]> git.proxmox.com Git - mirror_ubuntu-bionic-kernel.git/blame - include/linux/blkdev.h
block, cfq: reorganize cfq_io_context into generic and cfq specific parts
[mirror_ubuntu-bionic-kernel.git] / include / linux / blkdev.h
CommitLineData
1da177e4
LT
1#ifndef _LINUX_BLKDEV_H
2#define _LINUX_BLKDEV_H
3
f5ff8422
JA
4#ifdef CONFIG_BLOCK
5
bcfd8d36 6#include <linux/sched.h>
1da177e4
LT
7#include <linux/major.h>
8#include <linux/genhd.h>
9#include <linux/list.h>
10#include <linux/timer.h>
11#include <linux/workqueue.h>
12#include <linux/pagemap.h>
13#include <linux/backing-dev.h>
14#include <linux/wait.h>
15#include <linux/mempool.h>
16#include <linux/bio.h>
1da177e4 17#include <linux/stringify.h>
3e6053d7 18#include <linux/gfp.h>
d351af01 19#include <linux/bsg.h>
c7c22e4d 20#include <linux/smp.h>
1da177e4
LT
21
22#include <asm/scatterlist.h>
23
de477254 24struct module;
21b2f0c8
CH
25struct scsi_ioctl_command;
26
1da177e4 27struct request_queue;
1da177e4 28struct elevator_queue;
1da177e4 29struct request_pm_state;
2056a782 30struct blk_trace;
3d6392cf
JA
31struct request;
32struct sg_io_hdr;
aa387cc8 33struct bsg_job;
1da177e4
LT
34
35#define BLKDEV_MIN_RQ 4
36#define BLKDEV_MAX_RQ 128 /* Default maximum */
37
1da177e4 38struct request;
8ffdc655 39typedef void (rq_end_io_fn)(struct request *, int);
1da177e4
LT
40
41struct request_list {
1faa16d2
JA
42 /*
43 * count[], starved[], and wait[] are indexed by
44 * BLK_RW_SYNC/BLK_RW_ASYNC
45 */
1da177e4
LT
46 int count[2];
47 int starved[2];
cb98fc8b 48 int elvpriv;
1da177e4
LT
49 mempool_t *rq_pool;
50 wait_queue_head_t wait[2];
1da177e4
LT
51};
52
4aff5e23
JA
53/*
54 * request command types
55 */
56enum rq_cmd_type_bits {
57 REQ_TYPE_FS = 1, /* fs request */
58 REQ_TYPE_BLOCK_PC, /* scsi command */
59 REQ_TYPE_SENSE, /* sense request */
60 REQ_TYPE_PM_SUSPEND, /* suspend request */
61 REQ_TYPE_PM_RESUME, /* resume request */
62 REQ_TYPE_PM_SHUTDOWN, /* shutdown request */
4aff5e23 63 REQ_TYPE_SPECIAL, /* driver defined type */
4aff5e23
JA
64 /*
65 * for ATA/ATAPI devices. this really doesn't belong here, ide should
66 * use REQ_TYPE_SPECIAL and use rq->cmd[0] with the range of driver
67 * private REQ_LB opcodes to differentiate what type of request this is
68 */
4aff5e23 69 REQ_TYPE_ATA_TASKFILE,
cea2885a 70 REQ_TYPE_ATA_PC,
4aff5e23
JA
71};
72
1da177e4
LT
73#define BLK_MAX_CDB 16
74
75/*
63a71386 76 * try to put the fields that are referenced together in the same cacheline.
4d0d98b6 77 * if you modify this structure, be sure to check block/blk-core.c:blk_rq_init()
63a71386 78 * as well!
1da177e4
LT
79 */
80struct request {
ff856bad 81 struct list_head queuelist;
c7c22e4d 82 struct call_single_data csd;
ff856bad 83
165125e1 84 struct request_queue *q;
e6a1c874 85
4aff5e23
JA
86 unsigned int cmd_flags;
87 enum rq_cmd_type_bits cmd_type;
242f9dcb 88 unsigned long atomic_flags;
1da177e4 89
181fdde3
RK
90 int cpu;
91
a2dec7b3 92 /* the following two fields are internal, NEVER access directly */
a2dec7b3 93 unsigned int __data_len; /* total data len */
181fdde3 94 sector_t __sector; /* sector cursor */
1da177e4
LT
95
96 struct bio *bio;
97 struct bio *biotail;
98
9817064b 99 struct hlist_node hash; /* merge hash */
e6a1c874
JA
100 /*
101 * The rb_node is only used inside the io scheduler, requests
102 * are pruned when moved to the dispatch queue. So let the
c186794d 103 * completion_data share space with the rb_node.
e6a1c874
JA
104 */
105 union {
106 struct rb_node rb_node; /* sort/lookup */
c186794d 107 void *completion_data;
e6a1c874 108 };
9817064b 109
ff7d145f 110 /*
7f1dc8a2 111 * Three pointers are available for the IO schedulers, if they need
c186794d
MS
112 * more they have to dynamically allocate it. Flush requests are
113 * never put on the IO scheduler. So let the flush fields share
114 * space with the three elevator_private pointers.
ff7d145f 115 */
c186794d
MS
116 union {
117 void *elevator_private[3];
118 struct {
119 unsigned int seq;
120 struct list_head list;
4853abaa 121 rq_end_io_fn *saved_end_io;
c186794d
MS
122 } flush;
123 };
ff7d145f 124
8f34ee75 125 struct gendisk *rq_disk;
09e099d4 126 struct hd_struct *part;
1da177e4 127 unsigned long start_time;
9195291e
DS
128#ifdef CONFIG_BLK_CGROUP
129 unsigned long long start_time_ns;
130 unsigned long long io_start_time_ns; /* when passed to hardware */
131#endif
1da177e4
LT
132 /* Number of scatter-gather DMA addr+len pairs after
133 * physical address coalescing is performed.
134 */
135 unsigned short nr_phys_segments;
13f05c8d
MP
136#if defined(CONFIG_BLK_DEV_INTEGRITY)
137 unsigned short nr_integrity_segments;
138#endif
1da177e4 139
8f34ee75
JA
140 unsigned short ioprio;
141
181fdde3
RK
142 int ref_count;
143
731ec497
TH
144 void *special; /* opaque pointer available for LLD use */
145 char *buffer; /* kaddr of the current segment if available */
1da177e4 146
cdd60262
JA
147 int tag;
148 int errors;
149
1da177e4
LT
150 /*
151 * when request is used as a packet command carrier
152 */
d7e3c324
FT
153 unsigned char __cmd[BLK_MAX_CDB];
154 unsigned char *cmd;
181fdde3 155 unsigned short cmd_len;
1da177e4 156
7a85f889 157 unsigned int extra_len; /* length of alignment and padding */
1da177e4 158 unsigned int sense_len;
c3a4d78c 159 unsigned int resid_len; /* residual count */
1da177e4
LT
160 void *sense;
161
242f9dcb
JA
162 unsigned long deadline;
163 struct list_head timeout_list;
1da177e4 164 unsigned int timeout;
17e01f21 165 int retries;
1da177e4 166
1da177e4 167 /*
c00895ab 168 * completion callback.
1da177e4
LT
169 */
170 rq_end_io_fn *end_io;
171 void *end_io_data;
abae1fde
FT
172
173 /* for bidi */
174 struct request *next_rq;
1da177e4
LT
175};
176
766ca442
FLVC
177static inline unsigned short req_get_ioprio(struct request *req)
178{
179 return req->ioprio;
180}
181
1da177e4 182/*
4aff5e23 183 * State information carried for REQ_TYPE_PM_SUSPEND and REQ_TYPE_PM_RESUME
1da177e4
LT
184 * requests. Some step values could eventually be made generic.
