From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mta0.migadu.com (out-247.mta0.migadu.com [91.218.175.247]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C6B4C332EBB for ; Fri, 25 Sep 2026 13:37:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.247 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790343431; cv=none; b=BtiYiqSkIhtOTuOI0O5uBNWHeDv26OtMD8KMn+Pg8Xu3y9llkTreOdUcLlx4a5ZInO/N2IYWtslAx05ZVaFzzXr83E3wIMzBkfLr+wnqYaNkwQyS8aT4fbPO/KCgkwUjdu3+RYpc3tzzDhXeBpkK1zF/1vXT14fMhWb6WOF8i6I= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790343431; c=relaxed/simple; bh=yUbhz4q8Bk6ad7ykhWaGlMSrczLK4cYYxIxLGl+Ap/U=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=OOWjCCkrfJ1TAwDpoRUjMYbfnQugVS3rDuQ9kTTtlpLjXQezDbGsprMWUfc2o9BkDoV4fQQjhwY2gRcjn+Dr/6hbjbDEqjJONhAGvQULoHudldQclahIbYLYVInEuYVRTomsDe97BbdR5BHqZycLAjaAka3mOyxUVwccBkSaYBw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=Vn+8m5D3; arc=none smtp.client-ip=91.218.175.247 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="Vn+8m5D3" X-Envelope-To: linux-xfs@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=yUbhz4q8Bk6ad7ykhWaGlMSrczLK4cYYxIxLGl+Ap/U=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1790343427; v=1; x=1790948227; b=Vn+8m5D3XbZZbmpKW7i1GL+bvbo5sKSYuE2nPA2GuBqNylNoSfWFPYzhIe36e9OTc/1cu8wH ojAoxowslfc5l7IKiugjESin6K+vCIml6X0/DUSsE8DuIy6ZOEphUFKFcpb5RgIK3c9drm4l7Tu T1oBvIFQUn5SUs7kHN44bO1A= X-Envelope-To: linux-xfs@vger.kernel.org Received: by mta12.migadu.com with ESMTPS id 5d53d689c26fed9d; Fri, 25 Sep 2026 13:37:07 +0000 X-Mizu-Trace-ID: 5d53d689c26fed9d X-Migadu-Flow: FLOW_OUT Message-ID: <69579dae-285d-472c-ba69-4279e5170502@linux.dev> Date: Fri, 25 Sep 2026 14:37:06 +0100 Precedence: bulk X-Mailing-List: linux-xfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v5 5/9] block: fail a short atomic pin in bio_iov_iter_get_pages() To: Tal Zussman , Jens Axboe , Christoph Hellwig , Johannes Thumshirn , Luis Chamberlain , Hannes Reinecke , "Matthew Wilcox (Oracle)" , Christian Brauner , "Darrick J. Wong" , Keith Busch , "Martin K. Petersen" Cc: Shin'ichiro Kawasaki , linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, Sashiko References: <20260923-blkdev-fixes-v5-0-89e60d66eb38@columbia.edu> <20260923-blkdev-fixes-v5-5-89e60d66eb38@columbia.edu> Content-Language: en-US From: John Garry In-Reply-To: <20260923-blkdev-fixes-v5-5-89e60d66eb38@columbia.edu> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 9/24/26 00:56, Tal Zussman wrote: > On a partial page pin, __blkdev_direct_IO_simple() and > __blkdev_direct_IO_async() submit what was pinned with REQ_ATOMIC set > and leave the rest to the buffered fallback, tearing an IOCB_ATOMIC > write. > > This can be triggered deterministically. A 16K pwritev2(RWF_ATOMIC) > whose last page is PROT_NONE, on a scsi_debug device with atomic_wr=1, > completes short with only three of the four pages written, violating > RWF_ATOMIC semantics. I don't mean to load more work, but a blktests case for this would be great. I am consider doing it if you are too busy. Thanks!