sys_swapon: call swap_cgroup_swapon() earlier

The call to swap_cgroup_swapon is in the middle of loading the swap map
and extents. As it only does memory allocation and does not depend on
the swapfile layout (map/extents), it can be called earlier (or later).

Move it to just after the allocation of swap_map, since it is
conceptually similar (allocates a map).

Signed-off-by: Cesar Eduardo Barros <cesarb@cesarb.net>
Tested-by: Eric B Munson <emunson@mgebm.net>
Acked-by: Eric B Munson <emunson@mgebm.net>
Reviewed-by: Pekka Enberg <penberg@kernel.org>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/swapfile.c b/mm/swapfile.c
index 058a9df..10f2b33 100644 (file)
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -2074,6 +2074,10 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags)
                goto bad_swap;
        }
 
+       error = swap_cgroup_swapon(p->type, maxpages);
+       if (error)
+               goto bad_swap;
+
        nr_good_pages = maxpages - 1;   /* omit header page */
 
        for (i = 0; i < swap_header->info.nr_badpages; i++) {
@@ -2088,10 +2092,6 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags)
                }
        }
 
-       error = swap_cgroup_swapon(p->type, maxpages);
-       if (error)
-               goto bad_swap;
-
        if (nr_good_pages) {
                swap_map[0] = SWAP_MAP_BAD;
                p->max = maxpages;