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/types.h>
9 #include <linux/bvec.h>
13 struct bio_integrity_payload
;
17 struct cgroup_subsys_state
;
18 typedef void (bio_end_io_t
) (struct bio
*);
21 * Block error status values. See block/blk-core:blk_errors for the details.
23 typedef u8 __bitwise blk_status_t
;
25 #define BLK_STS_NOTSUPP ((__force blk_status_t)1)
26 #define BLK_STS_TIMEOUT ((__force blk_status_t)2)
27 #define BLK_STS_NOSPC ((__force blk_status_t)3)
28 #define BLK_STS_TRANSPORT ((__force blk_status_t)4)
29 #define BLK_STS_TARGET ((__force blk_status_t)5)
30 #define BLK_STS_NEXUS ((__force blk_status_t)6)
31 #define BLK_STS_MEDIUM ((__force blk_status_t)7)
32 #define BLK_STS_PROTECTION ((__force blk_status_t)8)
33 #define BLK_STS_RESOURCE ((__force blk_status_t)9)
34 #define BLK_STS_IOERR ((__force blk_status_t)10)
36 /* hack for device mapper, don't use elsewhere: */
37 #define BLK_STS_DM_REQUEUE ((__force blk_status_t)11)
39 #define BLK_STS_AGAIN ((__force blk_status_t)12)
41 struct blk_issue_stat
{
46 * main unit of I/O for the block layer and lower layers (ie drivers and
50 struct bio
*bi_next
; /* request queue link */
51 struct block_device
*bi_bdev
;
52 blk_status_t bi_status
;
53 unsigned int bi_opf
; /* bottom bits req flags,
54 * top bits REQ_OP. Use
57 unsigned short bi_flags
; /* status, etc and bvec pool number */
58 unsigned short bi_ioprio
;
59 unsigned short bi_write_hint
;
61 struct bvec_iter bi_iter
;
63 /* Number of segments in this BIO after
64 * physical address coalescing is performed.
66 unsigned int bi_phys_segments
;
69 * To keep track of the max segment size, we account for the
70 * sizes of the first and last mergeable segments in this bio.
72 unsigned int bi_seg_front_size
;
73 unsigned int bi_seg_back_size
;
75 atomic_t __bi_remaining
;
77 bio_end_io_t
*bi_end_io
;
80 #ifdef CONFIG_BLK_CGROUP
82 * Optional ioc and css associated with this bio. Put on bio
83 * release. Read comment on top of bio_associate_current().
85 struct io_context
*bi_ioc
;
86 struct cgroup_subsys_state
*bi_css
;
87 #ifdef CONFIG_BLK_DEV_THROTTLING_LOW
89 struct blk_issue_stat bi_issue_stat
;
93 #if defined(CONFIG_BLK_DEV_INTEGRITY)
94 struct bio_integrity_payload
*bi_integrity
; /* data integrity */
98 unsigned short bi_vcnt
; /* how many bio_vec's */
101 * Everything starting with bi_max_vecs will be preserved by bio_reset()
104 unsigned short bi_max_vecs
; /* max bvl_vecs we can hold */
106 atomic_t __bi_cnt
; /* pin count */
108 struct bio_vec
*bi_io_vec
; /* the actual vec list */
110 struct bio_set
*bi_pool
;
113 * We can inline a number of vecs at the end of the bio, to avoid
114 * double allocations for a small number of bio_vecs. This member
115 * MUST obviously be kept at the very end of the bio.
