On Mon, 12 Nov 2018 12:57:34 +0300 Pavel Tikhomirov <ptikhomirov@xxxxxxxxxxxxx> wrote: > If all pages are deleted from the mapping by memory reclaim and also > moved to the cleancache: > > __delete_from_page_cache > (no shadow case) > unaccount_page_cache_page > cleancache_put_page > page_cache_delete > mapping->nrpages -= nr > (nrpages becomes 0) > > We don't clean the cleancache for an inode after final file truncation > (removal). > > truncate_inode_pages_final > check (nrpages || nrexceptional) is false > no truncate_inode_pages > no cleancache_invalidate_inode(mapping) > > These way when reading the new file created with same inode we may get > these trash leftover pages from cleancache and see wrong data instead of > the contents of the new file. > > Fix it by always doing truncate_inode_pages which is already ready for > nrpages == 0 && nrexceptional == 0 case and just invalidates inode. > Data corruption sounds serious. Shouldn't we backport this into -stable kernels?
