Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * linux/fs/proc/inode.c |
| 3 | * |
| 4 | * Copyright (C) 1991, 1992 Linus Torvalds |
| 5 | */ |
| 6 | |
| 7 | #include <linux/time.h> |
| 8 | #include <linux/proc_fs.h> |
| 9 | #include <linux/kernel.h> |
Vasiliy Kulikov | 9741295 | 2012-01-10 15:11:27 -0800 | [diff] [blame] | 10 | #include <linux/pid_namespace.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 11 | #include <linux/mm.h> |
| 12 | #include <linux/string.h> |
| 13 | #include <linux/stat.h> |
Alexey Dobriyan | 786d7e1 | 2007-07-15 23:39:00 -0700 | [diff] [blame] | 14 | #include <linux/completion.h> |
Alexey Dobriyan | dd23aae | 2007-09-11 15:23:55 -0700 | [diff] [blame] | 15 | #include <linux/poll.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 16 | #include <linux/file.h> |
| 17 | #include <linux/limits.h> |
| 18 | #include <linux/init.h> |
| 19 | #include <linux/module.h> |
Al Viro | 9043476f | 2008-07-15 08:54:06 -0400 | [diff] [blame] | 20 | #include <linux/sysctl.h> |
Vasiliy Kulikov | 9741295 | 2012-01-10 15:11:27 -0800 | [diff] [blame] | 21 | #include <linux/seq_file.h> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 22 | #include <linux/slab.h> |
Vasiliy Kulikov | 9741295 | 2012-01-10 15:11:27 -0800 | [diff] [blame] | 23 | #include <linux/mount.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 24 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 25 | #include <asm/uaccess.h> |
| 26 | |
Adrian Bunk | fee781e | 2006-01-08 01:04:16 -0800 | [diff] [blame] | 27 | #include "internal.h" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 28 | |
Al Viro | 8267952 | 2010-06-04 22:17:56 -0400 | [diff] [blame] | 29 | static void proc_evict_inode(struct inode *inode) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 30 | { |
| 31 | struct proc_dir_entry *de; |
Al Viro | dfef6dcd3 | 2011-03-08 01:25:28 -0500 | [diff] [blame] | 32 | struct ctl_table_header *head; |
Eric W. Biederman | 6b4e306 | 2010-03-07 16:41:34 -0800 | [diff] [blame] | 33 | const struct proc_ns_operations *ns_ops; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 34 | |
Mark Fasheh | fef2665 | 2005-09-09 13:01:31 -0700 | [diff] [blame] | 35 | truncate_inode_pages(&inode->i_data, 0); |
Al Viro | 8267952 | 2010-06-04 22:17:56 -0400 | [diff] [blame] | 36 | end_writeback(inode); |
Mark Fasheh | fef2665 | 2005-09-09 13:01:31 -0700 | [diff] [blame] | 37 | |
Eric W. Biederman | 99f8955 | 2006-06-26 00:25:55 -0700 | [diff] [blame] | 38 | /* Stop tracking associated processes */ |
Eric W. Biederman | 13b41b0 | 2006-06-26 00:25:56 -0700 | [diff] [blame] | 39 | put_pid(PROC_I(inode)->pid); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 40 | |
| 41 | /* Let go of any associated proc directory entry */ |
| 42 | de = PROC_I(inode)->pde; |
Alexey Dobriyan | 99b7623 | 2009-03-25 22:48:06 +0300 | [diff] [blame] | 43 | if (de) |
Alexey Dobriyan | 135d565 | 2009-12-15 16:45:39 -0800 | [diff] [blame] | 44 | pde_put(de); |
Al Viro | dfef6dcd3 | 2011-03-08 01:25:28 -0500 | [diff] [blame] | 45 | head = PROC_I(inode)->sysctl; |
| 46 | if (head) { |
