Commit | Line | Data |
---|---|---|
1da177e4 | 1 | /* |
bd33d12f | 2 | * inode.c - part of debugfs, a tiny little debug file system |
1da177e4 LT |
3 | * |
4 | * Copyright (C) 2004 Greg Kroah-Hartman <greg@kroah.com> | |
5 | * Copyright (C) 2004 IBM Inc. | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or | |
8 | * modify it under the terms of the GNU General Public License version | |
9 | * 2 as published by the Free Software Foundation. | |
10 | * | |
11 | * debugfs is for people to use instead of /proc or /sys. | |
12 | * See Documentation/DocBook/kernel-api for more details. | |
13 | * | |
14 | */ | |
15 | ||
1da177e4 LT |
16 | #include <linux/module.h> |
17 | #include <linux/fs.h> | |
18 | #include <linux/mount.h> | |
19 | #include <linux/pagemap.h> | |
20 | #include <linux/init.h> | |
4d8ebddc | 21 | #include <linux/kobject.h> |
1da177e4 LT |
22 | #include <linux/namei.h> |
23 | #include <linux/debugfs.h> | |
4f36557f | 24 | #include <linux/fsnotify.h> |
66f54963 | 25 | #include <linux/string.h> |
d6e48686 LN |
26 | #include <linux/seq_file.h> |
27 | #include <linux/parser.h> | |
92562927 | 28 | #include <linux/magic.h> |
5a0e3ad6 | 29 | #include <linux/slab.h> |
1da177e4 | 30 | |
d6e48686 LN |
31 | #define DEBUGFS_DEFAULT_MODE 0755 |
32 | ||
1da177e4 LT |
33 | static struct vfsmount *debugfs_mount; |
34 | static int debugfs_mount_count; | |
c0f92ba9 | 35 | static bool debugfs_registered; |
1da177e4 | 36 | |
f4ae40a6 | 37 | static struct inode *debugfs_get_inode(struct super_block *sb, umode_t mode, dev_t dev, |
d3a3b0ad MD |
38 | void *data, const struct file_operations *fops) |
39 | ||
1da177e4 LT |
40 | { |
41 | struct inode *inode = new_inode(sb); | |
42 | ||
43 | if (inode) { | |
85fe4025 | 44 | inode->i_ino = get_next_ino(); |
1da177e4 | 45 | inode->i_mode = mode; |
1da177e4 LT |
46 | inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; |
47 | switch (mode & S_IFMT) { | |
48 | default: | |
49 | init_special_inode(inode, mode, dev); | |
50 | break; | |
51 | case S_IFREG: | |
d3a3b0ad MD |
52 | inode->i_fop = fops ? fops : &debugfs_file_operations; |
53 | inode->i_private = data; | |
1da177e4 | 54 | break; |
66f54963 PO |
55 | case S_IFLNK: |
56 | inode->i_op = &debugfs_link_operations; | |
d3a3b0ad MD |
57 | inode->i_fop = fops; |
58 | inode->i_private = data; | |
66f54963 | 59 | break; |
1da177e4 LT |
60 | case S_IFDIR: |
61 | inode->i_op = &simple_dir_inode_operations; | |
d3a3b0ad MD |
62 | inode->i_fop = fops ? fops : &simple_dir_operations; |
63 | inode->i_private = data; | |
1da177e4 | 64 | |
bafb232e MD |
65 | /* directory inodes start off with i_nlink == 2 |
66 | * (for "." entry) */ | |
d8c76e6f | 67 | inc_nlink(inode); |
1da177e4 LT |
68 | break; |
69 | } | |
70 | } | |
71 | return inode; | |
72 | } | |
73 | ||
74 | /* SMP-safe */ | |
75 | static int debugfs_mknod(struct inode *dir, struct dentry *dentry, | |
f4ae40a6 | 76 | umode_t mode, dev_t dev, void *data, |
d3a3b0ad | 77 | const struct file_operations *fops) |
1da177e4 | 78 | { |
71601e2b | 79 | struct inode *inode; |
1da177e4 LT |
80 | int error = -EPERM; |
81 | ||
82 | if (dentry->d_inode) | |
83 | return -EEXIST; | |
84 | ||
d3a3b0ad | 85 | inode = debugfs_get_inode(dir->i_sb, mode, dev, data, fops); |
1da177e4 LT |
