From patchwork Mon Dec 7 10:14:10 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Li, Liang Z" X-Patchwork-Id: 553327 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 682231402A0 for ; Mon, 7 Dec 2015 21:16:28 +1100 (AEDT) Received: from localhost ([::1]:53610 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1a5sqH-0003FJ-Nk for incoming@patchwork.ozlabs.org; Mon, 07 Dec 2015 05:16:25 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:45895) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1a5spx-0002bY-Tz for qemu-devel@nongnu.org; Mon, 07 Dec 2015 05:16:06 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1a5spt-0006Z5-Sl for qemu-devel@nongnu.org; Mon, 07 Dec 2015 05:16:05 -0500 Received: from mga02.intel.com ([134.134.136.20]:41947) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1a5spt-0006Yz-Nc for qemu-devel@nongnu.org; Mon, 07 Dec 2015 05:16:01 -0500 Received: from orsmga003.jf.intel.com ([10.7.209.27]) by orsmga101.jf.intel.com with ESMTP; 07 Dec 2015 02:16:01 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.20,394,1444719600"; d="scan'208";a="701678080" Received: from ll.sh.intel.com (HELO localhost) ([10.239.13.27]) by orsmga003.jf.intel.com with ESMTP; 07 Dec 2015 02:15:59 -0800 From: Liang Li To: qemu-devel@nongnu.org Date: Mon, 7 Dec 2015 18:14:10 +0800 Message-Id: <1449483251-23232-2-git-send-email-liang.z.li@intel.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1449483251-23232-1-git-send-email-liang.z.li@intel.com> References: <1449483251-23232-1-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: 134.134.136.20 Cc: amit.shah@redhat.com, stefanha@gmail.com, Liang Li , dgilbert@redhat.com, quintela@redhat.com Subject: [Qemu-devel] [v2 1/2] qemu-file: Fix qemu_put_compression_data flaw X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org 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. Signed-off-by: Liang Li --- migration/qemu-file.c | 23 +++++++++++++++++++++-- 1 file changed, 21 insertions(+), 2 deletions(-) diff --git a/migration/qemu-file.c b/migration/qemu-file.c index 0bbd257..b956ab6 100644 --- a/migration/qemu-file.c +++ b/migration/qemu-file.c @@ -606,8 +606,14 @@ 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 0 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 0. */ ssize_t qemu_put_compression_data(QEMUFile *f, const uint8_t *p, size_t size, @@ -616,7 +622,14 @@ 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 0; + } + qemu_fflush(f); + blen = IO_BUF_SIZE - sizeof(int32_t); + if (blen < compressBound(size)) { + return 0; + } } if (compress2(f->buf + f->buf_index + sizeof(int32_t), (uLongf *)&blen, (Bytef *)p, size, level) != Z_OK) { @@ -624,7 +637,13 @@ 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); }