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(I'm so sorry!) Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel os linux
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123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104// 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 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 = kernfs_get_tree,};
static int sysfs_init_fs_context(struct fs_context *fc){ struct kernfs_fs_context *kfc; struct ns_common *ns;
if (!(fc->sb_flags & SB_KERNMOUNT)) { if (!kobj_ns_current_may_mount(KOBJ_NS_TYPE_NET)) return -EPERM; }
kfc = kzalloc_obj(struct kernfs_fs_context); if (!kfc) return -ENOMEM;
kfc->ns_tag = ns = 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 (ns) { struct net *netns = to_net_ns(ns);
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){ struct ns_common *ns = (struct ns_common *)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 | FS_USERNS_MOUNT_RESTRICTED,};
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 = kernfs_root_to_node(sysfs_root);
err = register_filesystem(&sysfs_fs_type); if (err) { kernfs_destroy_root(sysfs_root); return err; }
return 0;}