/* * 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/smp_lock.h> #include <linux/mount.h> #include <linux/pid_namespace.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) { struct pid_namespace *ns; ns = (struct pid_namespace *)data; sb->s_fs_info = get_pid_ns(ns); return set_anon_super(sb, NULL); } static int proc_get_sb(struct file_system_type *fs_type, int flags, const char *dev_name, void *data, struct vfsmount *mnt) { int err; struct super_block *sb; struct pid_namespace *ns; struct proc_inode *ei; if (proc_mnt) { /* Seed the root directory with a pid so it doesn't need * to be special in base.c. I would do this earlier but * the only task alive when /proc is mounted the first time * is the init_task and it doesn't have any pids. */ ei = PROC_I(proc_mnt->mnt_sb->s_root->d_inode); if (!ei->pid) ei->pid = find_get_pid(1); } if (flags & MS_KERNMOUNT) ns = (struct pid_namespace *)data; else ns = current->nsproxy->pid_ns; sb = sget(fs_type, proc_test_super, proc_set_super, ns); if (IS_ERR(sb)) return PTR_ERR(sb); if (!sb->s_root) { sb->s_flags = flags; err = proc_fill_super(sb); if (err) { up_write(&sb->s_umount); deactivate_super(sb); return err; } 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(); } sb->s_flags |= MS_ACTIVE; ns->proc_mnt = mnt; } return simple_set_mnt(mnt, sb); } 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", .get_sb = proc_get_sb, .kill_sb = proc_kill_sb, }; void __init proc_root_init(void) { int err = proc_init_inodecache(); if (err) return; err = register_filesystem(&proc_fs_type); if (err) return; proc_mnt = kern_mount_data(&proc_fs_type, &init_pid_ns); err = PTR_ERR(proc_mnt); if (IS_ERR(proc_mnt)) { unregister_filesystem(&proc_fs_type); return; } proc_misc_init(); 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, struct nameidata *nd) { if (!proc_lookup(dir, dentry, nd)) { return NULL; } return proc_pid_lookup(dir, dentry, nd); } static int proc_root_readdir(struct file * filp, void * dirent, filldir_t filldir) { unsigned int nr = filp->f_pos; int ret; lock_kernel(); if (nr < FIRST_PROCESS_ENTRY) { int error = proc_readdir(filp, dirent, filldir); if (error <= 0) { unlock_kernel(); return error; } filp->f_pos = FIRST_PROCESS_ENTRY; } unlock_kernel(); 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, }; /* * 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, .name = "/proc", .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, }; 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); return 0; } void pid_ns_release_proc(struct pid_namespace *ns) { mntput(ns->proc_mnt); } EXPORT_SYMBOL(proc_symlink); EXPORT_SYMBOL(proc_mkdir); EXPORT_SYMBOL(create_proc_entry); EXPORT_SYMBOL(proc_create_data); EXPORT_SYMBOL(remove_proc_entry);