Commit | Line | Data |
---|---|---|
1da177e4 | 1 | /* |
6d66f5cd TH |
2 | * fs/sysfs/dir.c - sysfs core and dir operation implementation |
3 | * | |
4 | * Copyright (c) 2001-3 Patrick Mochel | |
5 | * Copyright (c) 2007 SUSE Linux Products GmbH | |
6 | * Copyright (c) 2007 Tejun Heo <teheo@suse.de> | |
7 | * | |
8 | * This file is released under the GPLv2. | |
9 | * | |
10 | * Please see Documentation/filesystems/sysfs.txt for more information. | |
1da177e4 LT |
11 | */ |
12 | ||
13 | #undef DEBUG | |
14 | ||
15 | #include <linux/fs.h> | |
16 | #include <linux/mount.h> | |
17 | #include <linux/module.h> | |
18 | #include <linux/kobject.h> | |
5f45f1a7 | 19 | #include <linux/namei.h> |
2b611bb7 | 20 | #include <linux/idr.h> |
8619f979 | 21 | #include <linux/completion.h> |
869512ab | 22 | #include <linux/mutex.h> |
c6f87733 | 23 | #include <linux/slab.h> |
4c3da220 | 24 | #include <linux/security.h> |
1da177e4 LT |
25 | #include "sysfs.h" |
26 | ||
3007e997 | 27 | DEFINE_MUTEX(sysfs_mutex); |
f7a75f0a | 28 | DEFINE_SPINLOCK(sysfs_assoc_lock); |
1da177e4 | 29 | |
f7a75f0a | 30 | static DEFINE_SPINLOCK(sysfs_ino_lock); |
2b611bb7 TH |
31 | static DEFINE_IDA(sysfs_ino_ida); |
32 | ||
0c73f18b TH |
33 | /** |
34 | * sysfs_link_sibling - link sysfs_dirent into sibling list | |
35 | * @sd: sysfs_dirent of interest | |
36 | * | |
37 | * Link @sd into its sibling list which starts from | |
bc747f37 | 38 | * sd->s_parent->s_dir.children. |
0c73f18b TH |
39 | * |
40 | * Locking: | |
3007e997 | 41 | * mutex_lock(sysfs_mutex) |
0c73f18b | 42 | */ |
41fc1c27 | 43 | static void sysfs_link_sibling(struct sysfs_dirent *sd) |
0c73f18b TH |
44 | { |
45 | struct sysfs_dirent *parent_sd = sd->s_parent; | |
3efa65b9 | 46 | struct sysfs_dirent **pos; |
0c73f18b TH |
47 | |
48 | BUG_ON(sd->s_sibling); | |
3efa65b9 EB |
49 | |
50 | /* Store directory entries in order by ino. This allows | |
51 | * readdir to properly restart without having to add a | |
bc747f37 | 52 | * cursor into the s_dir.children list. |
3efa65b9 | 53 | */ |
bc747f37 | 54 | for (pos = &parent_sd->s_dir.children; *pos; pos = &(*pos)->s_sibling) { |
3efa65b9 EB |
55 | if (sd->s_ino < (*pos)->s_ino) |
56 | break; | |
57 | } | |
58 | sd->s_sibling = *pos; | |
59 | *pos = sd; | |
0c73f18b TH |
60 | } |
61 | ||
62 | /** | |
63 | * sysfs_unlink_sibling - unlink sysfs_dirent from sibling list | |
64 | * @sd: sysfs_dirent of interest | |
65 | * | |
66 | * Unlink @sd from its sibling list which starts from | |
bc747f37 | 67 | * sd->s_parent->s_dir.children. |
0c73f18b TH |
68 | * |
69 | * Locking: | |
3007e997 | 70 | * mutex_lock(sysfs_mutex) |
0c73f18b | 71 | */ |
41fc1c27 | 72 | static void sysfs_unlink_sibling(struct sysfs_dirent *sd) |
0c73f18b TH |
73 | { |
74 | struct sysfs_dirent **pos; | |
75 | ||
bc747f37 TH |
76 | for (pos = &sd->s_parent->s_dir.children; *pos; |
77 | pos = &(*pos)->s_sibling) { | |
0c73f18b TH |
78 | if (*pos == sd) { |
79 | *pos = sd->s_sibling; | |
80 | sd->s_sibling = NULL; | |
81 | break; | |
82 | } | |
83 | } | |
84 | } | |
85 | ||
b6b4a439 TH |
86 | /** |
87 | * sysfs_get_active - get an active reference to sysfs_dirent | |
88 | * @sd: sysfs_dirent to get an active reference to | |
89 | * | |
90 | * Get an active reference of @sd. This function is noop if @sd | |
91 | * is NULL. | |
92 | * | |
93 | * RETURNS: | |
94 | * Pointer to @sd on success, NULL on failure. | |
95 | */ | |
e72ceb8c | 96 | struct sysfs_dirent *sysfs_get_active(struct sysfs_dirent *sd) |
b6b4a439 | 97 | { |
8619f979 TH |
98 | if (unlikely(!sd)) |
99 | return NULL; | |
100 | ||
101 | while (1) { | |
102 | int v, t; | |
103 | ||
104 | v = atomic_read(&sd->s_active); | |
105 | if (unlikely(v < 0)) | |
106 | return NULL; | |
107 | ||
108 | t = atomic_cmpxchg(&sd->s_active, v, v + 1); | |
846f9974 EB |
109 | if (likely(t == v)) { |
110 | rwsem_acquire_read(&sd->dep_map, 0, 1, _RET_IP_); | |
8619f979 | 111 | return sd; |
846f9974 | 112 | } |
8619f979 TH |
113 | if (t < 0) |
114 | return NULL; | |
115 | ||
116 | cpu_relax(); | |
b6b4a439 | 117 | } |
b6b4a439 TH |
118 | } |
119 | ||
120 | /** | |
121 | * sysfs_put_active - put an active reference to sysfs_dirent | |
122 | * @sd: sysfs_dirent to put an active reference to | |
123 | * | |
124 | * Put an active reference to @sd. This function is noop if @sd | |
125 | * is NULL. | |
126 | */ | |
e72ceb8c | 127 | void sysfs_put_active(struct sysfs_dirent *sd) |
