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7063fbf2 JB |
1 | /* -*- mode: c; c-basic-offset: 8; -*- |
2 | * vim: noexpandtab sw=8 ts=8 sts=0: | |
3 | * | |
4 | * dir.c - Operations for configfs directories. | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or | |
7 | * modify it under the terms of the GNU General Public | |
8 | * License as published by the Free Software Foundation; either | |
9 | * version 2 of the License, or (at your option) any later version. | |
10 | * | |
11 | * This program is distributed in the hope that it will be useful, | |
12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
14 | * General Public License for more details. | |
15 | * | |
16 | * You should have received a copy of the GNU General Public | |
17 | * License along with this program; if not, write to the | |
18 | * Free Software Foundation, Inc., 59 Temple Place - Suite 330, | |
19 | * Boston, MA 021110-1307, USA. | |
20 | * | |
21 | * Based on sysfs: | |
22 | * sysfs is Copyright (C) 2001, 2002, 2003 Patrick Mochel | |
23 | * | |
24 | * configfs Copyright (C) 2005 Oracle. All rights reserved. | |
25 | */ | |
26 | ||
27 | #undef DEBUG | |
28 | ||
29 | #include <linux/fs.h> | |
30 | #include <linux/mount.h> | |
31 | #include <linux/module.h> | |
32 | #include <linux/slab.h> | |
33 | ||
34 | #include <linux/configfs.h> | |
35 | #include "configfs_internal.h" | |
36 | ||
37 | DECLARE_RWSEM(configfs_rename_sem); | |
38 | ||
39 | static void configfs_d_iput(struct dentry * dentry, | |
40 | struct inode * inode) | |
41 | { | |
42 | struct configfs_dirent * sd = dentry->d_fsdata; | |
43 | ||
44 | if (sd) { | |
45 | BUG_ON(sd->s_dentry != dentry); | |
46 | sd->s_dentry = NULL; | |
47 | configfs_put(sd); | |
48 | } | |
49 | iput(inode); | |
50 | } | |
51 | ||
52 | /* | |
53 | * We _must_ delete our dentries on last dput, as the chain-to-parent | |
54 | * behavior is required to clear the parents of default_groups. | |
55 | */ | |
56 | static int configfs_d_delete(struct dentry *dentry) | |
57 | { | |
58 | return 1; | |
59 | } | |
60 | ||
61 | static struct dentry_operations configfs_dentry_ops = { | |
62 | .d_iput = configfs_d_iput, | |
63 | /* simple_delete_dentry() isn't exported */ | |
64 | .d_delete = configfs_d_delete, | |
65 | }; | |
66 | ||
67 | /* | |
68 | * Allocates a new configfs_dirent and links it to the parent configfs_dirent | |
69 | */ | |
70 | static struct configfs_dirent *configfs_new_dirent(struct configfs_dirent * parent_sd, | |
71 | void * element) | |
72 | { | |
73 | struct configfs_dirent * sd; | |
74 | ||
c3762229 | 75 | sd = kmem_cache_zalloc(configfs_dir_cachep, GFP_KERNEL); |
7063fbf2 JB |
76 | if (!sd) |
77 | return NULL; | |
78 | ||
7063fbf2 JB |
79 | atomic_set(&sd->s_count, 1); |
80 | INIT_LIST_HEAD(&sd->s_links); | |
81 | INIT_LIST_HEAD(&sd->s_children); | |
82 | list_add(&sd->s_sibling, &parent_sd->s_children); | |
83 | sd->s_element = element; | |
84 | ||
85 | return sd; | |
86 | } | |
87 | ||
b4c98f62 JB |
88 | /* |
89 | * | |
90 | * Return -EEXIST if there is already a configfs element with the same | |
91 | * name for the same parent. | |
92 | * | |
93 | * called with parent inode's i_mutex held | |
94 | */ | |
58d206c2 AB |
95 | static int configfs_dirent_exists(struct configfs_dirent *parent_sd, |
96 | const unsigned char *new) | |
b4c98f62 JB |
97 | { |
98 | struct configfs_dirent * sd; | |
99 | ||
100 | list_for_each_entry(sd, &parent_sd->s_children, s_sibling) { | |
101 | if (sd->s_element) { | |
102 | const unsigned char *existing = configfs_get_name(sd); | |
103 | if (strcmp(existing, new)) | |
104 | continue; | |
105 | else | |
106 | return -EEXIST; | |
107 | } | |
108 | } | |
109 | ||
110 | return 0; | |
111 | } | |
112 | ||
113 | ||
7063fbf2 JB |
114 | int configfs_make_dirent(struct configfs_dirent * parent_sd, |
115 | struct dentry * dentry, void * element, | |
116 | umode_t mode, int type) | |
117 | { | |
118 | struct configfs_dirent * sd; | |
119 | ||
120 | sd = configfs_new_dirent(parent_sd, element); | |
121 | if (!sd) | |
122 | return -ENOMEM; | |
123 | ||
124 | sd->s_mode = mode; | |
125 | sd->s_type = type; | |
126 | sd->s_dentry = dentry; | |
127 | if (dentry) { | |
128 | dentry->d_fsdata = configfs_get(sd); | |
129 | dentry->d_op = &configfs_dentry_ops; | |
130 | } | |
131 | ||
132 | return 0; | |
133 | } | |
134 | ||
135 | static int init_dir(struct inode * inode) | |
136 | { | |
137 | inode->i_op = &configfs_dir_inode_operations; | |
138 | inode->i_fop = &configfs_dir_operations; | |
139 | ||
140 | /* directory inodes start off with i_nlink == 2 (for "." entry) */ | |
d8c76e6f | 141 | inc_nlink(inode); |
7063fbf2 JB |
142 | return 0; |
143 | } | |
144 | ||
ce8d2cdf | 145 | static int configfs_init_file(struct inode * inode) |
7063fbf2 JB |
146 | { |
147 | inode->i_size = PAGE_SIZE; | |
148 | inode->i_fop = &configfs_file_operations; | |
149 | return 0; | |
150 | } | |
151 | ||
152 | static int init_symlink(struct inode * inode) | |
153 | { | |
154 | inode->i_op = &configfs_symlink_inode_operations; | |
155 | return 0; | |
156 | } | |
157 | ||
158 | static int create_dir(struct config_item * k, struct dentry * p, | |
159 | struct dentry * d) | |
160 | { | |
161 | int error; | |
162 | umode_t mode = S_IFDIR| S_IRWXU | S_IRUGO | S_IXUGO; | |
163 | ||
b4c98f62 JB |
164 | error = configfs_dirent_exists(p->d_fsdata, d->d_name.name); |
165 | if (!error) | |
166 | error = configfs_make_dirent(p->d_fsdata, d, k, mode, | |
167 | CONFIGFS_DIR); | |
7063fbf2 | 168 | if (!error) { |
3d0f89bb | 169 | error = configfs_create(d, mode, init_dir); |
7063fbf2 | 170 | if (!error) { |
d8c76e6f | 171 | inc_nlink(p->d_inode); |
7063fbf2 | 172 | (d)->d_op = &configfs_dentry_ops; |
3d0f89bb JB |
173 | } else { |
174 | struct configfs_dirent *sd = d->d_fsdata; | |
175 | if (sd) { | |
176 | list_del_init(&sd->s_sibling); | |
177 | configfs_put(sd); | |
178 | } | |
7063fbf2 JB |
179 | } |
180 | } | |
181 | return error; | |
182 | } | |
183 | ||
184 | ||
185 | /** | |
186 | * configfs_create_dir - create a directory for an config_item. | |
187 | * @item: config_itemwe're creating directory for. | |
188 | * @dentry: config_item's dentry. | |
189 | */ | |
190 | ||
191 | static int configfs_create_dir(struct config_item * item, struct dentry *dentry) | |
192 | { | |
193 | struct dentry * parent; | |
194 | int error = 0; | |
