xref: /openbmc/linux/block/blk.h (revision 6fa24b41)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef BLK_INTERNAL_H
3 #define BLK_INTERNAL_H
4 
5 #include <linux/blk-crypto.h>
6 #include <linux/memblock.h>	/* for max_pfn/max_low_pfn */
7 #include <xen/xen.h>
8 #include "blk-crypto-internal.h"
9 
10 struct elevator_type;
11 
12 /* Max future timer expiry for timeouts */
13 #define BLK_MAX_TIMEOUT		(5 * HZ)
14 
15 extern struct dentry *blk_debugfs_root;
16 
17 struct blk_flush_queue {
18 	spinlock_t		mq_flush_lock;
19 	unsigned int		flush_pending_idx:1;
20 	unsigned int		flush_running_idx:1;
21 	blk_status_t 		rq_status;
22 	unsigned long		flush_pending_since;
23 	struct list_head	flush_queue[2];
24 	unsigned long		flush_data_in_flight;
25 	struct request		*flush_rq;
26 };
27 
28 bool is_flush_rq(struct request *req);
29 
30 struct blk_flush_queue *blk_alloc_flush_queue(int node, int cmd_size,
31 					      gfp_t flags);
32 void blk_free_flush_queue(struct blk_flush_queue *q);
33 
34 void blk_freeze_queue(struct request_queue *q);
35 void __blk_mq_unfreeze_queue(struct request_queue *q, bool force_atomic);
36 void blk_queue_start_drain(struct request_queue *q);
37 int __bio_queue_enter(struct request_queue *q, struct bio *bio);
38 void submit_bio_noacct_nocheck(struct bio *bio);
39 
40 static inline bool blk_try_enter_queue(struct request_queue *q, bool pm)
41 {
42 	rcu_read_lock();
43 	if (!percpu_ref_tryget_live_rcu(&q->q_usage_counter))
44 		goto fail;
45 
46 	/*
47 	 * The code that increments the pm_only counter must ensure that the
48 	 * counter is globally visible before the queue is unfrozen.
49 	 */
50 	if (blk_queue_pm_only(q) &&
51 	    (!pm || queue_rpm_status(q) == RPM_SUSPENDED))
52 		goto fail_put;
53 
54 	rcu_read_unlock();
55 	return true;
56 
57 fail_put:
58 	blk_queue_exit(q);
59 fail:
60 	rcu_read_unlock();
61 	return false;
62 }
63 
64 static inline int bio_queue_enter(struct bio *bio)
65 {
66 	struct request_queue *q = bdev_get_queue(bio->bi_bdev);
67 
68 	if (blk_try_enter_queue(q, false))
69 		return 0;
70 	return __bio_queue_enter(q, bio);
71 }
72 
73 #define BIO_INLINE_VECS 4
74 struct bio_vec *bvec_alloc(mempool_t *pool, unsigned short *nr_vecs,
75 		gfp_t gfp_mask);
76 void bvec_free(mempool_t *pool, struct bio_vec *bv, unsigned short nr_vecs);
77 
78 bool bvec_try_merge_hw_page(struct request_queue *q, struct bio_vec *bv,
79 		struct page *page, unsigned len, unsigned offset,
80 		bool *same_page);
81 
82 static inline bool biovec_phys_mergeable(struct request_queue *q,
83 		struct bio_vec *vec1, struct bio_vec *vec2)
84 {
85 	unsigned long mask = queue_segment_boundary(q);
86 	phys_addr_t addr1 = page_to_phys(vec1->bv_page) + vec1->bv_offset;
87 	phys_addr_t addr2 = page_to_phys(vec2->bv_page) + vec2->bv_offset;
88 
89 	/*
90 	 * Merging adjacent physical pages may not work correctly under KMSAN
91 	 * if their metadata pages aren't adjacent. Just disable merging.
92 	 */
93 	if (IS_ENABLED(CONFIG_KMSAN))
94 		return false;
95 
96 	if (addr1 + vec1->bv_len != addr2)
97 		return false;
98 	if (xen_domain() && !xen_biovec_phys_mergeable(vec1, vec2->bv_page))
99 		return false;
100 	if ((addr1 | mask) != ((addr2 + vec2->bv_len - 1) | mask))
101 		return false;
102 	return true;
103 }
104 
105 static inline bool __bvec_gap_to_prev(const struct queue_limits *lim,
106 		struct bio_vec *bprv, unsigned int offset)
107 {
108 	return (offset & lim->virt_boundary_mask) ||
109 		((bprv->bv_offset + bprv->bv_len) & lim->virt_boundary_mask);
110 }
111 
112 /*
113  * Check if adding a bio_vec after bprv with offset would create a gap in
114  * the SG list. Most drivers don't care about this, but some do.