185 */
186struct request_pm_state
187{
188 /* PM state machine step value, currently driver specific */
189 int pm_step;
190 /* requested PM state value (S1, S2, S3, S4, ...) */
191 u32 pm_state;
192 void* data; /* for driver use */
193};
194
195#include <linux/elevator.h>
196
165125e1 197typedef void (request_fn_proc) (struct request_queue *q);
5a7bbad2 198typedef void (make_request_fn) (struct request_queue *q, struct bio *bio);
165125e1 199typedef int (prep_rq_fn) (struct request_queue *, struct request *);
28018c24 200typedef void (unprep_rq_fn) (struct request_queue *, struct request *);
1da177e4
LT
201
202struct bio_vec;
cc371e66
AK
203struct bvec_merge_data {
204 struct block_device *bi_bdev;
205 sector_t bi_sector;
206 unsigned bi_size;
207 unsigned long bi_rw;
208};
209typedef int (merge_bvec_fn) (struct request_queue *, struct bvec_merge_data *,
210 struct bio_vec *);
ff856bad 211typedef void (softirq_done_fn)(struct request *);
2fb98e84 212typedef int (dma_drain_needed_fn)(struct request *);
ef9e3fac 213typedef int (lld_busy_fn) (struct request_queue *q);
aa387cc8 214typedef int (bsg_job_fn) (struct bsg_job *);
1da177e4 215
242f9dcb
JA
216enum blk_eh_timer_return {
217 BLK_EH_NOT_HANDLED,
218 BLK_EH_HANDLED,
219 BLK_EH_RESET_TIMER,
220};
221
222typedef enum blk_eh_timer_return (rq_timed_out_fn)(struct request *);
223
1da177e4
LT
224enum blk_queue_state {
225 Queue_down,
226 Queue_up,
227};
228
1da177e4
LT
229struct blk_queue_tag {
230 struct request **tag_index; /* map of busy tags */
231 unsigned long *tag_map; /* bit map of free/busy tags */
1da177e4
LT
232 int busy; /* current depth */
233 int max_depth; /* what we will send to device */
ba025082 234 int real_max_depth; /* what the array can hold */
1da177e4
LT
235 atomic_t refcnt; /* map can be shared */
236};
237
abf54393
FT
238#define BLK_SCSI_MAX_CMDS (256)
239#define BLK_SCSI_CMD_PER_LONG (BLK_SCSI_MAX_CMDS / (sizeof(long) * 8))
240
025146e1
MP
241struct queue_limits {
242 unsigned long bounce_pfn;
243 unsigned long seg_boundary_mask;
244
245 unsigned int max_hw_sectors;
246 unsigned int max_sectors;
247 unsigned int max_segment_size;
c72758f3
MP
248 unsigned int physical_block_size;
249 unsigned int alignment_offset;
250 unsigned int io_min;
251 unsigned int io_opt;
67efc925 252 unsigned int max_discard_sectors;
86b37281
MP
253 unsigned int discard_granularity;
254 unsigned int discard_alignment;
025146e1
MP
255
256 unsigned short logical_block_size;
8a78362c 257 unsigned short max_segments;
13f05c8d 258 unsigned short max_integrity_segments;
025146e1 259
c72758f3 260 unsigned char misaligned;
86b37281 261 unsigned char discard_misaligned;
e692cb66 262 unsigned char cluster;
a934a00a 263 unsigned char discard_zeroes_data;
025146e1
MP
264};
265
d7b76301 266struct request_queue {
1da177e4
LT
267 /*
268 * Together with queue_head for cacheline sharing
269 */
270 struct list_head queue_head;
271 struct request *last_merge;
b374d18a 272 struct elevator_queue *elevator;
1da177e4
LT
273
274 /*
275 * the queue request freelist, one for reads and one for writes
276 */
277 struct request_list rq;
278
279 request_fn_proc *request_fn;
1da177e4
LT
280 make_request_fn *make_request_fn;
281 prep_rq_fn *prep_rq_fn;
28018c24 282 unprep_rq_fn *unprep_rq_fn;
1da177e4 283 merge_bvec_fn *merge_bvec_fn;
ff856bad 284 softirq_done_fn *softirq_done_fn;
242f9dcb 285 rq_timed_out_fn *rq_timed_out_fn;
2fb98e84 286 dma_drain_needed_fn *dma_drain_needed;
ef9e3fac 287 lld_busy_fn *lld_busy_fn;
1da177e4 288
8922e16c
TH
289 /*
290 * Dispatch queue sorting
291 */
1b47f531 292 sector_t end_sector;
8922e16c 293 struct request *boundary_rq;
8922e16c 294
1da177e4 295 /*
3cca6dc1 296 * Delayed queue handling
1da177e4 297 */
3cca6dc1 298 struct delayed_work delay_work;
1da177e4
LT
299
300 struct backing_dev_info backing_dev_info;
301
302 /*
303 * The queue owner gets to use this for whatever they like.
304 * ll_rw_blk doesn't touch it.
305 */
306 void *queuedata;
307
1da177e4 308 /*
d7b76301 309 * various queue flags, see QUEUE_* below
1da177e4 310 */
d7b76301 311 unsigned long queue_flags;
1da177e4 312
a73f730d
TH
313 /*
314 * ida allocated id for this queue. Used to index queues from
315 * ioctx.
316 */
317 int id;
318
1da177e4 319 /*
d7b76301 320 * queue needs bounce pages for pages above this limit
1da177e4 321 */
d7b76301 322 gfp_t bounce_gfp;
1da177e4
LT
323
324 /*
152587de
JA
325 * protects queue structures from reentrancy. ->__queue_lock should
326 * _never_ be used directly, it is queue private. always use
327 * ->queue_lock.
