Merge branch 'for-3.11' of git://linux-nfs.org/~bfields/linux

Pull nfsd changes from Bruce Fields:
 "Changes this time include:

   - 4.1 enabled on the server by default: the last 4.1-specific issues
     I know of are fixed, so we're not going to find the rest of the
     bugs without more exposure.
   - Experimental support for NFSv4.2 MAC Labeling (to allow running
     selinux over NFS), from Dave Quigley.
   - Fixes for some delicate cache/upcall races that could cause rare
     server hangs; thanks to Neil Brown and Bodo Stroesser for extreme
     debugging persistence.
   - Fixes for some bugs found at the recent NFS bakeathon, mostly v4
     and v4.1-specific, but also a generic bug handling fragmented rpc
     calls"

* 'for-3.11' of git://linux-nfs.org/~bfields/linux: (31 commits)
  nfsd4: support minorversion 1 by default
  nfsd4: allow destroy_session over destroyed session
  svcrpc: fix failures to handle -1 uid's
  sunrpc: Don't schedule an upcall on a replaced cache entry.
  net/sunrpc: xpt_auth_cache should be ignored when expired.
  sunrpc/cache: ensure items removed from cache do not have pending upcalls.
  sunrpc/cache: use cache_fresh_unlocked consistently and correctly.
  sunrpc/cache: remove races with queuing an upcall.
  nfsd4: return delegation immediately if lease fails
  nfsd4: do not throw away 4.1 lock state on last unlock
  nfsd4: delegation-based open reclaims should bypass permissions
  svcrpc: don't error out on small tcp fragment
  svcrpc: fix handling of too-short rpc's
  nfsd4: minor read_buf cleanup
  nfsd4: fix decoding of compounds across page boundaries
  nfsd4: clean up nfs4_open_delegation
  NFSD: Don't give out read delegations on creates
  nfsd4: allow client to send no cb_sec flavors
  nfsd4: fail attempts to request gss on the backchannel
  nfsd4: implement minimal SP4_MACH_CRED
  ...

1 files changed, 152 insertions, 73 deletions

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index f17051838b41..280acef6f0dc 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -97,19 +97,20 @@ nfs4_lock_state(void)
 
 static void free_session(struct nfsd4_session *);
 
-void nfsd4_put_session(struct nfsd4_session *ses)
+static bool is_session_dead(struct nfsd4_session *ses)
 {
-        atomic_dec(&ses->se_ref);
+        return ses->se_flags & NFS4_SESSION_DEAD;
 }
 
-static bool is_session_dead(struct nfsd4_session *ses)
+void nfsd4_put_session(struct nfsd4_session *ses)
 {
-        return ses->se_flags & NFS4_SESSION_DEAD;
+        if (atomic_dec_and_test(&ses->se_ref) && is_session_dead(ses))
+                free_session(ses);
 }
 
-static __be32 mark_session_dead_locked(struct nfsd4_session *ses)
+static __be32 mark_session_dead_locked(struct nfsd4_session *ses, int ref_held_by_me)
 {
-        if (atomic_read(&ses->se_ref))
+        if (atomic_read(&ses->se_ref) > ref_held_by_me)
                 return nfserr_jukebox;
         ses->se_flags |= NFS4_SESSION_DEAD;
         return nfs_ok;
@@ -364,19 +365,12 @@ static struct nfs4_ol_stateid * nfs4_alloc_stateid(struct nfs4_client *clp)
 }
 
 static struct nfs4_delegation *
-alloc_init_deleg(struct nfs4_client *clp, struct nfs4_ol_stateid *stp, struct svc_fh *current_fh, u32 type)
+alloc_init_deleg(struct nfs4_client *clp, struct nfs4_ol_stateid *stp, struct svc_fh *current_fh)
 {
         struct nfs4_delegation *dp;
         struct nfs4_file *fp = stp->st_file;
 
