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/device.h>
12#include <linux/ktime.h>
13#include <linux/rw_hint.h>
14
15struct bio_set;
16struct bio;
17struct bio_integrity_payload;
18struct page;
19struct io_context;
20struct cgroup_subsys_state;
21typedef void (bio_end_io_t) (struct bio *);
22struct bio_crypt_ctx;
23
24/*
25 * The basic unit of block I/O is a sector. It is used in a number of contexts
26 * in Linux (blk, bio, genhd). The size of one sector is 512 = 2**9
27 * bytes. Variables of type sector_t represent an offset or size that is a
28 * multiple of 512 bytes. Hence these two constants.
29 */
30#ifndef SECTOR_SHIFT
31#define SECTOR_SHIFT 9
32#endif
33#ifndef SECTOR_SIZE
34#define SECTOR_SIZE (1 << SECTOR_SHIFT)
35#endif
36
37#define PAGE_SECTORS_SHIFT (PAGE_SHIFT - SECTOR_SHIFT)
38#define PAGE_SECTORS (1 << PAGE_SECTORS_SHIFT)
39#define SECTOR_MASK (PAGE_SECTORS - 1)
40
41struct block_device {
42 sector_t bd_start_sect;
43 sector_t bd_nr_sectors;
44 struct gendisk * bd_disk;
45 struct request_queue * bd_queue;
46 struct disk_stats __percpu *bd_stats;
47 unsigned long bd_stamp;
48 bool bd_read_only; /* read-only policy */
49 u8 bd_partno;
50 bool bd_write_holder;
51 bool bd_has_submit_bio;
52 dev_t bd_dev;
53 struct inode *bd_inode; /* will die */
54
55 atomic_t bd_openers;
56 spinlock_t bd_size_lock; /* for bd_inode->i_size updates */
57 void * bd_claiming;
58 void * bd_holder;
59 const struct blk_holder_ops *bd_holder_ops;
60 struct mutex bd_holder_lock;
61 int bd_holders;
62 struct kobject *bd_holder_dir;
63
64 atomic_t bd_fsfreeze_count; /* number of freeze requests */
65 struct mutex bd_fsfreeze_mutex; /* serialize freeze/thaw */
66
67 struct partition_meta_info *bd_meta_info;
68#ifdef CONFIG_FAIL_MAKE_REQUEST
69 bool bd_make_it_fail;
70#endif
71 bool bd_ro_warned;
72 int bd_writers;
73 /*
74 * keep this out-of-line as it's both big and not needed in the fast
75 * path
76 */
77 struct device bd_device;
78} __randomize_layout;
79
80#define bdev_whole(_bdev) \
81 ((_bdev)->bd_disk->part0)
82
83#define dev_to_bdev(device) \
84 container_of((device), struct block_device, bd_device)
85
86#define bdev_kobj(_bdev) \
87 (&((_bdev)->bd_device.kobj))
88
89/*
90 * Block error status values. See block/blk-core:blk_errors for the details.
91 * Alpha cannot write a byte atomically, so we need to use 32-bit value.
92 */
93#if defined(CONFIG_ALPHA) && !defined(__alpha_bwx__)
94typedef u32 __bitwise blk_status_t;
95typedef u32 blk_short_t;
96#else
97typedef u8 __bitwise blk_status_t;
98typedef u16 blk_short_t;
99#endif
100#define BLK_STS_OK 0
101#define BLK_STS_NOTSUPP ((__force blk_status_t)1)
102#define BLK_STS_TIMEOUT ((__force blk_status_t)2)
103#define BLK_STS_NOSPC ((__force blk_status_t)3)
104#define BLK_STS_TRANSPORT ((__force blk_status_t)4)
105#define BLK_STS_TARGET ((__force blk_status_t)5)
106#define BLK_STS_RESV_CONFLICT ((__force blk_status_t)6)
107#define BLK_STS_MEDIUM ((__force blk_status_t)7)
108#define BLK_STS_PROTECTION ((__force blk_status_t)8)
109#define BLK_STS_RESOURCE ((__force blk_status_t)9)
110#define BLK_STS_IOERR ((__force blk_status_t)10)
111
112/* hack for device mapper, don't use elsewhere: */
113#define BLK_STS_DM_REQUEUE ((__force blk_status_t)11)
114
115/*
116 * BLK_STS_AGAIN should only be returned if RQF_NOWAIT is set
117 * and the bio would block (cf bio_wouldblock_error())
118 */
119#define BLK_STS_AGAIN ((__force blk_status_t)12)
120
121/*
122 * BLK_STS_DEV_RESOURCE is returned from the driver to the block layer if
123 * device related resources are unavailable, but the driver can guarantee
124 * that the queue will be rerun in the future once resources become
125 * available again. This is typically the case for device specific
126 * resources that are consumed for IO. If the driver fails allocating these
127 * resources, we know that inflight (or pending) IO will free these
128 * resource upon completion.
