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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 Axboee7e503a2009-07-28 10:15:30 +0200180static inline bool bio_rw_flagged(struct bio *bio, enum bio_rw_flags flag)
181{
182 return (bio->bi_rw & (1 << flag)) != 0;
183}
Jens Axboe1dfa17f2009-01-06 09:21:49 +0100184
185/*
186 * Old defines, these should eventually be replaced by direct usage of
187 * bio_rw_flagged()
188 */
189#define bio_barrier(bio) bio_rw_flagged(bio, BIO_RW_BARRIER)
190#define bio_sync(bio) bio_rw_flagged(bio, BIO_RW_SYNCIO)
191#define bio_unplug(bio) bio_rw_flagged(bio, BIO_RW_UNPLUG)
192#define bio_failfast_dev(bio) bio_rw_flagged(bio, BIO_RW_FAILFAST_DEV)
193#define bio_failfast_transport(bio) \
194 bio_rw_flagged(bio, BIO_RW_FAILFAST_TRANSPORT)
195#define bio_failfast_driver(bio) \
196 bio_rw_flagged(bio, BIO_RW_FAILFAST_DRIVER)
197#define bio_rw_ahead(bio) bio_rw_flagged(bio, BIO_RW_AHEAD)
198#define bio_rw_meta(bio) bio_rw_flagged(bio, BIO_RW_META)
199#define bio_discard(bio) bio_rw_flagged(bio, BIO_RW_DISCARD)
Jens Axboeaeb6faf2009-04-06 14:48:07 +0200200#define bio_noidle(bio) bio_rw_flagged(bio, BIO_RW_NOIDLE)
Jens Axboe1dfa17f2009-01-06 09:21:49 +0100201
Linus Torvalds1da177e2005-04-16 15:20:36 -0700202/*
Jens Axboe22e2c502005-06-27 10:55:12 +0200203 * upper 16 bits of bi_rw define the io priority of this bio
204 */
205#define BIO_PRIO_SHIFT (8 * sizeof(unsigned long) - IOPRIO_BITS)
206#define bio_prio(bio) ((bio)->bi_rw >> BIO_PRIO_SHIFT)
207#define bio_prio_valid(bio) ioprio_valid(bio_prio(bio))
208
209#define bio_set_prio(bio, prio) do { \
210 WARN_ON(prio >= (1 << IOPRIO_BITS)); \
211 (bio)->bi_rw &= ((1UL << BIO_PRIO_SHIFT) - 1); \
212 (bio)->bi_rw |= ((unsigned long) (prio) << BIO_PRIO_SHIFT); \
213} while (0)
214
215/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700216 * various member access, note that bio_data should of course not be used
217 * on highmem page vectors
218 */
219#define bio_iovec_idx(bio, idx) (&((bio)->bi_io_vec[(idx)]))
220#define bio_iovec(bio) bio_iovec_idx((bio), (bio)->bi_idx)
221#define bio_page(bio) bio_iovec((bio))->bv_page
222#define bio_offset(bio) bio_iovec((bio))->bv_offset
223#define bio_segments(bio) ((bio)->bi_vcnt - (bio)->bi_idx)
224#define bio_sectors(bio) ((bio)->bi_size >> 9)
David Woodhousee17fc0a2008-08-09 16:42:20 +0100225#define bio_empty_barrier(bio) (bio_barrier(bio) && !bio_has_data(bio) && !bio_discard(bio))
Jens Axboebf2de6f2007-09-27 13:01:25 +0200226
Tejun Heo2e46e8b2009-05-07 22:24:41 +0900227static inline unsigned int bio_cur_bytes(struct bio *bio)
Jens Axboebf2de6f2007-09-27 13:01:25 +0200228{
229 if (bio->bi_vcnt)
Tejun Heo2e46e8b2009-05-07 22:24:41 +0900230 return bio_iovec(bio)->bv_len;
David Woodhousefb2dce82008-08-05 18:01:53 +0100231 else /* dataless requests such as discard */
Tejun Heo2e46e8b2009-05-07 22:24:41 +0900232 return bio->bi_size;
Jens Axboebf2de6f2007-09-27 13:01:25 +0200233}
234
235static inline void *bio_data(struct bio *bio)
236{
237 if (bio->bi_vcnt)
238 return page_address(bio_page(bio)) + bio_offset(bio);
239
240 return NULL;
241}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700242
