blob: 452cfd1e785fd5b7304edc5472da66fde52f424e [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>
33
34#include <linux/configfs.h>
35#include "configfs_internal.h"
36
37DECLARE_RWSEM(configfs_rename_sem);
38
39static 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 */
56static int configfs_d_delete(struct dentry *dentry)
57{
58 return 1;
59}
60
61static 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 */
70static struct configfs_dirent *configfs_new_dirent(struct configfs_dirent * parent_sd,
71 void * element)
72{
73 struct configfs_dirent * sd;
74
Joel Becker3d0f89b2006-01-25 13:31:07 -080075 sd = kmem_cache_alloc(configfs_dir_cachep, GFP_KERNEL);
Joel Becker7063fbf2005-12-15 14:29:43 -080076 if (!sd)
77 return NULL;
78
79 memset(sd, 0, sizeof(*sd));
80 atomic_set(&sd->s_count, 1);
81 INIT_LIST_HEAD(&sd->s_links);
82 INIT_LIST_HEAD(&sd->s_children);
83 list_add(&sd->s_sibling, &parent_sd->s_children);
84 sd->s_element = element;
85
86 return sd;
87}
88
Joel Beckerb4c98f62006-09-13 11:01:19 -070089/*
90 *
91 * Return -EEXIST if there is already a configfs element with the same
92 * name for the same parent.
93 *
94 * called with parent inode's i_mutex held
95 */
96int configfs_dirent_exists(struct configfs_dirent *parent_sd,
97 const unsigned char *new)
98{
99 struct configfs_dirent * sd;
100
101 list_for_each_entry(sd, &parent_sd->s_children, s_sibling) {
102 if (sd->s_element) {
103 const unsigned char *existing = configfs_get_name(sd);
104 if (strcmp(existing, new))
105 continue;
106 else
107 return -EEXIST;
108 }
109 }
110
111 return 0;
112}
113
114
Joel Becker7063fbf2005-12-15 14:29:43 -0800115int configfs_make_dirent(struct configfs_dirent * parent_sd,
116 struct dentry * dentry, void * element,
117 umode_t mode, int type)
118{
119 struct configfs_dirent * sd;
120
121 sd = configfs_new_dirent(parent_sd, element);
122 if (!sd)
123 return -ENOMEM;
124
125 sd->s_mode = mode;
126 sd->s_type = type;
127 sd->s_dentry = dentry;
128 if (dentry) {
129 dentry->d_fsdata = configfs_get(sd);
130 dentry->d_op = &configfs_dentry_ops;
131 }
132
133 return 0;
134}
135
136static int init_dir(struct inode * inode)
137{
138 inode->i_op = &configfs_dir_inode_operations;
139 inode->i_fop = &configfs_dir_operations;
140
141 /* directory inodes start off with i_nlink == 2 (for "." entry) */
Dave Hansend8c76e62006-09-30 23:29:04 -0700142 inc_nlink(inode);
Joel Becker7063fbf2005-12-15 14:29:43 -0800143 return 0;
144}
145
146static int init_file(struct inode * inode)
147{
148 inode->i_size = PAGE_SIZE;
149 inode->i_fop = &configfs_file_operations;
150 return 0;
151}
152
153static int init_symlink(struct inode * inode)
154{
155 inode->i_op = &configfs_symlink_inode_operations;
156 return 0;
157}
158
159static int create_dir(struct config_item * k, struct dentry * p,
160 struct dentry * d)
161{
162 int error;
163 umode_t mode = S_IFDIR| S_IRWXU | S_IRUGO | S_IXUGO;
164
Joel Beckerb4c98f62006-09-13 11:01:19 -0700165 error = configfs_dirent_exists(p->d_fsdata, d->d_name.name);
166 if (!error)
167 error = configfs_make_dirent(p->d_fsdata, d, k, mode,
168 CONFIGFS_DIR);
Joel Becker7063fbf2005-12-15 14:29:43 -0800169 if (!error) {
Joel Becker3d0f89b2006-01-25 13:31:07 -0800170 error = configfs_create(d, mode, init_dir);
Joel Becker7063fbf2005-12-15 14:29:43 -0800171 if (!error) {
Dave Hansend8c76e62006-09-30 23:29:04 -0700172 inc_nlink(p->d_inode);
Joel Becker7063fbf2005-12-15 14:29:43 -0800173 (d)->d_op = &configfs_dentry_ops;
Joel Becker3d0f89b2006-01-25 13:31:07 -0800174 } else {
175 struct configfs_dirent *sd = d->d_fsdata;
176 if (sd) {
177 list_del_init(&sd->s_sibling);
178 configfs_put(sd);
179 }
Joel Becker7063fbf2005-12-15 14:29:43 -0800180 }
181 }
182 return error;
183}
184
185
186/**
187 * configfs_create_dir - create a directory for an config_item.
188 * @item: config_itemwe're creating directory for.
189 * @dentry: config_item's dentry.