195 | ||
196 | BUG_ON(!item); | |
197 | ||
198 | if (item->ci_parent) | |
199 | parent = item->ci_parent->ci_dentry; | |
200 | else if (configfs_mount && configfs_mount->mnt_sb) | |
201 | parent = configfs_mount->mnt_sb->s_root; | |
202 | else | |
203 | return -EFAULT; | |
204 | ||
205 | error = create_dir(item,parent,dentry); | |
206 | if (!error) | |
207 | item->ci_dentry = dentry; | |
208 | return error; | |
209 | } | |
210 | ||
211 | int configfs_create_link(struct configfs_symlink *sl, | |
212 | struct dentry *parent, | |
213 | struct dentry *dentry) | |
214 | { | |
215 | int err = 0; | |
216 | umode_t mode = S_IFLNK | S_IRWXUGO; | |
217 | ||
3d0f89bb JB |
218 | err = configfs_make_dirent(parent->d_fsdata, dentry, sl, mode, |
219 | CONFIGFS_ITEM_LINK); | |
7063fbf2 | 220 | if (!err) { |
3d0f89bb | 221 | err = configfs_create(dentry, mode, init_symlink); |
7063fbf2 JB |
222 | if (!err) |
223 | dentry->d_op = &configfs_dentry_ops; | |
3d0f89bb JB |
224 | else { |
225 | struct configfs_dirent *sd = dentry->d_fsdata; | |
226 | if (sd) { | |
227 | list_del_init(&sd->s_sibling); | |
228 | configfs_put(sd); | |
229 | } | |
230 | } | |
7063fbf2 JB |
231 | } |
232 | return err; | |
233 | } | |
234 | ||
235 | static void remove_dir(struct dentry * d) | |
236 | { | |
237 | struct dentry * parent = dget(d->d_parent); | |
238 | struct configfs_dirent * sd; | |
239 | ||
240 | sd = d->d_fsdata; | |
e7515d06 | 241 | list_del_init(&sd->s_sibling); |
7063fbf2 JB |
242 | configfs_put(sd); |
243 | if (d->d_inode) | |
244 | simple_rmdir(parent->d_inode,d); | |
245 | ||
246 | pr_debug(" o %s removing done (%d)\n",d->d_name.name, | |
247 | atomic_read(&d->d_count)); | |
248 | ||
249 | dput(parent); | |
250 | } | |
251 | ||
252 | /** | |
253 | * configfs_remove_dir - remove an config_item's directory. | |
254 | * @item: config_item we're removing. | |
255 | * | |
256 | * The only thing special about this is that we remove any files in | |
257 | * the directory before we remove the directory, and we've inlined | |
258 | * what used to be configfs_rmdir() below, instead of calling separately. | |
259 | */ | |
260 | ||
261 | static void configfs_remove_dir(struct config_item * item) | |
262 | { | |
263 | struct dentry * dentry = dget(item->ci_dentry); | |
264 | ||
265 | if (!dentry) | |
266 | return; | |
267 | ||
268 | remove_dir(dentry); | |
269 | /** | |
270 | * Drop reference from dget() on entrance. | |
271 | */ | |
272 | dput(dentry); | |
273 | } | |
274 | ||
275 | ||
276 | /* attaches attribute's configfs_dirent to the dentry corresponding to the | |
277 | * attribute file | |
278 | */ | |
279 | static int configfs_attach_attr(struct configfs_dirent * sd, struct dentry * dentry) | |
280 | { | |
281 | struct configfs_attribute * attr = sd->s_element; | |
282 | int error; | |
283 | ||
3d0f89bb JB |
284 | dentry->d_fsdata = configfs_get(sd); |
285 | sd->s_dentry = dentry; | |
ce8d2cdf DH |
286 | error = configfs_create(dentry, (attr->ca_mode & S_IALLUGO) | S_IFREG, |
287 | configfs_init_file); | |
3d0f89bb JB |
288 | if (error) { |
289 | configfs_put(sd); | |
7063fbf2 | 290 | return error; |
3d0f89bb | 291 | } |
7063fbf2 JB |
292 | |
293 | dentry->d_op = &configfs_dentry_ops; | |
7063fbf2 JB |
294 | d_rehash(dentry); |
295 | ||
296 | return 0; | |
297 | } | |
298 | ||
299 | static struct dentry * configfs_lookup(struct inode *dir, | |
300 | struct dentry *dentry, | |
301 | struct nameidata *nd) | |
302 | { | |
303 | struct configfs_dirent * parent_sd = dentry->d_parent->d_fsdata; | |
304 | struct configfs_dirent * sd; | |
305 | int found = 0; | |
306 | int err = 0; | |
307 | ||
308 | list_for_each_entry(sd, &parent_sd->s_children, s_sibling) { | |
309 | if (sd->s_type & CONFIGFS_NOT_PINNED) { | |
310 | const unsigned char * name = configfs_get_name(sd); | |
311 | ||
312 | if (strcmp(name, dentry->d_name.name)) | |
313 | continue; | |
314 | ||
315 | found = 1; | |
316 | err = configfs_attach_attr(sd, dentry); | |
317 | break; | |
318 | } | |
319 | } | |
320 | ||
321 | if (!found) { | |
322 | /* | |
323 | * If it doesn't exist and it isn't a NOT_PINNED item, | |
324 | * it must be negative. | |
325 | */ | |
326 | return simple_lookup(dir, dentry, nd); | |
327 | } | |
328 | ||
329 | return ERR_PTR(err); | |
330 | } | |
331 | ||
332 | /* | |
333 | * Only subdirectories count here. Files (CONFIGFS_NOT_PINNED) are | |
1b1dcc1b | 334 | * attributes and are removed by rmdir(). We recurse, taking i_mutex |
7063fbf2 JB |
335 | * on all children that are candidates for default detach. If the |
336 | * result is clean, then configfs_detach_group() will handle dropping | |
1b1dcc1b | 337 | * i_mutex. If there is an error, the caller will clean up the i_mutex |
7063fbf2 JB |
338 | * holders via configfs_detach_rollback(). |
339 | */ | |
340 | static int configfs_detach_prep(struct dentry *dentry) | |
341 | { | |
342 | struct configfs_dirent *parent_sd = dentry->d_fsdata; | |
343 | struct configfs_dirent *sd; | |
344 | int ret; | |
345 | ||
346 | ret = -EBUSY; | |
347 | if (!list_empty(&parent_sd->s_links)) | |
348 | goto out; | |
349 | ||
350 | ret = 0; | |
351 | list_for_each_entry(sd, &parent_sd->s_children, s_sibling) { | |
352 | if (sd->s_type & CONFIGFS_NOT_PINNED) | |
353 | continue; | |
354 | if (sd->s_type & CONFIGFS_USET_DEFAULT) { | |
1b1dcc1b JS |
355 | mutex_lock(&sd->s_dentry->d_inode->i_mutex); |
356 | /* Mark that we've taken i_mutex */ | |
7063fbf2 JB |
357 | sd->s_type |= CONFIGFS_USET_DROPPING; |
358 | ||
631d1feb JB |
359 | /* |
360 | * Yup, recursive. If there's a problem, blame | |
361 | * deep nesting of default_groups | |
362 | */ | |
7063fbf2 JB |
363 | ret = configfs_detach_prep(sd->s_dentry); |
364 | if (!ret) | |
e7515d06 | 365 | continue; |
7063fbf2 JB |
366 | } else |
367 | ret = -ENOTEMPTY; | |
368 | ||
369 | break; | |
370 | } | |
371 | ||
372 | out: | |
373 | return ret; | |
374 | } | |
375 | ||
376 | /* | |
1b1dcc1b | 377 | * Walk the tree, dropping i_mutex wherever CONFIGFS_USET_DROPPING is |
7063fbf2 JB |
378 | * set. |
379 | */ | |
380 | static void configfs_detach_rollback(struct dentry *dentry) | |
381 | { | |
382 | struct configfs_dirent *parent_sd = dentry->d_fsdata; | |
383 | struct configfs_dirent *sd; | |
384 | ||
385 | list_for_each_entry(sd, &parent_sd->s_children, s_sibling) { | |
386 | if (sd->s_type & CONFIGFS_USET_DEFAULT) { | |