Jens Axboe392ddc32008-12-23 12:42:54 +0100243static inline int bio_has_allocated_vec(struct bio *bio)
244{
245 return bio->bi_io_vec && bio->bi_io_vec != bio->bi_inline_vecs;
246}
247
Linus Torvalds1da177e2005-04-16 15:20:36 -0700248/*
249 * will die
250 */
251#define bio_to_phys(bio) (page_to_phys(bio_page((bio))) + (unsigned long) bio_offset((bio)))
252#define bvec_to_phys(bv) (page_to_phys((bv)->bv_page) + (unsigned long) (bv)->bv_offset)
253
254/*
255 * queues that have highmem support enabled may still need to revert to
256 * PIO transfers occasionally and thus map high pages temporarily. For
257 * permanent PIO fall back, user is probably better off disabling highmem
258 * I/O completely on that queue (see ide-dma for example)
259 */
260#define __bio_kmap_atomic(bio, idx, kmtype) \
261 (kmap_atomic(bio_iovec_idx((bio), (idx))->bv_page, kmtype) + \
262 bio_iovec_idx((bio), (idx))->bv_offset)
263
264#define __bio_kunmap_atomic(addr, kmtype) kunmap_atomic(addr, kmtype)
265
266/*
267 * merge helpers etc
268 */
269
270#define __BVEC_END(bio) bio_iovec_idx((bio), (bio)->bi_vcnt - 1)
271#define __BVEC_START(bio) bio_iovec_idx((bio), (bio)->bi_idx)
272
Jeremy Fitzhardingef92131c2008-10-29 14:10:51 +0100273/* Default implementation of BIOVEC_PHYS_MERGEABLE */
274#define __BIOVEC_PHYS_MERGEABLE(vec1, vec2) \
275 ((bvec_to_phys((vec1)) + (vec1)->bv_len) == bvec_to_phys((vec2)))
276
Linus Torvalds1da177e2005-04-16 15:20:36 -0700277/*
278 * allow arch override, for eg virtualized architectures (put in asm/io.h)
279 */
280#ifndef BIOVEC_PHYS_MERGEABLE
281#define BIOVEC_PHYS_MERGEABLE(vec1, vec2) \
Jeremy Fitzhardingef92131c2008-10-29 14:10:51 +0100282 __BIOVEC_PHYS_MERGEABLE(vec1, vec2)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700283#endif
284
Linus Torvalds1da177e2005-04-16 15:20:36 -0700285#define __BIO_SEG_BOUNDARY(addr1, addr2, mask) \
286 (((addr1) | (mask)) == (((addr2) - 1) | (mask)))
287#define BIOVEC_SEG_BOUNDARY(q, b1, b2) \
Martin K. Petersenae03bf62009-05-22 17:17:50 -0400288 __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 -0700289#define BIO_SEG_BOUNDARY(q, b1, b2) \
290 BIOVEC_SEG_BOUNDARY((q), __BVEC_END((b1)), __BVEC_START((b2)))
291
NeilBrown6712ecf2007-09-27 12:47:43 +0200292#define bio_io_error(bio) bio_endio((bio), -EIO)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700293
294/*
295 * drivers should not use the __ version unless they _really_ want to
296 * run through the entire bio and not just pending pieces
297 */
298#define __bio_for_each_segment(bvl, bio, i, start_idx) \
299 for (bvl = bio_iovec_idx((bio), (start_idx)), i = (start_idx); \
300 i < (bio)->bi_vcnt; \
301 bvl++, i++)
302
303#define bio_for_each_segment(bvl, bio, i) \
304 __bio_for_each_segment(bvl, bio, i, (bio)->bi_idx)
305
306/*
307 * get a reference to a bio, so it won't disappear. the intended use is
308 * something like:
309 *
310 * bio_get(bio);
311 * submit_bio(rw, bio);
312 * if (bio->bi_flags ...)
313 * do_something
314 * bio_put(bio);
315 *
316 * without the bio_get(), it could potentially complete I/O before submit_bio
317 * returns. and then bio would be freed memory when if (bio->bi_flags ...)
