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>
11 #include <linux/ktime.h>
15 struct bio_integrity_payload;
19 struct cgroup_subsys_state;
20 typedef void (bio_end_io_t) (struct bio *);
23 * Block error status values. See block/blk-core:blk_errors for the details.
24 * Alpha cannot write a byte atomically, so we need to use 32-bit value.
26 #if defined(CONFIG_ALPHA) && !defined(__alpha_bwx__)
27 typedef u32 __bitwise blk_status_t;
29 typedef u8 __bitwise blk_status_t;
32 #define BLK_STS_NOTSUPP ((__force blk_status_t)1)
33 #define BLK_STS_TIMEOUT ((__force blk_status_t)2)
34 #define BLK_STS_NOSPC ((__force blk_status_t)3)
35 #define BLK_STS_TRANSPORT ((__force blk_status_t)4)
36 #define BLK_STS_TARGET ((__force blk_status_t)5)
37 #define BLK_STS_NEXUS ((__force blk_status_t)6)
38 #define BLK_STS_MEDIUM ((__force blk_status_t)7)
39 #define BLK_STS_PROTECTION ((__force blk_status_t)8)
40 #define BLK_STS_RESOURCE ((__force blk_status_t)9)
41 #define BLK_STS_IOERR ((__force blk_status_t)10)
43 /* hack for device mapper, don't use elsewhere: */
44 #define BLK_STS_DM_REQUEUE ((__force blk_status_t)11)
46 #define BLK_STS_AGAIN ((__force blk_status_t)12)
49 * BLK_STS_DEV_RESOURCE is returned from the driver to the block layer if
50 * device related resources are unavailable, but the driver can guarantee
51 * that the queue will be rerun in the future once resources become
52 * available again. This is typically the case for device specific
53 * resources that are consumed for IO. If the driver fails allocating these
54 * resources, we know that inflight (or pending) IO will free these
55 * resource upon completion.
57 * This is different from BLK_STS_RESOURCE in that it explicitly references
58 * a device specific resource. For resources of wider scope, allocation
59 * failure can happen without having pending IO. This means that we can't
60 * rely on request completions freeing these resources, as IO may not be in
61 * flight. Examples of that are kernel memory allocations, DMA mappings, or
62 * any other system wide resources.
64 #define BLK_STS_DEV_RESOURCE ((__force blk_status_t)13)
67 * blk_path_error - returns true if error may be path related
68 * @error: status the request was completed with
71 * This classifies block error status into non-retryable errors and ones
72 * that may be successful if retried on a failover path.
75 * %false - retrying failover path will not help
76 * %true - may succeed if retried
78 static inline bool blk_path_error(blk_status_t error)
86 case BLK_STS_PROTECTION:
90 /* Anything else could be a path failure, so should be retried */
95 * From most significant bit:
96 * 1 bit: reserved for other usage, see below
97 * 12 bits: original size of bio
98 * 51 bits: issue time of bio
100 #define BIO_ISSUE_RES_BITS 1
101 #define BIO_ISSUE_SIZE_BITS 12
102 #define BIO_ISSUE_RES_SHIFT (64 - BIO_ISSUE_RES_BITS)
103 #define BIO_ISSUE_SIZE_SHIFT (BIO_ISSUE_RES_SHIFT - BIO_ISSUE_SIZE_BITS)
104 #define BIO_ISSUE_TIME_MASK ((1ULL << BIO_ISSUE_SIZE_SHIFT) - 1)
105 #define BIO_ISSUE_SIZE_MASK \
106 (((1ULL << BIO_ISSUE_SIZE_BITS) - 1) << BIO_ISSUE_SIZE_SHIFT)
