xref: /linux/block/blk.h (revision 24bce201d79807b668bf9d9e0aca801c5c0d5f78)
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 static inline void __blk_get_queue(struct request_queue *q)
35 {
36 	kobject_get(&q->kobj);
37 }
38 
39 bool is_flush_rq(struct request *req);
40 
41 struct blk_flush_queue *blk_alloc_flush_queue(int node, int cmd_size,
42 					      gfp_t flags);
43 void blk_free_flush_queue(struct blk_flush_queue *q);
44 
45 void blk_freeze_queue(struct request_queue *q);
46 void __blk_mq_unfreeze_queue(struct request_queue *q, bool force_atomic);
47 void blk_queue_start_drain(struct request_queue *q);
48 int __bio_queue_enter(struct request_queue *q, struct bio *bio);
49 void submit_bio_noacct_nocheck(struct bio *bio);
50 
51 static inline bool blk_try_enter_queue(struct request_queue *q, bool pm)
52 {
53 	rcu_read_lock();
54 	if (!percpu_ref_tryget_live_rcu(&q->q_usage_counter))
55 		goto fail;
56 
57 	/*
58 	 * The code that increments the pm_only counter must ensure that the
59 	 * counter is globally visible before the queue is unfrozen.
60 	 */
61 	if (blk_queue_pm_only(q) &&
62 	    (!pm || queue_rpm_status(q) == RPM_SUSPENDED))
63 		goto fail_put;
64 
65 	rcu_read_unlock();
66 	return true;
67 
68 fail_put:
69 	blk_queue_exit(q);
70 fail:
71 	rcu_read_unlock();
72 	return false;
73 }
74 
75 static inline int bio_queue_enter(struct bio *bio)
76 {
77 	struct request_queue *q = bdev_get_queue(bio->bi_bdev);
78 
79 	if (blk_try_enter_queue(q, false))
80 		return 0;
81 	return __bio_queue_enter(q, bio);
82 }
83 
84 #define BIO_INLINE_VECS 4
85 struct bio_vec *bvec_alloc(mempool_t *pool, unsigned short *nr_vecs,
86 		gfp_t gfp_mask);
87 void bvec_free(mempool_t *pool, struct bio_vec *bv, unsigned short nr_vecs);
88 
89 static inline bool biovec_phys_mergeable(struct request_queue *q,
90 		struct bio_vec *vec1, struct bio_vec *vec2)
91 {
92 	unsigned long mask = queue_segment_boundary(q);
93 	phys_addr_t addr1 = page_to_phys(vec1->bv_page) + vec1->bv_offset;
94 	phys_addr_t addr2 = page_to_phys(vec2->bv_page) + vec2->bv_offset;
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(struct request_queue *q,
106 		struct bio_vec *bprv, unsigned int offset)
107 {
108 	return (offset & queue_virt_boundary(q)) ||
109 		((bprv->bv_offset + bprv->bv_len) & queue_virt_boundary(q));
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(struct request_queue *q,
117 		struct bio_vec *bprv, unsigned int offset)
118 {
119 	if (!queue_virt_boundary(q))
120 		return false;
121 	return __bvec_gap_to_prev(q, 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 #ifdef CONFIG_BLK_DEV_INTEGRITY
163 void blk_flush_integrity(void);
164 bool __bio_integrity_endio(struct bio *);
165 void bio_integrity_free(struct bio *bio);
166 static inline bool bio_integrity_endio(struct bio *bio)
167 {
168 	if (bio_integrity(bio))
169 		return __bio_integrity_endio(bio);
170 	return true;
171 }
172 
173 bool blk_integrity_merge_rq(struct request_queue *, struct request *,
174 		struct request *);
175 bool blk_integrity_merge_bio(struct request_queue *, struct request *,
176 		struct bio *);
177 
178 static inline bool integrity_req_gap_back_merge(struct request *req,
179 		struct bio *next)
180 {
181 	struct bio_integrity_payload *bip = bio_integrity(req->bio);
182 	struct bio_integrity_payload *bip_next = bio_integrity(next);
183 
184 	return bvec_gap_to_prev(req->q, &bip->bip_vec[bip->bip_vcnt - 1],
185 				bip_next->bip_vec[0].bv_offset);
186 }
187 