129 *
130 * This is different from BLK_STS_RESOURCE in that it explicitly references
131 * a device specific resource. For resources of wider scope, allocation
132 * failure can happen without having pending IO. This means that we can't
133 * rely on request completions freeing these resources, as IO may not be in
134 * flight. Examples of that are kernel memory allocations, DMA mappings, or
135 * any other system wide resources.
136 */
137#define BLK_STS_DEV_RESOURCE ((__force blk_status_t)13)
138
139/*
140 * BLK_STS_ZONE_RESOURCE is returned from the driver to the block layer if zone
141 * related resources are unavailable, but the driver can guarantee the queue
142 * will be rerun in the future once the resources become available again.
143 *
144 * This is different from BLK_STS_DEV_RESOURCE in that it explicitly references
145 * a zone specific resource and IO to a different zone on the same device could
146 * still be served. Examples of that are zones that are write-locked, but a read
147 * to the same zone could be served.
148 */
149#define BLK_STS_ZONE_RESOURCE ((__force blk_status_t)14)
150
151/*
152 * BLK_STS_ZONE_OPEN_RESOURCE is returned from the driver in the completion
153 * path if the device returns a status indicating that too many zone resources
154 * are currently open. The same command should be successful if resubmitted
155 * after the number of open zones decreases below the device's limits, which is
156 * reported in the request_queue's max_open_zones.
157 */
158#define BLK_STS_ZONE_OPEN_RESOURCE ((__force blk_status_t)15)
159
160/*
161 * BLK_STS_ZONE_ACTIVE_RESOURCE is returned from the driver in the completion
162 * path if the device returns a status indicating that too many zone resources
163 * are currently active. The same command should be successful if resubmitted
164 * after the number of active zones decreases below the device's limits, which
165 * is reported in the request_queue's max_active_zones.
166 */
167#define BLK_STS_ZONE_ACTIVE_RESOURCE ((__force blk_status_t)16)
168
169/*
170 * BLK_STS_OFFLINE is returned from the driver when the target device is offline
171 * or is being taken offline. This could help differentiate the case where a
172 * device is intentionally being shut down from a real I/O error.
173 */
174#define BLK_STS_OFFLINE ((__force blk_status_t)17)
175
176/*
177 * BLK_STS_DURATION_LIMIT is returned from the driver when the target device
178 * aborted the command because it exceeded one of its Command Duration Limits.
179 */
180#define BLK_STS_DURATION_LIMIT ((__force blk_status_t)18)
181
182/**
183 * blk_path_error - returns true if error may be path related
184 * @error: status the request was completed with
185 *
186 * Description:
187 * This classifies block error status into non-retryable errors and ones
188 * that may be successful if retried on a failover path.
189 *
190 * Return:
191 * %false - retrying failover path will not help
192 * %true - may succeed if retried
193 */
194static inline bool blk_path_error(blk_status_t error)
195{
196 switch (error) {
197 case BLK_STS_NOTSUPP:
198 case BLK_STS_NOSPC:
199 case BLK_STS_TARGET:
200 case BLK_STS_RESV_CONFLICT:
201 case BLK_STS_MEDIUM:
202 case BLK_STS_PROTECTION:
203 return false;
204 }
205
206 /* Anything else could be a path failure, so should be retried */
207 return true;
208}
209
210struct bio_issue {
211 u64 value;
212};
213
214typedef __u32 __bitwise blk_opf_t;
215
216typedef unsigned int blk_qc_t;
217#define BLK_QC_T_NONE -1U
218
219/*
220 * main unit of I/O for the block layer and lower layers (ie drivers and
221 * stacking drivers)
222 */
223struct bio {
224 struct bio *bi_next; /* request queue link */
225 struct block_device *bi_bdev;
226 blk_opf_t bi_opf; /* bottom bits REQ_OP, top bits
227 * req_flags.
