[PATCH] Revert bd_mount_mutex back to a semaphore
Revert bd_mount_mutex back to a semaphore so that xfs_freeze -f /mnt/newtest;
xfs_freeze -u /mnt/newtest works safely and doesn't produce lockdep warnings.
(XFS unlocks the semaphore from a different task, by design. The mutex
code warns about this)
Signed-off-by: Dave Chinner <dgc@sgi.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/fs/buffer.c b/fs/buffer.c
index 263f88e..3b11607 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -180,7 +180,7 @@
* freeze_bdev -- lock a filesystem and force it into a consistent state
* @bdev: blockdevice to lock
*
- * This takes the block device bd_mount_mutex to make sure no new mounts
+ * This takes the block device bd_mount_sem to make sure no new mounts
* happen on bdev until thaw_bdev() is called.
* If a superblock is found on this device, we take the s_umount semaphore
* on it to make sure nobody unmounts until the snapshot creation is done.
@@ -189,7 +189,7 @@
{
struct super_block *sb;
- mutex_lock(&bdev->bd_mount_mutex);
+ down(&bdev->bd_mount_sem);
sb = get_super(bdev);
if (sb && !(sb->s_flags & MS_RDONLY)) {
sb->s_frozen = SB_FREEZE_WRITE;
@@ -231,7 +231,7 @@
drop_super(sb);
}
- mutex_unlock(&bdev->bd_mount_mutex);
+ up(&bdev->bd_mount_sem);
}
EXPORT_SYMBOL(thaw_bdev);