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> |
1da177e4 LT |
14 | #include <linux/file.h> |
15 | #include <linux/limits.h> | |
16 | #include <linux/init.h> | |
17 | #include <linux/module.h> | |
18 | #include <linux/smp_lock.h> | |
19 | ||
20 | #include <asm/system.h> | |
21 | #include <asm/uaccess.h> | |
22 | ||
fee781e6 | 23 | #include "internal.h" |
1da177e4 | 24 | |
7695650a | 25 | struct proc_dir_entry *de_get(struct proc_dir_entry *de) |
1da177e4 LT |
26 | { |
27 | if (de) | |
28 | atomic_inc(&de->count); | |
29 | return de; | |
30 | } | |
31 | ||
32 | /* | |
33 | * Decrements the use count and checks for deferred deletion. | |
34 | */ | |
7695650a | 35 | void de_put(struct proc_dir_entry *de) |
1da177e4 LT |
36 | { |
37 | if (de) { | |
38 | lock_kernel(); | |
39 | if (!atomic_read(&de->count)) { | |
40 | printk("de_put: entry %s already free!\n", de->name); | |
41 | unlock_kernel(); | |
42 | return; | |
43 | } | |
44 | ||
45 | if (atomic_dec_and_test(&de->count)) { | |
46 | if (de->deleted) { | |
47 | printk("de_put: deferred delete of %s\n", | |
48 | de->name); | |
49 | free_proc_entry(de); | |
50 | } | |
51 | } | |
52 | unlock_kernel(); | |
53 | } | |
54 | } | |
55 | ||
56 | /* | |
57 | * Decrement the use count of the proc_dir_entry. | |
58 | */ | |
59 | static void proc_delete_inode(struct inode *inode) | |
60 | { | |
61 | struct proc_dir_entry *de; | |
1da177e4 | 62 | |
fef26658 MF |
63 | truncate_inode_pages(&inode->i_data, 0); |
64 | ||
99f89551 | 65 | /* Stop tracking associated processes */ |
13b41b09 | 66 | put_pid(PROC_I(inode)->pid); |
1da177e4 LT |
67 | |
68 | /* Let go of any associated proc directory entry */ | |
69 | de = PROC_I(inode)->pde; | |
70 | if (de) { | |
71 | if (de->owner) | |
72 | module_put(de->owner); | |
73 | de_put(de); | |
74 | } | |
75 | clear_inode(inode); | |
76 | } | |
77 | ||
78 | struct vfsmount *proc_mnt; | |
79 | ||
80 | static void proc_read_inode(struct inode * inode) | |
81 | { | |
82 | inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; | |
83 | } | |
84 | ||
e18b890b | 85 | static struct kmem_cache * proc_inode_cachep; |
1da177e4 LT |
86 | |
87 | static struct inode *proc_alloc_inode(struct super_block *sb) | |
88 | { | |
89 | struct proc_inode *ei; | |
90 | struct inode *inode; | |
91 | ||
e94b1766 | 92 | ei = (struct proc_inode *)kmem_cache_alloc(proc_inode_cachep, GFP_KERNEL); |
1da177e4 LT |
93 | if (!ei) |
94 | return NULL; | |
13b41b09 | 95 | ei->pid = NULL; |
aed7a6c4 | 96 | ei->fd = 0; |
1da177e4 LT |
97 | ei->op.proc_get_link = NULL; |
98 | ei->pde = NULL; | |
99 | inode = &ei->vfs_inode; | |
100 | inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME; | |
101 | return inode; | |
102 | } | |
103 | ||
104 | static void proc_destroy_inode(struct inode *inode) | |
105 | { | |
106 | kmem_cache_free(proc_inode_cachep, PROC_I(inode)); | |
107 | } | |
108 | ||
e18b890b | 109 | static void init_once(void * foo, struct kmem_cache * cachep, unsigned long flags) |
1da177e4 LT |
110 | { |
111 | struct proc_inode *ei = (struct proc_inode *) foo; | |
112 | ||
a35afb83 | 113 | inode_init_once(&ei->vfs_inode); |
1da177e4 | 114 | } |
20c2df83 | 115 | |
1da177e4 LT |
116 | int __init proc_init_inodecache(void) |
117 | { | |
118 | proc_inode_cachep = kmem_cache_create("proc_inode_cache", | |
119 | sizeof(struct proc_inode), | |
fffb60f9 PJ |
120 | 0, (SLAB_RECLAIM_ACCOUNT| |
121 | SLAB_MEM_SPREAD), | |
20c2df83 | 122 | init_once); |
1da177e4 LT |
123 | if (proc_inode_cachep == NULL) |
124 | return -ENOMEM; | |
125 | return 0; | |
126 | } | |
127 | ||
128 | static int proc_remount(struct super_block *sb, int *flags, char *data) | |
