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)
66 * blk_path_error - returns true if error may be path related
67 * @error: status the request was completed with
70 * This classifies block error status into non-retryable errors and ones
71 * that may be successful if retried on a failover path.
74 * %false - retrying failover path will not help
75 * %true - may succeed if retried
77 static inline bool blk_path_error(blk_status_t error)
85 case BLK_STS_PROTECTION:
89 /* Anything else could be a path failure, so should be retried */
93 struct blk_issue_stat {
98 * main unit of I/O for the block layer and lower layers (ie drivers and
102 struct bio *bi_next; /* request queue link */
103 struct gendisk *bi_disk;
104 unsigned int bi_opf; /* bottom bits req flags,
105 * top bits REQ_OP. Use
108 unsigned short bi_flags; /* status, etc and bvec pool number */
109 unsigned short bi_ioprio;
110 unsigned short bi_write_hint;
111 blk_status_t bi_status;
114 /* Number of segments in this BIO after
115 * physical address coalescing is performed.
117 unsigned int bi_phys_segments;
120 * To keep track of the max segment size, we account for the
121 * sizes of the first and last mergeable segments in this bio.
123 unsigned int bi_seg_front_size;
124 unsigned int bi_seg_back_size;
126 struct bvec_iter bi_iter;
128 atomic_t __bi_remaining;
129 bio_end_io_t *bi_end_io;
132 #ifdef CONFIG_BLK_CGROUP
134 * Optional ioc and css associated with this bio. Put on bio
135 * release. Read comment on top of bio_associate_current().
137 struct io_context *bi_ioc;
138 struct cgroup_subsys_state *bi_css;
139 #ifdef CONFIG_BLK_DEV_THROTTLING_LOW
141 struct blk_issue_stat bi_issue_stat;
145 #if defined(CONFIG_BLK_DEV_INTEGRITY)
146 struct bio_integrity_payload *bi_integrity; /* data integrity */
150 unsigned short bi_vcnt; /* how many bio_vec's */
153 * Everything starting with bi_max_vecs will be preserved by bio_reset()
156 unsigned short bi_max_vecs; /* max bvl_vecs we can hold */
158 atomic_t __bi_cnt; /* pin count */
160 struct bio_vec *bi_io_vec; /* the actual vec list */
162 struct bio_set *bi_pool;
165 * We can inline a number of vecs at the end of the bio, to avoid
166 * double allocations for a small number of bio_vecs. This member
167 * MUST obviously be kept at the very end of the bio.
169 struct bio_vec bi_inline_vecs[0];
172 #define BIO_RESET_BYTES offsetof(struct bio, bi_max_vecs)
177 #define BIO_SEG_VALID 1 /* bi_phys_segments valid */
178 #define BIO_CLONED 2 /* doesn't own data */
179 #define BIO_BOUNCED 3 /* bio is a bounce bio */
180 #define BIO_USER_MAPPED 4 /* contains user pages */
181 #define BIO_NULL_MAPPED 5 /* contains invalid user pages */
182 #define BIO_QUIET 6 /* Make BIO Quiet */
183 #define BIO_CHAIN 7 /* chained bio, ->bi_remaining in effect */
184 #define BIO_REFFED 8 /* bio has elevated ->bi_cnt */
185 #define BIO_THROTTLED 9 /* This bio has already been subjected to
186 * throttling rules. Don't do it again. */
187 #define BIO_TRACE_COMPLETION 10 /* bio_endio() should trace the final completion
189 /* See BVEC_POOL_OFFSET below before adding new flags */
192 * We support 6 different bvec pools, the last one is magic in that it
193 * is backed by a mempool.
195 #define BVEC_POOL_NR 6
196 #define BVEC_POOL_MAX (BVEC_POOL_NR - 1)
199 * Top 3 bits of bio flags indicate the pool the bvecs came from. We add
200 * 1 to the actual index so that 0 indicates that there are no bvecs to be
203 #define BVEC_POOL_BITS (3)
204 #define BVEC_POOL_OFFSET (16 - BVEC_POOL_BITS)
205 #define BVEC_POOL_IDX(bio) ((bio)->bi_flags >> BVEC_POOL_OFFSET)
206 #if (1<< BVEC_POOL_BITS) < (BVEC_POOL_NR+1)
207 # error "BVEC_POOL_BITS is too small"
211 * Flags starting here get preserved by bio_reset() - this includes
212 * only BVEC_POOL_IDX()
214 #define BIO_RESET_BITS BVEC_POOL_OFFSET
216 typedef __u32 __bitwise blk_mq_req_flags_t;
219 * Operations and flags common to the bio and request structures.
220 * We use 8 bits for encoding the operation, and the remaining 24 for flags.
