Btrfs: Extent based page cache code. This uses an rbtree of extents a…

…nd tests

instead of buffer heads.

Signed-off-by: Chris Mason <chris.mason@oracle.com>

fs/btrfs/Makefile

@@ -4,7 +4,8 @@ ifneq ($(KERNELRELEASE),)
 obj-m  := btrfs.o
 btrfs-y := super.o ctree.o extent-tree.o print-tree.o root-tree.o dir-item.o \
 	   hash.o file-item.o inode-item.o inode-map.o disk-io.o \
-	   transaction.o bit-radix.o inode.o file.o tree-defrag.o
+	   transaction.o bit-radix.o inode.o file.o tree-defrag.o \
+	   extent_map.o
 
 #btrfs-y := ctree.o disk-io.o radix-tree.o extent-tree.o print-tree.o \
 #	  root-tree.o dir-item.o hash.o file-item.o inode-item.o \

fs/btrfs/btrfs_inode.h

@@ -19,11 +19,14 @@
 #ifndef __BTRFS_I__
 #define __BTRFS_I__
 
+#include "extent_map.h"
+
 /* in memory btrfs inode */
 struct btrfs_inode {
 	struct btrfs_root *root;
 	struct btrfs_block_group_cache *block_group;
 	struct btrfs_key location;
+	struct extent_map_tree extent_tree;
 	struct inode vfs_inode;
 
 	/*

fs/btrfs/ctree.h

@@ -1176,7 +1176,14 @@ int btrfs_commit_write(struct file *file, struct page *page,
 		       unsigned from, unsigned to);
 int btrfs_get_block(struct inode *inode, sector_t iblock,
 		    struct buffer_head *result, int create);
+struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page,
+				    size_t page_offset, u64 start, u64 end,
+				    int create);
+int btrfs_update_inode(struct btrfs_trans_handle *trans,
+			      struct btrfs_root *root,
+			      struct inode *inode);
 /* file.c */
+int btrfs_drop_extent_cache(struct inode *inode, u64 start, u64 end);
 extern struct file_operations btrfs_file_operations;
 int btrfs_drop_extents(struct btrfs_trans_handle *trans,
 		       struct btrfs_root *root, struct inode *inode,

fs/btrfs/disk-io.h

@@ -77,7 +77,6 @@ int btrfs_insert_dev_radix(struct btrfs_root *root,
 			   u64 num_blocks);
 int btrfs_map_bh_to_logical(struct btrfs_root *root, struct buffer_head *bh,
 			     u64 logical);
-int btrfs_releasepage(struct page *page, gfp_t flags);
 void btrfs_btree_balance_dirty(struct btrfs_root *root);
 int btrfs_free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root);
 void btrfs_mark_buffer_dirty(struct buffer_head *bh);