115  */
116 static inline bool bvec_gap_to_prev(const struct queue_limits *lim,
117 		struct bio_vec *bprv, unsigned int offset)
118 {
119 	if (!lim->virt_boundary_mask)
120 		return false;
121 	return __bvec_gap_to_prev(lim, bprv, offset);
122 }
123 
124 static inline bool rq_mergeable(struct request *rq)
125 {
126 	if (blk_rq_is_passthrough(rq))
127 		return false;
128 
129 	if (req_op(rq) == REQ_OP_FLUSH)
130 		return false;
131 
132 	if (req_op(rq) == REQ_OP_WRITE_ZEROES)
133 		return false;
134 
135 	if (req_op(rq) == REQ_OP_ZONE_APPEND)
136 		return false;
137 
138 	if (rq->cmd_flags & REQ_NOMERGE_FLAGS)
139 		return false;
140 	if (rq->rq_flags & RQF_NOMERGE_FLAGS)
141 		return false;
142 
143 	return true;
144 }
145 
146 /*
147  * There are two different ways to handle DISCARD merges:
148  *  1) If max_discard_segments > 1, the driver treats every bio as a range and
149  *     send the bios to controller together. The ranges don't need to be
150  *     contiguous.
151  *  2) Otherwise, the request will be normal read/write requests.  The ranges
152  *     need to be contiguous.
153  */
154 static inline bool blk_discard_mergable(struct request *req)
155 {
156 	if (req_op(req) == REQ_OP_DISCARD &&
157 	    queue_max_discard_segments(req->q) > 1)
158 		return true;
159 	return false;
160 }
161 
162 static inline unsigned int blk_rq_get_max_segments(struct request *rq)
163 {
164 	if (req_op(rq) == REQ_OP_DISCARD)
165 		return queue_max_discard_segments(rq->q);
166 	return queue_max_segments(rq->q);
167 }
168 
169 static inline unsigned int blk_queue_get_max_sectors(struct request_queue *q,
170 						     enum req_op op)
171 {
172 	if (unlikely(op == REQ_OP_DISCARD || op == REQ_OP_SECURE_ERASE))
173 		return min(q->limits.max_discard_sectors,
174 			   UINT_MAX >> SECTOR_SHIFT);
175 
176 	if (unlikely(op == REQ_OP_WRITE_ZEROES))
177 		return q->limits.max_write_zeroes_sectors;
178 
179 	return q->limits.max_sectors;
180 }
181 
182 #ifdef CONFIG_BLK_DEV_INTEGRITY
183 void blk_flush_integrity(void);
184 bool __bio_integrity_endio(struct bio *);
185 void bio_integrity_free(struct bio *bio);
186 static inline bool bio_integrity_endio(struct bio *bio)
187 {
188 	if (bio_integrity(bio))
189 		return __bio_integrity_endio(bio);
190 	return true;
191 }
192 
193 bool blk_integrity_merge_rq(struct request_queue *, struct request *,
194 		struct request *);
195 bool blk_integrity_merge_bio(struct request_queue *, struct request *,
196 		struct bio *);
197 
198 static inline bool integrity_req_gap_back_merge(struct request *req,
199 		struct bio *next)
200 {
201 	struct bio_integrity_payload *bip = bio_integrity(req->bio);
202 	struct bio_integrity_payload *bip_next = bio_integrity(next);
203 
204 	return bvec_gap_to_prev(&req->q->limits,
205 				&bip->bip_vec[bip->bip_vcnt - 1],
206 				bip_next->bip_vec[0].bv_offset);
207 }
208 
209 static inline bool integrity_req_gap_front_merge(struct request *req,
210 		struct bio *bio)
211 {
212 	struct bio_integrity_payload *bip = bio_integrity(bio);
213 	struct bio_integrity_payload *bip_next = bio_integrity(req->bio);
214 
215 	return bvec_gap_to_prev(&req->q->limits,
216 				&bip->bip_vec[bip->bip_vcnt - 1],
217 				bip_next->bip_vec[0].bv_offset);
218 }
219 
