PAGE_CACHE_PREV_HOLE(9)             Memory Management in Linux            PAGE_CACHE_PREV_HOLE(9)



NAME
       page_cache_prev_hole - find the prev hole (not-present entry)

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

ARGUMENTS
       mapping
           mapping

       index
           index

       max_scan
           maximum range to search

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

RETURN
       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.

COPYRIGHT
Kernel Hackers Manual 4.8.                 January 2017                   PAGE_CACHE_PREV_HOLE(9)