387 | configfs_detach_rollback(sd->s_dentry); | |
388 | ||
389 | if (sd->s_type & CONFIGFS_USET_DROPPING) { | |
390 | sd->s_type &= ~CONFIGFS_USET_DROPPING; | |
1b1dcc1b | 391 | mutex_unlock(&sd->s_dentry->d_inode->i_mutex); |
7063fbf2 JB |
392 | } |
393 | } | |
394 | } | |
395 | } | |
396 | ||
397 | static void detach_attrs(struct config_item * item) | |
398 | { | |
399 | struct dentry * dentry = dget(item->ci_dentry); | |
400 | struct configfs_dirent * parent_sd; | |
401 | struct configfs_dirent * sd, * tmp; | |
402 | ||
403 | if (!dentry) | |
404 | return; | |
405 | ||
406 | pr_debug("configfs %s: dropping attrs for dir\n", | |
407 | dentry->d_name.name); | |
408 | ||
409 | parent_sd = dentry->d_fsdata; | |
410 | list_for_each_entry_safe(sd, tmp, &parent_sd->s_children, s_sibling) { | |
411 | if (!sd->s_element || !(sd->s_type & CONFIGFS_NOT_PINNED)) | |
412 | continue; | |
413 | list_del_init(&sd->s_sibling); | |
414 | configfs_drop_dentry(sd, dentry); | |
415 | configfs_put(sd); | |
416 | } | |
417 | ||
418 | /** | |
419 | * Drop reference from dget() on entrance. | |
420 | */ | |
421 | dput(dentry); | |
422 | } | |
423 | ||
424 | static int populate_attrs(struct config_item *item) | |
425 | { | |
426 | struct config_item_type *t = item->ci_type; | |
427 | struct configfs_attribute *attr; | |
428 | int error = 0; | |
429 | int i; | |
430 | ||
431 | if (!t) | |
432 | return -EINVAL; | |
433 | if (t->ct_attrs) { | |
434 | for (i = 0; (attr = t->ct_attrs[i]) != NULL; i++) { | |
435 | if ((error = configfs_create_file(item, attr))) | |
436 | break; | |
437 | } | |
438 | } | |
439 | ||
440 | if (error) | |
441 | detach_attrs(item); | |
442 | ||
443 | return error; | |
444 | } | |
445 | ||
446 | static int configfs_attach_group(struct config_item *parent_item, | |
447 | struct config_item *item, | |
448 | struct dentry *dentry); | |
449 | static void configfs_detach_group(struct config_item *item); | |
450 | ||
451 | static void detach_groups(struct config_group *group) | |
452 | { | |
453 | struct dentry * dentry = dget(group->cg_item.ci_dentry); | |
454 | struct dentry *child; | |
455 | struct configfs_dirent *parent_sd; | |
456 | struct configfs_dirent *sd, *tmp; | |
457 | ||
458 | if (!dentry) | |
459 | return; | |
460 | ||
461 | parent_sd = dentry->d_fsdata; | |
462 | list_for_each_entry_safe(sd, tmp, &parent_sd->s_children, s_sibling) { | |
463 | if (!sd->s_element || | |
464 | !(sd->s_type & CONFIGFS_USET_DEFAULT)) | |
465 | continue; | |
466 | ||
467 | child = sd->s_dentry; | |
468 | ||
469 | configfs_detach_group(sd->s_element); | |
470 | child->d_inode->i_flags |= S_DEAD; | |
471 | ||
472 | /* | |
473 | * From rmdir/unregister, a configfs_detach_prep() pass | |
1b1dcc1b | 474 | * has taken our i_mutex for us. Drop it. |
7063fbf2 JB |
475 | * From mkdir/register cleanup, there is no sem held. |
476 | */ | |
477 | if (sd->s_type & CONFIGFS_USET_DROPPING) | |
1b1dcc1b | 478 | mutex_unlock(&child->d_inode->i_mutex); |
7063fbf2 JB |
479 | |
480 | d_delete(child); | |
481 | dput(child); | |
482 | } | |
483 | ||
484 | /** | |
485 | * Drop reference from dget() on entrance. | |
486 | */ | |
487 | dput(dentry); | |
488 | } | |
489 | ||
490 | /* | |
491 | * This fakes mkdir(2) on a default_groups[] entry. It | |
492 | * creates a dentry, attachs it, and then does fixup | |
493 | * on the sd->s_type. | |
494 | * | |
495 | * We could, perhaps, tweak our parent's ->mkdir for a minute and | |
496 | * try using vfs_mkdir. Just a thought. | |
497 | */ | |
498 | static int create_default_group(struct config_group *parent_group, | |
499 | struct config_group *group) | |
500 | { | |
501 | int ret; | |
502 | struct qstr name; | |
503 | struct configfs_dirent *sd; | |
504 | /* We trust the caller holds a reference to parent */ | |
505 | struct dentry *child, *parent = parent_group->cg_item.ci_dentry; | |
506 | ||
507 | if (!group->cg_item.ci_name) | |
508 | group->cg_item.ci_name = group->cg_item.ci_namebuf; | |
509 | name.name = group->cg_item.ci_name; | |
510 | name.len = strlen(name.name); | |
511 | name.hash = full_name_hash(name.name, name.len); | |
512 | ||
513 | ret = -ENOMEM; | |
514 | child = d_alloc(parent, &name); | |
515 | if (child) { | |
516 | d_add(child, NULL); | |
517 | ||
518 | ret = configfs_attach_group(&parent_group->cg_item, | |
519 | &group->cg_item, child); | |
520 | if (!ret) { | |
521 | sd = child->d_fsdata; | |
522 | sd->s_type |= CONFIGFS_USET_DEFAULT; | |
523 | } else { | |
524 | d_delete(child); | |
525 | dput(child); | |
526 | } | |
527 | } | |
528 | ||
529 | return ret; | |
530 | } | |
531 | ||
532 | static int populate_groups(struct config_group *group) | |
533 | { | |
534 | struct config_group *new_group; | |
535 | struct dentry *dentry = group->cg_item.ci_dentry; | |
536 | int ret = 0; | |
537 | int i; | |
538 | ||
cbca692c | 539 | if (group->default_groups) { |
eed7a0db JB |
540 | /* |
541 | * FYI, we're faking mkdir here | |
7063fbf2 JB |
542 | * I'm not sure we need this semaphore, as we're called |
543 | * from our parent's mkdir. That holds our parent's | |
1b1dcc1b | 544 | * i_mutex, so afaik lookup cannot continue through our |
7063fbf2 | 545 | * parent to find us, let alone mess with our tree. |
1b1dcc1b | 546 | * That said, taking our i_mutex is closer to mkdir |
eed7a0db JB |
547 | * emulation, and shouldn't hurt. |
548 | */ | |
ba611edf | 549 | mutex_lock_nested(&dentry->d_inode->i_mutex, I_MUTEX_CHILD); |
7063fbf2 JB |
550 | |
551 | for (i = 0; group->default_groups[i]; i++) { | |
552 | new_group = group->default_groups[i]; | |
553 | ||
554 | ret = create_default_group(group, new_group); | |
555 | if (ret) | |
556 | break; | |
557 | } | |
558 | ||
1b1dcc1b | 559 | mutex_unlock(&dentry->d_inode->i_mutex); |
7063fbf2 JB |
560 | } |
561 | ||
562 | if (ret) | |
563 | detach_groups(group); | |
564 | ||
565 | return ret; | |
566 | } | |
567 | ||
568 | /* | |
569 | * All of link_obj/unlink_obj/link_group/unlink_group require that | |
e6bd07ae | 570 | * subsys->su_mutex is held. |
7063fbf2 JB |
571 | */ |
572 | ||
573 | static void unlink_obj(struct config_item *item) | |
574 | { | |
575 | struct config_group *group; | |
576 | ||
577 | group = item->ci_group; | |
578 | if (group) { | |
579 | list_del_init(&item->ci_entry); | |
580 | ||
581 | item->ci_group = NULL; | |
582 | item->ci_parent = NULL; | |
eed7a0db JB |
583 | |
