1 files changed, 20 insertions, 72 deletions

diff --git a/mm/swapfile.c b/mm/swapfile.c
index d999f090dfda..dae42f380d6e 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -932,9 +932,7 @@ static inline int unuse_pmd_range(struct vm_area_struct *vma, pud_t *pud,
 	pmd = pmd_offset(pud, addr);
 	do {
 		next = pmd_addr_end(addr, end);
-		if (unlikely(pmd_trans_huge(*pmd)))
-			continue;
-		if (pmd_none_or_clear_bad(pmd))
+		if (pmd_none_or_trans_huge_or_clear_bad(pmd))
 			continue;
 		ret = unuse_pte_range(vma, pmd, addr, next, entry, page);
 		if (ret)
@@ -1563,6 +1561,8 @@ SYSCALL_DEFINE1(swapoff, const char __user *, specialfile)
 	if (!capable(CAP_SYS_ADMIN))
 		return -EPERM;
 
+	BUG_ON(!current->mm);
+
 	pathname = getname(specialfile);
 	err = PTR_ERR(pathname);
 	if (IS_ERR(pathname))
@@ -1590,7 +1590,7 @@ SYSCALL_DEFINE1(swapoff, const char __user *, specialfile)
 		spin_unlock(&swap_lock);
 		goto out_dput;
 	}
-	if (!security_vm_enough_memory(p->pages))
+	if (!security_vm_enough_memory_mm(current->mm, p->pages))
 		vm_unacct_memory(p->pages);
 	else {
 		err = -ENOMEM;
@@ -2105,7 +2105,7 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags)
 			p->flags |= SWP_SOLIDSTATE;
 			p->cluster_next = 1 + (random32() % p->highest_bit);
 		}
-		if (discard_swap(p) == 0 && (swap_flags & SWAP_FLAG_DISCARD))
+		if ((swap_flags & SWAP_FLAG_DISCARD) && discard_swap(p) == 0)
 			p->flags |= SWP_DISCARDABLE;
 	}
 
@@ -2290,58 +2290,6 @@ int swapcache_prepare(swp_entry_t entry)
 }
 
 /*
- * swap_lock prevents swap_map being freed. Don't grab an extra
- * reference on the swaphandle, it doesn't matter if it becomes unused.
- */
-int valid_swaphandles(swp_entry_t entry, unsigned long *offset)
-{
-	struct swap_info_struct *si;
-	int our_page_cluster = page_cluster;
-	pgoff_t target, toff;
-	pgoff_t base, end;
-	int nr_pages = 0;
-
-	if (!our_page_cluster)	/* no readahead */
-		return 0;
-
-	si = swap_info[swp_type(entry)];
-	target = swp_offset(entry);
-	base = (target >> our_page_cluster) << our_page_cluster;
-	end = base + (1 << our_page_cluster);
-	if (!base)		/* first page is swap header */
-		base++;
-
-	spin_lock(&swap_lock);
-	if (end > si->max)	/* don't go beyond end of map */
-		end = si->max;
-
-	/* Count contiguous allocated slots above our target */
-	for (toff = target; ++toff < end; nr_pages++) {
-		/* Don't read in free or bad pages */
-		if (!si->swap_map[toff])
-			break;
-		if (swap_count(si->swap_map[toff]) == SWAP_MAP_BAD)
-			break;
-	}
-	/* Count contiguous allocated slots below our target */
-	for (toff = target; --toff >= base; nr_pages++) {
-		/* Don't read in free or bad pages */
-		if (!si->swap_map[toff])
-			break;
-		if (swap_count(si->swap_map[toff]) == SWAP_MAP_BAD)
-			break;
-	}
-	spin_unlock(&swap_lock);
-
-	/*
-	 * Indicate starting offset, and return number of pages to get:
-	 * if only 1, say 0, since there's then no readahead to be done.
-	 */
-	*offset = ++toff;
-	return nr_pages? ++nr_pages: 0;
-}
-
-/*
  * add_swap_count_continuation - called when a swap count is duplicated
  * beyond SWAP_MAP_MAX, it allocates a new page and links that to the entry's
  * page of the original vmalloc'ed swap_map, to hold the continuation count
@@ -2427,9 +2375,9 @@ int add_swap_count_continuation(swp_entry_t entry, gfp_t gfp_mask)
 		if (!(count & COUNT_CONTINUED))
 			goto out;
 
