mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-11-24 20:54:10 +08:00
0c1bc6b845
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>
116 lines
2.5 KiB
C
116 lines
2.5 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* fs/sysfs/symlink.c - operations for initializing and mounting sysfs
|
|
*
|
|
* 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/magic.h>
|
|
#include <linux/mount.h>
|
|
#include <linux/init.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/user_namespace.h>
|
|
#include <linux/fs_context.h>
|
|
#include <net/net_namespace.h>
|
|
|
|
#include "sysfs.h"
|
|
|
|
static struct kernfs_root *sysfs_root;
|
|
struct kernfs_node *sysfs_root_kn;
|
|
|
|
static int sysfs_get_tree(struct fs_context *fc)
|
|
{
|
|
struct kernfs_fs_context *kfc = fc->fs_private;
|
|
int ret;
|
|
|
|
ret = kernfs_get_tree(fc);
|
|
if (ret)
|
|
return ret;
|
|
|
|
if (kfc->new_sb_created)
|
|
fc->root->d_sb->s_iflags |= SB_I_USERNS_VISIBLE;
|
|
return 0;
|
|
}
|
|
|
|
static void sysfs_fs_context_free(struct fs_context *fc)
|
|
{
|
|
struct kernfs_fs_context *kfc = fc->fs_private;
|
|
|
|
if (kfc->ns_tag)
|
|
kobj_ns_drop(KOBJ_NS_TYPE_NET, kfc->ns_tag);
|
|
kernfs_free_fs_context(fc);
|
|
kfree(kfc);
|
|
}
|
|
|
|
static const struct fs_context_operations sysfs_fs_context_ops = {
|
|
.free = sysfs_fs_context_free,
|
|
.get_tree = sysfs_get_tree,
|
|
};
|
|
|
|
static int sysfs_init_fs_context(struct fs_context *fc)
|
|
{
|
|
struct kernfs_fs_context *kfc;
|
|
struct net *netns;
|
|
|
|
if (!(fc->sb_flags & SB_KERNMOUNT)) {
|
|
if (!kobj_ns_current_may_mount(KOBJ_NS_TYPE_NET))
|
|
return -EPERM;
|
|
}
|
|
|
|
kfc = kzalloc(sizeof(struct kernfs_fs_context), GFP_KERNEL);
|
|
if (!kfc)
|
|
return -ENOMEM;
|
|
|
|
kfc->ns_tag = netns = kobj_ns_grab_current(KOBJ_NS_TYPE_NET);
|
|
kfc->root = sysfs_root;
|
|
kfc->magic = SYSFS_MAGIC;
|
|
fc->fs_private = kfc;
|
|
fc->ops = &sysfs_fs_context_ops;
|
|
if (netns) {
|
|
put_user_ns(fc->user_ns);
|
|
fc->user_ns = get_user_ns(netns->user_ns);
|
|
}
|
|
fc->global = true;
|
|
return 0;
|
|
}
|
|
|
|
static void sysfs_kill_sb(struct super_block *sb)
|
|
{
|
|
void *ns = (void *)kernfs_super_ns(sb);
|
|
|
|
kernfs_kill_sb(sb);
|
|
kobj_ns_drop(KOBJ_NS_TYPE_NET, ns);
|
|
}
|
|
|
|
static struct file_system_type sysfs_fs_type = {
|
|
.name = "sysfs",
|
|
.init_fs_context = sysfs_init_fs_context,
|
|
.kill_sb = sysfs_kill_sb,
|
|
.fs_flags = FS_USERNS_MOUNT,
|
|
};
|
|
|
|
int __init sysfs_init(void)
|
|
{
|
|
int err;
|
|
|
|
sysfs_root = kernfs_create_root(NULL, KERNFS_ROOT_EXTRA_OPEN_PERM_CHECK,
|
|
NULL);
|
|
if (IS_ERR(sysfs_root))
|
|
return PTR_ERR(sysfs_root);
|
|
|
|
sysfs_root_kn = sysfs_root->kn;
|
|
|
|
err = register_filesystem(&sysfs_fs_type);
|
|
if (err) {
|
|
kernfs_destroy_root(sysfs_root);
|
|
return err;
|
|
}
|
|
|
|
return 0;
|
|
}
|