xref: /linux/block/blk.h (revision 5ff328836dfde0cef9f28c8b8791a90a36d7a183)
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 
10 /* Max future timer expiry for timeouts */
11 #define BLK_MAX_TIMEOUT		(5 * HZ)
12 
13 #ifdef CONFIG_DEBUG_FS
14 extern struct dentry *blk_debugfs_root;
15 #endif
16 
17 struct blk_flush_queue {
18 	unsigned int		flush_queue_delayed:1;
19 	unsigned int		flush_pending_idx:1;
20 	unsigned int		flush_running_idx:1;
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 	/*
27 	 * flush_rq shares tag with this rq, both can't be active
28 	 * at the same time
29 	 */
30 	struct request		*orig_rq;
31 	spinlock_t		mq_flush_lock;
32 };
33 
34 extern struct kmem_cache *blk_requestq_cachep;
35 extern struct kobj_type blk_queue_ktype;
36 extern struct ida blk_queue_ida;
37 
38 static inline struct blk_flush_queue *
39 blk_get_flush_queue(struct request_queue *q, struct blk_mq_ctx *ctx)
40 {
41 	return blk_mq_map_queue(q, REQ_OP_FLUSH, ctx->cpu)->fq;
42 }
43 
44 static inline void __blk_get_queue(struct request_queue *q)
45 {
46 	kobject_get(&q->kobj);
47 }
48 
49 struct blk_flush_queue *blk_alloc_flush_queue(struct request_queue *q,
50 		int node, int cmd_size, gfp_t flags);
51 void blk_free_flush_queue(struct blk_flush_queue *q);
52 
53 void blk_exit_queue(struct request_queue *q);
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))
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 struct hd_struct *__disk_get_part(struct gendisk *disk, int partno);
185 
186 #ifdef CONFIG_FAIL_IO_TIMEOUT
187 int blk_should_fake_timeout(struct request_queue *);
188 ssize_t part_timeout_show(struct device *, struct device_attribute *, char *);
189 ssize_t part_timeout_store(struct device *, struct device_attribute *,
190 				const char *, size_t);
191 #else
192 static inline int blk_should_fake_timeout(struct request_queue *q)
193 {
194 	return 0;
195 }
196 #endif
197 
198 int ll_back_merge_fn(struct request_queue *q, struct request *req,
199 		     struct bio *bio);
200 int ll_front_merge_fn(struct request_queue *q, struct request *req,
201 		      struct bio *bio);
202 struct request *attempt_back_merge(struct request_queue *q, struct request *rq);
203 struct request *attempt_front_merge(struct request_queue *q, struct request *rq);
204 int blk_attempt_req_merge(struct request_queue *q, struct request *rq,
205 				struct request *next);
206 void blk_recalc_rq_segments(struct request *rq);
207 void blk_rq_set_mixed_merge(struct request *rq);
208 bool blk_rq_merge_ok(struct request *rq, struct bio *bio);
209 enum elv_merge blk_try_merge(struct request *rq, struct bio *bio);
210 
211 int blk_dev_init(void);
212 
213 /*
214  * Contribute to IO statistics IFF:
215  *
216  *	a) it's attached to a gendisk, and
217  *	b) the queue had IO stats enabled when this request was started, and
218  *	c) it's a file system request
219  */
220 static inline bool blk_do_io_stat(struct request *rq)
221 {
222 	return rq->rq_disk &&
223 	       (rq->rq_flags & RQF_IO_STAT) &&
224 		!blk_rq_is_passthrough(rq);
225 }
226 
227 static inline void req_set_nomerge(struct request_queue *q, struct request *req)
228 {
229 	req->cmd_flags |= REQ_NOMERGE;
230 	if (req == q->last_merge)
231 		q->last_merge = NULL;
232 }
233 
234 /*
235  * The max size one bio can handle is UINT_MAX becasue bvec_iter.bi_size
236  * is defined as 'unsigned int', meantime it has to aligned to with logical
237  * block size which is the minimum accepted unit by hardware.