1da177e4 328 */
152587de 329 spinlock_t __queue_lock;
1da177e4
LT
330 spinlock_t *queue_lock;
331
332 /*
333 * queue kobject
334 */
335 struct kobject kobj;
336
337 /*
338 * queue settings
339 */
340 unsigned long nr_requests; /* Max # of requests */
341 unsigned int nr_congestion_on;
342 unsigned int nr_congestion_off;
343 unsigned int nr_batching;
344
fa0ccd83 345 unsigned int dma_drain_size;
d7b76301 346 void *dma_drain_buffer;
e3790c7d 347 unsigned int dma_pad_mask;
1da177e4
LT
348 unsigned int dma_alignment;
349
350 struct blk_queue_tag *queue_tags;
6eca9004 351 struct list_head tag_busy_list;
1da177e4 352
15853af9 353 unsigned int nr_sorted;
0a7ae2ff 354 unsigned int in_flight[2];
1da177e4 355
242f9dcb
JA
356 unsigned int rq_timeout;
357 struct timer_list timeout;
358 struct list_head timeout_list;
359
025146e1
MP
360 struct queue_limits limits;
361
1da177e4
LT
362 /*
363 * sg stuff
364 */
365 unsigned int sg_timeout;
366 unsigned int sg_reserved_size;
1946089a 367 int node;
6c5c9341 368#ifdef CONFIG_BLK_DEV_IO_TRACE
2056a782 369 struct blk_trace *blk_trace;
6c5c9341 370#endif
1da177e4 371 /*
4913efe4 372 * for flush operations
1da177e4 373 */
4913efe4 374 unsigned int flush_flags;
f3876930 375 unsigned int flush_not_queueable:1;
3ac0cc45 376 unsigned int flush_queue_delayed:1;
ae1b1539
TH
377 unsigned int flush_pending_idx:1;
378 unsigned int flush_running_idx:1;
379 unsigned long flush_pending_since;
380 struct list_head flush_queue[2];
381 struct list_head flush_data_in_flight;
dd4c133f 382 struct request flush_rq;
483f4afc
AV
383
384 struct mutex sysfs_lock;
d351af01
FT
385
386#if defined(CONFIG_BLK_DEV_BSG)
aa387cc8
MC
387 bsg_job_fn *bsg_job_fn;
388 int bsg_job_size;
d351af01
FT
389 struct bsg_class_device bsg_dev;
390#endif
e43473b7
VG
391
392#ifdef CONFIG_BLK_DEV_THROTTLING
393 /* Throttle data */
394 struct throtl_data *td;
395#endif
b2efa052
TH
396#ifdef CONFIG_LOCKDEP
397 int ioc_release_depth;
398#endif
1da177e4
LT
399};
400
1da177e4
LT
401#define QUEUE_FLAG_QUEUED 1 /* uses generic tag queueing */
402#define QUEUE_FLAG_STOPPED 2 /* queue is stopped */
1faa16d2
JA
403#define QUEUE_FLAG_SYNCFULL 3 /* read queue has been filled */
404#define QUEUE_FLAG_ASYNCFULL 4 /* write queue has been filled */
1da177e4 405#define QUEUE_FLAG_DEAD 5 /* queue being torn down */
c21e6beb
JA
406#define QUEUE_FLAG_ELVSWITCH 6 /* don't use elevator, just do FIFO */
407#define QUEUE_FLAG_BIDI 7 /* queue supports bidi requests */
408#define QUEUE_FLAG_NOMERGES 8 /* disable merge attempts */
5757a6d7 409#define QUEUE_FLAG_SAME_COMP 9 /* complete on same CPU-group */
c21e6beb
JA
410#define QUEUE_FLAG_FAIL_IO 10 /* fake timeout */
411#define QUEUE_FLAG_STACKABLE 11 /* supports request stacking */
412#define QUEUE_FLAG_NONROT 12 /* non-rotational device (SSD) */
88e740f1 413#define QUEUE_FLAG_VIRT QUEUE_FLAG_NONROT /* paravirt device */
c21e6beb
JA
414#define QUEUE_FLAG_IO_STAT 13 /* do IO stats */
415#define QUEUE_FLAG_DISCARD 14 /* supports DISCARD */
416#define QUEUE_FLAG_NOXMERGES 15 /* No extended merges */
417#define QUEUE_FLAG_ADD_RANDOM 16 /* Contributes to random pool */
418#define QUEUE_FLAG_SECDISCARD 17 /* supports SECDISCARD */
5757a6d7 419#define QUEUE_FLAG_SAME_FORCE 18 /* force complete on same CPU */
bc58ba94
JA
420
421#define QUEUE_FLAG_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \
01e97f6b 422 (1 << QUEUE_FLAG_STACKABLE) | \
e2e1a148
JA
423 (1 << QUEUE_FLAG_SAME_COMP) | \
424 (1 << QUEUE_FLAG_ADD_RANDOM))
797e7dbb 425
8f45c1a5
LT
426static inline int queue_is_locked(struct request_queue *q)
427{
7663c1e2 428#ifdef CONFIG_SMP
8f45c1a5
LT
429 spinlock_t *lock = q->queue_lock;
430 return lock && spin_is_locked(lock);
7663c1e2
JA
431#else
432 return 1;
433#endif
8f45c1a5
LT
434}
435
75ad23bc
NP
436static inline void queue_flag_set_unlocked(unsigned int flag,
437 struct request_queue *q)
438{
439 __set_bit(flag, &q->queue_flags);
440}
441
e48ec690
JA
442static inline int queue_flag_test_and_clear(unsigned int flag,
443 struct request_queue *q)
444{
445 WARN_ON_ONCE(!queue_is_locked(q));
446
447 if (test_bit(flag, &q->queue_flags)) {
448 __clear_bit(flag, &q->queue_flags);
449 return 1;
450 }
451
452 return 0;
453}
454
455static inline int queue_flag_test_and_set(unsigned int flag,
456 struct request_queue *q)
457{
458 WARN_ON_ONCE(!queue_is_locked(q));
459
460 if (!test_bit(flag, &q->queue_flags)) {
461 __set_bit(flag, &q->queue_flags);
462 return 0;
463 }
464
465 return 1;
466}
467
75ad23bc
NP
468static inline void queue_flag_set(unsigned int flag, struct request_queue *q)
469{
8f45c1a5 470 WARN_ON_ONCE(!queue_is_locked(q));
75ad23bc
NP
471 __set_bit(flag, &q->queue_flags);
472}
473
474static inline void queue_flag_clear_unlocked(unsigned int flag,
475 struct request_queue *q)
476{
477 __clear_bit(flag, &q->queue_flags);
478}
479
0a7ae2ff
JA
480static inline int queue_in_flight(struct request_queue *q)
481{
482 return q->in_flight[0] + q->in_flight[1];
483}
484
75ad23bc
NP
485static inline void queue_flag_clear(unsigned int flag, struct request_queue *q)
486{
8f45c1a5 487 WARN_ON_ONCE(!queue_is_locked(q));
75ad23bc
NP
488 __clear_bit(flag, &q->queue_flags);
489}
490
1da177e4
LT
491#define blk_queue_tagged(q) test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags)
492#define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags)
34f6055c 493#define blk_queue_dead(q) test_bit(QUEUE_FLAG_DEAD, &(q)->queue_flags)
ac9fafa1 494#define blk_queue_nomerges(q) test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags)
488991e2
AB
495#define blk_queue_noxmerges(q) \
496 test_bit(QUEUE_FLAG_NOXMERGES, &(q)->queue_flags)
a68bbddb 497#define blk_queue_nonrot(q) test_bit(QUEUE_FLAG_NONROT, &(q)->queue_flags)
bc58ba94 498#define blk_queue_io_stat(q) test_bit(QUEUE_FLAG_IO_STAT, &(q)->queue_flags)
e2e1a148 499#define blk_queue_add_random(q) test_bit(QUEUE_FLAG_ADD_RANDOM, &(q)->queue_flags)
4ee5eaf4
KU
500#define blk_queue_stackable(q) \
501 test_bit(QUEUE_FLAG_STACKABLE, &(q)->queue_flags)
c15227de 502#define blk_queue_discard(q) test_bit(QUEUE_FLAG_DISCARD, &(q)->queue_flags)
8d57a98c
AH
503#define blk_queue_secdiscard(q) (blk_queue_discard(q) && \
504 test_bit(QUEUE_FLAG_SECDISCARD, &(q)->queue_flags))
1da177e4 505
33659ebb
CH
506#define blk_noretry_request(rq) \
507 ((rq)->cmd_flags & (REQ_FAILFAST_DEV|REQ_FAILFAST_TRANSPORT| \
508 REQ_FAILFAST_DRIVER))
509
510#define blk_account_rq(rq) \
511 (((rq)->cmd_flags & REQ_STARTED) && \
512 ((rq)->cmd_type == REQ_TYPE_FS || \
513 ((rq)->cmd_flags & REQ_DISCARD)))
514
1da177e4 515#define blk_pm_request(rq) \
33659ebb
CH
516 ((rq)->cmd_type == REQ_TYPE_PM_SUSPEND || \
517 (rq)->cmd_type == REQ_TYPE_PM_RESUME)
1da177e4 518
ab780f1e 519#define blk_rq_cpu_valid(rq) ((rq)->cpu != -1)
abae1fde 520#define blk_bidi_rq(rq) ((rq)->next_rq != NULL)
336cdb40
KU
521/* rq->queuelist of dequeued request must be list_empty() */
522#define blk_queued_rq(rq) (!list_empty(&(rq)->queuelist))
1da177e4
LT
523
524#define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist)
525
4aff5e23 526#define rq_data_dir(rq) ((rq)->cmd_flags & 1)
1da177e4 527
e692cb66
MP
528static inline unsigned int blk_queue_cluster(struct request_queue *q)
529{
530 return q->limits.cluster;
531}
532
9e2585a8 533/*
1faa16d2 534 * We regard a request as sync, if either a read or a sync write
9e2585a8 535 */
1faa16d2
JA
536static inline bool rw_is_sync(unsigned int rw_flags)
537{
7b6d91da 538 return !(rw_flags & REQ_WRITE) || (rw_flags & REQ_SYNC);
1faa16d2
JA
539}
540
541static inline bool rq_is_sync(struct request *rq)
542{
543 return rw_is_sync(rq->cmd_flags);
544}
545
1faa16d2 546static inline int blk_queue_full(struct request_queue *q, int sync)
1da177e4 547{
1faa16d2
JA
548 if (sync)
549 return test_bit(QUEUE_FLAG_SYNCFULL, &q->queue_flags);
550 return test_bit(QUEUE_FLAG_ASYNCFULL, &q->queue_flags);
1da177e4
LT
551}
552
1faa16d2 553static inline void blk_set_queue_full(struct request_queue *q, int sync)
1da177e4 554{
1faa16d2
JA
555 if (sync)
556 queue_flag_set(QUEUE_FLAG_SYNCFULL, q);
1da177e4 557 else
1faa16d2 558 queue_flag_set(QUEUE_FLAG_ASYNCFULL, q);
1da177e4
LT
559}
560
1faa16d2 561static inline void blk_clear_queue_full(struct request_queue *q, int sync)
1da177e4 562{
1faa16d2
JA
563 if (sync)
564 queue_flag_clear(QUEUE_FLAG_SYNCFULL, q);
1da177e4 565 else
1faa16d2 566 queue_flag_clear(QUEUE_FLAG_ASYNCFULL, q);
1da177e4
LT
567}
568
569
570/*
571 * mergeable request must not have _NOMERGE or _BARRIER bit set, nor may
572 * it already be started by driver.
