xref: /linux/block/blk.h (revision e488d4f5d6e4cd1e728ba4ddbdcd7ef5f4d13a21)
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 	unsigned int		flush_pending_idx:1;
19 	unsigned int		flush_running_idx:1;
20 	blk_status_t 		rq_status;
21 	unsigned long		flush_pending_since;
22 	struct list_head	flush_queue[2];
23 	struct list_head	flush_data_in_flight;
24 	struct request		*flush_rq;
25 
26 	spinlock_t		mq_flush_lock;
27 };
28 
29 extern struct kmem_cache *blk_requestq_cachep;
30 extern struct kmem_cache *blk_requestq_srcu_cachep;
31 extern struct kobj_type blk_queue_ktype;
32 extern struct ida blk_queue_ida;
33 
34 bool is_flush_rq(struct request *req);
35 
36 struct blk_flush_queue *blk_alloc_flush_queue(int node, int cmd_size,
37 					      gfp_t flags);
38 void blk_free_flush_queue(struct blk_flush_queue *q);
39 
40 void blk_freeze_queue(struct request_queue *q);
41 void __blk_mq_unfreeze_queue(struct request_queue *q, bool force_atomic);
42 void blk_queue_start_drain(struct request_queue *q);
43 int __bio_queue_enter(struct request_queue *q, struct bio *bio);
44 void submit_bio_noacct_nocheck(struct bio *bio);
45 
46 static inline bool blk_try_enter_queue(struct request_queue *q, bool pm)
47 {
48 	rcu_read_lock();
49 	if (!percpu_ref_tryget_live_rcu(&q->q_usage_counter))
50 		goto fail;
51 
52 	/*
53 	 * The code that increments the pm_only counter must ensure that the
54 	 * counter is globally visible before the queue is unfrozen.
55 	 */
56 	if (blk_queue_pm_only(q) &&
57 	    (!pm || queue_rpm_status(q) == RPM_SUSPENDED))
58 		goto fail_put;
59 
60 	rcu_read_unlock();
61 	return true;
62 
63 fail_put:
64 	blk_queue_exit(q);
65 fail:
66 	rcu_read_unlock();
67 	return false;
68 }
69 
70 static inline int bio_queue_enter(struct bio *bio)
71 {
72 	struct request_queue *q = bdev_get_queue(bio->bi_bdev);
73 
74 	if (blk_try_enter_queue(q, false))
75 		return 0;
76 	return __bio_queue_enter(q, bio);
77 }
78 
79 #define BIO_INLINE_VECS 4
80 struct bio_vec *bvec_alloc(mempool_t *pool, unsigned short *nr_vecs,
81 		gfp_t gfp_mask);
82 void bvec_free(mempool_t *pool, struct bio_vec *bv, unsigned short nr_vecs);
83 
84 static inline bool biovec_phys_mergeable(struct request_queue *q,
85 		struct bio_vec *vec1, struct bio_vec *vec2)
86 {
87 	unsigned long mask = queue_segment_boundary(q);
88 	phys_addr_t addr1 = page_to_phys(vec1->bv_page) + vec1->bv_offset;
89 	phys_addr_t addr2 = page_to_phys(vec2->bv_page) + vec2->bv_offset;
90 
91 	if (addr1 + vec1->bv_len != addr2)
92 		return false;
93 	if (xen_domain() && !xen_biovec_phys_mergeable(vec1, vec2->bv_page))
94 		return false;
95 	if ((addr1 | mask) != ((addr2 + vec2->bv_len - 1) | mask))
96 		return false;
97 	return true;
98 }
99 
100 static inline bool __bvec_gap_to_prev(struct request_queue *q,
101 		struct bio_vec *bprv, unsigned int offset)
102 {
103 	return (offset & queue_virt_boundary(q)) ||
104 		((bprv->bv_offset + bprv->bv_len) & queue_virt_boundary(q));
105 }
106 
107 /*
108  * Check if adding a bio_vec after bprv with offset would create a gap in
109  * the SG list. Most drivers don't care about this, but some do.
