From patchwork Tue Mar 26 16:50:02 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kevin Wolf X-Patchwork-Id: 231472 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 8273B2C04FB for ; Wed, 27 Mar 2013 03:54:19 +1100 (EST) Received: from localhost ([::1]:34732 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UKX8Z-0000fb-K1 for incoming@patchwork.ozlabs.org; Tue, 26 Mar 2013 12:54:15 -0400 Received: from eggs.gnu.org ([208.118.235.92]:55451) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UKX52-0003FZ-Id for qemu-devel@nongnu.org; Tue, 26 Mar 2013 12:50:38 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1UKX50-0001EM-I3 for qemu-devel@nongnu.org; Tue, 26 Mar 2013 12:50:36 -0400 Received: from mx1.redhat.com ([209.132.183.28]:54914) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UKX50-0001DQ-4i for qemu-devel@nongnu.org; Tue, 26 Mar 2013 12:50:34 -0400 Received: from int-mx02.intmail.prod.int.phx2.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id r2QGoXoA009215 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Tue, 26 Mar 2013 12:50:33 -0400 Received: from dhcp-200-207.str.redhat.com (ovpn-116-61.ams2.redhat.com [10.36.116.61]) by int-mx02.intmail.prod.int.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id r2QGoG2u030068; Tue, 26 Mar 2013 12:50:32 -0400 From: Kevin Wolf To: qemu-devel@nongnu.org Date: Tue, 26 Mar 2013 17:50:02 +0100 Message-Id: <1364316613-31223-11-git-send-email-kwolf@redhat.com> In-Reply-To: <1364316613-31223-1-git-send-email-kwolf@redhat.com> References: <1364316613-31223-1-git-send-email-kwolf@redhat.com> X-Scanned-By: MIMEDefang 2.67 on 10.5.11.12 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 209.132.183.28 Cc: kwolf@redhat.com, stefanha@redhat.com Subject: [Qemu-devel] [PATCH v2 10/21] qcow2: handle_alloc(): Get rid of keep_clusters parameter 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 handle_alloc() is now called with the offset at which the actual new allocation starts instead of the offset at which the whole write request starts, part of which may already be processed. Signed-off-by: Kevin Wolf --- block/qcow2-cluster.c | 44 +++++++++++++++++++++++++++----------------- block/qcow2.h | 5 +++++ 2 files changed, 32 insertions(+), 17 deletions(-) diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c index 009f62a..8f4ef0d 100644 --- a/block/qcow2-cluster.c +++ b/block/qcow2-cluster.c @@ -876,12 +876,12 @@ static int do_alloc_cluster_offset(BlockDriverState *bs, uint64_t guest_offset, * * -errno: in error cases * - * TODO Get rid of keep_clusters, n_start, n_end + * TODO Get rid of n_start, n_end * TODO Make *bytes actually behave as specified above */ static int handle_alloc(BlockDriverState *bs, uint64_t guest_offset, uint64_t *host_offset, uint64_t *bytes, QCowL2Meta **m, - int keep_clusters, int n_start, int n_end) + int n_start, int n_end) { BDRVQcowState *s = bs->opaque; int l2_index; @@ -892,7 +892,6 @@ static int handle_alloc(BlockDriverState *bs, uint64_t guest_offset, uint64_t alloc_offset; uint64_t alloc_cluster_offset; - uint64_t keep_bytes = keep_clusters * s->cluster_size; trace_qcow2_handle_alloc(qemu_coroutine_self(), guest_offset, *host_offset, *bytes); @@ -911,14 +910,13 @@ static int handle_alloc(BlockDriverState *bs, uint64_t guest_offset, return ret; } - entry = be64_to_cpu(l2_table[l2_index + keep_clusters]); + entry = be64_to_cpu(l2_table[l2_index]); /* For the moment, overwrite compressed clusters one by one */ if (entry & QCOW_OFLAG_COMPRESSED) { nb_clusters = 1; } else { - nb_clusters = count_cow_clusters(s, nb_clusters, l2_table, - l2_index + keep_clusters); + nb_clusters = count_cow_clusters(s, nb_clusters, l2_table, l2_index); } ret = qcow2_cache_put(bs, s->l2_table_cache, (void**) &l2_table); @@ -932,13 +930,8 @@ static int handle_alloc(BlockDriverState *bs, uint64_t guest_offset, } /* Calculate start and size of allocation */ - alloc_offset = guest_offset + keep_bytes; - - if (keep_clusters == 0) { - alloc_cluster_offset = 0; - } else { - alloc_cluster_offset = *host_offset + keep_bytes; - } + alloc_offset = guest_offset; + alloc_cluster_offset = *host_offset; /* Allocate, if necessary at a given offset in the image file */ ret = do_alloc_cluster_offset(bs, alloc_offset, &alloc_cluster_offset, @@ -961,13 +954,13 @@ static int handle_alloc(BlockDriverState *bs, uint64_t guest_offset, * newly allocated cluster to the end of the aread that the write * request actually writes to (excluding COW at the end) */ - int requested_sectors = n_end - keep_clusters * s->cluster_sectors; + int requested_sectors = n_end; int avail_sectors = nb_clusters << (s->cluster_bits - BDRV_SECTOR_BITS); - int alloc_n_start = keep_clusters == 0 ? n_start : 0; + int alloc_n_start = *host_offset == 0 ? n_start : 0; int nb_sectors = MIN(requested_sectors, avail_sectors); - if (keep_clusters == 0) { + if (*host_offset == 0) { *host_offset = alloc_cluster_offset; } @@ -1130,9 +1123,26 @@ again: goto done; } + int alloc_n_start; + int alloc_n_end; + + if (keep_clusters != 0) { + offset = start_of_cluster(s, offset + + keep_clusters * s->cluster_size); + cluster_offset = start_of_cluster(s, cluster_offset + + keep_clusters * s->cluster_size); + + alloc_n_start = 0; + alloc_n_end = n_end - keep_clusters * s->cluster_sectors; + } else { + alloc_n_start = n_start; + alloc_n_end = n_end; + } + cur_bytes = nb_clusters * s->cluster_size; + ret = handle_alloc(bs, offset, &cluster_offset, &cur_bytes, m, - keep_clusters, n_start, n_end); + alloc_n_start, alloc_n_end); if (ret < 0) { return ret; } diff --git a/block/qcow2.h b/block/qcow2.h index a99d51b..c4eaf67 100644 --- a/block/qcow2.h +++ b/block/qcow2.h @@ -266,6 +266,11 @@ enum { #define REFT_OFFSET_MASK 0xffffffffffffff00ULL +static inline int64_t start_of_cluster(BDRVQcowState *s, int64_t offset) +{ + return offset & ~(s->cluster_size - 1); +} + static inline int size_to_clusters(BDRVQcowState *s, int64_t size) { return (size + (s->cluster_size - 1)) >> s->cluster_bits;