f2fs: add a case of no need to read a page in write begin

If the range we write cover the whole valid data in the last page,
we do not need to read it.

Signed-off-by: Yunlei He <heyunlei@huawei.com>
[Jaegeuk Kim: nullify the remaining area (fix: xfstests/f2fs/001)]
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This commit is contained in:
Yunlei He 2016-12-20 11:11:35 +08:00 committed by Jaegeuk Kim
parent 7855eba4d6
commit 746e240392

View File

@ -1715,6 +1715,11 @@ static int f2fs_write_begin(struct file *file, struct address_space *mapping,
if (len == PAGE_SIZE || PageUptodate(page))
return 0;
if (!(pos & (PAGE_SIZE - 1)) && (pos + len) >= i_size_read(inode)) {
zero_user_segment(page, len, PAGE_SIZE);
return 0;
}
if (blkaddr == NEW_ADDR) {
zero_user_segment(page, 0, PAGE_SIZE);
SetPageUptodate(page);
@ -1768,7 +1773,7 @@ static int f2fs_write_end(struct file *file,
* let generic_perform_write() try to copy data again through copied=0.
*/
if (!PageUptodate(page)) {
if (unlikely(copied != PAGE_SIZE))
if (unlikely(copied != len))
copied = 0;
else
SetPageUptodate(page);