139  * memset *ra to zero.
142 file_ra_state_init(struct file_ra_state *ra, struct address_space *mapping)  in file_ra_state_init()  argument
144 	ra->ra_pages = inode_to_bdi(mapping->host)->ra_pages;  in file_ra_state_init()
145 	ra->prev_pos = -1;  in file_ra_state_init()
343 	struct file_ra_state *ra = ractl->ra;  in force_page_cache_ra()  local
354 	max_pages = max_t(unsigned long, bdi->io_pages, ra->ra_pages);  in force_page_cache_ra()
370  * for 128k (32 page) max ra
391 static unsigned long get_next_ra_size(struct file_ra_state *ra,  in get_next_ra_size()  argument
394 	unsigned long cur = ra->size;  in get_next_ra_size()
465 		struct file_ra_state *ra)  in page_cache_ra_order()  argument
472 	pgoff_t mark = index + ra->size - ra->async_size;  in page_cache_ra_order()
476 	unsigned int new_order = ra->order;  in page_cache_ra_order()
478 	trace_page_cache_ra_order(mapping->host, start, ra);  in page_cache_ra_order()
480 		ra->order = 0;  in page_cache_ra_order()
484 	limit = min(limit, index + ra->size - 1);  in page_cache_ra_order()
487 	new_order = min_t(unsigned int, new_order, ilog2(ra->size));  in page_cache_ra_order()
490 	ra->order = new_order;  in page_cache_ra_order()
534 	if (ra->size > index - start)  in page_cache_ra_order()
535 		do_page_cache_ra(ractl, ra->size - (index - start),  in page_cache_ra_order()
536 				 ra->async_size);  in page_cache_ra_order()
543 	unsigned long max_pages = ractl->ra->ra_pages;  in ractl_max_pages()
559 	struct file_ra_state *ra = ractl->ra;  in page_cache_sync_ra()  local
563 	trace_page_cache_sync_ra(ractl->mapping->host, index, ra, req_count);  in page_cache_sync_ra()
570 	if (!ra->ra_pages || blk_cgroup_congested()) {  in page_cache_sync_ra()
584 	prev_index = (unsigned long long)ra->prev_pos >> PAGE_SHIFT;  in page_cache_sync_ra()
591 		ra->start = index;  in page_cache_sync_ra()
592 		ra->size = get_init_ra_size(req_count, max_pages);  in page_cache_sync_ra()
593 		ra->async_size = ra->size > req_count ? ra->size - req_count :  in page_cache_sync_ra()
594 							ra->size >> 1;  in page_cache_sync_ra()
620 	ra->start = index;  in page_cache_sync_ra()
621 	ra->size = min(contig_count + req_count, max_pages);  in page_cache_sync_ra()
622 	ra->async_size = 1;  in page_cache_sync_ra()
624 	ra->order = 0;  in page_cache_sync_ra()
625 	ractl->_index = ra->start;  in page_cache_sync_ra()
626 	page_cache_ra_order(ractl, ra);  in page_cache_sync_ra()
634 	struct file_ra_state *ra = ractl->ra;  in page_cache_async_ra()  local
639 	if (!ra->ra_pages)  in page_cache_async_ra()
648 	trace_page_cache_async_ra(ractl->mapping->host, index, ra, req_count);  in page_cache_async_ra()
659 	expected = round_down(ra->start + ra->size - ra->async_size,  in page_cache_async_ra()
662 		ra->start += ra->size;  in page_cache_async_ra()
667 		ra->size = max(ra->size, get_next_ra_size(ra, max_pages));  in page_cache_async_ra()
684 	ra->start = start;  in page_cache_async_ra()
685 	ra->size = start - index;	/* old async_size */  in page_cache_async_ra()
686 	ra->size += req_count;  in page_cache_async_ra()
687 	ra->size = get_next_ra_size(ra, max_pages);  in page_cache_async_ra()
689 	ra->order += 2;  in page_cache_async_ra()
690 	align = 1UL << min(ra->order, ffs(max_pages) - 1);  in page_cache_async_ra()
691 	end = ra->start + ra->size;  in page_cache_async_ra()
693 	if (aligned_end > ra->start)  in page_cache_async_ra()
694 		ra->size -= end - aligned_end;  in page_cache_async_ra()
695 	ra->async_size = ra->size;  in page_cache_async_ra()
696 	ractl->_index = ra->start;  in page_cache_async_ra()
697 	page_cache_ra_order(ractl, ra);  in page_cache_async_ra()
767 	struct file_ra_state *ra = ractl->ra;  in readahead_expand()  local
832 		if (ra) {  in readahead_expand()
833 			ra->size += min_nrpages;  in readahead_expand()
834 			ra->async_size += min_nrpages;  in readahead_expand()