This is a new patch set for the nilfs2 file system.
The first submission is found at:
http://marc.info/?l=linux-fsdevel&m=121920195516073
The old patch was not divided, and this time I divided it into 27
patches:
The patch #1 adds a document to Documentation/filesystems/
The patch #2 adds a header file of the disk format to include/linux/
The patches #2-#26 adds nilfs2 source files to fs/nilfs2/
and the patch #27 updates Makefile and Kconfig.
This patch set also includes some cleanups and improvements. The main
changes from the previous patch are as follows:
* Use the standard mm/ cache instead of uniquely implemented page
cache to hold B-tree node buffers; the peculiar page cache was
removed by this.
* Integrate two similar allocators found in DAT and inode file.
* Read requests for GC blocks are now submitted in parallel to
mitigate GC overhead.
More than 2,000 lines are reduced by the cleanups.
The patch set is available from
http://www.nilfs.org/pub/patch/nilfs2-2.6.27-rc6/
If you like a git tree:
http://git.nilfs.org/nilfs2-2.6.git nilfs2
( gitweb: http://www.nilfs.org/git/?p=nilfs2-2.6.git )
The userland tools are included in the nilfs-utils package
which is available on
http://www.nilfs.org/en/download.html
Example:
In this example, /dev/sdb1 is used as a nilfs2 partition.
- To use nilfs2 as a local file system, simply:
# mkfs -t nilfs2 /dev/sdb1
# mount -t nilfs2 /dev/sdb1 /dir
This will also invoke the cleaner through the mount helper program
(mount.nilfs2).
- Checkpoints and snapshots are managed by the following commands.
Their manpages are included in the nilfs-utils package.
lscp list checkpoints or snapshots.
mkcp make a checkpoint or a snapshot.
chcp change an existing checkpoint to a snapshot or vice versa.
rmcp invalidate specified checkpoint(s).
For example,
# lscp /dev/sdb1
will list checkpoints on the device.
The block device argument is omissible if there is no other nilfs2
partition.
# chcp ss 2
will change the past checkpoint No. 2 into snapshot.
# mkcp -s
will make a snapshot of the current state.
# lscp -s
will list snapshots
- To mount a snapshot, use the read-only option and cp= option.
# mount -t nilfs2 -r -o cp=<cno> /dev/sdb1 /snap_dir
where <cno> is the checkpoint number of the snapshot.
Snapshots are mountable concurrently with the writable mount.
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