1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * Block data types and constants. Directly include this file only to
4 * break include dependency loop.
5 */
6#ifndef __LINUX_BLK_TYPES_H
7#define __LINUX_BLK_TYPES_H
8
9#include <linux/types.h>
10#include <linux/bvec.h>
11#include <linux/ktime.h>
12
13struct bio_set;
14struct bio;
15struct bio_integrity_payload;
16struct page;
17struct block_device;
18struct io_context;
19struct cgroup_subsys_state;
20typedef void (bio_end_io_t) (struct bio *);
21
22/*
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.
25 */
26#if defined(CONFIG_ALPHA) && !defined(__alpha_bwx__)
27typedef u32 __bitwise blk_status_t;
28#else
29typedef u8 __bitwise blk_status_t;
30#endif
31#define BLK_STS_OK 0
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)
42
43/* hack for device mapper, don't use elsewhere: */
44#define BLK_STS_DM_REQUEUE ((__force blk_status_t)11)
45
46#define BLK_STS_AGAIN ((__force blk_status_t)12)
47
48/*
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.
56 *
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.
63 */
64#define BLK_STS_DEV_RESOURCE ((__force blk_status_t)13)
65
66/**
67 * blk_path_error - returns true if error may be path related
68 * @error: status the request was completed with
69 *
70 * Description:
71 * This classifies block error status into non-retryable errors and ones
72 * that may be successful if retried on a failover path.
73 *
74 * Return:
75 * %false - retrying failover path will not help
76 * %true - may succeed if retried
77 */
78static inline bool blk_path_error(blk_status_t error)
79{
80 switch (error) {
81 case BLK_STS_NOTSUPP:
82 case BLK_STS_NOSPC:
83 case BLK_STS_TARGET:
84 case BLK_STS_NEXUS:
85 case BLK_STS_MEDIUM:
86 case BLK_STS_PROTECTION:
87 return false;
88 }
89
90 /* Anything else could be a path failure, so should be retried */
91 return true;
92}
93
94/*
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
99 */
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))
108
109/* Reserved bit for blk-throtl */
110#define BIO_ISSUE_THROTL_SKIP_LATENCY (1ULL << 63)
111
112struct bio_issue {
113 u64 value;
114};
115
116static inline u64 __bio_issue_time(u64 time)
117{
118 return time & BIO_ISSUE_TIME_MASK;
119}
120
121static inline u64 bio_issue_time(struct bio_issue *issue)
122{
123 return __bio_issue_time(issue->value);
124}
125
126static inline sector_t bio_issue_size(struct bio_issue *issue)
127{
128 return ((issue->value & BIO_ISSUE_SIZE_MASK) >> BIO_ISSUE_SIZE_SHIFT);
129}
130
131static inline void bio_issue_init(struct bio_issue *issue,
132 sector_t size)
133{
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));
138}
139
140/*
141 * main unit of I/O for the block layer and lower layers (ie drivers and
142 * stacking drivers)
143 */
144struct bio {
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
149 * accessors.
150 */
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;
155 u8 bi_partno;
156
157 /* Number of segments in this BIO after
158 * physical address coalescing is performed.
159 */
160 unsigned int bi_phys_segments;
161
162 /*
163 * To keep track of the max segment size, we account for the
164 * sizes of the first and last mergeable segments in this bio.
165 */
166 unsigned int bi_seg_front_size;
167 unsigned int bi_seg_back_size;
168
169 struct bvec_iter bi_iter;
170
171 atomic_t __bi_remaining;
172 bio_end_io_t *bi_end_io;
173
174 void *bi_private;
175#ifdef CONFIG_BLK_CGROUP
176 /*
177 * Represents the association of the css and request_queue for the bio.
178 * If a bio goes direct to device, it will not have a blkg as it will
179 * not have a request_queue associated with it. The reference is put
180 * on release of the bio.
181 */
182 struct blkcg_gq *bi_blkg;
183 struct bio_issue bi_issue;
184#endif
185 union {
186#if defined(CONFIG_BLK_DEV_INTEGRITY)
187 struct bio_integrity_payload *bi_integrity; /* data integrity */
188#endif
189 };
190
191 unsigned short bi_vcnt; /* how many bio_vec's */
192
193 /*
194 * Everything starting with bi_max_vecs will be preserved by bio_reset()
195 */
196
197 unsigned short bi_max_vecs; /* max bvl_vecs we can hold */
198
199 atomic_t __bi_cnt; /* pin count */
200
201 struct bio_vec *bi_io_vec; /* the actual vec list */
202
203 struct bio_set *bi_pool;
204
205 /*
206 * We can inline a number of vecs at the end of the bio, to avoid
207 * double allocations for a small number of bio_vecs. This member
208 * MUST obviously be kept at the very end of the bio.
