From 8666e638b07e2be143b91129d3499d2c25f26a5f Mon Sep 17 00:00:00 2001 From: Nikolay Borisov Date: Wed, 5 Jun 2019 14:50:04 +0300 Subject: [PATCH] btrfs: Document __etree_search The function has a lot of return values and specific conventions making it cumbersome to understand what's returned. Have a go at documenting its parameters and return values. Reviewed-by: Johannes Thumshirn Reviewed-by: Qu Wenruo Signed-off-by: Nikolay Borisov Signed-off-by: David Sterba --- fs/btrfs/extent_io.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index 105b3d2e86f2..43761ecd1201 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -359,6 +359,24 @@ static struct rb_node *tree_insert(struct rb_root *root, return NULL; } +/** + * __etree_search - searche @tree for an entry that contains @offset. Such + * entry would have entry->start <= offset && entry->end >= offset. + * + * @tree - the tree to search + * @offset - offset that should fall within an entry in @tree + * @next_ret - pointer to the first entry whose range ends after @offset + * @prev - pointer to the first entry whose range begins before @offset + * @p_ret - pointer where new node should be anchored (used when inserting an + * entry in the tree) + * @parent_ret - points to entry which would have been the parent of the entry, + * containing @offset + * + * This function returns a pointer to the entry that contains @offset byte + * address. If no such entry exists, then NULL is returned and the other + * pointer arguments to the function are filled, otherwise the found entry is + * returned and other pointers are left untouched. + */ static struct rb_node *__etree_search(struct extent_io_tree *tree, u64 offset, struct rb_node **next_ret, struct rb_node **prev_ret, -- GitLab