1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
|
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef BLK_INTERNAL_H
#define BLK_INTERNAL_H
#include <linux/bio-integrity.h>
#include <linux/blk-crypto.h>
#include <linux/memblock.h> /* for max_pfn/max_low_pfn */
#include <linux/sched/sysctl.h>
#include <linux/timekeeping.h>
#include <xen/xen.h>
#include "blk-crypto-internal.h"
struct elevator_type;
/* Max future timer expiry for timeouts */
#define BLK_MAX_TIMEOUT (5 * HZ)
extern struct dentry *blk_debugfs_root;
struct blk_flush_queue {
spinlock_t mq_flush_lock;
unsigned int flush_pending_idx:1;
unsigned int flush_running_idx:1;
blk_status_t rq_status;
unsigned long flush_pending_since;
struct list_head flush_queue[2];
unsigned long flush_data_in_flight;
struct request *flush_rq;
};
bool is_flush_rq(struct request *req);
struct blk_flush_queue *blk_alloc_flush_queue(int node, int cmd_size,
gfp_t flags);
void blk_free_flush_queue(struct blk_flush_queue *q);
void blk_freeze_queue(struct request_queue *q);
void __blk_mq_unfreeze_queue(struct request_queue *q, bool force_atomic);
void blk_queue_start_drain(struct request_queue *q);
int __bio_queue_enter(struct request_queue *q, struct bio *bio);
void submit_bio_noacct_nocheck(struct bio *bio);
void bio_await_chain(struct bio *bio);
static inline bool blk_try_enter_queue(struct request_queue *q, bool pm)
{
rcu_read_lock();
if (!percpu_ref_tryget_live_rcu(&q->q_usage_counter))
goto fail;
/*
* The code that increments the pm_only counter must ensure that the
* counter is globally visible before the queue is unfrozen.
*/
if (blk_queue_pm_only(q) &&
(!pm || queue_rpm_status(q) == RPM_SUSPENDED))
goto fail_put;
rcu_read_unlock();
return true;
fail_put:
blk_queue_exit(q);
fail:
rcu_read_unlock();
return false;
}
static inline int bio_queue_enter(struct bio *bio)
{
struct request_queue *q = bdev_get_queue(bio->bi_bdev);
if (blk_try_enter_queue(q, false))
return 0;
return __bio_queue_enter(q, bio);
}
static inline void blk_wait_io(struct completion *done)
{
/* Prevent hang_check timer from firing at us during very long I/O */
unsigned long timeout = sysctl_hung_task_timeout_secs * HZ / 2;
if (timeout)
while (!wait_for_completion_io_timeout(done, timeout))
;
else
wait_for_completion_io(done);
}
#define BIO_INLINE_VECS 4
struct bio_vec *bvec_alloc(mempool_t *pool, unsigned short *nr_vecs,
gfp_t gfp_mask);
void bvec_free(mempool_t *pool, struct bio_vec *bv, unsigned short nr_vecs);
bool bvec_try_merge_hw_page(struct request_queue *q, struct bio_vec *bv,
struct page *page, unsigned len, unsigned offset,
bool *same_page);
static inline bool biovec_phys_mergeable(struct request_queue *q,
struct bio_vec *vec1, struct bio_vec *vec2)
{
unsigned long mask = queue_segment_boundary(q);
phys_addr_t addr1 = bvec_phys(vec1);
phys_addr_t addr2 = bvec_phys(vec2);
/*
* Merging adjacent physical pages may not work correctly under KMSAN
* if their metadata pages aren't adjacent. Just disable merging.
*/
if (IS_ENABLED(CONFIG_KMSAN))
return false;
if (addr1 + vec1->bv_len != addr2)
return false;
if (xen_domain() && !xen_biovec_phys_mergeable(vec1, vec2->bv_page))
return false;
if ((addr1 | mask) != ((addr2 + vec2->bv_len - 1) | mask))
return false;
return true;
}
static inline bool __bvec_gap_to_prev(const struct queue_limits *lim,
struct bio_vec *bprv, unsigned int offset)
{
return (offset & lim->virt_boundary_mask) ||
((bprv->bv_offset + bprv->bv_len) & lim->virt_boundary_mask);
}
/*
* Check if adding a bio_vec after bprv with offset would create a gap in
* the SG list. Most drivers don't care about this, but some do.
