Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * linux/fs/proc/root.c |
| 3 | * |
| 4 | * Copyright (C) 1991, 1992 Linus Torvalds |
| 5 | * |
| 6 | * proc root directory handling functions |
| 7 | */ |
| 8 | |
| 9 | #include <asm/uaccess.h> |
| 10 | |
| 11 | #include <linux/errno.h> |
| 12 | #include <linux/time.h> |
| 13 | #include <linux/proc_fs.h> |
| 14 | #include <linux/stat.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 15 | #include <linux/init.h> |
Al Viro | 914e263 | 2006-10-18 13:55:46 -0400 | [diff] [blame] | 16 | #include <linux/sched.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 17 | #include <linux/module.h> |
| 18 | #include <linux/bitops.h> |
| 19 | #include <linux/smp_lock.h> |
Eric W. Biederman | f6c7a1f | 2006-10-02 02:17:07 -0700 | [diff] [blame] | 20 | #include <linux/mount.h> |
Pavel Emelyanov | 07543f5 | 2007-10-18 23:40:08 -0700 | [diff] [blame] | 21 | #include <linux/pid_namespace.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 22 | |
Adrian Bunk | fee781e | 2006-01-08 01:04:16 -0800 | [diff] [blame] | 23 | #include "internal.h" |
| 24 | |
Pavel Emelyanov | 07543f5 | 2007-10-18 23:40:08 -0700 | [diff] [blame] | 25 | static int proc_test_super(struct super_block *sb, void *data) |
| 26 | { |
| 27 | return sb->s_fs_info == data; |
| 28 | } |
| 29 | |
| 30 | static int proc_set_super(struct super_block *sb, void *data) |
| 31 | { |
| 32 | struct pid_namespace *ns; |
| 33 | |
| 34 | ns = (struct pid_namespace *)data; |
| 35 | sb->s_fs_info = get_pid_ns(ns); |
| 36 | return set_anon_super(sb, NULL); |
| 37 | } |
| 38 | |
David Howells | 454e239 | 2006-06-23 02:02:57 -0700 | [diff] [blame] | 39 | static int proc_get_sb(struct file_system_type *fs_type, |
| 40 | int flags, const char *dev_name, void *data, struct vfsmount *mnt) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 41 | { |
Pavel Emelyanov | 07543f5 | 2007-10-18 23:40:08 -0700 | [diff] [blame] | 42 | int err; |
| 43 | struct super_block *sb; |
| 44 | struct pid_namespace *ns; |
| 45 | struct proc_inode *ei; |
| 46 | |
Eric W. Biederman | f6c7a1f | 2006-10-02 02:17:07 -0700 | [diff] [blame] | 47 | if (proc_mnt) { |
| 48 | /* Seed the root directory with a pid so it doesn't need |
| 49 | * to be special in base.c. I would do this earlier but |
| 50 | * the only task alive when /proc is mounted the first time |
| 51 | * is the init_task and it doesn't have any pids. |
| 52 | */ |
Eric W. Biederman | f6c7a1f | 2006-10-02 02:17:07 -0700 | [diff] [blame] | 53 | ei = PROC_I(proc_mnt->mnt_sb->s_root->d_inode); |
| 54 | if (!ei->pid) |
| 55 | ei->pid = find_get_pid(1); |
| 56 | } |
Pavel Emelyanov | 07543f5 | 2007-10-18 23:40:08 -0700 | [diff] [blame] | 57 | |
| 58 | if (flags & MS_KERNMOUNT) |
| 59 | ns = (struct pid_namespace *)data; |
| 60 | else |
| 61 | ns = current->nsproxy->pid_ns; |
| 62 | |
| 63 | sb = sget(fs_type, proc_test_super, proc_set_super, ns); |
| 64 | if (IS_ERR(sb)) |
| 65 | return PTR_ERR(sb); |
| 66 | |
| 67 | if (!sb->s_root) { |
| 68 | sb->s_flags = flags; |
| 69 | err = proc_fill_super(sb); |
| 70 | if (err) { |
| 71 | up_write(&sb->s_umount); |
| 72 | deactivate_super(sb); |
| 73 | return err; |
| 74 | } |
| 75 | |
| 76 | ei = PROC_I(sb->s_root->d_inode); |
| 77 | if (!ei->pid) { |
| 78 | rcu_read_lock(); |
| 79 | ei->pid = get_pid(find_pid_ns(1, ns)); |
| 80 | rcu_read_unlock(); |
