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![David Howells](/assets/img/avatar_default.png)
Move proc_fill_super() to fs/proc/root.c as that's where the other superblock stuff is. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Alexey Dobriyan <adobriyan@gmail.com> cc: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
274 lines
6.1 KiB
C
274 lines
6.1 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* linux/fs/proc/root.c
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*
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* Copyright (C) 1991, 1992 Linus Torvalds
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*
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* proc root directory handling functions
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*/
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#include <linux/uaccess.h>
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#include <linux/errno.h>
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#include <linux/time.h>
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#include <linux/proc_fs.h>
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#include <linux/stat.h>
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#include <linux/init.h>
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#include <linux/sched.h>
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#include <linux/sched/stat.h>
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#include <linux/module.h>
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#include <linux/bitops.h>
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#include <linux/user_namespace.h>
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#include <linux/mount.h>
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#include <linux/pid_namespace.h>
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#include <linux/parser.h>
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#include <linux/cred.h>
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#include <linux/magic.h>
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#include "internal.h"
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enum {
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Opt_gid, Opt_hidepid, Opt_err,
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};
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static const match_table_t tokens = {
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{Opt_hidepid, "hidepid=%u"},
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{Opt_gid, "gid=%u"},
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{Opt_err, NULL},
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};
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static int proc_parse_options(char *options, struct pid_namespace *pid)
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{
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char *p;
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substring_t args[MAX_OPT_ARGS];
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int option;
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if (!options)
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return 1;
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while ((p = strsep(&options, ",")) != NULL) {
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int token;
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if (!*p)
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continue;
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args[0].to = args[0].from = NULL;
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token = match_token(p, tokens, args);
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switch (token) {
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case Opt_gid:
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if (match_int(&args[0], &option))
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return 0;
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pid->pid_gid = make_kgid(current_user_ns(), option);
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break;
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case Opt_hidepid:
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if (match_int(&args[0], &option))
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return 0;
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if (option < HIDEPID_OFF ||
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option > HIDEPID_INVISIBLE) {
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pr_err("proc: hidepid value must be between 0 and 2.\n");
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return 0;
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}
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pid->hide_pid = option;
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break;
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default:
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pr_err("proc: unrecognized mount option \"%s\" "
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"or missing value\n", p);
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return 0;
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}
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}
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return 1;
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}
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static int proc_fill_super(struct super_block *s, void *data, int silent)
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{
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struct pid_namespace *ns = get_pid_ns(s->s_fs_info);
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struct inode *root_inode;
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int ret;
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if (!proc_parse_options(data, ns))
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return -EINVAL;
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/* User space would break if executables or devices appear on proc */
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s->s_iflags |= SB_I_USERNS_VISIBLE | SB_I_NOEXEC | SB_I_NODEV;
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s->s_flags |= SB_NODIRATIME | SB_NOSUID | SB_NOEXEC;
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s->s_blocksize = 1024;
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s->s_blocksize_bits = 10;
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s->s_magic = PROC_SUPER_MAGIC;
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s->s_op = &proc_sops;
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s->s_time_gran = 1;
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/*
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* procfs isn't actually a stacking filesystem; however, there is
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* too much magic going on inside it to permit stacking things on
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* top of it
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*/
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s->s_stack_depth = FILESYSTEM_MAX_STACK_DEPTH;
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/* procfs dentries and inodes don't require IO to create */
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s->s_shrink.seeks = 0;
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pde_get(&proc_root);
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root_inode = proc_get_inode(s, &proc_root);
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if (!root_inode) {
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pr_err("proc_fill_super: get root inode failed\n");
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return -ENOMEM;
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}
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s->s_root = d_make_root(root_inode);
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if (!s->s_root) {
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pr_err("proc_fill_super: allocate dentry failed\n");
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return -ENOMEM;
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}
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ret = proc_setup_self(s);
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if (ret) {
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return ret;
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}
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return proc_setup_thread_self(s);
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}
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int proc_remount(struct super_block *sb, int *flags, char *data)
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{
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struct pid_namespace *pid = sb->s_fs_info;
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sync_filesystem(sb);
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return !proc_parse_options(data, pid);
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}
