xref: /linux/block/blk.h (revision 4eb7ae7a301d3586c3351e81d5c3cfe2304a1a6a)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef BLK_INTERNAL_H
3 #define BLK_INTERNAL_H
4 
5 #include <linux/idr.h>
6 #include <linux/blk-mq.h>
7 #include <xen/xen.h>
8 #include "blk-mq.h"
9 #include "blk-mq-sched.h"
10 
11 /* Max future timer expiry for timeouts */
12 #define BLK_MAX_TIMEOUT		(5 * HZ)
13 
14 #ifdef CONFIG_DEBUG_FS
15 extern struct dentry *blk_debugfs_root;
16 #endif
17 
18 struct blk_flush_queue {
19 	unsigned int		flush_queue_delayed:1;
20 	unsigned int		flush_pending_idx:1;
21 	unsigned int		flush_running_idx:1;
22 	blk_status_t 		rq_status;
23 	unsigned long		flush_pending_since;
24 	struct list_head	flush_queue[2];
25 	struct list_head	flush_data_in_flight;
26 	struct request		*flush_rq;
27 
28 	/*
29 	 * flush_rq shares tag with this rq, both can't be active
30 	 * at the same time
31 	 */
32 	struct request		*orig_rq;
33 	spinlock_t		mq_flush_lock;
34 };
35 
36 extern struct kmem_cache *blk_requestq_cachep;
37 extern struct kobj_type blk_queue_ktype;
38 extern struct ida blk_queue_ida;
39 
40 static inline struct blk_flush_queue *
41 blk_get_flush_queue(struct request_queue *q, struct blk_mq_ctx *ctx)
42 {
43 	return blk_mq_map_queue(q, REQ_OP_FLUSH, ctx)->fq;
44 }
45 
46 static inline void __blk_get_queue(struct request_queue *q)
47 {
48 	kobject_get(&q->kobj);
49 }
50 
51 static inline bool
52 is_flush_rq(struct request *req, struct blk_mq_hw_ctx *hctx)
53 {
54 	return hctx->fq->flush_rq == req;
55 }
56 
57 struct blk_flush_queue *blk_alloc_flush_queue(struct request_queue *q,
58 		int node, int cmd_size, gfp_t flags);
59 void blk_free_flush_queue(struct blk_flush_queue *q);
60 
61 void blk_freeze_queue(struct request_queue *q);
62 
63 static inline void blk_queue_enter_live(struct request_queue *q)
64 {
65 	/*
66 	 * Given that running in generic_make_request() context
67 	 * guarantees that a live reference against q_usage_counter has
68 	 * been established, further references under that same context
69 	 * need not check that the queue has been frozen (marked dead).
70 	 */
71 	percpu_ref_get(&q->q_usage_counter);
72 }
73 
74 static inline bool biovec_phys_mergeable(struct request_queue *q,
75 		struct bio_vec *vec1, struct bio_vec *vec2)
76 {
77 	unsigned long mask = queue_segment_boundary(q);
78 	phys_addr_t addr1 = page_to_phys(vec1->bv_page) + vec1->bv_offset;
79 	phys_addr_t addr2 = page_to_phys(vec2->bv_page) + vec2->bv_offset;
80 
81 	if (addr1 + vec1->bv_len != addr2)
82 		return false;
83 	if (xen_domain() && !xen_biovec_phys_mergeable(vec1, vec2->bv_page))
84 		return false;
85 	if ((addr1 | mask) != ((addr2 + vec2->bv_len - 1) | mask))
86 		return false;
87 	return true;
88 }
89 
90 static inline bool __bvec_gap_to_prev(struct request_queue *q,
91 		struct bio_vec *bprv, unsigned int offset)
92 {
93 	return (offset & queue_virt_boundary(q)) ||
94 		((bprv->bv_offset + bprv->bv_len) & queue_virt_boundary(q));
95 }
96 
97 /*
98  * Check if adding a bio_vec after bprv with offset would create a gap in
99  * the SG list. Most drivers don't care about this, but some do.
