From 86b0624e42d03a424e9571b8591d191c436f9af1 Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Wed, 11 May 2016 11:58:49 +0200 Subject: ext2: Avoid DAX zeroing to corrupt data Currently ext2 zeroes any data blocks allocated for DAX inode however it still returns them as BH_New. Thus DAX code zeroes them again in dax_insert_mapping() which can possibly overwrite the data that has been already stored to those blocks by a racing dax_io(). Avoid marking pre-zeroed buffers as new. Reviewed-by: Ross Zwisler Signed-off-by: Jan Kara Signed-off-by: Vishal Verma --- fs/ext2/inode.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'fs/ext2') diff --git a/fs/ext2/inode.c b/fs/ext2/inode.c index 038d0ed5f565..9a14af3b1a69 100644 --- a/fs/ext2/inode.c +++ b/fs/ext2/inode.c @@ -745,11 +745,11 @@ static int ext2_get_blocks(struct inode *inode, mutex_unlock(&ei->truncate_mutex); goto cleanup; } - } + } else + set_buffer_new(bh_result); ext2_splice_branch(inode, iblock, partial, indirect_blks, count); mutex_unlock(&ei->truncate_mutex); - set_buffer_new(bh_result); got_it: map_bh(bh_result, inode->i_sb, le32_to_cpu(chain[depth-1].key)); if (count > blocks_to_boundary) -- cgit