318 * runs
319 */
320#define bio_get(bio) atomic_inc(&(bio)->bi_cnt)
321
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200322#if defined(CONFIG_BLK_DEV_INTEGRITY)
323/*
324 * bio integrity payload
325 */
326struct bio_integrity_payload {
327 struct bio *bip_bio; /* parent bio */
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200328
329 sector_t bip_sector; /* virtual start sector */
330
331 void *bip_buf; /* generated integrity data */
332 bio_end_io_t *bip_end_io; /* saved I/O completion fn */
333
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200334 unsigned int bip_size;
335
Martin K. Petersen7878cba2009-06-26 15:37:49 +0200336 unsigned short bip_slab; /* slab the bip came from */
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200337 unsigned short bip_vcnt; /* # of integrity bio_vecs */
338 unsigned short bip_idx; /* current bip_vec index */
339
340 struct work_struct bip_work; /* I/O completion */
Martin K. Petersen7878cba2009-06-26 15:37:49 +0200341 struct bio_vec bip_vec[0]; /* embedded bvec array */
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200342};
343#endif /* CONFIG_BLK_DEV_INTEGRITY */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700344
345/*
346 * A bio_pair is used when we need to split a bio.
347 * This can only happen for a bio that refers to just one
348 * page of data, and in the unusual situation when the
349 * page crosses a chunk/device boundary
350 *
351 * The address of the master bio is stored in bio1.bi_private
352 * The address of the pool the pair was allocated from is stored
353 * in bio2.bi_private
354 */
355struct bio_pair {
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200356 struct bio bio1, bio2;
357 struct bio_vec bv1, bv2;
358#if defined(CONFIG_BLK_DEV_INTEGRITY)
359 struct bio_integrity_payload bip1, bip2;
360 struct bio_vec iv1, iv2;
361#endif
362 atomic_t cnt;
363 int error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700364};
Denis ChengRq6feef532008-10-09 08:57:05 +0200365extern struct bio_pair *bio_split(struct bio *bi, int first_sectors);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700366extern void bio_pair_release(struct bio_pair *dbio);
367
Jens Axboebb799ca2008-12-10 15:35:05 +0100368extern struct bio_set *bioset_create(unsigned int, unsigned int);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700369extern void bioset_free(struct bio_set *);
370
Al Virodd0fc662005-10-07 07:46:04 +0100371extern struct bio *bio_alloc(gfp_t, int);
Jens Axboe0a0d96b2008-09-11 13:17:37 +0200372extern struct bio *bio_kmalloc(gfp_t, int);
Al Virodd0fc662005-10-07 07:46:04 +0100373extern struct bio *bio_alloc_bioset(gfp_t, int, struct bio_set *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700374extern void bio_put(struct bio *);
Peter Osterlund36763472005-09-06 15:16:42 -0700375extern void bio_free(struct bio *, struct bio_set *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700376
NeilBrown6712ecf2007-09-27 12:47:43 +0200377extern void bio_endio(struct bio *, int);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700378struct request_queue;
379extern int bio_phys_segments(struct request_queue *, struct bio *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700380
381extern void __bio_clone(struct bio *, struct bio *);
Al Virodd0fc662005-10-07 07:46:04 +0100382extern struct bio *bio_clone(struct bio *, gfp_t);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700383
384extern void bio_init(struct bio *);
385
386extern int bio_add_page(struct bio *, struct page *, unsigned int,unsigned int);
Mike Christie6e68af62005-11-11 05:30:27 -0600387extern int bio_add_pc_page(struct request_queue *, struct bio *, struct page *,
388 unsigned int, unsigned int);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700389extern int bio_get_nr_vecs(struct block_device *);
Martin K. Petersenad3316b2008-10-01 22:42:53 -0400390extern sector_t bio_sector_offset(struct bio *, unsigned short, unsigned int);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700391extern struct bio *bio_map_user(struct request_queue *, struct block_device *,