107 #define BIO_ISSUE_RES_MASK (~((1ULL << BIO_ISSUE_RES_SHIFT) - 1))
109 /* Reserved bit for blk-throtl */
110 #define BIO_ISSUE_THROTL_SKIP_LATENCY (1ULL << 63)
116 static inline u64 __bio_issue_time(u64 time)
118 return time & BIO_ISSUE_TIME_MASK;
121 static inline u64 bio_issue_time(struct bio_issue *issue)
123 return __bio_issue_time(issue->value);
126 static inline sector_t bio_issue_size(struct bio_issue *issue)
128 return ((issue->value & BIO_ISSUE_SIZE_MASK) >> BIO_ISSUE_SIZE_SHIFT);
131 static inline void bio_issue_init(struct bio_issue *issue,
134 size &= (1ULL << BIO_ISSUE_SIZE_BITS) - 1;
135 issue->value = ((issue->value & BIO_ISSUE_RES_MASK) |
136 (ktime_get_ns() & BIO_ISSUE_TIME_MASK) |
137 ((u64)size << BIO_ISSUE_SIZE_SHIFT));
141 * main unit of I/O for the block layer and lower layers (ie drivers and
145 struct bio *bi_next; /* request queue link */
146 struct gendisk *bi_disk;
147 unsigned int bi_opf; /* bottom bits req flags,
148 * top bits REQ_OP. Use
151 unsigned short bi_flags; /* status, etc and bvec pool number */
152 unsigned short bi_ioprio;
153 unsigned short bi_write_hint;
154 blk_status_t bi_status;
157 struct bvec_iter bi_iter;
159 atomic_t __bi_remaining;
160 bio_end_io_t *bi_end_io;
163 #ifdef CONFIG_BLK_CGROUP
165 * Represents the association of the css and request_queue for the bio.
166 * If a bio goes direct to device, it will not have a blkg as it will
167 * not have a request_queue associated with it. The reference is put
168 * on release of the bio.
170 struct blkcg_gq *bi_blkg;
171 struct bio_issue bi_issue;
174 #if defined(CONFIG_BLK_DEV_INTEGRITY)
175 struct bio_integrity_payload *bi_integrity; /* data integrity */
179 unsigned short bi_vcnt; /* how many bio_vec's */
182 * Everything starting with bi_max_vecs will be preserved by bio_reset()
185 unsigned short bi_max_vecs; /* max bvl_vecs we can hold */
187 atomic_t __bi_cnt; /* pin count */
189 struct bio_vec *bi_io_vec; /* the actual vec list */
191 struct bio_set *bi_pool;
194 * We can inline a number of vecs at the end of the bio, to avoid
195 * double allocations for a small number of bio_vecs. This member
196 * MUST obviously be kept at the very end of the bio.
198 struct bio_vec bi_inline_vecs[0];
201 #define BIO_RESET_BYTES offsetof(struct bio, bi_max_vecs)
207 BIO_NO_PAGE_REF, /* don't put release vec pages */
208 BIO_CLONED, /* doesn't own data */
209 BIO_BOUNCED, /* bio is a bounce bio */
210 BIO_USER_MAPPED, /* contains user pages */
211 BIO_NULL_MAPPED, /* contains invalid user pages */
212 BIO_QUIET, /* Make BIO Quiet */
213 BIO_CHAIN, /* chained bio, ->bi_remaining in effect */
214 BIO_REFFED, /* bio has elevated ->bi_cnt */
215 BIO_THROTTLED, /* This bio has already been subjected to
216 * throttling rules. Don't do it again. */
217 BIO_TRACE_COMPLETION, /* bio_endio() should trace the final completion
219 BIO_QUEUE_ENTERED, /* can use blk_queue_enter_live() */
220 BIO_TRACKED, /* set if bio goes through the rq_qos path */
224 /* See BVEC_POOL_OFFSET below before adding new flags */
227 * We support 6 different bvec pools, the last one is magic in that it
228 * is backed by a mempool.
