centos man page for read_cache_page

READ_CACHE_PAGE(9)					    Memory Management in Linux						READ_CACHE_PAGE(9)

NAME
       read_cache_page - read into page cache, fill it if needed

SYNOPSIS
       struct page * read_cache_page(struct address_space * mapping, pgoff_t index, int (*filler) (void *, struct page *), void * data);

ARGUMENTS
       mapping
	   the page's address_space

       index
	   the page index

       filler
	   function to perform the read

       data
	   first arg to filler(data, page) function, often left as NULL

DESCRIPTION
       Read into the page cache. If a page already exists, and PageUptodate is not set, try to fill the page then wait for it to become unlocked.

       If the page does not get brought uptodate, return -EIO.

COPYRIGHT
Kernel Hackers Manual 3.10					     June 2014							READ_CACHE_PAGE(9)