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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
Tejun Heo7cc01582010-08-03 13:14:58 +020012 *
Linus Torvalds1da177e2005-04-16 15:20:36 -070013 * 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>
Paul Gortmaker187f1882011-11-23 20:12:59 -050026#include <linux/bug.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070027
David Howells02a5e0a2007-08-11 22:34:32 +020028#ifdef CONFIG_BLOCK
29
Linus Torvalds1da177e2005-04-16 15:20:36 -070030#include <asm/io.h>
31
Tejun Heo7cc01582010-08-03 13:14:58 +020032/* struct bio, bio_vec and BIO_* flags are defined in blk_types.h */
33#include <linux/blk_types.h>
34
Linus Torvalds1da177e2005-04-16 15:20:36 -070035#define BIO_DEBUG
36
37#ifdef BIO_DEBUG
38#define BIO_BUG_ON BUG_ON
39#else
40#define BIO_BUG_ON
41#endif
42
Alexey Dobriyand84a8472006-06-25 05:49:32 -070043#define BIO_MAX_PAGES 256
Linus Torvalds1da177e2005-04-16 15:20:36 -070044#define BIO_MAX_SIZE (BIO_MAX_PAGES << PAGE_CACHE_SHIFT)
45#define BIO_MAX_SECTORS (BIO_MAX_SIZE >> 9)
46
47/*
Jens Axboe22e2c502005-06-27 10:55:12 +020048 * upper 16 bits of bi_rw define the io priority of this bio
49 */
50#define BIO_PRIO_SHIFT (8 * sizeof(unsigned long) - IOPRIO_BITS)
51#define bio_prio(bio) ((bio)->bi_rw >> BIO_PRIO_SHIFT)
52#define bio_prio_valid(bio) ioprio_valid(bio_prio(bio))
53
54#define bio_set_prio(bio, prio) do { \
55 WARN_ON(prio >= (1 << IOPRIO_BITS)); \
56 (bio)->bi_rw &= ((1UL << BIO_PRIO_SHIFT) - 1); \
57 (bio)->bi_rw |= ((unsigned long) (prio) << BIO_PRIO_SHIFT); \
58} while (0)
59
60/*
Linus Torvalds1da177e2005-04-16 15:20:36 -070061 * various member access, note that bio_data should of course not be used
62 * on highmem page vectors
63 */
64#define bio_iovec_idx(bio, idx) (&((bio)->bi_io_vec[(idx)]))
65#define bio_iovec(bio) bio_iovec_idx((bio), (bio)->bi_idx)
66#define bio_page(bio) bio_iovec((bio))->bv_page
67#define bio_offset(bio) bio_iovec((bio))->bv_offset
68#define bio_segments(bio) ((bio)->bi_vcnt - (bio)->bi_idx)
69#define bio_sectors(bio) ((bio)->bi_size >> 9)
Kent Overstreetf73a1c72012-09-25 15:05:12 -070070#define bio_end_sector(bio) ((bio)->bi_sector + bio_sectors((bio)))
Jens Axboebf2de6f2007-09-27 13:01:25 +020071
Tejun Heo2e46e8b2009-05-07 22:24:41 +090072static inline unsigned int bio_cur_bytes(struct bio *bio)
Jens Axboebf2de6f2007-09-27 13:01:25 +020073{
74 if (bio->bi_vcnt)
Tejun Heo2e46e8b2009-05-07 22:24:41 +090075 return bio_iovec(bio)->bv_len;
David Woodhousefb2dce82008-08-05 18:01:53 +010076 else /* dataless requests such as discard */
Tejun Heo2e46e8b2009-05-07 22:24:41 +090077 return bio->bi_size;
Jens Axboebf2de6f2007-09-27 13:01:25 +020078}
79
80static inline void *bio_data(struct bio *bio)
81{
82 if (bio->bi_vcnt)
83 return page_address(bio_page(bio)) + bio_offset(bio);
84
85 return NULL;
86}
Linus Torvalds1da177e2005-04-16 15:20:36 -070087
88/*
89 * will die
90 */
91#define bio_to_phys(bio) (page_to_phys(bio_page((bio))) + (unsigned long) bio_offset((bio)))
92#define bvec_to_phys(bv) (page_to_phys((bv)->bv_page) + (unsigned long) (bv)->bv_offset)
93
94/*
95 * queues that have highmem support enabled may still need to revert to