| 47 | rcu_assign_pointer(PROC_I(inode)->sysctl, NULL); |
| 48 | sysctl_head_put(head); |
| 49 | } |
Eric W. Biederman | 6b4e306 | 2010-03-07 16:41:34 -0800 | [diff] [blame] | 50 | /* Release any associated namespace */ |
| 51 | ns_ops = PROC_I(inode)->ns_ops; |
| 52 | if (ns_ops && ns_ops->put) |
| 53 | ns_ops->put(PROC_I(inode)->ns); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 54 | } |
| 55 | |
Christoph Lameter | e18b890 | 2006-12-06 20:33:20 -0800 | [diff] [blame] | 56 | static struct kmem_cache * proc_inode_cachep; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 57 | |
| 58 | static struct inode *proc_alloc_inode(struct super_block *sb) |
| 59 | { |
| 60 | struct proc_inode *ei; |
| 61 | struct inode *inode; |
| 62 | |
Christoph Lameter | e94b176 | 2006-12-06 20:33:17 -0800 | [diff] [blame] | 63 | ei = (struct proc_inode *)kmem_cache_alloc(proc_inode_cachep, GFP_KERNEL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 64 | if (!ei) |
| 65 | return NULL; |
Eric W. Biederman | 13b41b0 | 2006-06-26 00:25:56 -0700 | [diff] [blame] | 66 | ei->pid = NULL; |
Eric W. Biederman | aed7a6c | 2006-06-26 00:25:44 -0700 | [diff] [blame] | 67 | ei->fd = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 68 | ei->op.proc_get_link = NULL; |
| 69 | ei->pde = NULL; |
Al Viro | 9043476f | 2008-07-15 08:54:06 -0400 | [diff] [blame] | 70 | ei->sysctl = NULL; |
| 71 | ei->sysctl_entry = NULL; |
Eric W. Biederman | 6b4e306 | 2010-03-07 16:41:34 -0800 | [diff] [blame] | 72 | ei->ns = NULL; |
| 73 | ei->ns_ops = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 74 | inode = &ei->vfs_inode; |
| 75 | inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; |
| 76 | return inode; |
| 77 | } |
| 78 | |
Nick Piggin | fa0d7e3d | 2011-01-07 17:49:49 +1100 | [diff] [blame] | 79 | static void proc_i_callback(struct rcu_head *head) |
| 80 | { |
| 81 | struct inode *inode = container_of(head, struct inode, i_rcu); |
Nick Piggin | fa0d7e3d | 2011-01-07 17:49:49 +1100 | [diff] [blame] | 82 | kmem_cache_free(proc_inode_cachep, PROC_I(inode)); |
| 83 | } |
| 84 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 85 | static void proc_destroy_inode(struct inode *inode) |
| 86 | { |
Nick Piggin | fa0d7e3d | 2011-01-07 17:49:49 +1100 | [diff] [blame] | 87 | call_rcu(&inode->i_rcu, proc_i_callback); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 88 | } |
| 89 | |
Alexey Dobriyan | 51cc506 | 2008-07-25 19:45:34 -0700 | [diff] [blame] | 90 | static void init_once(void *foo) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 91 | { |
| 92 | struct proc_inode *ei = (struct proc_inode *) foo; |
| 93 | |
Christoph Lameter | a35afb8 | 2007-05-16 22:10:57 -0700 | [diff] [blame] | 94 | inode_init_once(&ei->vfs_inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 95 | } |
Paul Mundt | 20c2df8 | 2007-07-20 10:11:58 +0900 | [diff] [blame] | 96 | |
Alexey Dobriyan | 5bcd7ff | 2008-10-17 03:43:55 +0400 | [diff] [blame] | 97 | void __init proc_init_inodecache(void) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 98 | { |
| 99 | proc_inode_cachep = kmem_cache_create("proc_inode_cache", |