190 */
191
192static int configfs_create_dir(struct config_item * item, struct dentry *dentry)
193{
194 struct dentry * parent;
195 int error = 0;
196
197 BUG_ON(!item);
198
199 if (item->ci_parent)
200 parent = item->ci_parent->ci_dentry;
201 else if (configfs_mount && configfs_mount->mnt_sb)
202 parent = configfs_mount->mnt_sb->s_root;
203 else
204 return -EFAULT;
205
206 error = create_dir(item,parent,dentry);
207 if (!error)
208 item->ci_dentry = dentry;
209 return error;
210}
211
212int configfs_create_link(struct configfs_symlink *sl,
213 struct dentry *parent,
214 struct dentry *dentry)
215{
216 int err = 0;
217 umode_t mode = S_IFLNK | S_IRWXUGO;
218
Joel Becker3d0f89b2006-01-25 13:31:07 -0800219 err = configfs_make_dirent(parent->d_fsdata, dentry, sl, mode,
220 CONFIGFS_ITEM_LINK);
Joel Becker7063fbf2005-12-15 14:29:43 -0800221 if (!err) {
Joel Becker3d0f89b2006-01-25 13:31:07 -0800222 err = configfs_create(dentry, mode, init_symlink);
Joel Becker7063fbf2005-12-15 14:29:43 -0800223 if (!err)
224 dentry->d_op = &configfs_dentry_ops;
Joel Becker3d0f89b2006-01-25 13:31:07 -0800225 else {
226 struct configfs_dirent *sd = dentry->d_fsdata;
227 if (sd) {
228 list_del_init(&sd->s_sibling);
229 configfs_put(sd);
230 }
231 }
Joel Becker7063fbf2005-12-15 14:29:43 -0800232 }
233 return err;
234}
235
236static void remove_dir(struct dentry * d)
237{
238 struct dentry * parent = dget(d->d_parent);
239 struct configfs_dirent * sd;
240
241 sd = d->d_fsdata;
Joel Beckere7515d02006-03-10 11:42:30 -0800242 list_del_init(&sd->s_sibling);
Joel Becker7063fbf2005-12-15 14:29:43 -0800243 configfs_put(sd);
244 if (d->d_inode)
245 simple_rmdir(parent->d_inode,d);
246
247 pr_debug(" o %s removing done (%d)\n",d->d_name.name,
248 atomic_read(&d->d_count));
249
250 dput(parent);
251}
252
253/**
254 * configfs_remove_dir - remove an config_item's directory.
255 * @item: config_item we're removing.
256 *
257 * The only thing special about this is that we remove any files in
258 * the directory before we remove the directory, and we've inlined
259 * what used to be configfs_rmdir() below, instead of calling separately.
260 */
261
262static void configfs_remove_dir(struct config_item * item)
263{
264 struct dentry * dentry = dget(item->ci_dentry);
265
266 if (!dentry)
267 return;
268
269 remove_dir(dentry);
270 /**
271 * Drop reference from dget() on entrance.
272 */
273 dput(dentry);
274}
275
276
277/* attaches attribute's configfs_dirent to the dentry corresponding to the
278 * attribute file
279 */
280static int configfs_attach_attr(struct configfs_dirent * sd, struct dentry * dentry)
281{
282 struct configfs_attribute * attr = sd->s_element;
283 int error;
284
Joel Becker7063fbf2005-12-15 14:29:43 -0800285 dentry->d_fsdata = configfs_get(sd);
286 sd->s_dentry = dentry;
Joel Becker3d0f89b2006-01-25 13:31:07 -0800287 error = configfs_create(dentry, (attr->ca_mode & S_IALLUGO) | S_IFREG, init_file);
288 if (error) {
289 configfs_put(sd);
290 return error;
291 }
292
293 dentry->d_op = &configfs_dentry_ops;
Joel Becker7063fbf2005-12-15 14:29:43 -0800294 d_rehash(dentry);
295
296 return 0;
297}
298
299static 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
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800334 * attributes and are removed by rmdir(). We recurse, taking i_mutex
Joel Becker7063fbf2005-12-15 14:29:43 -0800335 * on all children that are candidates for default detach. If the
336 * result is clean, then configfs_detach_group() will handle dropping
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800337 * i_mutex. If there is an error, the caller will clean up the i_mutex
Joel Becker7063fbf2005-12-15 14:29:43 -0800338 * holders via configfs_detach_rollback().
339 */
340static 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) {
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800355 mutex_lock(&sd->s_dentry->d_inode->i_mutex);
356 /* Mark that we've taken i_mutex */
Joel Becker7063fbf2005-12-15 14:29:43 -0800357 sd->s_type |= CONFIGFS_USET_DROPPING;
358
359 ret = configfs_detach_prep(sd->s_dentry);
360 if (!ret)
Joel Beckere7515d02006-03-10 11:42:30 -0800361 continue;
Joel Becker7063fbf2005-12-15 14:29:43 -0800362 } else
363 ret = -ENOTEMPTY;
364
365 break;
366 }
367
368out:
369 return ret;
370}
371
372/*
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800373 * Walk the tree, dropping i_mutex wherever CONFIGFS_USET_DROPPING is
Joel Becker7063fbf2005-12-15 14:29:43 -0800374 * set.
