From afa0aecaed5eff810cfd05dce22a6965f223c78b Mon Sep 17 00:00:00 2001
From: Antonio Huete Jimenez <tuxillo@quantumachine.net>
Date: Tue, 22 Jan 2013 23:25:54 +0100
Subject: [PATCH] msdosfs - Handle a 0-length buffer case.

If bread() returns a zero-length buffer, as can happen after a
failed write, return an error instead of looping forever.

Obtained-from: FreeBSD (r117200)
---
 sys/vfs/msdosfs/msdosfs_vnops.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/sys/vfs/msdosfs/msdosfs_vnops.c b/sys/vfs/msdosfs/msdosfs_vnops.c
index 222a29e..9785b9f 100644
--- a/sys/vfs/msdosfs/msdosfs_vnops.c
+++ b/sys/vfs/msdosfs/msdosfs_vnops.c
@@ -1629,6 +1629,10 @@ msdosfs_readdir(struct vop_readdir_args *ap)
 			goto done;
 		}
 		n = min(n, blsize - bp->b_resid);
+		if (n == 0) {
+			brelse(bp);
+			return (EIO);
+		}
 
 		/*
 		 * Convert from dos directory entries to fs-independent
-- 
1.7.12