| 100 | sizeof(struct proc_inode), |
Paul Jackson | fffb60f | 2006-03-24 03:16:06 -0800 | [diff] [blame] | 101 | 0, (SLAB_RECLAIM_ACCOUNT| |
Alexey Dobriyan | 040b5c6 | 2007-10-16 23:26:10 -0700 | [diff] [blame] | 102 | SLAB_MEM_SPREAD|SLAB_PANIC), |
Paul Mundt | 20c2df8 | 2007-07-20 10:11:58 +0900 | [diff] [blame] | 103 | init_once); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 104 | } |
| 105 | |
Vasiliy Kulikov | 9741295 | 2012-01-10 15:11:27 -0800 | [diff] [blame] | 106 | static int proc_show_options(struct seq_file *seq, struct dentry *root) |
| 107 | { |
Vasiliy Kulikov | 0499680 | 2012-01-10 15:11:31 -0800 | [diff] [blame] | 108 | struct super_block *sb = root->d_sb; |
| 109 | struct pid_namespace *pid = sb->s_fs_info; |
| 110 | |
| 111 | if (pid->pid_gid) |
| 112 | seq_printf(seq, ",gid=%lu", (unsigned long)pid->pid_gid); |
| 113 | if (pid->hide_pid != 0) |
| 114 | seq_printf(seq, ",hidepid=%u", pid->hide_pid); |
| 115 | |
Vasiliy Kulikov | 9741295 | 2012-01-10 15:11:27 -0800 | [diff] [blame] | 116 | return 0; |
| 117 | } |
| 118 | |
Josef 'Jeff' Sipek | ee9b6d6 | 2007-02-12 00:55:41 -0800 | [diff] [blame] | 119 | static const struct super_operations proc_sops = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 120 | .alloc_inode = proc_alloc_inode, |
| 121 | .destroy_inode = proc_destroy_inode, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 122 | .drop_inode = generic_delete_inode, |
Al Viro | 8267952 | 2010-06-04 22:17:56 -0400 | [diff] [blame] | 123 | .evict_inode = proc_evict_inode, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 124 | .statfs = simple_statfs, |
Vasiliy Kulikov | 9741295 | 2012-01-10 15:11:27 -0800 | [diff] [blame] | 125 | .remount_fs = proc_remount, |
| 126 | .show_options = proc_show_options, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 127 | }; |
| 128 | |
Alexey Dobriyan | 881adb8 | 2008-07-25 01:48:29 -0700 | [diff] [blame] | 129 | static void __pde_users_dec(struct proc_dir_entry *pde) |
Alexey Dobriyan | 786d7e1 | 2007-07-15 23:39:00 -0700 | [diff] [blame] | 130 | { |
Alexey Dobriyan | 786d7e1 | 2007-07-15 23:39:00 -0700 | [diff] [blame] | 131 | pde->pde_users--; |
| 132 | if (pde->pde_unload_completion && pde->pde_users == 0) |
| 133 | complete(pde->pde_unload_completion); |
Alexey Dobriyan | 881adb8 | 2008-07-25 01:48:29 -0700 | [diff] [blame] | 134 | } |
| 135 | |
Alexey Dobriyan | 3dec7f5 | 2009-02-20 17:04:33 +0300 | [diff] [blame] | 136 | void pde_users_dec(struct proc_dir_entry *pde) |
Alexey Dobriyan | 881adb8 | 2008-07-25 01:48:29 -0700 | [diff] [blame] | 137 | { |
| 138 | spin_lock(&pde->pde_unload_lock); |
| 139 | __pde_users_dec(pde); |
Alexey Dobriyan | 786d7e1 | 2007-07-15 23:39:00 -0700 | [diff] [blame] | 140 | spin_unlock(&pde->pde_unload_lock); |
| 141 | } |
| 142 | |
| 143 | static loff_t proc_reg_llseek(struct file *file, loff_t offset, int whence) |
| 144 | { |
| 145 | struct proc_dir_entry *pde = PDE(file->f_path.dentry->d_inode); |
| 146 | loff_t rv = -EINVAL; |
| 147 | loff_t (*llseek)(struct file *, loff_t, int); |
| 148 | |
| 149 | spin_lock(&pde->pde_unload_lock); |
