xref: /openbmc/linux/block/blk.h (revision f125e2d4)
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 	struct lock_class_key	key;
34 	spinlock_t		mq_flush_lock;
35 };
36 
37 extern struct kmem_cache *blk_requestq_cachep;
38 extern struct kobj_type blk_queue_ktype;
39 extern struct ida blk_queue_ida;
40 
41 static inline struct blk_flush_queue *
42 blk_get_flush_queue(struct request_queue *q, struct blk_mq_ctx *ctx)
43 {
44 	return blk_mq_map_queue(q, REQ_OP_FLUSH, ctx)->fq;
45 }
46 
47 static inline void __blk_get_queue(struct request_queue *q)
48 {
49 	kobject_get(&q->kobj);
50 }
51 
52 static inline bool
53 is_flush_rq(struct request *req, struct blk_mq_hw_ctx *hctx)
54 {
55 	return hctx->fq->flush_rq == req;
56 }
57 
58 struct blk_flush_queue *blk_alloc_flush_queue(struct request_queue *q,
59 		int node, int cmd_size, gfp_t flags);
60 void blk_free_flush_queue(struct blk_flush_queue *q);
61 
62 void blk_freeze_queue(struct request_queue *q);
63 
64 static inline void blk_queue_enter_live(struct request_queue *q)
65 {
66 	/*
67 	 * Given that running in generic_make_request() context
68 	 * guarantees that a live reference against q_usage_counter has
69 	 * been established, further references under that same context
70 	 * need not check that the queue has been frozen (marked dead).
71 	 */
72 	percpu_ref_get(&q->q_usage_counter);
73 }
74 
75 static inline bool biovec_phys_mergeable(struct request_queue *q,
76 		struct bio_vec *vec1, struct bio_vec *vec2)
77 {
78 	unsigned long mask = queue_segment_boundary(q);
79 	phys_addr_t addr1 = page_to_phys(vec1->bv_page) + vec1->bv_offset;
80 	phys_addr_t addr2 = page_to_phys(vec2->bv_page) + vec2->bv_offset;
81 
82 	if (addr1 + vec1->bv_len != addr2)
83 		return false;
84 	if (xen_domain() && !xen_biovec_phys_mergeable(vec1, vec2->bv_page))
85 		return false;
86 	if ((addr1 | mask) != ((addr2 + vec2->bv_len - 1) | mask))
87 		return false;
88 	return true;
89 }
90 
91 static inline bool __bvec_gap_to_prev(struct request_queue *q,
92 		struct bio_vec *bprv, unsigned int offset)
93 {
94 	return (offset & queue_virt_boundary(q)) ||
95 		((bprv->bv_offset + bprv->bv_len) & queue_virt_boundary(q));
96 }
97 
98 /*
99  * Check if adding a bio_vec after bprv with offset would create a gap in
100  * the SG list. Most drivers don't care about this, but some do.
101  */
102 static inline bool bvec_gap_to_prev(struct request_queue *q,
103 		struct bio_vec *bprv, unsigned int offset)
104 {
105 	if (!queue_virt_boundary(q))
106 		return false;
107 	return __bvec_gap_to_prev(q, bprv, offset);
108 }
109 
110 static inline void blk_rq_bio_prep(struct request *rq, struct bio *bio,
111 		unsigned int nr_segs)
112 {
113 	rq->nr_phys_segments = nr_segs;
114 	rq->__data_len = bio->bi_iter.bi_size;
115 	rq->bio = rq->biotail = bio;
116 	rq->ioprio = bio_prio(bio);
117 
118 	if (bio->bi_disk)
119 		rq->rq_disk = bio->bi_disk;
120 }
121 
122 #ifdef CONFIG_BLK_DEV_INTEGRITY
123 void blk_flush_integrity(void);
124 bool __bio_integrity_endio(struct bio *);
125 void bio_integrity_free(struct bio *bio);
126 static inline bool bio_integrity_endio(struct bio *bio)
127 {
128 	if (bio_integrity(bio))
129 		return __bio_integrity_endio(bio);
130 	return true;
131 }
132 
133 static inline bool integrity_req_gap_back_merge(struct request *req,
134 		struct bio *next)
135 {
136 	struct bio_integrity_payload *bip = bio_integrity(req->bio);
137 	struct bio_integrity_payload *bip_next = bio_integrity(next);
138 
139 	return bvec_gap_to_prev(req->q, &bip->bip_vec[bip->bip_vcnt - 1],
140 				bip_next->bip_vec[0].bv_offset);
141 }
142 
143 static inline bool integrity_req_gap_front_merge(struct request *req,
144 		struct bio *bio)
145 {
146 	struct bio_integrity_payload *bip = bio_integrity(bio);
147 	struct bio_integrity_payload *bip_next = bio_integrity(req->bio);
148 
149 	return bvec_gap_to_prev(req->q, &bip->bip_vec[bip->bip_vcnt - 1],
150 				bip_next->bip_vec[0].bv_offset);
151 }
152 #else /* CONFIG_BLK_DEV_INTEGRITY */
