Commit aa2c80a9 authored by Filipe Manana's avatar Filipe Manana Committed by David Sterba
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btrfs: avoid re-searching tree when setting bits in an extent range 



When setting bits for an extent range (set_extent_bit()), if the current
extent state record starts after the target range, we always do a jump to
the 'search_again' label, which will cause us to do a full tree search for
the next state if the current state ends before the target range. Unless
we need to reschedule, we can just grab the next state and process it,
avoiding a full tree search, even if that next state is not contiguous, as
we'll allocate and insert a new prealloc state if needed.

Signed-off-by: default avatarFilipe Manana <fdmanana@suse.com>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent b61dd9b1

fs/btrfs/extent-io-tree.c

+16 −0
Original line number Diff line number Diff line
@@ -1226,6 +1226,22 @@ static int set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end, 
		if (inserted_state == prealloc)

			prealloc = NULL;

		start = inserted_state->end + 1;



		/* Beyond target range, stop. */

		if (start > end)

			goto out;



		if (need_resched())

			goto search_again;



		state = next_search_state(inserted_state, end);

		/*

		 * If there's a next state, whether contiguous or not, we don't

		 * need to unlock and start search agian. If it's not contiguous

		 * we will end up here and try to allocate a prealloc state and insert.

		 */

		if (state)

			goto hit_next;

		goto search_again;

	}

	/*