-		map = kmap_atomic(list_page, KM_USER0) + offset;
+		map = kmap_atomic(list_page) + offset;
 		count = *map;
-		kunmap_atomic(map, KM_USER0);
+		kunmap_atomic(map);
 
 		/*
 		 * If this continuation count now has some space in it,
@@ -2472,7 +2420,7 @@ static bool swap_count_continued(struct swap_info_struct *si,
 
 	offset &= ~PAGE_MASK;
 	page = list_entry(head->lru.next, struct page, lru);
-	map = kmap_atomic(page, KM_USER0) + offset;
+	map = kmap_atomic(page) + offset;
 
 	if (count == SWAP_MAP_MAX)	/* initial increment from swap_map */
 		goto init_map;		/* jump over SWAP_CONT_MAX checks */
@@ -2482,26 +2430,26 @@ static bool swap_count_continued(struct swap_info_struct *si,
 		 * Think of how you add 1 to 999
 		 */
 		while (*map == (SWAP_CONT_MAX | COUNT_CONTINUED)) {
-			kunmap_atomic(map, KM_USER0);
+			kunmap_atomic(map);
 			page = list_entry(page->lru.next, struct page, lru);
 			BUG_ON(page == head);
-			map = kmap_atomic(page, KM_USER0) + offset;
+			map = kmap_atomic(page) + offset;
 		}
 		if (*map == SWAP_CONT_MAX) {
-			kunmap_atomic(map, KM_USER0);
+			kunmap_atomic(map);
 			page = list_entry(page->lru.next, struct page, lru);
 			if (page == head)
 				return false;	/* add count continuation */
-			map = kmap_atomic(page, KM_USER0) + offset;
+			map = kmap_atomic(page) + offset;
 init_map:		*map = 0;		/* we didn't zero the page */
 		}
 		*map += 1;
-		kunmap_atomic(map, KM_USER0);
+		kunmap_atomic(map);
 		page = list_entry(page->lru.prev, struct page, lru);
 		while (page != head) {
-			map = kmap_atomic(page, KM_USER0) + offset;
+			map = kmap_atomic(page) + offset;
 			*map = COUNT_CONTINUED;
-			kunmap_atomic(map, KM_USER0);
+			kunmap_atomic(map);
 			page = list_entry(page->lru.prev, struct page, lru);
 		}
 		return true;			/* incremented */
@@ -2512,22 +2460,22 @@ init_map:		*map = 0;		/* we didn't zero the page */
 		 */
 		BUG_ON(count != COUNT_CONTINUED);
 		while (*map == COUNT_CONTINUED) {
-			kunmap_atomic(map, KM_USER0);
+			kunmap_atomic(map);
 			page = list_entry(page->lru.next, struct page, lru);
 			BUG_ON(page == head);
-			map = kmap_atomic(page, KM_USER0) + offset;
+			map = kmap_atomic(page) + offset;
 		}
 		BUG_ON(*map == 0);
 		*map -= 1;
 		if (*map == 0)
 			count = 0;
-		kunmap_atomic(map, KM_USER0);
+		kunmap_atomic(map);
 		page = list_entry(page->lru.prev, struct page, lru);
 		while (page != head) {
-			map = kmap_atomic(page, KM_USER0) + offset;
+			map = kmap_atomic(page) + offset;
 			*map = SWAP_CONT_MAX | count;
 			count = COUNT_CONTINUED;
-			kunmap_atomic(map, KM_USER0);
+			kunmap_atomic(map);
 			page = list_entry(page->lru.prev, struct page, lru);
 		}
 		return count == COUNT_CONTINUED;