2024년 4월 8일 (월) 오후 1:09, Yuezhang.Mo@xxxxxxxx <Yuezhang.Mo@xxxxxxxx>님이 작성: > > It is not a good way to extend valid_size to the end of the > mmap area by writing zeros in mmap. Because after calling mmap, > no data may be written, or only a small amount of data may be > written to the head of the mmap area. > > This commit moves extending valid_size to exfat_page_mkwrite(). > In exfat_page_mkwrite() only extend valid_size to the starting > position of new data writing, which reduces unnecessary writing > of zeros. > > If the block is not mapped and is marked as new after being > mapped for writing, block_write_begin() will zero the page > cache corresponding to the block, so there is no need to call > zero_user_segment() in exfat_file_zeroed_range(). And after moving > extending valid_size to exfat_page_mkwrite(), the data written by > mmap will be copied to the page cache but the page cache may be > not mapped to the disk. Calling zero_user_segment() will cause > the data written by mmap to be cleared. So this commit removes > calling zero_user_segment() from exfat_file_zeroed_range() and > renames exfat_file_zeroed_range() to exfat_extend_valid_size(). > > Signed-off-by: Yuezhang Mo <Yuezhang.Mo@xxxxxxxx> Applied it to #dev. Thanks for your patch!
