dm: move include files

Publish the dm-io, dm-log and dm-kcopyd headers in include/linux.

Signed-off-by: Alasdair G Kergon <agk@redhat.com>

3 files changed, 263 insertions, 0 deletions

diff --git a/include/linux/dm-dirty-log.h b/include/linux/dm-dirty-log.h
new file mode 100644
index 00000000000..600c5fb2daa
--- /dev/null
+++ b/include/linux/dm-dirty-log.h
@@ -0,0 +1,131 @@
+/*
+ * Copyright (C) 2003 Sistina Software
+ * Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved.
+ *
+ * Device-Mapper dirty region log.
+ *
+ * This file is released under the LGPL.
+ */
+
+#ifndef _LINUX_DM_DIRTY_LOG
+#define _LINUX_DM_DIRTY_LOG
+
+#ifdef __KERNEL__
+
+#include <linux/types.h>
+#include <linux/device-mapper.h>
+
+typedef sector_t region_t;
+
+struct dm_dirty_log_type;
+
+struct dm_dirty_log {
+	struct dm_dirty_log_type *type;
+	void *context;
+};
+
+struct dm_dirty_log_type {
+	const char *name;
+	struct module *module;
+
+	int (*ctr)(struct dm_dirty_log *log, struct dm_target *ti,
+		   unsigned argc, char **argv);
+	void (*dtr)(struct dm_dirty_log *log);
+
+	/*
+	 * There are times when we don't want the log to touch
+	 * the disk.
+	 */
+	int (*presuspend)(struct dm_dirty_log *log);
+	int (*postsuspend)(struct dm_dirty_log *log);
+	int (*resume)(struct dm_dirty_log *log);
+
+	/*
+	 * Retrieves the smallest size of region that the log can
+	 * deal with.
+	 */
+	uint32_t (*get_region_size)(struct dm_dirty_log *log);
+
+	/*
+	 * A predicate to say whether a region is clean or not.
+	 * May block.
+	 */
+	int (*is_clean)(struct dm_dirty_log *log, region_t region);
+
+	/*
+	 *  Returns: 0, 1, -EWOULDBLOCK, < 0
+	 *
+	 * A predicate function to check the area given by
+	 * [sector, sector + len) is in sync.
+	 *
+	 * If -EWOULDBLOCK is returned the state of the region is
+	 * unknown, typically this will result in a read being
+	 * passed to a daemon to deal with, since a daemon is
+	 * allowed to block.
+	 */
+	int (*in_sync)(struct dm_dirty_log *log, region_t region,
+		       int can_block);
+
+	/*
+	 * Flush the current log state (eg, to disk).  This
+	 * function may block.
+	 */
+	int (*flush)(struct dm_dirty_log *log);
+
+	/*
+	 * Mark an area as clean or dirty.  These functions may
+	 * block, though for performance reasons blocking should
+	 * be extremely rare (eg, allocating another chunk of
+	 * memory for some reason).
+	 */
+	void (*mark_region)(struct dm_dirty_log *log, region_t region);
+	void (*clear_region)(struct dm_dirty_log *log, region_t region);
+
+	/*
+	 * Returns: <0 (error), 0 (no region), 1 (region)
+	 *
+	 * The mirrord will need perform recovery on regions of
+	 * the mirror that are in the NOSYNC state.  This
+	 * function asks the log to tell the caller about the
+	 * next region that this machine should recover.
+	 *
+	 * Do not confuse this function with 'in_sync()', one
+	 * tells you if an area is synchronised, the other
+	 * assigns recovery work.
+	*/
+	int (*get_resync_work)(struct dm_dirty_log *log, region_t *region);
+
+	/*
+	 * This notifies the log that the resync status of a region
+	 * has changed.  It also clears the region from the recovering
+	 * list (if present).
+	 */
+	void (*set_region_sync)(struct dm_dirty_log *log,
+				region_t region, int in_sync);
+
+	/*
+	 * Returns the number of regions that are in sync.
+	 */
+	region_t (*get_sync_count)(struct dm_dirty_log *log);
+
+	/*
+	 * Support function for mirror status requests.
+	 */
+	int (*status)(struct dm_dirty_log *log, status_type_t status_type,
+		      char *result, unsigned maxlen);
+};
+
+int dm_dirty_log_type_register(struct dm_dirty_log_type *type);
+int dm_dirty_log_type_unregister(struct dm_dirty_log_type *type);
+
+/*
+ * Make sure you use these two functions, rather than calling
+ * type->constructor/destructor() directly.
+ */
+struct dm_dirty_log *dm_dirty_log_create(const char *type_name,
+					 struct dm_target *ti,
+					 unsigned argc, char **argv);