110  */
111 static inline bool bvec_gap_to_prev(struct request_queue *q,
112 		struct bio_vec *bprv, unsigned int offset)
113 {
114 	if (!queue_virt_boundary(q))
115 		return false;
116 	return __bvec_gap_to_prev(q, bprv, offset);
117 }
118 
119 static inline bool rq_mergeable(struct request *rq)
120 {
121 	if (blk_rq_is_passthrough(rq))
122 		return false;
123 
124 	if (req_op(rq) == REQ_OP_FLUSH)
125 		return false;
126 
127 	if (req_op(rq) == REQ_OP_WRITE_ZEROES)
128 		return false;
129 
130 	if (req_op(rq) == REQ_OP_ZONE_APPEND)
131 		return false;
132 
133 	if (rq->cmd_flags & REQ_NOMERGE_FLAGS)
134 		return false;
135 	if (rq->rq_flags & RQF_NOMERGE_FLAGS)
136 		return false;
137 
138 	return true;
139 }
140 
141 /*
142  * There are two different ways to handle DISCARD merges:
143  *  1) If max_discard_segments > 1, the driver treats every bio as a range and
144  *     send the bios to controller together. The ranges don't need to be
145  *     contiguous.
146  *  2) Otherwise, the request will be normal read/write requests.  The ranges
147  *     need to be contiguous.
148  */
149 static inline bool blk_discard_mergable(struct request *req)
150 {
151 	if (req_op(req) == REQ_OP_DISCARD &&
152 	    queue_max_discard_segments(req->q) > 1)
153 		return true;
154 	return false;
155 }
156 
157 static inline unsigned int blk_queue_get_max_sectors(struct request_queue *q,
158 						     enum req_op op)
159 {
160 	if (unlikely(op == REQ_OP_DISCARD || op == REQ_OP_SECURE_ERASE))
161 		return min(q->limits.max_discard_sectors,
162 			   UINT_MAX >> SECTOR_SHIFT);
163 
164 	if (unlikely(op == REQ_OP_WRITE_ZEROES))
165 		return q->limits.max_write_zeroes_sectors;
166 
167 	return q->limits.max_sectors;
168 }
169 
170 #ifdef CONFIG_BLK_DEV_INTEGRITY
171 void blk_flush_integrity(void);
172 bool __bio_integrity_endio(struct bio *);
173 void bio_integrity_free(struct bio *bio);
174 static inline bool bio_integrity_endio(struct bio *bio)
175 {
176 	if (bio_integrity(bio))
177 		return __bio_integrity_endio(bio);
178 	return true;
179 }
180 
181 bool blk_integrity_merge_rq(struct request_queue *, struct request *,
182 		struct request *);
183 bool blk_integrity_merge_bio(struct request_queue *, struct request *,
184 		struct bio *);
185 
186 static inline bool integrity_req_gap_back_merge(struct request *req,
187 		struct bio *next)
188 {
189 	struct bio_integrity_payload *bip = bio_integrity(req->bio);
190 	struct bio_integrity_payload *bip_next = bio_integrity(next);
191 
192 	return bvec_gap_to_prev(req->q, &bip->bip_vec[bip->bip_vcnt - 1],
193 				bip_next->bip_vec[0].bv_offset);
194 }
195 
196 static inline bool integrity_req_gap_front_merge(struct request *req,
197 		struct bio *bio)
198 {
199 	struct bio_integrity_payload *bip = bio_integrity(bio);
200 	struct bio_integrity_payload *bip_next = bio_integrity(req->bio);
201 
202 	return bvec_gap_to_prev(req->q, &bip->bip_vec[bip->bip_vcnt - 1],
203 				bip_next->bip_vec[0].bv_offset);
204 }
205 
206 int blk_integrity_add(struct gendisk *disk);
207 void blk_integrity_del(struct gendisk *);
208 #else /* CONFIG_BLK_DEV_INTEGRITY */
209 static inline bool blk_integrity_merge_rq(struct request_queue *rq,
210 		struct request *r1, struct request *r2)
