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authorJens Axboe <jaxboe@fusionio.com>2011-07-01 16:17:13 +0200
committerJens Axboe <jaxboe@fusionio.com>2011-07-01 16:17:13 +0200
commit04bf7869ca0fd12009aee301cac2264a36df4d98 (patch)
tree66cb81ebf8b76560a31433c2c493dc430c914af9 /block/genhd.c
parentd2f31a5fd60d168b00fc4f7617b68a1287b21e90 (diff)
parent7b28afe01ab6ffb5f152f47831b44933facd2328 (diff)
downloadkernel-04bf7869ca0fd12009aee301cac2264a36df4d98.tar.gz
Merge branch 'for-linus' into for-3.1/core
Conflicts: block/blk-throttle.c block/cfq-iosched.c Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Diffstat (limited to 'block/genhd.c')
-rw-r--r--block/genhd.c79
1 files changed, 45 insertions, 34 deletions
diff --git a/block/genhd.c b/block/genhd.c
index ed3fe8224f9f..82d97c3594a8 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -1371,6 +1371,7 @@ struct disk_events {
struct gendisk *disk; /* the associated disk */
spinlock_t lock;
+ struct mutex block_mutex; /* protects blocking */
int block; /* event blocking depth */
unsigned int pending; /* events already sent out */
unsigned int clearing; /* events being cleared */
@@ -1414,22 +1415,44 @@ static unsigned long disk_events_poll_jiffies(struct gendisk *disk)
return msecs_to_jiffies(intv_msecs);
}
-static void __disk_block_events(struct gendisk *disk, bool sync)
+/**
+ * disk_block_events - block and flush disk event checking
+ * @disk: disk to block events for
+ *
+ * On return from this function, it is guaranteed that event checking
+ * isn't in progress and won't happen until unblocked by
+ * disk_unblock_events(). Events blocking is counted and the actual
+ * unblocking happens after the matching number of unblocks are done.
+ *
+ * Note that this intentionally does not block event checking from
+ * disk_clear_events().
+ *
+ * CONTEXT:
+ * Might sleep.
+ */
+void disk_block_events(struct gendisk *disk)
{
struct disk_events *ev = disk->ev;
unsigned long flags;
bool cancel;
+ if (!ev)
+ return;
+
+ /*
+ * Outer mutex ensures that the first blocker completes canceling
+ * the event work before further blockers are allowed to finish.
+ */
+ mutex_lock(&ev->block_mutex);
+
spin_lock_irqsave(&ev->lock, flags);
cancel = !ev->block++;
spin_unlock_irqrestore(&ev->lock, flags);
- if (cancel) {
- if (sync)
- cancel_delayed_work_sync(&disk->ev->dwork);
- else
- cancel_delayed_work(&disk->ev->dwork);
- }
+ if (cancel)
+ cancel_delayed_work_sync(&disk->ev->dwork);
+
+ mutex_unlock(&ev->block_mutex);
}
static void __disk_unblock_events(struct gendisk *disk, bool check_now)
@@ -1461,27 +1484,6 @@ out_unlock:
}
/**
- * disk_block_events - block and flush disk event checking
- * @disk: disk to block events for
- *
- * On return from this function, it is guaranteed that event checking
- * isn't in progress and won't happen until unblocked by
- * disk_unblock_events(). Events blocking is counted and the actual
- * unblocking happens after the matching number of unblocks are done.
- *
- * Note that this intentionally does not block event checking from
- * disk_clear_events().
- *
- * CONTEXT:
- * Might sleep.
- */
-void disk_block_events(struct gendisk *disk)
-{
- if (disk->ev)
- __disk_block_events(disk, true);
-}
-
-/**
* disk_unblock_events - unblock disk event checking
* @disk: disk to unblock events for
*
@@ -1508,10 +1510,18 @@ void disk_unblock_events(struct gendisk *disk)
*/
void disk_check_events(struct gendisk *disk)
{
- if (disk->ev) {
- __disk_block_events(disk, false);
- __disk_unblock_events(disk, true);
+ struct disk_events *ev = disk->ev;
+ unsigned long flags;
+
+ if (!ev)
+ return;
+
+ spin_lock_irqsave(&ev->lock, flags);
+ if (!ev->block) {
+ cancel_delayed_work(&ev->dwork);
+ queue_delayed_work(system_nrt_wq, &ev->dwork, 0);
}
+ spin_unlock_irqrestore(&ev->lock, flags);
}
EXPORT_SYMBOL_GPL(disk_check_events);
@@ -1546,7 +1556,7 @@ unsigned int disk_clear_events(struct gendisk *disk, unsigned int mask)
spin_unlock_irq(&ev->lock);
/* uncondtionally schedule event check and wait for it to finish */
- __disk_block_events(disk, true);
+ disk_block_events(disk);
queue_delayed_work(system_nrt_wq, &ev->dwork, 0);
flush_delayed_work(&ev->dwork);
__disk_unblock_events(disk, false);
@@ -1664,7 +1674,7 @@ static ssize_t disk_events_poll_msecs_store(struct device *dev,
if (intv < 0 && intv != -1)
return -EINVAL;
- __disk_block_events(disk, true);
+ disk_block_events(disk);
disk->ev->poll_msecs = intv;
__disk_unblock_events(disk, true);
@@ -1750,6 +1760,7 @@ static void disk_add_events(struct gendisk *disk)
INIT_LIST_HEAD(&ev->node);
ev->disk = disk;
spin_lock_init(&ev->lock);
+ mutex_init(&ev->block_mutex);
ev->block = 1;
ev->poll_msecs = -1;
INIT_DELAYED_WORK(&ev->dwork, disk_events_workfn);
@@ -1770,7 +1781,7 @@ static void disk_del_events(struct gendisk *disk)
if (!disk->ev)
return;
- __disk_block_events(disk, true);
+ disk_block_events(disk);
mutex_lock(&disk_events_mutex);
list_del_init(&disk->ev->node);