Btrfs: Create extent_buffer interface for large blocksizes

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

1 files changed, 73 insertions, 2 deletions

diff --git a/fs/btrfs/extent_map.h b/fs/btrfs/extent_map.h
index d913ce01248..430b997a70f 100644
--- a/fs/btrfs/extent_map.h
+++ b/fs/btrfs/extent_map.h
@@ -3,9 +3,20 @@
 
 #include <linux/rbtree.h>
 
+#define EXTENT_MAP_HOLE (u64)-3
 #define EXTENT_MAP_INLINE (u64)-2
 #define EXTENT_MAP_DELALLOC (u64)-1
 
+/* bits for the extent state */
+#define EXTENT_DIRTY 1
+#define EXTENT_WRITEBACK (1 << 1)
+#define EXTENT_UPTODATE (1 << 2)
+#define EXTENT_LOCKED (1 << 3)
+#define EXTENT_NEW (1 << 4)
+#define EXTENT_DELALLOC (1 << 5)
+#define EXTENT_IOBITS (EXTENT_LOCKED | EXTENT_WRITEBACK)
+
+
 struct extent_map_ops {
 	int (*fill_delalloc)(struct inode *inode, u64 start, u64 end);
 	int (*writepage_io_hook)(struct page *page, u64 start, u64 end);
@@ -51,10 +62,13 @@ struct extent_state {
 	struct list_head list;
 };
 
+#define EXTENT_BUFFER_SIZE(nr) (sizeof(struct extent_buffer) + \
+			       (nr - 1) * sizeof(struct page *))
 struct extent_buffer {
 	u64 start;
-	u64 end; /* inclusive */
-	char *addr;
+	unsigned long len;
+	atomic_t refs;
+	int flags;
 	struct page *pages[];
 };
 
@@ -87,8 +101,12 @@ int set_extent_new(struct extent_map_tree *tree, u64 start, u64 end,
 		   gfp_t mask);
 int set_extent_dirty(struct extent_map_tree *tree, u64 start, u64 end,
 		     gfp_t mask);
+int clear_extent_dirty(struct extent_map_tree *tree, u64 start, u64 end,
+		       gfp_t mask);
 int set_extent_delalloc(struct extent_map_tree *tree, u64 start, u64 end,
 		     gfp_t mask);
+int find_first_extent_bit(struct extent_map_tree *tree, u64 start,
+			  u64 *start_ret, u64 *end_ret, int bits);
 int extent_invalidatepage(struct extent_map_tree *tree,
 			  struct page *page, unsigned long offset);
 int extent_write_full_page(struct extent_map_tree *tree, struct page *page,
@@ -106,4 +124,57 @@ int set_range_dirty(struct extent_map_tree *tree, u64 start, u64 end);
 int set_state_private(struct extent_map_tree *tree, u64 start, u64 private);
 int get_state_private(struct extent_map_tree *tree, u64 start, u64 *private);
 void set_page_extent_mapped(struct page *page);
+
+struct extent_buffer *alloc_extent_buffer(struct extent_map_tree *tree,
+					  u64 start, unsigned long len,
+					  gfp_t mask);
+struct extent_buffer *find_extent_buffer(struct extent_map_tree *tree,
+					 u64 start, unsigned long len,
+					  gfp_t mask);
+void free_extent_buffer(struct extent_buffer *eb);
+int read_extent_buffer_pages(struct extent_map_tree *tree,
+			     struct extent_buffer *eb, int wait);
+
+static inline void extent_buffer_get(struct extent_buffer *eb)
+{
+	atomic_inc(&eb->refs);
+}
+
+static inline u64 extent_buffer_blocknr(struct extent_buffer *eb)
+{
+	return eb->start / 4096;
+}
+
+int memcmp_extent_buffer(struct extent_buffer *eb, const void *ptrv,
+			  unsigned long start,
+			  unsigned long len);
+void read_extent_buffer(struct extent_buffer *eb, void *dst,
+			unsigned long start,
+			unsigned long len);
+void write_extent_buffer(struct extent_buffer *eb, const void *src,
+			 unsigned long start, unsigned long len);
+void copy_extent_buffer(struct extent_buffer *dst, struct extent_buffer *src,
+			unsigned long dst_offset, unsigned long src_offset,
+			unsigned long len);
+void memcpy_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
+			   unsigned long src_offset, unsigned long len);
+void memmove_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
+			   unsigned long src_offset, unsigned long len);
+void memset_extent_buffer(struct extent_buffer *eb, char c,
+			  unsigned long start, unsigned long len);
+int wait_on_extent_buffer_writeback(struct extent_map_tree *tree,
+				    struct extent_buffer *eb);
+int clear_extent_buffer_dirty(struct extent_map_tree *tree,
+			      struct extent_buffer *eb);
+int set_extent_buffer_dirty(struct extent_map_tree *tree,
+			     struct extent_buffer *eb);
+int set_extent_buffer_uptodate(struct extent_map_tree *tree,
+			       struct extent_buffer *eb);
+int extent_buffer_uptodate(struct extent_map_tree *tree,
+			   struct extent_buffer *eb);
+int map_extent_buffer(struct extent_buffer *eb, unsigned long offset,
+		      char **token, char **map,
+		      unsigned long *map_start,
+		      unsigned long *map_len, int km);
+void unmap_extent_buffer(struct extent_buffer *eb, char *token, int km);
 #endif