375 */
376static void configfs_detach_rollback(struct dentry *dentry)
377{
378 struct configfs_dirent *parent_sd = dentry->d_fsdata;
379 struct configfs_dirent *sd;
380
381 list_for_each_entry(sd, &parent_sd->s_children, s_sibling) {
382 if (sd->s_type & CONFIGFS_USET_DEFAULT) {
383 configfs_detach_rollback(sd->s_dentry);
384
385 if (sd->s_type & CONFIGFS_USET_DROPPING) {
386 sd->s_type &= ~CONFIGFS_USET_DROPPING;
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800387 mutex_unlock(&sd->s_dentry->d_inode->i_mutex);
Joel Becker7063fbf2005-12-15 14:29:43 -0800388 }
389 }
390 }
391}
392
393static void detach_attrs(struct config_item * item)
394{
395 struct dentry * dentry = dget(item->ci_dentry);
396 struct configfs_dirent * parent_sd;
397 struct configfs_dirent * sd, * tmp;
398
399 if (!dentry)
400 return;
401
402 pr_debug("configfs %s: dropping attrs for dir\n",
403 dentry->d_name.name);
404
405 parent_sd = dentry->d_fsdata;
406 list_for_each_entry_safe(sd, tmp, &parent_sd->s_children, s_sibling) {
407 if (!sd->s_element || !(sd->s_type & CONFIGFS_NOT_PINNED))
408 continue;
409 list_del_init(&sd->s_sibling);
410 configfs_drop_dentry(sd, dentry);
411 configfs_put(sd);
412 }
413
414 /**
415 * Drop reference from dget() on entrance.
416 */
417 dput(dentry);
418}
419
420static int populate_attrs(struct config_item *item)
421{
422 struct config_item_type *t = item->ci_type;
423 struct configfs_attribute *attr;
424 int error = 0;
425 int i;
426
427 if (!t)
428 return -EINVAL;
429 if (t->ct_attrs) {
430 for (i = 0; (attr = t->ct_attrs[i]) != NULL; i++) {
431 if ((error = configfs_create_file(item, attr)))
432 break;
433 }
434 }
435
436 if (error)
437 detach_attrs(item);
438
439 return error;
440}
441
442static int configfs_attach_group(struct config_item *parent_item,
443 struct config_item *item,
444 struct dentry *dentry);
445static void configfs_detach_group(struct config_item *item);
446
447static void detach_groups(struct config_group *group)
448{
449 struct dentry * dentry = dget(group->cg_item.ci_dentry);
450 struct dentry *child;
451 struct configfs_dirent *parent_sd;
452 struct configfs_dirent *sd, *tmp;
453
454 if (!dentry)
455 return;
456
457 parent_sd = dentry->d_fsdata;
458 list_for_each_entry_safe(sd, tmp, &parent_sd->s_children, s_sibling) {
459 if (!sd->s_element ||
460 !(sd->s_type & CONFIGFS_USET_DEFAULT))
461 continue;
462
463 child = sd->s_dentry;
464
465 configfs_detach_group(sd->s_element);
466 child->d_inode->i_flags |= S_DEAD;
467
468 /*
469 * From rmdir/unregister, a configfs_detach_prep() pass
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800470 * has taken our i_mutex for us. Drop it.
Joel Becker7063fbf2005-12-15 14:29:43 -0800471 * From mkdir/register cleanup, there is no sem held.
472 */
473 if (sd->s_type & CONFIGFS_USET_DROPPING)
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800474 mutex_unlock(&child->d_inode->i_mutex);
Joel Becker7063fbf2005-12-15 14:29:43 -0800475
476 d_delete(child);
477 dput(child);
478 }
479
480 /**
481 * Drop reference from dget() on entrance.
482 */
483 dput(dentry);
484}
485
486/*
487 * This fakes mkdir(2) on a default_groups[] entry. It
488 * creates a dentry, attachs it, and then does fixup
489 * on the sd->s_type.
490 *
491 * We could, perhaps, tweak our parent's ->mkdir for a minute and
492 * try using vfs_mkdir. Just a thought.
493 */
494static int create_default_group(struct config_group *parent_group,
495 struct config_group *group)
496{
497 int ret;
498 struct qstr name;
499 struct configfs_dirent *sd;
500 /* We trust the caller holds a reference to parent */
501 struct dentry *child, *parent = parent_group->cg_item.ci_dentry;
502
503 if (!group->cg_item.ci_name)
504 group->cg_item.ci_name = group->cg_item.ci_namebuf;
505 name.name = group->cg_item.ci_name;
506 name.len = strlen(name.name);
507 name.hash = full_name_hash(name.name, name.len);
508
509 ret = -ENOMEM;
510 child = d_alloc(parent, &name);
511 if (child) {
512 d_add(child, NULL);
513
514 ret = configfs_attach_group(&parent_group->cg_item,
515 &group->cg_item, child);
516 if (!ret) {
517 sd = child->d_fsdata;
518 sd->s_type |= CONFIGFS_USET_DEFAULT;
519 } else {
520 d_delete(child);
521 dput(child);
522 }
523 }
524
525 return ret;
526}
527
528static int populate_groups(struct config_group *group)
529{
530 struct config_group *new_group;
531 struct dentry *dentry = group->cg_item.ci_dentry;
532 int ret = 0;
533 int i;
534
Eric Sesterhenncbca6922006-03-23 00:36:54 +0100535 if (group->default_groups) {
Joel Beckereed7a0d2006-04-11 21:37:20 -0700536 /*
537 * FYI, we're faking mkdir here
Joel Becker7063fbf2005-12-15 14:29:43 -0800538 * I'm not sure we need this semaphore, as we're called
539 * from our parent's mkdir. That holds our parent's
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800540 * i_mutex, so afaik lookup cannot continue through our
Joel Becker7063fbf2005-12-15 14:29:43 -0800541 * parent to find us, let alone mess with our tree.
