![Joel Becker](/assets/img/avatar_default.png)
Configfs, a file system for userspace-driven kernel object configuration. The OCFS2 stack makes extensive use of this for propagation of cluster configuration information into kernel. Signed-off-by: Joel Becker <joel.becker@oracle.com>
1103 lines
25 KiB
C
1103 lines
25 KiB
C
/* -*- mode: c; c-basic-offset: 8; -*-
|
|
* vim: noexpandtab sw=8 ts=8 sts=0:
|
|
*
|
|
* dir.c - Operations for configfs directories.
|
|
*
|
|
* This program 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 of the License, or (at your option) any later version.
|
|
*
|
|
* This program 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., 59 Temple Place - Suite 330,
|
|
* Boston, MA 021110-1307, USA.
|
|
*
|
|
* Based on sysfs:
|
|
* sysfs is Copyright (C) 2001, 2002, 2003 Patrick Mochel
|
|
*
|
|
* configfs Copyright (C) 2005 Oracle. All rights reserved.
|
|
*/
|
|
|
|
#undef DEBUG
|
|
|
|
#include <linux/fs.h>
|
|
#include <linux/mount.h>
|
|
#include <linux/module.h>
|
|
#include <linux/slab.h>
|
|
|
|
#include <linux/configfs.h>
|
|
#include "configfs_internal.h"
|
|
|
|
DECLARE_RWSEM(configfs_rename_sem);
|
|
|
|
static void configfs_d_iput(struct dentry * dentry,
|
|
struct inode * inode)
|
|
{
|
|
struct configfs_dirent * sd = dentry->d_fsdata;
|
|
|
|
if (sd) {
|
|
BUG_ON(sd->s_dentry != dentry);
|
|
sd->s_dentry = NULL;
|
|
configfs_put(sd);
|
|
}
|
|
iput(inode);
|
|
}
|
|
|
|
/*
|
|
* We _must_ delete our dentries on last dput, as the chain-to-parent
|
|
* behavior is required to clear the parents of default_groups.
|
|
*/
|
|
static int configfs_d_delete(struct dentry *dentry)
|
|
{
|
|
return 1;
|
|
}
|
|
|
|
static struct dentry_operations configfs_dentry_ops = {
|
|
.d_iput = configfs_d_iput,
|
|
/* simple_delete_dentry() isn't exported */
|
|
.d_delete = configfs_d_delete,
|
|
};
|
|
|
|
/*
|
|
* Allocates a new configfs_dirent and links it to the parent configfs_dirent
|
|
*/
|
|
static struct configfs_dirent *configfs_new_dirent(struct configfs_dirent * parent_sd,
|
|
void * element)
|
|
{
|
|
struct configfs_dirent * sd;
|
|
|
|
sd = kmalloc(sizeof(*sd), GFP_KERNEL);
|
|
if (!sd)
|
|
return NULL;
|
|
|
|
memset(sd, 0, sizeof(*sd));
|
|
atomic_set(&sd->s_count, 1);
|
|
INIT_LIST_HEAD(&sd->s_links);
|
|
INIT_LIST_HEAD(&sd->s_children);
|
|
list_add(&sd->s_sibling, &parent_sd->s_children);
|
|
sd->s_element = element;
|
|
|
|
return sd;
|
|
}
|
|
|
|
int configfs_make_dirent(struct configfs_dirent * parent_sd,
|
|
struct dentry * dentry, void * element,
|
|
umode_t mode, int type)
|
|
{
|
|
struct configfs_dirent * sd;
|
|
|
|
sd = configfs_new_dirent(parent_sd, element);
|
|
if (!sd)
|
|
return -ENOMEM;
|
|
|
|
sd->s_mode = mode;
|
|
sd->s_type = type;
|
|
sd->s_dentry = dentry;
|
|
if (dentry) {
|
|
dentry->d_fsdata = configfs_get(sd);
|
|
dentry->d_op = &configfs_dentry_ops;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int init_dir(struct inode * inode)
|
|
{
|
|
inode->i_op = &configfs_dir_inode_operations;
|
|
inode->i_fop = &configfs_dir_operations;
|
|
|
|
/* directory inodes start off with i_nlink == 2 (for "." entry) */
|
|
inode->i_nlink++;
|
|
return 0;
|
|
}
|
|
|
|
static int init_file(struct inode * inode)
|
|
{
|
|
inode->i_size = PAGE_SIZE;
|
|
inode->i_fop = &configfs_file_operations;
|
|
return 0;
|
|
}
|
|
|
|
static int init_symlink(struct inode * inode)
|
|
{
|
|
inode->i_op = &configfs_symlink_inode_operations;
|
|
return 0;
|
|
}
|
|
|
|
static int create_dir(struct config_item * k, struct dentry * p,
|
|
struct dentry * d)
|
|
{
|
|
int error;
|
|
umode_t mode = S_IFDIR| S_IRWXU | S_IRUGO | S_IXUGO;
|
|
|
|
error = configfs_create(d, mode, init_dir);
|
|
if (!error) {
|
|
error = configfs_make_dirent(p->d_fsdata, d, k, mode,
|
|
CONFIGFS_DIR);
|
|
if (!error) {
|
|
p->d_inode->i_nlink++;
|
|
(d)->d_op = &configfs_dentry_ops;
|
|
}
|
|
}
|
|
return error;
|
|
}
|
|
|
|
|
|
/**
|
|
* configfs_create_dir - create a directory for an config_item.