FUJITA Tomonoria3bce902008-08-28 16:17:05 +0900392 unsigned long, unsigned int, int, gfp_t);
James Bottomley f1970ba2005-06-20 14:06:52 +0200393struct sg_iovec;
FUJITA Tomonori152e2832008-08-28 16:17:06 +0900394struct rq_map_data;
James Bottomley f1970ba2005-06-20 14:06:52 +0200395extern struct bio *bio_map_user_iov(struct request_queue *,
396 struct block_device *,
FUJITA Tomonoria3bce902008-08-28 16:17:05 +0900397 struct sg_iovec *, int, int, gfp_t);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700398extern void bio_unmap_user(struct bio *);
Mike Christie df46b9a2005-06-20 14:04:44 +0200399extern struct bio *bio_map_kern(struct request_queue *, void *, unsigned int,
Al Viro27496a82005-10-21 03:20:48 -0400400 gfp_t);
FUJITA Tomonori68154e92008-04-25 12:47:50 +0200401extern struct bio *bio_copy_kern(struct request_queue *, void *, unsigned int,
402 gfp_t, int);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700403extern void bio_set_pages_dirty(struct bio *bio);
404extern void bio_check_pages_dirty(struct bio *bio);
FUJITA Tomonori152e2832008-08-28 16:17:06 +0900405extern struct bio *bio_copy_user(struct request_queue *, struct rq_map_data *,
406 unsigned long, unsigned int, int, gfp_t);
407extern struct bio *bio_copy_user_iov(struct request_queue *,
408 struct rq_map_data *, struct sg_iovec *,
FUJITA Tomonoria3bce902008-08-28 16:17:05 +0900409 int, int, gfp_t);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700410extern int bio_uncopy_user(struct bio *);
411void zero_fill_bio(struct bio *bio);
Martin K. Petersen51d654e2008-06-17 18:59:56 +0200412extern struct bio_vec *bvec_alloc_bs(gfp_t, int, unsigned long *, struct bio_set *);
Jens Axboebb799ca2008-12-10 15:35:05 +0100413extern void bvec_free_bs(struct bio_set *, struct bio_vec *, unsigned int);
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200414extern unsigned int bvec_nr_vecs(unsigned short idx);
Martin K. Petersen51d654e2008-06-17 18:59:56 +0200415
416/*
Jens Axboec7c22e42008-09-13 20:26:01 +0200417 * Allow queuer to specify a completion CPU for this bio
418 */
419static inline void bio_set_completion_cpu(struct bio *bio, unsigned int cpu)
420{
421 bio->bi_comp_cpu = cpu;
422}
423
424/*
Martin K. Petersen51d654e2008-06-17 18:59:56 +0200425 * bio_set is used to allow other portions of the IO system to
426 * allocate their own private memory pools for bio and iovec structures.
427 * These memory pools in turn all allocate from the bio_slab
428 * and the bvec_slabs[].
429 */
430#define BIO_POOL_SIZE 2
431#define BIOVEC_NR_POOLS 6
Jens Axboe7ff93452008-12-11 11:53:43 +0100432#define BIOVEC_MAX_IDX (BIOVEC_NR_POOLS - 1)
Martin K. Petersen51d654e2008-06-17 18:59:56 +0200433
434struct bio_set {
Jens Axboe1b434492008-10-22 20:32:58 +0200435 struct kmem_cache *bio_slab;
Jens Axboebb799ca2008-12-10 15:35:05 +0100436 unsigned int front_pad;
437
Martin K. Petersen51d654e2008-06-17 18:59:56 +0200438 mempool_t *bio_pool;
Martin K. Petersen7878cba2009-06-26 15:37:49 +0200439#if defined(CONFIG_BLK_DEV_INTEGRITY)
440 mempool_t *bio_integrity_pool;
441#endif
Jens Axboe7ff93452008-12-11 11:53:43 +0100442 mempool_t *bvec_pool;
Martin K. Petersen51d654e2008-06-17 18:59:56 +0200443};
444
445struct biovec_slab {
446 int nr_vecs;
447 char *name;
448 struct kmem_cache *slab;
449};
450
451extern struct bio_set *fs_bio_set;
Jens Axboebb799ca2008-12-10 15:35:05 +0100452extern struct biovec_slab bvec_slabs[BIOVEC_NR_POOLS] __read_mostly;
Martin K. Petersen51d654e2008-06-17 18:59:56 +0200453
454/*
455 * a small number of entries is fine, not going to be performance critical.
456 * basically we just need to survive
457 */
458#define BIO_SPLIT_ENTRIES 2
Linus Torvalds1da177e2005-04-16 15:20:36 -0700459
460#ifdef CONFIG_HIGHMEM
461/*
Alberto Bertogli20b636b2009-02-02 12:41:07 +0100462 * remember never ever reenable interrupts between a bvec_kmap_irq and
463 * bvec_kunmap_irq!
