From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-171.mta1.migadu.com (out-171.mta1.migadu.com [95.215.58.171]) (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 B4F9C39A7F3 for ; Tue, 24 Feb 2026 12:58:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.171 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771937937; cv=none; b=LTkfdsKKzGJsXRAHwXiK03fCawT8LoyZweRBRTIcfSg40fn5eq31WBCns9mc+RDUmrqqVHRJSOl71m0RcMWe5t/JFOVEPC7Wwj7XN3WtDalv4Fuj535SQrA7Ev9g/2y4W8SlCFQtIrvD8CIbGGQl6jCzMZ0hGvD7/GjVcCX4rOA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771937937; c=relaxed/simple; bh=DDw96xmoZbUt+zs0MoI3/CFecRPmq/Pl4/MVFM0h0dA=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=q3ovQOUIObHvVpT73FJWUOScQeMmCZGpomRRuk0/GVsmzF5ryX6xKtu2553rC4btVcdGU4OT7cnebz1P5OJRmcnWmUfSsIIsTXWtStR9IebsMSYqf7fYjeDSf3FVZYNhdHUkhdmgPmKnpNjTjBmebUr55FeETS3pZxZhfujsGjo= 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=ttQedrwE; arc=none smtp.client-ip=95.215.58.171 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="ttQedrwE" Date: Tue, 24 Feb 2026 12:58:31 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1771937923; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=u+wivhIr528+W6wLESqvbuF0C1RtOB8ByC0jlMyM6cc=; b=ttQedrwEbhqs8TPNzb9B3Y861TAKH54StDmEW8UqoxOWKwPfTGhRbkouy/LuWORW1iTAq6 3iX6s7XAptUtrsVJdnqPjv+U6/FPE/E3+kZLl+JhKrSQgHWm2mr9VDj5jIgTonPhNqUJ6H dhUIkRCp0FElxpQjDjSRyKjLXG75it4= X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: "Pankaj Raghav (Samsung)" To: "Darrick J. Wong" Cc: miklos@szeredi.hu, joannelkoong@gmail.com, bpf@vger.kernel.org, bernd@bsbernd.com, neal@gompa.dev, linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org Subject: Re: [PATCH 29/33] fuse: support atomic writes with iomap Message-ID: References: <177188734044.3935739.1368557343243072212.stgit@frogsfrogsfrogs> <177188734865.3935739.5549380606123677673.stgit@frogsfrogsfrogs> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <177188734865.3935739.5549380606123677673.stgit@frogsfrogsfrogs> X-Migadu-Flow: FLOW_OUT > + } > + > /* > * Unaligned direct writes require zeroing of unwritten head and tail > * blocks. Extending writes require zeroing of post-EOF tail blocks. > @@ -1873,6 +1909,12 @@ static ssize_t fuse_iomap_buffered_write(struct kiocb *iocb, > if (!iov_iter_count(from)) > return 0; > > + if (iocb->ki_flags & IOCB_ATOMIC) { > + ret = fuse_iomap_atomic_write_valid(iocb, from); > + if (ret) > + return ret; > + } > + I still haven't gone through the whole patch blizzard but I had a general question here: we don't give ATOMIC guarantees to buffered IO, so I am wondering how we give that here. For example, we might mix atomic and non atomic buffered IO during writeback. Am I missing some implementation detail that makes it possible here? I don't think we should enable this for buffered IO. -- Pankaj