584 | /* Drop the reference for ci_entry */ | |
7063fbf2 JB |
585 | config_item_put(item); |
586 | ||
eed7a0db | 587 | /* Drop the reference for ci_parent */ |
7063fbf2 JB |
588 | config_group_put(group); |
589 | } | |
590 | } | |
591 | ||
592 | static void link_obj(struct config_item *parent_item, struct config_item *item) | |
593 | { | |
eed7a0db JB |
594 | /* |
595 | * Parent seems redundant with group, but it makes certain | |
596 | * traversals much nicer. | |
597 | */ | |
7063fbf2 | 598 | item->ci_parent = parent_item; |
eed7a0db JB |
599 | |
600 | /* | |
601 | * We hold a reference on the parent for the child's ci_parent | |
602 | * link. | |
603 | */ | |
7063fbf2 JB |
604 | item->ci_group = config_group_get(to_config_group(parent_item)); |
605 | list_add_tail(&item->ci_entry, &item->ci_group->cg_children); | |
606 | ||
eed7a0db JB |
607 | /* |
608 | * We hold a reference on the child for ci_entry on the parent's | |
609 | * cg_children | |
610 | */ | |
7063fbf2 JB |
611 | config_item_get(item); |
612 | } | |
613 | ||
614 | static void unlink_group(struct config_group *group) | |
615 | { | |
616 | int i; | |
617 | struct config_group *new_group; | |
618 | ||
619 | if (group->default_groups) { | |
620 | for (i = 0; group->default_groups[i]; i++) { | |
621 | new_group = group->default_groups[i]; | |
622 | unlink_group(new_group); | |
623 | } | |
624 | } | |
625 | ||
626 | group->cg_subsys = NULL; | |
627 | unlink_obj(&group->cg_item); | |
628 | } | |
629 | ||
630 | static void link_group(struct config_group *parent_group, struct config_group *group) | |
631 | { | |
632 | int i; | |
633 | struct config_group *new_group; | |
634 | struct configfs_subsystem *subsys = NULL; /* gcc is a turd */ | |
635 | ||
636 | link_obj(&parent_group->cg_item, &group->cg_item); | |
637 | ||
638 | if (parent_group->cg_subsys) | |
639 | subsys = parent_group->cg_subsys; | |
640 | else if (configfs_is_root(&parent_group->cg_item)) | |
641 | subsys = to_configfs_subsystem(group); | |
642 | else | |
643 | BUG(); | |
644 | group->cg_subsys = subsys; | |
645 | ||
646 | if (group->default_groups) { | |
647 | for (i = 0; group->default_groups[i]; i++) { | |
648 | new_group = group->default_groups[i]; | |
649 | link_group(group, new_group); | |
650 | } | |
651 | } | |
652 | } | |
653 | ||
654 | /* | |
655 | * The goal is that configfs_attach_item() (and | |
656 | * configfs_attach_group()) can be called from either the VFS or this | |
657 | * module. That is, they assume that the items have been created, | |
658 | * the dentry allocated, and the dcache is all ready to go. | |
659 | * | |
660 | * If they fail, they must clean up after themselves as if they | |
661 | * had never been called. The caller (VFS or local function) will | |
662 | * handle cleaning up the dcache bits. | |
663 | * | |
664 | * configfs_detach_group() and configfs_detach_item() behave similarly on | |
665 | * the way out. They assume that the proper semaphores are held, they | |
666 | * clean up the configfs items, and they expect their callers will | |
667 | * handle the dcache bits. | |
668 | */ | |
669 | static int configfs_attach_item(struct config_item *parent_item, | |
670 | struct config_item *item, | |
671 | struct dentry *dentry) | |
672 | { | |
673 | int ret; | |
674 | ||
675 | ret = configfs_create_dir(item, dentry); | |
676 | if (!ret) { | |
677 | ret = populate_attrs(item); | |
678 | if (ret) { | |
679 | configfs_remove_dir(item); | |
680 | d_delete(dentry); | |
681 | } | |
682 | } | |
683 | ||
684 | return ret; | |
685 | } | |
686 | ||
687 | static void configfs_detach_item(struct config_item *item) | |
688 | { | |
689 | detach_attrs(item); | |
690 | configfs_remove_dir(item); | |
691 | } | |
692 | ||
693 | static int configfs_attach_group(struct config_item *parent_item, | |
694 | struct config_item *item, | |
695 | struct dentry *dentry) | |
696 | { | |
697 | int ret; | |
698 | struct configfs_dirent *sd; | |
699 | ||
700 | ret = configfs_attach_item(parent_item, item, dentry); | |
701 | if (!ret) { | |
702 | sd = dentry->d_fsdata; | |
703 | sd->s_type |= CONFIGFS_USET_DIR; | |
704 | ||
705 | ret = populate_groups(to_config_group(item)); | |
706 | if (ret) { | |
707 | configfs_detach_item(item); | |
708 | d_delete(dentry); | |
709 | } | |
710 | } | |
711 | ||
712 | return ret; | |
713 | } | |
714 | ||
715 | static void configfs_detach_group(struct config_item *item) | |
716 | { | |
717 | detach_groups(to_config_group(item)); | |
718 | configfs_detach_item(item); | |
719 | } | |
720 | ||
299894cc JB |
721 | /* |
722 | * After the item has been detached from the filesystem view, we are | |
723 | * ready to tear it out of the hierarchy. Notify the client before | |
724 | * we do that so they can perform any cleanup that requires | |
725 | * navigating the hierarchy. A client does not need to provide this | |
726 | * callback. The subsystem semaphore MUST be held by the caller, and | |
727 | * references must be valid for both items. It also assumes the | |
728 | * caller has validated ci_type. | |
729 | */ | |
730 | static void client_disconnect_notify(struct config_item *parent_item, | |
731 | struct config_item *item) | |
732 | { | |
733 | struct config_item_type *type; | |
734 | ||
735 | type = parent_item->ci_type; | |
736 | BUG_ON(!type); | |
737 | ||
738 | if (type->ct_group_ops && type->ct_group_ops->disconnect_notify) | |
739 | type->ct_group_ops->disconnect_notify(to_config_group(parent_item), | |
740 | item); | |
741 | } | |
742 | ||
7063fbf2 JB |
743 | /* |
744 | * Drop the initial reference from make_item()/make_group() | |
745 | * This function assumes that reference is held on item | |
746 | * and that item holds a valid reference to the parent. Also, it | |
747 | * assumes the caller has validated ci_type. | |
748 | */ | |
749 | static void client_drop_item(struct config_item *parent_item, | |
750 | struct config_item *item) | |
751 | { | |
752 | struct config_item_type *type; | |
753 | ||
754 | type = parent_item->ci_type; | |
755 | BUG_ON(!type); | |
756 | ||
eed7a0db JB |
757 | /* |
758 | * If ->drop_item() exists, it is responsible for the | |
759 | * config_item_put(). | |
760 | */ | |
7063fbf2 JB |
761 | if (type->ct_group_ops && type->ct_group_ops->drop_item) |
762 | type->ct_group_ops->drop_item(to_config_group(parent_item), | |
299894cc | 763 | item); |
7063fbf2 JB |