Linus Torvalds1da177e2005-04-16 15:20:36 -0700464 *
465 * This function MUST be inlined - it plays with the CPU interrupt flags.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700466 */
Alberto Bertoglic52440a2009-02-02 12:41:07 +0100467static __always_inline char *bvec_kmap_irq(struct bio_vec *bvec,
468 unsigned long *flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700469{
470 unsigned long addr;
471
472 /*
473 * might not be a highmem page, but the preempt/irq count
474 * balancing is a lot nicer this way
475 */
476 local_irq_save(*flags);
477 addr = (unsigned long) kmap_atomic(bvec->bv_page, KM_BIO_SRC_IRQ);
478
479 BUG_ON(addr & ~PAGE_MASK);
480
481 return (char *) addr + bvec->bv_offset;
482}
483
Alberto Bertoglic52440a2009-02-02 12:41:07 +0100484static __always_inline void bvec_kunmap_irq(char *buffer,
485 unsigned long *flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700486{
487 unsigned long ptr = (unsigned long) buffer & PAGE_MASK;
488
489 kunmap_atomic((void *) ptr, KM_BIO_SRC_IRQ);
490 local_irq_restore(*flags);
491}
492
493#else
494#define bvec_kmap_irq(bvec, flags) (page_address((bvec)->bv_page) + (bvec)->bv_offset)
495#define bvec_kunmap_irq(buf, flags) do { *(flags) = 0; } while (0)
496#endif
497
Adrian Bunkc2d08da2005-09-10 00:27:18 -0700498static inline char *__bio_kmap_irq(struct bio *bio, unsigned short idx,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700499 unsigned long *flags)
500{
501 return bvec_kmap_irq(bio_iovec_idx(bio, idx), flags);
502}
503#define __bio_kunmap_irq(buf, flags) bvec_kunmap_irq(buf, flags)
504
505#define bio_kmap_irq(bio, flags) \
506 __bio_kmap_irq((bio), (bio)->bi_idx, (flags))
507#define bio_kunmap_irq(buf,flags) __bio_kunmap_irq(buf, flags)
508
Jens Axboe7a67f632008-08-08 11:17:12 +0200509/*
510 * Check whether this bio carries any data or not. A NULL bio is allowed.
511 */
512static inline int bio_has_data(struct bio *bio)
513{
514 return bio && bio->bi_io_vec != NULL;
515}
516
Christoph Hellwig8f3d8ba2009-04-07 19:55:13 +0200517/*
Akinobu Mitae6863072009-04-17 08:41:21 +0200518 * BIO list management for use by remapping drivers (e.g. DM or MD) and loop.
Christoph Hellwig8f3d8ba2009-04-07 19:55:13 +0200519 *
520 * A bio_list anchors a singly-linked list of bios chained through the bi_next
521 * member of the bio. The bio_list also caches the last list member to allow
522 * fast access to the tail.
523 */
524struct bio_list {
525 struct bio *head;
526 struct bio *tail;
527};
528
529static inline int bio_list_empty(const struct bio_list *bl)
530{
531 return bl->head == NULL;
532}
533
534static inline void bio_list_init(struct bio_list *bl)
535{
536 bl->head = bl->tail = NULL;
537}
538
539#define bio_list_for_each(bio, bl) \
540 for (bio = (bl)->head; bio; bio = bio->bi_next)
541
542static inline unsigned bio_list_size(const struct bio_list *bl)
543{
544 unsigned sz = 0;
545 struct bio *bio;
546
547 bio_list_for_each(bio, bl)
548 sz++;
549
550 return sz;
551}
552
553static inline void bio_list_add(struct bio_list *bl, struct bio *bio)
554{
555 bio->bi_next = NULL;
556
557 if (bl->tail)
558 bl->tail->bi_next = bio;
559 else
560 bl->head = bio;
561
562 bl->tail = bio;
563}
564
565static inline void bio_list_add_head(struct bio_list *bl, struct bio *bio)
566{
567 bio->bi_next = bl->head;
568
569 bl->head = bio;
570
571 if (!bl->tail)
572 bl->tail = bio;
573}
574
575static inline void bio_list_merge(struct bio_list *bl, struct bio_list *bl2)
576{
577 if (!bl2->head)
578 return;
579
580 if (bl->tail)
581 bl->tail->bi_next = bl2->head;
582 else
583 bl->head = bl2->head;
584
585 bl->tail = bl2->tail;
586}
587
588static inline void bio_list_merge_head(struct bio_list *bl,
589 struct bio_list *bl2)
590{
591 if (!bl2->head)
592 return;
593
594 if (bl->head)
595 bl2->tail->bi_next = bl->head;
596 else
597 bl->tail = bl2->tail;
598
599 bl->head = bl2->head;
600}
