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| author |   Christian Brauner <brauner@kernel.org> | 2025-02-21 14:13:15 +0100 |
|---|---|---|
| committer | Christian Brauner <brauner@kernel.org> | 2025-03-04 09:29:54 +0100 |
| commit | 7bece690a990177ee4dda9640b4d7236e360d826 (patch) | |
| tree | 0ce6ca07af18ac178bce92406616519de6aeb3f4 | |
| parent | selftests: sixth test for mounting detached mounts onto detached mounts (diff) | |
| download | linux-rng-7bece690a990177ee4dda9640b4d7236e360d826.tar.xz linux-rng-7bece690a990177ee4dda9640b4d7236e360d826.zip | |
selftests: seventh test for mounting detached mounts onto detached mounts
Add a test to verify that detached mounts behave correctly.
Link: https://lore.kernel.org/r/20250221-brauner-open_tree-v1-16-dbcfcb98c676@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
| -rw-r--r-- | tools/testing/selftests/mount_setattr/mount_setattr_test.c | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/tools/testing/selftests/mount_setattr/mount_setattr_test.c b/tools/testing/selftests/mount_setattr/mount_setattr_test.c index d2bf8b77df3f..1e0508cb5c2d 100644 --- a/tools/testing/selftests/mount_setattr/mount_setattr_test.c +++ b/tools/testing/selftests/mount_setattr/mount_setattr_test.c @@ -2061,4 +2061,40 @@ TEST_F(mount_setattr, two_detached_mounts_referring_to_same_anonymous_mount_name ASSERT_NE(move_mount(fd_tree1, "", -EBADF, "/tmp/target1", MOVE_MOUNT_F_EMPTY_PATH), 0); } +TEST_F(mount_setattr, two_detached_subtrees_of_same_anonymous_mount_namespace) +{ + int fd_tree1 = -EBADF, fd_tree2 = -EBADF; + + /* + * Copy the following mount tree: + * + * |-/mnt/A testing tmpfs + * `-/mnt/A/AA testing tmpfs + * `-/mnt/A/AA/B testing tmpfs + * `-/mnt/A/AA/B/BB testing tmpfs + */ + fd_tree1 = sys_open_tree(-EBADF, "/mnt/A", + AT_NO_AUTOMOUNT | AT_SYMLINK_NOFOLLOW | + AT_RECURSIVE | OPEN_TREE_CLOEXEC | + OPEN_TREE_CLONE); + ASSERT_GE(fd_tree1, 0); + + /* + * Create an O_PATH file descriptors with a separate struct file that + * refers to a subtree of the same detached mount tree as @fd_tree1 + */ + fd_tree2 = sys_open_tree(fd_tree1, "AA", + AT_NO_AUTOMOUNT | AT_SYMLINK_NOFOLLOW | + AT_EMPTY_PATH | OPEN_TREE_CLOEXEC); + ASSERT_GE(fd_tree2, 0); + + /* + * This must fail as it is only possible to attach the root of a + * detached mount tree. + */ + ASSERT_NE(move_mount(fd_tree2, "", -EBADF, "/tmp/target1", MOVE_MOUNT_F_EMPTY_PATH), 0); + + ASSERT_EQ(move_mount(fd_tree1, "", -EBADF, "/tmp/target1", MOVE_MOUNT_F_EMPTY_PATH), 0); +} + TEST_HARNESS_MAIN |