blob: 7fc5606e6ea584d71fc1104f97b1a7e479c640bd [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 Axboe1f98a132009-09-11 14:32:04 +0200180/*
181 * First four bits must match between bio->bi_rw and rq->cmd_flags, make
182 * that explicit here.
183 */
184#define BIO_RW_RQ_MASK 0xf
185
Jens Axboee7e503a2009-07-28 10:15:30 +0200186static inline bool bio_rw_flagged(struct bio *bio, enum bio_rw_flags flag)
187{
188 return (bio->bi_rw & (1 << flag)) != 0;
189}
Jens Axboe1dfa17f2009-01-06 09:21:49 +0100190
191/*
Jens Axboe22e2c502005-06-27 10:55:12 +0200192 * upper 16 bits of bi_rw define the io priority of this bio
193 */
194#define BIO_PRIO_SHIFT (8 * sizeof(unsigned long) - IOPRIO_BITS)
195#define bio_prio(bio) ((bio)->bi_rw >> BIO_PRIO_SHIFT)
196#define bio_prio_valid(bio) ioprio_valid(bio_prio(bio))
197
198#define bio_set_prio(bio, prio) do { \
199 WARN_ON(prio >= (1 << IOPRIO_BITS)); \
200 (bio)->bi_rw &= ((1UL << BIO_PRIO_SHIFT) - 1); \
201 (bio)->bi_rw |= ((unsigned long) (prio) << BIO_PRIO_SHIFT); \
202} while (0)
203
204/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700205 * various member access, note that bio_data should of course not be used
206 * on highmem page vectors
207 */
208#define bio_iovec_idx(bio, idx) (&((bio)->bi_io_vec[(idx)]))
209#define bio_iovec(bio) bio_iovec_idx((bio), (bio)->bi_idx)
210#define bio_page(bio) bio_iovec((bio))->bv_page
211#define bio_offset(bio) bio_iovec((bio))->bv_offset
212#define bio_segments(bio) ((bio)->bi_vcnt - (bio)->bi_idx)
213#define bio_sectors(bio) ((bio)->bi_size >> 9)
Jens Axboe1f98a132009-09-11 14:32:04 +0200214#define bio_empty_barrier(bio) (bio_rw_flagged(bio, BIO_RW_BARRIER) && !bio_has_data(bio) && !bio_rw_flagged(bio, BIO_RW_DISCARD))
Jens Axboebf2de6f2007-09-27 13:01:25 +0200215
Tejun Heo2e46e8b2009-05-07 22:24:41 +0900216static inline unsigned int bio_cur_bytes(struct bio *bio)
Jens Axboebf2de6f2007-09-27 13:01:25 +0200217{
218 if (bio->bi_vcnt)
Tejun Heo2e46e8b2009-05-07 22:24:41 +0900219 return bio_iovec(bio)->bv_len;
David Woodhousefb2dce82008-08-05 18:01:53 +0100220 else /* dataless requests such as discard */
Tejun Heo2e46e8b2009-05-07 22:24:41 +0900221 return bio->bi_size;
Jens Axboebf2de6f2007-09-27 13:01:25 +0200222}
223
224static inline void *bio_data(struct bio *bio)
225{
226 if (bio->bi_vcnt)
227 return page_address(bio_page(bio)) + bio_offset(bio);
228
229 return NULL;
230}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700231
Jens Axboe392ddc32008-12-23 12:42:54 +0100232static inline int bio_has_allocated_vec(struct bio *bio)
233{
234 return bio->bi_io_vec && bio->bi_io_vec != bio->bi_inline_vecs;
235}
236
Linus Torvalds1da177e2005-04-16 15:20:36 -0700237/*
238 * will die
239 */
240#define bio_to_phys(bio) (page_to_phys(bio_page((bio))) + (unsigned long) bio_offset((bio)))
241#define bvec_to_phys(bv) (page_to_phys((bv)->bv_page) + (unsigned long) (bv)->bv_offset)
242
243/*
244 * queues that have highmem support enabled may still need to revert to
245 * PIO transfers occasionally and thus map high pages temporarily. For
246 * permanent PIO fall back, user is probably better off disabling highmem
247 * I/O completely on that queue (see ide-dma for example)
248 */
249#define __bio_kmap_atomic(bio, idx, kmtype) \
250 (kmap_atomic(bio_iovec_idx((bio), (idx))->bv_page, kmtype) + \
251 bio_iovec_idx((bio), (idx))->bv_offset)
252
253#define __bio_kunmap_atomic(addr, kmtype) kunmap_atomic(addr, kmtype)
254