| 150 | /* |
| 151 | * remove_proc_entry() is going to delete PDE (as part of module |
| 152 | * cleanup sequence). No new callers into module allowed. |
| 153 | */ |
| 154 | if (!pde->proc_fops) { |
| 155 | spin_unlock(&pde->pde_unload_lock); |
| 156 | return rv; |
| 157 | } |
| 158 | /* |
| 159 | * Bump refcount so that remove_proc_entry will wail for ->llseek to |
| 160 | * complete. |
| 161 | */ |
| 162 | pde->pde_users++; |
| 163 | /* |
| 164 | * Save function pointer under lock, to protect against ->proc_fops |
| 165 | * NULL'ifying right after ->pde_unload_lock is dropped. |
| 166 | */ |
| 167 | llseek = pde->proc_fops->llseek; |
| 168 | spin_unlock(&pde->pde_unload_lock); |
| 169 | |
| 170 | if (!llseek) |
| 171 | llseek = default_llseek; |
| 172 | rv = llseek(file, offset, whence); |
| 173 | |
| 174 | pde_users_dec(pde); |
| 175 | return rv; |
| 176 | } |
| 177 | |
| 178 | static ssize_t proc_reg_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) |
| 179 | { |
| 180 | struct proc_dir_entry *pde = PDE(file->f_path.dentry->d_inode); |
| 181 | ssize_t rv = -EIO; |
| 182 | ssize_t (*read)(struct file *, char __user *, size_t, loff_t *); |
| 183 | |
| 184 | spin_lock(&pde->pde_unload_lock); |
| 185 | if (!pde->proc_fops) { |
| 186 | spin_unlock(&pde->pde_unload_lock); |
| 187 | return rv; |
| 188 | } |
| 189 | pde->pde_users++; |
| 190 | read = pde->proc_fops->read; |
| 191 | spin_unlock(&pde->pde_unload_lock); |
| 192 | |
| 193 | if (read) |
| 194 | rv = read(file, buf, count, ppos); |
| 195 | |
| 196 | pde_users_dec(pde); |
| 197 | return rv; |
| 198 | } |
| 199 | |
| 200 | static ssize_t proc_reg_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) |
| 201 | { |
| 202 | struct proc_dir_entry *pde = PDE(file->f_path.dentry->d_inode); |
| 203 | ssize_t rv = -EIO; |
| 204 | ssize_t (*write)(struct file *, const char __user *, size_t, loff_t *); |
| 205 | |
| 206 | spin_lock(&pde->pde_unload_lock); |
| 207 | if (!pde->proc_fops) { |
| 208 | spin_unlock(&pde->pde_unload_lock); |
| 209 | return rv; |
| 210 | } |
| 211 | pde->pde_users++; |
| 212 | write = pde->proc_fops->write; |
| 213 | spin_unlock(&pde->pde_unload_lock); |
| 214 | |
| 215 | if (write) |
| 216 | rv = write(file, buf, count, ppos); |
| 217 | |
| 218 | pde_users_dec(pde); |
| 219 | return rv; |
| 220 | } |
| 221 | |
| 222 | static unsigned int proc_reg_poll(struct file *file, struct poll_table_struct *pts) |
| 223 | { |
| 224 | struct proc_dir_entry *pde = PDE(file->f_path.dentry->d_inode); |
Alexey Dobriyan | dd23aae | 2007-09-11 15:23:55 -0700 | [diff] [blame] | 225 | unsigned int rv = DEFAULT_POLLMASK; |
Alexey Dobriyan | 786d7e1 | 2007-07-15 23:39:00 -0700 | [diff] [blame] | 226 | unsigned int (*poll)(struct file *, struct poll_table_struct *); |
| 227 | |
| 228 | spin_lock(&pde->pde_unload_lock); |
| 229 | if (!pde->proc_fops) { |
| 230 | spin_unlock(&pde->pde_unload_lock); |
| 231 | return rv; |
| 232 | } |
| 233 | pde->pde_users++; |
| 234 | poll = pde->proc_fops->poll; |
| 235 | spin_unlock(&pde->pde_unload_lock); |
| 236 | |
| 237 | if (poll) |
| 238 | rv = poll(file, pts); |
