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