From patchwork Thu Feb 7 16:15:02 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Hajnoczi X-Patchwork-Id: 218969 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 017DD2C0091 for ; Fri, 8 Feb 2013 04:38:23 +1100 (EST) Received: from localhost ([::1]:39501 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1U3U9B-0008Ol-Jv for incoming@patchwork.ozlabs.org; Thu, 07 Feb 2013 11:16:25 -0500 Received: from eggs.gnu.org ([208.118.235.92]:46718) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1U3U8d-0007ja-DJ for qemu-devel@nongnu.org; Thu, 07 Feb 2013 11:16:01 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1U3U8A-0001Ka-4H for qemu-devel@nongnu.org; Thu, 07 Feb 2013 11:15:36 -0500 Received: from mx1.redhat.com ([209.132.183.28]:56262) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1U3U89-0001KN-Sa for qemu-devel@nongnu.org; Thu, 07 Feb 2013 11:15:22 -0500 Received: from int-mx12.intmail.prod.int.phx2.redhat.com (int-mx12.intmail.prod.int.phx2.redhat.com [10.5.11.25]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id r17GFLE8000329 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Thu, 7 Feb 2013 11:15:21 -0500 Received: from localhost (ovpn-112-34.ams2.redhat.com [10.36.112.34]) by int-mx12.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id r17GFKrk007697; Thu, 7 Feb 2013 11:15:20 -0500 From: Stefan Hajnoczi To: Date: Thu, 7 Feb 2013 17:15:02 +0100 Message-Id: <1360253705-10400-3-git-send-email-stefanha@redhat.com> In-Reply-To: <1360253705-10400-1-git-send-email-stefanha@redhat.com> References: <1360253705-10400-1-git-send-email-stefanha@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.25 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 209.132.183.28 Cc: Kevin Wolf , fsimonce@redhat.com, Stefan Hajnoczi , crobinso@redhat.com Subject: [Qemu-devel] [PATCH v3 2/5] qcow2: record fragmentation statistics during check 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 The qemu-img check command can display fragmentation statistics: * Total number of clusters in virtual disk * Number of allocated clusters * Number of fragmented clusters This patch adds fragmentation statistics support to qcow2. Compressed and normal clusters count as allocated. Zero clusters are not counted as allocated unless their L2 entry has a non-zero offset (e.g. preallocation). Only the current L1 table counts towards the statistics - snapshots are ignored. Signed-off-by: Stefan Hajnoczi --- block/qcow2-refcount.c | 25 ++++++++++++++++++++++++- 1 file changed, 24 insertions(+), 1 deletion(-) diff --git a/block/qcow2-refcount.c b/block/qcow2-refcount.c index 4eec4b1..771b7b2 100644 --- a/block/qcow2-refcount.c +++ b/block/qcow2-refcount.c @@ -917,6 +917,7 @@ static void inc_refcounts(BlockDriverState *bs, /* Flags for check_refcounts_l1() and check_refcounts_l2() */ enum { CHECK_OFLAG_COPIED = 0x1, /* check QCOW_OFLAG_COPIED matches refcount */ + CHECK_FRAG_INFO = 0x2, /* update BlockFragInfo counters */ }; /* @@ -933,6 +934,7 @@ static int check_refcounts_l2(BlockDriverState *bs, BdrvCheckResult *res, { BDRVQcowState *s = bs->opaque; uint64_t *l2_table, l2_entry; + uint64_t next_contiguous_offset = 0; int i, l2_size, nb_csectors, refcount; /* Read L2 table from disk */ @@ -963,6 +965,17 @@ static int check_refcounts_l2(BlockDriverState *bs, BdrvCheckResult *res, l2_entry &= s->cluster_offset_mask; inc_refcounts(bs, res, refcount_table, refcount_table_size, l2_entry & ~511, nb_csectors * 512); + + if (flags & CHECK_FRAG_INFO) { + res->bfi.allocated_clusters++; + + /* Compressed clusters are fragmented by nature. Since they + * take up sub-sector space but we only have sector granularity + * I/O we need to re-read the same sectors even for adjacent + * compressed clusters. + */ + res->bfi.fragmented_clusters++; + } break; case QCOW2_CLUSTER_ZERO: @@ -990,6 +1003,15 @@ static int check_refcounts_l2(BlockDriverState *bs, BdrvCheckResult *res, } } + if (flags & CHECK_FRAG_INFO) { + res->bfi.allocated_clusters++; + if (next_contiguous_offset && + offset != next_contiguous_offset) { + res->bfi.fragmented_clusters++; + } + next_contiguous_offset = offset + s->cluster_size; + } + /* Mark cluster as used */ inc_refcounts(bs, res, refcount_table,refcount_table_size, offset, s->cluster_size); @@ -1125,6 +1147,7 @@ int qcow2_check_refcounts(BlockDriverState *bs, BdrvCheckResult *res, size = bdrv_getlength(bs->file); nb_clusters = size_to_clusters(s, size); + res->bfi.total_clusters = nb_clusters; refcount_table = g_malloc0(nb_clusters * sizeof(uint16_t)); /* header */ @@ -1134,7 +1157,7 @@ int qcow2_check_refcounts(BlockDriverState *bs, BdrvCheckResult *res, /* current L1 table */ ret = check_refcounts_l1(bs, res, refcount_table, nb_clusters, s->l1_table_offset, s->l1_size, - CHECK_OFLAG_COPIED); + CHECK_OFLAG_COPIED | CHECK_FRAG_INFO); if (ret < 0) { goto fail; }