Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris...
[pandora-kernel.git] / net / sunrpc / auth_gss / auth_gss.c
index 4e4ccc5..4bbc59c 100644 (file)
 #include <linux/sunrpc/gss_api.h>
 #include <asm/uaccess.h>
 
-static struct rpc_authops authgss_ops;
+static const struct rpc_authops authgss_ops;
 
-static struct rpc_credops gss_credops;
+static const struct rpc_credops gss_credops;
+static const struct rpc_credops gss_nullops;
 
 #ifdef RPC_DEBUG
 # define RPCDBG_FACILITY       RPCDBG_AUTH
@@ -64,7 +65,6 @@ static struct rpc_credops gss_credops;
 
 #define NFS_NGROUPS    16
 
-#define GSS_CRED_EXPIRE                (60 * HZ)       /* XXX: reasonable? */
 #define GSS_CRED_SLACK         1024            /* XXX: unused */
 /* length of a krb5 verifier (48), plus data added before arguments when
  * using integrity (two 4-byte integers): */
@@ -79,19 +79,16 @@ static struct rpc_credops gss_credops;
 /* dump the buffer in `emacs-hexl' style */
 #define isprint(c)      ((c > 0x1f) && (c < 0x7f))
 
-static DEFINE_RWLOCK(gss_ctx_lock);
-
 struct gss_auth {
+       struct kref kref;
        struct rpc_auth rpc_auth;
        struct gss_api_mech *mech;
        enum rpc_gss_svc service;
-       struct list_head upcalls;
        struct rpc_clnt *client;
        struct dentry *dentry;
-       spinlock_t lock;
 };
 
-static void gss_destroy_ctx(struct gss_cl_ctx *);
+static void gss_free_ctx(struct gss_cl_ctx *);
 static struct rpc_pipe_ops gss_upcall_ops;
 
 static inline struct gss_cl_ctx *
@@ -105,20 +102,24 @@ static inline void
 gss_put_ctx(struct gss_cl_ctx *ctx)
 {
        if (atomic_dec_and_test(&ctx->count))
-               gss_destroy_ctx(ctx);
+               gss_free_ctx(ctx);
 }
 
+/* gss_cred_set_ctx:
+ * called by gss_upcall_callback and gss_create_upcall in order
+ * to set the gss context. The actual exchange of an old context
+ * and a new one is protected by the inode->i_lock.
+ */
 static void
 gss_cred_set_ctx(struct rpc_cred *cred, struct gss_cl_ctx *ctx)
 {
        struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
        struct gss_cl_ctx *old;
-       write_lock(&gss_ctx_lock);
+
        old = gss_cred->gc_ctx;
-       gss_cred->gc_ctx = ctx;
-       cred->cr_flags |= RPCAUTH_CRED_UPTODATE;
-       cred->cr_flags &= ~RPCAUTH_CRED_NEW;
-       write_unlock(&gss_ctx_lock);
+       rcu_assign_pointer(gss_cred->gc_ctx, ctx);
+       set_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
+       clear_bit(RPCAUTH_CRED_NEW, &cred->cr_flags);
        if (old)
                gss_put_ctx(old);
 }
@@ -129,10 +130,10 @@ gss_cred_is_uptodate_ctx(struct rpc_cred *cred)
        struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
        int res = 0;
 
-       read_lock(&gss_ctx_lock);
-       if ((cred->cr_flags & RPCAUTH_CRED_UPTODATE) && gss_cred->gc_ctx)
+       rcu_read_lock();
+       if (test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) && gss_cred->gc_ctx)
                res = 1;
-       read_unlock(&gss_ctx_lock);
+       rcu_read_unlock();
        return res;
 }
 
@@ -171,10 +172,10 @@ gss_cred_get_ctx(struct rpc_cred *cred)
        struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
        struct gss_cl_ctx *ctx = NULL;
 
