commit 64c363146fe8b4b26285d36fad0fc01b9c8c1285
author José Adolfo Galdámez <josegalre@pac-rom.com> Mon Sep 21 22:00:27 2015 -0600
committer William Bellavance <flintman@flintmancomputers.com> Wed Feb 10 20:03:50 2016 -0500
tree f4597aeccc6d37aadbf3a719dfefc62632e4ee10
parent 900469d0b0c337db19908f77d172f4b17f4573ba

Merge tag 'v3.4.109' into mm-6.0

Change-Id: I93b29443377e338fc5d3b031b130da720f788879
Signed-off-by: José Adolfo Galdámez <josegalre@pac-rom.com>

fs/btrfs/ioctl.c

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 3a65f43..d46c481 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -2374,6 +2374,11 @@
 	if (off + len == src->i_size)
 		len = ALIGN(src->i_size, bs) - off;
 
+	if (len == 0) {
+		ret = 0;
+		goto out_unlock;
+	}
+
 	/* verify the end result is block aligned */
 	if (!IS_ALIGNED(off, bs) || !IS_ALIGNED(off + len, bs) ||
 	    !IS_ALIGNED(destoff, bs))