linux/fs/gfs2
Christoph Lameter eebd2aa355 Pagecache zeroing: zero_user_segment, zero_user_segments and zero_user
Simplify page cache zeroing of segments of pages through 3 functions

zero_user_segments(page, start1, end1, start2, end2)

        Zeros two segments of the page. It takes the position where to
        start and end the zeroing which avoids length calculations and
	makes code clearer.

zero_user_segment(page, start, end)

        Same for a single segment.

zero_user(page, start, length)

        Length variant for the case where we know the length.

We remove the zero_user_page macro. Issues:

1. Its a macro. Inline functions are preferable.

2. The KM_USER0 macro is only defined for HIGHMEM.

   Having to treat this special case everywhere makes the
   code needlessly complex. The parameter for zeroing is always
   KM_USER0 except in one single case that we open code.

Avoiding KM_USER0 makes a lot of code not having to be dealing
with the special casing for HIGHMEM anymore. Dealing with
kmap is only necessary for HIGHMEM configurations. In those
configurations we use KM_USER0 like we do for a series of other
functions defined in highmem.h.

Since KM_USER0 is depends on HIGHMEM the existing zero_user_page
function could not be a macro. zero_user_* functions introduced
here can be be inline because that constant is not used when these
functions are called.

Also extract the flushing of the caches to be outside of the kmap.

[akpm@linux-foundation.org: fix nfs and ntfs build]
[akpm@linux-foundation.org: fix ntfs build some more]
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Steven French <sfrench@us.ibm.com>
Cc: Michael Halcrow <mhalcrow@us.ibm.com>
Cc: <linux-ext4@vger.kernel.org>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Anton Altaparmakov <aia21@cantab.net>
Cc: Mark Fasheh <mark.fasheh@oracle.com>
Cc: David Chinner <dgc@sgi.com>
Cc: Michael Halcrow <mhalcrow@us.ibm.com>
Cc: Steven French <sfrench@us.ibm.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-05 09:44:13 -08:00
..
locking Merge git://git.kernel.org/pub/scm/linux/kernel/git/steve/gfs2-2.6-nmw 2008-01-25 08:39:18 -08:00
acl.c
acl.h
bmap.c Pagecache zeroing: zero_user_segment, zero_user_segments and zero_user 2008-02-05 09:44:13 -08:00
bmap.h [GFS2] Remove function gfs2_get_block 2008-01-25 08:08:25 +00:00
daemon.c
daemon.h
dir.c [GFS2] Reduce inode size by moving i_alloc out of line 2008-01-25 08:18:25 +00:00
dir.h
eaops.c
eaops.h
eattr.c [GFS2] Reduce inode size by moving i_alloc out of line 2008-01-25 08:18:25 +00:00
eattr.h
gfs2.h
glock.c [GFS2] Reorganize function gfs2_glmutex_lock 2008-01-25 08:13:52 +00:00
glock.h
glops.c
glops.h
incore.h [GFS2] Remove unneeded i_spin 2008-01-25 08:18:44 +00:00
inode.c [GFS2] Lockup on error 2008-01-25 08:21:04 +00:00
inode.h
Kconfig
lm.c
lm.h
locking.c
log.c [GFS2] Fix assert in log code 2008-01-25 08:18:03 +00:00
log.h
lops.c
lops.h
main.c [GFS2] Remove unneeded i_spin 2008-01-25 08:18:44 +00:00
Makefile
meta_io.c [GFS2] Fix typo 2008-01-25 08:19:51 +00:00
meta_io.h
mount.c
mount.h
ops_address.c Pagecache zeroing: zero_user_segment, zero_user_segments and zero_user 2008-02-05 09:44:13 -08:00
ops_address.h [GFS2] Remove function gfs2_get_block 2008-01-25 08:08:25 +00:00
ops_dentry.c
ops_dentry.h
ops_export.c
ops_file.c [GFS2] Fix page_mkwrite truncation race path 2008-01-25 08:20:15 +00:00
ops_fstype.c [GFS2] Initialize extent_list earlier 2008-01-25 08:17:04 +00:00
ops_fstype.h
ops_inode.c [GFS2] Reduce inode size by moving i_alloc out of line 2008-01-25 08:18:25 +00:00
ops_inode.h
ops_super.c
ops_super.h
quota.c [GFS2] Reduce inode size by moving i_alloc out of line 2008-01-25 08:18:25 +00:00
quota.h
recovery.c fs/: Spelling fixes 2008-02-03 17:33:42 +02:00
recovery.h
rgrp.c [GFS2] Reduce inode size by moving i_alloc out of line 2008-01-25 08:18:25 +00:00
rgrp.h [GFS2] Reduce inode size by moving i_alloc out of line 2008-01-25 08:18:25 +00:00
super.c [GFS2] Initialize extent_list earlier 2008-01-25 08:17:04 +00:00
super.h
sys.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/steve/gfs2-2.6-nmw 2008-01-25 08:39:18 -08:00
sys.h
trans.c
trans.h
util.c
util.h