Commit | Line | Data |
---|---|---|
1da177e4 LT |
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> | |
10 | #include <linux/mm.h> | |
11 | #include <linux/string.h> | |
12 | #include <linux/stat.h> | |
786d7e16 | 13 | #include <linux/completion.h> |
dd23aae4 | 14 | #include <linux/poll.h> |
1da177e4 LT |
15 | #include <linux/file.h> |
16 | #include <linux/limits.h> | |
17 | #include <linux/init.h> | |
18 | #include <linux/module.h> | |
19 | #include <linux/smp_lock.h> | |
20 | ||
21 | #include <asm/system.h> | |
22 | #include <asm/uaccess.h> | |
23 | ||
fee781e6 | 24 | #include "internal.h" |
1da177e4 | 25 | |
7695650a | 26 | struct proc_dir_entry *de_get(struct proc_dir_entry *de) |
1da177e4 LT |
27 | { |
28 | if (de) | |
29 | atomic_inc(&de->count); | |
30 | return de; | |
31 | } | |
32 | ||
33 | /* | |
34 | * Decrements the use count and checks for deferred deletion. | |
35 | */ | |
7695650a | 36 | void de_put(struct proc_dir_entry *de) |
1da177e4 LT |
37 | { |
38 | if (de) { | |
39 | lock_kernel(); | |
40 | if (!atomic_read(&de->count)) { | |
41 | printk("de_put: entry %s already free!\n", de->name); | |
42 | unlock_kernel(); | |
43 | return; | |
44 | } | |
45 | ||
5a622f2d AD |
46 | if (atomic_dec_and_test(&de->count)) |
47 | free_proc_entry(de); | |
1da177e4 LT |
48 | unlock_kernel(); |
49 | } | |
50 | } | |
51 | ||
52 | /* | |
53 | * Decrement the use count of the proc_dir_entry. | |
54 | */ | |
55 | static void proc_delete_inode(struct inode *inode) | |
56 | { | |
57 | struct proc_dir_entry *de; | |
1da177e4 | 58 | |
fef26658 MF |
59 | truncate_inode_pages(&inode->i_data, 0); |
60 | ||
99f89551 | 61 | /* Stop tracking associated processes */ |
13b41b09 | 62 | put_pid(PROC_I(inode)->pid); |
1da177e4 LT |
63 | |
64 | /* Let go of any associated proc directory entry */ | |
65 | de = PROC_I(inode)->pde; | |
66 | if (de) { | |
67 | if (de->owner) | |
68 | module_put(de->owner); | |
69 | de_put(de); | |
70 | } | |
71 | clear_inode(inode); | |
72 | } | |
73 | ||
74 | struct vfsmount *proc_mnt; | |
75 | ||
e18b890b | 76 | static struct kmem_cache * proc_inode_cachep; |
1da177e4 LT |
77 | |
78 | static struct inode *proc_alloc_inode(struct super_block *sb) | |
79 | { | |
80 | struct proc_inode *ei; | |
81 | struct inode *inode; | |
82 | ||
e94b1766 | 83 | ei = (struct proc_inode *)kmem_cache_alloc(proc_inode_cachep, GFP_KERNEL); |
1da177e4 LT |
84 | if (!ei) |
85 | return NULL; | |
13b41b09 | 86 | ei->pid = NULL; |
aed7a6c4 | 87 | ei->fd = 0; |
1da177e4 LT |
88 | ei->op.proc_get_link = NULL; |
89 | ei->pde = NULL; | |
90 | inode = &ei->vfs_inode; | |
91 | inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; | |
92 | return inode; | |
93 | } | |
94 | ||
95 | static void proc_destroy_inode(struct inode *inode) | |
96 | { | |
97 | kmem_cache_free(proc_inode_cachep, PROC_I(inode)); | |
98 | } | |
99 | ||
4ba9b9d0 | 100 | static void init_once(struct kmem_cache * cachep, void *foo) |
1da177e4 LT |
101 | { |
102 | struct proc_inode *ei = (struct proc_inode *) foo; | |
103 | ||