-       read_lock(&gss_ctx_lock);
+       rcu_read_lock();
        if (gss_cred->gc_ctx)
                ctx = gss_get_ctx(gss_cred->gc_ctx);
-       read_unlock(&gss_ctx_lock);
+       rcu_read_unlock();
        return ctx;
 }
 
@@ -269,10 +270,10 @@ gss_release_msg(struct gss_upcall_msg *gss_msg)
 }
 
 static struct gss_upcall_msg *
-__gss_find_upcall(struct gss_auth *gss_auth, uid_t uid)
+__gss_find_upcall(struct rpc_inode *rpci, uid_t uid)
 {
        struct gss_upcall_msg *pos;
-       list_for_each_entry(pos, &gss_auth->upcalls, list) {
+       list_for_each_entry(pos, &rpci->in_downcall, list) {
                if (pos->uid != uid)
                        continue;
                atomic_inc(&pos->count);
@@ -290,24 +291,24 @@ __gss_find_upcall(struct gss_auth *gss_auth, uid_t uid)
 static inline struct gss_upcall_msg *
 gss_add_msg(struct gss_auth *gss_auth, struct gss_upcall_msg *gss_msg)
 {
+       struct inode *inode = gss_auth->dentry->d_inode;
+       struct rpc_inode *rpci = RPC_I(inode);
        struct gss_upcall_msg *old;
 
-       spin_lock(&gss_auth->lock);
-       old = __gss_find_upcall(gss_auth, gss_msg->uid);
+       spin_lock(&inode->i_lock);
+       old = __gss_find_upcall(rpci, gss_msg->uid);
        if (old == NULL) {
                atomic_inc(&gss_msg->count);
-               list_add(&gss_msg->list, &gss_auth->upcalls);
+               list_add(&gss_msg->list, &rpci->in_downcall);
        } else
                gss_msg = old;
-       spin_unlock(&gss_auth->lock);
+       spin_unlock(&inode->i_lock);
        return gss_msg;
 }
 
 static void
 __gss_unhash_msg(struct gss_upcall_msg *gss_msg)
 {
-       if (list_empty(&gss_msg->list))
-               return;
        list_del_init(&gss_msg->list);
        rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
        wake_up_all(&gss_msg->waitqueue);
@@ -318,10 +319,14 @@ static void
 gss_unhash_msg(struct gss_upcall_msg *gss_msg)
 {
        struct gss_auth *gss_auth = gss_msg->auth;
+       struct inode *inode = gss_auth->dentry->d_inode;
 
-       spin_lock(&gss_auth->lock);
-       __gss_unhash_msg(gss_msg);
-       spin_unlock(&gss_auth->lock);
+       if (list_empty(&gss_msg->list))
+               return;
+       spin_lock(&inode->i_lock);
+       if (!list_empty(&gss_msg->list))
+               __gss_unhash_msg(gss_msg);
+       spin_unlock(&inode->i_lock);
 }
 
 static void
@@ -330,16 +335,16 @@ gss_upcall_callback(struct rpc_task *task)
        struct gss_cred *gss_cred = container_of(task->tk_msg.rpc_cred,
                        struct gss_cred, gc_base);
        struct gss_upcall_msg *gss_msg = gss_cred->gc_upcall;
+       struct inode *inode = gss_msg->auth->dentry->d_inode;
 
-       BUG_ON(gss_msg == NULL);
+       spin_lock(&inode->i_lock);
        if (gss_msg->ctx)
                gss_cred_set_ctx(task->tk_msg.rpc_cred, gss_get_ctx(gss_msg->ctx));
        else
                task->tk_status = gss_msg->msg.errno;
-       spin_lock(&gss_msg->auth->lock);
        gss_cred->gc_upcall = NULL;
        rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
-       spin_unlock(&gss_msg->auth->lock);
+       spin_unlock(&inode->i_lock);
        gss_release_msg(gss_msg);
 }
 
