Btrfs: add the ability to cache a pointer into the eb
This cuts down on the CPU time used by map_private_extent_buffer
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 85ab1c5..c2e17cd 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -1546,6 +1546,17 @@
#define BTRFS_INODE_ROOT_ITEM_INIT (1 << 31)
+struct btrfs_map_token {
+ struct extent_buffer *eb;
+ char *kaddr;
+ unsigned long offset;
+};
+
+static inline void btrfs_init_map_token (struct btrfs_map_token *token)
+{
+ memset(token, 0, sizeof(*token));
+}
+
/* some macros to generate set/get funcs for the struct fields. This
* assumes there is a lefoo_to_cpu for every type, so lets make a simple
* one for u8:
@@ -1569,6 +1580,8 @@
#ifndef BTRFS_SETGET_FUNCS
#define BTRFS_SETGET_FUNCS(name, type, member, bits) \
u##bits btrfs_##name(struct extent_buffer *eb, type *s); \
+u##bits btrfs_token_##name(struct extent_buffer *eb, type *s, struct btrfs_map_token *token); \
+void btrfs_set_token_##name(struct extent_buffer *eb, type *s, u##bits val, struct btrfs_map_token *token);\
void btrfs_set_##name(struct extent_buffer *eb, type *s, u##bits val);
#endif