Linux kernel mirror (for testing)
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linux
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 atomic_t __bd_flags; // partition number + flags
49#define BD_PARTNO 255 // lower 8 bits; assign-once
50#define BD_READ_ONLY (1u<<8) // read-only policy
51#define BD_WRITE_HOLDER (1u<<9)
52#define BD_HAS_SUBMIT_BIO (1u<<10)
53#define BD_RO_WARNED (1u<<11)
54#ifdef CONFIG_FAIL_MAKE_REQUEST
55#define BD_MAKE_IT_FAIL (1u<<12)
56#endif
57 dev_t bd_dev;
58 struct address_space *bd_mapping; /* page cache */
59
60 atomic_t bd_openers;
61 spinlock_t bd_size_lock; /* for bd_inode->i_size updates */
62 void * bd_claiming;
63 void * bd_holder;
64 const struct blk_holder_ops *bd_holder_ops;
65 struct mutex bd_holder_lock;
66 int bd_holders;
67 struct kobject *bd_holder_dir;
68
69 atomic_t bd_fsfreeze_count; /* number of freeze requests */
70 struct mutex bd_fsfreeze_mutex; /* serialize freeze/thaw */
71
72 struct partition_meta_info *bd_meta_info;
73 int bd_writers;
74#ifdef CONFIG_SECURITY
75 void *bd_security;
76#endif
77 /*
78 * keep this out-of-line as it's both big and not needed in the fast
79 * path
80 */
81 struct device bd_device;
82} __randomize_layout;
83
84#define bdev_whole(_bdev) \
85 ((_bdev)->bd_disk->part0)
86
87#define dev_to_bdev(device) \
88 container_of((device), struct block_device, bd_device)
89
90#define bdev_kobj(_bdev) \
91 (&((_bdev)->bd_device.kobj))
92
93/*
94 * Block error status values. See block/blk-core:blk_errors for the details.
95 */
96typedef u8 __bitwise blk_status_t;
97typedef u16 blk_short_t;
98#define BLK_STS_OK 0
99#define BLK_STS_NOTSUPP ((__force blk_status_t)1)
100#define BLK_STS_TIMEOUT ((__force blk_status_t)2)
101#define BLK_STS_NOSPC ((__force blk_status_t)3)
102#define BLK_STS_TRANSPORT ((__force blk_status_t)4)
103#define BLK_STS_TARGET ((__force blk_status_t)5)
104#define BLK_STS_RESV_CONFLICT ((__force blk_status_t)6)
105#define BLK_STS_MEDIUM ((__force blk_status_t)7)
106#define BLK_STS_PROTECTION ((__force blk_status_t)8)
107#define BLK_STS_RESOURCE ((__force blk_status_t)9)
108#define BLK_STS_IOERR ((__force blk_status_t)10)
109
110/* hack for device mapper, don't use elsewhere: */
111#define BLK_STS_DM_REQUEUE ((__force blk_status_t)11)
112
113/*
114 * BLK_STS_AGAIN should only be returned if RQF_NOWAIT is set
115 * and the bio would block (cf bio_wouldblock_error())
116 */
117#define BLK_STS_AGAIN ((__force blk_status_t)12)
118
119/*
120 * BLK_STS_DEV_RESOURCE is returned from the driver to the block layer if
121 * device related resources are unavailable, but the driver can guarantee
122 * that the queue will be rerun in the future once resources become
123 * available again. This is typically the case for device specific
124 * resources that are consumed for IO. If the driver fails allocating these
125 * resources, we know that inflight (or pending) IO will free these
126 * resource upon completion.
127 *
128 * This is different from BLK_STS_RESOURCE in that it explicitly references
129 * a device specific resource. For resources of wider scope, allocation
130 * failure can happen without having pending IO. This means that we can't
131 * rely on request completions freeing these resources, as IO may not be in
132 * flight. Examples of that are kernel memory allocations, DMA mappings, or
133 * any other system wide resources.
134 */
135#define BLK_STS_DEV_RESOURCE ((__force blk_status_t)13)
136
137/*
138 * BLK_STS_ZONE_OPEN_RESOURCE is returned from the driver in the completion
139 * path if the device returns a status indicating that too many zone resources
140 * are currently open. The same command should be successful if resubmitted
141 * after the number of open zones decreases below the device's limits, which is
142 * reported in the request_queue's max_open_zones.
