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 | |
82aceae4 | 31 | #define DEBUGFS_DEFAULT_MODE 0700 |
d6e48686 | 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 | 57 | inode->i_private = data; |
66f54963 | 58 | break; |
1da177e4 LT |
59 | case S_IFDIR: |
60 | inode->i_op = &simple_dir_inode_operations; | |
ac481d6c | 61 | inode->i_fop = &simple_dir_operations; |
1da177e4 | 62 | |
bafb232e MD |
63 | /* directory inodes start off with i_nlink == 2 |
64 | * (for "." entry) */ | |
d8c76e6f | 65 | inc_nlink(inode); |
1da177e4 LT |
66 | break; |
67 | } | |
68 | } | |
88e412ea | 69 | return inode; |
1da177e4 LT |
70 | } |
71 | ||
1da177e4 LT |
72 | static inline int debugfs_positive(struct dentry *dentry) |
73 | { | |
74 | return dentry->d_inode && !d_unhashed(dentry); | |
75 | } | |
76 | ||
d6e48686 | 77 | struct debugfs_mount_opts { |
7dc05881 EB |
78 | kuid_t uid; |
79 | kgid_t gid; | |
d6e48686 LN |
80 | umode_t mode; |
81 | }; | |
82 | ||
83 | enum { | |
84 | Opt_uid, | |
85 | Opt_gid, | |
86 | Opt_mode, | |
87 | Opt_err | |
88 | }; | |
89 | ||
90 | static const match_table_t tokens = { | |
91 | {Opt_uid, "uid=%u"}, | |
92 | {Opt_gid, "gid=%u"}, | |
93 | {Opt_mode, "mode=%o"}, | |
94 | {Opt_err, NULL} | |
95 | }; | |
96 | ||
97 | struct debugfs_fs_info { | |
98 | struct debugfs_mount_opts mount_opts; | |
99 | }; | |
100 | ||
101 | static int debugfs_parse_options(char *data, struct debugfs_mount_opts *opts) | |
102 | { | |
103 | substring_t args[MAX_OPT_ARGS]; | |
104 | int option; | |
105 | int token; | |
7dc05881 EB |
106 | kuid_t uid; |
107 | kgid_t gid; | |
d6e48686 LN |
108 | char *p; |
109 | ||
110 | opts->mode = DEBUGFS_DEFAULT_MODE; | |
111 | ||
112 | while ((p = strsep(&data, ",")) != NULL) { | |
113 | if (!*p) | |
114 | continue; | |
115 | ||
116 | token = match_token(p, tokens, args); | |
117 | switch (token) { | |
118 | case Opt_uid: | |
119 | if (match_int(&args[0], &option)) | |
120 | return -EINVAL; | |
7dc05881 EB |
121 | uid = make_kuid(current_user_ns(), option); |
122 | if (!uid_valid(uid)) | |
123 | return -EINVAL; | |
124 | opts->uid = uid; | |
d6e48686 LN |
125 | break; |
126 | case Opt_gid: | |
f1688e04 | 127 | if (match_int(&args[0], &option)) |
d6e48686 | 128 | return -EINVAL; |
7dc05881 EB |
129 | gid = make_kgid(current_user_ns(), option); |
130 | if (!gid_valid(gid)) | |
131 | return -EINVAL; | |
132 | opts->gid = gid; | |
d6e48686 LN |
133 | break; |
134 | case Opt_mode: | |
135 | if (match_octal(&args[0], &option)) | |
136 | return -EINVAL; | |
137 | opts->mode = option & S_IALLUGO; | |
138 | break; | |
139 | /* | |
140 | * We might like to report bad mount options here; | |
141 | * but traditionally debugfs has ignored all mount options | |
142 | */ | |
143 | } | |
144 | } | |
145 | ||
146 | return 0; | |
147 | } | |
148 | ||
149 | static int debugfs_apply_options(struct super_block *sb) | |
150 | { | |
151 | struct debugfs_fs_info *fsi = sb->s_fs_info; | |
152 | struct inode *inode = sb->s_root->d_inode; | |
153 | struct debugfs_mount_opts *opts = &fsi->mount_opts; | |
154 | ||
155 | inode->i_mode &= ~S_IALLUGO; | |
156 | inode->i_mode |= opts->mode; | |
157 | ||
158 | inode->i_uid = opts->uid; | |
159 | inode->i_gid = opts->gid; | |
160 | ||
161 | return 0; | |
162 | } | |
163 | ||
164 | static int debugfs_remount(struct super_block *sb, int *flags, char *data) | |
