btrfs: open code inexact rbtree search in tree_search

The call chain from

tree_search
  tree_search_for_insert
    __etree_search

can be open coded and allow further simplifications, here we need a tree
search with fallback to the next node in case it's not found. This is
represented as __etree_search parameters next_ret=valid, prev_ret=NULL.

Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
David Sterba 2020-06-25 18:35:24 +02:00
parent c367602a78
commit bebb22c13d

View file

@ -453,10 +453,35 @@ tree_search_for_insert(struct extent_io_tree *tree,
return ret;
}
static inline struct rb_node *tree_search(struct extent_io_tree *tree,
u64 offset)
/*
* Inexact rb-tree search, return the next entry if @offset is not found
*/
static inline struct rb_node *tree_search(struct extent_io_tree *tree, u64 offset)
{
return tree_search_for_insert(tree, offset, NULL, NULL);
struct rb_root *root = &tree->state;
struct rb_node **node = &root->rb_node;
struct rb_node *prev = NULL;
struct tree_entry *entry;
while (*node) {
prev = *node;
entry = rb_entry(prev, struct tree_entry, rb_node);
if (offset < entry->start)
node = &(*node)->rb_left;
else if (offset > entry->end)
node = &(*node)->rb_right;
else
return *node;
}
/* Search neighbors until we find the first one past the end */
while (prev && offset > entry->end) {
prev = rb_next(prev);
entry = rb_entry(prev, struct tree_entry, rb_node);
}
return prev;
}
/*