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/android_kabi.h>
14
15 struct bio_set;
16 struct bio;
17 struct bio_integrity_payload;
18 struct page;
19 struct io_context;
20 struct cgroup_subsys_state;
21 typedef void (bio_end_io_t) (struct bio *);
22 struct 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
41 struct block_device {
42 sector_t bd_start_sect;
43 sector_t bd_nr_sectors;
44 struct disk_stats __percpu *bd_stats;
45 unsigned long bd_stamp;
46 bool bd_read_only; /* read-only policy */
47 dev_t bd_dev;
48 atomic_t bd_openers;
49 struct inode * bd_inode; /* will die */
50 struct super_block * bd_super;
51 void * bd_claiming;
52 struct device bd_device;
53 void * bd_holder;
54 int bd_holders;
55 bool bd_write_holder;
56 struct kobject *bd_holder_dir;
57 u8 bd_partno;
58 spinlock_t bd_size_lock; /* for bd_inode->i_size updates */
59 struct gendisk * bd_disk;
60 struct request_queue * bd_queue;
61
62 /* The counter of freeze processes */
63 int bd_fsfreeze_count;
64 /* Mutex for freeze */
65 struct mutex bd_fsfreeze_mutex;
66 struct super_block *bd_fsfreeze_sb;
67
68 struct partition_meta_info *bd_meta_info;
69 #ifdef CONFIG_FAIL_MAKE_REQUEST
70 bool bd_make_it_fail;
71 #endif
72 } __randomize_layout;
73
74 #define bdev_whole(_bdev) \
75 ((_bdev)->bd_disk->part0)
76
77 #define dev_to_bdev(device) \
78 container_of((device), struct block_device, bd_device)
79
80 #define bdev_kobj(_bdev) \
81 (&((_bdev)->bd_device.kobj))
82
83 /*
84 * Block error status values. See block/blk-core:blk_errors for the details.
85 * Alpha cannot write a byte atomically, so we need to use 32-bit value.
86 */
87 #if defined(CONFIG_ALPHA) && !defined(__alpha_bwx__)
88 typedef u32 __bitwise blk_status_t;
89 typedef u32 blk_short_t;
90 #else
91 typedef u8 __bitwise blk_status_t;
92 typedef u16 blk_short_t;
93 #endif
94 #define BLK_STS_OK 0
95 #define BLK_STS_NOTSUPP ((__force blk_status_t)1)
96 #define BLK_STS_TIMEOUT ((__force blk_status_t)2)
97 #define BLK_STS_NOSPC ((__force blk_status_t)3)
98 #define BLK_STS_TRANSPORT ((__force blk_status_t)4)
99 #define BLK_STS_TARGET ((__force blk_status_t)5)
100 #define BLK_STS_NEXUS ((__force blk_status_t)6)
101 #define BLK_STS_MEDIUM ((__force blk_status_t)7)
102 #define BLK_STS_PROTECTION ((__force blk_status_t)8)
103 #define BLK_STS_RESOURCE ((__force blk_status_t)9)
104 #define BLK_STS_IOERR ((__force blk_status_t)10)
105
106 /* hack for device mapper, don't use elsewhere: */
107 #define BLK_STS_DM_REQUEUE ((__force blk_status_t)11)
108
109 /*
110 * BLK_STS_AGAIN should only be returned if RQF_NOWAIT is set
111 * and the bio would block (cf bio_wouldblock_error())
112 */
113 #define BLK_STS_AGAIN ((__force blk_status_t)12)
114
115 /*
116 * BLK_STS_DEV_RESOURCE is returned from the driver to the block layer if
117 * device related resources are unavailable, but the driver can guarantee
118 * that the queue will be rerun in the future once resources become
119 * available again. This is typically the case for device specific
120 * resources that are consumed for IO. If the driver fails allocating these
121 * resources, we know that inflight (or pending) IO will free these
122 * resource upon completion.