96 * PIO transfers occasionally and thus map high pages temporarily. For
97 * permanent PIO fall back, user is probably better off disabling highmem
98 * I/O completely on that queue (see ide-dma for example)
99 */
Zhao Hongjiang0eb5afb2013-07-08 15:22:50 +0800100#define __bio_kmap_atomic(bio, idx) \
Cong Wange8e3c3d2011-11-25 23:14:27 +0800101 (kmap_atomic(bio_iovec_idx((bio), (idx))->bv_page) + \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700102 bio_iovec_idx((bio), (idx))->bv_offset)
103
Zhao Hongjiang0eb5afb2013-07-08 15:22:50 +0800104#define __bio_kunmap_atomic(addr) kunmap_atomic(addr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700105
106/*
107 * merge helpers etc
108 */
109
110#define __BVEC_END(bio) bio_iovec_idx((bio), (bio)->bi_vcnt - 1)
111#define __BVEC_START(bio) bio_iovec_idx((bio), (bio)->bi_idx)
112
Jeremy Fitzhardingef92131c2008-10-29 14:10:51 +0100113/* Default implementation of BIOVEC_PHYS_MERGEABLE */
114#define __BIOVEC_PHYS_MERGEABLE(vec1, vec2) \
115 ((bvec_to_phys((vec1)) + (vec1)->bv_len) == bvec_to_phys((vec2)))
116
Linus Torvalds1da177e2005-04-16 15:20:36 -0700117/*
118 * allow arch override, for eg virtualized architectures (put in asm/io.h)
119 */
120#ifndef BIOVEC_PHYS_MERGEABLE
121#define BIOVEC_PHYS_MERGEABLE(vec1, vec2) \
Jeremy Fitzhardingef92131c2008-10-29 14:10:51 +0100122 __BIOVEC_PHYS_MERGEABLE(vec1, vec2)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700123#endif
124
Linus Torvalds1da177e2005-04-16 15:20:36 -0700125#define __BIO_SEG_BOUNDARY(addr1, addr2, mask) \
126 (((addr1) | (mask)) == (((addr2) - 1) | (mask)))
127#define BIOVEC_SEG_BOUNDARY(q, b1, b2) \
Martin K. Petersenae03bf62009-05-22 17:17:50 -0400128 __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 -0700129#define BIO_SEG_BOUNDARY(q, b1, b2) \
130 BIOVEC_SEG_BOUNDARY((q), __BVEC_END((b1)), __BVEC_START((b2)))
131
NeilBrown6712ecf2007-09-27 12:47:43 +0200132#define bio_io_error(bio) bio_endio((bio), -EIO)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700133
134/*
Kent Overstreetd74c6d52013-02-06 12:23:11 -0800135 * drivers should not use the __ version unless they _really_ know what
136 * they're doing
Linus Torvalds1da177e2005-04-16 15:20:36 -0700137 */
138#define __bio_for_each_segment(bvl, bio, i, start_idx) \
139 for (bvl = bio_iovec_idx((bio), (start_idx)), i = (start_idx); \
140 i < (bio)->bi_vcnt; \
141 bvl++, i++)
142
Kent Overstreetd74c6d52013-02-06 12:23:11 -0800143/*
144 * drivers should _never_ use the all version - the bio may have been split
145 * before it got to the driver and the driver won't own all of it
146 */
147#define bio_for_each_segment_all(bvl, bio, i) \
148 for (i = 0; \
149 bvl = bio_iovec_idx((bio), (i)), i < (bio)->bi_vcnt; \
150 i++)
151
Linus Torvalds1da177e2005-04-16 15:20:36 -0700152#define bio_for_each_segment(bvl, bio, i) \
Kent Overstreetd74c6d52013-02-06 12:23:11 -0800153 for (i = (bio)->bi_idx; \
154 bvl = bio_iovec_idx((bio), (i)), i < (bio)->bi_vcnt; \
155 i++)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700156
157/*
158 * get a reference to a bio, so it won't disappear. the intended use is
159 * something like:
160 *
161 * bio_get(bio);
162 * submit_bio(rw, bio);
163 * if (bio->bi_flags ...)
