1// SPDX-License-Identifier: GPL-2.0
2/*
3 *  Functions to handle the cached directory entries
4 *
5 *  Copyright (c) 2022, Ronnie Sahlberg <lsahlber@redhat.com>
6 */
7
8#include <linux/namei.h>
9#include "cifsglob.h"
10#include "cifsproto.h"
11#include "cifs_debug.h"
12#include "smb2proto.h"
13#include "cached_dir.h"
14
15static struct cached_fid *init_cached_dir(const char *path);
16static void free_cached_dir(struct cached_fid *cfid);
17static void smb2_close_cached_fid(struct kref *ref);
18static void cfids_laundromat_worker(struct work_struct *work);
19
20static struct cached_fid *find_or_create_cached_dir(struct cached_fids *cfids,
21						    const char *path,
22						    bool lookup_only,
23						    __u32 max_cached_dirs)
24{
25	struct cached_fid *cfid;
26
27	spin_lock(&cfids->cfid_list_lock);
28	list_for_each_entry(cfid, &cfids->entries, entry) {
29		if (!strcmp(cfid->path, path)) {
30			/*
31			 * If it doesn't have a lease it is either not yet
32			 * fully cached or it may be in the process of
33			 * being deleted due to a lease break.
34			 */
35			if (!cfid->time || !cfid->has_lease) {
36				spin_unlock(&cfids->cfid_list_lock);
37				return NULL;
38			}
39			kref_get(&cfid->refcount);
40			spin_unlock(&cfids->cfid_list_lock);
41			return cfid;
42		}
43	}
44	if (lookup_only) {
45		spin_unlock(&cfids->cfid_list_lock);
46		return NULL;
47	}
48	if (cfids->num_entries >= max_cached_dirs) {
49		spin_unlock(&cfids->cfid_list_lock);
50		return NULL;
51	}
52	cfid = init_cached_dir(path);
53	if (cfid == NULL) {
54		spin_unlock(&cfids->cfid_list_lock);
55		return NULL;
56	}
57	cfid->cfids = cfids;
58	cfids->num_entries++;
59	list_add(&cfid->entry, &cfids->entries);
60	cfid->on_list = true;
61	kref_get(&cfid->refcount);
62	spin_unlock(&cfids->cfid_list_lock);
63	return cfid;
64}
65
66static struct dentry *
67path_to_dentry(struct cifs_sb_info *cifs_sb, const char *path)
68{
69	struct dentry *dentry;
70	const char *s, *p;
71	char sep;
72
73	sep = CIFS_DIR_SEP(cifs_sb);
74	dentry = dget(cifs_sb->root);
75	s = path;
76
77	do {
78		struct inode *dir = d_inode(dentry);
79		struct dentry *child;
80
81		if (!S_ISDIR(dir->i_mode)) {
82			dput(dentry);
83			dentry = ERR_PTR(-ENOTDIR);
84			break;
85		}
86
87		/* skip separators */
88		while (*s == sep)
89			s++;
90		if (!*s)
91			break;
92		p = s++;
93		/* next separator */
94		while (*s && *s != sep)
95			s++;
96
97		child = lookup_positive_unlocked(p, dentry, s - p);
98		dput(dentry);
99		dentry = child;
100	} while (!IS_ERR(dentry));
101	return dentry;
102}
103
104static const char *path_no_prefix(struct cifs_sb_info *cifs_sb,
105				  const char *path)
106{
107	size_t len = 0;
108
109	if (!*path)
110		return path;
111
112	if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH) &&
113	    cifs_sb->prepath) {
114		len = strlen(cifs_sb->prepath) + 1;
115		if (unlikely(len > strlen(path)))
116			return ERR_PTR(-EINVAL);
117	}
118	return path + len;
119}
120
121/*
122 * Open the and cache a directory handle.
123 * If error then *cfid is not initialized.