b6b4a439 | 128 | { |
8619f979 TH |
129 | struct completion *cmpl; |
130 | int v; | |
131 | ||
132 | if (unlikely(!sd)) | |
133 | return; | |
134 | ||
846f9974 | 135 | rwsem_release(&sd->dep_map, 1, _RET_IP_); |
8619f979 TH |
136 | v = atomic_dec_return(&sd->s_active); |
137 | if (likely(v != SD_DEACTIVATED_BIAS)) | |
138 | return; | |
139 | ||
140 | /* atomic_dec_return() is a mb(), we'll always see the updated | |
0c73f18b | 141 | * sd->s_sibling. |
8619f979 | 142 | */ |
0c73f18b | 143 | cmpl = (void *)sd->s_sibling; |
8619f979 | 144 | complete(cmpl); |
b6b4a439 TH |
145 | } |
146 | ||
b6b4a439 TH |
147 | /** |
148 | * sysfs_deactivate - deactivate sysfs_dirent | |
149 | * @sd: sysfs_dirent to deactivate | |
150 | * | |
8619f979 | 151 | * Deny new active references and drain existing ones. |
b6b4a439 | 152 | */ |
fb6896da | 153 | static void sysfs_deactivate(struct sysfs_dirent *sd) |
b6b4a439 | 154 | { |
8619f979 TH |
155 | DECLARE_COMPLETION_ONSTACK(wait); |
156 | int v; | |
b6b4a439 | 157 | |
380e6fbb | 158 | BUG_ON(sd->s_sibling || !(sd->s_flags & SYSFS_FLAG_REMOVED)); |
a2db6842 EB |
159 | |
160 | if (!(sysfs_type(sd) & SYSFS_ACTIVE_REF)) | |
161 | return; | |
162 | ||
0c73f18b | 163 | sd->s_sibling = (void *)&wait; |
8619f979 | 164 | |
846f9974 | 165 | rwsem_acquire(&sd->dep_map, 0, 0, _RET_IP_); |
8619f979 | 166 | /* atomic_add_return() is a mb(), put_active() will always see |
0c73f18b | 167 | * the updated sd->s_sibling. |
b6b4a439 | 168 | */ |
8619f979 TH |
169 | v = atomic_add_return(SD_DEACTIVATED_BIAS, &sd->s_active); |
170 | ||
846f9974 EB |
171 | if (v != SD_DEACTIVATED_BIAS) { |
172 | lock_contended(&sd->dep_map, _RET_IP_); | |
8619f979 | 173 | wait_for_completion(&wait); |
846f9974 | 174 | } |
8619f979 | 175 | |
0c73f18b | 176 | sd->s_sibling = NULL; |
846f9974 EB |
177 | |
178 | lock_acquired(&sd->dep_map, _RET_IP_); | |
179 | rwsem_release(&sd->dep_map, 1, _RET_IP_); | |
b6b4a439 TH |
180 | } |
181 | ||
42b37df6 | 182 | static int sysfs_alloc_ino(ino_t *pino) |
2b611bb7 TH |
183 | { |
184 | int ino, rc; | |
185 | ||
186 | retry: | |
187 | spin_lock(&sysfs_ino_lock); | |
188 | rc = ida_get_new_above(&sysfs_ino_ida, 2, &ino); | |
189 | spin_unlock(&sysfs_ino_lock); | |
190 | ||
191 | if (rc == -EAGAIN) { | |
192 | if (ida_pre_get(&sysfs_ino_ida, GFP_KERNEL)) | |
193 | goto retry; | |
194 | rc = -ENOMEM; | |
195 | } | |
196 | ||
197 | *pino = ino; | |
198 | return rc; | |
199 | } | |
200 | ||
201 | static void sysfs_free_ino(ino_t ino) | |
202 | { | |
203 | spin_lock(&sysfs_ino_lock); | |
204 | ida_remove(&sysfs_ino_ida, ino); | |
205 | spin_unlock(&sysfs_ino_lock); | |
206 | } | |
207 | ||
fa7f912a TH |
208 | void release_sysfs_dirent(struct sysfs_dirent * sd) |
209 | { | |
13b3086d TH |
210 | struct sysfs_dirent *parent_sd; |
211 | ||
212 | repeat: | |
3007e997 TH |
213 | /* Moving/renaming is always done while holding reference. |
214 | * sd->s_parent won't change beneath us. | |
215 | */ | |
13b3086d TH |
216 | parent_sd = sd->s_parent; |
217 | ||
b402d72c | 218 | if (sysfs_type(sd) == SYSFS_KOBJ_LINK) |
b1fc3d61 | 219 | sysfs_put(sd->s_symlink.target_sd); |
b402d72c | 220 | if (sysfs_type(sd) & SYSFS_COPY_NAME) |
0c096b50 | 221 | kfree(sd->s_name); |
4c3da220 EB |
222 | if (sd->s_iattr && sd->s_iattr->ia_secdata) |
223 | security_release_secctx(sd->s_iattr->ia_secdata, | |
224 | sd->s_iattr->ia_secdata_len); | |
fa7f912a | 225 | kfree(sd->s_iattr); |
2b611bb7 | 226 | sysfs_free_ino(sd->s_ino); |
fa7f912a | 227 | kmem_cache_free(sysfs_dir_cachep, sd); |
13b3086d TH |
228 | |
229 | sd = parent_sd; | |
230 | if (sd && atomic_dec_and_test(&sd->s_count)) | |
231 | goto repeat; | |
fa7f912a TH |
232 | } |
233 | ||
e8f077c8 EB |
234 | static int sysfs_dentry_delete(struct dentry *dentry) |
235 | { | |
236 | struct sysfs_dirent *sd = dentry->d_fsdata; | |
237 | return !!(sd->s_flags & SYSFS_FLAG_REMOVED); | |
238 | } | |
239 | ||
240 | static int sysfs_dentry_revalidate(struct dentry *dentry, struct nameidata *nd) | |
241 | { | |
242 | struct sysfs_dirent *sd = dentry->d_fsdata; | |
243 | int is_dir; | |
244 | ||
245 | mutex_lock(&sysfs_mutex); | |
246 | ||
247 | /* The sysfs dirent has been deleted */ | |
248 | if (sd->s_flags & SYSFS_FLAG_REMOVED) | |
249 | goto out_bad; | |
250 | ||
832b6af1 EB |
251 | /* The sysfs dirent has been moved? */ |
252 | if (dentry->d_parent->d_fsdata != sd->s_parent) | |
253 | goto out_bad; | |