255/*
256 * merge helpers etc
257 */
258
259#define __BVEC_END(bio) bio_iovec_idx((bio), (bio)->bi_vcnt - 1)
260#define __BVEC_START(bio) bio_iovec_idx((bio), (bio)->bi_idx)
261
Jeremy Fitzhardingef92131c2008-10-29 14:10:51 +0100262/* Default implementation of BIOVEC_PHYS_MERGEABLE */
263#define __BIOVEC_PHYS_MERGEABLE(vec1, vec2) \
264 ((bvec_to_phys((vec1)) + (vec1)->bv_len) == bvec_to_phys((vec2)))
265
Linus Torvalds1da177e2005-04-16 15:20:36 -0700266/*
267 * allow arch override, for eg virtualized architectures (put in asm/io.h)
268 */
269#ifndef BIOVEC_PHYS_MERGEABLE
270#define BIOVEC_PHYS_MERGEABLE(vec1, vec2) \
Jeremy Fitzhardingef92131c2008-10-29 14:10:51 +0100271 __BIOVEC_PHYS_MERGEABLE(vec1, vec2)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700272#endif
273
Linus Torvalds1da177e2005-04-16 15:20:36 -0700274#define __BIO_SEG_BOUNDARY(addr1, addr2, mask) \
275 (((addr1) | (mask)) == (((addr2) - 1) | (mask)))
276#define BIOVEC_SEG_BOUNDARY(q, b1, b2) \
Martin K. Petersenae03bf62009-05-22 17:17:50 -0400277 __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 -0700278#define BIO_SEG_BOUNDARY(q, b1, b2) \
279 BIOVEC_SEG_BOUNDARY((q), __BVEC_END((b1)), __BVEC_START((b2)))
280
NeilBrown6712ecf2007-09-27 12:47:43 +0200281#define bio_io_error(bio) bio_endio((bio), -EIO)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700282
283/*
284 * drivers should not use the __ version unless they _really_ want to
285 * run through the entire bio and not just pending pieces
286 */
287#define __bio_for_each_segment(bvl, bio, i, start_idx) \
288 for (bvl = bio_iovec_idx((bio), (start_idx)), i = (start_idx); \
289 i < (bio)->bi_vcnt; \
290 bvl++, i++)
291
292#define bio_for_each_segment(bvl, bio, i) \
293 __bio_for_each_segment(bvl, bio, i, (bio)->bi_idx)
294
295/*
296 * get a reference to a bio, so it won't disappear. the intended use is
297 * something like:
298 *
299 * bio_get(bio);
300 * submit_bio(rw, bio);
301 * if (bio->bi_flags ...)
302 * do_something
303 * bio_put(bio);
304 *
305 * without the bio_get(), it could potentially complete I/O before submit_bio
306 * returns. and then bio would be freed memory when if (bio->bi_flags ...)
307 * runs
308 */
309#define bio_get(bio) atomic_inc(&(bio)->bi_cnt)
310
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200311#if defined(CONFIG_BLK_DEV_INTEGRITY)
312/*
313 * bio integrity payload
314 */
315struct bio_integrity_payload {
316 struct bio *bip_bio; /* parent bio */
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200317
318 sector_t bip_sector; /* virtual start sector */
319
320 void *bip_buf; /* generated integrity data */
321 bio_end_io_t *bip_end_io; /* saved I/O completion fn */
322
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200323 unsigned int bip_size;
324
Martin K. Petersen7878cba2009-06-26 15:37:49 +0200325 unsigned short bip_slab; /* slab the bip came from */
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200326 unsigned short bip_vcnt; /* # of integrity bio_vecs */
327 unsigned short bip_idx; /* current bip_vec index */
328
329 struct work_struct bip_work; /* I/O completion */
Martin K. Petersen7878cba2009-06-26 15:37:49 +0200330 struct bio_vec bip_vec[0]; /* embedded bvec array */
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200331};
332#endif /* CONFIG_BLK_DEV_INTEGRITY */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700333
334/*
335 * A bio_pair is used when we need to split a bio.