123 *
124 * This is different from BLK_STS_RESOURCE in that it explicitly references
125 * a device specific resource. For resources of wider scope, allocation
126 * failure can happen without having pending IO. This means that we can't
127 * rely on request completions freeing these resources, as IO may not be in
128 * flight. Examples of that are kernel memory allocations, DMA mappings, or
129 * any other system wide resources.
130 */
131 #define BLK_STS_DEV_RESOURCE ((__force blk_status_t)13)
132
133 /*
134 * BLK_STS_ZONE_RESOURCE is returned from the driver to the block layer if zone
135 * related resources are unavailable, but the driver can guarantee the queue
136 * will be rerun in the future once the resources become available again.
137 *
138 * This is different from BLK_STS_DEV_RESOURCE in that it explicitly references
139 * a zone specific resource and IO to a different zone on the same device could
140 * still be served. Examples of that are zones that are write-locked, but a read
141 * to the same zone could be served.
142 */
143 #define BLK_STS_ZONE_RESOURCE ((__force blk_status_t)14)
144
145 /*
146 * BLK_STS_ZONE_OPEN_RESOURCE is returned from the driver in the completion
147 * path if the device returns a status indicating that too many zone resources
148 * are currently open. The same command should be successful if resubmitted
149 * after the number of open zones decreases below the device's limits, which is
150 * reported in the request_queue's max_open_zones.
151 */
152 #define BLK_STS_ZONE_OPEN_RESOURCE ((__force blk_status_t)15)
153
154 /*
155 * BLK_STS_ZONE_ACTIVE_RESOURCE is returned from the driver in the completion
156 * path if the device returns a status indicating that too many zone resources
157 * are currently active. The same command should be successful if resubmitted
158 * after the number of active zones decreases below the device's limits, which
159 * is reported in the request_queue's max_active_zones.
160 */
161 #define BLK_STS_ZONE_ACTIVE_RESOURCE ((__force blk_status_t)16)
162
163 /*
164 * BLK_STS_OFFLINE is returned from the driver when the target device is offline
165 * or is being taken offline. This could help differentiate the case where a
166 * device is intentionally being shut down from a real I/O error.
167 */
168 #define BLK_STS_OFFLINE ((__force blk_status_t)17)
169
170 /**
171 * blk_path_error - returns true if error may be path related
172 * @error: status the request was completed with
173 *
174 * Description:
175 * This classifies block error status into non-retryable errors and ones
176 * that may be successful if retried on a failover path.
177 *
178 * Return:
179 * %false - retrying failover path will not help
180 * %true - may succeed if retried
181 */
blk_path_error(blk_status_t error)182 static inline bool blk_path_error(blk_status_t error)
183 {
184 switch (error) {
185 case BLK_STS_NOTSUPP:
186 case BLK_STS_NOSPC:
187 case BLK_STS_TARGET:
188 case BLK_STS_NEXUS:
189 case BLK_STS_MEDIUM:
190 case BLK_STS_PROTECTION:
191 return false;
192 }
193
194 /* Anything else could be a path failure, so should be retried */
195 return true;
196 }
197
198 /*
199 * From most significant bit:
200 * 1 bit: reserved for other usage, see below
201 * 12 bits: original size of bio
202 * 51 bits: issue time of bio
203 */
204 #define BIO_ISSUE_RES_BITS 1
205 #define BIO_ISSUE_SIZE_BITS 12