| 81 | } |
| 82 | |
| 83 | sb->s_flags |= MS_ACTIVE; |
| 84 | ns->proc_mnt = mnt; |
| 85 | } |
| 86 | |
| 87 | return simple_set_mnt(mnt, sb); |
| 88 | } |
| 89 | |
| 90 | static void proc_kill_sb(struct super_block *sb) |
| 91 | { |
| 92 | struct pid_namespace *ns; |
| 93 | |
| 94 | ns = (struct pid_namespace *)sb->s_fs_info; |
| 95 | kill_anon_super(sb); |
| 96 | put_pid_ns(ns); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 97 | } |
| 98 | |
Alexey Dobriyan | c231954 | 2007-11-28 16:21:23 -0800 | [diff] [blame] | 99 | static struct file_system_type proc_fs_type = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 100 | .name = "proc", |
| 101 | .get_sb = proc_get_sb, |
Pavel Emelyanov | 07543f5 | 2007-10-18 23:40:08 -0700 | [diff] [blame] | 102 | .kill_sb = proc_kill_sb, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 103 | }; |
| 104 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 105 | void __init proc_root_init(void) |
| 106 | { |
Alexey Dobriyan | 5bcd7ff | 2008-10-17 03:43:55 +0400 | [diff] [blame] | 107 | int err; |
| 108 | |
| 109 | proc_init_inodecache(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 110 | err = register_filesystem(&proc_fs_type); |
| 111 | if (err) |
| 112 | return; |
Pavel Emelyanov | 07543f5 | 2007-10-18 23:40:08 -0700 | [diff] [blame] | 113 | proc_mnt = kern_mount_data(&proc_fs_type, &init_pid_ns); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 114 | err = PTR_ERR(proc_mnt); |
| 115 | if (IS_ERR(proc_mnt)) { |
| 116 | unregister_filesystem(&proc_fs_type); |
| 117 | return; |
| 118 | } |
Pavel Emelyanov | 07543f5 | 2007-10-18 23:40:08 -0700 | [diff] [blame] | 119 | |
Alexey Dobriyan | 59c7572 | 2008-10-06 14:49:39 +0400 | [diff] [blame^] | 120 | proc_symlink("mounts", NULL, "self/mounts"); |
Eric W. Biederman | 457c4cb | 2007-09-12 12:01:34 +0200 | [diff] [blame] | 121 | |
| 122 | proc_net_init(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 123 | |
| 124 | #ifdef CONFIG_SYSVIPC |
| 125 | proc_mkdir("sysvipc", NULL); |
| 126 | #endif |
Alexey Dobriyan | 36a5aeb | 2008-04-29 01:01:42 -0700 | [diff] [blame] | 127 | proc_mkdir("fs", NULL); |
Alexey Dobriyan | 928b4d8 | 2008-04-29 01:01:44 -0700 | [diff] [blame] | 128 | proc_mkdir("driver", NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 129 | proc_mkdir("fs/nfsd", NULL); /* somewhere for the nfsd filesystem to be mounted */ |
| 130 | #if defined(CONFIG_SUN_OPENPROMFS) || defined(CONFIG_SUN_OPENPROMFS_MODULE) |
| 131 | /* just give it a mountpoint */ |
| 132 | proc_mkdir("openprom", NULL); |
| 133 | #endif |
| 134 | proc_tty_init(); |
| 135 | #ifdef CONFIG_PROC_DEVICETREE |
| 136 | proc_device_tree_init(); |
| 137 | #endif |
Alexey Dobriyan | 9c37066 | 2008-04-29 01:01:41 -0700 | [diff] [blame] | 138 | proc_mkdir("bus", NULL); |
Eric W. Biederman | 77b14db | 2007-02-14 00:34:12 -0800 | [diff] [blame] | 139 | proc_sys_init(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 140 | } |
| 141 | |
Al Viro | 76b6159 | 2006-02-08 14:37:40 -0500 | [diff] [blame] | 142 | static int proc_root_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat |
| 143 | ) |
| 144 | { |
| 145 | generic_fillattr(dentry->d_inode, stat); |
| 146 | stat->nlink = proc_root.nlink + nr_processes(); |
| 147 | return 0; |
| 148 | } |
