On 10 Apr 2007, at 07:10, Andrew Morton wrote:
On Mon, 09 Apr 2007 21:31:37 -0700 Nate Diller <[EMAIL PROTECTED]> wrote:It's very common for file systems to need to zero part or all of a page, the simplist way is just to use kmap_atomic() and memset(). There's actually a library function in include/linux/highmem.h that does exactly that, but it's confusingly named memclear_highpage_flush(), which is descriptive of *how* it does the work rather than what the *purpose* is. So this patch renames the function to zero_page_data(), and calls it from the various places thatcurrently open code it.Compile tested in x86_64. signed-off-by: Nate Diller <[EMAIL PROTECTED]> --- drivers/block/loop.c | 6 --- fs/affs/file.c | 6 ---fs/buffer.c | 53 ++++ +--------------------------fs/direct-io.c | 8 +--- fs/ecryptfs/mmap.c | 14 +------- fs/ext3/inode.c | 12 +------ fs/ext4/inode.c | 12 +------ fs/ext4/writeback.c | 12 +------ fs/gfs2/bmap.c | 6 --- fs/mpage.c | 11 +----- fs/nfs/read.c | 10 ++--- fs/nfs/write.c | 2 - fs/ntfs/aops.c | 32 +++---------------fs/ntfs/file.c | 47 ++++ +----------------------fs/ocfs2/aops.c | 5 -- fs/reiser4/plugin/file/cryptcompress.c | 19 +---------- fs/reiser4/plugin/file/file.c | 6 --- fs/reiser4/plugin/item/ctail.c | 6 --- fs/reiser4/plugin/item/extent_file_ops.c | 19 +++-------- fs/reiser4/plugin/item/tail.c | 8 +---fs/reiserfs/file.c | 39 +++++ +----------------fs/reiserfs/inode.c | 13 +------ fs/xfs/linux-2.6/xfs_lrw.c | 2 - include/linux/highmem.h | 2 - mm/filemap_xip.c | 7 ---- mm/truncate.c | 2 - 26 files changed, 78 insertions(+), 281 deletions(-)Not sure that I agree with the name zero_page_data(). People might use it to, err, zero a page's data. Whereas it is really only for use against*user* pages. zero_user_page(), perhaps. Plus..This patch as presented causes me surprising amounts of trouble. I need tosplit it up into- core plus filesystems which don't have maintainers (for me to merge)- filesystems which do have maintainers (one patch per), for maintainers to merge. - another patch for reiser4, to remain in -mm.And this is actually not possible to do, because my merge and the subsystem maintainers' merges will happen at different times. In the interveningwindow, the kernel won't compile. So instead I need to - split off the reiser4 bit - get acks from fs maintainers on the rest - merge the whole thing in one hit (minus reiser4) And I can do that, but it is the less preferable option. The better way to do this merge is: patch #1: static inline void memclear_highpage_flush(...) __deprecated { zero_user_page(...); } patch #2..n: convert filesystems. then, when all filesystems are converted, we're ready to removememclear_highpage_flush(). But we do that six months later - let's notscrew out-of-tree fs maintainers (and their users) unnecessarily.
Nate, I think you either do not understand what the KM_* constants passed to kmap_atomic() mean or you were overeager in your code replacement... You really, really cannot replace KM_BIO_SRC_IRQ with KM_USER0 in the NTFS i/o completion handler without trashing people's data left right an centre!
Best regards,
Anton
--
Anton Altaparmakov <aia21 at cam.ac.uk> (replace at with @)
Unix Support, Computing Service, University of Cambridge, CB2 3QH, UK
Linux NTFS maintainer, http://www.linux-ntfs.org/
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