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Tue, 1 Sep 2020 14:35:24 +0000 (UTC) Received: from localhost (ovpn-113-83.ams2.redhat.com [10.36.113.83]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 46EE87DA24; Tue, 1 Sep 2020 14:35:24 +0000 (UTC) From: Max Reitz To: qemu-block@nongnu.org Subject: [PATCH v8 25/43] blockdev: Use CAF in external_snapshot_prepare() Date: Tue, 1 Sep 2020 16:34:06 +0200 Message-Id: <20200901143424.884735-26-mreitz@redhat.com> In-Reply-To: <20200901143424.884735-1-mreitz@redhat.com> References: <20200901143424.884735-1-mreitz@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=mreitz@redhat.com X-Mimecast-Spam-Score: 0.002 X-Mimecast-Originator: redhat.com Received-SPF: pass client-ip=207.211.31.120; envelope-from=mreitz@redhat.com; helo=us-smtp-1.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/09/01 00:57:59 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Kevin Wolf , Andrey Shinkevich , Vladimir Sementsov-Ogievskiy , qemu-devel@nongnu.org, Max Reitz Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" This allows us to differentiate between filters and nodes with COW backing files: Filters cannot be used as overlays at all (for this function). Signed-off-by: Max Reitz Reviewed-by: Andrey Shinkevich Reviewed-by: Kevin Wolf --- blockdev.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/blockdev.c b/blockdev.c index 862aa1b9aa..57ee41b73e 100644 --- a/blockdev.c +++ b/blockdev.c @@ -1562,7 +1562,12 @@ static void external_snapshot_prepare(BlkActionState *common, goto out; } - if (state->new_bs->backing != NULL) { + if (state->new_bs->drv->is_filter) { + error_setg(errp, "Filters cannot be used as overlays"); + goto out; + } + + if (bdrv_cow_child(state->new_bs)) { error_setg(errp, "The overlay already has a backing image"); goto out; }