releases/3.18.85/nfsd-deal-with-revoked-delegations-appropriately.patch

   1 From 95da1b3a5aded124dd1bda1e3cdb876184813140 Mon Sep 17 00:00:00 2001
   2 From: Andrew Elble <aweits@rit.edu>
   3 Date: Fri, 3 Nov 2017 14:06:31 -0400
   4 Subject: nfsd: deal with revoked delegations appropriately
   5
   6 From: Andrew Elble <aweits@rit.edu>
   7
   8 commit 95da1b3a5aded124dd1bda1e3cdb876184813140 upstream.
   9
  10 If a delegation has been revoked by the server, operations using that
  11 delegation should error out with NFS4ERR_DELEG_REVOKED in the >4.1
  12 case, and NFS4ERR_BAD_STATEID otherwise.
  13
  14 The server needs NFSv4.1 clients to explicitly free revoked delegations.
  15 If the server returns NFS4ERR_DELEG_REVOKED, the client will do that;
  16 otherwise it may just forget about the delegation and be unable to
  17 recover when it later sees SEQ4_STATUS_RECALLABLE_STATE_REVOKED set on a
  18 SEQUENCE reply.  That can cause the Linux 4.1 client to loop in its
  19 stage manager.
  20
  21 Signed-off-by: Andrew Elble <aweits@rit.edu>
  22 Reviewed-by: Trond Myklebust <trond.myklebust@primarydata.com>
  23 Signed-off-by: J. Bruce Fields <bfields@redhat.com>
  24 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  25
  26 ---
  27  fs/nfsd/nfs4state.c |   25 ++++++++++++++++++++++++-
  28  1 file changed, 24 insertions(+), 1 deletion(-)
  29
  30 --- a/fs/nfsd/nfs4state.c
  31 +++ b/fs/nfsd/nfs4state.c
  32 @@ -3602,7 +3602,8 @@ static struct nfs4_delegation *find_dele
  33  {
  34         struct nfs4_stid *ret;
  35
  36 -       ret = find_stateid_by_type(cl, s, NFS4_DELEG_STID);
  37 +       ret = find_stateid_by_type(cl, s,
  38 +                               NFS4_DELEG_STID|NFS4_REVOKED_DELEG_STID);
  39         if (!ret)
  40                 return NULL;
  41         return delegstateid(ret);
  42 @@ -3625,6 +3626,12 @@ nfs4_check_deleg(struct nfs4_client *cl,
  43         deleg = find_deleg_stateid(cl, &open->op_delegate_stateid);
  44         if (deleg == NULL)
  45                 goto out;
  46 +       if (deleg->dl_stid.sc_type == NFS4_REVOKED_DELEG_STID) {
  47 +               nfs4_put_stid(&deleg->dl_stid);
  48 +               if (cl->cl_minorversion)
  49 +                       status = nfserr_deleg_revoked;
  50 +               goto out;
  51 +       }
  52         flags = share_access_to_flags(open->op_share_access);
  53         status = nfs4_check_delegmode(deleg, flags);
  54         if (status) {
  55 @@ -4451,6 +4458,16 @@ nfsd4_lookup_stateid(struct nfsd4_compou
  56                      struct nfs4_stid **s, struct nfsd_net *nn)
  57  {
  58         __be32 status;
  59 +       bool return_revoked = false;
  60 +
  61 +       /*
  62 +        *  only return revoked delegations if explicitly asked.
  63 +        *  otherwise we report revoked or bad_stateid status.
  64 +        */
  65 +       if (typemask & NFS4_REVOKED_DELEG_STID)
  66 +               return_revoked = true;
  67 +       else if (typemask & NFS4_DELEG_STID)
  68 +               typemask |= NFS4_REVOKED_DELEG_STID;
  69
  70         if (ZERO_STATEID(stateid) || ONE_STATEID(stateid))
  71                 return nfserr_bad_stateid;
  72 @@ -4465,6 +4482,12 @@ nfsd4_lookup_stateid(struct nfsd4_compou
  73         *s = find_stateid_by_type(cstate->clp, stateid, typemask);
  74         if (!*s)
  75                 return nfserr_bad_stateid;
  76 +       if (((*s)->sc_type == NFS4_REVOKED_DELEG_STID) && !return_revoked) {
  77 +               nfs4_put_stid(*s);
  78 +               if (cstate->minorversion)
  79 +                       return nfserr_deleg_revoked;
  80 +               return nfserr_bad_stateid;
  81 +       }
  82         return nfs_ok;
  83  }
  84