764 | else |
765 | config_item_put(item); | |
766 | } | |
767 | ||
631d1feb JB |
768 | #ifdef DEBUG |
769 | static void configfs_dump_one(struct configfs_dirent *sd, int level) | |
770 | { | |
771 | printk(KERN_INFO "%*s\"%s\":\n", level, " ", configfs_get_name(sd)); | |
772 | ||
773 | #define type_print(_type) if (sd->s_type & _type) printk(KERN_INFO "%*s %s\n", level, " ", #_type); | |
774 | type_print(CONFIGFS_ROOT); | |
775 | type_print(CONFIGFS_DIR); | |
776 | type_print(CONFIGFS_ITEM_ATTR); | |
777 | type_print(CONFIGFS_ITEM_LINK); | |
778 | type_print(CONFIGFS_USET_DIR); | |
779 | type_print(CONFIGFS_USET_DEFAULT); | |
780 | type_print(CONFIGFS_USET_DROPPING); | |
781 | #undef type_print | |
782 | } | |
783 | ||
784 | static int configfs_dump(struct configfs_dirent *sd, int level) | |
785 | { | |
786 | struct configfs_dirent *child_sd; | |
787 | int ret = 0; | |
788 | ||
789 | configfs_dump_one(sd, level); | |
790 | ||
791 | if (!(sd->s_type & (CONFIGFS_DIR|CONFIGFS_ROOT))) | |
792 | return 0; | |
793 | ||
794 | list_for_each_entry(child_sd, &sd->s_children, s_sibling) { | |
795 | ret = configfs_dump(child_sd, level + 2); | |
796 | if (ret) | |
797 | break; | |
798 | } | |
799 | ||
800 | return ret; | |
801 | } | |
802 | #endif | |
803 | ||
804 | ||
805 | /* | |
806 | * configfs_depend_item() and configfs_undepend_item() | |
807 | * | |
808 | * WARNING: Do not call these from a configfs callback! | |
809 | * | |
810 | * This describes these functions and their helpers. | |
811 | * | |
812 | * Allow another kernel system to depend on a config_item. If this | |
813 | * happens, the item cannot go away until the dependant can live without | |
814 | * it. The idea is to give client modules as simple an interface as | |
815 | * possible. When a system asks them to depend on an item, they just | |
816 | * call configfs_depend_item(). If the item is live and the client | |
817 | * driver is in good shape, we'll happily do the work for them. | |
818 | * | |
819 | * Why is the locking complex? Because configfs uses the VFS to handle | |
820 | * all locking, but this function is called outside the normal | |
821 | * VFS->configfs path. So it must take VFS locks to prevent the | |
822 | * VFS->configfs stuff (configfs_mkdir(), configfs_rmdir(), etc). This is | |
823 | * why you can't call these functions underneath configfs callbacks. | |
824 | * | |
825 | * Note, btw, that this can be called at *any* time, even when a configfs | |
826 | * subsystem isn't registered, or when configfs is loading or unloading. | |
827 | * Just like configfs_register_subsystem(). So we take the same | |
828 | * precautions. We pin the filesystem. We lock each i_mutex _in_order_ | |
829 | * on our way down the tree. If we can find the target item in the | |
830 | * configfs tree, it must be part of the subsystem tree as well, so we | |
831 | * do not need the subsystem semaphore. Holding the i_mutex chain locks | |
832 | * out mkdir() and rmdir(), who might be racing us. | |
833 | */ | |
834 | ||
835 | /* | |
836 | * configfs_depend_prep() | |
837 | * | |
838 | * Only subdirectories count here. Files (CONFIGFS_NOT_PINNED) are | |
839 | * attributes. This is similar but not the same to configfs_detach_prep(). | |
840 | * Note that configfs_detach_prep() expects the parent to be locked when it | |
841 | * is called, but we lock the parent *inside* configfs_depend_prep(). We | |
842 | * do that so we can unlock it if we find nothing. | |
843 | * | |
844 | * Here we do a depth-first search of the dentry hierarchy looking for | |
845 | * our object. We take i_mutex on each step of the way down. IT IS | |
846 | * ESSENTIAL THAT i_mutex LOCKING IS ORDERED. If we come back up a branch, | |
847 | * we'll drop the i_mutex. | |
848 | * | |
849 | * If the target is not found, -ENOENT is bubbled up and we have released | |
850 | * all locks. If the target was found, the locks will be cleared by | |
851 | * configfs_depend_rollback(). | |
852 | * | |
853 | * This adds a requirement that all config_items be unique! | |
854 | * | |
855 | * This is recursive because the locking traversal is tricky. There isn't | |
856 | * much on the stack, though, so folks that need this function - be careful | |
857 | * about your stack! Patches will be accepted to make it iterative. | |
858 | */ | |
859 | static int configfs_depend_prep(struct dentry *origin, | |
860 | struct config_item *target) | |
861 | { | |
862 | struct configfs_dirent *child_sd, *sd = origin->d_fsdata; | |
863 | int ret = 0; | |
864 | ||
865 | BUG_ON(!origin || !sd); | |
866 | ||
867 | /* Lock this guy on the way down */ | |
868 | mutex_lock(&sd->s_dentry->d_inode->i_mutex); | |
869 | if (sd->s_element == target) /* Boo-yah */ | |
870 | goto out; | |
871 | ||
872 | list_for_each_entry(child_sd, &sd->s_children, s_sibling) { | |
873 | if (child_sd->s_type & CONFIGFS_DIR) { | |
874 | ret = configfs_depend_prep(child_sd->s_dentry, | |
875 | target); | |
876 | if (!ret) | |
877 | goto out; /* Child path boo-yah */ | |
878 | } | |
879 | } | |
880 | ||
881 | /* We looped all our children and didn't find target */ | |
882 | mutex_unlock(&sd->s_dentry->d_inode->i_mutex); | |
883 | ret = -ENOENT; | |
884 | ||
885 | out: | |
886 | return ret; | |
887 | } | |
888 | ||
889 | /* | |
890 | * This is ONLY called if configfs_depend_prep() did its job. So we can | |
891 | * trust the entire path from item back up to origin. | |
892 | * | |
893 | * We walk backwards from item, unlocking each i_mutex. We finish by | |
894 | * unlocking origin. | |
895 | */ | |
896 | static void configfs_depend_rollback(struct dentry *origin, | |
897 | struct config_item *item) | |
898 | { | |
899 | struct dentry *dentry = item->ci_dentry; | |
900 | ||
901 | while (dentry != origin) { | |
902 | mutex_unlock(&dentry->d_inode->i_mutex); | |
903 | dentry = dentry->d_parent; | |
904 | } | |
905 | ||
906 | mutex_unlock(&origin->d_inode->i_mutex); | |
907 | } | |
908 | ||
909 | int configfs_depend_item(struct configfs_subsystem *subsys, | |
910 | struct config_item *target) | |
911 | { | |
912 | int ret; | |
913 | struct configfs_dirent *p, *root_sd, *subsys_sd = NULL; | |
914 | struct config_item *s_item = &subsys->su_group.cg_item; | |
915 | ||
916 | /* | |
917 | * Pin the configfs filesystem. This means we can safely access | |
918 | * the root of the configfs filesystem. | |