143 */
144#define BLK_STS_ZONE_OPEN_RESOURCE ((__force blk_status_t)14)
145
146/*
147 * BLK_STS_ZONE_ACTIVE_RESOURCE is returned from the driver in the completion
148 * path if the device returns a status indicating that too many zone resources
149 * are currently active. The same command should be successful if resubmitted
150 * after the number of active zones decreases below the device's limits, which
151 * is reported in the request_queue's max_active_zones.
152 */
153#define BLK_STS_ZONE_ACTIVE_RESOURCE ((__force blk_status_t)15)
154
155/*
156 * BLK_STS_OFFLINE is returned from the driver when the target device is offline
157 * or is being taken offline. This could help differentiate the case where a
158 * device is intentionally being shut down from a real I/O error.
159 */
160#define BLK_STS_OFFLINE ((__force blk_status_t)16)
161
162/*
163 * BLK_STS_DURATION_LIMIT is returned from the driver when the target device
164 * aborted the command because it exceeded one of its Command Duration Limits.
165 */
166#define BLK_STS_DURATION_LIMIT ((__force blk_status_t)17)
167
168/*
169 * Invalid size or alignment.
170 */
171#define BLK_STS_INVAL ((__force blk_status_t)19)
172
173/**
174 * blk_path_error - returns true if error may be path related
175 * @error: status the request was completed with
176 *
177 * Description:
178 * This classifies block error status into non-retryable errors and ones
179 * that may be successful if retried on a failover path.
180 *
181 * Return:
182 * %false - retrying failover path will not help
183 * %true - may succeed if retried
184 */
185static inline bool blk_path_error(blk_status_t error)
186{
187 switch (error) {
188 case BLK_STS_NOTSUPP:
189 case BLK_STS_NOSPC:
190 case BLK_STS_TARGET:
191 case BLK_STS_RESV_CONFLICT:
192 case BLK_STS_MEDIUM:
193 case BLK_STS_PROTECTION:
194 return false;
195 }
196
197 /* Anything else could be a path failure, so should be retried */
198 return true;
199}
200
201typedef __u32 __bitwise blk_opf_t;
202
203typedef unsigned int blk_qc_t;
204#define BLK_QC_T_NONE -1U
205
206/*
207 * main unit of I/O for the block layer and lower layers (ie drivers and
208 * stacking drivers)
209 */
210struct bio {
211 struct bio *bi_next; /* request queue link */
212 struct block_device *bi_bdev;
213 blk_opf_t bi_opf; /* bottom bits REQ_OP, top bits
214 * req_flags.
215 */
216 unsigned short bi_flags; /* BIO_* below */
217 unsigned short bi_ioprio;
218 enum rw_hint bi_write_hint;
219 u8 bi_write_stream;
220 blk_status_t bi_status;
221
222 /*
223 * The bvec gap bit indicates the lowest set bit in any address offset
224 * between all bi_io_vecs. This field is initialized only after the bio
225 * is split to the hardware limits (see bio_split_io_at()). The value
226 * may be used to consider DMA optimization when performing that
227 * mapping. The value is compared to a power of two mask where the
228 * result depends on any bit set within the mask, so saving the lowest
229 * bit is sufficient to know if any segment gap collides with the mask.
230 */
231 u8 bi_bvec_gap_bit;
232
233 atomic_t __bi_remaining;
234
235 /* The actual vec list, preserved by bio_reset() */
236 struct bio_vec *bi_io_vec;
237 struct bvec_iter bi_iter;
238
239 union {
240 /* for polled bios: */
241 blk_qc_t bi_cookie;
242 /* for plugged zoned writes only: */
243 unsigned int __bi_nr_segments;
244 };
245 bio_end_io_t *bi_end_io;
246 void *bi_private;
247#ifdef CONFIG_BLK_CGROUP
248 /*
249 * Represents the association of the css and request_queue for the bio.
250 * If a bio goes direct to device, it will not have a blkg as it will
251 * not have a request_queue associated with it. The reference is put
252 * on release of the bio.
