summaryrefslogtreecommitdiff
path: root/fs/smb/client/cached_dir.c
blob: d64a306a414be0580e910842b19f150bf43863a9 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
// SPDX-License-Identifier: GPL-2.0
/*
 *  Functions to handle the cached directory entries
 *
 *  Copyright (c) 2022, Ronnie Sahlberg <lsahlber@redhat.com>
 */

#include <linux/namei.h>
#include "cifsglob.h"
#include "cifsproto.h"
#include "cifs_debug.h"
#include "smb2proto.h"
#include "cached_dir.h"

static struct cached_fid *init_cached_dir(const char *path);
static void free_cached_dir(struct cached_fid *cfid);
static void smb2_close_cached_fid(struct kref *ref);
static void cfids_laundromat_worker(struct work_struct *work);

static struct cached_fid *find_or_create_cached_dir(struct cached_fids *cfids,
						    const char *path,
						    bool lookup_only,
						    __u32 max_cached_dirs)
{
	struct cached_fid *cfid;

	spin_lock(&cfids->cfid_list_lock);
	list_for_each_entry(cfid, &cfids->entries, entry) {
		if (!strcmp(cfid->path, path)) {
			/*
			 * If it doesn't have a lease it is either not yet
			 * fully cached or it may be in the process of
			 * being deleted due to a lease break.
			 */
			if (!cfid->time || !cfid->has_lease) {
				spin_unlock(&cfids->cfid_list_lock);
				return NULL;
			}
			kref_get(&cfid->refcount);
			spin_unlock(&cfids->cfid_list_lock);
			return cfid;
		}
	}
	if (lookup_only) {
		spin_unlock(&cfids->cfid_list_lock);
		return NULL;
	}
	if (cfids->num_entries >= max_cached_dirs) {
		spin_unlock(&cfids->cfid_list_lock);
		return NULL;
	}
	cfid = init_cached_dir(path);
	if (cfid == NULL) {
		spin_unlock(&cfids->cfid_list_lock);
		return NULL;
	}
	cfid->cfids = cfids;
	cfids->num_entries++;
	list_add(&cfid->entry, &cfids->entries);
	cfid->on_list = true;
	kref_get(&cfid->refcount);
	spin_unlock(&cfids->cfid_list_lock);
	return cfid;
}

static struct dentry *
path_to_dentry(struct cifs_sb_info *cifs_sb, const char *path)
{
	struct dentry *dentry;
	const char *s, *p;
	char sep;

	sep = CIFS_DIR_SEP(cifs_sb);
	dentry = dget(cifs_sb->root);
	s = path;

	do {
		struct inode *dir = d_inode(dentry);
		struct dentry *child;

		if (!S_ISDIR(dir->i_mode)) {
			dput(dentry);
			dentry = ERR_PTR(-ENOTDIR);
			break;
		}

		/* skip separators */
		while (*s == sep)
			s++;
		if (!*s)
			break;
		p = s++;
		/* next separator */
		while (*s && *s != sep)
			s++;

		child = lookup_positive_unlocked(p, dentry, s - p);
		dput(dentry);
		dentry = child;
	} while (!IS_ERR(dentry));
	return dentry;
}

static const char *path_no_prefix(struct cifs_sb_info *cifs_sb,
				  const char *path)
{
	size_t len = 0;

	if (!*path)
		return path;

	if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH) &&
	    cifs_sb->prepath) {
		len = strlen(cifs_sb->prepath) + 1;
		if (unlikely(len > strlen(path)))
			return ERR_PTR(-EINVAL);
	}
	return path + len;
}

