From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from ipmail06.adl2.internode.on.net ([150.101.137.129]:52765 "EHLO ipmail06.adl2.internode.on.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751610AbcBJF6l (ORCPT ); Wed, 10 Feb 2016 00:58:41 -0500 Date: Wed, 10 Feb 2016 16:58:39 +1100 From: Dave Chinner Subject: Re: [PATCH 10/12] generic: disable generic/027 for tmpfs Message-ID: <20160210055838.GT19486@dastard> References: <1455069001-17846-1-git-send-email-tytso@mit.edu> <1455069001-17846-11-git-send-email-tytso@mit.edu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1455069001-17846-11-git-send-email-tytso@mit.edu> Sender: fstests-owner@vger.kernel.org To: Theodore Ts'o Cc: fstests@vger.kernel.org, hughd@google.com List-ID: On Tue, Feb 09, 2016 at 08:49:59PM -0500, Theodore Ts'o wrote: > The generic/027 test creates a large number of 1k files until the file > creation fails. On other file systems there will be a large number > zero length files because the block allocation has failed, but there > are still inodes available, and so the file creation loop runs until > the file system runs out of inodes. > > With tmpfs, we can limit the size of the file system, which limits the > block allocation, but there is no limit to the number of inodes that > can be created until kmalloc() fails --- or the OOM killer kills the > test. So this causes this test to run for a long, long time, and in > some cases the test or the test runner will get OOM killed instead. > We have other ENOSPC tests, so given that tmpfs is just so different > from all other file systems, it's simpler just to disable this test > for tmpfs than to try to make it work. This sounds like a bug in tmpfs and a potential user level DOS vector, too. Hence I dont think not running the test is the right thing to do here - tmpfs should be handling this gracefully by applying sane resource limits. Cheers, Dave. -- Dave Chinner david@fromorbit.com