![David Howells](/assets/img/avatar_default.png)
Pass mount flags to sget() so that it can use them in initialising a new superblock before the set function is called. They could also be passed to the compare function. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
277 lines
5.6 KiB
C
277 lines
5.6 KiB
C
/*
|
|
* linux/fs/proc/root.c
|
|
*
|
|
* Copyright (C) 1991, 1992 Linus Torvalds
|
|
*
|
|
* proc root directory handling functions
|
|
*/
|
|
|
|
#include <asm/uaccess.h>
|
|
|
|
#include <linux/errno.h>
|
|
#include <linux/time.h>
|
|
#include <linux/proc_fs.h>
|
|
#include <linux/stat.h>
|
|
#include <linux/init.h>
|
|
#include <linux/sched.h>
|
|
#include <linux/module.h>
|
|
#include <linux/bitops.h>
|
|
#include <linux/mount.h>
|
|
#include <linux/pid_namespace.h>
|
|
#include <linux/parser.h>
|
|
|
|
#include "internal.h"
|
|
|
|
static int proc_test_super(struct super_block *sb, void *data)
|
|
{
|
|
return sb->s_fs_info == data;
|
|
}
|
|
|
|
static int proc_set_super(struct super_block *sb, void *data)
|
|
{
|
|
int err = set_anon_super(sb, NULL);
|
|
if (!err) {
|
|
struct pid_namespace *ns = (struct pid_namespace *)data;
|
|
sb->s_fs_info = get_pid_ns(ns);
|
|
}
|
|
return err;
|
|
}
|
|
|
|
enum {
|
|
Opt_gid, Opt_hidepid, Opt_err,
|
|
};
|
|
|
|
static const match_table_t tokens = {
|
|
{Opt_hidepid, "hidepid=%u"},
|
|
{Opt_gid, "gid=%u"},
|
|
{Opt_err, NULL},
|
|
};
|
|
|
|
static int proc_parse_options(char *options, struct pid_namespace *pid)
|
|
{
|
|
char *p;
|
|
substring_t args[MAX_OPT_ARGS];
|
|
int option;
|
|
|
|
if (!options)
|
|
return 1;
|
|
|
|
while ((p = strsep(&options, ",")) != NULL) {
|
|
int token;
|
|
if (!*p)
|
|
continue;
|
|
|
|
args[0].to = args[0].from = 0;
|
|
token = match_token(p, tokens, args);
|
|
switch (token) {
|
|
case Opt_gid:
|
|
if (match_int(&args[0], &option))
|
|
return 0;
|
|
pid->pid_gid = make_kgid(current_user_ns(), option);
|
|
break;
|
|
case Opt_hidepid:
|
|
if (match_int(&args[0], &option))
|
|
return 0;
|
|
if (option < 0 || option > 2) {
|
|
pr_err("proc: hidepid value must be between 0 and 2.\n");
|
|
return 0;
|
|
}
|
|
pid->hide_pid = option;
|
|
break;
|
|
default:
|
|
pr_err("proc: unrecognized mount option \"%s\" "
|
|
"or missing value\n", p);
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
return 1;
|
|
}
|
|
|
|
int proc_remount(struct super_block *sb, int *flags, char *data)
|
|
{
|
|
struct pid_namespace *pid = sb->s_fs_info;
|
|
return !proc_parse_options(data, pid);
|
|
}
|
|
|
|
static struct dentry *proc_mount(struct file_system_type *fs_type,
|
|
int flags, const char *dev_name, void *data)
|
|
{
|
|
int err;
|
|
struct super_block *sb;
|
|
struct pid_namespace *ns;
|
|
struct proc_inode *ei;
|
|
char *options;
|
|
|
|
if (flags & MS_KERNMOUNT) {
|
|
ns = (struct pid_namespace *)data;
|
|
options = NULL;
|
|
} else {
|
|
ns = current->nsproxy->pid_ns;
|
|
options = data;
|
|
}
|
|
|
|
sb = sget(fs_type, proc_test_super, proc_set_super, flags, ns);
|
|
if (IS_ERR(sb))
|
|
return ERR_CAST(sb);
|
|
|
|
if (!proc_parse_options(options, ns)) {
|
|
deactivate_locked_super(sb);
|
|
return ERR_PTR(-EINVAL);
|
|
}
|
|
|
|
if (!sb->s_root) {
|
|
err = proc_fill_super(sb);
|
|
if (err) {
|
|
deactivate_locked_super(sb);
|
|
return ERR_PTR(err);
|
|
}
|
|
|
|
sb->s_flags |= MS_ACTIVE;
|
|
}
|
|
|
|
ei = PROC_I(sb->s_root->d_inode);
|
|
if (!ei->pid) {
|
|
rcu_read_lock();
|
|
ei->pid = get_pid(find_pid_ns(1, ns));
