Blame SOURCES/libvirt-qemu-snapshot-Allow-snapshots-of-read-only-disks-when-we-can-create-them.patch

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From a229c76e2a5008dbdbcad996ae4f75a3d51b709f Mon Sep 17 00:00:00 2001
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Message-Id: <a229c76e2a5008dbdbcad996ae4f75a3d51b709f@dist-git>
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From: Peter Krempa <pkrempa@redhat.com>
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Date: Tue, 12 May 2020 17:24:10 +0200
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Subject: [PATCH] qemu: snapshot: Allow snapshots of read-only disks when we
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 can create them
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MIME-Version: 1.0
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Content-Type: text/plain; charset=UTF-8
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Content-Transfer-Encoding: 8bit
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With -blockdev or when reusing externally created images and thus
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without the need for formatting the image we actually can support
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snapshots of read-only disks. Arguably it's not very useful so they are
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not done by default but users of libvirt such as oVirt are actually
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using this.
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https://bugzilla.redhat.com/show_bug.cgi?id=1832204
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Signed-off-by: Peter Krempa <pkrempa@redhat.com>
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Reviewed-by: Ján Tomko <jtomko@redhat.com>
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(cherry picked from commit fe574ea1f52daebddfdc91dd27234059c375e4bf)
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Message-Id: <2f8f6e53de334a6e3c2d91711fe4dbd81d8b3ee8.1589296861.git.pkrempa@redhat.com>
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Reviewed-by: Jiri Denemark <jdenemar@redhat.com>
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---
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 src/qemu/qemu_driver.c | 2 +-
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 1 file changed, 1 insertion(+), 1 deletion(-)
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diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
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index 26215f8d6a..7ae8641577 100644
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--- a/src/qemu/qemu_driver.c
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+++ b/src/qemu/qemu_driver.c
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@@ -14968,7 +14968,7 @@ qemuDomainSnapshotPrepareDiskExternal(virDomainDiskDefPtr disk,
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     int err;
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     int rc;
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-    if (disk->src->readonly) {
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+    if (disk->src->readonly && !(reuse || blockdev)) {
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         virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
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                        _("external snapshot for readonly disk %s "
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                          "is not supported"), disk->dst);
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-- 
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2.26.2
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