*/
static inline bool bvec_gap_to_prev(const struct queue_limits *lim,
struct bio_vec *bprv, unsigned int offset)
{
if (!lim->virt_boundary_mask)
return false;
return __bvec_gap_to_prev(lim, bprv, offset);
}
static inline bool rq_mergeable(struct request *rq)
{
if (blk_rq_is_passthrough(rq))
return false;
if (req_op(rq) == REQ_OP_FLUSH)
return false;
if (req_op(rq) == REQ_OP_WRITE_ZEROES)
return false;
if (req_op(rq) == REQ_OP_ZONE_APPEND)
return false;
if (rq->cmd_flags & REQ_NOMERGE_FLAGS)
return false;
if (rq->rq_flags & RQF_NOMERGE_FLAGS)
return false;
return true;
}
/*
* There are two different ways to handle DISCARD merges:
* 1) If max_discard_segments > 1, the driver treats every bio as a range and
* send the bios to controller together. The ranges don't need to be
* contiguous.
* 2) Otherwise, the request will be normal read/write requests. The ranges
* need to be contiguous.
*/
static inline bool blk_discard_mergable(struct request *req)
{
if (req_op(req) == REQ_OP_DISCARD &&
queue_max_discard_segments(req->q) > 1)
return true;
return false;
}
static inline unsigned int blk_rq_get_max_segments(struct request *rq)
{
if (req_op(rq) == REQ_OP_DISCARD)
return queue_max_discard_segments(rq->q);
return queue_max_segments(rq->q);
}
static inline unsigned int blk_queue_get_max_sectors(struct request *rq)
{
struct request_queue *q = rq->q;
enum req_op op = req_op(rq);
if (unlikely(op == REQ_OP_DISCARD || op == REQ_OP_SECURE_ERASE))
return min(q->limits.max_discard_sectors,
UINT_MAX >> SECTOR_SHIFT);
if (unlikely(op == REQ_OP_WRITE_ZEROES))
return q->limits.max_write_zeroes_sectors;
if (rq->cmd_flags & REQ_ATOMIC)
return q->limits.atomic_write_max_sectors;
return q->limits.max_sectors;
}
#ifdef CONFIG_BLK_DEV_INTEGRITY
void blk_flush_integrity(void);
void bio_integrity_free(struct bio *bio);
/*
* Integrity payloads can either be owned by the submitter, in which case
* bio_uninit will free them, or owned and generated by the block layer,
* in which case we'll verify them here (for reads) and free them before
* the bio is handed back to the submitted.
*/
bool __bio_integrity_endio(struct bio *bio);
static inline bool bio_integrity_endio(struct bio *bio)
{
struct bio_integrity_payload *bip = bio_integrity(bio);
if (bip && (bip->bip_flags & BIP_BLOCK_INTEGRITY))
return __bio_integrity_endio(bio);
return true;
}
bool blk_integrity_merge_rq(struct request_queue *, struct request *,
struct request *);
bool blk_integrity_merge_bio(struct request_queue *, struct request *,
struct bio *);
static inline bool integrity_req_gap_back_merge(struct request *req,
struct bio *next)
{
struct bio_integrity_payload *bip = bio_integrity(req->bio);
struct bio_integrity_payload *bip_next = bio_integrity(next);
return bvec_gap_to_prev(&req->q->limits,
&bip->bip_vec[bip->bip_vcnt - 1],
bip_next->bip_vec[0].bv_offset);
}
static inline bool integrity_req_gap_front_merge(struct request *req,
struct bio *bio)
{
struct bio_integrity_payload *bip = bio_integrity(bio);
struct bio_integrity_payload *bip_next = bio_integrity(req->bio);
return bvec_gap_to_prev(&req->q->limits,
&bip->bip_vec[bip->bip_vcnt - 1],
bip_next->bip_vec[0].bv_offset);
}
extern const struct attribute_group blk_integrity_attr_group;
#else /* CONFIG_BLK_DEV_INTEGRITY */
static inline bool blk_integrity_merge_rq(struct request_queue *rq,
struct request *r1, struct request *r2)
{
return true;
}
static inline bool blk_integrity_merge_bio(struct request_queue *rq,
struct request *r, struct bio *b)
{