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800542 * That said, taking our i_mutex is closer to mkdir
Joel Beckereed7a0d2006-04-11 21:37:20 -0700543 * emulation, and shouldn't hurt.
544 */
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800545 mutex_lock(&dentry->d_inode->i_mutex);
Joel Becker7063fbf2005-12-15 14:29:43 -0800546
547 for (i = 0; group->default_groups[i]; i++) {
548 new_group = group->default_groups[i];
549
550 ret = create_default_group(group, new_group);
551 if (ret)
552 break;
553 }
554
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800555 mutex_unlock(&dentry->d_inode->i_mutex);
Joel Becker7063fbf2005-12-15 14:29:43 -0800556 }
557
558 if (ret)
559 detach_groups(group);
560
561 return ret;
562}
563
564/*
565 * All of link_obj/unlink_obj/link_group/unlink_group require that
566 * subsys->su_sem is held.
567 */
568
569static void unlink_obj(struct config_item *item)
570{
571 struct config_group *group;
572
573 group = item->ci_group;
574 if (group) {
575 list_del_init(&item->ci_entry);
576
577 item->ci_group = NULL;
578 item->ci_parent = NULL;
Joel Beckereed7a0d2006-04-11 21:37:20 -0700579
580 /* Drop the reference for ci_entry */
Joel Becker7063fbf2005-12-15 14:29:43 -0800581 config_item_put(item);
582
Joel Beckereed7a0d2006-04-11 21:37:20 -0700583 /* Drop the reference for ci_parent */
Joel Becker7063fbf2005-12-15 14:29:43 -0800584 config_group_put(group);
585 }
586}
587
588static void link_obj(struct config_item *parent_item, struct config_item *item)
589{
Joel Beckereed7a0d2006-04-11 21:37:20 -0700590 /*
591 * Parent seems redundant with group, but it makes certain
592 * traversals much nicer.
593 */
Joel Becker7063fbf2005-12-15 14:29:43 -0800594 item->ci_parent = parent_item;
Joel Beckereed7a0d2006-04-11 21:37:20 -0700595
596 /*
597 * We hold a reference on the parent for the child's ci_parent
598 * link.
599 */
Joel Becker7063fbf2005-12-15 14:29:43 -0800600 item->ci_group = config_group_get(to_config_group(parent_item));
601 list_add_tail(&item->ci_entry, &item->ci_group->cg_children);
602
Joel Beckereed7a0d2006-04-11 21:37:20 -0700603 /*
604 * We hold a reference on the child for ci_entry on the parent's
605 * cg_children
606 */
Joel Becker7063fbf2005-12-15 14:29:43 -0800607 config_item_get(item);
608}
609
610static void unlink_group(struct config_group *group)
611{
612 int i;
613 struct config_group *new_group;
614
615 if (group->default_groups) {
616 for (i = 0; group->default_groups[i]; i++) {
617 new_group = group->default_groups[i];
618 unlink_group(new_group);
619 }
620 }
621
622 group->cg_subsys = NULL;
623 unlink_obj(&group->cg_item);
624}
625
626static void link_group(struct config_group *parent_group, struct config_group *group)
627{
628 int i;
629 struct config_group *new_group;
630 struct configfs_subsystem *subsys = NULL; /* gcc is a turd */
631
632 link_obj(&parent_group->cg_item, &group->cg_item);
633
634 if (parent_group->cg_subsys)
635 subsys = parent_group->cg_subsys;
636 else if (configfs_is_root(&parent_group->cg_item))
637 subsys = to_configfs_subsystem(group);
638 else
639 BUG();
640 group->cg_subsys = subsys;
641
642 if (group->default_groups) {
643 for (i = 0; group->default_groups[i]; i++) {
644 new_group = group->default_groups[i];
645 link_group(group, new_group);
646 }
647 }
648}
649
650/*
651 * The goal is that configfs_attach_item() (and
652 * configfs_attach_group()) can be called from either the VFS or this
653 * module. That is, they assume that the items have been created,
654 * the dentry allocated, and the dcache is all ready to go.
655 *
656 * If they fail, they must clean up after themselves as if they
657 * had never been called. The caller (VFS or local function) will
658 * handle cleaning up the dcache bits.
659 *
660 * configfs_detach_group() and configfs_detach_item() behave similarly on
661 * the way out. They assume that the proper semaphores are held, they
662 * clean up the configfs items, and they expect their callers will
663 * handle the dcache bits.