220 extern const struct attribute_group blk_integrity_attr_group;
221 #else /* CONFIG_BLK_DEV_INTEGRITY */
222 static inline bool blk_integrity_merge_rq(struct request_queue *rq,
223 		struct request *r1, struct request *r2)
224 {
225 	return true;
226 }
227 static inline bool blk_integrity_merge_bio(struct request_queue *rq,
228 		struct request *r, struct bio *b)
229 {
230 	return true;
231 }
232 static inline bool integrity_req_gap_back_merge(struct request *req,
233 		struct bio *next)
234 {
235 	return false;
236 }
237 static inline bool integrity_req_gap_front_merge(struct request *req,
238 		struct bio *bio)
239 {
240 	return false;
241 }
242 
243 static inline void blk_flush_integrity(void)
244 {
245 }
246 static inline bool bio_integrity_endio(struct bio *bio)
247 {
248 	return true;
249 }
250 static inline void bio_integrity_free(struct bio *bio)
251 {
252 }
253 #endif /* CONFIG_BLK_DEV_INTEGRITY */
254 
255 unsigned long blk_rq_timeout(unsigned long timeout);
256 void blk_add_timer(struct request *req);
257 
258 bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio,
259 		unsigned int nr_segs);
260 bool blk_bio_list_merge(struct request_queue *q, struct list_head *list,
261 			struct bio *bio, unsigned int nr_segs);
262 
263 /*
264  * Plug flush limits
265  */
266 #define BLK_MAX_REQUEST_COUNT	32
267 #define BLK_PLUG_FLUSH_SIZE	(128 * 1024)
268 
269 /*
270  * Internal elevator interface
271  */
272 #define ELV_ON_HASH(rq) ((rq)->rq_flags & RQF_HASHED)
273 
274 bool blk_insert_flush(struct request *rq);
275 
276 int elevator_switch(struct request_queue *q, struct elevator_type *new_e);
277 void elevator_disable(struct request_queue *q);
278 void elevator_exit(struct request_queue *q);
279 int elv_register_queue(struct request_queue *q, bool uevent);
280 void elv_unregister_queue(struct request_queue *q);
281 
282 ssize_t part_size_show(struct device *dev, struct device_attribute *attr,
283 		char *buf);
284 ssize_t part_stat_show(struct device *dev, struct device_attribute *attr,
285 		char *buf);
286 ssize_t part_inflight_show(struct device *dev, struct device_attribute *attr,
287 		char *buf);
288 ssize_t part_fail_show(struct device *dev, struct device_attribute *attr,
289 		char *buf);
290 ssize_t part_fail_store(struct device *dev, struct device_attribute *attr,
291 		const char *buf, size_t count);
292 ssize_t part_timeout_show(struct device *, struct device_attribute *, char *);
293 ssize_t part_timeout_store(struct device *, struct device_attribute *,
294 				const char *, size_t);
295 
296 static inline bool bio_may_exceed_limits(struct bio *bio,
297 					 const struct queue_limits *lim)
298 {
299 	switch (bio_op(bio)) {
300 	case REQ_OP_DISCARD:
301 	case REQ_OP_SECURE_ERASE:
302 	case REQ_OP_WRITE_ZEROES:
303 		return true; /* non-trivial splitting decisions */
304 	default:
305 		break;
306 	}
307 
308 	/*
309 	 * All drivers must accept single-segments bios that are <= PAGE_SIZE.
310 	 * This is a quick and dirty check that relies on the fact that
311 	 * bi_io_vec[0] is always valid if a bio has data.  The check might
312 	 * lead to occasional false negatives when bios are cloned, but compared
313 	 * to the performance impact of cloned bios themselves the loop below
314 	 * doesn't matter anyway.
