blob: 05373db21a4e8e4a8a297b3c83fb8ef85a0cb175 [file] [log] [blame]
Joel Becker7063fbf2005-12-15 14:29:43 -08001/* -*- 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>
Louis Rilling107ed402008-06-16 19:01:00 +020033#include <linux/err.h>
Joel Becker7063fbf2005-12-15 14:29:43 -080034
35#include <linux/configfs.h>
36#include "configfs_internal.h"
37
38DECLARE_RWSEM(configfs_rename_sem);
Louis Rilling6f610762008-06-16 19:00:58 +020039/*
40 * Protects mutations of configfs_dirent linkage together with proper i_mutex
Louis Rilling5301a772008-06-16 19:00:59 +020041 * Also protects mutations of symlinks linkage to target configfs_dirent
Louis Rilling6f610762008-06-16 19:00:58 +020042 * Mutators of configfs_dirent linkage must *both* have the proper inode locked
43 * and configfs_dirent_lock locked, in that order.
Louis Rilling5301a772008-06-16 19:00:59 +020044 * This allows one to safely traverse configfs_dirent trees and symlinks without
45 * having to lock inodes.
Louis Rillingb3e76af2008-06-16 19:01:01 +020046 *
47 * Protects setting of CONFIGFS_USET_DROPPING: checking the flag
48 * unlocked is not reliable unless in detach_groups() called from
49 * rmdir()/unregister() and from configfs_attach_group()
Louis Rilling6f610762008-06-16 19:00:58 +020050 */
51DEFINE_SPINLOCK(configfs_dirent_lock);
Joel Becker7063fbf2005-12-15 14:29:43 -080052
53static void configfs_d_iput(struct dentry * dentry,
54 struct inode * inode)
55{
56 struct configfs_dirent * sd = dentry->d_fsdata;
57
58 if (sd) {
59 BUG_ON(sd->s_dentry != dentry);
60 sd->s_dentry = NULL;
61 configfs_put(sd);
62 }
63 iput(inode);
64}
65
66/*
67 * We _must_ delete our dentries on last dput, as the chain-to-parent
68 * behavior is required to clear the parents of default_groups.
69 */
70static int configfs_d_delete(struct dentry *dentry)
71{
72 return 1;
73}
74
Al Viro296c2d82009-02-20 06:02:01 +000075static const struct dentry_operations configfs_dentry_ops = {
Joel Becker7063fbf2005-12-15 14:29:43 -080076 .d_iput = configfs_d_iput,
77 /* simple_delete_dentry() isn't exported */
78 .d_delete = configfs_d_delete,
79};
80
81/*
82 * Allocates a new configfs_dirent and links it to the parent configfs_dirent
83 */
84static struct configfs_dirent *configfs_new_dirent(struct configfs_dirent * parent_sd,
85 void * element)
86{
87 struct configfs_dirent * sd;
88
Robert P. J. Dayc3762222007-02-10 01:45:03 -080089 sd = kmem_cache_zalloc(configfs_dir_cachep, GFP_KERNEL);
Joel Becker7063fbf2005-12-15 14:29:43 -080090 if (!sd)
Louis Rilling107ed402008-06-16 19:01:00 +020091 return ERR_PTR(-ENOMEM);
Joel Becker7063fbf2005-12-15 14:29:43 -080092
Joel Becker7063fbf2005-12-15 14:29:43 -080093 atomic_set(&sd->s_count, 1);
94 INIT_LIST_HEAD(&sd->s_links);
95 INIT_LIST_HEAD(&sd->s_children);
Joel Becker7063fbf2005-12-15 14:29:43 -080096 sd->s_element = element;
Louis Rilling6f610762008-06-16 19:00:58 +020097 spin_lock(&configfs_dirent_lock);
Louis Rillingb3e76af2008-06-16 19:01:01 +020098 if (parent_sd->s_type & CONFIGFS_USET_DROPPING) {
99 spin_unlock(&configfs_dirent_lock);
100 kmem_cache_free(configfs_dir_cachep, sd);
101 return ERR_PTR(-ENOENT);
102 }
Louis Rilling6f610762008-06-16 19:00:58 +0200103 list_add(&sd->s_sibling, &parent_sd->s_children);
104 spin_unlock(&configfs_dirent_lock);
Joel Becker7063fbf2005-12-15 14:29:43 -0800105
106 return sd;
107}
108
Joel Beckerb4c98f62006-09-13 11:01:19 -0700109/*
110 *
111 * Return -EEXIST if there is already a configfs element with the same
112 * name for the same parent.
113 *
114 * called with parent inode's i_mutex held
115 */
Adrian Bunk58d206c2006-11-20 03:24:00 +0100116static int configfs_dirent_exists(struct configfs_dirent *parent_sd,
117 const unsigned char *new)
Joel Beckerb4c98f62006-09-13 11:01:19 -0700118{
119 struct configfs_dirent * sd;
120
121 list_for_each_entry(sd, &parent_sd->s_children, s_sibling) {
122 if (sd->s_element) {
123 const unsigned char *existing = configfs_get_name(sd);
124 if (strcmp(existing, new))
125 continue;
126 else
127 return -EEXIST;
128 }
129 }
130
131 return 0;
132}
133
134
Joel Becker7063fbf2005-12-15 14:29:43 -0800135int configfs_make_dirent(struct configfs_dirent * parent_sd,
136 struct dentry * dentry, void * element,
137 umode_t mode, int type)
138{
139 struct configfs_dirent * sd;
140
141 sd = configfs_new_dirent(parent_sd, element);
Louis Rilling107ed402008-06-16 19:01:00 +0200142 if (IS_ERR(sd))
143 return PTR_ERR(sd);
Joel Becker7063fbf2005-12-15 14:29:43 -0800144
145 sd->s_mode = mode;
146 sd->s_type = type;
147 sd->s_dentry = dentry;
148 if (dentry) {
149 dentry->d_fsdata = configfs_get(sd);
150 dentry->d_op = &configfs_dentry_ops;
151 }
152
153 return 0;
154}
155
156static int init_dir(struct inode * inode)
157{
158 inode->i_op = &configfs_dir_inode_operations;
159 inode->i_fop = &configfs_dir_operations;
160
161 /* directory inodes start off with i_nlink == 2 (for "." entry) */
Dave Hansend8c76e62006-09-30 23:29:04 -0700162 inc_nlink(inode);
Joel Becker7063fbf2005-12-15 14:29:43 -0800163 return 0;
164}
165
Dave Hansence8d2cd2007-10-16 23:31:13 -0700166static int configfs_init_file(struct inode * inode)
Joel Becker7063fbf2005-12-15 14:29:43 -0800167{
168 inode->i_size = PAGE_SIZE;
169 inode->i_fop = &configfs_file_operations;
170 return 0;
171}
172
173static int init_symlink(struct inode * inode)
174{
175 inode->i_op = &configfs_symlink_inode_operations;
176 return 0;
177}
178
179static int create_dir(struct config_item * k, struct dentry * p,
180 struct dentry * d)
181{
182 int error;
183 umode_t mode = S_IFDIR| S_IRWXU | S_IRUGO | S_IXUGO;
184
Joel Beckerb4c98f62006-09-13 11:01:19 -0700185 error = configfs_dirent_exists(p->d_fsdata, d->d_name.name);
186 if (!error)
187 error = configfs_make_dirent(p->d_fsdata, d, k, mode,
Louis Rilling2a109f22008-07-04 16:56:05 +0200188 CONFIGFS_DIR | CONFIGFS_USET_CREATING);
Joel Becker7063fbf2005-12-15 14:29:43 -0800189 if (!error) {
Joel Becker3d0f89b2006-01-25 13:31:07 -0800190 error = configfs_create(d, mode, init_dir);
Joel Becker7063fbf2005-12-15 14:29:43 -0800191 if (!error) {
Dave Hansend8c76e62006-09-30 23:29:04 -0700192 inc_nlink(p->d_inode);
Joel Becker7063fbf2005-12-15 14:29:43 -0800193 (d)->d_op = &configfs_dentry_ops;
Joel Becker3d0f89b2006-01-25 13:31:07 -0800194 } else {
195 struct configfs_dirent *sd = d->d_fsdata;
196 if (sd) {
Louis Rilling6f610762008-06-16 19:00:58 +0200197 spin_lock(&configfs_dirent_lock);
Joel Becker3d0f89b2006-01-25 13:31:07 -0800198 list_del_init(&sd->s_sibling);
Louis Rilling6f610762008-06-16 19:00:58 +0200199 spin_unlock(&configfs_dirent_lock);
Joel Becker3d0f89b2006-01-25 13:31:07 -0800200 configfs_put(sd);
201 }
Joel Becker7063fbf2005-12-15 14:29:43 -0800202 }
203 }
204 return error;
205}
206
207
208/**
209 * configfs_create_dir - create a directory for an config_item.
210 * @item: config_itemwe're creating directory for.
211 * @dentry: config_item's dentry.
