1 /* SPDX-License-Identifier: GPL-2.0 */
3 * Block data types and constants. Directly include this file only to
4 * break include dependency loop.
6 #ifndef __LINUX_BLK_TYPES_H
7 #define __LINUX_BLK_TYPES_H
9 #include <linux/types.h>
10 #include <linux/bvec.h>
14 struct bio_integrity_payload
;
18 struct cgroup_subsys_state
;
19 typedef void (bio_end_io_t
) (struct bio
*);
22 * Block error status values. See block/blk-core:blk_errors for the details.
23 * Alpha cannot write a byte atomically, so we need to use 32-bit value.
25 #if defined(CONFIG_ALPHA) && !defined(__alpha_bwx__)
26 typedef u32 __bitwise blk_status_t
;
28 typedef u8 __bitwise blk_status_t
;
31 #define BLK_STS_NOTSUPP ((__force blk_status_t)1)
32 #define BLK_STS_TIMEOUT ((__force blk_status_t)2)
33 #define BLK_STS_NOSPC ((__force blk_status_t)3)
34 #define BLK_STS_TRANSPORT ((__force blk_status_t)4)
35 #define BLK_STS_TARGET ((__force blk_status_t)5)
36 #define BLK_STS_NEXUS ((__force blk_status_t)6)
37 #define BLK_STS_MEDIUM ((__force blk_status_t)7)
38 #define BLK_STS_PROTECTION ((__force blk_status_t)8)
39 #define BLK_STS_RESOURCE ((__force blk_status_t)9)
40 #define BLK_STS_IOERR ((__force blk_status_t)10)
42 /* hack for device mapper, don't use elsewhere: */
43 #define BLK_STS_DM_REQUEUE ((__force blk_status_t)11)
45 #define BLK_STS_AGAIN ((__force blk_status_t)12)
48 * BLK_STS_DEV_RESOURCE is returned from the driver to the block layer if
49 * device related resources are unavailable, but the driver can guarantee
50 * that the queue will be rerun in the future once resources become
51 * available again. This is typically the case for device specific
52 * resources that are consumed for IO. If the driver fails allocating these
53 * resources, we know that inflight (or pending) IO will free these
54 * resource upon completion.
56 * This is different from BLK_STS_RESOURCE in that it explicitly references
57 * a device specific resource. For resources of wider scope, allocation
58 * failure can happen without having pending IO. This means that we can't
59 * rely on request completions freeing these resources, as IO may not be in
60 * flight. Examples of that are kernel memory allocations, DMA mappings, or
61 * any other system wide resources.
63 #define BLK_STS_DEV_RESOURCE ((__force blk_status_t)13)
65 struct blk_issue_stat
{
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 gendisk
*bi_disk
;
76 unsigned int bi_opf
; /* bottom bits req flags,
77 * top bits REQ_OP. Use
80 unsigned short bi_flags
; /* status, etc and bvec pool number */
81 unsigned short bi_ioprio
;
82 unsigned short bi_write_hint
;
83 blk_status_t bi_status
;
86 /* Number of segments in this BIO after
87 * physical address coalescing is performed.
89 unsigned int bi_phys_segments
;
92 * To keep track of the max segment size, we account for the
93 * sizes of the first and last mergeable segments in this bio.
95 unsigned int bi_seg_front_size
;
96 unsigned int bi_seg_back_size
;
98 struct bvec_iter bi_iter
;
100 atomic_t __bi_remaining
;
101 bio_end_io_t
*bi_end_io
;
104 #ifdef CONFIG_BLK_CGROUP
106 * Optional ioc and css associated with this bio. Put on bio
107 * release. Read comment on top of bio_associate_current().
109 struct io_context
*bi_ioc
;
110 struct cgroup_subsys_state
*bi_css
;
111 #ifdef CONFIG_BLK_DEV_THROTTLING_LOW
113 struct blk_issue_stat bi_issue_stat
;
117 #if defined(CONFIG_BLK_DEV_INTEGRITY)
118 struct bio_integrity_payload
*bi_integrity
; /* data integrity */
122 unsigned short bi_vcnt
; /* how many bio_vec's */
125 * Everything starting with bi_max_vecs will be preserved by bio_reset()
128 unsigned short bi_max_vecs
; /* max bvl_vecs we can hold */
130 atomic_t __bi_cnt
; /* pin count */
132 struct bio_vec
*bi_io_vec
; /* the actual vec list */
134 struct bio_set
*bi_pool
;
137 * We can inline a number of vecs at the end of the bio, to avoid
138 * double allocations for a small number of bio_vecs. This member
139 * MUST obviously be kept at the very end of the bio.
