From 94cef36797600d11a50d09828fa80df8a73dfd1c Mon Sep 17 00:00:00 2001 From: "Michael I. Bushnell" Date: Thu, 18 Jul 1996 04:35:29 +0000 Subject: *** empty log message *** --- libtreefs/dir-hooks.c | 136 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 136 insertions(+) create mode 100644 libtreefs/dir-hooks.c (limited to 'libtreefs/dir-hooks.c') diff --git a/libtreefs/dir-hooks.c b/libtreefs/dir-hooks.c new file mode 100644 index 00000000..5c54039a --- /dev/null +++ b/libtreefs/dir-hooks.c @@ -0,0 +1,136 @@ +/* Default hooks for directory nodes + + Copyright (C) 1995 Free Software Foundation, Inc. + + Written by Miles Bader + + This file is part of the GNU Hurd. + + The GNU Hurd is free software; you can redistribute it and/or + modify it under the terms of the GNU General Public License as + published by the Free Software Foundation; either version 2, or (at + your option) any later version. + + The GNU Hurd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ + +#include + +#include "treefs.h" + +/* ---------------------------------------------------------------- */ + +/* Return in CHILD a new node with one reference, presumably a possible child + of DIR, with a mode MODE. All attempts to create a new node go through + this hook, so it may be overridden to easily control creation (e.g., + replacing it with a hook that always returns EPERM). Note that this + routine doesn't actually enter the child into the directory, or give the + node a non-zero link count, that should be done by the caller. */ +error_t +_treefs_dir_create_child (struct treefs_node *dir, + mode_t mode, struct treefs_auth *auth, + struct treefs_node **child) +{ + error_t err; + + if (!treefs_node_isdir (dir)) + return ENOTDIR; + + err = treefs_fsys_create_node (dir->fsys, dir, mode, auth, child); + if (err) + return err; + + return 0; +} + +/* ---------------------------------------------------------------- */ + +/* Lookup NAME in DIR, returning the result in CHILD; AUTH should be used to + do authentication. FLAGS is the open flags; if FLAGS contains O_CREAT, + and NAME is not found, then an entry should be created with a mode of + CREATE_MODE (which includes the S_IFMT bits, e.g., S_IFREG means a normal + file), unless O_EXCL is also set, in which case EEXIST should be returned. + Possible special errors returned include: EAGAIN -- result would be the + parent of our filesystem root. */ +error_t +_treefs_dir_lookup (struct treefs_node *dir, char *name, + struct treefs_auth *auth, + int flags, int create_mode, + struct treefs_node **child) +{ + error_t err; + + if (strcmp (name, "..") == 0 && dir == dir->fsys->root) + /* Whoops, the result is above our heads. */ + err = EAGAIN; + else + /* See if we've got an in-core entry for this file. */ + err = treefs_mdir_get (dir, name, child); + + if (err == 0 && (flags & O_EXCL)) + return EEXIST; + + if (err == ENOENT) + /* See if there's some other way of getting this file. */ + err = treefs_dir_noent (dir, name, auth, flags, create_mode, child); + + if (err == ENOENT && (flags & O_CREAT)) + /* No such file, but the user wants to create it. */ + { + err = treefs_dir_create_child (dir, create_mode, auth, child); + if (!err) + { + err = treefs_dir_link (dir, name, *child, auth); + if (err) + treefs_node_unref (*child); + } + } + + return err; +} + +/* ---------------------------------------------------------------- */ + +/* Link the node CHILD into DIR as NAME, using AUTH to check authentication. + DIR should be locked and CHILD shouldn't be. The default hook puts it + into DIR's in-core directory, and uses a reference to CHILD. */ +error_t +_treefs_dir_link (struct treefs_node *dir, char *name, + struct treefs_node *child, struct treefs_auth *auth) +{ + struct treefs_node *old_child; + error_t err = treefs_node_mod_link_count (child, 1); + if (!err) + { + err = treefs_mdir_add (dir, name, child, &old_child); + if (err) + /* back out */ + treefs_node_mod_link_count (child, -1); + else if (old_child) + treefs_node_mod_link_count (old_child, -1); + } + return err; +} + +/* Remove the entry NAME from DIR, using AUTH to check authentication. DIR + should be locked. The default hook removes NAME from DIR's in-core + directory. */ +error_t +_treefs_dir_unlink (struct treefs_node *dir, char *name, + struct treefs_auth *auth) +{ + struct treefs_node *old_child; + error_t err = treefs_mdir_remove (dir, name, &old_child); + if (!err && old_child) + { + treefs_node_mod_link_count (old_child, -1); + treefs_node_unref (old_child); + } + return err; +} -- cgit v1.2.3