         dprintk("NFSD alloc_init_deleg\n");
-        /*
-         * Major work on the lease subsystem (for example, to support
-         * calbacks on stat) will be required before we can support
-         * write delegations properly.
-         */
-        if (type != NFS4_OPEN_DELEGATE_READ)
-                return NULL;
         if (fp->fi_had_conflict)
                 return NULL;
         if (num_delegations > max_delegations)
@@ -397,7 +391,7 @@ alloc_init_deleg(struct nfs4_client *clp, struct nfs4_ol_stateid *stp, struct sv
         INIT_LIST_HEAD(&dp->dl_recall_lru);
         get_nfs4_file(fp);
         dp->dl_file = fp;
-        dp->dl_type = type;
+        dp->dl_type = NFS4_OPEN_DELEGATE_READ;
         fh_copy_shallow(&dp->dl_fh, &current_fh->fh_handle);
         dp->dl_time = 0;
         atomic_set(&dp->dl_count, 1);
@@ -1188,6 +1182,9 @@ static int copy_cred(struct svc_cred *target, struct svc_cred *source)
         target->cr_gid = source->cr_gid;
         target->cr_group_info = source->cr_group_info;
         get_group_info(target->cr_group_info);
+        target->cr_gss_mech = source->cr_gss_mech;
+        if (source->cr_gss_mech)
+                gss_mech_get(source->cr_gss_mech);
         return 0;
 }
 
@@ -1262,6 +1259,31 @@ same_creds(struct svc_cred *cr1, struct svc_cred *cr2)
         return 0 == strcmp(cr1->cr_principal, cr2->cr_principal);
 }
 
+static bool svc_rqst_integrity_protected(struct svc_rqst *rqstp)
+{
+        struct svc_cred *cr = &rqstp->rq_cred;
+        u32 service;
+
+        service = gss_pseudoflavor_to_service(cr->cr_gss_mech, cr->cr_flavor);
+        return service == RPC_GSS_SVC_INTEGRITY ||
+               service == RPC_GSS_SVC_PRIVACY;
+}
+
+static bool mach_creds_match(struct nfs4_client *cl, struct svc_rqst *rqstp)
+{
+        struct svc_cred *cr = &rqstp->rq_cred;
+
+        if (!cl->cl_mach_cred)
+                return true;
+        if (cl->cl_cred.cr_gss_mech != cr->cr_gss_mech)
+                return false;
+        if (!svc_rqst_integrity_protected(rqstp))
+                return false;
+        if (!cr->cr_principal)
+                return false;
+        return 0 == strcmp(cl->cl_cred.cr_principal, cr->cr_principal);
+}
+
 static void gen_clid(struct nfs4_client *clp, struct nfsd_net *nn)
 {
         static u32 current_clientid = 1;
@@ -1639,16 +1661,16 @@ nfsd4_exchange_id(struct svc_rqst *rqstp,
         if (exid->flags & ~EXCHGID4_FLAG_MASK_A)
                 return nfserr_inval;
 
-        /* Currently only support SP4_NONE */
         switch (exid->spa_how) {
+        case SP4_MACH_CRED:
+                if (!svc_rqst_integrity_protected(rqstp))
+                        return nfserr_inval;
         case SP4_NONE:
                 break;
         default:                                /* checked by xdr code */
                 WARN_ON_ONCE(1);
         case SP4_SSV:
                 return nfserr_encr_alg_unsupp;
-        case SP4_MACH_CRED:
-                return nfserr_serverfault;      /* no excuse :-/ */
         }
 