153 static inline bool integrity_req_gap_back_merge(struct request *req,
154 		struct bio *next)
155 {
156 	return false;
157 }
158 static inline bool integrity_req_gap_front_merge(struct request *req,
159 		struct bio *bio)
160 {
161 	return false;
162 }
163 
164 static inline void blk_flush_integrity(void)
165 {
166 }
167 static inline bool bio_integrity_endio(struct bio *bio)
168 {
169 	return true;
170 }
171 static inline void bio_integrity_free(struct bio *bio)
172 {
173 }
174 #endif /* CONFIG_BLK_DEV_INTEGRITY */
175 
176 unsigned long blk_rq_timeout(unsigned long timeout);
177 void blk_add_timer(struct request *req);
178 
179 bool bio_attempt_front_merge(struct request *req, struct bio *bio,
180 		unsigned int nr_segs);
181 bool bio_attempt_back_merge(struct request *req, struct bio *bio,
182 		unsigned int nr_segs);
183 bool bio_attempt_discard_merge(struct request_queue *q, struct request *req,
184 		struct bio *bio);
185 bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio,
186 		unsigned int nr_segs, struct request **same_queue_rq);
187 
188 void blk_account_io_start(struct request *req, bool new_io);
189 void blk_account_io_completion(struct request *req, unsigned int bytes);
190 void blk_account_io_done(struct request *req, u64 now);
191 
192 /*
193  * Internal elevator interface
194  */
195 #define ELV_ON_HASH(rq) ((rq)->rq_flags & RQF_HASHED)
196 
197 void blk_insert_flush(struct request *rq);
198 
199 void elevator_init_mq(struct request_queue *q);
200 int elevator_switch_mq(struct request_queue *q,
201 			      struct elevator_type *new_e);
202 void __elevator_exit(struct request_queue *, struct elevator_queue *);
203 int elv_register_queue(struct request_queue *q, bool uevent);
204 void elv_unregister_queue(struct request_queue *q);
205 
206 static inline void elevator_exit(struct request_queue *q,
207 		struct elevator_queue *e)
208 {
209 	lockdep_assert_held(&q->sysfs_lock);
210 
211 	blk_mq_sched_free_requests(q);
212 	__elevator_exit(q, e);
213 }
214 
215 struct hd_struct *__disk_get_part(struct gendisk *disk, int partno);
216 
217 #ifdef CONFIG_FAIL_IO_TIMEOUT
218 int blk_should_fake_timeout(struct request_queue *);
219 ssize_t part_timeout_show(struct device *, struct device_attribute *, char *);
220 ssize_t part_timeout_store(struct device *, struct device_attribute *,
221 				const char *, size_t);
222 #else
223 static inline int blk_should_fake_timeout(struct request_queue *q)
224 {
225 	return 0;
226 }
227 #endif
228 
229 void __blk_queue_split(struct request_queue *q, struct bio **bio,
230 		unsigned int *nr_segs);
231 int ll_back_merge_fn(struct request *req, struct bio *bio,
232 		unsigned int nr_segs);
233 int ll_front_merge_fn(struct request *req,  struct bio *bio,
234 		unsigned int nr_segs);
235 struct request *attempt_back_merge(struct request_queue *q, struct request *rq);
236 struct request *attempt_front_merge(struct request_queue *q, struct request *rq);
237 int blk_attempt_req_merge(struct request_queue *q, struct request *rq,
238 				struct request *next);
239 unsigned int blk_recalc_rq_segments(struct request *rq);
240 void blk_rq_set_mixed_merge(struct request *rq);
241 bool blk_rq_merge_ok(struct request *rq, struct bio *bio);
242 enum elv_merge blk_try_merge(struct request *rq, struct bio *bio);
243 
244 int blk_dev_init(void);
245 
246 /*
247  * Contribute to IO statistics IFF:
248  *
249  *	a) it's attached to a gendisk, and
250  *	b) the queue had IO stats enabled when this request was started
251  */
252 static inline bool blk_do_io_stat(struct request *rq)
253 {
254 	return rq->rq_disk && (rq->rq_flags & RQF_IO_STAT);
255 }
256 
257 static inline void req_set_nomerge(struct request_queue *q, struct request *req)
258 {
259 	req->cmd_flags |= REQ_NOMERGE;
260 	if (req == q->last_merge)
261 		q->last_merge = NULL;
262 }
263 
264 /*
265  * The max size one bio can handle is UINT_MAX becasue bvec_iter.bi_size
266  * is defined as 'unsigned int', meantime it has to aligned to with logical
267  * block size which is the minimum accepted unit by hardware.
