cluster/dht : Rebalance process crashes due to double fd_unref

The dst_fd was being unrefed twice in case the call
to __dht_rebalance_create_dst_file failed.

> BUG: 1296611
> Signed-off-by: N Balachandran <nbalacha@redhat.com>
> Reviewed-on: http://review.gluster.org/13193
> Reviewed-by: Susant Palai <spalai@redhat.com>
> Reviewed-by: Raghavendra G <rgowdapp@redhat.com>
> Tested-by: Raghavendra G <rgowdapp@redhat.com>
(cherry picked from commit 36fcaf275952202ce3f1e621d3b3a34d58054c99)

Change-Id: I56c5aff7fa3827887e67936b8aa1ecbd1a08a9e9
BUG: 1297309
Signed-off-by: N Balachandran <nbalacha@redhat.com>
Reviewed-on: http://review.gluster.org/13212
Reviewed-by: Raghavendra G <rgowdapp@redhat.com>
Reviewed-by: Pranith Kumar Karampuri <pkarampu@redhat.com>
Tested-by: Pranith Kumar Karampuri <pkarampu@redhat.com>
CentOS-regression: Gluster Build System <jenkins@build.gluster.com>
Smoke: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Vijay Bellur <vbellur@redhat.com>
NetBSD-regression: NetBSD Build System <jenkins@build.gluster.org>

1 files changed, 11 insertions, 6 deletions

diff --git a/xlators/cluster/dht/src/dht-rebalance.c b/xlators/cluster/dht/src/dht-rebalance.c
index a9fceb366f0..3698b340fef 100644
--- a/xlators/cluster/dht/src/dht-rebalance.c
+++ b/xlators/cluster/dht/src/dht-rebalance.c
@@ -519,7 +519,7 @@ __dht_rebalance_create_dst_file (xlator_t *to, xlator_t *from, loc_t *loc, struc
                                 DHT_MSG_GFID_MISMATCH,
                                 "file %s exists in %s with different gfid",
                                 loc->path, to->name);
-                        fd_unref (fd);
+                        ret = -1;
                         goto out;
                 }
         }
@@ -563,8 +563,7 @@ __dht_rebalance_create_dst_file (xlator_t *to, xlator_t *from, loc_t *loc, struc
         }
 
         fd_bind (fd);
-        if (dst_fd)
-                *dst_fd = fd;
+
         /*Reason of doing lookup after create again:
          *In the create, there is some time-gap between opening fd at the
          *server (posix_layer) and binding it in server (incrementing fd count),
@@ -575,7 +574,6 @@ __dht_rebalance_create_dst_file (xlator_t *to, xlator_t *from, loc_t *loc, struc
          *at  the backend.
          */
 
-
         ret = syncop_lookup (to, loc, &check_stbuf, NULL, NULL, NULL);
         if (!ret) {
 
@@ -586,7 +584,6 @@ __dht_rebalance_create_dst_file (xlator_t *to, xlator_t *from, loc_t *loc, struc
                                 "found in lookup after create",
                                 loc->path, to->name);
                         ret = -1;
-                        fd_unref (fd);
                         goto out;
                 }
 
@@ -597,7 +594,6 @@ __dht_rebalance_create_dst_file (xlator_t *to, xlator_t *from, loc_t *loc, struc
                         DHT_MSG_MIGRATE_FILE_FAILED, "%s: file does not exists"
                         "on %s (%s)", loc->path, to->name, strerror (-ret));
                 ret = -1;
-                fd_unref (fd);
                 goto out;
         }
 
@@ -627,7 +623,15 @@ __dht_rebalance_create_dst_file (xlator_t *to, xlator_t *from, loc_t *loc, struc
         /* success */
         ret = 0;
 
+        if (dst_fd)
+                *dst_fd = fd;
+
 out:
+        if (ret) {
+                if (fd) {
+                        fd_unref (fd);
+                }
+        }
         if (dict)
                 dict_unref (dict);
 
@@ -898,6 +902,7 @@ __dht_rebalance_open_src_file (xlator_t *from, xlator_t *to, loc_t *loc,
         }
 
         fd_bind (fd);
+
         if (src_fd)
                 *src_fd = fd;