164 * do_something
165 * bio_put(bio);
166 *
167 * without the bio_get(), it could potentially complete I/O before submit_bio
168 * returns. and then bio would be freed memory when if (bio->bi_flags ...)
169 * runs
170 */
171#define bio_get(bio) atomic_inc(&(bio)->bi_cnt)
172
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200173#if defined(CONFIG_BLK_DEV_INTEGRITY)
174/*
175 * bio integrity payload
176 */
177struct bio_integrity_payload {
178 struct bio *bip_bio; /* parent bio */
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200179
180 sector_t bip_sector; /* virtual start sector */
181
182 void *bip_buf; /* generated integrity data */
183 bio_end_io_t *bip_end_io; /* saved I/O completion fn */
184
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200185 unsigned int bip_size;
186
Martin K. Petersen7878cba2009-06-26 15:37:49 +0200187 unsigned short bip_slab; /* slab the bip came from */
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200188 unsigned short bip_vcnt; /* # of integrity bio_vecs */
189 unsigned short bip_idx; /* current bip_vec index */
Kent Overstreet29ed7812012-09-04 09:54:22 -0700190 unsigned bip_owns_buf:1; /* should free bip_buf */
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200191
192 struct work_struct bip_work; /* I/O completion */
Kent Overstreet6fda9812012-10-12 13:18:27 -0700193
194 struct bio_vec *bip_vec;
195 struct bio_vec bip_inline_vecs[0];/* embedded bvec array */
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200196};
197#endif /* CONFIG_BLK_DEV_INTEGRITY */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700198
199/*
200 * A bio_pair is used when we need to split a bio.
201 * This can only happen for a bio that refers to just one
202 * page of data, and in the unusual situation when the
203 * page crosses a chunk/device boundary
204 *
205 * The address of the master bio is stored in bio1.bi_private
206 * The address of the pool the pair was allocated from is stored
207 * in bio2.bi_private
208 */
209struct bio_pair {
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200210 struct bio bio1, bio2;
211 struct bio_vec bv1, bv2;
212#if defined(CONFIG_BLK_DEV_INTEGRITY)
213 struct bio_integrity_payload bip1, bip2;
214 struct bio_vec iv1, iv2;
215#endif
216 atomic_t cnt;
217 int error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700218};
Denis ChengRq6feef532008-10-09 08:57:05 +0200219extern struct bio_pair *bio_split(struct bio *bi, int first_sectors);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700220extern void bio_pair_release(struct bio_pair *dbio);
Kent Overstreet6678d832013-08-07 11:14:32 -0700221extern void bio_trim(struct bio *bio, int offset, int size);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700222
Jens Axboebb799ca2008-12-10 15:35:05 +0100223extern struct bio_set *bioset_create(unsigned int, unsigned int);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700224extern void bioset_free(struct bio_set *);
Kent Overstreet9f060e22012-10-12 15:29:33 -0700225extern mempool_t *biovec_create_pool(struct bio_set *bs, int pool_entries);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700226
Al Virodd0fc662005-10-07 07:46:04 +0100227extern struct bio *bio_alloc_bioset(gfp_t, int, struct bio_set *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700228extern void bio_put(struct bio *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700229
Kent Overstreetbf800ef2012-09-06 15:35:02 -0700230extern void __bio_clone(struct bio *, struct bio *);
231extern struct bio *bio_clone_bioset(struct bio *, gfp_t, struct bio_set *bs);
232
Kent Overstreet3f86a822012-09-06 15:35:01 -0700233extern struct bio_set *fs_bio_set;
