cluster/dht: Fix coverity bug in tiering code

The bug was:

*** CID 1291734:  Error handling issues  (CHECKED_RETURN)
/xlators/cluster/dht/src/tier.c: 451 in tier_build_migration_qfile()

The fix is to check the return code to the remove library call.
It is legal to fail, we just log an INFO level message.

Change-Id: I026eb49276b394efa3b8092ee2cc209c470aacb2
BUG: 1194753
Signed-off-by: Dan Lambright <dlambrig@redhat.com>
Reviewed-on: http://review.gluster.org/10000
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Niels de Vos <ndevos@redhat.com>

1 files changed, 17 insertions, 2 deletions

diff --git a/xlators/cluster/dht/src/tier.c b/xlators/cluster/dht/src/tier.c
index 028a42f7a1a..7e3eaa02c02 100644
--- a/xlators/cluster/dht/src/tier.c
+++ b/xlators/cluster/dht/src/tier.c
@@ -448,10 +448,25 @@ tier_build_migration_qfile (demotion_args_t *args,
         gfdb_time_t                     time_in_past;
         int                             ret = -1;
 
-        remove (GET_QFILE_PATH (is_promotion));
+        /*
+         *  The first time this function is called, query file will
+         *  not exist on a given instance of running the migration daemon.
+         * The remove call is optimistic and it is legal if it fails.
+         */
+
+        ret = remove (GET_QFILE_PATH (is_promotion));
+        if (ret == -1) {
+                gf_msg (args->this->name, GF_LOG_INFO, 0,
+                        DHT_MSG_LOG_TIER_STATUS,
+                        "Failed to remove %s",
+                        GET_QFILE_PATH (is_promotion));
+        }
+
         time_in_past.tv_sec = args->freq_time;
         time_in_past.tv_usec = 0;
-        if (gettimeofday (&current_time, NULL) == -1) {
+
+        ret = gettimeofday (&current_time, NULL);
+        if (ret == -1) {
                 gf_log (args->this->name, GF_LOG_ERROR,
                         "Failed to get current timen");
                 goto out;