xref: /openbmc/linux/block/blk.h (revision b021d05e)
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 bool is_flush_rq(struct request *req);
30 
31 struct blk_flush_queue *blk_alloc_flush_queue(int node, int cmd_size,
32 					      gfp_t flags);
33 void blk_free_flush_queue(struct blk_flush_queue *q);
34 
35 void blk_freeze_queue(struct request_queue *q);
36 void __blk_mq_unfreeze_queue(struct request_queue *q, bool force_atomic);
37 void blk_queue_start_drain(struct request_queue *q);
38 int __bio_queue_enter(struct request_queue *q, struct bio *bio);
39 void submit_bio_noacct_nocheck(struct bio *bio);
40 
41 static inline bool blk_try_enter_queue(struct request_queue *q, bool pm)
42 {
43 	rcu_read_lock();
44 	if (!percpu_ref_tryget_live_rcu(&q->q_usage_counter))
45 		goto fail;
46 
47 	/*
48 	 * The code that increments the pm_only counter must ensure that the
49 	 * counter is globally visible before the queue is unfrozen.
50 	 */
51 	if (blk_queue_pm_only(q) &&
52 	    (!pm || queue_rpm_status(q) == RPM_SUSPENDED))
53 		goto fail_put;
54 
55 	rcu_read_unlock();
56 	return true;
57 
58 fail_put:
59 	blk_queue_exit(q);
60 fail:
61 	rcu_read_unlock();
62 	return false;
63 }
64 
65 static inline int bio_queue_enter(struct bio *bio)
66 {
67 	struct request_queue *q = bdev_get_queue(bio->bi_bdev);
68 
69 	if (blk_try_enter_queue(q, false))
70 		return 0;
71 	return __bio_queue_enter(q, bio);
72 }
73 
74 #define BIO_INLINE_VECS 4
75 struct bio_vec *bvec_alloc(mempool_t *pool, unsigned short *nr_vecs,
76 		gfp_t gfp_mask);
77 void bvec_free(mempool_t *pool, struct bio_vec *bv, unsigned short nr_vecs);
78 
79 static inline bool biovec_phys_mergeable(struct request_queue *q,
80 		struct bio_vec *vec1, struct bio_vec *vec2)
81 {
82 	unsigned long mask = queue_segment_boundary(q);
83 	phys_addr_t addr1 = page_to_phys(vec1->bv_page) + vec1->bv_offset;
84 	phys_addr_t addr2 = page_to_phys(vec2->bv_page) + vec2->bv_offset;
85 
86 	/*
87 	 * Merging adjacent physical pages may not work correctly under KMSAN
88 	 * if their metadata pages aren't adjacent. Just disable merging.
89 	 */
90 	if (IS_ENABLED(CONFIG_KMSAN))
91 		return false;
92 
93 	if (addr1 + vec1->bv_len != addr2)
94 		return false;
95 	if (xen_domain() && !xen_biovec_phys_mergeable(vec1, vec2->bv_page))
96 		return false;
97 	if ((addr1 | mask) != ((addr2 + vec2->bv_len - 1) | mask))
98 		return false;
99 	return true;
100 }
101 
102 static inline bool __bvec_gap_to_prev(const struct queue_limits *lim,
103 		struct bio_vec *bprv, unsigned int offset)
104 {
105 	return (offset & lim->virt_boundary_mask) ||
106 		((bprv->bv_offset + bprv->bv_len) & lim->virt_boundary_mask);
107 }
108 
109 /*
110  * Check if adding a bio_vec after bprv with offset would create a gap in
111  * the SG list. Most drivers don't care about this, but some do.
