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linux-next/fs/sysfs/symlink.c
Tejun Heo df23fc39bc kernfs: s/sysfs/kernfs/ in constants
kernfs has just been separated out from sysfs and we're already in
full conflict mode.  Nothing can make the situation any worse.  Let's
take the chance to name things properly.

This patch performs the following renames.

* s/SYSFS_DIR/KERNFS_DIR/
* s/SYSFS_KOBJ_ATTR/KERNFS_FILE/
* s/SYSFS_KOBJ_LINK/KERNFS_LINK/
* s/SYSFS_{TYPE_FLAGS}/KERNFS_{TYPE_FLAGS}/
* s/SYSFS_FLAG_{FLAG}/KERNFS_{FLAG}/
* s/sysfs_type()/kernfs_type()/
* s/SD_DEACTIVATED_BIAS/KN_DEACTIVATED_BIAS/

This patch is strictly rename only and doesn't introduce any
functional difference.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-11 17:39:20 -08:00

198 lines
4.8 KiB
C

/*
* 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>
*
* This file is released under the GPLv2.
*
* Please see Documentation/filesystems/sysfs.txt 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;
BUG_ON(!name || !parent);
/*
* 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);
}
/**
* 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);