124 */
125int open_cached_dir(unsigned int xid, struct cifs_tcon *tcon,
126		    const char *path,
127		    struct cifs_sb_info *cifs_sb,
128		    bool lookup_only, struct cached_fid **ret_cfid)
129{
130	struct cifs_ses *ses;
131	struct TCP_Server_Info *server;
132	struct cifs_open_parms oparms;
133	struct smb2_create_rsp *o_rsp = NULL;
134	struct smb2_query_info_rsp *qi_rsp = NULL;
135	int resp_buftype[2];
136	struct smb_rqst rqst[2];
137	struct kvec rsp_iov[2];
138	struct kvec open_iov[SMB2_CREATE_IOV_SIZE];
139	struct kvec qi_iov[1];
140	int rc, flags = 0;
141	__le16 *utf16_path = NULL;
142	u8 oplock = SMB2_OPLOCK_LEVEL_II;
143	struct cifs_fid *pfid;
144	struct dentry *dentry = NULL;
145	struct cached_fid *cfid;
146	struct cached_fids *cfids;
147	const char *npath;
148	int retries = 0, cur_sleep = 1;
149
150	if (tcon == NULL || tcon->cfids == NULL || tcon->nohandlecache ||
151	    is_smb1_server(tcon->ses->server) || (dir_cache_timeout == 0))
152		return -EOPNOTSUPP;
153
154	ses = tcon->ses;
155	cfids = tcon->cfids;
156
157	if (cifs_sb->root == NULL)
158		return -ENOENT;
159
160replay_again:
161	/* reinitialize for possible replay */
162	flags = 0;
163	oplock = SMB2_OPLOCK_LEVEL_II;
164	server = cifs_pick_channel(ses);
165
166	if (!server->ops->new_lease_key)
167		return -EIO;
168
169	utf16_path = cifs_convert_path_to_utf16(path, cifs_sb);
170	if (!utf16_path)
171		return -ENOMEM;
172
173	cfid = find_or_create_cached_dir(cfids, path, lookup_only, tcon->max_cached_dirs);
174	if (cfid == NULL) {
175		kfree(utf16_path);
176		return -ENOENT;
177	}
178	/*
179	 * Return cached fid if it has a lease.  Otherwise, it is either a new
180	 * entry or laundromat worker removed it from @cfids->entries.  Caller
181	 * will put last reference if the latter.
182	 */
183	spin_lock(&cfids->cfid_list_lock);
184	if (cfid->has_lease) {
185		spin_unlock(&cfids->cfid_list_lock);
186		*ret_cfid = cfid;
187		kfree(utf16_path);
188		return 0;
189	}
190	spin_unlock(&cfids->cfid_list_lock);
191
192	/*
193	 * Skip any prefix paths in @path as lookup_positive_unlocked() ends up
194	 * calling ->lookup() which already adds those through
195	 * build_path_from_dentry().  Also, do it earlier as we might reconnect
196	 * below when trying to send compounded request and then potentially
197	 * having a different prefix path (e.g. after DFS failover).
198	 */
199	npath = path_no_prefix(cifs_sb, path);
200	if (IS_ERR(npath)) {
201		rc = PTR_ERR(npath);
202		goto out;
203	}
204
205	if (!npath[0]) {
206		dentry = dget(cifs_sb->root);
207	} else {
208		dentry = path_to_dentry(cifs_sb, npath);
209		if (IS_ERR(dentry)) {
210			rc = -ENOENT;
211			goto out;
212		}
213	}
214	cfid->dentry = dentry;
215
216	/*
217	 * We do not hold the lock for the open because in case
218	 * SMB2_open needs to reconnect.
219	 * This is safe because no other thread will be able to get a ref
220	 * to the cfid until we have finished opening the file and (possibly)
221	 * acquired a lease.
