page_cache_prev_hole (9)

pgoff_t page_cache_prev_hole(struct address_space * mapping, pgoff_t index, unsigned long max_scan);

mapping

mapping

index

index

max_scan

maximum range to search

Search backwards in the range [max(index-max_scan+1, 0), index] for the first hole.

the index of the hole if found, otherwise returns an index outside of the set specified (in which case 'index - return >= max_scan' will be true). In rare cases of wrap-around, ULONG_MAX will be returned.

page_cache_prev_hole may be called under rcu_read_lock. However, like radix_tree_gang_lookup, this will not atomically search a snapshot of the tree at a single point in time. For example, if a hole is created at index 10, then subsequently a hole is created at index 5, page_cache_prev_hole covering both indexes may return 5 if called under rcu_read_lock.