| 239 | |
| 240 | pde_users_dec(pde); |
| 241 | return rv; |
| 242 | } |
| 243 | |
| 244 | static long proc_reg_unlocked_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
| 245 | { |
| 246 | struct proc_dir_entry *pde = PDE(file->f_path.dentry->d_inode); |
| 247 | long rv = -ENOTTY; |
Arnd Bergmann | b19dd42 | 2010-07-04 00:15:10 +0200 | [diff] [blame] | 248 | long (*ioctl)(struct file *, unsigned int, unsigned long); |
Alexey Dobriyan | 786d7e1 | 2007-07-15 23:39:00 -0700 | [diff] [blame] | 249 | |
| 250 | spin_lock(&pde->pde_unload_lock); |
| 251 | if (!pde->proc_fops) { |
| 252 | spin_unlock(&pde->pde_unload_lock); |
| 253 | return rv; |
| 254 | } |
| 255 | pde->pde_users++; |
Arnd Bergmann | b19dd42 | 2010-07-04 00:15:10 +0200 | [diff] [blame] | 256 | ioctl = pde->proc_fops->unlocked_ioctl; |
Alexey Dobriyan | 786d7e1 | 2007-07-15 23:39:00 -0700 | [diff] [blame] | 257 | spin_unlock(&pde->pde_unload_lock); |
| 258 | |
Arnd Bergmann | b19dd42 | 2010-07-04 00:15:10 +0200 | [diff] [blame] | 259 | if (ioctl) |
| 260 | rv = ioctl(file, cmd, arg); |
Alexey Dobriyan | 786d7e1 | 2007-07-15 23:39:00 -0700 | [diff] [blame] | 261 | |
| 262 | pde_users_dec(pde); |
| 263 | return rv; |
| 264 | } |
| 265 | |
| 266 | #ifdef CONFIG_COMPAT |
| 267 | static long proc_reg_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
| 268 | { |
| 269 | struct proc_dir_entry *pde = PDE(file->f_path.dentry->d_inode); |
| 270 | long rv = -ENOTTY; |
| 271 | long (*compat_ioctl)(struct file *, unsigned int, unsigned long); |
| 272 | |
| 273 | spin_lock(&pde->pde_unload_lock); |
| 274 | if (!pde->proc_fops) { |
| 275 | spin_unlock(&pde->pde_unload_lock); |
| 276 | return rv; |
| 277 | } |
| 278 | pde->pde_users++; |
| 279 | compat_ioctl = pde->proc_fops->compat_ioctl; |
| 280 | spin_unlock(&pde->pde_unload_lock); |
| 281 | |
| 282 | if (compat_ioctl) |
| 283 | rv = compat_ioctl(file, cmd, arg); |
| 284 | |
| 285 | pde_users_dec(pde); |
| 286 | return rv; |
| 287 | } |
| 288 | #endif |
| 289 | |
| 290 | static int proc_reg_mmap(struct file *file, struct vm_area_struct *vma) |
| 291 | { |
| 292 | struct proc_dir_entry *pde = PDE(file->f_path.dentry->d_inode); |
| 293 | int rv = -EIO; |
| 294 | int (*mmap)(struct file *, struct vm_area_struct *); |
| 295 | |
| 296 | spin_lock(&pde->pde_unload_lock); |
| 297 | if (!pde->proc_fops) { |
| 298 | spin_unlock(&pde->pde_unload_lock); |
| 299 | return rv; |
| 300 | } |
| 301 | pde->pde_users++; |
| 302 | mmap = pde->proc_fops->mmap; |
| 303 | spin_unlock(&pde->pde_unload_lock); |
| 304 | |
| 305 | if (mmap) |
| 306 | rv = mmap(file, vma); |
| 307 | |
| 308 | pde_users_dec(pde); |
| 309 | return rv; |
| 310 | } |
| 311 | |
| 312 | static int proc_reg_open(struct inode *inode, struct file *file) |
| 313 | { |
| 314 | struct proc_dir_entry *pde = PDE(inode); |
| 315 | int rv = 0; |
| 316 | int (*open)(struct inode *, struct file *); |
Alexey Dobriyan | 881adb8 | 2008-07-25 01:48:29 -0700 | [diff] [blame] | 317 | int (*release)(struct inode *, struct file *); |
| 318 | struct pde_opener *pdeo; |
| 319 | |
| 320 | /* |
