From 66d5fd223afbf662589611f3d6a22ff7bcc38bb0 Mon Sep 17 00:00:00 2001
From: Kevin Wolf <kwolf@redhat.com>
Date: Wed, 6 Feb 2019 15:58:28 +0100
Subject: [PATCH 08/33] scsi-disk: Don't use empty string as device id
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RH-Author: Kevin Wolf <kwolf@redhat.com>
Message-id: <20190206155829.14641-2-kwolf@redhat.com>
Patchwork-id: 84253
O-Subject: [RHEL-7.7/8.0-AV qemu-kvm-rhev PATCH 1/2] scsi-disk: Don't use empty string as device id
Bugzilla: 1673080
RH-Acked-by: Max Reitz <mreitz@redhat.com>
RH-Acked-by: Thomas Huth <thuth@redhat.com>
RH-Acked-by: Paolo Bonzini <pbonzini@redhat.com>
scsi-disk includes in the Device Identification VPD page, depending on
configuration amongst others, a vendor specific designator that consists
either of the serial number if given or the BlockBackend name (which is
a host detail that better shouldn't have been leaked to the guest, but
now we have to maintain it for compatibility).
With anonymous BlockBackends, i.e. scsi-disk devices constructed with
drive=<node-name>, and no serial number explicitly specified, this ends
up as an empty string. If this happens to more than one disk, we have
accidentally signalled to the OS that this is a multipath setup, which
is obviously not what was intended.
Instead of using an empty string for the vendor specific designator,
simply leave out that designator, which makes Linux detect such setups
as separate disks again.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
(cherry picked from commit a8f58afcdb86e266e06c9dc41a71605e570244c3)
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
---
hw/scsi/scsi-disk.c | 14 ++++++++------
1 file changed, 8 insertions(+), 6 deletions(-)
diff --git a/hw/scsi/scsi-disk.c b/hw/scsi/scsi-disk.c
index a20ef91..de6c7bc 100644
--- a/hw/scsi/scsi-disk.c
+++ b/hw/scsi/scsi-disk.c
@@ -648,12 +648,14 @@ static int scsi_disk_emulate_vpd_page(SCSIRequest *req, uint8_t *outbuf)
DPRINTF("Inquiry EVPD[Device identification] "
"buffer size %zd\n", req->cmd.xfer);
- outbuf[buflen++] = 0x2; /* ASCII */
- outbuf[buflen++] = 0; /* not officially assigned */
- outbuf[buflen++] = 0; /* reserved */
- outbuf[buflen++] = id_len; /* length of data following */
- memcpy(outbuf + buflen, str, id_len);
- buflen += id_len;
+ if (id_len) {
+ outbuf[buflen++] = 0x2; /* ASCII */
+ outbuf[buflen++] = 0; /* not officially assigned */
+ outbuf[buflen++] = 0; /* reserved */
+ outbuf[buflen++] = id_len; /* length of data following */
+ memcpy(outbuf + buflen, str, id_len);
+ buflen += id_len;
+ }
if (s->qdev.wwn) {
outbuf[buflen++] = 0x1; /* Binary */
--
1.8.3.1