129 | { | |
130 | *flags |= MS_NODIRATIME; | |
131 | return 0; | |
132 | } | |
133 | ||
ee9b6d61 | 134 | static const struct super_operations proc_sops = { |
1da177e4 LT |
135 | .alloc_inode = proc_alloc_inode, |
136 | .destroy_inode = proc_destroy_inode, | |
137 | .read_inode = proc_read_inode, | |
138 | .drop_inode = generic_delete_inode, | |
139 | .delete_inode = proc_delete_inode, | |
140 | .statfs = simple_statfs, | |
141 | .remount_fs = proc_remount, | |
142 | }; | |
143 | ||
786d7e16 AD |
144 | static void pde_users_dec(struct proc_dir_entry *pde) |
145 | { | |
146 | spin_lock(&pde->pde_unload_lock); | |
147 | pde->pde_users--; | |
148 | if (pde->pde_unload_completion && pde->pde_users == 0) | |
149 | complete(pde->pde_unload_completion); | |
150 | spin_unlock(&pde->pde_unload_lock); | |
151 | } | |
152 | ||
153 | static loff_t proc_reg_llseek(struct file *file, loff_t offset, int whence) | |
154 | { | |
155 | struct proc_dir_entry *pde = PDE(file->f_path.dentry->d_inode); | |
156 | loff_t rv = -EINVAL; | |
157 | loff_t (*llseek)(struct file *, loff_t, int); | |
158 | ||
159 | spin_lock(&pde->pde_unload_lock); | |
160 | /* | |
161 | * remove_proc_entry() is going to delete PDE (as part of module | |
162 | * cleanup sequence). No new callers into module allowed. | |
163 | */ | |
164 | if (!pde->proc_fops) { | |
165 | spin_unlock(&pde->pde_unload_lock); | |
166 | return rv; | |
167 | } | |
168 | /* | |
169 | * Bump refcount so that remove_proc_entry will wail for ->llseek to | |
170 | * complete. | |
171 | */ | |
172 | pde->pde_users++; | |
173 | /* | |
174 | * Save function pointer under lock, to protect against ->proc_fops | |
175 | * NULL'ifying right after ->pde_unload_lock is dropped. | |
176 | */ | |
177 | llseek = pde->proc_fops->llseek; | |
178 | spin_unlock(&pde->pde_unload_lock); | |
179 | ||
180 | if (!llseek) | |
181 | llseek = default_llseek; | |
182 | rv = llseek(file, offset, whence); | |
183 | ||
184 | pde_users_dec(pde); | |
185 | return rv; | |
186 | } | |
187 | ||
188 | static ssize_t proc_reg_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) | |
189 | { | |
190 | struct proc_dir_entry *pde = PDE(file->f_path.dentry->d_inode); | |
191 | ssize_t rv = -EIO; | |
192 | ssize_t (*read)(struct file *, char __user *, size_t, loff_t *); | |
193 | ||
194 | spin_lock(&pde->pde_unload_lock); | |
195 | if (!pde->proc_fops) { | |
196 | spin_unlock(&pde->pde_unload_lock); | |
197 | return rv; | |
198 | } | |
199 | pde->pde_users++; | |
200 | read = pde->proc_fops->read; | |
201 | spin_unlock(&pde->pde_unload_lock); | |
202 | ||
203 | if (read) | |
204 | rv = read(file, buf, count, ppos); | |
205 | ||
206 | pde_users_dec(pde); | |
207 | return rv; | |
208 | } | |
209 | ||
210 | static ssize_t proc_reg_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) | |
211 | { | |
212 | struct proc_dir_entry *pde = PDE(file->f_path.dentry->d_inode); | |
213 | ssize_t rv = -EIO; | |
214 | ssize_t (*write)(struct file *, const char __user *, size_t, loff_t *); | |
215 | ||
216 | spin_lock(&pde->pde_unload_lock); | |
217 | if (!pde->proc_fops) { | |
218 | spin_unlock(&pde->pde_unload_lock); | |
219 | return rv; | |
220 | } | |
221 | pde->pde_users++; | |
222 | write = pde->proc_fops->write; | |
223 | spin_unlock(&pde->pde_unload_lock); | |
224 | ||
225 | if (write) | |
226 | rv = write(file, buf, count, ppos); | |
227 | ||
228 | pde_users_dec(pde); | |
229 | return rv; | |
230 | } | |
231 | ||
232 | static unsigned int proc_reg_poll(struct file *file, struct poll_table_struct *pts) | |
233 | { | |
