nfsd: Fix sort_pacl in fs/nfsd/nf4acl.c to actually sort groups

We have been doing some extensive testing of Linux support for ACLs on
NFDS v4. We have noticed that the server rejects ACLs where the groups
are out of order, for example, the following ACL is rejected:

A::OWNER@:rwaxtTcCy
A::user101@domain:rwaxtcy
A::GROUP@:rwaxtcy
A:g:group102@domain:rwaxtcy
A:g:group101@domain:rwaxtcy
A::EVERYONE@:rwaxtcy

Examining the server code, I found that after converting an NFS v4 ACL
to POSIX, sort_pacl is called to sort the user ACEs and group ACEs.
Unfortunately, a minor bug causes the group sort to be skipped.

Signed-off-by: Frank Filz <ffilzlnx@us.ibm.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

1 files changed, 1 insertions, 1 deletions

diff --git a/fs/nfsd/nfs4acl.c b/fs/nfsd/nfs4acl.c
index 725d02f210e..6d9c6aabc85 100644
--- a/fs/nfsd/nfs4acl.c
+++ b/fs/nfsd/nfs4acl.c
@@ -389,7 +389,7 @@ sort_pacl(struct posix_acl *pacl)
         sort_pacl_range(pacl, 1, i-1);
 
         BUG_ON(pacl->a_entries[i].e_tag != ACL_GROUP_OBJ);
-        j = i++;
+        j = ++i;
         while (pacl->a_entries[j].e_tag == ACL_GROUP)
                 j++;
         sort_pacl_range(pacl, i, j-1);