234
235static inline struct bio *bio_alloc(gfp_t gfp_mask, unsigned int nr_iovecs)
236{
237 return bio_alloc_bioset(gfp_mask, nr_iovecs, fs_bio_set);
238}
239
Kent Overstreetbf800ef2012-09-06 15:35:02 -0700240static inline struct bio *bio_clone(struct bio *bio, gfp_t gfp_mask)
241{
242 return bio_clone_bioset(bio, gfp_mask, fs_bio_set);
243}
244
Kent Overstreet3f86a822012-09-06 15:35:01 -0700245static inline struct bio *bio_kmalloc(gfp_t gfp_mask, unsigned int nr_iovecs)
246{
247 return bio_alloc_bioset(gfp_mask, nr_iovecs, NULL);
248}
249
Kent Overstreetbf800ef2012-09-06 15:35:02 -0700250static inline struct bio *bio_clone_kmalloc(struct bio *bio, gfp_t gfp_mask)
251{
252 return bio_clone_bioset(bio, gfp_mask, NULL);
253
254}
255
NeilBrown6712ecf2007-09-27 12:47:43 +0200256extern void bio_endio(struct bio *, int);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700257struct request_queue;
258extern int bio_phys_segments(struct request_queue *, struct bio *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700259
Kent Overstreet9e882242012-09-10 14:41:12 -0700260extern int submit_bio_wait(int rw, struct bio *bio);
Kent Overstreet054bdf62012-09-28 13:17:55 -0700261extern void bio_advance(struct bio *, unsigned);
262
Linus Torvalds1da177e2005-04-16 15:20:36 -0700263extern void bio_init(struct bio *);
Kent Overstreetf44b48c2012-09-06 15:34:58 -0700264extern void bio_reset(struct bio *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700265
266extern int bio_add_page(struct bio *, struct page *, unsigned int,unsigned int);
Mike Christie6e68af62005-11-11 05:30:27 -0600267extern int bio_add_pc_page(struct request_queue *, struct bio *, struct page *,
268 unsigned int, unsigned int);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700269extern int bio_get_nr_vecs(struct block_device *);
Martin K. Petersenad3316b2008-10-01 22:42:53 -0400270extern sector_t bio_sector_offset(struct bio *, unsigned short, unsigned int);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700271extern struct bio *bio_map_user(struct request_queue *, struct block_device *,
FUJITA Tomonoria3bce902008-08-28 16:17:05 +0900272 unsigned long, unsigned int, int, gfp_t);
James Bottomley f1970ba2005-06-20 14:06:52 +0200273struct sg_iovec;
FUJITA Tomonori152e2832008-08-28 16:17:06 +0900274struct rq_map_data;
James Bottomley f1970ba2005-06-20 14:06:52 +0200275extern struct bio *bio_map_user_iov(struct request_queue *,
276 struct block_device *,
FUJITA Tomonoria3bce902008-08-28 16:17:05 +0900277 struct sg_iovec *, int, int, gfp_t);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700278extern void bio_unmap_user(struct bio *);
Mike Christie df46b9a2005-06-20 14:04:44 +0200279extern struct bio *bio_map_kern(struct request_queue *, void *, unsigned int,
Al Viro27496a82005-10-21 03:20:48 -0400280 gfp_t);
FUJITA Tomonori68154e92008-04-25 12:47:50 +0200281extern struct bio *bio_copy_kern(struct request_queue *, void *, unsigned int,
282 gfp_t, int);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700283extern void bio_set_pages_dirty(struct bio *bio);
284extern void bio_check_pages_dirty(struct bio *bio);
Ilya Loginov2d4dc892009-11-26 09:16:19 +0100285
286#ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
287# error "You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform"
288#endif
289#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
290extern void bio_flush_dcache_pages(struct bio *bi);
291#else
292static inline void bio_flush_dcache_pages(struct bio *bi)
293{
294}
295#endif
296
Kent Overstreet16ac3d62012-09-10 13:57:51 -0700297extern void bio_copy_data(struct bio *dst, struct bio *src);