209 */
210 struct bio_vec bi_inline_vecs[0];
211};
212
213#define BIO_RESET_BYTES offsetof(struct bio, bi_max_vecs)
214
215/*
216 * bio flags
217 */
218#define BIO_NO_PAGE_REF 0 /* don't put release vec pages */
219#define BIO_SEG_VALID 1 /* bi_phys_segments valid */
220#define BIO_CLONED 2 /* doesn't own data */
221#define BIO_BOUNCED 3 /* bio is a bounce bio */
222#define BIO_USER_MAPPED 4 /* contains user pages */
223#define BIO_NULL_MAPPED 5 /* contains invalid user pages */
224#define BIO_QUIET 6 /* Make BIO Quiet */
225#define BIO_CHAIN 7 /* chained bio, ->bi_remaining in effect */
226#define BIO_REFFED 8 /* bio has elevated ->bi_cnt */
227#define BIO_THROTTLED 9 /* This bio has already been subjected to
228 * throttling rules. Don't do it again. */
229#define BIO_TRACE_COMPLETION 10 /* bio_endio() should trace the final completion
230 * of this bio. */
231#define BIO_QUEUE_ENTERED 11 /* can use blk_queue_enter_live() */
232#define BIO_TRACKED 12 /* set if bio goes through the rq_qos path */
233
234/* See BVEC_POOL_OFFSET below before adding new flags */
235
236/*
237 * We support 6 different bvec pools, the last one is magic in that it
238 * is backed by a mempool.
239 */
240#define BVEC_POOL_NR 6
241#define BVEC_POOL_MAX (BVEC_POOL_NR - 1)
242
243/*
244 * Top 3 bits of bio flags indicate the pool the bvecs came from. We add
245 * 1 to the actual index so that 0 indicates that there are no bvecs to be
246 * freed.
247 */
248#define BVEC_POOL_BITS (3)
249#define BVEC_POOL_OFFSET (16 - BVEC_POOL_BITS)
250#define BVEC_POOL_IDX(bio) ((bio)->bi_flags >> BVEC_POOL_OFFSET)
251#if (1<< BVEC_POOL_BITS) < (BVEC_POOL_NR+1)
252# error "BVEC_POOL_BITS is too small"
253#endif
254
255/*
256 * Flags starting here get preserved by bio_reset() - this includes
257 * only BVEC_POOL_IDX()
258 */
259#define BIO_RESET_BITS BVEC_POOL_OFFSET
260
261typedef __u32 __bitwise blk_mq_req_flags_t;
262
263/*
264 * Operations and flags common to the bio and request structures.
265 * We use 8 bits for encoding the operation, and the remaining 24 for flags.
266 *
267 * The least significant bit of the operation number indicates the data
268 * transfer direction:
269 *
270 * - if the least significant bit is set transfers are TO the device
271 * - if the least significant bit is not set transfers are FROM the device
272 *
273 * If a operation does not transfer data the least significant bit has no
274 * meaning.
275 */
276#define REQ_OP_BITS 8
277#define REQ_OP_MASK ((1 << REQ_OP_BITS) - 1)
278#define REQ_FLAG_BITS 24
279
280enum req_opf {
281 /* read sectors from the device */
282 REQ_OP_READ = 0,
283 /* write sectors to the device */
284 REQ_OP_WRITE = 1,
285 /* flush the volatile write cache */
286 REQ_OP_FLUSH = 2,
287 /* discard sectors */
288 REQ_OP_DISCARD = 3,
289 /* securely erase sectors */
290 REQ_OP_SECURE_ERASE = 5,
291 /* reset a zone write pointer */
292 REQ_OP_ZONE_RESET = 6,
293 /* write the same sector many times */
294 REQ_OP_WRITE_SAME = 7,
295 /* write the zero filled sector many times */
296 REQ_OP_WRITE_ZEROES = 9,
297
298 /* SCSI passthrough using struct scsi_request */
299 REQ_OP_SCSI_IN = 32,
300 REQ_OP_SCSI_OUT = 33,
301 /* Driver private requests */
302 REQ_OP_DRV_IN = 34,
303 REQ_OP_DRV_OUT = 35,
304
305 REQ_OP_LAST,
306};
307
308enum req_flag_bits {
309 __REQ_FAILFAST_DEV = /* no driver retries of device errors */
310 REQ_OP_BITS,
311 __REQ_FAILFAST_TRANSPORT, /* no driver retries of transport errors */
312 __REQ_FAILFAST_DRIVER, /* no driver retries of driver errors */
313 __REQ_SYNC, /* request is sync (sync write or read) */
314 __REQ_META, /* metadata io request */
315 __REQ_PRIO, /* boost priority in cfq */
316 __REQ_NOMERGE, /* don't touch this for merging */
317 __REQ_IDLE, /* anticipate more IO after this one */
