Btrfs: Allocator improvements
Reduce CPU time searching for free blocks by optimizing find_first_extent_bit
Fix find_free_extent to make better use of the last_alloc hint. Before it
was often finding blocks just before the hint.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h
index 151fdad..fcc4bb0 100644
--- a/fs/btrfs/extent_io.h
+++ b/fs/btrfs/extent_io.h
@@ -81,6 +81,15 @@
struct extent_map_tree;
+static inline struct extent_state *extent_state_next(struct extent_state *state)
+{
+ struct rb_node *node;
+ node = rb_next(&state->rb_node);
+ if (!node)
+ return NULL;
+ return rb_entry(node, struct extent_state, rb_node);
+}
+
typedef struct extent_map *(get_extent_t)(struct inode *inode,
struct page *page,
size_t page_offset,
@@ -122,6 +131,8 @@
gfp_t mask);
int find_first_extent_bit(struct extent_io_tree *tree, u64 start,
u64 *start_ret, u64 *end_ret, int bits);
+struct extent_state *find_first_extent_bit_state(struct extent_io_tree *tree,
+ u64 start, int bits);
int extent_invalidatepage(struct extent_io_tree *tree,
struct page *page, unsigned long offset);
int extent_write_full_page(struct extent_io_tree *tree, struct page *page,