return true;
}
static inline bool integrity_req_gap_back_merge(struct request *req,
struct bio *next)
{
return false;
}
static inline bool integrity_req_gap_front_merge(struct request *req,
struct bio *bio)
{
return false;
}
static inline void blk_flush_integrity(void)
{
}
static inline bool bio_integrity_endio(struct bio *bio)
{
return true;
}
static inline void bio_integrity_free(struct bio *bio)
{
}
#endif /* CONFIG_BLK_DEV_INTEGRITY */
unsigned long blk_rq_timeout(unsigned long timeout);
void blk_add_timer(struct request *req);
enum bio_merge_status {
BIO_MERGE_OK,
BIO_MERGE_NONE,
BIO_MERGE_FAILED,
};
enum bio_merge_status bio_attempt_back_merge(struct request *req,
struct bio *bio, unsigned int nr_segs);
bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio,
unsigned int nr_segs);
bool blk_bio_list_merge(struct request_queue *q, struct list_head *list,
struct bio *bio, unsigned int nr_segs);
/*
* Plug flush limits
*/
#define BLK_MAX_REQUEST_COUNT 32
#define BLK_PLUG_FLUSH_SIZE (128 * 1024)
/*
* Internal elevator interface
*/
#define ELV_ON_HASH(rq) ((rq)->rq_flags & RQF_HASHED)
bool blk_insert_flush(struct request *rq);
int elevator_switch(struct request_queue *q, struct elevator_type *new_e);
void elevator_disable(struct request_queue *q);
void elevator_exit(struct request_queue *q);
int elv_register_queue(struct request_queue *q, bool uevent);
void elv_unregister_queue(struct request_queue *q);
ssize_t part_size_show(struct device *dev, struct device_attribute *attr,
char *buf);
ssize_t part_stat_show(struct device *dev, struct device_attribute *attr,
char *buf);
ssize_t part_inflight_show(struct device *dev, struct device_attribute *attr,
char *buf);
ssize_t part_fail_show(struct device *dev, struct device_attribute *attr,
char *buf);
ssize_t part_fail_store(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count);
ssize_t part_timeout_show(struct device *, struct device_attribute *, char *);
ssize_t part_timeout_store(struct device *, struct device_attribute *,
const char *, size_t);
struct bio *bio_split_discard(struct bio *bio, const struct queue_limits *lim,
unsigned *nsegs);
struct bio *bio_split_write_zeroes(struct bio *bio,
const struct queue_limits *lim, unsigned *nsegs);
struct bio *bio_split_rw(struct bio *bio, const struct queue_limits *lim,
unsigned *nr_segs);
struct bio *bio_split_zone_append(struct bio *bio,
const struct queue_limits *lim, unsigned *nr_segs);
/*
* All drivers must accept single-segments bios that are smaller than PAGE_SIZE.
*
* This is a quick and dirty check that relies on the fact that bi_io_vec[0] is
* always valid if a bio has data. The check might lead to occasional false
* positives when bios are cloned, but compared to the performance impact of
* cloned bios themselves the loop below doesn't matter anyway.
*/
static inline bool bio_may_need_split(struct bio *bio,
const struct queue_limits *lim)
{
return lim->chunk_sectors || bio->bi_vcnt != 1 ||
bio->bi_io_vec->bv_len + bio->bi_io_vec->bv_offset > PAGE_SIZE;
}
/**
* __bio_split_to_limits - split a bio to fit the queue limits
* @bio: bio to be split
* @lim: queue limits to split based on
* @nr_segs: returns the number of segments in the returned bio
*
* Check if @bio needs splitting based on the queue limits, and if so split off
* a bio fitting the limits from the beginning of @bio and return it. @bio is
* shortened to the remainder and re-submitted.
*
* The split bio is allocated from @q->bio_split, which is provided by the
* block layer.