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static struct dentry *proc_mount(struct file_system_type *fs_type,
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int flags, const char *dev_name, void *data)
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{
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struct pid_namespace *ns;
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if (flags & SB_KERNMOUNT) {
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ns = data;
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data = NULL;
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} else {
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ns = task_active_pid_ns(current);
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}
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return mount_ns(fs_type, flags, data, ns, ns->user_ns, proc_fill_super);
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}
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static void proc_kill_sb(struct super_block *sb)
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{
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struct pid_namespace *ns;
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ns = (struct pid_namespace *)sb->s_fs_info;
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if (ns->proc_self)
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dput(ns->proc_self);
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if (ns->proc_thread_self)
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dput(ns->proc_thread_self);
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kill_anon_super(sb);
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put_pid_ns(ns);
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}
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static struct file_system_type proc_fs_type = {
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.name = "proc",
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.mount = proc_mount,
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.kill_sb = proc_kill_sb,
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.fs_flags = FS_USERNS_MOUNT,
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};
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void __init proc_root_init(void)
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{
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proc_init_kmemcache();
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set_proc_pid_nlink();
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proc_self_init();
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proc_thread_self_init();
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proc_symlink("mounts", NULL, "self/mounts");
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proc_net_init();
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proc_mkdir("fs", NULL);
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proc_mkdir("driver", NULL);
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proc_create_mount_point("fs/nfsd"); /* somewhere for the nfsd filesystem to be mounted */
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#if defined(CONFIG_SUN_OPENPROMFS) || defined(CONFIG_SUN_OPENPROMFS_MODULE)
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/* just give it a mountpoint */
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proc_create_mount_point("openprom");
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#endif
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proc_tty_init();
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proc_mkdir("bus", NULL);
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proc_sys_init();
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register_filesystem(&proc_fs_type);
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}
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static int proc_root_getattr(const struct path *path, struct kstat *stat,
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u32 request_mask, unsigned int query_flags)
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{
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generic_fillattr(d_inode(path->dentry), stat);
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stat->nlink = proc_root.nlink + nr_processes();
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return 0;
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}
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static struct dentry *proc_root_lookup(struct inode * dir, struct dentry * dentry, unsigned int flags)
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{
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if (!proc_pid_lookup(dir, dentry, flags))
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return NULL;
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return proc_lookup(dir, dentry, flags);
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}
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static int proc_root_readdir(struct file *file, struct dir_context *ctx)
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{
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if (ctx->pos < FIRST_PROCESS_ENTRY) {
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int error = proc_readdir(file, ctx);
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if (unlikely(error <= 0))
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return error;
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ctx->pos = FIRST_PROCESS_ENTRY;
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}
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return proc_pid_readdir(file, ctx);
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}
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/*
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* The root /proc directory is special, as it has the
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* <pid> directories. Thus we don't use the generic
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* directory handling functions for that..
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*/
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static const struct file_operations proc_root_operations = {
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.read = generic_read_dir,
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.iterate_shared = proc_root_readdir,
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.llseek = generic_file_llseek,
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};
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/*
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* proc root can do almost nothing..
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*/
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static const struct inode_operations proc_root_inode_operations = {
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.lookup = proc_root_lookup,
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.getattr = proc_root_getattr,
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};
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/*
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* This is the root "inode" in the /proc tree..
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*/
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struct proc_dir_entry proc_root = {
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.low_ino = PROC_ROOT_INO,
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.namelen = 5,
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.mode = S_IFDIR | S_IRUGO | S_IXUGO,
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.nlink = 2,
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.refcnt = REFCOUNT_INIT(1),
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.proc_iops = &proc_root_inode_operations,
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.proc_fops = &proc_root_operations,
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.parent = &proc_root,
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.subdir = RB_ROOT,
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.name = "/proc",
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};
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int pid_ns_prepare_proc(struct pid_namespace *ns)
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{
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struct vfsmount *mnt;
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mnt = kern_mount_data(&proc_fs_type, ns);
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if (IS_ERR(mnt))
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return PTR_ERR(mnt);
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ns->proc_mnt = mnt;
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return 0;
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}
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void pid_ns_release_proc(struct pid_namespace *ns)
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{
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kern_unmount(ns->proc_mnt);
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}
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