xref: /linux/block/blk.h (revision b7019ac550eb3916f34d79db583e9b7ea2524afa)
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 	unsigned long		flush_pending_since;
23 	struct list_head	flush_queue[2];
24 	struct list_head	flush_data_in_flight;
25 	struct request		*flush_rq;
26 
27 	/*
28 	 * flush_rq shares tag with this rq, both can't be active
29 	 * at the same time
30 	 */
31 	struct request		*orig_rq;
32 	spinlock_t		mq_flush_lock;
33 };
34 
35 extern struct kmem_cache *blk_requestq_cachep;
36 extern struct kobj_type blk_queue_ktype;
37 extern struct ida blk_queue_ida;
38 
39 static inline struct blk_flush_queue *
40 blk_get_flush_queue(struct request_queue *q, struct blk_mq_ctx *ctx)
41 {
42 	return blk_mq_map_queue(q, REQ_OP_FLUSH, ctx)->fq;
43 }
44 
45 static inline void __blk_get_queue(struct request_queue *q)
46 {
47 	kobject_get(&q->kobj);
48 }
49 
50 struct blk_flush_queue *blk_alloc_flush_queue(struct request_queue *q,
51 		int node, int cmd_size, gfp_t flags);
52 void blk_free_flush_queue(struct blk_flush_queue *q);
53 
54 void blk_rq_bio_prep(struct request_queue *q, struct request *rq,
55 			struct bio *bio);
56 void blk_freeze_queue(struct request_queue *q);
57 
58 static inline void blk_queue_enter_live(struct request_queue *q)
59 {
60 	/*
61 	 * Given that running in generic_make_request() context
62 	 * guarantees that a live reference against q_usage_counter has
63 	 * been established, further references under that same context
64 	 * need not check that the queue has been frozen (marked dead).
65 	 */
66 	percpu_ref_get(&q->q_usage_counter);
67 }
68 
69 static inline bool biovec_phys_mergeable(struct request_queue *q,
70 		struct bio_vec *vec1, struct bio_vec *vec2)
71 {
72 	unsigned long mask = queue_segment_boundary(q);
73 	phys_addr_t addr1 = page_to_phys(vec1->bv_page) + vec1->bv_offset;
74 	phys_addr_t addr2 = page_to_phys(vec2->bv_page) + vec2->bv_offset;
75 
76 	if (addr1 + vec1->bv_len != addr2)
77 		return false;
78 	if (xen_domain() && !xen_biovec_phys_mergeable(vec1, vec2->bv_page))
79 		return false;
80 	if ((addr1 | mask) != ((addr2 + vec2->bv_len - 1) | mask))
81 		return false;
82 	return true;
83 }
84 
85 static inline bool __bvec_gap_to_prev(struct request_queue *q,
86 		struct bio_vec *bprv, unsigned int offset)
87 {
88 	return (offset & queue_virt_boundary(q)) ||
89 		((bprv->bv_offset + bprv->bv_len) & queue_virt_boundary(q));
90 }
91 
92 /*
93  * Check if adding a bio_vec after bprv with offset would create a gap in
94  * the SG list. Most drivers don't care about this, but some do.