165 | { | |
166 | int err; | |
167 | struct debugfs_fs_info *fsi = sb->s_fs_info; | |
168 | ||
02b9984d | 169 | sync_filesystem(sb); |
d6e48686 LN |
170 | err = debugfs_parse_options(data, &fsi->mount_opts); |
171 | if (err) | |
172 | goto fail; | |
173 | ||
174 | debugfs_apply_options(sb); | |
175 | ||
176 | fail: | |
177 | return err; | |
178 | } | |
179 | ||
180 | static int debugfs_show_options(struct seq_file *m, struct dentry *root) | |
181 | { | |
182 | struct debugfs_fs_info *fsi = root->d_sb->s_fs_info; | |
183 | struct debugfs_mount_opts *opts = &fsi->mount_opts; | |
184 | ||
7dc05881 EB |
185 | if (!uid_eq(opts->uid, GLOBAL_ROOT_UID)) |
186 | seq_printf(m, ",uid=%u", | |
187 | from_kuid_munged(&init_user_ns, opts->uid)); | |
188 | if (!gid_eq(opts->gid, GLOBAL_ROOT_GID)) | |
189 | seq_printf(m, ",gid=%u", | |
190 | from_kgid_munged(&init_user_ns, opts->gid)); | |
d6e48686 LN |
191 | if (opts->mode != DEBUGFS_DEFAULT_MODE) |
192 | seq_printf(m, ",mode=%o", opts->mode); | |
193 | ||
194 | return 0; | |
195 | } | |
196 | ||
197 | static const struct super_operations debugfs_super_operations = { | |
198 | .statfs = simple_statfs, | |
199 | .remount_fs = debugfs_remount, | |
200 | .show_options = debugfs_show_options, | |
201 | }; | |
202 | ||
1da177e4 LT |
203 | static int debug_fill_super(struct super_block *sb, void *data, int silent) |
204 | { | |
205 | static struct tree_descr debug_files[] = {{""}}; | |
d6e48686 LN |
206 | struct debugfs_fs_info *fsi; |
207 | int err; | |
208 | ||
209 | save_mount_options(sb, data); | |
210 | ||
211 | fsi = kzalloc(sizeof(struct debugfs_fs_info), GFP_KERNEL); | |
212 | sb->s_fs_info = fsi; | |
213 | if (!fsi) { | |
214 | err = -ENOMEM; | |
215 | goto fail; | |
216 | } | |
217 | ||
218 | err = debugfs_parse_options(data, &fsi->mount_opts); | |
219 | if (err) | |
220 | goto fail; | |
221 | ||
222 | err = simple_fill_super(sb, DEBUGFS_MAGIC, debug_files); | |
223 | if (err) | |
224 | goto fail; | |
225 | ||
226 | sb->s_op = &debugfs_super_operations; | |
227 | ||
228 | debugfs_apply_options(sb); | |
229 | ||
230 | return 0; | |
1da177e4 | 231 | |
d6e48686 LN |
232 | fail: |
233 | kfree(fsi); | |
234 | sb->s_fs_info = NULL; | |
235 | return err; | |
1da177e4 LT |
236 | } |
237 | ||
fc14f2fe | 238 | static struct dentry *debug_mount(struct file_system_type *fs_type, |
454e2398 | 239 | int flags, const char *dev_name, |
fc14f2fe | 240 | void *data) |
1da177e4 | 241 | { |
fc14f2fe | 242 | return mount_single(fs_type, flags, data, debug_fill_super); |
1da177e4 LT |
243 | } |
244 | ||
245 | static struct file_system_type debug_fs_type = { | |
246 | .owner = THIS_MODULE, | |
247 | .name = "debugfs", | |
fc14f2fe | 248 | .mount = debug_mount, |
1da177e4 LT |
249 | .kill_sb = kill_litter_super, |
250 | }; | |
7f78e035 | 251 | MODULE_ALIAS_FS("debugfs"); |
1da177e4 | 252 | |
190afd81 | 253 | static struct dentry *start_creating(const char *name, struct dentry *parent) |
1da177e4 | 254 | { |
190afd81 | 255 | struct dentry *dentry; |
cfa57c11 AV |
256 | int error; |
257 | ||
258 | pr_debug("debugfs: creating file '%s'\n",name); | |
259 | ||
260 | error = simple_pin_fs(&debug_fs_type, &debugfs_mount, | |
261 | &debugfs_mount_count); | |
262 | if (error) | |
190afd81 | 263 | return ERR_PTR(error); |
1da177e4 LT |
264 | |