Louis Rilling2a109f22008-07-04 16:56:05 +0200212 *
213 * Note: user-created entries won't be allowed under this new directory
214 * until it is validated by configfs_dir_set_ready()
Joel Becker7063fbf2005-12-15 14:29:43 -0800215 */
216
217static int configfs_create_dir(struct config_item * item, struct dentry *dentry)
218{
219 struct dentry * parent;
220 int error = 0;
221
222 BUG_ON(!item);
223
224 if (item->ci_parent)
225 parent = item->ci_parent->ci_dentry;
226 else if (configfs_mount && configfs_mount->mnt_sb)
227 parent = configfs_mount->mnt_sb->s_root;
228 else
229 return -EFAULT;
230
231 error = create_dir(item,parent,dentry);
232 if (!error)
233 item->ci_dentry = dentry;
234 return error;
235}
236
Louis Rilling2a109f22008-07-04 16:56:05 +0200237/*
238 * Allow userspace to create new entries under a new directory created with
239 * configfs_create_dir(), and under all of its chidlren directories recursively.
240 * @sd configfs_dirent of the new directory to validate
241 *
242 * Caller must hold configfs_dirent_lock.
243 */
244static void configfs_dir_set_ready(struct configfs_dirent *sd)
245{
246 struct configfs_dirent *child_sd;
247
248 sd->s_type &= ~CONFIGFS_USET_CREATING;
249 list_for_each_entry(child_sd, &sd->s_children, s_sibling)
250 if (child_sd->s_type & CONFIGFS_USET_CREATING)
251 configfs_dir_set_ready(child_sd);
252}
253
254/*
255 * Check that a directory does not belong to a directory hierarchy being
256 * attached and not validated yet.
257 * @sd configfs_dirent of the directory to check
258 *
259 * @return non-zero iff the directory was validated
260 *
261 * Note: takes configfs_dirent_lock, so the result may change from false to true
262 * in two consecutive calls, but never from true to false.
263 */
264int configfs_dirent_is_ready(struct configfs_dirent *sd)
265{
266 int ret;
267
268 spin_lock(&configfs_dirent_lock);
269 ret = !(sd->s_type & CONFIGFS_USET_CREATING);
270 spin_unlock(&configfs_dirent_lock);
271
272 return ret;
273}
274
Joel Becker7063fbf2005-12-15 14:29:43 -0800275int configfs_create_link(struct configfs_symlink *sl,
276 struct dentry *parent,
277 struct dentry *dentry)
278{
279 int err = 0;
280 umode_t mode = S_IFLNK | S_IRWXUGO;
281
Joel Becker3d0f89b2006-01-25 13:31:07 -0800282 err = configfs_make_dirent(parent->d_fsdata, dentry, sl, mode,
283 CONFIGFS_ITEM_LINK);
Joel Becker7063fbf2005-12-15 14:29:43 -0800284 if (!err) {
Joel Becker3d0f89b2006-01-25 13:31:07 -0800285 err = configfs_create(dentry, mode, init_symlink);
Joel Becker7063fbf2005-12-15 14:29:43 -0800286 if (!err)
287 dentry->d_op = &configfs_dentry_ops;
Joel Becker3d0f89b2006-01-25 13:31:07 -0800288 else {
289 struct configfs_dirent *sd = dentry->d_fsdata;
290 if (sd) {
Louis Rilling6f610762008-06-16 19:00:58 +0200291 spin_lock(&configfs_dirent_lock);
Joel Becker3d0f89b2006-01-25 13:31:07 -0800292 list_del_init(&sd->s_sibling);
Louis Rilling6f610762008-06-16 19:00:58 +0200293 spin_unlock(&configfs_dirent_lock);
Joel Becker3d0f89b2006-01-25 13:31:07 -0800294 configfs_put(sd);
295 }
296 }
Joel Becker7063fbf2005-12-15 14:29:43 -0800297 }
298 return err;
299}
300
301static void remove_dir(struct dentry * d)
302{
303 struct dentry * parent = dget(d->d_parent);
304 struct configfs_dirent * sd;
305
306 sd = d->d_fsdata;
Louis Rilling6f610762008-06-16 19:00:58 +0200307 spin_lock(&configfs_dirent_lock);
Joel Beckere7515d02006-03-10 11:42:30 -0800308 list_del_init(&sd->s_sibling);
Louis Rilling6f610762008-06-16 19:00:58 +0200309 spin_unlock(&configfs_dirent_lock);
Joel Becker7063fbf2005-12-15 14:29:43 -0800310 configfs_put(sd);
311 if (d->d_inode)
312 simple_rmdir(parent->d_inode,d);
313
314 pr_debug(" o %s removing done (%d)\n",d->d_name.name,
315 atomic_read(&d->d_count));
316
317 dput(parent);
318}
319
320/**
321 * configfs_remove_dir - remove an config_item's directory.
322 * @item: config_item we're removing.
323 *
324 * The only thing special about this is that we remove any files in
325 * the directory before we remove the directory, and we've inlined
326 * what used to be configfs_rmdir() below, instead of calling separately.
Louis Rilling2e2ce172008-07-04 16:56:06 +0200327 *
328 * Caller holds the mutex of the item's inode
Joel Becker7063fbf2005-12-15 14:29:43 -0800329 */
330
331static void configfs_remove_dir(struct config_item * item)
332{
333 struct dentry * dentry = dget(item->ci_dentry);
334
335 if (!dentry)
336 return;
337
338 remove_dir(dentry);
339 /**
340 * Drop reference from dget() on entrance.
341 */
342 dput(dentry);
343}
344
345
346/* attaches attribute's configfs_dirent to the dentry corresponding to the
347 * attribute file
348 */
349static int configfs_attach_attr(struct configfs_dirent * sd, struct dentry * dentry)
350{
351 struct configfs_attribute * attr = sd->s_element;
352 int error;
353
Joel Becker7063fbf2005-12-15 14:29:43 -0800354 dentry->d_fsdata = configfs_get(sd);
355 sd->s_dentry = dentry;
Dave Hansence8d2cd2007-10-16 23:31:13 -0700356 error = configfs_create(dentry, (attr->ca_mode & S_IALLUGO) | S_IFREG,
357 configfs_init_file);
Joel Becker3d0f89b2006-01-25 13:31:07 -0800358 if (error) {
359 configfs_put(sd);
360 return error;
361 }
362
363 dentry->d_op = &configfs_dentry_ops;
Joel Becker7063fbf2005-12-15 14:29:43 -0800364 d_rehash(dentry);
365
366 return 0;
367}
368
369static struct dentry * configfs_lookup(struct inode *dir,
370 struct dentry *dentry,
371 struct nameidata *nd)
372{
373 struct configfs_dirent * parent_sd = dentry->d_parent->d_fsdata;
374 struct configfs_dirent * sd;
375 int found = 0;
Louis Rilling2a109f22008-07-04 16:56:05 +0200376 int err;
377
378 /*
379 * Fake invisibility if dir belongs to a group/default groups hierarchy
380 * being attached
381 *
382 * This forbids userspace to read/write attributes of items which may
383 * not complete their initialization, since the dentries of the
384 * attributes won't be instantiated.
385 */
386 err = -ENOENT;
387 if (!configfs_dirent_is_ready(parent_sd))
388 goto out;
Joel Becker7063fbf2005-12-15 14:29:43 -0800389
390 list_for_each_entry(sd, &parent_sd->s_children, s_sibling) {
391 if (sd->s_type & CONFIGFS_NOT_PINNED) {
392 const unsigned char * name = configfs_get_name(sd);
393
394 if (strcmp(name, dentry->d_name.name))
395 continue;
396
397 found = 1;
398 err = configfs_attach_attr(sd, dentry);
399 break;
400 }
401 }
402
403 if (!found) {
404 /*
405 * If it doesn't exist and it isn't a NOT_PINNED item,
406 * it must be negative.
407 */
408 return simple_lookup(dir, dentry, nd);
409 }
410
Louis Rilling2a109f22008-07-04 16:56:05 +0200411out:
Joel Becker7063fbf2005-12-15 14:29:43 -0800412 return ERR_PTR(err);
413}
414
415/*
416 * Only subdirectories count here. Files (CONFIGFS_NOT_PINNED) are
Louis Rillingb3e76af2008-06-16 19:01:01 +0200417 * attributes and are removed by rmdir(). We recurse, setting
418 * CONFIGFS_USET_DROPPING on all children that are candidates for
419 * default detach.
420 * If there is an error, the caller will reset the flags via
421 * configfs_detach_rollback().
Joel Becker7063fbf2005-12-15 14:29:43 -0800422 */
Louis Rilling6d8344b2008-06-16 19:01:02 +0200423static int configfs_detach_prep(struct dentry *dentry, struct mutex **wait_mutex)
Joel Becker7063fbf2005-12-15 14:29:43 -0800424{
425 struct configfs_dirent *parent_sd = dentry->d_fsdata;
426 struct configfs_dirent *sd;
427 int ret;
428
Louis Rilling4768e9b2008-06-23 14:16:17 +0200429 /* Mark that we're trying to drop the group */
430 parent_sd->s_type |= CONFIGFS_USET_DROPPING;
431
Joel Becker7063fbf2005-12-15 14:29:43 -0800432 ret = -EBUSY;
433 if (!list_empty(&parent_sd->s_links))
434 goto out;
435
436 ret = 0;
437 list_for_each_entry(sd, &parent_sd->s_children, s_sibling) {
Louis Rilling99cefda2008-06-27 13:10:25 +0200438 if (!sd->s_element ||
439 (sd->s_type & CONFIGFS_NOT_PINNED))
Joel Becker7063fbf2005-12-15 14:29:43 -0800440 continue;
441 if (sd->s_type & CONFIGFS_USET_DEFAULT) {
Louis Rilling6d8344b2008-06-16 19:01:02 +0200442 /* Abort if racing with mkdir() */
443 if (sd->s_type & CONFIGFS_USET_IN_MKDIR) {
444 if (wait_mutex)
445 *wait_mutex = &sd->s_dentry->d_inode->i_mutex;
446 return -EAGAIN;
447 }
Joel Becker7063fbf2005-12-15 14:29:43 -0800448
Joel Becker631d1fe2007-06-18 18:06:09 -0700449 /*
450 * Yup, recursive. If there's a problem, blame
451 * deep nesting of default_groups
452 */
Louis Rilling6d8344b2008-06-16 19:01:02 +0200453 ret = configfs_detach_prep(sd->s_dentry, wait_mutex);
Joel Becker7063fbf2005-12-15 14:29:43 -0800454 if (!ret)
Joel Beckere7515d02006-03-10 11:42:30 -0800455 continue;
Joel Becker7063fbf2005-12-15 14:29:43 -0800456 } else
457 ret = -ENOTEMPTY;
458
459 break;
460 }
461
462out:
463 return ret;
464}
465
466/*
Louis Rillingb3e76af2008-06-16 19:01:01 +0200467 * Walk the tree, resetting CONFIGFS_USET_DROPPING wherever it was
Joel Becker7063fbf2005-12-15 14:29:43 -0800468 * set.
