2 * Block data types and constants. Directly include this file only to
3 * break include dependency loop.
5 #ifndef __LINUX_BLK_TYPES_H
6 #define __LINUX_BLK_TYPES_H
8 #include <linux/atomic.h>
9 #include <linux/types.h>
10 #include <linux/bvec.h>
11 #include <linux/kobject.h>
15 typedef void (bio_end_io_t) (struct bio *);
17 #define BDEVNAME_SIZE 32
19 struct request_queue {
20 struct backing_dev_info *backing_dev_info;
24 struct backing_dev_info *bdi;
25 struct backing_dev_info __bdi;
35 char name[BDEVNAME_SIZE];
36 struct inode *bd_inode;
37 struct request_queue queue;
39 struct gendisk * bd_disk;
40 struct gendisk __bd_disk;
44 #define bdev_kobj(_bdev) (&((_bdev)->kobj))
47 * Block error status values. See block/blk-core:blk_errors for the details.
49 typedef u8 __bitwise blk_status_t;
51 #define BLK_STS_NOTSUPP ((__force blk_status_t)1)
52 #define BLK_STS_TIMEOUT ((__force blk_status_t)2)
53 #define BLK_STS_NOSPC ((__force blk_status_t)3)
54 #define BLK_STS_TRANSPORT ((__force blk_status_t)4)
55 #define BLK_STS_TARGET ((__force blk_status_t)5)
56 #define BLK_STS_NEXUS ((__force blk_status_t)6)
57 #define BLK_STS_MEDIUM ((__force blk_status_t)7)
58 #define BLK_STS_PROTECTION ((__force blk_status_t)8)
59 #define BLK_STS_RESOURCE ((__force blk_status_t)9)
60 #define BLK_STS_IOERR ((__force blk_status_t)10)
62 /* hack for device mapper, don't use elsewhere: */
63 #define BLK_STS_DM_REQUEUE ((__force blk_status_t)11)
65 #define BLK_STS_AGAIN ((__force blk_status_t)12)
67 #define BIO_INLINE_VECS 4
70 * main unit of I/O for the block layer and lower layers (ie drivers and
74 struct bio *bi_next; /* request queue link */
75 struct block_device *bi_bdev;
76 blk_status_t bi_status;
77 unsigned int bi_opf; /* bottom bits req flags,
78 * top bits REQ_OP. Use
81 unsigned short bi_flags; /* status, command, etc */
82 unsigned short bi_ioprio;
84 struct bvec_iter bi_iter;
86 atomic_t __bi_remaining;
88 bio_end_io_t *bi_end_io;
91 unsigned short bi_vcnt; /* how many bio_vec's */
94 * Everything starting with bi_max_vecs will be preserved by bio_reset()
97 unsigned short bi_max_vecs; /* max bvl_vecs we can hold */
99 atomic_t __bi_cnt; /* pin count */
101 struct bio_vec *bi_io_vec; /* the actual vec list */
103 struct bio_set *bi_pool;
106 * We can inline a number of vecs at the end of the bio, to avoid
107 * double allocations for a small number of bio_vecs. This member
108 * MUST obviously be kept at the very end of the bio.
110 struct bio_vec bi_inline_vecs[0];
113 #define BIO_RESET_BYTES offsetof(struct bio, bi_max_vecs)
118 #define BIO_SEG_VALID 1 /* bi_phys_segments valid */
119 #define BIO_CLONED 2 /* doesn't own data */
120 #define BIO_BOUNCED 3 /* bio is a bounce bio */
121 #define BIO_USER_MAPPED 4 /* contains user pages */
122 #define BIO_NULL_MAPPED 5 /* contains invalid user pages */
123 #define BIO_QUIET 6 /* Make BIO Quiet */
124 #define BIO_CHAIN 7 /* chained bio, ->bi_remaining in effect */
125 #define BIO_REFFED 8 /* bio has elevated ->bi_cnt */
128 * Flags starting here get preserved by bio_reset() - this includes
131 #define BIO_RESET_BITS 10
134 * We support 6 different bvec pools, the last one is magic in that it
135 * is backed by a mempool.
