swapfile: remove SWP_ACTIVE mask

Remove the SWP_ACTIVE mask: it just obscures the SWP_WRITEOK flag.
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/linux/swap.h

@@ -120,7 +120,6 @@ struct swap_extent {
 enum {
 	SWP_USED	= (1 << 0),	/* is slot in swap_info[] used? */
 	SWP_WRITEOK	= (1 << 1),	/* ok to write to this swap?	*/
-	SWP_ACTIVE	= (SWP_USED | SWP_WRITEOK),
 					/* add others here before... */
 	SWP_SCANNING	= (1 << 8),	/* refcount in scan_swap_map */
 };

mm/swapfile.c

@@ -1222,7 +1222,7 @@ asmlinkage long sys_swapoff(const char __user * specialfile)
 	spin_lock(&swap_lock);
 	for (type = swap_list.head; type >= 0; type = swap_info[type].next) {
 		p = swap_info + type;
-		if ((p->flags & SWP_ACTIVE) == SWP_ACTIVE) {
+		if (p->flags & SWP_WRITEOK) {
 			if (p->swap_file->f_mapping == mapping)
 				break;
 		}
@@ -1674,7 +1674,7 @@ asmlinkage long sys_swapon(const char __user * specialfile, int swap_flags)
 	else
 		p->prio = --least_priority;
 	p->swap_map = swap_map;
-	p->flags = SWP_ACTIVE;
+	p->flags |= SWP_WRITEOK;
 	nr_swap_pages += nr_good_pages;
 	total_swap_pages += nr_good_pages;