664 */
665static int configfs_attach_item(struct config_item *parent_item,
666 struct config_item *item,
667 struct dentry *dentry)
668{
669 int ret;
670
671 ret = configfs_create_dir(item, dentry);
672 if (!ret) {
673 ret = populate_attrs(item);
674 if (ret) {
675 configfs_remove_dir(item);
676 d_delete(dentry);
677 }
678 }
679
680 return ret;
681}
682
683static void configfs_detach_item(struct config_item *item)
684{
685 detach_attrs(item);
686 configfs_remove_dir(item);
687}
688
689static int configfs_attach_group(struct config_item *parent_item,
690 struct config_item *item,
691 struct dentry *dentry)
692{
693 int ret;
694 struct configfs_dirent *sd;
695
696 ret = configfs_attach_item(parent_item, item, dentry);
697 if (!ret) {
698 sd = dentry->d_fsdata;
699 sd->s_type |= CONFIGFS_USET_DIR;
700
701 ret = populate_groups(to_config_group(item));
702 if (ret) {
703 configfs_detach_item(item);
704 d_delete(dentry);
705 }
706 }
707
708 return ret;
709}
710
711static void configfs_detach_group(struct config_item *item)
712{
713 detach_groups(to_config_group(item));
714 configfs_detach_item(item);
715}
716
717/*
718 * Drop the initial reference from make_item()/make_group()
719 * This function assumes that reference is held on item
720 * and that item holds a valid reference to the parent. Also, it
721 * assumes the caller has validated ci_type.
722 */
723static void client_drop_item(struct config_item *parent_item,
724 struct config_item *item)
725{
726 struct config_item_type *type;
727
728 type = parent_item->ci_type;
729 BUG_ON(!type);
730
Joel Beckereed7a0d2006-04-11 21:37:20 -0700731 /*
732 * If ->drop_item() exists, it is responsible for the
733 * config_item_put().
734 */
Joel Becker7063fbf2005-12-15 14:29:43 -0800735 if (type->ct_group_ops && type->ct_group_ops->drop_item)
736 type->ct_group_ops->drop_item(to_config_group(parent_item),
737 item);
738 else
739 config_item_put(item);
740}
741
742
743static int configfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
744{
Joel Beckereed7a0d2006-04-11 21:37:20 -0700745 int ret, module_got = 0;
Joel Becker7063fbf2005-12-15 14:29:43 -0800746 struct config_group *group;
747 struct config_item *item;
748 struct config_item *parent_item;
749 struct configfs_subsystem *subsys;
750 struct configfs_dirent *sd;
751 struct config_item_type *type;
Joel Beckereed7a0d2006-04-11 21:37:20 -0700752 struct module *owner = NULL;
Joel Becker7063fbf2005-12-15 14:29:43 -0800753 char *name;
754
Joel Becker84efad12006-03-27 18:46:09 -0800755 if (dentry->d_parent == configfs_sb->s_root) {
756 ret = -EPERM;
757 goto out;
758 }
Joel Becker7063fbf2005-12-15 14:29:43 -0800759
760 sd = dentry->d_parent->d_fsdata;
Joel Becker84efad12006-03-27 18:46:09 -0800761 if (!(sd->s_type & CONFIGFS_USET_DIR)) {
762 ret = -EPERM;
763 goto out;
764 }
Joel Becker7063fbf2005-12-15 14:29:43 -0800765
Joel Becker84efad12006-03-27 18:46:09 -0800766 /* Get a working ref for the duration of this function */
Joel Becker7063fbf2005-12-15 14:29:43 -0800767 parent_item = configfs_get_config_item(dentry->d_parent);
768 type = parent_item->ci_type;
769 subsys = to_config_group(parent_item)->cg_subsys;
770 BUG_ON(!subsys);
771
772 if (!type || !type->ct_group_ops ||
773 (!type->ct_group_ops->make_group &&
774 !type->ct_group_ops->make_item)) {
Joel Becker84efad12006-03-27 18:46:09 -0800775 ret = -EPERM; /* Lack-of-mkdir returns -EPERM */
776 goto out_put;
Joel Becker7063fbf2005-12-15 14:29:43 -0800777 }
778
779 name = kmalloc(dentry->d_name.len + 1, GFP_KERNEL);
780 if (!name) {
Joel Becker84efad12006-03-27 18:46:09 -0800781 ret = -ENOMEM;
782 goto out_put;
Joel Becker7063fbf2005-12-15 14:29:43 -0800783 }
Joel Becker84efad12006-03-27 18:46:09 -0800784
Joel Becker7063fbf2005-12-15 14:29:43 -0800785 snprintf(name, dentry->d_name.len + 1, "%s", dentry->d_name.name);
786
787 down(&subsys->su_sem);
788 group = NULL;
789 item = NULL;
790 if (type->ct_group_ops->make_group) {
791 group = type->ct_group_ops->make_group(to_config_group(parent_item), name);
792 if (group) {
793 link_group(to_config_group(parent_item), group);
794 item = &group->cg_item;
795 }
796 } else {
797 item = type->ct_group_ops->make_item(to_config_group(parent_item), name);
798 if (item)
799 link_obj(parent_item, item);
800 }
801 up(&subsys->su_sem);
802
803 kfree(name);
804 if (!item) {
Joel Beckereed7a0d2006-04-11 21:37:20 -0700805 /*
806 * If item == NULL, then link_obj() was never called.
807 * There are no extra references to clean up.
