SUNRPC: Fix a 'Busy inodes' error in rpc_pipefs

Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

include/linux/sunrpc/clnt.h

@@ -60,6 +60,7 @@ struct rpc_clnt {
 	int			cl_nodelen;	/* nodename length */
 	char 			cl_nodename[UNX_MAXNODENAME];
 	char			cl_pathname[30];/* Path in rpc_pipe_fs */
+	struct vfsmount *	cl_vfsmnt;
 	struct dentry *		cl_dentry;	/* inode */
 	struct rpc_clnt *	cl_parent;	/* Points to parent of clones */
 	struct rpc_rtt		cl_rtt_default;

include/linux/sunrpc/rpc_pipe_fs.h

@@ -45,6 +45,8 @@ extern struct dentry *rpc_mkdir(char *, struct rpc_clnt *);
 extern int rpc_rmdir(char *);
 extern struct dentry *rpc_mkpipe(char *, void *, struct rpc_pipe_ops *, int flags);
 extern int rpc_unlink(char *);
+extern struct vfsmount *rpc_get_mount(void);
+extern void rpc_put_mount(void);
 
 #endif
 #endif

net/sunrpc/clnt.c

@@ -70,8 +70,15 @@ rpc_setup_pipedir(struct rpc_clnt *clnt, char *dir_name)
 	static uint32_t clntid;
 	int error;
 
+	clnt->cl_vfsmnt = ERR_PTR(-ENOENT);
+	clnt->cl_dentry = ERR_PTR(-ENOENT);
 	if (dir_name == NULL)
 		return 0;
+
+	clnt->cl_vfsmnt = rpc_get_mount();
+	if (IS_ERR(clnt->cl_vfsmnt))
+		return PTR_ERR(clnt->cl_vfsmnt);
+
 	for (;;) {
 		snprintf(clnt->cl_pathname, sizeof(clnt->cl_pathname),
 				"%s/clnt%x", dir_name,
@@ -84,6 +91,7 @@ rpc_setup_pipedir(struct rpc_clnt *clnt, char *dir_name)
 		if (error != -EEXIST) {
 			printk(KERN_INFO "RPC: Couldn't create pipefs entry %s, error %d\n",
 					clnt->cl_pathname, error);
+			rpc_put_mount();
 			return error;
 		}
 	}
@@ -175,7 +183,11 @@ rpc_new_client(struct rpc_xprt *xprt, char *servname,
 	return clnt;
 
 out_no_auth:
-	rpc_rmdir(clnt->cl_pathname);
+	if (!IS_ERR(clnt->cl_dentry)) {
+		rpc_rmdir(clnt->cl_pathname);
+		dput(clnt->cl_dentry);
+		rpc_put_mount();
+	}
 out_no_path:
 	if (clnt->cl_server != clnt->cl_inline_name)
 		kfree(clnt->cl_server);
@@ -240,13 +252,15 @@ rpc_clone_client(struct rpc_clnt *clnt)
 	new->cl_autobind = 0;
 	new->cl_oneshot = 0;
 	new->cl_dead = 0;
-	dget(new->cl_dentry);
+	if (!IS_ERR(new->cl_dentry)) {
+		dget(new->cl_dentry);
+		rpc_get_mount();
+	}
 	rpc_init_rtt(&new->cl_rtt_default, clnt->cl_xprt->timeout.to_initval);
 	if (new->cl_auth)
 		atomic_inc(&new->cl_auth->au_count);
 	new->cl_pmap		= &new->cl_pmap_default;
 	new->cl_metrics         = rpc_alloc_iostats(clnt);
-	rpc_init_wait_queue(&new->cl_pmap_default.pm_bindwait, "bindwait");
 	return new;
 out_no_clnt:
 	printk(KERN_INFO "RPC: out of memory in %s\n", __FUNCTION__);
@@ -318,8 +332,10 @@ rpc_destroy_client(struct rpc_clnt *clnt)
 out_free:
 	rpc_free_iostats(clnt->cl_metrics);
 	clnt->cl_metrics = NULL;
-	if (clnt->cl_dentry)
+	if (!IS_ERR(clnt->cl_dentry)) {
 		dput(clnt->cl_dentry);
+		rpc_put_mount();
+	}
 	kfree(clnt);
 	return 0;
 }

net/sunrpc/rpc_pipe.c

@@ -435,14 +435,17 @@ static struct rpc_filelist authfiles[] = {
 	},
 };
 
-static int
-rpc_get_mount(void)
+struct vfsmount *rpc_get_mount(void)
 {
-	return simple_pin_fs("rpc_pipefs", &rpc_mount, &rpc_mount_count);
+	int err;
+
+	err = simple_pin_fs("rpc_pipefs", &rpc_mount, &rpc_mount_count);
+	if (err != 0)
+		return ERR_PTR(err);
+	return rpc_mount;
 }
 
-static void
-rpc_put_mount(void)
+void rpc_put_mount(void)
 {
 	simple_release_fs(&rpc_mount, &rpc_mount_count);
 }
@@ -452,12 +455,13 @@ rpc_lookup_parent(char *path, struct nameidata *nd)
 {
 	if (path[0] == '\0')
 		return -ENOENT;
-	if (rpc_get_mount()) {
+	nd->mnt = rpc_get_mount();
+	if (IS_ERR(nd->mnt)) {
 		printk(KERN_WARNING "%s: %s failed to mount "
 			       "pseudofilesystem \n", __FILE__, __FUNCTION__);
-		return -ENODEV;
+		return PTR_ERR(nd->mnt);
 	}
-	nd->mnt = mntget(rpc_mount);
+	mntget(nd->mnt);
 	nd->dentry = dget(rpc_mount->mnt_root);
 	nd->last_type = LAST_ROOT;
 	nd->flags = LOOKUP_PARENT;
@@ -594,7 +598,6 @@ __rpc_mkdir(struct inode *dir, struct dentry *dentry)
 	d_instantiate(dentry, inode);
 	dir->i_nlink++;
 	inode_dir_notify(dir, DN_CREATE);
-	rpc_get_mount();
 	return 0;
 out_err:
 	printk(KERN_WARNING "%s: %s failed to allocate inode for dentry %s\n",
@@ -615,7 +618,6 @@ __rpc_rmdir(struct inode *dir, struct dentry *dentry)
 	if (!error) {
 		inode_dir_notify(dir, DN_DELETE);
 		d_drop(dentry);
-		rpc_put_mount();
 	}
 	return 0;
 }