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>

6 files changed, 96 insertions, 35 deletions

diff --git a/tests/bugs/bug-860663.t b/tests/bugs/bug-860663.t
new file mode 100644
index 00000000..a36c8e46
--- /dev/null
+++ b/tests/bugs/bug-860663.t
@@ -0,0 +1,49 @@
+#!/bin/bash
+
+. $(dirname $0)/../include.rc
+
+cleanup;
+
+function file_count()
+{
+        val=1
+
+        if [ "$1" == "$2" ]
+        then
+                val=0
+        fi
+        echo $val
+}
+
+BRICK_COUNT=3
+
+TEST glusterd
+TEST pidof glusterd
+
+TEST $CLI volume create $V0 $H0:$B0/${V0}0 $H0:$B0/${V0}1 $H0:$B0/${V0}2
+TEST $CLI volume start $V0
+
+## Mount FUSE
+TEST glusterfs -s $H0 --volfile-id $V0 $M0;
+sleep 5;
+
+touch $M0/files{1..10000} >/dev/null;
+
+ORIG_FILE_COUNT=`ls -l $M0 | wc -l`;
+
+# Kill a brick process
+kill -9 `cat /var/lib/glusterd/vols/$V0/run/$H0-d-backends-${V0}1.pid`;
+
+TEST $CLI volume rebalance $V0 fix-layout start
+
+sleep 30;
+
+touch $M0/files{1..10000} >/dev/null;
+
+TEST $CLI volume start $V0 force
+
+sleep 5;
+
+NEW_FILE_COUNT=`ls -l $M0 | wc -l`;
+
+EXPECT "0" file_count $ORIG_FILE_COUNT $NEW_FILE_COUNT
diff --git a/xlators/cluster/dht/src/dht-common.c b/xlators/cluster/dht/src/dht-common.c
index 0925b6d2..70e737c8 100644
--- a/xlators/cluster/dht/src/dht-common.c
+++ b/xlators/cluster/dht/src/dht-common.c
@@ -2398,9 +2398,13 @@ dht_setxattr (call_frame_t *frame, xlator_t *this,
                 gf_log (this->name, GF_LOG_INFO,
                         "fixing the layout of %s", loc->path);
 
-                dht_fix_directory_layout (frame, dht_common_setxattr_cbk,
-                                          layout);
-                return 0;
+                ret = dht_fix_directory_layout (frame, dht_common_setxattr_cbk,
+                                                layout);
+                if (ret) {
+                        op_errno = ENOTCONN;
+                        goto err;
+                }
+                return ret;
         }
 
         tmp = dict_get (xattr, "distribute.directory-spread-count");
@@ -2412,10 +2416,14 @@ dht_setxattr (call_frame_t *frame, xlator_t *this,
                              (dir_spread > 0))) {
                         layout->spread_cnt = dir_spread;
 
-                        dht_fix_directory_layout (frame,
-                                                  dht_common_setxattr_cbk,
-                                                  layout);
-                        return 0;
+                        ret = dht_fix_directory_layout (frame,
+                                                        dht_common_setxattr_cbk,
+                                                        layout);
+                        if (ret) {
+                                op_errno = ENOTCONN;
+                                goto err;
+                        }
+                        return ret;
                 }
                 gf_log (this->name, GF_LOG_ERROR,
                         "wrong 'directory-spread-count' value (%s)", value);
diff --git a/xlators/cluster/dht/src/dht-common.h b/xlators/cluster/dht/src/dht-common.h
index 1a69feba..1f3ccc1c 100644
--- a/xlators/cluster/dht/src/dht-common.h
+++ b/xlators/cluster/dht/src/dht-common.h
@@ -140,7 +140,6 @@ struct dht_local {
         struct {
                 uint32_t         hole_cnt;
                 uint32_t         overlaps_cnt;
-                uint32_t         missing;
                 uint32_t         down;
                 uint32_t         misc;
                 dht_selfheal_dir_cbk_t   dir_cbk;
@@ -380,7 +379,7 @@ int                                      dht_layout_normalize (xlator_t *this, l
 int dht_layout_anomalies (xlator_t      *this, loc_t *loc, dht_layout_t *layout,
                           uint32_t      *holes_p, uint32_t *overlaps_p,
                           uint32_t      *missing_p, uint32_t *down_p,
-                          uint32_t      *misc_p);
+                          uint32_t      *misc_p, uint32_t *no_space_p);
 int dht_layout_dir_mismatch (xlator_t   *this, dht_layout_t *layout,
                              xlator_t   *subvol, loc_t *loc, dict_t *xattr);
 