*/
static inline struct bio *__bio_split_to_limits(struct bio *bio,
const struct queue_limits *lim, unsigned int *nr_segs)
{
switch (bio_op(bio)) {
case REQ_OP_READ:
case REQ_OP_WRITE:
if (bio_may_need_split(bio, lim))
return bio_split_rw(bio, lim, nr_segs);
*nr_segs = 1;
return bio;
case REQ_OP_ZONE_APPEND:
return bio_split_zone_append(bio, lim, nr_segs);
case REQ_OP_DISCARD:
case REQ_OP_SECURE_ERASE:
return bio_split_discard(bio, lim, nr_segs);
case REQ_OP_WRITE_ZEROES:
return bio_split_write_zeroes(bio, lim, nr_segs);
default:
/* other operations can't be split */
*nr_segs = 0;
return bio;
}
}
int ll_back_merge_fn(struct request *req, struct bio *bio,
unsigned int nr_segs);
bool blk_attempt_req_merge(struct request_queue *q, struct request *rq,
struct request *next);
unsigned int blk_recalc_rq_segments(struct request *rq);
bool blk_rq_merge_ok(struct request *rq, struct bio *bio);
enum elv_merge blk_try_merge(struct request *rq, struct bio *bio);
int blk_set_default_limits(struct queue_limits *lim);
void blk_apply_bdi_limits(struct backing_dev_info *bdi,
struct queue_limits *lim);
int blk_dev_init(void);
/*
* Contribute to IO statistics IFF:
*
* a) it's attached to a gendisk, and
* b) the queue had IO stats enabled when this request was started
*/
static inline bool blk_do_io_stat(struct request *rq)
{
return (rq->rq_flags & RQF_IO_STAT) && !blk_rq_is_passthrough(rq);
}
void update_io_ticks(struct block_device *part, unsigned long now, bool end);
unsigned int part_in_flight(struct block_device *part);
static inline void req_set_nomerge(struct request_queue *q, struct request *req)
{
req->cmd_flags |= REQ_NOMERGE;
if (req == q->last_merge)
q->last_merge = NULL;
}
/*
* Internal io_context interface
*/
struct io_cq *ioc_find_get_icq(struct request_queue *q);
struct io_cq *ioc_lookup_icq(struct request_queue *q);
#ifdef CONFIG_BLK_ICQ
void ioc_clear_queue(struct request_queue *q);
#else
static inline void ioc_clear_queue(struct request_queue *q)
{
}
#endif /* CONFIG_BLK_ICQ */
struct bio *__blk_queue_bounce(struct bio *bio, struct request_queue *q);
static inline bool blk_queue_may_bounce(struct request_queue *q)
{
return IS_ENABLED(CONFIG_BOUNCE) &&
(q->limits.features & BLK_FEAT_BOUNCE_HIGH) &&
max_low_pfn >= max_pfn;
}
static inline struct bio *blk_queue_bounce(struct bio *bio,
struct request_queue *q)
{
if (unlikely(blk_queue_may_bounce(q) && bio_has_data(bio)))
return __blk_queue_bounce(bio, q);
return bio;
}
#ifdef CONFIG_BLK_DEV_ZONED
void disk_init_zone_resources(struct gendisk *disk);
void disk_free_zone_resources(struct gendisk *disk);
static inline bool bio_zone_write_plugging(struct bio *bio)
{
return bio_flagged(bio, BIO_ZONE_WRITE_PLUGGING);
}
static inline bool bio_is_zone_append(struct bio *bio)
{
return bio_op(bio) == REQ_OP_ZONE_APPEND ||
bio_flagged(bio, BIO_EMULATES_ZONE_APPEND);
}
void blk_zone_write_plug_bio_merged(struct bio *bio);
void blk_zone_write_plug_init_request(struct request *rq);
static inline void blk_zone_update_request_bio(struct request *rq,
struct bio *bio)
{
/*
* For zone append requests, the request sector indicates the location
* at which the BIO data was written. Return this value to the BIO
* issuer through the BIO iter sector.
* For plugged zone writes, which include emulated zone append, we need
* the original BIO sector so that blk_zone_write_plug_bio_endio() can
* lookup the zone write plug.
*/
if (req_op(rq) == REQ_OP_ZONE_APPEND || bio_zone_write_plugging(bio))
bio->bi_iter.bi_sector = rq->__sector;
}
void blk_zone_write_plug_bio_endio(struct bio *bio);
static inline void blk_zone_bio_endio(struct bio *bio)
{
/*
* For write BIOs to zoned devices, signal the completion of the BIO so
* that the next write BIO can be submitted by zone write plugging.
