From patchwork Wed Feb 6 12:31:37 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Beno=C3=AEt_Canet?= X-Patchwork-Id: 218637 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 947632C02B4 for ; Thu, 7 Feb 2013 01:23:15 +1100 (EST) Received: from localhost ([::1]:33911 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1U34B0-0006Da-GU for incoming@patchwork.ozlabs.org; Wed, 06 Feb 2013 07:32:34 -0500 Received: from eggs.gnu.org ([208.118.235.92]:55136) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1U34AS-0004kL-O4 for qemu-devel@nongnu.org; Wed, 06 Feb 2013 07:32:08 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1U34AP-0004fb-7j for qemu-devel@nongnu.org; Wed, 06 Feb 2013 07:32:00 -0500 Received: from nodalink.pck.nerim.net ([62.212.105.220]:43545 helo=paradis.irqsave.net) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1U34AO-0004fH-NV for qemu-devel@nongnu.org; Wed, 06 Feb 2013 07:31:57 -0500 Received: by paradis.irqsave.net (Postfix, from userid 1002) id 1A27B874358; Wed, 6 Feb 2013 13:31:56 +0100 (CET) Received: from localhost.localdomain (unknown [192.168.77.1]) by paradis.irqsave.net (Postfix) with ESMTP id 72CE0874320; Wed, 6 Feb 2013 13:31:19 +0100 (CET) From: =?UTF-8?q?Beno=C3=AEt=20Canet?= To: qemu-devel@nongnu.org Date: Wed, 6 Feb 2013 13:31:37 +0100 Message-Id: <1360153926-9492-5-git-send-email-benoit@irqsave.net> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1360153926-9492-1-git-send-email-benoit@irqsave.net> References: <1360153926-9492-1-git-send-email-benoit@irqsave.net> MIME-Version: 1.0 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 62.212.105.220 Cc: kwolf@redhat.com, =?UTF-8?q?Beno=C3=AEt=20Canet?= , stefanha@redhat.com Subject: [Qemu-devel] =?utf-8?q?=5BRFC_V6_04/33=5D_qcow2=3A_Add_qcow2=5Fde?= =?utf-8?q?dup=5Fread=5Fmissing=5Fand=5Fconcatenate?= 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 This function is used to read missing data when unaligned writes are done. This function also concatenate missing data with the given qiov data in order to prepare a buffer used to look for duplicated clusters. Signed-off-by: Benoit Canet --- block/Makefile.objs | 1 + block/qcow2-dedup.c | 119 +++++++++++++++++++++++++++++++++++++++++++++++++++ block/qcow2.c | 35 +++++++++++++++ block/qcow2.h | 12 ++++++ 4 files changed, 167 insertions(+) create mode 100644 block/qcow2-dedup.c diff --git a/block/Makefile.objs b/block/Makefile.objs index c067f38..21afc85 100644 --- a/block/Makefile.objs +++ b/block/Makefile.objs @@ -1,5 +1,6 @@ block-obj-y += raw.o cow.o qcow.o vdi.o vmdk.o cloop.o dmg.o bochs.o vpc.o vvfat.o block-obj-y += qcow2.o qcow2-refcount.o qcow2-cluster.o qcow2-snapshot.o qcow2-cache.o +block-obj-y += qcow2-dedup.o block-obj-y += qed.o qed-gencb.o qed-l2-cache.o qed-table.o qed-cluster.o block-obj-y += qed-check.o block-obj-y += parallels.o blkdebug.o blkverify.o diff --git a/block/qcow2-dedup.c b/block/qcow2-dedup.c new file mode 100644 index 0000000..4e99eb1 --- /dev/null +++ b/block/qcow2-dedup.c @@ -0,0 +1,119 @@ +/* + * Deduplication for the QCOW2 format + * + * Copyright (C) Nodalink, SARL. 2012-2013 + * + * Author: + * Benoît Canet + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ + +#include "block/block_int.h" +#include "qemu-common.h" +#include "qcow2.h" + +/* + * Prepare a buffer containing all the required data required to compute cluster + * sized deduplication hashes. + * If sector_num or nb_sectors are not cluster-aligned, missing data + * before/after the qiov will be read. + * + * @qiov: the qiov for which missing data must be read + * @sector_num: the first sectors that must be read into the qiov + * @nb_sectors: the number of sectors to read into the qiov + * @data: the place where the data will be concatenated and stored + * @nb_data_sectors: the resulting size of the contatenated data (in sectors) + * @ret: negative on error + */ +int qcow2_dedup_read_missing_and_concatenate(BlockDriverState *bs, + QEMUIOVector *qiov, + uint64_t