| 321 | * What for, you ask? Well, we can have open, rmmod, remove_proc_entry |
| 322 | * sequence. ->release won't be called because ->proc_fops will be |
| 323 | * cleared. Depending on complexity of ->release, consequences vary. |
| 324 | * |
| 325 | * We can't wait for mercy when close will be done for real, it's |
| 326 | * deadlockable: rmmod foo </proc/foo . So, we're going to do ->release |
| 327 | * by hand in remove_proc_entry(). For this, save opener's credentials |
| 328 | * for later. |
| 329 | */ |
| 330 | pdeo = kmalloc(sizeof(struct pde_opener), GFP_KERNEL); |
| 331 | if (!pdeo) |
| 332 | return -ENOMEM; |
Alexey Dobriyan | 786d7e1 | 2007-07-15 23:39:00 -0700 | [diff] [blame] | 333 | |
| 334 | spin_lock(&pde->pde_unload_lock); |
| 335 | if (!pde->proc_fops) { |
| 336 | spin_unlock(&pde->pde_unload_lock); |
Alexey Dobriyan | 881adb8 | 2008-07-25 01:48:29 -0700 | [diff] [blame] | 337 | kfree(pdeo); |
Daisuke Ogino | d2857e7 | 2011-07-26 16:08:37 -0700 | [diff] [blame] | 338 | return -ENOENT; |
Alexey Dobriyan | 786d7e1 | 2007-07-15 23:39:00 -0700 | [diff] [blame] | 339 | } |
| 340 | pde->pde_users++; |
| 341 | open = pde->proc_fops->open; |
Alexey Dobriyan | 881adb8 | 2008-07-25 01:48:29 -0700 | [diff] [blame] | 342 | release = pde->proc_fops->release; |
Alexey Dobriyan | 786d7e1 | 2007-07-15 23:39:00 -0700 | [diff] [blame] | 343 | spin_unlock(&pde->pde_unload_lock); |
| 344 | |
| 345 | if (open) |
| 346 | rv = open(inode, file); |
| 347 | |
Alexey Dobriyan | 881adb8 | 2008-07-25 01:48:29 -0700 | [diff] [blame] | 348 | spin_lock(&pde->pde_unload_lock); |
| 349 | if (rv == 0 && release) { |
| 350 | /* To know what to release. */ |
| 351 | pdeo->inode = inode; |
| 352 | pdeo->file = file; |
| 353 | /* Strictly for "too late" ->release in proc_reg_release(). */ |
| 354 | pdeo->release = release; |
| 355 | list_add(&pdeo->lh, &pde->pde_openers); |
| 356 | } else |
| 357 | kfree(pdeo); |
| 358 | __pde_users_dec(pde); |
| 359 | spin_unlock(&pde->pde_unload_lock); |
Alexey Dobriyan | 786d7e1 | 2007-07-15 23:39:00 -0700 | [diff] [blame] | 360 | return rv; |
| 361 | } |
| 362 | |
Alexey Dobriyan | 881adb8 | 2008-07-25 01:48:29 -0700 | [diff] [blame] | 363 | static struct pde_opener *find_pde_opener(struct proc_dir_entry *pde, |
| 364 | struct inode *inode, struct file *file) |
| 365 | { |
| 366 | struct pde_opener *pdeo; |
| 367 | |
| 368 | list_for_each_entry(pdeo, &pde->pde_openers, lh) { |
| 369 | if (pdeo->inode == inode && pdeo->file == file) |
| 370 | return pdeo; |
| 371 | } |
| 372 | return NULL; |
| 373 | } |
| 374 | |
Alexey Dobriyan | 786d7e1 | 2007-07-15 23:39:00 -0700 | [diff] [blame] | 375 | static int proc_reg_release(struct inode *inode, struct file *file) |
| 376 | { |
| 377 | struct proc_dir_entry *pde = PDE(inode); |
| 378 | int rv = 0; |
| 379 | int (*release)(struct inode *, struct file *); |
Alexey Dobriyan | 881adb8 | 2008-07-25 01:48:29 -0700 | [diff] [blame] | 380 | struct pde_opener *pdeo; |
Alexey Dobriyan | 786d7e1 | 2007-07-15 23:39:00 -0700 | [diff] [blame] | 381 | |
| 382 | spin_lock(&pde->pde_unload_lock); |
