autofs attempts unmount on directory in use

Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2056321

There is a case where a multi-mount tree can be be umounted when it's
still in use.

This MR resolves one (hopefully the only remaining one) of those cases.

Resolves: rhbz#2056321

Signed-off-by: Ian Kent ikent@redhat.com

autofs-5.1.8-fix-handling-of-incorrect-return-from-umount_ent.patch

@@ -0,0 +1,110 @@
+autofs-5.1.8 - fix handling of incorrect return from umount_ent()
+
+From: Ian Kent <raven@themaw.net>
+
+Commit 0210535df4b ("autofs-5.1.0 - gaurd against incorrect umount
+return") guards against umount_ent() returning a fail when the mount
+has actually been umounted.
+
+But we also see umount_ent() return success when in fact the mount has
+not been umounted leading to incorrect handling of automounts.
+
+So checking the return of umount_ent() isn't always giving the correct
+result in more than just one case, consequently we should ignore the
+result from the spawned umount(8) and check if the mount has in fact
+been umounted.
+
+Signed-off-by: Ian Kent <raven@themaw.net>
+---
+ CHANGELOG          |    1 +
+ daemon/automount.c |    3 +--
+ lib/mounts.c       |   19 ++++++++++---------
+ 3 files changed, 12 insertions(+), 11 deletions(-)
+
+--- autofs-5.1.7.orig/CHANGELOG
++++ autofs-5.1.7/CHANGELOG
+@@ -95,6 +95,7 @@
+ - avoid calling pthread_getspecific() with NULL key_thread_attempt_id.
+ - fix sysconf(3) return handling.
+ - remove nonstrict parameter from tree_mapent_umount_offsets().
++- fix handling of incorrect return from umount_ent().
+ 
+ 25/01/2021 autofs-5.1.7
+ - make bind mounts propagation slave by default.
+--- autofs-5.1.7.orig/daemon/automount.c
++++ autofs-5.1.7/daemon/automount.c
+@@ -605,8 +605,7 @@ static int umount_subtree_mounts(struct
+ 		struct mnt_list *mnt;
+ 
+ 		debug(ap->logopt, "unmounting dir = %s", path);
+-		if (umount_ent(ap, path) &&
+-		    is_mounted(path, MNTS_REAL)) {
++		if (umount_ent(ap, path)) {
+ 			warn(ap->logopt, "could not umount dir %s", path);
+ 			left++;
+ 			goto done;
+--- autofs-5.1.7.orig/lib/mounts.c
++++ autofs-5.1.7/lib/mounts.c
+@@ -1869,8 +1869,7 @@ static int tree_mapent_umount_offset(str
+ 	 */
+ 	if (oe->ioctlfd != -1 ||
+ 	    is_mounted(oe->key, MNTS_REAL)) {
+-		if (umount_ent(ap, oe->key) &&
+-		    is_mounted(oe->key, MNTS_REAL)) {
++		if (umount_ent(ap, oe->key)) {
+ 			debug(ap->logopt,
+ 			      "offset %s has active mount, invalidate",
+ 			      oe->key);
+@@ -2010,8 +2009,7 @@ int tree_mapent_umount_offsets(struct ma
+ 		 */
+ 		if (is_mounted(mp, MNTS_REAL)) {
+ 			info(ap->logopt, "unmounting dir = %s", mp);
+-			if (umount_ent(ap, mp) &&
+-			    is_mounted(mp, MNTS_REAL)) {
++			if (umount_ent(ap, mp)) {
+ 				if (!tree_mapent_mount_offsets(oe, 1))
+ 					warn(ap->logopt,
+ 					     "failed to remount offset triggers");
+@@ -2982,6 +2980,7 @@ void set_direct_mount_tree_catatonic(str
+ 
+ int umount_ent(struct autofs_point *ap, const char *path)
+ {
++	unsigned int mounted;
+ 	int rv;
+ 
+ 	if (ap->state != ST_SHUTDOWN_FORCE)
+@@ -2993,6 +2992,8 @@ int umount_ent(struct autofs_point *ap,
+ 		rv = spawn_umount(ap->logopt, "-l", path, NULL);
+ 	}
+ 
++	mounted = is_mounted(path, MNTS_REAL);
++
+ 	if (rv && (ap->state == ST_SHUTDOWN_FORCE || ap->state == ST_SHUTDOWN)) {
+ 		/*
+ 		 * Verify that we actually unmounted the thing.  This is a
+@@ -3004,20 +3005,20 @@ int umount_ent(struct autofs_point *ap,
+ 		 * so that we do not try to call rmdir_path on the
+ 		 * directory.
+ 		 */
+-		if (is_mounted(path, MNTS_REAL)) {
++		if (mounted) {
+ 			crit(ap->logopt,
+ 			     "the umount binary reported that %s was "
+ 			     "unmounted, but there is still something "
+ 			     "mounted on this path.", path);
+-			rv = -1;
++			mounted = -1;
+ 		}
+ 	}
+ 
+-	/* On success, check for mounted mount and remove it if found */
+-	if (!rv)
++	/* If mount is gone remove it from mounted mounts list. */
++	if (!mounted)
+ 		mnts_remove_mount(path, MNTS_MOUNTED);
+ 
+-	return rv;
++	return mounted;
+ }
+ 
+ int umount_amd_ext_mount(struct autofs_point *ap, const char *path)