469 */
470static void configfs_detach_rollback(struct dentry *dentry)
471{
472 struct configfs_dirent *parent_sd = dentry->d_fsdata;
473 struct configfs_dirent *sd;
474
Louis Rilling4768e9b2008-06-23 14:16:17 +0200475 parent_sd->s_type &= ~CONFIGFS_USET_DROPPING;
476
477 list_for_each_entry(sd, &parent_sd->s_children, s_sibling)
478 if (sd->s_type & CONFIGFS_USET_DEFAULT)
Joel Becker7063fbf2005-12-15 14:29:43 -0800479 configfs_detach_rollback(sd->s_dentry);
Joel Becker7063fbf2005-12-15 14:29:43 -0800480}
481
482static void detach_attrs(struct config_item * item)
483{
484 struct dentry * dentry = dget(item->ci_dentry);
485 struct configfs_dirent * parent_sd;
486 struct configfs_dirent * sd, * tmp;
487
488 if (!dentry)
489 return;
490
491 pr_debug("configfs %s: dropping attrs for dir\n",
492 dentry->d_name.name);
493
494 parent_sd = dentry->d_fsdata;
495 list_for_each_entry_safe(sd, tmp, &parent_sd->s_children, s_sibling) {
496 if (!sd->s_element || !(sd->s_type & CONFIGFS_NOT_PINNED))
497 continue;
Louis Rilling6f610762008-06-16 19:00:58 +0200498 spin_lock(&configfs_dirent_lock);
Joel Becker7063fbf2005-12-15 14:29:43 -0800499 list_del_init(&sd->s_sibling);
Louis Rilling6f610762008-06-16 19:00:58 +0200500 spin_unlock(&configfs_dirent_lock);
Joel Becker7063fbf2005-12-15 14:29:43 -0800501 configfs_drop_dentry(sd, dentry);
502 configfs_put(sd);
503 }
504
505 /**
506 * Drop reference from dget() on entrance.
507 */
508 dput(dentry);
509}
510
511static int populate_attrs(struct config_item *item)
512{
513 struct config_item_type *t = item->ci_type;
514 struct configfs_attribute *attr;
515 int error = 0;
516 int i;
517
518 if (!t)
519 return -EINVAL;
520 if (t->ct_attrs) {
521 for (i = 0; (attr = t->ct_attrs[i]) != NULL; i++) {
522 if ((error = configfs_create_file(item, attr)))
523 break;
524 }
525 }
526
527 if (error)
528 detach_attrs(item);
529
530 return error;
531}
532
533static int configfs_attach_group(struct config_item *parent_item,
534 struct config_item *item,
535 struct dentry *dentry);
536static void configfs_detach_group(struct config_item *item);
537
538static void detach_groups(struct config_group *group)
539{
540 struct dentry * dentry = dget(group->cg_item.ci_dentry);
541 struct dentry *child;
542 struct configfs_dirent *parent_sd;
543 struct configfs_dirent *sd, *tmp;
544
545 if (!dentry)
546 return;
547
548 parent_sd = dentry->d_fsdata;
549 list_for_each_entry_safe(sd, tmp, &parent_sd->s_children, s_sibling) {
550 if (!sd->s_element ||
551 !(sd->s_type & CONFIGFS_USET_DEFAULT))
552 continue;
553
554 child = sd->s_dentry;
555
Louis Rillingb3e76af2008-06-16 19:01:01 +0200556 mutex_lock(&child->d_inode->i_mutex);
557
Joel Becker7063fbf2005-12-15 14:29:43 -0800558 configfs_detach_group(sd->s_element);
559 child->d_inode->i_flags |= S_DEAD;
560
Louis Rillingb3e76af2008-06-16 19:01:01 +0200561 mutex_unlock(&child->d_inode->i_mutex);
Joel Becker7063fbf2005-12-15 14:29:43 -0800562
563 d_delete(child);
564 dput(child);
565 }
566
567 /**
568 * Drop reference from dget() on entrance.
569 */
570 dput(dentry);
571}
572
573/*
574 * This fakes mkdir(2) on a default_groups[] entry. It
575 * creates a dentry, attachs it, and then does fixup
576 * on the sd->s_type.
577 *
578 * We could, perhaps, tweak our parent's ->mkdir for a minute and
579 * try using vfs_mkdir. Just a thought.
580 */
581static int create_default_group(struct config_group *parent_group,
582 struct config_group *group)
583{
584 int ret;
585 struct qstr name;
586 struct configfs_dirent *sd;
587 /* We trust the caller holds a reference to parent */
588 struct dentry *child, *parent = parent_group->cg_item.ci_dentry;
589
590 if (!group->cg_item.ci_name)
591 group->cg_item.ci_name = group->cg_item.ci_namebuf;
592 name.name = group->cg_item.ci_name;
593 name.len = strlen(name.name);
594 name.hash = full_name_hash(name.name, name.len);
595
596 ret = -ENOMEM;
597 child = d_alloc(parent, &name);
598 if (child) {
599 d_add(child, NULL);
600
601 ret = configfs_attach_group(&parent_group->cg_item,
602 &group->cg_item, child);
603 if (!ret) {
604 sd = child->d_fsdata;
605 sd->s_type |= CONFIGFS_USET_DEFAULT;
606 } else {
607 d_delete(child);
608 dput(child);
609 }
610 }
611
612 return ret;
613}
614
615static int populate_groups(struct config_group *group)
616{
617 struct config_group *new_group;
Joel Becker7063fbf2005-12-15 14:29:43 -0800618 int ret = 0;
619 int i;
620
Eric Sesterhenncbca6922006-03-23 00:36:54 +0100621 if (group->default_groups) {
Joel Becker7063fbf2005-12-15 14:29:43 -0800622 for (i = 0; group->default_groups[i]; i++) {
623 new_group = group->default_groups[i];
624
625 ret = create_default_group(group, new_group);
Louis Rilling2e2ce172008-07-04 16:56:06 +0200626 if (ret) {
627 detach_groups(group);
Joel Becker7063fbf2005-12-15 14:29:43 -0800628 break;
Louis Rilling2e2ce172008-07-04 16:56:06 +0200629 }
Joel Becker7063fbf2005-12-15 14:29:43 -0800630 }
Joel Becker7063fbf2005-12-15 14:29:43 -0800631 }
632
Joel Becker7063fbf2005-12-15 14:29:43 -0800633 return ret;
634}
635
636/*
637 * All of link_obj/unlink_obj/link_group/unlink_group require that
Joel Beckere6bd07a2007-07-06 23:33:17 -0700638 * subsys->su_mutex is held.
Joel Becker7063fbf2005-12-15 14:29:43 -0800639 */
640
641static void unlink_obj(struct config_item *item)
642{
643 struct config_group *group;
644
645 group = item->ci_group;
646 if (group) {
647 list_del_init(&item->ci_entry);
648
649 item->ci_group = NULL;
650 item->ci_parent = NULL;
Joel Beckereed7a0d2006-04-11 21:37:20 -0700651
652 /* Drop the reference for ci_entry */
Joel Becker7063fbf2005-12-15 14:29:43 -0800653 config_item_put(item);
654
Joel Beckereed7a0d2006-04-11 21:37:20 -0700655 /* Drop the reference for ci_parent */
Joel Becker7063fbf2005-12-15 14:29:43 -0800656 config_group_put(group);
657 }
658}
659
660static void link_obj(struct config_item *parent_item, struct config_item *item)
661{
Joel Beckereed7a0d2006-04-11 21:37:20 -0700662 /*
663 * Parent seems redundant with group, but it makes certain
664 * traversals much nicer.
665 */
Joel Becker7063fbf2005-12-15 14:29:43 -0800666 item->ci_parent = parent_item;
Joel Beckereed7a0d2006-04-11 21:37:20 -0700667
668 /*
669 * We hold a reference on the parent for the child's ci_parent
670 * link.
