laptop-kernel/tools/testing/selftests/filesystems/mount_cycle, branch master

selftests/filesystems: test covered mounts

2026-10-06T22:45:50Z

Test that mount cycles are resolved and test that mount covers behave as expected. Link: https://patch.msgid.link/20261002-work-mount-cover-v1-3-232a8f52b43c@kernel.org Signed-off-by: Christian Brauner (Amutable)

selftests/filesystems: check that a mount namespace file on top doesn't bury a mount

2026-10-01T12:20:06Z

Add a test for moving a mount with a mount namespace file on top of it: - S, a bind mount of a file, with a newer mount namespace's file on top - A shared with a slave B that has Q on B/file - S moved onto A/file, its copy lands on B/file below Q B/file keeps reading Q and once Q is unmounted it reads the copy. Link: https://patch.msgid.link/20260930-work-mount-fixes-3-v1-9-be34c83956ae@kernel.org Signed-off-by: Christian Brauner (Amutable)

selftests/filesystems: check that a recursive bind mount can't pin the caller's mount namespace

2026-10-01T12:20:05Z

Add a test for a recursive bind mount of a namespace file in another mount namespace: - a bind mount of the network namespace file, held through a descriptor - the caller's own mount namespace file stacked on top of it there - the recursive bind mount through the descriptor fails with EINVAL - a plain bind mount of the file still works The copy would pin the namespace it is put in otherwise. Link: https://patch.msgid.link/20260930-work-mount-fixes-3-v1-5-be34c83956ae@kernel.org Signed-off-by: Christian Brauner (Amutable)

selftests/filesystems: check that a dead mount's overmount isn't followed

2026-09-26T13:47:42Z

Add overmount_reparent_test: - a mount that a file descriptor keeps alive after propagate_umount() reparented its overmount and unmounted it must not be walked into the freed overmount by move_mount(MOVE_MOUNT_BENEATH) Link: https://patch.msgid.link/20260926-work-mount-fixes-2-v1-10-f357abf3d17b@kernel.org Signed-off-by: Christian Brauner (Amutable)

selftests/filesystems: check that an unmounted mount tree isn't walked

2026-09-26T13:47:41Z

Add unmounted_tree_test: - a detached nsfs or pidfs bind mount that a file descriptor keeps alive can't be copied recursively, a copy of the mount itself and a copy of a mounted one still work - a detached tree with a child that was vacated behind it can't be copied recursively either - a copy of a detached bind mount is an ordinary mount: unlinking its mountpoint from another mount namespace unmounts it - mount_setattr() refuses to change the propagation of a detached tree and still allows it for the root of an anonymous mount namespace Every case runs in a user and mount namespace of its own. Link: https://patch.msgid.link/20260926-work-mount-fixes-2-v1-9-f357abf3d17b@kernel.org Signed-off-by: Christian Brauner (Amutable)