a35afb83 | 104 | inode_init_once(&ei->vfs_inode); |
1da177e4 | 105 | } |
20c2df83 | 106 | |
1da177e4 LT |
107 | int __init proc_init_inodecache(void) |
108 | { | |
109 | proc_inode_cachep = kmem_cache_create("proc_inode_cache", | |
110 | sizeof(struct proc_inode), | |
fffb60f9 | 111 | 0, (SLAB_RECLAIM_ACCOUNT| |
040b5c6f | 112 | SLAB_MEM_SPREAD|SLAB_PANIC), |
20c2df83 | 113 | init_once); |
1da177e4 LT |
114 | return 0; |
115 | } | |
116 | ||
117 | static int proc_remount(struct super_block *sb, int *flags, char *data) | |
118 | { | |
119 | *flags |= MS_NODIRATIME; | |
120 | return 0; | |
121 | } | |
122 | ||
ee9b6d61 | 123 | static const struct super_operations proc_sops = { |
1da177e4 LT |
124 | .alloc_inode = proc_alloc_inode, |
125 | .destroy_inode = proc_destroy_inode, | |
1da177e4 LT |
126 | .drop_inode = generic_delete_inode, |
127 | .delete_inode = proc_delete_inode, | |
128 | .statfs = simple_statfs, | |
129 | .remount_fs = proc_remount, | |
130 | }; | |
131 | ||
786d7e16 AD |
132 | static void pde_users_dec(struct proc_dir_entry *pde) |
133 | { | |
134 | spin_lock(&pde->pde_unload_lock); | |
135 | pde->pde_users--; | |
136 | if (pde->pde_unload_completion && pde->pde_users == 0) | |
137 | complete(pde->pde_unload_completion); | |
138 | spin_unlock(&pde->pde_unload_lock); | |
139 | } | |
140 | ||
141 | static loff_t proc_reg_llseek(struct file *file, loff_t offset, int whence) | |
142 | { | |
143 | struct proc_dir_entry *pde = PDE(file->f_path.dentry->d_inode); | |
144 | loff_t rv = -EINVAL; | |
145 | loff_t (*llseek)(struct file *, loff_t, int); | |
146 | ||
147 | spin_lock(&pde->pde_unload_lock); | |
148 | /* | |
149 | * remove_proc_entry() is going to delete PDE (as part of module | |
150 | * cleanup sequence). No new callers into module allowed. | |
151 | */ | |
152 | if (!pde->proc_fops) { | |
153 | spin_unlock(&pde->pde_unload_lock); | |
154 | return rv; | |
155 | } | |
156 | /* | |
157 | * Bump refcount so that remove_proc_entry will wail for ->llseek to | |
158 | * complete. | |
159 | */ | |
160 | pde->pde_users++; | |
161 | /* | |
162 | * Save function pointer under lock, to protect against ->proc_fops | |
163 | * NULL'ifying right after ->pde_unload_lock is dropped. | |
164 | */ | |
165 | llseek = pde->proc_fops->llseek; | |
166 | spin_unlock(&pde->pde_unload_lock); | |
167 | ||
168 | if (!llseek) | |
169 | llseek = default_llseek; | |
170 | rv = llseek(file, offset, whence); | |
171 | ||
172 | pde_users_dec(pde); | |
173 | return rv; | |
174 | } | |
175 | ||
176 | static ssize_t proc_reg_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) | |
177 | { | |
178 | struct proc_dir_entry *pde = PDE(file->f_path.dentry->d_inode); | |
179 | ssize_t rv = -EIO; | |
180 | ssize_t (*read)(struct file *, char __user *, size_t, loff_t *); | |
181 | ||
182 | spin_lock(&pde->pde_unload_lock); | |
183 | if (!pde->proc_fops) { | |
184 | spin_unlock(&pde->pde_unload_lock); | |
185 | return rv; | |
186 | } | |
187 | pde->pde_users++; | |
188 | read = pde->proc_fops->read; | |