808 */
Joel Becker84efad12006-03-27 18:46:09 -0800809 ret = -ENOMEM;
810 goto out_put;
Joel Becker7063fbf2005-12-15 14:29:43 -0800811 }
812
Joel Beckereed7a0d2006-04-11 21:37:20 -0700813 /*
814 * link_obj() has been called (via link_group() for groups).
815 * From here on out, errors must clean that up.
816 */
817
Joel Becker7063fbf2005-12-15 14:29:43 -0800818 type = item->ci_type;
Joel Beckereed7a0d2006-04-11 21:37:20 -0700819 if (!type) {
820 ret = -EINVAL;
821 goto out_unlink;
822 }
Joel Becker7063fbf2005-12-15 14:29:43 -0800823
Joel Beckereed7a0d2006-04-11 21:37:20 -0700824 owner = type->ct_owner;
825 if (!try_module_get(owner)) {
826 ret = -EINVAL;
827 goto out_unlink;
828 }
Joel Becker7063fbf2005-12-15 14:29:43 -0800829
Joel Beckereed7a0d2006-04-11 21:37:20 -0700830 /*
831 * I hate doing it this way, but if there is
832 * an error, module_put() probably should
833 * happen after any cleanup.
834 */
835 module_got = 1;
836
837 if (group)
838 ret = configfs_attach_group(parent_item, item, dentry);
839 else
840 ret = configfs_attach_item(parent_item, item, dentry);
841
842out_unlink:
843 if (ret) {
844 /* Tear down everything we built up */
845 down(&subsys->su_sem);
846 if (group)
847 unlink_group(group);
848 else
849 unlink_obj(item);
850 client_drop_item(parent_item, item);
851 up(&subsys->su_sem);
852
853 if (module_got)
854 module_put(owner);
Joel Becker7063fbf2005-12-15 14:29:43 -0800855 }
856
Joel Becker84efad12006-03-27 18:46:09 -0800857out_put:
858 /*
Joel Beckereed7a0d2006-04-11 21:37:20 -0700859 * link_obj()/link_group() took a reference from child->parent,
860 * so the parent is safely pinned. We can drop our working
861 * reference.
Joel Becker84efad12006-03-27 18:46:09 -0800862 */
863 config_item_put(parent_item);
864
865out:
Joel Becker7063fbf2005-12-15 14:29:43 -0800866 return ret;
867}
868
869static int configfs_rmdir(struct inode *dir, struct dentry *dentry)
870{
871 struct config_item *parent_item;
872 struct config_item *item;
873 struct configfs_subsystem *subsys;
874 struct configfs_dirent *sd;
875 struct module *owner = NULL;
876 int ret;
877
878 if (dentry->d_parent == configfs_sb->s_root)
879 return -EPERM;
880
881 sd = dentry->d_fsdata;
882 if (sd->s_type & CONFIGFS_USET_DEFAULT)
883 return -EPERM;
884
Joel Becker84efad12006-03-27 18:46:09 -0800885 /* Get a working ref until we have the child */
Joel Becker7063fbf2005-12-15 14:29:43 -0800886 parent_item = configfs_get_config_item(dentry->d_parent);
887 subsys = to_config_group(parent_item)->cg_subsys;
888 BUG_ON(!subsys);
889
890 if (!parent_item->ci_type) {
891 config_item_put(parent_item);
892 return -EINVAL;
893 }
894
895 ret = configfs_detach_prep(dentry);
896 if (ret) {
897 configfs_detach_rollback(dentry);
898 config_item_put(parent_item);
899 return ret;
900 }
901
Joel Becker84efad12006-03-27 18:46:09 -0800902 /* Get a working ref for the duration of this function */
Joel Becker7063fbf2005-12-15 14:29:43 -0800903 item = configfs_get_config_item(dentry);
904
905 /* Drop reference from above, item already holds one. */
906 config_item_put(parent_item);
907
908 if (item->ci_type)
909 owner = item->ci_type->ct_owner;
910
911 if (sd->s_type & CONFIGFS_USET_DIR) {
912 configfs_detach_group(item);
913
914 down(&subsys->su_sem);
915 unlink_group(to_config_group(item));
916 } else {
917 configfs_detach_item(item);
918
919 down(&subsys->su_sem);
920 unlink_obj(item);
921 }
922
923 client_drop_item(parent_item, item);
924 up(&subsys->su_sem);
925
926 /* Drop our reference from above */
927 config_item_put(item);
928
929 module_put(owner);
930
931 return 0;
932}
933
934struct inode_operations configfs_dir_inode_operations = {
935 .mkdir = configfs_mkdir,
936 .rmdir = configfs_rmdir,
937 .symlink = configfs_symlink,
938 .unlink = configfs_unlink,
939 .lookup = configfs_lookup,
Joel Becker3d0f89b2006-01-25 13:31:07 -0800940 .setattr = configfs_setattr,
Joel Becker7063fbf2005-12-15 14:29:43 -0800941};
942
943#if 0
944int configfs_rename_dir(struct config_item * item, const char *new_name)
945{
946 int error = 0;
947 struct dentry * new_dentry, * parent;
948
949 if (!strcmp(config_item_name(item), new_name))