|
|
* @item: config_itemwe're creating directory for.
|
|
* @dentry: config_item's dentry.
|
|
*/
|
|
|
|
static int configfs_create_dir(struct config_item * item, struct dentry *dentry)
|
|
{
|
|
struct dentry * parent;
|
|
int error = 0;
|
|
|
|
BUG_ON(!item);
|
|
|
|
if (item->ci_parent)
|
|
parent = item->ci_parent->ci_dentry;
|
|
else if (configfs_mount && configfs_mount->mnt_sb)
|
|
parent = configfs_mount->mnt_sb->s_root;
|
|
else
|
|
return -EFAULT;
|
|
|
|
error = create_dir(item,parent,dentry);
|
|
if (!error)
|
|
item->ci_dentry = dentry;
|
|
return error;
|
|
}
|
|
|
|
int configfs_create_link(struct configfs_symlink *sl,
|
|
struct dentry *parent,
|
|
struct dentry *dentry)
|
|
{
|
|
int err = 0;
|
|
umode_t mode = S_IFLNK | S_IRWXUGO;
|
|
|
|
err = configfs_create(dentry, mode, init_symlink);
|
|
if (!err) {
|
|
err = configfs_make_dirent(parent->d_fsdata, dentry, sl,
|
|
mode, CONFIGFS_ITEM_LINK);
|
|
if (!err)
|
|
dentry->d_op = &configfs_dentry_ops;
|
|
}
|
|
return err;
|
|
}
|
|
|
|
static void remove_dir(struct dentry * d)
|
|
{
|
|
struct dentry * parent = dget(d->d_parent);
|
|
struct configfs_dirent * sd;
|
|
|
|
sd = d->d_fsdata;
|
|
list_del_init(&sd->s_sibling);
|
|
configfs_put(sd);
|
|
if (d->d_inode)
|
|
simple_rmdir(parent->d_inode,d);
|
|
|
|
pr_debug(" o %s removing done (%d)\n",d->d_name.name,
|
|
atomic_read(&d->d_count));
|
|
|
|
dput(parent);
|
|
}
|
|
|
|
/**
|
|
* configfs_remove_dir - remove an config_item's directory.
|
|
* @item: config_item we're removing.
|
|
*
|
|
* The only thing special about this is that we remove any files in
|
|
* the directory before we remove the directory, and we've inlined
|
|
* what used to be configfs_rmdir() below, instead of calling separately.
|
|
*/
|
|
|
|
static void configfs_remove_dir(struct config_item * item)
|
|
{
|
|
struct dentry * dentry = dget(item->ci_dentry);
|
|
|
|
if (!dentry)
|
|
return;
|
|
|
|
remove_dir(dentry);
|
|
/**
|
|
* Drop reference from dget() on entrance.
|
|
*/
|
|
dput(dentry);
|
|
}
|
|
|
|
|
|
/* attaches attribute's configfs_dirent to the dentry corresponding to the
|
|
* attribute file
|
|
*/
|
|
static int configfs_attach_attr(struct configfs_dirent * sd, struct dentry * dentry)
|
|
{
|
|
struct configfs_attribute * attr = sd->s_element;
|
|
int error;
|
|
|
|
error = configfs_create(dentry, (attr->ca_mode & S_IALLUGO) | S_IFREG, init_file);
|
|
if (error)
|
|
return error;
|
|
|
|
dentry->d_op = &configfs_dentry_ops;
|
|
dentry->d_fsdata = configfs_get(sd);
|
|
sd->s_dentry = dentry;
|
|
d_rehash(dentry);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static struct dentry * configfs_lookup(struct inode *dir,
|
|
struct dentry *dentry,
|
|
struct nameidata *nd)
|
|
{
|
|
struct configfs_dirent * parent_sd = dentry->d_parent->d_fsdata;
|
|
struct configfs_dirent * sd;
|
|
int found = 0;
|
|
int err = 0;
|
|
|
|
list_for_each_entry(sd, &parent_sd->s_children, s_sibling) {
|
|
if (sd->s_type & CONFIGFS_NOT_PINNED) {
|
|
const unsigned char * name = configfs_get_name(sd);
|
|
|
|
if (strcmp(name, dentry->d_name.name))
|
|
continue;
|
|
|
|
found = 1;
|
|
err = configfs_attach_attr(sd, dentry);
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (!found) {
|
|
/*
|
|
* If it doesn't exist and it isn't a NOT_PINNED item,
|
|
* it must be negative.
