Add a minimal example how to specify layers via file descriptors. Signed-off-by: Christian Brauner <brauner@xxxxxxxxxx> --- Documentation/filesystems/overlayfs.rst | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/Documentation/filesystems/overlayfs.rst b/Documentation/filesystems/overlayfs.rst index 3436447123409726cbd78badea2f8b4f002e0640..4c8387e1c88068fa10c640191fe3bcc20587f6b0 100644 --- a/Documentation/filesystems/overlayfs.rst +++ b/Documentation/filesystems/overlayfs.rst @@ -440,6 +440,23 @@ For example:: fsconfig(fs_fd, FSCONFIG_SET_STRING, "datadir+", "/do2", 0); +Specifying layers via file descriptors +-------------------------------------- + +Since kernel v6.13, overlayfs supports specifying layers via file descriptors in +addition to specifying them as paths. This feature is available for the +"datadir+", "lowerdir+", "upperdir", and "workdir+" mount options with the +fsconfig syscall from the new mount api:: + + fsconfig(fs_fd, FSCONFIG_SET_FD, "lowerdir+", NULL, fd_lower1); + fsconfig(fs_fd, FSCONFIG_SET_FD, "lowerdir+", NULL, fd_lower2); + fsconfig(fs_fd, FSCONFIG_SET_FD, "lowerdir+", NULL, fd_lower3); + fsconfig(fs_fd, FSCONFIG_SET_FD, "datadir+", NULL, fd_data1); + fsconfig(fs_fd, FSCONFIG_SET_FD, "datadir+", NULL, fd_data2); + fsconfig(fs_fd, FSCONFIG_SET_FD, "workdir", NULL, fd_work); + fsconfig(fs_fd, FSCONFIG_SET_FD, "upperdir", NULL, fd_upper); + + fs-verity support ----------------- -- 2.45.2