         /* Cases below refer to rfc 5661 section 18.35.4: */
@@ -1663,6 +1685,10 @@ nfsd4_exchange_id(struct svc_rqst *rqstp,
                                 status = nfserr_inval;
                                 goto out;
                         }
+                        if (!mach_creds_match(conf, rqstp)) {
+                                status = nfserr_wrong_cred;
+                                goto out;
+                        }
                         if (!creds_match) { /* case 9 */
                                 status = nfserr_perm;
                                 goto out;
@@ -1709,7 +1735,8 @@ out_new:
                 status = nfserr_jukebox;
                 goto out;
         }
-        new->cl_minorversion = 1;
+        new->cl_minorversion = cstate->minorversion;
+        new->cl_mach_cred = (exid->spa_how == SP4_MACH_CRED);
 
         gen_clid(new, nn);
         add_to_unconfirmed(new);
@@ -1839,6 +1866,24 @@ static __be32 check_backchannel_attrs(struct nfsd4_channel_attrs *ca)
         return nfs_ok;
 }
 
+static __be32 nfsd4_check_cb_sec(struct nfsd4_cb_sec *cbs)
+{
+        switch (cbs->flavor) {
+        case RPC_AUTH_NULL:
+        case RPC_AUTH_UNIX:
+                return nfs_ok;
+        default:
+                /*
+                 * GSS case: the spec doesn't allow us to return this
+                 * error.  But it also doesn't allow us not to support
+                 * GSS.
+                 * I'd rather this fail hard than return some error the
+                 * client might think it can already handle:
+                 */
+                return nfserr_encr_alg_unsupp;
+        }
+}
+
 __be32
 nfsd4_create_session(struct svc_rqst *rqstp,
                      struct nfsd4_compound_state *cstate,
@@ -1854,6 +1899,9 @@ nfsd4_create_session(struct svc_rqst *rqstp,
 
         if (cr_ses->flags & ~SESSION4_FLAG_MASK_A)
                 return nfserr_inval;
+        status = nfsd4_check_cb_sec(&cr_ses->cb_sec);
+        if (status)
+                return status;
         status = check_forechannel_attrs(&cr_ses->fore_channel, nn);
         if (status)
                 return status;
@@ -1874,6 +1922,9 @@ nfsd4_create_session(struct svc_rqst *rqstp,
         WARN_ON_ONCE(conf && unconf);
 
         if (conf) {
+                status = nfserr_wrong_cred;
+                if (!mach_creds_match(conf, rqstp))
+                        goto out_free_conn;
                 cs_slot = &conf->cl_cs_slot;
                 status = check_slot_seqid(cr_ses->seqid, cs_slot->sl_seqid, 0);
                 if (status == nfserr_replay_cache) {
@@ -1890,6 +1941,9 @@ nfsd4_create_session(struct svc_rqst *rqstp,
                         status = nfserr_clid_inuse;
                         goto out_free_conn;
                 }
+                status = nfserr_wrong_cred;
+                if (!mach_creds_match(unconf, rqstp))
+                        goto out_free_conn;
                 cs_slot = &unconf->cl_cs_slot;
                 status = check_slot_seqid(cr_ses->seqid, cs_slot->sl_seqid, 0);
                 if (status) {
@@ -1957,7 +2011,11 @@ __be32 nfsd4_backchannel_ctl(struct svc_rqst *rqstp, struct nfsd4_compound_state
 {
         struct nfsd4_session *session = cstate->session;
         struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
+        __be32 status;
 
+        status = nfsd4_check_cb_sec(&bc->bc_cb_sec);
+        if (status)
+                return status;
         spin_lock(&nn->client_lock);
         session->se_cb_prog = bc->bc_cb_program;
         session->se_cb_sec = bc->bc_cb_sec;
@@ -1986,6 +2044,9 @@ __be32 nfsd4_bind_conn_to_session(struct svc_rqst *rqstp,
         status = nfserr_badsession;
         if (!session)
                 goto out;
+        status = nfserr_wrong_cred;
+        if (!mach_creds_match(session->se_client, rqstp))
+                goto out;
         status = nfsd4_map_bcts_dir(&bcts->dir);
         if (status)
                 goto out;
@@ -2014,6 +2075,7 @@ nfsd4_destroy_session(struct svc_rqst *r,
 {
         struct nfsd4_session *ses;
         __be32 status;
+        int ref_held_by_me = 0;
         struct nfsd_net *nn = net_generic(SVC_NET(r), nfsd_net_id);
 