211 {
212 	return true;
213 }
214 static inline bool blk_integrity_merge_bio(struct request_queue *rq,
215 		struct request *r, struct bio *b)
216 {
217 	return true;
218 }
219 static inline bool integrity_req_gap_back_merge(struct request *req,
220 		struct bio *next)
221 {
222 	return false;
223 }
224 static inline bool integrity_req_gap_front_merge(struct request *req,
225 		struct bio *bio)
226 {
227 	return false;
228 }
229 
230 static inline void blk_flush_integrity(void)
231 {
232 }
233 static inline bool bio_integrity_endio(struct bio *bio)
234 {
235 	return true;
236 }
237 static inline void bio_integrity_free(struct bio *bio)
238 {
239 }
240 static inline int blk_integrity_add(struct gendisk *disk)
241 {
242 	return 0;
243 }
244 static inline void blk_integrity_del(struct gendisk *disk)
245 {
246 }
247 #endif /* CONFIG_BLK_DEV_INTEGRITY */
248 
249 unsigned long blk_rq_timeout(unsigned long timeout);
250 void blk_add_timer(struct request *req);
251 const char *blk_status_to_str(blk_status_t status);
252 
253 bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio,
254 		unsigned int nr_segs);
255 bool blk_bio_list_merge(struct request_queue *q, struct list_head *list,
256 			struct bio *bio, unsigned int nr_segs);
257 
258 /*
259  * Plug flush limits
260  */
261 #define BLK_MAX_REQUEST_COUNT	32
262 #define BLK_PLUG_FLUSH_SIZE	(128 * 1024)
263 
264 /*
265  * Internal elevator interface
266  */
267 #define ELV_ON_HASH(rq) ((rq)->rq_flags & RQF_HASHED)
268 
269 void blk_insert_flush(struct request *rq);
270 
271 int elevator_switch_mq(struct request_queue *q,
272 			      struct elevator_type *new_e);
273 void elevator_exit(struct request_queue *q);
274 int elv_register_queue(struct request_queue *q, bool uevent);
275 void elv_unregister_queue(struct request_queue *q);
276 
277 ssize_t part_size_show(struct device *dev, struct device_attribute *attr,
278 		char *buf);
279 ssize_t part_stat_show(struct device *dev, struct device_attribute *attr,
280 		char *buf);
281 ssize_t part_inflight_show(struct device *dev, struct device_attribute *attr,
282 		char *buf);
283 ssize_t part_fail_show(struct device *dev, struct device_attribute *attr,
284 		char *buf);
285 ssize_t part_fail_store(struct device *dev, struct device_attribute *attr,
286 		const char *buf, size_t count);
287 ssize_t part_timeout_show(struct device *, struct device_attribute *, char *);
288 ssize_t part_timeout_store(struct device *, struct device_attribute *,
289 				const char *, size_t);
290 
291 static inline bool blk_may_split(struct request_queue *q, struct bio *bio)
292 {
293 	switch (bio_op(bio)) {
294 	case REQ_OP_DISCARD:
295 	case REQ_OP_SECURE_ERASE:
296 	case REQ_OP_WRITE_ZEROES:
297 		return true; /* non-trivial splitting decisions */
298 	default:
299 		break;
300 	}
301 
302 	/*
303 	 * All drivers must accept single-segments bios that are <= PAGE_SIZE.
304 	 * This is a quick and dirty check that relies on the fact that
305 	 * bi_io_vec[0] is always valid if a bio has data.  The check might
306 	 * lead to occasional false negatives when bios are cloned, but compared
307 	 * to the performance impact of cloned bios themselves the loop below
308 	 * doesn't matter anyway.