671 */
Joel Becker7063fbf2005-12-15 14:29:43 -0800672 item->ci_group = config_group_get(to_config_group(parent_item));
673 list_add_tail(&item->ci_entry, &item->ci_group->cg_children);
674
Joel Beckereed7a0d2006-04-11 21:37:20 -0700675 /*
676 * We hold a reference on the child for ci_entry on the parent's
677 * cg_children
678 */
Joel Becker7063fbf2005-12-15 14:29:43 -0800679 config_item_get(item);
680}
681
682static void unlink_group(struct config_group *group)
683{
684 int i;
685 struct config_group *new_group;
686
687 if (group->default_groups) {
688 for (i = 0; group->default_groups[i]; i++) {
689 new_group = group->default_groups[i];
690 unlink_group(new_group);
691 }
692 }
693
694 group->cg_subsys = NULL;
695 unlink_obj(&group->cg_item);
696}
697
698static void link_group(struct config_group *parent_group, struct config_group *group)
699{
700 int i;
701 struct config_group *new_group;
702 struct configfs_subsystem *subsys = NULL; /* gcc is a turd */
703
704 link_obj(&parent_group->cg_item, &group->cg_item);
705
706 if (parent_group->cg_subsys)
707 subsys = parent_group->cg_subsys;
708 else if (configfs_is_root(&parent_group->cg_item))
709 subsys = to_configfs_subsystem(group);
710 else
711 BUG();
712 group->cg_subsys = subsys;
713
714 if (group->default_groups) {
715 for (i = 0; group->default_groups[i]; i++) {
716 new_group = group->default_groups[i];
717 link_group(group, new_group);
718 }
719 }
720}
721
722/*
723 * The goal is that configfs_attach_item() (and
724 * configfs_attach_group()) can be called from either the VFS or this
725 * module. That is, they assume that the items have been created,
726 * the dentry allocated, and the dcache is all ready to go.
727 *
728 * If they fail, they must clean up after themselves as if they
729 * had never been called. The caller (VFS or local function) will
730 * handle cleaning up the dcache bits.
731 *
732 * configfs_detach_group() and configfs_detach_item() behave similarly on
733 * the way out. They assume that the proper semaphores are held, they
734 * clean up the configfs items, and they expect their callers will
735 * handle the dcache bits.
736 */
737static int configfs_attach_item(struct config_item *parent_item,
738 struct config_item *item,
739 struct dentry *dentry)
740{
741 int ret;
742
743 ret = configfs_create_dir(item, dentry);
744 if (!ret) {
745 ret = populate_attrs(item);
746 if (ret) {
Louis Rilling2e2ce172008-07-04 16:56:06 +0200747 /*
748 * We are going to remove an inode and its dentry but
749 * the VFS may already have hit and used them. Thus,
750 * we must lock them as rmdir() would.
751 */
752 mutex_lock(&dentry->d_inode->i_mutex);
Joel Becker7063fbf2005-12-15 14:29:43 -0800753 configfs_remove_dir(item);
Louis Rilling2e2ce172008-07-04 16:56:06 +0200754 dentry->d_inode->i_flags |= S_DEAD;
755 mutex_unlock(&dentry->d_inode->i_mutex);
Joel Becker7063fbf2005-12-15 14:29:43 -0800756 d_delete(dentry);
757 }
758 }
759
760 return ret;
761}
762
Louis Rilling2e2ce172008-07-04 16:56:06 +0200763/* Caller holds the mutex of the item's inode */
Joel Becker7063fbf2005-12-15 14:29:43 -0800764static void configfs_detach_item(struct config_item *item)
765{
766 detach_attrs(item);
767 configfs_remove_dir(item);
768}
769
770static int configfs_attach_group(struct config_item *parent_item,
771 struct config_item *item,
772 struct dentry *dentry)
773{
774 int ret;
775 struct configfs_dirent *sd;
776
777 ret = configfs_attach_item(parent_item, item, dentry);
778 if (!ret) {
779 sd = dentry->d_fsdata;
780 sd->s_type |= CONFIGFS_USET_DIR;
781
Louis Rilling2e2ce172008-07-04 16:56:06 +0200782 /*
783 * FYI, we're faking mkdir in populate_groups()
784 * We must lock the group's inode to avoid races with the VFS
785 * which can already hit the inode and try to add/remove entries
786 * under it.
787 *
788 * We must also lock the inode to remove it safely in case of
789 * error, as rmdir() would.
790 */
791 mutex_lock_nested(&dentry->d_inode->i_mutex, I_MUTEX_CHILD);
Joel Becker7063fbf2005-12-15 14:29:43 -0800792 ret = populate_groups(to_config_group(item));
793 if (ret) {
794 configfs_detach_item(item);
Louis Rilling2e2ce172008-07-04 16:56:06 +0200795 dentry->d_inode->i_flags |= S_DEAD;
Joel Becker7063fbf2005-12-15 14:29:43 -0800796 }
Louis Rilling2e2ce172008-07-04 16:56:06 +0200797 mutex_unlock(&dentry->d_inode->i_mutex);
798 if (ret)
799 d_delete(dentry);
Joel Becker7063fbf2005-12-15 14:29:43 -0800800 }
801
802 return ret;
803}
804
Louis Rilling2e2ce172008-07-04 16:56:06 +0200805/* Caller holds the mutex of the group's inode */
Joel Becker7063fbf2005-12-15 14:29:43 -0800806static void configfs_detach_group(struct config_item *item)
807{
808 detach_groups(to_config_group(item));
809 configfs_detach_item(item);
810}
811
812/*
Joel Becker299894c2006-10-06 17:33:23 -0700813 * After the item has been detached from the filesystem view, we are
814 * ready to tear it out of the hierarchy. Notify the client before
815 * we do that so they can perform any cleanup that requires
816 * navigating the hierarchy. A client does not need to provide this
817 * callback. The subsystem semaphore MUST be held by the caller, and
818 * references must be valid for both items. It also assumes the
819 * caller has validated ci_type.
820 */
821static void client_disconnect_notify(struct config_item *parent_item,
822 struct config_item *item)
823{
824 struct config_item_type *type;
825
826 type = parent_item->ci_type;
827 BUG_ON(!type);
828
829 if (type->ct_group_ops && type->ct_group_ops->disconnect_notify)
830 type->ct_group_ops->disconnect_notify(to_config_group(parent_item),
831 item);
832}
833
834/*
Joel Becker7063fbf2005-12-15 14:29:43 -0800835 * Drop the initial reference from make_item()/make_group()
836 * This function assumes that reference is held on item
837 * and that item holds a valid reference to the parent. Also, it
838 * assumes the caller has validated ci_type.
839 */
840static void client_drop_item(struct config_item *parent_item,
841 struct config_item *item)
842{
843 struct config_item_type *type;
844
845 type = parent_item->ci_type;
846 BUG_ON(!type);
847
Joel Beckereed7a0d2006-04-11 21:37:20 -0700848 /*
849 * If ->drop_item() exists, it is responsible for the
850 * config_item_put().
851 */
Joel Becker7063fbf2005-12-15 14:29:43 -0800852 if (type->ct_group_ops && type->ct_group_ops->drop_item)
853 type->ct_group_ops->drop_item(to_config_group(parent_item),
Joel Becker299894c2006-10-06 17:33:23 -0700854 item);
Joel Becker7063fbf2005-12-15 14:29:43 -0800855 else
856 config_item_put(item);
857}
858
Joel Becker631d1fe2007-06-18 18:06:09 -0700859#ifdef DEBUG
860static void configfs_dump_one(struct configfs_dirent *sd, int level)
861{
862 printk(KERN_INFO "%*s\"%s\":\n", level, " ", configfs_get_name(sd));
863
864#define type_print(_type) if (sd->s_type & _type) printk(KERN_INFO "%*s %s\n", level, " ", #_type);
865 type_print(CONFIGFS_ROOT);
866 type_print(CONFIGFS_DIR);
867 type_print(CONFIGFS_ITEM_ATTR);
868 type_print(CONFIGFS_ITEM_LINK);
869 type_print(CONFIGFS_USET_DIR);
870 type_print(CONFIGFS_USET_DEFAULT);
871 type_print(CONFIGFS_USET_DROPPING);
872#undef type_print
873}
874
875static int configfs_dump(struct configfs_dirent *sd, int level)
876{
877 struct configfs_dirent *child_sd;
878 int ret = 0;
879
880 configfs_dump_one(sd, level);
881
882 if (!(sd->s_type & (CONFIGFS_DIR|CONFIGFS_ROOT)))
883 return 0;
884
885 list_for_each_entry(child_sd, &sd->s_children, s_sibling) {
886 ret = configfs_dump(child_sd, level + 2);
887 if (ret)
888 break;
889 }
890
891 return ret;
892}
893#endif
894
895
896/*
897 * configfs_depend_item() and configfs_undepend_item()
898 *
899 * WARNING: Do not call these from a configfs callback!
900 *
901 * This describes these functions and their helpers.
902 *
903 * Allow another kernel system to depend on a config_item. If this
904 * happens, the item cannot go away until the dependant can live without
905 * it. The idea is to give client modules as simple an interface as
906 * possible. When a system asks them to depend on an item, they just
907 * call configfs_depend_item(). If the item is live and the client
908 * driver is in good shape, we'll happily do the work for them.
909 *
910 * Why is the locking complex? Because configfs uses the VFS to handle
911 * all locking, but this function is called outside the normal
912 * VFS->configfs path. So it must take VFS locks to prevent the
913 * VFS->configfs stuff (configfs_mkdir(), configfs_rmdir(), etc). This is
914 * why you can't call these functions underneath configfs callbacks.
