cluster/gfs2-kernel/src/gfs2 log.c lops.c

cluster/gfs2-kernel/src/gfs2 log.c lops.c

[swhiteho]

CVSROOT:	/cvs/cluster
Module name:	cluster
Changes by:	swhiteho@sourceware.org	2006-01-11 17:39:57

Modified files:
	gfs2-kernel/src/gfs2: log.c lops.c 

Log message:
	Write a list of the block numbers of the succeding metadata blocks which
	are about to be committed into the log. This uses the spare space at the
	end of the log descriptor block, so mostly it doesn't actually require
	any more disk I/O to do this, and when it does, its very little.
	
	This doesn't actually change recovery (yet) since the recovery side is
	still making use of the mh_blkno field in the metadata header still. The
	intention is to use the list of block numbers instead. This has a slight
	speed advantage in recovery since we no longer need to read any block
	which is in the revoke list, since we will have already read a list of
	the block numbers ahead of time.
	
	Once this is done, we'll no longer need to use the mh_blkno field in
	the common metadata header which gives two advantages:
	
	o We don't need the bmap ioctl() since its only use is the online version
	of mkfs
	o We don't need to rewrite all the metadata headers when converting gfs1
	to gfs2
	
	I plan to use an almost identical system to deal with data blocks in
	the journal, with the addition of an extra field to flag whether the
	data block begins with the GFS magic number or not, which is required
	so that we can escape any data blocks which do start with the magic
	number. When thats done, it will greatly simplify dealing with
	journaled data files.

Patches:
http://sourceware.org/cgi-bin/cvsweb.cgi/cluster/gfs2-kernel/src/gfs2/log.c.diff?cvsroot=cluster&r1=1.28&r2=1.29
http://sourceware.org/cgi-bin/cvsweb.cgi/cluster/gfs2-kernel/src/gfs2/lops.c.diff?cvsroot=cluster&r1=1.20&r2=1.21