254 | ||
255 | /* The sysfs dirent has been renamed */ | |
256 | if (strcmp(dentry->d_name.name, sd->s_name) != 0) | |
257 | goto out_bad; | |
258 | ||
e8f077c8 EB |
259 | mutex_unlock(&sysfs_mutex); |
260 | out_valid: | |
261 | return 1; | |
262 | out_bad: | |
263 | /* Remove the dentry from the dcache hashes. | |
264 | * If this is a deleted dentry we use d_drop instead of d_delete | |
265 | * so sysfs doesn't need to cope with negative dentries. | |
832b6af1 EB |
266 | * |
267 | * If this is a dentry that has simply been renamed we | |
268 | * use d_drop to remove it from the dcache lookup on its | |
269 | * old parent. If this dentry persists later when a lookup | |
270 | * is performed at its new name the dentry will be readded | |
271 | * to the dcache hashes. | |
e8f077c8 EB |
272 | */ |
273 | is_dir = (sysfs_type(sd) == SYSFS_DIR); | |
274 | mutex_unlock(&sysfs_mutex); | |
275 | if (is_dir) { | |
276 | /* If we have submounts we must allow the vfs caches | |
277 | * to lie about the state of the filesystem to prevent | |
278 | * leaks and other nasty things. | |
279 | */ | |
280 | if (have_submounts(dentry)) | |
281 | goto out_valid; | |
282 | shrink_dcache_parent(dentry); | |
283 | } | |
284 | d_drop(dentry); | |
285 | return 0; | |
286 | } | |
287 | ||
28a027cf | 288 | static void sysfs_dentry_iput(struct dentry *dentry, struct inode *inode) |
1da177e4 LT |
289 | { |
290 | struct sysfs_dirent * sd = dentry->d_fsdata; | |
291 | ||
5a26b79c | 292 | sysfs_put(sd); |
1da177e4 LT |
293 | iput(inode); |
294 | } | |
295 | ||
ee1ec329 | 296 | static const struct dentry_operations sysfs_dentry_ops = { |
e8f077c8 EB |
297 | .d_revalidate = sysfs_dentry_revalidate, |
298 | .d_delete = sysfs_dentry_delete, | |
28a027cf | 299 | .d_iput = sysfs_dentry_iput, |
1da177e4 LT |
300 | }; |
301 | ||
3e519038 | 302 | struct sysfs_dirent *sysfs_new_dirent(const char *name, umode_t mode, int type) |
1da177e4 | 303 | { |
0c096b50 | 304 | char *dup_name = NULL; |
01da2425 | 305 | struct sysfs_dirent *sd; |
0c096b50 TH |
306 | |
307 | if (type & SYSFS_COPY_NAME) { | |
308 | name = dup_name = kstrdup(name, GFP_KERNEL); | |
309 | if (!name) | |
01da2425 | 310 | return NULL; |
0c096b50 | 311 | } |
1da177e4 | 312 | |
c3762229 | 313 | sd = kmem_cache_zalloc(sysfs_dir_cachep, GFP_KERNEL); |
1da177e4 | 314 | if (!sd) |
01da2425 | 315 | goto err_out1; |
1da177e4 | 316 | |
0c096b50 | 317 | if (sysfs_alloc_ino(&sd->s_ino)) |
01da2425 | 318 | goto err_out2; |
2b611bb7 | 319 | |
1da177e4 | 320 | atomic_set(&sd->s_count, 1); |
8619f979 | 321 | atomic_set(&sd->s_active, 0); |
a26cd722 | 322 | |
0c096b50 | 323 | sd->s_name = name; |
a26cd722 | 324 | sd->s_mode = mode; |
b402d72c | 325 | sd->s_flags = type; |
1da177e4 LT |
326 | |
327 | return sd; | |
0c096b50 | 328 | |
01da2425 | 329 | err_out2: |
0c096b50 | 330 | kmem_cache_free(sysfs_dir_cachep, sd); |
01da2425 AM |
331 | err_out1: |
332 | kfree(dup_name); | |
0c096b50 | 333 | return NULL; |
1da177e4 LT |
334 | } |
335 | ||
3007e997 | 336 | /** |
fb6896da TH |
337 | * sysfs_addrm_start - prepare for sysfs_dirent add/remove |
338 | * @acxt: pointer to sysfs_addrm_cxt to be used | |
339 | * @parent_sd: parent sysfs_dirent | |
3007e997 | 340 | * |
fb6896da TH |
341 | * This function is called when the caller is about to add or |
342 | * remove sysfs_dirent under @parent_sd. This function acquires | |
a16bbc34 | 343 | * sysfs_mutex. @acxt is used to keep and pass context to |
fb6896da | 344 | * other addrm functions. |
3007e997 TH |
345 | * |
346 | * LOCKING: | |
fb6896da | 347 | * Kernel thread context (may sleep). sysfs_mutex is locked on |
a16bbc34 | 348 | * return. |
3007e997 | 349 | */ |
fb6896da TH |
350 | void sysfs_addrm_start(struct sysfs_addrm_cxt *acxt, |
351 | struct sysfs_dirent *parent_sd) | |
b592fcfe | 352 | { |
fb6896da TH |
353 | memset(acxt, 0, sizeof(*acxt)); |
354 | acxt->parent_sd = parent_sd; | |
355 | ||
fb6896da | 356 | mutex_lock(&sysfs_mutex); |
fb6896da TH |
357 | } |
358 | ||
359 | /** | |
36ce6dad | 360 | * __sysfs_add_one - add sysfs_dirent to parent without warning |
fb6896da TH |
361 | * @acxt: addrm context to use |
362 | * @sd: sysfs_dirent to be added | |
363 | * | |
364 | * Get @acxt->parent_sd and set sd->s_parent to it and increment | |
181b2e4b TH |
365 | * nlink of parent inode if @sd is a directory and link into the |
366 | * children list of the parent. | |
fb6896da TH |
