From: Junxiao Bi junxiao.bi@oracle.com Subject: ocfs2: fix zero out valid data

If append-dio feature is enabled, direct-io write and fallocate could run in parallel to extend file size, fallocate used "orig_isize" to record i_size before taking "ip_alloc_sem", when ocfs2_zeroout_partial_cluster() zeroout EOF blocks, i_size maybe already extended by ocfs2_dio_end_io_write(), that will cause valid data zeroed out.

Link: https://lkml.kernel.org/r/20210722054923.24389-1-junxiao.bi@oracle.com Fixes: 6bba4471f0cc ("ocfs2: fix data corruption by fallocate") Signed-off-by: Junxiao Bi junxiao.bi@oracle.com Reviewed-by: Joseph Qi joseph.qi@linux.alibaba.com Cc: Changwei Ge gechangwei@live.cn Cc: Gang He ghe@suse.com Cc: Joel Becker jlbec@evilplan.org Cc: Jun Piao piaojun@huawei.com Cc: Mark Fasheh mark@fasheh.com Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org ---

fs/ocfs2/file.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/fs/ocfs2/file.c~ocfs2-fix-zero-out-valid-data +++ a/fs/ocfs2/file.c @@ -1935,7 +1935,6 @@ static int __ocfs2_change_file_space(str goto out_inode_unlock; }

- orig_isize = i_size_read(inode); switch (sr->l_whence) { case 0: /*SEEK_SET*/ break; @@ -1943,7 +1942,7 @@ static int __ocfs2_change_file_space(str sr->l_start += f_pos; break; case 2: /*SEEK_END*/ - sr->l_start += orig_isize; + sr->l_start += i_size_read(inode); break; default: ret = -EINVAL; @@ -1998,6 +1997,7 @@ static int __ocfs2_change_file_space(str ret = -EINVAL; }

+ orig_isize = i_size_read(inode); /* zeroout eof blocks in the cluster. */ if (!ret && change_size && orig_isize < size) { ret = ocfs2_zeroout_partial_cluster(inode, orig_isize, _