From patchwork Thu Jun 23 16:53:38 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: "Dr. David Alan Gilbert" X-Patchwork-Id: 12892976 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 62A9DCCA482 for ; Thu, 23 Jun 2022 17:03:45 +0000 (UTC) Received: from localhost ([::1]:40600 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1o4QF6-0005XB-Hf for qemu-devel@archiver.kernel.org; Thu, 23 Jun 2022 13:03:44 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:60396) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1o4Q5y-0005yN-UD for qemu-devel@nongnu.org; Thu, 23 Jun 2022 12:54:20 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:30338) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1o4Q5v-0005xh-Q1 for qemu-devel@nongnu.org; Thu, 23 Jun 2022 12:54:18 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1656003254; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=XzYOGcOy1v/w7qlG3QUq+c89iqqIhsvwCuZxC/PtYlM=; b=gascZ9jMhgDJ4wFLe+e9rRUe2Z2gCLOlyEsTBve1tsuR/Hp8xyxN2nAotBlunan602HXVr 9weTRcaYHZGK2v+7lydYlYv+qt6LctIwk95ijzTWA1xxFvQsNaK6SI+Ry0z1B2v+ChTATT uvr6oBLf3myw971Q6PFUd8qHSxXWRbg= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-610-sGOZMaJZOje_tbCtF9FVtw-1; Thu, 23 Jun 2022 12:54:11 -0400 X-MC-Unique: sGOZMaJZOje_tbCtF9FVtw-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 2757B811E7A; Thu, 23 Jun 2022 16:54:11 +0000 (UTC) Received: from dgilbert-t580.localhost (unknown [10.33.36.159]) by smtp.corp.redhat.com (Postfix) with ESMTP id 2C1F72026D64; Thu, 23 Jun 2022 16:54:10 +0000 (UTC) From: "Dr. David Alan Gilbert (git)" To: qemu-devel@nongnu.org, berrange@redhat.com, huangy81@chinatelecom.cn, quintela@redhat.com, leobras@redhat.com, peterx@redhat.com Cc: jdenemar@redhat.com Subject: [PULL 09/25] migration: rename 'pos' field in QEMUFile to 'bytes_processed' Date: Thu, 23 Jun 2022 17:53:38 +0100 Message-Id: <20220623165354.197792-10-dgilbert@redhat.com> In-Reply-To: <20220623165354.197792-1-dgilbert@redhat.com> References: <20220623165354.197792-1-dgilbert@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.78 on 10.11.54.4 Received-SPF: pass client-ip=170.10.133.124; envelope-from=dgilbert@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -28 X-Spam_score: -2.9 X-Spam_bar: -- X-Spam_report: (-2.9 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.082, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" From: Daniel P. Berrangé The field name 'pos' gives the misleading impression that the QEMUFile objects are seekable. This is not the case, as in general we just have an opaque stream. The users of this method are only interested in the total bytes processed. This switches to a new name that reflects the intended usage. Every QIOChannel backed impl of QEMUFile is currently ignoring the 'pos' field. The only QEMUFile impl using 'pos' as an offset for I/O is the block device vmstate. A later patch is introducing a QIOChannel impl for the vmstate, and to handle this it is tracking a file offset itself internally to the QIOChannel impl. So when we later eliminate the QEMUFileOps callbacks later, the 'pos' field will no longer be used from any I/O read/write methods. Reviewed-by: Dr. David Alan Gilbert Signed-off-by: Daniel P. Berrangé Reviewed-by: Juan Quintela Signed-off-by: Juan Quintela Signed-off-by: Dr. David Alan Gilbert dgilbert: Fixed long line --- migration/qemu-file.c | 21 +++++++++++---------- 1 file changed, 11 insertions(+), 10 deletions(-) diff --git a/migration/qemu-file.c b/migration/qemu-file.c index 03f0b13a55..eabc2d7c6e 100644 --- a/migration/qemu-file.c +++ b/migration/qemu-file.c @@ -50,8 +50,9 @@ struct QEMUFile { */ int64_t rate_limit_used; - int64_t pos; /* start of buffer when writing, end of buffer - when reading */ + /* The sum of bytes transferred on the wire */ + int64_t total_transferred; + int buf_index; int buf_size; /* 0 when writing */ uint8_t buf[IO_BUF_SIZE]; @@ -241,14 +242,14 @@ void qemu_fflush(QEMUFile *f) } if (f->iovcnt > 0) { expect = iov_size(f->iov, f->iovcnt); - ret = f->ops->writev_buffer(f->opaque, f->iov, f->iovcnt, f->pos, - &local_error); + ret = f->ops->writev_buffer(f->opaque, f->iov, f->iovcnt, + f->total_transferred, &local_error); qemu_iovec_release_ram(f); } if (ret >= 0) { - f->pos += ret; + f->total_transferred += ret; } /* We expect the QEMUFile write impl to send the full * data set we requested, so sanity check that. @@ -357,11 +358,11 @@ static ssize_t qemu_fill_buffer(QEMUFile *f) return 0; } - len = f->ops->get_buffer(f->opaque, f->buf + pending, f->pos, + len = f->ops->get_buffer(f->opaque, f->buf + pending, f->total_transferred, IO_BUF_SIZE - pending, &local_error); if (len > 0) { f->buf_size += len; - f->pos += len; + f->total_transferred += len; } else if (len == 0) { qemu_file_set_error_obj(f, -EIO, local_error); } else if (len != -EAGAIN) { @@ -375,7 +376,7 @@ static ssize_t qemu_fill_buffer(QEMUFile *f) void qemu_update_position(QEMUFile *f, size_t size) { - f->pos += size; + f->total_transferred += size; } /** Closes the file @@ -658,7 +659,7 @@ int qemu_get_byte(QEMUFile *f) int64_t qemu_ftell_fast(QEMUFile *f) { - int64_t ret = f->pos; + int64_t ret = f->total_transferred; int i; for (i = 0; i < f->iovcnt; i++) { @@ -671,7 +672,7 @@ int64_t qemu_ftell_fast(QEMUFile *f) int64_t qemu_ftell(QEMUFile *f) { qemu_fflush(f); - return f->pos; + return f->total_transferred; } int qemu_file_rate_limit(QEMUFile *f)