Kent Overstreeta0787602012-09-10 14:03:28 -0700298extern int bio_alloc_pages(struct bio *bio, gfp_t gfp);
Kent Overstreet16ac3d62012-09-10 13:57:51 -0700299
FUJITA Tomonori152e2832008-08-28 16:17:06 +0900300extern struct bio *bio_copy_user(struct request_queue *, struct rq_map_data *,
301 unsigned long, unsigned int, int, gfp_t);
302extern struct bio *bio_copy_user_iov(struct request_queue *,
303 struct rq_map_data *, struct sg_iovec *,
FUJITA Tomonoria3bce902008-08-28 16:17:05 +0900304 int, int, gfp_t);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700305extern int bio_uncopy_user(struct bio *);
306void zero_fill_bio(struct bio *bio);
Kent Overstreet9f060e22012-10-12 15:29:33 -0700307extern struct bio_vec *bvec_alloc(gfp_t, int, unsigned long *, mempool_t *);
308extern void bvec_free(mempool_t *, struct bio_vec *, unsigned int);
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200309extern unsigned int bvec_nr_vecs(unsigned short idx);
Martin K. Petersen51d654e2008-06-17 18:59:56 +0200310
Tejun Heo852c7882012-03-05 13:15:27 -0800311#ifdef CONFIG_BLK_CGROUP
312int bio_associate_current(struct bio *bio);
313void bio_disassociate_task(struct bio *bio);
314#else /* CONFIG_BLK_CGROUP */
315static inline int bio_associate_current(struct bio *bio) { return -ENOENT; }
316static inline void bio_disassociate_task(struct bio *bio) { }
317#endif /* CONFIG_BLK_CGROUP */
318
Linus Torvalds1da177e2005-04-16 15:20:36 -0700319#ifdef CONFIG_HIGHMEM
320/*
Alberto Bertogli20b636b2009-02-02 12:41:07 +0100321 * remember never ever reenable interrupts between a bvec_kmap_irq and
322 * bvec_kunmap_irq!
Linus Torvalds1da177e2005-04-16 15:20:36 -0700323 */
Alberto Bertogli4f570f92009-11-02 11:40:16 +0100324static inline char *bvec_kmap_irq(struct bio_vec *bvec, unsigned long *flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700325{
326 unsigned long addr;
327
328 /*
329 * might not be a highmem page, but the preempt/irq count
330 * balancing is a lot nicer this way
331 */
332 local_irq_save(*flags);
Cong Wange8e3c3d2011-11-25 23:14:27 +0800333 addr = (unsigned long) kmap_atomic(bvec->bv_page);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700334
335 BUG_ON(addr & ~PAGE_MASK);
336
337 return (char *) addr + bvec->bv_offset;
338}
339
Alberto Bertogli4f570f92009-11-02 11:40:16 +0100340static inline void bvec_kunmap_irq(char *buffer, unsigned long *flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700341{
342 unsigned long ptr = (unsigned long) buffer & PAGE_MASK;
343
Cong Wange8e3c3d2011-11-25 23:14:27 +0800344 kunmap_atomic((void *) ptr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700345 local_irq_restore(*flags);
346}
347
348#else
Geert Uytterhoeven11a691b2010-10-21 10:32:29 +0200349static inline char *bvec_kmap_irq(struct bio_vec *bvec, unsigned long *flags)
350{
351 return page_address(bvec->bv_page) + bvec->bv_offset;
352}
353
354static inline void bvec_kunmap_irq(char *buffer, unsigned long *flags)
355{
356 *flags = 0;
357}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700358#endif
359
Adrian Bunkc2d08da2005-09-10 00:27:18 -0700360static inline char *__bio_kmap_irq(struct bio *bio, unsigned short idx,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700361 unsigned long *flags)
362{
363 return bvec_kmap_irq(bio_iovec_idx(bio, idx), flags);
364}
365#define __bio_kunmap_irq(buf, flags) bvec_kunmap_irq(buf, flags)
366
367#define bio_kmap_irq(bio, flags) \
368 __bio_kmap_irq((bio), (bio)->bi_idx, (flags))
369#define bio_kunmap_irq(buf,flags) __bio_kunmap_irq(buf, flags)
370
Jens Axboe7a67f632008-08-08 11:17:12 +0200371/*
372 * Check whether this bio carries any data or not. A NULL bio is allowed.