         nfs4_lock_state();
@@ -2021,6 +2083,7 @@ nfsd4_destroy_session(struct svc_rqst *r,
         if (nfsd4_compound_in_session(cstate->session, &sessionid->sessionid)) {
                 if (!nfsd4_last_compound_op(r))
                         goto out;
+                ref_held_by_me++;
         }
         dump_sessionid(__func__, &sessionid->sessionid);
         spin_lock(&nn->client_lock);
@@ -2028,17 +2091,22 @@ nfsd4_destroy_session(struct svc_rqst *r,
         status = nfserr_badsession;
         if (!ses)
                 goto out_client_lock;
-        status = mark_session_dead_locked(ses);
-        if (status)
+        status = nfserr_wrong_cred;
+        if (!mach_creds_match(ses->se_client, r))
                 goto out_client_lock;
+        nfsd4_get_session_locked(ses);
+        status = mark_session_dead_locked(ses, 1 + ref_held_by_me);
+        if (status)
+                goto out_put_session;
         unhash_session(ses);
         spin_unlock(&nn->client_lock);
 
         nfsd4_probe_callback_sync(ses->se_client);
 
         spin_lock(&nn->client_lock);
-        free_session(ses);
         status = nfs_ok;
+out_put_session:
+        nfsd4_put_session(ses);
 out_client_lock:
         spin_unlock(&nn->client_lock);
 out:
@@ -2058,26 +2126,31 @@ static struct nfsd4_conn *__nfsd4_find_conn(struct svc_xprt *xpt, struct nfsd4_s
         return NULL;
 }
 
-static void nfsd4_sequence_check_conn(struct nfsd4_conn *new, struct nfsd4_session *ses)
+static __be32 nfsd4_sequence_check_conn(struct nfsd4_conn *new, struct nfsd4_session *ses)
 {
         struct nfs4_client *clp = ses->se_client;
         struct nfsd4_conn *c;
+        __be32 status = nfs_ok;
         int ret;
 
         spin_lock(&clp->cl_lock);
         c = __nfsd4_find_conn(new->cn_xprt, ses);
-        if (c) {
-                spin_unlock(&clp->cl_lock);
-                free_conn(new);
-                return;
-        }
+        if (c)
+                goto out_free;
+        status = nfserr_conn_not_bound_to_session;
+        if (clp->cl_mach_cred)
+                goto out_free;
         __nfsd4_hash_conn(new, ses);
         spin_unlock(&clp->cl_lock);
         ret = nfsd4_register_conn(new);
         if (ret)
                 /* oops; xprt is already down: */
                 nfsd4_conn_lost(&new->cn_xpt_user);
-        return;
+        return nfs_ok;
+out_free:
+        spin_unlock(&clp->cl_lock);
+        free_conn(new);
+        return status;
 }
 
 static bool nfsd4_session_too_many_ops(struct svc_rqst *rqstp, struct nfsd4_session *session)
@@ -2169,8 +2242,10 @@ nfsd4_sequence(struct svc_rqst *rqstp,
         if (status)
                 goto out_put_session;
 
-        nfsd4_sequence_check_conn(conn, session);
+        status = nfsd4_sequence_check_conn(conn, session);
         conn = NULL;
+        if (status)
+                goto out_put_session;
 
         /* Success! bump slot seqid */
         slot->sl_seqid = seq->seqid;
@@ -2232,7 +2307,10 @@ nfsd4_destroy_clientid(struct svc_rqst *rqstp, struct nfsd4_compound_state *csta
                 status = nfserr_stale_clientid;
                 goto out;
         }
-
+        if (!mach_creds_match(clp, rqstp)) {
+                status = nfserr_wrong_cred;
+                goto out;
+        }
         expire_client(clp);
 out:
         nfs4_unlock_state();
@@ -2940,13 +3018,13 @@ static struct file_lock *nfs4_alloc_init_lease(struct nfs4_delegation *dp, int f
         return fl;
 }
 