112  */
113 static inline bool bvec_gap_to_prev(const struct queue_limits *lim,
114 		struct bio_vec *bprv, unsigned int offset)
115 {
116 	if (!lim->virt_boundary_mask)
117 		return false;
118 	return __bvec_gap_to_prev(lim, bprv, offset);
119 }
120 
121 static inline bool rq_mergeable(struct request *rq)
122 {
123 	if (blk_rq_is_passthrough(rq))
124 		return false;
125 
126 	if (req_op(rq) == REQ_OP_FLUSH)
127 		return false;
128 
129 	if (req_op(rq) == REQ_OP_WRITE_ZEROES)
130 		return false;
131 
132 	if (req_op(rq) == REQ_OP_ZONE_APPEND)
133 		return false;
134 
135 	if (rq->cmd_flags & REQ_NOMERGE_FLAGS)
136 		return false;
137 	if (rq->rq_flags & RQF_NOMERGE_FLAGS)
138 		return false;
139 
140 	return true;
141 }
142 
143 /*
144  * There are two different ways to handle DISCARD merges:
145  *  1) If max_discard_segments > 1, the driver treats every bio as a range and
146  *     send the bios to controller together. The ranges don't need to be
147  *     contiguous.
148  *  2) Otherwise, the request will be normal read/write requests.  The ranges
149  *     need to be contiguous.
150  */
151 static inline bool blk_discard_mergable(struct request *req)
152 {
153 	if (req_op(req) == REQ_OP_DISCARD &&
154 	    queue_max_discard_segments(req->q) > 1)
155 		return true;
156 	return false;
157 }
158 
159 static inline unsigned int blk_rq_get_max_segments(struct request *rq)
160 {
161 	if (req_op(rq) == REQ_OP_DISCARD)
162 		return queue_max_discard_segments(rq->q);
163 	return queue_max_segments(rq->q);
164 }
165 
166 static inline unsigned int blk_queue_get_max_sectors(struct request_queue *q,
167 						     enum req_op op)
168 {
169 	if (unlikely(op == REQ_OP_DISCARD || op == REQ_OP_SECURE_ERASE))
170 		return min(q->limits.max_discard_sectors,
171 			   UINT_MAX >> SECTOR_SHIFT);
172 
173 	if (unlikely(op == REQ_OP_WRITE_ZEROES))
174 		return q->limits.max_write_zeroes_sectors;
175 
176 	return q->limits.max_sectors;
177 }
178 
179 #ifdef CONFIG_BLK_DEV_INTEGRITY
180 void blk_flush_integrity(void);
181 bool __bio_integrity_endio(struct bio *);
182 void bio_integrity_free(struct bio *bio);
183 static inline bool bio_integrity_endio(struct bio *bio)
184 {
185 	if (bio_integrity(bio))
186 		return __bio_integrity_endio(bio);
187 	return true;
188 }
189 
190 bool blk_integrity_merge_rq(struct request_queue *, struct request *,
191 		struct request *);
192 bool blk_integrity_merge_bio(struct request_queue *, struct request *,
193 		struct bio *);
194 
195 static inline bool integrity_req_gap_back_merge(struct request *req,
196 		struct bio *next)
197 {
198 	struct bio_integrity_payload *bip = bio_integrity(req->bio);
199 	struct bio_integrity_payload *bip_next = bio_integrity(next);
200 
201 	return bvec_gap_to_prev(&req->q->limits,
202 				&bip->bip_vec[bip->bip_vcnt - 1],
203 				bip_next->bip_vec[0].bv_offset);
204 }
205 
206 static inline bool integrity_req_gap_front_merge(struct request *req,
207 		struct bio *bio)
208 {
209 	struct bio_integrity_payload *bip = bio_integrity(bio);
210 	struct bio_integrity_payload *bip_next = bio_integrity(req->bio);
211 
212 	return bvec_gap_to_prev(&req->q->limits,
213 				&bip->bip_vec[bip->bip_vcnt - 1],
214 				bip_next->bip_vec[0].bv_offset);
215 }
216 
217 extern const struct attribute_group blk_integrity_attr_group;