86 | if (inode) { |
87 | d_instantiate(dentry, inode); | |
88 | dget(dentry); | |
89 | error = 0; | |
90 | } | |
91 | return error; | |
92 | } | |
93 | ||
f4ae40a6 | 94 | static int debugfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode, |
d3a3b0ad | 95 | void *data, const struct file_operations *fops) |
1da177e4 LT |
96 | { |
97 | int res; | |
98 | ||
99 | mode = (mode & (S_IRWXUGO | S_ISVTX)) | S_IFDIR; | |
d3a3b0ad | 100 | res = debugfs_mknod(dir, dentry, mode, 0, data, fops); |
4f36557f | 101 | if (!res) { |
d8c76e6f | 102 | inc_nlink(dir); |
4f36557f MD |
103 | fsnotify_mkdir(dir, dentry); |
104 | } | |
1da177e4 LT |
105 | return res; |
106 | } | |
107 | ||
f4ae40a6 | 108 | static int debugfs_link(struct inode *dir, struct dentry *dentry, umode_t mode, |
d3a3b0ad | 109 | void *data, const struct file_operations *fops) |
66f54963 PO |
110 | { |
111 | mode = (mode & S_IALLUGO) | S_IFLNK; | |
d3a3b0ad | 112 | return debugfs_mknod(dir, dentry, mode, 0, data, fops); |
66f54963 PO |
113 | } |
114 | ||
f4ae40a6 | 115 | static int debugfs_create(struct inode *dir, struct dentry *dentry, umode_t mode, |
d3a3b0ad | 116 | void *data, const struct file_operations *fops) |
1da177e4 | 117 | { |
4f36557f MD |
118 | int res; |
119 | ||
1da177e4 | 120 | mode = (mode & S_IALLUGO) | S_IFREG; |
d3a3b0ad | 121 | res = debugfs_mknod(dir, dentry, mode, 0, data, fops); |
4f36557f MD |
122 | if (!res) |
123 | fsnotify_create(dir, dentry); | |
124 | return res; | |
1da177e4 LT |
125 | } |
126 | ||
127 | static inline int debugfs_positive(struct dentry *dentry) | |
128 | { | |
129 | return dentry->d_inode && !d_unhashed(dentry); | |
130 | } | |
131 | ||
d6e48686 LN |
132 | struct debugfs_mount_opts { |
133 | uid_t uid; | |
134 | gid_t gid; | |
135 | umode_t mode; | |
136 | }; | |
137 | ||
138 | enum { | |
139 | Opt_uid, | |
140 | Opt_gid, | |
141 | Opt_mode, | |
142 | Opt_err | |
143 | }; | |
144 | ||
145 | static const match_table_t tokens = { | |
146 | {Opt_uid, "uid=%u"}, | |
147 | {Opt_gid, "gid=%u"}, | |
148 | {Opt_mode, "mode=%o"}, | |
149 | {Opt_err, NULL} | |
150 | }; | |
151 | ||
152 | struct debugfs_fs_info { | |
153 | struct debugfs_mount_opts mount_opts; | |
154 | }; | |
155 | ||
156 | static int debugfs_parse_options(char *data, struct debugfs_mount_opts *opts) | |
157 | { | |
158 | substring_t args[MAX_OPT_ARGS]; | |
159 | int option; | |
160 | int token; | |
161 | char *p; | |
162 | ||
163 | opts->mode = DEBUGFS_DEFAULT_MODE; | |
164 | ||
165 | while ((p = strsep(&data, ",")) != NULL) { | |
166 | if (!*p) | |
167 | continue; | |
168 | ||
169 | token = match_token(p, tokens, args); | |
170 | switch (token) { | |
171 | case Opt_uid: | |
172 | if (match_int(&args[0], &option)) | |
173 | return -EINVAL; | |
174 | opts->uid = option; | |
175 | break; | |
176 | case Opt_gid: | |
177 | if (match_octal(&args[0], &option)) | |
178 | return -EINVAL; | |
179 | opts->gid = option; | |
180 | break; | |
181 | case Opt_mode: | |
182 | if (match_octal(&args[0], &option)) | |
183 | return -EINVAL; | |
184 | opts->mode = option & S_IALLUGO; | |
185 | break; | |
186 | /* | |
187 | * We might like to report bad mount options here; | |
188 | * but traditionally debugfs has ignored all mount options | |
189 | */ | |
190 | } | |
191 | } | |
