nilfs2: update makefile and Kconfig

This adds a Makefile for the nilfs2 file system, and updates the
makefile and Kconfig file in the file system directory.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 26 insertions, 1 deletions

diff --git a/fs/Kconfig b/fs/Kconfig
index 86b203fc3c56..9f7270f36b2a 100644
--- a/fs/Kconfig
+++ b/fs/Kconfig
@@ -175,9 +175,34 @@ source "fs/qnx4/Kconfig"
 source "fs/romfs/Kconfig"
 source "fs/sysv/Kconfig"
 source "fs/ufs/Kconfig"
-
 source "fs/exofs/Kconfig"
 
+config NILFS2_FS
+        tristate "NILFS2 file system support (EXPERIMENTAL)"
+        depends on BLOCK && EXPERIMENTAL
+        select CRC32
+        help
+          NILFS2 is a log-structured file system (LFS) supporting continuous
+          snapshotting.  In addition to versioning capability of the entire
+          file system, users can even restore files mistakenly overwritten or
+          destroyed just a few seconds ago.  Since this file system can keep
+          consistency like conventional LFS, it achieves quick recovery after
+          system crashes.
+
+          NILFS2 creates a number of checkpoints every few seconds or per
+          synchronous write basis (unless there is no change).  Users can
+          select significant versions among continuously created checkpoints,
+          and can change them into snapshots which will be preserved for long
+          periods until they are changed back to checkpoints.  Each
+          snapshot is mountable as a read-only file system concurrently with
+          its writable mount, and this feature is convenient for online backup.
+
+          Some features including atime, extended attributes, and POSIX ACLs,
+          are not supported yet.
+
+          To compile this file system support as a module, choose M here: the
+          module will be called nilfs2.  If unsure, say N.
+
 endif # MISC_FILESYSTEMS
 
 menuconfig NETWORK_FILESYSTEMS