cluster/dht: Handle get cached/hashed subvol failures gracefully

Change-Id: I7a41c2876be04acd166b2004d9aa66af078d32ea
BUG: 790328
Signed-off-by: shishir gowda <shishirng@gluster.com>
Reviewed-on: http://review.gluster.com/2757
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Amar Tumballi <amarts@redhat.com>

3 files changed, 47 insertions, 4 deletions

diff --git a/xlators/cluster/dht/src/dht-common.c b/xlators/cluster/dht/src/dht-common.c
index d55750dde..f76dba40f 100644
--- a/xlators/cluster/dht/src/dht-common.c
+++ b/xlators/cluster/dht/src/dht-common.c
@@ -1333,8 +1333,16 @@ dht_lookup (call_frame_t *frame, xlator_t *this,
                 return 0;
         }
 
-        if (!hashed_subvol)
+        if (!hashed_subvol) {
                 hashed_subvol = dht_subvol_get_hashed (this, loc);
+                if (!hashed_subvol) {
+                        gf_log (this->name, GF_LOG_ERROR,
+                                "Failed to get hashed subvol for %s",
+                                loc->path);
+                        op_errno = EINVAL;
+                        goto err;
+                }
+        }
         local->hashed_subvol = hashed_subvol;
 
         if (is_revalidate (loc)) {
@@ -1846,6 +1854,14 @@ dht_getxattr (call_frame_t *frame, xlator_t *this,
 
         if (key && (strcmp (key, GF_XATTR_PATHINFO_KEY) == 0)) {
                 hashed_subvol = dht_subvol_get_hashed (this, loc);
+                if (!hashed_subvol) {
+                        gf_log (this->name, GF_LOG_ERROR,
+                                "Failed to get hashed_subvol for %s",
+                                loc->path);
+                        op_errno = EINVAL;
+                        goto err;
+                }
+
                 cached_subvol = local->cached_subvol;
 
                 local->call_cnt = 1;
@@ -1861,7 +1877,21 @@ dht_getxattr (call_frame_t *frame, xlator_t *this,
         }
         if (key && (strcmp (key, GF_XATTR_LINKINFO_KEY) == 0)) {
                 hashed_subvol = dht_subvol_get_hashed (this, loc);
+                if (!hashed_subvol) {
+                        gf_log (this->name, GF_LOG_ERROR, "Failed to get"
+                                "hashed subvol for %s", loc->path);
+                        op_errno = EINVAL;
+                        goto err;
+                }
+
                 cached_subvol = dht_subvol_get_cached (this, loc->inode);
+                if (!cached_subvol) {
+                        gf_log (this->name, GF_LOG_ERROR, "Failed to get"
+                                "cached subvol for %s", loc->path);
+                        op_errno = EINVAL;
+                        goto err;
+                }
+
                 if (hashed_subvol == cached_subvol) {
                         op_errno = ENODATA;
                         goto err;
@@ -2187,6 +2217,13 @@ dht_setxattr (call_frame_t *frame, xlator_t *this,
                         forced_rebalance = 1;
 
                 local->rebalance.target_node = dht_subvol_get_hashed (this, loc);
+                if (!local->rebalance.target_node) {
+                        gf_log (this->name, GF_LOG_ERROR, "Failed to get "
+                                "hashed subvol for %s", loc->path);
+                        op_errno = EINVAL;
+                        goto err;
+                }
+
                 local->rebalance.from_subvol = local->cached_subvol;
 
                 if (local->rebalance.target_node == local->rebalance.from_subvol) {
diff --git a/xlators/cluster/dht/src/dht-common.h b/xlators/cluster/dht/src/dht-common.h
index d97ef9f58..e44c947dd 100644
--- a/xlators/cluster/dht/src/dht-common.h
+++ b/xlators/cluster/dht/src/dht-common.h
@@ -265,8 +265,6 @@ typedef struct dht_disk_layout dht_disk_layout_t;
 
 #define ENTRY_MISSING(op_ret, op_errno) (op_ret == -1 && op_errno == ENOENT)
 
-#define is_fs_root(loc) (strcmp (loc->path, "/") == 0)
-
 #define is_revalidate(loc) (inode_ctx_get (loc->inode, this, NULL) == 0)
 
 #define is_last_call(cnt) (cnt == 0)
diff --git a/xlators/cluster/dht/src/dht-helper.c b/xlators/cluster/dht/src/dht-helper.c
index 80de4d738..dea69dd9f 100644
--- a/xlators/cluster/dht/src/dht-helper.c
+++ b/xlators/cluster/dht/src/dht-helper.c
@@ -358,11 +358,17 @@ dht_subvol_get_hashed (xlator_t *this, loc_t *loc)
         dht_layout_t *layout = NULL;
         xlator_t     *subvol = NULL;
 
-        if (is_fs_root (loc)) {
+        GF_VALIDATE_OR_GOTO ("dht", this, out);
+        GF_VALIDATE_OR_GOTO (this->name, loc, out);
+
+        if (__is_root_gfid (loc->gfid)) {
                 subvol = dht_first_up_subvol (this);
                 goto out;
         }
 
+        GF_VALIDATE_OR_GOTO (this->name, loc->parent, out);
+        GF_VALIDATE_OR_GOTO (this->name, loc->name, out);
+
         layout = dht_layout_get (this, loc->parent);
 
         if (!layout) {
@@ -396,6 +402,8 @@ dht_subvol_get_cached (xlator_t *this, inode_t *inode)
         dht_layout_t *layout = NULL;
         xlator_t     *subvol = NULL;
 
+        GF_VALIDATE_OR_GOTO (this->name, this, out);
+        GF_VALIDATE_OR_GOTO (this->name, inode, out);
 
         layout = dht_layout_get (this, inode);