[PATCH] dm: use revalidate_disk to update device size after set_capacity

[Mike Snitzer <snitzer@redhat.com>]

Avoid taking md->bdev->bd_inode->i_mutex to update the DM block device's
size.  Doing so eliminates the potential for deadlock if an fsync is
racing with a device resize.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
---
 drivers/md/dm.c |    5 +----
 1 files changed, 1 insertions(+), 4 deletions(-)

diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index f934e98..fd315a7 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -1995,10 +1995,7 @@ static void event_callback(void *context)
 static void __set_size(struct mapped_device *md, sector_t size)
 {
 	set_capacity(md->disk, size);
-
-	mutex_lock(&md->bdev->bd_inode->i_mutex);
-	i_size_write(md->bdev->bd_inode, (loff_t)size << SECTOR_SHIFT);
-	mutex_unlock(&md->bdev->bd_inode->i_mutex);
+	revalidate_disk(md->disk);
 }
 
 /*