[PATCH] RPC: [PATCH] improve rpcauthauth_create error returns

 Currently we return -ENOMEM for every single failure to create a new auth.
 This is actually accurate for auth_null and auth_unix, but for auth_gss it's a
 bit confusing.

 Allow rpcauth_create (and the ->create methods) to return errors.  With this
 patch, the user may sometimes see an EINVAL instead.  Whee.

 Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
 Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

5 files changed, 35 insertions, 20 deletions

diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index 350c48c12639..97b3fe7ece63 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -160,11 +160,10 @@ nfs_clear_inode(struct inode *inode)
 void
 nfs_umount_begin(struct super_block *sb)
 {
-        struct nfs_server *server = NFS_SB(sb);
-        struct rpc_clnt *rpc;
+        struct rpc_clnt *rpc = NFS_SB(sb)->client;
 
         /* -EIO all pending I/O */
-        if ((rpc = server->client) != NULL)
+        if (!IS_ERR(rpc))
                 rpc_killall_tasks(rpc);
 }
 
@@ -450,11 +449,14 @@ nfs_fill_super(struct super_block *sb, struct nfs_mount_data *data, int silent)
                 return PTR_ERR(server->client);
         /* RFC 2623, sec 2.3.2 */
         if (authflavor != RPC_AUTH_UNIX) {
+                struct rpc_auth *auth;
+
                 server->client_sys = rpc_clone_client(server->client);
                 if (IS_ERR(server->client_sys))
                         return PTR_ERR(server->client_sys);
-                if (!rpcauth_create(RPC_AUTH_UNIX, server->client_sys))
-                        return -ENOMEM;
+                auth = rpcauth_create(RPC_AUTH_UNIX, server->client_sys);
+                if (IS_ERR(auth))
+                        return PTR_ERR(auth);
         } else {
                 atomic_inc(&server->client->cl_count);
                 server->client_sys = server->client;
@@ -1450,6 +1452,7 @@ static struct super_block *nfs_get_sb(struct file_system_type *fs_type,
         memset(server, 0, sizeof(struct nfs_server));
         /* Zero out the NFS state stuff */
         init_nfsv4_state(server);
+        server->client = server->client_sys = ERR_PTR(-EINVAL);
 
         root = &server->fh;
         if (data->flags & NFS_MOUNT_VER3)
@@ -1506,9 +1509,9 @@ static void nfs_kill_super(struct super_block *s)
 
         kill_anon_super(s);
 
-        if (server->client != NULL && !IS_ERR(server->client))
+        if (!IS_ERR(server->client))
                 rpc_shutdown_client(server->client);
-        if (server->client_sys != NULL && !IS_ERR(server->client_sys))
+        if (!IS_ERR(server->client_sys))
                 rpc_shutdown_client(server->client_sys);
 
         if (!(server->flags & NFS_MOUNT_NONLM))
@@ -1650,7 +1653,7 @@ static int nfs4_fill_super(struct super_block *sb, struct nfs4_mount_data *data,
         }
 
         down_write(&clp->cl_sem);
-        if (clp->cl_rpcclient == NULL) {
+        if (IS_ERR(clp->cl_rpcclient)) {
                 xprt = xprt_create_proto(proto, &server->addr, &timeparms);
                 if (IS_ERR(xprt)) {
                         up_write(&clp->cl_sem);
@@ -1711,9 +1714,12 @@ static int nfs4_fill_super(struct super_block *sb, struct nfs4_mount_data *data,
         }
 
         if (clnt->cl_auth->au_flavor != authflavour) {
-                if (rpcauth_create(authflavour, clnt) == NULL) {
+                struct rpc_auth *auth;
+
+                auth = rpcauth_create(authflavour, clnt);
+                if (IS_ERR(auth)) {
                         dprintk("%s: couldn't create credcache!\n", __FUNCTION__);
-                        return -ENOMEM;
+                        return PTR_ERR(auth);
                 }
         }
 
@@ -1788,6 +1794,7 @@ static struct super_block *nfs4_get_sb(struct file_system_type *fs_type,
         memset(server, 0, sizeof(struct nfs_server));
         /* Zero out the NFS state stuff */
         init_nfsv4_state(server);
+        server->client = server->client_sys = ERR_PTR(-EINVAL);
 