230 #define BVEC_POOL_NR 6
231 #define BVEC_POOL_MAX (BVEC_POOL_NR - 1)
234 * Top 3 bits of bio flags indicate the pool the bvecs came from. We add
235 * 1 to the actual index so that 0 indicates that there are no bvecs to be
238 #define BVEC_POOL_BITS (3)
239 #define BVEC_POOL_OFFSET (16 - BVEC_POOL_BITS)
240 #define BVEC_POOL_IDX(bio) ((bio)->bi_flags >> BVEC_POOL_OFFSET)
241 #if (1<< BVEC_POOL_BITS) < (BVEC_POOL_NR+1)
242 # error "BVEC_POOL_BITS is too small"
246 * Flags starting here get preserved by bio_reset() - this includes
247 * only BVEC_POOL_IDX()
249 #define BIO_RESET_BITS BVEC_POOL_OFFSET
251 typedef __u32 __bitwise blk_mq_req_flags_t;
254 * Operations and flags common to the bio and request structures.
255 * We use 8 bits for encoding the operation, and the remaining 24 for flags.
257 * The least significant bit of the operation number indicates the data
258 * transfer direction:
260 * - if the least significant bit is set transfers are TO the device
261 * - if the least significant bit is not set transfers are FROM the device
263 * If a operation does not transfer data the least significant bit has no
266 #define REQ_OP_BITS 8
267 #define REQ_OP_MASK ((1 << REQ_OP_BITS) - 1)
268 #define REQ_FLAG_BITS 24
271 /* read sectors from the device */
273 /* write sectors to the device */
275 /* flush the volatile write cache */
277 /* discard sectors */
279 /* securely erase sectors */
280 REQ_OP_SECURE_ERASE = 5,
281 /* reset a zone write pointer */
282 REQ_OP_ZONE_RESET = 6,
283 /* write the same sector many times */
284 REQ_OP_WRITE_SAME = 7,
285 /* write the zero filled sector many times */
286 REQ_OP_WRITE_ZEROES = 9,
288 /* SCSI passthrough using struct scsi_request */
290 REQ_OP_SCSI_OUT = 33,
291 /* Driver private requests */
299 __REQ_FAILFAST_DEV = /* no driver retries of device errors */
301 __REQ_FAILFAST_TRANSPORT, /* no driver retries of transport errors */
302 __REQ_FAILFAST_DRIVER, /* no driver retries of driver errors */
303 __REQ_SYNC, /* request is sync (sync write or read) */
304 __REQ_META, /* metadata io request */
305 __REQ_PRIO, /* boost priority in cfq */
306 __REQ_NOMERGE, /* don't touch this for merging */
307 __REQ_IDLE, /* anticipate more IO after this one */
308 __REQ_INTEGRITY, /* I/O includes block integrity payload */
309 __REQ_FUA, /* forced unit access */
310 __REQ_PREFLUSH, /* request for cache flush */
311 __REQ_RAHEAD, /* read ahead, can fail anytime */
312 __REQ_BACKGROUND, /* background IO */
313 __REQ_NOWAIT, /* Don't wait if request will block */
314 __REQ_NOWAIT_INLINE, /* Return would-block error inline */
316 * When a shared kthread needs to issue a bio for a cgroup, doing
317 * so synchronously can lead to priority inversions as the kthread
318 * can be trapped waiting for that cgroup. CGROUP_PUNT flag makes
319 * submit_bio() punt the actual issuing to a dedicated per-blkcg
320 * work item to avoid such priority inversions.
