From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mta1.migadu.com (out-197.mta1.migadu.com [95.215.58.197]) (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 98C434A2070 for ; Fri, 25 Sep 2026 13:37:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.197 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790343432; cv=none; b=ghN4CsW7volGdXMtT/IlRL5fsc2pRLLKIf1W7negOFObcyKhOMxrywfAK83oW7vkxNSEfFmPe5pgSD972hFL91yc4Y8ZD55ETSCndOIK5/7uNgg7XgA3GXe5rMchdnkRFoU1XNht9hcgyTnbEQllLrO700Djcg1tm7BkqC0Yxcs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790343432; c=relaxed/simple; bh=yUbhz4q8Bk6ad7ykhWaGlMSrczLK4cYYxIxLGl+Ap/U=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=LJ6gpp4SZJX7OB4rM3JWIUZz6WxfosWSGqe/yOK7E3caW+4W0wlcnhOXviVpb0YSXRzDEYUC9UORr8mk3dveL77hwfDfzvtkGfUzd3pvFfXA0bG9kAl2DsH61eiZeD6FklW4aEGXEBUIZmXM6Nc81V8hmAki1SsVnwePp3Qk3+0= 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=vcxsB362; arc=none smtp.client-ip=95.215.58.197 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="vcxsB362" X-Envelope-To: linux-kernel@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=1790343428; v=1; x=1790948228; b=vcxsB3625tFAL4PybA5yYvTPD9o3Ji3J8lNkM/K7VMe9fSXuBcyE6W0LVi5ObLYWEq07ZQqY /vCO2yAPdz13DpjC6cWKr1aXX34foP5I/Dek+cu0JaFfyC2Pkq4RNPyUDLsYHOpHOdopT6yGy7o Pc3CHfHevyuFya2CgHOF9K0Y= X-Envelope-To: linux-kernel@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-kernel@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!