/*
 * Open the and cache a directory handle.
 * If error then *cfid is not initialized.
 */
int open_cached_dir(unsigned int xid, struct cifs_tcon *tcon,
		    const char *path,
		    struct cifs_sb_info *cifs_sb,
		    bool lookup_only, struct cached_fid **ret_cfid)
{
	struct cifs_ses *ses;
	struct TCP_Server_Info *server;
	struct cifs_open_parms oparms;
	struct smb2_create_rsp *o_rsp = NULL;
	struct smb2_query_info_rsp *qi_rsp = NULL;
	int resp_buftype[2];
	struct smb_rqst rqst[2];
	struct kvec rsp_iov[2];
	struct kvec open_iov[SMB2_CREATE_IOV_SIZE];
	struct kvec qi_iov[1];
	int rc, flags = 0;
	__le16 *utf16_path = NULL;
	u8 oplock = SMB2_OPLOCK_LEVEL_II;
	struct cifs_fid *pfid;
	struct dentry *dentry = NULL;
	struct cached_fid *cfid;
	struct cached_fids *cfids;
	const char *npath;

	if (tcon == NULL || tcon->cfids == NULL || tcon->nohandlecache ||
	    is_smb1_server(tcon->ses->server) || (dir_cache_timeout == 0))
		return -EOPNOTSUPP;

	ses = tcon->ses;
	server = ses->server;
	cfids = tcon->cfids;

	if (!server->ops->new_lease_key)
		return -EIO;

	if (cifs_sb->root == NULL)
		return -ENOENT;

	utf16_path = cifs_convert_path_to_utf16(path, cifs_sb);
	if (!utf16_path)
		return -ENOMEM;

	cfid = find_or_create_cached_dir(cfids, path, lookup_only, tcon->max_cached_dirs);
	if (cfid == NULL) {
		kfree(utf16_path);
		return -ENOENT;
	}
	/*
	 * Return cached fid if it has a lease.  Otherwise, it is either a new
	 * entry or laundromat worker removed it from @cfids->entries.  Caller
	 * will put last reference if the latter.
	 */
	spin_lock(&cfids->cfid_list_lock);
	if (cfid->has_lease) {
		spin_unlock(&cfids->cfid_list_lock);
		*ret_cfid = cfid;
		kfree(utf16_path);
		return 0;
	}
	spin_unlock(&cfids->cfid_list_lock);

	/*
	 * Skip any prefix paths in @path as lookup_positive_unlocked() ends up
	 * calling ->lookup() which already adds those through
	 * build_path_from_dentry().  Also, do it earlier as we might reconnect
	 * below when trying to send compounded request and then potentially
	 * having a different prefix path (e.g. after DFS failover).
	 */
	npath = path_no_prefix(cifs_sb, path);
	if (IS_ERR(npath)) {
		rc = PTR_ERR(npath);
		goto out;
	}

	if (!npath[0]) {
		dentry = dget(cifs_sb->root);
	} else {
		dentry = path_to_dentry(cifs_sb, npath);
		if (IS_ERR(dentry)) {
			rc = -ENOENT;
			goto out;
		}
	}
	cfid->dentry = dentry;

	/*
	 * We do not hold the lock for the open because in case
	 * SMB2_open needs to reconnect.
	 * This is safe because no other thread will be able to get a ref
	 * to the cfid until we have finished opening the file and (possibly)
	 * acquired a lease.
	 */
	if (smb3_encryption_required(tcon))
		flags |= CIFS_TRANSFORM_REQ;

	pfid = &cfid->fid;
	server->ops->new_lease_key(pfid);

	memset(rqst, 0, sizeof(rqst));
	resp_buftype[0] = resp_buftype[1] = CIFS_NO_BUFFER;
	memset(rsp_iov, 0, sizeof(rsp_iov));

