Commit 0449314a authored by Liu Bo's avatar Liu Bo Committed by David Sterba
Browse files

Btrfs: skip states when they does not contain bits to clear 



Clearing a range's bits is different with setting them, since we don't
need to touch them when states do not contain bits we want.

Signed-off-by: default avatarLiu Bo <liubo2009@cn.fujitsu.com>
parent 285190d9

fs/btrfs/extent_io.c

+10 −5
Original line number Diff line number Diff line
@@ -513,6 +513,15 @@ int clear_extent_bit(struct extent_io_tree *tree, u64 start, u64 end, 
	WARN_ON(state->end < start);

	last_end = state->end;



	if (state->end < end && !need_resched())

		next_node = rb_next(&state->rb_node);

	else

		next_node = NULL;



	/* the state doesn't have the wanted bits, go ahead */

	if (!(state->state & bits))

		goto next;



	/*

	 *     | ---- desired range ---- |

	 *  | state | or
@@ -565,12 +574,8 @@ int clear_extent_bit(struct extent_io_tree *tree, u64 start, u64 end, 
		goto out;

	}



	if (state->end < end && prealloc && !need_resched())

		next_node = rb_next(&state->rb_node);

	else

		next_node = NULL;



	set |= clear_state_bit(tree, state, &bits, wake);

next:

	if (last_end == (u64)-1)

		goto out;

	start = last_end + 1;