;
548}
549
550static inline void bio_list_add(struct bio_list *bl, struct bio *bio)
551{
552 bio->bi_next = NULL;
553
554 if (bl->tail)
555 bl->tail->bi_next = bio;
556 else
557 bl->head = bio;
558
559 bl->tail = bio;
560}
561
562static inline void bio_list_add_head(struct bio_list *bl, struct bio *bio)
563{
564 bio->bi_next = bl->head;
565
566 bl->head = bio;
567
568 if (!bl->tail)
569 bl->tail = bio;
570}
571
572static inline void bio_list_merge(struct bio_list *bl, struct bio_list *bl2)
573{
574 if (!bl2->head)
575 return;
576
577 if (bl->tail)
578 bl->tail->bi_next = bl2->head;
579 else
580 bl->head = bl2->head;
581
582 bl->tail = bl2->tail;
583}
584
585static inline void bio_list_merge_head(struct bio_list *bl,
586 struct bio_list *bl2)
587{
588 if (!bl2->head)
589 return;
590
591 if (bl->head)
592 bl2->tail->bi_next = bl->head;
593 else
594 bl->tail = bl2->tail;
595
596 bl->head = bl2->head;
597}
598
Geert Uytterhoeven13685a12009-06-10 04:38:40 +0000599static inline struct bio *bio_list_peek(struct bio_list *bl)
600{
601 return bl->head;
602}
603
Christoph Hellwig8f3d8ba2009-04-07 19:55:13 +0200604static inline struct bio *bio_list_pop(struct bio_list *bl)
605{
606 struct bio *bio = bl->head;
607
608 if (bio) {
609 bl->head = bl->head->bi_next;
610 if (!bl->head)
611 bl->tail = NULL;
612
613 bio->bi_next = NULL;
614 }
615
616 return bio;
617}
618
619static inline struct bio *bio_list_get(struct bio_list *bl)
620{
621 struct bio *bio = bl->head;
622
623 bl->head = bl->tail = NULL;
624
625 return bio;
626}
627
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200628#if defined(CONFIG_BLK_DEV_INTEGRITY)
629
630#define bip_vec_idx(bip, idx) (&(bip->bip_vec[(idx)]))
631#define bip_vec(bip) bip_vec_idx(bip, 0)
632
633#define __bip_for_each_vec(bvl, bip, i, start_idx) \
634 for (bvl = bip_vec_idx((bip), (start_idx)), i = (start_idx); \
635 i < (bip)->bip_vcnt; \
636 bvl++, i++)
637
638#define bip_for_each_vec(bvl, bip, i) \
639 __bip_for_each_vec(bvl, bip, i, (bip)->bip_idx)
640
Alberto Bertogli8deaf722008-10-02 12:46:53 +0200641#define bio_integrity(bio) (bio->bi_integrity != NULL)
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200642
Martin K. Petersen7878cba2009-06-26 15:37:49 +0200643extern struct bio_integrity_payload *bio_integrity_alloc_bioset(struct bio *, gfp_t, unsigned int, struct bio_set *);
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200644extern struct bio_integrity_payload *bio_integrity_alloc(struct bio *, gfp_t, unsigned int);
Martin K. Petersen7878cba2009-06-26 15:37:49 +0200645extern void bio_integrity_free(struct bio *, struct bio_set *);
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200646extern int bio_integrity_add_page(struct bio *, struct page *, unsigned int, unsigned int);
647extern int bio_integrity_enabled(struct bio *bio);
648extern int bio_integrity_set_tag(struct bio *, void *, unsigned int);
649extern int bio_integrity_get_tag(struct bio *, void *, unsigned int);
650extern int bio_integrity_prep(struct bio *);
651extern void bio_integrity_endio(struct bio *, int);
652extern void bio_integrity_advance(struct bio *, unsigned int);
653extern void bio_integrity_trim(struct bio *, unsigned int, unsigned int);
654extern void bio_integrity_split(struct bio *, struct bio_pair *, int);
Martin K. Petersen7878cba2009-06-26 15:37:49 +0200655extern int bio_integrity_clone(struct bio *, struct bio *, gfp_t, struct bio_set *);
656extern int bioset_integrity_create(struct bio_set *, int);
657extern void bioset_integrity_free(struct bio_set *);
658extern void bio_integrity_init(void);
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200659
660#else /* CONFIG_BLK_DEV_INTEGRITY */
661
662#define bio_integrity(a) (0)
Martin K. Petersen7878cba2009-06-26 15:37:49 +0200663#define bioset_integrity_create(a, b) (0)
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200664#define bio_integrity_prep(a) (0)
665#define bio_integrity_enabled(a) (0)
Martin K. Petersen7878cba2009-06-26 15:37:49 +0200666#define bio_integrity_clone(a, b, c, d) (0)
667#define bioset_integrity_free(a) do { } while (0)
668#define bio_integrity_free(a, b) do { } while (0)
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200669#define bio_integrity_endio(a, b) do { } while (0)
670#define bio_integrity_advance(a, b) do { } while (0)
671#define bio_integrity_trim(a, b, c) do { } while (0)
672#define bio_integrity_split(a, b, c) do { } while (0)
673#define bio_integrity_set_tag(a, b, c) do { } while (0)
674#define bio_integrity_get_tag(a, b, c) do { } while (0)
Martin K. Petersen7878cba2009-06-26 15:37:49 +0200675#define bio_integrity_init(a) do { } while (0)
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200676
677#endif /* CONFIG_BLK_DEV_INTEGRITY */
678
David Howells02a5e0a2007-08-11 22:34:32 +0200679#endif /* CONFIG_BLOCK */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700680#endif /* __LINUX_BIO_H */