autofs-5.0.6 - add disable move mount configure option

From: Ian Kent <ikent@redhat.com>

With the introduction of systemd the root filesystem is now usually

marked as shared instead of private as part of the systemd sandbox

functionality. As a consequence moving a mount from one mount point

to another is not allowed.

To resolve this a configure option (--disable-move-mount) to disable

autofs preparing mount tree and then moving it into place has been

added. The move mount use in autofs was needed for a small set of

automount types with older kernels (prior to 2.6.39). So to disable

the use of move mount it's necessary to use a recent kernel.

---

 CHANGELOG           |    1 +

 autofs.spec         |    2 +-

 configure           |   18 ++++++++++++++++++

 configure.in        |   10 ++++++++++

 daemon/automount.c  |   11 +++++++++++

 include/config.h.in |    3 +++

 modules/mount_nfs.c |    5 -----

 modules/parse_sun.c |   40 +++++++++++++++++++++++++++++++++++-----

 8 files changed, 79 insertions(+), 11 deletions(-)

diff --git a/CHANGELOG b/CHANGELOG

index 304b6a2..c682f94 100644

--- a/CHANGELOG

+++ b/CHANGELOG

@@ -12,6 +12,7 @@

 - fix wait for master source mutex.

 - fix submount shutdown race.

 - fix fix map source check in file lookup.

+- add disable move mount configure option.

 28/06/2011 autofs-5.0.6

 -----------------------

diff --git a/autofs.spec b/autofs.spec

index 82edd1e..510ef76 100644

--- a/autofs.spec

+++ b/autofs.spec

@@ -57,7 +57,7 @@ inkludera n

 echo %{version}-%{release} > .version

 %build

-CFLAGS="$RPM_OPT_FLAGS -Wall" ./configure --libdir=%{_libdir} --disable-mount-locking --enable-ignore-busy --with-libtirpc

+CFLAGS="$RPM_OPT_FLAGS -Wall" ./configure --libdir=%{_libdir} --disable-mount-locking --enable-ignore-busy --with-libtirpc --disable-mount-move

 CFLAGS="$RPM_OPT_FLAGS -Wall" make initdir=/etc/rc.d/init.d DONTSTRIP=1

 %install

diff --git a/configure b/configure

index b5a3608..76b6d86 100755

--- a/configure

+++ b/configure

@@ -704,6 +704,7 @@ with_openldap

 with_sasl

 enable_ext_env

 enable_mount_locking

+enable_mount_move

 enable_forced_shutdown

 enable_ignore_busy

 '

@@ -1326,6 +1327,7 @@ Optional Features:

   --enable-FEATURE[=ARG]  include FEATURE [ARG=yes]

   --disable-ext-env	  disable search in environment for substitution variable

   --disable-mount-locking disable use of locking when spawning mount command

+  --disable-mount-move    disable use of mount move when when preparing tree of mounts

   --enable-force-shutdown enable USR1 signal to force unlink umount of any

 			  busy mounts during shutdown

   --enable-ignore-busy	  enable exit without umounting busy mounts during

@@ -5349,6 +5351,22 @@ $as_echo "#define ENABLE_MOUNT_LOCKING 1" >>confdefs.h

 fi

 #

+# Disable use of mount move

+#

+# Check whether --enable-mount-move was given.

+if test "${enable_mount_move+set}" = set; then :

+  enableval=$enable_mount_move;

+else

+  enableval=yes

+fi

+

+if test x$enable_mount_move = xyes -o x$enableval = xyes; then

+

+$as_echo "#define ENABLE_MOUNT_MOVE 1" >>confdefs.h

+

+fi

+

+#

 # Enable forced shutdown on USR1 signal (unlink umounts all mounts).

 #

 # Check whether --enable-forced-shutdown was given.

diff --git a/configure.in b/configure.in

index 46de65a..d3e4e54 100644

--- a/configure.in

+++ b/configure.in

@@ -324,6 +324,16 @@ if test x$enable_mount_locking = xyes -o x$enableval = xyes; then

 fi

 #

+# Disable use of mount move

+#

+AC_ARG_ENABLE(mount-move,

+[  --disable-mount-move    disable use of mount move when when preparing tree of mounts],,

+	enableval=yes)

+if test x$enable_mount_move = xyes -o x$enableval = xyes; then

+	AC_DEFINE(ENABLE_MOUNT_MOVE, 1, [Disable use of mount move when preparing tree of mounts])