950 return -EINVAL;
951
952 if (!item->parent)
953 return -EINVAL;
954
955 down_write(&configfs_rename_sem);
956 parent = item->parent->dentry;
957
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800958 mutex_lock(&parent->d_inode->i_mutex);
Joel Becker7063fbf2005-12-15 14:29:43 -0800959
960 new_dentry = lookup_one_len(new_name, parent, strlen(new_name));
961 if (!IS_ERR(new_dentry)) {
Joel Beckere7515d02006-03-10 11:42:30 -0800962 if (!new_dentry->d_inode) {
Joel Becker7063fbf2005-12-15 14:29:43 -0800963 error = config_item_set_name(item, "%s", new_name);
964 if (!error) {
965 d_add(new_dentry, NULL);
966 d_move(item->dentry, new_dentry);
967 }
968 else
969 d_delete(new_dentry);
970 } else
971 error = -EEXIST;
972 dput(new_dentry);
973 }
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800974 mutex_unlock(&parent->d_inode->i_mutex);
Joel Becker7063fbf2005-12-15 14:29:43 -0800975 up_write(&configfs_rename_sem);
976
977 return error;
978}
979#endif
980
981static int configfs_dir_open(struct inode *inode, struct file *file)
982{
983 struct dentry * dentry = file->f_dentry;
984 struct configfs_dirent * parent_sd = dentry->d_fsdata;
985
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800986 mutex_lock(&dentry->d_inode->i_mutex);
Joel Becker7063fbf2005-12-15 14:29:43 -0800987 file->private_data = configfs_new_dirent(parent_sd, NULL);
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800988 mutex_unlock(&dentry->d_inode->i_mutex);
Joel Becker7063fbf2005-12-15 14:29:43 -0800989
990 return file->private_data ? 0 : -ENOMEM;
991
992}
993
994static int configfs_dir_close(struct inode *inode, struct file *file)
995{
996 struct dentry * dentry = file->f_dentry;
997 struct configfs_dirent * cursor = file->private_data;
998
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800999 mutex_lock(&dentry->d_inode->i_mutex);
Joel Becker7063fbf2005-12-15 14:29:43 -08001000 list_del_init(&cursor->s_sibling);
Jes Sorensen1b1dcc12006-01-09 15:59:24 -08001001 mutex_unlock(&dentry->d_inode->i_mutex);
Joel Becker7063fbf2005-12-15 14:29:43 -08001002
1003 release_configfs_dirent(cursor);
1004
1005 return 0;
1006}
1007
1008/* Relationship between s_mode and the DT_xxx types */
1009static inline unsigned char dt_type(struct configfs_dirent *sd)
1010{
1011 return (sd->s_mode >> 12) & 15;
1012}
1013
1014static int configfs_readdir(struct file * filp, void * dirent, filldir_t filldir)
1015{
1016 struct dentry *dentry = filp->f_dentry;
1017 struct configfs_dirent * parent_sd = dentry->d_fsdata;
1018 struct configfs_dirent *cursor = filp->private_data;
1019 struct list_head *p, *q = &cursor->s_sibling;
1020 ino_t ino;
1021 int i = filp->f_pos;
1022
1023 switch (i) {
1024 case 0:
1025 ino = dentry->d_inode->i_ino;
1026 if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0)
1027 break;
1028 filp->f_pos++;
1029 i++;
1030 /* fallthrough */
1031 case 1:
1032 ino = parent_ino(dentry);
1033 if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0)
1034 break;
1035 filp->f_pos++;
1036 i++;
1037 /* fallthrough */
1038 default:
1039 if (filp->f_pos == 2) {
Akinobu Mitaf1166292006-06-26 00:24:46 -07001040 list_move(q, &parent_sd->s_children);
Joel Becker7063fbf2005-12-15 14:29:43 -08001041 }
1042 for (p=q->next; p!= &parent_sd->s_children; p=p->next) {
1043 struct configfs_dirent *next;
1044 const char * name;
1045 int len;
1046
1047 next = list_entry(p, struct configfs_dirent,
1048 s_sibling);
1049 if (!next->s_element)
1050 continue;
1051
1052 name = configfs_get_name(next);
1053 len = strlen(name);
1054 if (next->s_dentry)
1055 ino = next->s_dentry->d_inode->i_ino;
1056 else
1057 ino = iunique(configfs_sb, 2);
1058
1059 if (filldir(dirent, name, len, filp->f_pos, ino,
1060 dt_type(next)) < 0)
1061 return 0;
1062
Akinobu Mitaf1166292006-06-26 00:24:46 -07001063 list_move(q, p);
Joel Becker7063fbf2005-12-15 14:29:43 -08001064 p = q;
1065 filp->f_pos++;
1066 }
1067 }
1068 return 0;
1069}
1070
1071static loff_t configfs_dir_lseek(struct file * file, loff_t offset, int origin)
1072{
1073 struct dentry * dentry = file->f_dentry;
1074
Jes Sorensen1b1dcc12006-01-09 15:59:24 -08001075 mutex_lock(&dentry->d_inode->i_mutex);
