locks: Handle negative values for flock->l_len

As per 'man 3 fcntl',
"If l_len is positive, the area affected shall start at
l_start and end at l_start+l_len−1. If l_len is negative,
the area affected shall start at l_start+l_len and end at
l_start−1. Locks may start and extend beyond the current
end of a file, but shall not extend before the beginning
of the file."

Currently we return EINVAL if l_len is found to be negative.
Fixed the same as mentioned in the man page.

This is backport of the below patch
    - http://review.gluster.org/11613

Change-Id: I493ce202c543185fc4ae7266d1aaf9d7e2a66991
BUG: 1312200
Signed-off-by: Soumya Koduri <skoduri@redhat.com>
Reviewed-on: http://review.gluster.org/11613
Reviewed-by: Kaleb KEITHLEY <kkeithle@redhat.com>
Reviewed-by: Niels de Vos <ndevos@redhat.com>
Reviewed-by: Raghavendra G <rgowdapp@redhat.com>
Reviewed-on: http://review.gluster.org/13526
Smoke: Gluster Build System <jenkins@build.gluster.com>
NetBSD-regression: NetBSD Build System <jenkins@build.gluster.org>
CentOS-regression: Gluster Build System <jenkins@build.gluster.com>

1 files changed, 30 insertions, 0 deletions

diff --git a/tests/basic/gfapi/bug-1241104.sh b/tests/basic/gfapi/bug-1241104.sh
new file mode 100755
index 00000000000..e071835758d
--- /dev/null
+++ b/tests/basic/gfapi/bug-1241104.sh
@@ -0,0 +1,30 @@
+#!/bin/bash
+
+. $(dirname $0)/../../include.rc
+. $(dirname $0)/../../volume.rc
+
+cleanup;
+
+TEST glusterd
+
+TEST $CLI volume create $V0 localhost:$B0/brick1;
+EXPECT 'Created' volinfo_field $V0 'Status';
+
+TEST $CLI volume start $V0;
+EXPECT 'Started' volinfo_field $V0 'Status';
+
+logdir=`gluster --print-logdir`
+
+## Enable Upcall cache-invalidation feature
+TEST $CLI volume set $V0 features.cache-invalidation on;
+
+build_tester $(dirname $0)/bug-1241104.c -lgfapi -o $(dirname $0)/bug-1241104
+
+TEST ./$(dirname $0)/bug-1241104 $V0  $logdir/bug-1241104.log
+
+cleanup_tester $(dirname $0)/bug1241104
+
+TEST $CLI volume stop $V0
+TEST $CLI volume delete $V0
+
+cleanup;