188 static inline bool integrity_req_gap_front_merge(struct request *req,
189 		struct bio *bio)
190 {
191 	struct bio_integrity_payload *bip = bio_integrity(bio);
192 	struct bio_integrity_payload *bip_next = bio_integrity(req->bio);
193 
194 	return bvec_gap_to_prev(req->q, &bip->bip_vec[bip->bip_vcnt - 1],
195 				bip_next->bip_vec[0].bv_offset);
196 }
197 
198 int blk_integrity_add(struct gendisk *disk);
199 void blk_integrity_del(struct gendisk *);
200 #else /* CONFIG_BLK_DEV_INTEGRITY */
201 static inline bool blk_integrity_merge_rq(struct request_queue *rq,
202 		struct request *r1, struct request *r2)
203 {
204 	return true;
205 }
206 static inline bool blk_integrity_merge_bio(struct request_queue *rq,
207 		struct request *r, struct bio *b)
208 {
209 	return true;
210 }
211 static inline bool integrity_req_gap_back_merge(struct request *req,
212 		struct bio *next)
213 {
214 	return false;
215 }
216 static inline bool integrity_req_gap_front_merge(struct request *req,
217 		struct bio *bio)
218 {
219 	return false;
220 }
221 
222 static inline void blk_flush_integrity(void)
223 {
224 }
225 static inline bool bio_integrity_endio(struct bio *bio)
226 {
227 	return true;
228 }
229 static inline void bio_integrity_free(struct bio *bio)
230 {
231 }
232 static inline int blk_integrity_add(struct gendisk *disk)
233 {
234 	return 0;
235 }
236 static inline void blk_integrity_del(struct gendisk *disk)
237 {
238 }
239 #endif /* CONFIG_BLK_DEV_INTEGRITY */
240 
241 unsigned long blk_rq_timeout(unsigned long timeout);
242 void blk_add_timer(struct request *req);
243 const char *blk_status_to_str(blk_status_t status);
244 
245 bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio,
246 		unsigned int nr_segs);
247 bool blk_bio_list_merge(struct request_queue *q, struct list_head *list,
248 			struct bio *bio, unsigned int nr_segs);
249 
250 /*
251  * Plug flush limits
252  */
253 #define BLK_MAX_REQUEST_COUNT	32
254 #define BLK_PLUG_FLUSH_SIZE	(128 * 1024)
255 
256 /*
257  * Internal elevator interface
258  */
259 #define ELV_ON_HASH(rq) ((rq)->rq_flags & RQF_HASHED)
260 
261 void blk_insert_flush(struct request *rq);
262 
263 int elevator_switch_mq(struct request_queue *q,
264 			      struct elevator_type *new_e);
265 void elevator_exit(struct request_queue *q);
266 int elv_register_queue(struct request_queue *q, bool uevent);
267 void elv_unregister_queue(struct request_queue *q);
268 
269 ssize_t part_size_show(struct device *dev, struct device_attribute *attr,
270 		char *buf);
271 ssize_t part_stat_show(struct device *dev, struct device_attribute *attr,
272 		char *buf);
273 ssize_t part_inflight_show(struct device *dev, struct device_attribute *attr,
274 		char *buf);
275 ssize_t part_fail_show(struct device *dev, struct device_attribute *attr,
276 		char *buf);
277 ssize_t part_fail_store(struct device *dev, struct device_attribute *attr,
278 		const char *buf, size_t count);
279 ssize_t part_timeout_show(struct device *, struct device_attribute *, char *);
280 ssize_t part_timeout_store(struct device *, struct device_attribute *,
281 				const char *, size_t);
282 
283 static inline bool blk_may_split(struct request_queue *q, struct bio *bio)
284 {
285 	switch (bio_op(bio)) {
286 	case REQ_OP_DISCARD:
287 	case REQ_OP_SECURE_ERASE:
288 	case REQ_OP_WRITE_ZEROES:
289 		return true; /* non-trivial splitting decisions */
290 	default:
291 		break;
292 	}
293 
294 	/*
295 	 * All drivers must accept single-segments bios that are <= PAGE_SIZE.
