From 3778903dd4568b9f5f8a8cd0ea3c09b40307ecd0 Mon Sep 17 00:00:00 2001 From: Goldwyn Rodrigues Date: Thu, 17 Feb 2011 09:44:40 -0600 Subject: [PATCH] Treat writes as new when holes span across page boundaries commit 272b62c1f0f6f742046e45b50b6fec98860208a0 upstream. 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: Goldwyn Rodrigues Signed-off-by: jlbec Signed-off-by: Greg Kroah-Hartman Signed-off-by: Andi Kleen --- fs/ocfs2/aops.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/fs/ocfs2/aops.c b/fs/ocfs2/aops.c index 96337a4fbbdf..1514e271d1b9 100644 --- a/fs/ocfs2/aops.c +++ b/fs/ocfs2/aops.c @@ -1039,6 +1039,12 @@ 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; -- 2.39.5