sector_num, + int nb_sectors, + uint8_t **data, + int *nb_data_sectors) +{ + BDRVQcowState *s = bs->opaque; + int ret = 0; + uint64_t cluster_beginning_sector; + uint64_t first_sector_after_qiov; + int cluster_beginning_nr; + int cluster_ending_nr; + int unaligned_ending_nr; + uint64_t max_cluster_ending_nr; + + /* compute how much and where to read at the beginning */ + cluster_beginning_nr = sector_num & (s->cluster_sectors - 1); + cluster_beginning_sector = sector_num - cluster_beginning_nr; + + /* for the ending */ + first_sector_after_qiov = sector_num + nb_sectors; + unaligned_ending_nr = first_sector_after_qiov & (s->cluster_sectors - 1); + cluster_ending_nr = unaligned_ending_nr ? + s->cluster_sectors - unaligned_ending_nr : 0; + + /* compute total size in sectors and allocate memory */ + *nb_data_sectors = cluster_beginning_nr + nb_sectors + cluster_ending_nr; + *data = qemu_blockalign(bs, *nb_data_sectors * BDRV_SECTOR_SIZE); + + /* read beginning */ + if (cluster_beginning_nr) { + ret = qcow2_read_cluster_data(bs, + *data, + cluster_beginning_sector, + cluster_beginning_nr); + } + + if (ret < 0) { + goto fail; + } + + /* append qiov content */ + qemu_iovec_to_buf(qiov, 0, *data + cluster_beginning_nr * BDRV_SECTOR_SIZE, + qiov->size); + + /* Fix cluster_ending_nr if we are at risk of reading outside the image + * (Cluster unaligned image size) + */ + max_cluster_ending_nr = bs->total_sectors - first_sector_after_qiov; + cluster_ending_nr = max_cluster_ending_nr < (uint64_t) cluster_ending_nr ? + (int) max_cluster_ending_nr : cluster_ending_nr; + + /* read and add ending */ + if (cluster_ending_nr) { + ret = qcow2_read_cluster_data(bs, + *data + + (cluster_beginning_nr + + nb_sectors) * + BDRV_SECTOR_SIZE, + first_sector_after_qiov, + cluster_ending_nr); + } + + if (ret < 0) { + goto fail; + } + + return 0; + +fail: + qemu_vfree(*data); + *data = NULL; + return ret; +} diff --git a/block/qcow2.c b/block/qcow2.c index 7610e56..ecbe352 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -1110,6 +1110,41 @@ fail: return ret; } +/** + * Read some data from the QCOW2 file + * + * Important: s->lock is dropped. Things can change before the function returns + * to the caller. + * + * @data: the buffer where the data must be stored + * @sector_num: the sector number to read in the QCOW2 file + * @nb_sectors: the number of sectors to read + * @ret: negative on error + */ +int qcow2_read_cluster_data(BlockDriverState *bs, + uint8_t *data, + uint64_t sector_num, + int nb_sectors) +{ + BDRVQcowState *s = bs->opaque; + QEMUIOVector qiov; + struct iovec iov; + int ret; + + iov.iov_len = nb_sectors * BDRV_SECTOR_SIZE; + iov.iov_base = data; + qemu_iovec_init_external(&qiov, &iov, 1); + qemu_co_mutex_unlock(&s->lock); + ret = bdrv_co_readv(bs, sector_num, nb_sectors, &qiov); + qemu_co_mutex_lock(&s->lock); + if (ret < 0) { + error_report("failed to read %d sectors at offset %" PRIu64 "\n", + nb_sectors, sector_num); + } + + return ret; +} + static int qcow2_change_backing_file(BlockDriverState *bs, const char *backing_file, const char *backing_fmt) { diff --git a/block/qcow2.h b/block/qcow2.h index c7b6860..0197a2b 100644 --- a/block/qcow2.h +++ b/block/qcow2.h @@ -373,6 +373,10 @@ int qcow2_backing_read1(BlockDriverState *bs, QEMUIOVector *qiov, int qcow2_mark_dirty(BlockDriverState *bs); int qcow2_update_header(BlockDriverState *bs); +int qcow2_read_cluster_data(BlockDriverState *bs, + uint8_t *data, + uint64_t sector_num, + int nb_sectors); /* qcow2-refcount.c functions */ int qcow2_refcount_init(BlockDriverState *bs); @@ -441,4 +445,12 @@ int qcow2_cache_get_empty(BlockDriverState *bs, Qcow2Cache *c, uint64_t offset, void **table); int qcow2_cache_put(BlockDriverState *bs, Qcow2Cache *c, void **table); +/* qcow2-dedup.c functions */ +int qcow2_dedup_read_missing_and_concatenate(BlockDriverState *bs, + QEMUIOVector *qiov, + uint64_t sector, + int sectors_nr, + uint8_t **dedup_cluster_data, + int *dedup_cluster_data_nr); + #endif