mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-23 01:10:04 +00:00
![Mauro Carvalho Chehab](/assets/img/avatar_default.png)
Some filesystem references got broken by a previous patch series I submitted. Address those. Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Acked-by: David Sterba <dsterba@suse.com> # fs/affs/Kconfig Link: https://lore.kernel.org/r/57318c53008dbda7f6f4a5a9e5787f4d37e8565a.1586881715.git.mchehab+huawei@kernel.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
198 lines
4.8 KiB
C
198 lines
4.8 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* fs/sysfs/symlink.c - sysfs symlink implementation
|
|
*
|
|
* Copyright (c) 2001-3 Patrick Mochel
|
|
* Copyright (c) 2007 SUSE Linux Products GmbH
|
|
* Copyright (c) 2007 Tejun Heo <teheo@suse.de>
|
|
*
|
|
* Please see Documentation/filesystems/sysfs.rst for more information.
|
|
*/
|
|
|
|
#include <linux/fs.h>
|
|
#include <linux/module.h>
|
|
#include <linux/kobject.h>
|
|
#include <linux/mutex.h>
|
|
#include <linux/security.h>
|
|
|
|
#include "sysfs.h"
|
|
|
|
static int sysfs_do_create_link_sd(struct kernfs_node *parent,
|
|
struct kobject *target_kobj,
|
|
const char *name, int warn)
|
|
{
|
|
struct kernfs_node *kn, *target = NULL;
|
|
|
|
if (WARN_ON(!name || !parent))
|
|
return -EINVAL;
|
|
|
|
/*
|
|
* We don't own @target_kobj and it may be removed at any time.
|
|
* Synchronize using sysfs_symlink_target_lock. See
|
|
* sysfs_remove_dir() for details.
|
|
*/
|
|
spin_lock(&sysfs_symlink_target_lock);
|
|
if (target_kobj->sd) {
|
|
target = target_kobj->sd;
|
|
kernfs_get(target);
|
|
}
|
|
spin_unlock(&sysfs_symlink_target_lock);
|
|
|
|
if (!target)
|
|
return -ENOENT;
|
|
|
|
kn = kernfs_create_link(parent, name, target);
|
|
kernfs_put(target);
|
|
|
|
if (!IS_ERR(kn))
|
|
return 0;
|
|
|
|
if (warn && PTR_ERR(kn) == -EEXIST)
|
|
sysfs_warn_dup(parent, name);
|
|
return PTR_ERR(kn);
|
|
}
|
|
|
|
/**
|
|
* sysfs_create_link_sd - create symlink to a given object.
|
|
* @kn: directory we're creating the link in.
|
|
* @target: object we're pointing to.
|
|
* @name: name of the symlink.
|
|
*/
|
|
int sysfs_create_link_sd(struct kernfs_node *kn, struct kobject *target,
|
|
const char *name)
|
|
{
|
|
return sysfs_do_create_link_sd(kn, target, name, 1);
|
|
}
|
|
|
|
static int sysfs_do_create_link(struct kobject *kobj, struct kobject *target,
|
|
const char *name, int warn)
|
|
{
|
|
struct kernfs_node *parent = NULL;
|
|
|
|
if (!kobj)
|
|
parent = sysfs_root_kn;
|
|
else
|
|
parent = kobj->sd;
|
|
|
|
if (!parent)
|
|
return -EFAULT;
|
|
|
|
return sysfs_do_create_link_sd(parent, target, name, warn);
|
|
}
|
|
|
|
/**
|
|
* sysfs_create_link - create symlink between two objects.
|
|
* @kobj: object whose directory we're creating the link in.
|
|
* @target: object we're pointing to.
|
|
* @name: name of the symlink.
|
|
*/
|
|
int sysfs_create_link(struct kobject *kobj, struct kobject *target,
|
|
const char *name)
|
|
{
|
|
return sysfs_do_create_link(kobj, target, name, 1);
|
|
}
|
|
EXPORT_SYMBOL_GPL(sysfs_create_link);
|
|
|
|
/**
|
|
* sysfs_create_link_nowarn - create symlink between two objects.