192 | ||
193 | return 0; | |
194 | } | |
195 | ||
196 | static int debugfs_apply_options(struct super_block *sb) | |
197 | { | |
198 | struct debugfs_fs_info *fsi = sb->s_fs_info; | |
199 | struct inode *inode = sb->s_root->d_inode; | |
200 | struct debugfs_mount_opts *opts = &fsi->mount_opts; | |
201 | ||
202 | inode->i_mode &= ~S_IALLUGO; | |
203 | inode->i_mode |= opts->mode; | |
204 | ||
205 | inode->i_uid = opts->uid; | |
206 | inode->i_gid = opts->gid; | |
207 | ||
208 | return 0; | |
209 | } | |
210 | ||
211 | static int debugfs_remount(struct super_block *sb, int *flags, char *data) | |
212 | { | |
213 | int err; | |
214 | struct debugfs_fs_info *fsi = sb->s_fs_info; | |
215 | ||
216 | err = debugfs_parse_options(data, &fsi->mount_opts); | |
217 | if (err) | |
218 | goto fail; | |
219 | ||
220 | debugfs_apply_options(sb); | |
221 | ||
222 | fail: | |
223 | return err; | |
224 | } | |
225 | ||
226 | static int debugfs_show_options(struct seq_file *m, struct dentry *root) | |
227 | { | |
228 | struct debugfs_fs_info *fsi = root->d_sb->s_fs_info; | |
229 | struct debugfs_mount_opts *opts = &fsi->mount_opts; | |
230 | ||
231 | if (opts->uid != 0) | |
232 | seq_printf(m, ",uid=%u", opts->uid); | |
233 | if (opts->gid != 0) | |
234 | seq_printf(m, ",gid=%u", opts->gid); | |
235 | if (opts->mode != DEBUGFS_DEFAULT_MODE) | |
236 | seq_printf(m, ",mode=%o", opts->mode); | |
237 | ||
238 | return 0; | |
239 | } | |
240 | ||
241 | static const struct super_operations debugfs_super_operations = { | |
242 | .statfs = simple_statfs, | |
243 | .remount_fs = debugfs_remount, | |
244 | .show_options = debugfs_show_options, | |
245 | }; | |
246 | ||
1da177e4 LT |
247 | static int debug_fill_super(struct super_block *sb, void *data, int silent) |
248 | { | |
249 | static struct tree_descr debug_files[] = {{""}}; | |
d6e48686 LN |
250 | struct debugfs_fs_info *fsi; |
251 | int err; | |
252 | ||
253 | save_mount_options(sb, data); | |
254 | ||
255 | fsi = kzalloc(sizeof(struct debugfs_fs_info), GFP_KERNEL); | |
256 | sb->s_fs_info = fsi; | |
257 | if (!fsi) { | |
258 | err = -ENOMEM; | |
259 | goto fail; | |
260 | } | |
261 | ||
262 | err = debugfs_parse_options(data, &fsi->mount_opts); | |
263 | if (err) | |
264 | goto fail; | |
265 | ||
266 | err = simple_fill_super(sb, DEBUGFS_MAGIC, debug_files); | |
267 | if (err) | |
268 | goto fail; | |
269 | ||
270 | sb->s_op = &debugfs_super_operations; | |
271 | ||
272 | debugfs_apply_options(sb); | |
273 | ||
274 | return 0; | |
1da177e4 | 275 | |
d6e48686 LN |
276 | fail: |
277 | kfree(fsi); | |
278 | sb->s_fs_info = NULL; | |
279 | return err; | |
1da177e4 LT |
280 | } |
281 | ||
fc14f2fe | 282 | static struct dentry *debug_mount(struct file_system_type *fs_type, |
454e2398 | 283 | int flags, const char *dev_name, |
fc14f2fe | 284 | void *data) |
1da177e4 | 285 | { |
fc14f2fe | 286 | return mount_single(fs_type, flags, data, debug_fill_super); |
1da177e4 LT |
287 | } |
288 | ||
289 | static struct file_system_type debug_fs_type = { | |
290 | .owner = THIS_MODULE, | |
291 | .name = "debugfs", | |
fc14f2fe | 292 | .mount = debug_mount, |
1da177e4 LT |
293 | .kill_sb = kill_litter_super, |
294 | }; | |
295 | ||
f4ae40a6 | 296 | static int debugfs_create_by_name(const char *name, umode_t mode, |
