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From f9b42568a13151521cb8edf38f567e8c5cf25396 Mon Sep 17 00:00:00 2001
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From: Max Reitz <mreitz@redhat.com>
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Date: Mon, 4 Nov 2013 22:32:23 +0100
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Subject: [PATCH 30/87] qcow2: Correct snapshots size for overlap check
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RH-Author: Max Reitz <mreitz@redhat.com>
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Message-id: <1383604354-12743-33-git-send-email-mreitz@redhat.com>
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Patchwork-id: 55332
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O-Subject: [RHEL-7.0 qemu-kvm PATCH 32/43] qcow2: Correct snapshots size for overlap check
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Bugzilla: 1004347
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RH-Acked-by: Kevin Wolf <kwolf@redhat.com>
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RH-Acked-by: Laszlo Ersek <lersek@redhat.com>
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RH-Acked-by: Fam Zheng <famz@redhat.com>
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RH-Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
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BZ: 1004347
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Using s->snapshots_size instead of snapshots_size for the metadata
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overlap check in qcow2_write_snapshots leads to the detection of an
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overlap with the main qcow2 image header when deleting the last
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snapshot, since s->snapshots_size has not yet been updated and is
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therefore non-zero. However, the offset returned by qcow2_alloc_clusters
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will be zero since snapshots_size is zero. Therefore, an overlap is
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detected albeit no such will occur.
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This patch fixes this by replacing s->snapshots_size by snapshots_size
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when calling qcow2_pre_write_overlap_check.
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Signed-off-by: Max Reitz <mreitz@redhat.com>
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Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
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(cherry picked from commit 0f39ac9a07cc10278e37d87076b143008f28aa3b)
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Signed-off-by: Max Reitz <mreitz@redhat.com>
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---
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 block/qcow2-snapshot.c | 2 +-
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 1 file changed, 1 insertion(+), 1 deletion(-)
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Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
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---
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 block/qcow2-snapshot.c |    2 +-
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 1 files changed, 1 insertions(+), 1 deletions(-)
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diff --git a/block/qcow2-snapshot.c b/block/qcow2-snapshot.c
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index e7e6013..450e4f5 100644
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--- a/block/qcow2-snapshot.c
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+++ b/block/qcow2-snapshot.c
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@@ -192,7 +192,7 @@ static int qcow2_write_snapshots(BlockDriverState *bs)
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     /* The snapshot list position has not yet been updated, so these clusters
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      * must indeed be completely free */
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     ret = qcow2_pre_write_overlap_check(bs, QCOW2_OL_DEFAULT, offset,
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-                                        s->snapshots_size);
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+                                        snapshots_size);
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     if (ret < 0) {
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         return ret;
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     }
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-- 
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1.7.1
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