-static int nfs4_setlease(struct nfs4_delegation *dp, int flag)
+static int nfs4_setlease(struct nfs4_delegation *dp)
 {
         struct nfs4_file *fp = dp->dl_file;
         struct file_lock *fl;
         int status;
 
-        fl = nfs4_alloc_init_lease(dp, flag);
+        fl = nfs4_alloc_init_lease(dp, NFS4_OPEN_DELEGATE_READ);
         if (!fl)
                 return -ENOMEM;
         fl->fl_file = find_readable_file(fp);
@@ -2964,12 +3042,12 @@ static int nfs4_setlease(struct nfs4_delegation *dp, int flag)
         return 0;
 }
 
-static int nfs4_set_delegation(struct nfs4_delegation *dp, int flag)
+static int nfs4_set_delegation(struct nfs4_delegation *dp)
 {
         struct nfs4_file *fp = dp->dl_file;
 
         if (!fp->fi_lease)
-                return nfs4_setlease(dp, flag);
+                return nfs4_setlease(dp);
         spin_lock(&recall_lock);
         if (fp->fi_had_conflict) {
                 spin_unlock(&recall_lock);
@@ -3005,6 +3083,9 @@ static void nfsd4_open_deleg_none_ext(struct nfsd4_open *open, int status)
 
 /*
  * Attempt to hand out a delegation.
+ *
+ * Note we don't support write delegations, and won't until the vfs has
+ * proper support for them.
  */
 static void
 nfs4_open_delegation(struct net *net, struct svc_fh *fh,
@@ -3013,39 +3094,45 @@ nfs4_open_delegation(struct net *net, struct svc_fh *fh,
         struct nfs4_delegation *dp;
         struct nfs4_openowner *oo = container_of(stp->st_stateowner, struct nfs4_openowner, oo_owner);
         int cb_up;
-        int status = 0, flag = 0;
+        int status = 0;
 
         cb_up = nfsd4_cb_channel_good(oo->oo_owner.so_client);
-        flag = NFS4_OPEN_DELEGATE_NONE;
         open->op_recall = 0;
         switch (open->op_claim_type) {
                 case NFS4_OPEN_CLAIM_PREVIOUS:
                         if (!cb_up)
                                 open->op_recall = 1;
-                        flag = open->op_delegate_type;
-                        if (flag == NFS4_OPEN_DELEGATE_NONE)
-                                goto out;
+                        if (open->op_delegate_type != NFS4_OPEN_DELEGATE_READ)
+                                goto out_no_deleg;
                         break;
                 case NFS4_OPEN_CLAIM_NULL:
-                        /* Let's not give out any delegations till everyone's
-                         * had the chance to reclaim theirs.... */
+                        /*
+                         * Let's not give out any delegations till everyone's
+                         * had the chance to reclaim theirs....
+                         */
                         if (locks_in_grace(net))
-                                goto out;
+                                goto out_no_deleg;
                         if (!cb_up || !(oo->oo_flags & NFS4_OO_CONFIRMED))
-                                goto out;
+                                goto out_no_deleg;
+                        /*
+                         * Also, if the file was opened for write or
+                         * create, there's a good chance the client's
+                         * about to write to it, resulting in an
+                         * immediate recall (since we don't support
+                         * write delegations):
+                         */
                         if (open->op_share_access & NFS4_SHARE_ACCESS_WRITE)
-                                flag = NFS4_OPEN_DELEGATE_WRITE;
-                        else
-                                flag = NFS4_OPEN_DELEGATE_READ;
+                                goto out_no_deleg;
+                        if (open->op_create == NFS4_OPEN_CREATE)
+                                goto out_no_deleg;
                         break;
                 default:
-                        goto out;
+                        goto out_no_deleg;
         }
-
-        dp = alloc_init_deleg(oo->oo_owner.so_client, stp, fh, flag);
+        dp = alloc_init_deleg(oo->oo_owner.so_client, stp, fh);
         if (dp == NULL)
                 goto out_no_deleg;
-        status = nfs4_set_delegation(dp, flag);
+        status = nfs4_set_delegation(dp);
         if (status)
                 goto out_free;
 
