Allow overlayfs to use O_PATH file descriptors when specifying layers. Userspace must currently use non-O_PATH file desriptors which is often pointless especially if the file descriptors have been created via open_tree(OPEN_TREE_CLONE). This has been a frequent request and came up again in [1]. Link: https://lore.kernel.org/r/fd8f6574-f737-4743-b220-79c815ee1554@xxxxxxxxxxxx [1] Signed-off-by: Christian Brauner <brauner@xxxxxxxxxx> --- Christian Brauner (2): fs: support O_PATH fds with FSCONFIG_SET_FD selftests/overlayfs: test specifying layers as O_PATH file descriptors fs/fs_parser.c | 12 ++-- fs/fsopen.c | 7 ++- fs/overlayfs/params.c | 10 ++-- include/linux/fs_context.h | 1 + include/linux/fs_parser.h | 6 +- .../filesystems/overlayfs/set_layers_via_fds.c | 65 ++++++++++++++++++++++ 6 files changed, 87 insertions(+), 14 deletions(-) --- base-commit: 2014c95afecee3e76ca4a56956a936e23283f05b change-id: 20250207-work-overlayfs-38fb9156d4c4
