From patchwork Mon Apr 19 13:21:21 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kevin Wolf X-Patchwork-Id: 50467 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [199.232.76.165]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 0DD8BB7080 for ; Mon, 19 Apr 2010 23:29:25 +1000 (EST) Received: from localhost ([127.0.0.1]:50679 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1O3r1m-0005ue-Th for incoming@patchwork.ozlabs.org; Mon, 19 Apr 2010 09:28:42 -0400 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1O3qvH-0002RJ-2z for qemu-devel@nongnu.org; Mon, 19 Apr 2010 09:21:59 -0400 Received: from [140.186.70.92] (port=33744 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1O3qvE-0002QC-3x for qemu-devel@nongnu.org; Mon, 19 Apr 2010 09:21:58 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.69) (envelope-from ) id 1O3qv8-0006QV-Cv for qemu-devel@nongnu.org; Mon, 19 Apr 2010 09:21:55 -0400 Received: from mx1.redhat.com ([209.132.183.28]:20153) by eggs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1O3qv7-0006QE-MG for qemu-devel@nongnu.org; Mon, 19 Apr 2010 09:21:50 -0400 Received: from int-mx03.intmail.prod.int.phx2.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.16]) by mx1.redhat.com (8.13.8/8.13.8) with ESMTP id o3JDLmKt002425 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Mon, 19 Apr 2010 09:21:49 -0400 Received: from localhost.localdomain (dhcp-5-175.str.redhat.com [10.32.5.175]) by int-mx03.intmail.prod.int.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id o3JDLlLa001210; Mon, 19 Apr 2010 09:21:47 -0400 From: Kevin Wolf To: qemu-devel@nongnu.org Date: Mon, 19 Apr 2010 15:21:21 +0200 Message-Id: <1271683281-26825-1-git-send-email-kwolf@redhat.com> X-Scanned-By: MIMEDefang 2.67 on 10.5.11.16 X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. Cc: kwolf@redhat.com, quintela@redhat.com Subject: [Qemu-devel] [PATCH v2] qcow2: Fix creation of large images X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org qcow_create2 assumes that the new image will only need one cluster for its refcount table initially. Obviously that's not true any more when the image is big enough (exact value depends on the cluster size). This patch calculates the refcount table size dynamically. Signed-off-by: Kevin Wolf Acked-by: Juan Quintela Reviewed-by: Christoph Hellwig --- v2: - Made cluster calculation a bit more readable block/qcow2.c | 43 +++++++++++++++++++++++++++++++++---------- 1 files changed, 33 insertions(+), 10 deletions(-) diff --git a/block/qcow2.c b/block/qcow2.c index 80c99af..67affa6 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -850,10 +850,11 @@ static int qcow_create2(const char *filename, int64_t total_size, { int fd, header_size, backing_filename_len, l1_size, i, shift, l2_bits; - int ref_clusters, backing_format_len = 0; + int ref_clusters, reftable_clusters, backing_format_len = 0; int rounded_ext_bf_len = 0; QCowHeader header; uint64_t tmp, offset; + uint64_t old_ref_clusters; QCowCreateState s1, *s = &s1; QCowExtension ext_bf = {0, 0}; int ret; @@ -912,17 +913,37 @@ static int qcow_create2(const char *filename, int64_t total_size, header.l1_size = cpu_to_be32(l1_size); offset += align_offset(l1_size * sizeof(uint64_t), s->cluster_size); - s->refcount_table = qemu_mallocz(s->cluster_size); + /* count how many refcount blocks needed */ + +#define NUM_CLUSTERS(bytes) \ + (((bytes) + (s->cluster_size) - 1) / (s->cluster_size)) + + ref_clusters = NUM_CLUSTERS(NUM_CLUSTERS(offset) * sizeof(uint16_t)); + + do { + uint64_t image_clusters; + old_ref_clusters = ref_clusters; + + /* Number of clusters used for the refcount table */ + reftable_clusters = NUM_CLUSTERS(ref_clusters * sizeof(uint64_t)); + + /* Number of clusters that the whole image will have */ + image_clusters = NUM_CLUSTERS(offset) + ref_clusters + + reftable_clusters; + + /* Number of refcount blocks needed for the image */ + ref_clusters = NUM_CLUSTERS(image_clusters * sizeof(uint16_t)); + + } while (ref_clusters != old_ref_clusters); + + s->refcount_table = qemu_mallocz(reftable_clusters * s->cluster_size); s->refcount_table_offset = offset; header.refcount_table_offset = cpu_to_be64(offset); - header.refcount_table_clusters = cpu_to_be32(1); - offset += s->cluster_size; + header.refcount_table_clusters = cpu_to_be32(reftable_clusters); + offset += (reftable_clusters * s->cluster_size); s->refcount_block_offset = offset; - /* count how many refcount blocks needed */ - tmp = offset >> s->cluster_bits; - ref_clusters = (tmp >> (s->cluster_bits - REFCOUNT_SHIFT)) + 1; for (i=0; i < ref_clusters; i++) { s->refcount_table[i] = cpu_to_be64(offset); offset += s->cluster_size; @@ -934,7 +955,8 @@ static int qcow_create2(const char *filename, int64_t total_size, qcow2_create_refcount_update(s, 0, header_size); qcow2_create_refcount_update(s, s->l1_table_offset, l1_size * sizeof(uint64_t)); - qcow2_create_refcount_update(s, s->refcount_table_offset, s->cluster_size); + qcow2_create_refcount_update(s, s->refcount_table_offset, + reftable_clusters * s->cluster_size); qcow2_create_refcount_update(s, s->refcount_block_offset, ref_clusters * s->cluster_size); @@ -986,8 +1008,9 @@ static int qcow_create2(const char *filename, int64_t total_size, } } lseek(fd, s->refcount_table_offset, SEEK_SET); - ret = qemu_write_full(fd, s->refcount_table, s->cluster_size); - if (ret != s->cluster_size) { + ret = qemu_write_full(fd, s->refcount_table, + reftable_clusters * s->cluster_size); + if (ret != reftable_clusters * s->cluster_size) { ret = -errno; goto exit; }