336 * This can only happen for a bio that refers to just one
337 * page of data, and in the unusual situation when the
338 * page crosses a chunk/device boundary
339 *
340 * The address of the master bio is stored in bio1.bi_private
341 * The address of the pool the pair was allocated from is stored
342 * in bio2.bi_private
343 */
344struct bio_pair {
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200345 struct bio bio1, bio2;
346 struct bio_vec bv1, bv2;
347#if defined(CONFIG_BLK_DEV_INTEGRITY)
348 struct bio_integrity_payload bip1, bip2;
349 struct bio_vec iv1, iv2;
350#endif
351 atomic_t cnt;
352 int error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700353};
Denis ChengRq6feef532008-10-09 08:57:05 +0200354extern struct bio_pair *bio_split(struct bio *bi, int first_sectors);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700355extern void bio_pair_release(struct bio_pair *dbio);
356
Jens Axboebb799ca2008-12-10 15:35:05 +0100357extern struct bio_set *bioset_create(unsigned int, unsigned int);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700358extern void bioset_free(struct bio_set *);
359
Al Virodd0fc662005-10-07 07:46:04 +0100360extern struct bio *bio_alloc(gfp_t, int);
Jens Axboe0a0d96b2008-09-11 13:17:37 +0200361extern struct bio *bio_kmalloc(gfp_t, int);
Al Virodd0fc662005-10-07 07:46:04 +0100362extern struct bio *bio_alloc_bioset(gfp_t, int, struct bio_set *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700363extern void bio_put(struct bio *);
Peter Osterlund36763472005-09-06 15:16:42 -0700364extern void bio_free(struct bio *, struct bio_set *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700365
NeilBrown6712ecf2007-09-27 12:47:43 +0200366extern void bio_endio(struct bio *, int);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700367struct request_queue;
368extern int bio_phys_segments(struct request_queue *, struct bio *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700369
370extern void __bio_clone(struct bio *, struct bio *);
Al Virodd0fc662005-10-07 07:46:04 +0100371extern struct bio *bio_clone(struct bio *, gfp_t);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700372
373extern void bio_init(struct bio *);
374
375extern int bio_add_page(struct bio *, struct page *, unsigned int,unsigned int);
Mike Christie6e68af62005-11-11 05:30:27 -0600376extern int bio_add_pc_page(struct request_queue *, struct bio *, struct page *,
377 unsigned int, unsigned int);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700378extern int bio_get_nr_vecs(struct block_device *);
Martin K. Petersenad3316b2008-10-01 22:42:53 -0400379extern sector_t bio_sector_offset(struct bio *, unsigned short, unsigned int);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700380extern struct bio *bio_map_user(struct request_queue *, struct block_device *,
FUJITA Tomonoria3bce902008-08-28 16:17:05 +0900381 unsigned long, unsigned int, int, gfp_t);
James Bottomley f1970ba2005-06-20 14:06:52 +0200382struct sg_iovec;
FUJITA Tomonori152e2832008-08-28 16:17:06 +0900383struct rq_map_data;
James Bottomley f1970ba2005-06-20 14:06:52 +0200384extern struct bio *bio_map_user_iov(struct request_queue *,
385 struct block_device *,
FUJITA Tomonoria3bce902008-08-28 16:17:05 +0900386 struct sg_iovec *, int, int, gfp_t);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700387extern void bio_unmap_user(struct bio *);
Mike Christie df46b9a2005-06-20 14:04:44 +0200388extern struct bio *bio_map_kern(struct request_queue *, void *, unsigned int,
Al Viro27496a82005-10-21 03:20:48 -0400389 gfp_t);
FUJITA Tomonori68154e92008-04-25 12:47:50 +0200390extern struct bio *bio_copy_kern(struct request_queue *, void *, unsigned int,
391 gfp_t, int);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700392extern void bio_set_pages_dirty(struct bio *bio);
393extern void bio_check_pages_dirty(struct bio *bio);
Ilya Loginov2d4dc892009-11-26 09:16:19 +0100394