@@ -386,11 +391,12 @@ static inline int
 gss_refresh_upcall(struct rpc_task *task)
 {
        struct rpc_cred *cred = task->tk_msg.rpc_cred;
-       struct gss_auth *gss_auth = container_of(task->tk_client->cl_auth,
+       struct gss_auth *gss_auth = container_of(cred->cr_auth,
                        struct gss_auth, rpc_auth);
        struct gss_cred *gss_cred = container_of(cred,
                        struct gss_cred, gc_base);
        struct gss_upcall_msg *gss_msg;
+       struct inode *inode = gss_auth->dentry->d_inode;
        int err = 0;
 
        dprintk("RPC: %5u gss_refresh_upcall for uid %u\n", task->tk_pid,
@@ -400,7 +406,7 @@ gss_refresh_upcall(struct rpc_task *task)
                err = PTR_ERR(gss_msg);
                goto out;
        }
-       spin_lock(&gss_auth->lock);
+       spin_lock(&inode->i_lock);
        if (gss_cred->gc_upcall != NULL)
                rpc_sleep_on(&gss_cred->gc_upcall->rpc_waitqueue, task, NULL, NULL);
        else if (gss_msg->ctx == NULL && gss_msg->msg.errno >= 0) {
@@ -411,7 +417,7 @@ gss_refresh_upcall(struct rpc_task *task)
                rpc_sleep_on(&gss_msg->rpc_waitqueue, task, gss_upcall_callback, NULL);
        } else
                err = gss_msg->msg.errno;
-       spin_unlock(&gss_auth->lock);
+       spin_unlock(&inode->i_lock);
        gss_release_msg(gss_msg);
 out:
        dprintk("RPC: %5u gss_refresh_upcall for uid %u result %d\n",
@@ -422,6 +428,7 @@ out:
 static inline int
 gss_create_upcall(struct gss_auth *gss_auth, struct gss_cred *gss_cred)
 {
+       struct inode *inode = gss_auth->dentry->d_inode;
        struct rpc_cred *cred = &gss_cred->gc_base;
        struct gss_upcall_msg *gss_msg;
        DEFINE_WAIT(wait);
@@ -435,12 +442,11 @@ gss_create_upcall(struct gss_auth *gss_auth, struct gss_cred *gss_cred)
        }
        for (;;) {
                prepare_to_wait(&gss_msg->waitqueue, &wait, TASK_INTERRUPTIBLE);
-               spin_lock(&gss_auth->lock);
+               spin_lock(&inode->i_lock);
                if (gss_msg->ctx != NULL || gss_msg->msg.errno < 0) {
-                       spin_unlock(&gss_auth->lock);
                        break;
                }
-               spin_unlock(&gss_auth->lock);
+               spin_unlock(&inode->i_lock);
                if (signalled()) {
                        err = -ERESTARTSYS;
                        goto out_intr;
@@ -451,6 +457,7 @@ gss_create_upcall(struct gss_auth *gss_auth, struct gss_cred *gss_cred)
                gss_cred_set_ctx(cred, gss_get_ctx(gss_msg->ctx));
        else
                err = gss_msg->msg.errno;
+       spin_unlock(&inode->i_lock);
 out_intr:
        finish_wait(&gss_msg->waitqueue, &wait);
        gss_release_msg(gss_msg);
@@ -489,12 +496,11 @@ gss_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
        const void *p, *end;
        void *buf;
        struct rpc_clnt *clnt;
-       struct gss_auth *gss_auth;
-       struct rpc_cred *cred;
        struct gss_upcall_msg *gss_msg;
+       struct inode *inode = filp->f_path.dentry->d_inode;
        struct gss_cl_ctx *ctx;
        uid_t uid;
-       int err = -EFBIG;
+       ssize_t err = -EFBIG;
 
        if (mlen > MSG_BUF_MAXSIZE)
                goto out;
@@ -503,7 +509,7 @@ gss_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
        if (!buf)
                goto out;
 