315 	 */
316 	return lim->chunk_sectors || bio->bi_vcnt != 1 ||
317 		bio->bi_io_vec->bv_len + bio->bi_io_vec->bv_offset > PAGE_SIZE;
318 }
319 
320 struct bio *__bio_split_to_limits(struct bio *bio,
321 				  const struct queue_limits *lim,
322 				  unsigned int *nr_segs);
323 int ll_back_merge_fn(struct request *req, struct bio *bio,
324 		unsigned int nr_segs);
325 bool blk_attempt_req_merge(struct request_queue *q, struct request *rq,
326 				struct request *next);
327 unsigned int blk_recalc_rq_segments(struct request *rq);
328 void blk_rq_set_mixed_merge(struct request *rq);
329 bool blk_rq_merge_ok(struct request *rq, struct bio *bio);
330 enum elv_merge blk_try_merge(struct request *rq, struct bio *bio);
331 
332 void blk_set_default_limits(struct queue_limits *lim);
333 int blk_dev_init(void);
334 
335 /*
336  * Contribute to IO statistics IFF:
337  *
338  *	a) it's attached to a gendisk, and
339  *	b) the queue had IO stats enabled when this request was started
340  */
341 static inline bool blk_do_io_stat(struct request *rq)
342 {
343 	return (rq->rq_flags & RQF_IO_STAT) && !blk_rq_is_passthrough(rq);
344 }
345 
346 void update_io_ticks(struct block_device *part, unsigned long now, bool end);
347 unsigned int part_in_flight(struct block_device *part);
348 
349 static inline void req_set_nomerge(struct request_queue *q, struct request *req)
350 {
351 	req->cmd_flags |= REQ_NOMERGE;
352 	if (req == q->last_merge)
353 		q->last_merge = NULL;
354 }
355 
356 /*
357  * Internal io_context interface
358  */
359 struct io_cq *ioc_find_get_icq(struct request_queue *q);
360 struct io_cq *ioc_lookup_icq(struct request_queue *q);
361 #ifdef CONFIG_BLK_ICQ
362 void ioc_clear_queue(struct request_queue *q);
363 #else
364 static inline void ioc_clear_queue(struct request_queue *q)
365 {
366 }
367 #endif /* CONFIG_BLK_ICQ */
368 
369 #ifdef CONFIG_BLK_DEV_THROTTLING_LOW
370 extern ssize_t blk_throtl_sample_time_show(struct request_queue *q, char *page);
371 extern ssize_t blk_throtl_sample_time_store(struct request_queue *q,
372 	const char *page, size_t count);
373 extern void blk_throtl_bio_endio(struct bio *bio);
374 extern void blk_throtl_stat_add(struct request *rq, u64 time);
375 #else
376 static inline void blk_throtl_bio_endio(struct bio *bio) { }
377 static inline void blk_throtl_stat_add(struct request *rq, u64 time) { }
378 #endif
379 
380 struct bio *__blk_queue_bounce(struct bio *bio, struct request_queue *q);
381 
382 static inline bool blk_queue_may_bounce(struct request_queue *q)
383 {
384 	return IS_ENABLED(CONFIG_BOUNCE) &&
385 		q->limits.bounce == BLK_BOUNCE_HIGH &&
386 		max_low_pfn >= max_pfn;
387 }
388 
389 static inline struct bio *blk_queue_bounce(struct bio *bio,
390 		struct request_queue *q)
391 {
392 	if (unlikely(blk_queue_may_bounce(q) && bio_has_data(bio)))
393 		return __blk_queue_bounce(bio, q);
394 	return bio;
395 }
396 
397 #ifdef CONFIG_BLK_DEV_ZONED
398 void disk_free_zone_bitmaps(struct gendisk *disk);
399 void disk_clear_zone_settings(struct gendisk *disk);
400 int blkdev_report_zones_ioctl(struct block_device *bdev, unsigned int cmd,
401 		unsigned long arg);
402 int blkdev_zone_mgmt_ioctl(struct block_device *bdev, blk_mode_t mode,
403 		unsigned int cmd, unsigned long arg);
404 #else /* CONFIG_BLK_DEV_ZONED */
405 static inline void disk_free_zone_bitmaps(struct gendisk *disk) {}
406 static inline void disk_clear_zone_settings(struct gendisk *disk) {}
407 static inline int blkdev_report_zones_ioctl(struct block_device *bdev,
408 		unsigned int cmd, unsigned long arg)
409 {
410 	return -ENOTTY;
411 }
412 static inline int blkdev_zone_mgmt_ioctl(struct block_device *bdev,
413 		blk_mode_t mode, unsigned int cmd, unsigned long arg)
414 {
415 	return -ENOTTY;
416 }
417 #endif /* CONFIG_BLK_DEV_ZONED */
418 
419 struct block_device *bdev_alloc(struct gendisk *disk, u8 partno);
420 void bdev_add(struct block_device *bdev, dev_t dev);
421 
422 int blk_alloc_ext_minor(void);
423 void blk_free_ext_minor(unsigned int minor);
424 #define ADDPART_FLAG_NONE	0
425 #define ADDPART_FLAG_RAID	1
426 #define ADDPART_FLAG_WHOLEDISK	2
427 int bdev_add_partition(struct gendisk *disk, int partno, sector_t start,
428 		sector_t length);
429 int bdev_del_partition(struct gendisk *disk, int partno);
430 int bdev_resize_partition(struct gendisk *disk, int partno, sector_t start,
431 		sector_t length);
432 void drop_partition(struct block_device *part);
433 
434 void bdev_set_nr_sectors(struct block_device *bdev, sector_t sectors);
435 
436 struct gendisk *__alloc_disk_node(struct request_queue *q, int node_id,
437 		struct lock_class_key *lkclass);
438 
439 int bio_add_hw_page(struct request_queue *q, struct bio *bio,
440 		struct page *page, unsigned int len, unsigned int offset,
441 		unsigned int max_sectors, bool *same_page);
442 
443 /*
444  * Clean up a page appropriately, where the page may be pinned, may have a
445  * ref taken on it or neither.