265 | /* If the parent is not specified, we create it in the root. | |
88e412ea | 266 | * We need the root dentry to do this, which is in the super |
1da177e4 LT |
267 | * block. A pointer to that is in the struct vfsmount that we |
268 | * have around. | |
269 | */ | |
ef52c75e | 270 | if (!parent) |
4c1d5a64 | 271 | parent = debugfs_mount->mnt_root; |
1da177e4 | 272 | |
1b1dcc1b | 273 | mutex_lock(&parent->d_inode->i_mutex); |
cfa57c11 | 274 | dentry = lookup_one_len(name, parent, strlen(name)); |
190afd81 | 275 | if (!IS_ERR(dentry) && dentry->d_inode) { |
cfa57c11 | 276 | dput(dentry); |
190afd81 AV |
277 | dentry = ERR_PTR(-EEXIST); |
278 | } | |
279 | if (IS_ERR(dentry)) | |
280 | mutex_unlock(&parent->d_inode->i_mutex); | |
281 | return dentry; | |
282 | } | |
283 | ||
284 | static struct dentry *end_creating(struct dentry *dentry, int error) | |
285 | { | |
286 | mutex_unlock(&dentry->d_parent->d_inode->i_mutex); | |
287 | dput(dentry); | |
1da177e4 | 288 | |
c3b1a350 AV |
289 | if (error) { |
290 | dentry = NULL; | |
291 | simple_release_fs(&debugfs_mount, &debugfs_mount_count); | |
292 | } | |
c3b1a350 AV |
293 | return dentry; |
294 | } | |
295 | ||
1da177e4 LT |
296 | /** |
297 | * debugfs_create_file - create a file in the debugfs filesystem | |
1da177e4 | 298 | * @name: a pointer to a string containing the name of the file to create. |
be030e65 | 299 | * @mode: the permission that the file should have. |
1da177e4 | 300 | * @parent: a pointer to the parent dentry for this file. This should be a |
e227867f | 301 | * directory dentry if set. If this parameter is NULL, then the |
1da177e4 LT |
302 | * file will be created in the root of the debugfs filesystem. |
303 | * @data: a pointer to something that the caller will want to get to later | |
8e18e294 | 304 | * on. The inode.i_private pointer will point to this value on |
1da177e4 LT |
305 | * the open() call. |
306 | * @fops: a pointer to a struct file_operations that should be used for | |
307 | * this file. | |
308 | * | |
309 | * This is the basic "create a file" function for debugfs. It allows for a | |
be030e65 AB |
310 | * wide range of flexibility in creating a file, or a directory (if you want |
311 | * to create a directory, the debugfs_create_dir() function is | |
1da177e4 LT |
312 | * recommended to be used instead.) |
313 | * | |
314 | * This function will return a pointer to a dentry if it succeeds. This | |
315 | * pointer must be passed to the debugfs_remove() function when the file is | |
316 | * to be removed (no automatic cleanup happens if your module is unloaded, | |
6468b3af | 317 | * you are responsible here.) If an error occurs, %NULL will be returned. |
1da177e4 | 318 | * |
6468b3af | 319 | * If debugfs is not enabled in the kernel, the value -%ENODEV will be |
873760fb | 320 | * returned. |
1da177e4 | 321 | */ |
f4ae40a6 | 322 | struct dentry *debugfs_create_file(const char *name, umode_t mode, |
1da177e4 | 323 | struct dentry *parent, void *data, |
99ac48f5 | 324 | const struct file_operations *fops) |
1da177e4 | 325 | { |
ad5abd5b | 326 | struct dentry *dentry; |
680b3024 | 327 | struct inode *inode; |
ad5abd5b AV |
328 | |
329 | if (!(mode & S_IFMT)) | |
330 | mode |= S_IFREG; | |
331 | BUG_ON(!S_ISREG(mode)); | |
332 | dentry = start_creating(name, parent); | |
333 | ||
334 | if (IS_ERR(dentry)) | |
335 | return NULL; | |