141 struct bio_vec bi_inline_vecs
[0];
144 #define BIO_RESET_BYTES offsetof(struct bio, bi_max_vecs)
149 #define BIO_SEG_VALID 1 /* bi_phys_segments valid */
150 #define BIO_CLONED 2 /* doesn't own data */
151 #define BIO_BOUNCED 3 /* bio is a bounce bio */
152 #define BIO_USER_MAPPED 4 /* contains user pages */
153 #define BIO_NULL_MAPPED 5 /* contains invalid user pages */
154 #define BIO_QUIET 6 /* Make BIO Quiet */
155 #define BIO_CHAIN 7 /* chained bio, ->bi_remaining in effect */
156 #define BIO_REFFED 8 /* bio has elevated ->bi_cnt */
157 #define BIO_THROTTLED 9 /* This bio has already been subjected to
158 * throttling rules. Don't do it again. */
159 #define BIO_TRACE_COMPLETION 10 /* bio_endio() should trace the final completion
161 /* See BVEC_POOL_OFFSET below before adding new flags */
164 * We support 6 different bvec pools, the last one is magic in that it
165 * is backed by a mempool.
167 #define BVEC_POOL_NR 6
168 #define BVEC_POOL_MAX (BVEC_POOL_NR - 1)
171 * Top 3 bits of bio flags indicate the pool the bvecs came from. We add
172 * 1 to the actual index so that 0 indicates that there are no bvecs to be
175 #define BVEC_POOL_BITS (3)
176 #define BVEC_POOL_OFFSET (16 - BVEC_POOL_BITS)
177 #define BVEC_POOL_IDX(bio) ((bio)->bi_flags >> BVEC_POOL_OFFSET)
178 #if (1<< BVEC_POOL_BITS) < (BVEC_POOL_NR+1)
179 # error "BVEC_POOL_BITS is too small"
183 * Flags starting here get preserved by bio_reset() - this includes
184 * only BVEC_POOL_IDX()
186 #define BIO_RESET_BITS BVEC_POOL_OFFSET
188 typedef __u32 __bitwise blk_mq_req_flags_t
;
191 * Operations and flags common to the bio and request structures.
192 * We use 8 bits for encoding the operation, and the remaining 24 for flags.
194 * The least significant bit of the operation number indicates the data
195 * transfer direction:
197 * - if the least significant bit is set transfers are TO the device
198 * - if the least significant bit is not set transfers are FROM the device
200 * If a operation does not transfer data the least significant bit has no
203 #define REQ_OP_BITS 8
204 #define REQ_OP_MASK ((1 << REQ_OP_BITS) - 1)
205 #define REQ_FLAG_BITS 24
208 /* read sectors from the device */
210 /* write sectors to the device */
212 /* flush the volatile write cache */
214 /* discard sectors */
216 /* get zone information */
217 REQ_OP_ZONE_REPORT
= 4,
218 /* securely erase sectors */
219 REQ_OP_SECURE_ERASE
= 5,
220 /* seset a zone write pointer */
221 REQ_OP_ZONE_RESET
= 6,
222 /* write the same sector many times */
223 REQ_OP_WRITE_SAME
= 7,
224 /* write the zero filled sector many times */
225 REQ_OP_WRITE_ZEROES
= 9,
227 /* SCSI passthrough using struct scsi_request */
229 REQ_OP_SCSI_OUT
= 33,
230 /* Driver private requests */
238 __REQ_FAILFAST_DEV
= /* no driver retries of device errors */
240 __REQ_FAILFAST_TRANSPORT
, /* no driver retries of transport errors */
241 __REQ_FAILFAST_DRIVER
, /* no driver retries of driver errors */
242 __REQ_SYNC
, /* request is sync (sync write or read) */
243 __REQ_META
, /* metadata io request */
244 __REQ_PRIO
, /* boost priority in cfq */
245 __REQ_NOMERGE
, /* don't touch this for merging */