915 *
916 * Note, btw, that this can be called at *any* time, even when a configfs
917 * subsystem isn't registered, or when configfs is loading or unloading.
918 * Just like configfs_register_subsystem(). So we take the same
919 * precautions. We pin the filesystem. We lock each i_mutex _in_order_
920 * on our way down the tree. If we can find the target item in the
921 * configfs tree, it must be part of the subsystem tree as well, so we
922 * do not need the subsystem semaphore. Holding the i_mutex chain locks
923 * out mkdir() and rmdir(), who might be racing us.
924 */
925
926/*
927 * configfs_depend_prep()
928 *
929 * Only subdirectories count here. Files (CONFIGFS_NOT_PINNED) are
930 * attributes. This is similar but not the same to configfs_detach_prep().
931 * Note that configfs_detach_prep() expects the parent to be locked when it
932 * is called, but we lock the parent *inside* configfs_depend_prep(). We
933 * do that so we can unlock it if we find nothing.
934 *
935 * Here we do a depth-first search of the dentry hierarchy looking for
936 * our object. We take i_mutex on each step of the way down. IT IS
937 * ESSENTIAL THAT i_mutex LOCKING IS ORDERED. If we come back up a branch,
938 * we'll drop the i_mutex.
939 *
940 * If the target is not found, -ENOENT is bubbled up and we have released
941 * all locks. If the target was found, the locks will be cleared by
942 * configfs_depend_rollback().
943 *
944 * This adds a requirement that all config_items be unique!
945 *
946 * This is recursive because the locking traversal is tricky. There isn't
947 * much on the stack, though, so folks that need this function - be careful
948 * about your stack! Patches will be accepted to make it iterative.
949 */
950static int configfs_depend_prep(struct dentry *origin,
951 struct config_item *target)
952{
953 struct configfs_dirent *child_sd, *sd = origin->d_fsdata;
954 int ret = 0;
955
956 BUG_ON(!origin || !sd);
957
958 /* Lock this guy on the way down */
959 mutex_lock(&sd->s_dentry->d_inode->i_mutex);
960 if (sd->s_element == target) /* Boo-yah */
961 goto out;
962
963 list_for_each_entry(child_sd, &sd->s_children, s_sibling) {
964 if (child_sd->s_type & CONFIGFS_DIR) {
965 ret = configfs_depend_prep(child_sd->s_dentry,
966 target);
967 if (!ret)
968 goto out; /* Child path boo-yah */
969 }
970 }
971
972 /* We looped all our children and didn't find target */
973 mutex_unlock(&sd->s_dentry->d_inode->i_mutex);
974 ret = -ENOENT;
975
976out:
977 return ret;
978}
979
980/*
981 * This is ONLY called if configfs_depend_prep() did its job. So we can
982 * trust the entire path from item back up to origin.
983 *
984 * We walk backwards from item, unlocking each i_mutex. We finish by
985 * unlocking origin.
986 */
987static void configfs_depend_rollback(struct dentry *origin,
988 struct config_item *item)
989{
990 struct dentry *dentry = item->ci_dentry;
991
992 while (dentry != origin) {
993 mutex_unlock(&dentry->d_inode->i_mutex);
994 dentry = dentry->d_parent;
995 }
996
997 mutex_unlock(&origin->d_inode->i_mutex);
998}
999
1000int configfs_depend_item(struct configfs_subsystem *subsys,
1001 struct config_item *target)
1002{
1003 int ret;
1004 struct configfs_dirent *p, *root_sd, *subsys_sd = NULL;
1005 struct config_item *s_item = &subsys->su_group.cg_item;
1006
1007 /*
1008 * Pin the configfs filesystem. This means we can safely access
1009 * the root of the configfs filesystem.
1010 */
1011 ret = configfs_pin_fs();
1012 if (ret)
1013 return ret;
1014
1015 /*
1016 * Next, lock the root directory. We're going to check that the
1017 * subsystem is really registered, and so we need to lock out
1018 * configfs_[un]register_subsystem().
1019 */
1020 mutex_lock(&configfs_sb->s_root->d_inode->i_mutex);
1021
1022 root_sd = configfs_sb->s_root->d_fsdata;
1023
1024 list_for_each_entry(p, &root_sd->s_children, s_sibling) {
1025 if (p->s_type & CONFIGFS_DIR) {
1026 if (p->s_element == s_item) {
1027 subsys_sd = p;
1028 break;
1029 }
1030 }
1031 }
1032
1033 if (!subsys_sd) {
1034 ret = -ENOENT;
1035 goto out_unlock_fs;
1036 }
1037
1038 /* Ok, now we can trust subsys/s_item */
1039
1040 /* Scan the tree, locking i_mutex recursively, return 0 if found */
1041 ret = configfs_depend_prep(subsys_sd->s_dentry, target);
1042 if (ret)
1043 goto out_unlock_fs;
1044
1045 /* We hold all i_mutexes from the subsystem down to the target */
1046 p = target->ci_dentry->d_fsdata;
1047 p->s_dependent_count += 1;
1048
1049 configfs_depend_rollback(subsys_sd->s_dentry, target);
1050
1051out_unlock_fs:
1052 mutex_unlock(&configfs_sb->s_root->d_inode->i_mutex);
1053
1054 /*
1055 * If we succeeded, the fs is pinned via other methods. If not,
1056 * we're done with it anyway. So release_fs() is always right.
1057 */
1058 configfs_release_fs();
1059
1060 return ret;
1061}
1062EXPORT_SYMBOL(configfs_depend_item);
1063
1064/*
1065 * Release the dependent linkage. This is much simpler than
1066 * configfs_depend_item() because we know that that the client driver is
1067 * pinned, thus the subsystem is pinned, and therefore configfs is pinned.
1068 */
1069void configfs_undepend_item(struct configfs_subsystem *subsys,
1070 struct config_item *target)
1071{
1072 struct configfs_dirent *sd;
1073
1074 /*
1075 * Since we can trust everything is pinned, we just need i_mutex
1076 * on the item.
1077 */
1078 mutex_lock(&target->ci_dentry->d_inode->i_mutex);
1079
1080 sd = target->ci_dentry->d_fsdata;
1081 BUG_ON(sd->s_dependent_count < 1);
1082
1083 sd->s_dependent_count -= 1;
1084
1085 /*
1086 * After this unlock, we cannot trust the item to stay alive!
1087 * DO NOT REFERENCE item after this unlock.
1088 */
1089 mutex_unlock(&target->ci_dentry->d_inode->i_mutex);
1090}
1091EXPORT_SYMBOL(configfs_undepend_item);
Joel Becker7063fbf2005-12-15 14:29:43 -08001092
1093static int configfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
1094{
Joel Beckera6795e92008-07-17 15:21:29 -07001095 int ret = 0;
1096 int module_got = 0;
1097 struct config_group *group = NULL;
1098 struct config_item *item = NULL;
Joel Becker7063fbf2005-12-15 14:29:43 -08001099 struct config_item *parent_item;
1100 struct configfs_subsystem *subsys;
1101 struct configfs_dirent *sd;
1102 struct config_item_type *type;
Joel Becker70526b62008-06-17 15:34:32 -07001103 struct module *subsys_owner = NULL, *new_item_owner = NULL;
Joel Becker7063fbf2005-12-15 14:29:43 -08001104 char *name;
1105
Joel Becker84efad12006-03-27 18:46:09 -08001106 if (dentry->d_parent == configfs_sb->s_root) {
1107 ret = -EPERM;
1108 goto out;
1109 }
Joel Becker7063fbf2005-12-15 14:29:43 -08001110
1111 sd = dentry->d_parent->d_fsdata;
Louis Rilling2a109f22008-07-04 16:56:05 +02001112
1113 /*
1114 * Fake invisibility if dir belongs to a group/default groups hierarchy
1115 * being attached
1116 */
1117 if (!configfs_dirent_is_ready(sd)) {
1118 ret = -ENOENT;
1119 goto out;
1120 }
1121
Joel Becker84efad12006-03-27 18:46:09 -08001122 if (!(sd->s_type & CONFIGFS_USET_DIR)) {
1123 ret = -EPERM;
1124 goto out;
1125 }
Joel Becker7063fbf2005-12-15 14:29:43 -08001126
Joel Becker84efad12006-03-27 18:46:09 -08001127 /* Get a working ref for the duration of this function */
Joel Becker7063fbf2005-12-15 14:29:43 -08001128 parent_item = configfs_get_config_item(dentry->d_parent);
1129 type = parent_item->ci_type;
1130 subsys = to_config_group(parent_item)->cg_subsys;
1131 BUG_ON(!subsys);
1132
1133 if (!type || !type->ct_group_ops ||
1134 (!type->ct_group_ops->make_group &&
1135 !type->ct_group_ops->make_item)) {
Joel Becker84efad12006-03-27 18:46:09 -08001136 ret = -EPERM; /* Lack-of-mkdir returns -EPERM */
1137 goto out_put;
Joel Becker7063fbf2005-12-15 14:29:43 -08001138 }
1139
Joel Becker70526b62008-06-17 15:34:32 -07001140 /*
1141 * The subsystem may belong to a different module than the item
1142 * being created. We don't want to safely pin the new item but
1143 * fail to pin the subsystem it sits under.
