~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/block/blk.h

Version: ~ [ linux-5.10-rc5 ] ~ [ linux-5.9.10 ] ~ [ linux-5.8.18 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.79 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.159 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.208 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.245 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.245 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.85 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  1 #ifndef BLK_INTERNAL_H
  2 #define BLK_INTERNAL_H
  3 
  4 #include <linux/idr.h>
  5 #include <linux/blk-mq.h>
  6 #include "blk-mq.h"
  7 
  8 /* Amount of time in which a process may batch requests */
  9 #define BLK_BATCH_TIME  (HZ/50UL)
 10 
 11 /* Number of requests a "batching" process may submit */
 12 #define BLK_BATCH_REQ   32
 13 
 14 /* Max future timer expiry for timeouts */
 15 #define BLK_MAX_TIMEOUT         (5 * HZ)
 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         spinlock_t              mq_flush_lock;
 26 };
 27 
 28 extern struct kmem_cache *blk_requestq_cachep;
 29 extern struct kmem_cache *request_cachep;
 30 extern struct kobj_type blk_queue_ktype;
 31 extern struct ida blk_queue_ida;
 32 
 33 static inline struct blk_flush_queue *blk_get_flush_queue(
 34                 struct request_queue *q, struct blk_mq_ctx *ctx)
 35 {
 36         struct blk_mq_hw_ctx *hctx;
 37 
 38         if (!q->mq_ops)
 39                 return q->fq;
 40 
 41         hctx = q->mq_ops->map_queue(q, ctx->cpu);
 42 
 43         return hctx->fq;
 44 }
 45 
 46 static inline void __blk_get_queue(struct request_queue *q)
 47 {
 48         kobject_get(&q->kobj);
 49 }
 50 
 51 struct blk_flush_queue *blk_alloc_flush_queue(struct request_queue *q,
 52                 int node, int cmd_size);
 53 void blk_free_flush_queue(struct blk_flush_queue *q);
 54 
 55 int blk_init_rl(struct request_list *rl, struct request_queue *q,
 56                 gfp_t gfp_mask);
 57 void blk_exit_rl(struct request_list *rl);
 58 void init_request_from_bio(struct request *req, struct bio *bio);
 59 void blk_rq_bio_prep(struct request_queue *q, struct request *rq,
 60                         struct bio *bio);
 61 int blk_rq_append_bio(struct request_queue *q, struct request *rq,
 62                       struct bio *bio);
 63 void blk_queue_bypass_start(struct request_queue *q);
 64 void blk_queue_bypass_end(struct request_queue *q);
 65 void blk_dequeue_request(struct request *rq);
 66 void __blk_queue_free_tags(struct request_queue *q);
 67 bool __blk_end_bidi_request(struct request *rq, int error,
 68                             unsigned int nr_bytes, unsigned int bidi_bytes);
 69 
 70 void blk_rq_timed_out_timer(unsigned long data);
 71 unsigned long blk_rq_timeout(unsigned long timeout);
 72 void blk_add_timer(struct request *req);
 73 void blk_delete_timer(struct request *);
 74 
 75 
 76 bool bio_attempt_front_merge(struct request_queue *q, struct request *req,
 77                              struct bio *bio);
 78 bool bio_attempt_back_merge(struct request_queue *q, struct request *req,
 79                             struct bio *bio);
 80 bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio,
 81                             unsigned int *request_count);
 82 
 83 void blk_account_io_start(struct request *req, bool new_io);
 84 void blk_account_io_completion(struct request *req, unsigned int bytes);
 85 void blk_account_io_done(struct request *req);
 86 
 87 /*
 88  * Internal atomic flags for request handling
 89  */
 90 enum rq_atomic_flags {
 91         REQ_ATOM_COMPLETE = 0,
 92         REQ_ATOM_STARTED,
 93 };
 94 
 95 /*
 96  * EH timer and IO completion will both attempt to 'grab' the request, make
 97  * sure that only one of them succeeds
 98  */
 99 static inline int blk_mark_rq_complete(struct request *rq)
100 {
101         return test_and_set_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags);
102 }
103 
104 static inline void blk_clear_rq_complete(struct request *rq)
105 {
106         clear_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags);
107 }
108 
109 /*
110  * Internal elevator interface
111  */
112 #define ELV_ON_HASH(rq) ((rq)->cmd_flags & REQ_HASHED)
113 
114 void blk_insert_flush(struct request *rq);
115 
116 static inline struct request *__elv_next_request(struct request_queue *q)
117 {
118         struct request *rq;
119         struct blk_flush_queue *fq = blk_get_flush_queue(q, NULL);
120 
121         while (1) {
122                 if (!list_empty(&q->queue_head)) {
123                         rq = list_entry_rq(q->queue_head.next);
124                         return rq;
125                 }
126 
127                 /*
128                  * Flush request is running and flush request isn't queueable
129                  * in the drive, we can hold the queue till flush request is
130                  * finished. Even we don't do this, driver can't dispatch next
131                  * requests and will requeue them. And this can improve
132                  * throughput too. For example, we have request flush1, write1,
133                  * flush 2. flush1 is dispatched, then queue is hold, write1
134                  * isn't inserted to queue. After flush1 is finished, flush2
135                  * will be dispatched. Since disk cache is already clean,
136                  * flush2 will be finished very soon, so looks like flush2 is
137                  * folded to flush1.
138                  * Since the queue is hold, a flag is set to indicate the queue
139                  * should be restarted later. Please see flush_end_io() for
140                  * details.
