From 2640c19dcab0f6530007dfb4ee5870f5d61b0772 Mon Sep 17 00:00:00 2001 From: Mauro Carvalho Chehab Date: Mon, 17 Feb 2020 17:12:12 +0100 Subject: [PATCH] docs: filesystems: convert nilfs2.txt to ReST - Add a SPDX header; - Add a document title; - Adjust document title; - Mark literal blocks as such; - use :field: markup; - Add table markups; - Add it to filesystems/index.rst. Signed-off-by: Mauro Carvalho Chehab Link: https://lore.kernel.org/r/f7989ca501585f5990fffd2d365cfca4fe9fdd6f.1581955849.git.mchehab+huawei@kernel.org Signed-off-by: Jonathan Corbet --- Documentation/filesystems/index.rst | 3 +- .../filesystems/{nilfs2.txt => nilfs2.rst} | 40 ++++++++++++++-------- 2 files changed, 27 insertions(+), 16 deletions(-) rename Documentation/filesystems/{nilfs2.txt => nilfs2.rst} (89%) diff --git a/Documentation/filesystems/index.rst b/Documentation/filesystems/index.rst index 8c8813a..0158770 100644 --- a/Documentation/filesystems/index.rst +++ b/Documentation/filesystems/index.rst @@ -70,9 +70,10 @@ Documentation for filesystem implementations. hfs hfsplus hpfs + fuse inotify isofs - fuse + nilfs2 overlayfs virtiofs vfat diff --git a/Documentation/filesystems/nilfs2.txt b/Documentation/filesystems/nilfs2.rst similarity index 89% rename from Documentation/filesystems/nilfs2.txt rename to Documentation/filesystems/nilfs2.rst index f2f3f85..6c49f04 100644 --- a/Documentation/filesystems/nilfs2.txt +++ b/Documentation/filesystems/nilfs2.rst @@ -1,5 +1,8 @@ +.. SPDX-License-Identifier: GPL-2.0 + +====== NILFS2 ------- +====== NILFS2 is a log-structured file system (LFS) supporting continuous snapshotting. In addition to versioning capability of the entire file @@ -25,9 +28,9 @@ available from the following download page. At least "mkfs.nilfs2", cleaner or garbage collector) are required. Details on the tools are described in the man pages included in the package. -Project web page: https://nilfs.sourceforge.io/ -Download page: https://nilfs.sourceforge.io/en/download.html -List info: http://vger.kernel.org/vger-lists.html#linux-nilfs +:Project web page: https://nilfs.sourceforge.io/ +:Download page: https://nilfs.sourceforge.io/en/download.html +:List info: http://vger.kernel.org/vger-lists.html#linux-nilfs Caveats ======= @@ -47,6 +50,7 @@ Mount options NILFS2 supports the following mount options: (*) == default +======================= ======================================================= barrier(*) This enables/disables the use of write barriers. This nobarrier requires an IO stack which can support barriers, and if nilfs gets an error on a barrier write, it will @@ -79,6 +83,7 @@ discard This enables/disables the use of discard/TRIM commands. nodiscard(*) The discard/TRIM commands are sent to the underlying block device when blocks are freed. This is useful for SSD devices and sparse/thinly-provisioned LUNs. +======================= ======================================================= Ioctls ====== @@ -87,9 +92,11 @@ There is some NILFS2 specific functionality which can be accessed by application through the system call interfaces. The list of all NILFS2 specific ioctls are shown in the table below. -Table of NILFS2 specific ioctls -.............................................................................. +Table of NILFS2 specific ioctls: + + ============================== =============================================== Ioctl Description + ============================== =============================================== NILFS_IOCTL_CHANGE_CPMODE Change mode of given checkpoint between checkpoint and snapshot state. This ioctl is used in chcp and mkcp utilities. @@ -142,11 +149,12 @@ Table of NILFS2 specific ioctls NILFS_IOCTL_SET_ALLOC_RANGE Define lower limit of segments in bytes and upper limit of segments in bytes. This ioctl is used by nilfs_resize utility. + ============================== =============================================== NILFS2 usage ============ -To use nilfs2 as a local file system, simply: +To use nilfs2 as a local file system, simply:: # mkfs -t nilfs2 /dev/block_device # mount -t nilfs2 /dev/block_device /dir @@ -157,18 +165,20 @@ This will also invoke the cleaner through the mount helper program Checkpoints and snapshots are managed by the following commands. Their manpages are included in the nilfs-utils package above. + ==== =========================================================== 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). + ==== =========================================================== -To mount a snapshot, +To mount a snapshot:: # mount -t nilfs2 -r -o cp= /dev/block_device /snap_dir where is the checkpoint number of the snapshot. -To unmount the NILFS2 mount point or snapshot, simply: +To unmount the NILFS2 mount point or snapshot, simply:: # umount /dir @@ -181,7 +191,7 @@ Disk format A nilfs2 volume is equally divided into a number of segments except for the super block (SB) and segment #0. A segment is the container of logs. Each log is composed of summary information blocks, payload -blocks, and an optional super root block (SR): +blocks, and an optional super root block (SR):: ______________________________________________________ | |SB| | Segment | Segment | Segment | ... | Segment | | @@ -200,7 +210,7 @@ blocks, and an optional super root block (SR): |_blocks__|_________________|__| The payload blocks are organized per file, and each file consists of -data blocks and B-tree node blocks: +data blocks and B-tree node blocks:: |<--- File-A --->|<--- File-B --->| _______________________________________________________________ @@ -213,7 +223,7 @@ files without data blocks or B-tree node blocks. The organization of the blocks is recorded in the summary information blocks, which contains a header structure (nilfs_segment_summary), per -file structures (nilfs_finfo), and per block structures (nilfs_binfo): +file structures (nilfs_finfo), and per block structures (nilfs_binfo):: _________________________________________________________________________ | Summary | finfo | binfo | ... | binfo | finfo | binfo | ... | binfo |... @@ -223,7 +233,7 @@ file structures (nilfs_finfo), and per block structures (nilfs_binfo): The logs include regular files, directory files, symbolic link files and several meta data files. The mata data files are the files used to maintain file system meta data. The current version of NILFS2 uses -the following meta data files: +the following meta data files:: 1) Inode file (ifile) -- Stores on-disk inodes 2) Checkpoint file (cpfile) -- Stores checkpoints @@ -232,7 +242,7 @@ the following meta data files: (DAT) block numbers. This file serves to make on-disk blocks relocatable. -The following figure shows a typical organization of the logs: +The following figure shows a typical organization of the logs:: _________________________________________________________________________ | Summary | regular file | file | ... | ifile | cpfile | sufile | DAT |SR| @@ -250,7 +260,7 @@ three special inodes, inodes for the DAT, cpfile, and sufile. Inodes of regular files, directories, symlinks and other special files, are included in the ifile. The inode of ifile itself is included in the corresponding checkpoint entry in the cpfile. Thus, the hierarchy -among NILFS2 files can be depicted as follows: +among NILFS2 files can be depicted as follows:: Super block (SB) | -- 2.7.4