         p = nfs_copy_user_string(NULL, &data->hostname, 256);
         if (IS_ERR(p))
diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c
index 17b187f2d776..591ad1d51880 100644
--- a/fs/nfs/nfs4state.c
+++ b/fs/nfs/nfs4state.c
@@ -110,6 +110,7 @@ nfs4_alloc_client(struct in_addr *addr)
         INIT_LIST_HEAD(&clp->cl_superblocks);
         init_waitqueue_head(&clp->cl_waitq);
         rpc_init_wait_queue(&clp->cl_rpcwaitq, "NFS4 client");
+        clp->cl_rpcclient = ERR_PTR(-EINVAL);
         clp->cl_boot_time = CURRENT_TIME;
         clp->cl_state = 1 << NFS4CLNT_OK;
         return clp;
@@ -131,7 +132,7 @@ nfs4_free_client(struct nfs4_client *clp)
         if (clp->cl_cred)
                 put_rpccred(clp->cl_cred);
         nfs_idmap_delete(clp);
-        if (clp->cl_rpcclient)
+        if (!IS_ERR(clp->cl_rpcclient))
                 rpc_shutdown_client(clp->cl_rpcclient);
         kfree(clp);
         nfs_callback_down();
diff --git a/net/sunrpc/auth.c b/net/sunrpc/auth.c
index 9bcec9b927b9..505e2d4b3d62 100644
--- a/net/sunrpc/auth.c
+++ b/net/sunrpc/auth.c
@@ -66,10 +66,10 @@ rpcauth_create(rpc_authflavor_t pseudoflavor, struct rpc_clnt *clnt)
         u32                     flavor = pseudoflavor_to_flavor(pseudoflavor);
 
         if (flavor >= RPC_AUTH_MAXFLAVOR || !(ops = auth_flavors[flavor]))
-                return NULL;
+                return ERR_PTR(-EINVAL);
         auth = ops->create(clnt, pseudoflavor);
-        if (!auth)
-                return NULL;
+        if (IS_ERR(auth))
+                return auth;
         if (clnt->cl_auth)
                 rpcauth_destroy(clnt->cl_auth);
         clnt->cl_auth = auth;
diff --git a/net/sunrpc/auth_gss/auth_gss.c b/net/sunrpc/auth_gss/auth_gss.c
index 7d88db83ab12..2f7b867161d2 100644
--- a/net/sunrpc/auth_gss/auth_gss.c
+++ b/net/sunrpc/auth_gss/auth_gss.c
@@ -660,14 +660,16 @@ gss_create(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
 {
         struct gss_auth *gss_auth;
         struct rpc_auth * auth;
+        int err = -ENOMEM; /* XXX? */
 
         dprintk("RPC:      creating GSS authenticator for client %p\n",clnt);
 
         if (!try_module_get(THIS_MODULE))
-                return NULL;
+                return ERR_PTR(err);
         if (!(gss_auth = kmalloc(sizeof(*gss_auth), GFP_KERNEL)))
                 goto out_dec;
         gss_auth->client = clnt;
+        err = -EINVAL;
         gss_auth->mech = gss_mech_get_by_pseudoflavor(flavor);
         if (!gss_auth->mech) {
                 printk(KERN_WARNING "%s: Pseudoflavor %d not found!",
@@ -686,15 +688,18 @@ gss_create(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
         auth->au_flavor = flavor;
         atomic_set(&auth->au_count, 1);
 
-        if (rpcauth_init_credcache(auth, GSS_CRED_EXPIRE) < 0)
+        err = rpcauth_init_credcache(auth, GSS_CRED_EXPIRE);
+        if (err)
                 goto err_put_mech;
 
         snprintf(gss_auth->path, sizeof(gss_auth->path), "%s/%s",
                         clnt->cl_pathname,
                         gss_auth->mech->gm_name);
         gss_auth->dentry = rpc_mkpipe(gss_auth->path, clnt, &gss_upcall_ops, RPC_PIPE_WAIT_FOR_OPEN);
-        if (IS_ERR(gss_auth->dentry))
+        if (IS_ERR(gss_auth->dentry)) {
+                err = PTR_ERR(gss_auth->dentry);
                 goto err_put_mech;
+        }
 
         return auth;
 err_put_mech:
@@ -703,7 +708,7 @@ err_free:
         kfree(gss_auth);
 out_dec:
         module_put(THIS_MODULE);
-        return NULL;
+        return ERR_PTR(err);
 }
 
 static void
diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index b36797ad8083..9da1deb482e2 100644
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -103,6 +103,7 @@ rpc_new_client(struct rpc_xprt *xprt, char *servname,
 {
         struct rpc_version      *version;
         struct rpc_clnt         *clnt = NULL;
+        struct rpc_auth         *auth;
         int err;
         int len;
 
@@ -157,10 +158,11 @@ rpc_new_client(struct rpc_xprt *xprt, char *servname,
         if (err < 0)
                 goto out_no_path;
 
-        err = -ENOMEM;
-        if (!rpcauth_create(flavor, clnt)) {
+        auth = rpcauth_create(flavor, clnt);
+        if (IS_ERR(auth)) {
                 printk(KERN_INFO "RPC: Couldn't create auth handle (flavor %u)\n",
                                 flavor);
+                err = PTR_ERR(auth);
                 goto out_no_auth;
         }