vfs: Add BUG_ON for delayed and unwritten flags in submit_bh()
The BH_Delay and BH_Unwritten flags should never leak out to
submit_bh(). So add some BUG_ON() checks to submit_bh so we can get a
stack trace and determine how and why this might have happened.
(Note that only XFS and ext4 use these buffer head flags, and XFS does
not use submit_bh(). So this patch should only modify behavior for
ext4.)
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: linux-fsdevel@vger.kernel.org
diff --git a/fs/buffer.c b/fs/buffer.c
index aed2977..ad01129 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -2933,6 +2933,8 @@
BUG_ON(!buffer_locked(bh));
BUG_ON(!buffer_mapped(bh));
BUG_ON(!bh->b_end_io);
+ BUG_ON(buffer_delay(bh));
+ BUG_ON(buffer_unwritten(bh));
/*
* Mask in barrier bit for a write (could be either a WRITE or a