c3b1a350 | 336 | |
680b3024 AV |
337 | inode = debugfs_get_inode(dentry->d_sb, mode, 0, data, fops); |
338 | if (unlikely(!inode)) | |
339 | return end_creating(dentry, -ENOMEM); | |
340 | ||
341 | d_instantiate(dentry, inode); | |
342 | dget(dentry); | |
343 | fsnotify_create(dentry->d_parent->d_inode, dentry); | |
344 | return end_creating(dentry, 0); | |
1da177e4 LT |
345 | } |
346 | EXPORT_SYMBOL_GPL(debugfs_create_file); | |
347 | ||
348 | /** | |
349 | * debugfs_create_dir - create a directory in the debugfs filesystem | |
1da177e4 LT |
350 | * @name: a pointer to a string containing the name of the directory to |
351 | * create. | |
352 | * @parent: a pointer to the parent dentry for this file. This should be a | |
e227867f | 353 | * directory dentry if set. If this parameter is NULL, then the |
1da177e4 LT |
354 | * directory will be created in the root of the debugfs filesystem. |
355 | * | |
356 | * This function creates a directory in debugfs with the given name. | |
357 | * | |
358 | * This function will return a pointer to a dentry if it succeeds. This | |
359 | * pointer must be passed to the debugfs_remove() function when the file is | |
360 | * to be removed (no automatic cleanup happens if your module is unloaded, | |
6468b3af | 361 | * you are responsible here.) If an error occurs, %NULL will be returned. |
1da177e4 | 362 | * |
6468b3af | 363 | * If debugfs is not enabled in the kernel, the value -%ENODEV will be |
873760fb | 364 | * returned. |
1da177e4 LT |
365 | */ |
366 | struct dentry *debugfs_create_dir(const char *name, struct dentry *parent) | |
367 | { | |
ad5abd5b | 368 | struct dentry *dentry = start_creating(name, parent); |
680b3024 | 369 | struct inode *inode; |
ad5abd5b AV |
370 | |
371 | if (IS_ERR(dentry)) | |
372 | return NULL; | |
373 | ||
680b3024 AV |
374 | inode = debugfs_get_inode(dentry->d_sb, |
375 | S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO, | |
376 | 0, NULL, NULL); | |
377 | if (unlikely(!inode)) | |
378 | return end_creating(dentry, -ENOMEM); | |
379 | ||
380 | d_instantiate(dentry, inode); | |
381 | dget(dentry); | |
382 | inc_nlink(dentry->d_parent->d_inode); | |
383 | fsnotify_mkdir(dentry->d_parent->d_inode, dentry); | |
384 | return end_creating(dentry, 0); | |
1da177e4 LT |
385 | } |
386 | EXPORT_SYMBOL_GPL(debugfs_create_dir); | |
387 | ||
66f54963 PO |
388 | /** |
389 | * debugfs_create_symlink- create a symbolic link in the debugfs filesystem | |
390 | * @name: a pointer to a string containing the name of the symbolic link to | |
391 | * create. | |
392 | * @parent: a pointer to the parent dentry for this symbolic link. This | |
e227867f | 393 | * should be a directory dentry if set. If this parameter is NULL, |
66f54963 PO |
394 | * then the symbolic link will be created in the root of the debugfs |
395 | * filesystem. | |
396 | * @target: a pointer to a string containing the path to the target of the | |
397 | * symbolic link. | |
398 | * | |
399 | * This function creates a symbolic link with the given name in debugfs that | |
400 | * links to the given target path. | |
401 | * | |
402 | * This function will return a pointer to a dentry if it succeeds. This | |
403 | * pointer must be passed to the debugfs_remove() function when the symbolic | |
404 | * link is to be removed (no automatic cleanup happens if your module is | |