919 | */ | |
920 | ret = configfs_pin_fs(); | |
921 | if (ret) | |
922 | return ret; | |
923 | ||
924 | /* | |
925 | * Next, lock the root directory. We're going to check that the | |
926 | * subsystem is really registered, and so we need to lock out | |
927 | * configfs_[un]register_subsystem(). | |
928 | */ | |
929 | mutex_lock(&configfs_sb->s_root->d_inode->i_mutex); | |
930 | ||
931 | root_sd = configfs_sb->s_root->d_fsdata; | |
932 | ||
933 | list_for_each_entry(p, &root_sd->s_children, s_sibling) { | |
934 | if (p->s_type & CONFIGFS_DIR) { | |
935 | if (p->s_element == s_item) { | |
936 | subsys_sd = p; | |
937 | break; | |
938 | } | |
939 | } | |
940 | } | |
941 | ||
942 | if (!subsys_sd) { | |
943 | ret = -ENOENT; | |
944 | goto out_unlock_fs; | |
945 | } | |
946 | ||
947 | /* Ok, now we can trust subsys/s_item */ | |
948 | ||
949 | /* Scan the tree, locking i_mutex recursively, return 0 if found */ | |
950 | ret = configfs_depend_prep(subsys_sd->s_dentry, target); | |
951 | if (ret) | |
952 | goto out_unlock_fs; | |
953 | ||
954 | /* We hold all i_mutexes from the subsystem down to the target */ | |
955 | p = target->ci_dentry->d_fsdata; | |
956 | p->s_dependent_count += 1; | |
957 | ||
958 | configfs_depend_rollback(subsys_sd->s_dentry, target); | |
959 | ||
960 | out_unlock_fs: | |
961 | mutex_unlock(&configfs_sb->s_root->d_inode->i_mutex); | |
962 | ||
963 | /* | |
964 | * If we succeeded, the fs is pinned via other methods. If not, | |
965 | * we're done with it anyway. So release_fs() is always right. | |
966 | */ | |
967 | configfs_release_fs(); | |
968 | ||
969 | return ret; | |
970 | } | |
971 | EXPORT_SYMBOL(configfs_depend_item); | |
972 | ||
973 | /* | |
974 | * Release the dependent linkage. This is much simpler than | |
975 | * configfs_depend_item() because we know that that the client driver is | |
976 | * pinned, thus the subsystem is pinned, and therefore configfs is pinned. | |
977 | */ | |
978 | void configfs_undepend_item(struct configfs_subsystem *subsys, | |
979 | struct config_item *target) | |
980 | { | |
981 | struct configfs_dirent *sd; | |
982 | ||
983 | /* | |
984 | * Since we can trust everything is pinned, we just need i_mutex | |
985 | * on the item. | |
986 | */ | |
987 | mutex_lock(&target->ci_dentry->d_inode->i_mutex); | |
988 | ||
989 | sd = target->ci_dentry->d_fsdata; | |
990 | BUG_ON(sd->s_dependent_count < 1); | |
991 | ||
992 | sd->s_dependent_count -= 1; | |
993 | ||
994 | /* | |
995 | * After this unlock, we cannot trust the item to stay alive! | |
996 | * DO NOT REFERENCE item after this unlock. | |
997 | */ | |
998 | mutex_unlock(&target->ci_dentry->d_inode->i_mutex); | |
999 | } | |
1000 | EXPORT_SYMBOL(configfs_undepend_item); | |
7063fbf2 JB |
1001 | |
1002 | static int configfs_mkdir(struct inode *dir, struct dentry *dentry, int mode) | |
1003 | { | |
eed7a0db | 1004 | int ret, module_got = 0; |
7063fbf2 JB |
1005 | struct config_group *group; |
1006 | struct config_item *item; | |
1007 | struct config_item *parent_item; | |
1008 | struct configfs_subsystem *subsys; | |
1009 | struct configfs_dirent *sd; | |
1010 | struct config_item_type *type; | |
eed7a0db | 1011 | struct module *owner = NULL; |
7063fbf2 JB |
1012 | char *name; |
1013 | ||
84efad1a JB |
1014 | if (dentry->d_parent == configfs_sb->s_root) { |
1015 | ret = -EPERM; | |
1016 | goto out; | |
1017 | } | |
7063fbf2 JB |
1018 | |
1019 | sd = dentry->d_parent->d_fsdata; | |
84efad1a JB |
1020 | if (!(sd->s_type & CONFIGFS_USET_DIR)) { |
1021 | ret = -EPERM; | |
1022 | goto out; | |
1023 | } | |
7063fbf2 | 1024 | |
84efad1a | 1025 | /* Get a working ref for the duration of this function */ |
7063fbf2 JB |
1026 | parent_item = configfs_get_config_item(dentry->d_parent); |
1027 | type = parent_item->ci_type; | |
1028 | subsys = to_config_group(parent_item)->cg_subsys; | |
1029 | BUG_ON(!subsys); | |
1030 | ||
1031 | if (!type || !type->ct_group_ops || | |
1032 | (!type->ct_group_ops->make_group && | |
1033 | !type->ct_group_ops->make_item)) { | |
84efad1a JB |
1034 | ret = -EPERM; /* Lack-of-mkdir returns -EPERM */ |
1035 | goto out_put; | |
7063fbf2 JB |
1036 | } |
1037 | ||
1038 | name = kmalloc(dentry->d_name.len + 1, GFP_KERNEL); | |
1039 | if (!name) { | |
84efad1a JB |
1040 | ret = -ENOMEM; |
1041 | goto out_put; | |
7063fbf2 | 1042 | } |
84efad1a | 1043 | |
7063fbf2 JB |
1044 | snprintf(name, dentry->d_name.len + 1, "%s", dentry->d_name.name); |
1045 | ||
e6bd07ae | 1046 | mutex_lock(&subsys->su_mutex); |
7063fbf2 JB |
1047 | group = NULL; |
1048 | item = NULL; | |
1049 | if (type->ct_group_ops->make_group) { | |
1050 | group = type->ct_group_ops->make_group(to_config_group(parent_item), name); | |
1051 | if (group) { | |
1052 | link_group(to_config_group(parent_item), group); | |
1053 | item = &group->cg_item; | |
1054 | } | |
1055 | } else { | |
1056 | item = type->ct_group_ops->make_item(to_config_group(parent_item), name); | |
1057 | if (item) | |
1058 | link_obj(parent_item, item); | |
1059 | } | |
e6bd07ae | 1060 | mutex_unlock(&subsys->su_mutex); |
7063fbf2 JB |
1061 | |
1062 | kfree(name); | |
1063 | if (!item) { | |
eed7a0db JB |
1064 | /* |
1065 | * If item == NULL, then link_obj() was never called. | |
1066 | * There are no extra references to clean up. | |
1067 | */ | |
84efad1a JB |
1068 | ret = -ENOMEM; |
1069 | goto out_put; | |
7063fbf2 JB |
1070 | } |
1071 | ||
eed7a0db JB |
1072 | /* |
1073 | * link_obj() has been called (via link_group() for groups). | |
1074 | * From here on out, errors must clean that up. | |
1075 | */ | |
1076 | ||
7063fbf2 | 1077 | type = item->ci_type; |
eed7a0db JB |
1078 | if (!type) { |
1079 | ret = -EINVAL; | |
1080 | goto out_unlink; | |
1081 | } | |
7063fbf2 | 1082 | |
eed7a0db JB |
1083 | owner = type->ct_owner; |
1084 | if (!try_module_get(owner)) { | |
1085 | ret = -EINVAL; | |
1086 | goto out_unlink; | |
1087 | } | |
7063fbf2 | 1088 | |
eed7a0db JB |
1089 | /* |
1090 | * I hate doing it this way, but if there is | |
1091 | * an error, module_put() probably should | |
1092 | * happen after any cleanup. | |
1093 | */ | |
1094 | module_got = 1; | |
1095 | ||
1096 | if (group) | |
1097 | ret = configfs_attach_group(parent_item, item, dentry); | |
1098 | else | |
1099 | ret = configfs_attach_item(parent_item, item, dentry); | |
1100 | ||
1101 | out_unlink: | |
