From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:59821) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Upfpa-0000j5-4B for qemu-devel@nongnu.org; Thu, 20 Jun 2013 10:27:28 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1UpfpT-0000yG-Et for qemu-devel@nongnu.org; Thu, 20 Jun 2013 10:27:22 -0400 Received: from nodalink.pck.nerim.net ([62.212.105.220]:37554 helo=paradis.irqsave.net) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UpfpS-0000y6-Ru for qemu-devel@nongnu.org; Thu, 20 Jun 2013 10:27:15 -0400 From: =?UTF-8?q?Beno=C3=AEt=20Canet?= Date: Thu, 20 Jun 2013 16:26:15 +0200 Message-Id: <1371738392-9594-8-git-send-email-benoit@irqsave.net> In-Reply-To: <1371738392-9594-1-git-send-email-benoit@irqsave.net> References: <1371738392-9594-1-git-send-email-benoit@irqsave.net> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Subject: [Qemu-devel] =?utf-8?q?=5BRFC_V8_07/24=5D_qcow2=3A_Add_qcow2=5Fde?= =?utf-8?q?dup=5Fread=5Fmissing=5Fand=5Fconcatenate?= List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: kwolf@redhat.com, =?UTF-8?q?Beno=C3=AEt=20Canet?= , stefanha@redhat.com 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 | 2 +- block/qcow2-dedup.c | 121 +++++++++++++++++++++++++++++++++++++++++++++= ++++++ block/qcow2.c | 35 +++++++++++++++ block/qcow2.h | 13 ++++++ 4 files changed, 170 insertions(+), 1 deletion(-) create mode 100644 block/qcow2-dedup.c diff --git a/block/Makefile.objs b/block/Makefile.objs index 2d1a269..088407a 100644 --- a/block/Makefile.objs +++ b/block/Makefile.objs @@ -1,6 +1,6 @@ block-obj-y +=3D raw.o cow.o qcow.o vdi.o vmdk.o cloop.o dmg.o bochs.o v= pc.o vvfat.o block-obj-y +=3D qcow2.o qcow2-refcount.o qcow2-cluster.o qcow2-snapshot= .o qcow2-cache.o -block-obj-y +=3D qcow2-journal.o qcow2-log-store.o qcow2-hash-store.o qc= ow2-store.o +block-obj-y +=3D qcow2-journal.o qcow2-log-store.o qcow2-hash-store.o qc= ow2-store.o qcow2-dedup.o block-obj-y +=3D qed.o qed-gencb.o qed-l2-cache.o qed-table.o qed-cluste= r.o block-obj-y +=3D qed-check.o block-obj-y +=3D vhdx.o diff --git a/block/qcow2-dedup.c b/block/qcow2-dedup.c new file mode 100644 index 0000000..bc6e2c2 --- /dev/null +++ b/block/qcow2-dedup.c @@ -0,0 +1,121 @@ +/* + * Deduplication for the QCOW2 format + * + * Copyright (C) Nodalink, SARL. 2012-2013 + * + * Author: + * Beno=C3=AEt 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 includ= ed in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRE= SS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILI= TY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHA= LL + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR = OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISI= NG FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALING= S IN + * THE SOFTWARE. + */ + +#include "block/block_int.h" +#include "qemu-common.h" +#include "qcow2.h" + +/* + * Prepare a buffer containing everything 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 qio= v + * @nb_sectors: the number of sectors to read into the qiov + * @data: the place where the data will be concatenated an= d stored + * the caller is responsible to use qemu_vfree= () to + * data on success. + * @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 =3D bs->opaque; + int ret =3D 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 =3D sector_num & (s->cluster_sectors - 1); + cluster_beginning_sector =3D sector_num - cluster_beginning_nr; + + /* for the ending */ + first_sector_after_qiov =3D sector_num + nb_sectors; + unaligned_ending_nr =3D first_sector_after_qiov & (s->cluster_sector= s - 1); + cluster_ending_nr =3D unaligned_ending_nr ? + s->cluster_sectors - unaligned_ending_nr : 0; + + /* compute total size in sectors and allocate memory */ + *nb_data_sectors =3D cluster_beginning_nr + nb_sectors + cluster_end= ing_nr; + *data =3D qemu_blockalign(bs, *nb_data_sectors * BDRV_SECTOR_SIZE); + + /* read beginning */ + if (cluster_beginning_nr) { + ret =3D 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_SECTO= R_SIZE, + qiov->size); + + /* Fix cluster_ending_nr if we are at risk of reading outside the im= age + * (Cluster unaligned image size) + */ + max_cluster_ending_nr =3D bs->total_sectors - first_sector_after_qio= v; + cluster_ending_nr =3D max_cluster_ending_nr < (uint64_t) cluster_end= ing_nr ? + (int) max_cluster_ending_nr : cluster_ending_nr; + + /* read and add ending */ + if (cluster_ending_nr) { + ret =3D 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 =3D NULL; + return ret; +} diff --git a/block/qcow2.c b/block/qcow2.c index 2e346d8..34b2a87 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -1157,6 +1157,41 @@ fail: return ret; } =20 +/** + * 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 + */ +coroutine_fn int qcow2_read_cluster_data(BlockDriverState *bs, + uint8_t *data, + uint64_t sector_num, + int nb_sectors) +{ + BDRVQcowState *s =3D bs->opaque; + QEMUIOVector qiov; + struct iovec iov; + int ret; + + iov.iov_len =3D nb_sectors * BDRV_SECTOR_SIZE; + iov.iov_base =3D data; + qemu_iovec_init_external(&qiov, &iov, 1); + qemu_co_mutex_unlock(&s->lock); + ret =3D qcow2_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 c0dbfe3..9a9abd3 100644 --- a/block/qcow2.h +++ b/block/qcow2.h @@ -539,6 +539,10 @@ int qcow2_backing_read1(BlockDriverState *bs, QEMUIO= Vector *qiov, =20 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); =20 /* qcow2-refcount.c functions */ int qcow2_refcount_init(BlockDriverState *bs); @@ -717,4 +721,13 @@ int qcow2_store_load(BlockDriverState *bs, QCowStore= *store); int qcow2_store_start(BlockDriverState *bs, QCowStore *store); int qcow2_store_forget(BlockDriverState *bs, QCowStore *store); =20 +/* 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_dat= a, + int *dedup_cluster_data_nr)= ; + + #endif --=20 1.7.10.4