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> 15 #include <linux/init.h> 16 #include <linux/sched.h> 17 #include <linux/module.h> 18 #include <linux/bitops.h> 19 #include <linux/smp_lock.h> 20 #include <linux/mount.h> 21 22 #include "internal.h" 23 24 struct proc_dir_entry *proc_net, *proc_net_stat, *proc_bus, *proc_root_fs, *proc_root_driver; 25 26 static int proc_get_sb(struct file_system_type *fs_type, 27 int flags, const char *dev_name, void *data, struct vfsmount *mnt) 28 { 29 if (proc_mnt) { 30 /* Seed the root directory with a pid so it doesn't need 31 * to be special in base.c. I would do this earlier but 32 * the only task alive when /proc is mounted the first time 33 * is the init_task and it doesn't have any pids. 34 */ 35 struct proc_inode *ei; 36 ei = PROC_I(proc_mnt->mnt_sb->s_root->d_inode); 37 if (!ei->pid) 38 ei->pid = find_get_pid(1); 39 } 40 return get_sb_single(fs_type, flags, data, proc_fill_super, mnt); 41 } 42 43 static struct file_system_type proc_fs_type = { 44 .name = "proc", 45 .get_sb = proc_get_sb, 46 .kill_sb = kill_anon_super, 47 }; 48 49 void __init proc_root_init(void) 50 { 51 int err = proc_init_inodecache(); 52 if (err) 53 return; 54 err = register_filesystem(&proc_fs_type); 55 if (err) 56 return; 57 proc_mnt = kern_mount(&proc_fs_type); 58 err = PTR_ERR(proc_mnt); 59 if (IS_ERR(proc_mnt)) { 60 unregister_filesystem(&proc_fs_type); 61 return; 62 } 63 proc_misc_init(); 64 proc_net = proc_mkdir("net", NULL); 65 proc_net_stat = proc_mkdir("net/stat", NULL); 66 67 #ifdef CONFIG_SYSVIPC 68 proc_mkdir("sysvipc", NULL); 69 #endif 70 proc_root_fs = proc_mkdir("fs", NULL); 71 proc_root_driver = proc_mkdir("driver", NULL); 72 proc_mkdir("fs/nfsd", NULL); /* somewhere for the nfsd filesystem to be mounted */ 73 #if defined(CONFIG_SUN_OPENPROMFS) || defined(CONFIG_SUN_OPENPROMFS_MODULE) 74 /* just give it a mountpoint */ 75 proc_mkdir("openprom", NULL); 76 #endif 77 proc_tty_init(); 78 #ifdef CONFIG_PROC_DEVICETREE 79 proc_device_tree_init(); 80 #endif 81 proc_bus = proc_mkdir("bus", NULL); 82 proc_sys_init(); 83 } 84 85 static int proc_root_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat 86 ) 87 { 88 generic_fillattr(dentry->d_inode, stat); 89 stat->nlink = proc_root.nlink + nr_processes(); 90 return 0; 91 } 92 93 static struct dentry *proc_root_lookup(struct inode * dir, struct dentry * dentry, struct nameidata *nd) 94 { 95 if (!proc_lookup(dir, dentry, nd)) { 96 return NULL; 97 } 98 99 return proc_pid_lookup(dir, dentry, nd); 100 } 101 102 static int proc_root_readdir(struct file * filp, 103 void * dirent, filldir_t filldir) 104 { 105 unsigned int nr = filp->f_pos; 106 int ret; 107 108 lock_kernel(); 109 110 if (nr < FIRST_PROCESS_ENTRY) { 111 int error = proc_readdir(filp, dirent, filldir); 112 if (error <= 0) { 113 unlock_kernel(); 114 return error; 115 } 116 filp->f_pos = FIRST_PROCESS_ENTRY; 117 } 118 unlock_kernel(); 119 120 ret = proc_pid_readdir(filp, dirent, filldir); 121 return ret; 122 } 123 124 /* 125 * The root /proc directory is special, as it has the 126 * <pid> directories. Thus we don't use the generic 127 * directory handling functions for that.. 128 */ 129 static const struct file_operations proc_root_operations = { 130 .read = generic_read_dir, 131 .readdir = proc_root_readdir, 132 }; 133 134 /* 135 * proc root can do almost nothing.. 136 */ 137 static const struct inode_operations proc_root_inode_operations = { 138 .lookup = proc_root_lookup, 139 .getattr = proc_root_getattr, 140 }; 141 142 /* 143 * This is the root "inode" in the /proc tree.. 144 */ 145 struct proc_dir_entry proc_root = { 146 .low_ino = PROC_ROOT_INO, 147 .namelen = 5, 148 .name = "/proc", 149 .mode = S_IFDIR | S_IRUGO | S_IXUGO, 150 .nlink = 2, 151 .proc_iops = &proc_root_inode_operations, 152 .proc_fops = &proc_root_operations, 153 .parent = &proc_root, 154 }; 155 156 EXPORT_SYMBOL(proc_symlink); 157 EXPORT_SYMBOL(proc_mkdir); 158 EXPORT_SYMBOL(create_proc_entry); 159 EXPORT_SYMBOL(remove_proc_entry); 160 EXPORT_SYMBOL(proc_root); 161 EXPORT_SYMBOL(proc_root_fs); 162 EXPORT_SYMBOL(proc_net); 163 EXPORT_SYMBOL(proc_net_stat); 164 EXPORT_SYMBOL(proc_bus); 165 EXPORT_SYMBOL(proc_root_driver); 166