TAKE 946679 - fix, speedup and simplify atime handling

[Christoph Hellwig <hch@xxxxxxxxxxxxx>]

let the VFS handle atime updates and only sync back to the xfs inode when
nessecary

Date:  Wed Dec  7 11:02:48 PST 2005
Workarea:  naboo.americas.sgi.com:/go/space/hch/xfs-2.4.x
Inspected by:  dgc

The following file(s) were checked into:
  bonnie.engr.sgi.com:/isms/linux/2.4.x-xfs


Modid:  xfs-linux:xfs-kern:203362a
fs/xfs/xfs_vnodeops.c - 1.661 - changed
http://oss.sgi.com/cgi-bin/cvsweb.cgi/xfs-linux/xfs_vnodeops.c.diff?r1=text&tr1=1.661&r2=text&tr2=1.660&f=h
fs/xfs/xfs_itable.c - 1.133 - changed
http://oss.sgi.com/cgi-bin/cvsweb.cgi/xfs-linux/xfs_itable.c.diff?r1=text&tr1=1.133&r2=text&tr2=1.132&f=h
fs/xfs/xfs_dmapi.c - 1.136 - changed
http://oss.sgi.com/cgi-bin/cvsweb.cgi/xfs-linux/xfs_dmapi.c.diff?r1=text&tr1=1.136&r2=text&tr2=1.135&f=h
fs/xfs/xfs_inode_item.c - 1.123 - changed
http://oss.sgi.com/cgi-bin/cvsweb.cgi/xfs-linux/xfs_inode_item.c.diff?r1=text&tr1=1.123&r2=text&tr2=1.122&f=h
fs/xfs/xfs_inode.c - 1.424 - changed
http://oss.sgi.com/cgi-bin/cvsweb.cgi/xfs-linux/xfs_inode.c.diff?r1=text&tr1=1.424&r2=text&tr2=1.423&f=h
fs/xfs/xfs_inode.h - 1.206 - changed
http://oss.sgi.com/cgi-bin/cvsweb.cgi/xfs-linux/xfs_inode.h.diff?r1=text&tr1=1.206&r2=text&tr2=1.205&f=h
fs/xfs/linux-2.6/xfs_lrw.c - 1.231 - changed
http://oss.sgi.com/cgi-bin/cvsweb.cgi/xfs-linux/linux-2.6/xfs_lrw.c.diff?r1=text&tr1=1.231&r2=text&tr2=1.230&f=h
fs/xfs/linux-2.6/xfs_vnode.c - 1.135 - changed
http://oss.sgi.com/cgi-bin/cvsweb.cgi/xfs-linux/linux-2.6/xfs_vnode.c.diff?r1=text&tr1=1.135&r2=text&tr2=1.134&f=h
fs/xfs/linux-2.6/xfs_iops.c - 1.231 - changed
http://oss.sgi.com/cgi-bin/cvsweb.cgi/xfs-linux/linux-2.6/xfs_iops.c.diff?r1=text&tr1=1.231&r2=text&tr2=1.230&f=h
fs/xfs/linux-2.4/xfs_lrw.c - 1.226 - changed
http://oss.sgi.com/cgi-bin/cvsweb.cgi/xfs-linux/linux-2.4/xfs_lrw.c.diff?r1=text&tr1=1.226&r2=text&tr2=1.225&f=h
fs/xfs/linux-2.4/xfs_vnode.c - 1.135 - changed
http://oss.sgi.com/cgi-bin/cvsweb.cgi/xfs-linux/linux-2.4/xfs_vnode.c.diff?r1=text&tr1=1.135&r2=text&tr2=1.134&f=h
fs/xfs/linux-2.4/xfs_iops.c - 1.214 - changed
http://oss.sgi.com/cgi-bin/cvsweb.cgi/xfs-linux/linux-2.4/xfs_iops.c.diff?r1=text&tr1=1.214&r2=text&tr2=1.213&f=h