234 | struct proc_dir_entry *pde = PDE(file->f_path.dentry->d_inode); | |
235 | unsigned int rv = 0; | |
236 | unsigned int (*poll)(struct file *, struct poll_table_struct *); | |
237 | ||
238 | spin_lock(&pde->pde_unload_lock); | |
239 | if (!pde->proc_fops) { | |
240 | spin_unlock(&pde->pde_unload_lock); | |
241 | return rv; | |
242 | } | |
243 | pde->pde_users++; | |
244 | poll = pde->proc_fops->poll; | |
245 | spin_unlock(&pde->pde_unload_lock); | |
246 | ||
247 | if (poll) | |
248 | rv = poll(file, pts); | |
249 | ||
250 | pde_users_dec(pde); | |
251 | return rv; | |
252 | } | |
253 | ||
254 | static long proc_reg_unlocked_ioctl(struct file *file, unsigned int cmd, unsigned long arg) | |
255 | { | |
256 | struct proc_dir_entry *pde = PDE(file->f_path.dentry->d_inode); | |
257 | long rv = -ENOTTY; | |
258 | long (*unlocked_ioctl)(struct file *, unsigned int, unsigned long); | |
259 | int (*ioctl)(struct inode *, struct file *, unsigned int, unsigned long); | |
260 | ||
261 | spin_lock(&pde->pde_unload_lock); | |
262 | if (!pde->proc_fops) { | |
263 | spin_unlock(&pde->pde_unload_lock); | |
264 | return rv; | |
265 | } | |
266 | pde->pde_users++; | |
267 | unlocked_ioctl = pde->proc_fops->unlocked_ioctl; | |
268 | ioctl = pde->proc_fops->ioctl; | |
269 | spin_unlock(&pde->pde_unload_lock); | |
270 | ||
271 | if (unlocked_ioctl) { | |
272 | rv = unlocked_ioctl(file, cmd, arg); | |
273 | if (rv == -ENOIOCTLCMD) | |
274 | rv = -EINVAL; | |
275 | } else if (ioctl) { | |
276 | lock_kernel(); | |
277 | rv = ioctl(file->f_path.dentry->d_inode, file, cmd, arg); | |
278 | unlock_kernel(); | |
279 | } | |
280 | ||
281 | pde_users_dec(pde); | |
282 | return rv; | |
283 | } | |
284 | ||
285 | #ifdef CONFIG_COMPAT | |
286 | static long proc_reg_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg) | |
287 | { | |
288 | struct proc_dir_entry *pde = PDE(file->f_path.dentry->d_inode); | |
289 | long rv = -ENOTTY; | |
290 | long (*compat_ioctl)(struct file *, unsigned int, unsigned long); | |
291 | ||
292 | spin_lock(&pde->pde_unload_lock); | |
293 | if (!pde->proc_fops) { | |
294 | spin_unlock(&pde->pde_unload_lock); | |
295 | return rv; | |
296 | } | |
297 | pde->pde_users++; | |
298 | compat_ioctl = pde->proc_fops->compat_ioctl; | |
299 | spin_unlock(&pde->pde_unload_lock); | |
300 | ||
301 | if (compat_ioctl) | |
302 | rv = compat_ioctl(file, cmd, arg); | |
303 | ||
304 | pde_users_dec(pde); | |
305 | return rv; | |
306 | } | |
307 | #endif | |
308 | ||
309 | static int proc_reg_mmap(struct file *file, struct vm_area_struct *vma) | |
310 | { | |
311 | struct proc_dir_entry *pde = PDE(file->f_path.dentry->d_inode); | |
312 | int rv = -EIO; | |
313 | int (*mmap)(struct file *, struct vm_area_struct *); | |
314 | ||
315 | spin_lock(&pde->pde_unload_lock); | |
316 | if (!pde->proc_fops) { | |
317 | spin_unlock(&pde->pde_unload_lock); | |
318 | return rv; | |
319 | } | |
320 | pde->pde_users++; | |
321 | mmap = pde->proc_fops->mmap; | |
322 | spin_unlock(&pde->pde_unload_lock); | |
323 | ||
324 | if (mmap) | |
325 | rv = mmap(file, vma); | |
326 | ||
327 | pde_users_dec(pde); | |
328 | return rv; | |
329 | } | |
330 | ||
331 | static int proc_reg_open(struct inode *inode, struct file *file) | |
332 | { | |
333 | struct proc_dir_entry *pde = PDE(inode); | |
334 | int rv = 0; | |
335 | int (*open)(struct inode *, struct file *); | |
336 | ||
337 | spin_lock(&pde->pde_unload_lock); | |
338 | if (!pde->proc_fops) { | |
339 | spin_unlock(&pde->pde_unload_lock); | |
340 | return rv; | |
341 | } | |
342 | pde->pde_users++; | |
343 | open = pde->proc_fops->open; | |
