linux/fs/ext4
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
..
acl.c Introduce is_owner_or_cap() to wrap CAP_FOWNER use with fsuid check 2007-07-17 12:00:03 -07:00
acl.h [PATCH] ext4: rename ext4 symbols to avoid duplication of ext3 symbols 2006-10-11 11:14:15 -07:00
balloc.c ext4: Add multi block allocator for ext4 2008-01-29 00:19:52 -05:00
bitmap.c fs: mark nibblemap const 2007-10-17 08:42:47 -07:00
dir.c ext4: Introduce ext4_lblk_t 2008-01-28 23:58:27 -05:00
ext4_jbd2.c [PATCH] ext4: uninline large functions 2006-12-07 08:39:35 -08:00
extents.c ext4: Use the ext4_ext_actual_len() helper function 2008-01-28 23:58:27 -05:00
file.c ext4: store maxbytes for bitmapped files and return EFBIG as appropriate 2008-01-28 23:58:27 -05:00
fsync.c ext4: sparse fixes 2007-10-17 18:50:03 -04:00
group.h ext4: add ext4_group_t, and change all group variables to this type. 2008-01-28 23:58:27 -05:00
hash.c [PATCH] remove many unneeded #includes of sched.h 2007-02-14 08:09:54 -08:00
ialloc.c ext4: fix up EXT4FS_DEBUG builds 2008-01-28 23:58:27 -05:00
inode.c Pagecache zeroing: zero_user_segment, zero_user_segments and zero_user 2008-02-05 09:44:13 -08:00
ioctl.c ext4: Add EXT4_IOC_MIGRATE ioctl 2008-01-28 23:58:26 -05:00
Makefile ext4: Add multi block allocator for ext4 2008-01-29 00:19:52 -05:00
mballoc.c ext4: Add multi block allocator for ext4 2008-01-29 00:19:52 -05:00
migrate.c ext4: Add multi block allocator for ext4 2008-01-29 00:19:52 -05:00
namei.c ext4: remove unused code from ext4_find_entry() 2008-01-28 23:58:27 -05:00
namei.h [PATCH] ext4: rename ext4 symbols to avoid duplication of ext3 symbols 2006-10-11 11:14:15 -07:00
resize.c ext4: fix up EXT4FS_DEBUG builds 2008-01-28 23:58:27 -05:00
super.c ext4: Check for return value from sb_set_blocksize 2008-01-28 23:58:27 -05:00
symlink.c [PATCH] mark struct inode_operations const 1 2007-02-12 09:48:46 -08:00
xattr_security.c header cleaning: don't include smp_lock.h when not used 2007-05-08 11:15:07 -07:00
xattr_trusted.c header cleaning: don't include smp_lock.h when not used 2007-05-08 11:15:07 -07:00
xattr_user.c header cleaning: don't include smp_lock.h when not used 2007-05-08 11:15:07 -07:00
xattr.c ext4: Add multi block allocator for ext4 2008-01-29 00:19:52 -05:00
xattr.h ext4: Expand extra_inodes space per the s_{want,min}_extra_isize fields 2007-07-18 09:19:57 -04:00