1144 */
1145 if (!subsys->su_group.cg_item.ci_type) {
1146 ret = -EINVAL;
1147 goto out_put;
1148 }
1149 subsys_owner = subsys->su_group.cg_item.ci_type->ct_owner;
1150 if (!try_module_get(subsys_owner)) {
1151 ret = -EINVAL;
1152 goto out_put;
1153 }
1154
Joel Becker7063fbf2005-12-15 14:29:43 -08001155 name = kmalloc(dentry->d_name.len + 1, GFP_KERNEL);
1156 if (!name) {
Joel Becker84efad12006-03-27 18:46:09 -08001157 ret = -ENOMEM;
Joel Becker70526b62008-06-17 15:34:32 -07001158 goto out_subsys_put;
Joel Becker7063fbf2005-12-15 14:29:43 -08001159 }
Joel Becker84efad12006-03-27 18:46:09 -08001160
Joel Becker7063fbf2005-12-15 14:29:43 -08001161 snprintf(name, dentry->d_name.len + 1, "%s", dentry->d_name.name);
1162
Joel Beckere6bd07a2007-07-06 23:33:17 -07001163 mutex_lock(&subsys->su_mutex);
Joel Becker7063fbf2005-12-15 14:29:43 -08001164 if (type->ct_group_ops->make_group) {
Joel Beckerf89ab862008-07-17 14:53:48 -07001165 group = type->ct_group_ops->make_group(to_config_group(parent_item), name);
Joel Beckera6795e92008-07-17 15:21:29 -07001166 if (!group)
1167 group = ERR_PTR(-ENOMEM);
1168 if (!IS_ERR(group)) {
Joel Becker7063fbf2005-12-15 14:29:43 -08001169 link_group(to_config_group(parent_item), group);
1170 item = &group->cg_item;
Joel Beckera6795e92008-07-17 15:21:29 -07001171 } else
1172 ret = PTR_ERR(group);
Joel Becker7063fbf2005-12-15 14:29:43 -08001173 } else {
Joel Beckerf89ab862008-07-17 14:53:48 -07001174 item = type->ct_group_ops->make_item(to_config_group(parent_item), name);
Joel Beckera6795e92008-07-17 15:21:29 -07001175 if (!item)
1176 item = ERR_PTR(-ENOMEM);
1177 if (!IS_ERR(item))
Joel Becker7063fbf2005-12-15 14:29:43 -08001178 link_obj(parent_item, item);
Joel Beckera6795e92008-07-17 15:21:29 -07001179 else
1180 ret = PTR_ERR(item);
Joel Becker7063fbf2005-12-15 14:29:43 -08001181 }
Joel Beckere6bd07a2007-07-06 23:33:17 -07001182 mutex_unlock(&subsys->su_mutex);
Joel Becker7063fbf2005-12-15 14:29:43 -08001183
1184 kfree(name);
Joel Beckera6795e92008-07-17 15:21:29 -07001185 if (ret) {
Joel Beckereed7a0d2006-04-11 21:37:20 -07001186 /*
Joel Beckerdacdd0e2008-07-17 16:54:19 -07001187 * If ret != 0, then link_obj() was never called.
Joel Beckereed7a0d2006-04-11 21:37:20 -07001188 * There are no extra references to clean up.
1189 */
Joel Becker70526b62008-06-17 15:34:32 -07001190 goto out_subsys_put;
Joel Becker7063fbf2005-12-15 14:29:43 -08001191 }
1192
Joel Beckereed7a0d2006-04-11 21:37:20 -07001193 /*
1194 * link_obj() has been called (via link_group() for groups).
1195 * From here on out, errors must clean that up.
1196 */
1197
Joel Becker7063fbf2005-12-15 14:29:43 -08001198 type = item->ci_type;
Joel Beckereed7a0d2006-04-11 21:37:20 -07001199 if (!type) {
1200 ret = -EINVAL;
1201 goto out_unlink;
1202 }
Joel Becker7063fbf2005-12-15 14:29:43 -08001203
Joel Becker70526b62008-06-17 15:34:32 -07001204 new_item_owner = type->ct_owner;
1205 if (!try_module_get(new_item_owner)) {
Joel Beckereed7a0d2006-04-11 21:37:20 -07001206 ret = -EINVAL;
1207 goto out_unlink;
1208 }
Joel Becker7063fbf2005-12-15 14:29:43 -08001209
Joel Beckereed7a0d2006-04-11 21:37:20 -07001210 /*
1211 * I hate doing it this way, but if there is
1212 * an error, module_put() probably should
1213 * happen after any cleanup.
1214 */
1215 module_got = 1;
1216
Louis Rilling6d8344b2008-06-16 19:01:02 +02001217 /*
1218 * Make racing rmdir() fail if it did not tag parent with
1219 * CONFIGFS_USET_DROPPING
1220 * Note: if CONFIGFS_USET_DROPPING is already set, attach_group() will
1221 * fail and let rmdir() terminate correctly
1222 */
1223 spin_lock(&configfs_dirent_lock);
1224 /* This will make configfs_detach_prep() fail */
1225 sd->s_type |= CONFIGFS_USET_IN_MKDIR;
1226 spin_unlock(&configfs_dirent_lock);
1227
Joel Beckereed7a0d2006-04-11 21:37:20 -07001228 if (group)
1229 ret = configfs_attach_group(parent_item, item, dentry);
1230 else
1231 ret = configfs_attach_item(parent_item, item, dentry);
1232
Louis Rilling6d8344b2008-06-16 19:01:02 +02001233 spin_lock(&configfs_dirent_lock);
1234 sd->s_type &= ~CONFIGFS_USET_IN_MKDIR;
Louis Rilling2a109f22008-07-04 16:56:05 +02001235 if (!ret)
1236 configfs_dir_set_ready(dentry->d_fsdata);
Louis Rilling6d8344b2008-06-16 19:01:02 +02001237 spin_unlock(&configfs_dirent_lock);
1238
Joel Beckereed7a0d2006-04-11 21:37:20 -07001239out_unlink:
1240 if (ret) {
1241 /* Tear down everything we built up */
Joel Beckere6bd07a2007-07-06 23:33:17 -07001242 mutex_lock(&subsys->su_mutex);
Joel Becker299894c2006-10-06 17:33:23 -07001243
1244 client_disconnect_notify(parent_item, item);
Joel Beckereed7a0d2006-04-11 21:37:20 -07001245 if (group)
1246 unlink_group(group);
1247 else
1248 unlink_obj(item);
1249 client_drop_item(parent_item, item);
Joel Becker299894c2006-10-06 17:33:23 -07001250
Joel Beckere6bd07a2007-07-06 23:33:17 -07001251 mutex_unlock(&subsys->su_mutex);
Joel Beckereed7a0d2006-04-11 21:37:20 -07001252
1253 if (module_got)
Joel Becker70526b62008-06-17 15:34:32 -07001254 module_put(new_item_owner);
Joel Becker7063fbf2005-12-15 14:29:43 -08001255 }
1256
Joel Becker70526b62008-06-17 15:34:32 -07001257out_subsys_put:
1258 if (ret)
1259 module_put(subsys_owner);
1260
Joel Becker84efad12006-03-27 18:46:09 -08001261out_put:
1262 /*
Joel Beckereed7a0d2006-04-11 21:37:20 -07001263 * link_obj()/link_group() took a reference from child->parent,
1264 * so the parent is safely pinned. We can drop our working
1265 * reference.
Joel Becker84efad12006-03-27 18:46:09 -08001266 */
1267 config_item_put(parent_item);
1268
1269out:
Joel Becker7063fbf2005-12-15 14:29:43 -08001270 return ret;
1271}
1272
1273static int configfs_rmdir(struct inode *dir, struct dentry *dentry)
1274{
1275 struct config_item *parent_item;
1276 struct config_item *item;
1277 struct configfs_subsystem *subsys;
1278 struct configfs_dirent *sd;
Joel Becker70526b62008-06-17 15:34:32 -07001279 struct module *subsys_owner = NULL, *dead_item_owner = NULL;
Joel Becker7063fbf2005-12-15 14:29:43 -08001280 int ret;
1281
1282 if (dentry->d_parent == configfs_sb->s_root)
1283 return -EPERM;
1284
1285 sd = dentry->d_fsdata;
1286 if (sd->s_type & CONFIGFS_USET_DEFAULT)
1287 return -EPERM;
1288
Joel Becker631d1fe2007-06-18 18:06:09 -07001289 /*
1290 * Here's where we check for dependents. We're protected by
1291 * i_mutex.
