[PATCH v2 1/9] mm: Fix the return type of __do_page_cache_readahead

[Matthew Wilcox <willy@infradead.org>]

From: "Matthew Wilcox (Oracle)" <willy@infradead.org>

ra_submit() which is a wrapper around __do_page_cache_readahead() already
returns an unsigned long, and the 'nr_to_read' parameter is an unsigned
long, so fix __do_page_cache_readahead() to return an unsigned long,
even though I'm pretty sure we're not going to readahead more than 2^32
pages ever.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
---
 mm/internal.h  | 2 +-
 mm/readahead.c | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/mm/internal.h b/mm/internal.h
index 3cf20ab3ca01..41b93c4b3ab7 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -49,7 +49,7 @@ void unmap_page_range(struct mmu_gather *tlb,
 			     unsigned long addr, unsigned long end,
 			     struct zap_details *details);
 
-extern unsigned int __do_page_cache_readahead(struct address_space *mapping,
+extern unsigned long __do_page_cache_readahead(struct address_space *mapping,
 		struct file *filp, pgoff_t offset, unsigned long nr_to_read,
 		unsigned long lookahead_size);
 
diff --git a/mm/readahead.c b/mm/readahead.c
index 2fe72cd29b47..6bf73ef33b7e 100644
--- a/mm/readahead.c
+++ b/mm/readahead.c
@@ -152,7 +152,7 @@ static int read_pages(struct address_space *mapping, struct file *filp,
  *
  * Returns the number of pages requested, or the maximum amount of I/O allowed.
  */
-unsigned int __do_page_cache_readahead(struct address_space *mapping,
+unsigned long __do_page_cache_readahead(struct address_space *mapping,
 		struct file *filp, pgoff_t offset, unsigned long nr_to_read,
 		unsigned long lookahead_size)
 {
@@ -161,7 +161,7 @@ unsigned int __do_page_cache_readahead(struct address_space *mapping,
 	unsigned long end_index;	/* The last page we want to read */
 	LIST_HEAD(page_pool);
 	int page_idx;
-	unsigned int nr_pages = 0;
+	unsigned long nr_pages = 0;
 	loff_t isize = i_size_read(inode);
 	gfp_t gfp_mask = readahead_gfp_mask(mapping);
 
-- 
2.24.1