601
Geert Uytterhoeven13685a12009-06-10 04:38:40 +0000602static inline struct bio *bio_list_peek(struct bio_list *bl)
603{
604 return bl->head;
605}
606
Christoph Hellwig8f3d8ba2009-04-07 19:55:13 +0200607static inline struct bio *bio_list_pop(struct bio_list *bl)
608{
609 struct bio *bio = bl->head;
610
611 if (bio) {
612 bl->head = bl->head->bi_next;
613 if (!bl->head)
614 bl->tail = NULL;
615
616 bio->bi_next = NULL;
617 }
618
619 return bio;
620}
621
622static inline struct bio *bio_list_get(struct bio_list *bl)
623{
624 struct bio *bio = bl->head;
625
626 bl->head = bl->tail = NULL;
627
628 return bio;
629}
630
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200631#if defined(CONFIG_BLK_DEV_INTEGRITY)
632
633#define bip_vec_idx(bip, idx) (&(bip->bip_vec[(idx)]))
634#define bip_vec(bip) bip_vec_idx(bip, 0)
635
636#define __bip_for_each_vec(bvl, bip, i, start_idx) \
637 for (bvl = bip_vec_idx((bip), (start_idx)), i = (start_idx); \
638 i < (bip)->bip_vcnt; \
639 bvl++, i++)
640
641#define bip_for_each_vec(bvl, bip, i) \
642 __bip_for_each_vec(bvl, bip, i, (bip)->bip_idx)
643
Alberto Bertogli8deaf722008-10-02 12:46:53 +0200644#define bio_integrity(bio) (bio->bi_integrity != NULL)
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200645
Martin K. Petersen7878cba2009-06-26 15:37:49 +0200646extern 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 +0200647extern struct bio_integrity_payload *bio_integrity_alloc(struct bio *, gfp_t, unsigned int);
Martin K. Petersen7878cba2009-06-26 15:37:49 +0200648extern void bio_integrity_free(struct bio *, struct bio_set *);
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200649extern int bio_integrity_add_page(struct bio *, struct page *, unsigned int, unsigned int);
650extern int bio_integrity_enabled(struct bio *bio);
651extern int bio_integrity_set_tag(struct bio *, void *, unsigned int);
652extern int bio_integrity_get_tag(struct bio *, void *, unsigned int);
653extern int bio_integrity_prep(struct bio *);
654extern void bio_integrity_endio(struct bio *, int);
655extern void bio_integrity_advance(struct bio *, unsigned int);
656extern void bio_integrity_trim(struct bio *, unsigned int, unsigned int);
657extern void bio_integrity_split(struct bio *, struct bio_pair *, int);
Martin K. Petersen7878cba2009-06-26 15:37:49 +0200658extern int bio_integrity_clone(struct bio *, struct bio *, gfp_t, struct bio_set *);
659extern int bioset_integrity_create(struct bio_set *, int);
660extern void bioset_integrity_free(struct bio_set *);
661extern void bio_integrity_init(void);
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200662
663#else /* CONFIG_BLK_DEV_INTEGRITY */
664
665#define bio_integrity(a) (0)
Martin K. Petersen7878cba2009-06-26 15:37:49 +0200666#define bioset_integrity_create(a, b) (0)
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200667#define bio_integrity_prep(a) (0)
668#define bio_integrity_enabled(a) (0)
Martin K. Petersen7878cba2009-06-26 15:37:49 +0200669#define bio_integrity_clone(a, b, c, d) (0)
670#define bioset_integrity_free(a) do { } while (0)
671#define bio_integrity_free(a, b) do { } while (0)
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200672#define bio_integrity_endio(a, b) do { } while (0)
673#define bio_integrity_advance(a, b) do { } while (0)
674#define bio_integrity_trim(a, b, c) do { } while (0)
675#define bio_integrity_split(a, b, c) do { } while (0)
676#define bio_integrity_set_tag(a, b, c) do { } while (0)
677#define bio_integrity_get_tag(a, b, c) do { } while (0)
Martin K. Petersen7878cba2009-06-26 15:37:49 +0200678#define bio_integrity_init(a) do { } while (0)
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200679
680#endif /* CONFIG_BLK_DEV_INTEGRITY */
681
David Howells02a5e0a2007-08-11 22:34:32 +0200682#endif /* CONFIG_BLOCK */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700683#endif /* __LINUX_BIO_H */