Commit 272b62c1 authored by Goldwyn Rodrigues's avatar Goldwyn Rodrigues Committed by Joel Becker
Browse files

Treat writes as new when holes span across page boundaries 



When a hole spans across page boundaries, the next write forces
a read of the block. This could end up reading existing garbage
data from the disk in ocfs2_map_page_blocks. This leads to
non-zero holes. In order to avoid this, mark the writes as new
when the holes span across page boundaries.

Signed-off-by: default avatarGoldwyn Rodrigues <rgoldwyn@suse.de>
Signed-off-by: default avatarjlbec <jlbec@evilplan.org>
parent 99bdc388

fs/ocfs2/aops.c

+6 −0
Original line number Diff line number Diff line
@@ -1015,6 +1015,12 @@ static int ocfs2_prepare_page_for_write(struct inode *inode, u64 *p_blkno, 
	ocfs2_figure_cluster_boundaries(OCFS2_SB(inode->i_sb), cpos,

					&cluster_start, &cluster_end);



	/* treat the write as new if the a hole/lseek spanned across

	 * the page boundary.

	 */

	new = new | ((i_size_read(inode) <= page_offset(page)) &&

			(page_offset(page) <= user_pos));



	if (page == wc->w_target_page) {

		map_from = user_pos & (PAGE_CACHE_SIZE - 1);

		map_to = map_from + user_len;