405 | * unloaded, you are responsible here.) If an error occurs, %NULL will be | |
406 | * returned. | |
407 | * | |
408 | * If debugfs is not enabled in the kernel, the value -%ENODEV will be | |
873760fb | 409 | * returned. |
66f54963 PO |
410 | */ |
411 | struct dentry *debugfs_create_symlink(const char *name, struct dentry *parent, | |
412 | const char *target) | |
413 | { | |
ad5abd5b | 414 | struct dentry *dentry; |
680b3024 AV |
415 | struct inode *inode; |
416 | char *link = kstrdup(target, GFP_KERNEL); | |
66f54963 PO |
417 | if (!link) |
418 | return NULL; | |
419 | ||
ad5abd5b | 420 | dentry = start_creating(name, parent); |
ad5abd5b | 421 | if (IS_ERR(dentry)) { |
66f54963 | 422 | kfree(link); |
ad5abd5b AV |
423 | return NULL; |
424 | } | |
425 | ||
680b3024 AV |
426 | inode = debugfs_get_inode(dentry->d_sb, S_IFLNK | S_IRWXUGO, 0, |
427 | link, NULL); | |
428 | if (unlikely(!inode)) { | |
ad5abd5b | 429 | kfree(link); |
680b3024 AV |
430 | return end_creating(dentry, -ENOMEM); |
431 | } | |
432 | d_instantiate(dentry, inode); | |
433 | dget(dentry); | |
434 | return end_creating(dentry, 0); | |
66f54963 PO |
435 | } |
436 | EXPORT_SYMBOL_GPL(debugfs_create_symlink); | |
437 | ||
25d41d84 | 438 | static int __debugfs_remove(struct dentry *dentry, struct dentry *parent) |
9505e637 HS |
439 | { |
440 | int ret = 0; | |
441 | ||
442 | if (debugfs_positive(dentry)) { | |
443 | if (dentry->d_inode) { | |
444 | dget(dentry); | |
445 | switch (dentry->d_inode->i_mode & S_IFMT) { | |
446 | case S_IFDIR: | |
447 | ret = simple_rmdir(parent->d_inode, dentry); | |
448 | break; | |
449 | case S_IFLNK: | |
450 | kfree(dentry->d_inode->i_private); | |
451 | /* fall through */ | |
452 | default: | |
453 | simple_unlink(parent->d_inode, dentry); | |
454 | break; | |
455 | } | |
456 | if (!ret) | |
457 | d_delete(dentry); | |
458 | dput(dentry); | |
459 | } | |
460 | } | |
25d41d84 | 461 | return ret; |
9505e637 HS |
462 | } |
463 | ||
1da177e4 LT |
464 | /** |
465 | * debugfs_remove - removes a file or directory from the debugfs filesystem | |
1da177e4 LT |
466 | * @dentry: a pointer to a the dentry of the file or directory to be |
467 | * removed. | |
468 | * | |
469 | * This function removes a file or directory in debugfs that was previously | |
470 | * created with a call to another debugfs function (like | |
5a65980e | 471 | * debugfs_create_file() or variants thereof.) |
1da177e4 LT |
472 | * |
473 | * This function is required to be called in order for the file to be | |
474 | * removed, no automatic cleanup of files will happen when a module is | |
475 | * removed, you are responsible here. | |
476 | */ | |
477 | void debugfs_remove(struct dentry *dentry) | |
478 | { | |
479 | struct dentry *parent; | |
25d41d84 JK |
480 | int ret; |
481 | ||
a59d6293 | 482 | if (IS_ERR_OR_NULL(dentry)) |
1da177e4 LT |
483 | return; |
484 | ||
485 | parent = dentry->d_parent; | |
486 | if (!parent || !parent->d_inode) | |
487 | return; | |
488 | ||
1b1dcc1b | 489 | mutex_lock(&parent->d_inode->i_mutex); |
25d41d84 | 490 | ret = __debugfs_remove(dentry, parent); |
9505e637 | 491 | mutex_unlock(&parent->d_inode->i_mutex); |
25d41d84 JK |
492 | if (!ret) |
493 | simple_release_fs(&debugfs_mount, &debugfs_mount_count); | |
9505e637 HS |
494 | } |
495 | EXPORT_SYMBOL_GPL(debugfs_remove); | |
496 | ||