253 */
254 struct blkcg_gq *bi_blkg;
255 /* Time that this bio was issued. */
256 u64 issue_time_ns;
257#ifdef CONFIG_BLK_CGROUP_IOCOST
258 u64 bi_iocost_cost;
259#endif
260#endif
261
262#ifdef CONFIG_BLK_INLINE_ENCRYPTION
263 struct bio_crypt_ctx *bi_crypt_context;
264#endif
265
266#if defined(CONFIG_BLK_DEV_INTEGRITY)
267 struct bio_integrity_payload *bi_integrity; /* data integrity */
268#endif
269
270 unsigned short bi_vcnt; /* how many bio_vec's */
271
272 /*
273 * Everything starting with bi_max_vecs will be preserved by bio_reset()
274 */
275
276 /*
277 * Number of elements in `bi_io_vec` that were allocated for this bio.
278 * Only used by the bio submitter to make `bio_add_page` fail once full
279 * and to free the `bi_io_vec` allocation. Must not be used in drivers
280 * and does not hold a useful value for cloned bios.
281 */
282 unsigned short bi_max_vecs;
283
284 atomic_t __bi_cnt; /* pin count */
285
286 struct bio_set *bi_pool;
287};
288
289#define BIO_RESET_BYTES offsetof(struct bio, bi_max_vecs)
290#define BIO_MAX_SIZE UINT_MAX /* max value of bi_iter.bi_size */
291#define BIO_MAX_SECTORS (BIO_MAX_SIZE >> SECTOR_SHIFT)
292
293static inline struct bio_vec *bio_inline_vecs(struct bio *bio)
294{
295 return (struct bio_vec *)(bio + 1);
296}
297
298/*
299 * bio flags
300 */
301enum {
302 BIO_PAGE_PINNED, /* Unpin pages in bio_release_pages() */
303 BIO_CLONED, /* doesn't own data */
304 BIO_QUIET, /* Make BIO Quiet */
305 BIO_CHAIN, /* chained bio, ->bi_remaining in effect */
306 BIO_REFFED, /* bio has elevated ->bi_cnt */
307 BIO_BPS_THROTTLED, /* This bio has already been subjected to
308 * throttling rules. Don't do it again. */
309 BIO_TRACE_COMPLETION, /* bio_endio() should trace the final completion
310 * of this bio. */
311 BIO_CGROUP_ACCT, /* has been accounted to a cgroup */
312 BIO_QOS_THROTTLED, /* bio went through rq_qos throttle path */
313 /*
314 * This bio has completed bps throttling at the single tg granularity,
315 * which is different from BIO_BPS_THROTTLED. When the bio is enqueued
316 * into the sq->queued of the upper tg, or is about to be dispatched,
317 * this flag needs to be cleared. Since blk-throttle and rq_qos are not
318 * on the same hierarchical level, reuse the value.
319 */
320 BIO_TG_BPS_THROTTLED = BIO_QOS_THROTTLED,
321 BIO_QOS_MERGED, /* but went through rq_qos merge path */
322 BIO_REMAPPED,
323 BIO_ZONE_WRITE_PLUGGING, /* bio handled through zone write plugging */
324 BIO_EMULATES_ZONE_APPEND, /* bio emulates a zone append operation */
325 BIO_FLAG_LAST
326};
327
328typedef __u32 __bitwise blk_mq_req_flags_t;
329
330#define REQ_OP_BITS 8
331#define REQ_OP_MASK (__force blk_opf_t)((1 << REQ_OP_BITS) - 1)
332#define REQ_FLAG_BITS 24
333
334/**
335 * enum req_op - Operations common to the bio and request structures.
336 * We use 8 bits for encoding the operation, and the remaining 24 for flags.
337 *
338 * The least significant bit of the operation number indicates the data
339 * transfer direction:
340 *
341 * - if the least significant bit is set transfers are TO the device
342 * - if the least significant bit is not set transfers are FROM the device
343 *
344 * If a operation does not transfer data the least significant bit has no
345 * meaning.