206 #define BIO_ISSUE_RES_SHIFT (64 - BIO_ISSUE_RES_BITS)
207 #define BIO_ISSUE_SIZE_SHIFT (BIO_ISSUE_RES_SHIFT - BIO_ISSUE_SIZE_BITS)
208 #define BIO_ISSUE_TIME_MASK ((1ULL << BIO_ISSUE_SIZE_SHIFT) - 1)
209 #define BIO_ISSUE_SIZE_MASK \
210 (((1ULL << BIO_ISSUE_SIZE_BITS) - 1) << BIO_ISSUE_SIZE_SHIFT)
211 #define BIO_ISSUE_RES_MASK (~((1ULL << BIO_ISSUE_RES_SHIFT) - 1))
212
213 /* Reserved bit for blk-throtl */
214 #define BIO_ISSUE_THROTL_SKIP_LATENCY (1ULL << 63)
215
216 struct bio_issue {
217 u64 value;
218 };
219
__bio_issue_time(u64 time)220 static inline u64 __bio_issue_time(u64 time)
221 {
222 return time & BIO_ISSUE_TIME_MASK;
223 }
224
bio_issue_time(struct bio_issue * issue)225 static inline u64 bio_issue_time(struct bio_issue *issue)
226 {
227 return __bio_issue_time(issue->value);
228 }
229
bio_issue_size(struct bio_issue * issue)230 static inline sector_t bio_issue_size(struct bio_issue *issue)
231 {
232 return ((issue->value & BIO_ISSUE_SIZE_MASK) >> BIO_ISSUE_SIZE_SHIFT);
233 }
234
bio_issue_init(struct bio_issue * issue,sector_t size)235 static inline void bio_issue_init(struct bio_issue *issue,
236 sector_t size)
237 {
238 size &= (1ULL << BIO_ISSUE_SIZE_BITS) - 1;
239 issue->value = ((issue->value & BIO_ISSUE_RES_MASK) |
240 (ktime_get_ns() & BIO_ISSUE_TIME_MASK) |
241 ((u64)size << BIO_ISSUE_SIZE_SHIFT));
242 }
243
244 typedef __u32 __bitwise blk_opf_t;
245
246 typedef unsigned int blk_qc_t;
247 #define BLK_QC_T_NONE -1U
248
249 /*
250 * main unit of I/O for the block layer and lower layers (ie drivers and
251 * stacking drivers)
252 */
253 struct bio {
254 struct bio *bi_next; /* request queue link */
255 struct block_device *bi_bdev;
256 blk_opf_t bi_opf; /* bottom bits REQ_OP, top bits
257 * req_flags.
258 */
259 unsigned short bi_flags; /* BIO_* below */
260 unsigned short bi_ioprio;
261 blk_status_t bi_status;
262 atomic_t __bi_remaining;
263
264 struct bvec_iter bi_iter;
265
266 blk_qc_t bi_cookie;
267 bio_end_io_t *bi_end_io;
268 void *bi_private;
269 #ifdef CONFIG_BLK_CGROUP
270 /*
271 * Represents the association of the css and request_queue for the bio.
272 * If a bio goes direct to device, it will not have a blkg as it will
273 * not have a request_queue associated with it. The reference is put
274 * on release of the bio.
275 */
276 struct blkcg_gq *bi_blkg;
277 struct bio_issue bi_issue;
278 #ifdef CONFIG_BLK_CGROUP_IOCOST
279 u64 bi_iocost_cost;
280 #endif
281 #endif
282
283 #ifdef CONFIG_BLK_INLINE_ENCRYPTION
284 struct bio_crypt_ctx *bi_crypt_context;
285 #if IS_ENABLED(CONFIG_DM_DEFAULT_KEY)
286 bool bi_skip_dm_default_key;
287 #endif
288 #endif
289
290 union {
291 #if defined(CONFIG_BLK_DEV_INTEGRITY)
292 struct bio_integrity_payload *bi_integrity; /* data integrity */
293 #endif
294 };
295
296 unsigned short bi_vcnt; /* how many bio_vec's */
297
298 /*
299 * Everything starting with bi_max_vecs will be preserved by bio_reset()
300 */
301
302 unsigned short bi_max_vecs; /* max bvl_vecs we can hold */
303
304 atomic_t __bi_cnt; /* pin count */
305
306 struct bio_vec *bi_io_vec; /* the actual vec list */
307
308 struct bio_set *bi_pool;
309
310 ANDROID_OEM_DATA(1);
311 ANDROID_KABI_RESERVE(1);
312 ANDROID_KABI_RESERVE(2);
313
314 /*
315 * We can inline a number of vecs at the end of the bio, to avoid
316 * double allocations for a small number of bio_vecs. This member
317 * MUST obviously be kept at the very end of the bio.