|
|
*/
|
|
return simple_lookup(dir, dentry, nd);
|
|
}
|
|
|
|
return ERR_PTR(err);
|
|
}
|
|
|
|
/*
|
|
* Only subdirectories count here. Files (CONFIGFS_NOT_PINNED) are
|
|
* attributes and are removed by rmdir(). We recurse, taking i_sem
|
|
* on all children that are candidates for default detach. If the
|
|
* result is clean, then configfs_detach_group() will handle dropping
|
|
* i_sem. If there is an error, the caller will clean up the i_sem
|
|
* holders via configfs_detach_rollback().
|
|
*/
|
|
static int configfs_detach_prep(struct dentry *dentry)
|
|
{
|
|
struct configfs_dirent *parent_sd = dentry->d_fsdata;
|
|
struct configfs_dirent *sd;
|
|
int ret;
|
|
|
|
ret = -EBUSY;
|
|
if (!list_empty(&parent_sd->s_links))
|
|
goto out;
|
|
|
|
ret = 0;
|
|
list_for_each_entry(sd, &parent_sd->s_children, s_sibling) {
|
|
if (sd->s_type & CONFIGFS_NOT_PINNED)
|
|
continue;
|
|
if (sd->s_type & CONFIGFS_USET_DEFAULT) {
|
|
down(&sd->s_dentry->d_inode->i_sem);
|
|
/* Mark that we've taken i_sem */
|
|
sd->s_type |= CONFIGFS_USET_DROPPING;
|
|
|
|
ret = configfs_detach_prep(sd->s_dentry);
|
|
if (!ret)
|
|
continue;
|
|
} else
|
|
ret = -ENOTEMPTY;
|
|
|
|
break;
|
|
}
|
|
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Walk the tree, dropping i_sem wherever CONFIGFS_USET_DROPPING is
|
|
* set.
|
|
*/
|
|
static void configfs_detach_rollback(struct dentry *dentry)
|
|
{
|
|
struct configfs_dirent *parent_sd = dentry->d_fsdata;
|
|
struct configfs_dirent *sd;
|
|
|
|
list_for_each_entry(sd, &parent_sd->s_children, s_sibling) {
|
|
if (sd->s_type & CONFIGFS_USET_DEFAULT) {
|
|
configfs_detach_rollback(sd->s_dentry);
|
|
|
|
if (sd->s_type & CONFIGFS_USET_DROPPING) {
|
|
sd->s_type &= ~CONFIGFS_USET_DROPPING;
|
|
up(&sd->s_dentry->d_inode->i_sem);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
static void detach_attrs(struct config_item * item)
|
|
{
|
|
struct dentry * dentry = dget(item->ci_dentry);
|
|
struct configfs_dirent * parent_sd;
|
|
struct configfs_dirent * sd, * tmp;
|
|
|
|
if (!dentry)
|
|
return;
|
|
|
|
pr_debug("configfs %s: dropping attrs for dir\n",
|
|
dentry->d_name.name);
|
|
|
|
parent_sd = dentry->d_fsdata;
|
|
list_for_each_entry_safe(sd, tmp, &parent_sd->s_children, s_sibling) {
|
|
if (!sd->s_element || !(sd->s_type & CONFIGFS_NOT_PINNED))
|
|
continue;
|
|
list_del_init(&sd->s_sibling);
|
|
configfs_drop_dentry(sd, dentry);
|
|
configfs_put(sd);
|
|
}
|
|
|
|
/**
|
|
* Drop reference from dget() on entrance.