346 */
347enum req_op {
348 /** @REQ_OP_READ: read sectors from the device */
349 REQ_OP_READ = (__force blk_opf_t)0,
350 /** @REQ_OP_WRITE: write sectors to the device */
351 REQ_OP_WRITE = (__force blk_opf_t)1,
352 /** @REQ_OP_FLUSH: flush the volatile write cache */
353 REQ_OP_FLUSH = (__force blk_opf_t)2,
354 /** @REQ_OP_DISCARD: discard sectors */
355 REQ_OP_DISCARD = (__force blk_opf_t)3,
356 /** @REQ_OP_SECURE_ERASE: securely erase sectors */
357 REQ_OP_SECURE_ERASE = (__force blk_opf_t)5,
358 /** @REQ_OP_ZONE_APPEND: write data at the current zone write pointer */
359 REQ_OP_ZONE_APPEND = (__force blk_opf_t)7,
360 /** @REQ_OP_WRITE_ZEROES: write the zero filled sector many times */
361 REQ_OP_WRITE_ZEROES = (__force blk_opf_t)9,
362 /** @REQ_OP_ZONE_OPEN: Open a zone */
363 REQ_OP_ZONE_OPEN = (__force blk_opf_t)11,
364 /** @REQ_OP_ZONE_CLOSE: Close a zone */
365 REQ_OP_ZONE_CLOSE = (__force blk_opf_t)13,
366 /** @REQ_OP_ZONE_FINISH: Transition a zone to full */
367 REQ_OP_ZONE_FINISH = (__force blk_opf_t)15,
368 /** @REQ_OP_ZONE_RESET: reset a zone write pointer */
369 REQ_OP_ZONE_RESET = (__force blk_opf_t)17,
370 /** @REQ_OP_ZONE_RESET_ALL: reset all the zone present on the device */
371 REQ_OP_ZONE_RESET_ALL = (__force blk_opf_t)19,
372
373 /* Driver private requests */
374 /* private: */
375 REQ_OP_DRV_IN = (__force blk_opf_t)34,
376 REQ_OP_DRV_OUT = (__force blk_opf_t)35,
377
378 REQ_OP_LAST = (__force blk_opf_t)36,
379};
380
381/* Keep cmd_flag_name[] in sync with the definitions below */
382enum req_flag_bits {
383 __REQ_FAILFAST_DEV = /* no driver retries of device errors */
384 REQ_OP_BITS,
385 __REQ_FAILFAST_TRANSPORT, /* no driver retries of transport errors */
386 __REQ_FAILFAST_DRIVER, /* no driver retries of driver errors */
387 __REQ_SYNC, /* request is sync (sync write or read) */
388 __REQ_META, /* metadata io request */
389 __REQ_PRIO, /* boost priority in cfq */
390 __REQ_NOMERGE, /* don't touch this for merging */
391 __REQ_IDLE, /* anticipate more IO after this one */
392 __REQ_INTEGRITY, /* I/O includes block integrity payload */
393 __REQ_FUA, /* forced unit access */
394 __REQ_PREFLUSH, /* request for cache flush */
395 __REQ_RAHEAD, /* read ahead, can fail anytime */
396 __REQ_BACKGROUND, /* background IO */
397 __REQ_NOWAIT, /* Don't wait if request will block */
398 __REQ_POLLED, /* caller polls for completion using bio_poll */
399 __REQ_ALLOC_CACHE, /* allocate IO from cache if available */
400 __REQ_SWAP, /* swap I/O */
401 __REQ_DRV, /* for driver use */
402 __REQ_FS_PRIVATE, /* for file system (submitter) use */
403 __REQ_ATOMIC, /* for atomic write operations */
404 /*
405 * Command specific flags, keep last:
406 */
407 /* for REQ_OP_WRITE_ZEROES: */
408 __REQ_NOUNMAP, /* do not free blocks when zeroing */
409
410 __REQ_NR_BITS, /* stops here */
411};
412
413#define REQ_FAILFAST_DEV \
414 (__force blk_opf_t)(1ULL << __REQ_FAILFAST_DEV)
415#define REQ_FAILFAST_TRANSPORT \
416 (__force blk_opf_t)(1ULL << __REQ_FAILFAST_TRANSPORT)
417#define REQ_FAILFAST_DRIVER \