Alexey Dobriyan | 881adb8 | 2008-07-25 01:48:29 -0700 | [diff] [blame] | 383 | pdeo = find_pde_opener(pde, inode, file); |
Alexey Dobriyan | 786d7e1 | 2007-07-15 23:39:00 -0700 | [diff] [blame] | 384 | if (!pde->proc_fops) { |
Alexey Dobriyan | 881adb8 | 2008-07-25 01:48:29 -0700 | [diff] [blame] | 385 | /* |
| 386 | * Can't simply exit, __fput() will think that everything is OK, |
| 387 | * and move on to freeing struct file. remove_proc_entry() will |
| 388 | * find slacker in opener's list and will try to do non-trivial |
| 389 | * things with struct file. Therefore, remove opener from list. |
| 390 | * |
| 391 | * But if opener is removed from list, who will ->release it? |
| 392 | */ |
| 393 | if (pdeo) { |
| 394 | list_del(&pdeo->lh); |
| 395 | spin_unlock(&pde->pde_unload_lock); |
| 396 | rv = pdeo->release(inode, file); |
| 397 | kfree(pdeo); |
| 398 | } else |
| 399 | spin_unlock(&pde->pde_unload_lock); |
Alexey Dobriyan | 786d7e1 | 2007-07-15 23:39:00 -0700 | [diff] [blame] | 400 | return rv; |
| 401 | } |
| 402 | pde->pde_users++; |
| 403 | release = pde->proc_fops->release; |
Alexey Dobriyan | 881adb8 | 2008-07-25 01:48:29 -0700 | [diff] [blame] | 404 | if (pdeo) { |
| 405 | list_del(&pdeo->lh); |
| 406 | kfree(pdeo); |
| 407 | } |
Alexey Dobriyan | 786d7e1 | 2007-07-15 23:39:00 -0700 | [diff] [blame] | 408 | spin_unlock(&pde->pde_unload_lock); |
| 409 | |
| 410 | if (release) |
| 411 | rv = release(inode, file); |
| 412 | |
| 413 | pde_users_dec(pde); |
| 414 | return rv; |
| 415 | } |
| 416 | |
| 417 | static const struct file_operations proc_reg_file_ops = { |
| 418 | .llseek = proc_reg_llseek, |
| 419 | .read = proc_reg_read, |
| 420 | .write = proc_reg_write, |
| 421 | .poll = proc_reg_poll, |
| 422 | .unlocked_ioctl = proc_reg_unlocked_ioctl, |
| 423 | #ifdef CONFIG_COMPAT |
| 424 | .compat_ioctl = proc_reg_compat_ioctl, |
| 425 | #endif |
| 426 | .mmap = proc_reg_mmap, |
| 427 | .open = proc_reg_open, |
| 428 | .release = proc_reg_release, |
| 429 | }; |
| 430 | |
David Miller | 778f3dd | 2007-07-27 22:58:37 -0700 | [diff] [blame] | 431 | #ifdef CONFIG_COMPAT |
| 432 | static const struct file_operations proc_reg_file_ops_no_compat = { |
| 433 | .llseek = proc_reg_llseek, |
| 434 | .read = proc_reg_read, |
| 435 | .write = proc_reg_write, |
| 436 | .poll = proc_reg_poll, |
| 437 | .unlocked_ioctl = proc_reg_unlocked_ioctl, |
| 438 | .mmap = proc_reg_mmap, |
| 439 | .open = proc_reg_open, |
| 440 | .release = proc_reg_release, |
| 441 | }; |
| 442 | #endif |
| 443 | |
Alexey Dobriyan | 6d1b6e4 | 2011-01-12 17:00:33 -0800 | [diff] [blame] | 444 | struct inode *proc_get_inode(struct super_block *sb, struct proc_dir_entry *de) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 445 | { |
| 446 | struct inode * inode; |
| 447 | |
Alexey Dobriyan | 6d1b6e4 | 2011-01-12 17:00:33 -0800 | [diff] [blame] | 448 | inode = iget_locked(sb, de->low_ino); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 449 | if (!inode) |
Alexey Dobriyan | 99b7623 | 2009-03-25 22:48:06 +0300 | [diff] [blame] | 450 | return NULL; |
David Howells | a1d4aeb | 2008-02-07 00:15:45 -0800 | [diff] [blame] | 451 | if (inode->i_state & I_NEW) { |