268  */
269 static inline unsigned int bio_allowed_max_sectors(struct request_queue *q)
270 {
271 	return round_down(UINT_MAX, queue_logical_block_size(q)) >> 9;
272 }
273 
274 /*
275  * Internal io_context interface
276  */
277 void get_io_context(struct io_context *ioc);
278 struct io_cq *ioc_lookup_icq(struct io_context *ioc, struct request_queue *q);
279 struct io_cq *ioc_create_icq(struct io_context *ioc, struct request_queue *q,
280 			     gfp_t gfp_mask);
281 void ioc_clear_queue(struct request_queue *q);
282 
283 int create_task_io_context(struct task_struct *task, gfp_t gfp_mask, int node);
284 
285 /**
286  * create_io_context - try to create task->io_context
287  * @gfp_mask: allocation mask
288  * @node: allocation node
289  *
290  * If %current->io_context is %NULL, allocate a new io_context and install
291  * it.  Returns the current %current->io_context which may be %NULL if
292  * allocation failed.
293  *
294  * Note that this function can't be called with IRQ disabled because
295  * task_lock which protects %current->io_context is IRQ-unsafe.
296  */
297 static inline struct io_context *create_io_context(gfp_t gfp_mask, int node)
298 {
299 	WARN_ON_ONCE(irqs_disabled());
300 	if (unlikely(!current->io_context))
301 		create_task_io_context(current, gfp_mask, node);
302 	return current->io_context;
303 }
304 
305 /*
306  * Internal throttling interface
307  */
308 #ifdef CONFIG_BLK_DEV_THROTTLING
309 extern void blk_throtl_drain(struct request_queue *q);
310 extern int blk_throtl_init(struct request_queue *q);
311 extern void blk_throtl_exit(struct request_queue *q);
312 extern void blk_throtl_register_queue(struct request_queue *q);
313 #else /* CONFIG_BLK_DEV_THROTTLING */
314 static inline void blk_throtl_drain(struct request_queue *q) { }
315 static inline int blk_throtl_init(struct request_queue *q) { return 0; }
316 static inline void blk_throtl_exit(struct request_queue *q) { }
317 static inline void blk_throtl_register_queue(struct request_queue *q) { }
318 #endif /* CONFIG_BLK_DEV_THROTTLING */
319 #ifdef CONFIG_BLK_DEV_THROTTLING_LOW
320 extern ssize_t blk_throtl_sample_time_show(struct request_queue *q, char *page);
321 extern ssize_t blk_throtl_sample_time_store(struct request_queue *q,
322 	const char *page, size_t count);
323 extern void blk_throtl_bio_endio(struct bio *bio);
324 extern void blk_throtl_stat_add(struct request *rq, u64 time);
325 #else
326 static inline void blk_throtl_bio_endio(struct bio *bio) { }
327 static inline void blk_throtl_stat_add(struct request *rq, u64 time) { }
328 #endif
329 
330 #ifdef CONFIG_BOUNCE
331 extern int init_emergency_isa_pool(void);
332 extern void blk_queue_bounce(struct request_queue *q, struct bio **bio);
333 #else
334 static inline int init_emergency_isa_pool(void)
335 {
336 	return 0;
337 }
338 static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio)
339 {
340 }
341 #endif /* CONFIG_BOUNCE */
342 
343 #ifdef CONFIG_BLK_CGROUP_IOLATENCY
344 extern int blk_iolatency_init(struct request_queue *q);
345 #else
346 static inline int blk_iolatency_init(struct request_queue *q) { return 0; }
347 #endif
348 
349 struct bio *blk_next_bio(struct bio *bio, unsigned int nr_pages, gfp_t gfp);
350 
351 #ifdef CONFIG_BLK_DEV_ZONED
352 void blk_queue_free_zone_bitmaps(struct request_queue *q);
353 #else
354 static inline void blk_queue_free_zone_bitmaps(struct request_queue *q) {}
355 #endif
356 
357 #endif /* BLK_INTERNAL_H */
358