222	 */
223	if (smb3_encryption_required(tcon))
224		flags |= CIFS_TRANSFORM_REQ;
225
226	pfid = &cfid->fid;
227	server->ops->new_lease_key(pfid);
228
229	memset(rqst, 0, sizeof(rqst));
230	resp_buftype[0] = resp_buftype[1] = CIFS_NO_BUFFER;
231	memset(rsp_iov, 0, sizeof(rsp_iov));
232
233	/* Open */
234	memset(&open_iov, 0, sizeof(open_iov));
235	rqst[0].rq_iov = open_iov;
236	rqst[0].rq_nvec = SMB2_CREATE_IOV_SIZE;
237
238	oparms = (struct cifs_open_parms) {
239		.tcon = tcon,
240		.path = path,
241		.create_options = cifs_create_options(cifs_sb, CREATE_NOT_FILE),
242		.desired_access =  FILE_READ_DATA | FILE_READ_ATTRIBUTES |
243				   FILE_READ_EA,
244		.disposition = FILE_OPEN,
245		.fid = pfid,
246		.replay = !!(retries),
247	};
248
249	rc = SMB2_open_init(tcon, server,
250			    &rqst[0], &oplock, &oparms, utf16_path);
251	if (rc)
252		goto oshr_free;
253	smb2_set_next_command(tcon, &rqst[0]);
254
255	memset(&qi_iov, 0, sizeof(qi_iov));
256	rqst[1].rq_iov = qi_iov;
257	rqst[1].rq_nvec = 1;
258
259	rc = SMB2_query_info_init(tcon, server,
260				  &rqst[1], COMPOUND_FID,
261				  COMPOUND_FID, FILE_ALL_INFORMATION,
262				  SMB2_O_INFO_FILE, 0,
263				  sizeof(struct smb2_file_all_info) +
264				  PATH_MAX * 2, 0, NULL);
265	if (rc)
266		goto oshr_free;
267
268	smb2_set_related(&rqst[1]);
269
270	/*
271	 * Set @cfid->has_lease to true before sending out compounded request so
272	 * its lease reference can be put in cached_dir_lease_break() due to a
273	 * potential lease break right after the request is sent or while @cfid
274	 * is still being cached.  Concurrent processes won't be to use it yet
275	 * due to @cfid->time being zero.
276	 */
277	cfid->has_lease = true;
278
279	if (retries) {
280		smb2_set_replay(server, &rqst[0]);
281		smb2_set_replay(server, &rqst[1]);
282	}
283
284	rc = compound_send_recv(xid, ses, server,
285				flags, 2, rqst,
286				resp_buftype, rsp_iov);
287	if (rc) {
288		if (rc == -EREMCHG) {
289			tcon->need_reconnect = true;
290			pr_warn_once("server share %s deleted\n",
291				     tcon->tree_name);
292		}
293		goto oshr_free;
294	}
295	cfid->tcon = tcon;
296	cfid->is_open = true;
297
298	spin_lock(&cfids->cfid_list_lock);
299
300	o_rsp = (struct smb2_create_rsp *)rsp_iov[0].iov_base;
301	oparms.fid->persistent_fid = o_rsp->PersistentFileId;
302	oparms.fid->volatile_fid = o_rsp->VolatileFileId;
303#ifdef CONFIG_CIFS_DEBUG2
304	oparms.fid->mid = le64_to_cpu(o_rsp->hdr.MessageId);
305#endif /* CIFS_DEBUG2 */
306
307
308	if (o_rsp->OplockLevel != SMB2_OPLOCK_LEVEL_LEASE) {
309		spin_unlock(&cfids->cfid_list_lock);
310		rc = -EINVAL;
311		goto oshr_free;
312	}
313
314	rc = smb2_parse_contexts(server, rsp_iov,
315				 &oparms.fid->epoch,
316				 oparms.fid->lease_key,
317				 &oplock, NULL, NULL);
318	if (rc) {
319		spin_unlock(&cfids->cfid_list_lock);
320		goto oshr_free;
321	}
322
323	rc = -EINVAL;
324	if (!(oplock & SMB2_LEASE_READ_CACHING_HE)) {
325		spin_unlock(&cfids->cfid_list_lock);
326		goto oshr_free;
327	}
328	qi_rsp = (struct smb2_query_info_rsp *)rsp_iov[1].iov_base;
329	if (le32_to_cpu(qi_rsp->OutputBufferLength) < sizeof(struct smb2_file_all_info)) {
330		spin_unlock(&cfids->cfid_list_lock);
331		goto oshr_free;
332	}
333	if (!smb2_validate_and_copy_iov(
334				le16_to_cpu(qi_rsp->OutputBufferOffset),
335				sizeof(struct smb2_file_all_info),
336				&rsp_iov[1], sizeof(struct smb2_file_all_info),
337				(char *)&cfid->file_all_info))
338		cfid->file_all_info_is_valid = true;
339
340	cfid->time = jiffies;
341	spin_unlock(&cfids->cfid_list_lock);
342	/* At this point the directory handle is fully cached */
343	rc = 0;
344
345oshr_free:
346	SMB2_open_free(&rqst[0]);
347	SMB2_query_info_free(&rqst[1]);
348	free_rsp_buf(resp_buftype[0], rsp_iov[0].iov_base);
349	free_rsp_buf(resp_buftype[1], rsp_iov[1].iov_base);
350	if (rc) {
351		spin_lock(&cfids->cfid_list_lock);
352		if (cfid->on_list) {
353			list_del(&cfid->entry);
354			cfid->on_list = false;
355			cfids->num_entries--;
356		}
357		if (cfid->has_lease) {
358			/*
359			 * We are guaranteed to have two references at this
360			 * point. One for the caller and one for a potential
361			 * lease. Release the Lease-ref so that the directory
362			 * will be closed when the caller closes the cached
363			 * handle.