autofs-5.1.8-remove-nonstrict-parameter-from-tree_mapent_umount_offsets.patch

@@ -0,0 +1,77 @@
+autofs-5.1.8 - remove nonstrict parameter from tree_mapent_umount_offsets()
+
+From: Ian Kent <raven@themaw.net>
+
+The nonstrict parameter of tree_mapent_umount_offsets() ins't useful
+because if a real mount at the base of a sub-tree fails to umount all
+we can do is re-instate the offset mounts under it which must succeed
+for the mount tree to remain useful.
+
+Signed-off-by: Ian Kent <raven@themaw.net>
+---
+ CHANGELOG          |    1 +
+ daemon/automount.c |    2 +-
+ include/mounts.h   |    2 +-
+ lib/mounts.c       |    6 +++---
+ 4 files changed, 6 insertions(+), 5 deletions(-)
+
+--- autofs-5.1.7.orig/CHANGELOG
++++ autofs-5.1.7/CHANGELOG
+@@ -94,6 +94,7 @@
+ - fix memory leak in xdr_exports().
+ - avoid calling pthread_getspecific() with NULL key_thread_attempt_id.
+ - fix sysconf(3) return handling.
++- remove nonstrict parameter from tree_mapent_umount_offsets().
+ 
+ 25/01/2021 autofs-5.1.7
+ - make bind mounts propagation slave by default.
+--- autofs-5.1.7.orig/daemon/automount.c
++++ autofs-5.1.7/daemon/automount.c
+@@ -554,7 +554,7 @@ static int umount_subtree_mounts(struct
+ 		struct mapent *tmp;
+ 		int ret;
+ 
+-		ret = tree_mapent_umount_offsets(me, 1);
++		ret = tree_mapent_umount_offsets(me);
+ 		if (!ret) {
+ 			warn(ap->logopt,
+ 			     "some offset mounts still present under %s", path);
+--- autofs-5.1.7.orig/include/mounts.h
++++ autofs-5.1.7/include/mounts.h
+@@ -182,7 +182,7 @@ int tree_mapent_add_node(struct mapent_c
+ int tree_mapent_delete_offsets(struct mapent_cache *mc, const char *key);
+ void tree_mapent_cleanup_offsets(struct mapent *oe);
+ int tree_mapent_mount_offsets(struct mapent *oe, int nonstrict);
+-int tree_mapent_umount_offsets(struct mapent *oe, int nonstrict);
++int tree_mapent_umount_offsets(struct mapent *oe);
+ int unlink_mount_tree(struct autofs_point *ap, const char *mp);
+ void free_mnt_list(struct mnt_list *list);
+ int is_mounted(const char *mp, unsigned int type);
+--- autofs-5.1.7.orig/lib/mounts.c
++++ autofs-5.1.7/lib/mounts.c
+@@ -1843,7 +1843,7 @@ static int tree_mapent_umount_offset(str
+ 	 * Check for and umount subtree offsets resulting from
+ 	 * nonstrict mount fail.
+ 	 */
+-	ret = tree_mapent_umount_offsets(oe, ctxt->strict);
++	ret = tree_mapent_umount_offsets(oe);
+ 	if (!ret)
+ 		return 0;
+ 
+@@ -1975,14 +1975,14 @@ static int tree_mapent_umount_offsets_wo
+ 	return tree_mapent_umount_offset(oe, ptr);
+ }
+ 
+-int tree_mapent_umount_offsets(struct mapent *oe, int nonstrict)
++int tree_mapent_umount_offsets(struct mapent *oe)
+ {
+ 	struct tree_node *base = MAPENT_NODE(oe);
+ 	struct autofs_point *ap = oe->mc->ap;
+ 	struct traverse_subtree_context ctxt = {
+ 		.ap = ap,
+ 		.base = base,
+-		.strict = !nonstrict,
++		.strict = 1,
+ 	};
+ 	int ret;
+ 

autofs.spec

@@ -12,7 +12,7 @@
 Summary: A tool for automatically mounting and unmounting filesystems
 Name: autofs
 Version: 5.1.7
-Release: 28%{?dist}
+Release: 29%{?dist}
 Epoch: 1
 License: GPLv2+
 Source: https://www.kernel.org/pub/linux/daemons/autofs/v5/autofs-%{version}-2.tar.gz
@@ -118,6 +118,9 @@ Patch93: autofs-5.1.8-fix-memory-leak-in-xdr_exports.patch
 Patch94: autofs-5.1.8-avoid-calling-pthread_getspecific-with-NULL-key_thread_attempt_id.patch
 Patch95: autofs-5.1.8-fix-sysconf-return-handling.patch
 
+Patch96: autofs-5.1.8-remove-nonstrict-parameter-from-tree_mapent_umount_offsets.patch
+Patch97: autofs-5.1.8-fix-handling-of-incorrect-return-from-umount_ent.patch
+
 %if %{with_systemd}
 BuildRequires: systemd-units
 BuildRequires: systemd-devel
@@ -280,6 +283,8 @@ echo %{version}-%{release} > .version
 %patch93 -p1
 %patch94 -p1
 %patch95 -p1
+%patch96 -p1
+%patch97 -p1
 
 %build
 LDFLAGS=-Wl,-z,now
@@ -388,6 +393,12 @@ fi
 %dir /etc/auto.master.d
 
 %changelog
+* Fri May 13 2022 Ian Kent <ikent@redhat.com> - 1:5.1.7-29
+- bz2056321 - autofs attempts unmount on directory in use
+  - remove nonstrict parameter from tree_mapent_umount_offsets().
+  - fix handling of incorrect return from umount_ent().
+- Resolves: rhbz#2056321
+
 * Wed May 11 2022 Ian Kent <ikent@redhat.com> - 1:5.1.7-28
 - bz2056320 - Using -hosts option does not work in RHEL 9
   - fix root offset error handling.