117 struct bio_vec bi_inline_vecs
[0];
120 #define BIO_RESET_BYTES offsetof(struct bio, bi_max_vecs)
125 #define BIO_SEG_VALID 1 /* bi_phys_segments valid */
126 #define BIO_CLONED 2 /* doesn't own data */
127 #define BIO_BOUNCED 3 /* bio is a bounce bio */
128 #define BIO_USER_MAPPED 4 /* contains user pages */
129 #define BIO_NULL_MAPPED 5 /* contains invalid user pages */
130 #define BIO_QUIET 6 /* Make BIO Quiet */
131 #define BIO_CHAIN 7 /* chained bio, ->bi_remaining in effect */
132 #define BIO_REFFED 8 /* bio has elevated ->bi_cnt */
133 #define BIO_THROTTLED 9 /* This bio has already been subjected to
134 * throttling rules. Don't do it again. */
135 #define BIO_TRACE_COMPLETION 10 /* bio_endio() should trace the final completion
137 /* See BVEC_POOL_OFFSET below before adding new flags */
140 * We support 6 different bvec pools, the last one is magic in that it
141 * is backed by a mempool.
143 #define BVEC_POOL_NR 6
144 #define BVEC_POOL_MAX (BVEC_POOL_NR - 1)
147 * Top 3 bits of bio flags indicate the pool the bvecs came from. We add
148 * 1 to the actual index so that 0 indicates that there are no bvecs to be
151 #define BVEC_POOL_BITS (3)
152 #define BVEC_POOL_OFFSET (16 - BVEC_POOL_BITS)
153 #define BVEC_POOL_IDX(bio) ((bio)->bi_flags >> BVEC_POOL_OFFSET)
154 #if (1<< BVEC_POOL_BITS) < (BVEC_POOL_NR+1)
155 # error "BVEC_POOL_BITS is too small"
159 * Flags starting here get preserved by bio_reset() - this includes
160 * only BVEC_POOL_IDX()
162 #define BIO_RESET_BITS BVEC_POOL_OFFSET
165 * Operations and flags common to the bio and request structures.
166 * We use 8 bits for encoding the operation, and the remaining 24 for flags.
168 * The least significant bit of the operation number indicates the data
169 * transfer direction:
171 * - if the least significant bit is set transfers are TO the device
172 * - if the least significant bit is not set transfers are FROM the device
174 * If a operation does not transfer data the least significant bit has no
177 #define REQ_OP_BITS 8
178 #define REQ_OP_MASK ((1 << REQ_OP_BITS) - 1)
179 #define REQ_FLAG_BITS 24
182 /* read sectors from the device */
184 /* write sectors to the device */
186 /* flush the volatile write cache */
188 /* discard sectors */
190 /* get zone information */
191 REQ_OP_ZONE_REPORT
= 4,
192 /* securely erase sectors */
193 REQ_OP_SECURE_ERASE
= 5,
194 /* seset a zone write pointer */
195 REQ_OP_ZONE_RESET
= 6,
196 /* write the same sector many times */
197 REQ_OP_WRITE_SAME
= 7,
198 /* write the zero filled sector many times */
199 REQ_OP_WRITE_ZEROES
= 9,
201 /* SCSI passthrough using struct scsi_request */
203 REQ_OP_SCSI_OUT
= 33,
204 /* Driver private requests */
212 __REQ_FAILFAST_DEV
= /* no driver retries of device errors */
214 __REQ_FAILFAST_TRANSPORT
, /* no driver retries of transport errors */
215 __REQ_FAILFAST_DRIVER
, /* no driver retries of driver errors */
216 __REQ_SYNC
, /* request is sync (sync write or read) */
217 __REQ_META
, /* metadata io request */
218 __REQ_PRIO
, /* boost priority in cfq */
219 __REQ_NOMERGE
, /* don't touch this for merging */