246 __REQ_IDLE
, /* anticipate more IO after this one */
247 __REQ_INTEGRITY
, /* I/O includes block integrity payload */
248 __REQ_FUA
, /* forced unit access */
249 __REQ_PREFLUSH
, /* request for cache flush */
250 __REQ_RAHEAD
, /* read ahead, can fail anytime */
251 __REQ_BACKGROUND
, /* background IO */
252 __REQ_NOWAIT
, /* Don't wait if request will block */
254 /* command specific flags for REQ_OP_WRITE_ZEROES: */
255 __REQ_NOUNMAP
, /* do not free blocks when zeroing */
260 __REQ_NR_BITS
, /* stops here */
263 #define REQ_FAILFAST_DEV (1ULL << __REQ_FAILFAST_DEV)
264 #define REQ_FAILFAST_TRANSPORT (1ULL << __REQ_FAILFAST_TRANSPORT)
265 #define REQ_FAILFAST_DRIVER (1ULL << __REQ_FAILFAST_DRIVER)
266 #define REQ_SYNC (1ULL << __REQ_SYNC)
267 #define REQ_META (1ULL << __REQ_META)
268 #define REQ_PRIO (1ULL << __REQ_PRIO)
269 #define REQ_NOMERGE (1ULL << __REQ_NOMERGE)
270 #define REQ_IDLE (1ULL << __REQ_IDLE)
271 #define REQ_INTEGRITY (1ULL << __REQ_INTEGRITY)
272 #define REQ_FUA (1ULL << __REQ_FUA)
273 #define REQ_PREFLUSH (1ULL << __REQ_PREFLUSH)
274 #define REQ_RAHEAD (1ULL << __REQ_RAHEAD)
275 #define REQ_BACKGROUND (1ULL << __REQ_BACKGROUND)
276 #define REQ_NOWAIT (1ULL << __REQ_NOWAIT)
278 #define REQ_NOUNMAP (1ULL << __REQ_NOUNMAP)
280 #define REQ_DRV (1ULL << __REQ_DRV)
282 #define REQ_FAILFAST_MASK \
283 (REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT | REQ_FAILFAST_DRIVER)
285 #define REQ_NOMERGE_FLAGS \
286 (REQ_NOMERGE | REQ_PREFLUSH | REQ_FUA)
288 #define bio_op(bio) \
289 ((bio)->bi_opf & REQ_OP_MASK)
290 #define req_op(req) \
291 ((req)->cmd_flags & REQ_OP_MASK)
293 /* obsolete, don't use in new code */
294 static inline void bio_set_op_attrs(struct bio
*bio
, unsigned op
,
297 bio
->bi_opf
= op
| op_flags
;
300 static inline bool op_is_write(unsigned int op
)
306 * Check if the bio or request is one that needs special treatment in the
307 * flush state machine.
309 static inline bool op_is_flush(unsigned int op
)
311 return op
& (REQ_FUA
| REQ_PREFLUSH
);
315 * Reads are always treated as synchronous, as are requests with the FUA or
316 * PREFLUSH flag. Other operations may be marked as synchronous using the
319 static inline bool op_is_sync(unsigned int op
)
321 return (op
& REQ_OP_MASK
) == REQ_OP_READ
||
322 (op
& (REQ_SYNC
| REQ_FUA
| REQ_PREFLUSH
));
325 typedef unsigned int blk_qc_t
;
326 #define BLK_QC_T_NONE -1U
327 #define BLK_QC_T_SHIFT 16
328 #define BLK_QC_T_INTERNAL (1U << 31)
330 static inline bool blk_qc_t_valid(blk_qc_t cookie
)
332 return cookie
!= BLK_QC_T_NONE
;
335 static inline blk_qc_t
blk_tag_to_qc_t(unsigned int tag
, unsigned int queue_num
,
338 blk_qc_t ret
= tag
| (queue_num
<< BLK_QC_T_SHIFT
);
341 ret
|= BLK_QC_T_INTERNAL
;
346 static inline unsigned int blk_qc_t_to_queue_num(blk_qc_t cookie
)
348 return (cookie
& ~BLK_QC_T_INTERNAL
) >> BLK_QC_T_SHIFT
;
351 static inline unsigned int blk_qc_t_to_tag(blk_qc_t cookie
)
353 return cookie
& ((1u << BLK_QC_T_SHIFT
) - 1);
356 static inline bool blk_qc_t_is_internal(blk_qc_t cookie
)
358 return (cookie
& BLK_QC_T_INTERNAL
) != 0;
369 #endif /* __LINUX_BLK_TYPES_H */