100  */
101 static inline bool bvec_gap_to_prev(struct request_queue *q,
102 		struct bio_vec *bprv, unsigned int offset)
103 {
104 	if (!queue_virt_boundary(q))
105 		return false;
106 	return __bvec_gap_to_prev(q, bprv, offset);
107 }
108 
109 static inline void blk_rq_bio_prep(struct request *rq, struct bio *bio,
110 		unsigned int nr_segs)
111 {
112 	rq->nr_phys_segments = nr_segs;
113 	rq->__data_len = bio->bi_iter.bi_size;
114 	rq->bio = rq->biotail = bio;
115 	rq->ioprio = bio_prio(bio);
116 
117 	if (bio->bi_disk)
118 		rq->rq_disk = bio->bi_disk;
119 }
120 
121 #ifdef CONFIG_BLK_DEV_INTEGRITY
122 void blk_flush_integrity(void);
123 bool __bio_integrity_endio(struct bio *);
124 void bio_integrity_free(struct bio *bio);
125 static inline bool bio_integrity_endio(struct bio *bio)
126 {
127 	if (bio_integrity(bio))
128 		return __bio_integrity_endio(bio);
129 	return true;
130 }
131 
132 static inline bool integrity_req_gap_back_merge(struct request *req,
133 		struct bio *next)
134 {
135 	struct bio_integrity_payload *bip = bio_integrity(req->bio);
136 	struct bio_integrity_payload *bip_next = bio_integrity(next);
137 
138 	return bvec_gap_to_prev(req->q, &bip->bip_vec[bip->bip_vcnt - 1],
139 				bip_next->bip_vec[0].bv_offset);
140 }
141 
142 static inline bool integrity_req_gap_front_merge(struct request *req,
143 		struct bio *bio)
144 {
145 	struct bio_integrity_payload *bip = bio_integrity(bio);
146 	struct bio_integrity_payload *bip_next = bio_integrity(req->bio);
147 
148 	return bvec_gap_to_prev(req->q, &bip->bip_vec[bip->bip_vcnt - 1],
149 				bip_next->bip_vec[0].bv_offset);
150 }
151 #else /* CONFIG_BLK_DEV_INTEGRITY */
152 static inline bool integrity_req_gap_back_merge(struct request *req,
153 		struct bio *next)
154 {
155 	return false;
156 }
157 static inline bool integrity_req_gap_front_merge(struct request *req,
158 		struct bio *bio)
159 {
160 	return false;
161 }
162 
163 static inline void blk_flush_integrity(void)
164 {
165 }
166 static inline bool bio_integrity_endio(struct bio *bio)
167 {
168 	return true;
169 }
170 static inline void bio_integrity_free(struct bio *bio)
171 {
172 }
173 #endif /* CONFIG_BLK_DEV_INTEGRITY */
174 
175 unsigned long blk_rq_timeout(unsigned long timeout);
176 void blk_add_timer(struct request *req);
177 
178 bool bio_attempt_front_merge(struct request *req, struct bio *bio,
179 		unsigned int nr_segs);
180 bool bio_attempt_back_merge(struct request *req, struct bio *bio,
181 		unsigned int nr_segs);
182 bool bio_attempt_discard_merge(struct request_queue *q, struct request *req,
183 		struct bio *bio);
184 bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio,
185 		unsigned int nr_segs, struct request **same_queue_rq);
186 
187 void blk_account_io_start(struct request *req, bool new_io);
188 void blk_account_io_completion(struct request *req, unsigned int bytes);
189 void blk_account_io_done(struct request *req, u64 now);
190 
191 /*
192  * Internal elevator interface
193  */
194 #define ELV_ON_HASH(rq) ((rq)->rq_flags & RQF_HASHED)
195 
196 void blk_insert_flush(struct request *rq);
197 
198 void elevator_init_mq(struct request_queue *q);
199 int elevator_switch_mq(struct request_queue *q,
200 			      struct elevator_type *new_e);
201 void __elevator_exit(struct request_queue *, struct elevator_queue *);
202 int elv_register_queue(struct request_queue *q, bool uevent);
203 void elv_unregister_queue(struct request_queue *q);
204 
205 static inline void elevator_exit(struct request_queue *q,
206 		struct elevator_queue *e)
207 {
208 	lockdep_assert_held(&q->sysfs_lock);
209 
210 	blk_mq_sched_free_requests(q);
211 	__elevator_exit(q, e);
212 }
213 
214 struct hd_struct *__disk_get_part(struct gendisk *disk, int partno);
215 
216 #ifdef CONFIG_FAIL_IO_TIMEOUT
217 int blk_should_fake_timeout(struct request_queue *);
218 ssize_t part_timeout_show(struct device *, struct device_attribute *, char *);
219 ssize_t part_timeout_store(struct device *, struct device_attribute *,
220 				const char *, size_t);
221 #else
222 static inline int blk_should_fake_timeout(struct request_queue *q)
223 {
224 	return 0;
225 }
226 #endif
227 
228 void __blk_queue_split(struct request_queue *q, struct bio **bio,
229 		unsigned int *nr_segs);
230 int ll_back_merge_fn(struct request *req, struct bio *bio,
231 		unsigned int nr_segs);
232 int ll_front_merge_fn(struct request *req,  struct bio *bio,
233 		unsigned int nr_segs);
234 struct request *attempt_back_merge(struct request_queue *q, struct request *rq);
235 struct request *attempt_front_merge(struct request_queue *q, struct request *rq);
236 int blk_attempt_req_merge(struct request_queue *q, struct request *rq,
237 				struct request *next);
238 unsigned int blk_recalc_rq_segments(struct request *rq);
239 void blk_rq_set_mixed_merge(struct request *rq);
240 bool blk_rq_merge_ok(struct request *rq, struct bio *bio);
241 enum elv_merge blk_try_merge(struct request *rq, struct bio *bio);
242 
243 int blk_dev_init(void);
244 
245 /*
246  * Contribute to IO statistics IFF:
247  *
248  *	a) it's attached to a gendisk, and
249  *	b) the queue had IO stats enabled when this request was started
250  */
251 static inline bool blk_do_io_stat(struct request *rq)
252 {
253 	return rq->rq_disk && (rq->rq_flags & RQF_IO_STAT);
254 }
255 
256 static inline void req_set_nomerge(struct request_queue *q, struct request *req)
257 {
258 	req->cmd_flags |= REQ_NOMERGE;
259 	if (req == q->last_merge)
260 		q->last_merge = NULL;
261 }
262 
263 /*
264  * The max size one bio can handle is UINT_MAX becasue bvec_iter.bi_size
265  * is defined as 'unsigned int', meantime it has to aligned to with logical
266  * block size which is the minimum accepted unit by hardware.