+fi

+

+#

 # Enable forced shutdown on USR1 signal (unlink umounts all mounts).

 #

 AC_ARG_ENABLE(forced-shutdown,

diff --git a/daemon/automount.c b/daemon/automount.c

index 4f3151f..6bb5aa8 100644

--- a/daemon/automount.c

+++ b/daemon/automount.c

@@ -1743,9 +1743,20 @@ static void show_build_info(void)

 	count = 22;

 #endif

+#ifndef ENABLE_MOUNT_MOVE

+	printf("DISABLE_MOUNT_MOVE ");

+	count = count + 19;

+#endif

+

 #ifdef ENABLE_FORCED_SHUTDOWN

 	printf("ENABLE_FORCED_SHUTDOWN ");

 	count = count + 23;

+

+	if (count > 60) {

+		printf("\n  ");

+		count = 0;

+	}

+

 #endif

 #ifdef ENABLE_IGNORE_BUSY_MOUNTS

diff --git a/include/config.h.in b/include/config.h.in

index 4a3a990..97a8d2d 100644

--- a/include/config.h.in

+++ b/include/config.h.in

@@ -12,6 +12,9 @@

 /* Disable use of locking when spawning mount command */

 #undef ENABLE_MOUNT_LOCKING

+/* Disable use of mount move when preparing tree of mounts */

+#undef ENABLE_MOUNT_MOVE

+

 /* define if you have E2FSCK */

 #undef HAVE_E2FSCK

diff --git a/modules/mount_nfs.c b/modules/mount_nfs.c

index 8b567d2..7eab728 100644

--- a/modules/mount_nfs.c

+++ b/modules/mount_nfs.c

@@ -163,11 +163,6 @@ int mount_mount(struct autofs_point *ap, const char *root, const char *name, int

 	if (root[len - 1] == '/') {

 		len = snprintf(fullpath, len, "%s", root);

 	} else if (*name == '/') {

-		/*

-		 * Direct or offset mount, name is absolute path so

-		 * don't use root (but with move mount changes root

-		 * is now the same as name).

-		 */

 		len = sprintf(fullpath, "%s", root);

 	} else {

 		len = sprintf(fullpath, "%s/%s", root, name);

diff --git a/modules/parse_sun.c b/modules/parse_sun.c

index 021850d..13b8af8 100644

--- a/modules/parse_sun.c

+++ b/modules/parse_sun.c

@@ -1028,6 +1028,7 @@ static int parse_mapent(const char *ent, char *g_options, char **options, char *

 	return (p - ent);

 }

+#ifdef ENABLE_MOUNT_MOVE

 static int move_mount(struct autofs_point *ap,

 		      const char *mm_tmp_root, const char *mm_root,

 		      unsigned int move)

@@ -1063,6 +1064,7 @@ static int move_mount(struct autofs_point *ap,

 	return 1;

 }

+#endif

 static void cleanup_multi_root(struct autofs_point *ap, const char *root,

 					 const char *path, unsigned int move)

@@ -1145,6 +1147,7 @@ static void cleanup_multi_triggers(struct autofs_point *ap,

 	return;

 }

+#ifdef ENABLE_MOUNT_MOVE

 static int check_fstype_autofs_option(const char *options)

 {

 	char *tok, *tokbuf;

@@ -1171,24 +1174,27 @@ static int check_fstype_autofs_option(const char *options)

 	return found;

 }

+#endif

 static int mount_subtree(struct autofs_point *ap, struct mapent *me,

 			 const char *name, char *loc, char *options, void *ctxt)

 {

 	struct mapent *mm;

 	struct mapent *ro;

-	char t_dir[] = "/tmp/autoXXXXXX";

-	char *mnt_tmp_root, *mm_root, *mm_base, *mm_key;

+	char *mm_root, *mm_base, *mm_key;

 	const char *mnt_root, *target;

 	unsigned int mm_root_len, mnt_root_len;

 	int start, ret = 0, rv;

-	unsigned int move;

+	unsigned int move = MOUNT_MOVE_NONE;

+#ifdef ENABLE_MOUNT_MOVE

+	char t_dir[] = "/tmp/autoXXXXXX";

+	char *mnt_tmp_root = NULL;

+#endif

 	rv = 0;

 	mm = me->multi;

 	mm_key = mm->key;