367 | * |
368 | * This function should be called between calls to | |
369 | * sysfs_addrm_start() and sysfs_addrm_finish() and should be | |
370 | * passed the same @acxt as passed to sysfs_addrm_start(). | |
371 | * | |
372 | * LOCKING: | |
373 | * Determined by sysfs_addrm_start(). | |
23dc2799 TH |
374 | * |
375 | * RETURNS: | |
376 | * 0 on success, -EEXIST if entry with the given name already | |
377 | * exists. | |
fb6896da | 378 | */ |
36ce6dad | 379 | int __sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd) |
fb6896da | 380 | { |
6b0bfe93 EB |
381 | struct sysfs_inode_attrs *ps_iattr; |
382 | ||
3ff195b0 | 383 | if (sysfs_find_dirent(acxt->parent_sd, sd->s_ns, sd->s_name)) |
23dc2799 TH |
384 | return -EEXIST; |
385 | ||
fb6896da TH |
386 | sd->s_parent = sysfs_get(acxt->parent_sd); |
387 | ||
41fc1c27 | 388 | sysfs_link_sibling(sd); |
23dc2799 | 389 | |
6b0bfe93 EB |
390 | /* Update timestamps on the parent */ |
391 | ps_iattr = acxt->parent_sd->s_iattr; | |
392 | if (ps_iattr) { | |
393 | struct iattr *ps_iattrs = &ps_iattr->ia_iattr; | |
394 | ps_iattrs->ia_ctime = ps_iattrs->ia_mtime = CURRENT_TIME; | |
395 | } | |
396 | ||
23dc2799 | 397 | return 0; |
fb6896da TH |
398 | } |
399 | ||
425cb029 AC |
400 | /** |
401 | * sysfs_pathname - return full path to sysfs dirent | |
402 | * @sd: sysfs_dirent whose path we want | |
403 | * @path: caller allocated buffer | |
404 | * | |
405 | * Gives the name "/" to the sysfs_root entry; any path returned | |
406 | * is relative to wherever sysfs is mounted. | |
407 | * | |
408 | * XXX: does no error checking on @path size | |
409 | */ | |
410 | static char *sysfs_pathname(struct sysfs_dirent *sd, char *path) | |
411 | { | |
412 | if (sd->s_parent) { | |
413 | sysfs_pathname(sd->s_parent, path); | |
414 | strcat(path, "/"); | |
415 | } | |
416 | strcat(path, sd->s_name); | |
417 | return path; | |
418 | } | |
419 | ||
36ce6dad CH |
420 | /** |
421 | * sysfs_add_one - add sysfs_dirent to parent | |
422 | * @acxt: addrm context to use | |
423 | * @sd: sysfs_dirent to be added | |
424 | * | |
425 | * Get @acxt->parent_sd and set sd->s_parent to it and increment | |
426 | * nlink of parent inode if @sd is a directory and link into the | |
427 | * children list of the parent. | |
428 | * | |
429 | * This function should be called between calls to | |
430 | * sysfs_addrm_start() and sysfs_addrm_finish() and should be | |
431 | * passed the same @acxt as passed to sysfs_addrm_start(). | |
432 | * | |
433 | * LOCKING: | |
434 | * Determined by sysfs_addrm_start(). | |
435 | * | |
436 | * RETURNS: | |
437 | * 0 on success, -EEXIST if entry with the given name already | |
438 | * exists. | |
439 | */ | |
440 | int sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd) | |
441 | { | |
442 | int ret; | |
443 | ||
444 | ret = __sysfs_add_one(acxt, sd); | |
425cb029 AC |
445 | if (ret == -EEXIST) { |
446 | char *path = kzalloc(PATH_MAX, GFP_KERNEL); | |
447 | WARN(1, KERN_WARNING | |
448 | "sysfs: cannot create duplicate filename '%s'\n", | |
449 | (path == NULL) ? sd->s_name : | |
450 | strcat(strcat(sysfs_pathname(acxt->parent_sd, path), "/"), | |
451 | sd->s_name)); | |
452 | kfree(path); | |
453 | } | |
454 | ||
36ce6dad CH |
455 | return ret; |
456 | } | |
457 | ||
fb6896da TH |
458 | /** |
459 | * sysfs_remove_one - remove sysfs_dirent from parent | |
460 | * @acxt: addrm context to use | |
9fd5b1c9 | 461 | * @sd: sysfs_dirent to be removed |
fb6896da TH |
462 | * |
463 | * Mark @sd removed and drop nlink of parent inode if @sd is a | |
181b2e4b | 464 | * directory. @sd is unlinked from the children list. |
fb6896da TH |
465 | * |
466 | * This function should be called between calls to | |
467 | * sysfs_addrm_start() and sysfs_addrm_finish() and should be | |
468 | * passed the same @acxt as passed to sysfs_addrm_start(). | |
469 | * | |
470 | * LOCKING: | |
471 | * Determined by sysfs_addrm_start(). | |
472 | */ | |
473 | void sysfs_remove_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd) | |
474 | { | |
6b0bfe93 EB |
475 | struct sysfs_inode_attrs *ps_iattr; |
476 | ||
41fc1c27 TH |
477 | BUG_ON(sd->s_flags & SYSFS_FLAG_REMOVED); |
478 | ||
479 | sysfs_unlink_sibling(sd); | |
fb6896da | 480 | |
6b0bfe93 EB |
481 | /* Update timestamps on the parent */ |
482 | ps_iattr = acxt->parent_sd->s_iattr; | |
483 | if (ps_iattr) { | |
484 | struct iattr *ps_iattrs = &ps_iattr->ia_iattr; | |
