From: Lucas De Marchi <lucas.demarchi@profusion.mobi>
Date: Sat, 31 Dec 2011 21:28:31 +0000 (-0200)
Subject: Add call to check if resources are valid
X-Git-Tag: v3~23
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c4dc3ca8a22d96fde95c34ba0cd7e0b3aa11032d;p=thirdparty%2Fkmod.git

Add call to check if resources are valid
---

diff --git a/TODO b/TODO
index 6ecbf200..03962c81 100644
--- a/TODO
+++ b/TODO
@@ -19,10 +19,6 @@ Features:
 * provide 1:1 compatibility with module-init-tools's modprobe
    - dump configuration
 
-* Add kmod_validate(). It checks if all config files and indexes are still
-  valid. We need to save the mtime of each config dir when starting up and when
-  this function is called we stat the dir and compare the mtimes.
-
 * review API, maybe unify all of these setters:
    - kmod_module_version_get_symbol()
    - kmod_module_version_get_crc()
diff --git a/libkmod/libkmod.c b/libkmod/libkmod.c
index 794cc54e..7acd8d88 100644
--- a/libkmod/libkmod.c
+++ b/libkmod/libkmod.c
@@ -29,6 +29,7 @@
 #include <string.h>
 #include <ctype.h>
 #include <sys/utsname.h>
+#include <sys/stat.h>
 
 #include "libkmod.h"
 #include "libkmod-private.h"
@@ -611,6 +612,62 @@ int kmod_lookup_alias_from_commands(struct kmod_ctx *ctx, const char *name,
 	return nmatch;
 }
 
+static bool is_cache_invalid(const char *path, unsigned long long stamp)
+{
+	struct stat st;
+
+	if (stat(path, &st) < 0)
+		return true;
+
+	if (stamp != ts_usec(&st.st_mtim))
+		return true;
+
+	return false;
+}
+
+/**
+ * kmod_validate_resources:
+ * @ctx: kmod library context
+ *
+ * Check if indexes and configuration files changed on disk and the current
+ * context is not valid anymore.
+ *
+ * Returns KMOD_RESOURCES_OK if resources are still valid,
+ * KMOD_RESOURCES_MUST_RELOAD if it's sufficient to call
+ * kmod_unload_resources() and kmod_load_resources() or
+ * KMOD_RESOURCES_MUST_RECREATE if @ctx must be re-created.
+ */
+KMOD_EXPORT int kmod_validate_resources(struct kmod_ctx *ctx)
+{
+	struct kmod_list *l;
+	size_t i;
+
+	if (ctx == NULL || ctx->config == NULL)
+		return KMOD_RESOURCES_MUST_RECREATE;
+
+	kmod_list_foreach(l, ctx->config->paths) {
+		struct kmod_config_path *cf = l->data;
+
+		if (is_cache_invalid(cf->path, cf->stamp))
+			return KMOD_RESOURCES_MUST_RECREATE;
+	}
+
+	for (i = 0; i < _KMOD_INDEX_LAST; i++) {
+		char path[PATH_MAX];
+
+		if (ctx->indexes[i] == NULL)
+			continue;
+
+		snprintf(path, sizeof(path), "%s/%s.bin", ctx->dirname,
+							index_files[i]);
+
+		if (is_cache_invalid(path, ctx->indexes_stamp[i]))
+			return KMOD_RESOURCES_MUST_RELOAD;
+	}
+
+	return KMOD_RESOURCES_OK;
+}
+
 /**
  * kmod_load_resources:
  * @ctx: kmod library context
diff --git a/libkmod/libkmod.h b/libkmod/libkmod.h
index 9f48cf02..a57f518b 100644
--- a/libkmod/libkmod.h
+++ b/libkmod/libkmod.h
@@ -52,6 +52,14 @@ void kmod_set_userdata(struct kmod_ctx *ctx, const void *userdata);
 int kmod_load_resources(struct kmod_ctx *ctx);
 void kmod_unload_resources(struct kmod_ctx *ctx);
 
+enum kmod_resources {
+	KMOD_RESOURCES_OK = 0,
+	KMOD_RESOURCES_MUST_RELOAD = 1,
+	KMOD_RESOURCES_MUST_RECREATE = 2,
+};
+
+int kmod_validate_resources(struct kmod_ctx *ctx);
+
 /*
  * kmod_list
  *
diff --git a/libkmod/libkmod.sym b/libkmod/libkmod.sym
index f5bebf90..316fcc25 100644
--- a/libkmod/libkmod.sym
+++ b/libkmod/libkmod.sym
@@ -66,6 +66,8 @@ global:
 
 LIBKMOD_3 {
 global:
+	kmod_validate_resources;
+
 	kmod_module_get_symbols;
 	kmod_module_symbol_get_symbol;
 	kmod_module_symbol_get_crc;