-	move = MOUNT_MOVE_NONE;

 	if (*mm_key == '/') {

 		mm_root = mm_key;

@@ -1202,7 +1208,10 @@ static int mount_subtree(struct autofs_point *ap, struct mapent *me,

 	}

 	mm_root_len = strlen(mm_root);

-	mnt_tmp_root = NULL;

+#ifndef ENABLE_MOUNT_MOVE

+	mnt_root = mm_root;

+	mnt_root_len = mm_root_len;

+#else

 	if (ap->flags & MOUNT_FLAG_REMOUNT) {

 		mnt_root = mm_root;

 		mnt_root_len = mm_root_len;

@@ -1213,6 +1222,7 @@ static int mount_subtree(struct autofs_point *ap, struct mapent *me,

 		mnt_root_len = strlen(mnt_root);

 		mnt_tmp_root = (char *) mnt_root;

 	}

+#endif

 	if (me == me->multi) {

 		/* name = NULL */

@@ -1238,11 +1248,13 @@ static int mount_subtree(struct autofs_point *ap, struct mapent *me,

 			}

 			ro_len = strlen(ro_loc);

+#ifdef ENABLE_MOUNT_MOVE

 			if (!(ap->flags & MOUNT_FLAG_REMOUNT)) {

 				move = MOUNT_MOVE_OTHER;

 				if (check_fstype_autofs_option(myoptions))

 					move = MOUNT_MOVE_AUTOFS;

 			}

+#endif

 			tmp = alloca(mnt_root_len + 1);

 			strcpy(tmp, mnt_root);

@@ -1266,7 +1278,9 @@ static int mount_subtree(struct autofs_point *ap, struct mapent *me,

 				goto error_out;

 			}

 		} else if (rv <= 0) {

+#ifdef ENABLE_MOUNT_MOVE

 			move = MOUNT_MOVE_NONE;

+#endif

 			ret = mount_multi_triggers(ap, me, mm_root, start, mm_base);

 			if (ret == -1) {

 				error(ap->logopt, MODPREFIX

@@ -1279,11 +1293,21 @@ static int mount_subtree(struct autofs_point *ap, struct mapent *me,

 		int loclen = strlen(loc);

 		int namelen = strlen(name);

+#ifndef ENABLE_MOUNT_MOVE

+		/*

+		 * When using move mount to mount offsets or direct mounts

+		 * the base of the tree can be the base of the temporary

+		 * mount point it needs to be the full path when not moving

+		 * the mount after construction.

+		 */

+		mnt_root = name;

+#else

 		if (!(ap->flags & MOUNT_FLAG_REMOUNT)) {

 			move = MOUNT_MOVE_OTHER;

 			if (check_fstype_autofs_option(options))

 				move = MOUNT_MOVE_AUTOFS;

 		}

+#endif

 		/* name = mm_root + mm_base */

 		/* destination = mm_root + mm_base = name */

@@ -1303,7 +1327,9 @@ static int mount_subtree(struct autofs_point *ap, struct mapent *me,

 		} else if (rv < 0) {

 			char *mm_root_base = alloca(strlen(mm_root) + strlen(mm_base) + 1);

+#ifdef ENABLE_MOUNT_MOVE

 			move = MOUNT_MOVE_NONE;

+#endif

 			strcpy(mm_root_base, mm_root);

 			strcat(mm_root_base, mm_base);

@@ -1318,6 +1344,7 @@ static int mount_subtree(struct autofs_point *ap, struct mapent *me,

 		}

 	}

+#ifdef ENABLE_MOUNT_MOVE

 	if (!move_mount(ap, mnt_root, target, move)) {

 		cleanup_multi_triggers(ap, me, mnt_root, start, mm_base);

 		cleanup_multi_root(ap, mnt_root, mm_root, move);

@@ -1326,6 +1353,7 @@ static int mount_subtree(struct autofs_point *ap, struct mapent *me,

 	if (mnt_tmp_root)

 		rmdir(mnt_tmp_root);

+#endif

 	/* Mount for base of tree failed */

 	if (rv > 0)

@@ -1341,8 +1369,10 @@ static int mount_subtree(struct autofs_point *ap, struct mapent *me,

 	return rv;

 error_out:

+#ifdef ENABLE_MOUNT_MOVE

 	if (mnt_tmp_root)

 		rmdir(mnt_tmp_root);

+#endif

 	return 1;

 }