485 | ps_iattrs->ia_ctime = ps_iattrs->ia_mtime = CURRENT_TIME; | |
486 | } | |
487 | ||
fb6896da TH |
488 | sd->s_flags |= SYSFS_FLAG_REMOVED; |
489 | sd->s_sibling = acxt->removed; | |
490 | acxt->removed = sd; | |
a0edd7c8 TH |
491 | } |
492 | ||
fb6896da TH |
493 | /** |
494 | * sysfs_addrm_finish - finish up sysfs_dirent add/remove | |
495 | * @acxt: addrm context to finish up | |
496 | * | |
497 | * Finish up sysfs_dirent add/remove. Resources acquired by | |
498 | * sysfs_addrm_start() are released and removed sysfs_dirents are | |
a16bbc34 | 499 | * cleaned up. |
fb6896da TH |
500 | * |
501 | * LOCKING: | |
a16bbc34 | 502 | * sysfs_mutex is released. |
fb6896da | 503 | */ |
990e53f8 | 504 | void sysfs_addrm_finish(struct sysfs_addrm_cxt *acxt) |
fb6896da TH |
505 | { |
506 | /* release resources acquired by sysfs_addrm_start() */ | |
507 | mutex_unlock(&sysfs_mutex); | |
fb6896da TH |
508 | |
509 | /* kill removed sysfs_dirents */ | |
510 | while (acxt->removed) { | |
511 | struct sysfs_dirent *sd = acxt->removed; | |
512 | ||
513 | acxt->removed = sd->s_sibling; | |
514 | sd->s_sibling = NULL; | |
515 | ||
fb6896da | 516 | sysfs_deactivate(sd); |
e0edd3c6 | 517 | unmap_bin_file(sd); |
fb6896da | 518 | sysfs_put(sd); |
13b3086d | 519 | } |
b592fcfe EB |
520 | } |
521 | ||
f0b0af47 TH |
522 | /** |
523 | * sysfs_find_dirent - find sysfs_dirent with the given name | |
524 | * @parent_sd: sysfs_dirent to search under | |
525 | * @name: name to look for | |
526 | * | |
527 | * Look for sysfs_dirent with name @name under @parent_sd. | |
c516865c | 528 | * |
f0b0af47 | 529 | * LOCKING: |
3007e997 | 530 | * mutex_lock(sysfs_mutex) |
c516865c | 531 | * |
f0b0af47 TH |
532 | * RETURNS: |
533 | * Pointer to sysfs_dirent if found, NULL if not. | |
c516865c | 534 | */ |
f0b0af47 | 535 | struct sysfs_dirent *sysfs_find_dirent(struct sysfs_dirent *parent_sd, |
3ff195b0 | 536 | const void *ns, |
f0b0af47 | 537 | const unsigned char *name) |
c516865c | 538 | { |
f0b0af47 TH |
539 | struct sysfs_dirent *sd; |
540 | ||
3ff195b0 | 541 | for (sd = parent_sd->s_dir.children; sd; sd = sd->s_sibling) { |
af10ec77 | 542 | if (ns && sd->s_ns && (sd->s_ns != ns)) |
3ff195b0 | 543 | continue; |
3efa65b9 | 544 | if (!strcmp(sd->s_name, name)) |
f0b0af47 | 545 | return sd; |
3ff195b0 | 546 | } |
f0b0af47 TH |
547 | return NULL; |
548 | } | |
c516865c | 549 | |
f0b0af47 TH |
550 | /** |
551 | * sysfs_get_dirent - find and get sysfs_dirent with the given name | |
552 | * @parent_sd: sysfs_dirent to search under | |
553 | * @name: name to look for | |
554 | * | |
555 | * Look for sysfs_dirent with name @name under @parent_sd and get | |
556 | * it if found. | |
557 | * | |
558 | * LOCKING: | |
3007e997 | 559 | * Kernel thread context (may sleep). Grabs sysfs_mutex. |
f0b0af47 TH |
560 | * |
561 | * RETURNS: | |
562 | * Pointer to sysfs_dirent if found, NULL if not. | |
563 | */ | |
564 | struct sysfs_dirent *sysfs_get_dirent(struct sysfs_dirent *parent_sd, | |
3ff195b0 | 565 | const void *ns, |
f0b0af47 TH |
566 | const unsigned char *name) |
567 | { | |
568 | struct sysfs_dirent *sd; | |
569 | ||
3007e997 | 570 | mutex_lock(&sysfs_mutex); |
3ff195b0 | 571 | sd = sysfs_find_dirent(parent_sd, ns, name); |
f0b0af47 | 572 | sysfs_get(sd); |
3007e997 | 573 | mutex_unlock(&sysfs_mutex); |
f0b0af47 TH |
574 | |
575 | return sd; | |
c516865c | 576 | } |
f1282c84 | 577 | EXPORT_SYMBOL_GPL(sysfs_get_dirent); |
c516865c | 578 | |
608e266a | 579 | static int create_dir(struct kobject *kobj, struct sysfs_dirent *parent_sd, |
3ff195b0 EB |
580 | enum kobj_ns_type type, const void *ns, const char *name, |
581 | struct sysfs_dirent **p_sd) | |
1da177e4 | 582 | { |
1da177e4 | 583 | umode_t mode = S_IFDIR| S_IRWXU | S_IRUGO | S_IXUGO; |
51225039 | 584 | struct sysfs_addrm_cxt acxt; |
dfeb9fb0 | 585 | struct sysfs_dirent *sd; |
23dc2799 | 586 | int rc; |
1da177e4 | 587 | |
fc9f54b9 | 588 | /* allocate */ |
3e519038 | 589 | sd = sysfs_new_dirent(name, mode, SYSFS_DIR); |
a26cd722 | 590 | if (!sd) |
51225039 | 591 | return -ENOMEM; |
3ff195b0 EB |
592 | |
593 | sd->s_flags |= (type << SYSFS_NS_TYPE_SHIFT); | |
594 | sd->s_ns = ns; | |
b1fc3d61 | 595 | sd->s_dir.kobj = kobj; |
dfeb9fb0 | 596 | |
fc9f54b9 | 597 | /* link in */ |
51225039 | 598 | sysfs_addrm_start(&acxt, parent_sd); |
23dc2799 TH |
599 | rc = sysfs_add_one(&acxt, sd); |
600 | sysfs_addrm_finish(&acxt); | |
