SUNRPC: Clean up the sillyrename code

Fix a couple of bugs:
 - Don't rely on the parent dentry still being valid when the call completes.
   Fixes a race with shrink_dcache_for_umount_subtree()

 - Don't remove the file if the filehandle has been labelled as stale.

Fix a couple of inefficiencies
 - Remove the global list of sillyrenamed files. Instead we can cache the
   sillyrename information in the dentry->d_fsdata
 - Move common code from unlink_setup/unlink_done into fs/nfs/unlink.c

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

fs/nfs/dir.c

@@ -869,7 +869,7 @@ static void nfs_dentry_iput(struct dentry *dentry, struct inode *inode)
 	if (dentry->d_flags & DCACHE_NFSFS_RENAMED) {
 		lock_kernel();
 		drop_nlink(inode);
-		nfs_complete_unlink(dentry);
+		nfs_complete_unlink(dentry, inode);
 		unlock_kernel();
 	}
 	/* When creating a negative dentry, we want to renew d_time */
@@ -1411,7 +1411,7 @@ static int nfs_sillyrename(struct inode *dir, struct dentry *dentry)
 		nfs_renew_times(dentry);
 		nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
 		d_move(dentry, sdentry);
-		error = nfs_async_unlink(dentry);
+		error = nfs_async_unlink(dir, dentry);
  		/* If we return 0 we don't unlink */
 	}
 	dput(sdentry);

fs/nfs/nfs3proc.c

@@ -370,41 +370,21 @@ nfs3_proc_remove(struct inode *dir, struct qstr *name)
 	return status;
 }
 
-static int
-nfs3_proc_unlink_setup(struct rpc_message *msg, struct dentry *dir, struct qstr *name)
+static void
+nfs3_proc_unlink_setup(struct rpc_message *msg, struct inode *dir)
 {
-	struct unlinkxdr {
-		struct nfs_removeargs arg;
-		struct nfs_removeres res;
-	} *ptr;
-
-	ptr = kmalloc(sizeof(*ptr), GFP_KERNEL);
-	if (!ptr)
-		return -ENOMEM;
-	ptr->arg.fh = NFS_FH(dir->d_inode);
-	ptr->arg.name.name = name->name;
-	ptr->arg.name.len = name->len;
-	nfs_fattr_init(&ptr->res.dir_attr);
 	msg->rpc_proc = &nfs3_procedures[NFS3PROC_REMOVE];
-	msg->rpc_argp = &ptr->arg;
-	msg->rpc_resp = &ptr->res;
-	return 0;
 }
 
 static int
-nfs3_proc_unlink_done(struct dentry *dir, struct rpc_task *task)
+nfs3_proc_unlink_done(struct rpc_task *task, struct inode *dir)
 {
-	struct rpc_message *msg = &task->tk_msg;
-	struct nfs_fattr	*dir_attr;
-
-	if (nfs3_async_handle_jukebox(task, dir->d_inode))
-		return 1;
-	if (msg->rpc_argp) {
-		dir_attr = &((struct nfs_removeres*)msg->rpc_resp)->dir_attr;
-		nfs_post_op_update_inode(dir->d_inode, dir_attr);
-		kfree(msg->rpc_argp);
-	}
-	return 0;
+	struct nfs_removeres *res;
+	if (nfs3_async_handle_jukebox(task, dir))
+		return 0;
+	res = task->tk_msg.rpc_resp;
+	nfs_post_op_update_inode(dir, &res->dir_attr);
+	return 1;
 }
 
 static int

fs/nfs/nfs4proc.c

@@ -1962,48 +1962,26 @@ static int nfs4_proc_remove(struct inode *dir, struct qstr *name)
 	return err;
 }
 
-struct unlink_desc {
-	struct nfs_removeargs args;
-	struct nfs_removeres res;
-};
-
-static int nfs4_proc_unlink_setup(struct rpc_message *msg, struct dentry *dir,
-		struct qstr *name)
+static void nfs4_proc_unlink_setup(struct rpc_message *msg, struct inode *dir)
 {
-	struct nfs_server *server = NFS_SERVER(dir->d_inode);
-	struct unlink_desc *up;
+	struct nfs_server *server = NFS_SERVER(dir);
+	struct nfs_removeargs *args = msg->rpc_argp;
+	struct nfs_removeres *res = msg->rpc_resp;
 
-	up = kmalloc(sizeof(*up), GFP_KERNEL);
-	if (!up)
-		return -ENOMEM;
-
-	up->args.fh = NFS_FH(dir->d_inode);
-	up->args.name.len = name->len;
-	up->args.name.name = name->name;
-	up->args.bitmask = server->attr_bitmask;
-	up->res.server = server;
-	nfs_fattr_init(&up->res.dir_attr);
-
+	args->bitmask = server->attr_bitmask;
+	res->server = server;
 	msg->rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_REMOVE];
-	msg->rpc_argp = &up->args;
-	msg->rpc_resp = &up->res;
-	return 0;
 }
 
-static int nfs4_proc_unlink_done(struct dentry *dir, struct rpc_task *task)
+static int nfs4_proc_unlink_done(struct rpc_task *task, struct inode *dir)
 {
-	struct rpc_message *msg = &task->tk_msg;
-	struct unlink_desc *up;
-
-	if (msg->rpc_resp != NULL) {
-		up = container_of(msg->rpc_resp, struct unlink_desc, res);
-		update_changeattr(dir->d_inode, &up->res.cinfo);
-		nfs_post_op_update_inode(dir->d_inode, &up->res.dir_attr);
-		kfree(up);
-		msg->rpc_resp = NULL;
-		msg->rpc_argp = NULL;
-	}
-	return 0;
+	struct nfs_removeres *res = task->tk_msg.rpc_resp;
+
+	if (nfs4_async_handle_error(task, res->server) == -EAGAIN)
+		return 0;
+	update_changeattr(dir, &res->cinfo);
+	nfs_post_op_update_inode(dir, &res->dir_attr);
+	return 1;
 }
 
 static int _nfs4_proc_rename(struct inode *old_dir, struct qstr *old_name,

fs/nfs/proc.c

@@ -291,32 +291,16 @@ nfs_proc_remove(struct inode *dir, struct qstr *name)
 	return status;
 }
 
-static int
-nfs_proc_unlink_setup(struct rpc_message *msg, struct dentry *dir, struct qstr *name)
+static void
+nfs_proc_unlink_setup(struct rpc_message *msg, struct inode *dir)
 {
-	struct nfs_removeargs *arg;
-
-	arg = kmalloc(sizeof(*arg), GFP_KERNEL);
-	if (!arg)
-		return -ENOMEM;
-	arg->fh = NFS_FH(dir->d_inode);
-	arg->name.name = name->name;
-	arg->name.len = name->len;
 	msg->rpc_proc = &nfs_procedures[NFSPROC_REMOVE];
-	msg->rpc_argp = arg;
-	return 0;
 }
 
-static int
-nfs_proc_unlink_done(struct dentry *dir, struct rpc_task *task)
+static int nfs_proc_unlink_done(struct rpc_task *task, struct inode *dir)
 {
-	struct rpc_message *msg = &task->tk_msg;
-
-	if (msg->rpc_argp) {
-		nfs_mark_for_revalidate(dir->d_inode);
-		kfree(msg->rpc_argp);
-	}
-	return 0;
+	nfs_mark_for_revalidate(dir);
+	return 1;
 }
 
 static int