189 | spin_unlock(&pde->pde_unload_lock); | |
190 | ||
191 | if (read) | |
192 | rv = read(file, buf, count, ppos); | |
193 | ||
194 | pde_users_dec(pde); | |
195 | return rv; | |
196 | } | |
197 | ||
198 | static ssize_t proc_reg_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) | |
199 | { | |
200 | struct proc_dir_entry *pde = PDE(file->f_path.dentry->d_inode); | |
201 | ssize_t rv = -EIO; | |
202 | ssize_t (*write)(struct file *, const char __user *, size_t, loff_t *); | |
203 | ||
204 | spin_lock(&pde->pde_unload_lock); | |
205 | if (!pde->proc_fops) { | |
206 | spin_unlock(&pde->pde_unload_lock); | |
207 | return rv; | |
208 | } | |
209 | pde->pde_users++; | |
210 | write = pde->proc_fops->write; | |
211 | spin_unlock(&pde->pde_unload_lock); | |
212 | ||
213 | if (write) | |
214 | rv = write(file, buf, count, ppos); | |
215 | ||
216 | pde_users_dec(pde); | |
217 | return rv; | |
218 | } | |
219 | ||
220 | static unsigned int proc_reg_poll(struct file *file, struct poll_table_struct *pts) | |
221 | { | |
222 | struct proc_dir_entry *pde = PDE(file->f_path.dentry->d_inode); | |
dd23aae4 | 223 | unsigned int rv = DEFAULT_POLLMASK; |
786d7e16 AD |
224 | unsigned int (*poll)(struct file *, struct poll_table_struct *); |
225 | ||
226 | spin_lock(&pde->pde_unload_lock); | |
227 | if (!pde->proc_fops) { | |
228 | spin_unlock(&pde->pde_unload_lock); | |
229 | return rv; | |
230 | } | |
231 | pde->pde_users++; | |
232 | poll = pde->proc_fops->poll; | |
233 | spin_unlock(&pde->pde_unload_lock); | |
234 | ||
235 | if (poll) | |
236 | rv = poll(file, pts); | |
237 | ||
238 | pde_users_dec(pde); | |
239 | return rv; | |
240 | } | |
241 | ||
242 | static long proc_reg_unlocked_ioctl(struct file *file, unsigned int cmd, unsigned long arg) | |
243 | { | |
244 | struct proc_dir_entry *pde = PDE(file->f_path.dentry->d_inode); | |
245 | long rv = -ENOTTY; | |
246 | long (*unlocked_ioctl)(struct file *, unsigned int, unsigned long); | |
247 | int (*ioctl)(struct inode *, struct file *, unsigned int, unsigned long); | |
248 | ||
249 | spin_lock(&pde->pde_unload_lock); | |
250 | if (!pde->proc_fops) { | |
251 | spin_unlock(&pde->pde_unload_lock); | |
252 | return rv; | |
253 | } | |
254 | pde->pde_users++; | |
255 | unlocked_ioctl = pde->proc_fops->unlocked_ioctl; | |
256 | ioctl = pde->proc_fops->ioctl; | |
257 | spin_unlock(&pde->pde_unload_lock); | |
258 | ||
259 | if (unlocked_ioctl) { | |
260 | rv = unlocked_ioctl(file, cmd, arg); | |
261 | if (rv == -ENOIOCTLCMD) | |
262 | rv = -EINVAL; | |
263 | } else if (ioctl) { | |
264 | lock_kernel(); | |
265 | rv = ioctl(file->f_path.dentry->d_inode, file, cmd, arg); | |
266 | unlock_kernel(); | |
267 | } | |
268 | ||
269 | pde_users_dec(pde); | |
270 | return rv; | |
271 | } | |
272 | ||
273 | #ifdef CONFIG_COMPAT | |
274 | static long proc_reg_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg) | |
275 | { | |
276 | struct proc_dir_entry *pde = PDE(file->f_path.dentry->d_inode); | |
277 | long rv = -ENOTTY; | |