497 | /** | |
498 | * debugfs_remove_recursive - recursively removes a directory | |
499 | * @dentry: a pointer to a the dentry of the directory to be removed. | |
500 | * | |
501 | * This function recursively removes a directory tree in debugfs that | |
502 | * was previously created with a call to another debugfs function | |
503 | * (like debugfs_create_file() or variants thereof.) | |
504 | * | |
505 | * This function is required to be called in order for the file to be | |
506 | * removed, no automatic cleanup of files will happen when a module is | |
507 | * removed, you are responsible here. | |
508 | */ | |
509 | void debugfs_remove_recursive(struct dentry *dentry) | |
510 | { | |
485d4402 | 511 | struct dentry *child, *parent; |
9505e637 | 512 | |
a59d6293 | 513 | if (IS_ERR_OR_NULL(dentry)) |
9505e637 HS |
514 | return; |
515 | ||
516 | parent = dentry->d_parent; | |
517 | if (!parent || !parent->d_inode) | |
518 | return; | |
519 | ||
520 | parent = dentry; | |
776164c1 | 521 | down: |
9505e637 | 522 | mutex_lock(&parent->d_inode->i_mutex); |
485d4402 SR |
523 | loop: |
524 | /* | |
525 | * The parent->d_subdirs is protected by the d_lock. Outside that | |
526 | * lock, the child can be unlinked and set to be freed which can | |
527 | * use the d_u.d_child as the rcu head and corrupt this list. | |
528 | */ | |
529 | spin_lock(&parent->d_lock); | |
946e51f2 | 530 | list_for_each_entry(child, &parent->d_subdirs, d_child) { |
776164c1 ON |
531 | if (!debugfs_positive(child)) |
532 | continue; | |
9505e637 | 533 | |
776164c1 | 534 | /* perhaps simple_empty(child) makes more sense */ |
9505e637 | 535 | if (!list_empty(&child->d_subdirs)) { |
485d4402 | 536 | spin_unlock(&parent->d_lock); |
9505e637 HS |
537 | mutex_unlock(&parent->d_inode->i_mutex); |
538 | parent = child; | |
776164c1 | 539 | goto down; |
1da177e4 | 540 | } |
485d4402 SR |
541 | |
542 | spin_unlock(&parent->d_lock); | |
543 | ||
776164c1 ON |
544 | if (!__debugfs_remove(child, parent)) |
545 | simple_release_fs(&debugfs_mount, &debugfs_mount_count); | |
485d4402 SR |
546 | |
547 | /* | |
548 | * The parent->d_lock protects agaist child from unlinking | |
549 | * from d_subdirs. When releasing the parent->d_lock we can | |
550 | * no longer trust that the next pointer is valid. | |
551 | * Restart the loop. We'll skip this one with the | |
552 | * debugfs_positive() check. | |
553 | */ | |
554 | goto loop; | |
1da177e4 | 555 | } |
485d4402 | 556 | spin_unlock(&parent->d_lock); |
9505e637 | 557 | |
776164c1 ON |
558 | mutex_unlock(&parent->d_inode->i_mutex); |
559 | child = parent; | |
560 | parent = parent->d_parent; | |
9505e637 | 561 | mutex_lock(&parent->d_inode->i_mutex); |
776164c1 | 562 | |
485d4402 SR |
563 | if (child != dentry) |
564 | /* go up */ | |
565 | goto loop; | |
776164c1 ON |
566 | |
567 | if (!__debugfs_remove(child, parent)) | |
568 | simple_release_fs(&debugfs_mount, &debugfs_mount_count); | |
1b1dcc1b | 569 | mutex_unlock(&parent->d_inode->i_mutex); |
1da177e4 | 570 | } |
9505e637 | 571 | EXPORT_SYMBOL_GPL(debugfs_remove_recursive); |
1da177e4 | 572 | |
cfc94cdf JK |
573 | /** |
574 | * debugfs_rename - rename a file/directory in the debugfs filesystem | |
575 | * @old_dir: a pointer to the parent dentry for the renamed object. This | |
576 | * should be a directory dentry. | |