418 (__force blk_opf_t)(1ULL << __REQ_FAILFAST_DRIVER)
419#define REQ_SYNC (__force blk_opf_t)(1ULL << __REQ_SYNC)
420#define REQ_META (__force blk_opf_t)(1ULL << __REQ_META)
421#define REQ_PRIO (__force blk_opf_t)(1ULL << __REQ_PRIO)
422#define REQ_NOMERGE (__force blk_opf_t)(1ULL << __REQ_NOMERGE)
423#define REQ_IDLE (__force blk_opf_t)(1ULL << __REQ_IDLE)
424#define REQ_INTEGRITY (__force blk_opf_t)(1ULL << __REQ_INTEGRITY)
425#define REQ_FUA (__force blk_opf_t)(1ULL << __REQ_FUA)
426#define REQ_PREFLUSH (__force blk_opf_t)(1ULL << __REQ_PREFLUSH)
427#define REQ_RAHEAD (__force blk_opf_t)(1ULL << __REQ_RAHEAD)
428#define REQ_BACKGROUND (__force blk_opf_t)(1ULL << __REQ_BACKGROUND)
429#define REQ_NOWAIT (__force blk_opf_t)(1ULL << __REQ_NOWAIT)
430#define REQ_POLLED (__force blk_opf_t)(1ULL << __REQ_POLLED)
431#define REQ_ALLOC_CACHE (__force blk_opf_t)(1ULL << __REQ_ALLOC_CACHE)
432#define REQ_SWAP (__force blk_opf_t)(1ULL << __REQ_SWAP)
433#define REQ_DRV (__force blk_opf_t)(1ULL << __REQ_DRV)
434#define REQ_FS_PRIVATE (__force blk_opf_t)(1ULL << __REQ_FS_PRIVATE)
435#define REQ_ATOMIC (__force blk_opf_t)(1ULL << __REQ_ATOMIC)
436
437#define REQ_NOUNMAP (__force blk_opf_t)(1ULL << __REQ_NOUNMAP)
438
439#define REQ_FAILFAST_MASK \
440 (REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT | REQ_FAILFAST_DRIVER)
441
442#define REQ_NOMERGE_FLAGS \
443 (REQ_NOMERGE | REQ_PREFLUSH | REQ_FUA)
444
445enum stat_group {
446 STAT_READ,
447 STAT_WRITE,
448 STAT_DISCARD,
449 STAT_FLUSH,
450
451 NR_STAT_GROUPS
452};
453
454static inline enum req_op bio_op(const struct bio *bio)
455{
456 return bio->bi_opf & REQ_OP_MASK;
457}
458
459static inline bool op_is_write(blk_opf_t op)
460{
461 return !!(op & (__force blk_opf_t)1);
462}
463
464/*
465 * Check if the bio or request is one that needs special treatment in the
466 * flush state machine.
467 */
468static inline bool op_is_flush(blk_opf_t op)
469{
470 return op & (REQ_FUA | REQ_PREFLUSH);
471}
472
473/*
474 * Reads are always treated as synchronous, as are requests with the FUA or
475 * PREFLUSH flag. Other operations may be marked as synchronous using the
476 * REQ_SYNC flag.
477 */
478static inline bool op_is_sync(blk_opf_t op)
479{
480 return (op & REQ_OP_MASK) == REQ_OP_READ ||
481 (op & (REQ_SYNC | REQ_FUA | REQ_PREFLUSH));
482}
483
484static inline bool op_is_discard(blk_opf_t op)
485{
486 return (op & REQ_OP_MASK) == REQ_OP_DISCARD;
487}
488
489/*
490 * Check if a bio or request operation is a zone management operation.
491 */
492static inline bool op_is_zone_mgmt(enum req_op op)
493{
494 switch (op & REQ_OP_MASK) {
495 case REQ_OP_ZONE_RESET:
496 case REQ_OP_ZONE_RESET_ALL:
497 case REQ_OP_ZONE_OPEN:
498 case REQ_OP_ZONE_CLOSE:
499 case REQ_OP_ZONE_FINISH:
500 return true;
501 default:
502 return false;
503 }
504}
505
506static inline int op_stat_group(enum req_op op)
507{
508 if (op_is_discard(op))
509 return STAT_DISCARD;
510 return op_is_write(op);
511}
512
513struct blk_rq_stat {
514 u64 mean;
515 u64 min;
516 u64 max;
517 u32 nr_samples;
518 u64 batch;
519};
520
521#endif /* __LINUX_BLK_TYPES_H */