1da177e4 | 297 | struct dentry *parent, |
d3a3b0ad MD |
298 | struct dentry **dentry, |
299 | void *data, | |
300 | const struct file_operations *fops) | |
1da177e4 LT |
301 | { |
302 | int error = 0; | |
303 | ||
304 | /* If the parent is not specified, we create it in the root. | |
305 | * We need the root dentry to do this, which is in the super | |
306 | * block. A pointer to that is in the struct vfsmount that we | |
307 | * have around. | |
308 | */ | |
ef52c75e | 309 | if (!parent) |
4c1d5a64 | 310 | parent = debugfs_mount->mnt_root; |
1da177e4 LT |
311 | |
312 | *dentry = NULL; | |
1b1dcc1b | 313 | mutex_lock(&parent->d_inode->i_mutex); |
5f45f1a7 | 314 | *dentry = lookup_one_len(name, parent, strlen(name)); |
7bb0386f | 315 | if (!IS_ERR(*dentry)) { |
66f54963 PO |
316 | switch (mode & S_IFMT) { |
317 | case S_IFDIR: | |
d3a3b0ad MD |
318 | error = debugfs_mkdir(parent->d_inode, *dentry, mode, |
319 | data, fops); | |
66f54963 PO |
320 | break; |
321 | case S_IFLNK: | |
d3a3b0ad MD |
322 | error = debugfs_link(parent->d_inode, *dentry, mode, |
323 | data, fops); | |
66f54963 PO |
324 | break; |
325 | default: | |
d3a3b0ad MD |
326 | error = debugfs_create(parent->d_inode, *dentry, mode, |
327 | data, fops); | |
66f54963 PO |
328 | break; |
329 | } | |
65c33336 | 330 | dput(*dentry); |
1da177e4 | 331 | } else |
7bb0386f | 332 | error = PTR_ERR(*dentry); |
1b1dcc1b | 333 | mutex_unlock(&parent->d_inode->i_mutex); |
1da177e4 LT |
334 | |
335 | return error; | |
336 | } | |
337 | ||
c3b1a350 AV |
338 | struct dentry *__create_file(const char *name, umode_t mode, |
339 | struct dentry *parent, void *data, | |
340 | const struct file_operations *fops) | |
341 | { | |
342 | struct dentry *dentry = NULL; | |
343 | int error; | |
344 | ||
345 | pr_debug("debugfs: creating file '%s'\n",name); | |
346 | ||
347 | error = simple_pin_fs(&debug_fs_type, &debugfs_mount, | |
348 | &debugfs_mount_count); | |
349 | if (error) | |
350 | goto exit; | |
351 | ||
352 | error = debugfs_create_by_name(name, mode, parent, &dentry, | |
353 | data, fops); | |
354 | if (error) { | |
355 | dentry = NULL; | |
356 | simple_release_fs(&debugfs_mount, &debugfs_mount_count); | |
357 | } | |
358 | exit: | |
359 | return dentry; | |
360 | } | |
361 | ||
1da177e4 LT |
362 | /** |
363 | * debugfs_create_file - create a file in the debugfs filesystem | |
1da177e4 | 364 | * @name: a pointer to a string containing the name of the file to create. |
be030e65 | 365 | * @mode: the permission that the file should have. |
1da177e4 LT |
366 | * @parent: a pointer to the parent dentry for this file. This should be a |
367 | * directory dentry if set. If this paramater is NULL, then the | |
368 | * file will be created in the root of the debugfs filesystem. | |
369 | * @data: a pointer to something that the caller will want to get to later | |
8e18e294 | 370 | * on. The inode.i_private pointer will point to this value on |
1da177e4 LT |
371 | * the open() call. |
372 | * @fops: a pointer to a struct file_operations that should be used for | |
373 | * this file. | |
374 | * | |
375 | * This is the basic "create a file" function for debugfs. It allows for a | |
be030e65 AB |
376 | * wide range of flexibility in creating a file, or a directory (if you want |