*/
if (bio_zone_write_plugging(bio))
blk_zone_write_plug_bio_endio(bio);
}
void blk_zone_write_plug_finish_request(struct request *rq);
static inline void blk_zone_finish_request(struct request *rq)
{
if (rq->rq_flags & RQF_ZONE_WRITE_PLUGGING)
blk_zone_write_plug_finish_request(rq);
}
int blkdev_report_zones_ioctl(struct block_device *bdev, unsigned int cmd,
unsigned long arg);
int blkdev_zone_mgmt_ioctl(struct block_device *bdev, blk_mode_t mode,
unsigned int cmd, unsigned long arg);
#else /* CONFIG_BLK_DEV_ZONED */
static inline void disk_init_zone_resources(struct gendisk *disk)
{
}
static inline void disk_free_zone_resources(struct gendisk *disk)
{
}
static inline bool bio_zone_write_plugging(struct bio *bio)
{
return false;
}
static inline bool bio_is_zone_append(struct bio *bio)
{
return false;
}
static inline void blk_zone_write_plug_bio_merged(struct bio *bio)
{
}
static inline void blk_zone_write_plug_init_request(struct request *rq)
{
}
static inline void blk_zone_update_request_bio(struct request *rq,
struct bio *bio)
{
}
static inline void blk_zone_bio_endio(struct bio *bio)
{
}
static inline void blk_zone_finish_request(struct request *rq)
{
}
static inline int blkdev_report_zones_ioctl(struct block_device *bdev,
unsigned int cmd, unsigned long arg)
{
return -ENOTTY;
}
static inline int blkdev_zone_mgmt_ioctl(struct block_device *bdev,
blk_mode_t mode, unsigned int cmd, unsigned long arg)
{
return -ENOTTY;
}
#endif /* CONFIG_BLK_DEV_ZONED */
struct block_device *bdev_alloc(struct gendisk *disk, u8 partno);
void bdev_add(struct block_device *bdev, dev_t dev);
void bdev_unhash(struct block_device *bdev);
void bdev_drop(struct block_device *bdev);
int blk_alloc_ext_minor(void);
void blk_free_ext_minor(unsigned int minor);
#define ADDPART_FLAG_NONE 0
#define ADDPART_FLAG_RAID 1
#define ADDPART_FLAG_WHOLEDISK 2
int bdev_add_partition(struct gendisk *disk, int partno, sector_t start,
sector_t length);
int bdev_del_partition(struct gendisk *disk, int partno);
int bdev_resize_partition(struct gendisk *disk, int partno, sector_t start,
sector_t length);
void drop_partition(struct block_device *part);
void bdev_set_nr_sectors(struct block_device *bdev, sector_t sectors);
struct gendisk *__alloc_disk_node(struct request_queue *q, int node_id,
struct lock_class_key *lkclass);
int bio_add_hw_page(struct request_queue *q, struct bio *bio,
struct page *page, unsigned int len, unsigned int offset,
unsigned int max_sectors, bool *same_page);
/*
* Clean up a page appropriately, where the page may be pinned, may have a
* ref taken on it or neither.
*/
static inline void bio_release_page(struct bio *bio, struct page *page)
{
if (bio_flagged(bio, BIO_PAGE_PINNED))
unpin_user_page(page);
}
struct request_queue *blk_alloc_queue(struct queue_limits *lim, int node_id);
int disk_scan_partitions(struct gendisk *disk, blk_mode_t mode);
int disk_alloc_events(struct gendisk *disk);
void disk_add_events(struct gendisk *disk);
void disk_del_events(struct gendisk *disk);
void disk_release_events(struct gendisk *disk);
void disk_block_events(struct gendisk *disk);
void disk_unblock_events(struct gendisk *disk);
void disk_flush_events(struct gendisk *disk, unsigned int mask);
extern struct device_attribute dev_attr_events;
extern struct device_attribute dev_attr_events_async;
extern struct device_attribute dev_attr_events_poll_msecs;
extern struct attribute_group blk_trace_attr_group;
blk_mode_t file_to_blk_mode(struct file *file);
int truncate_bdev_range(struct block_device *bdev, blk_mode_t mode,
loff_t lstart, loff_t lend);
long blkdev_ioctl(struct file *file, unsigned cmd, unsigned long arg);
