readahead: move max_sane_readahead() calls into force_page_cache_readahead()

Impact: code simplification.

Cc: Nick Piggin <npiggin@suse.de>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Cc: Ying Han <yinghan@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/fadvise.c

@@ -101,7 +101,7 @@ SYSCALL_DEFINE(fadvise64_64)(int fd, loff_t offset, loff_t len, int advice)
 		
 		ret = force_page_cache_readahead(mapping, file,
 				start_index,
-				max_sane_readahead(nrpages));
+				nrpages);
 		if (ret > 0)
 			ret = 0;
 		break;

mm/filemap.c

@@ -1390,8 +1390,7 @@ do_readahead(struct address_space *mapping, struct file *filp,
 	if (!mapping || !mapping->a_ops || !mapping->a_ops->readpage)
 		return -EINVAL;
 
-	force_page_cache_readahead(mapping, filp, index,
-					max_sane_readahead(nr));
+	force_page_cache_readahead(mapping, filp, index, nr);
 	return 0;
 }
 

mm/madvise.c

@@ -123,8 +123,7 @@ static long madvise_willneed(struct vm_area_struct * vma,
 		end = vma->vm_end;
 	end = ((end - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff;
 
-	force_page_cache_readahead(file->f_mapping,
-			file, start, max_sane_readahead(end - start));
+	force_page_cache_readahead(file->f_mapping, file, start, end - start);
 	return 0;
 }
 

mm/readahead.c

@@ -210,6 +210,7 @@ int force_page_cache_readahead(struct address_space *mapping, struct file *filp,
 	if (unlikely(!mapping->a_ops->readpage && !mapping->a_ops->readpages))
 		return -EINVAL;
 
+	nr_to_read = max_sane_readahead(nr_to_read);
 	while (nr_to_read) {
 		int err;