diff --git a/xlators/cluster/dht/src/dht-layout.c b/xlators/cluster/dht/src/dht-layout.c
index 993f6166..da0e449f 100644
--- a/xlators/cluster/dht/src/dht-layout.c
+++ b/xlators/cluster/dht/src/dht-layout.c
@@ -478,7 +478,8 @@ dht_layout_sort_volname (dht_layout_t *layout)
 int
 dht_layout_anomalies (xlator_t *this, loc_t *loc, dht_layout_t *layout,
                       uint32_t *holes_p, uint32_t *overlaps_p,
-                      uint32_t *missing_p, uint32_t *down_p, uint32_t *misc_p)
+                      uint32_t *missing_p, uint32_t *down_p, uint32_t *misc_p,
+                      uint32_t *no_space_p)
 {
         uint32_t    overlaps = 0;
         uint32_t    missing  = 0;
@@ -491,6 +492,7 @@ dht_layout_anomalies (xlator_t *this, loc_t *loc, dht_layout_t *layout,
         uint32_t    prev_stop = 0;
         uint32_t    last_stop = 0;
         char        is_virgin = 1;
+        uint32_t    no_space  = 0;
 
         /* TODO: explain what is happening */
 
@@ -508,7 +510,7 @@ dht_layout_anomalies (xlator_t *this, loc_t *loc, dht_layout_t *layout,
                                 down++;
                                 break;
                         case ENOSPC:
-                                down++;
+                                no_space++;
                                 break;
                         default:
                                 misc++;
@@ -547,6 +549,9 @@ dht_layout_anomalies (xlator_t *this, loc_t *loc, dht_layout_t *layout,
         if (misc_p)
                 *misc_p = misc;
 
+        if (no_space_p)
+                *no_space_p = no_space;
+
         return ret;
 }
 
@@ -571,7 +576,7 @@ dht_layout_normalize (xlator_t *this, loc_t *loc, dht_layout_t *layout)
 
         ret = dht_layout_anomalies (this, loc, layout,
                                     &holes, &overlaps,
-                                    &missing, &down, &misc);
+                                    &missing, &down, &misc, NULL);
         if (ret == -1) {
                 gf_log (this->name, GF_LOG_WARNING,
                         "error while finding anomalies in %s -- not good news",
diff --git a/xlators/cluster/dht/src/dht-rebalance.c b/xlators/cluster/dht/src/dht-rebalance.c
index d31f8a01..a2e96a1b 100644
--- a/xlators/cluster/dht/src/dht-rebalance.c
+++ b/xlators/cluster/dht/src/dht-rebalance.c
@@ -1383,6 +1383,7 @@ gf_defrag_fix_layout (xlator_t *this, gf_defrag_info_t *defrag, loc_t *loc,
                                         "failed for %s", entry_loc.path);
                                 defrag->defrag_status =
                                 GF_DEFRAG_STATUS_FAILED;
+                                defrag->total_failures ++;
                                 goto out;
                         }
                         ret = gf_defrag_fix_layout (this, defrag, &entry_loc,
@@ -1391,6 +1392,7 @@ gf_defrag_fix_layout (xlator_t *this, gf_defrag_info_t *defrag, loc_t *loc,
                         if (ret) {
                                 gf_log (this->name, GF_LOG_ERROR, "Fix layout "
                                         "failed for %s", entry_loc.path);
+                                defrag->total_failures++;
                                 goto out;
                         }
 
@@ -1481,6 +1483,7 @@ gf_defrag_start_crawl (void *data)
         if (ret) {
                 gf_log (this->name, GF_LOG_ERROR, "fix layout on %s failed",
                         loc.path);
+                defrag->total_failures++;
                 goto out;
         }
 
diff --git a/xlators/cluster/dht/src/dht-selfheal.c b/xlators/cluster/dht/src/dht-selfheal.c
index 7a5d4d11..4840034a 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;