long compat_blkdev_ioctl(struct file *file, unsigned cmd, unsigned long arg);
extern const struct address_space_operations def_blk_aops;
int disk_register_independent_access_ranges(struct gendisk *disk);
void disk_unregister_independent_access_ranges(struct gendisk *disk);
#ifdef CONFIG_FAIL_MAKE_REQUEST
bool should_fail_request(struct block_device *part, unsigned int bytes);
#else /* CONFIG_FAIL_MAKE_REQUEST */
static inline bool should_fail_request(struct block_device *part,
unsigned int bytes)
{
return false;
}
#endif /* CONFIG_FAIL_MAKE_REQUEST */
/*
* Optimized request reference counting. Ideally we'd make timeouts be more
* clever, as that's the only reason we need references at all... But until
* this happens, this is faster than using refcount_t. Also see:
*
* abc54d634334 ("io_uring: switch to atomic_t for io_kiocb reference count")
*/
#define req_ref_zero_or_close_to_overflow(req) \
((unsigned int) atomic_read(&(req->ref)) + 127u <= 127u)
static inline bool req_ref_inc_not_zero(struct request *req)
{
return atomic_inc_not_zero(&req->ref);
}
static inline bool req_ref_put_and_test(struct request *req)
{
WARN_ON_ONCE(req_ref_zero_or_close_to_overflow(req));
return atomic_dec_and_test(&req->ref);
}
static inline void req_ref_set(struct request *req, int value)
{
atomic_set(&req->ref, value);
}
static inline int req_ref_read(struct request *req)
{
return atomic_read(&req->ref);
}
static inline u64 blk_time_get_ns(void)
{
struct blk_plug *plug = current->plug;
if (!plug || !in_task())
return ktime_get_ns();
/*
* 0 could very well be a valid time, but rather than flag "this is
* a valid timestamp" separately, just accept that we'll do an extra
* ktime_get_ns() if we just happen to get 0 as the current time.
*/
if (!plug->cur_ktime) {
plug->cur_ktime = ktime_get_ns();
current->flags |= PF_BLOCK_TS;
}
return plug->cur_ktime;
}
static inline ktime_t blk_time_get(void)
{
return ns_to_ktime(blk_time_get_ns());
}
/*
* From most significant bit:
* 1 bit: reserved for other usage, see below
* 12 bits: original size of bio
* 51 bits: issue time of bio
*/
#define BIO_ISSUE_RES_BITS 1
#define BIO_ISSUE_SIZE_BITS 12
#define BIO_ISSUE_RES_SHIFT (64 - BIO_ISSUE_RES_BITS)
#define BIO_ISSUE_SIZE_SHIFT (BIO_ISSUE_RES_SHIFT - BIO_ISSUE_SIZE_BITS)
#define BIO_ISSUE_TIME_MASK ((1ULL << BIO_ISSUE_SIZE_SHIFT) - 1)
#define BIO_ISSUE_SIZE_MASK \
(((1ULL << BIO_ISSUE_SIZE_BITS) - 1) << BIO_ISSUE_SIZE_SHIFT)
#define BIO_ISSUE_RES_MASK (~((1ULL << BIO_ISSUE_RES_SHIFT) - 1))
/* Reserved bit for blk-throtl */
#define BIO_ISSUE_THROTL_SKIP_LATENCY (1ULL << 63)
static inline u64 __bio_issue_time(u64 time)
{
return time & BIO_ISSUE_TIME_MASK;
}
static inline u64 bio_issue_time(struct bio_issue *issue)
{
return __bio_issue_time(issue->value);
}
static inline sector_t bio_issue_size(struct bio_issue *issue)
{
return ((issue->value & BIO_ISSUE_SIZE_MASK) >> BIO_ISSUE_SIZE_SHIFT);
}
static inline void bio_issue_init(struct bio_issue *issue,
sector_t size)
{
size &= (1ULL << BIO_ISSUE_SIZE_BITS) - 1;
issue->value = ((issue->value & BIO_ISSUE_RES_MASK) |
(blk_time_get_ns() & BIO_ISSUE_TIME_MASK) |
((u64)size << BIO_ISSUE_SIZE_SHIFT));
}
void bdev_release(struct file *bdev_file);
int bdev_open(struct block_device *bdev, blk_mode_t mode, void *holder,
const struct blk_holder_ops *hops, struct file *bdev_file);
int bdev_permission(dev_t dev, blk_mode_t mode, void *holder);
void blk_integrity_generate(struct bio *bio);
void blk_integrity_verify(struct bio *bio);
void blk_integrity_prepare(struct request *rq);
void blk_integrity_complete(struct request *rq, unsigned int nr_bytes);
#endif /* BLK_INTERNAL_H */
|