discover: Handle unresolved resources

This change adds an unresolved resource queue - any unresolved resources
discovered by parsers are added to this queue rather than being reported
to the clients.

When we discover a new device, we try to resolve any resources in the
queue against the new device. If resolution succeeds, we can send the
option to clients.

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

diff --git a/discover/device-handler.c b/discover/device-handler.c
index c0f60669d287857e7c9520399756ad564f98fc44..a8df295df1b6e4763516b68de240c6fa907240a7 100644 (file)
--- a/discover/device-handler.c
+++ b/discover/device-handler.c
@@ -29,6 +29,8 @@ struct device_handler {
 
        struct discover_device  **devices;
        unsigned int            n_devices;
+
+       struct list             unresolved_boot_options;
 };
 
 static bool resource_is_resolved(struct resource *res)
@@ -46,6 +48,25 @@ static bool __attribute__((used)) boot_option_is_resolved(
                resource_is_resolved(opt->icon);
 }
 
+static bool resource_resolve(struct resource *res, struct parser *parser,
+               struct device_handler *handler)
+{
+       if (resource_is_resolved(res))
+               return true;
+
+       parser->resolve_resource(handler, res);
+
+       return res->resolved;
+}
+
+static bool boot_option_resolve(struct discover_boot_option *opt,
+               struct device_handler *handler)
+{
+       return resource_resolve(opt->boot_image, opt->source, handler) &&
+               resource_resolve(opt->initrd, opt->source, handler) &&
+               resource_resolve(opt->icon, opt->source, handler);
+}
+
 static void boot_option_finalise(struct discover_boot_option *opt)
 {
        assert(boot_option_is_resolved(opt));
@@ -63,6 +84,25 @@ static void boot_option_finalise(struct discover_boot_option *opt)
                opt->option->icon_file = opt->icon->url->full;
 }
 
+static void process_boot_option_queue(struct device_handler *handler)
+{
+       struct discover_boot_option *opt, *tmp;
+
+       list_for_each_entry_safe(&handler->unresolved_boot_options,
+                       opt, tmp, list) {
+
+               if (!boot_option_resolve(opt, handler))
+                       continue;
+
+               list_remove(&opt->list);
+               list_add(&opt->device->boot_options, &opt->list);
+               talloc_steal(opt->device, opt);
+               boot_option_finalise(opt);
+               discover_server_notify_boot_option_add(handler->server,
+                                                       opt->option);
+       }
+}
+
 /**
  * context_commit - Commit a temporary discovery context to the handler,
  * and notify the clients about any new options / devices
@@ -91,23 +131,34 @@ static void context_commit(struct device_handler *handler,
                talloc_steal(handler, dev);
 
                discover_server_notify_device_add(handler->server, dev->device);
+
+               /* this new device might be able to resolve existing boot
+                * options */
+               process_boot_option_queue(handler);
        }
 
 
        /* move boot options from the context to the device */
        list_for_each_entry_safe(&ctx->boot_options, opt, tmp, list) {
                list_remove(&opt->list);
-               list_add(&dev->boot_options, &opt->list);
-               talloc_steal(dev, opt);
-               boot_option_finalise(opt);
-               discover_server_notify_boot_option_add(handler->server,
-                                                       opt->option);
+
+               if (boot_option_resolve(opt, handler)) {
+                       list_add(&dev->boot_options, &opt->list);
+                       talloc_steal(dev, opt);
+                       boot_option_finalise(opt);
+                       discover_server_notify_boot_option_add(handler->server,
+                                                               opt->option);
+               } else {
+                       list_add(&handler->unresolved_boot_options, &opt->list);
+                       talloc_steal(handler, opt);
+               }
        }
 }
 
 void discover_context_add_boot_option(struct discover_context *ctx,
                struct discover_boot_option *boot_option)
 {
+       boot_option->source = ctx->parser;
        list_add(&ctx->boot_options, &boot_option->list);
        talloc_steal(ctx, boot_option);
 }
@@ -437,6 +488,7 @@ struct device_handler *device_handler_init(struct discover_server *server,
        handler->n_devices = 0;
        handler->server = server;
        handler->dry_run = dry_run;
+       list_init(&handler->unresolved_boot_options);
 
        /* set up our mount point base */
        pb_mkdir_recursive(mount_base());

diff --git a/discover/device-handler.h b/discover/device-handler.h
index 5dead2459d0217c08361a41c9f2ebc1fb43ac3ef..be55f738293748725ac87d311f57163555913f9b 100644 (file)
--- a/discover/device-handler.h
+++ b/discover/device-handler.h
@@ -27,6 +27,7 @@ struct discover_device {
 };
 
 struct discover_boot_option {
+       struct parser           *source;
        struct discover_device  *device;
        struct boot_option      *option;
        struct list_item        list;
@@ -38,6 +39,7 @@ struct discover_boot_option {
 
 
 struct discover_context {
+       struct parser           *parser;
        struct event            *event;
        struct discover_device  *device;
        struct list             boot_options;

diff --git a/discover/parser.c b/discover/parser.c
index 462d614a5c1abeae1866a79f3748428fc956e9ec..0df8a737c103c5265782c75a6b140ef0fb945648 100644 (file)
--- a/discover/parser.c
+++ b/discover/parser.c
@@ -18,7 +18,7 @@ struct parser __kboot_parser;
 struct parser __native_parser;
 struct parser __yaboot_parser;
 
-static const struct parser *const parsers[] = {
+static struct parser *const parsers[] = {
 //     &__native_parser,
        &__kboot_parser,
        &__grub2_parser,
@@ -116,8 +116,10 @@ void iterate_parsers(struct discover_context *ctx)
 
        for (i = 0; parsers[i]; i++) {
                pb_log("\ttrying parser '%s'\n", parsers[i]->name);
+               ctx->parser = parsers[i];
                iterate_parser_files(ctx, parsers[i]);
        }
+       ctx->parser = NULL;
 }
 
 void parser_init(void)