395#ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
396# error "You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform"
397#endif
398#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
399extern void bio_flush_dcache_pages(struct bio *bi);
400#else
401static inline void bio_flush_dcache_pages(struct bio *bi)
402{
403}
404#endif
405
FUJITA Tomonori152e2832008-08-28 16:17:06 +0900406extern struct bio *bio_copy_user(struct request_queue *, struct rq_map_data *,
407 unsigned long, unsigned int, int, gfp_t);
408extern struct bio *bio_copy_user_iov(struct request_queue *,
409 struct rq_map_data *, struct sg_iovec *,
FUJITA Tomonoria3bce902008-08-28 16:17:05 +0900410 int, int, gfp_t);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700411extern int bio_uncopy_user(struct bio *);
412void zero_fill_bio(struct bio *bio);
Martin K. Petersen51d654e2008-06-17 18:59:56 +0200413extern struct bio_vec *bvec_alloc_bs(gfp_t, int, unsigned long *, struct bio_set *);
Jens Axboebb799ca2008-12-10 15:35:05 +0100414extern void bvec_free_bs(struct bio_set *, struct bio_vec *, unsigned int);
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200415extern unsigned int bvec_nr_vecs(unsigned short idx);
Martin K. Petersen51d654e2008-06-17 18:59:56 +0200416
417/*
Jens Axboec7c22e42008-09-13 20:26:01 +0200418 * Allow queuer to specify a completion CPU for this bio
419 */
420static inline void bio_set_completion_cpu(struct bio *bio, unsigned int cpu)
421{
422 bio->bi_comp_cpu = cpu;
423}
424
425/*
Martin K. Petersen51d654e2008-06-17 18:59:56 +0200426 * bio_set is used to allow other portions of the IO system to
427 * allocate their own private memory pools for bio and iovec structures.
428 * These memory pools in turn all allocate from the bio_slab
429 * and the bvec_slabs[].
430 */
431#define BIO_POOL_SIZE 2
432#define BIOVEC_NR_POOLS 6
Jens Axboe7ff93452008-12-11 11:53:43 +0100433#define BIOVEC_MAX_IDX (BIOVEC_NR_POOLS - 1)
Martin K. Petersen51d654e2008-06-17 18:59:56 +0200434
435struct bio_set {
Jens Axboe1b434492008-10-22 20:32:58 +0200436 struct kmem_cache *bio_slab;
Jens Axboebb799ca2008-12-10 15:35:05 +0100437 unsigned int front_pad;
438
Martin K. Petersen51d654e2008-06-17 18:59:56 +0200439 mempool_t *bio_pool;
Martin K. Petersen7878cba2009-06-26 15:37:49 +0200440#if defined(CONFIG_BLK_DEV_INTEGRITY)
441 mempool_t *bio_integrity_pool;
442#endif
Jens Axboe7ff93452008-12-11 11:53:43 +0100443 mempool_t *bvec_pool;
Martin K. Petersen51d654e2008-06-17 18:59:56 +0200444};
445
446struct biovec_slab {
447 int nr_vecs;
448 char *name;
449 struct kmem_cache *slab;
450};
451
452extern struct bio_set *fs_bio_set;
Jens Axboebb799ca2008-12-10 15:35:05 +0100453extern struct biovec_slab bvec_slabs[BIOVEC_NR_POOLS] __read_mostly;
Martin K. Petersen51d654e2008-06-17 18:59:56 +0200454
455/*
456 * a small number of entries is fine, not going to be performance critical.
457 * basically we just need to survive
458 */
459#define BIO_SPLIT_ENTRIES 2
Linus Torvalds1da177e2005-04-16 15:20:36 -0700460
461#ifdef CONFIG_HIGHMEM
462/*
Alberto Bertogli20b636b2009-02-02 12:41:07 +0100463 * remember never ever reenable interrupts between a bvec_kmap_irq and
464 * bvec_kunmap_irq!
Linus Torvalds1da177e2005-04-16 15:20:36 -0700465 */
Alberto Bertogli4f570f92009-11-02 11:40:16 +0100466static inline char *bvec_kmap_irq(struct bio_vec *bvec, unsigned long *flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700467{
468 unsigned long addr;
469
470 /*
471 * might not be a highmem page, but the preempt/irq count
472 * balancing is a lot nicer this way
473 */
474 local_irq_save(*flags);
475 addr = (unsigned long) kmap_atomic(bvec->bv_page, KM_BIO_SRC_IRQ);
476
477 BUG_ON(addr & ~PAGE_MASK);
478
479 return (char *) addr + bvec->bv_offset;
480}
481
Alberto Bertogli4f570f92009-11-02 11:40:16 +0100482static inline void bvec_kunmap_irq(char *buffer, 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 */