sys_swapon: move printk outside lock

The block in sys_swapon which does the final adjustments to the
swap_info_struct and to swap_list is the same as the block which
re-inserts it again at sys_swapoff on failure of try_to_unuse(). To be
able to make both share the same code, move the printk() call in the
middle of it to just after it.
Signed-off-by: NCesar Eduardo Barros <cesarb@cesarb.net>
Tested-by: NEric B Munson <emunson@mgebm.net>
Acked-by: NEric B Munson <emunson@mgebm.net>
Reviewed-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

mm/swapfile.c

@@ -2144,13 +2144,6 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags)
 	nr_swap_pages += p->pages;
 	total_swap_pages += p->pages;
 
-	printk(KERN_INFO "Adding %uk swap on %s.  "
-			"Priority:%d extents:%d across:%lluk %s%s\n",
-		p->pages<<(PAGE_SHIFT-10), name, p->prio,
-		nr_extents, (unsigned long long)span<<(PAGE_SHIFT-10),
-		(p->flags & SWP_SOLIDSTATE) ? "SS" : "",
-		(p->flags & SWP_DISCARDABLE) ? "D" : "");
-
 	/* insert swap space into swap_list: */
 	prev = -1;
 	for (i = swap_list.head; i >= 0; i = swap_info[i]->next) {
@@ -2164,6 +2157,14 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags)
 	else
 		swap_info[prev]->next = p->type;
 	spin_unlock(&swap_lock);
+
+	printk(KERN_INFO "Adding %uk swap on %s.  "
+			"Priority:%d extents:%d across:%lluk %s%s\n",
+		p->pages<<(PAGE_SHIFT-10), name, p->prio,
+		nr_extents, (unsigned long long)span<<(PAGE_SHIFT-10),
+		(p->flags & SWP_SOLIDSTATE) ? "SS" : "",
+		(p->flags & SWP_DISCARDABLE) ? "D" : "");
+
 	mutex_unlock(&swapon_mutex);
 	atomic_inc(&proc_poll_event);
 	wake_up_interruptible(&proc_poll_wait);