This tests mounting a subdirectory without ever having to expose the filesystem to a non-anonymous mount namespace. Signed-off-by: Christian Brauner <brauner@xxxxxxxxxx> --- .../selftests/mount_setattr/mount_setattr_test.c | 81 ++++++++++------------ 1 file changed, 36 insertions(+), 45 deletions(-) diff --git a/tools/testing/selftests/mount_setattr/mount_setattr_test.c b/tools/testing/selftests/mount_setattr/mount_setattr_test.c index 33fa1f53fdf5..48a000cabc97 100644 --- a/tools/testing/selftests/mount_setattr/mount_setattr_test.c +++ b/tools/testing/selftests/mount_setattr/mount_setattr_test.c @@ -20,6 +20,7 @@ #include <stdarg.h> #include <linux/mount.h> +#include "../filesystems/overlayfs/wrappers.h" #include "../kselftest_harness.h" #ifndef CLONE_NEWNS @@ -177,51 +178,6 @@ static inline int sys_open_tree(int dfd, const char *filename, unsigned int flag return syscall(__NR_open_tree, dfd, filename, flags); } -/* move_mount() flags */ -#ifndef MOVE_MOUNT_F_SYMLINKS -#define MOVE_MOUNT_F_SYMLINKS 0x00000001 /* Follow symlinks on from path */ -#endif - -#ifndef MOVE_MOUNT_F_AUTOMOUNTS -#define MOVE_MOUNT_F_AUTOMOUNTS 0x00000002 /* Follow automounts on from path */ -#endif - -#ifndef MOVE_MOUNT_F_EMPTY_PATH -#define MOVE_MOUNT_F_EMPTY_PATH 0x00000004 /* Empty from path permitted */ -#endif - -#ifndef MOVE_MOUNT_T_SYMLINKS -#define MOVE_MOUNT_T_SYMLINKS 0x00000010 /* Follow symlinks on to path */ -#endif - -#ifndef MOVE_MOUNT_T_AUTOMOUNTS -#define MOVE_MOUNT_T_AUTOMOUNTS 0x00000020 /* Follow automounts on to path */ -#endif - -#ifndef MOVE_MOUNT_T_EMPTY_PATH -#define MOVE_MOUNT_T_EMPTY_PATH 0x00000040 /* Empty to path permitted */ -#endif - -#ifndef MOVE_MOUNT_SET_GROUP -#define MOVE_MOUNT_SET_GROUP 0x00000100 /* Set sharing group instead */ -#endif - -#ifndef MOVE_MOUNT_BENEATH -#define MOVE_MOUNT_BENEATH 0x00000200 /* Mount beneath top mount */ -#endif - -#ifndef MOVE_MOUNT__MASK -#define MOVE_MOUNT__MASK 0x00000377 -#endif - -static inline int sys_move_mount(int from_dfd, const char *from_pathname, - int to_dfd, const char *to_pathname, - unsigned int flags) -{ - return syscall(__NR_move_mount, from_dfd, from_pathname, to_dfd, - to_pathname, flags); -} - static ssize_t write_nointr(int fd, const void *buf, size_t count) { ssize_t ret; @@ -1789,6 +1745,41 @@ TEST_F(mount_setattr, open_tree_detached_fail3) ASSERT_EQ(errno, EINVAL); } +TEST_F(mount_setattr, open_tree_subfolder) +{ + int fd_context, fd_tmpfs, fd_tree; + + fd_context = sys_fsopen("tmpfs", 0); + ASSERT_GE(fd_context, 0); + + ASSERT_EQ(sys_fsconfig(fd_context, FSCONFIG_CMD_CREATE, NULL, NULL, 0), 0); + + fd_tmpfs = sys_fsmount(fd_context, 0, 0); + ASSERT_GE(fd_tmpfs, 0); + + EXPECT_EQ(close(fd_context), 0); + + ASSERT_EQ(mkdirat(fd_tmpfs, "subdir", 0755), 0); + + fd_tree = sys_open_tree(fd_tmpfs, "subdir", + AT_NO_AUTOMOUNT | AT_SYMLINK_NOFOLLOW | + AT_RECURSIVE | OPEN_TREE_CLOEXEC | + OPEN_TREE_CLONE); + ASSERT_GE(fd_tree, 0); + + EXPECT_EQ(close(fd_tmpfs), 0); + + ASSERT_EQ(mkdirat(-EBADF, "/mnt/open_tree_subfolder", 0755), 0); + + ASSERT_EQ(sys_move_mount(fd_tree, "", -EBADF, "/mnt/open_tree_subfolder", MOVE_MOUNT_F_EMPTY_PATH), 0); + + EXPECT_EQ(close(fd_tree), 0); + + ASSERT_EQ(umount2("/mnt/open_tree_subfolder", 0), 0); + + EXPECT_EQ(rmdir("/mnt/open_tree_subfolder"), 0); +} + TEST_F(mount_setattr, mount_detached_mount_on_detached_mount_then_close) { int fd_tree_base = -EBADF, fd_tree_subdir = -EBADF; -- 2.47.2