318 */
319 struct bio_vec bi_inline_vecs[];
320 };
321
322 #define BIO_RESET_BYTES offsetof(struct bio, bi_max_vecs)
323 #define BIO_MAX_SECTORS (UINT_MAX >> SECTOR_SHIFT)
324
325 /*
326 * bio flags
327 */
328 enum {
329 BIO_NO_PAGE_REF, /* don't put release vec pages */
330 BIO_CLONED, /* doesn't own data */
331 BIO_BOUNCED, /* bio is a bounce bio */
332 BIO_QUIET, /* Make BIO Quiet */
333 BIO_CHAIN, /* chained bio, ->bi_remaining in effect */
334 BIO_REFFED, /* bio has elevated ->bi_cnt */
335 BIO_BPS_THROTTLED, /* This bio has already been subjected to
336 * throttling rules. Don't do it again. */
337 BIO_TRACE_COMPLETION, /* bio_endio() should trace the final completion
338 * of this bio. */
339 BIO_CGROUP_ACCT, /* has been accounted to a cgroup */
340 BIO_QOS_THROTTLED, /* bio went through rq_qos throttle path */
341 BIO_QOS_MERGED, /* but went through rq_qos merge path */
342 BIO_REMAPPED,
343 BIO_ZONE_WRITE_LOCKED, /* Owns a zoned device zone write lock */
344 BIO_FLAG_LAST
345 };
346
347 typedef __u32 __bitwise blk_mq_req_flags_t;
348
349 #define REQ_OP_BITS 8
350 #define REQ_OP_MASK (__force blk_opf_t)((1 << REQ_OP_BITS) - 1)
351 #define REQ_FLAG_BITS 24
352
353 /**
354 * enum req_op - Operations common to the bio and request structures.
355 * We use 8 bits for encoding the operation, and the remaining 24 for flags.
356 *
357 * The least significant bit of the operation number indicates the data
358 * transfer direction:
359 *
360 * - if the least significant bit is set transfers are TO the device
361 * - if the least significant bit is not set transfers are FROM the device
362 *
363 * If a operation does not transfer data the least significant bit has no
364 * meaning.
365 */
366 enum req_op {
367 /* read sectors from the device */
368 REQ_OP_READ = (__force blk_opf_t)0,
369 /* write sectors to the device */
370 REQ_OP_WRITE = (__force blk_opf_t)1,
371 /* flush the volatile write cache */
372 REQ_OP_FLUSH = (__force blk_opf_t)2,
373 /* discard sectors */
374 REQ_OP_DISCARD = (__force blk_opf_t)3,
375 /* securely erase sectors */
376 REQ_OP_SECURE_ERASE = (__force blk_opf_t)5,
377 /* write the zero filled sector many times */
378 REQ_OP_WRITE_ZEROES = (__force blk_opf_t)9,
379 /* Open a zone */
380 REQ_OP_ZONE_OPEN = (__force blk_opf_t)10,
381 /* Close a zone */
382 REQ_OP_ZONE_CLOSE = (__force blk_opf_t)11,
383 /* Transition a zone to full */
384 REQ_OP_ZONE_FINISH = (__force blk_opf_t)12,
385 /* write data at the current zone write pointer */
386 REQ_OP_ZONE_APPEND = (__force blk_opf_t)13,
387 /* reset a zone write pointer */
388 REQ_OP_ZONE_RESET = (__force blk_opf_t)15,
389 /* reset all the zone present on the device */
390 REQ_OP_ZONE_RESET_ALL = (__force blk_opf_t)17,
391
392 /* Driver private requests */
393 REQ_OP_DRV_IN = (__force blk_opf_t)34,
