From: "Aneesh Kumar K.V" Subject: Re: ext4 fallocate related crash on 2.6.26 Date: Fri, 18 Jul 2008 18:37:51 +0530 Message-ID: <20080718130751.GA25771@skywalker> References: <487C223D.6060704@cse.unsw.edu.au> <20080718120024.GA23898@skywalker> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org To: Shehjar Tikoo , Mingming Cao Return-path: Content-Disposition: inline In-Reply-To: <20080718120024.GA23898@skywalker> Sender: linux-fsdevel-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org On Fri, Jul 18, 2008 at 05:30:24PM +0530, Aneesh Kumar K.V wrote: > On Tue, Jul 15, 2008 at 02:06:21PM +1000, Shehjar Tikoo wrote: > > Hi all > > > > I've observed the following kernel crash during tests against ext4 > > fallocate'ion support on 2.6.26. > > > > Stack trace is at: > > http://www.gelato.unsw.edu.au/~shehjart/docs/ext4_fallocate_test_trace_2.6.26.txt > > > > The test involved running the following program which fallocates a given > > length in bytes then writes to it. The above crash was seen when writing > > to an ext4 disk, 2G file, in blocks of 64k with fallocate requests of > > 1mb. After each 1mb of data is written to the fallocated space, another > > 1mb is requested. This write-fallocate cycle continues till the requested > > file size is reached. The trace is from one of the crashes from the > > various runs(all crashed). I must emphasise that after one of the runs, > > the test disk could not be mounted as the filesystem was unrecognized. > > ext4dev was mounted in data=ordered mode. > > > > See the test code at: > > http://www.gelato.unsw.edu.au/~shehjart/docs/writefallocate.c > > > > The command line arguments are self-explanatory. Run without any > > arguments to see the usage message. Do change the _NR_fallocate define > > at the beginning of the file to your architecture's syscall number for > > sys_fallocate. > > > > I can run a few more tests if more info is needed. > > > Can you try this patch ? > I tested this on powerpc and x86 where i was able to reproduce the problem earlier. With the fix the test runs fine. -aneesh