cluster/dht: fail fix-layout if any of the subvol is down

If any subvolume is down, and a layout is re-written and hash
values change, entry names in the downed subvol can be reused
in the other subvol which got the same hash range. when the
downed subvol is brought back up, duplicate entried might appear

Also separated handling of ENOSPC and ENOTCONN error.

Change-Id: I5ed93990425a4cee70df2dab7c7c119fdc87ad56
BUG: 860663
Signed-off-by: shishir gowda <sgowda@redhat.com>
Reviewed-on: http://review.gluster.org/4000
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Anand Avati <avati@redhat.com>

1 files changed, 20 insertions, 23 deletions

diff --git a/xlators/cluster/dht/src/dht-selfheal.c b/xlators/cluster/dht/src/dht-selfheal.c
index 7a5d4d116ad..4840034a97f 100644
--- a/xlators/cluster/dht/src/dht-selfheal.c
+++ b/xlators/cluster/dht/src/dht-selfheal.c
@@ -593,6 +593,8 @@ dht_fix_layout_of_directory (call_frame_t *frame, loc_t *loc,
         dht_layout_t *new_layout   = NULL;
         dht_conf_t   *priv         = NULL;
         dht_local_t  *local        = NULL;
+        uint32_t      subvol_down  = 0;
+        int           ret          = 0;
 
         this  = frame->this;
         priv  = this->private;
@@ -608,6 +610,17 @@ dht_fix_layout_of_directory (call_frame_t *frame, loc_t *loc,
         if (!new_layout)
                 goto done;
 
+        /* If a subvolume is down, do not re-write the layout. */
+        ret = dht_layout_anomalies (this, loc, layout, NULL, NULL, NULL,
+                                    &subvol_down, NULL, NULL);
+
+        if (subvol_down || (ret == -1)) {
+                gf_log (this->name, GF_LOG_WARNING, "%u subvolume(s) are down"
+                        ". Skipping fix layout.", subvol_down);
+                GF_FREE (new_layout);
+                return NULL;
+        }
+
         for (i = 0; i < new_layout->cnt; i++) {
 		if (layout->list[i].err != ENOSPC)
 			new_layout->list[i].err = layout->list[i].err;
@@ -695,35 +708,17 @@ int
 dht_selfheal_dir_getafix (call_frame_t *frame, loc_t *loc,
                           dht_layout_t *layout)
 {
-        dht_conf_t  *conf = NULL;
-        xlator_t    *this = NULL;
         dht_local_t *local = NULL;
-        int          missing = -1;
-        int          down = -1;
-        int          holes = -1;
+        uint32_t     holes = 0;
         int          ret = -1;
         int          i = -1;
-        int          overlaps = -1;
+        uint32_t     overlaps = 0;
 
-        this = frame->this;
-        conf = this->private;
         local = frame->local;
 
-        missing = local->selfheal.missing;
-        down = local->selfheal.down;
         holes = local->selfheal.hole_cnt;
         overlaps = local->selfheal.overlaps_cnt;
 
-        if ((missing + down) == conf->subvolume_cnt) {
-                dht_selfheal_layout_new_directory (frame, loc, layout);
-                ret = 0;
-        }
-
-        if (holes <= down) {
-                /* the down subvol might fill up the holes */
-                ret = 0;
-        }
-
         if (holes || overlaps) {
                 dht_selfheal_layout_new_directory (frame, loc, layout);
                 ret = 0;
@@ -775,6 +770,9 @@ dht_fix_directory_layout (call_frame_t *frame,
 
         /* No layout sorting required here */
         tmp_layout = dht_fix_layout_of_directory (frame, &local->loc, layout);
+        if (!tmp_layout) {
+                return -1;
+        }
         dht_fix_dir_xattr (frame, &local->loc, tmp_layout);
 
         return 0;
@@ -797,9 +795,8 @@ dht_selfheal_directory (call_frame_t *frame, dht_selfheal_dir_cbk_t dir_cbk,
         dht_layout_anomalies (this, loc, layout,
                               &local->selfheal.hole_cnt,
                               &local->selfheal.overlaps_cnt,
-                              &local->selfheal.missing,
-                              &local->selfheal.down,
-                              &local->selfheal.misc);
+                              NULL, &local->selfheal.down,
+                              &local->selfheal.misc, NULL);
 
         down     = local->selfheal.down;
         misc     = local->selfheal.misc;