| 149 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 150 | static struct dentry *proc_root_lookup(struct inode * dir, struct dentry * dentry, struct nameidata *nd) |
| 151 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 152 | if (!proc_lookup(dir, dentry, nd)) { |
| 153 | return NULL; |
| 154 | } |
| 155 | |
| 156 | return proc_pid_lookup(dir, dentry, nd); |
| 157 | } |
| 158 | |
| 159 | static int proc_root_readdir(struct file * filp, |
| 160 | void * dirent, filldir_t filldir) |
| 161 | { |
| 162 | unsigned int nr = filp->f_pos; |
| 163 | int ret; |
| 164 | |
| 165 | lock_kernel(); |
| 166 | |
| 167 | if (nr < FIRST_PROCESS_ENTRY) { |
| 168 | int error = proc_readdir(filp, dirent, filldir); |
| 169 | if (error <= 0) { |
| 170 | unlock_kernel(); |
| 171 | return error; |
| 172 | } |
| 173 | filp->f_pos = FIRST_PROCESS_ENTRY; |
| 174 | } |
| 175 | unlock_kernel(); |
| 176 | |
| 177 | ret = proc_pid_readdir(filp, dirent, filldir); |
| 178 | return ret; |
| 179 | } |
| 180 | |
| 181 | /* |
| 182 | * The root /proc directory is special, as it has the |
| 183 | * <pid> directories. Thus we don't use the generic |
| 184 | * directory handling functions for that.. |
| 185 | */ |
Arjan van de Ven | 00977a5 | 2007-02-12 00:55:34 -0800 | [diff] [blame] | 186 | static const struct file_operations proc_root_operations = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 187 | .read = generic_read_dir, |
| 188 | .readdir = proc_root_readdir, |
| 189 | }; |
| 190 | |
| 191 | /* |
| 192 | * proc root can do almost nothing.. |
| 193 | */ |
Arjan van de Ven | c5ef1c4 | 2007-02-12 00:55:40 -0800 | [diff] [blame] | 194 | static const struct inode_operations proc_root_inode_operations = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 195 | .lookup = proc_root_lookup, |
Al Viro | 76b6159 | 2006-02-08 14:37:40 -0500 | [diff] [blame] | 196 | .getattr = proc_root_getattr, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 197 | }; |
| 198 | |
| 199 | /* |
| 200 | * This is the root "inode" in the /proc tree.. |
| 201 | */ |
| 202 | struct proc_dir_entry proc_root = { |
| 203 | .low_ino = PROC_ROOT_INO, |
| 204 | .namelen = 5, |
| 205 | .name = "/proc", |
| 206 | .mode = S_IFDIR | S_IRUGO | S_IXUGO, |
| 207 | .nlink = 2, |
Alexey Dobriyan | 5a622f2 | 2007-12-04 23:45:28 -0800 | [diff] [blame] | 208 | .count = ATOMIC_INIT(1), |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 209 | .proc_iops = &proc_root_inode_operations, |
| 210 | .proc_fops = &proc_root_operations, |
| 211 | .parent = &proc_root, |
| 212 | }; |
| 213 | |
Pavel Emelyanov | 6f4e643 | 2007-10-18 23:40:11 -0700 | [diff] [blame] | 214 | int pid_ns_prepare_proc(struct pid_namespace *ns) |
| 215 | { |
| 216 | struct vfsmount *mnt; |
| 217 | |
| 218 | mnt = kern_mount_data(&proc_fs_type, ns); |
| 219 | if (IS_ERR(mnt)) |
| 220 | return PTR_ERR(mnt); |
| 221 | |
| 222 | return 0; |
| 223 | } |
| 224 | |
| 225 | void pid_ns_release_proc(struct pid_namespace *ns) |
| 226 | { |
| 227 | mntput(ns->proc_mnt); |
| 228 | } |
| 229 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 230 | EXPORT_SYMBOL(proc_symlink); |
| 231 | EXPORT_SYMBOL(proc_mkdir); |
| 232 | EXPORT_SYMBOL(create_proc_entry); |
Denis V. Lunev | 59b7435 | 2008-04-29 01:02:00 -0700 | [diff] [blame] | 233 | EXPORT_SYMBOL(proc_create_data); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 234 | EXPORT_SYMBOL(remove_proc_entry); |