573 */
574#define RQ_NOMERGE_FLAGS \
02e031cb 575 (REQ_NOMERGE | REQ_STARTED | REQ_SOFTBARRIER | REQ_FLUSH | REQ_FUA)
1da177e4 576#define rq_mergeable(rq) \
e17fc0a1 577 (!((rq)->cmd_flags & RQ_NOMERGE_FLAGS) && \
33659ebb
CH
578 (((rq)->cmd_flags & REQ_DISCARD) || \
579 (rq)->cmd_type == REQ_TYPE_FS))
1da177e4 580
1da177e4
LT
581/*
582 * q->prep_rq_fn return values
583 */
584#define BLKPREP_OK 0 /* serve it */
585#define BLKPREP_KILL 1 /* fatal error, kill */
586#define BLKPREP_DEFER 2 /* leave on queue */
587
588extern unsigned long blk_max_low_pfn, blk_max_pfn;
589
590/*
591 * standard bounce addresses:
592 *
593 * BLK_BOUNCE_HIGH : bounce all highmem pages
594 * BLK_BOUNCE_ANY : don't bounce anything
595 * BLK_BOUNCE_ISA : bounce pages above ISA DMA boundary
596 */
2472892a
AK
597
598#if BITS_PER_LONG == 32
1da177e4 599#define BLK_BOUNCE_HIGH ((u64)blk_max_low_pfn << PAGE_SHIFT)
2472892a
AK
600#else
601#define BLK_BOUNCE_HIGH -1ULL
602#endif
603#define BLK_BOUNCE_ANY (-1ULL)
bfe17231 604#define BLK_BOUNCE_ISA (DMA_BIT_MASK(24))
1da177e4 605
3d6392cf
JA
606/*
607 * default timeout for SG_IO if none specified
608 */
609#define BLK_DEFAULT_SG_TIMEOUT (60 * HZ)
f2f1fa78 610#define BLK_MIN_SG_TIMEOUT (7 * HZ)
3d6392cf 611
2a7326b5 612#ifdef CONFIG_BOUNCE
1da177e4 613extern int init_emergency_isa_pool(void);
165125e1 614extern void blk_queue_bounce(struct request_queue *q, struct bio **bio);
1da177e4
LT
615#else
616static inline int init_emergency_isa_pool(void)
617{
618 return 0;
619}
165125e1 620static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio)
1da177e4
LT
621{
622}
623#endif /* CONFIG_MMU */
624
152e283f
FT
625struct rq_map_data {
626 struct page **pages;
627 int page_order;
628 int nr_entries;
56c451f4 629 unsigned long offset;
97ae77a1 630 int null_mapped;
ecb554a8 631 int from_user;
152e283f
FT
632};
633
5705f702
N
634struct req_iterator {
635 int i;
636 struct bio *bio;
637};
638
639/* This should not be used directly - use rq_for_each_segment */
1e428079
JA
640#define for_each_bio(_bio) \
641 for (; _bio; _bio = _bio->bi_next)
5705f702 642#define __rq_for_each_bio(_bio, rq) \
1da177e4
LT
643 if ((rq->bio)) \
644 for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next)
645
5705f702
N
646#define rq_for_each_segment(bvl, _rq, _iter) \
647 __rq_for_each_bio(_iter.bio, _rq) \
648 bio_for_each_segment(bvl, _iter.bio, _iter.i)
649
650#define rq_iter_last(rq, _iter) \
651 (_iter.bio->bi_next == NULL && _iter.i == _iter.bio->bi_vcnt-1)
652
2d4dc890
IL
653#ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
654# error "You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform"
655#endif
656#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
657extern void rq_flush_dcache_pages(struct request *rq);
658#else
659static inline void rq_flush_dcache_pages(struct request *rq)
660{
661}
662#endif
663
1da177e4
LT
664extern int blk_register_queue(struct gendisk *disk);
665extern void blk_unregister_queue(struct gendisk *disk);
1da177e4 666extern void generic_make_request(struct bio *bio);
2a4aa30c 667extern void blk_rq_init(struct request_queue *q, struct request *rq);
1da177e4 668extern void blk_put_request(struct request *);
165125e1 669extern void __blk_put_request(struct request_queue *, struct request *);
165125e1 670extern struct request *blk_get_request(struct request_queue *, int, gfp_t);
79eb63e9
BH
671extern struct request *blk_make_request(struct request_queue *, struct bio *,
672 gfp_t);
165125e1 673extern void blk_requeue_request(struct request_queue *, struct request *);
66ac0280
CH
674extern void blk_add_request_payload(struct request *rq, struct page *page,
675 unsigned int len);
82124d60 676extern int blk_rq_check_limits(struct request_queue *q, struct request *rq);
ef9e3fac 677extern int blk_lld_busy(struct request_queue *q);
b0fd271d
KU
678extern int blk_rq_prep_clone(struct request *rq, struct request *rq_src,
679 struct bio_set *bs, gfp_t gfp_mask,
680 int (*bio_ctr)(struct bio *, struct bio *, void *),
681 void *data);
682extern void blk_rq_unprep_clone(struct request *rq);
82124d60
KU
683extern int blk_insert_cloned_request(struct request_queue *q,
684 struct request *rq);
3cca6dc1 685extern void blk_delay_queue(struct request_queue *, unsigned long);
165125e1 686extern void blk_recount_segments(struct request_queue *, struct bio *);
74f3c8af
AV
687extern int scsi_cmd_ioctl(struct request_queue *, struct gendisk *, fmode_t,
688 unsigned int, void __user *);
e915e872
AV
689extern int sg_scsi_ioctl(struct request_queue *, struct gendisk *, fmode_t,
690 struct scsi_ioctl_command __user *);
3fcfab16 691
5a7bbad2 692extern void blk_queue_bio(struct request_queue *q, struct bio *bio);
166e1f90 693
3fcfab16
AM
694/*
695 * A queue has just exitted congestion. Note this in the global counter of
696 * congested queues, and wake up anyone who was waiting for requests to be
697 * put back.