1292 */
1293 if (sd->s_dependent_count)
1294 return -EBUSY;
1295
Joel Becker84efad12006-03-27 18:46:09 -08001296 /* Get a working ref until we have the child */
Joel Becker7063fbf2005-12-15 14:29:43 -08001297 parent_item = configfs_get_config_item(dentry->d_parent);
1298 subsys = to_config_group(parent_item)->cg_subsys;
1299 BUG_ON(!subsys);
1300
1301 if (!parent_item->ci_type) {
1302 config_item_put(parent_item);
1303 return -EINVAL;
1304 }
1305
Joel Becker70526b62008-06-17 15:34:32 -07001306 /* configfs_mkdir() shouldn't have allowed this */
1307 BUG_ON(!subsys->su_group.cg_item.ci_type);
1308 subsys_owner = subsys->su_group.cg_item.ci_type->ct_owner;
1309
Louis Rilling9a73d782008-06-20 14:09:22 +02001310 /*
1311 * Ensure that no racing symlink() will make detach_prep() fail while
1312 * the new link is temporarily attached
1313 */
Louis Rilling6d8344b2008-06-16 19:01:02 +02001314 do {
1315 struct mutex *wait_mutex;
1316
Louis Rillingde6bf182008-08-15 12:37:23 -07001317 mutex_lock(&configfs_symlink_mutex);
1318 spin_lock(&configfs_dirent_lock);
Louis Rilling6d8344b2008-06-16 19:01:02 +02001319 ret = configfs_detach_prep(dentry, &wait_mutex);
Louis Rillingde6bf182008-08-15 12:37:23 -07001320 if (ret)
Louis Rilling6d8344b2008-06-16 19:01:02 +02001321 configfs_detach_rollback(dentry);
Louis Rillingde6bf182008-08-15 12:37:23 -07001322 spin_unlock(&configfs_dirent_lock);
1323 mutex_unlock(&configfs_symlink_mutex);
1324
1325 if (ret) {
Louis Rilling6d8344b2008-06-16 19:01:02 +02001326 if (ret != -EAGAIN) {
1327 config_item_put(parent_item);
1328 return ret;
1329 }
1330
1331 /* Wait until the racing operation terminates */
1332 mutex_lock(wait_mutex);
1333 mutex_unlock(wait_mutex);
Louis Rilling6d8344b2008-06-16 19:01:02 +02001334 }
1335 } while (ret == -EAGAIN);
Joel Becker7063fbf2005-12-15 14:29:43 -08001336
Joel Becker84efad12006-03-27 18:46:09 -08001337 /* Get a working ref for the duration of this function */
Joel Becker7063fbf2005-12-15 14:29:43 -08001338 item = configfs_get_config_item(dentry);
1339
1340 /* Drop reference from above, item already holds one. */
1341 config_item_put(parent_item);
1342
1343 if (item->ci_type)
Joel Becker70526b62008-06-17 15:34:32 -07001344 dead_item_owner = item->ci_type->ct_owner;
Joel Becker7063fbf2005-12-15 14:29:43 -08001345
1346 if (sd->s_type & CONFIGFS_USET_DIR) {
1347 configfs_detach_group(item);
1348
Joel Beckere6bd07a2007-07-06 23:33:17 -07001349 mutex_lock(&subsys->su_mutex);
Joel Becker299894c2006-10-06 17:33:23 -07001350 client_disconnect_notify(parent_item, item);
Joel Becker7063fbf2005-12-15 14:29:43 -08001351 unlink_group(to_config_group(item));
1352 } else {
1353 configfs_detach_item(item);
1354
Joel Beckere6bd07a2007-07-06 23:33:17 -07001355 mutex_lock(&subsys->su_mutex);
Joel Becker299894c2006-10-06 17:33:23 -07001356 client_disconnect_notify(parent_item, item);
Joel Becker7063fbf2005-12-15 14:29:43 -08001357 unlink_obj(item);
1358 }
1359
1360 client_drop_item(parent_item, item);
Joel Beckere6bd07a2007-07-06 23:33:17 -07001361 mutex_unlock(&subsys->su_mutex);
Joel Becker7063fbf2005-12-15 14:29:43 -08001362
1363 /* Drop our reference from above */
1364 config_item_put(item);
1365
Joel Becker70526b62008-06-17 15:34:32 -07001366 module_put(dead_item_owner);
1367 module_put(subsys_owner);
Joel Becker7063fbf2005-12-15 14:29:43 -08001368
1369 return 0;
1370}
1371
Arjan van de Ven754661f2007-02-12 00:55:38 -08001372const struct inode_operations configfs_dir_inode_operations = {
Joel Becker7063fbf2005-12-15 14:29:43 -08001373 .mkdir = configfs_mkdir,
1374 .rmdir = configfs_rmdir,
1375 .symlink = configfs_symlink,
1376 .unlink = configfs_unlink,
1377 .lookup = configfs_lookup,
Joel Becker3d0f89b2006-01-25 13:31:07 -08001378 .setattr = configfs_setattr,
Joel Becker7063fbf2005-12-15 14:29:43 -08001379};
1380
1381#if 0
1382int configfs_rename_dir(struct config_item * item, const char *new_name)
1383{
1384 int error = 0;
1385 struct dentry * new_dentry, * parent;
1386
1387 if (!strcmp(config_item_name(item), new_name))
1388 return -EINVAL;
1389
1390 if (!item->parent)
1391 return -EINVAL;
1392
1393 down_write(&configfs_rename_sem);
1394 parent = item->parent->dentry;
1395
Jes Sorensen1b1dcc12006-01-09 15:59:24 -08001396 mutex_lock(&parent->d_inode->i_mutex);
Joel Becker7063fbf2005-12-15 14:29:43 -08001397
1398 new_dentry = lookup_one_len(new_name, parent, strlen(new_name));
1399 if (!IS_ERR(new_dentry)) {
Joel Beckere7515d02006-03-10 11:42:30 -08001400 if (!new_dentry->d_inode) {
Joel Becker7063fbf2005-12-15 14:29:43 -08001401 error = config_item_set_name(item, "%s", new_name);
1402 if (!error) {
1403 d_add(new_dentry, NULL);
1404 d_move(item->dentry, new_dentry);
1405 }
1406 else
1407 d_delete(new_dentry);
1408 } else
1409 error = -EEXIST;
1410 dput(new_dentry);
1411 }
Jes Sorensen1b1dcc12006-01-09 15:59:24 -08001412 mutex_unlock(&parent->d_inode->i_mutex);
Joel Becker7063fbf2005-12-15 14:29:43 -08001413 up_write(&configfs_rename_sem);
1414
1415 return error;
1416}
1417#endif
1418
1419static int configfs_dir_open(struct inode *inode, struct file *file)
1420{
Josef "Jeff" Sipek867fa492006-12-08 02:36:47 -08001421 struct dentry * dentry = file->f_path.dentry;
Joel Becker7063fbf2005-12-15 14:29:43 -08001422 struct configfs_dirent * parent_sd = dentry->d_fsdata;
Louis Rilling2a109f22008-07-04 16:56:05 +02001423 int err;
Joel Becker7063fbf2005-12-15 14:29:43 -08001424
Jes Sorensen1b1dcc12006-01-09 15:59:24 -08001425 mutex_lock(&dentry->d_inode->i_mutex);
Louis Rilling2a109f22008-07-04 16:56:05 +02001426 /*
1427 * Fake invisibility if dir belongs to a group/default groups hierarchy
1428 * being attached
1429 */
1430 err = -ENOENT;
1431 if (configfs_dirent_is_ready(parent_sd)) {
1432 file->private_data = configfs_new_dirent(parent_sd, NULL);
1433 if (IS_ERR(file->private_data))
1434 err = PTR_ERR(file->private_data);
1435 else
1436 err = 0;
1437 }
Jes Sorensen1b1dcc12006-01-09 15:59:24 -08001438 mutex_unlock(&dentry->d_inode->i_mutex);
Joel Becker7063fbf2005-12-15 14:29:43 -08001439
Louis Rilling2a109f22008-07-04 16:56:05 +02001440 return err;
Joel Becker7063fbf2005-12-15 14:29:43 -08001441}
1442
1443static int configfs_dir_close(struct inode *inode, struct file *file)
1444{
Josef "Jeff" Sipek867fa492006-12-08 02:36:47 -08001445 struct dentry * dentry = file->f_path.dentry;
Joel Becker7063fbf2005-12-15 14:29:43 -08001446 struct configfs_dirent * cursor = file->private_data;
1447
Jes Sorensen1b1dcc12006-01-09 15:59:24 -08001448 mutex_lock(&dentry->d_inode->i_mutex);
Louis Rilling6f610762008-06-16 19:00:58 +02001449 spin_lock(&configfs_dirent_lock);
Joel Becker7063fbf2005-12-15 14:29:43 -08001450 list_del_init(&cursor->s_sibling);
Louis Rilling6f610762008-06-16 19:00:58 +02001451 spin_unlock(&configfs_dirent_lock);
Jes Sorensen1b1dcc12006-01-09 15:59:24 -08001452 mutex_unlock(&dentry->d_inode->i_mutex);
Joel Becker7063fbf2005-12-15 14:29:43 -08001453
1454 release_configfs_dirent(cursor);
1455
1456 return 0;
1457}
1458
1459/* Relationship between s_mode and the DT_xxx types */
1460static inline unsigned char dt_type(struct configfs_dirent *sd)
1461{
1462 return (sd->s_mode >> 12) & 15;
1463}
1464
1465static int configfs_readdir(struct file * filp, void * dirent, filldir_t filldir)
1466{
Josef "Jeff" Sipek867fa492006-12-08 02:36:47 -08001467 struct dentry *dentry = filp->f_path.dentry;