1102 | if (ret) { | |
1103 | /* Tear down everything we built up */ | |
e6bd07ae | 1104 | mutex_lock(&subsys->su_mutex); |
299894cc JB |
1105 | |
1106 | client_disconnect_notify(parent_item, item); | |
eed7a0db JB |
1107 | if (group) |
1108 | unlink_group(group); | |
1109 | else | |
1110 | unlink_obj(item); | |
1111 | client_drop_item(parent_item, item); | |
299894cc | 1112 | |
e6bd07ae | 1113 | mutex_unlock(&subsys->su_mutex); |
eed7a0db JB |
1114 | |
1115 | if (module_got) | |
1116 | module_put(owner); | |
7063fbf2 JB |
1117 | } |
1118 | ||
84efad1a JB |
1119 | out_put: |
1120 | /* | |
eed7a0db JB |
1121 | * link_obj()/link_group() took a reference from child->parent, |
1122 | * so the parent is safely pinned. We can drop our working | |
1123 | * reference. | |
84efad1a JB |
1124 | */ |
1125 | config_item_put(parent_item); | |
1126 | ||
1127 | out: | |
7063fbf2 JB |
1128 | return ret; |
1129 | } | |
1130 | ||
1131 | static int configfs_rmdir(struct inode *dir, struct dentry *dentry) | |
1132 | { | |
1133 | struct config_item *parent_item; | |
1134 | struct config_item *item; | |
1135 | struct configfs_subsystem *subsys; | |
1136 | struct configfs_dirent *sd; | |
1137 | struct module *owner = NULL; | |
1138 | int ret; | |
1139 | ||
1140 | if (dentry->d_parent == configfs_sb->s_root) | |
1141 | return -EPERM; | |
1142 | ||
1143 | sd = dentry->d_fsdata; | |
1144 | if (sd->s_type & CONFIGFS_USET_DEFAULT) | |
1145 | return -EPERM; | |
1146 | ||
631d1feb JB |
1147 | /* |
1148 | * Here's where we check for dependents. We're protected by | |
1149 | * i_mutex. | |
1150 | */ | |
1151 | if (sd->s_dependent_count) | |
1152 | return -EBUSY; | |
1153 | ||
84efad1a | 1154 | /* Get a working ref until we have the child */ |
7063fbf2 JB |
1155 | parent_item = configfs_get_config_item(dentry->d_parent); |
1156 | subsys = to_config_group(parent_item)->cg_subsys; | |
1157 | BUG_ON(!subsys); | |
1158 | ||
1159 | if (!parent_item->ci_type) { | |
1160 | config_item_put(parent_item); | |
1161 | return -EINVAL; | |
1162 | } | |
1163 | ||
1164 | ret = configfs_detach_prep(dentry); | |
1165 | if (ret) { | |
1166 | configfs_detach_rollback(dentry); | |
1167 | config_item_put(parent_item); | |
1168 | return ret; | |
1169 | } | |
1170 | ||
84efad1a | 1171 | /* Get a working ref for the duration of this function */ |
7063fbf2 JB |
1172 | item = configfs_get_config_item(dentry); |
1173 | ||
1174 | /* Drop reference from above, item already holds one. */ | |
1175 | config_item_put(parent_item); | |
1176 | ||
1177 | if (item->ci_type) | |
1178 | owner = item->ci_type->ct_owner; | |
1179 | ||
1180 | if (sd->s_type & CONFIGFS_USET_DIR) { | |
1181 | configfs_detach_group(item); | |
1182 | ||
e6bd07ae | 1183 | mutex_lock(&subsys->su_mutex); |
299894cc | 1184 | client_disconnect_notify(parent_item, item); |
7063fbf2 JB |
1185 | unlink_group(to_config_group(item)); |
1186 | } else { | |
1187 | configfs_detach_item(item); | |
1188 | ||
e6bd07ae | 1189 | mutex_lock(&subsys->su_mutex); |
299894cc | 1190 | client_disconnect_notify(parent_item, item); |
7063fbf2 JB |
1191 | unlink_obj(item); |
1192 | } | |
1193 | ||
1194 | client_drop_item(parent_item, item); | |
e6bd07ae | 1195 | mutex_unlock(&subsys->su_mutex); |
7063fbf2 JB |
1196 | |
1197 | /* Drop our reference from above */ | |
1198 | config_item_put(item); | |
1199 | ||
1200 | module_put(owner); | |
1201 | ||
1202 | return 0; | |
1203 | } | |
1204 | ||
754661f1 | 1205 | const struct inode_operations configfs_dir_inode_operations = { |
7063fbf2 JB |
1206 | .mkdir = configfs_mkdir, |
1207 | .rmdir = configfs_rmdir, | |
1208 | .symlink = configfs_symlink, | |
1209 | .unlink = configfs_unlink, | |
1210 | .lookup = configfs_lookup, | |
3d0f89bb | 1211 | .setattr = configfs_setattr, |
7063fbf2 JB |
1212 | }; |
1213 | ||
1214 | #if 0 | |
1215 | int configfs_rename_dir(struct config_item * item, const char *new_name) | |
1216 | { | |
1217 | int error = 0; | |
1218 | struct dentry * new_dentry, * parent; | |
1219 | ||
1220 | if (!strcmp(config_item_name(item), new_name)) | |
1221 | return -EINVAL; | |
1222 | ||
1223 | if (!item->parent) | |
1224 | return -EINVAL; | |
1225 | ||
1226 | down_write(&configfs_rename_sem); | |
1227 | parent = item->parent->dentry; | |
1228 | ||
1b1dcc1b | 1229 | mutex_lock(&parent->d_inode->i_mutex); |
7063fbf2 JB |
1230 | |
1231 | new_dentry = lookup_one_len(new_name, parent, strlen(new_name)); | |
1232 | if (!IS_ERR(new_dentry)) { | |
e7515d06 | 1233 | if (!new_dentry->d_inode) { |
7063fbf2 JB |
1234 | error = config_item_set_name(item, "%s", new_name); |
1235 | if (!error) { | |
1236 | d_add(new_dentry, NULL); | |
1237 | d_move(item->dentry, new_dentry); | |
1238 | } | |
1239 | else | |
1240 | d_delete(new_dentry); | |
1241 | } else | |
1242 | error = -EEXIST; | |
1243 | dput(new_dentry); | |
1244 | } | |
1b1dcc1b | 1245 | mutex_unlock(&parent->d_inode->i_mutex); |
7063fbf2 JB |
1246 | up_write(&configfs_rename_sem); |
1247 | ||
1248 | return error; | |
1249 | } | |
1250 | #endif | |
1251 | ||
1252 | static int configfs_dir_open(struct inode *inode, struct file *file) | |
1253 | { | |
867fa491 | 1254 | struct dentry * dentry = file->f_path.dentry; |
7063fbf2 JB |
1255 | struct configfs_dirent * parent_sd = dentry->d_fsdata; |
1256 | ||
1b1dcc1b | 1257 | mutex_lock(&dentry->d_inode->i_mutex); |
7063fbf2 | 1258 | file->private_data = configfs_new_dirent(parent_sd, NULL); |
1b1dcc1b | 1259 | mutex_unlock(&dentry->d_inode->i_mutex); |
7063fbf2 JB |
1260 | |
1261 | return file->private_data ? 0 : -ENOMEM; | |
1262 | ||
1263 | } | |
1264 | ||
1265 | static int configfs_dir_close(struct inode *inode, struct file *file) | |
1266 | { | |
867fa491 | 1267 | struct dentry * dentry = file->f_path.dentry; |
7063fbf2 JB |
1268 | struct configfs_dirent * cursor = file->private_data; |
1269 | ||
1b1dcc1b | 1270 | mutex_lock(&dentry->d_inode->i_mutex); |
7063fbf2 | 1271 | list_del_init(&cursor->s_sibling); |
1b1dcc1b | 1272 | mutex_unlock(&dentry->d_inode->i_mutex); |
7063fbf2 JB |
1273 | |
1274 | release_configfs_dirent(cursor); | |
1275 | ||
1276 | return 0; | |
1277 | } | |
1278 | ||
1279 | /* Relationship between s_mode and the DT_xxx types */ | |
1280 | static inline unsigned char dt_type(struct configfs_dirent *sd) | |
1281 | { | |
1282 | return (sd->s_mode >> 12) & 15; | |
1283 | } | |
1284 | ||