373 */
Martin K. Petersene2a60da2012-09-18 12:19:25 -0400374static inline bool bio_has_data(struct bio *bio)
Jens Axboe7a67f632008-08-08 11:17:12 +0200375{
Martin K. Petersene2a60da2012-09-18 12:19:25 -0400376 if (bio && bio->bi_vcnt)
377 return true;
378
379 return false;
380}
381
382static inline bool bio_is_rw(struct bio *bio)
383{
384 if (!bio_has_data(bio))
385 return false;
386
Martin K. Petersen4363ac72012-09-18 12:19:27 -0400387 if (bio->bi_rw & REQ_WRITE_SAME)
388 return false;
389
Martin K. Petersene2a60da2012-09-18 12:19:25 -0400390 return true;
391}
392
393static inline bool bio_mergeable(struct bio *bio)
394{
395 if (bio->bi_rw & REQ_NOMERGE_FLAGS)
396 return false;
397
398 return true;
Jens Axboe7a67f632008-08-08 11:17:12 +0200399}
400
Christoph Hellwig8f3d8ba2009-04-07 19:55:13 +0200401/*
Akinobu Mitae6863072009-04-17 08:41:21 +0200402 * BIO list management for use by remapping drivers (e.g. DM or MD) and loop.
Christoph Hellwig8f3d8ba2009-04-07 19:55:13 +0200403 *
404 * A bio_list anchors a singly-linked list of bios chained through the bi_next
405 * member of the bio. The bio_list also caches the last list member to allow
406 * fast access to the tail.
407 */
408struct bio_list {
409 struct bio *head;
410 struct bio *tail;
411};
412
413static inline int bio_list_empty(const struct bio_list *bl)
414{
415 return bl->head == NULL;
416}
417
418static inline void bio_list_init(struct bio_list *bl)
419{
420 bl->head = bl->tail = NULL;
421}
422
Jens Axboe320ae512013-10-24 09:20:05 +0100423#define BIO_EMPTY_LIST { NULL, NULL }
424
Christoph Hellwig8f3d8ba2009-04-07 19:55:13 +0200425#define bio_list_for_each(bio, bl) \
426 for (bio = (bl)->head; bio; bio = bio->bi_next)
427
428static inline unsigned bio_list_size(const struct bio_list *bl)
429{
430 unsigned sz = 0;
431 struct bio *bio;
432
433 bio_list_for_each(bio, bl)
434 sz++;
435
436 return sz;
437}
438
439static inline void bio_list_add(struct bio_list *bl, struct bio *bio)
440{
441 bio->bi_next = NULL;
442
443 if (bl->tail)
444 bl->tail->bi_next = bio;
445 else
446 bl->head = bio;
447
448 bl->tail = bio;
449}
450
451static inline void bio_list_add_head(struct bio_list *bl, struct bio *bio)
452{
453 bio->bi_next = bl->head;
454
455 bl->head = bio;
456
457 if (!bl->tail)
458 bl->tail = bio;
459}
460
461static inline void bio_list_merge(struct bio_list *bl, struct bio_list *bl2)
462{
463 if (!bl2->head)
464 return;