|
|
*/
|
|
dput(dentry);
|
|
}
|
|
|
|
static int populate_attrs(struct config_item *item)
|
|
{
|
|
struct config_item_type *t = item->ci_type;
|
|
struct configfs_attribute *attr;
|
|
int error = 0;
|
|
int i;
|
|
|
|
if (!t)
|
|
return -EINVAL;
|
|
if (t->ct_attrs) {
|
|
for (i = 0; (attr = t->ct_attrs[i]) != NULL; i++) {
|
|
if ((error = configfs_create_file(item, attr)))
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (error)
|
|
detach_attrs(item);
|
|
|
|
return error;
|
|
}
|
|
|
|
static int configfs_attach_group(struct config_item *parent_item,
|
|
struct config_item *item,
|
|
struct dentry *dentry);
|
|
static void configfs_detach_group(struct config_item *item);
|
|
|
|
static void detach_groups(struct config_group *group)
|
|
{
|
|
struct dentry * dentry = dget(group->cg_item.ci_dentry);
|
|
struct dentry *child;
|
|
struct configfs_dirent *parent_sd;
|
|
struct configfs_dirent *sd, *tmp;
|
|
|
|
if (!dentry)
|
|
return;
|
|
|
|
parent_sd = dentry->d_fsdata;
|
|
list_for_each_entry_safe(sd, tmp, &parent_sd->s_children, s_sibling) {
|
|
if (!sd->s_element ||
|
|
!(sd->s_type & CONFIGFS_USET_DEFAULT))
|
|
continue;
|
|
|
|
child = sd->s_dentry;
|
|
|
|
configfs_detach_group(sd->s_element);
|
|
child->d_inode->i_flags |= S_DEAD;
|
|
|
|
/*
|
|
* From rmdir/unregister, a configfs_detach_prep() pass
|
|
* has taken our i_sem for us. Drop it.
|
|
* From mkdir/register cleanup, there is no sem held.
|
|
*/
|
|
if (sd->s_type & CONFIGFS_USET_DROPPING)
|
|
up(&child->d_inode->i_sem);
|
|
|
|
d_delete(child);
|
|
dput(child);
|
|
}
|
|
|
|
/**
|
|
* Drop reference from dget() on entrance.
|
|
*/
|
|
dput(dentry);
|
|
}
|
|
|
|
/*
|
|
* This fakes mkdir(2) on a default_groups[] entry. It
|
|
* creates a dentry, attachs it, and then does fixup
|
|
* on the sd->s_type.
|
|
*
|
|
* We could, perhaps, tweak our parent's ->mkdir for a minute and
|
|
* try using vfs_mkdir. Just a thought.
|
|
*/
|
|
static int create_default_group(struct config_group *parent_group,
|
|
struct config_group *group)
|
|
{
|
|
int ret;
|
|
struct qstr name;
|
|
struct configfs_dirent *sd;
|
|
/* We trust the caller holds a reference to parent */
|
|
struct dentry *child, *parent = parent_group->cg_item.ci_dentry;
|
|
|
|
if (!group->cg_item.ci_name)
|
|
group->cg_item.ci_name = group->cg_item.ci_namebuf;
|
|
name.name = group->cg_item.ci_name;
|
|
name.len = strlen(name.name);
|
|
name.hash = full_name_hash(name.name, name.len);
|
|
|
|
ret = -ENOMEM;
|
|
child = d_alloc(parent, &name);
|
|
if (child) {
|
|
d_add(child, NULL);
|
|
|
|
ret = configfs_attach_group(&parent_group->cg_item,
|
|
&group->cg_item, child);
|
|
if (!ret) {
|
|
sd = child->d_fsdata;
|
|
sd->s_type |= CONFIGFS_USET_DEFAULT;
|
|
} else {
|
|
d_delete(child);
|
|
dput(child);
|
|
}
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int populate_groups(struct config_group *group)
|
|
{
|
|
struct config_group *new_group;
|
|
struct dentry *dentry = group->cg_item.ci_dentry;
|
|
int ret = 0;
|
|
int i;
|
|
|
|
if (group && group->default_groups) {
|
|
/* FYI, we're faking mkdir here
|
|
* I'm not sure we need this semaphore, as we're called
|
|
* from our parent's mkdir. That holds our parent's
|
|
* i_sem, so afaik lookup cannot continue through our
|
|
* parent to find us, let alone mess with our tree.
|
|
* That said, taking our i_sem is closer to mkdir
|
|
* emulation, and shouldn't hurt. */
|
|
down(&dentry->d_inode->i_sem);
|
|
|
|
for (i = 0; group->default_groups[i]; i++) {
|
|
new_group = group->default_groups[i];
|
|
|
|
ret = create_default_group(group, new_group);
|
|
if (ret)
|
|
break;
|
|
}
|
|
|
|
up(&dentry->d_inode->i_sem);
|
|
}
|
|
|
|
if (ret)
|
|
detach_groups(group);
|
|
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* All of link_obj/unlink_obj/link_group/unlink_group require that
|
|
* subsys->su_sem is held.