446  */
447 static inline void bio_release_page(struct bio *bio, struct page *page)
448 {
449 	if (bio_flagged(bio, BIO_PAGE_PINNED))
450 		unpin_user_page(page);
451 }
452 
453 struct request_queue *blk_alloc_queue(int node_id);
454 
455 int disk_scan_partitions(struct gendisk *disk, blk_mode_t mode);
456 
457 int disk_alloc_events(struct gendisk *disk);
458 void disk_add_events(struct gendisk *disk);
459 void disk_del_events(struct gendisk *disk);
460 void disk_release_events(struct gendisk *disk);
461 void disk_block_events(struct gendisk *disk);
462 void disk_unblock_events(struct gendisk *disk);
463 void disk_flush_events(struct gendisk *disk, unsigned int mask);
464 extern struct device_attribute dev_attr_events;
465 extern struct device_attribute dev_attr_events_async;
466 extern struct device_attribute dev_attr_events_poll_msecs;
467 
468 extern struct attribute_group blk_trace_attr_group;
469 
470 blk_mode_t file_to_blk_mode(struct file *file);
471 int truncate_bdev_range(struct block_device *bdev, blk_mode_t mode,
472 		loff_t lstart, loff_t lend);
473 long blkdev_ioctl(struct file *file, unsigned cmd, unsigned long arg);
474 long compat_blkdev_ioctl(struct file *file, unsigned cmd, unsigned long arg);
475 
476 extern const struct address_space_operations def_blk_aops;
477 
478 int disk_register_independent_access_ranges(struct gendisk *disk);
479 void disk_unregister_independent_access_ranges(struct gendisk *disk);
480 
481 #ifdef CONFIG_FAIL_MAKE_REQUEST
482 bool should_fail_request(struct block_device *part, unsigned int bytes);
483 #else /* CONFIG_FAIL_MAKE_REQUEST */
484 static inline bool should_fail_request(struct block_device *part,
485 					unsigned int bytes)
486 {
487 	return false;
488 }
489 #endif /* CONFIG_FAIL_MAKE_REQUEST */
490 
491 /*
492  * Optimized request reference counting. Ideally we'd make timeouts be more
493  * clever, as that's the only reason we need references at all... But until
494  * this happens, this is faster than using refcount_t. Also see:
495  *
496  * abc54d634334 ("io_uring: switch to atomic_t for io_kiocb reference count")
497  */
498 #define req_ref_zero_or_close_to_overflow(req)	\
499 	((unsigned int) atomic_read(&(req->ref)) + 127u <= 127u)
500 
501 static inline bool req_ref_inc_not_zero(struct request *req)
502 {
503 	return atomic_inc_not_zero(&req->ref);
504 }
505 
506 static inline bool req_ref_put_and_test(struct request *req)
507 {
508 	WARN_ON_ONCE(req_ref_zero_or_close_to_overflow(req));
509 	return atomic_dec_and_test(&req->ref);
510 }
511 
512 static inline void req_ref_set(struct request *req, int value)
513 {
514 	atomic_set(&req->ref, value);
515 }
516 
517 static inline int req_ref_read(struct request *req)
518 {
519 	return atomic_read(&req->ref);
520 }
521 
522 #endif /* BLK_INTERNAL_H */
523