267  */
268 static inline unsigned int bio_allowed_max_sectors(struct request_queue *q)
269 {
270 	return round_down(UINT_MAX, queue_logical_block_size(q)) >> 9;
271 }
272 
273 /*
274  * Internal io_context interface
275  */
276 void get_io_context(struct io_context *ioc);
277 struct io_cq *ioc_lookup_icq(struct io_context *ioc, struct request_queue *q);
278 struct io_cq *ioc_create_icq(struct io_context *ioc, struct request_queue *q,
279 			     gfp_t gfp_mask);
280 void ioc_clear_queue(struct request_queue *q);
281 
282 int create_task_io_context(struct task_struct *task, gfp_t gfp_mask, int node);
283 
284 /**
285  * create_io_context - try to create task->io_context
286  * @gfp_mask: allocation mask
287  * @node: allocation node
288  *
289  * If %current->io_context is %NULL, allocate a new io_context and install
290  * it.  Returns the current %current->io_context which may be %NULL if
291  * allocation failed.
292  *
293  * Note that this function can't be called with IRQ disabled because
294  * task_lock which protects %current->io_context is IRQ-unsafe.
295  */
296 static inline struct io_context *create_io_context(gfp_t gfp_mask, int node)
297 {
298 	WARN_ON_ONCE(irqs_disabled());
299 	if (unlikely(!current->io_context))
300 		create_task_io_context(current, gfp_mask, node);
301 	return current->io_context;
302 }
303 
304 /*
305  * Internal throttling interface
306  */
307 #ifdef CONFIG_BLK_DEV_THROTTLING
308 extern void blk_throtl_drain(struct request_queue *q);
309 extern int blk_throtl_init(struct request_queue *q);
310 extern void blk_throtl_exit(struct request_queue *q);
311 extern void blk_throtl_register_queue(struct request_queue *q);
312 #else /* CONFIG_BLK_DEV_THROTTLING */
313 static inline void blk_throtl_drain(struct request_queue *q) { }
314 static inline int blk_throtl_init(struct request_queue *q) { return 0; }
315 static inline void blk_throtl_exit(struct request_queue *q) { }
316 static inline void blk_throtl_register_queue(struct request_queue *q) { }
317 #endif /* CONFIG_BLK_DEV_THROTTLING */
318 #ifdef CONFIG_BLK_DEV_THROTTLING_LOW
319 extern ssize_t blk_throtl_sample_time_show(struct request_queue *q, char *page);
320 extern ssize_t blk_throtl_sample_time_store(struct request_queue *q,
321 	const char *page, size_t count);
322 extern void blk_throtl_bio_endio(struct bio *bio);
323 extern void blk_throtl_stat_add(struct request *rq, u64 time);
324 #else
325 static inline void blk_throtl_bio_endio(struct bio *bio) { }
326 static inline void blk_throtl_stat_add(struct request *rq, u64 time) { }
327 #endif
328 
329 #ifdef CONFIG_BOUNCE
330 extern int init_emergency_isa_pool(void);
331 extern void blk_queue_bounce(struct request_queue *q, struct bio **bio);
332 #else
333 static inline int init_emergency_isa_pool(void)
334 {
335 	return 0;
336 }
337 static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio)
338 {
339 }
340 #endif /* CONFIG_BOUNCE */
341 
342 #ifdef CONFIG_BLK_CGROUP_IOLATENCY
343 extern int blk_iolatency_init(struct request_queue *q);
344 #else
345 static inline int blk_iolatency_init(struct request_queue *q) { return 0; }
346 #endif
347 
348 struct bio *blk_next_bio(struct bio *bio, unsigned int nr_pages, gfp_t gfp);
349 
350 #ifdef CONFIG_BLK_DEV_ZONED
351 void blk_queue_free_zone_bitmaps(struct request_queue *q);
352 #else
353 static inline void blk_queue_free_zone_bitmaps(struct request_queue *q) {}
354 #endif
355 
356 #endif /* BLK_INTERNAL_H */
357