From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lj1-f197.google.com (mail-lj1-f197.google.com [209.85.208.197]) by kanga.kvack.org (Postfix) with ESMTP id C7B396B027E for ; Mon, 12 Nov 2018 07:00:13 -0500 (EST) Received: by mail-lj1-f197.google.com with SMTP id e8-v6so2646870ljg.22 for ; Mon, 12 Nov 2018 04:00:13 -0800 (PST) Received: from relay.sw.ru (relay.sw.ru. [185.231.240.75]) by mx.google.com with ESMTPS id q5-v6si16548373lji.207.2018.11.12.04.00.11 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 12 Nov 2018 04:00:12 -0800 (PST) From: Pavel Tikhomirov Subject: [PATCH v2] mm: cleancache: fix corruption on missed inode invalidation Date: Mon, 12 Nov 2018 15:00:03 +0300 Message-Id: <20181112120003.23245-1-ptikhomirov@virtuozzo.com> In-Reply-To: <20181112113153.GC7175@quack2.suse.cz> References: <20181112113153.GC7175@quack2.suse.cz> Sender: owner-linux-mm@kvack.org List-ID: To: Jan Kara Cc: Vasily Averin , Andrey Ryabinin , Konstantin Khorenko , Pavel Tikhomirov , Johannes Weiner , Mel Gorman , Matthew Wilcox , Andi Kleen , linux-mm@kvack.org, linux-kernel@vger.kernel.org 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. v2: add comment Fixes: commit 91b0abe36a7b ("mm + fs: store shadow entries in page cache") To: Andrew Morton Cc: Johannes Weiner Cc: Mel Gorman Cc: Jan Kara Cc: Matthew Wilcox Cc: Andi Kleen Cc: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org Reviewed-by: Vasily Averin Reviewed-by: Andrey Ryabinin Reviewed-by: Jan Kara Signed-off-by: Pavel Tikhomirov --- mm/truncate.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/mm/truncate.c b/mm/truncate.c index 45d68e90b703..2c5285767ce5 100644 --- a/mm/truncate.c +++ b/mm/truncate.c @@ -517,9 +517,14 @@ void truncate_inode_pages_final(struct address_space *mapping) */ xa_lock_irq(&mapping->i_pages); xa_unlock_irq(&mapping->i_pages); - - truncate_inode_pages(mapping, 0); } + + /* + * Cleancache needs notification even if there are no pages or shadow + * entries, else we will leave leftover pages in the cleancache for + * a deleted inode. + */ + truncate_inode_pages(mapping, 0); } EXPORT_SYMBOL(truncate_inode_pages_final); -- 2.17.1