344 | spin_unlock(&pde->pde_unload_lock); | |
345 | ||
346 | if (open) | |
347 | rv = open(inode, file); | |
348 | ||
349 | pde_users_dec(pde); | |
350 | return rv; | |
351 | } | |
352 | ||
353 | static int proc_reg_release(struct inode *inode, struct file *file) | |
354 | { | |
355 | struct proc_dir_entry *pde = PDE(inode); | |
356 | int rv = 0; | |
357 | int (*release)(struct inode *, struct file *); | |
358 | ||
359 | spin_lock(&pde->pde_unload_lock); | |
360 | if (!pde->proc_fops) { | |
361 | spin_unlock(&pde->pde_unload_lock); | |
362 | return rv; | |
363 | } | |
364 | pde->pde_users++; | |
365 | release = pde->proc_fops->release; | |
366 | spin_unlock(&pde->pde_unload_lock); | |
367 | ||
368 | if (release) | |
369 | rv = release(inode, file); | |
370 | ||
371 | pde_users_dec(pde); | |
372 | return rv; | |
373 | } | |
374 | ||
375 | static const struct file_operations proc_reg_file_ops = { | |
376 | .llseek = proc_reg_llseek, | |
377 | .read = proc_reg_read, | |
378 | .write = proc_reg_write, | |
379 | .poll = proc_reg_poll, | |
380 | .unlocked_ioctl = proc_reg_unlocked_ioctl, | |
381 | #ifdef CONFIG_COMPAT | |
382 | .compat_ioctl = proc_reg_compat_ioctl, | |
383 | #endif | |
384 | .mmap = proc_reg_mmap, | |
385 | .open = proc_reg_open, | |
386 | .release = proc_reg_release, | |
387 | }; | |
388 | ||
1da177e4 LT |
389 | struct inode *proc_get_inode(struct super_block *sb, unsigned int ino, |
390 | struct proc_dir_entry *de) | |
391 | { | |
392 | struct inode * inode; | |
393 | ||
e9543659 KK |
394 | if (de != NULL && !try_module_get(de->owner)) |
395 | goto out_mod; | |
396 | ||
1da177e4 LT |
397 | inode = iget(sb, ino); |
398 | if (!inode) | |
e9543659 KK |
399 | goto out_ino; |
400 | ||
77b14db5 | 401 | PROC_I(inode)->fd = 0; |
1da177e4 LT |
402 | PROC_I(inode)->pde = de; |
403 | if (de) { | |
404 | if (de->mode) { | |
405 | inode->i_mode = de->mode; | |
406 | inode->i_uid = de->uid; | |
407 | inode->i_gid = de->gid; | |
408 | } | |
409 | if (de->size) | |
410 | inode->i_size = de->size; | |
411 | if (de->nlink) | |
412 | inode->i_nlink = de->nlink; | |
1da177e4 LT |
413 | if (de->proc_iops) |
414 | inode->i_op = de->proc_iops; | |
786d7e16 AD |
415 | if (de->proc_fops) { |
416 | if (S_ISREG(inode->i_mode)) | |
417 | inode->i_fop = &proc_reg_file_ops; | |
418 | else | |
419 | inode->i_fop = de->proc_fops; | |
420 | } | |
1da177e4 LT |
421 | } |
422 | ||
1da177e4 LT |
423 | return inode; |
424 | ||
e9543659 KK |
425 | out_ino: |
426 | if (de != NULL) | |
427 | module_put(de->owner); | |
428 | out_mod: | |
e9543659 | 429 | return NULL; |
1da177e4 LT |
430 | } |
431 | ||
432 | int proc_fill_super(struct super_block *s, void *data, int silent) | |
433 | { | |
434 | struct inode * root_inode; | |
435 | ||
92d03285 | 436 | s->s_flags |= MS_NODIRATIME | MS_NOSUID | MS_NOEXEC; |
1da177e4 LT |
437 | s->s_blocksize = 1024; |
438 | s->s_blocksize_bits = 10; | |
439 | s->s_magic = PROC_SUPER_MAGIC; | |
440 | s->s_op = &proc_sops; | |
441 | s->s_time_gran = 1; | |
442 | ||
7695650a | 443 | de_get(&proc_root); |
1da177e4 LT |
444 | root_inode = proc_get_inode(s, PROC_ROOT_INO, &proc_root); |
445 | if (!root_inode) | |
446 | goto out_no_root; | |
1da177e4 LT |
447 | root_inode->i_uid = 0; |
448 | root_inode->i_gid = 0; | |
449 | s->s_root = d_alloc_root(root_inode); | |
450 | if (!s->s_root) | |
451 | goto out_no_root; | |
452 | return 0; | |
453 | ||
454 | out_no_root: | |
455 | printk("proc_read_super: get root inode failed\n"); | |
456 | iput(root_inode); | |
7695650a | 457 | de_put(&proc_root); |
1da177e4 LT |
458 | return -ENOMEM; |
459 | } | |
460 | MODULE_LICENSE("GPL"); |