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.
[[email protected]: fix shift overflow]
Signed-off-by: Hugh Dickins <[email protected]>
Cc: KAMEZAWA Hiroyuki <[email protected]>
Cc: Nick Piggin <[email protected]>
Cc: David Woodhouse <[email protected]>
Cc: Jens Axboe <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Joern Engel <[email protected]>
Cc: James Bottomley <[email protected]>
Cc: Donjun Shin <[email protected]>
Cc: Tejun Heo <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
diff --git a/mm/swapfile.c b/mm/swapfile.c
index 7632107..6a07855 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -96,7 +96,7 @@
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 @@
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;