|
|
*/
|
|
|
|
static void unlink_obj(struct config_item *item)
|
|
{
|
|
struct config_group *group;
|
|
|
|
group = item->ci_group;
|
|
if (group) {
|
|
list_del_init(&item->ci_entry);
|
|
|
|
item->ci_group = NULL;
|
|
item->ci_parent = NULL;
|
|
config_item_put(item);
|
|
|
|
config_group_put(group);
|
|
}
|
|
}
|
|
|
|
static void link_obj(struct config_item *parent_item, struct config_item *item)
|
|
{
|
|
/* Parent seems redundant with group, but it makes certain
|
|
* traversals much nicer. */
|
|
item->ci_parent = parent_item;
|
|
item->ci_group = config_group_get(to_config_group(parent_item));
|
|
list_add_tail(&item->ci_entry, &item->ci_group->cg_children);
|
|
|
|
config_item_get(item);
|
|
}
|
|
|
|
static void unlink_group(struct config_group *group)
|
|
{
|
|
int i;
|
|
struct config_group *new_group;
|
|
|
|
if (group->default_groups) {
|
|
for (i = 0; group->default_groups[i]; i++) {
|
|
new_group = group->default_groups[i];
|
|
unlink_group(new_group);
|
|
}
|
|
}
|
|
|
|
group->cg_subsys = NULL;
|
|
unlink_obj(&group->cg_item);
|
|
}
|
|
|
|
static void link_group(struct config_group *parent_group, struct config_group *group)
|
|
{
|
|
int i;
|
|
struct config_group *new_group;
|
|
struct configfs_subsystem *subsys = NULL; /* gcc is a turd */
|
|
|
|
link_obj(&parent_group->cg_item, &group->cg_item);
|
|
|
|
if (parent_group->cg_subsys)
|
|
subsys = parent_group->cg_subsys;
|
|
else if (configfs_is_root(&parent_group->cg_item))
|
|
subsys = to_configfs_subsystem(group);
|
|
else
|
|
BUG();
|
|
group->cg_subsys = subsys;
|
|
|
|
if (group->default_groups) {
|
|
for (i = 0; group->default_groups[i]; i++) {
|
|
new_group = group->default_groups[i];
|
|
link_group(group, new_group);
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* The goal is that configfs_attach_item() (and
|
|
* configfs_attach_group()) can be called from either the VFS or this
|
|
* module. That is, they assume that the items have been created,
|
|
* the dentry allocated, and the dcache is all ready to go.
|
|
*
|
|
* If they fail, they must clean up after themselves as if they
|
|
* had never been called. The caller (VFS or local function) will
|
|
* handle cleaning up the dcache bits.
|
|
*
|
|
* configfs_detach_group() and configfs_detach_item() behave similarly on
|
|
* the way out. They assume that the proper semaphores are held, they
|
|
* clean up the configfs items, and they expect their callers will
|
|
* handle the dcache bits.
|
|
*/
|
|
static int configfs_attach_item(struct config_item *parent_item,
|
|
struct config_item *item,
|
|
struct dentry *dentry)
|
|
{
|
|
int ret;
|
|
|
|
ret = configfs_create_dir(item, dentry);
|
|
if (!ret) {
|
|
ret = populate_attrs(item);
|
|
if (ret) {
|
|
configfs_remove_dir(item);
|
|
d_delete(dentry);
|
|
}
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void configfs_detach_item(struct config_item *item)
|
|
{
|
|
detach_attrs(item);
|
|
configfs_remove_dir(item);
|
|
}
|
|
|
|
static int configfs_attach_group(struct config_item *parent_item,
|
|
struct config_item *item,
|
|
struct dentry *dentry)
|
|
{
|
|
int ret;
|
|
struct configfs_dirent *sd;
|
|
|
|
ret = configfs_attach_item(parent_item, item, dentry);
|
|
if (!ret) {
|
|
sd = dentry->d_fsdata;
|
|
sd->s_type |= CONFIGFS_USET_DIR;
|
|
|
|
ret = populate_groups(to_config_group(item));
|
|
if (ret) {
|
|
configfs_detach_item(item);
|
|
d_delete(dentry);
|
|
}
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void configfs_detach_group(struct config_item *item)
|
|
{
|
|
detach_groups(to_config_group(item));
|
|
configfs_detach_item(item);
|
|
}
|
|
|
|
/*
|
|
* Drop the initial reference from make_item()/make_group()
|
|
* This function assumes that reference is held on item
|
|
* and that item holds a valid reference to the parent. Also, it
|
|
* assumes the caller has validated ci_type.