278 | long (*compat_ioctl)(struct file *, unsigned int, unsigned long); | |
279 | ||
280 | spin_lock(&pde->pde_unload_lock); | |
281 | if (!pde->proc_fops) { | |
282 | spin_unlock(&pde->pde_unload_lock); | |
283 | return rv; | |
284 | } | |
285 | pde->pde_users++; | |
286 | compat_ioctl = pde->proc_fops->compat_ioctl; | |
287 | spin_unlock(&pde->pde_unload_lock); | |
288 | ||
289 | if (compat_ioctl) | |
290 | rv = compat_ioctl(file, cmd, arg); | |
291 | ||
292 | pde_users_dec(pde); | |
293 | return rv; | |
294 | } | |
295 | #endif | |
296 | ||
297 | static int proc_reg_mmap(struct file *file, struct vm_area_struct *vma) | |
298 | { | |
299 | struct proc_dir_entry *pde = PDE(file->f_path.dentry->d_inode); | |
300 | int rv = -EIO; | |
301 | int (*mmap)(struct file *, struct vm_area_struct *); | |
302 | ||
303 | spin_lock(&pde->pde_unload_lock); | |
304 | if (!pde->proc_fops) { | |
305 | spin_unlock(&pde->pde_unload_lock); | |
306 | return rv; | |
307 | } | |
308 | pde->pde_users++; | |
309 | mmap = pde->proc_fops->mmap; | |
310 | spin_unlock(&pde->pde_unload_lock); | |
311 | ||
312 | if (mmap) | |
313 | rv = mmap(file, vma); | |
314 | ||
315 | pde_users_dec(pde); | |
316 | return rv; | |
317 | } | |
318 | ||
319 | static int proc_reg_open(struct inode *inode, struct file *file) | |
320 | { | |
321 | struct proc_dir_entry *pde = PDE(inode); | |
322 | int rv = 0; | |
323 | int (*open)(struct inode *, struct file *); | |
324 | ||
325 | spin_lock(&pde->pde_unload_lock); | |
326 | if (!pde->proc_fops) { | |
327 | spin_unlock(&pde->pde_unload_lock); | |
328 | return rv; | |
329 | } | |
330 | pde->pde_users++; | |
331 | open = pde->proc_fops->open; | |
332 | spin_unlock(&pde->pde_unload_lock); | |
333 | ||
334 | if (open) | |
335 | rv = open(inode, file); | |
336 | ||
337 | pde_users_dec(pde); | |
338 | return rv; | |
339 | } | |
340 | ||
341 | static int proc_reg_release(struct inode *inode, struct file *file) | |
342 | { | |
343 | struct proc_dir_entry *pde = PDE(inode); | |
344 | int rv = 0; | |
345 | int (*release)(struct inode *, struct file *); | |
346 | ||
347 | spin_lock(&pde->pde_unload_lock); | |
348 | if (!pde->proc_fops) { | |
349 | spin_unlock(&pde->pde_unload_lock); | |
350 | return rv; | |
351 | } | |
352 | pde->pde_users++; | |
353 | release = pde->proc_fops->release; | |
354 | spin_unlock(&pde->pde_unload_lock); | |
355 | ||
356 | if (release) | |
357 | rv = release(inode, file); | |
358 | ||
359 | pde_users_dec(pde); | |
360 | return rv; | |
361 | } | |
362 | ||
363 | static const struct file_operations proc_reg_file_ops = { | |
364 | .llseek = proc_reg_llseek, | |
365 | .read = proc_reg_read, | |
366 | .write = proc_reg_write, | |
367 | .poll = proc_reg_poll, | |
368 | .unlocked_ioctl = proc_reg_unlocked_ioctl, | |
369 | #ifdef CONFIG_COMPAT | |
370 | .compat_ioctl = proc_reg_compat_ioctl, | |
371 | #endif | |
372 | .mmap = proc_reg_mmap, | |
373 | .open = proc_reg_open, | |
374 | .release = proc_reg_release, | |
375 | }; | |
376 | ||
778f3dd5 DM |
377 | #ifdef CONFIG_COMPAT |