228 */
229 unsigned short bi_flags; /* BIO_* below */
230 unsigned short bi_ioprio;
231 enum rw_hint bi_write_hint;
232 blk_status_t bi_status;
233 atomic_t __bi_remaining;
234
235 struct bvec_iter bi_iter;
236
237 blk_qc_t bi_cookie;
238 bio_end_io_t *bi_end_io;
239 void *bi_private;
240#ifdef CONFIG_BLK_CGROUP
241 /*
242 * Represents the association of the css and request_queue for the bio.
243 * If a bio goes direct to device, it will not have a blkg as it will
244 * not have a request_queue associated with it. The reference is put
245 * on release of the bio.
246 */
247 struct blkcg_gq *bi_blkg;
248 struct bio_issue bi_issue;
249#ifdef CONFIG_BLK_CGROUP_IOCOST
250 u64 bi_iocost_cost;
251#endif
252#endif
253
254#ifdef CONFIG_BLK_INLINE_ENCRYPTION
255 struct bio_crypt_ctx *bi_crypt_context;
256#endif
257
258 union {
259#if defined(CONFIG_BLK_DEV_INTEGRITY)
260 struct bio_integrity_payload *bi_integrity; /* data integrity */
261#endif
262 };
263
264 unsigned short bi_vcnt; /* how many bio_vec's */
265
266 /*
267 * Everything starting with bi_max_vecs will be preserved by bio_reset()
268 */
269
270 unsigned short bi_max_vecs; /* max bvl_vecs we can hold */
271
272 atomic_t __bi_cnt; /* pin count */
273
274 struct bio_vec *bi_io_vec; /* the actual vec list */
275
276 struct bio_set *bi_pool;
277
278 /*
279 * We can inline a number of vecs at the end of the bio, to avoid
280 * double allocations for a small number of bio_vecs. This member
281 * MUST obviously be kept at the very end of the bio.
282 */
283 struct bio_vec bi_inline_vecs[];
284};
285
286#define BIO_RESET_BYTES offsetof(struct bio, bi_max_vecs)
287#define BIO_MAX_SECTORS (UINT_MAX >> SECTOR_SHIFT)
288
289/*
290 * bio flags
291 */
292enum {
293 BIO_PAGE_PINNED, /* Unpin pages in bio_release_pages() */
294 BIO_CLONED, /* doesn't own data */
295 BIO_BOUNCED, /* bio is a bounce bio */
296 BIO_QUIET, /* Make BIO Quiet */
297 BIO_CHAIN, /* chained bio, ->bi_remaining in effect */
298 BIO_REFFED, /* bio has elevated ->bi_cnt */
299 BIO_BPS_THROTTLED, /* This bio has already been subjected to
300 * throttling rules. Don't do it again. */
301 BIO_TRACE_COMPLETION, /* bio_endio() should trace the final completion
302 * of this bio. */
303 BIO_CGROUP_ACCT, /* has been accounted to a cgroup */
304 BIO_QOS_THROTTLED, /* bio went through rq_qos throttle path */
305 BIO_QOS_MERGED, /* but went through rq_qos merge path */
306 BIO_REMAPPED,
307 BIO_ZONE_WRITE_LOCKED, /* Owns a zoned device zone write lock */
308 BIO_FLAG_LAST
309};
310
311typedef __u32 __bitwise blk_mq_req_flags_t;
312
313#define REQ_OP_BITS 8
314#define REQ_OP_MASK (__force blk_opf_t)((1 << REQ_OP_BITS) - 1)
315#define REQ_FLAG_BITS 24
316
317/**
318 * enum req_op - Operations common to the bio and request structures.
319 * We use 8 bits for encoding the operation, and the remaining 24 for flags.