296 	 * This is a quick and dirty check that relies on the fact that
297 	 * bi_io_vec[0] is always valid if a bio has data.  The check might
298 	 * lead to occasional false negatives when bios are cloned, but compared
299 	 * to the performance impact of cloned bios themselves the loop below
300 	 * doesn't matter anyway.
301 	 */
302 	return q->limits.chunk_sectors || bio->bi_vcnt != 1 ||
303 		bio->bi_io_vec->bv_len + bio->bi_io_vec->bv_offset > PAGE_SIZE;
304 }
305 
306 void __blk_queue_split(struct request_queue *q, struct bio **bio,
307 			unsigned int *nr_segs);
308 int ll_back_merge_fn(struct request *req, struct bio *bio,
309 		unsigned int nr_segs);
310 bool blk_attempt_req_merge(struct request_queue *q, struct request *rq,
311 				struct request *next);
312 unsigned int blk_recalc_rq_segments(struct request *rq);
313 void blk_rq_set_mixed_merge(struct request *rq);
314 bool blk_rq_merge_ok(struct request *rq, struct bio *bio);
315 enum elv_merge blk_try_merge(struct request *rq, struct bio *bio);
316 
317 int blk_dev_init(void);
318 
319 /*
320  * Contribute to IO statistics IFF:
321  *
322  *	a) it's attached to a gendisk, and
323  *	b) the queue had IO stats enabled when this request was started
324  */
325 static inline bool blk_do_io_stat(struct request *rq)
326 {
327 	return (rq->rq_flags & RQF_IO_STAT) && !blk_rq_is_passthrough(rq);
328 }
329 
330 void update_io_ticks(struct block_device *part, unsigned long now, bool end);
331 
332 static inline void req_set_nomerge(struct request_queue *q, struct request *req)
333 {
334 	req->cmd_flags |= REQ_NOMERGE;
335 	if (req == q->last_merge)
336 		q->last_merge = NULL;
337 }
338 
339 /*
340  * The max size one bio can handle is UINT_MAX becasue bvec_iter.bi_size
341  * is defined as 'unsigned int', meantime it has to aligned to with logical
342  * block size which is the minimum accepted unit by hardware.
343  */
344 static inline unsigned int bio_allowed_max_sectors(struct request_queue *q)
345 {
346 	return round_down(UINT_MAX, queue_logical_block_size(q)) >> 9;
347 }
348 
349 /*
350  * Internal io_context interface
351  */
352 struct io_cq *ioc_find_get_icq(struct request_queue *q);
353 struct io_cq *ioc_lookup_icq(struct request_queue *q);
354 #ifdef CONFIG_BLK_ICQ
355 void ioc_clear_queue(struct request_queue *q);
356 #else
357 static inline void ioc_clear_queue(struct request_queue *q)
358 {
359 }
360 #endif /* CONFIG_BLK_ICQ */
361 
362 #ifdef CONFIG_BLK_DEV_THROTTLING_LOW
363 extern ssize_t blk_throtl_sample_time_show(struct request_queue *q, char *page);
364 extern ssize_t blk_throtl_sample_time_store(struct request_queue *q,
365 	const char *page, size_t count);
366 extern void blk_throtl_bio_endio(struct bio *bio);
367 extern void blk_throtl_stat_add(struct request *rq, u64 time);
368 #else
369 static inline void blk_throtl_bio_endio(struct bio *bio) { }
370 static inline void blk_throtl_stat_add(struct request *rq, u64 time) { }
371 #endif
372 
373 void __blk_queue_bounce(struct request_queue *q, struct bio **bio);
374 
375 static inline bool blk_queue_may_bounce(struct request_queue *q)
376 {
377 	return IS_ENABLED(CONFIG_BOUNCE) &&
378 		q->limits.bounce == BLK_BOUNCE_HIGH &&
379 		max_low_pfn >= max_pfn;
380 }
381 
382 static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio)
383 {
384 	if (unlikely(blk_queue_may_bounce(q) && bio_has_data(*bio)))
385 		__blk_queue_bounce(q, bio);
386 }
387 
388 #ifdef CONFIG_BLK_CGROUP_IOLATENCY
389 extern int blk_iolatency_init(struct request_queue *q);
390 #else
391 static inline int blk_iolatency_init(struct request_queue *q) { return 0; }
392 #endif
393 
394 #ifdef CONFIG_BLK_DEV_ZONED
