libgfapi: Fix lookup on root

Lookup on root was sending "/" as the path.
This will break the basename calculation in
loc_copy and hence lookup on root was failing
if the loc_copy was involved in the stack.

With ctime, a first lookup on root initiates
a metadata self heal because of ctime xattr
not being same on all afr subvolumes. This
results in loc_copy and hence the failure
of lookup.

Fix would be to send path with "." for the root.

Backport of:
  > Patch: https://review.gluster.org/#/c/20086/
  > BUG: 1582516
  > Change-Id: Iafe4b99f249a4f5034ad34c1d30590de0e35aa0d
(cherry picked from commit 3d38e4e47f129bdb36c3fbbd481dabe4ba4413d6)


fixes: bz#1583016
Change-Id: Iafe4b99f249a4f5034ad34c1d30590de0e35aa0d
Signed-off-by: Kotresh HR <khiremat@redhat.com>

3 files changed, 94 insertions, 2 deletions

diff --git a/api/src/glfs-resolve.c b/api/src/glfs-resolve.c
index 6c9fc38901f..51b31d2ae61 100644
--- a/api/src/glfs-resolve.c
+++ b/api/src/glfs-resolve.c
@@ -241,9 +241,9 @@ glfs_resolve_root (struct glfs *fs, xlator_t *subvol, inode_t *inode,
 
         loc.inode = inode_ref (inode);
 
-        ret = inode_path (loc.inode, NULL, &path);
+        ret = inode_path (loc.inode, ".", &path);
         loc.path = path;
-        loc.name = "";
+        loc.name = ".";
         /* Having a value in loc.name will help to bypass md-cache check for
          * nameless lookup.
          * TODO: Re-visit on nameless lookup and md-cache.
diff --git a/tests/basic/ctime/ctime-glfs-init.c b/tests/basic/ctime/ctime-glfs-init.c
new file mode 100644
index 00000000000..57a3dc7820e
--- /dev/null
+++ b/tests/basic/ctime/ctime-glfs-init.c
@@ -0,0 +1,67 @@
+#include <fcntl.h>
+#include <unistd.h>
+#include <time.h>
+#include <limits.h>
+#include <string.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <glusterfs/api/glfs.h>
+#include <glusterfs/api/glfs-handles.h>
+
+#define LOG_ERR(msg) do { \
+        fprintf (stderr, "%s : Error (%s)\n", msg, strerror (errno)); \
+        } while (0)
+
+int
+main (int argc, char *argv[])
+{
+        int         ret      = 0;
+        char       *hostname = NULL;
+        char       *volname  = NULL;
+        char       *logfile  = NULL;
+        glfs_t     *fs       = NULL;
+
+        if (argc != 4) {
+                fprintf (stderr, "Invalid argument\n");
+                exit(1);
+        }
+
+        hostname = argv[1];
+        volname = argv[2];
+        logfile = argv[3];
+
+        fs = glfs_new (volname);
+        if (!fs) {
+                LOG_ERR ("glfs_new failed");
+                return -1;
+        }
+
+        ret = glfs_set_volfile_server (fs, "tcp", hostname, 24007);
+        if (ret < 0) {
+                LOG_ERR ("glfs_set_volfile_server failed");
+                goto err;
+        }
+
+        ret = glfs_set_logging (fs, logfile, 7);
+        if (ret < 0) {
+                LOG_ERR ("glfs_set_logging failed");
+                goto err;
+        }
+
+        ret = glfs_init (fs);
+        if (ret < 0) {
+                LOG_ERR ("glfs_init failed");
+                goto err;
+        }
+
+        glfs_fini (fs);
+        fs = NULL;
+        return 0;
+err:
+        glfs_fini (fs);
+        fs = NULL;
+
+        return -1;
+}
diff --git a/tests/basic/ctime/ctime-glfs-init.t b/tests/basic/ctime/ctime-glfs-init.t
new file mode 100644
index 00000000000..0ecd80c2680
--- /dev/null
+++ b/tests/basic/ctime/ctime-glfs-init.t
@@ -0,0 +1,25 @@
+#!/bin/bash
+
+. $(dirname $0)/../../include.rc
+. $(dirname $0)/../../volume.rc
+
+cleanup;
+
+TEST glusterd
+
+TEST $CLI volume create $V0 replica 3 ${H0}:$B0/brick{1,2,3};
+TEST $CLI volume set $V0 performance.stat-prefetch off
+TEST $CLI volume set $V0 ctime on
+TEST $CLI volume set $V0 utime on
+TEST $CLI volume start $V0;
+
+logdir=`gluster --print-logdir`
+
+TEST build_tester $(dirname $0)/ctime-glfs-init.c -lgfapi -lpthread
+
+TEST ./$(dirname $0)/ctime-glfs-init ${H0} $V0 $logdir/ctime-glfs-init.log
+
+cleanup_tester $(dirname $0)/ctime-glfs-init
+
+cleanup;
+