318 __REQ_INTEGRITY, /* I/O includes block integrity payload */
319 __REQ_FUA, /* forced unit access */
320 __REQ_PREFLUSH, /* request for cache flush */
321 __REQ_RAHEAD, /* read ahead, can fail anytime */
322 __REQ_BACKGROUND, /* background IO */
323 __REQ_NOWAIT, /* Don't wait if request will block */
324
325 /* command specific flags for REQ_OP_WRITE_ZEROES: */
326 __REQ_NOUNMAP, /* do not free blocks when zeroing */
327
328 __REQ_HIPRI,
329
330 /* for driver use */
331 __REQ_DRV,
332 __REQ_SWAP, /* swapping request. */
333 __REQ_NR_BITS, /* stops here */
334};
335
336#define REQ_FAILFAST_DEV (1ULL << __REQ_FAILFAST_DEV)
337#define REQ_FAILFAST_TRANSPORT (1ULL << __REQ_FAILFAST_TRANSPORT)
338#define REQ_FAILFAST_DRIVER (1ULL << __REQ_FAILFAST_DRIVER)
339#define REQ_SYNC (1ULL << __REQ_SYNC)
340#define REQ_META (1ULL << __REQ_META)
341#define REQ_PRIO (1ULL << __REQ_PRIO)
342#define REQ_NOMERGE (1ULL << __REQ_NOMERGE)
343#define REQ_IDLE (1ULL << __REQ_IDLE)
344#define REQ_INTEGRITY (1ULL << __REQ_INTEGRITY)
345#define REQ_FUA (1ULL << __REQ_FUA)
346#define REQ_PREFLUSH (1ULL << __REQ_PREFLUSH)
347#define REQ_RAHEAD (1ULL << __REQ_RAHEAD)
348#define REQ_BACKGROUND (1ULL << __REQ_BACKGROUND)
349#define REQ_NOWAIT (1ULL << __REQ_NOWAIT)
350#define REQ_NOUNMAP (1ULL << __REQ_NOUNMAP)
351#define REQ_HIPRI (1ULL << __REQ_HIPRI)
352
353#define REQ_DRV (1ULL << __REQ_DRV)
354#define REQ_SWAP (1ULL << __REQ_SWAP)
355
356#define REQ_FAILFAST_MASK \
357 (REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT | REQ_FAILFAST_DRIVER)
358
359#define REQ_NOMERGE_FLAGS \
360 (REQ_NOMERGE | REQ_PREFLUSH | REQ_FUA)
361
362enum stat_group {
363 STAT_READ,
364 STAT_WRITE,
365 STAT_DISCARD,
366
367 NR_STAT_GROUPS
368};
369
370#define bio_op(bio) \
371 ((bio)->bi_opf & REQ_OP_MASK)
372#define req_op(req) \
373 ((req)->cmd_flags & REQ_OP_MASK)
374
375/* obsolete, don't use in new code */
376static inline void bio_set_op_attrs(struct bio *bio, unsigned op,
377 unsigned op_flags)
378{
379 bio->bi_opf = op | op_flags;
380}
381
382static inline bool op_is_write(unsigned int op)
383{
384 return (op & 1);
385}
386
387/*
388 * Check if the bio or request is one that needs special treatment in the
389 * flush state machine.
390 */
391static inline bool op_is_flush(unsigned int op)
392{
393 return op & (REQ_FUA | REQ_PREFLUSH);
394}
395
396/*
397 * Reads are always treated as synchronous, as are requests with the FUA or
398 * PREFLUSH flag. Other operations may be marked as synchronous using the
399 * REQ_SYNC flag.
400 */
401static inline bool op_is_sync(unsigned int op)
402{
403 return (op & REQ_OP_MASK) == REQ_OP_READ ||
404 (op & (REQ_SYNC | REQ_FUA | REQ_PREFLUSH));
405}
406
407static inline bool op_is_discard(unsigned int op)
408{
409 return (op & REQ_OP_MASK) == REQ_OP_DISCARD;
410}
411
412static inline int op_stat_group(unsigned int op)
413{
414 if (op_is_discard(op))
415 return STAT_DISCARD;
416 return op_is_write(op);
417}
418
419typedef unsigned int blk_qc_t;
420#define BLK_QC_T_NONE -1U
421#define BLK_QC_T_SHIFT 16
422#define BLK_QC_T_INTERNAL (1U << 31)
423
424static inline bool blk_qc_t_valid(blk_qc_t cookie)
425{
426 return cookie != BLK_QC_T_NONE;
427}
428
429static inline unsigned int blk_qc_t_to_queue_num(blk_qc_t cookie)
430{
431 return (cookie & ~BLK_QC_T_INTERNAL) >> BLK_QC_T_SHIFT;
432}
433
434static inline unsigned int blk_qc_t_to_tag(blk_qc_t cookie)
435{
436 return cookie & ((1u << BLK_QC_T_SHIFT) - 1);
437}
438
439static inline bool blk_qc_t_is_internal(blk_qc_t cookie)
440{
441 return (cookie & BLK_QC_T_INTERNAL) != 0;
442}
443
444struct blk_rq_stat {
445 u64 mean;
446 u64 min;
447 u64 max;
448 u32 nr_samples;
449 u64 batch;
450};
451
452#endif /* __LINUX_BLK_TYPES_H */
453