377 | * to create a directory, the debugfs_create_dir() function is | |
1da177e4 LT |
378 | * recommended to be used instead.) |
379 | * | |
380 | * This function will return a pointer to a dentry if it succeeds. This | |
381 | * pointer must be passed to the debugfs_remove() function when the file is | |
382 | * to be removed (no automatic cleanup happens if your module is unloaded, | |
6468b3af | 383 | * you are responsible here.) If an error occurs, %NULL will be returned. |
1da177e4 | 384 | * |
6468b3af | 385 | * If debugfs is not enabled in the kernel, the value -%ENODEV will be |
873760fb | 386 | * returned. |
1da177e4 | 387 | */ |
f4ae40a6 | 388 | struct dentry *debugfs_create_file(const char *name, umode_t mode, |
1da177e4 | 389 | struct dentry *parent, void *data, |
99ac48f5 | 390 | const struct file_operations *fops) |
1da177e4 | 391 | { |
c3b1a350 AV |
392 | switch (mode & S_IFMT) { |
393 | case S_IFREG: | |
394 | case 0: | |
395 | break; | |
396 | default: | |
397 | BUG(); | |
1da177e4 | 398 | } |
c3b1a350 AV |
399 | |
400 | return __create_file(name, mode, parent, data, fops); | |
1da177e4 LT |
401 | } |
402 | EXPORT_SYMBOL_GPL(debugfs_create_file); | |
403 | ||
404 | /** | |
405 | * debugfs_create_dir - create a directory in the debugfs filesystem | |
1da177e4 LT |
406 | * @name: a pointer to a string containing the name of the directory to |
407 | * create. | |
408 | * @parent: a pointer to the parent dentry for this file. This should be a | |
409 | * directory dentry if set. If this paramater is NULL, then the | |
410 | * directory will be created in the root of the debugfs filesystem. | |
411 | * | |
412 | * This function creates a directory in debugfs with the given name. | |
413 | * | |
414 | * This function will return a pointer to a dentry if it succeeds. This | |
415 | * pointer must be passed to the debugfs_remove() function when the file is | |
416 | * to be removed (no automatic cleanup happens if your module is unloaded, | |
6468b3af | 417 | * you are responsible here.) If an error occurs, %NULL will be returned. |
1da177e4 | 418 | * |
6468b3af | 419 | * If debugfs is not enabled in the kernel, the value -%ENODEV will be |
873760fb | 420 | * returned. |
1da177e4 LT |
421 | */ |
422 | struct dentry *debugfs_create_dir(const char *name, struct dentry *parent) | |
423 | { | |
c3b1a350 | 424 | return __create_file(name, S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO, |
1da177e4 LT |
425 | parent, NULL, NULL); |
426 | } | |
427 | EXPORT_SYMBOL_GPL(debugfs_create_dir); | |
428 | ||
66f54963 PO |
429 | /** |
430 | * debugfs_create_symlink- create a symbolic link in the debugfs filesystem | |
431 | * @name: a pointer to a string containing the name of the symbolic link to | |
432 | * create. | |
433 | * @parent: a pointer to the parent dentry for this symbolic link. This | |
434 | * should be a directory dentry if set. If this paramater is NULL, | |
435 | * then the symbolic link will be created in the root of the debugfs | |
436 | * filesystem. | |
437 | * @target: a pointer to a string containing the path to the target of the | |
438 | * symbolic link. | |
439 | * | |
440 | * This function creates a symbolic link with the given name in debugfs that | |