95  */
96 static inline bool bvec_gap_to_prev(struct request_queue *q,
97 		struct bio_vec *bprv, unsigned int offset)
98 {
99 	if (!queue_virt_boundary(q))
100 		return false;
101 	return __bvec_gap_to_prev(q, bprv, offset);
102 }
103 
104 #ifdef CONFIG_BLK_DEV_INTEGRITY
105 void blk_flush_integrity(void);
106 bool __bio_integrity_endio(struct bio *);
107 static inline bool bio_integrity_endio(struct bio *bio)
108 {
109 	if (bio_integrity(bio))
110 		return __bio_integrity_endio(bio);
111 	return true;
112 }
113 
114 static inline bool integrity_req_gap_back_merge(struct request *req,
115 		struct bio *next)
116 {
117 	struct bio_integrity_payload *bip = bio_integrity(req->bio);
118 	struct bio_integrity_payload *bip_next = bio_integrity(next);
119 
120 	return bvec_gap_to_prev(req->q, &bip->bip_vec[bip->bip_vcnt - 1],
121 				bip_next->bip_vec[0].bv_offset);
122 }
123 
124 static inline bool integrity_req_gap_front_merge(struct request *req,
125 		struct bio *bio)
126 {
127 	struct bio_integrity_payload *bip = bio_integrity(bio);
128 	struct bio_integrity_payload *bip_next = bio_integrity(req->bio);
129 
130 	return bvec_gap_to_prev(req->q, &bip->bip_vec[bip->bip_vcnt - 1],
131 				bip_next->bip_vec[0].bv_offset);
132 }
133 #else /* CONFIG_BLK_DEV_INTEGRITY */
134 static inline bool integrity_req_gap_back_merge(struct request *req,
135 		struct bio *next)
136 {
137 	return false;
138 }
139 static inline bool integrity_req_gap_front_merge(struct request *req,
140 		struct bio *bio)
141 {
142 	return false;
143 }
144 
145 static inline void blk_flush_integrity(void)
146 {
147 }
148 static inline bool bio_integrity_endio(struct bio *bio)
149 {
150 	return true;
151 }
152 #endif /* CONFIG_BLK_DEV_INTEGRITY */
153 
154 unsigned long blk_rq_timeout(unsigned long timeout);
155 void blk_add_timer(struct request *req);
156 
157 bool bio_attempt_front_merge(struct request_queue *q, struct request *req,
158 			     struct bio *bio);
159 bool bio_attempt_back_merge(struct request_queue *q, struct request *req,
160 			    struct bio *bio);
161 bool bio_attempt_discard_merge(struct request_queue *q, struct request *req,
162 		struct bio *bio);
163 bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio,
164 			    struct request **same_queue_rq);
165 
166 void blk_account_io_start(struct request *req, bool new_io);
167 void blk_account_io_completion(struct request *req, unsigned int bytes);
168 void blk_account_io_done(struct request *req, u64 now);
169 
170 /*
171  * Internal elevator interface
172  */
173 #define ELV_ON_HASH(rq) ((rq)->rq_flags & RQF_HASHED)
174 
175 void blk_insert_flush(struct request *rq);
176 
177 int elevator_init_mq(struct request_queue *q);
178 int elevator_switch_mq(struct request_queue *q,
179 			      struct elevator_type *new_e);
180 void __elevator_exit(struct request_queue *, struct elevator_queue *);
181 int elv_register_queue(struct request_queue *q);
182 void elv_unregister_queue(struct request_queue *q);
183 
184 static inline void elevator_exit(struct request_queue *q,
185 		struct elevator_queue *e)
186 {
187 	blk_mq_sched_free_requests(q);
188 	__elevator_exit(q, e);
189 }
190 
191 struct hd_struct *__disk_get_part(struct gendisk *disk, int partno);
192 
193 #ifdef CONFIG_FAIL_IO_TIMEOUT
194 int blk_should_fake_timeout(struct request_queue *);
195 ssize_t part_timeout_show(struct device *, struct device_attribute *, char *);
196 ssize_t part_timeout_store(struct device *, struct device_attribute *,
197 				const char *, size_t);
198 #else
199 static inline int blk_should_fake_timeout(struct request_queue *q)
200 {
201 	return 0;
202 }
203 #endif
204 
205 int ll_back_merge_fn(struct request_queue *q, struct request *req,
206 		     struct bio *bio);
207 int ll_front_merge_fn(struct request_queue *q, struct request *req,
208 		      struct bio *bio);
209 struct request *attempt_back_merge(struct request_queue *q, struct request *rq);
210 struct request *attempt_front_merge(struct request_queue *q, struct request *rq);
211 int blk_attempt_req_merge(struct request_queue *q, struct request *rq,
212 				struct request *next);
213 void blk_recalc_rq_segments(struct request *rq);
214 void blk_rq_set_mixed_merge(struct request *rq);
215 bool blk_rq_merge_ok(struct request *rq, struct bio *bio);
216 enum elv_merge blk_try_merge(struct request *rq, struct bio *bio);
217 
218 int blk_dev_init(void);
219 
220 /*
221  * Contribute to IO statistics IFF:
222  *
223  *	a) it's attached to a gendisk, and
224  *	b) the queue had IO stats enabled when this request was started, and
225  *	c) it's a file system request
226  */
227 static inline bool blk_do_io_stat(struct request *rq)
228 {
229 	return rq->rq_disk &&
230 	       (rq->rq_flags & RQF_IO_STAT) &&
231 		!blk_rq_is_passthrough(rq);
232 }
233 
234 static inline void req_set_nomerge(struct request_queue *q, struct request *req)
235 {
236 	req->cmd_flags |= REQ_NOMERGE;
237 	if (req == q->last_merge)
238 		q->last_merge = NULL;
239 }
240 
241 /*
242  * The max size one bio can handle is UINT_MAX becasue bvec_iter.bi_size
243  * is defined as 'unsigned int', meantime it has to aligned to with logical
244  * block size which is the minimum accepted unit by hardware.