320 *
321 * The least significant bit of the operation number indicates the data
322 * transfer direction:
323 *
324 * - if the least significant bit is set transfers are TO the device
325 * - if the least significant bit is not set transfers are FROM the device
326 *
327 * If a operation does not transfer data the least significant bit has no
328 * meaning.
329 */
330enum req_op {
331 /* read sectors from the device */
332 REQ_OP_READ = (__force blk_opf_t)0,
333 /* write sectors to the device */
334 REQ_OP_WRITE = (__force blk_opf_t)1,
335 /* flush the volatile write cache */
336 REQ_OP_FLUSH = (__force blk_opf_t)2,
337 /* discard sectors */
338 REQ_OP_DISCARD = (__force blk_opf_t)3,
339 /* securely erase sectors */
340 REQ_OP_SECURE_ERASE = (__force blk_opf_t)5,
341 /* write data at the current zone write pointer */
342 REQ_OP_ZONE_APPEND = (__force blk_opf_t)7,
343 /* write the zero filled sector many times */
344 REQ_OP_WRITE_ZEROES = (__force blk_opf_t)9,
345 /* Open a zone */
346 REQ_OP_ZONE_OPEN = (__force blk_opf_t)10,
347 /* Close a zone */
348 REQ_OP_ZONE_CLOSE = (__force blk_opf_t)11,
349 /* Transition a zone to full */
350 REQ_OP_ZONE_FINISH = (__force blk_opf_t)12,
351 /* reset a zone write pointer */
352 REQ_OP_ZONE_RESET = (__force blk_opf_t)13,
353 /* reset all the zone present on the device */
354 REQ_OP_ZONE_RESET_ALL = (__force blk_opf_t)15,
355
356 /* Driver private requests */
357 REQ_OP_DRV_IN = (__force blk_opf_t)34,
358 REQ_OP_DRV_OUT = (__force blk_opf_t)35,
359
360 REQ_OP_LAST = (__force blk_opf_t)36,
361};
362
363enum req_flag_bits {
364 __REQ_FAILFAST_DEV = /* no driver retries of device errors */
365 REQ_OP_BITS,
366 __REQ_FAILFAST_TRANSPORT, /* no driver retries of transport errors */
367 __REQ_FAILFAST_DRIVER, /* no driver retries of driver errors */
368 __REQ_SYNC, /* request is sync (sync write or read) */
369 __REQ_META, /* metadata io request */
370 __REQ_PRIO, /* boost priority in cfq */
371 __REQ_NOMERGE, /* don't touch this for merging */
372 __REQ_IDLE, /* anticipate more IO after this one */
373 __REQ_INTEGRITY, /* I/O includes block integrity payload */
374 __REQ_FUA, /* forced unit access */
375 __REQ_PREFLUSH, /* request for cache flush */
376 __REQ_RAHEAD, /* read ahead, can fail anytime */
377 __REQ_BACKGROUND, /* background IO */
378 __REQ_NOWAIT, /* Don't wait if request will block */
379 __REQ_POLLED, /* caller polls for completion using bio_poll */
380 __REQ_ALLOC_CACHE, /* allocate IO from cache if available */
381 __REQ_SWAP, /* swap I/O */
382 __REQ_DRV, /* for driver use */
383 __REQ_FS_PRIVATE, /* for file system (submitter) use */
384
385 /*
386 * Command specific flags, keep last:
387 */
388 /* for REQ_OP_WRITE_ZEROES: */
389 __REQ_NOUNMAP, /* do not free blocks when zeroing */
390
391 __REQ_NR_BITS, /* stops here */
392};
393
394#define REQ_FAILFAST_DEV \
395 (__force blk_opf_t)(1ULL << __REQ_FAILFAST_DEV)
396#define REQ_FAILFAST_TRANSPORT \
397 (__force blk_opf_t)(1ULL << __REQ_FAILFAST_TRANSPORT)
398#define REQ_FAILFAST_DRIVER \
399 (__force blk_opf_t)(1ULL << __REQ_FAILFAST_DRIVER)
400#define REQ_SYNC (__force blk_opf_t)(1ULL << __REQ_SYNC)
