aboutsummaryrefslogtreecommitdiffstats
path: root/include/linux/bio.h
diff options
context:
space:
mode:
Diffstat (limited to 'include/linux/bio.h')
-rw-r--r--include/linux/bio.h158
1 files changed, 8 insertions, 150 deletions
diff --git a/include/linux/bio.h b/include/linux/bio.h
index 7fc5606e6ea5..5274103434ad 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -9,7 +9,7 @@
9 * 9 *
10 * This program is distributed in the hope that it will be useful, 10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 12 *
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details. 14 * GNU General Public License for more details.
15 * 15 *
@@ -28,6 +28,9 @@
28 28
29#include <asm/io.h> 29#include <asm/io.h>
30 30
31/* struct bio, bio_vec and BIO_* flags are defined in blk_types.h */
32#include <linux/blk_types.h>
33
31#define BIO_DEBUG 34#define BIO_DEBUG
32 35
33#ifdef BIO_DEBUG 36#ifdef BIO_DEBUG
@@ -41,154 +44,6 @@
41#define BIO_MAX_SECTORS (BIO_MAX_SIZE >> 9) 44#define BIO_MAX_SECTORS (BIO_MAX_SIZE >> 9)
42 45
43/* 46/*
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;
54struct bio_integrity_payload;
55typedef void (bio_end_io_t) (struct bio *, int);
56typedef void (bio_destructor_t) (struct bio *);
57
58/*
59 * main unit of I/O for the block layer and lower layers (ie drivers and
60 * stacking drivers)
61 */
62struct bio {
63 sector_t bi_sector; /* device address in 512 byte
64 sectors */
65 struct bio *bi_next; /* request queue link */
66 struct block_device *bi_bdev;
67 unsigned long bi_flags; /* status, command, etc */
68 unsigned long bi_rw; /* bottom bits READ/WRITE,
69 * top bits priority
70 */
71
72 unsigned short bi_vcnt; /* how many bio_vec's */
73 unsigned short bi_idx; /* current index into bvl_vec */
74
75 /* Number of segments in this BIO after
76 * physical address coalescing is performed.
77 */
78 unsigned int bi_phys_segments;
79
80 unsigned int bi_size; /* residual I/O count */
81
82 /*
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
89 unsigned int bi_max_vecs; /* max bvl_vecs we can hold */
90
91 unsigned int bi_comp_cpu; /* completion CPU */
92
93 atomic_t bi_cnt; /* pin count */
94
95 struct bio_vec *bi_io_vec; /* the actual vec list */
96
97 bio_end_io_t *bi_end_io;
98
99 void *bi_private;
100#if defined(CONFIG_BLK_DEV_INTEGRITY)
101 struct bio_integrity_payload *bi_integrity; /* data integrity */
102#endif
103
104 bio_destructor_t *bi_destructor; /* destructor */
105
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];
112};
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 */
120#define BIO_SEG_VALID 3 /* bi_phys_segments valid */
121#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 */
125#define BIO_CPU_AFFINE 8 /* complete bio on same CPU as submitted */
126#define BIO_NULL_MAPPED 9 /* contains invalid user pages */
127#define BIO_FS_INTEGRITY 10 /* fs owns integrity data, not block layer */
128#define BIO_QUIET 11 /* Make BIO Quiet */
129#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)
135#define BIO_POOL_NONE ((1UL << BIO_POOL_BITS) - 1)
136#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 *
143 * bit 0 -- data direction
144 * If not set, bio is a read from device. If set, it's a write to device.
145 * 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
150 * Insert a serialization point in the IO queue, forcing previously
151 * submitted IO to be completed before this one is issued.
152 * bit 6 -- synchronous I/O hint.
153 * bit 7 -- Unplug the device immediately after submitting this bio.
154 * bit 8 -- metadata request
155 * Used for tracing to differentiate metadata and data IO. May also
156 * get some preferential treatment in the IO scheduler
157 * bit 9 -- discard sectors
158 * 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.
161 * Don't want driver retries for any fast fail whatever the reason.
162 * 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.
164 */
165enum 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};
179
180/*
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
186static inline bool bio_rw_flagged(struct bio *bio, enum bio_rw_flags flag)
187{
188 return (bio->bi_rw & (1 << flag)) != 0;
189}
190
191/*
192 * upper 16 bits of bi_rw define the io priority of this bio 47 * upper 16 bits of bi_rw define the io priority of this bio
193 */ 48 */
194#define BIO_PRIO_SHIFT (8 * sizeof(unsigned long) - IOPRIO_BITS) 49#define BIO_PRIO_SHIFT (8 * sizeof(unsigned long) - IOPRIO_BITS)
@@ -211,7 +66,10 @@ static inline bool bio_rw_flagged(struct bio *bio, enum bio_rw_flags flag)
211#define bio_offset(bio) bio_iovec((bio))->bv_offset 66#define bio_offset(bio) bio_iovec((bio))->bv_offset
212#define bio_segments(bio) ((bio)->bi_vcnt - (bio)->bi_idx) 67#define bio_segments(bio) ((bio)->bi_vcnt - (bio)->bi_idx)
213#define bio_sectors(bio) ((bio)->bi_size >> 9) 68#define bio_sectors(bio) ((bio)->bi_size >> 9)
214#define bio_empty_barrier(bio) (bio_rw_flagged(bio, BIO_RW_BARRIER) && !bio_has_data(bio) && !bio_rw_flagged(bio, BIO_RW_DISCARD)) 69#define bio_empty_barrier(bio) \
70 ((bio->bi_rw & REQ_HARDBARRIER) && \
71 !bio_has_data(bio) && \
72 !(bio->bi_rw & REQ_DISCARD))
215 73
216static inline unsigned int bio_cur_bytes(struct bio *bio) 74static inline unsigned int bio_cur_bytes(struct bio *bio)
217{ 75{