|
|
*/
|
|
static void client_drop_item(struct config_item *parent_item,
|
|
struct config_item *item)
|
|
{
|
|
struct config_item_type *type;
|
|
|
|
type = parent_item->ci_type;
|
|
BUG_ON(!type);
|
|
|
|
if (type->ct_group_ops && type->ct_group_ops->drop_item)
|
|
type->ct_group_ops->drop_item(to_config_group(parent_item),
|
|
item);
|
|
else
|
|
config_item_put(item);
|
|
}
|
|
|
|
|
|
static int configfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
|
|
{
|
|
int ret;
|
|
struct config_group *group;
|
|
struct config_item *item;
|
|
struct config_item *parent_item;
|
|
struct configfs_subsystem *subsys;
|
|
struct configfs_dirent *sd;
|
|
struct config_item_type *type;
|
|
struct module *owner;
|
|
char *name;
|
|
|
|
if (dentry->d_parent == configfs_sb->s_root)
|
|
return -EPERM;
|
|
|
|
sd = dentry->d_parent->d_fsdata;
|
|
if (!(sd->s_type & CONFIGFS_USET_DIR))
|
|
return -EPERM;
|
|
|
|
parent_item = configfs_get_config_item(dentry->d_parent);
|
|
type = parent_item->ci_type;
|
|
subsys = to_config_group(parent_item)->cg_subsys;
|
|
BUG_ON(!subsys);
|
|
|
|
if (!type || !type->ct_group_ops ||
|
|
(!type->ct_group_ops->make_group &&
|
|
!type->ct_group_ops->make_item)) {
|
|
config_item_put(parent_item);
|
|
return -EPERM; /* What lack-of-mkdir returns */
|
|
}
|
|
|
|
name = kmalloc(dentry->d_name.len + 1, GFP_KERNEL);
|
|
if (!name) {
|
|
config_item_put(parent_item);
|
|
return -ENOMEM;
|
|
}
|
|
snprintf(name, dentry->d_name.len + 1, "%s", dentry->d_name.name);
|
|
|
|
down(&subsys->su_sem);
|
|
group = NULL;
|
|
item = NULL;
|
|
if (type->ct_group_ops->make_group) {
|
|
group = type->ct_group_ops->make_group(to_config_group(parent_item), name);
|
|
if (group) {
|
|
link_group(to_config_group(parent_item), group);
|
|
item = &group->cg_item;
|
|
}
|
|
} else {
|
|
item = type->ct_group_ops->make_item(to_config_group(parent_item), name);
|
|
if (item)
|
|
link_obj(parent_item, item);
|
|
}
|
|
up(&subsys->su_sem);
|
|
|
|
kfree(name);
|
|
if (!item) {
|
|
config_item_put(parent_item);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
ret = -EINVAL;
|
|
type = item->ci_type;
|
|
if (type) {
|
|
owner = type->ct_owner;
|
|
if (try_module_get(owner)) {
|
|
if (group) {
|
|
ret = configfs_attach_group(parent_item,
|
|
item,
|
|
dentry);
|
|
} else {
|
|
ret = configfs_attach_item(parent_item,
|
|
item,
|
|
dentry);
|
|
}
|
|
|
|
if (ret) {
|
|
down(&subsys->su_sem);
|
|
if (group)
|
|
unlink_group(group);
|
|
else
|
|
unlink_obj(item);
|
|
client_drop_item(parent_item, item);
|
|
up(&subsys->su_sem);
|
|
|
|
config_item_put(parent_item);
|
|
module_put(owner);
|
|
}
|
|
}
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int configfs_rmdir(struct inode *dir, struct dentry *dentry)
|
|
{
|
|
struct config_item *parent_item;
|
|
struct config_item *item;
|
|
struct configfs_subsystem *subsys;
|
|
struct configfs_dirent *sd;
|
|
struct module *owner = NULL;
|
|
int ret;
|
|
|
|
if (dentry->d_parent == configfs_sb->s_root)
|
|
return -EPERM;
|
|
|
|
sd = dentry->d_fsdata;
|
|
if (sd->s_type & CONFIGFS_USET_DEFAULT)
|
|
return -EPERM;
|
|
|
|
parent_item = configfs_get_config_item(dentry->d_parent);
|
|
subsys = to_config_group(parent_item)->cg_subsys;
|
|
BUG_ON(!subsys);
|
|
|
|
if (!parent_item->ci_type) {
|
|
config_item_put(parent_item);
|
|
return -EINVAL;
|
|
}
|
|
|
|
ret = configfs_detach_prep(dentry);
|
|
if (ret) {
|
|
configfs_detach_rollback(dentry);
|
|
config_item_put(parent_item);
|
|
return ret;
|
|
}
|
|
|
|
item = configfs_get_config_item(dentry);
|
|
|
|
/* Drop reference from above, item already holds one. */
|
|
config_item_put(parent_item);
