4 * Copyright (C) 1991, 1992 Linus Torvalds
6 * proc root directory handling functions
9 #include <asm/uaccess.h>
11 #include <linux/errno.h>
12 #include <linux/time.h>
13 #include <linux/proc_fs.h>
14 #include <linux/stat.h>
15 #include <linux/init.h>
16 #include <linux/sched.h>
17 #include <linux/module.h>
18 #include <linux/bitops.h>
19 #include <linux/mount.h>
20 #include <linux/pid_namespace.h>
24 static int proc_test_super(struct super_block *sb, void *data)
26 return sb->s_fs_info == data;
29 static int proc_set_super(struct super_block *sb, void *data)
31 int err = set_anon_super(sb, NULL);
33 struct pid_namespace *ns = (struct pid_namespace *)data;
34 sb->s_fs_info = get_pid_ns(ns);
39 static struct dentry *proc_mount(struct file_system_type *fs_type,
40 int flags, const char *dev_name, void *data)
43 struct super_block *sb;
44 struct pid_namespace *ns;
45 struct proc_inode *ei;
47 if (flags & MS_KERNMOUNT)
48 ns = (struct pid_namespace *)data;
50 ns = current->nsproxy->pid_ns;
52 sb = sget(fs_type, proc_test_super, proc_set_super, ns);
57 * procfs isn't actually a stacking filesystem; however, there is
58 * too much magic going on inside it to permit stacking things on
61 sb->s_stack_depth = FILESYSTEM_MAX_STACK_DEPTH;
65 err = proc_fill_super(sb);
67 deactivate_locked_super(sb);
71 sb->s_flags |= MS_ACTIVE;
74 ei = PROC_I(sb->s_root->d_inode);
77 ei->pid = get_pid(find_pid_ns(1, ns));
81 return dget(sb->s_root);
84 static void proc_kill_sb(struct super_block *sb)
86 struct pid_namespace *ns;
88 ns = (struct pid_namespace *)sb->s_fs_info;
93 static struct file_system_type proc_fs_type = {
96 .kill_sb = proc_kill_sb,
99 void __init proc_root_init(void)
103 proc_init_inodecache();
104 err = register_filesystem(&proc_fs_type);
107 err = pid_ns_prepare_proc(&init_pid_ns);
109 unregister_filesystem(&proc_fs_type);
113 proc_symlink("mounts", NULL, "self/mounts");
117 #ifdef CONFIG_SYSVIPC
118 proc_mkdir("sysvipc", NULL);
120 proc_mkdir("fs", NULL);
121 proc_mkdir("driver", NULL);
122 proc_mkdir("fs/nfsd", NULL); /* somewhere for the nfsd filesystem to be mounted */
123 #if defined(CONFIG_SUN_OPENPROMFS) || defined(CONFIG_SUN_OPENPROMFS_MODULE)
124 /* just give it a mountpoint */
125 proc_mkdir("openprom", NULL);
128 #ifdef CONFIG_PROC_DEVICETREE
129 proc_device_tree_init();
131 proc_mkdir("bus", NULL);
135 static int proc_root_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat
138 generic_fillattr(dentry->d_inode, stat);
139 stat->nlink = proc_root.nlink + nr_processes();
143 static struct dentry *proc_root_lookup(struct inode * dir, struct dentry * dentry, struct nameidata *nd)
145 if (!proc_lookup(dir, dentry, nd)) {
149 return proc_pid_lookup(dir, dentry, nd);
152 static int proc_root_readdir(struct file * filp,
153 void * dirent, filldir_t filldir)
155 unsigned int nr = filp->f_pos;
158 if (nr < FIRST_PROCESS_ENTRY) {
159 int error = proc_readdir(filp, dirent, filldir);
162 filp->f_pos = FIRST_PROCESS_ENTRY;
165 ret = proc_pid_readdir(filp, dirent, filldir);
170 * The root /proc directory is special, as it has the
171 * <pid> directories. Thus we don't use the generic
172 * directory handling functions for that..
174 static const struct file_operations proc_root_operations = {
175 .read = generic_read_dir,
176 .readdir = proc_root_readdir,
177 .llseek = default_llseek,
181 * proc root can do almost nothing..
183 static const struct inode_operations proc_root_inode_operations = {
184 .lookup = proc_root_lookup,
185 .getattr = proc_root_getattr,
189 * This is the root "inode" in the /proc tree..
191 struct proc_dir_entry proc_root = {
192 .low_ino = PROC_ROOT_INO,
194 .mode = S_IFDIR | S_IRUGO | S_IXUGO,
196 .count = ATOMIC_INIT(1),
197 .proc_iops = &proc_root_inode_operations,
198 .proc_fops = &proc_root_operations,
199 .parent = &proc_root,
203 int pid_ns_prepare_proc(struct pid_namespace *ns)
205 struct vfsmount *mnt;
207 mnt = kern_mount_data(&proc_fs_type, ns);
215 void pid_ns_release_proc(struct pid_namespace *ns)
217 kern_unmount(ns->proc_mnt);