-       clnt = RPC_I(filp->f_path.dentry->d_inode)->private;
+       clnt = RPC_I(inode)->private;
        err = -EFAULT;
        if (copy_from_user(buf, src, mlen))
                goto err;
@@ -519,43 +525,38 @@ gss_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
        ctx = gss_alloc_context();
        if (ctx == NULL)
                goto err;
-       err = 0;
-       gss_auth = container_of(clnt->cl_auth, struct gss_auth, rpc_auth);
-       p = gss_fill_context(p, end, ctx, gss_auth->mech);
+
+       err = -ENOENT;
+       /* Find a matching upcall */
+       spin_lock(&inode->i_lock);
+       gss_msg = __gss_find_upcall(RPC_I(inode), uid);
+       if (gss_msg == NULL) {
+               spin_unlock(&inode->i_lock);
+               goto err_put_ctx;
+       }
+       list_del_init(&gss_msg->list);
+       spin_unlock(&inode->i_lock);
+
+       p = gss_fill_context(p, end, ctx, gss_msg->auth->mech);
        if (IS_ERR(p)) {
                err = PTR_ERR(p);
-               if (err != -EACCES)
-                       goto err_put_ctx;
-       }
-       spin_lock(&gss_auth->lock);
-       gss_msg = __gss_find_upcall(gss_auth, uid);
-       if (gss_msg) {
-               if (err == 0 && gss_msg->ctx == NULL)
-                       gss_msg->ctx = gss_get_ctx(ctx);
-               gss_msg->msg.errno = err;
-               __gss_unhash_msg(gss_msg);
-               spin_unlock(&gss_auth->lock);
-               gss_release_msg(gss_msg);
-       } else {
-               struct auth_cred acred = { .uid = uid };
-               spin_unlock(&gss_auth->lock);
-               cred = rpcauth_lookup_credcache(clnt->cl_auth, &acred, RPCAUTH_LOOKUP_NEW);
-               if (IS_ERR(cred)) {
-                       err = PTR_ERR(cred);
-                       goto err_put_ctx;
-               }
-               gss_cred_set_ctx(cred, gss_get_ctx(ctx));
+               gss_msg->msg.errno = (err == -EACCES) ? -EACCES : -EAGAIN;
+               goto err_release_msg;
        }
-       gss_put_ctx(ctx);
-       kfree(buf);
-       dprintk("RPC:       gss_pipe_downcall returning length %Zu\n", mlen);
-       return mlen;
+       gss_msg->ctx = gss_get_ctx(ctx);
+       err = mlen;
+
+err_release_msg:
+       spin_lock(&inode->i_lock);
+       __gss_unhash_msg(gss_msg);
+       spin_unlock(&inode->i_lock);
+       gss_release_msg(gss_msg);
 err_put_ctx:
        gss_put_ctx(ctx);
 err:
        kfree(buf);
 out:
-       dprintk("RPC:       gss_pipe_downcall returning %d\n", err);
+       dprintk("RPC:       gss_pipe_downcall returning %Zd\n", err);
        return err;
 }
 
@@ -563,27 +564,21 @@ static void
 gss_pipe_release(struct inode *inode)
 {
        struct rpc_inode *rpci = RPC_I(inode);
-       struct rpc_clnt *clnt;
-       struct rpc_auth *auth;
-       struct gss_auth *gss_auth;
+       struct gss_upcall_msg *gss_msg;
 
-       clnt = rpci->private;
-       auth = clnt->cl_auth;
-       gss_auth = container_of(auth, struct gss_auth, rpc_auth);
-       spin_lock(&gss_auth->lock);
-       while (!list_empty(&gss_auth->upcalls)) {
-               struct gss_upcall_msg *gss_msg;
+       spin_lock(&inode->i_lock);
+       while (!list_empty(&rpci->in_downcall)) {
 