|
|
|
|
if (item->ci_type)
|
|
owner = item->ci_type->ct_owner;
|
|
|
|
if (sd->s_type & CONFIGFS_USET_DIR) {
|
|
configfs_detach_group(item);
|
|
|
|
down(&subsys->su_sem);
|
|
unlink_group(to_config_group(item));
|
|
} else {
|
|
configfs_detach_item(item);
|
|
|
|
down(&subsys->su_sem);
|
|
unlink_obj(item);
|
|
}
|
|
|
|
client_drop_item(parent_item, item);
|
|
up(&subsys->su_sem);
|
|
|
|
/* Drop our reference from above */
|
|
config_item_put(item);
|
|
|
|
module_put(owner);
|
|
|
|
return 0;
|
|
}
|
|
|
|
struct inode_operations configfs_dir_inode_operations = {
|
|
.mkdir = configfs_mkdir,
|
|
.rmdir = configfs_rmdir,
|
|
.symlink = configfs_symlink,
|
|
.unlink = configfs_unlink,
|
|
.lookup = configfs_lookup,
|
|
};
|
|
|
|
#if 0
|
|
int configfs_rename_dir(struct config_item * item, const char *new_name)
|
|
{
|
|
int error = 0;
|
|
struct dentry * new_dentry, * parent;
|
|
|
|
if (!strcmp(config_item_name(item), new_name))
|
|
return -EINVAL;
|
|
|
|
if (!item->parent)
|
|
return -EINVAL;
|
|
|
|
down_write(&configfs_rename_sem);
|
|
parent = item->parent->dentry;
|
|
|
|
down(&parent->d_inode->i_sem);
|
|
|
|
new_dentry = lookup_one_len(new_name, parent, strlen(new_name));
|
|
if (!IS_ERR(new_dentry)) {
|
|
if (!new_dentry->d_inode) {
|
|
error = config_item_set_name(item, "%s", new_name);
|
|
if (!error) {
|
|
d_add(new_dentry, NULL);
|
|
d_move(item->dentry, new_dentry);
|
|
}
|
|
else
|
|
d_delete(new_dentry);
|
|
} else
|
|
error = -EEXIST;
|
|
dput(new_dentry);
|
|
}
|
|
up(&parent->d_inode->i_sem);
|
|
up_write(&configfs_rename_sem);
|
|
|
|
return error;
|
|
}
|
|
#endif
|
|
|
|
static int configfs_dir_open(struct inode *inode, struct file *file)
|
|
{
|
|
struct dentry * dentry = file->f_dentry;
|
|
struct configfs_dirent * parent_sd = dentry->d_fsdata;
|
|
|
|
down(&dentry->d_inode->i_sem);
|
|
file->private_data = configfs_new_dirent(parent_sd, NULL);
|
|
up(&dentry->d_inode->i_sem);
|
|
|
|
return file->private_data ? 0 : -ENOMEM;
|
|
|
|
}
|
|
|
|
static int configfs_dir_close(struct inode *inode, struct file *file)
|
|
{
|
|
struct dentry * dentry = file->f_dentry;
|
|
struct configfs_dirent * cursor = file->private_data;
|
|
|
|
down(&dentry->d_inode->i_sem);
|
|
list_del_init(&cursor->s_sibling);
|
|
up(&dentry->d_inode->i_sem);
|
|
|
|
release_configfs_dirent(cursor);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* Relationship between s_mode and the DT_xxx types */
|
|
static inline unsigned char dt_type(struct configfs_dirent *sd)
|
|
{
|
|
return (sd->s_mode >> 12) & 15;
|
|
}
|
|
|
|
static int configfs_readdir(struct file * filp, void * dirent, filldir_t filldir)
|
|
{
|
|
struct dentry *dentry = filp->f_dentry;
|
|
struct configfs_dirent * parent_sd = dentry->d_fsdata;
|
|
struct configfs_dirent *cursor = filp->private_data;
|
|
struct list_head *p, *q = &cursor->s_sibling;
|
|
ino_t ino;
|
|
int i = filp->f_pos;
|
|
|
|
switch (i) {
|
|
case 0:
|
|
ino = dentry->d_inode->i_ino;
|
|
if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0)
|
|
break;
|
|
filp->f_pos++;
|
|
i++;
|
|
/* fallthrough */
|
|
case 1:
|
|
ino = parent_ino(dentry);
|
|
if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0)
|
|
break;
|
|
filp->f_pos++;
|
|
i++;
|
|
/* fallthrough */
|
|
default:
|
|
if (filp->f_pos == 2) {
|
|
list_del(q);
|
|
list_add(q, &parent_sd->s_children);
|
|
}
|
|
for (p=q->next; p!= &parent_sd->s_children; p=p->next) {
|
|
struct configfs_dirent *next;
|
|
const char * name;
|
|
int len;
|
|
|
|
next = list_entry(p, struct configfs_dirent,
|
|
s_sibling);
|
|
if (!next->s_element)
|
|
continue;
|
|
|
|
name = configfs_get_name(next);