465
466 if (bl->tail)
467 bl->tail->bi_next = bl2->head;
468 else
469 bl->head = bl2->head;
470
471 bl->tail = bl2->tail;
472}
473
474static inline void bio_list_merge_head(struct bio_list *bl,
475 struct bio_list *bl2)
476{
477 if (!bl2->head)
478 return;
479
480 if (bl->head)
481 bl2->tail->bi_next = bl->head;
482 else
483 bl->tail = bl2->tail;
484
485 bl->head = bl2->head;
486}
487
Geert Uytterhoeven13685a12009-06-10 04:38:40 +0000488static inline struct bio *bio_list_peek(struct bio_list *bl)
489{
490 return bl->head;
491}
492
Christoph Hellwig8f3d8ba2009-04-07 19:55:13 +0200493static inline struct bio *bio_list_pop(struct bio_list *bl)
494{
495 struct bio *bio = bl->head;
496
497 if (bio) {
498 bl->head = bl->head->bi_next;
499 if (!bl->head)
500 bl->tail = NULL;
501
502 bio->bi_next = NULL;
503 }
504
505 return bio;
506}
507
508static inline struct bio *bio_list_get(struct bio_list *bl)
509{
510 struct bio *bio = bl->head;
511
512 bl->head = bl->tail = NULL;
513
514 return bio;
515}
516
Kent Overstreet57fb2332012-08-24 04:56:11 -0700517/*
518 * bio_set is used to allow other portions of the IO system to
519 * allocate their own private memory pools for bio and iovec structures.
520 * These memory pools in turn all allocate from the bio_slab
521 * and the bvec_slabs[].
522 */
523#define BIO_POOL_SIZE 2
524#define BIOVEC_NR_POOLS 6
525#define BIOVEC_MAX_IDX (BIOVEC_NR_POOLS - 1)
526
527struct bio_set {
528 struct kmem_cache *bio_slab;
529 unsigned int front_pad;
530
531 mempool_t *bio_pool;
Kent Overstreet9f060e22012-10-12 15:29:33 -0700532 mempool_t *bvec_pool;
Kent Overstreet57fb2332012-08-24 04:56:11 -0700533#if defined(CONFIG_BLK_DEV_INTEGRITY)
534 mempool_t *bio_integrity_pool;
Kent Overstreet9f060e22012-10-12 15:29:33 -0700535 mempool_t *bvec_integrity_pool;
Kent Overstreet57fb2332012-08-24 04:56:11 -0700536#endif
Kent Overstreetdf2cb6d2012-09-10 14:33:46 -0700537
538 /*
539 * Deadlock avoidance for stacking block drivers: see comments in
540 * bio_alloc_bioset() for details
541 */
542 spinlock_t rescue_lock;
543 struct bio_list rescue_list;
544 struct work_struct rescue_work;
545 struct workqueue_struct *rescue_workqueue;
Kent Overstreet57fb2332012-08-24 04:56:11 -0700546};
547
548struct biovec_slab {
549 int nr_vecs;
550 char *name;
551 struct kmem_cache *slab;
552};
553
554/*
555 * a small number of entries is fine, not going to be performance critical.