364			 */
365			cfid->has_lease = false;
366			spin_unlock(&cfids->cfid_list_lock);
367			kref_put(&cfid->refcount, smb2_close_cached_fid);
368			goto out;
369		}
370		spin_unlock(&cfids->cfid_list_lock);
371	}
372out:
373	if (rc) {
374		if (cfid->is_open)
375			SMB2_close(0, cfid->tcon, cfid->fid.persistent_fid,
376				   cfid->fid.volatile_fid);
377		free_cached_dir(cfid);
378	} else {
379		*ret_cfid = cfid;
380		atomic_inc(&tcon->num_remote_opens);
381	}
382	kfree(utf16_path);
383
384	if (is_replayable_error(rc) &&
385	    smb2_should_replay(tcon, &retries, &cur_sleep))
386		goto replay_again;
387
388	return rc;
389}
390
391int open_cached_dir_by_dentry(struct cifs_tcon *tcon,
392			      struct dentry *dentry,
393			      struct cached_fid **ret_cfid)
394{
395	struct cached_fid *cfid;
396	struct cached_fids *cfids = tcon->cfids;
397
398	if (cfids == NULL)
399		return -ENOENT;
400
401	spin_lock(&cfids->cfid_list_lock);
402	list_for_each_entry(cfid, &cfids->entries, entry) {
403		if (dentry && cfid->dentry == dentry) {
404			cifs_dbg(FYI, "found a cached root file handle by dentry\n");
405			kref_get(&cfid->refcount);
406			*ret_cfid = cfid;
407			spin_unlock(&cfids->cfid_list_lock);
408			return 0;
409		}
410	}
411	spin_unlock(&cfids->cfid_list_lock);
412	return -ENOENT;
413}
414
415static void
416smb2_close_cached_fid(struct kref *ref)
417{
418	struct cached_fid *cfid = container_of(ref, struct cached_fid,
419					       refcount);
420	int rc;
421
422	spin_lock(&cfid->cfids->cfid_list_lock);
423	if (cfid->on_list) {
424		list_del(&cfid->entry);
425		cfid->on_list = false;
426		cfid->cfids->num_entries--;
427	}
428	spin_unlock(&cfid->cfids->cfid_list_lock);
429
430	dput(cfid->dentry);
431	cfid->dentry = NULL;
432
433	if (cfid->is_open) {
434		rc = SMB2_close(0, cfid->tcon, cfid->fid.persistent_fid,
435			   cfid->fid.volatile_fid);
436		if (rc) /* should we retry on -EBUSY or -EAGAIN? */
437			cifs_dbg(VFS, "close cached dir rc %d\n", rc);
438	}
439
440	free_cached_dir(cfid);
441}
442
443void drop_cached_dir_by_name(const unsigned int xid, struct cifs_tcon *tcon,
444			     const char *name, struct cifs_sb_info *cifs_sb)
445{
446	struct cached_fid *cfid = NULL;
447	int rc;
448
449	rc = open_cached_dir(xid, tcon, name, cifs_sb, true, &cfid);
450	if (rc) {
451		cifs_dbg(FYI, "no cached dir found for rmdir(%s)\n", name);
452		return;
453	}
454	spin_lock(&cfid->cfids->cfid_list_lock);
455	if (cfid->has_lease) {
456		cfid->has_lease = false;
457		kref_put(&cfid->refcount, smb2_close_cached_fid);
458	}
459	spin_unlock(&cfid->cfids->cfid_list_lock);
460	close_cached_dir(cfid);
461}
462
463
464void close_cached_dir(struct cached_fid *cfid)
465{
466	kref_put(&cfid->refcount, smb2_close_cached_fid);
467}
468
469/*
470 * Called from cifs_kill_sb when we unmount a share
471 */
472void close_all_cached_dirs(struct cifs_sb_info *cifs_sb)
473{
474	struct rb_root *root = &cifs_sb->tlink_tree;
475	struct rb_node *node;
476	struct cached_fid *cfid;
477	struct cifs_tcon *tcon;
478	struct tcon_link *tlink;
479	struct cached_fids *cfids;
480
481	for (node = rb_first(root); node; node = rb_next(node)) {
482		tlink = rb_entry(node, struct tcon_link, tl_rbnode);
483		tcon = tlink_tcon(tlink);
484		if (IS_ERR(tcon))
485			continue;
486		cfids = tcon->cfids;
487		if (cfids == NULL)
488			continue;
489		list_for_each_entry(cfid, &cfids->entries, entry) {
490			dput(cfid->dentry);
491			cfid->dentry = NULL;
492		}
493	}
494}
495
496/*
497 * Invalidate all cached dirs when a TCON has been reset
498 * due to a session loss.
