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>
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 9ac2625..2c5df1d 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -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);