|
|
len = strlen(name);
|
|
if (next->s_dentry)
|
|
ino = next->s_dentry->d_inode->i_ino;
|
|
else
|
|
ino = iunique(configfs_sb, 2);
|
|
|
|
if (filldir(dirent, name, len, filp->f_pos, ino,
|
|
dt_type(next)) < 0)
|
|
return 0;
|
|
|
|
list_del(q);
|
|
list_add(q, p);
|
|
p = q;
|
|
filp->f_pos++;
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static loff_t configfs_dir_lseek(struct file * file, loff_t offset, int origin)
|
|
{
|
|
struct dentry * dentry = file->f_dentry;
|
|
|
|
down(&dentry->d_inode->i_sem);
|
|
switch (origin) {
|
|
case 1:
|
|
offset += file->f_pos;
|
|
case 0:
|
|
if (offset >= 0)
|
|
break;
|
|
default:
|
|
up(&file->f_dentry->d_inode->i_sem);
|
|
return -EINVAL;
|
|
}
|
|
if (offset != file->f_pos) {
|
|
file->f_pos = offset;
|
|
if (file->f_pos >= 2) {
|
|
struct configfs_dirent *sd = dentry->d_fsdata;
|
|
struct configfs_dirent *cursor = file->private_data;
|
|
struct list_head *p;
|
|
loff_t n = file->f_pos - 2;
|
|
|
|
list_del(&cursor->s_sibling);
|
|
p = sd->s_children.next;
|
|
while (n && p != &sd->s_children) {
|
|
struct configfs_dirent *next;
|
|
next = list_entry(p, struct configfs_dirent,
|
|
s_sibling);
|
|
if (next->s_element)
|
|
n--;
|
|
p = p->next;
|
|
}
|
|
list_add_tail(&cursor->s_sibling, p);
|
|
}
|
|
}
|
|
up(&dentry->d_inode->i_sem);
|
|
return offset;
|
|
}
|
|
|
|
struct file_operations configfs_dir_operations = {
|
|
.open = configfs_dir_open,
|
|
.release = configfs_dir_close,
|
|
.llseek = configfs_dir_lseek,
|
|
.read = generic_read_dir,
|
|
.readdir = configfs_readdir,
|
|
};
|
|
|
|
int configfs_register_subsystem(struct configfs_subsystem *subsys)
|
|
{
|
|
int err;
|
|
struct config_group *group = &subsys->su_group;
|
|
struct qstr name;
|
|
struct dentry *dentry;
|
|
struct configfs_dirent *sd;
|
|
|
|
err = configfs_pin_fs();
|
|
if (err)
|
|
return err;
|
|
|
|
if (!group->cg_item.ci_name)
|
|
group->cg_item.ci_name = group->cg_item.ci_namebuf;
|
|
|
|
sd = configfs_sb->s_root->d_fsdata;
|
|
link_group(to_config_group(sd->s_element), group);
|
|
|
|
down(&configfs_sb->s_root->d_inode->i_sem);
|
|
|
|
name.name = group->cg_item.ci_name;
|
|
name.len = strlen(name.name);
|
|
name.hash = full_name_hash(name.name, name.len);
|
|
|
|
err = -ENOMEM;
|
|
dentry = d_alloc(configfs_sb->s_root, &name);
|
|
if (!dentry)
|
|
goto out_release;
|
|
|
|
d_add(dentry, NULL);
|
|
|
|
err = configfs_attach_group(sd->s_element, &group->cg_item,
|
|
dentry);
|
|
if (!err)
|
|
dentry = NULL;
|
|
else
|
|
d_delete(dentry);
|
|
|
|
up(&configfs_sb->s_root->d_inode->i_sem);
|
|
|
|
if (dentry) {
|
|
dput(dentry);
|
|
out_release:
|
|
unlink_group(group);
|
|
configfs_release_fs();
|
|
}
|
|
|
|
return err;
|
|
}
|
|
|
|
void configfs_unregister_subsystem(struct configfs_subsystem *subsys)
|
|
{
|
|
struct config_group *group = &subsys->su_group;
|
|
struct dentry *dentry = group->cg_item.ci_dentry;
|
|
|
|
if (dentry->d_parent != configfs_sb->s_root) {
|
|
printk(KERN_ERR "configfs: Tried to unregister non-subsystem!\n");
|
|
return;
|
|
}
|
|
|
|
down(&configfs_sb->s_root->d_inode->i_sem);
|
|
down(&dentry->d_inode->i_sem);
|
|
if (configfs_detach_prep(dentry)) {
|
|
printk(KERN_ERR "configfs: Tried to unregister non-empty subsystem!\n");
|
|
}
|
|
configfs_detach_group(&group->cg_item);
|
|
dentry->d_inode->i_flags |= S_DEAD;
|
|
up(&dentry->d_inode->i_sem);
|
|
|
|
d_delete(dentry);
|
|
|
|
up(&configfs_sb->s_root->d_inode->i_sem);
|
|
|
|
dput(dentry);
|
|
|
|
unlink_group(group);
|
|
configfs_release_fs();
|
|
}
|
|
|
|
EXPORT_SYMBOL(configfs_register_subsystem);
|
|
EXPORT_SYMBOL(configfs_unregister_subsystem);
|