698 */
8aa7e847 699static inline void blk_clear_queue_congested(struct request_queue *q, int sync)
3fcfab16 700{
8aa7e847 701 clear_bdi_congested(&q->backing_dev_info, sync);
3fcfab16
AM
702}
703
704/*
705 * A queue has just entered congestion. Flag that in the queue's VM-visible
706 * state flags and increment the global gounter of congested queues.
707 */
8aa7e847 708static inline void blk_set_queue_congested(struct request_queue *q, int sync)
3fcfab16 709{
8aa7e847 710 set_bdi_congested(&q->backing_dev_info, sync);
3fcfab16
AM
711}
712
165125e1
JA
713extern void blk_start_queue(struct request_queue *q);
714extern void blk_stop_queue(struct request_queue *q);
1da177e4 715extern void blk_sync_queue(struct request_queue *q);
165125e1 716extern void __blk_stop_queue(struct request_queue *q);
24ecfbe2 717extern void __blk_run_queue(struct request_queue *q);
165125e1 718extern void blk_run_queue(struct request_queue *);
c21e6beb 719extern void blk_run_queue_async(struct request_queue *q);
a3bce90e 720extern int blk_rq_map_user(struct request_queue *, struct request *,
152e283f
FT
721 struct rq_map_data *, void __user *, unsigned long,
722 gfp_t);
8e5cfc45 723extern int blk_rq_unmap_user(struct bio *);
165125e1
JA
724extern int blk_rq_map_kern(struct request_queue *, struct request *, void *, unsigned int, gfp_t);
725extern int blk_rq_map_user_iov(struct request_queue *, struct request *,
152e283f
FT
726 struct rq_map_data *, struct sg_iovec *, int,
727 unsigned int, gfp_t);
165125e1 728extern int blk_execute_rq(struct request_queue *, struct gendisk *,
994ca9a1 729 struct request *, int);
165125e1 730extern void blk_execute_rq_nowait(struct request_queue *, struct gendisk *,
15fc858a 731 struct request *, int, rq_end_io_fn *);
6e39b69e 732
165125e1 733static inline struct request_queue *bdev_get_queue(struct block_device *bdev)
1da177e4
LT
734{
735 return bdev->bd_disk->queue;
736}
737
5efccd17 738/*
80a761fd
TH
739 * blk_rq_pos() : the current sector
740 * blk_rq_bytes() : bytes left in the entire request
741 * blk_rq_cur_bytes() : bytes left in the current segment
742 * blk_rq_err_bytes() : bytes left till the next error boundary
743 * blk_rq_sectors() : sectors left in the entire request
744 * blk_rq_cur_sectors() : sectors left in the current segment
5efccd17 745 */
5b93629b
TH
746static inline sector_t blk_rq_pos(const struct request *rq)
747{
a2dec7b3 748 return rq->__sector;
2e46e8b2
TH
749}
750
751static inline unsigned int blk_rq_bytes(const struct request *rq)
752{
a2dec7b3 753 return rq->__data_len;
5b93629b
TH
754}
755
2e46e8b2
TH
756static inline int blk_rq_cur_bytes(const struct request *rq)
757{
758 return rq->bio ? bio_cur_bytes(rq->bio) : 0;
759}
5efccd17 760
80a761fd
TH
761extern unsigned int blk_rq_err_bytes(const struct request *rq);
762
5b93629b
TH
763static inline unsigned int blk_rq_sectors(const struct request *rq)
764{
2e46e8b2 765 return blk_rq_bytes(rq) >> 9;
5b93629b
TH
766}
767
768static inline unsigned int blk_rq_cur_sectors(const struct request *rq)
769{
2e46e8b2 770 return blk_rq_cur_bytes(rq) >> 9;
5b93629b
TH
771}
772
9934c8c0
TH
773/*
774 * Request issue related functions.
775 */
776extern struct request *blk_peek_request(struct request_queue *q);
777extern void blk_start_request(struct request *rq);
778extern struct request *blk_fetch_request(struct request_queue *q);
779
1da177e4 780/*
2e60e022
TH
781 * Request completion related functions.
782 *
783 * blk_update_request() completes given number of bytes and updates
784 * the request without completing it.
785 *
f06d9a2b
TH
786 * blk_end_request() and friends. __blk_end_request() must be called
787 * with the request queue spinlock acquired.
1da177e4
LT
788 *
789 * Several drivers define their own end_request and call
3bcddeac
KU
790 * blk_end_request() for parts of the original function.
791 * This prevents code duplication in drivers.
1da177e4 792 */
2e60e022
TH
793extern bool blk_update_request(struct request *rq, int error,
794 unsigned int nr_bytes);
b1f74493
FT
795extern bool blk_end_request(struct request *rq, int error,
796 unsigned int nr_bytes);
797extern void blk_end_request_all(struct request *rq, int error);
798extern bool blk_end_request_cur(struct request *rq, int error);
80a761fd 799extern bool blk_end_request_err(struct request *rq, int error);
b1f74493
FT
800extern bool __blk_end_request(struct request *rq, int error,
801 unsigned int nr_bytes);
802extern void __blk_end_request_all(struct request *rq, int error);
803extern bool __blk_end_request_cur(struct request *rq, int error);
80a761fd 804extern bool __blk_end_request_err(struct request *rq, int error);
2e60e022 805
ff856bad 806extern void blk_complete_request(struct request *);
242f9dcb
JA
807extern void __blk_complete_request(struct request *);
808extern void blk_abort_request(struct request *);
11914a53 809extern void blk_abort_queue(struct request_queue *);
28018c24 810extern void blk_unprep_request(struct request *);
ff856bad 811
1da177e4
LT
812/*
813 * Access functions for manipulating queue properties
814 */
165125e1 815extern struct request_queue *blk_init_queue_node(request_fn_proc *rfn,
1946089a 816 spinlock_t *lock, int node_id);
01effb0d
MS
817extern struct request_queue *blk_init_allocated_queue_node(struct request_queue *,
818 request_fn_proc *,
819 spinlock_t *, int node_id);
165125e1 820extern struct request_queue *blk_init_queue(request_fn_proc *, spinlock_t *);
01effb0d
MS
821extern struct request_queue *blk_init_allocated_queue(struct request_queue *,
822 request_fn_proc *, spinlock_t *);
165125e1
JA
823extern void blk_cleanup_queue(struct request_queue *);
824extern void blk_queue_make_request(struct request_queue *, make_request_fn *);
825extern void blk_queue_bounce_limit(struct request_queue *, u64);
72d4cd9f 826extern void blk_limits_max_hw_sectors(struct queue_limits *, unsigned int);
086fa5ff 827extern void blk_queue_max_hw_sectors(struct request_queue *, unsigned int);
8a78362c 828extern void blk_queue_max_segments(struct request_queue *, unsigned short);
165125e1 829extern void blk_queue_max_segment_size(struct request_queue *, unsigned int);
67efc925
CH
830extern void blk_queue_max_discard_sectors(struct request_queue *q,
831 unsigned int max_discard_sectors);
e1defc4f 832extern void blk_queue_logical_block_size(struct request_queue *, unsigned short);
892b6f90 833extern void blk_queue_physical_block_size(struct request_queue *, unsigned int);
c72758f3
MP
834extern void blk_queue_alignment_offset(struct request_queue *q,
835 unsigned int alignment);
