From patchwork Wed May 4 03:40:58 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Liang Li X-Patchwork-Id: 9009301 Return-Path: X-Original-To: patchwork-qemu-devel@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 4112F9F1C1 for ; Wed, 4 May 2016 03:42:16 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 9887D20373 for ; Wed, 4 May 2016 03:42:15 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id D3921202FF for ; Wed, 4 May 2016 03:42:14 +0000 (UTC) Received: from localhost ([::1]:45550 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1axnhS-0001Iw-UY for patchwork-qemu-devel@patchwork.kernel.org; Tue, 03 May 2016 23:42:10 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:50840) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1axnhA-0000y0-I8 for qemu-devel@nongnu.org; Tue, 03 May 2016 23:41:58 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1axngp-0002hK-DZ for qemu-devel@nongnu.org; Tue, 03 May 2016 23:41:47 -0400 Received: from mga11.intel.com ([192.55.52.93]:3099) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1axngp-0002cZ-8n for qemu-devel@nongnu.org; Tue, 03 May 2016 23:41:31 -0400 Received: from orsmga002.jf.intel.com ([10.7.209.21]) by fmsmga102.fm.intel.com with ESMTP; 03 May 2016 20:41:09 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.24,574,1455004800"; d="scan'208";a="968201204" Received: from ll.sh.intel.com (HELO localhost) ([10.239.13.27]) by orsmga002.jf.intel.com with ESMTP; 03 May 2016 20:41:08 -0700 From: Liang Li To: qemu-devel@nongnu.org Date: Wed, 4 May 2016 11:40:58 +0800 Message-Id: <1462333259-3237-5-git-send-email-liang.z.li@intel.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1462333259-3237-1-git-send-email-liang.z.li@intel.com> References: <1462333259-3237-1-git-send-email-liang.z.li@intel.com> X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 192.55.52.93 Subject: [Qemu-devel] [PATCH 4/5] qemu-file: Fix qemu_put_compression_data flaw X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: amit.shah@redhat.com, Liang Li , dgilbert@redhat.com, quintela@redhat.com Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Current qemu_put_compression_data can only work with no writable QEMUFile, and can't work with the writable QEMUFile. But it does not provide any measure to prevent users from using it with a writable QEMUFile. We should fix this flaw to make it works with writable QEMUFile. Suggested-by: Juan Quintela Signed-off-by: Liang Li --- migration/qemu-file.c | 23 +++++++++++++++++++++-- migration/ram.c | 6 +++++- 2 files changed, 26 insertions(+), 3 deletions(-) diff --git a/migration/qemu-file.c b/migration/qemu-file.c index 6f4a129..b0ef1f3 100644 --- a/migration/qemu-file.c +++ b/migration/qemu-file.c @@ -607,8 +607,14 @@ uint64_t qemu_get_be64(QEMUFile *f) return v; } -/* compress size bytes of data start at p with specific compression +/* Compress size bytes of data start at p with specific compression * level and store the compressed data to the buffer of f. + * + * When f is not writable, return -1 if f has no space to save the + * compressed data. + * When f is wirtable and it has no space to save the compressed data, + * do fflush first, if f still has no space to save the compressed + * data, return -1. */ ssize_t qemu_put_compression_data(QEMUFile *f, const uint8_t *p, size_t size, @@ -617,7 +623,14 @@ ssize_t qemu_put_compression_data(QEMUFile *f, const uint8_t *p, size_t size, ssize_t blen = IO_BUF_SIZE - f->buf_index - sizeof(int32_t); if (blen < compressBound(size)) { - return 0; + if (!qemu_file_is_writable(f)) { + return -1; + } + qemu_fflush(f); + blen = IO_BUF_SIZE - sizeof(int32_t); + if (blen < compressBound(size)) { + return -1; + } } if (compress2(f->buf + f->buf_index + sizeof(int32_t), (uLongf *)&blen, (Bytef *)p, size, level) != Z_OK) { @@ -625,7 +638,13 @@ ssize_t qemu_put_compression_data(QEMUFile *f, const uint8_t *p, size_t size, return 0; } qemu_put_be32(f, blen); + if (f->ops->writev_buffer) { + add_to_iovec(f, f->buf + f->buf_index, blen); + } f->buf_index += blen; + if (f->buf_index == IO_BUF_SIZE) { + qemu_fflush(f); + } return blen + sizeof(int32_t); } diff --git a/migration/ram.c b/migration/ram.c index bc34bc5..7e62d8d 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -821,7 +821,11 @@ static int do_compress_ram_page(CompressParam *param) RAM_SAVE_FLAG_COMPRESS_PAGE); blen = qemu_put_compression_data(param->file, p, TARGET_PAGE_SIZE, migrate_compress_level()); - bytes_sent += blen; + if (blen < 0) { + error_report("Insufficient buffer for compressed data!"); + } else { + bytes_sent += blen; + } return bytes_sent; }