324 /* command specific flags for REQ_OP_WRITE_ZEROES: */
325 __REQ_NOUNMAP, /* do not free blocks when zeroing */
331 __REQ_SWAP, /* swapping request. */
332 __REQ_NR_BITS, /* stops here */
335 #define REQ_FAILFAST_DEV (1ULL << __REQ_FAILFAST_DEV)
336 #define REQ_FAILFAST_TRANSPORT (1ULL << __REQ_FAILFAST_TRANSPORT)
337 #define REQ_FAILFAST_DRIVER (1ULL << __REQ_FAILFAST_DRIVER)
338 #define REQ_SYNC (1ULL << __REQ_SYNC)
339 #define REQ_META (1ULL << __REQ_META)
340 #define REQ_PRIO (1ULL << __REQ_PRIO)
341 #define REQ_NOMERGE (1ULL << __REQ_NOMERGE)
342 #define REQ_IDLE (1ULL << __REQ_IDLE)
343 #define REQ_INTEGRITY (1ULL << __REQ_INTEGRITY)
344 #define REQ_FUA (1ULL << __REQ_FUA)
345 #define REQ_PREFLUSH (1ULL << __REQ_PREFLUSH)
346 #define REQ_RAHEAD (1ULL << __REQ_RAHEAD)
347 #define REQ_BACKGROUND (1ULL << __REQ_BACKGROUND)
348 #define REQ_NOWAIT (1ULL << __REQ_NOWAIT)
349 #define REQ_NOWAIT_INLINE (1ULL << __REQ_NOWAIT_INLINE)
350 #define REQ_CGROUP_PUNT (1ULL << __REQ_CGROUP_PUNT)
352 #define REQ_NOUNMAP (1ULL << __REQ_NOUNMAP)
353 #define REQ_HIPRI (1ULL << __REQ_HIPRI)
355 #define REQ_DRV (1ULL << __REQ_DRV)
356 #define REQ_SWAP (1ULL << __REQ_SWAP)
358 #define REQ_FAILFAST_MASK \
359 (REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT | REQ_FAILFAST_DRIVER)
361 #define REQ_NOMERGE_FLAGS \
362 (REQ_NOMERGE | REQ_PREFLUSH | REQ_FUA)
372 #define bio_op(bio) \
373 ((bio)->bi_opf & REQ_OP_MASK)
374 #define req_op(req) \
375 ((req)->cmd_flags & REQ_OP_MASK)
377 /* obsolete, don't use in new code */
378 static inline void bio_set_op_attrs(struct bio *bio, unsigned op,
381 bio->bi_opf = op | op_flags;
384 static inline bool op_is_write(unsigned int op)
390 * Check if the bio or request is one that needs special treatment in the
391 * flush state machine.
393 static inline bool op_is_flush(unsigned int op)
395 return op & (REQ_FUA | REQ_PREFLUSH);
399 * Reads are always treated as synchronous, as are requests with the FUA or
400 * PREFLUSH flag. Other operations may be marked as synchronous using the
403 static inline bool op_is_sync(unsigned int op)
405 return (op & REQ_OP_MASK) == REQ_OP_READ ||
406 (op & (REQ_SYNC | REQ_FUA | REQ_PREFLUSH));
409 static inline bool op_is_discard(unsigned int op)
411 return (op & REQ_OP_MASK) == REQ_OP_DISCARD;
414 static inline int op_stat_group(unsigned int op)
416 if (op_is_discard(op))
418 return op_is_write(op);
421 typedef unsigned int blk_qc_t;
422 #define BLK_QC_T_NONE -1U
423 #define BLK_QC_T_EAGAIN -2U
424 #define BLK_QC_T_SHIFT 16
425 #define BLK_QC_T_INTERNAL (1U << 31)
427 static inline bool blk_qc_t_valid(blk_qc_t cookie)
429 return cookie != BLK_QC_T_NONE && cookie != BLK_QC_T_EAGAIN;
432 static inline unsigned int blk_qc_t_to_queue_num(blk_qc_t cookie)
434 return (cookie & ~BLK_QC_T_INTERNAL) >> BLK_QC_T_SHIFT;
437 static inline unsigned int blk_qc_t_to_tag(blk_qc_t cookie)
439 return cookie & ((1u << BLK_QC_T_SHIFT) - 1);
442 static inline bool blk_qc_t_is_internal(blk_qc_t cookie)
444 return (cookie & BLK_QC_T_INTERNAL) != 0;
455 #endif /* __LINUX_BLK_TYPES_H */