7c958e32 836extern void blk_limits_io_min(struct queue_limits *limits, unsigned int min);
c72758f3 837extern void blk_queue_io_min(struct request_queue *q, unsigned int min);
3c5820c7 838extern void blk_limits_io_opt(struct queue_limits *limits, unsigned int opt);
c72758f3 839extern void blk_queue_io_opt(struct request_queue *q, unsigned int opt);
e475bba2 840extern void blk_set_default_limits(struct queue_limits *lim);
c72758f3
MP
841extern int blk_stack_limits(struct queue_limits *t, struct queue_limits *b,
842 sector_t offset);
17be8c24
MP
843extern int bdev_stack_limits(struct queue_limits *t, struct block_device *bdev,
844 sector_t offset);
c72758f3
MP
845extern void disk_stack_limits(struct gendisk *disk, struct block_device *bdev,
846 sector_t offset);
165125e1 847extern void blk_queue_stack_limits(struct request_queue *t, struct request_queue *b);
e3790c7d 848extern void blk_queue_dma_pad(struct request_queue *, unsigned int);
27f8221a 849extern void blk_queue_update_dma_pad(struct request_queue *, unsigned int);
2fb98e84
TH
850extern int blk_queue_dma_drain(struct request_queue *q,
851 dma_drain_needed_fn *dma_drain_needed,
852 void *buf, unsigned int size);
ef9e3fac 853extern void blk_queue_lld_busy(struct request_queue *q, lld_busy_fn *fn);
165125e1
JA
854extern void blk_queue_segment_boundary(struct request_queue *, unsigned long);
855extern void blk_queue_prep_rq(struct request_queue *, prep_rq_fn *pfn);
28018c24 856extern void blk_queue_unprep_rq(struct request_queue *, unprep_rq_fn *ufn);
165125e1
JA
857extern void blk_queue_merge_bvec(struct request_queue *, merge_bvec_fn *);
858extern void blk_queue_dma_alignment(struct request_queue *, int);
11c3e689 859extern void blk_queue_update_dma_alignment(struct request_queue *, int);
165125e1 860extern void blk_queue_softirq_done(struct request_queue *, softirq_done_fn *);
242f9dcb
JA
861extern void blk_queue_rq_timed_out(struct request_queue *, rq_timed_out_fn *);
862extern void blk_queue_rq_timeout(struct request_queue *, unsigned int);
4913efe4 863extern void blk_queue_flush(struct request_queue *q, unsigned int flush);
f3876930 864extern void blk_queue_flush_queueable(struct request_queue *q, bool queueable);
1da177e4 865extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev);
1da177e4 866
165125e1 867extern int blk_rq_map_sg(struct request_queue *, struct request *, struct scatterlist *);
1da177e4 868extern void blk_dump_rq_flags(struct request *, char *);
1da177e4 869extern long nr_blockdev_pages(void);
1da177e4 870
09ac46c4 871bool __must_check blk_get_queue(struct request_queue *);
165125e1
JA
872struct request_queue *blk_alloc_queue(gfp_t);
873struct request_queue *blk_alloc_queue_node(gfp_t, int);
874extern void blk_put_queue(struct request_queue *);
1da177e4 875
316cc67d 876/*
75df7136
SJ
877 * blk_plug permits building a queue of related requests by holding the I/O
878 * fragments for a short period. This allows merging of sequential requests
879 * into single larger request. As the requests are moved from a per-task list to
880 * the device's request_queue in a batch, this results in improved scalability
881 * as the lock contention for request_queue lock is reduced.
882 *
883 * It is ok not to disable preemption when adding the request to the plug list
884 * or when attempting a merge, because blk_schedule_flush_list() will only flush
885 * the plug list when the task sleeps by itself. For details, please see
886 * schedule() where blk_schedule_flush_plug() is called.
316cc67d 887 */
73c10101 888struct blk_plug {
75df7136
SJ
889 unsigned long magic; /* detect uninitialized use-cases */
890 struct list_head list; /* requests */
891 struct list_head cb_list; /* md requires an unplug callback */
892 unsigned int should_sort; /* list to be sorted before flushing? */
73c10101 893};
55c022bb
SL
894#define BLK_MAX_REQUEST_COUNT 16
895
048c9374
N
896struct blk_plug_cb {
897 struct list_head list;
898 void (*callback)(struct blk_plug_cb *);
899};
73c10101
JA
900
901extern void blk_start_plug(struct blk_plug *);
902extern void blk_finish_plug(struct blk_plug *);
f6603783 903extern void blk_flush_plug_list(struct blk_plug *, bool);
73c10101
JA
904
905static inline void blk_flush_plug(struct task_struct *tsk)
906{
907 struct blk_plug *plug = tsk->plug;
908
a237c1c5
JA
909 if (plug)
910 blk_flush_plug_list(plug, false);
911}
912
913static inline void blk_schedule_flush_plug(struct task_struct *tsk)
914{
915 struct blk_plug *plug = tsk->plug;
916
88b996cd 917 if (plug)
f6603783 918 blk_flush_plug_list(plug, true);
73c10101
JA
919}
920
921static inline bool blk_needs_flush_plug(struct task_struct *tsk)
922{
923 struct blk_plug *plug = tsk->plug;
924
048c9374 925 return plug && (!list_empty(&plug->list) || !list_empty(&plug->cb_list));
73c10101
JA
926}
927
1da177e4
LT
928/*
929 * tag stuff
930 */
4aff5e23 931#define blk_rq_tagged(rq) ((rq)->cmd_flags & REQ_QUEUED)
165125e1
JA
932extern int blk_queue_start_tag(struct request_queue *, struct request *);
933extern struct request *blk_queue_find_tag(struct request_queue *, int);
934extern void blk_queue_end_tag(struct request_queue *, struct request *);
935extern int blk_queue_init_tags(struct request_queue *, int, struct blk_queue_tag *);
936extern void blk_queue_free_tags(struct request_queue *);
937extern int blk_queue_resize_tags(struct request_queue *, int);
938extern void blk_queue_invalidate_tags(struct request_queue *);
492dfb48
JB
939extern struct blk_queue_tag *blk_init_tags(int);
940extern void blk_free_tags(struct blk_queue_tag *);
1da177e4 941
f583f492
DS
942static inline struct request *blk_map_queue_find_tag(struct blk_queue_tag *bqt,
943 int tag)
944{
945 if (unlikely(bqt == NULL || tag >= bqt->real_max_depth))
946 return NULL;
947 return bqt->tag_index[tag];
948}
dd3932ed
CH
949
950#define BLKDEV_DISCARD_SECURE 0x01 /* secure discard */
951
952extern int blkdev_issue_flush(struct block_device *, gfp_t, sector_t *);
fbd9b09a
DM
953extern int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
954 sector_t nr_sects, gfp_t gfp_mask, unsigned long flags);
3f14d792 955extern int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
dd3932ed 956 sector_t nr_sects, gfp_t gfp_mask);
2cf6d26a
CH
957static inline int sb_issue_discard(struct super_block *sb, sector_t block,
958 sector_t nr_blocks, gfp_t gfp_mask, unsigned long flags)
fb2dce86 959{
2cf6d26a
CH
960 return blkdev_issue_discard(sb->s_bdev, block << (sb->s_blocksize_bits - 9),
961 nr_blocks << (sb->s_blocksize_bits - 9),
962 gfp_mask, flags);
fb2dce86 963}
e6fa0be6 964static inline int sb_issue_zeroout(struct super_block *sb, sector_t block,
