36  * memset *ra to zero.
39 file_ra_state_init(struct file_ra_state *ra, struct address_space *mapping)  in file_ra_state_init()  argument
41 	ra->ra_pages = inode_to_bdi(mapping->host)->ra_pages;  in file_ra_state_init()
42 	ra->prev_pos = -1;  in file_ra_state_init()
289 		struct file_ra_state *ra, unsigned long nr_to_read)  in force_page_cache_ra()  argument
307 	max_pages = max_t(unsigned long, bdi->io_pages, ra->ra_pages);  in force_page_cache_ra()
339  * for 128k (32 page) max ra
360 static unsigned long get_next_ra_size(struct file_ra_state *ra,  in get_next_ra_size()  argument
363 	unsigned long cur = ra->size;  in get_next_ra_size()
433 				 struct file_ra_state *ra,  in try_context_readahead()  argument
456 	ra->start = index;  in try_context_readahead()
457 	ra->size = min(size + req_size, max);  in try_context_readahead()
458 	ra->async_size = 1;  in try_context_readahead()
467 		struct file_ra_state *ra, bool hit_readahead_marker,  in ondemand_readahead()  argument
471 	unsigned long max_pages = ra->ra_pages;  in ondemand_readahead()
495 	if ((index == (ra->start + ra->size - ra->async_size) ||  in ondemand_readahead()
496 	     index == (ra->start + ra->size))) {  in ondemand_readahead()
497 		ra->start += ra->size;  in ondemand_readahead()
498 		ra->size = get_next_ra_size(ra, max_pages);  in ondemand_readahead()
499 		ra->async_size = ra->size;  in ondemand_readahead()
520 		ra->start = start;  in ondemand_readahead()
521 		ra->size = start - index;	/* old async_size */  in ondemand_readahead()
522 		ra->size += req_size;  in ondemand_readahead()
523 		ra->size = get_next_ra_size(ra, max_pages);  in ondemand_readahead()
524 		ra->async_size = ra->size;  in ondemand_readahead()
539 	prev_index = (unsigned long long)ra->prev_pos >> PAGE_SHIFT;  in ondemand_readahead()
547 	if (try_context_readahead(ractl->mapping, ra, index, req_size,  in ondemand_readahead()
559 	ra->start = index;  in ondemand_readahead()
560 	ra->size = get_init_ra_size(req_size, max_pages);  in ondemand_readahead()
561 	ra->async_size = ra->size > req_size ? ra->size - req_size : ra->size;  in ondemand_readahead()
570 	if (index == ra->start && ra->size == ra->async_size) {  in ondemand_readahead()
571 		add_pages = get_next_ra_size(ra, max_pages);  in ondemand_readahead()
572 		if (ra->size + add_pages <= max_pages) {  in ondemand_readahead()
573 			ra->async_size = add_pages;  in ondemand_readahead()
574 			ra->size += add_pages;  in ondemand_readahead()
576 			ra->size = max_pages;  in ondemand_readahead()
577 			ra->async_size = max_pages >> 1;  in ondemand_readahead()
581 	ractl->_index = ra->start;  in ondemand_readahead()
582 	do_page_cache_ra(ractl, ra->size, ra->async_size);  in ondemand_readahead()
586 		struct file_ra_state *ra, unsigned long req_count)  in page_cache_sync_ra()  argument
596 	if (!ra->ra_pages || blk_cgroup_congested()) {  in page_cache_sync_ra()
605 		force_page_cache_ra(ractl, ra, req_count);  in page_cache_sync_ra()
610 	ondemand_readahead(ractl, ra, false, req_count);  in page_cache_sync_ra()
615 		struct file_ra_state *ra, struct page *page,  in page_cache_async_ra()  argument
619 	if (!ra->ra_pages)  in page_cache_async_ra()
640 	ondemand_readahead(ractl, ra, true, req_count);  in page_cache_async_ra()