	/* Open */
	memset(&open_iov, 0, sizeof(open_iov));
	rqst[0].rq_iov = open_iov;
	rqst[0].rq_nvec = SMB2_CREATE_IOV_SIZE;

	oparms = (struct cifs_open_parms) {
		.tcon = tcon,
		.path = path,
		.create_options = cifs_create_options(cifs_sb, CREATE_NOT_FILE),
		.desired_access =  FILE_READ_DATA | FILE_READ_ATTRIBUTES,
		.disposition = FILE_OPEN,
		.fid = pfid,
	};

	rc = SMB2_open_init(tcon, server,
			    &rqst[0], &oplock, &oparms, utf16_path);
	if (rc)
		goto oshr_free;
	smb2_set_next_command(tcon, &rqst[0]);

	memset(&qi_iov, 0, sizeof(qi_iov));
	rqst[1].rq_iov = qi_iov;
	rqst[1].rq_nvec = 1;

	rc = SMB2_query_info_init(tcon, server,
				  &rqst[1], COMPOUND_FID,
				  COMPOUND_FID, FILE_ALL_INFORMATION,
				  SMB2_O_INFO_FILE, 0,
				  sizeof(struct smb2_file_all_info) +
				  PATH_MAX * 2, 0, NULL);
	if (rc)
		goto oshr_free;

	smb2_set_related(&rqst[1]);

	/*
	 * Set @cfid->has_lease to true before sending out compounded request so
	 * its lease reference can be put in cached_dir_lease_break() due to a
	 * potential lease break right after the request is sent or while @cfid
	 * is still being cached.  Concurrent processes won't be to use it yet
	 * due to @cfid->time being zero.
	 */
	cfid->has_lease = true;

	rc = compound_send_recv(xid, ses, server,
				flags, 2, rqst,
				resp_buftype, rsp_iov);
	if (rc) {
		if (rc == -EREMCHG) {
			tcon->need_reconnect = true;
			pr_warn_once("server share %s deleted\n",
				     tcon->tree_name);
		}
		goto oshr_free;
	}
	cfid->tcon = tcon;
	cfid->is_open = true;

	spin_lock(&cfids->cfid_list_lock);

	o_rsp = (struct smb2_create_rsp *)rsp_iov[0].iov_base;
	oparms.fid->persistent_fid = o_rsp->PersistentFileId;
	oparms.fid->volatile_fid = o_rsp->VolatileFileId;
#ifdef CONFIG_CIFS_DEBUG2
	oparms.fid->mid = le64_to_cpu(o_rsp->hdr.MessageId);
#endif /* CIFS_DEBUG2 */


	if (o_rsp->OplockLevel != SMB2_OPLOCK_LEVEL_LEASE) {
		spin_unlock(&cfids->cfid_list_lock);
		rc = -EINVAL;
		goto oshr_free;
	}

	rc = smb2_parse_contexts(server, rsp_iov,
				 &oparms.fid->epoch,
				 oparms.fid->lease_key,
				 &oplock, NULL, NULL);
	if (rc) {
		spin_unlock(&cfids->cfid_list_lock);
		goto oshr_free;
	}

	rc = -EINVAL;
	if (!(oplock & SMB2_LEASE_READ_CACHING_HE)) {
		spin_unlock(&cfids->cfid_list_lock);
		goto oshr_free;
	}
	qi_rsp = (struct smb2_query_info_rsp *)rsp_iov[1].iov_base;
	if (le32_to_cpu(qi_rsp->OutputBufferLength) < sizeof(struct smb2_file_all_info)) {
		spin_unlock(&cfids->cfid_list_lock);
		goto oshr_free;
	}
	if (!smb2_validate_and_copy_iov(
				le16_to_cpu(qi_rsp->OutputBufferOffset),
				sizeof(struct smb2_file_all_info),
				&rsp_iov[1], sizeof(struct smb2_file_all_info),
				(char *)&cfid->file_all_info))
		cfid->file_all_info_is_valid = true;

	cfid->time = jiffies;
	spin_unlock(&cfids->cfid_list_lock);
	/* At this point the directory handle is fully cached */
	rc = 0;

