* Fix checking for symlinks in umount from /tmp. Reported by Al

Viro
* Fix umounting if /tmp is a symlink.  Reported by Franco Broi
* Fix stack alignment for clone()

ChangeLog

@@ -1,3 +1,18 @@
+2010-04-26  Miklos Szeredi <miklos@szeredi.hu>
+
+	* Released 2.7.6
+
+2010-04-26  Miklos Szeredi <miklos@szeredi.hu>
+
+	* Fix checking for symlinks in umount from /tmp.  Reported by Al
+	Viro
+
+	* Fix umounting if /tmp is a symlink.  Reported by Franco Broi
+
+2010-02-03  Miklos Szeredi <miklos@szeredi.hu>
+
+	* Fix stack alignment for clone()
+
 2010-01-26  Miklos Szeredi <miklos@szeredi.hu>
 
 	* Released 2.7.5

configure.in

@@ -1,4 +1,4 @@
-AC_INIT(fuse, 2.7.5)
+AC_INIT(fuse, 2.7.6)
 AC_CANONICAL_TARGET
 AM_INIT_AUTOMAKE
 AM_CONFIG_HEADER(include/config.h)

kernel/configure.ac

@@ -1,4 +1,4 @@
-AC_INIT(fuse-kernel, 2.7.5)
+AC_INIT(fuse-kernel, 2.7.6)
 AC_CONFIG_HEADERS([config.h])
 
 AC_PROG_INSTALL

lib/Makefile.am

@@ -34,7 +34,7 @@ libfuse_la_SOURCES = 		\
 	$(iconv_source)		\
 	$(mount_source)
 
-libfuse_la_LDFLAGS = @libfuse_libs@ -version-number 2:7:5 \
+libfuse_la_LDFLAGS = @libfuse_libs@ -version-number 2:7:6 \
 	-Wl,--version-script,$(srcdir)/fuse_versionscript
 
 libulockmgr_la_SOURCES = ulockmgr.c

util/fusermount.c

@@ -41,8 +41,8 @@
 #ifndef MS_REC
 #define MS_REC 16384
 #endif
-#ifndef MS_SLAVE
-#define MS_SLAVE (1<<19)
+#ifndef MS_PRIVATE
+#define MS_PRIVATE (1<<18)
 #endif
 
 static const char *progname;
@@ -200,15 +200,16 @@ static int may_unmount(const char *mnt, int quiet)
  * killed for any reason, mounts are automatically cleaned up.
  *
  * First make sure nothing is propagated back into the parent
- * namespace by marking all mounts "slave".
+ * namespace by marking all mounts "private".
  *
  * Then bind mount parent onto a stable base where the user can't move
- * it around.  Use "/tmp", since it will almost certainly exist, but
- * anything similar would do as well.
+ * it around.
  *
  * Finally check /proc/mounts for an entry matching the requested
  * mountpoint.  If it's found then we are OK, and the user can't move
- * it around within the parent directory as rename() will return EBUSY.
+ * it around within the parent directory as rename() will return
+ * EBUSY.  Be careful to ignore any mounts that existed before the
+ * bind.
  */
 static int check_is_mount_child(void *p)
 {
@@ -220,17 +221,11 @@ static int check_is_mount_child(void *p)
 	int found;
 	FILE *fp;
 	struct mntent *entp;
+	int count;
 
-	res = mount("", "/", "", MS_SLAVE | MS_REC, NULL);
+	res = mount("", "/", "", MS_PRIVATE | MS_REC, NULL);
 	if (res == -1) {
-		fprintf(stderr, "%s: failed to mark mounts slave: %s\n",
-			progname, strerror(errno));
-		return 1;
-	}
-
-	res = mount(".", "/tmp", "", MS_BIND | MS_REC, NULL);
-	if (res == -1) {
-		fprintf(stderr, "%s: failed to bind parent to /tmp: %s\n",
+		fprintf(stderr, "%s: failed to mark mounts private: %s\n",
 			progname, strerror(errno));
 		return 1;
 	}
@@ -242,10 +237,33 @@ static int check_is_mount_child(void *p)
 		return 1;
 	}
 
+	count = 0;
+	while ((entp = getmntent(fp)) != NULL)
+		count++;
+	endmntent(fp);
+
+	fp = setmntent(procmounts, "r");
+	if (fp == NULL) {
+		fprintf(stderr, "%s: failed to open %s: %s\n", progname,
+			procmounts, strerror(errno));
+		return 1;
+	}
+
+	res = mount(".", "/", "", MS_BIND | MS_REC, NULL);
+	if (res == -1) {
+		fprintf(stderr, "%s: failed to bind parent to /: %s\n",
+			progname, strerror(errno));
+		return 1;
+	}
+
 	found = 0;
 	while ((entp = getmntent(fp)) != NULL) {
-		if (strncmp(entp->mnt_dir, "/tmp/", 5) == 0 &&
-		    strcmp(entp->mnt_dir + 5, last) == 0) {
+		if (count > 0) {
+			count--;
+			continue;
+		}
+		if (entp->mnt_dir[0] == '/' &&
+		    strcmp(entp->mnt_dir + 1, last) == 0) {
 			found = 1;
 			break;
 		}
@@ -262,9 +280,8 @@ static int check_is_mount_child(void *p)
 
 static pid_t clone_newns(void *a)
 {
-	long long buf[16384];
-	size_t stacksize = sizeof(buf) / 2;
-	char *stack = ((char *) buf) + stacksize;
+	char buf[131072];
+	char *stack = buf + (sizeof(buf) / 2 - ((size_t) buf & 15));
 
 #ifdef __ia64__
 	extern int __clone2(int (*fn)(void *),
@@ -272,8 +289,8 @@ static pid_t clone_newns(void *a)
 			    int flags, void *arg, pid_t *ptid,
 			    void *tls, pid_t *ctid);
 
-	return __clone2(check_is_mount_child, stack, stacksize, CLONE_NEWNS, a,
-			NULL, NULL, NULL);
+	return __clone2(check_is_mount_child, stack, sizeof(buf) / 2,
+			CLONE_NEWNS, a, NULL, NULL, NULL);
 #else
 	return clone(check_is_mount_child, stack, CLONE_NEWNS, a);
 #endif