-               gss_msg = list_entry(gss_auth->upcalls.next,
+               gss_msg = list_entry(rpci->in_downcall.next,
                                struct gss_upcall_msg, list);
                gss_msg->msg.errno = -EPIPE;
                atomic_inc(&gss_msg->count);
                __gss_unhash_msg(gss_msg);
-               spin_unlock(&gss_auth->lock);
+               spin_unlock(&inode->i_lock);
                gss_release_msg(gss_msg);
-               spin_lock(&gss_auth->lock);
+               spin_lock(&inode->i_lock);
        }
-       spin_unlock(&gss_auth->lock);
+       spin_unlock(&inode->i_lock);
 }
 
 static void
@@ -637,18 +632,13 @@ gss_create(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
        gss_auth->service = gss_pseudoflavor_to_service(gss_auth->mech, flavor);
        if (gss_auth->service == 0)
                goto err_put_mech;
-       INIT_LIST_HEAD(&gss_auth->upcalls);
-       spin_lock_init(&gss_auth->lock);
        auth = &gss_auth->rpc_auth;
        auth->au_cslack = GSS_CRED_SLACK >> 2;
        auth->au_rslack = GSS_VERF_SLACK >> 2;
        auth->au_ops = &authgss_ops;
        auth->au_flavor = flavor;
        atomic_set(&auth->au_count, 1);
-
-       err = rpcauth_init_credcache(auth, GSS_CRED_EXPIRE);
-       if (err)
-               goto err_put_mech;
+       kref_init(&gss_auth->kref);
 
        gss_auth->dentry = rpc_mkpipe(clnt->cl_dentry, gss_auth->mech->gm_name,
                        clnt, &gss_upcall_ops, RPC_PIPE_WAIT_FOR_OPEN);
@@ -657,7 +647,13 @@ gss_create(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
                goto err_put_mech;
        }
 
+       err = rpcauth_init_credcache(auth);
+       if (err)
+               goto err_unlink_pipe;
+
        return auth;
+err_unlink_pipe:
+       rpc_unlink(gss_auth->dentry);
 err_put_mech:
        gss_mech_put(gss_auth->mech);
 err_free:
@@ -667,6 +663,25 @@ out_dec:
        return ERR_PTR(err);
 }
 
+static void
+gss_free(struct gss_auth *gss_auth)
+{
+       rpc_unlink(gss_auth->dentry);
+       gss_auth->dentry = NULL;
+       gss_mech_put(gss_auth->mech);
+
+       kfree(gss_auth);
+       module_put(THIS_MODULE);
+}
+
+static void
+gss_free_callback(struct kref *kref)
+{
+       struct gss_auth *gss_auth = container_of(kref, struct gss_auth, kref);
+
+       gss_free(gss_auth);
+}
+
 static void
 gss_destroy(struct rpc_auth *auth)
 {
@@ -675,23 +690,51 @@ gss_destroy(struct rpc_auth *auth)
        dprintk("RPC:       destroying GSS authenticator %p flavor %d\n",
                        auth, auth->au_flavor);
 
+       rpcauth_destroy_credcache(auth);
+
        gss_auth = container_of(auth, struct gss_auth, rpc_auth);
-       rpc_unlink(gss_auth->dentry);
-       gss_auth->dentry = NULL;
-       gss_mech_put(gss_auth->mech);
+       kref_put(&gss_auth->kref, gss_free_callback);
+}
 
-       rpcauth_free_credcache(auth);
-       kfree(gss_auth);
-       module_put(THIS_MODULE);
+/*
+ * gss_destroying_context will cause the RPCSEC_GSS to send a NULL RPC call
+ * to the server with the GSS control procedure field set to
+ * RPC_GSS_PROC_DESTROY. This should normally cause the server to release
+ * all RPCSEC_GSS state associated with that context.
+ */
+static int
+gss_destroying_context(struct rpc_cred *cred)
+{
+       struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
+       struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
+       struct rpc_task *task;
+
+       if (gss_cred->gc_ctx == NULL ||
+                       gss_cred->gc_ctx->gc_proc == RPC_GSS_PROC_DESTROY)
+               return 0;
+
+       gss_cred->gc_ctx->gc_proc = RPC_GSS_PROC_DESTROY;
+       cred->cr_ops = &gss_nullops;
+
+       /* Take a reference to ensure the cred will be destroyed either
+        * by the RPC call or by the put_rpccred() below */
+       get_rpccred(cred);
+
+       task = rpc_call_null(gss_auth->client, cred, RPC_TASK_ASYNC);
+       if (!IS_ERR(task))
+               rpc_put_task(task);
+
+       put_rpccred(cred);
+       return 1;
 }
 
