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;
45 #define bdev_kobj(_bdev) (&((_bdev)->kobj))
48 * Block error status values. See block/blk-core:blk_errors for the details.
50 typedef u8 __bitwise blk_status_t;
52 #define BLK_STS_NOTSUPP ((__force blk_status_t)1)
53 #define BLK_STS_TIMEOUT ((__force blk_status_t)2)
54 #define BLK_STS_NOSPC ((__force blk_status_t)3)
55 #define BLK_STS_TRANSPORT ((__force blk_status_t)4)
56 #define BLK_STS_TARGET ((__force blk_status_t)5)
57 #define BLK_STS_NEXUS ((__force blk_status_t)6)
58 #define BLK_STS_MEDIUM ((__force blk_status_t)7)
59 #define BLK_STS_PROTECTION ((__force blk_status_t)8)
60 #define BLK_STS_RESOURCE ((__force blk_status_t)9)
61 #define BLK_STS_IOERR ((__force blk_status_t)10)
63 /* hack for device mapper, don't use elsewhere: */
64 #define BLK_STS_DM_REQUEUE ((__force blk_status_t)11)
66 #define BLK_STS_AGAIN ((__force blk_status_t)12)
69 * main unit of I/O for the block layer and lower layers (ie drivers and
73 struct bio *bi_next; /* request queue link */
74 struct block_device *bi_bdev;
75 blk_status_t bi_status;
76 unsigned int bi_opf; /* bottom bits req flags,
77 * top bits REQ_OP. Use
80 unsigned short bi_flags; /* status, command, etc */
81 unsigned short bi_ioprio;
83 struct bvec_iter bi_iter;
85 atomic_t __bi_remaining;
87 bio_end_io_t *bi_end_io;
90 unsigned short bi_vcnt; /* how many bio_vec's */
93 * Everything starting with bi_max_vecs will be preserved by bio_reset()
96 unsigned short bi_max_vecs; /* max bvl_vecs we can hold */
98 atomic_t __bi_cnt; /* pin count */
100 struct bio_vec *bi_io_vec; /* the actual vec list */
102 struct bio_set *bi_pool;
105 * We can inline a number of vecs at the end of the bio, to avoid
106 * double allocations for a small number of bio_vecs. This member
107 * MUST obviously be kept at the very end of the bio.
109 struct bio_vec bi_inline_vecs[0];
112 #define BIO_RESET_BYTES offsetof(struct bio, bi_max_vecs)
117 #define BIO_SEG_VALID 1 /* bi_phys_segments valid */
118 #define BIO_CLONED 2 /* doesn't own data */
119 #define BIO_BOUNCED 3 /* bio is a bounce bio */
120 #define BIO_USER_MAPPED 4 /* contains user pages */
121 #define BIO_NULL_MAPPED 5 /* contains invalid user pages */
122 #define BIO_QUIET 6 /* Make BIO Quiet */
123 #define BIO_CHAIN 7 /* chained bio, ->bi_remaining in effect */
124 #define BIO_REFFED 8 /* bio has elevated ->bi_cnt */
127 * Flags starting here get preserved by bio_reset() - this includes
130 #define BIO_RESET_BITS 10
133 * We support 6 different bvec pools, the last one is magic in that it
134 * is backed by a mempool.
136 #define BVEC_POOL_NR 6
137 #define BVEC_POOL_MAX (BVEC_POOL_NR - 1)
140 * Top 4 bits of bio flags indicate the pool the bvecs came from. We add
141 * 1 to the actual index so that 0 indicates that there are no bvecs to be
144 #define BVEC_POOL_BITS (4)
145 #define BVEC_POOL_OFFSET (16 - BVEC_POOL_BITS)
146 #define BVEC_POOL_IDX(bio) ((bio)->bi_flags >> BVEC_POOL_OFFSET)
149 * Operations and flags common to the bio and request structures.
150 * We use 8 bits for encoding the operation, and the remaining 24 for flags.
152 * The least significant bit of the operation number indicates the data
153 * transfer direction:
155 * - if the least significant bit is set transfers are TO the device
156 * - if the least significant bit is not set transfers are FROM the device
158 * If a operation does not transfer data the least significant bit has no
161 #define REQ_OP_BITS 8
162 #define REQ_OP_MASK ((1 << REQ_OP_BITS) - 1)
163 #define REQ_FLAG_BITS 24
166 /* read sectors from the device */
168 /* write sectors to the device */
170 /* flush the volatile write cache */
172 /* discard sectors */
174 /* get zone information */
175 REQ_OP_ZONE_REPORT = 4,
176 /* securely erase sectors */
177 REQ_OP_SECURE_ERASE = 5,
178 /* seset a zone write pointer */
179 REQ_OP_ZONE_RESET = 6,
180 /* write the same sector many times */
181 REQ_OP_WRITE_SAME = 7,
182 /* write the zero filled sector many times */
183 REQ_OP_WRITE_ZEROES = 8,
185 /* SCSI passthrough using struct scsi_request */
187 REQ_OP_SCSI_OUT = 33,
188 /* Driver private requests */
196 __REQ_FAILFAST_DEV = /* no driver retries of device errors */
198 __REQ_FAILFAST_TRANSPORT, /* no driver retries of transport errors */
199 __REQ_FAILFAST_DRIVER, /* no driver retries of driver errors */
200 __REQ_SYNC, /* request is sync (sync write or read) */
201 __REQ_META, /* metadata io request */
202 __REQ_PRIO, /* boost priority in cfq */
203 __REQ_NOMERGE, /* don't touch this for merging */
204 __REQ_IDLE, /* anticipate more IO after this one */
205 __REQ_INTEGRITY, /* I/O includes block integrity payload */
206 __REQ_FUA, /* forced unit access */
207 __REQ_PREFLUSH, /* request for cache flush */
208 __REQ_RAHEAD, /* read ahead, can fail anytime */
209 __REQ_BACKGROUND, /* background IO */
210 __REQ_NR_BITS, /* stops here */
213 #define REQ_SYNC (1ULL << __REQ_SYNC)
214 #define REQ_META (1ULL << __REQ_META)
215 #define REQ_PRIO (1ULL << __REQ_PRIO)
217 #define REQ_NOMERGE_FLAGS (REQ_PREFLUSH | REQ_FUA)
219 #define bio_op(bio) \
220 ((bio)->bi_opf & REQ_OP_MASK)
222 static inline void bio_set_op_attrs(struct bio *bio, unsigned op,
225 bio->bi_opf = op | op_flags;
228 #define REQ_RAHEAD (1ULL << __REQ_RAHEAD)
229 #define REQ_THROTTLED (1ULL << __REQ_THROTTLED)
231 #define REQ_FUA (1ULL << __REQ_FUA)
232 #define REQ_PREFLUSH (1ULL << __REQ_PREFLUSH)
234 #define RW_MASK REQ_OP_WRITE
236 #define READ REQ_OP_READ
237 #define WRITE REQ_OP_WRITE
239 #define READ_SYNC REQ_SYNC
240 #define WRITE_SYNC (REQ_SYNC)
241 #define WRITE_ODIRECT REQ_SYNC
242 #define WRITE_FLUSH (REQ_SYNC | REQ_PREFLUSH)
243 #define WRITE_FUA (REQ_SYNC | REQ_FUA)
244 #define WRITE_FLUSH_FUA (REQ_SYNC | REQ_PREFLUSH | REQ_FUA)
246 #endif /* __LINUX_BLK_TYPES_H */