From patchwork Thu May 5 07:32:54 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Li, Liang Z" X-Patchwork-Id: 618864 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 3r0n0p5Chhz9ssM for ; Thu, 5 May 2016 17:41:46 +1000 (AEST) Received: from localhost ([::1]:52193 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ayDun-00008t-58 for incoming@patchwork.ozlabs.org; Thu, 05 May 2016 03:41:41 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:58183) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ayDqj-0000P0-F7 for qemu-devel@nongnu.org; Thu, 05 May 2016 03:37:45 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ayDqX-0001DM-JI for qemu-devel@nongnu.org; Thu, 05 May 2016 03:37:24 -0400 Received: from mga02.intel.com ([134.134.136.20]:38070) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ayDqX-00012b-Cn for qemu-devel@nongnu.org; Thu, 05 May 2016 03:37:17 -0400 Received: from orsmga002.jf.intel.com ([10.7.209.21]) by orsmga101.jf.intel.com with ESMTP; 05 May 2016 00:36:52 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.24,581,1455004800"; d="scan'208";a="969174566" Received: from ll.sh.intel.com (HELO localhost) ([10.239.13.27]) by orsmga002.jf.intel.com with ESMTP; 05 May 2016 00:36:51 -0700 From: Liang Li To: qemu-devel@nongnu.org Date: Thu, 5 May 2016 15:32:54 +0800 Message-Id: <1462433579-13691-5-git-send-email-liang.z.li@intel.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1462433579-13691-1-git-send-email-liang.z.li@intel.com> References: <1462433579-13691-1-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 Subject: [Qemu-devel] [PATCH v2 4/9] 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+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" 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 Suggested-by: Juan Quintela --- migration/qemu-file.c | 23 +++++++++++++++++++++-- migration/ram.c | 18 +++++++++++++----- 2 files changed, 34 insertions(+), 7 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 5d544c0..8a21c2c 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -821,7 +821,13 @@ 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) { + bytes_sent = 0; + qemu_file_set_error(migrate_get_current()->to_dst_file, blen); + error_report("compressed data failed!"); + } else { + bytes_sent += blen; + } return bytes_sent; } @@ -965,10 +971,12 @@ static int ram_save_compressed_page(QEMUFile *f, PageSearchStatus *pss, * first page is sent out before other pages */ bytes_xmit = do_compress_ram_page(&comp_param[0]); - acct_info.norm_pages++; - qemu_put_qemu_file(f, comp_param[0].file); - *bytes_transferred += bytes_xmit; - pages = 1; + if (bytes_xmit > 0) { + acct_info.norm_pages++; + qemu_put_qemu_file(f, comp_param[0].file); + *bytes_transferred += bytes_xmit; + pages = 1; + } } } else { pages = save_zero_page(f, block, offset, p, bytes_transferred);