137 #define BVEC_POOL_NR 6
138 #define BVEC_POOL_MAX (BVEC_POOL_NR - 1)
141 * Top 4 bits of bio flags indicate the pool the bvecs came from. We add
142 * 1 to the actual index so that 0 indicates that there are no bvecs to be
145 #define BVEC_POOL_BITS (4)
146 #define BVEC_POOL_OFFSET (16 - BVEC_POOL_BITS)
147 #define BVEC_POOL_IDX(bio) ((bio)->bi_flags >> BVEC_POOL_OFFSET)
150 * Operations and flags common to the bio and request structures.
151 * We use 8 bits for encoding the operation, and the remaining 24 for flags.
153 * The least significant bit of the operation number indicates the data
154 * transfer direction:
156 * - if the least significant bit is set transfers are TO the device
157 * - if the least significant bit is not set transfers are FROM the device
159 * If a operation does not transfer data the least significant bit has no
162 #define REQ_OP_BITS 8
163 #define REQ_OP_MASK ((1 << REQ_OP_BITS) - 1)
164 #define REQ_FLAG_BITS 24
167 /* read sectors from the device */
169 /* write sectors to the device */
171 /* flush the volatile write cache */
173 /* discard sectors */
175 /* get zone information */
176 REQ_OP_ZONE_REPORT = 4,
177 /* securely erase sectors */
178 REQ_OP_SECURE_ERASE = 5,
179 /* seset a zone write pointer */
180 REQ_OP_ZONE_RESET = 6,
181 /* write the same sector many times */
182 REQ_OP_WRITE_SAME = 7,
183 /* write the zero filled sector many times */
184 REQ_OP_WRITE_ZEROES = 8,
186 /* SCSI passthrough using struct scsi_request */
188 REQ_OP_SCSI_OUT = 33,
189 /* Driver private requests */
197 __REQ_FAILFAST_DEV = /* no driver retries of device errors */
199 __REQ_FAILFAST_TRANSPORT, /* no driver retries of transport errors */
200 __REQ_FAILFAST_DRIVER, /* no driver retries of driver errors */
201 __REQ_SYNC, /* request is sync (sync write or read) */
202 __REQ_META, /* metadata io request */
203 __REQ_PRIO, /* boost priority in cfq */
204 __REQ_NOMERGE, /* don't touch this for merging */
205 __REQ_IDLE, /* anticipate more IO after this one */
206 __REQ_INTEGRITY, /* I/O includes block integrity payload */
207 __REQ_FUA, /* forced unit access */
208 __REQ_PREFLUSH, /* request for cache flush */
209 __REQ_RAHEAD, /* read ahead, can fail anytime */
210 __REQ_BACKGROUND, /* background IO */
211 __REQ_NR_BITS, /* stops here */
214 #define REQ_SYNC (1ULL << __REQ_SYNC)
215 #define REQ_META (1ULL << __REQ_META)
216 #define REQ_PRIO (1ULL << __REQ_PRIO)
218 #define REQ_NOMERGE_FLAGS (REQ_PREFLUSH | REQ_FUA)
220 #define bio_op(bio) \
221 ((bio)->bi_opf & REQ_OP_MASK)
223 static inline void bio_set_op_attrs(struct bio *bio, unsigned op,
226 bio->bi_opf = op | op_flags;
229 #define REQ_RAHEAD (1ULL << __REQ_RAHEAD)
230 #define REQ_THROTTLED (1ULL << __REQ_THROTTLED)
232 #define REQ_FUA (1ULL << __REQ_FUA)
233 #define REQ_PREFLUSH (1ULL << __REQ_PREFLUSH)
235 #define RW_MASK REQ_OP_WRITE
237 #define READ REQ_OP_READ
238 #define WRITE REQ_OP_WRITE
240 #define READ_SYNC REQ_SYNC
241 #define WRITE_SYNC (REQ_SYNC)
242 #define WRITE_ODIRECT REQ_SYNC
243 #define WRITE_FLUSH (REQ_SYNC | REQ_PREFLUSH)
244 #define WRITE_FUA (REQ_SYNC | REQ_FUA)
245 #define WRITE_FLUSH_FUA (REQ_SYNC | REQ_PREFLUSH | REQ_FUA)
247 #endif /* __LINUX_BLK_TYPES_H */