discover: Integrate ipmi bootdev settings into the priority system

Currently, we expose the boot device priorities through an array in
struct config, which will either be the default (network -> disk), or a
single device type specified by the IPMI code.

Rather than hide the implementation details in this array, we'd like to
expose the details of the machine configuration instead. This allows
user visibility of the real boot configuration (for example, if an IPMI
boot preference is set).

This change removes the priority array, and replaces it with the
ipmi_bootdev data (and a persistent flag). We update the
default-conflict-resolution code to reflect the priorities between IPMI
and UUID preferences.

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>

1 files changed, 88 insertions, 33 deletions

diff --git a/discover/device-handler.c b/discover/device-handler.c
index 64fc9fa..fd6f1d3 100644
--- a/discover/device-handler.c
+++ b/discover/device-handler.c
@@ -36,6 +36,15 @@
 #include "boot.h"
 #include "udev.h"
 #include "network.h"
+#include "ipmi.h"
+
+enum default_priority {
+	DEFAULT_PRIORITY_REMOTE		= 1,
+	DEFAULT_PRIORITY_LOCAL_UUID	= 2,
+	DEFAULT_PRIORITY_LOCAL_FIRST	= 3,
+	DEFAULT_PRIORITY_LOCAL_LAST	= 0xfe,
+	DEFAULT_PRIORITY_DISABLED	= 0xff,
+};
 
 struct device_handler {
 	struct discover_server	*server;
@@ -54,6 +63,8 @@ struct device_handler {
 	unsigned int		sec_to_boot;
 
 	struct discover_boot_option *default_boot_option;
+	int			default_boot_option_priority;
+
 	struct list		unresolved_boot_options;
 
 	struct boot_task	*pending_boot;
@@ -429,75 +440,118 @@ static int default_timeout(void *arg)
 	return 0;
 }
 
-static bool priority_match(struct boot_priority *prio,
+struct {
+	enum ipmi_bootdev	ipmi_type;
+	enum device_type	device_type;
+} device_type_map[] = {
+	{ IPMI_BOOTDEV_NETWORK, DEVICE_TYPE_NETWORK },
+	{ IPMI_BOOTDEV_DISK, DEVICE_TYPE_DISK },
+	{ IPMI_BOOTDEV_CDROM, DEVICE_TYPE_OPTICAL },
+};
+
+static bool ipmi_device_type_matches(enum ipmi_bootdev ipmi_type,
+		enum device_type device_type)
+{
+	unsigned int i;
+
+	for (i = 0; i < ARRAY_SIZE(device_type_map); i++) {
+		if (device_type_map[i].device_type == device_type)
+			return device_type_map[i].ipmi_type == ipmi_type;
+	}
+
+	return false;
+}
+
+static bool priority_matches(struct boot_priority *prio,
 		struct discover_boot_option *opt)
 {
 	return prio->type == opt->device->device->type ||
 		prio->type == DEVICE_TYPE_ANY;
 }
 
-static int default_option_priority(struct discover_boot_option *opt)
+/*
+ * We have different priorities to resolve conflicts between boot options that
+ * report to be the default for their device. This function assigns a priority
+ * for these options.
+ */
+static enum default_priority default_option_priority(
+		struct discover_boot_option *opt)
 {
 	const struct config *config;
-	struct boot_priority *prio;
+	const char *dev_str;
 	unsigned int i;
 
 	config = config_get();
 
-	for (i = 0; i < config->n_boot_priorities; i++) {
-		prio = &config->boot_priorities[i];
-		if (priority_match(prio, opt))
-			return prio->priority;
+	/* We give highest priority to IPMI-configured boot options. If
+	 * we have an IPMI bootdev configuration set, then we don't allow
+	 * any other defaults */
+	if (config->ipmi_bootdev) {
+		bool ipmi_match = ipmi_device_type_matches(config->ipmi_bootdev,
+				opt->device->device->type);
+		if (ipmi_match)
+			return DEFAULT_PRIORITY_REMOTE;
+
+		pb_debug("handler: disabled default priority due to "
+				"non-matching IPMI type %x\n",
+				config->ipmi_bootdev);
+		return DEFAULT_PRIORITY_DISABLED;
 	}
 
-	return 0;
-}
-
-static bool device_allows_default(struct discover_device *dev)
-{
-	const char *dev_str;
-
-	dev_str = config_get()->boot_device;
+	/* Next, allow matching by device UUID. If we have one set but it
+	 * doesn't match, disallow the default entirely */
+	dev_str = config->boot_device;
+	if (dev_str && dev_str[0]) {
+		if (!strcmp(opt->device->uuid, dev_str))
+			return DEFAULT_PRIORITY_LOCAL_UUID;
 
-	if (!dev_str || !strlen(dev_str))
-		return true;
+		pb_debug("handler: disabled default priority due to "
+				"non-matching UUID\n");
+		return DEFAULT_PRIORITY_DISABLED;
+	}
 
-	/* default devices are specified by UUIDs at present */
-	if (strcmp(dev->uuid, dev_str))
-		return false;
+	/* Lastly, use the local priorities */
+	for (i = 0; i < config->n_boot_priorities; i++) {
+		struct boot_priority *prio = &config->boot_priorities[i];
+		if (priority_matches(prio, opt))
+			return DEFAULT_PRIORITY_LOCAL_FIRST + prio->priority;
+	}
 
-	return true;
+	return DEFAULT_PRIORITY_DISABLED;
 }
 
 static void set_default(struct device_handler *handler,
 		struct discover_boot_option *opt)
 {
-	int new_prio;
+	enum default_priority cur_prio, new_prio;
 
 	if (!handler->autoboot_enabled)
 		return;
 
-	/* do we allow default-booting from this device? */
-	if (!device_allows_default(opt->device))
-		return;
+	pb_debug("handler: new default option: %s\n", opt->option->id);
 
 	new_prio = default_option_priority(opt);
 
-	/* A negative priority indicates that we don't want to boot this device
-	 * by default */
-	if (new_prio < 0)
+	/* Anything outside our range prevents a default boot */
+	if (new_prio >= DEFAULT_PRIORITY_DISABLED)
 		return;
 
+	pb_debug("handler: calculated priority %d\n", new_prio);
+
 	/* Resolve any conflicts: if we have a new default option, it only
 	 * replaces the current if it has a higher priority. */
 	if (handler->default_boot_option) {
-		int cur_prio;
 
-		cur_prio = default_option_priority(
-					handler->default_boot_option);
+		cur_prio = handler->default_boot_option_priority;
 
-		if (new_prio > cur_prio) {
+		if (new_prio < cur_prio) {
+			pb_log("handler: new prio %d beats "
+					"old prio %d for %s\n",
+					new_prio, cur_prio,
+					handler->default_boot_option
+						->option->id);
 			handler->default_boot_option = opt;
+			handler->default_boot_option_priority = new_prio;
 			/* extend the timeout a little, so the user sees some
 			 * indication of the change */
 			handler->sec_to_boot += 2;
@@ -508,8 +562,9 @@ static void set_default(struct device_handler *handler,
 
 	handler->sec_to_boot = config_get()->autoboot_timeout_sec;
 	handler->default_boot_option = opt;
+	handler->default_boot_option_priority = new_prio;
 
-	pb_log("Boot option %s set as default, timeout %u sec.\n",
+	pb_log("handler: boot option %s set as default, timeout %u sec.\n",
 	       opt->option->id, handler->sec_to_boot);
 
 	default_timeout(handler);