summaryrefslogtreecommitdiff
path: root/block/blk-core.c
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2008-10-17 09:29:55 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2008-10-17 09:29:55 -0700
commitc53dbf54863e7f3b0b8810dda2bdd0290006bdac (patch)
treef783074f1bec1112bf1148a077e0114a38403ad4 /block/blk-core.c
parentb73b636e8987f8728c6c700377615757691b9a55 (diff)
parentf73e2d13a16cc88c4faa4729967f92bfeec8a142 (diff)
Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-block
* 'for-linus' of git://git.kernel.dk/linux-2.6-block: block: remove __generic_unplug_device() from exports block: move q->unplug_work initialization blktrace: pass zfcp driver data blktrace: add support for driver data block: fix current kernel-doc warnings block: only call ->request_fn when the queue is not stopped block: simplify string handling in elv_iosched_store() block: fix kernel-doc for blk_alloc_devt() block: fix nr_phys_segments miscalculation bug block: add partition attribute for partition number block: add BIG FAT WARNING to CONFIG_DEBUG_BLOCK_EXT_DEVT softirq: Add support for triggering softirq work on softirqs.
Diffstat (limited to 'block/blk-core.c')
-rw-r--r--block/blk-core.c26
1 files changed, 21 insertions, 5 deletions
diff --git a/block/blk-core.c b/block/blk-core.c
index 9e79a485e4f3..c3df30cfb3fc 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -257,7 +257,6 @@ void __generic_unplug_device(struct request_queue *q)
q->request_fn(q);
}
-EXPORT_SYMBOL(__generic_unplug_device);
/**
* generic_unplug_device - fire a request queue
@@ -325,6 +324,9 @@ EXPORT_SYMBOL(blk_unplug);
static void blk_invoke_request_fn(struct request_queue *q)
{
+ if (unlikely(blk_queue_stopped(q)))
+ return;
+
/*
* one level of recursion is ok and is much faster than kicking
* the unplug handling
@@ -399,8 +401,13 @@ void blk_sync_queue(struct request_queue *q)
EXPORT_SYMBOL(blk_sync_queue);
/**
- * blk_run_queue - run a single device queue
+ * __blk_run_queue - run a single device queue
* @q: The queue to run
+ *
+ * Description:
+ * See @blk_run_queue. This variant must be called with the queue lock
+ * held and interrupts disabled.
+ *
*/
void __blk_run_queue(struct request_queue *q)
{
@@ -418,6 +425,12 @@ EXPORT_SYMBOL(__blk_run_queue);
/**
* blk_run_queue - run a single device queue
* @q: The queue to run
+ *
+ * Description:
+ * Invoke request handling on this queue, if it has pending work to do.
+ * May be used to restart queueing when a request has completed. Also
+ * See @blk_start_queueing.
+ *
*/
void blk_run_queue(struct request_queue *q)
{
@@ -501,6 +514,7 @@ struct request_queue *blk_alloc_queue_node(gfp_t gfp_mask, int node_id)
init_timer(&q->unplug_timer);
setup_timer(&q->timeout, blk_rq_timed_out_timer, (unsigned long) q);
INIT_LIST_HEAD(&q->timeout_list);
+ INIT_WORK(&q->unplug_work, blk_unplug_work);
kobject_init(&q->kobj, &blk_queue_ktype);
@@ -884,7 +898,8 @@ EXPORT_SYMBOL(blk_get_request);
*
* This is basically a helper to remove the need to know whether a queue
* is plugged or not if someone just wants to initiate dispatch of requests
- * for this queue.
+ * for this queue. Should be used to start queueing on a device outside
+ * of ->request_fn() context. Also see @blk_run_queue.
*
* The queue lock must be held with interrupts disabled.
*/
@@ -1003,8 +1018,9 @@ static void part_round_stats_single(int cpu, struct hd_struct *part,
}
/**
- * part_round_stats() - Round off the performance stats on a struct
- * disk_stats.
+ * part_round_stats() - Round off the performance stats on a struct disk_stats.
+ * @cpu: cpu number for stats access
+ * @part: target partition
*
* The average IO queue length and utilisation statistics are maintained
* by observing the current state of the queue length and the amount of