|
|
rcu_read_unlock();
|
|
}
|
|
|
|
return dget(sb->s_root);
|
|
}
|
|
|
|
static void proc_kill_sb(struct super_block *sb)
|
|
{
|
|
struct pid_namespace *ns;
|
|
|
|
ns = (struct pid_namespace *)sb->s_fs_info;
|
|
kill_anon_super(sb);
|
|
put_pid_ns(ns);
|
|
}
|
|
|
|
static struct file_system_type proc_fs_type = {
|
|
.name = "proc",
|
|
.mount = proc_mount,
|
|
.kill_sb = proc_kill_sb,
|
|
};
|
|
|
|
void __init proc_root_init(void)
|
|
{
|
|
int err;
|
|
|
|
proc_init_inodecache();
|
|
err = register_filesystem(&proc_fs_type);
|
|
if (err)
|
|
return;
|
|
err = pid_ns_prepare_proc(&init_pid_ns);
|
|
if (err) {
|
|
unregister_filesystem(&proc_fs_type);
|
|
return;
|
|
}
|
|
|
|
proc_symlink("mounts", NULL, "self/mounts");
|
|
|
|
proc_net_init();
|
|
|
|
#ifdef CONFIG_SYSVIPC
|
|
proc_mkdir("sysvipc", NULL);
|
|
#endif
|
|
proc_mkdir("fs", NULL);
|
|
proc_mkdir("driver", NULL);
|
|
proc_mkdir("fs/nfsd", NULL); /* somewhere for the nfsd filesystem to be mounted */
|
|
#if defined(CONFIG_SUN_OPENPROMFS) || defined(CONFIG_SUN_OPENPROMFS_MODULE)
|
|
/* just give it a mountpoint */
|
|
proc_mkdir("openprom", NULL);
|
|
#endif
|
|
proc_tty_init();
|
|
#ifdef CONFIG_PROC_DEVICETREE
|
|
proc_device_tree_init();
|
|
#endif
|
|
proc_mkdir("bus", NULL);
|
|
proc_sys_init();
|
|
}
|
|
|
|
static int proc_root_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat
|
|
)
|
|
{
|
|
generic_fillattr(dentry->d_inode, stat);
|
|
stat->nlink = proc_root.nlink + nr_processes();
|
|
return 0;
|
|
}
|
|
|
|
static struct dentry *proc_root_lookup(struct inode * dir, struct dentry * dentry, unsigned int flags)
|
|
{
|
|
if (!proc_lookup(dir, dentry, flags))
|
|
return NULL;
|
|
|
|
return proc_pid_lookup(dir, dentry, flags);
|
|
}
|
|
|
|
static int proc_root_readdir(struct file * filp,
|
|
void * dirent, filldir_t filldir)
|
|
{
|
|
unsigned int nr = filp->f_pos;
|
|
int ret;
|
|
|
|
if (nr < FIRST_PROCESS_ENTRY) {
|
|
int error = proc_readdir(filp, dirent, filldir);
|
|
if (error <= 0)
|
|
return error;
|
|
filp->f_pos = FIRST_PROCESS_ENTRY;
|
|
}
|
|
|
|
ret = proc_pid_readdir(filp, dirent, filldir);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* The root /proc directory is special, as it has the
|
|
* <pid> directories. Thus we don't use the generic
|
|
* directory handling functions for that..
|
|
*/
|
|
static const struct file_operations proc_root_operations = {
|
|
.read = generic_read_dir,
|
|
.readdir = proc_root_readdir,
|
|
.llseek = default_llseek,
|
|
};
|
|
|
|
/*
|
|
* proc root can do almost nothing..
|
|
*/
|
|
static const struct inode_operations proc_root_inode_operations = {
|
|
.lookup = proc_root_lookup,
|
|
.getattr = proc_root_getattr,
|
|
};
|
|
|
|
/*
|
|
* This is the root "inode" in the /proc tree..
|
|
*/
|
|
struct proc_dir_entry proc_root = {
|
|
.low_ino = PROC_ROOT_INO,
|
|
.namelen = 5,
|
|
.mode = S_IFDIR | S_IRUGO | S_IXUGO,
|
|
.nlink = 2,
|
|
.count = ATOMIC_INIT(1),
|
|
.proc_iops = &proc_root_inode_operations,
|
|
.proc_fops = &proc_root_operations,
|
|
.parent = &proc_root,
|
|
.name = "/proc",
|
|
};
|
|
|
|
int pid_ns_prepare_proc(struct pid_namespace *ns)
|
|
{
|
|
struct vfsmount *mnt;
|
|
|
|
mnt = kern_mount_data(&proc_fs_type, ns);
|
|
if (IS_ERR(mnt))
|
|
return PTR_ERR(mnt);
|
|
|
|
ns->proc_mnt = mnt;
|
|
return 0;
|
|
}
|
|
|
|
void pid_ns_release_proc(struct pid_namespace *ns)
|
|
{
|
|
kern_unmount(ns->proc_mnt);
|
|
}
|