378 | static const struct file_operations proc_reg_file_ops_no_compat = { | |
379 | .llseek = proc_reg_llseek, | |
380 | .read = proc_reg_read, | |
381 | .write = proc_reg_write, | |
382 | .poll = proc_reg_poll, | |
383 | .unlocked_ioctl = proc_reg_unlocked_ioctl, | |
384 | .mmap = proc_reg_mmap, | |
385 | .open = proc_reg_open, | |
386 | .release = proc_reg_release, | |
387 | }; | |
388 | #endif | |
389 | ||
1da177e4 LT |
390 | struct inode *proc_get_inode(struct super_block *sb, unsigned int ino, |
391 | struct proc_dir_entry *de) | |
392 | { | |
393 | struct inode * inode; | |
394 | ||
e9543659 KK |
395 | if (de != NULL && !try_module_get(de->owner)) |
396 | goto out_mod; | |
397 | ||
a1d4aebb | 398 | inode = iget_locked(sb, ino); |
1da177e4 | 399 | if (!inode) |
e9543659 | 400 | goto out_ino; |
a1d4aebb DH |
401 | if (inode->i_state & I_NEW) { |
402 | inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; | |
403 | PROC_I(inode)->fd = 0; | |
404 | PROC_I(inode)->pde = de; | |
405 | if (de) { | |
406 | if (de->mode) { | |
407 | inode->i_mode = de->mode; | |
408 | inode->i_uid = de->uid; | |
409 | inode->i_gid = de->gid; | |
410 | } | |
411 | if (de->size) | |
412 | inode->i_size = de->size; | |
413 | if (de->nlink) | |
414 | inode->i_nlink = de->nlink; | |
415 | if (de->proc_iops) | |
416 | inode->i_op = de->proc_iops; | |
417 | if (de->proc_fops) { | |
418 | if (S_ISREG(inode->i_mode)) { | |
778f3dd5 | 419 | #ifdef CONFIG_COMPAT |
a1d4aebb DH |
420 | if (!de->proc_fops->compat_ioctl) |
421 | inode->i_fop = | |
422 | &proc_reg_file_ops_no_compat; | |
423 | else | |
778f3dd5 | 424 | #endif |
a1d4aebb DH |
425 | inode->i_fop = &proc_reg_file_ops; |
426 | } else { | |
427 | inode->i_fop = de->proc_fops; | |
428 | } | |
778f3dd5 | 429 | } |
786d7e16 | 430 | } |
a1d4aebb | 431 | unlock_new_inode(inode); |
1da177e4 | 432 | } |
1da177e4 LT |
433 | return inode; |
434 | ||
e9543659 KK |
435 | out_ino: |
436 | if (de != NULL) | |
437 | module_put(de->owner); | |
438 | out_mod: | |
e9543659 | 439 | return NULL; |
1da177e4 LT |
440 | } |
441 | ||
07543f5c | 442 | int proc_fill_super(struct super_block *s) |
1da177e4 LT |
443 | { |
444 | struct inode * root_inode; | |
445 | ||
92d03285 | 446 | s->s_flags |= MS_NODIRATIME | MS_NOSUID | MS_NOEXEC; |
1da177e4 LT |
447 | s->s_blocksize = 1024; |
448 | s->s_blocksize_bits = 10; | |
449 | s->s_magic = PROC_SUPER_MAGIC; | |
450 | s->s_op = &proc_sops; | |
451 | s->s_time_gran = 1; | |
452 | ||
7695650a | 453 | de_get(&proc_root); |
1da177e4 LT |
454 | root_inode = proc_get_inode(s, PROC_ROOT_INO, &proc_root); |
455 | if (!root_inode) | |
456 | goto out_no_root; | |
1da177e4 LT |
457 | root_inode->i_uid = 0; |
458 | root_inode->i_gid = 0; | |
459 | s->s_root = d_alloc_root(root_inode); | |
460 | if (!s->s_root) | |
461 | goto out_no_root; | |
462 | return 0; | |
463 | ||
464 | out_no_root: | |
465 | printk("proc_read_super: get root inode failed\n"); | |
466 | iput(root_inode); | |
7695650a | 467 | de_put(&proc_root); |
1da177e4 LT |
468 | return -ENOMEM; |
469 | } |