+void dm_dirty_log_destroy(struct dm_dirty_log *log);
+
+#endif	/* __KERNEL__ */
+#endif	/* _LINUX_DM_DIRTY_LOG_H */
diff --git a/include/linux/dm-io.h b/include/linux/dm-io.h
new file mode 100644
index 00000000000..b6bf17ee2f6
--- /dev/null
+++ b/include/linux/dm-io.h
@@ -0,0 +1,85 @@
+/*
+ * Copyright (C) 2003 Sistina Software
+ * Copyright (C) 2004 - 2008 Red Hat, Inc. All rights reserved.
+ *
+ * Device-Mapper low-level I/O.
+ *
+ * This file is released under the GPL.
+ */
+
+#ifndef _LINUX_DM_IO_H
+#define _LINUX_DM_IO_H
+
+#ifdef __KERNEL__
+
+#include <linux/types.h>
+
+struct dm_io_region {
+	struct block_device *bdev;
+	sector_t sector;
+	sector_t count;		/* If this is zero the region is ignored. */
+};
+
+struct page_list {
+	struct page_list *next;
+	struct page *page;
+};
+
+typedef void (*io_notify_fn)(unsigned long error, void *context);
+
+enum dm_io_mem_type {
+	DM_IO_PAGE_LIST,/* Page list */
+	DM_IO_BVEC,	/* Bio vector */
+	DM_IO_VMA,	/* Virtual memory area */
+	DM_IO_KMEM,	/* Kernel memory */
+};
+
+struct dm_io_memory {
+	enum dm_io_mem_type type;
+
+	union {
+		struct page_list *pl;
+		struct bio_vec *bvec;
+		void *vma;
+		void *addr;
+	} ptr;
+
+	unsigned offset;
+};
+
+struct dm_io_notify {
+	io_notify_fn fn;	/* Callback for asynchronous requests */
+	void *context;		/* Passed to callback */
+};
+
+/*
+ * IO request structure
+ */
+struct dm_io_client;
+struct dm_io_request {
+	int bi_rw;			/* READ|WRITE - not READA */
+	struct dm_io_memory mem;	/* Memory to use for io */
+	struct dm_io_notify notify;	/* Synchronous if notify.fn is NULL */
+	struct dm_io_client *client;	/* Client memory handler */
+};
+
+/*
+ * For async io calls, users can alternatively use the dm_io() function below
+ * and dm_io_client_create() to create private mempools for the client.
+ *
+ * Create/destroy may block.
+ */
+struct dm_io_client *dm_io_client_create(unsigned num_pages);
+int dm_io_client_resize(unsigned num_pages, struct dm_io_client *client);
+void dm_io_client_destroy(struct dm_io_client *client);
+
+/*
+ * IO interface using private per-client pools.
+ * Each bit in the optional 'sync_error_bits' bitset indicates whether an
+ * error occurred doing io to the corresponding region.
+ */
+int dm_io(struct dm_io_request *io_req, unsigned num_regions,
+	  struct dm_io_region *region, unsigned long *sync_error_bits);
+
+#endif	/* __KERNEL__ */
+#endif	/* _LINUX_DM_IO_H */
diff --git a/include/linux/dm-kcopyd.h b/include/linux/dm-kcopyd.h
new file mode 100644
index 00000000000..5db21631169
--- /dev/null
+++ b/include/linux/dm-kcopyd.h
@@ -0,0 +1,47 @@
+/*
+ * Copyright (C) 2001 - 2003 Sistina Software
+ * Copyright (C) 2004 - 2008 Red Hat, Inc. All rights reserved.
+ *
+ * kcopyd provides a simple interface for copying an area of one
+ * block-device to one or more other block-devices, either synchronous
+ * or with an asynchronous completion notification.
+ *
+ * This file is released under the GPL.
+ */
+
+#ifndef _LINUX_DM_KCOPYD_H
+#define _LINUX_DM_KCOPYD_H
+
+#ifdef __KERNEL__
+
+#include <linux/dm-io.h>
+
+/* FIXME: make this configurable */
+#define DM_KCOPYD_MAX_REGIONS 8
+
+#define DM_KCOPYD_IGNORE_ERROR 1
+
+/*
+ * To use kcopyd you must first create a dm_kcopyd_client object.
+ */
+struct dm_kcopyd_client;
+int dm_kcopyd_client_create(unsigned num_pages,
+			    struct dm_kcopyd_client **result);
+void dm_kcopyd_client_destroy(struct dm_kcopyd_client *kc);
+
+/*
+ * Submit a copy job to kcopyd.  This is built on top of the
+ * previous three fns.
+ *
+ * read_err is a boolean,
+ * write_err is a bitset, with 1 bit for each destination region
+ */
+typedef void (*dm_kcopyd_notify_fn)(int read_err, unsigned long write_err,
+				    void *context);
+
+int dm_kcopyd_copy(struct dm_kcopyd_client *kc, struct dm_io_region *from,
+		   unsigned num_dests, struct dm_io_region *dests,
+		   unsigned flags, dm_kcopyd_notify_fn fn, void *context);
+
+#endif	/* __KERNEL__ */
+#endif	/* _LINUX_DM_KCOPYD_H */