Merge branch 'bugfixes' into nfs-for-next

1 files changed, 70 insertions, 34 deletions

diff --git a/fs/nfs/idmap.c b/fs/nfs/idmap.c
index 27dde503a6b..675b389cba5 100644
--- a/fs/nfs/idmap.c
+++ b/fs/nfs/idmap.c
@@ -55,18 +55,19 @@
 static const struct cred *id_resolver_cache;
 static struct key_type key_type_id_resolver_legacy;
 
-struct idmap {
-        struct rpc_pipe         *idmap_pipe;
-        struct key_construction *idmap_key_cons;
-        struct mutex            idmap_mutex;
-};
-
 struct idmap_legacy_upcalldata {
         struct rpc_pipe_msg pipe_msg;
         struct idmap_msg idmap_msg;
+        struct key_construction *key_cons;
         struct idmap *idmap;
 };
 
+struct idmap {
+        struct rpc_pipe         *idmap_pipe;
+        struct idmap_legacy_upcalldata *idmap_upcall_data;
+        struct mutex            idmap_mutex;
+};
+
 /**
  * nfs_fattr_init_names - initialise the nfs_fattr owner_name/group_name fields
  * @fattr: fully initialised struct nfs_fattr
@@ -330,7 +331,6 @@ static ssize_t nfs_idmap_get_key(const char *name, size_t namelen,
                 ret = nfs_idmap_request_key(&key_type_id_resolver_legacy,
                                             name, namelen, type, data,
                                             data_size, idmap);
-                idmap->idmap_key_cons = NULL;
                 mutex_unlock(&idmap->idmap_mutex);
         }
         return ret;
@@ -465,8 +465,6 @@ nfs_idmap_new(struct nfs_client *clp)
         struct rpc_pipe *pipe;
         int error;
 
-        BUG_ON(clp->cl_idmap != NULL);
-
         idmap = kzalloc(sizeof(*idmap), GFP_KERNEL);
         if (idmap == NULL)
                 return -ENOMEM;
@@ -510,7 +508,6 @@ static int __rpc_pipefs_event(struct nfs_client *clp, unsigned long event,
 
         switch (event) {
         case RPC_PIPEFS_MOUNT:
-                BUG_ON(clp->cl_rpcclient->cl_dentry == NULL);
                 err = __nfs_idmap_register(clp->cl_rpcclient->cl_dentry,
                                                 clp->cl_idmap,
                                                 clp->cl_idmap->idmap_pipe);
@@ -662,6 +659,35 @@ out:
         return ret;
 }
 
+static bool
+nfs_idmap_prepare_pipe_upcall(struct idmap *idmap,
+                struct idmap_legacy_upcalldata *data)
+{
+        if (idmap->idmap_upcall_data != NULL) {
+                WARN_ON_ONCE(1);
+                return false;
+        }
+        idmap->idmap_upcall_data = data;
+        return true;
+}
+
+static void
+nfs_idmap_complete_pipe_upcall_locked(struct idmap *idmap, int ret)
+{
+        struct key_construction *cons = idmap->idmap_upcall_data->key_cons;
+
+        kfree(idmap->idmap_upcall_data);
+        idmap->idmap_upcall_data = NULL;
+        complete_request_key(cons, ret);
+}
+
+static void
+nfs_idmap_abort_pipe_upcall(struct idmap *idmap, int ret)
+{
+        if (idmap->idmap_upcall_data != NULL)
+                nfs_idmap_complete_pipe_upcall_locked(idmap, ret);
+}
+
 static int nfs_idmap_legacy_upcall(struct key_construction *cons,
                                    const char *op,
                                    void *aux)
@@ -686,17 +712,15 @@ static int nfs_idmap_legacy_upcall(struct key_construction *cons,
         if (ret < 0)
                 goto out2;
 
-        BUG_ON(idmap->idmap_key_cons != NULL);
-        idmap->idmap_key_cons = cons;
+        ret = -EAGAIN;
+        if (!nfs_idmap_prepare_pipe_upcall(idmap, data))
+                goto out2;
 
         ret = rpc_queue_upcall(idmap->idmap_pipe, msg);
         if (ret < 0)
-                goto out3;
+                nfs_idmap_abort_pipe_upcall(idmap, ret);
 
         return ret;
-
-out3:
-        idmap->idmap_key_cons = NULL;
 out2:
         kfree(data);
 out1:
@@ -711,21 +735,32 @@ static int nfs_idmap_instantiate(struct key *key, struct key *authkey, char *dat
                                         authkey);
 }
 