238  */
239 static inline unsigned int bio_allowed_max_sectors(struct request_queue *q)
240 {
241 	return round_down(UINT_MAX, queue_logical_block_size(q)) >> 9;
242 }
243 
244 /*
245  * Internal io_context interface
246  */
247 void get_io_context(struct io_context *ioc);
248 struct io_cq *ioc_lookup_icq(struct io_context *ioc, struct request_queue *q);
249 struct io_cq *ioc_create_icq(struct io_context *ioc, struct request_queue *q,
250 			     gfp_t gfp_mask);
251 void ioc_clear_queue(struct request_queue *q);
252 
253 int create_task_io_context(struct task_struct *task, gfp_t gfp_mask, int node);
254 
255 /**
256  * create_io_context - try to create task->io_context
257  * @gfp_mask: allocation mask
258  * @node: allocation node
259  *
260  * If %current->io_context is %NULL, allocate a new io_context and install
261  * it.  Returns the current %current->io_context which may be %NULL if
262  * allocation failed.
263  *
264  * Note that this function can't be called with IRQ disabled because
265  * task_lock which protects %current->io_context is IRQ-unsafe.
266  */
267 static inline struct io_context *create_io_context(gfp_t gfp_mask, int node)
268 {
269 	WARN_ON_ONCE(irqs_disabled());
270 	if (unlikely(!current->io_context))
271 		create_task_io_context(current, gfp_mask, node);
272 	return current->io_context;
273 }
274 
275 /*
276  * Internal throttling interface
277  */
278 #ifdef CONFIG_BLK_DEV_THROTTLING
279 extern void blk_throtl_drain(struct request_queue *q);
280 extern int blk_throtl_init(struct request_queue *q);
281 extern void blk_throtl_exit(struct request_queue *q);
282 extern void blk_throtl_register_queue(struct request_queue *q);
283 #else /* CONFIG_BLK_DEV_THROTTLING */
284 static inline void blk_throtl_drain(struct request_queue *q) { }
285 static inline int blk_throtl_init(struct request_queue *q) { return 0; }
286 static inline void blk_throtl_exit(struct request_queue *q) { }
287 static inline void blk_throtl_register_queue(struct request_queue *q) { }
288 #endif /* CONFIG_BLK_DEV_THROTTLING */
289 #ifdef CONFIG_BLK_DEV_THROTTLING_LOW
290 extern ssize_t blk_throtl_sample_time_show(struct request_queue *q, char *page);
291 extern ssize_t blk_throtl_sample_time_store(struct request_queue *q,
292 	const char *page, size_t count);
293 extern void blk_throtl_bio_endio(struct bio *bio);
294 extern void blk_throtl_stat_add(struct request *rq, u64 time);
295 #else
296 static inline void blk_throtl_bio_endio(struct bio *bio) { }
297 static inline void blk_throtl_stat_add(struct request *rq, u64 time) { }
298 #endif
299 
300 #ifdef CONFIG_BOUNCE
301 extern int init_emergency_isa_pool(void);
302 extern void blk_queue_bounce(struct request_queue *q, struct bio **bio);
303 #else
304 static inline int init_emergency_isa_pool(void)
305 {
306 	return 0;
307 }
308 static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio)
309 {
310 }
311 #endif /* CONFIG_BOUNCE */
312 
313 #ifdef CONFIG_BLK_CGROUP_IOLATENCY
314 extern int blk_iolatency_init(struct request_queue *q);
315 #else
316 static inline int blk_iolatency_init(struct request_queue *q) { return 0; }
317 #endif
318 
319 struct bio *blk_next_bio(struct bio *bio, unsigned int nr_pages, gfp_t gfp);
320 
321 #ifdef CONFIG_BLK_DEV_ZONED
322 void blk_queue_free_zone_bitmaps(struct request_queue *q);
323 #else
324 static inline void blk_queue_free_zone_bitmaps(struct request_queue *q) {}
325 #endif
326 
327 #endif /* BLK_INTERNAL_H */
328