From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.14]) (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 392CD811F1 for ; Mon, 15 Apr 2024 16:17:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.14 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713197833; cv=none; b=L+GBslvxODE8h/vg9vqBHZ1pYnJOubBdpruvJPw8JEdWdxP9kDXRZwbH/wSRVgj0qP3SkNyrtUqhbIt6s3Qhtna0Cx4cULGT96g+rec2fec06XtAkQCNBeBCm7yKtU221ZyaQgXSk/5kha1+BJYLORwymGJxxInbOD/M6sF6V4Y= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713197833; c=relaxed/simple; bh=8hoFeujVd3Tdq+czm95H3yJuF1paGoOF85xTWnY9Xds=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=gvzXUPkaCCG/Vb9TaopTCRKrOjn4aXMov4jEDF03ogdcMRshhRffGdc7MMcVrjyNQVKCIh9r+E65aWSHqIvcLfYn18DT24Vz+3qXP2rtoaS+UmKaQSwb89ZBXzkyqwi/vN/mSbftDoIQlJP4L7WdRcxCSbVcCphZCgkS5wnELJU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=aIlDR55E; arc=none smtp.client-ip=198.175.65.14 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="aIlDR55E" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1713197830; x=1744733830; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=8hoFeujVd3Tdq+czm95H3yJuF1paGoOF85xTWnY9Xds=; b=aIlDR55EfKkTKnTRfXJQ6ONJhumCvmitDewWqENIiKBtS6o+gSiFXhEt +cF/UzKAA0nH+fjc2hASOfeRFapRlmYM6y7Rvdsm+cWGxTxnEQ9A6wTFJ 8Xu7barVtiETVDXlcfOuuGYWMFpmFD3fUzyJxJpFkoRrePoO1Kfyul3zh DwkUMWXcqCp377sKm+Ao6p/y/0coemw4DoVvdOX6vk5zOO/oYadb7Eyd4 joNTNMVcL1Up91HP7/ID7bR8gBCsJP9/1d+qzL3+bEdehLvLPRQeGn2R/ Kn6EaDmvbBo1KZElzPX9pT2GNc8Oqk5s9PqyrqQegm/qrekNOKCyGVwxt A==; X-CSE-ConnectionGUID: TJEXpiuyTeCAFxq+Pz+MTA== X-CSE-MsgGUID: Sgb2agyCRGmzsjFv0ROYbA== X-IronPort-AV: E=McAfee;i="6600,9927,11045"; a="12446899" X-IronPort-AV: E=Sophos;i="6.07,203,1708416000"; d="scan'208";a="12446899" Received: from orviesa001.jf.intel.com ([10.64.159.141]) by orvoesa106.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 Apr 2024 09:17:10 -0700 X-CSE-ConnectionGUID: hNvy9VkORdylCcrpDFVraQ== X-CSE-MsgGUID: re2Ny30YQqCTH7LFlnetAQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.07,203,1708416000"; d="scan'208";a="59403325" Received: from djiang5-mobl3.amr.corp.intel.com (HELO [10.212.61.52]) ([10.212.61.52]) by smtpauth.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 Apr 2024 09:17:09 -0700 Message-ID: <308450ff-00ad-4884-a62e-22d69a4727db@intel.com> Date: Mon, 15 Apr 2024 09:17:08 -0700 Precedence: bulk X-Mailing-List: linux-cxl@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH ndctl 1/2] daxctl/device.c: Handle special case of destroying daxX.0 To: Vishal Verma , nvdimm@lists.linux.dev, linux-cxl@vger.kernel.org Cc: Dan Williams , Alison Schofield , Ira Weiny References: <20240412-vv-daxctl-fixes-v1-0-6e808174e24f@intel.com> <20240412-vv-daxctl-fixes-v1-1-6e808174e24f@intel.com> Content-Language: en-US From: Dave Jiang In-Reply-To: <20240412-vv-daxctl-fixes-v1-1-6e808174e24f@intel.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 4/12/24 2:05 PM, Vishal Verma wrote: > The kernel has special handling for destroying the 0th dax device under > any given DAX region (daxX.0). It ensures the size is set to 0, but > doesn't actually remove the device, instead it returns an EBUSY, > indicating that this device cannot be removed. > > Add an expectation in daxctl's dev_destroy() helper to handle this case > instead of returning the error - as far as the user is concerned, the > size has been set to zero, and the destroy operation has been completed, > even if the kernel indicated an EBUSY. > > Cc: Dan Williams > Cc: Alison Schofield > Reported-by: Ira Weiny > Reported-by: Dave Jiang > Signed-off-by: Vishal Verma Reviewed-by: Dave Jiang > --- > daxctl/device.c | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/daxctl/device.c b/daxctl/device.c > index 83913430..83c61389 100644 > --- a/daxctl/device.c > +++ b/daxctl/device.c > @@ -675,6 +675,13 @@ static int dev_destroy(struct daxctl_dev *dev) > return rc; > > rc = daxctl_region_destroy_dev(daxctl_dev_get_region(dev), dev); > + /* > + * The kernel treats daxX.0 specially. It can't be deleted to ensure > + * there is always a /sys/bus/dax/ present. If this happens, an > + * EBUSY is returned. Expect it and don't treat it as an error. > + */ > + if (daxctl_dev_get_id(dev) == 0 && rc == -EBUSY) > + return 0; > if (rc < 0) > return rc; > >