-/* gss_destroy_cred (and gss_destroy_ctx) are used to clean up after failure
+/* gss_destroy_cred (and gss_free_ctx) are used to clean up after failure
  * to create a new cred or context, so they check that things have been
  * allocated before freeing them. */
 static void
-gss_destroy_ctx(struct gss_cl_ctx *ctx)
+gss_do_free_ctx(struct gss_cl_ctx *ctx)
 {
-       dprintk("RPC:       gss_destroy_ctx\n");
+       dprintk("RPC:       gss_free_ctx\n");
 
        if (ctx->gc_gss_ctx)
                gss_delete_sec_context(&ctx->gc_gss_ctx);
@@ -701,15 +744,46 @@ gss_destroy_ctx(struct gss_cl_ctx *ctx)
 }
 
 static void
-gss_destroy_cred(struct rpc_cred *rc)
+gss_free_ctx_callback(struct rcu_head *head)
 {
-       struct gss_cred *cred = container_of(rc, struct gss_cred, gc_base);
+       struct gss_cl_ctx *ctx = container_of(head, struct gss_cl_ctx, gc_rcu);
+       gss_do_free_ctx(ctx);
+}
 
-       dprintk("RPC:       gss_destroy_cred \n");
+static void
+gss_free_ctx(struct gss_cl_ctx *ctx)
+{
+       call_rcu(&ctx->gc_rcu, gss_free_ctx_callback);
+}
 
-       if (cred->gc_ctx)
-               gss_put_ctx(cred->gc_ctx);
-       kfree(cred);
+static void
+gss_free_cred(struct gss_cred *gss_cred)
+{
+       dprintk("RPC:       gss_free_cred %p\n", gss_cred);
+       kfree(gss_cred);
+}
+
+static void
+gss_free_cred_callback(struct rcu_head *head)
+{
+       struct gss_cred *gss_cred = container_of(head, struct gss_cred, gc_base.cr_rcu);
+       gss_free_cred(gss_cred);
+}
+
+static void
+gss_destroy_cred(struct rpc_cred *cred)
+{
+       struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
+       struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
+       struct gss_cl_ctx *ctx = gss_cred->gc_ctx;
+
+       if (gss_destroying_context(cred))
+               return;
+       rcu_assign_pointer(gss_cred->gc_ctx, NULL);
+       call_rcu(&cred->cr_rcu, gss_free_cred_callback);
+       if (ctx)
+               gss_put_ctx(ctx);
+       kref_put(&gss_auth->kref, gss_free_callback);
 }
 
 /*
@@ -734,16 +808,14 @@ gss_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
        if (!(cred = kzalloc(sizeof(*cred), GFP_KERNEL)))
                goto out_err;
 
-       atomic_set(&cred->gc_count, 1);
-       cred->gc_uid = acred->uid;
+       rpcauth_init_cred(&cred->gc_base, acred, auth, &gss_credops);
        /*
         * Note: in order to force a call to call_refresh(), we deliberately
         * fail to flag the credential as RPCAUTH_CRED_UPTODATE.
         */
-       cred->gc_flags = 0;
-       cred->gc_base.cr_ops = &gss_credops;
-       cred->gc_base.cr_flags = RPCAUTH_CRED_NEW;
+       cred->gc_base.cr_flags = 1UL << RPCAUTH_CRED_NEW;
        cred->gc_service = gss_auth->service;
+       kref_get(&gss_auth->kref);
        return &cred->gc_base;
 
