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authorKim Kibum <kb0929.kim@samsung.com>2012-04-29 16:59:19 +0900
committerKim Kibum <kb0929.kim@samsung.com>2012-04-29 16:59:19 +0900
commitc1775d1a93a77a57380a4ce87ac3a8f807c944b2 (patch)
treee1f233f2af38ee247a677082198dd3a69a12a5a1 /block/blk.h
parent2c2dcd5ffef2e97176e6a55e45512177e55e6fb9 (diff)
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Diffstat (limited to 'block/blk.h')
-rw-r--r--block/blk.h174
1 files changed, 174 insertions, 0 deletions
diff --git a/block/blk.h b/block/blk.h
new file mode 100644
index 00000000..d6b911ac
--- /dev/null
+++ b/block/blk.h
@@ -0,0 +1,174 @@
+#ifndef BLK_INTERNAL_H
+#define BLK_INTERNAL_H
+
+/* Amount of time in which a process may batch requests */
+#define BLK_BATCH_TIME (HZ/50UL)
+
+/* Number of requests a "batching" process may submit */
+#define BLK_BATCH_REQ 32
+
+extern struct kmem_cache *blk_requestq_cachep;
+extern struct kobj_type blk_queue_ktype;
+
+void init_request_from_bio(struct request *req, struct bio *bio);
+void blk_rq_bio_prep(struct request_queue *q, struct request *rq,
+ struct bio *bio);
+int blk_rq_append_bio(struct request_queue *q, struct request *rq,
+ struct bio *bio);
+void blk_dequeue_request(struct request *rq);
+void __blk_queue_free_tags(struct request_queue *q);
+
+void blk_unplug_work(struct work_struct *work);
+void blk_unplug_timeout(unsigned long data);
+void blk_rq_timed_out_timer(unsigned long data);
+void blk_delete_timer(struct request *);
+void blk_add_timer(struct request *);
+void __generic_unplug_device(struct request_queue *);
+
+/*
+ * Internal atomic flags for request handling
+ */
+enum rq_atomic_flags {
+ REQ_ATOM_COMPLETE = 0,
+};
+
+/*
+ * EH timer and IO completion will both attempt to 'grab' the request, make
+ * sure that only one of them suceeds
+ */
+static inline int blk_mark_rq_complete(struct request *rq)
+{
+ return test_and_set_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags);
+}
+
+static inline void blk_clear_rq_complete(struct request *rq)
+{
+ clear_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags);
+}
+
+/*
+ * Internal elevator interface
+ */
+#define ELV_ON_HASH(rq) (!hlist_unhashed(&(rq)->hash))
+
+static inline struct request *__elv_next_request(struct request_queue *q)
+{
+ struct request *rq;
+
+ while (1) {
+ while (!list_empty(&q->queue_head)) {
+ rq = list_entry_rq(q->queue_head.next);
+ if (blk_do_ordered(q, &rq))
+ return rq;
+ }
+
+ if (!q->elevator->ops->elevator_dispatch_fn(q, 0))
+ return NULL;
+ }
+}
+
+static inline void elv_activate_rq(struct request_queue *q, struct request *rq)
+{
+ struct elevator_queue *e = q->elevator;
+
+ if (e->ops->elevator_activate_req_fn)
+ e->ops->elevator_activate_req_fn(q, rq);
+}
+
+static inline void elv_deactivate_rq(struct request_queue *q, struct request *rq)
+{
+ struct elevator_queue *e = q->elevator;
+
+ if (e->ops->elevator_deactivate_req_fn)
+ e->ops->elevator_deactivate_req_fn(q, rq);
+}
+
+#ifdef CONFIG_FAIL_IO_TIMEOUT
+int blk_should_fake_timeout(struct request_queue *);
+ssize_t part_timeout_show(struct device *, struct device_attribute *, char *);
+ssize_t part_timeout_store(struct device *, struct device_attribute *,
+ const char *, size_t);
+#else
+static inline int blk_should_fake_timeout(struct request_queue *q)
+{
+ return 0;
+}
+#endif
+
+struct io_context *current_io_context(gfp_t gfp_flags, int node);
+
+int ll_back_merge_fn(struct request_queue *q, struct request *req,
+ struct bio *bio);
+int ll_front_merge_fn(struct request_queue *q, struct request *req,
+ struct bio *bio);
+int attempt_back_merge(struct request_queue *q, struct request *rq);
+int attempt_front_merge(struct request_queue *q, struct request *rq);
+void blk_recalc_rq_segments(struct request *rq);
+void blk_rq_set_mixed_merge(struct request *rq);
+
+void blk_queue_congestion_threshold(struct request_queue *q);
+
+int blk_dev_init(void);
+
+void elv_quiesce_start(struct request_queue *q);
+void elv_quiesce_end(struct request_queue *q);
+
+
+/*
+ * Return the threshold (number of used requests) at which the queue is
+ * considered to be congested. It include a little hysteresis to keep the
+ * context switch rate down.
+ */
+static inline int queue_congestion_on_threshold(struct request_queue *q)
+{
+ return q->nr_congestion_on;
+}
+
+/*
+ * The threshold at which a queue is considered to be uncongested
+ */
+static inline int queue_congestion_off_threshold(struct request_queue *q)
+{
+ return q->nr_congestion_off;
+}
+
+#if defined(CONFIG_BLK_DEV_INTEGRITY)
+
+#define rq_for_each_integrity_segment(bvl, _rq, _iter) \
+ __rq_for_each_bio(_iter.bio, _rq) \
+ bip_for_each_vec(bvl, _iter.bio->bi_integrity, _iter.i)
+
+#endif /* BLK_DEV_INTEGRITY */
+
+static inline int blk_cpu_to_group(int cpu)
+{
+ int group = NR_CPUS;
+#ifdef CONFIG_SCHED_MC
+ const struct cpumask *mask = cpu_coregroup_mask(cpu);
+ group = cpumask_first(mask);
+#elif defined(CONFIG_SCHED_SMT)
+ group = cpumask_first(topology_thread_cpumask(cpu));
+#else
+ return cpu;
+#endif
+ if (likely(group < NR_CPUS))
+ return group;
+ return cpu;
+}
+
+/*
+ * Contribute to IO statistics IFF:
+ *
+ * a) it's attached to a gendisk, and
+ * b) the queue had IO stats enabled when this request was started, and
+ * c) it's a file system request or a discard request
+ */
+static inline int blk_do_io_stat(struct request *rq)
+{
+ return rq->rq_disk &&
+ (rq->cmd_flags & REQ_IO_STAT) &&
+ (rq->cmd_type == REQ_TYPE_FS ||
+ (rq->cmd_flags & REQ_DISCARD));
+}
+
+#endif