tier: Demotion failed if the file was renamed when it was in cold

During migration if the file is present we just open the file
in hashed subvol. Now if the linkfile present on hashed is just
linkfile to another subvol, we actually open in hashed subvol.

But subsequent operation will go to linkto subvol ie,
to non-hashed subvol. This operation will get failed
since we haven't opened d on non-hashed.

Change-Id: I9753ad3a48f0384c25509612ba76e7e10645add3
BUG: 1292067
Signed-off-by: Mohammed Rafi KC <rkavunga@redhat.com>
Reviewed-on: http://review.gluster.org/12980
Tested-by: NetBSD Build System <jenkins@build.gluster.org>
Reviewed-by: Susant Palai <spalai@redhat.com>
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Dan Lambright <dlambrig@redhat.com>
Tested-by: Dan Lambright <dlambrig@redhat.com>

1 files changed, 26 insertions, 11 deletions

diff --git a/xlators/cluster/dht/src/dht-rebalance.c b/xlators/cluster/dht/src/dht-rebalance.c
index 08dbae0547a..7cac0657a83 100644
--- a/xlators/cluster/dht/src/dht-rebalance.c
+++ b/xlators/cluster/dht/src/dht-rebalance.c
@@ -531,18 +531,33 @@ __dht_rebalance_create_dst_file (xlator_t *to, xlator_t *from, loc_t *loc, struc
         }
 
         /* Create the destination with LINKFILE mode, and linkto xattr,
-           if the linkfile already exists, it will just open the file */
-        ret = syncop_create (to, loc, O_RDWR, DHT_LINKFILE_MODE, fd,
-                             &new_stbuf, dict, NULL);
-        if (ret < 0) {
-                gf_msg (this->name, GF_LOG_ERROR, 0,
-                        DHT_MSG_MIGRATE_FILE_FAILED,
-                        "failed to create %s on %s (%s)",
-                        loc->path, to->name, strerror (-ret));
-                ret = -1;
-                goto out;
-        }
+           if the linkfile already exists, just open the file */
+        if (!ret) {
+                /*
+                 * File already present, just open the file.
+                 */
+                ret = syncop_open (to, loc, O_RDWR, fd, NULL, NULL);
+                 if (ret < 0) {
+                        gf_msg (this->name, GF_LOG_ERROR, -ret,
+                                DHT_MSG_MIGRATE_FILE_FAILED,
+                                "failed to open %s on %s",
+                                loc->path, to->name);
+                        ret = -1;
+                        goto out;
+                 }
+        } else {
+                ret = syncop_create (to, loc, O_RDWR, DHT_LINKFILE_MODE, fd,
+                                     &new_stbuf, dict, NULL);
+                 if (ret < 0) {
+                        gf_msg (this->name, GF_LOG_ERROR, -ret,
+                                DHT_MSG_MIGRATE_FILE_FAILED,
+                                "failed to create %s on %s",
+                                loc->path, to->name);
+                        ret = -1;
+                        goto out;
+                }
 
+        }
 
         fd_bind (fd);
         if (dst_fd)