556 * basically we just need to survive
557 */
558#define BIO_SPLIT_ENTRIES 2
559
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200560#if defined(CONFIG_BLK_DEV_INTEGRITY)
561
562#define bip_vec_idx(bip, idx) (&(bip->bip_vec[(idx)]))
563#define bip_vec(bip) bip_vec_idx(bip, 0)
564
565#define __bip_for_each_vec(bvl, bip, i, start_idx) \
566 for (bvl = bip_vec_idx((bip), (start_idx)), i = (start_idx); \
567 i < (bip)->bip_vcnt; \
568 bvl++, i++)
569
570#define bip_for_each_vec(bvl, bip, i) \
571 __bip_for_each_vec(bvl, bip, i, (bip)->bip_idx)
572
Martin K. Petersen13f05c82010-09-10 20:50:10 +0200573#define bio_for_each_integrity_vec(_bvl, _bio, _iter) \
574 for_each_bio(_bio) \
575 bip_for_each_vec(_bvl, _bio->bi_integrity, _iter)
576
Alberto Bertogli8deaf722008-10-02 12:46:53 +0200577#define bio_integrity(bio) (bio->bi_integrity != NULL)
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200578
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200579extern struct bio_integrity_payload *bio_integrity_alloc(struct bio *, gfp_t, unsigned int);
Kent Overstreet1e2a410f2012-09-06 15:34:56 -0700580extern void bio_integrity_free(struct bio *);
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200581extern int bio_integrity_add_page(struct bio *, struct page *, unsigned int, unsigned int);
582extern int bio_integrity_enabled(struct bio *bio);
583extern int bio_integrity_set_tag(struct bio *, void *, unsigned int);
584extern int bio_integrity_get_tag(struct bio *, void *, unsigned int);
585extern int bio_integrity_prep(struct bio *);
586extern void bio_integrity_endio(struct bio *, int);
587extern void bio_integrity_advance(struct bio *, unsigned int);
588extern void bio_integrity_trim(struct bio *, unsigned int, unsigned int);
589extern void bio_integrity_split(struct bio *, struct bio_pair *, int);
Kent Overstreet1e2a410f2012-09-06 15:34:56 -0700590extern int bio_integrity_clone(struct bio *, struct bio *, gfp_t);
Martin K. Petersen7878cba2009-06-26 15:37:49 +0200591extern int bioset_integrity_create(struct bio_set *, int);
592extern void bioset_integrity_free(struct bio_set *);
593extern void bio_integrity_init(void);
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200594
595#else /* CONFIG_BLK_DEV_INTEGRITY */
596
Martin K. Petersen6898e3b2012-01-13 08:15:33 +0100597static inline int bio_integrity(struct bio *bio)
598{
599 return 0;
600}
601
602static inline int bio_integrity_enabled(struct bio *bio)
603{
604 return 0;
605}
606
607static inline int bioset_integrity_create(struct bio_set *bs, int pool_size)
608{
609 return 0;
610}
611
612static inline void bioset_integrity_free (struct bio_set *bs)
613{
614 return;
615}
616
617static inline int bio_integrity_prep(struct bio *bio)
618{
619 return 0;
620}
621
Kent Overstreet1e2a410f2012-09-06 15:34:56 -0700622static inline void bio_integrity_free(struct bio *bio)
Martin K. Petersen6898e3b2012-01-13 08:15:33 +0100623{
624 return;
625}
626
Stephen Rothwell0c614e22011-11-16 09:21:48 +0100627static inline int bio_integrity_clone(struct bio *bio, struct bio *bio_src,
Kent Overstreet1e2a410f2012-09-06 15:34:56 -0700628 gfp_t gfp_mask)
Stephen Rothwell0c614e22011-11-16 09:21:48 +0100629{
630 return 0;
631}
Martin K. Petersen6898e3b2012-01-13 08:15:33 +0100632
633static inline void bio_integrity_split(struct bio *bio, struct bio_pair *bp,
634 int sectors)
635{
636 return;
637}
638
639static inline void bio_integrity_advance(struct bio *bio,
640 unsigned int bytes_done)
641{
642 return;
643}
644
645static inline void bio_integrity_trim(struct bio *bio, unsigned int offset,
646 unsigned int sectors)
647{
648 return;
649}
650
651static inline void bio_integrity_init(void)
652{
653 return;
654}
Martin K. Petersen7ba1ba12008-06-30 20:04:41 +0200655
656#endif /* CONFIG_BLK_DEV_INTEGRITY */
657
David Howells02a5e0a2007-08-11 22:34:32 +0200658#endif /* CONFIG_BLOCK */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700659#endif /* __LINUX_BIO_H */