libglusterfsclient: Re-validate root inode on every path resolution

If the root inode's is outdated, send a revalidate on it.
A revalidate on root inode also reduces the window in which an
op will fail over distribute because the layout of the root
directory did not  get constructed when we sent the lookup on
root in glusterfs_init. That can happen when not all children of a
distribute volume were up at the time of glusterfs_init.

Signed-off-by: Anand V. Avati <avati@dev.gluster.com>

BUG: 256 (revalidates should be sent on '/' in libglusterfsclient.)
URL: http://bugs.gluster.com/cgi-bin/bugzilla3/show_bug.cgi?id=256

1 files changed, 23 insertions, 0 deletions

diff --git a/libglusterfsclient/src/libglusterfsclient-dentry.c b/libglusterfsclient/src/libglusterfsclient-dentry.c
index 1c8910159..22b9bc50c 100644
--- a/libglusterfsclient/src/libglusterfsclient-dentry.c
+++ b/libglusterfsclient/src/libglusterfsclient-dentry.c
@@ -103,6 +103,8 @@ __libgf_client_path_to_parenti (libglusterfs_client_ctx_t *ctx,
         inode_t *curr = NULL;
         inode_t *parent = NULL;
         size_t pathlen = 0;
+        loc_t rootloc = {0, };
+        int ret = -1;
 
         pathlen = STRLEN_0 (path);
         resolved_till = CALLOC (1, pathlen);
@@ -112,6 +114,27 @@ __libgf_client_path_to_parenti (libglusterfs_client_ctx_t *ctx,
         GF_VALIDATE_OR_GOTO("libglusterfsclient-dentry", pathdup, out);
 
         parent = inode_ref (itable->root);
+        /* If the root inode's is outdated, send a revalidate on it.
+         * A revalidate on root inode also reduces the window in which an
+         * op will fail over distribute because the layout of the root
+         * directory did not  get constructed when we sent the lookup on
+         * root in glusterfs_init. That can happen when not all children of a
+         * distribute volume were up at the time of glusterfs_init.
+         */
+        if (!libgf_is_iattr_cache_valid (ctx, parent, NULL,
+                                        LIBGF_VALIDATE_LOOKUP)) {
+                libgf_client_loc_fill (&rootloc, ctx, 1, 0, "/");
+                ret = libgf_client_lookup (ctx, &rootloc, NULL, NULL, NULL);
+                if (ret == -1) {
+                        gf_log ("libglusterfsclient-dentry", GF_LOG_ERROR,
+                                "Root inode revalidation failed");
+                        inode_unref (parent);
+                        parent = NULL;
+                        goto out;
+                }
+                libgf_client_loc_wipe (&rootloc);
+        }
+
         curr = NULL;
 
         component = strtok_r (pathdup, "/", &strtokptr);