1 files changed, 130 insertions, 0 deletions
diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h
new file mode 100644
index 000000000000..83c7d207b80e
--- /dev/null
+++ b/include/linux/device-mapper.h
@@ -0,0 +1,130 @@
+/*
+ * Copyright (C) 2001 Sistina Software (UK) Limited.
+ * Copyright (C) 2004 Red Hat, Inc. All rights reserved.
+ *
+ * This file is released under the LGPL.
+ */
+
+#ifndef _LINUX_DEVICE_MAPPER_H
+#define _LINUX_DEVICE_MAPPER_H
+
+struct dm_target;
+struct dm_table;
+struct dm_dev;
+
+typedef enum { STATUSTYPE_INFO, STATUSTYPE_TABLE } status_type_t;
+
+union map_info {
+	void *ptr;
+	unsigned long long ll;
+};
+
+/*
+ * In the constructor the target parameter will already have the
+ * table, type, begin and len fields filled in.
+ */
+typedef int (*dm_ctr_fn) (struct dm_target *target,
+			  unsigned int argc, char **argv);
+
+/*
+ * The destructor doesn't need to free the dm_target, just
+ * anything hidden ti->private.
+ */
+typedef void (*dm_dtr_fn) (struct dm_target *ti);
+
+/*
+ * The map function must return:
+ * < 0: error
+ * = 0: The target will handle the io by resubmitting it later
+ * > 0: simple remap complete
+ */
+typedef int (*dm_map_fn) (struct dm_target *ti, struct bio *bio,
+			  union map_info *map_context);
+
+/*
+ * Returns:
+ * < 0 : error (currently ignored)
+ * 0   : ended successfully
+ * 1   : for some reason the io has still not completed (eg,
+ *       multipath target might want to requeue a failed io).
+ */
+typedef int (*dm_endio_fn) (struct dm_target *ti,
+			    struct bio *bio, int error,
+			    union map_info *map_context);
+
+typedef void (*dm_presuspend_fn) (struct dm_target *ti);
+typedef void (*dm_postsuspend_fn) (struct dm_target *ti);
+typedef void (*dm_resume_fn) (struct dm_target *ti);
+
+typedef int (*dm_status_fn) (struct dm_target *ti, status_type_t status_type,
+			     char *result, unsigned int maxlen);
+
+typedef int (*dm_message_fn) (struct dm_target *ti, unsigned argc, char **argv);
+
+void dm_error(const char *message);
+
+/*
+ * Constructors should call these functions to ensure destination devices
+ * are opened/closed correctly.
+ * FIXME: too many arguments.
+ */
+int dm_get_device(struct dm_target *ti, const char *path, sector_t start,
+		  sector_t len, int mode, struct dm_dev **result);
+void dm_put_device(struct dm_target *ti, struct dm_dev *d);
+
+/*
+ * Information about a target type
+ */
+struct target_type {
+	const char *name;
+	struct module *module;
+        unsigned version[3];
+	dm_ctr_fn ctr;
+	dm_dtr_fn dtr;
+	dm_map_fn map;
+	dm_endio_fn end_io;
+	dm_presuspend_fn presuspend;
+	dm_postsuspend_fn postsuspend;
+	dm_resume_fn resume;
+	dm_status_fn status;
+	dm_message_fn message;
+};
+
+struct io_restrictions {
+	unsigned short		max_sectors;
+	unsigned short		max_phys_segments;
+	unsigned short		max_hw_segments;
+	unsigned short		hardsect_size;
+	unsigned int		max_segment_size;
+	unsigned long		seg_boundary_mask;
+};
+
+struct dm_target {
+	struct dm_table *table;
+	struct target_type *type;
+
+	/* target limits */
+	sector_t begin;
+	sector_t len;
+
+	/* FIXME: turn this into a mask, and merge with io_restrictions */
+	/* Always a power of 2 */
+	sector_t split_io;
+
+	/*
+	 * These are automatically filled in by
+	 * dm_table_get_device.
+	 */
+	struct io_restrictions limits;
+
+	/* target specific data */
+	void *private;
+
+	/* Used to provide an error string from the ctr */
+	char *error;
+};
+
+int dm_register_target(struct target_type *t);
+int dm_unregister_target(struct target_type *t);
+
+#endif				/* _LINUX_DEVICE_MAPPER_H */