oshr_free:
	SMB2_open_free(&rqst[0]);
	SMB2_query_info_free(&rqst[1]);
	free_rsp_buf(resp_buftype[0], rsp_iov[0].iov_base);
	free_rsp_buf(resp_buftype[1], rsp_iov[1].iov_base);
	if (rc) {
		spin_lock(&cfids->cfid_list_lock);
		if (cfid->on_list) {
			list_del(&cfid->entry);
			cfid->on_list = false;
			cfids->num_entries--;
		}
		if (cfid->has_lease) {
			/*
			 * We are guaranteed to have two references at this
			 * point. One for the caller and one for a potential
			 * lease. Release the Lease-ref so that the directory
			 * will be closed when the caller closes the cached
			 * handle.
			 */
			cfid->has_lease = false;
			spin_unlock(&cfids->cfid_list_lock);
			kref_put(&cfid->refcount, smb2_close_cached_fid);
			goto out;
		}
		spin_unlock(&cfids->cfid_list_lock);
	}
out:
	if (rc) {
		if (cfid->is_open)
			SMB2_close(0, cfid->tcon, cfid->fid.persistent_fid,
				   cfid->fid.volatile_fid);
		free_cached_dir(cfid);
	} else {
		*ret_cfid = cfid;
		atomic_inc(&tcon->num_remote_opens);
	}
	kfree(utf16_path);
	return rc;
}

int open_cached_dir_by_dentry(struct cifs_tcon *tcon,
			      struct dentry *dentry,
			      struct cached_fid **ret_cfid)
{
	struct cached_fid *cfid;
	struct cached_fids *cfids = tcon->cfids;

	if (cfids == NULL)
		return -ENOENT;

	spin_lock(&cfids->cfid_list_lock);
	list_for_each_entry(cfid, &cfids->entries, entry) {
		if (dentry && cfid->dentry == dentry) {
			cifs_dbg(FYI, "found a cached root file handle by dentry\n");
			kref_get(&cfid->refcount);
			*ret_cfid = cfid;
			spin_unlock(&cfids->cfid_list_lock);
			return 0;
		}
	}
	spin_unlock(&cfids->cfid_list_lock);
	return -ENOENT;
}

static void
smb2_close_cached_fid(struct kref *ref)
{
	struct cached_fid *cfid = container_of(ref, struct cached_fid,
					       refcount);

	spin_lock(&cfid->cfids->cfid_list_lock);
	if (cfid->on_list) {
		list_del(&cfid->entry);
		cfid->on_list = false;
		cfid->cfids->num_entries--;
	}
	spin_unlock(&cfid->cfids->cfid_list_lock);

	dput(cfid->dentry);
	cfid->dentry = NULL;

	if (cfid->is_open) {
		SMB2_close(0, cfid->tcon, cfid->fid.persistent_fid,
			   cfid->fid.volatile_fid);
		atomic_dec(&cfid->tcon->num_remote_opens);
	}

	free_cached_dir(cfid);
}

void drop_cached_dir_by_name(const unsigned int xid, struct cifs_tcon *tcon,
			     const char *name, struct cifs_sb_info *cifs_sb)
{
	struct cached_fid *cfid = NULL;
	int rc;

	rc = open_cached_dir(xid, tcon, name, cifs_sb, true, &cfid);
	if (rc) {
		cifs_dbg(FYI, "no cached dir found for rmdir(%s)\n", name);
		return;
	}
	spin_lock(&cfid->cfids->cfid_list_lock);
	if (cfid->has_lease) {
		cfid->has_lease = false;
		kref_put(&cfid->refcount, smb2_close_cached_fid);
	}
	spin_unlock(&cfid->cfids->cfid_list_lock);
	close_cached_dir(cfid);
}


void close_cached_dir(struct cached_fid *cfid)
{
	kref_put(&cfid->refcount, smb2_close_cached_fid);
}