| 452 | inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; |
| 453 | PROC_I(inode)->fd = 0; |
| 454 | PROC_I(inode)->pde = de; |
Alexey Dobriyan | 5e971dc | 2008-04-29 01:01:41 -0700 | [diff] [blame] | 455 | |
| 456 | if (de->mode) { |
| 457 | inode->i_mode = de->mode; |
| 458 | inode->i_uid = de->uid; |
| 459 | inode->i_gid = de->gid; |
| 460 | } |
| 461 | if (de->size) |
| 462 | inode->i_size = de->size; |
| 463 | if (de->nlink) |
Miklos Szeredi | bfe8684 | 2011-10-28 14:13:29 +0200 | [diff] [blame] | 464 | set_nlink(inode, de->nlink); |
Alexey Dobriyan | 5e971dc | 2008-04-29 01:01:41 -0700 | [diff] [blame] | 465 | if (de->proc_iops) |
| 466 | inode->i_op = de->proc_iops; |
| 467 | if (de->proc_fops) { |
| 468 | if (S_ISREG(inode->i_mode)) { |
David Howells | a1d4aeb | 2008-02-07 00:15:45 -0800 | [diff] [blame] | 469 | #ifdef CONFIG_COMPAT |
Alexey Dobriyan | 5e971dc | 2008-04-29 01:01:41 -0700 | [diff] [blame] | 470 | if (!de->proc_fops->compat_ioctl) |
| 471 | inode->i_fop = |
| 472 | &proc_reg_file_ops_no_compat; |
| 473 | else |
David Howells | a1d4aeb | 2008-02-07 00:15:45 -0800 | [diff] [blame] | 474 | #endif |
Alexey Dobriyan | 5e971dc | 2008-04-29 01:01:41 -0700 | [diff] [blame] | 475 | inode->i_fop = &proc_reg_file_ops; |
| 476 | } else { |
| 477 | inode->i_fop = de->proc_fops; |
David Howells | a1d4aeb | 2008-02-07 00:15:45 -0800 | [diff] [blame] | 478 | } |
Alexey Dobriyan | 786d7e1 | 2007-07-15 23:39:00 -0700 | [diff] [blame] | 479 | } |
David Howells | a1d4aeb | 2008-02-07 00:15:45 -0800 | [diff] [blame] | 480 | unlock_new_inode(inode); |
Alexey Dobriyan | 99b7623 | 2009-03-25 22:48:06 +0300 | [diff] [blame] | 481 | } else |
Alexey Dobriyan | 135d565 | 2009-12-15 16:45:39 -0800 | [diff] [blame] | 482 | pde_put(de); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 483 | return inode; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 484 | } |
| 485 | |
Pavel Emelyanov | 07543f5 | 2007-10-18 23:40:08 -0700 | [diff] [blame] | 486 | int proc_fill_super(struct super_block *s) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 487 | { |
Linus Torvalds | 92d0328 | 2006-07-15 12:20:05 -0700 | [diff] [blame] | 488 | s->s_flags |= MS_NODIRATIME | MS_NOSUID | MS_NOEXEC; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 489 | s->s_blocksize = 1024; |
| 490 | s->s_blocksize_bits = 10; |
| 491 | s->s_magic = PROC_SUPER_MAGIC; |
| 492 | s->s_op = &proc_sops; |
| 493 | s->s_time_gran = 1; |
| 494 | |
Alexey Dobriyan | 135d565 | 2009-12-15 16:45:39 -0800 | [diff] [blame] | 495 | pde_get(&proc_root); |
Al Viro | 48fde70 | 2012-01-08 22:15:13 -0500 | [diff] [blame] | 496 | s->s_root = d_make_root(proc_get_inode(s, &proc_root)); |
| 497 | if (s->s_root) |
| 498 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 499 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 500 | printk("proc_read_super: get root inode failed\n"); |
Alexey Dobriyan | 135d565 | 2009-12-15 16:45:39 -0800 | [diff] [blame] | 501 | pde_put(&proc_root); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 502 | return -ENOMEM; |
| 503 | } |