218 #else /* CONFIG_BLK_DEV_INTEGRITY */
219 static inline bool blk_integrity_merge_rq(struct request_queue *rq,
220 		struct request *r1, struct request *r2)
221 {
222 	return true;
223 }
224 static inline bool blk_integrity_merge_bio(struct request_queue *rq,
225 		struct request *r, struct bio *b)
226 {
227 	return true;
228 }
229 static inline bool integrity_req_gap_back_merge(struct request *req,
230 		struct bio *next)
231 {
232 	return false;
233 }
234 static inline bool integrity_req_gap_front_merge(struct request *req,
235 		struct bio *bio)
236 {
237 	return false;
238 }
239 
240 static inline void blk_flush_integrity(void)
241 {
242 }
243 static inline bool bio_integrity_endio(struct bio *bio)
244 {
245 	return true;
246 }
247 static inline void bio_integrity_free(struct bio *bio)
248 {
249 }
250 #endif /* CONFIG_BLK_DEV_INTEGRITY */
251 
252 unsigned long blk_rq_timeout(unsigned long timeout);
253 void blk_add_timer(struct request *req);
254 const char *blk_status_to_str(blk_status_t status);
255 
256 bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio,
257 		unsigned int nr_segs);
258 bool blk_bio_list_merge(struct request_queue *q, struct list_head *list,
259 			struct bio *bio, unsigned int nr_segs);
260 
261 /*
262  * Plug flush limits
263  */
264 #define BLK_MAX_REQUEST_COUNT	32
265 #define BLK_PLUG_FLUSH_SIZE	(128 * 1024)
266 
267 /*
268  * Internal elevator interface
269  */
270 #define ELV_ON_HASH(rq) ((rq)->rq_flags & RQF_HASHED)
271 
272 bool blk_insert_flush(struct request *rq);
273 
274 int elevator_switch(struct request_queue *q, struct elevator_type *new_e);
275 void elevator_disable(struct request_queue *q);
276 void elevator_exit(struct request_queue *q);
277 int elv_register_queue(struct request_queue *q, bool uevent);
278 void elv_unregister_queue(struct request_queue *q);
279 
280 ssize_t part_size_show(struct device *dev, struct device_attribute *attr,
281 		char *buf);
282 ssize_t part_stat_show(struct device *dev, struct device_attribute *attr,
283 		char *buf);
284 ssize_t part_inflight_show(struct device *dev, struct device_attribute *attr,
285 		char *buf);
286 ssize_t part_fail_show(struct device *dev, struct device_attribute *attr,
287 		char *buf);
288 ssize_t part_fail_store(struct device *dev, struct device_attribute *attr,
289 		const char *buf, size_t count);
290 ssize_t part_timeout_show(struct device *, struct device_attribute *, char *);
291 ssize_t part_timeout_store(struct device *, struct device_attribute *,
292 				const char *, size_t);
293 
294 static inline bool bio_may_exceed_limits(struct bio *bio,
295 					 const struct queue_limits *lim)
296 {
297 	switch (bio_op(bio)) {
298 	case REQ_OP_DISCARD:
299 	case REQ_OP_SECURE_ERASE:
300 	case REQ_OP_WRITE_ZEROES:
301 		return true; /* non-trivial splitting decisions */
302 	default:
303 		break;
304 	}
305 
306 	/*
307 	 * All drivers must accept single-segments bios that are <= PAGE_SIZE.
308 	 * This is a quick and dirty check that relies on the fact that
309 	 * bi_io_vec[0] is always valid if a bio has data.  The check might
310 	 * lead to occasional false negatives when bios are cloned, but compared
311 	 * to the performance impact of cloned bios themselves the loop below
312 	 * doesn't matter anyway.