220 __REQ_IDLE
, /* anticipate more IO after this one */
221 __REQ_INTEGRITY
, /* I/O includes block integrity payload */
222 __REQ_FUA
, /* forced unit access */
223 __REQ_PREFLUSH
, /* request for cache flush */
224 __REQ_RAHEAD
, /* read ahead, can fail anytime */
225 __REQ_BACKGROUND
, /* background IO */
227 /* command specific flags for REQ_OP_WRITE_ZEROES: */
228 __REQ_NOUNMAP
, /* do not free blocks when zeroing */
230 __REQ_NOWAIT
, /* Don't wait if request will block */
231 __REQ_NR_BITS
, /* stops here */
234 #define REQ_FAILFAST_DEV (1ULL << __REQ_FAILFAST_DEV)
235 #define REQ_FAILFAST_TRANSPORT (1ULL << __REQ_FAILFAST_TRANSPORT)
236 #define REQ_FAILFAST_DRIVER (1ULL << __REQ_FAILFAST_DRIVER)
237 #define REQ_SYNC (1ULL << __REQ_SYNC)
238 #define REQ_META (1ULL << __REQ_META)
239 #define REQ_PRIO (1ULL << __REQ_PRIO)
240 #define REQ_NOMERGE (1ULL << __REQ_NOMERGE)
241 #define REQ_IDLE (1ULL << __REQ_IDLE)
242 #define REQ_INTEGRITY (1ULL << __REQ_INTEGRITY)
243 #define REQ_FUA (1ULL << __REQ_FUA)
244 #define REQ_PREFLUSH (1ULL << __REQ_PREFLUSH)
245 #define REQ_RAHEAD (1ULL << __REQ_RAHEAD)
246 #define REQ_BACKGROUND (1ULL << __REQ_BACKGROUND)
248 #define REQ_NOUNMAP (1ULL << __REQ_NOUNMAP)
249 #define REQ_NOWAIT (1ULL << __REQ_NOWAIT)
251 #define REQ_FAILFAST_MASK \
252 (REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT | REQ_FAILFAST_DRIVER)
254 #define REQ_NOMERGE_FLAGS \
255 (REQ_NOMERGE | REQ_PREFLUSH | REQ_FUA)
257 #define bio_op(bio) \
258 ((bio)->bi_opf & REQ_OP_MASK)
259 #define req_op(req) \
260 ((req)->cmd_flags & REQ_OP_MASK)
262 /* obsolete, don't use in new code */
263 static inline void bio_set_op_attrs(struct bio
*bio
, unsigned op
,
266 bio
->bi_opf
= op
| op_flags
;
269 static inline bool op_is_write(unsigned int op
)
275 * Check if the bio or request is one that needs special treatment in the
276 * flush state machine.
278 static inline bool op_is_flush(unsigned int op
)
280 return op
& (REQ_FUA
| REQ_PREFLUSH
);
284 * Reads are always treated as synchronous, as are requests with the FUA or
285 * PREFLUSH flag. Other operations may be marked as synchronous using the
288 static inline bool op_is_sync(unsigned int op
)
290 return (op
& REQ_OP_MASK
) == REQ_OP_READ
||
291 (op
& (REQ_SYNC
| REQ_FUA
| REQ_PREFLUSH
));
294 typedef unsigned int blk_qc_t
;
295 #define BLK_QC_T_NONE -1U
296 #define BLK_QC_T_SHIFT 16
297 #define BLK_QC_T_INTERNAL (1U << 31)
299 static inline bool blk_qc_t_valid(blk_qc_t cookie
)
301 return cookie
!= BLK_QC_T_NONE
;
304 static inline blk_qc_t
blk_tag_to_qc_t(unsigned int tag
, unsigned int queue_num
,
307 blk_qc_t ret
= tag
| (queue_num
<< BLK_QC_T_SHIFT
);
310 ret
|= BLK_QC_T_INTERNAL
;
315 static inline unsigned int blk_qc_t_to_queue_num(blk_qc_t cookie
)
317 return (cookie
& ~BLK_QC_T_INTERNAL
) >> BLK_QC_T_SHIFT
;
320 static inline unsigned int blk_qc_t_to_tag(blk_qc_t cookie
)
322 return cookie
& ((1u << BLK_QC_T_SHIFT
) - 1);
325 static inline bool blk_qc_t_is_internal(blk_qc_t cookie
)
327 return (cookie
& BLK_QC_T_INTERNAL
) != 0;
339 #endif /* __LINUX_BLK_TYPES_H */