On 10/28/21 3:09 PM, Joseph Qi wrote: > Hi Jan, > > On 10/25/21 11:13 PM, Jan Kara wrote: >> ocfs2_truncate_file() did unmap invalidate page cache pages before >> zeroing partial tail cluster and setting i_size. Thus some pages could >> be left (and likely have left if the cluster zeroing happened) in the >> page cache beyond i_size after truncate finished letting user possibly >> see stale data once the file was extended again. Also the tail cluster > > I don't quite understand the case. > truncate_inode_pages() will truncate pages from new_i_size to i_size, > and the following ocfs2_orphan_for_truncate() will zero range and then > update i_size for inode as well as dinode. > So once truncate finished, how stale data exposing happens? Or do you > mean a race case between the above two steps? > Or do you mean ocfs2_zero_range_for_truncate() will grab and zero eof pages? Though it depends on block_write_full_page() to write out, the pages are zeroed now. Still a little confused...
