diff --git a/mm/swapfile.c b/mm/swapfile.c
index 90132b74d6a0..281ee2762358 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -110,6 +110,7 @@ struct swap_info_struct *swap_info[MAX_SWAPFILES];
 
 static struct kmem_cache *swap_table_cachep;
 
+/* Protects si->swap_file for /proc/swaps usage */
 static DEFINE_MUTEX(swapon_mutex);
 
 static DECLARE_WAIT_QUEUE_HEAD(proc_poll_wait);
@@ -2532,7 +2533,8 @@ static void drain_mmlist(void)
 /*
  * Free all of a swapdev's extent information
  */
-static void destroy_swap_extents(struct swap_info_struct *sis)
+static void destroy_swap_extents(struct swap_info_struct *sis,
+				 struct file *swap_file)
 {
 	while (!RB_EMPTY_ROOT(&sis->swap_extent_root)) {
 		struct rb_node *rb = sis->swap_extent_root.rb_node;
@@ -2543,7 +2545,6 @@ static void destroy_swap_extents(struct swap_info_struct *sis)
 	}
 
 	if (sis->flags & SWP_ACTIVATED) {
-		struct file *swap_file = sis->swap_file;
 		struct address_space *mapping = swap_file->f_mapping;
 
 		sis->flags &= ~SWP_ACTIVATED;
@@ -2626,9 +2627,9 @@ EXPORT_SYMBOL_GPL(add_swap_extent);
  * Typically it is in the 1-4 megabyte range.  So we can have hundreds of
  * extents in the rbtree. - akpm.
  */
-static int setup_swap_extents(struct swap_info_struct *sis, sector_t *span)
+static int setup_swap_extents(struct swap_info_struct *sis,
+			      struct file *swap_file, sector_t *span)
 {
-	struct file *swap_file = sis->swap_file;
 	struct address_space *mapping = swap_file->f_mapping;
 	struct inode *inode = mapping->host;
 	int ret;
@@ -2646,7 +2647,7 @@ static int setup_swap_extents(struct swap_info_struct *sis, sector_t *span)
 		sis->flags |= SWP_ACTIVATED;
 		if ((sis->flags & SWP_FS_OPS) &&
 		    sio_pool_init() != 0) {
-			destroy_swap_extents(sis);
+			destroy_swap_extents(sis, swap_file);
 			return -ENOMEM;
 		}
 		return ret;
@@ -2857,7 +2858,7 @@ SYSCALL_DEFINE1(swapoff, const char __user *, specialfile)
 	flush_work(&p->reclaim_work);
 	flush_percpu_swap_cluster(p);
 
-	destroy_swap_extents(p);
+	destroy_swap_extents(p, p->swap_file);
 	if (p->flags & SWP_CONTINUED)
 		free_swap_count_continuations(p);
 
@@ -2945,7 +2946,7 @@ static void *swap_start(struct seq_file *swap, loff_t *pos)
 		return SEQ_START_TOKEN;
 
 	for (type = 0; (si = swap_type_to_info(type)); type++) {
-		if (!(si->flags & SWP_USED) || !si->swap_map)
+		if (!(si->swap_file))
 			continue;
 		if (!--l)
 			return si;
@@ -2966,7 +2967,7 @@ static void *swap_next(struct seq_file *swap, void *v, loff_t *pos)
 
 	++(*pos);
 	for (; (si = swap_type_to_info(type)); type++) {
-		if (!(si->flags & SWP_USED) || !si->swap_map)
+		if (!(si->swap_file))
 			continue;
 		return si;
 	}
@@ -3376,7 +3377,6 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags)
 		goto bad_swap;
 	}
 
-	si->swap_file = swap_file;
 	mapping = swap_file->f_mapping;
 	dentry = swap_file->f_path.dentry;
 	inode = mapping->host;
@@ -3426,7 +3426,7 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags)
 
 	si->max = maxpages;
 	si->pages = maxpages - 1;
-	nr_extents = setup_swap_extents(si, &span);
+	nr_extents = setup_swap_extents(si, swap_file, &span);
 	if (nr_extents < 0) {
 		error = nr_extents;
 		goto bad_swap_unlock_inode;
@@ -3535,6 +3535,8 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags)
 	prio = DEF_SWAP_PRIO;
 	if (swap_flags & SWAP_FLAG_PREFER)
 		prio = swap_flags & SWAP_FLAG_PRIO_MASK;
+
+	si->swap_file = swap_file;
 	enable_swap_info(si, prio, swap_map, cluster_info, zeromap);
 
 	pr_info("Adding %uk swap on %s.  Priority:%d extents:%d across:%lluk %s%s%s%s\n",
@@ -3559,10 +3561,9 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags)
 	kfree(si->global_cluster);
 	si->global_cluster = NULL;
 	inode = NULL;
-	destroy_swap_extents(si);
+	destroy_swap_extents(si, swap_file);
 	swap_cgroup_swapoff(si->type);
 	spin_lock(&swap_lock);
-	si->swap_file = NULL;
 	si->flags = 0;
 	spin_unlock(&swap_lock);
 	vfree(swap_map);