222 * The least significant bit of the operation number indicates the data
223 * transfer direction:
225 * - if the least significant bit is set transfers are TO the device
226 * - if the least significant bit is not set transfers are FROM the device
228 * If a operation does not transfer data the least significant bit has no
231 #define REQ_OP_BITS 8
232 #define REQ_OP_MASK ((1 << REQ_OP_BITS) - 1)
233 #define REQ_FLAG_BITS 24
236 /* read sectors from the device */
238 /* write sectors to the device */
240 /* flush the volatile write cache */
242 /* discard sectors */
244 /* get zone information */
245 REQ_OP_ZONE_REPORT = 4,
246 /* securely erase sectors */
247 REQ_OP_SECURE_ERASE = 5,
248 /* seset a zone write pointer */
249 REQ_OP_ZONE_RESET = 6,
250 /* write the same sector many times */
251 REQ_OP_WRITE_SAME = 7,
252 /* write the zero filled sector many times */
253 REQ_OP_WRITE_ZEROES = 9,
255 /* SCSI passthrough using struct scsi_request */
257 REQ_OP_SCSI_OUT = 33,
258 /* Driver private requests */
266 __REQ_FAILFAST_DEV = /* no driver retries of device errors */
268 __REQ_FAILFAST_TRANSPORT, /* no driver retries of transport errors */
269 __REQ_FAILFAST_DRIVER, /* no driver retries of driver errors */
270 __REQ_SYNC, /* request is sync (sync write or read) */
271 __REQ_META, /* metadata io request */
272 __REQ_PRIO, /* boost priority in cfq */
273 __REQ_NOMERGE, /* don't touch this for merging */
274 __REQ_IDLE, /* anticipate more IO after this one */
275 __REQ_INTEGRITY, /* I/O includes block integrity payload */
276 __REQ_FUA, /* forced unit access */
277 __REQ_PREFLUSH, /* request for cache flush */
278 __REQ_RAHEAD, /* read ahead, can fail anytime */
279 __REQ_BACKGROUND, /* background IO */
280 __REQ_NOWAIT, /* Don't wait if request will block */
282 /* command specific flags for REQ_OP_WRITE_ZEROES: */
283 __REQ_NOUNMAP, /* do not free blocks when zeroing */
288 __REQ_NR_BITS, /* stops here */
291 #define REQ_FAILFAST_DEV (1ULL << __REQ_FAILFAST_DEV)
292 #define REQ_FAILFAST_TRANSPORT (1ULL << __REQ_FAILFAST_TRANSPORT)
293 #define REQ_FAILFAST_DRIVER (1ULL << __REQ_FAILFAST_DRIVER)
294 #define REQ_SYNC (1ULL << __REQ_SYNC)
295 #define REQ_META (1ULL << __REQ_META)
296 #define REQ_PRIO (1ULL << __REQ_PRIO)
297 #define REQ_NOMERGE (1ULL << __REQ_NOMERGE)
298 #define REQ_IDLE (1ULL << __REQ_IDLE)
299 #define REQ_INTEGRITY (1ULL << __REQ_INTEGRITY)
300 #define REQ_FUA (1ULL << __REQ_FUA)
301 #define REQ_PREFLUSH (1ULL << __REQ_PREFLUSH)
302 #define REQ_RAHEAD (1ULL << __REQ_RAHEAD)
303 #define REQ_BACKGROUND (1ULL << __REQ_BACKGROUND)
304 #define REQ_NOWAIT (1ULL << __REQ_NOWAIT)
306 #define REQ_NOUNMAP (1ULL << __REQ_NOUNMAP)
308 #define REQ_DRV (1ULL << __REQ_DRV)
310 #define REQ_FAILFAST_MASK \
311 (REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT | REQ_FAILFAST_DRIVER)
313 #define REQ_NOMERGE_FLAGS \
314 (REQ_NOMERGE | REQ_PREFLUSH | REQ_FUA)
316 #define bio_op(bio) \
317 ((bio)->bi_opf & REQ_OP_MASK)
318 #define req_op(req) \
319 ((req)->cmd_flags & REQ_OP_MASK)
321 /* obsolete, don't use in new code */
322 static inline void bio_set_op_attrs(struct bio *bio, unsigned op,
325 bio->bi_opf = op | op_flags;
328 static inline bool op_is_write(unsigned int op)
334 * Check if the bio or request is one that needs special treatment in the
335 * flush state machine.
337 static inline bool op_is_flush(unsigned int op)
339 return op & (REQ_FUA | REQ_PREFLUSH);
343 * Reads are always treated as synchronous, as are requests with the FUA or
344 * PREFLUSH flag. Other operations may be marked as synchronous using the
347 static inline bool op_is_sync(unsigned int op)
349 return (op & REQ_OP_MASK) == REQ_OP_READ ||
350 (op & (REQ_SYNC | REQ_FUA | REQ_PREFLUSH));
353 typedef unsigned int blk_qc_t;
354 #define BLK_QC_T_NONE -1U
355 #define BLK_QC_T_SHIFT 16
356 #define BLK_QC_T_INTERNAL (1U << 31)
358 static inline bool blk_qc_t_valid(blk_qc_t cookie)
360 return cookie != BLK_QC_T_NONE;
363 static inline blk_qc_t blk_tag_to_qc_t(unsigned int tag, unsigned int queue_num,
366 blk_qc_t ret = tag | (queue_num << BLK_QC_T_SHIFT);
369 ret |= BLK_QC_T_INTERNAL;
374 static inline unsigned int blk_qc_t_to_queue_num(blk_qc_t cookie)
376 return (cookie & ~BLK_QC_T_INTERNAL) >> BLK_QC_T_SHIFT;
379 static inline unsigned int blk_qc_t_to_tag(blk_qc_t cookie)
381 return cookie & ((1u << BLK_QC_T_SHIFT) - 1);
384 static inline bool blk_qc_t_is_internal(blk_qc_t cookie)
386 return (cookie & BLK_QC_T_INTERNAL) != 0;
397 #endif /* __LINUX_BLK_TYPES_H */