From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (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 403571E8359 for ; Thu, 20 Mar 2025 15:26:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742484380; cv=none; b=gxwvGebyn3H5h+kZufhPh6hS0yZZxCxFyMMCd9K8N8AAXSS0nSZFPiEkOEw/gemyTIr8wFpqcv8SeUyF2xYlD1WLGqbwoXQQVvVlaHtPEro8XdkfzTJ6IfnUslTJatO2wZ9WbR7DTh+5NK5WSwLaeqJ1CC4VFHGsMg7liaQLF18= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742484380; c=relaxed/simple; bh=TR1eTBA7fRTupQfcNBL8gfm9cGkD0wK7jgIIEFhsD/I=; h=From:In-Reply-To:References:To:Cc:Subject:MIME-Version: Content-Type:Date:Message-ID; b=D3+Kj5QwEmjJnc43Mb6bTPaW4VrhVV6584vooGUsH87HUHHj9JO6tUTPCwwbRs/VAZzg9Qc0q5d0X9sr897657rC8y1GPquZdP8LO7hHizoJ9U7J2mcacw7MLFThf7HboVYLzai8+3ZC568xRwh/mHv3prHEQfL9OKSPyY/ta1U= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=YSklXsnD; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="YSklXsnD" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1742484378; 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=79P3Rj9ZIxn8gB2XJc6nRUWm/vSrFhJbw3HtD7EvGj0=; b=YSklXsnDvsjZhAznCMvqvcQEJqLWL6H2EFRxJucAxEOQlt4hxOJ52Zl9YL7riBLKumDVJX 9rQLHGNqkdRDvLZcPhBJ0QNu+uqHOnr8/3fwfBj0NwqZFJN7P+KX57Ebc8/fCBIy+hWCOg sa13cE8XuztHyjVNJP3/Fe8jdsD7UK0= Received: from mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-68-0M1WztXYMpy43it4VearTw-1; Thu, 20 Mar 2025 11:26:13 -0400 X-MC-Unique: 0M1WztXYMpy43it4VearTw-1 X-Mimecast-MFC-AGG-ID: 0M1WztXYMpy43it4VearTw_1742484372 Received: from mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.40]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id BC3121828B26; Thu, 20 Mar 2025 15:26:01 +0000 (UTC) Received: from warthog.procyon.org.uk (unknown [10.42.28.61]) by mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id E4B3C19560AF; Thu, 20 Mar 2025 15:25:57 +0000 (UTC) Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 From: David Howells In-Reply-To: References: <20250313233341.1675324-1-dhowells@redhat.com> <20250313233341.1675324-33-dhowells@redhat.com> To: Viacheslav Dubeyko Cc: dhowells@redhat.com, Alex Markuze , "slava@dubeyko.com" , "linux-block@vger.kernel.org" , "idryomov@gmail.com" , "jlayton@kernel.org" , "linux-fsdevel@vger.kernel.org" , "ceph-devel@vger.kernel.org" , "dongsheng.yang@easystack.cn" , "linux-kernel@vger.kernel.org" Subject: Re: [RFC PATCH 32/35] netfs: Add some more RMW support for ceph Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-ID: <3173769.1742484356.1@warthog.procyon.org.uk> Date: Thu, 20 Mar 2025 15:25:56 +0000 Message-ID: <3173770.1742484356@warthog.procyon.org.uk> X-Scanned-By: MIMEDefang 3.0 on 10.30.177.40 Viacheslav Dubeyko wrote: > > + rreq->buffer.iter = *iter; > > The struct iov_iter structure is complex enough and we assign it by value to > rreq->buffer.iter. So, the initial pointer will not receive any changes > then. Is it desired behavior here? Yes. The buffer described by the iterator is going to get partitioned across a number of subrequests, each of which will get a copy of the iterator suitably advanced and truncated. As they may run in parallel, there's no way for them to share the original iterator. David