void
xenbus_dev_verror(device_t dev, int err, const char *fmt, va_list ap)
{
int ret;
unsigned int len;
char *printf_buffer = NULL, *path_buffer = NULL;
#define PRINTF_BUFFER_SIZE 4096
printf_buffer = malloc(PRINTF_BUFFER_SIZE,M_XENBUS, M_WAITOK);
len = sprintf(printf_buffer, "%i ", err);
ret = vsnprintf(printf_buffer+len, PRINTF_BUFFER_SIZE-len, fmt, ap);
KASSERT(len + ret <= PRINTF_BUFFER_SIZE-1, ("xenbus error message too big"));
device_printf(dev, "Error %s\n", printf_buffer);
path_buffer = error_path(dev);
if (path_buffer == NULL) {
printf("xenbus: failed to write error node for %s (%s)\n",
xenbus_get_node(dev), printf_buffer);
goto fail;
}
if (xs_write(XST_NIL, path_buffer, "error", printf_buffer) != 0) {
printf("xenbus: failed to write error node for %s (%s)\n",
xenbus_get_node(dev), printf_buffer);
goto fail;
}
fail:
if (printf_buffer)
free(printf_buffer,M_XENBUS);
if (path_buffer)
free(path_buffer,M_XENBUS);
}
/**
* \brief Construct the error path corresponding to the given XenBus
* device.
*
* \param dev The XenBus device for which we are constructing an error path.
*
* \return On success, the contructed error path. Otherwise NULL.
*
* It is the caller's responsibility to free any returned error path
* node using the M_XENBUS malloc type.
*/
static char *
error_path(device_t dev)
{
char *path_buffer = malloc(strlen("error/")
+ strlen(xenbus_get_node(dev)) + 1,M_XENBUS, M_WAITOK);
strcpy(path_buffer, "error/");
strcpy(path_buffer + strlen("error/"), xenbus_get_node(dev));
return (path_buffer);
}
/**
* Handler for all generic XenBus device systcl nodes.
*/
static int
xenbusb_device_sysctl_handler(SYSCTL_HANDLER_ARGS)
{
device_t dev;
const char *value;
dev = (device_t)arg1;
switch (arg2) {
case XENBUS_IVAR_NODE:
value = xenbus_get_node(dev);
break;
case XENBUS_IVAR_TYPE:
value = xenbus_get_type(dev);
break;
case XENBUS_IVAR_STATE:
value = xenbus_strstate(xenbus_get_state(dev));
break;
case XENBUS_IVAR_OTHEREND_ID:
return (sysctl_handle_int(oidp, NULL,
xenbus_get_otherend_id(dev),
req));
/* NOTREACHED */
case XENBUS_IVAR_OTHEREND_PATH:
value = xenbus_get_otherend_path(dev);
break;
default:
return (EINVAL);
}
return (SYSCTL_OUT_STR(req, value));
}
/**
* \brief Backend XenBus method implementing responses to local
* XenStore changes.
*
* \param bus The XenBus bus parent of child.
* \param child The XenBus child whose peer stat has changed.
* \param_path The tree relative sub-path to the modified node. The empty
* string indicates the root of the tree was destroyed.
*/
static void
xenbusb_back_localend_changed(device_t bus, device_t child, const char *path)
{
xenbusb_localend_changed(bus, child, path);
if (strcmp(path, "/state") != 0
&& strcmp(path, "/online") != 0)
return;
if (xenbus_get_state(child) != XenbusStateClosed
|| xenbus_dev_is_online(child) != 0)
return;
/*
* Cleanup the hotplug entry in the XenStore if
* present. The control domain expects any userland
* component associated with this device to destroy
* this node in order to signify it is safe to
* teardown the device. However, not all backends
* rely on userland components, and those that
* do should either use a communication channel
* other than the XenStore, or ensure the hotplug
* data is already cleaned up.
*
* This removal ensures that no matter what path
* is taken to mark a back-end closed, the control
* domain will understand that it is closed.
*/
xs_rm(XST_NIL, xenbus_get_node(child), "hotplug-status");
}
/**
* \param dev The NewBus device representing this XenBus bus.
* \param child The NewBus device representing a child of dev%'s XenBus bus.
*/
static void
xenbusb_verify_device(device_t dev, device_t child)
{
if (xs_exists(XST_NIL, xenbus_get_node(child), "") == 0) {
/*
* Device tree has been removed from Xenbus.
* Tear down the device.
*/
xenbusb_delete_child(dev, child);
}
}
int
xenbus_dev_is_online(device_t dev)
{
const char *path;
int error;
int value;
path = xenbus_get_node(dev);
error = xs_gather(XST_NIL, path, "online", "%d", &value, NULL);
if (error != 0) {
/* Default to not online. */
value = 0;
}
return (value);
}
