Linux-2.6.12-rc2v2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 93 insertions, 0 deletions

diff --git a/drivers/md/dm-path-selector.h b/drivers/md/dm-path-selector.h
new file mode 100644
index 000000000000..732d06a84f85
--- /dev/null
+++ b/drivers/md/dm-path-selector.h
@@ -0,0 +1,93 @@
+/*
+ * Copyright (C) 2003 Sistina Software.
+ * Copyright (C) 2004 Red Hat, Inc. All rights reserved.
+ *
+ * Module Author: Heinz Mauelshagen
+ *
+ * This file is released under the GPL.
+ *
+ * Path-Selector registration.
+ */
+
+#ifndef DM_PATH_SELECTOR_H
+#define DM_PATH_SELECTOR_H
+
+#include <linux/device-mapper.h>
+
+#include "dm-mpath.h"
+
+/*
+ * We provide an abstraction for the code that chooses which path
+ * to send some io down.
+ */
+struct path_selector_type;
+struct path_selector {
+        struct path_selector_type *type;
+        void *context;
+};
+
+/* Information about a path selector type */
+struct path_selector_type {
+        char *name;
+        struct module *module;
+
+        unsigned int table_args;
+        unsigned int info_args;
+
+        /*
+         * Constructs a path selector object, takes custom arguments
+         */
+        int (*create) (struct path_selector *ps, unsigned argc, char **argv);
+        void (*destroy) (struct path_selector *ps);
+
+        /*
+         * Add an opaque path object, along with some selector specific
+         * path args (eg, path priority).
+         */
+        int (*add_path) (struct path_selector *ps, struct path *path,
+                         int argc, char **argv, char **error);
+
+        /*
+         * Chooses a path for this io, if no paths are available then
+         * NULL will be returned.
+         *
+         * repeat_count is the number of times to use the path before
+         * calling the function again.  0 means don't call it again unless
+         * the path fails.
+         */
+        struct path *(*select_path) (struct path_selector *ps,
+                                     unsigned *repeat_count);
+
+        /*
+         * Notify the selector that a path has failed.
+         */
+        void (*fail_path) (struct path_selector *ps, struct path *p);
+
+        /*
+         * Ask selector to reinstate a path.
+         */
+        int (*reinstate_path) (struct path_selector *ps, struct path *p);
+
+        /*
+         * Table content based on parameters added in ps_add_path_fn
+         * or path selector status
+         */
+        int (*status) (struct path_selector *ps, struct path *path,
+                       status_type_t type, char *result, unsigned int maxlen);
+
+        int (*end_io) (struct path_selector *ps, struct path *path);
+};
+
+/* Register a path selector */
+int dm_register_path_selector(struct path_selector_type *type);
+
+/* Unregister a path selector */
+int dm_unregister_path_selector(struct path_selector_type *type);
+
+/* Returns a registered path selector type */
+struct path_selector_type *dm_get_path_selector(const char *name);
+
+/* Releases a path selector  */
+void dm_put_path_selector(struct path_selector_type *pst);
+
+#endif