Do not hardcode umount(8) path, emulate lazy umount

1) Use a system-dependent macro for umount(8) location instead of
relying on $PATH  to find it, for security and portability sake.

2) Introduce gf_umount_lazy() to replace umount -l (-l for lazy) invocations,
which is only supported on Linux; On Linux behavior in unchanged. On other
systems, we fork an external process (umountd) that will take care of
periodically attempt to unmount, and optionally rmdir.

Backport of Ia91167c0652f8ddab85136324b08f87c5ac1edd51d

BUG: 1138897
Change-Id: I9d82c87e85af0dee79f2de39bc697c486b7103c8
Signed-off-by: Emmanuel Dreyfus <manu@netbsd.org>
Reviewed-on: http://review.gluster.org/8863
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Csaba Henk <csaba@redhat.com>
Reviewed-by: Vijay Bellur <vbellur@redhat.com>

1 files changed, 5 insertions, 14 deletions

diff --git a/xlators/mgmt/glusterd/src/glusterd-volume-ops.c b/xlators/mgmt/glusterd/src/glusterd-volume-ops.c
index 334aef9f412..837e4ec763f 100644
--- a/xlators/mgmt/glusterd/src/glusterd-volume-ops.c
+++ b/xlators/mgmt/glusterd/src/glusterd-volume-ops.c
@@ -2003,7 +2003,6 @@ glusterd_stop_volume (glusterd_volinfo_t *volinfo)
         int                     ret                     = -1;
         glusterd_brickinfo_t    *brickinfo              = NULL;
         char                    mountdir[PATH_MAX]      = {0,};
-        runner_t                runner                  = {0,};
         char                    pidfile[PATH_MAX]       = {0,};
         xlator_t                *this                   = NULL;
 
@@ -2040,19 +2039,11 @@ glusterd_stop_volume (glusterd_volinfo_t *volinfo)
                 GLUSTERD_GET_QUOTA_AUX_MOUNT_PATH (mountdir, volinfo->volname,
                                                    "/");
 
-                runinit (&runner);
-                runner_add_args (&runner, "umount",
-
-                #if GF_LINUX_HOST_OS
-                                "-l",
-                #endif
-                                mountdir, NULL);
-                ret = runner_run_reuse (&runner);
+                ret = gf_umount_lazy (this->name, mountdir, 0);
                 if (ret)
-                        gf_log (this->name, GF_LOG_ERROR, "umount on %s failed, "
-                                "reason : %s", mountdir, strerror (errno));
-
-                runner_end (&runner);
+                        gf_log (this->name, GF_LOG_ERROR,
+                                "umount on %s failed, reason : %s",
+                                mountdir, strerror (errno));
         }
 
         ret = glusterd_handle_snapd_option (volinfo);
@@ -2258,7 +2249,7 @@ glusterd_clearlocks_unmount (glusterd_volinfo_t *volinfo, char *mntpt)
          * stat() on mount can be due to network failures.*/
 
         runinit (&runner);
-        runner_add_args (&runner, "/bin/umount", "-f", NULL);
+        runner_add_args (&runner, _PATH_UMOUNT, "-f", NULL);
         runner_argprintf (&runner, "%s", mntpt);
 
         synclock_unlock (&priv->big_lock);