1285 | static int configfs_readdir(struct file * filp, void * dirent, filldir_t filldir) | |
1286 | { | |
867fa491 | 1287 | struct dentry *dentry = filp->f_path.dentry; |
7063fbf2 JB |
1288 | struct configfs_dirent * parent_sd = dentry->d_fsdata; |
1289 | struct configfs_dirent *cursor = filp->private_data; | |
1290 | struct list_head *p, *q = &cursor->s_sibling; | |
1291 | ino_t ino; | |
1292 | int i = filp->f_pos; | |
1293 | ||
1294 | switch (i) { | |
1295 | case 0: | |
1296 | ino = dentry->d_inode->i_ino; | |
1297 | if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0) | |
1298 | break; | |
1299 | filp->f_pos++; | |
1300 | i++; | |
1301 | /* fallthrough */ | |
1302 | case 1: | |
1303 | ino = parent_ino(dentry); | |
1304 | if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0) | |
1305 | break; | |
1306 | filp->f_pos++; | |
1307 | i++; | |
1308 | /* fallthrough */ | |
1309 | default: | |
1310 | if (filp->f_pos == 2) { | |
f116629d | 1311 | list_move(q, &parent_sd->s_children); |
7063fbf2 JB |
1312 | } |
1313 | for (p=q->next; p!= &parent_sd->s_children; p=p->next) { | |
1314 | struct configfs_dirent *next; | |
1315 | const char * name; | |
1316 | int len; | |
1317 | ||
1318 | next = list_entry(p, struct configfs_dirent, | |
1319 | s_sibling); | |
1320 | if (!next->s_element) | |
1321 | continue; | |
1322 | ||
1323 | name = configfs_get_name(next); | |
1324 | len = strlen(name); | |
1325 | if (next->s_dentry) | |
1326 | ino = next->s_dentry->d_inode->i_ino; | |
1327 | else | |
1328 | ino = iunique(configfs_sb, 2); | |
1329 | ||
1330 | if (filldir(dirent, name, len, filp->f_pos, ino, | |
1331 | dt_type(next)) < 0) | |
1332 | return 0; | |
1333 | ||
f116629d | 1334 | list_move(q, p); |
7063fbf2 JB |
1335 | p = q; |
1336 | filp->f_pos++; | |
1337 | } | |
1338 | } | |
1339 | return 0; | |
1340 | } | |
1341 | ||
1342 | static loff_t configfs_dir_lseek(struct file * file, loff_t offset, int origin) | |
1343 | { | |
867fa491 | 1344 | struct dentry * dentry = file->f_path.dentry; |
7063fbf2 | 1345 | |
1b1dcc1b | 1346 | mutex_lock(&dentry->d_inode->i_mutex); |
7063fbf2 JB |
1347 | switch (origin) { |
1348 | case 1: | |
1349 | offset += file->f_pos; | |
1350 | case 0: | |
1351 | if (offset >= 0) | |
1352 | break; | |
1353 | default: | |
867fa491 | 1354 | mutex_unlock(&file->f_path.dentry->d_inode->i_mutex); |
7063fbf2 JB |
1355 | return -EINVAL; |
1356 | } | |
1357 | if (offset != file->f_pos) { | |
1358 | file->f_pos = offset; | |
1359 | if (file->f_pos >= 2) { | |
1360 | struct configfs_dirent *sd = dentry->d_fsdata; | |
1361 | struct configfs_dirent *cursor = file->private_data; | |
1362 | struct list_head *p; | |
1363 | loff_t n = file->f_pos - 2; | |
1364 | ||
1365 | list_del(&cursor->s_sibling); | |
1366 | p = sd->s_children.next; | |
1367 | while (n && p != &sd->s_children) { | |
1368 | struct configfs_dirent *next; | |
1369 | next = list_entry(p, struct configfs_dirent, | |
1370 | s_sibling); | |
1371 | if (next->s_element) | |
1372 | n--; | |
1373 | p = p->next; | |
1374 | } | |
1375 | list_add_tail(&cursor->s_sibling, p); | |
1376 | } | |
1377 | } | |
1b1dcc1b | 1378 | mutex_unlock(&dentry->d_inode->i_mutex); |
7063fbf2 JB |
1379 | return offset; |
1380 | } | |
1381 | ||
4b6f5d20 | 1382 | const struct file_operations configfs_dir_operations = { |
7063fbf2 JB |
1383 | .open = configfs_dir_open, |
1384 | .release = configfs_dir_close, | |
1385 | .llseek = configfs_dir_lseek, | |
1386 | .read = generic_read_dir, | |
1387 | .readdir = configfs_readdir, | |
1388 | }; | |
1389 | ||
1390 | int configfs_register_subsystem(struct configfs_subsystem *subsys) | |
1391 | { | |
1392 | int err; | |
1393 | struct config_group *group = &subsys->su_group; | |
1394 | struct qstr name; | |
1395 | struct dentry *dentry; | |
1396 | struct configfs_dirent *sd; | |
1397 | ||
1398 | err = configfs_pin_fs(); | |
1399 | if (err) | |
1400 | return err; | |
1401 | ||
1402 | if (!group->cg_item.ci_name) | |
1403 | group->cg_item.ci_name = group->cg_item.ci_namebuf; | |
1404 | ||
1405 | sd = configfs_sb->s_root->d_fsdata; | |
1406 | link_group(to_config_group(sd->s_element), group); | |
1407 | ||
ba611edf JP |
1408 | mutex_lock_nested(&configfs_sb->s_root->d_inode->i_mutex, |
1409 | I_MUTEX_PARENT); | |
7063fbf2 JB |
1410 | |
1411 | name.name = group->cg_item.ci_name; | |
1412 | name.len = strlen(name.name); | |
1413 | name.hash = full_name_hash(name.name, name.len); | |
1414 | ||
1415 | err = -ENOMEM; | |
1416 | dentry = d_alloc(configfs_sb->s_root, &name); | |
afdf04ea JB |
1417 | if (dentry) { |
1418 | d_add(dentry, NULL); | |
7063fbf2 | 1419 | |
afdf04ea JB |
1420 | err = configfs_attach_group(sd->s_element, &group->cg_item, |
1421 | dentry); | |
1422 | if (err) { | |
1423 | d_delete(dentry); | |
1424 | dput(dentry); | |
1425 | } | |
1426 | } | |
7063fbf2 | 1427 | |
1b1dcc1b | 1428 | mutex_unlock(&configfs_sb->s_root->d_inode->i_mutex); |
7063fbf2 | 1429 | |
afdf04ea JB |
1430 | if (err) { |
1431 | unlink_group(group); | |
1432 | configfs_release_fs(); | |
7063fbf2 JB |
1433 | } |
1434 | ||
1435 | return err; | |
1436 | } | |
1437 | ||
1438 | void configfs_unregister_subsystem(struct configfs_subsystem *subsys) | |
1439 | { | |
1440 | struct config_group *group = &subsys->su_group; | |
1441 | struct dentry *dentry = group->cg_item.ci_dentry; | |
1442 | ||
1443 | if (dentry->d_parent != configfs_sb->s_root) { | |
1444 | printk(KERN_ERR "configfs: Tried to unregister non-subsystem!\n"); | |
1445 | return; | |
1446 | } | |
1447 | ||
55ed1602 MF |
1448 | mutex_lock_nested(&configfs_sb->s_root->d_inode->i_mutex, |
1449 | I_MUTEX_PARENT); | |
1450 | mutex_lock_nested(&dentry->d_inode->i_mutex, I_MUTEX_CHILD); | |
7063fbf2 JB |
1451 | if (configfs_detach_prep(dentry)) { |
1452 | printk(KERN_ERR "configfs: Tried to unregister non-empty subsystem!\n"); | |
1453 | } | |
1454 | configfs_detach_group(&group->cg_item); | |
1455 | dentry->d_inode->i_flags |= S_DEAD; | |
1b1dcc1b | 1456 | mutex_unlock(&dentry->d_inode->i_mutex); |
7063fbf2 JB |
1457 | |
1458 | d_delete(dentry); | |
1459 | ||
1b1dcc1b | 1460 | mutex_unlock(&configfs_sb->s_root->d_inode->i_mutex); |
7063fbf2 JB |
1461 | |
1462 | dput(dentry); | |
1463 | ||
1464 | unlink_group(group); | |
1465 | configfs_release_fs(); | |
1466 | } | |
1467 | ||
1468 | EXPORT_SYMBOL(configfs_register_subsystem); | |
1469 | EXPORT_SYMBOL(configfs_unregister_subsystem); |