577 | * @old_dentry: dentry of an object to be renamed. | |
578 | * @new_dir: a pointer to the parent dentry where the object should be | |
579 | * moved. This should be a directory dentry. | |
580 | * @new_name: a pointer to a string containing the target name. | |
581 | * | |
582 | * This function renames a file/directory in debugfs. The target must not | |
583 | * exist for rename to succeed. | |
584 | * | |
585 | * This function will return a pointer to old_dentry (which is updated to | |
586 | * reflect renaming) if it succeeds. If an error occurs, %NULL will be | |
587 | * returned. | |
588 | * | |
589 | * If debugfs is not enabled in the kernel, the value -%ENODEV will be | |
590 | * returned. | |
591 | */ | |
592 | struct dentry *debugfs_rename(struct dentry *old_dir, struct dentry *old_dentry, | |
593 | struct dentry *new_dir, const char *new_name) | |
594 | { | |
595 | int error; | |
596 | struct dentry *dentry = NULL, *trap; | |
597 | const char *old_name; | |
598 | ||
599 | trap = lock_rename(new_dir, old_dir); | |
600 | /* Source or destination directories don't exist? */ | |
601 | if (!old_dir->d_inode || !new_dir->d_inode) | |
602 | goto exit; | |
603 | /* Source does not exist, cyclic rename, or mountpoint? */ | |
604 | if (!old_dentry->d_inode || old_dentry == trap || | |
605 | d_mountpoint(old_dentry)) | |
606 | goto exit; | |
607 | dentry = lookup_one_len(new_name, new_dir, strlen(new_name)); | |
608 | /* Lookup failed, cyclic rename or target exists? */ | |
609 | if (IS_ERR(dentry) || dentry == trap || dentry->d_inode) | |
610 | goto exit; | |
611 | ||
612 | old_name = fsnotify_oldname_init(old_dentry->d_name.name); | |
613 | ||
614 | error = simple_rename(old_dir->d_inode, old_dentry, new_dir->d_inode, | |
615 | dentry); | |
616 | if (error) { | |
617 | fsnotify_oldname_free(old_name); | |
618 | goto exit; | |
619 | } | |
620 | d_move(old_dentry, dentry); | |
621 | fsnotify_move(old_dir->d_inode, new_dir->d_inode, old_name, | |
123df294 | 622 | S_ISDIR(old_dentry->d_inode->i_mode), |
5a190ae6 | 623 | NULL, old_dentry); |
cfc94cdf JK |
624 | fsnotify_oldname_free(old_name); |
625 | unlock_rename(new_dir, old_dir); | |
626 | dput(dentry); | |
627 | return old_dentry; | |
628 | exit: | |
629 | if (dentry && !IS_ERR(dentry)) | |
630 | dput(dentry); | |
631 | unlock_rename(new_dir, old_dir); | |
632 | return NULL; | |
633 | } | |
634 | EXPORT_SYMBOL_GPL(debugfs_rename); | |
635 | ||
c0f92ba9 FW |
636 | /** |
637 | * debugfs_initialized - Tells whether debugfs has been registered | |
638 | */ | |
639 | bool debugfs_initialized(void) | |
640 | { | |
641 | return debugfs_registered; | |
642 | } | |
643 | EXPORT_SYMBOL_GPL(debugfs_initialized); | |
644 | ||
645 | ||
191e186b | 646 | static struct kobject *debug_kobj; |
1da177e4 LT |
647 | |
648 | static int __init debugfs_init(void) | |
649 | { | |
650 | int retval; | |
651 | ||
0ff21e46 | 652 | debug_kobj = kobject_create_and_add("debug", kernel_kobj); |
191e186b GKH |
653 | if (!debug_kobj) |
654 | return -EINVAL; | |
1da177e4 LT |
655 | |
656 | retval = register_filesystem(&debug_fs_type); | |
657 | if (retval) | |
197b12d6 | 658 | kobject_put(debug_kobj); |
c0f92ba9 FW |
659 | else |
660 | debugfs_registered = true; | |
661 | ||
1da177e4 LT |
662 | return retval; |
663 | } | |
1da177e4 | 664 | core_initcall(debugfs_init); |
1da177e4 | 665 |