395 void blk_queue_free_zone_bitmaps(struct request_queue *q);
396 void blk_queue_clear_zone_settings(struct request_queue *q);
397 #else
398 static inline void blk_queue_free_zone_bitmaps(struct request_queue *q) {}
399 static inline void blk_queue_clear_zone_settings(struct request_queue *q) {}
400 #endif
401 
402 int blk_alloc_ext_minor(void);
403 void blk_free_ext_minor(unsigned int minor);
404 #define ADDPART_FLAG_NONE	0
405 #define ADDPART_FLAG_RAID	1
406 #define ADDPART_FLAG_WHOLEDISK	2
407 int bdev_add_partition(struct gendisk *disk, int partno, sector_t start,
408 		sector_t length);
409 int bdev_del_partition(struct gendisk *disk, int partno);
410 int bdev_resize_partition(struct gendisk *disk, int partno, sector_t start,
411 		sector_t length);
412 void blk_drop_partitions(struct gendisk *disk);
413 
414 int bio_add_hw_page(struct request_queue *q, struct bio *bio,
415 		struct page *page, unsigned int len, unsigned int offset,
416 		unsigned int max_sectors, bool *same_page);
417 
418 static inline struct kmem_cache *blk_get_queue_kmem_cache(bool srcu)
419 {
420 	if (srcu)
421 		return blk_requestq_srcu_cachep;
422 	return blk_requestq_cachep;
423 }
424 struct request_queue *blk_alloc_queue(int node_id, bool alloc_srcu);
425 
426 int disk_scan_partitions(struct gendisk *disk, fmode_t mode);
427 
428 int disk_alloc_events(struct gendisk *disk);
429 void disk_add_events(struct gendisk *disk);
430 void disk_del_events(struct gendisk *disk);
431 void disk_release_events(struct gendisk *disk);
432 void disk_block_events(struct gendisk *disk);
433 void disk_unblock_events(struct gendisk *disk);
434 void disk_flush_events(struct gendisk *disk, unsigned int mask);
435 extern struct device_attribute dev_attr_events;
436 extern struct device_attribute dev_attr_events_async;
437 extern struct device_attribute dev_attr_events_poll_msecs;
438 
439 long blkdev_ioctl(struct file *file, unsigned cmd, unsigned long arg);
440 long compat_blkdev_ioctl(struct file *file, unsigned cmd, unsigned long arg);
441 
442 extern const struct address_space_operations def_blk_aops;
443 
444 int disk_register_independent_access_ranges(struct gendisk *disk,
445 				struct blk_independent_access_ranges *new_iars);
446 void disk_unregister_independent_access_ranges(struct gendisk *disk);
447 
448 #ifdef CONFIG_FAIL_MAKE_REQUEST
449 bool should_fail_request(struct block_device *part, unsigned int bytes);
450 #else /* CONFIG_FAIL_MAKE_REQUEST */
451 static inline bool should_fail_request(struct block_device *part,
452 					unsigned int bytes)
453 {
454 	return false;
455 }
456 #endif /* CONFIG_FAIL_MAKE_REQUEST */
457 
458 /*
459  * Optimized request reference counting. Ideally we'd make timeouts be more
460  * clever, as that's the only reason we need references at all... But until
461  * this happens, this is faster than using refcount_t. Also see:
462  *
463  * abc54d634334 ("io_uring: switch to atomic_t for io_kiocb reference count")
464  */
465 #define req_ref_zero_or_close_to_overflow(req)	\
466 	((unsigned int) atomic_read(&(req->ref)) + 127u <= 127u)
467 
468 static inline bool req_ref_inc_not_zero(struct request *req)
469 {
470 	return atomic_inc_not_zero(&req->ref);
471 }
472 
473 static inline bool req_ref_put_and_test(struct request *req)
474 {
475 	WARN_ON_ONCE(req_ref_zero_or_close_to_overflow(req));
476 	return atomic_dec_and_test(&req->ref);
477 }
478 
479 static inline void req_ref_set(struct request *req, int value)
480 {
481 	atomic_set(&req->ref, value);
482 }
483 
484 static inline int req_ref_read(struct request *req)
485 {
486 	return atomic_read(&req->ref);
487 }
488 
489 #endif /* BLK_INTERNAL_H */
490