967e35dc | 601 | |
23dc2799 TH |
602 | if (rc == 0) |
603 | *p_sd = sd; | |
604 | else | |
967e35dc | 605 | sysfs_put(sd); |
dfeb9fb0 | 606 | |
23dc2799 | 607 | return rc; |
1da177e4 LT |
608 | } |
609 | ||
608e266a TH |
610 | int sysfs_create_subdir(struct kobject *kobj, const char *name, |
611 | struct sysfs_dirent **p_sd) | |
1da177e4 | 612 | { |
3ff195b0 EB |
613 | return create_dir(kobj, kobj->sd, |
614 | KOBJ_NS_TYPE_NONE, NULL, name, p_sd); | |
615 | } | |
616 | ||
be867b19 SH |
617 | /** |
618 | * sysfs_read_ns_type: return associated ns_type | |
619 | * @kobj: the kobject being queried | |
620 | * | |
621 | * Each kobject can be tagged with exactly one namespace type | |
622 | * (i.e. network or user). Return the ns_type associated with | |
623 | * this object if any | |
624 | */ | |
3ff195b0 EB |
625 | static enum kobj_ns_type sysfs_read_ns_type(struct kobject *kobj) |
626 | { | |
627 | const struct kobj_ns_type_operations *ops; | |
628 | enum kobj_ns_type type; | |
629 | ||
630 | ops = kobj_child_ns_ops(kobj); | |
631 | if (!ops) | |
632 | return KOBJ_NS_TYPE_NONE; | |
633 | ||
634 | type = ops->type; | |
635 | BUG_ON(type <= KOBJ_NS_TYPE_NONE); | |
636 | BUG_ON(type >= KOBJ_NS_TYPES); | |
637 | BUG_ON(!kobj_ns_type_registered(type)); | |
638 | ||
639 | return type; | |
1da177e4 LT |
640 | } |
641 | ||
642 | /** | |
643 | * sysfs_create_dir - create a directory for an object. | |
1da177e4 LT |
644 | * @kobj: object we're creating directory for. |
645 | */ | |
90bc6135 | 646 | int sysfs_create_dir(struct kobject * kobj) |
1da177e4 | 647 | { |
3ff195b0 | 648 | enum kobj_ns_type type; |
608e266a | 649 | struct sysfs_dirent *parent_sd, *sd; |
3ff195b0 | 650 | const void *ns = NULL; |
1da177e4 LT |
651 | int error = 0; |
652 | ||
653 | BUG_ON(!kobj); | |
654 | ||
90bc6135 | 655 | if (kobj->parent) |
608e266a | 656 | parent_sd = kobj->parent->sd; |
1da177e4 | 657 | else |
7d0c7d67 | 658 | parent_sd = &sysfs_root; |
1da177e4 | 659 | |
3ff195b0 EB |
660 | if (sysfs_ns_type(parent_sd)) |
661 | ns = kobj->ktype->namespace(kobj); | |
662 | type = sysfs_read_ns_type(kobj); | |
663 | ||
664 | error = create_dir(kobj, parent_sd, type, ns, kobject_name(kobj), &sd); | |
1da177e4 | 665 | if (!error) |
608e266a | 666 | kobj->sd = sd; |
1da177e4 LT |
667 | return error; |
668 | } | |
669 | ||
1da177e4 LT |
670 | static struct dentry * sysfs_lookup(struct inode *dir, struct dentry *dentry, |
671 | struct nameidata *nd) | |
672 | { | |
6cb52147 | 673 | struct dentry *ret = NULL; |
3ff195b0 EB |
674 | struct dentry *parent = dentry->d_parent; |
675 | struct sysfs_dirent *parent_sd = parent->d_fsdata; | |
a7a04754 | 676 | struct sysfs_dirent *sd; |
fc9f54b9 | 677 | struct inode *inode; |
3ff195b0 EB |
678 | enum kobj_ns_type type; |
679 | const void *ns; | |
1da177e4 | 680 | |
6cb52147 TH |
681 | mutex_lock(&sysfs_mutex); |
682 | ||
3ff195b0 EB |
683 | type = sysfs_ns_type(parent_sd); |
684 | ns = sysfs_info(dir->i_sb)->ns[type]; | |
685 | ||
686 | sd = sysfs_find_dirent(parent_sd, ns, dentry->d_name.name); | |
1da177e4 | 687 | |
fc9f54b9 | 688 | /* no such entry */ |
e49452c6 TH |
689 | if (!sd) { |
690 | ret = ERR_PTR(-ENOENT); | |
6cb52147 | 691 | goto out_unlock; |
e49452c6 | 692 | } |
fc9f54b9 TH |
693 | |
694 | /* attach dentry and inode */ | |
fac2622b | 695 | inode = sysfs_get_inode(dir->i_sb, sd); |
6cb52147 TH |
696 | if (!inode) { |
697 | ret = ERR_PTR(-ENOMEM); | |
698 | goto out_unlock; | |
699 | } | |
3007e997 | 700 | |
d6b4fd2f | 701 | /* instantiate and hash dentry */ |
832b6af1 EB |
702 | ret = d_find_alias(inode); |
703 | if (!ret) { | |
704 | dentry->d_op = &sysfs_dentry_ops; | |
705 | dentry->d_fsdata = sysfs_get(sd); | |
706 | d_add(dentry, inode); | |
707 | } else { | |
708 | d_move(ret, dentry); | |
709 | iput(inode); | |
710 | } | |
fc9f54b9 | 711 | |
6cb52147 | 712 | out_unlock: |
3007e997 | 713 | mutex_unlock(&sysfs_mutex); |
6cb52147 | 714 | return ret; |
1da177e4 LT |
715 | } |
716 | ||
c5ef1c42 | 717 | const struct inode_operations sysfs_dir_inode_operations = { |
1da177e4 | 718 | .lookup = sysfs_lookup, |
e61ab4ae | 719 | .permission = sysfs_permission, |
988d186d | 720 | .setattr = sysfs_setattr, |
e61ab4ae | 721 | .getattr = sysfs_getattr, |
ddd29ec6 | 722 | .setxattr = sysfs_setxattr, |
1da177e4 LT |
723 | }; |
724 | ||
608e266a | 725 | static void remove_dir(struct sysfs_dirent *sd) |
1da177e4 | 726 | { |