a107e5a3 965 sector_t nr_blocks, gfp_t gfp_mask)
e6fa0be6
LC
966{
967 return blkdev_issue_zeroout(sb->s_bdev,
968 block << (sb->s_blocksize_bits - 9),
969 nr_blocks << (sb->s_blocksize_bits - 9),
a107e5a3 970 gfp_mask);
e6fa0be6 971}
1da177e4 972
018e0446 973extern int blk_verify_command(unsigned char *cmd, fmode_t has_write_perm);
0b07de85 974
eb28d31b
MP
975enum blk_default_limits {
976 BLK_MAX_SEGMENTS = 128,
977 BLK_SAFE_MAX_SECTORS = 255,
978 BLK_DEF_MAX_SECTORS = 1024,
979 BLK_MAX_SEGMENT_SIZE = 65536,
980 BLK_SEG_BOUNDARY_MASK = 0xFFFFFFFFUL,
981};
0e435ac2 982
1da177e4
LT
983#define blkdev_entry_to_request(entry) list_entry((entry), struct request, queuelist)
984
ae03bf63
MP
985static inline unsigned long queue_bounce_pfn(struct request_queue *q)
986{
025146e1 987 return q->limits.bounce_pfn;
ae03bf63
MP
988}
989
990static inline unsigned long queue_segment_boundary(struct request_queue *q)
991{
025146e1 992 return q->limits.seg_boundary_mask;
ae03bf63
MP
993}
994
995static inline unsigned int queue_max_sectors(struct request_queue *q)
996{
025146e1 997 return q->limits.max_sectors;
ae03bf63
MP
998}
999
1000static inline unsigned int queue_max_hw_sectors(struct request_queue *q)
1001{
025146e1 1002 return q->limits.max_hw_sectors;
ae03bf63
MP
1003}
1004
8a78362c 1005static inline unsigned short queue_max_segments(struct request_queue *q)
ae03bf63 1006{
8a78362c 1007 return q->limits.max_segments;
ae03bf63
MP
1008}
1009
1010static inline unsigned int queue_max_segment_size(struct request_queue *q)
1011{
025146e1 1012 return q->limits.max_segment_size;
ae03bf63
MP
1013}
1014
e1defc4f 1015static inline unsigned short queue_logical_block_size(struct request_queue *q)
1da177e4
LT
1016{
1017 int retval = 512;
1018
025146e1
MP
1019 if (q && q->limits.logical_block_size)
1020 retval = q->limits.logical_block_size;
1da177e4
LT
1021
1022 return retval;
1023}
1024
e1defc4f 1025static inline unsigned short bdev_logical_block_size(struct block_device *bdev)
1da177e4 1026{
e1defc4f 1027 return queue_logical_block_size(bdev_get_queue(bdev));
1da177e4
LT
1028}
1029
c72758f3
MP
1030static inline unsigned int queue_physical_block_size(struct request_queue *q)
1031{
1032 return q->limits.physical_block_size;
1033}
1034
892b6f90 1035static inline unsigned int bdev_physical_block_size(struct block_device *bdev)
ac481c20
MP
1036{
1037 return queue_physical_block_size(bdev_get_queue(bdev));
1038}
1039
c72758f3
MP
1040static inline unsigned int queue_io_min(struct request_queue *q)
1041{
1042 return q->limits.io_min;
1043}
1044
ac481c20
MP
1045static inline int bdev_io_min(struct block_device *bdev)
1046{
1047 return queue_io_min(bdev_get_queue(bdev));
1048}
1049
c72758f3
MP
1050static inline unsigned int queue_io_opt(struct request_queue *q)
1051{
1052 return q->limits.io_opt;
1053}
1054
ac481c20
MP
1055static inline int bdev_io_opt(struct block_device *bdev)
1056{
1057 return queue_io_opt(bdev_get_queue(bdev));
1058}
1059
c72758f3
MP
1060static inline int queue_alignment_offset(struct request_queue *q)
1061{
ac481c20 1062 if (q->limits.misaligned)
c72758f3
MP
1063 return -1;
1064
ac481c20 1065 return q->limits.alignment_offset;
c72758f3
MP
1066}
1067
e03a72e1 1068static inline int queue_limit_alignment_offset(struct queue_limits *lim, sector_t sector)
81744ee4
MP
1069{
1070 unsigned int granularity = max(lim->physical_block_size, lim->io_min);
e03a72e1 1071 unsigned int alignment = (sector << 9) & (granularity - 1);
81744ee4 1072
e03a72e1
MP
1073 return (granularity + lim->alignment_offset - alignment)
1074 & (granularity - 1);
c72758f3
MP
1075}
1076
ac481c20
MP
1077static inline int bdev_alignment_offset(struct block_device *bdev)
1078{
1079 struct request_queue *q = bdev_get_queue(bdev);
1080
1081 if (q->limits.misaligned)
1082 return -1;
1083
1084 if (bdev != bdev->bd_contains)
1085 return bdev->bd_part->alignment_offset;
1086
1087 return q->limits.alignment_offset;
1088}
1089
86b37281
MP
1090static inline int queue_discard_alignment(struct request_queue *q)
1091{
1092 if (q->limits.discard_misaligned)
1093 return -1;
1094
1095 return q->limits.discard_alignment;
1096}
1097
e03a72e1 1098static inline int queue_limit_discard_alignment(struct queue_limits *lim, sector_t sector)
86b37281 1099{
dd3d145d
MP
1100 unsigned int alignment = (sector << 9) & (lim->discard_granularity - 1);
1101
a934a00a
MP
1102 if (!lim->max_discard_sectors)
1103 return 0;
1104
dd3d145d
MP
1105 return (lim->discard_granularity + lim->discard_alignment - alignment)
1106 & (lim->discard_granularity - 1);
86b37281
MP
1107}
1108
98262f27
MP
1109static inline unsigned int queue_discard_zeroes_data(struct request_queue *q)
1110{
a934a00a 1111 if (q->limits.max_discard_sectors && q->limits.discard_zeroes_data == 1)
98262f27
MP
1112 return 1;
1113
1114 return 0;
1115}
1116
1117static inline unsigned int bdev_discard_zeroes_data(struct block_device *bdev)
1118{
1119 return queue_discard_zeroes_data(bdev_get_queue(bdev));
1120}
1121
165125e1 1122static inline int queue_dma_alignment(struct request_queue *q)
1da177e4 1123{
482eb689 1124 return q ? q->dma_alignment : 511;
1da177e4
LT
1125}
1126
14417799 1127static inline int blk_rq_aligned(struct request_queue *q, unsigned long addr,
87904074
FT
1128 unsigned int len)
1129{
1130 unsigned int alignment = queue_dma_alignment(q) | q->dma_pad_mask;
14417799 1131 return !(addr & alignment) && !(len & alignment);
87904074
FT
1132}
1133
1da177e4
LT
1134/* assumes size > 256 */
1135static inline unsigned int blksize_bits(unsigned int size)
1136{
1137 unsigned int bits = 8;
1138 do {
1139 bits++;
1140 size >>= 1;
1141 } while (size > 256);
1142 return bits;
1143}
1144
2befb9e3 1145static inline unsigned int block_size(struct block_device *bdev)
1da177e4
LT
1146{
1147 return bdev->bd_block_size;
1148}
1149
f3876930 1150static inline bool queue_flush_queueable(struct request_queue *q)
1151{
1152 return !q->flush_not_queueable;
1153}
1154
1da177e4
LT
1155typedef struct {struct page *v;} Sector;
1156
1157unsigned char *read_dev_sector(struct block_device *, sector_t, Sector *);
1158
1159static inline void put_dev_sector(Sector p)
1160{
1161 page_cache_release(p.v);
1162}
1163
1164struct work_struct;
18887ad9 1165int kblockd_schedule_work(struct request_queue *q, struct work_struct *work);
1da177e4 1166
9195291e 1167#ifdef CONFIG_BLK_CGROUP
28f4197e
JA
1168/*
1169 * This should not be using sched_clock(). A real patch is in progress
1170 * to fix this up, until that is in place we need to disable preemption
1171 * around sched_clock() in this function and set_io_start_time_ns().