309 	 */
310 	return q->limits.chunk_sectors || bio->bi_vcnt != 1 ||
311 		bio->bi_io_vec->bv_len + bio->bi_io_vec->bv_offset > PAGE_SIZE;
312 }
313 
314 void __blk_queue_split(struct request_queue *q, struct bio **bio,
315 			unsigned int *nr_segs);
316 int ll_back_merge_fn(struct request *req, struct bio *bio,
317 		unsigned int nr_segs);
318 bool blk_attempt_req_merge(struct request_queue *q, struct request *rq,
319 				struct request *next);
320 unsigned int blk_recalc_rq_segments(struct request *rq);
321 void blk_rq_set_mixed_merge(struct request *rq);
322 bool blk_rq_merge_ok(struct request *rq, struct bio *bio);
323 enum elv_merge blk_try_merge(struct request *rq, struct bio *bio);
324 
325 int blk_dev_init(void);
326 
327 /*
328  * Contribute to IO statistics IFF:
329  *
330  *	a) it's attached to a gendisk, and
331  *	b) the queue had IO stats enabled when this request was started
332  */
333 static inline bool blk_do_io_stat(struct request *rq)
334 {
335 	return (rq->rq_flags & RQF_IO_STAT) && !blk_rq_is_passthrough(rq);
336 }
337 
338 void update_io_ticks(struct block_device *part, unsigned long now, bool end);
339 
340 static inline void req_set_nomerge(struct request_queue *q, struct request *req)
341 {
342 	req->cmd_flags |= REQ_NOMERGE;
343 	if (req == q->last_merge)
344 		q->last_merge = NULL;
345 }
346 
347 /*
348  * The max size one bio can handle is UINT_MAX becasue bvec_iter.bi_size
349  * is defined as 'unsigned int', meantime it has to aligned to with logical
350  * block size which is the minimum accepted unit by hardware.
351  */
352 static inline unsigned int bio_allowed_max_sectors(struct request_queue *q)
353 {
354 	return round_down(UINT_MAX, queue_logical_block_size(q)) >> 9;
355 }
356 
357 /*
358  * Internal io_context interface
359  */
360 struct io_cq *ioc_find_get_icq(struct request_queue *q);
361 struct io_cq *ioc_lookup_icq(struct request_queue *q);
362 #ifdef CONFIG_BLK_ICQ
363 void ioc_clear_queue(struct request_queue *q);
364 #else
365 static inline void ioc_clear_queue(struct request_queue *q)
366 {
367 }
368 #endif /* CONFIG_BLK_ICQ */
369 
370 #ifdef CONFIG_BLK_DEV_THROTTLING_LOW
371 extern ssize_t blk_throtl_sample_time_show(struct request_queue *q, char *page);
372 extern ssize_t blk_throtl_sample_time_store(struct request_queue *q,
373 	const char *page, size_t count);
374 extern void blk_throtl_bio_endio(struct bio *bio);
375 extern void blk_throtl_stat_add(struct request *rq, u64 time);
376 #else
377 static inline void blk_throtl_bio_endio(struct bio *bio) { }
378 static inline void blk_throtl_stat_add(struct request *rq, u64 time) { }
379 #endif
380 
381 void __blk_queue_bounce(struct request_queue *q, struct bio **bio);
382 
383 static inline bool blk_queue_may_bounce(struct request_queue *q)
384 {
385 	return IS_ENABLED(CONFIG_BOUNCE) &&
386 		q->limits.bounce == BLK_BOUNCE_HIGH &&
387 		max_low_pfn >= max_pfn;
388 }
389 
390 static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio)
391 {
392 	if (unlikely(blk_queue_may_bounce(q) && bio_has_data(*bio)))
393 		__blk_queue_bounce(q, bio);
394 }
395 
396 #ifdef CONFIG_BLK_CGROUP_IOLATENCY
397 extern int blk_iolatency_init(struct request_queue *q);
398 #else
399 static inline int blk_iolatency_init(struct request_queue *q) { return 0; }
400 #endif
401 
402 #ifdef CONFIG_BLK_DEV_ZONED
403 void disk_free_zone_bitmaps(struct gendisk *disk);
404 void disk_clear_zone_settings(struct gendisk *disk);
405 #else
406 static inline void disk_free_zone_bitmaps(struct gendisk *disk) {}