313 	 */
314 	return lim->chunk_sectors || bio->bi_vcnt != 1 ||
315 		bio->bi_io_vec->bv_len + bio->bi_io_vec->bv_offset > PAGE_SIZE;
316 }
317 
318 struct bio *__bio_split_to_limits(struct bio *bio,
319 				  const struct queue_limits *lim,
320 				  unsigned int *nr_segs);
321 int ll_back_merge_fn(struct request *req, struct bio *bio,
322 		unsigned int nr_segs);
323 bool blk_attempt_req_merge(struct request_queue *q, struct request *rq,
324 				struct request *next);
325 unsigned int blk_recalc_rq_segments(struct request *rq);
326 void blk_rq_set_mixed_merge(struct request *rq);
327 bool blk_rq_merge_ok(struct request *rq, struct bio *bio);
328 enum elv_merge blk_try_merge(struct request *rq, struct bio *bio);
329 
330 void blk_set_default_limits(struct queue_limits *lim);
331 int blk_dev_init(void);
332 
333 /*
334  * Contribute to IO statistics IFF:
335  *
336  *	a) it's attached to a gendisk, and
337  *	b) the queue had IO stats enabled when this request was started
338  */
339 static inline bool blk_do_io_stat(struct request *rq)
340 {
341 	return (rq->rq_flags & RQF_IO_STAT) && !blk_rq_is_passthrough(rq);
342 }
343 
344 void update_io_ticks(struct block_device *part, unsigned long now, bool end);
345 
346 static inline void req_set_nomerge(struct request_queue *q, struct request *req)
347 {
348 	req->cmd_flags |= REQ_NOMERGE;
349 	if (req == q->last_merge)
350 		q->last_merge = NULL;
351 }
352 
353 /*
354  * Internal io_context interface
355  */
356 struct io_cq *ioc_find_get_icq(struct request_queue *q);
357 struct io_cq *ioc_lookup_icq(struct request_queue *q);
358 #ifdef CONFIG_BLK_ICQ
359 void ioc_clear_queue(struct request_queue *q);
360 #else
361 static inline void ioc_clear_queue(struct request_queue *q)
362 {
363 }
364 #endif /* CONFIG_BLK_ICQ */
365 
366 #ifdef CONFIG_BLK_DEV_THROTTLING_LOW
367 extern ssize_t blk_throtl_sample_time_show(struct request_queue *q, char *page);
368 extern ssize_t blk_throtl_sample_time_store(struct request_queue *q,
369 	const char *page, size_t count);
370 extern void blk_throtl_bio_endio(struct bio *bio);
371 extern void blk_throtl_stat_add(struct request *rq, u64 time);
372 #else
373 static inline void blk_throtl_bio_endio(struct bio *bio) { }
374 static inline void blk_throtl_stat_add(struct request *rq, u64 time) { }
375 #endif
376 
377 struct bio *__blk_queue_bounce(struct bio *bio, struct request_queue *q);
378 
379 static inline bool blk_queue_may_bounce(struct request_queue *q)
380 {
381 	return IS_ENABLED(CONFIG_BOUNCE) &&
382 		q->limits.bounce == BLK_BOUNCE_HIGH &&
383 		max_low_pfn >= max_pfn;
384 }
385 
386 static inline struct bio *blk_queue_bounce(struct bio *bio,
387 		struct request_queue *q)
388 {
389 	if (unlikely(blk_queue_may_bounce(q) && bio_has_data(bio)))
390 		return __blk_queue_bounce(bio, q);
391 	return bio;
392 }
393 
394 #ifdef CONFIG_BLK_DEV_ZONED
395 void disk_free_zone_bitmaps(struct gendisk *disk);
396 void disk_clear_zone_settings(struct gendisk *disk);
397 int blkdev_report_zones_ioctl(struct block_device *bdev, unsigned int cmd,
398 		unsigned long arg);
399 int blkdev_zone_mgmt_ioctl(struct block_device *bdev, blk_mode_t mode,
400 		unsigned int cmd, unsigned long arg);
401 #else /* CONFIG_BLK_DEV_ZONED */
402 static inline void disk_free_zone_bitmaps(struct gendisk *disk) {}
403 static inline void disk_clear_zone_settings(struct gendisk *disk) {}
404 static inline int blkdev_report_zones_ioctl(struct block_device *bdev,
405 		unsigned int cmd, unsigned long arg)
406 {
407 	return -ENOTTY;
408 }
409 static inline int blkdev_zone_mgmt_ioctl(struct block_device *bdev,
410 		blk_mode_t mode, unsigned int cmd, unsigned long arg)
411 {
412 	return -ENOTTY;
413 }
414 #endif /* CONFIG_BLK_DEV_ZONED */
415 
416 struct block_device *bdev_alloc(struct gendisk *disk, u8 partno);
417 void bdev_add(struct block_device *bdev, dev_t dev);
418 
419 int blk_alloc_ext_minor(void);
420 void blk_free_ext_minor(unsigned int minor);
421 #define ADDPART_FLAG_NONE	0
422 #define ADDPART_FLAG_RAID	1
423 #define ADDPART_FLAG_WHOLEDISK	2
424 int bdev_add_partition(struct gendisk *disk, int partno, sector_t start,
425 		sector_t length);
426 int bdev_del_partition(struct gendisk *disk, int partno);
427 int bdev_resize_partition(struct gendisk *disk, int partno, sector_t start,
428 		sector_t length);
429 void drop_partition(struct block_device *part);
430 
431 void bdev_set_nr_sectors(struct block_device *bdev, sector_t sectors);
432 
433 struct gendisk *__alloc_disk_node(struct request_queue *q, int node_id,
434 		struct lock_class_key *lkclass);
435 
436 int bio_add_hw_page(struct request_queue *q, struct bio *bio,
437 		struct page *page, unsigned int len, unsigned int offset,
438 		unsigned int max_sectors, bool *same_page);
439 
440 /*
441  * Clean up a page appropriately, where the page may be pinned, may have a
442  * ref taken on it or neither.