394 REQ_OP_DRV_OUT = (__force blk_opf_t)35,
395
396 REQ_OP_LAST = (__force blk_opf_t)36,
397 };
398
399 enum req_flag_bits {
400 __REQ_FAILFAST_DEV = /* no driver retries of device errors */
401 REQ_OP_BITS,
402 __REQ_FAILFAST_TRANSPORT, /* no driver retries of transport errors */
403 __REQ_FAILFAST_DRIVER, /* no driver retries of driver errors */
404 __REQ_SYNC, /* request is sync (sync write or read) */
405 __REQ_META, /* metadata io request */
406 __REQ_PRIO, /* boost priority in cfq */
407 __REQ_NOMERGE, /* don't touch this for merging */
408 __REQ_IDLE, /* anticipate more IO after this one */
409 __REQ_INTEGRITY, /* I/O includes block integrity payload */
410 __REQ_FUA, /* forced unit access */
411 __REQ_PREFLUSH, /* request for cache flush */
412 __REQ_RAHEAD, /* read ahead, can fail anytime */
413 __REQ_BACKGROUND, /* background IO */
414 __REQ_NOWAIT, /* Don't wait if request will block */
415 /*
416 * When a shared kthread needs to issue a bio for a cgroup, doing
417 * so synchronously can lead to priority inversions as the kthread
418 * can be trapped waiting for that cgroup. CGROUP_PUNT flag makes
419 * submit_bio() punt the actual issuing to a dedicated per-blkcg
420 * work item to avoid such priority inversions.
421 */
422 __REQ_CGROUP_PUNT,
423 __REQ_POLLED, /* caller polls for completion using bio_poll */
424 __REQ_ALLOC_CACHE, /* allocate IO from cache if available */
425 __REQ_SWAP, /* swap I/O */
426 __REQ_DRV, /* for driver use */
427
428 /*
429 * Command specific flags, keep last:
430 */
431 /* for REQ_OP_WRITE_ZEROES: */
432 __REQ_NOUNMAP, /* do not free blocks when zeroing */
433
434 __REQ_NR_BITS, /* stops here */
435 };
436
437 #define REQ_FAILFAST_DEV \
438 (__force blk_opf_t)(1ULL << __REQ_FAILFAST_DEV)
439 #define REQ_FAILFAST_TRANSPORT \
440 (__force blk_opf_t)(1ULL << __REQ_FAILFAST_TRANSPORT)
441 #define REQ_FAILFAST_DRIVER \
442 (__force blk_opf_t)(1ULL << __REQ_FAILFAST_DRIVER)
443 #define REQ_SYNC (__force blk_opf_t)(1ULL << __REQ_SYNC)
444 #define REQ_META (__force blk_opf_t)(1ULL << __REQ_META)
445 #define REQ_PRIO (__force blk_opf_t)(1ULL << __REQ_PRIO)
446 #define REQ_NOMERGE (__force blk_opf_t)(1ULL << __REQ_NOMERGE)
447 #define REQ_IDLE (__force blk_opf_t)(1ULL << __REQ_IDLE)
448 #define REQ_INTEGRITY (__force blk_opf_t)(1ULL << __REQ_INTEGRITY)
449 #define REQ_FUA (__force blk_opf_t)(1ULL << __REQ_FUA)
450 #define REQ_PREFLUSH (__force blk_opf_t)(1ULL << __REQ_PREFLUSH)
451 #define REQ_RAHEAD (__force blk_opf_t)(1ULL << __REQ_RAHEAD)
452 #define REQ_BACKGROUND (__force blk_opf_t)(1ULL << __REQ_BACKGROUND)
453 #define REQ_NOWAIT (__force blk_opf_t)(1ULL << __REQ_NOWAIT)
454 #define REQ_CGROUP_PUNT (__force blk_opf_t)(1ULL << __REQ_CGROUP_PUNT)
455
456 #define REQ_NOUNMAP (__force blk_opf_t)(1ULL << __REQ_NOUNMAP)
