From 858a29900ea2d639759e697be901a60b759cdcfb Mon Sep 17 00:00:00 2001 From: Hugh Dickins Date: Tue, 6 Jan 2009 14:39:56 -0800 Subject: [PATCH] swapfile: change discard pgoff_t to sector_t Change pgoff_t nr_blocks in discard_swap() and discard_swap_cluster() to sector_t: given the constraints on swap offsets (in particular, the 5 bits of swap type accommodated in the same unsigned long), pgoff_t was actually safe as is, but it certainly looked worrying when shifted left. [akpm@linux-foundation.org: fix shift overflow] Signed-off-by: Hugh Dickins Cc: KAMEZAWA Hiroyuki Cc: Nick Piggin Cc: David Woodhouse Cc: Jens Axboe Cc: Matthew Wilcox Cc: Joern Engel Cc: James Bottomley Cc: Donjun Shin Cc: Tejun Heo Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/swapfile.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/mm/swapfile.c b/mm/swapfile.c index 763210732b5f..6a078557306a 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -96,7 +96,7 @@ static int discard_swap(struct swap_info_struct *si) list_for_each_entry(se, &si->extent_list, list) { sector_t start_block = se->start_block << (PAGE_SHIFT - 9); - pgoff_t nr_blocks = se->nr_pages << (PAGE_SHIFT - 9); + sector_t nr_blocks = (sector_t)se->nr_pages << (PAGE_SHIFT - 9); if (se->start_page == 0) { /* Do not discard the swap header page! */ @@ -133,7 +133,7 @@ static void discard_swap_cluster(struct swap_info_struct *si, start_page < se->start_page + se->nr_pages) { pgoff_t offset = start_page - se->start_page; sector_t start_block = se->start_block + offset; - pgoff_t nr_blocks = se->nr_pages - offset; + sector_t nr_blocks = se->nr_pages - offset; if (nr_blocks > nr_pages) nr_blocks = nr_pages; -- 2.20.1