#ifndef BLK_INTERNAL_H
#define BLK_INTERNAL_H
+#include <linux/idr.h>
+
/* Amount of time in which a process may batch requests */
#define BLK_BATCH_TIME (HZ/50UL)
extern struct kmem_cache *blk_requestq_cachep;
extern struct kobj_type blk_queue_ktype;
+extern struct ida blk_queue_ida;
+
+static inline void __blk_get_queue(struct request_queue *q)
+{
+ kobject_get(&q->kobj);
+}
-void rq_init(struct request_queue *q, struct request *rq);
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_drain_queue(struct request_queue *q, bool drain_all);
+void blk_dequeue_request(struct request *rq);
void __blk_queue_free_tags(struct request_queue *q);
+bool __blk_end_bidi_request(struct request *rq, int error,
+ unsigned int nr_bytes, unsigned int bidi_bytes);
+
+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 succeeds
+ */
+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))
+
+void blk_insert_flush(struct request *rq);
+void blk_abort_flushes(struct request_queue *q);
+
+static inline struct request *__elv_next_request(struct request_queue *q)
+{
+ struct request *rq;
+
+ while (1) {
+ if (!list_empty(&q->queue_head)) {
+ rq = list_entry_rq(q->queue_head.next);
+ return rq;
+ }
+
+ /*
+ * Flush request is running and flush request isn't queueable
+ * in the drive, we can hold the queue till flush request is
+ * finished. Even we don't do this, driver can't dispatch next
+ * requests and will requeue them. And this can improve
+ * throughput too. For example, we have request flush1, write1,
+ * flush 2. flush1 is dispatched, then queue is hold, write1
+ * isn't inserted to queue. After flush1 is finished, flush2
+ * will be dispatched. Since disk cache is already clean,
+ * flush2 will be finished very soon, so looks like flush2 is
+ * folded to flush1.
+ * Since the queue is hold, a flag is set to indicate the queue
+ * should be restarted later. Please see flush_end_io() for
+ * details.
+ */
+ if (q->flush_pending_idx != q->flush_running_idx &&
+ !queue_flush_queueable(q)) {
+ q->flush_queue_delayed = 1;
+ return NULL;
+ }
+ if (unlikely(blk_queue_dead(q)) ||
+ !q->elevator->type->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->type->ops.elevator_activate_req_fn)
+ e->type->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;
-void blk_unplug_work(struct work_struct *work);
-void blk_unplug_timeout(unsigned long data);
+ if (e->type->ops.elevator_deactivate_req_fn)
+ e->type->ops.elevator_deactivate_req_fn(q, rq);
+}
-struct io_context *current_io_context(gfp_t gfp_flags, int node);
+#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
int ll_back_merge_fn(struct request_queue *q, struct request *req,
struct bio *bio);
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);
+int blk_attempt_req_merge(struct request_queue *q, struct request *rq,
+ struct request *next);
void blk_recalc_rq_segments(struct request *rq);
-void blk_recalc_rq_sectors(struct request *rq, int nsect);
+void blk_rq_set_mixed_merge(struct request *rq);
+bool blk_rq_merge_ok(struct request *rq, struct bio *bio);
+int blk_try_merge(struct request *rq, struct bio *bio);
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
return q->nr_congestion_off;
}
-#endif
+/*
+ * 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));
+}
+
+/*
+ * Internal io_context interface
+ */
+void get_io_context(struct io_context *ioc);
+struct io_cq *ioc_lookup_icq(struct io_context *ioc, struct request_queue *q);
+struct io_cq *ioc_create_icq(struct request_queue *q, gfp_t gfp_mask);
+void ioc_clear_queue(struct request_queue *q);
+
+void create_io_context_slowpath(struct task_struct *task, gfp_t gfp_mask,
+ int node);
+
+/**
+ * create_io_context - try to create task->io_context
+ * @task: target task
+ * @gfp_mask: allocation mask
+ * @node: allocation node
+ *
+ * If @task->io_context is %NULL, allocate a new io_context and install it.
+ * Returns the current @task->io_context which may be %NULL if allocation
+ * failed.
+ *
+ * Note that this function can't be called with IRQ disabled because
+ * task_lock which protects @task->io_context is IRQ-unsafe.
+ */
+static inline struct io_context *create_io_context(struct task_struct *task,
+ gfp_t gfp_mask, int node)
+{
+ WARN_ON_ONCE(irqs_disabled());
+ if (unlikely(!task->io_context))
+ create_io_context_slowpath(task, gfp_mask, node);
+ return task->io_context;
+}
+
+/*
+ * Internal throttling interface
+ */
+#ifdef CONFIG_BLK_DEV_THROTTLING
+extern bool blk_throtl_bio(struct request_queue *q, struct bio *bio);
+extern void blk_throtl_drain(struct request_queue *q);
+extern int blk_throtl_init(struct request_queue *q);
+extern void blk_throtl_exit(struct request_queue *q);
+extern void blk_throtl_release(struct request_queue *q);
+#else /* CONFIG_BLK_DEV_THROTTLING */
+static inline bool blk_throtl_bio(struct request_queue *q, struct bio *bio)
+{
+ return false;
+}
+static inline void blk_throtl_drain(struct request_queue *q) { }
+static inline int blk_throtl_init(struct request_queue *q) { return 0; }
+static inline void blk_throtl_exit(struct request_queue *q) { }
+static inline void blk_throtl_release(struct request_queue *q) { }
+#endif /* CONFIG_BLK_DEV_THROTTLING */
+
+#endif /* BLK_INTERNAL_H */
projects / linux-flexiantxendom0-3.2.10.git / blobdiff