From 03509b781ae98d4cf5cc139f89a3e75467b829a8 Mon Sep 17 00:00:00 2001 From: Qu Wenruo Date: Wed, 21 Oct 2020 14:24:50 +0800 Subject: [PATCH] btrfs: update the comment for find_first_extent_bit The pitfall here is, if the parameter @bits has multiple bits set, we will return the first range which just has one of the specified bits set. This is a little tricky if we want an exact match. Anyway, update the comment to make that clear. Signed-off-by: Qu Wenruo Reviewed-by: David Sterba Signed-off-by: David Sterba --- fs/btrfs/extent_io.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index a268cc6923e0d..539dab345d241 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -1554,11 +1554,12 @@ out: } /* - * find the first offset in the io tree with 'bits' set. zero is - * returned if we find something, and *start_ret and *end_ret are - * set to reflect the state struct that was found. + * Find the first offset in the io tree with one or more @bits set. * - * If nothing was found, 1 is returned. If found something, return 0. + * Note: If there are multiple bits set in @bits, any of them will match. + * + * Return 0 if we find something, and update @start_ret and @end_ret. + * Return 1 if we found nothing. */ int find_first_extent_bit(struct extent_io_tree *tree, u64 start, u64 *start_ret, u64 *end_ret, unsigned bits, -- 2.30.2