|
|
* @kobj: object whose directory we're creating the link in.
|
|
* @target: object we're pointing to.
|
|
* @name: name of the symlink.
|
|
*
|
|
* This function does the same as sysfs_create_link(), but it
|
|
* doesn't warn if the link already exists.
|
|
*/
|
|
int sysfs_create_link_nowarn(struct kobject *kobj, struct kobject *target,
|
|
const char *name)
|
|
{
|
|
return sysfs_do_create_link(kobj, target, name, 0);
|
|
}
|
|
EXPORT_SYMBOL_GPL(sysfs_create_link_nowarn);
|
|
|
|
/**
|
|
* sysfs_delete_link - remove symlink in object's directory.
|
|
* @kobj: object we're acting for.
|
|
* @targ: object we're pointing to.
|
|
* @name: name of the symlink to remove.
|
|
*
|
|
* Unlike sysfs_remove_link sysfs_delete_link has enough information
|
|
* to successfully delete symlinks in tagged directories.
|
|
*/
|
|
void sysfs_delete_link(struct kobject *kobj, struct kobject *targ,
|
|
const char *name)
|
|
{
|
|
const void *ns = NULL;
|
|
|
|
/*
|
|
* We don't own @target and it may be removed at any time.
|
|
* Synchronize using sysfs_symlink_target_lock. See
|
|
* sysfs_remove_dir() for details.
|
|
*/
|
|
spin_lock(&sysfs_symlink_target_lock);
|
|
if (targ->sd && kernfs_ns_enabled(kobj->sd))
|
|
ns = targ->sd->ns;
|
|
spin_unlock(&sysfs_symlink_target_lock);
|
|
kernfs_remove_by_name_ns(kobj->sd, name, ns);
|
|
}
|
|
|
|
/**
|
|
* sysfs_remove_link - remove symlink in object's directory.
|
|
* @kobj: object we're acting for.
|
|
* @name: name of the symlink to remove.
|
|
*/
|
|
void sysfs_remove_link(struct kobject *kobj, const char *name)
|
|
{
|
|
struct kernfs_node *parent = NULL;
|
|
|
|
if (!kobj)
|
|
parent = sysfs_root_kn;
|
|
else
|
|
parent = kobj->sd;
|
|
|
|
kernfs_remove_by_name(parent, name);
|
|
}
|
|
EXPORT_SYMBOL_GPL(sysfs_remove_link);
|
|
|
|
/**
|
|
* sysfs_rename_link_ns - rename symlink in object's directory.
|
|
* @kobj: object we're acting for.
|
|
* @targ: object we're pointing to.
|
|
* @old: previous name of the symlink.
|
|
* @new: new name of the symlink.
|
|
* @new_ns: new namespace of the symlink.
|
|
*
|
|
* A helper function for the common rename symlink idiom.
|
|
*/
|
|
int sysfs_rename_link_ns(struct kobject *kobj, struct kobject *targ,
|
|
const char *old, const char *new, const void *new_ns)
|
|
{
|
|
struct kernfs_node *parent, *kn = NULL;
|
|
const void *old_ns = NULL;
|
|
int result;
|
|
|
|
if (!kobj)
|
|
parent = sysfs_root_kn;
|
|
else
|
|
parent = kobj->sd;
|
|
|
|
if (targ->sd)
|
|
old_ns = targ->sd->ns;
|
|
|
|
result = -ENOENT;
|
|
kn = kernfs_find_and_get_ns(parent, old, old_ns);
|
|
if (!kn)
|
|
goto out;
|
|
|
|
result = -EINVAL;
|
|
if (kernfs_type(kn) != KERNFS_LINK)
|
|
goto out;
|
|
if (kn->symlink.target_kn->priv != targ)
|
|
goto out;
|
|
|
|
result = kernfs_rename_ns(kn, parent, new, new_ns);
|
|
|
|
out:
|
|
kernfs_put(kn);
|
|
return result;
|
|
}
|
|
EXPORT_SYMBOL_GPL(sysfs_rename_link_ns);
|