441 | * links to the given target path. | |
442 | * | |
443 | * This function will return a pointer to a dentry if it succeeds. This | |
444 | * pointer must be passed to the debugfs_remove() function when the symbolic | |
445 | * link is to be removed (no automatic cleanup happens if your module is | |
446 | * unloaded, you are responsible here.) If an error occurs, %NULL will be | |
447 | * returned. | |
448 | * | |
449 | * If debugfs is not enabled in the kernel, the value -%ENODEV will be | |
873760fb | 450 | * returned. |
66f54963 PO |
451 | */ |
452 | struct dentry *debugfs_create_symlink(const char *name, struct dentry *parent, | |
453 | const char *target) | |
454 | { | |
455 | struct dentry *result; | |
456 | char *link; | |
457 | ||
458 | link = kstrdup(target, GFP_KERNEL); | |
459 | if (!link) | |
460 | return NULL; | |
461 | ||
c3b1a350 | 462 | result = __create_file(name, S_IFLNK | S_IRWXUGO, parent, link, NULL); |
66f54963 PO |
463 | if (!result) |
464 | kfree(link); | |
465 | return result; | |
466 | } | |
467 | EXPORT_SYMBOL_GPL(debugfs_create_symlink); | |
468 | ||
25d41d84 | 469 | static int __debugfs_remove(struct dentry *dentry, struct dentry *parent) |
9505e637 HS |
470 | { |
471 | int ret = 0; | |
472 | ||
473 | if (debugfs_positive(dentry)) { | |
474 | if (dentry->d_inode) { | |
475 | dget(dentry); | |
476 | switch (dentry->d_inode->i_mode & S_IFMT) { | |
477 | case S_IFDIR: | |
478 | ret = simple_rmdir(parent->d_inode, dentry); | |
479 | break; | |
480 | case S_IFLNK: | |
481 | kfree(dentry->d_inode->i_private); | |
482 | /* fall through */ | |
483 | default: | |
484 | simple_unlink(parent->d_inode, dentry); | |
485 | break; | |
486 | } | |
487 | if (!ret) | |
488 | d_delete(dentry); | |
489 | dput(dentry); | |
490 | } | |
491 | } | |
25d41d84 | 492 | return ret; |
9505e637 HS |
493 | } |
494 | ||
1da177e4 LT |
495 | /** |
496 | * debugfs_remove - removes a file or directory from the debugfs filesystem | |
1da177e4 LT |
497 | * @dentry: a pointer to a the dentry of the file or directory to be |
498 | * removed. | |
499 | * | |
500 | * This function removes a file or directory in debugfs that was previously | |
501 | * created with a call to another debugfs function (like | |
5a65980e | 502 | * debugfs_create_file() or variants thereof.) |
1da177e4 LT |
503 | * |
504 | * This function is required to be called in order for the file to be | |
505 | * removed, no automatic cleanup of files will happen when a module is | |
506 | * removed, you are responsible here. | |
507 | */ | |
508 | void debugfs_remove(struct dentry *dentry) | |
509 | { | |
510 | struct dentry *parent; | |
25d41d84 JK |
511 | int ret; |
512 | ||
1da177e4 LT |
513 | if (!dentry) |
514 | return; | |
515 | ||
516 | parent = dentry->d_parent; | |
517 | if (!parent || !parent->d_inode) | |
518 | return; | |
519 | ||
1b1dcc1b | 520 | mutex_lock(&parent->d_inode->i_mutex); |
25d41d84 | 521 | ret = __debugfs_remove(dentry, parent); |
9505e637 | 522 | mutex_unlock(&parent->d_inode->i_mutex); |
25d41d84 JK |
523 | if (!ret) |
524 | simple_release_fs(&debugfs_mount, &debugfs_mount_count); | |
9505e637 HS |
525 | } |
526 | EXPORT_SYMBOL_GPL(debugfs_remove); | |
527 | ||
528 | /** | |
529 | * debugfs_remove_recursive - recursively removes a directory | |
