GIT: unionfs2-2.6.27.y: tmpfs: mpol=bind:0 don't cause mount error.

[Erez Zadok]

commit 6b200155aefee405a74149df740fb92b10d727bc
Author: KOSAKI Motohiro <kosaki.motohiro at jp.fujitsu.com>
Date:   Tue Mar 23 13:35:30 2010 -0700

    tmpfs: mpol=bind:0 don't cause mount error.
    
    commit d69b2e63e9172afb4d07c305601b79a55509ac4c upstream.
    
    Currently, following mount operation cause mount error.
    
    % mount -t tmpfs -ompol=bind:0 none /tmp
    
    Because commit 71fe804b6d5 (mempolicy: use struct mempolicy pointer in
    shmem_sb_info) corrupted MPOL_BIND parse code.
    
    This patch restore the needed one.
    
    Signed-off-by: KOSAKI Motohiro <kosaki.motohiro at jp.fujitsu.com>
    Cc: Ravikiran Thirumalai <kiran at scalex86.org>
    Cc: Christoph Lameter <cl at linux-foundation.org>
    Cc: Mel Gorman <mel at csn.ul.ie>
    Acked-by: Lee Schermerhorn <lee.schermerhorn at hp.com>
    Cc: Hugh Dickins <hugh.dickins at tiscali.co.uk>
    Signed-off-by: Andrew Morton <akpm at linux-foundation.org>
    Signed-off-by: Linus Torvalds <torvalds at linux-foundation.org>
    Signed-off-by: Greg Kroah-Hartman <gregkh at suse.de>

diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index b732aca..b62bf1d 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -2056,9 +2056,13 @@ int mpol_parse_str(char *str, struct mempolicy **mpol, int no_context)
 		if (!nodelist)
 			err = 0;
 		goto out;
-	/*
-	 * case MPOL_BIND:    mpol_new() enforces non-empty nodemask.
-	 */
+	case MPOL_BIND:
+		/*
+		 * Insist on a nodelist
+		 */
+		if (!nodelist)
+			goto out;
+		err = 0;
 	}
 
 	mode_flags = 0;