1# SPDX-License-Identifier: GPL-2.0-only 2config NILFS2_FS 3 tristate "NILFS2 file system support" 4 select CRC32 5 help 6 NILFS2 is a log-structured file system (LFS) supporting continuous 7 snapshotting. In addition to versioning capability of the entire 8 file system, users can even restore files mistakenly overwritten or 9 destroyed just a few seconds ago. Since this file system can keep 10 consistency like conventional LFS, it achieves quick recovery after 11 system crashes. 12 13 NILFS2 creates a number of checkpoints every few seconds or per 14 synchronous write basis (unless there is no change). Users can 15 select significant versions among continuously created checkpoints, 16 and can change them into snapshots which will be preserved for long 17 periods until they are changed back to checkpoints. Each 18 snapshot is mountable as a read-only file system concurrently with 19 its writable mount, and this feature is convenient for online backup. 20 21 Some features including atime, extended attributes, and POSIX ACLs, 22 are not supported yet. 23 24 To compile this file system support as a module, choose M here: the 25 module will be called nilfs2. If unsure, say N. 26