530 | * @dentry: a pointer to a the dentry of the directory to be removed. | |
531 | * | |
532 | * This function recursively removes a directory tree in debugfs that | |
533 | * was previously created with a call to another debugfs function | |
534 | * (like debugfs_create_file() or variants thereof.) | |
535 | * | |
536 | * This function is required to be called in order for the file to be | |
537 | * removed, no automatic cleanup of files will happen when a module is | |
538 | * removed, you are responsible here. | |
539 | */ | |
540 | void debugfs_remove_recursive(struct dentry *dentry) | |
541 | { | |
542 | struct dentry *child; | |
543 | struct dentry *parent; | |
544 | ||
545 | if (!dentry) | |
546 | return; | |
547 | ||
548 | parent = dentry->d_parent; | |
549 | if (!parent || !parent->d_inode) | |
550 | return; | |
551 | ||
552 | parent = dentry; | |
553 | mutex_lock(&parent->d_inode->i_mutex); | |
554 | ||
555 | while (1) { | |
556 | /* | |
557 | * When all dentries under "parent" has been removed, | |
558 | * walk up the tree until we reach our starting point. | |
559 | */ | |
560 | if (list_empty(&parent->d_subdirs)) { | |
561 | mutex_unlock(&parent->d_inode->i_mutex); | |
562 | if (parent == dentry) | |
66f54963 | 563 | break; |
9505e637 HS |
564 | parent = parent->d_parent; |
565 | mutex_lock(&parent->d_inode->i_mutex); | |
566 | } | |
567 | child = list_entry(parent->d_subdirs.next, struct dentry, | |
568 | d_u.d_child); | |
56a83cc9 | 569 | next_sibling: |
9505e637 HS |
570 | |
571 | /* | |
572 | * If "child" isn't empty, walk down the tree and | |
573 | * remove all its descendants first. | |
574 | */ | |
575 | if (!list_empty(&child->d_subdirs)) { | |
576 | mutex_unlock(&parent->d_inode->i_mutex); | |
577 | parent = child; | |
578 | mutex_lock(&parent->d_inode->i_mutex); | |
579 | continue; | |
1da177e4 | 580 | } |
9505e637 HS |
581 | __debugfs_remove(child, parent); |
582 | if (parent->d_subdirs.next == &child->d_u.d_child) { | |
56a83cc9 SR |
583 | /* |
584 | * Try the next sibling. | |
585 | */ | |
586 | if (child->d_u.d_child.next != &parent->d_subdirs) { | |
587 | child = list_entry(child->d_u.d_child.next, | |
588 | struct dentry, | |
589 | d_u.d_child); | |
590 | goto next_sibling; | |
591 | } | |
592 | ||
9505e637 HS |
593 | /* |
594 | * Avoid infinite loop if we fail to remove | |
595 | * one dentry. | |
596 | */ | |
597 | mutex_unlock(&parent->d_inode->i_mutex); | |
598 | break; | |
599 | } | |
600 | simple_release_fs(&debugfs_mount, &debugfs_mount_count); | |
1da177e4 | 601 | } |
9505e637 HS |
602 | |
603 | parent = dentry->d_parent; | |
604 | mutex_lock(&parent->d_inode->i_mutex); | |
605 | __debugfs_remove(dentry, parent); | |
1b1dcc1b | 606 | mutex_unlock(&parent->d_inode->i_mutex); |
1da177e4 LT |
607 | simple_release_fs(&debugfs_mount, &debugfs_mount_count); |
608 | } | |
9505e637 | 609 | EXPORT_SYMBOL_GPL(debugfs_remove_recursive); |
1da177e4 | 610 | |
cfc94cdf JK |
611 | /** |
612 | * debugfs_rename - rename a file/directory in the debugfs filesystem | |
613 | * @old_dir: a pointer to the parent dentry for the renamed object. This | |
614 | * should be a directory dentry. | |
615 | * @old_dentry: dentry of an object to be renamed. | |