401#define REQ_META (__force blk_opf_t)(1ULL << __REQ_META)
402#define REQ_PRIO (__force blk_opf_t)(1ULL << __REQ_PRIO)
403#define REQ_NOMERGE (__force blk_opf_t)(1ULL << __REQ_NOMERGE)
404#define REQ_IDLE (__force blk_opf_t)(1ULL << __REQ_IDLE)
405#define REQ_INTEGRITY (__force blk_opf_t)(1ULL << __REQ_INTEGRITY)
406#define REQ_FUA (__force blk_opf_t)(1ULL << __REQ_FUA)
407#define REQ_PREFLUSH (__force blk_opf_t)(1ULL << __REQ_PREFLUSH)
408#define REQ_RAHEAD (__force blk_opf_t)(1ULL << __REQ_RAHEAD)
409#define REQ_BACKGROUND (__force blk_opf_t)(1ULL << __REQ_BACKGROUND)
410#define REQ_NOWAIT (__force blk_opf_t)(1ULL << __REQ_NOWAIT)
411#define REQ_POLLED (__force blk_opf_t)(1ULL << __REQ_POLLED)
412#define REQ_ALLOC_CACHE (__force blk_opf_t)(1ULL << __REQ_ALLOC_CACHE)
413#define REQ_SWAP (__force blk_opf_t)(1ULL << __REQ_SWAP)
414#define REQ_DRV (__force blk_opf_t)(1ULL << __REQ_DRV)
415#define REQ_FS_PRIVATE (__force blk_opf_t)(1ULL << __REQ_FS_PRIVATE)
416
417#define REQ_NOUNMAP (__force blk_opf_t)(1ULL << __REQ_NOUNMAP)
418
419#define REQ_FAILFAST_MASK \
420 (REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT | REQ_FAILFAST_DRIVER)
421
422#define REQ_NOMERGE_FLAGS \
423 (REQ_NOMERGE | REQ_PREFLUSH | REQ_FUA)
424
425enum stat_group {
426 STAT_READ,
427 STAT_WRITE,
428 STAT_DISCARD,
429 STAT_FLUSH,
430
431 NR_STAT_GROUPS
432};
433
434static inline enum req_op bio_op(const struct bio *bio)
435{
436 return bio->bi_opf & REQ_OP_MASK;
437}
438
439static inline bool op_is_write(blk_opf_t op)
440{
441 return !!(op & (__force blk_opf_t)1);
442}
443
444/*
445 * Check if the bio or request is one that needs special treatment in the
446 * flush state machine.
447 */
448static inline bool op_is_flush(blk_opf_t op)
449{
450 return op & (REQ_FUA | REQ_PREFLUSH);
451}
452
453/*
454 * Reads are always treated as synchronous, as are requests with the FUA or
455 * PREFLUSH flag. Other operations may be marked as synchronous using the
456 * REQ_SYNC flag.
457 */
458static inline bool op_is_sync(blk_opf_t op)
459{
460 return (op & REQ_OP_MASK) == REQ_OP_READ ||
461 (op & (REQ_SYNC | REQ_FUA | REQ_PREFLUSH));
462}
463
464static inline bool op_is_discard(blk_opf_t op)
465{
466 return (op & REQ_OP_MASK) == REQ_OP_DISCARD;
467}
468
469/*
470 * Check if a bio or request operation is a zone management operation, with
471 * the exception of REQ_OP_ZONE_RESET_ALL which is treated as a special case
472 * due to its different handling in the block layer and device response in
473 * case of command failure.
474 */
475static inline bool op_is_zone_mgmt(enum req_op op)
476{
477 switch (op & REQ_OP_MASK) {
478 case REQ_OP_ZONE_RESET:
479 case REQ_OP_ZONE_OPEN:
480 case REQ_OP_ZONE_CLOSE:
481 case REQ_OP_ZONE_FINISH:
482 return true;
483 default:
484 return false;
485 }
486}
487
488static inline int op_stat_group(enum req_op op)
489{
490 if (op_is_discard(op))
491 return STAT_DISCARD;
492 return op_is_write(op);
493}
494
495struct blk_rq_stat {
496 u64 mean;
497 u64 min;
498 u64 max;
499 u32 nr_samples;
500 u64 batch;
501};
502
503#endif /* __LINUX_BLK_TYPES_H */
504

source code of linux/include/linux/blk_types.h