@@ -3053,24 +3140,23 @@ nfs4_open_delegation(struct net *net, struct svc_fh *fh,
 
         dprintk("NFSD: delegation stateid=" STATEID_FMT "\n",
                 STATEID_VAL(&dp->dl_stid.sc_stateid));
-out:
-        open->op_delegate_type = flag;
-        if (flag == NFS4_OPEN_DELEGATE_NONE) {
-                if (open->op_claim_type == NFS4_OPEN_CLAIM_PREVIOUS &&
-                    open->op_delegate_type != NFS4_OPEN_DELEGATE_NONE)
-                        dprintk("NFSD: WARNING: refusing delegation reclaim\n");
-
-                /* 4.1 client asking for a delegation? */
-                if (open->op_deleg_want)
-                        nfsd4_open_deleg_none_ext(open, status);
-        }
+        open->op_delegate_type = NFS4_OPEN_DELEGATE_READ;
         return;
 out_free:
         unhash_stid(&dp->dl_stid);
         nfs4_put_delegation(dp);
 out_no_deleg:
-        flag = NFS4_OPEN_DELEGATE_NONE;
-        goto out;
+        open->op_delegate_type = NFS4_OPEN_DELEGATE_NONE;
+        if (open->op_claim_type == NFS4_OPEN_CLAIM_PREVIOUS &&
+            open->op_delegate_type != NFS4_OPEN_DELEGATE_NONE) {
+                dprintk("NFSD: WARNING: refusing delegation reclaim\n");
+                open->op_recall = 1;
+        }
+
+        /* 4.1 client asking for a delegation? */
+        if (open->op_deleg_want)
+                nfsd4_open_deleg_none_ext(open, status);
+        return;
 }
 
 static void nfsd4_deleg_xgrade_none_ext(struct nfsd4_open *open,
@@ -3427,7 +3513,7 @@ grace_disallows_io(struct net *net, struct inode *inode)
 /* Returns true iff a is later than b: */
 static bool stateid_generation_after(stateid_t *a, stateid_t *b)
 {
-        return (s32)a->si_generation - (s32)b->si_generation > 0;
+        return (s32)(a->si_generation - b->si_generation) > 0;
 }
 
 static __be32 check_stateid_generation(stateid_t *in, stateid_t *ref, bool has_session)
@@ -4435,7 +4521,6 @@ __be32
 nfsd4_locku(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
             struct nfsd4_locku *locku)
 {
-        struct nfs4_lockowner *lo;
         struct nfs4_ol_stateid *stp;
         struct file *filp = NULL;
         struct file_lock *file_lock = NULL;
@@ -4468,10 +4553,9 @@ nfsd4_locku(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
                 status = nfserr_jukebox;
                 goto out;
         }
-        lo = lockowner(stp->st_stateowner);
         locks_init_lock(file_lock);
         file_lock->fl_type = F_UNLCK;
-        file_lock->fl_owner = (fl_owner_t)lo;
+        file_lock->fl_owner = (fl_owner_t)lockowner(stp->st_stateowner);
         file_lock->fl_pid = current->tgid;
         file_lock->fl_file = filp;
         file_lock->fl_flags = FL_POSIX;
@@ -4490,11 +4574,6 @@ nfsd4_locku(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
         update_stateid(&stp->st_stid.sc_stateid);
         memcpy(&locku->lu_stateid, &stp->st_stid.sc_stateid, sizeof(stateid_t));
 
-        if (nfsd4_has_session(cstate) && !check_for_locks(stp->st_file, lo)) {
-                WARN_ON_ONCE(cstate->replay_owner);
-                release_lockowner(lo);
-        }
-
 out:
         nfsd4_bump_seqid(cstate, status);
         if (!cstate->replay_owner)