141                  */
142                 if (fq->flush_pending_idx != fq->flush_running_idx &&
143                                 !queue_flush_queueable(q)) {
144                         fq->flush_queue_delayed = 1;
145                         return NULL;
146                 }
147                 if (unlikely(blk_queue_bypass(q)) ||
148                     !q->elevator->type->ops.elevator_dispatch_fn(q, 0))
149                         return NULL;
150         }
151 }
152 
153 static inline void elv_activate_rq(struct request_queue *q, struct request *rq)
154 {
155         struct elevator_queue *e = q->elevator;
156 
157         if (e->type->ops.elevator_activate_req_fn)
158                 e->type->ops.elevator_activate_req_fn(q, rq);
159 }
160 
161 static inline void elv_deactivate_rq(struct request_queue *q, struct request *rq)
162 {
163         struct elevator_queue *e = q->elevator;
164 
165         if (e->type->ops.elevator_deactivate_req_fn)
166                 e->type->ops.elevator_deactivate_req_fn(q, rq);
167 }
168 
169 #ifdef CONFIG_FAIL_IO_TIMEOUT
170 int blk_should_fake_timeout(struct request_queue *);
171 ssize_t part_timeout_show(struct device *, struct device_attribute *, char *);
172 ssize_t part_timeout_store(struct device *, struct device_attribute *,
173                                 const char *, size_t);
174 #else
175 static inline int blk_should_fake_timeout(struct request_queue *q)
176 {
177         return 0;
178 }
179 #endif
180 
181 int ll_back_merge_fn(struct request_queue *q, struct request *req,
182                      struct bio *bio);
183 int ll_front_merge_fn(struct request_queue *q, struct request *req, 
184                       struct bio *bio);
185 int attempt_back_merge(struct request_queue *q, struct request *rq);
186 int attempt_front_merge(struct request_queue *q, struct request *rq);
187 int blk_attempt_req_merge(struct request_queue *q, struct request *rq,
188                                 struct request *next);
189 void blk_recalc_rq_segments(struct request *rq);
190 void blk_rq_set_mixed_merge(struct request *rq);
191 bool blk_rq_merge_ok(struct request *rq, struct bio *bio);
192 int blk_try_merge(struct request *rq, struct bio *bio);
193 
194 void blk_queue_congestion_threshold(struct request_queue *q);
195 
196 void __blk_run_queue_uncond(struct request_queue *q);
197 
198 int blk_dev_init(void);
199 
200 
201 /*
202  * Return the threshold (number of used requests) at which the queue is
203  * considered to be congested.  It include a little hysteresis to keep the
204  * context switch rate down.
205  */
206 static inline int queue_congestion_on_threshold(struct request_queue *q)
207 {
208         return q->nr_congestion_on;
209 }
210 
211 /*
212  * The threshold at which a queue is considered to be uncongested
213  */
214 static inline int queue_congestion_off_threshold(struct request_queue *q)
215 {
216         return q->nr_congestion_off;
217 }
218 
219 extern int blk_update_nr_requests(struct request_queue *, unsigned int);
220 
221 /*
222  * Contribute to IO statistics IFF:
223  *
224  *      a) it's attached to a gendisk, and
225  *      b) the queue had IO stats enabled when this request was started, and
226  *      c) it's a file system request
227  */
228 static inline int blk_do_io_stat(struct request *rq)
229 {
230         return rq->rq_disk &&
231                (rq->cmd_flags & REQ_IO_STAT) &&
232                 (rq->cmd_type == REQ_TYPE_FS);
233 }
234 
235 /*
236  * Internal io_context interface
237  */
238 void get_io_context(struct io_context *ioc);
239 struct io_cq *ioc_lookup_icq(struct io_context *ioc, struct request_queue *q);
240 struct io_cq *ioc_create_icq(struct io_context *ioc, struct request_queue *q,
241                              gfp_t gfp_mask);
242 void ioc_clear_queue(struct request_queue *q);
243 
244 int create_task_io_context(struct task_struct *task, gfp_t gfp_mask, int node);
245 
246 /**
247  * create_io_context - try to create task->io_context
248  * @gfp_mask: allocation mask
249  * @node: allocation node
250  *
251  * If %current->io_context is %NULL, allocate a new io_context and install
252  * it.  Returns the current %current->io_context which may be %NULL if
253  * allocation failed.
254  *
255  * Note that this function can't be called with IRQ disabled because
256  * task_lock which protects %current->io_context is IRQ-unsafe.
257  */
258 static inline struct io_context *create_io_context(gfp_t gfp_mask, int node)
259 {
260         WARN_ON_ONCE(irqs_disabled());
261         if (unlikely(!current->io_context))
262                 create_task_io_context(current, gfp_mask, node);
263         return current->io_context;
264 }
265 
266 /*
267  * Internal throttling interface
268  */
269 #ifdef CONFIG_BLK_DEV_THROTTLING
270 extern bool blk_throtl_bio(struct request_queue *q, struct bio *bio);
271 extern void blk_throtl_drain(struct request_queue *q);
272 extern int blk_throtl_init(struct request_queue *q);
273 extern void blk_throtl_exit(struct request_queue *q);
274 #else /* CONFIG_BLK_DEV_THROTTLING */
275 static inline bool blk_throtl_bio(struct request_queue *q, struct bio *bio)
276 {
277         return false;
278 }
279 static inline void blk_throtl_drain(struct request_queue *q) { }
280 static inline int blk_throtl_init(struct request_queue *q) { return 0; }
281 static inline void blk_throtl_exit(struct request_queue *q) { }
282 #endif /* CONFIG_BLK_DEV_THROTTLING */
283 
284 #endif /* BLK_INTERNAL_H */
285 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp