korg/linux
0
0
Fork 0
mirror of https://mirrors.bfsu.edu.cn/git/linux.git synced 2024-11-26 05:34:13 +08:00
Code Issues Packages Projects Releases Wiki Activity

nilfs2: insert explanations in gcinode file

Browse Source 
The file gcinode.c gives buffer cache functions for on-disk blocks
moved in garbage collection.  Joern Engel has suggested inserting its
explanations in the source file (Message-ID:
<20080917144146.GD8750@logfs.org> and
<20080917224953.GB14644@logfs.org>).

This follows the comment.

Cc: Joern Engel <joern@logfs.org>
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>
This commit is contained in:
Ryusuke Konishi 2009-04-06 19:01:45 -07:00 committed by Linus Torvalds
parent 47420c7998
commit 047180f2d7
1 changed files with 20 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

21
fs/nilfs2/gcinode.c
View File

@ -1,5 +1,5 @@
/*
* gcinode.c - NILFS memory inode for GC
* gcinode.c - dummy inodes to buffer blocks for garbage collection
*
* Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
*
@ -22,6 +22,25 @@
* Revised by Ryusuke Konishi <ryusuke@osrg.net>.
*
*/
/*
* This file adds the cache of on-disk blocks to be moved in garbage
* collection. The disk blocks are held with dummy inodes (called
* gcinodes), and this file provides lookup function of the dummy
* inodes and their buffer read function.
*
* Since NILFS2 keeps up multiple checkpoints/snapshots accross GC, it
* has to treat blocks that belong to a same file but have different
* checkpoint numbers. To avoid interference among generations, dummy
* inodes are managed separatly from actual inodes, and their lookup
* function (nilfs_gc_iget) is designed to be specified with a
* checkpoint number argument as well as an inode number.
*
* Buffers and pages held by the dummy inodes will be released each
* time after they are copied to a new log. Dirty blocks made on the
* current generation and the blocks to be moved by GC never overlap
* because the dirty blocks make a new generation; they rather must be
* written individually.
*/
#include <linux/buffer_head.h>
#include <linux/mpage.h>