From: Christoph Hellwig <hch@infradead.org>
Date: Mon, 2 Jul 2012 10:00:04 +0000 (-0400)
Subject: xfs: prevent recursion in xfs_buf_iorequest
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=08023d6dbe840dc4271805a9ea376fcbdee9f744;p=linux-beck.git

xfs: prevent recursion in xfs_buf_iorequest

If the b_iodone handler is run in calling context in xfs_buf_iorequest we
can run into a recursion where xfs_buf_iodone_callbacks keeps calling back
into xfs_buf_iorequest because an I/O error happened, which keeps calling
back into xfs_buf_iorequest.  This chain will usually not take long
because the filesystem gets shut down because of log I/O errors, but even
over a short time it can cause stack overflows if run on the same context.

As a short term workaround make sure we always call the iodone handler in
workqueue context.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
---

diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c
index 39c5d7622dec..d1edfa1a8112 100644
--- a/fs/xfs/xfs_buf.c
+++ b/fs/xfs/xfs_buf.c
@@ -1355,7 +1355,7 @@ xfs_buf_iorequest(
 	 */
 	atomic_set(&bp->b_io_remaining, 1);
 	_xfs_buf_ioapply(bp);
-	_xfs_buf_ioend(bp, 0);
+	_xfs_buf_ioend(bp, 1);
 
 	xfs_buf_rele(bp);
 }