245  */
246 static inline unsigned int bio_allowed_max_sectors(struct request_queue *q)
247 {
248 	return round_down(UINT_MAX, queue_logical_block_size(q)) >> 9;
249 }
250 
251 /*
252  * Internal io_context interface
253  */
254 void get_io_context(struct io_context *ioc);
255 struct io_cq *ioc_lookup_icq(struct io_context *ioc, struct request_queue *q);
256 struct io_cq *ioc_create_icq(struct io_context *ioc, struct request_queue *q,
257 			     gfp_t gfp_mask);
258 void ioc_clear_queue(struct request_queue *q);
259 
260 int create_task_io_context(struct task_struct *task, gfp_t gfp_mask, int node);
261 
262 /**
263  * create_io_context - try to create task->io_context
264  * @gfp_mask: allocation mask
265  * @node: allocation node
266  *
267  * If %current->io_context is %NULL, allocate a new io_context and install
268  * it.  Returns the current %current->io_context which may be %NULL if
269  * allocation failed.
270  *
271  * Note that this function can't be called with IRQ disabled because
272  * task_lock which protects %current->io_context is IRQ-unsafe.
273  */
274 static inline struct io_context *create_io_context(gfp_t gfp_mask, int node)
275 {
276 	WARN_ON_ONCE(irqs_disabled());
277 	if (unlikely(!current->io_context))
278 		create_task_io_context(current, gfp_mask, node);
279 	return current->io_context;
280 }
281 
282 /*
283  * Internal throttling interface
284  */
285 #ifdef CONFIG_BLK_DEV_THROTTLING
286 extern void blk_throtl_drain(struct request_queue *q);
287 extern int blk_throtl_init(struct request_queue *q);
288 extern void blk_throtl_exit(struct request_queue *q);
289 extern void blk_throtl_register_queue(struct request_queue *q);
290 #else /* CONFIG_BLK_DEV_THROTTLING */
291 static inline void blk_throtl_drain(struct request_queue *q) { }
292 static inline int blk_throtl_init(struct request_queue *q) { return 0; }
293 static inline void blk_throtl_exit(struct request_queue *q) { }
294 static inline void blk_throtl_register_queue(struct request_queue *q) { }
295 #endif /* CONFIG_BLK_DEV_THROTTLING */
296 #ifdef CONFIG_BLK_DEV_THROTTLING_LOW
297 extern ssize_t blk_throtl_sample_time_show(struct request_queue *q, char *page);
298 extern ssize_t blk_throtl_sample_time_store(struct request_queue *q,
299 	const char *page, size_t count);
300 extern void blk_throtl_bio_endio(struct bio *bio);
301 extern void blk_throtl_stat_add(struct request *rq, u64 time);
302 #else
303 static inline void blk_throtl_bio_endio(struct bio *bio) { }
304 static inline void blk_throtl_stat_add(struct request *rq, u64 time) { }
305 #endif
306 
307 #ifdef CONFIG_BOUNCE
308 extern int init_emergency_isa_pool(void);
309 extern void blk_queue_bounce(struct request_queue *q, struct bio **bio);
310 #else
311 static inline int init_emergency_isa_pool(void)
312 {
313 	return 0;
314 }
315 static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio)
316 {
317 }
318 #endif /* CONFIG_BOUNCE */
319 
320 #ifdef CONFIG_BLK_CGROUP_IOLATENCY
321 extern int blk_iolatency_init(struct request_queue *q);
322 #else
323 static inline int blk_iolatency_init(struct request_queue *q) { return 0; }
324 #endif
325 
326 struct bio *blk_next_bio(struct bio *bio, unsigned int nr_pages, gfp_t gfp);
327 
328 #ifdef CONFIG_BLK_DEV_ZONED
329 void blk_queue_free_zone_bitmaps(struct request_queue *q);
330 #else
331 static inline void blk_queue_free_zone_bitmaps(struct request_queue *q) {}
332 #endif
333 
334 #endif /* BLK_INTERNAL_H */
335