1172 */
9195291e
DS
1173static inline void set_start_time_ns(struct request *req)
1174{
28f4197e 1175 preempt_disable();
9195291e 1176 req->start_time_ns = sched_clock();
28f4197e 1177 preempt_enable();
9195291e
DS
1178}
1179
1180static inline void set_io_start_time_ns(struct request *req)
1181{
28f4197e 1182 preempt_disable();
9195291e 1183 req->io_start_time_ns = sched_clock();
28f4197e 1184 preempt_enable();
9195291e 1185}
84c124da
DS
1186
1187static inline uint64_t rq_start_time_ns(struct request *req)
1188{
1189 return req->start_time_ns;
1190}
1191
1192static inline uint64_t rq_io_start_time_ns(struct request *req)
1193{
1194 return req->io_start_time_ns;
1195}
9195291e
DS
1196#else
1197static inline void set_start_time_ns(struct request *req) {}
1198static inline void set_io_start_time_ns(struct request *req) {}
84c124da
DS
1199static inline uint64_t rq_start_time_ns(struct request *req)
1200{
1201 return 0;
1202}
1203static inline uint64_t rq_io_start_time_ns(struct request *req)
1204{
1205 return 0;
1206}
9195291e
DS
1207#endif
1208
1da177e4
LT
1209#define MODULE_ALIAS_BLOCKDEV(major,minor) \
1210 MODULE_ALIAS("block-major-" __stringify(major) "-" __stringify(minor))
1211#define MODULE_ALIAS_BLOCKDEV_MAJOR(major) \
1212 MODULE_ALIAS("block-major-" __stringify(major) "-*")
1213
7ba1ba12
MP
1214#if defined(CONFIG_BLK_DEV_INTEGRITY)
1215
b24498d4
JA
1216#define INTEGRITY_FLAG_READ 2 /* verify data integrity on read */
1217#define INTEGRITY_FLAG_WRITE 4 /* generate data integrity on write */
7ba1ba12
MP
1218
1219struct blk_integrity_exchg {
1220 void *prot_buf;
1221 void *data_buf;
1222 sector_t sector;
1223 unsigned int data_size;
1224 unsigned short sector_size;
1225 const char *disk_name;
1226};
1227
1228typedef void (integrity_gen_fn) (struct blk_integrity_exchg *);
1229typedef int (integrity_vrfy_fn) (struct blk_integrity_exchg *);
1230typedef void (integrity_set_tag_fn) (void *, void *, unsigned int);
1231typedef void (integrity_get_tag_fn) (void *, void *, unsigned int);
1232
1233struct blk_integrity {
1234 integrity_gen_fn *generate_fn;
1235 integrity_vrfy_fn *verify_fn;
1236 integrity_set_tag_fn *set_tag_fn;
1237 integrity_get_tag_fn *get_tag_fn;
1238
1239 unsigned short flags;
1240 unsigned short tuple_size;
1241 unsigned short sector_size;
1242 unsigned short tag_size;
1243
1244 const char *name;
1245
1246 struct kobject kobj;
1247};
1248
a63a5cf8 1249extern bool blk_integrity_is_initialized(struct gendisk *);
7ba1ba12
MP
1250extern int blk_integrity_register(struct gendisk *, struct blk_integrity *);
1251extern void blk_integrity_unregister(struct gendisk *);
ad7fce93 1252extern int blk_integrity_compare(struct gendisk *, struct gendisk *);
13f05c8d
MP
1253extern int blk_rq_map_integrity_sg(struct request_queue *, struct bio *,
1254 struct scatterlist *);
1255extern int blk_rq_count_integrity_sg(struct request_queue *, struct bio *);
1256extern int blk_integrity_merge_rq(struct request_queue *, struct request *,
1257 struct request *);
1258extern int blk_integrity_merge_bio(struct request_queue *, struct request *,
1259 struct bio *);
7ba1ba12 1260
b04accc4
JA
1261static inline
1262struct blk_integrity *bdev_get_integrity(struct block_device *bdev)
1263{
1264 return bdev->bd_disk->integrity;
1265}
1266
b02739b0
MP
1267static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk)
1268{
1269 return disk->integrity;
1270}
1271
7ba1ba12
MP
1272static inline int blk_integrity_rq(struct request *rq)
1273{
d442cc44
MP
1274 if (rq->bio == NULL)
1275 return 0;
1276
7ba1ba12
MP
1277 return bio_integrity(rq->bio);
1278}
1279
13f05c8d
MP
1280static inline void blk_queue_max_integrity_segments(struct request_queue *q,
1281 unsigned int segs)
1282{
1283 q->limits.max_integrity_segments = segs;
1284}
1285
1286static inline unsigned short
1287queue_max_integrity_segments(struct request_queue *q)
1288{
1289 return q->limits.max_integrity_segments;
1290}
1291
7ba1ba12
MP
1292#else /* CONFIG_BLK_DEV_INTEGRITY */
1293
1294#define blk_integrity_rq(rq) (0)
13f05c8d
MP
1295#define blk_rq_count_integrity_sg(a, b) (0)
1296#define blk_rq_map_integrity_sg(a, b, c) (0)
b04accc4 1297#define bdev_get_integrity(a) (0)
b02739b0 1298#define blk_get_integrity(a) (0)
7ba1ba12
MP
1299#define blk_integrity_compare(a, b) (0)
1300#define blk_integrity_register(a, b) (0)
ea9d6553
NK
1301#define blk_integrity_unregister(a) do { } while (0)
1302#define blk_queue_max_integrity_segments(a, b) do { } while (0)
13f05c8d
MP
1303#define queue_max_integrity_segments(a) (0)
1304#define blk_integrity_merge_rq(a, b, c) (0)
1305#define blk_integrity_merge_bio(a, b, c) (0)
a63a5cf8 1306#define blk_integrity_is_initialized(a) (0)
7ba1ba12
MP
1307
1308#endif /* CONFIG_BLK_DEV_INTEGRITY */
1309
08f85851 1310struct block_device_operations {
d4430d62
AV
1311 int (*open) (struct block_device *, fmode_t);
1312 int (*release) (struct gendisk *, fmode_t);
d4430d62
AV
1313 int (*ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
1314 int (*compat_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
08f85851
AV
1315 int (*direct_access) (struct block_device *, sector_t,
1316 void **, unsigned long *);
77ea887e
TH
1317 unsigned int (*check_events) (struct gendisk *disk,
1318 unsigned int clearing);
1319 /* ->media_changed() is DEPRECATED, use ->check_events() instead */
08f85851 1320 int (*media_changed) (struct gendisk *);
c3e33e04 1321 void (*unlock_native_capacity) (struct gendisk *);
08f85851
AV
1322 int (*revalidate_disk) (struct gendisk *);
1323 int (*getgeo)(struct block_device *, struct hd_geometry *);
b3a27d05
NG
1324 /* this callback is with swap_lock and sometimes page table lock held */
1325 void (*swap_slot_free_notify) (struct block_device *, unsigned long);
08f85851
AV
1326 struct module *owner;
1327};
1328
633a08b8
AV
1329extern int __blkdev_driver_ioctl(struct block_device *, fmode_t, unsigned int,
1330 unsigned long);
9361401e
DH
1331#else /* CONFIG_BLOCK */
1332/*
1333 * stubs for when the block layer is configured out
1334 */
1335#define buffer_heads_over_limit 0
1336
9361401e
DH
1337static inline long nr_blockdev_pages(void)
1338{
1339 return 0;
1340}
1341
1f940bdf
JA
1342struct blk_plug {
1343};
1344
1345static inline void blk_start_plug(struct blk_plug *plug)
73c10101
JA
1346{
1347}
1348
1f940bdf 1349static inline void blk_finish_plug(struct blk_plug *plug)
73c10101
JA
1350{
1351}
1352
1f940bdf 1353static inline void blk_flush_plug(struct task_struct *task)
73c10101
JA
1354{
1355}
1356
a237c1c5
JA
1357static inline void blk_schedule_flush_plug(struct task_struct *task)
1358{
1359}
1360
1361
73c10101
JA
1362static inline bool blk_needs_flush_plug(struct task_struct *tsk)
1363{
1364 return false;
1365}
1366
9361401e
DH
1367#endif /* CONFIG_BLOCK */
1368
1da177e4 1369#endif