From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 73124347BCA; Wed, 12 Nov 2025 18:15:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762971334; cv=none; b=nHydcTr/ooTQl6HJ0/mdJ9Fpi12o4YHPt3BwEqZt9a6NfkmZ5LuMNbq4/v4W/L1BNU4rfdsPMsFsvlEhIv2ds/vsUp7EGA4pdZCFuyKr50bZFr3plSF78dBTGIaFQ+KUwYyLW2/KooQXKZGH/5zFB+QDseJEtxF+KZe706KZQ6k= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762971334; c=relaxed/simple; bh=5sj5AT6ZW1JYcc0GL5ougXifFuChNyhoOoOgCYfR5YI=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=kshuiQEyGd8wwgkdRHL75QcImMBmZ+hvHQh5nEWx7OrQOjIXd3kWzyXbXu+kq7mz3k9sSOCK1lSe5f83tn4ggvsnZCSStwVAB8rdupUcPx/woA3qUthkTTYEJ3Ha/fq2N/LDzFiWn5Z51hfOc4PRFDlEg3j5uQ83PqwLo3Rhblg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=m3TehXnr; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="m3TehXnr" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0053FC4CEF1; Wed, 12 Nov 2025 18:15:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1762971334; bh=5sj5AT6ZW1JYcc0GL5ougXifFuChNyhoOoOgCYfR5YI=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=m3TehXnrBlZslNgtOhB6Uwj+KoVHRdcP9DjQlwK+NbRrr/nCm+0pdm5Da0rOKoyST mqVhD4rtF3PqSLC/mtJDda5wVrOAsVYnZKMDFrouxeYPn1PZr7EzVw0VLlN5CwTAG2 kOgs+0HzPXSfv5qI7LFK7OW4Za5bfCwLcQx1HsIgU0ZYcyGJCT9yDr4gFdZPg+eVA/ bLM0Ijtyq3LQwkiS0Uk8h0hdejnKyZM+FwAW1CIX9x7+gL0tU4IvdF89Ed1JRDYC9m zuPrh5BOyyIkHv2wVS1AsM6S7CBm76VaXHI0yFFVkx5W8AAMGHWRFRRTUe8u1eJ9yc ok3tbtJjabpEg== Date: Wed, 12 Nov 2025 10:15:33 -0800 From: "Darrick J. Wong" To: John Garry Cc: zlang@redhat.com, fstests@vger.kernel.org, linux-ext4@vger.kernel.org Subject: Re: [PATCH 7/7] generic/774: turn off lfsr Message-ID: <20251112181533.GE196366@frogsfrogsfrogs> References: <176279908967.605950.2192923313361120314.stgit@frogsfrogsfrogs> <176279909135.605950.17114455316765178991.stgit@frogsfrogsfrogs> <8d9dc58f-ba64-4abe-91b9-251636527a65@oracle.com> Precedence: bulk X-Mailing-List: linux-ext4@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <8d9dc58f-ba64-4abe-91b9-251636527a65@oracle.com> On Tue, Nov 11, 2025 at 09:01:59AM +0000, John Garry wrote: > On 10/11/2025 18:27, Darrick J. Wong wrote: > > From: Darrick J. Wong > > > > This test fails mostly-predictably across my testing fleet with: > > > > --- /run/fstests/bin/tests/generic/774.out 2025-10-20 10:03:43.432910446 -0700 > > +++ /var/tmp/fstests/generic/774.out.bad 2025-11-10 01:14:58.941775866 -0800 > > @@ -1,2 +1,11 @@ > > QA output created by 774 > > +fio: failed initializing LFSR > > +verify: bad magic header 0, wanted acca at file /opt/test-file offset 0, length 33554432 (requested block: offset=0, length=33554432) > > +verify: bad magic header 0, wanted acca at file /opt/test-file offset 33554432, length 33554432 (requested block: offset=33554432, length=33554432) > > +verify: bad magic header 0, wanted acca at file /opt/test-file offset 67108864, length 33554432 (requested block: offset=67108864, length=33554432) > > +verify: bad magic header 0, wanted acca at file /opt/test-file offset 100663296, length 33554432 (requested block: offset=100663296, length=33554432) > > +verify: bad magic header 0, wanted acca at file /opt/test-file offset 134217728, length 33554432 (requested block: offset=134217728, length=33554432) > > +verify: bad magic header 0, wanted acca at file /opt/test-file offset 167772160, length 33554432 (requested block: offset=167772160, length=33554432) > > +verify: bad magic header 0, wanted acca at file /opt/test-file offset 201326592, length 33554432 (requested block: offset=201326592, length=33554432) > > +verify: bad magic header 0, wanted acca at file /opt/test-file offset 234881024, length 33554432 (requested block: offset=234881024, length=33554432) > > Silence is golden > > > > I'm not sure why the linear feedback shift register algorithm is > > specifically needed for this test. > > > > Cc: # v2025.10.20 > > Fixes: 9117fb93b41c38 ("generic: Add atomic write test using fio verify on file mixed mappings") > > Signed-off-by: "Darrick J. Wong" > > Reviewed-by: John Garry > > BTW, if you would like to make further tidy ups, then I don't think that > verify_write_sequence=0 is required (for verify config). That is only > relevant when we have multiple threads writing to the same region, which I > don't think is the case here. No I would not. Send a separate patch with a separate justification please. --D > cheers > > > --- > > tests/generic/774 | 4 ---- > > 1 file changed, 4 deletions(-) > > > > > > diff --git a/tests/generic/774 b/tests/generic/774 > > index 28886ed5b09ff7..86ab01fbd35874 100755 > > --- a/tests/generic/774 > > +++ b/tests/generic/774 > > @@ -56,14 +56,12 @@ group_reporting=1 > > ioengine=libaio > > rw=randwrite > > io_size=$((filesize/3)) > > -random_generator=lfsr > > # Create unwritten extents > > [prep_unwritten_blocks] > > ioengine=falloc > > rw=randwrite > > io_size=$((filesize/3)) > > -random_generator=lfsr > > EOF > > cat >$fio_aw_config < > @@ -73,7 +71,6 @@ ioengine=libaio > > rw=randwrite > > direct=1 > > atomic=1 > > -random_generator=lfsr > > group_reporting=1 > > filename=$testfile > > @@ -93,7 +90,6 @@ cat >$fio_verify_config < > [verify_job] > > ioengine=libaio > > rw=read > > -random_generator=lfsr > > group_reporting=1 > > filename=$testfile > > > >