[libvirt] [PATCH] qemu: command: Report stderr from qemu-bridge-helper
There's a couple reports of things failing in this area (bug 1259070),
but it's tough to tell what's going wrong without stderr from
qemu-bridge-helper. So let's report stderr in the error message
Couple new examples:
virbr0 is inactive:
internal error: /usr/libexec/qemu-bridge-helper --use-vnet --br=virbr0 --fd=21: failed to
retrieve file descriptor: Transport endpoint is not connected
stderr=failed to get mtu of bridge `virbr0': No such device
bridge isn't on the ACL:
internal error: /usr/libexec/qemu-bridge-helper --use-vnet --br=br0 --fd=21: failed to
retrieve file descriptor: Transport endpoint is not connected
stderr=access denied by acl file
---
src/qemu/qemu_command.c | 24 ++++++++++++++++++++++--
1 file changed, 22 insertions(+), 2 deletions(-)
diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
index ec5e3d4..fc22f36 100644
--- a/src/qemu/qemu_command.c
+++ b/src/qemu/qemu_command.c
@@ -285,6 +285,7 @@ static int qemuCreateInBridgePortWithHelper(virQEMUDriverConfigPtr
cfg,
unsigned int flags)
{
virCommandPtr cmd;
+ char *errbuf = NULL, *cmdstr = NULL;
int pair[2] = { -1, -1 };
if ((flags & ~VIR_NETDEV_TAP_CREATE_VNET_HDR) != VIR_NETDEV_TAP_CREATE_IFUP)
@@ -306,6 +307,8 @@ static int qemuCreateInBridgePortWithHelper(virQEMUDriverConfigPtr
cfg,
virCommandAddArgFormat(cmd, "--use-vnet");
virCommandAddArgFormat(cmd, "--br=%s", brname);
virCommandAddArgFormat(cmd, "--fd=%d", pair[1]);
+ virCommandSetErrorBuffer(cmd, &errbuf);
+ virCommandDoAsyncIO(cmd);
virCommandPassFD(cmd, pair[1],
VIR_COMMAND_PASS_FD_CLOSE_PARENT);
virCommandClearCaps(cmd);
@@ -320,9 +323,24 @@ static int qemuCreateInBridgePortWithHelper(virQEMUDriverConfigPtr
cfg,
do {
*tapfd = recvfd(pair[0], 0);
} while (*tapfd < 0 && errno == EINTR);
+
if (*tapfd < 0) {
- virReportSystemError(errno, "%s",
- _("failed to retrieve file descriptor for
interface"));
+ char ebuf[1024];
+ char *errstr = NULL;
+
+ if (!(cmdstr = virCommandToString(cmd)))
+ goto cleanup;
+ virCommandAbort(cmd);
+
+ if (errbuf && *errbuf &&
+ virAsprintf(&errstr, "\nstderr=%s", errbuf) < 0)
+ goto cleanup;
+
+ virReportError(VIR_ERR_INTERNAL_ERROR,
+ _("%s: failed to retrieve file descriptor: %s%s"),
+ cmdstr, virStrerror(errno, ebuf, sizeof(ebuf)),
+ errstr ? errstr : "");
+ VIR_FREE(errstr);
goto cleanup;
}
@@ -333,6 +351,8 @@ static int qemuCreateInBridgePortWithHelper(virQEMUDriverConfigPtr
cfg,
}
cleanup:
+ VIR_FREE(cmdstr);
+ VIR_FREE(errbuf);
virCommandFree(cmd);
VIR_FORCE_CLOSE(pair[0]);
return *tapfd < 0 ? -1 : 0;
--
2.5.0