616 | * @new_dir: a pointer to the parent dentry where the object should be | |
617 | * moved. This should be a directory dentry. | |
618 | * @new_name: a pointer to a string containing the target name. | |
619 | * | |
620 | * This function renames a file/directory in debugfs. The target must not | |
621 | * exist for rename to succeed. | |
622 | * | |
623 | * This function will return a pointer to old_dentry (which is updated to | |
624 | * reflect renaming) if it succeeds. If an error occurs, %NULL will be | |
625 | * returned. | |
626 | * | |
627 | * If debugfs is not enabled in the kernel, the value -%ENODEV will be | |
628 | * returned. | |
629 | */ | |
630 | struct dentry *debugfs_rename(struct dentry *old_dir, struct dentry *old_dentry, | |
631 | struct dentry *new_dir, const char *new_name) | |
632 | { | |
633 | int error; | |
634 | struct dentry *dentry = NULL, *trap; | |
635 | const char *old_name; | |
636 | ||
637 | trap = lock_rename(new_dir, old_dir); | |
638 | /* Source or destination directories don't exist? */ | |
639 | if (!old_dir->d_inode || !new_dir->d_inode) | |
640 | goto exit; | |
641 | /* Source does not exist, cyclic rename, or mountpoint? */ | |
642 | if (!old_dentry->d_inode || old_dentry == trap || | |
643 | d_mountpoint(old_dentry)) | |
644 | goto exit; | |
645 | dentry = lookup_one_len(new_name, new_dir, strlen(new_name)); | |
646 | /* Lookup failed, cyclic rename or target exists? */ | |
647 | if (IS_ERR(dentry) || dentry == trap || dentry->d_inode) | |
648 | goto exit; | |
649 | ||
650 | old_name = fsnotify_oldname_init(old_dentry->d_name.name); | |
651 | ||
652 | error = simple_rename(old_dir->d_inode, old_dentry, new_dir->d_inode, | |
653 | dentry); | |
654 | if (error) { | |
655 | fsnotify_oldname_free(old_name); | |
656 | goto exit; | |
657 | } | |
658 | d_move(old_dentry, dentry); | |
659 | fsnotify_move(old_dir->d_inode, new_dir->d_inode, old_name, | |
123df294 | 660 | S_ISDIR(old_dentry->d_inode->i_mode), |
5a190ae6 | 661 | NULL, old_dentry); |
cfc94cdf JK |
662 | fsnotify_oldname_free(old_name); |
663 | unlock_rename(new_dir, old_dir); | |
664 | dput(dentry); | |
665 | return old_dentry; | |
666 | exit: | |
667 | if (dentry && !IS_ERR(dentry)) | |
668 | dput(dentry); | |
669 | unlock_rename(new_dir, old_dir); | |
670 | return NULL; | |
671 | } | |
672 | EXPORT_SYMBOL_GPL(debugfs_rename); | |
673 | ||
c0f92ba9 FW |
674 | /** |
675 | * debugfs_initialized - Tells whether debugfs has been registered | |
676 | */ | |
677 | bool debugfs_initialized(void) | |
678 | { | |
679 | return debugfs_registered; | |
680 | } | |
681 | EXPORT_SYMBOL_GPL(debugfs_initialized); | |
682 | ||
683 | ||
191e186b | 684 | static struct kobject *debug_kobj; |
1da177e4 LT |
685 | |
686 | static int __init debugfs_init(void) | |
687 | { | |
688 | int retval; | |
689 | ||
0ff21e46 | 690 | debug_kobj = kobject_create_and_add("debug", kernel_kobj); |
191e186b GKH |
691 | if (!debug_kobj) |
692 | return -EINVAL; | |
1da177e4 LT |
693 | |
694 | retval = register_filesystem(&debug_fs_type); | |
695 | if (retval) | |
197b12d6 | 696 | kobject_put(debug_kobj); |
c0f92ba9 FW |
697 | else |
698 | debugfs_registered = true; | |
699 | ||
1da177e4 LT |
700 | return retval; |
701 | } | |
1da177e4 | 702 | core_initcall(debugfs_init); |
1da177e4 | 703 |