From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by smtp.subspace.kernel.org (Postfix) with ESMTP id F143B1F4622; Tue, 15 Apr 2025 15:54:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=13.77.154.182 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744732465; cv=none; b=JT8blZAoTeLeEI+gMHCv52BgQ4Z8OeMx7GVb7bnpNbmZYO+YeVuhUoQKnLJgGW2L5dKQ+id/xdyfTqwZmKPhMGBzKuO1Dn2DgeghDKauJBGN5FfYJIpQksHcwqpXdMVVuuXhs7xg+NhfmJr58suY485WcYI8JPRpxQ8S9vj2vbw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744732465; c=relaxed/simple; bh=LSLbk51kH8F5qyOJzFmFGWhuZwgYpItKXvCuFHph0bk=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=DT2hZtPSACgSMymWpQlNlNqw4lt/6wAQmiUqZCRB/pegePVGO+7LxlmnSrABqBV38hwUfkGyMHDu3JWPIvELEjjH5XU4XxPlz68YwxA4FHmK1FLHF1mdkpQ07/KrIYR7V4G+g/hLM5z9xwHV5pHmFsjUUqohFZPAZ42PxIwn2x0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com; spf=pass smtp.mailfrom=linux.microsoft.com; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b=jYUT5lLN; arc=none smtp.client-ip=13.77.154.182 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b="jYUT5lLN" Received: from [100.79.96.170] (unknown [4.194.122.170]) by linux.microsoft.com (Postfix) with ESMTPSA id 70D01210C444; Tue, 15 Apr 2025 08:54:20 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 70D01210C444 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1744732463; bh=D86U+RjHrQIgQJficqmYAFKe44MOHCmygYqf7pnRLJU=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=jYUT5lLNNPaGdGMd07wKyGVW8bZr1XbnrhRjErpsqDjlhymwE3rejd7J48GFP+Dut O7Xx4XAU9ZRGOtGBJG1Z1/izSp71wX75mXcn/QrwOS/r92dJOL4+sBAhSwG7Jp+v5I ELje62XnGnx5zw0Cw+vclKPGpLylWau/GbNEapsU= Message-ID: Date: Tue, 15 Apr 2025 21:24:16 +0530 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v4 1/2] uio_hv_generic: Fix sysfs creation path for ring buffer To: Greg Kroah-Hartman Cc: "K . Y . Srinivasan" , Haiyang Zhang , Wei Liu , Dexuan Cui , Stephen Hemminger , linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org, stable@kernel.org, Saurabh Sengar , Michael Kelley References: <20250410060847.82407-1-namjain@linux.microsoft.com> <20250410060847.82407-2-namjain@linux.microsoft.com> <2025041527-cesarean-facial-cdca@gregkh> Content-Language: en-US From: Naman Jain In-Reply-To: <2025041527-cesarean-facial-cdca@gregkh> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 4/15/2025 8:40 PM, Greg Kroah-Hartman wrote: > On Thu, Apr 10, 2025 at 11:38:46AM +0530, Naman Jain wrote: >> On regular bootup, devices get registered to VMBus first, so when >> uio_hv_generic driver for a particular device type is probed, >> the device is already initialized and added, so sysfs creation in >> uio_hv_generic probe works fine. However, when device is removed >> and brought back, the channel rescinds and device again gets >> registered to VMBus. However this time, the uio_hv_generic driver is >> already registered to probe for that device and in this case sysfs >> creation is tried before the device's kobject gets initialized >> completely. >> >> Fix this by moving the core logic of sysfs creation for ring buffer, >> from uio_hv_generic to HyperV's VMBus driver, where rest of the sysfs >> attributes for the channels are defined. While doing that, make use >> of attribute groups and macros, instead of creating sysfs directly, >> to ensure better error handling and code flow. >> >> Problem path: >> vmbus_process_offer (new offer comes for the VMBus device) >> vmbus_add_channel_work >> vmbus_device_register >> |-> device_register >> | |... >> | |-> hv_uio_probe >> | |... >> | |-> sysfs_create_bin_file (leads to a warning as >> | primary channel's kobject, which is used to >> | create sysfs is not yet initialized) >> |-> kset_create_and_add >> |-> vmbus_add_channel_kobj (initialization of primary channel's >> kobject happens later) >> >> Above code flow is sequential and the warning is always reproducible in >> this path. >> >> Fixes: 9ab877a6ccf8 ("uio_hv_generic: make ring buffer attribute for primary channel") >> Cc: stable@kernel.org >> Suggested-by: Saurabh Sengar >> Suggested-by: Michael Kelley >> Signed-off-by: Naman Jain >> --- >> drivers/hv/hyperv_vmbus.h | 6 ++ >> drivers/hv/vmbus_drv.c | 110 ++++++++++++++++++++++++++++++++++- >> drivers/uio/uio_hv_generic.c | 39 ++++++------- >> include/linux/hyperv.h | 6 ++ >> 4 files changed, 138 insertions(+), 23 deletions(-) > > Always run checkpatch on a patch before submitting it for review :( > Hi Greg, I verified again and I could not see checkpatch warnings with patch 1,2. There was a warning regarding length of characters for link to previous versions in the cover letter but I ignored it. I tried on latest linux-next tip with this series fetched from lore using b4. I'm sorry, if I am missing something, but can you please try again. Thanks, Naman