457 #define REQ_POLLED (__force blk_opf_t)(1ULL << __REQ_POLLED)
458 #define REQ_ALLOC_CACHE (__force blk_opf_t)(1ULL << __REQ_ALLOC_CACHE)
459
460 #define REQ_DRV (__force blk_opf_t)(1ULL << __REQ_DRV)
461 #define REQ_SWAP (__force blk_opf_t)(1ULL << __REQ_SWAP)
462
463 #define REQ_FAILFAST_MASK \
464 (REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT | REQ_FAILFAST_DRIVER)
465
466 #define REQ_NOMERGE_FLAGS \
467 (REQ_NOMERGE | REQ_PREFLUSH | REQ_FUA)
468
469 enum stat_group {
470 STAT_READ,
471 STAT_WRITE,
472 STAT_DISCARD,
473 STAT_FLUSH,
474
475 NR_STAT_GROUPS
476 };
477
bio_op(const struct bio * bio)478 static inline enum req_op bio_op(const struct bio *bio)
479 {
480 return bio->bi_opf & REQ_OP_MASK;
481 }
482
483 /* obsolete, don't use in new code */
bio_set_op_attrs(struct bio * bio,enum req_op op,blk_opf_t op_flags)484 static inline void bio_set_op_attrs(struct bio *bio, enum req_op op,
485 blk_opf_t op_flags)
486 {
487 bio->bi_opf = op | op_flags;
488 }
489
op_is_write(blk_opf_t op)490 static inline bool op_is_write(blk_opf_t op)
491 {
492 return !!(op & (__force blk_opf_t)1);
493 }
494
495 /*
496 * Check if the bio or request is one that needs special treatment in the
497 * flush state machine.
498 */
op_is_flush(blk_opf_t op)499 static inline bool op_is_flush(blk_opf_t op)
500 {
501 return op & (REQ_FUA | REQ_PREFLUSH);
502 }
503
504 /*
505 * Reads are always treated as synchronous, as are requests with the FUA or
506 * PREFLUSH flag. Other operations may be marked as synchronous using the
507 * REQ_SYNC flag.
508 */
op_is_sync(blk_opf_t op)509 static inline bool op_is_sync(blk_opf_t op)
510 {
511 return (op & REQ_OP_MASK) == REQ_OP_READ ||
512 (op & (REQ_SYNC | REQ_FUA | REQ_PREFLUSH));
513 }
514
op_is_discard(blk_opf_t op)515 static inline bool op_is_discard(blk_opf_t op)
516 {
517 return (op & REQ_OP_MASK) == REQ_OP_DISCARD;
518 }
519
520 /*
521 * Check if a bio or request operation is a zone management operation, with
522 * the exception of REQ_OP_ZONE_RESET_ALL which is treated as a special case
523 * due to its different handling in the block layer and device response in
524 * case of command failure.
525 */
op_is_zone_mgmt(enum req_op op)526 static inline bool op_is_zone_mgmt(enum req_op op)
527 {
528 switch (op & REQ_OP_MASK) {
529 case REQ_OP_ZONE_RESET:
530 case REQ_OP_ZONE_OPEN:
531 case REQ_OP_ZONE_CLOSE:
532 case REQ_OP_ZONE_FINISH:
533 return true;
534 default:
535 return false;
536 }
537 }
538
op_stat_group(enum req_op op)539 static inline int op_stat_group(enum req_op op)
540 {
541 if (op_is_discard(op))
542 return STAT_DISCARD;
543 return op_is_write(op);
544 }
545
546 struct blk_rq_stat {
547 u64 mean;
548 u64 min;
549 u64 max;
550 u32 nr_samples;
551 u64 batch;
552 };
553
554 #endif /* __LINUX_BLK_TYPES_H */
555