hugetlb: allow sticky directory mount option

Allow sticky directory mount option for hugetlbfs.  This allows admin
to create a shared hugetlbfs mount point for multiple users, while
prevent accidental file deletion that users may step on each other.
It is similiar to default tmpfs mount option, or typical option used
on /tmp.

Signed-off-by: Ken Chen <kenchen@google.com>
Cc: Badari Pulavarty <pbadari@us.ibm.com>
Cc: Adam Litke <agl@us.ibm.com>
Cc: David Gibson <hermes@gibson.dropbear.id.au>
Cc: William Lee Irwin III <wli@holomorphy.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
index 09ee07f026630501869eb0bd53131e46b7f8d82d..3b3cc28cdefcaf5929be2a3d13be24bf4791fd6c 100644 (file)
--- a/fs/hugetlbfs/inode.c
+++ b/fs/hugetlbfs/inode.c
@@ -768,7 +768,7 @@ hugetlbfs_parse_options(char *options, struct hugetlbfs_config *pconfig)
                case Opt_mode:
                        if (match_octal(&args[0], &option))
                                goto bad_val;
-                       pconfig->mode = option & 0777U;
+                       pconfig->mode = option & 01777U;
                        break;
 
                case Opt_size: {