443  */
444 static inline void bio_release_page(struct bio *bio, struct page *page)
445 {
446 	if (bio_flagged(bio, BIO_PAGE_PINNED))
447 		unpin_user_page(page);
448 }
449 
450 struct request_queue *blk_alloc_queue(int node_id);
451 
452 int disk_scan_partitions(struct gendisk *disk, blk_mode_t mode);
453 
454 int disk_alloc_events(struct gendisk *disk);
455 void disk_add_events(struct gendisk *disk);
456 void disk_del_events(struct gendisk *disk);
457 void disk_release_events(struct gendisk *disk);
458 void disk_block_events(struct gendisk *disk);
459 void disk_unblock_events(struct gendisk *disk);
460 void disk_flush_events(struct gendisk *disk, unsigned int mask);
461 extern struct device_attribute dev_attr_events;
462 extern struct device_attribute dev_attr_events_async;
463 extern struct device_attribute dev_attr_events_poll_msecs;
464 
465 extern struct attribute_group blk_trace_attr_group;
466 
467 blk_mode_t file_to_blk_mode(struct file *file);
468 int truncate_bdev_range(struct block_device *bdev, blk_mode_t mode,
469 		loff_t lstart, loff_t lend);
470 long blkdev_ioctl(struct file *file, unsigned cmd, unsigned long arg);
471 long compat_blkdev_ioctl(struct file *file, unsigned cmd, unsigned long arg);
472 
473 extern const struct address_space_operations def_blk_aops;
474 
475 int disk_register_independent_access_ranges(struct gendisk *disk);
476 void disk_unregister_independent_access_ranges(struct gendisk *disk);
477 
478 #ifdef CONFIG_FAIL_MAKE_REQUEST
479 bool should_fail_request(struct block_device *part, unsigned int bytes);
480 #else /* CONFIG_FAIL_MAKE_REQUEST */
481 static inline bool should_fail_request(struct block_device *part,
482 					unsigned int bytes)
483 {
484 	return false;
485 }
486 #endif /* CONFIG_FAIL_MAKE_REQUEST */
487 
488 /*
489  * Optimized request reference counting. Ideally we'd make timeouts be more
490  * clever, as that's the only reason we need references at all... But until
491  * this happens, this is faster than using refcount_t. Also see:
492  *
493  * abc54d634334 ("io_uring: switch to atomic_t for io_kiocb reference count")
494  */
495 #define req_ref_zero_or_close_to_overflow(req)	\
496 	((unsigned int) atomic_read(&(req->ref)) + 127u <= 127u)
497 
498 static inline bool req_ref_inc_not_zero(struct request *req)
499 {
500 	return atomic_inc_not_zero(&req->ref);
501 }
502 
503 static inline bool req_ref_put_and_test(struct request *req)
504 {
505 	WARN_ON_ONCE(req_ref_zero_or_close_to_overflow(req));
506 	return atomic_dec_and_test(&req->ref);
507 }
508 
509 static inline void req_ref_set(struct request *req, int value)
510 {
511 	atomic_set(&req->ref, value);
512 }
513 
514 static inline int req_ref_read(struct request *req)
515 {
516 	return atomic_read(&req->ref);
517 }
518 
519 #endif /* BLK_INTERNAL_H */
520