fb6896da | 727 | struct sysfs_addrm_cxt acxt; |
1da177e4 | 728 | |
fb6896da | 729 | sysfs_addrm_start(&acxt, sd->s_parent); |
fb6896da TH |
730 | sysfs_remove_one(&acxt, sd); |
731 | sysfs_addrm_finish(&acxt); | |
1da177e4 LT |
732 | } |
733 | ||
608e266a | 734 | void sysfs_remove_subdir(struct sysfs_dirent *sd) |
1da177e4 | 735 | { |
608e266a | 736 | remove_dir(sd); |
1da177e4 LT |
737 | } |
738 | ||
739 | ||
608e266a | 740 | static void __sysfs_remove_dir(struct sysfs_dirent *dir_sd) |
1da177e4 | 741 | { |
fb6896da | 742 | struct sysfs_addrm_cxt acxt; |
0c73f18b | 743 | struct sysfs_dirent **pos; |
1da177e4 | 744 | |
608e266a | 745 | if (!dir_sd) |
1da177e4 LT |
746 | return; |
747 | ||
608e266a | 748 | pr_debug("sysfs %s: removing dir\n", dir_sd->s_name); |
fb6896da | 749 | sysfs_addrm_start(&acxt, dir_sd); |
bc747f37 | 750 | pos = &dir_sd->s_dir.children; |
0c73f18b TH |
751 | while (*pos) { |
752 | struct sysfs_dirent *sd = *pos; | |
753 | ||
3efa65b9 | 754 | if (sysfs_type(sd) != SYSFS_DIR) |
fb6896da | 755 | sysfs_remove_one(&acxt, sd); |
41fc1c27 | 756 | else |
0c73f18b | 757 | pos = &(*pos)->s_sibling; |
1da177e4 | 758 | } |
fb6896da | 759 | sysfs_addrm_finish(&acxt); |
0ab66088 | 760 | |
608e266a | 761 | remove_dir(dir_sd); |
b592fcfe EB |
762 | } |
763 | ||
764 | /** | |
765 | * sysfs_remove_dir - remove an object's directory. | |
766 | * @kobj: object. | |
767 | * | |
768 | * The only thing special about this is that we remove any files in | |
769 | * the directory before we remove the directory, and we've inlined | |
770 | * what used to be sysfs_rmdir() below, instead of calling separately. | |
771 | */ | |
772 | ||
773 | void sysfs_remove_dir(struct kobject * kobj) | |
774 | { | |
608e266a | 775 | struct sysfs_dirent *sd = kobj->sd; |
aecdceda | 776 | |
5f995323 | 777 | spin_lock(&sysfs_assoc_lock); |
608e266a | 778 | kobj->sd = NULL; |
5f995323 | 779 | spin_unlock(&sysfs_assoc_lock); |
aecdceda | 780 | |
608e266a | 781 | __sysfs_remove_dir(sd); |
1da177e4 LT |
782 | } |
783 | ||
ca1bab38 | 784 | int sysfs_rename(struct sysfs_dirent *sd, |
3ff195b0 EB |
785 | struct sysfs_dirent *new_parent_sd, const void *new_ns, |
786 | const char *new_name) | |
1da177e4 | 787 | { |
51225039 | 788 | const char *dup_name = NULL; |
996b7376 | 789 | int error; |
1da177e4 | 790 | |
832b6af1 | 791 | mutex_lock(&sysfs_mutex); |
932ea2e3 | 792 | |
9918f9a4 | 793 | error = 0; |
3ff195b0 | 794 | if ((sd->s_parent == new_parent_sd) && (sd->s_ns == new_ns) && |
ca1bab38 | 795 | (strcmp(sd->s_name, new_name) == 0)) |
9918f9a4 EB |
796 | goto out; /* nothing to rename */ |
797 | ||
9918f9a4 | 798 | error = -EEXIST; |
3ff195b0 | 799 | if (sysfs_find_dirent(new_parent_sd, new_ns, new_name)) |
832b6af1 | 800 | goto out; |
996b7376 | 801 | |
0b4a4fea | 802 | /* rename sysfs_dirent */ |
ca1bab38 EB |
803 | if (strcmp(sd->s_name, new_name) != 0) { |
804 | error = -ENOMEM; | |
805 | new_name = dup_name = kstrdup(new_name, GFP_KERNEL); | |
806 | if (!new_name) | |
807 | goto out; | |
808 | ||
809 | dup_name = sd->s_name; | |
810 | sd->s_name = new_name; | |
811 | } | |
0c096b50 | 812 | |
ca1bab38 EB |
813 | /* Remove from old parent's list and insert into new parent's list. */ |
814 | if (sd->s_parent != new_parent_sd) { | |
815 | sysfs_unlink_sibling(sd); | |
816 | sysfs_get(new_parent_sd); | |
817 | sysfs_put(sd->s_parent); | |
818 | sd->s_parent = new_parent_sd; | |
819 | sysfs_link_sibling(sd); | |
820 | } | |
3ff195b0 | 821 | sd->s_ns = new_ns; |
0c096b50 | 822 | |
996b7376 | 823 | error = 0; |
832b6af1 | 824 | out: |
9918f9a4 | 825 | mutex_unlock(&sysfs_mutex); |
51225039 | 826 | kfree(dup_name); |
1da177e4 LT |
827 | return error; |
828 | } | |
829 | ||
ca1bab38 EB |
830 | int sysfs_rename_dir(struct kobject *kobj, const char *new_name) |
831 | { | |
3ff195b0 EB |
832 | struct sysfs_dirent *parent_sd = kobj->sd->s_parent; |
833 | const void *new_ns = NULL; | |
834 | ||
835 | if (sysfs_ns_type(parent_sd)) | |
836 | new_ns = kobj->ktype->namespace(kobj); | |
837 | ||
838 | return sysfs_rename(kobj->sd, parent_sd, new_ns, new_name); | |
ca1bab38 EB |
839 | } |
840 | ||
51225039 | 841 | int sysfs_move_dir(struct kobject *kobj, struct kobject *new_parent_kobj) |
8a82472f | 842 | { |
51225039 TH |
843 | struct sysfs_dirent *sd = kobj->sd; |
844 | struct sysfs_dirent *new_parent_sd; | |
3ff195b0 | 845 | const void *new_ns = NULL; |
8a82472f | 846 | |