 out_err:
@@ -774,7 +846,7 @@ gss_match(struct auth_cred *acred, struct rpc_cred *rc, int flags)
         * we don't really care if the credential has expired or not,
         * since the caller should be prepared to reinitialise it.
         */
-       if ((flags & RPCAUTH_LOOKUP_NEW) && (rc->cr_flags & RPCAUTH_CRED_NEW))
+       if ((flags & RPCAUTH_LOOKUP_NEW) && test_bit(RPCAUTH_CRED_NEW, &rc->cr_flags))
                goto out;
        /* Don't match with creds that have expired. */
        if (gss_cred->gc_ctx && time_after(jiffies, gss_cred->gc_ctx->gc_expiry))
@@ -830,7 +902,7 @@ gss_marshal(struct rpc_task *task, __be32 *p)
        mic.data = (u8 *)(p + 1);
        maj_stat = gss_get_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
        if (maj_stat == GSS_S_CONTEXT_EXPIRED) {
-               cred->cr_flags &= ~RPCAUTH_CRED_UPTODATE;
+               clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
        } else if (maj_stat != 0) {
                printk("gss_marshal: gss_get_mic FAILED (%d)\n", maj_stat);
                goto out_put_ctx;
@@ -855,6 +927,13 @@ gss_refresh(struct rpc_task *task)
        return 0;
 }
 
+/* Dummy refresh routine: used only when destroying the context */
+static int
+gss_refresh_null(struct rpc_task *task)
+{
+       return -EACCES;
+}
+
 static __be32 *
 gss_validate(struct rpc_task *task, __be32 *p)
 {
@@ -883,12 +962,15 @@ gss_validate(struct rpc_task *task, __be32 *p)
 
        maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
        if (maj_stat == GSS_S_CONTEXT_EXPIRED)
-               cred->cr_flags &= ~RPCAUTH_CRED_UPTODATE;
-       if (maj_stat)
+               clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
+       if (maj_stat) {
+               dprintk("RPC: %5u gss_validate: gss_verify_mic returned"
+                               "error 0x%08x\n", task->tk_pid, maj_stat);
                goto out_bad;
+       }
        /* We leave it to unwrap to calculate au_rslack. For now we just
         * calculate the length of the verifier: */
-       task->tk_auth->au_verfsize = XDR_QUADLEN(len) + 2;
+       cred->cr_auth->au_verfsize = XDR_QUADLEN(len) + 2;
        gss_put_ctx(ctx);
        dprintk("RPC: %5u gss_validate: gss_verify_mic succeeded.\n",
                        task->tk_pid);
@@ -917,7 +999,7 @@ gss_wrap_req_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
        offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
        *p++ = htonl(rqstp->rq_seqno);
 
-       status = encode(rqstp, p, obj);
+       status = rpc_call_xdrproc(encode, rqstp, p, obj);
        if (status)
                return status;
 
@@ -937,7 +1019,7 @@ gss_wrap_req_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
        maj_stat = gss_get_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
        status = -EIO; /* XXX? */
        if (maj_stat == GSS_S_CONTEXT_EXPIRED)
-               cred->cr_flags &= ~RPCAUTH_CRED_UPTODATE;
+               clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
        else if (maj_stat)
                return status;
        q = xdr_encode_opaque(p, NULL, mic.len);
@@ -1011,7 +1093,7 @@ gss_wrap_req_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
        offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
        *p++ = htonl(rqstp->rq_seqno);
 
-       status = encode(rqstp, p, obj);
+       status = rpc_call_xdrproc(encode, rqstp, p, obj);
        if (status)
                return status;
 
@@ -1036,7 +1118,7 @@ gss_wrap_req_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
        /* We're assuming that when GSS_S_CONTEXT_EXPIRED, the encryption was
         * done anyway, so it's safe to put the request on the wire: */
        if (maj_stat == GSS_S_CONTEXT_EXPIRED)
-               cred->cr_flags &= ~RPCAUTH_CRED_UPTODATE;
+               clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
        else if (maj_stat)
                return status;
 