407 static inline void disk_clear_zone_settings(struct gendisk *disk) {}
408 #endif
409 
410 int blk_alloc_ext_minor(void);
411 void blk_free_ext_minor(unsigned int minor);
412 #define ADDPART_FLAG_NONE	0
413 #define ADDPART_FLAG_RAID	1
414 #define ADDPART_FLAG_WHOLEDISK	2
415 int bdev_add_partition(struct gendisk *disk, int partno, sector_t start,
416 		sector_t length);
417 int bdev_del_partition(struct gendisk *disk, int partno);
418 int bdev_resize_partition(struct gendisk *disk, int partno, sector_t start,
419 		sector_t length);
420 void blk_drop_partitions(struct gendisk *disk);
421 
422 struct gendisk *__alloc_disk_node(struct request_queue *q, int node_id,
423 		struct lock_class_key *lkclass);
424 
425 int bio_add_hw_page(struct request_queue *q, struct bio *bio,
426 		struct page *page, unsigned int len, unsigned int offset,
427 		unsigned int max_sectors, bool *same_page);
428 
429 static inline struct kmem_cache *blk_get_queue_kmem_cache(bool srcu)
430 {
431 	if (srcu)
432 		return blk_requestq_srcu_cachep;
433 	return blk_requestq_cachep;
434 }
435 struct request_queue *blk_alloc_queue(int node_id, bool alloc_srcu);
436 
437 int disk_scan_partitions(struct gendisk *disk, fmode_t mode);
438 
439 int disk_alloc_events(struct gendisk *disk);
440 void disk_add_events(struct gendisk *disk);
441 void disk_del_events(struct gendisk *disk);
442 void disk_release_events(struct gendisk *disk);
443 void disk_block_events(struct gendisk *disk);
444 void disk_unblock_events(struct gendisk *disk);
445 void disk_flush_events(struct gendisk *disk, unsigned int mask);
446 extern struct device_attribute dev_attr_events;
447 extern struct device_attribute dev_attr_events_async;
448 extern struct device_attribute dev_attr_events_poll_msecs;
449 
450 extern struct attribute_group blk_trace_attr_group;
451 
452 long blkdev_ioctl(struct file *file, unsigned cmd, unsigned long arg);
453 long compat_blkdev_ioctl(struct file *file, unsigned cmd, unsigned long arg);
454 
455 extern const struct address_space_operations def_blk_aops;
456 
457 int disk_register_independent_access_ranges(struct gendisk *disk);
458 void disk_unregister_independent_access_ranges(struct gendisk *disk);
459 
460 #ifdef CONFIG_FAIL_MAKE_REQUEST
461 bool should_fail_request(struct block_device *part, unsigned int bytes);
462 #else /* CONFIG_FAIL_MAKE_REQUEST */
463 static inline bool should_fail_request(struct block_device *part,
464 					unsigned int bytes)
465 {
466 	return false;
467 }
468 #endif /* CONFIG_FAIL_MAKE_REQUEST */
469 
470 /*
471  * Optimized request reference counting. Ideally we'd make timeouts be more
472  * clever, as that's the only reason we need references at all... But until
473  * this happens, this is faster than using refcount_t. Also see:
474  *
475  * abc54d634334 ("io_uring: switch to atomic_t for io_kiocb reference count")
476  */
477 #define req_ref_zero_or_close_to_overflow(req)	\
478 	((unsigned int) atomic_read(&(req->ref)) + 127u <= 127u)
479 
480 static inline bool req_ref_inc_not_zero(struct request *req)
481 {
482 	return atomic_inc_not_zero(&req->ref);
483 }
484 
485 static inline bool req_ref_put_and_test(struct request *req)
486 {
487 	WARN_ON_ONCE(req_ref_zero_or_close_to_overflow(req));
488 	return atomic_dec_and_test(&req->ref);
489 }
490 
491 static inline void req_ref_set(struct request *req, int value)
492 {
493 	atomic_set(&req->ref, value);
494 }
495 
496 static inline int req_ref_read(struct request *req)
497 {
498 	return atomic_read(&req->ref);
499 }
500 
501 #endif /* BLK_INTERNAL_H */
502