/*
 * Called from cifs_kill_sb when we unmount a share
 */
void close_all_cached_dirs(struct cifs_sb_info *cifs_sb)
{
	struct rb_root *root = &cifs_sb->tlink_tree;
	struct rb_node *node;
	struct cached_fid *cfid;
	struct cifs_tcon *tcon;
	struct tcon_link *tlink;
	struct cached_fids *cfids;

	for (node = rb_first(root); node; node = rb_next(node)) {
		tlink = rb_entry(node, struct tcon_link, tl_rbnode);
		tcon = tlink_tcon(tlink);
		if (IS_ERR(tcon))
			continue;
		cfids = tcon->cfids;
		if (cfids == NULL)
			continue;
		list_for_each_entry(cfid, &cfids->entries, entry) {
			dput(cfid->dentry);
			cfid->dentry = NULL;
		}
	}
}

/*
 * Invalidate all cached dirs when a TCON has been reset
 * due to a session loss.
 */
void invalidate_all_cached_dirs(struct cifs_tcon *tcon)
{
	struct cached_fids *cfids = tcon->cfids;
	struct cached_fid *cfid, *q;
	LIST_HEAD(entry);

	if (cfids == NULL)
		return;

	spin_lock(&cfids->cfid_list_lock);
	list_for_each_entry_safe(cfid, q, &cfids->entries, entry) {
		list_move(&cfid->entry, &entry);
		cfids->num_entries--;
		cfid->is_open = false;
		cfid->on_list = false;
		/* To prevent race with smb2_cached_lease_break() */
		kref_get(&cfid->refcount);
	}
	spin_unlock(&cfids->cfid_list_lock);

	list_for_each_entry_safe(cfid, q, &entry, entry) {
		list_del(&cfid->entry);
		cancel_work_sync(&cfid->lease_break);
		if (cfid->has_lease) {
			/*
			 * We lease was never cancelled from the server so we
			 * need to drop the reference.
			 */
			spin_lock(&cfids->cfid_list_lock);
			cfid->has_lease = false;
			spin_unlock(&cfids->cfid_list_lock);
			kref_put(&cfid->refcount, smb2_close_cached_fid);
		}
		/* Drop the extra reference opened above*/
		kref_put(&cfid->refcount, smb2_close_cached_fid);
	}
}

static void
smb2_cached_lease_break(struct work_struct *work)
{
	struct cached_fid *cfid = container_of(work,
				struct cached_fid, lease_break);

	spin_lock(&cfid->cfids->cfid_list_lock);
	cfid->has_lease = false;
	spin_unlock(&cfid->cfids->cfid_list_lock);
	kref_put(&cfid->refcount, smb2_close_cached_fid);
}

int cached_dir_lease_break(struct cifs_tcon *tcon, __u8 lease_key[16])
{
	struct cached_fids *cfids = tcon->cfids;
	struct cached_fid *cfid;

	if (cfids == NULL)
		return false;

	spin_lock(&cfids->cfid_list_lock);
	list_for_each_entry(cfid, &cfids->entries, entry) {
		if (cfid->has_lease &&
		    !memcmp(lease_key,
			    cfid->fid.lease_key,
			    SMB2_LEASE_KEY_SIZE)) {
			cfid->time = 0;
			/*
			 * We found a lease remove it from the list
			 * so no threads can access it.
			 */
			list_del(&cfid->entry);
			cfid->on_list = false;
			cfids->num_entries--;

			queue_work(cifsiod_wq,
				   &cfid->lease_break);
			spin_unlock(&cfids->cfid_list_lock);
			return true;
		}
	}
	spin_unlock(&cfids->cfid_list_lock);
	return false;
}

static struct cached_fid *init_cached_dir(const char *path)
{
	struct cached_fid *cfid;

	cfid = kzalloc(sizeof(*cfid), GFP_ATOMIC);
	if (!cfid)
		return NULL;
	cfid->path = kstrdup(path, GFP_ATOMIC);
	if (!cfid->path) {
		kfree(cfid);
		return NULL;
	}