@@ -1070,12 +1152,12 @@ gss_wrap_req(struct rpc_task *task,
                /* The spec seems a little ambiguous here, but I think that not
                 * wrapping context destruction requests makes the most sense.
                 */
-               status = encode(rqstp, p, obj);
+               status = rpc_call_xdrproc(encode, rqstp, p, obj);
                goto out;
        }
        switch (gss_cred->gc_service) {
                case RPC_GSS_SVC_NONE:
-                       status = encode(rqstp, p, obj);
+                       status = rpc_call_xdrproc(encode, rqstp, p, obj);
                        break;
                case RPC_GSS_SVC_INTEGRITY:
                        status = gss_wrap_req_integ(cred, ctx, encode,
@@ -1123,7 +1205,7 @@ gss_unwrap_resp_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
 
        maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
        if (maj_stat == GSS_S_CONTEXT_EXPIRED)
-               cred->cr_flags &= ~RPCAUTH_CRED_UPTODATE;
+               clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
        if (maj_stat != GSS_S_COMPLETE)
                return status;
        return 0;
@@ -1148,7 +1230,7 @@ gss_unwrap_resp_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
 
        maj_stat = gss_unwrap(ctx->gc_gss_ctx, offset, rcv_buf);
        if (maj_stat == GSS_S_CONTEXT_EXPIRED)
-               cred->cr_flags &= ~RPCAUTH_CRED_UPTODATE;
+               clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
        if (maj_stat != GSS_S_COMPLETE)
                return status;
        if (ntohl(*(*p)++) != rqstp->rq_seqno)
@@ -1188,10 +1270,10 @@ gss_unwrap_resp(struct rpc_task *task,
                        break;
        }
        /* take into account extra slack for integrity and privacy cases: */
-       task->tk_auth->au_rslack = task->tk_auth->au_verfsize + (p - savedp)
+       cred->cr_auth->au_rslack = cred->cr_auth->au_verfsize + (p - savedp)
                                                + (savedlen - head->iov_len);
 out_decode:
-       status = decode(rqstp, p, obj);
+       status = rpc_call_xdrproc(decode, rqstp, p, obj);
 out:
        gss_put_ctx(ctx);
        dprintk("RPC: %5u gss_unwrap_resp returning %d\n", task->tk_pid,
@@ -1199,7 +1281,7 @@ out:
        return status;
 }
 
-static struct rpc_authops authgss_ops = {
+static const struct rpc_authops authgss_ops = {
        .owner          = THIS_MODULE,
        .au_flavor      = RPC_AUTH_GSS,
 #ifdef RPC_DEBUG
@@ -1211,7 +1293,7 @@ static struct rpc_authops authgss_ops = {
        .crcreate       = gss_create_cred
 };
 
-static struct rpc_credops gss_credops = {
+static const struct rpc_credops gss_credops = {
        .cr_name        = "AUTH_GSS",
        .crdestroy      = gss_destroy_cred,
        .cr_init        = gss_cred_init,
@@ -1223,6 +1305,17 @@ static struct rpc_credops gss_credops = {
        .crunwrap_resp  = gss_unwrap_resp,
 };
 
+static const struct rpc_credops gss_nullops = {
+       .cr_name        = "AUTH_GSS",
+       .crdestroy      = gss_destroy_cred,
+       .crmatch        = gss_match,
+       .crmarshal      = gss_marshal,
+       .crrefresh      = gss_refresh_null,
+       .crvalidate     = gss_validate,
+       .crwrap_req     = gss_wrap_req,
+       .crunwrap_resp  = gss_unwrap_resp,
+};
+
 static struct rpc_pipe_ops gss_upcall_ops = {
        .upcall         = gss_pipe_upcall,
        .downcall       = gss_pipe_downcall,