From patchwork Tue Feb 27 04:40:21 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Darrick J. Wong" X-Patchwork-Id: 13573249 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 4C8794F1F2; Tue, 27 Feb 2024 04:40:21 +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=1709008822; cv=none; b=kFnn2t6dmE6hwu8fA/A0b96+Bvl6UcheJrrvVxZJZvVCrk/cTlxSxJywepOaxJ9Yb5gJ/TDzl4h3fyOqBmmB7G2YQFuDecx+8kOUg1wkmVO8TKaT3R6um8e5tumowo29cAzqR/ivjtRmg3Uy24J+NSO9It7ar5iUq/D2ImJpsp4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709008822; c=relaxed/simple; bh=gh27Pzf7dE7+lEXjdVtsyqFVT0HebT7CruYVsqhW3gA=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=F84jOOrY6oYorSZPqr1KWRoIJ8Dy01fFd79xs9Es5/MtECV8PBCStyZ9wk5YnyIClyEZyC/tcUL3ZzwZzP3gM2+KfOjPVVKo0Xo76+dXPK2B1l7bbCutcY2BfFf2NbSfT8p8IX6UXLNKSC4KvUkg7eEFGqQCGP6Q8SU2SypFeVI= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Y/bmuqNz; 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="Y/bmuqNz" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C1B46C43390; Tue, 27 Feb 2024 04:40:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1709008821; bh=gh27Pzf7dE7+lEXjdVtsyqFVT0HebT7CruYVsqhW3gA=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Y/bmuqNzT6v02yfNpR1n1l+Htyj8qCrKdnIB0Iw2uW/76tUTblZIluBh73+wS9KP0 jr3hPjr/MUG63BorkXyWRt5IDzCCPbcZEZtJ3FcC/axoS3TBl1KrLZ96OjhnXy678v BvYpWs32+EYkYWiRZKC2UcWeU+iZDP+Xvcfhvp03andGO1uESHKLfNSSE1Phcy0GQQ LULMVG8A4R3tnqd8yrY5czRwx43L1xsVpbXKmMwayuhVaRMGpDcQ6qJc0oKfSSvLAq Njf2yPUGethsVNSU/ObSNyQGrVbbMsh5/zhzfQgUy6/Z1lEUAbPvV/XygzzZ/iPLeu ceKgHK9K+MhQQ== Date: Mon, 26 Feb 2024 20:40:21 -0800 From: "Darrick J. Wong" To: zlang@redhat.com Cc: linux-xfs@vger.kernel.org, guan@eryu.me, fstests@vger.kernel.org Subject: [PATCH v1.1 1/8] generic/604: try to make race occur reliably Message-ID: <20240227044021.GT616564@frogsfrogsfrogs> References: <170899915207.896550.7285890351450610430.stgit@frogsfrogsfrogs> <170899915233.896550.17140520436176386775.stgit@frogsfrogsfrogs> Precedence: bulk X-Mailing-List: linux-xfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <170899915233.896550.17140520436176386775.stgit@frogsfrogsfrogs> This test will occasionaly fail like so: --- /tmp/fstests/tests/generic/604.out 2024-02-03 12:08:52.349924277 -0800 +++ /var/tmp/fstests/generic/604.out.bad 2024-02-05 04:35:55.020000000 -0800 @@ -1,2 +1,5 @@ QA output created by 604 -Silence is golden +mount: /opt: /dev/sda4 already mounted on /opt. + dmesg(1) may have more information after failed mount system call. +mount -o usrquota,grpquota,prjquota, /dev/sda4 /opt failed +(see /var/tmp/fstests/generic/604.full for details) As far as I can tell, the cause of this seems to be _scratch_mount getting forked and exec'd before the backgrounded umount process has a chance to enter the kernel. When this occurs, the mount() system call will return -EBUSY because this isn't an attempt to make a bind mount. Slow things down slightly by stalling the mount by 10ms. Signed-off-by: Darrick J. Wong Reviewed-by: Zorro Lang --- v1.1: indent commit message, fix busted comment --- tests/generic/604 | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/tests/generic/604 b/tests/generic/604 index cc6a4b214f..00da56dd70 100755 --- a/tests/generic/604 +++ b/tests/generic/604 @@ -24,10 +24,12 @@ _scratch_mount for i in $(seq 0 500); do $XFS_IO_PROG -f -c "pwrite 0 4K" $SCRATCH_MNT/$i >/dev/null done -# For overlayfs, avoid unmouting the base fs after _scratch_mount -# tries to mount the base fs +# For overlayfs, avoid unmouting the base fs after _scratch_mount tries to +# mount the base fs. Delay the mount attempt by a small amount in the hope +# that the mount() call will try to lock s_umount /after/ umount has already +# taken it. $UMOUNT_PROG $SCRATCH_MNT & -_scratch_mount +sleep 0.01s ; _scratch_mount wait echo "Silence is golden"