Btrfs: Add support for multiple devices per filesystem

Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
new file mode 100644
index 0000000..4a47dcb
--- /dev/null
+++ b/fs/btrfs/volumes.h
@@ -0,0 +1,78 @@
+/*
+ * Copyright (C) 2007 Oracle.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#ifndef __BTRFS_VOLUMES_
+#define __BTRFS_VOLUMES_
+struct btrfs_device {
+	struct list_head dev_list;
+	struct btrfs_root *dev_root;
+	struct btrfs_key dev_key;
+
+	struct block_device *bdev;
+
+	/* the internal btrfs device id */
+	u64 devid;
+
+	/* size of the device */
+	u64 total_bytes;
+
+	/* bytes used */
+	u64 bytes_used;
+
+	/* optimal io alignment for this device */
+	u32 io_align;
+
+	/* optimal io width for this device */
+	u32 io_width;
+
+	/* minimal io size for this device */
+	u32 sector_size;
+
+	/* the kernel device number */
+	u64 rdev;
+
+	/* type and info about this device */
+	u64 type;
+
+	/* partition number, 0 for whole dev */
+	int partition;
+
+	/* length of the name data at the end of the item */
+	int name_len;
+
+	/* physical drive uuid (or lvm uuid) */
+	u8 uuid[BTRFS_DEV_UUID_SIZE];
+
+	char *name;
+};
+
+int btrfs_alloc_dev_extent(struct btrfs_trans_handle *trans,
+			   struct btrfs_device *device,
+			   u64 owner, u64 num_bytes, u64 *start);
+int btrfs_map_block(struct btrfs_mapping_tree *map_tree,
+		    u64 logical, u64 *phys, u64 *length,
+		    struct btrfs_device **dev);
+int btrfs_read_sys_array(struct btrfs_root *root);
+int btrfs_read_chunk_tree(struct btrfs_root *root);
+int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
+		      struct btrfs_root *extent_root, u64 *start,
+		      u64 *num_bytes, u32 type);
+void btrfs_mapping_init(struct btrfs_mapping_tree *tree);
+void btrfs_mapping_tree_free(struct btrfs_mapping_tree *tree);
+int btrfs_map_bio(struct btrfs_root *root, int rw, struct bio *bio);
+#endif