499 */
500void invalidate_all_cached_dirs(struct cifs_tcon *tcon)
501{
502	struct cached_fids *cfids = tcon->cfids;
503	struct cached_fid *cfid, *q;
504	LIST_HEAD(entry);
505
506	if (cfids == NULL)
507		return;
508
509	spin_lock(&cfids->cfid_list_lock);
510	list_for_each_entry_safe(cfid, q, &cfids->entries, entry) {
511		list_move(&cfid->entry, &entry);
512		cfids->num_entries--;
513		cfid->is_open = false;
514		cfid->on_list = false;
515		/* To prevent race with smb2_cached_lease_break() */
516		kref_get(&cfid->refcount);
517	}
518	spin_unlock(&cfids->cfid_list_lock);
519
520	list_for_each_entry_safe(cfid, q, &entry, entry) {
521		list_del(&cfid->entry);
522		cancel_work_sync(&cfid->lease_break);
523		if (cfid->has_lease) {
524			/*
525			 * We lease was never cancelled from the server so we
526			 * need to drop the reference.
527			 */
528			spin_lock(&cfids->cfid_list_lock);
529			cfid->has_lease = false;
530			spin_unlock(&cfids->cfid_list_lock);
531			kref_put(&cfid->refcount, smb2_close_cached_fid);
532		}
533		/* Drop the extra reference opened above*/
534		kref_put(&cfid->refcount, smb2_close_cached_fid);
535	}
536}
537
538static void
539smb2_cached_lease_break(struct work_struct *work)
540{
541	struct cached_fid *cfid = container_of(work,
542				struct cached_fid, lease_break);
543
544	spin_lock(&cfid->cfids->cfid_list_lock);
545	cfid->has_lease = false;
546	spin_unlock(&cfid->cfids->cfid_list_lock);
547	kref_put(&cfid->refcount, smb2_close_cached_fid);
548}
549
550int cached_dir_lease_break(struct cifs_tcon *tcon, __u8 lease_key[16])
551{
552	struct cached_fids *cfids = tcon->cfids;
553	struct cached_fid *cfid;
554
555	if (cfids == NULL)
556		return false;
557
558	spin_lock(&cfids->cfid_list_lock);
559	list_for_each_entry(cfid, &cfids->entries, entry) {
560		if (cfid->has_lease &&
561		    !memcmp(lease_key,
562			    cfid->fid.lease_key,
563			    SMB2_LEASE_KEY_SIZE)) {
564			cfid->time = 0;
565			/*
566			 * We found a lease remove it from the list
567			 * so no threads can access it.
