fuse: sync with upstream

Cherry-picked following commits from
git://fuse.git.sourceforge.net/gitroot/fuse/fuse
form 555d6b50..acc5c79d interval:

  commit 1193a39c0869a3608f22472735bcffdcccb6b2a5
  Author: Reuben Hawkins <reubenhwk@gmail.com>

      cleaning up warnings

  commit dba9185999dfa35161d4c810735df0ab3fde5104
  Author: Laszlo Papp <ext-laszlo.papp@nokia.com>

      Check the 'mtablock' for negative value

  commit e63a9d8ee6529c9d15a87745276f45c9bdad3961
  Author: Miklos Szeredi <miklos@szeredi.hu>

      fusermount: clean up do_mount() function

  commit 81fee822a098a3e26969401fc486f136465f96f0
  Author: Laszlo Papp <ext-laszlo.papp@nokia.com>

      Eliminate the unused value

  commit 60eb44ee5eb2756465610b215968f176f4aaac6e
  Author: Laszlo Papp <ext-laszlo.papp@nokia.com>

      Fix resource leaks in fusermount

  commit d6bec4020fddd4dd67248789a1af600580f2cbda
  Author: Miklos Szeredi <mszeredi@suse.cz>

      In case of failure to add to /etc/mtab don't umount.

  commit 1e7607ff89c65b005f69e27aeb1649d624099873
  Author: Miklos Szeredi <mszeredi@suse.cz>

      fusermount: chdir to / before performing mount/umount

  commit 2fcbc2a5a94983813c533c015134c6974f8ee636
  Author: Miklos Szeredi <miklos@szeredi.hu>

      fusermount: don't save/restore cwd

  commit bd99f9cf24e16643752b02fb4fa7b48f2124ab4e
  Author: Miklos Szeredi <miklos@szeredi.hu>

      Fix check for read-only fs in mtab update

Nb.:
- not picked changes that implement and enforce mount/umount
  mechanisms based on newer util-linux features (umount --fake
  and --no-canonicalize)
- not picked fusermount "auto-unmount" feature

Change-Id: Ib9498516184336e77ec047e5414125332d0a4292
BUG: 762389
Signed-off-by: Csaba Henk <csaba@redhat.com>
Reviewed-on: http://review.gluster.com/3343
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Anand Avati <avati@redhat.com>

2 files changed, 21 insertions, 2 deletions

diff --git a/contrib/fuse-lib/mount-common.c b/contrib/fuse-lib/mount-common.c
index 7411e56c89b..fd6cce44e3d 100644
--- a/contrib/fuse-lib/mount-common.c
+++ b/contrib/fuse-lib/mount-common.c
@@ -20,10 +20,11 @@
  * - there are some other minor things
  *
  * For changes that were made later and syncs with upstream,
- * see the commit log.
+ * see the commit log and per-function comments.
  */
 
 #ifndef __NetBSD__
+/* FUSE: cherry-picked bd99f9cf */
 static int
 mtab_needs_update (const char *mnt)
 {
@@ -47,11 +48,22 @@ mtab_needs_update (const char *mnt)
                 if (errno == ENOENT)
                         return 0;
         } else {
+                uid_t ruid;
+                int err;
+
                 if (S_ISLNK (stbuf.st_mode))
                         return 0;
 
+                ruid = getuid ();
+                if (ruid != 0)
+                        setreuid (0, -1);
+
                 res = access (_PATH_MOUNTED, W_OK);
-                if (res == -1 && errno == EROFS)
+                err = (res == -1) ? errno : 0;
+                if (ruid != 0)
+                        setreuid (ruid, -1);
+
+                if (err == EROFS)
                         return 0;
         }
 
@@ -61,6 +73,7 @@ mtab_needs_update (const char *mnt)
 #define mtab_needs_update(x) 1
 #endif /* __NetBSD__ */
 
+/* FUSE: called add_mount_legacy(); R.I.P. as of cbd3a2a8 */
 int
 fuse_mnt_add_mount (const char *progname, const char *fsname,
                     const char *mnt, const char *type, const char *opts)
@@ -194,6 +207,11 @@ fuse_mnt_resolve_path (const char *progname, const char *orig)
         return dst;
 }
 
+/* FUSE: to support some changes that were reverted since
+ * then, it was split in two (fuse_mnt_umount() and
+ * exec_umount()); however the actual code is same as here
+ * since 0197ce40
+ */
 int
 fuse_mnt_umount (const char *progname, const char *abs_mnt,
                  const char *rel_mnt, int lazy)
diff --git a/contrib/fuse-lib/mount.c b/contrib/fuse-lib/mount.c
index 8787064fc04..f02a835b3a8 100644
--- a/contrib/fuse-lib/mount.c
+++ b/contrib/fuse-lib/mount.c
@@ -18,6 +18,7 @@
 #define FUSE_DEVFD_ENV "_FUSE_DEVFD"
 
 
+/* FUSE: function is called fuse_kern_unmount() */
 void
 gf_fuse_unmount (const char *mountpoint, int fd)
 {