Joel Becker7063fbf2005-12-15 14:29:43 -08001076 switch (origin) {
1077 case 1:
1078 offset += file->f_pos;
1079 case 0:
1080 if (offset >= 0)
1081 break;
1082 default:
Jes Sorensen1b1dcc12006-01-09 15:59:24 -08001083 mutex_unlock(&file->f_dentry->d_inode->i_mutex);
Joel Becker7063fbf2005-12-15 14:29:43 -08001084 return -EINVAL;
1085 }
1086 if (offset != file->f_pos) {
1087 file->f_pos = offset;
1088 if (file->f_pos >= 2) {
1089 struct configfs_dirent *sd = dentry->d_fsdata;
1090 struct configfs_dirent *cursor = file->private_data;
1091 struct list_head *p;
1092 loff_t n = file->f_pos - 2;
1093
1094 list_del(&cursor->s_sibling);
1095 p = sd->s_children.next;
1096 while (n && p != &sd->s_children) {
1097 struct configfs_dirent *next;
1098 next = list_entry(p, struct configfs_dirent,
1099 s_sibling);
1100 if (next->s_element)
1101 n--;
1102 p = p->next;
1103 }
1104 list_add_tail(&cursor->s_sibling, p);
1105 }
1106 }
Jes Sorensen1b1dcc12006-01-09 15:59:24 -08001107 mutex_unlock(&dentry->d_inode->i_mutex);
Joel Becker7063fbf2005-12-15 14:29:43 -08001108 return offset;
1109}
1110
Arjan van de Ven4b6f5d22006-03-28 01:56:42 -08001111const struct file_operations configfs_dir_operations = {
Joel Becker7063fbf2005-12-15 14:29:43 -08001112 .open = configfs_dir_open,
1113 .release = configfs_dir_close,
1114 .llseek = configfs_dir_lseek,
1115 .read = generic_read_dir,
1116 .readdir = configfs_readdir,
1117};
1118
1119int configfs_register_subsystem(struct configfs_subsystem *subsys)
1120{
1121 int err;
1122 struct config_group *group = &subsys->su_group;
1123 struct qstr name;
1124 struct dentry *dentry;
1125 struct configfs_dirent *sd;
1126
1127 err = configfs_pin_fs();
1128 if (err)
1129 return err;
1130
1131 if (!group->cg_item.ci_name)
1132 group->cg_item.ci_name = group->cg_item.ci_namebuf;
1133
1134 sd = configfs_sb->s_root->d_fsdata;
1135 link_group(to_config_group(sd->s_element), group);
1136
Jes Sorensen1b1dcc12006-01-09 15:59:24 -08001137 mutex_lock(&configfs_sb->s_root->d_inode->i_mutex);
Joel Becker7063fbf2005-12-15 14:29:43 -08001138
1139 name.name = group->cg_item.ci_name;
1140 name.len = strlen(name.name);
1141 name.hash = full_name_hash(name.name, name.len);
1142
1143 err = -ENOMEM;
1144 dentry = d_alloc(configfs_sb->s_root, &name);
1145 if (!dentry)
1146 goto out_release;
1147
1148 d_add(dentry, NULL);
1149
1150 err = configfs_attach_group(sd->s_element, &group->cg_item,
1151 dentry);
1152 if (!err)
1153 dentry = NULL;
1154 else
1155 d_delete(dentry);
1156
Jes Sorensen1b1dcc12006-01-09 15:59:24 -08001157 mutex_unlock(&configfs_sb->s_root->d_inode->i_mutex);
Joel Becker7063fbf2005-12-15 14:29:43 -08001158
1159 if (dentry) {
1160 dput(dentry);
1161out_release:
1162 unlink_group(group);
1163 configfs_release_fs();
1164 }
1165
1166 return err;
1167}
1168
1169void configfs_unregister_subsystem(struct configfs_subsystem *subsys)
1170{
1171 struct config_group *group = &subsys->su_group;
1172 struct dentry *dentry = group->cg_item.ci_dentry;
1173
1174 if (dentry->d_parent != configfs_sb->s_root) {
1175 printk(KERN_ERR "configfs: Tried to unregister non-subsystem!\n");
1176 return;
1177 }
1178
Mark Fasheh55ed1602006-10-20 14:55:54 -07001179 mutex_lock_nested(&configfs_sb->s_root->d_inode->i_mutex,
1180 I_MUTEX_PARENT);
1181 mutex_lock_nested(&dentry->d_inode->i_mutex, I_MUTEX_CHILD);
Joel Becker7063fbf2005-12-15 14:29:43 -08001182 if (configfs_detach_prep(dentry)) {
1183 printk(KERN_ERR "configfs: Tried to unregister non-empty subsystem!\n");
1184 }
1185 configfs_detach_group(&group->cg_item);
1186 dentry->d_inode->i_flags |= S_DEAD;
Jes Sorensen1b1dcc12006-01-09 15:59:24 -08001187 mutex_unlock(&dentry->d_inode->i_mutex);
Joel Becker7063fbf2005-12-15 14:29:43 -08001188
1189 d_delete(dentry);
1190
Jes Sorensen1b1dcc12006-01-09 15:59:24 -08001191 mutex_unlock(&configfs_sb->s_root->d_inode->i_mutex);
Joel Becker7063fbf2005-12-15 14:29:43 -08001192
1193 dput(dentry);
1194
1195 unlink_group(group);
1196 configfs_release_fs();
1197}
1198
1199EXPORT_SYMBOL(configfs_register_subsystem);
1200EXPORT_SYMBOL(configfs_unregister_subsystem);