568			 */
569			list_del(&cfid->entry);
570			cfid->on_list = false;
571			cfids->num_entries--;
572
573			queue_work(cifsiod_wq,
574				   &cfid->lease_break);
575			spin_unlock(&cfids->cfid_list_lock);
576			return true;
577		}
578	}
579	spin_unlock(&cfids->cfid_list_lock);
580	return false;
581}
582
583static struct cached_fid *init_cached_dir(const char *path)
584{
585	struct cached_fid *cfid;
586
587	cfid = kzalloc(sizeof(*cfid), GFP_ATOMIC);
588	if (!cfid)
589		return NULL;
590	cfid->path = kstrdup(path, GFP_ATOMIC);
591	if (!cfid->path) {
592		kfree(cfid);
593		return NULL;
594	}
595
596	INIT_WORK(&cfid->lease_break, smb2_cached_lease_break);
597	INIT_LIST_HEAD(&cfid->entry);
598	INIT_LIST_HEAD(&cfid->dirents.entries);
599	mutex_init(&cfid->dirents.de_mutex);
600	spin_lock_init(&cfid->fid_lock);
601	kref_init(&cfid->refcount);
602	return cfid;
603}
604
605static void free_cached_dir(struct cached_fid *cfid)
606{
607	struct cached_dirent *dirent, *q;
608
609	dput(cfid->dentry);
610	cfid->dentry = NULL;
611
612	/*
613	 * Delete all cached dirent names
614	 */
615	list_for_each_entry_safe(dirent, q, &cfid->dirents.entries, entry) {
616		list_del(&dirent->entry);
617		kfree(dirent->name);
618		kfree(dirent);
619	}
620
621	kfree(cfid->path);
622	cfid->path = NULL;
623	kfree(cfid);
624}
625
626static void cfids_laundromat_worker(struct work_struct *work)
627{
628	struct cached_fids *cfids;
629	struct cached_fid *cfid, *q;
630	LIST_HEAD(entry);
631
632	cfids = container_of(work, struct cached_fids, laundromat_work.work);
633
634	spin_lock(&cfids->cfid_list_lock);
635	list_for_each_entry_safe(cfid, q, &cfids->entries, entry) {
636		if (cfid->time &&
637		    time_after(jiffies, cfid->time + HZ * dir_cache_timeout)) {
638			cfid->on_list = false;
639			list_move(&cfid->entry, &entry);
640			cfids->num_entries--;
641			/* To prevent race with smb2_cached_lease_break() */
642			kref_get(&cfid->refcount);
643		}
644	}
645	spin_unlock(&cfids->cfid_list_lock);
646
647	list_for_each_entry_safe(cfid, q, &entry, entry) {
648		list_del(&cfid->entry);
649		/*
650		 * Cancel and wait for the work to finish in case we are racing
651		 * with it.
652		 */
653		cancel_work_sync(&cfid->lease_break);
654		if (cfid->has_lease) {
655			/*
656			 * Our lease has not yet been cancelled from the server
657			 * so we need to drop the reference.
658			 */
659			spin_lock(&cfids->cfid_list_lock);
660			cfid->has_lease = false;
661			spin_unlock(&cfids->cfid_list_lock);
662			kref_put(&cfid->refcount, smb2_close_cached_fid);
663		}
664		/* Drop the extra reference opened above */
665		kref_put(&cfid->refcount, smb2_close_cached_fid);
666	}
667	queue_delayed_work(cifsiod_wq, &cfids->laundromat_work,
668			   dir_cache_timeout * HZ);
669}
670
671struct cached_fids *init_cached_dirs(void)
672{
673	struct cached_fids *cfids;
674
675	cfids = kzalloc(sizeof(*cfids), GFP_KERNEL);
676	if (!cfids)
677		return NULL;
678	spin_lock_init(&cfids->cfid_list_lock);
679	INIT_LIST_HEAD(&cfids->entries);
680
681	INIT_DELAYED_WORK(&cfids->laundromat_work, cfids_laundromat_worker);
682	queue_delayed_work(cifsiod_wq, &cfids->laundromat_work,
683			   dir_cache_timeout * HZ);
684
685	return cfids;
686}
687
688/*
689 * Called from tconInfoFree when we are tearing down the tcon.
690 * There are no active users or open files/directories at this point.
691 */
692void free_cached_dirs(struct cached_fids *cfids)
693{
694	struct cached_fid *cfid, *q;
695	LIST_HEAD(entry);
696
697	if (cfids == NULL)
698		return;
699
700	cancel_delayed_work_sync(&cfids->laundromat_work);
701
702	spin_lock(&cfids->cfid_list_lock);
703	list_for_each_entry_safe(cfid, q, &cfids->entries, entry) {
704		cfid->on_list = false;
705		cfid->is_open = false;
706		list_move(&cfid->entry, &entry);
707	}
708	spin_unlock(&cfids->cfid_list_lock);
709
710	list_for_each_entry_safe(cfid, q, &entry, entry) {
711		list_del(&cfid->entry);
712		free_cached_dir(cfid);
713	}
714
715	kfree(cfids);
716}
717