-static int nfs_idmap_read_message(struct idmap_msg *im, struct key *key, struct key *authkey)
+static int nfs_idmap_read_and_verify_message(struct idmap_msg *im,
+                struct idmap_msg *upcall,
+                struct key *key, struct key *authkey)
 {
         char id_str[NFS_UINT_MAXLEN];
-        int ret = -EINVAL;
+        int ret = -ENOKEY;
 
+        /* ret = -ENOKEY */
+        if (upcall->im_type != im->im_type || upcall->im_conv != im->im_conv)
+                goto out;
         switch (im->im_conv) {
         case IDMAP_CONV_NAMETOID:
+                if (strcmp(upcall->im_name, im->im_name) != 0)
+                        break;
                 sprintf(id_str, "%d", im->im_id);
                 ret = nfs_idmap_instantiate(key, authkey, id_str);
                 break;
         case IDMAP_CONV_IDTONAME:
+                if (upcall->im_id != im->im_id)
+                        break;
                 ret = nfs_idmap_instantiate(key, authkey, im->im_name);
                 break;
+        default:
+                ret = -EINVAL;
         }
-
+out:
         return ret;
 }
 
@@ -737,14 +772,16 @@ idmap_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
         struct key_construction *cons;
         struct idmap_msg im;
         size_t namelen_in;
-        int ret;
+        int ret = -ENOKEY;
 
         /* If instantiation is successful, anyone waiting for key construction
          * will have been woken up and someone else may now have used
          * idmap_key_cons - so after this point we may no longer touch it.
          */
-        cons = ACCESS_ONCE(idmap->idmap_key_cons);
-        idmap->idmap_key_cons = NULL;
+        if (idmap->idmap_upcall_data == NULL)
+                goto out_noupcall;
+
+        cons = idmap->idmap_upcall_data->key_cons;
 
         if (mlen != sizeof(im)) {
                 ret = -ENOSPC;
@@ -765,16 +802,19 @@ idmap_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
         if (namelen_in == 0 || namelen_in == IDMAP_NAMESZ) {
                 ret = -EINVAL;
                 goto out;
-        }
+}
 
-        ret = nfs_idmap_read_message(&im, cons->key, cons->authkey);
+        ret = nfs_idmap_read_and_verify_message(&im,
+                        &idmap->idmap_upcall_data->idmap_msg,
+                        cons->key, cons->authkey);
         if (ret >= 0) {
                 key_set_timeout(cons->key, nfs_idmap_cache_timeout);
                 ret = mlen;
         }
 
 out:
-        complete_request_key(cons, ret);
+        nfs_idmap_complete_pipe_upcall_locked(idmap, ret);
+out_noupcall:
         return ret;
 }
 
@@ -785,14 +825,9 @@ idmap_pipe_destroy_msg(struct rpc_pipe_msg *msg)
                         struct idmap_legacy_upcalldata,
                         pipe_msg);
         struct idmap *idmap = data->idmap;
-        struct key_construction *cons;
-        if (msg->errno) {
-                cons = ACCESS_ONCE(idmap->idmap_key_cons);
-                idmap->idmap_key_cons = NULL;
-                complete_request_key(cons, msg->errno);
-        }
-        /* Free memory allocated in nfs_idmap_legacy_upcall() */
-        kfree(data);
+
+        if (msg->errno)
+                nfs_idmap_abort_pipe_upcall(idmap, msg->errno);
 }
 
 static void
@@ -800,7 +835,8 @@ idmap_release_pipe(struct inode *inode)
 {
         struct rpc_inode *rpci = RPC_I(inode);
         struct idmap *idmap = (struct idmap *)rpci->private;
-        idmap->idmap_key_cons = NULL;
+
+        nfs_idmap_abort_pipe_upcall(idmap, -EPIPE);
 }
 
 int nfs_map_name_to_uid(const struct nfs_server *server, const char *name, size_t namelen, __u32 *uid)