From patchwork Sat May 14 12:45:52 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Denis V. Lunev" X-Patchwork-Id: 622228 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 3r6RLs5V4Sz9t62 for ; Sat, 14 May 2016 22:47:01 +1000 (AEST) Received: from localhost ([::1]:37617 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1b1YyB-0006NR-PP for incoming@patchwork.ozlabs.org; Sat, 14 May 2016 08:46:59 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:44167) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1b1Yxc-000540-5e for qemu-devel@nongnu.org; Sat, 14 May 2016 08:46:25 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1b1Yxa-0006tr-Ts for qemu-devel@nongnu.org; Sat, 14 May 2016 08:46:24 -0400 Received: from mailhub.sw.ru ([195.214.232.25]:14906 helo=relay.sw.ru) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1b1Yxa-0006tW-Gl for qemu-devel@nongnu.org; Sat, 14 May 2016 08:46:22 -0400 Received: from irbis.sw.ru ([10.24.38.119]) by relay.sw.ru (8.13.4/8.13.4) with ESMTP id u4ECjviZ001269; Sat, 14 May 2016 15:46:08 +0300 (MSK) From: "Denis V. Lunev" To: qemu-devel@nongnu.org Date: Sat, 14 May 2016 15:45:52 +0300 Message-Id: <1463229957-14253-5-git-send-email-den@openvz.org> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1463229957-14253-1-git-send-email-den@openvz.org> References: <1463229957-14253-1-git-send-email-den@openvz.org> X-detected-operating-system: by eggs.gnu.org: OpenBSD 3.x X-Received-From: 195.214.232.25 Subject: [Qemu-devel] [PATCH 04/10] qcow: add qcow_co_write_compressed 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: Kevin Wolf , Pavel Butsykin , Jeff Cody , Markus Armbruster , Stefan Hajnoczi , den@openvz.org, John Snow Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" From: Pavel Butsykin Added implementation of the qcow_co_write_compressed function that will allow us to safely use compressed writes for the qcow from running VMs. Signed-off-by: Pavel Butsykin Signed-off-by: Denis V. Lunev CC: Jeff Cody CC: Markus Armbruster CC: Eric Blake CC: John Snow CC: Stefan Hajnoczi CC: Kevin Wolf --- block/qcow.c | 78 +++++++++++++++++++++++++++++++++++------------------------- 1 file changed, 45 insertions(+), 33 deletions(-) diff --git a/block/qcow.c b/block/qcow.c index d6dc1b0..80a4ce8 100644 --- a/block/qcow.c +++ b/block/qcow.c @@ -909,38 +909,37 @@ static int qcow_make_empty(BlockDriverState *bs) /* XXX: put compressed sectors first, then all the cluster aligned tables to avoid losing bytes in alignment */ -static int qcow_write_compressed(BlockDriverState *bs, int64_t sector_num, - const uint8_t *buf, int nb_sectors) +static coroutine_fn int +qcow_co_write_compressed(BlockDriverState *bs, int64_t sector_num, + int nb_sectors, QEMUIOVector *qiov) { BDRVQcowState *s = bs->opaque; + QEMUIOVector hd_qiov; + struct iovec iov; z_stream strm; int ret, out_len; - uint8_t *out_buf; + uint8_t *buf, *out_buf; uint64_t cluster_offset; + buf = qemu_blockalign(bs, s->cluster_size); if (nb_sectors != s->cluster_sectors) { - ret = -EINVAL; - - /* Zero-pad last write if image size is not cluster aligned */ - if (sector_num + nb_sectors == bs->total_sectors && - nb_sectors < s->cluster_sectors) { - uint8_t *pad_buf = qemu_blockalign(bs, s->cluster_size); - memset(pad_buf, 0, s->cluster_size); - memcpy(pad_buf, buf, nb_sectors * BDRV_SECTOR_SIZE); - ret = qcow_write_compressed(bs, sector_num, - pad_buf, s->cluster_sectors); - qemu_vfree(pad_buf); + if (nb_sectors > s->cluster_sectors || + sector_num + nb_sectors != bs->total_sectors) + { + qemu_vfree(buf); + return -EINVAL; } - return ret; + /* Zero-pad last write if image size is not cluster aligned */ + memset(buf, 0, s->cluster_size); } + qemu_iovec_to_buf(qiov, 0, buf, qiov->size); out_buf = g_malloc(s->cluster_size + (s->cluster_size / 1000) + 128); /* best compression, small window, no zlib header */ memset(&strm, 0, sizeof(strm)); - ret = deflateInit2(&strm, Z_DEFAULT_COMPRESSION, - Z_DEFLATED, -12, - 9, Z_DEFAULT_STRATEGY); + ret = deflateInit2(&strm, Z_DEFAULT_COMPRESSION, Z_DEFLATED, + -12, 9, Z_DEFAULT_STRATEGY); if (ret != 0) { ret = -EINVAL; goto fail; @@ -962,28 +961,41 @@ static int qcow_write_compressed(BlockDriverState *bs, int64_t sector_num, deflateEnd(&strm); if (ret != Z_STREAM_END || out_len >= s->cluster_size) { + struct iovec iov = { + .iov_base = buf, + .iov_len = out_len, + }; + qemu_iovec_init_external(&hd_qiov, &iov, 1); /* could not compress: write normal cluster */ - ret = bdrv_write(bs, sector_num, buf, s->cluster_sectors); - if (ret < 0) { - goto fail; - } - } else { - cluster_offset = get_cluster_offset(bs, sector_num << 9, 2, - out_len, 0, 0); - if (cluster_offset == 0) { - ret = -EIO; - goto fail; - } - - cluster_offset &= s->cluster_offset_mask; - ret = bdrv_pwrite(bs->file->bs, cluster_offset, out_buf, out_len); + ret = qcow_co_writev(bs, sector_num, s->cluster_sectors, &hd_qiov); if (ret < 0) { goto fail; } + goto success; } + qemu_co_mutex_lock(&s->lock); + cluster_offset = get_cluster_offset(bs, sector_num << 9, 2, out_len, 0, 0); + qemu_co_mutex_unlock(&s->lock); + if (cluster_offset == 0) { + ret = -EIO; + goto fail; + } + cluster_offset &= s->cluster_offset_mask; + + iov = (struct iovec) { + .iov_base = out_buf, + .iov_len = out_len, + }; + qemu_iovec_init_external(&hd_qiov, &iov, 1); + ret = bdrv_co_pwritev(bs->file->bs, cluster_offset, out_len, &hd_qiov, 0); + if (ret < 0) { + goto fail; + } +success: ret = 0; fail: + qemu_vfree(buf); g_free(out_buf); return ret; } @@ -1036,7 +1048,7 @@ static BlockDriver bdrv_qcow = { .bdrv_set_key = qcow_set_key, .bdrv_make_empty = qcow_make_empty, - .bdrv_write_compressed = qcow_write_compressed, + .bdrv_co_write_compressed = qcow_co_write_compressed, .bdrv_get_info = qcow_get_info, .create_opts = &qcow_create_opts,