51225039 | 847 | BUG_ON(!sd->s_parent); |
3ff195b0 EB |
848 | if (sysfs_ns_type(sd->s_parent)) |
849 | new_ns = kobj->ktype->namespace(kobj); | |
ca1bab38 | 850 | new_parent_sd = new_parent_kobj && new_parent_kobj->sd ? |
a6a83577 | 851 | new_parent_kobj->sd : &sysfs_root; |
51225039 | 852 | |
3ff195b0 | 853 | return sysfs_rename(sd, new_parent_sd, new_ns, sd->s_name); |
8a82472f CH |
854 | } |
855 | ||
1da177e4 LT |
856 | /* Relationship between s_mode and the DT_xxx types */ |
857 | static inline unsigned char dt_type(struct sysfs_dirent *sd) | |
858 | { | |
859 | return (sd->s_mode >> 12) & 15; | |
860 | } | |
861 | ||
1e5289c9 EB |
862 | static int sysfs_dir_release(struct inode *inode, struct file *filp) |
863 | { | |
864 | sysfs_put(filp->private_data); | |
865 | return 0; | |
866 | } | |
867 | ||
3ff195b0 EB |
868 | static struct sysfs_dirent *sysfs_dir_pos(const void *ns, |
869 | struct sysfs_dirent *parent_sd, ino_t ino, struct sysfs_dirent *pos) | |
1e5289c9 EB |
870 | { |
871 | if (pos) { | |
872 | int valid = !(pos->s_flags & SYSFS_FLAG_REMOVED) && | |
873 | pos->s_parent == parent_sd && | |
874 | ino == pos->s_ino; | |
875 | sysfs_put(pos); | |
3ff195b0 EB |
876 | if (!valid) |
877 | pos = NULL; | |
1e5289c9 | 878 | } |
3ff195b0 | 879 | if (!pos && (ino > 1) && (ino < INT_MAX)) { |
1e5289c9 EB |
880 | pos = parent_sd->s_dir.children; |
881 | while (pos && (ino > pos->s_ino)) | |
882 | pos = pos->s_sibling; | |
883 | } | |
af10ec77 | 884 | while (pos && pos->s_ns && pos->s_ns != ns) |
3ff195b0 | 885 | pos = pos->s_sibling; |
1e5289c9 EB |
886 | return pos; |
887 | } | |
888 | ||
3ff195b0 EB |
889 | static struct sysfs_dirent *sysfs_dir_next_pos(const void *ns, |
890 | struct sysfs_dirent *parent_sd, ino_t ino, struct sysfs_dirent *pos) | |
1e5289c9 | 891 | { |
3ff195b0 | 892 | pos = sysfs_dir_pos(ns, parent_sd, ino, pos); |
1e5289c9 EB |
893 | if (pos) |
894 | pos = pos->s_sibling; | |
af10ec77 | 895 | while (pos && pos->s_ns && pos->s_ns != ns) |
3ff195b0 | 896 | pos = pos->s_sibling; |
1e5289c9 EB |
897 | return pos; |
898 | } | |
899 | ||
1da177e4 LT |
900 | static int sysfs_readdir(struct file * filp, void * dirent, filldir_t filldir) |
901 | { | |
f427f5d5 | 902 | struct dentry *dentry = filp->f_path.dentry; |
1da177e4 | 903 | struct sysfs_dirent * parent_sd = dentry->d_fsdata; |
1e5289c9 | 904 | struct sysfs_dirent *pos = filp->private_data; |
3ff195b0 EB |
905 | enum kobj_ns_type type; |
906 | const void *ns; | |
1da177e4 | 907 | ino_t ino; |
1da177e4 | 908 | |
3ff195b0 EB |
909 | type = sysfs_ns_type(parent_sd); |
910 | ns = sysfs_info(dentry->d_sb)->ns[type]; | |
911 | ||
3efa65b9 EB |
912 | if (filp->f_pos == 0) { |
913 | ino = parent_sd->s_ino; | |
914 | if (filldir(dirent, ".", 1, filp->f_pos, ino, DT_DIR) == 0) | |
1da177e4 | 915 | filp->f_pos++; |
3efa65b9 EB |
916 | } |
917 | if (filp->f_pos == 1) { | |
918 | if (parent_sd->s_parent) | |
919 | ino = parent_sd->s_parent->s_ino; | |
920 | else | |
921 | ino = parent_sd->s_ino; | |
922 | if (filldir(dirent, "..", 2, filp->f_pos, ino, DT_DIR) == 0) | |
1da177e4 | 923 | filp->f_pos++; |
3efa65b9 | 924 | } |
1e5289c9 | 925 | mutex_lock(&sysfs_mutex); |
3ff195b0 | 926 | for (pos = sysfs_dir_pos(ns, parent_sd, filp->f_pos, pos); |
1e5289c9 | 927 | pos; |
3ff195b0 | 928 | pos = sysfs_dir_next_pos(ns, parent_sd, filp->f_pos, pos)) { |
1e5289c9 EB |
929 | const char * name; |
930 | unsigned int type; | |
931 | int len, ret; | |
932 | ||
933 | name = pos->s_name; | |
934 | len = strlen(name); | |
935 | ino = pos->s_ino; | |
936 | type = dt_type(pos); | |
937 | filp->f_pos = ino; | |
938 | filp->private_data = sysfs_get(pos); | |
1da177e4 | 939 | |
3007e997 | 940 | mutex_unlock(&sysfs_mutex); |
1e5289c9 EB |
941 | ret = filldir(dirent, name, len, filp->f_pos, ino, type); |
942 | mutex_lock(&sysfs_mutex); | |
943 | if (ret < 0) | |
944 | break; | |
945 | } | |
946 | mutex_unlock(&sysfs_mutex); | |
947 | if ((filp->f_pos > 1) && !pos) { /* EOF */ | |
948 | filp->f_pos = INT_MAX; | |
949 | filp->private_data = NULL; | |
1da177e4 | 950 | } |
3efa65b9 | 951 | return 0; |
1da177e4 LT |
952 | } |
953 | ||
3efa65b9 | 954 | |
4b6f5d20 | 955 | const struct file_operations sysfs_dir_operations = { |
1da177e4 LT |
956 | .read = generic_read_dir, |
957 | .readdir = sysfs_readdir, | |
1e5289c9 | 958 | .release = sysfs_dir_release, |
3222a3e5 | 959 | .llseek = generic_file_llseek, |
1da177e4 | 960 | }; |