Joel Becker7063fbf2005-12-15 14:29:43 -08001468 struct configfs_dirent * parent_sd = dentry->d_fsdata;
1469 struct configfs_dirent *cursor = filp->private_data;
1470 struct list_head *p, *q = &cursor->s_sibling;
1471 ino_t ino;
1472 int i = filp->f_pos;
1473
1474 switch (i) {
1475 case 0:
1476 ino = dentry->d_inode->i_ino;
1477 if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0)
1478 break;
1479 filp->f_pos++;
1480 i++;
1481 /* fallthrough */
1482 case 1:
1483 ino = parent_ino(dentry);
1484 if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0)
1485 break;
1486 filp->f_pos++;
1487 i++;
1488 /* fallthrough */
1489 default:
1490 if (filp->f_pos == 2) {
Louis Rilling6f610762008-06-16 19:00:58 +02001491 spin_lock(&configfs_dirent_lock);
Akinobu Mitaf1166292006-06-26 00:24:46 -07001492 list_move(q, &parent_sd->s_children);
Louis Rilling6f610762008-06-16 19:00:58 +02001493 spin_unlock(&configfs_dirent_lock);
Joel Becker7063fbf2005-12-15 14:29:43 -08001494 }
1495 for (p=q->next; p!= &parent_sd->s_children; p=p->next) {
1496 struct configfs_dirent *next;
1497 const char * name;
1498 int len;
1499
1500 next = list_entry(p, struct configfs_dirent,
1501 s_sibling);
1502 if (!next->s_element)
1503 continue;
1504
1505 name = configfs_get_name(next);
1506 len = strlen(name);
1507 if (next->s_dentry)
1508 ino = next->s_dentry->d_inode->i_ino;
1509 else
1510 ino = iunique(configfs_sb, 2);
1511
1512 if (filldir(dirent, name, len, filp->f_pos, ino,
1513 dt_type(next)) < 0)
1514 return 0;
1515
Louis Rilling6f610762008-06-16 19:00:58 +02001516 spin_lock(&configfs_dirent_lock);
Akinobu Mitaf1166292006-06-26 00:24:46 -07001517 list_move(q, p);
Louis Rilling6f610762008-06-16 19:00:58 +02001518 spin_unlock(&configfs_dirent_lock);
Joel Becker7063fbf2005-12-15 14:29:43 -08001519 p = q;
1520 filp->f_pos++;
1521 }
1522 }
1523 return 0;
1524}
1525
1526static loff_t configfs_dir_lseek(struct file * file, loff_t offset, int origin)
1527{
Josef "Jeff" Sipek867fa492006-12-08 02:36:47 -08001528 struct dentry * dentry = file->f_path.dentry;
Joel Becker7063fbf2005-12-15 14:29:43 -08001529
Jes Sorensen1b1dcc12006-01-09 15:59:24 -08001530 mutex_lock(&dentry->d_inode->i_mutex);
Joel Becker7063fbf2005-12-15 14:29:43 -08001531 switch (origin) {
1532 case 1:
1533 offset += file->f_pos;
1534 case 0:
1535 if (offset >= 0)
1536 break;
1537 default:
Josef "Jeff" Sipek867fa492006-12-08 02:36:47 -08001538 mutex_unlock(&file->f_path.dentry->d_inode->i_mutex);
Joel Becker7063fbf2005-12-15 14:29:43 -08001539 return -EINVAL;
1540 }
1541 if (offset != file->f_pos) {
1542 file->f_pos = offset;
1543 if (file->f_pos >= 2) {
1544 struct configfs_dirent *sd = dentry->d_fsdata;
1545 struct configfs_dirent *cursor = file->private_data;
1546 struct list_head *p;
1547 loff_t n = file->f_pos - 2;
1548
Louis Rilling6f610762008-06-16 19:00:58 +02001549 spin_lock(&configfs_dirent_lock);
Joel Becker7063fbf2005-12-15 14:29:43 -08001550 list_del(&cursor->s_sibling);
1551 p = sd->s_children.next;
1552 while (n && p != &sd->s_children) {
1553 struct configfs_dirent *next;
1554 next = list_entry(p, struct configfs_dirent,
1555 s_sibling);
1556 if (next->s_element)
1557 n--;
1558 p = p->next;
1559 }
1560 list_add_tail(&cursor->s_sibling, p);
Louis Rilling6f610762008-06-16 19:00:58 +02001561 spin_unlock(&configfs_dirent_lock);
Joel Becker7063fbf2005-12-15 14:29:43 -08001562 }
1563 }
Jes Sorensen1b1dcc12006-01-09 15:59:24 -08001564 mutex_unlock(&dentry->d_inode->i_mutex);
Joel Becker7063fbf2005-12-15 14:29:43 -08001565 return offset;
1566}
1567
Arjan van de Ven4b6f5d22006-03-28 01:56:42 -08001568const struct file_operations configfs_dir_operations = {
Joel Becker7063fbf2005-12-15 14:29:43 -08001569 .open = configfs_dir_open,
1570 .release = configfs_dir_close,
1571 .llseek = configfs_dir_lseek,
1572 .read = generic_read_dir,
1573 .readdir = configfs_readdir,
1574};
1575
1576int configfs_register_subsystem(struct configfs_subsystem *subsys)
1577{
1578 int err;
1579 struct config_group *group = &subsys->su_group;
1580 struct qstr name;
1581 struct dentry *dentry;
1582 struct configfs_dirent *sd;
1583
1584 err = configfs_pin_fs();
1585 if (err)
1586 return err;
1587
1588 if (!group->cg_item.ci_name)
1589 group->cg_item.ci_name = group->cg_item.ci_namebuf;
1590
1591 sd = configfs_sb->s_root->d_fsdata;
1592 link_group(to_config_group(sd->s_element), group);
1593
Joonwoo Parkba611ed2007-12-26 12:09:57 +09001594 mutex_lock_nested(&configfs_sb->s_root->d_inode->i_mutex,
1595 I_MUTEX_PARENT);
Joel Becker7063fbf2005-12-15 14:29:43 -08001596
1597 name.name = group->cg_item.ci_name;
1598 name.len = strlen(name.name);
1599 name.hash = full_name_hash(name.name, name.len);
1600
1601 err = -ENOMEM;
1602 dentry = d_alloc(configfs_sb->s_root, &name);
Joel Beckerafdf04e2007-03-05 15:49:49 -08001603 if (dentry) {
1604 d_add(dentry, NULL);
Joel Becker7063fbf2005-12-15 14:29:43 -08001605
Joel Beckerafdf04e2007-03-05 15:49:49 -08001606 err = configfs_attach_group(sd->s_element, &group->cg_item,
1607 dentry);
1608 if (err) {
1609 d_delete(dentry);
1610 dput(dentry);
Louis Rilling2a109f22008-07-04 16:56:05 +02001611 } else {
1612 spin_lock(&configfs_dirent_lock);
1613 configfs_dir_set_ready(dentry->d_fsdata);
1614 spin_unlock(&configfs_dirent_lock);
Joel Beckerafdf04e2007-03-05 15:49:49 -08001615 }
1616 }
Joel Becker7063fbf2005-12-15 14:29:43 -08001617
Jes Sorensen1b1dcc12006-01-09 15:59:24 -08001618 mutex_unlock(&configfs_sb->s_root->d_inode->i_mutex);
Joel Becker7063fbf2005-12-15 14:29:43 -08001619
Joel Beckerafdf04e2007-03-05 15:49:49 -08001620 if (err) {
1621 unlink_group(group);
1622 configfs_release_fs();
Joel Becker7063fbf2005-12-15 14:29:43 -08001623 }
1624
1625 return err;
1626}
1627
1628void configfs_unregister_subsystem(struct configfs_subsystem *subsys)
1629{
1630 struct config_group *group = &subsys->su_group;
1631 struct dentry *dentry = group->cg_item.ci_dentry;
1632
1633 if (dentry->d_parent != configfs_sb->s_root) {
1634 printk(KERN_ERR "configfs: Tried to unregister non-subsystem!\n");
1635 return;
1636 }
1637
Mark Fasheh55ed1602006-10-20 14:55:54 -07001638 mutex_lock_nested(&configfs_sb->s_root->d_inode->i_mutex,
1639 I_MUTEX_PARENT);
1640 mutex_lock_nested(&dentry->d_inode->i_mutex, I_MUTEX_CHILD);
Louis Rilling9a73d782008-06-20 14:09:22 +02001641 mutex_lock(&configfs_symlink_mutex);
Louis Rillingb3e76af2008-06-16 19:01:01 +02001642 spin_lock(&configfs_dirent_lock);
Louis Rilling6d8344b2008-06-16 19:01:02 +02001643 if (configfs_detach_prep(dentry, NULL)) {
Joel Becker7063fbf2005-12-15 14:29:43 -08001644 printk(KERN_ERR "configfs: Tried to unregister non-empty subsystem!\n");
1645 }
Louis Rillingb3e76af2008-06-16 19:01:01 +02001646 spin_unlock(&configfs_dirent_lock);
Louis Rilling9a73d782008-06-20 14:09:22 +02001647 mutex_unlock(&configfs_symlink_mutex);
Joel Becker7063fbf2005-12-15 14:29:43 -08001648 configfs_detach_group(&group->cg_item);
1649 dentry->d_inode->i_flags |= S_DEAD;
Jes Sorensen1b1dcc12006-01-09 15:59:24 -08001650 mutex_unlock(&dentry->d_inode->i_mutex);
Joel Becker7063fbf2005-12-15 14:29:43 -08001651
1652 d_delete(dentry);
1653
Jes Sorensen1b1dcc12006-01-09 15:59:24 -08001654 mutex_unlock(&configfs_sb->s_root->d_inode->i_mutex);
Joel Becker7063fbf2005-12-15 14:29:43 -08001655
1656 dput(dentry);
1657
1658 unlink_group(group);
1659 configfs_release_fs();
1660}
1661
1662EXPORT_SYMBOL(configfs_register_subsystem);
1663EXPORT_SYMBOL(configfs_unregister_subsystem);