	INIT_WORK(&cfid->lease_break, smb2_cached_lease_break);
	INIT_LIST_HEAD(&cfid->entry);
	INIT_LIST_HEAD(&cfid->dirents.entries);
	mutex_init(&cfid->dirents.de_mutex);
	spin_lock_init(&cfid->fid_lock);
	kref_init(&cfid->refcount);
	return cfid;
}

static void free_cached_dir(struct cached_fid *cfid)
{
	struct cached_dirent *dirent, *q;

	dput(cfid->dentry);
	cfid->dentry = NULL;

	/*
	 * Delete all cached dirent names
	 */
	list_for_each_entry_safe(dirent, q, &cfid->dirents.entries, entry) {
		list_del(&dirent->entry);
		kfree(dirent->name);
		kfree(dirent);
	}

	kfree(cfid->path);
	cfid->path = NULL;
	kfree(cfid);
}

static void cfids_laundromat_worker(struct work_struct *work)
{
	struct cached_fids *cfids;
	struct cached_fid *cfid, *q;
	LIST_HEAD(entry);

	cfids = container_of(work, struct cached_fids, laundromat_work.work);

	spin_lock(&cfids->cfid_list_lock);
	list_for_each_entry_safe(cfid, q, &cfids->entries, entry) {
		if (cfid->time &&
		    time_after(jiffies, cfid->time + HZ * dir_cache_timeout)) {
			cfid->on_list = false;
			list_move(&cfid->entry, &entry);
			cfids->num_entries--;
			/* To prevent race with smb2_cached_lease_break() */
			kref_get(&cfid->refcount);
		}
	}
	spin_unlock(&cfids->cfid_list_lock);

	list_for_each_entry_safe(cfid, q, &entry, entry) {
		list_del(&cfid->entry);
		/*
		 * Cancel and wait for the work to finish in case we are racing
		 * with it.
		 */
		cancel_work_sync(&cfid->lease_break);
		if (cfid->has_lease) {
			/*
			 * Our lease has not yet been cancelled from the server
			 * so we need to drop the reference.
			 */
			spin_lock(&cfids->cfid_list_lock);
			cfid->has_lease = false;
			spin_unlock(&cfids->cfid_list_lock);
			kref_put(&cfid->refcount, smb2_close_cached_fid);
		}
		/* Drop the extra reference opened above */
		kref_put(&cfid->refcount, smb2_close_cached_fid);
	}
	queue_delayed_work(cifsiod_wq, &cfids->laundromat_work,
			   dir_cache_timeout * HZ);
}

struct cached_fids *init_cached_dirs(void)
{
	struct cached_fids *cfids;

	cfids = kzalloc(sizeof(*cfids), GFP_KERNEL);
	if (!cfids)
		return NULL;
	spin_lock_init(&cfids->cfid_list_lock);
	INIT_LIST_HEAD(&cfids->entries);

	INIT_DELAYED_WORK(&cfids->laundromat_work, cfids_laundromat_worker);
	queue_delayed_work(cifsiod_wq, &cfids->laundromat_work,
			   dir_cache_timeout * HZ);

	return cfids;
}

/*
 * Called from tconInfoFree when we are tearing down the tcon.
 * There are no active users or open files/directories at this point.
 */
void free_cached_dirs(struct cached_fids *cfids)
{
	struct cached_fid *cfid, *q;
	LIST_HEAD(entry);

	if (cfids == NULL)
		return;

	cancel_delayed_work_sync(&cfids->laundromat_work);

	spin_lock(&cfids->cfid_list_lock);
	list_for_each_entry_safe(cfid, q, &cfids->entries, entry) {
		cfid->on_list = false;
		cfid->is_open = false;
		list_move(&cfid->entry, &entry);
	}
	spin_unlock(&cfids->cfid_list_lock);

	list_for_each_entry_safe(cfid, q, &entry, entry) {
		list_del(&cfid->entry);
		free_cached_dir(cfid);
	}

	kfree(cfids);
}