mempolicy: don't call mpol_set_nodemask() when no_context

No need to call mpol_set_nodemask() when we have no context for the
mempolicy.  This can occur when we're parsing a tmpfs 'mpol' mount option.
 Just save the raw nodemask in the mempolicy's w.user_nodemask member for
use when a tmpfs/shmem file is created.  mpol_shared_policy_init() will
"contextualize" the policy for the new file based on the creating task's
context.

Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: Ravikiran Thirumalai <kiran@scalex86.org>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 4 insertions, 5 deletions

diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index ac5aeafaec9a..0e1b293e4054 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -2239,7 +2239,10 @@ int mpol_parse_str(char *str, struct mempolicy **mpol, int no_context)
         if (IS_ERR(new))
                 goto out;
 
-        {
+        if (no_context) {
+                /* save for contextualization */
+                new->w.user_nodemask = nodes;
+        } else {
                 int ret;
                 NODEMASK_SCRATCH(scratch);
                 if (scratch) {
@@ -2255,10 +2258,6 @@ int mpol_parse_str(char *str, struct mempolicy **mpol, int no_context)
                 }
         }
         err = 0;
-        if (no_context) {
-                /* save for contextualization */
-                new->w.user_nodemask = nodes;
-        }
 
 out:
         /* Restore string for error message */