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gpio: rcar: Fix runtime PM imbalance on error
[linux/fpc-iii.git] / fs / cifs / dfs_cache.c
bloba67f88bf7ae1fd68a185568480b7a70628819003
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * DFS referral cache routines
4 *
5 * Copyright (c) 2018-2019 Paulo Alcantara <palcantara@suse.de>
6 */
7
8 #include <linux/jhash.h>
9 #include <linux/ktime.h>
10 #include <linux/slab.h>
11 #include <linux/proc_fs.h>
12 #include <linux/nls.h>
13 #include <linux/workqueue.h>
14 #include "cifsglob.h"
15 #include "smb2pdu.h"
16 #include "smb2proto.h"
17 #include "cifsproto.h"
18 #include "cifs_debug.h"
19 #include "cifs_unicode.h"
20 #include "smb2glob.h"
21
22 #include "dfs_cache.h"
23
24 #define CACHE_HTABLE_SIZE 32
25 #define CACHE_MAX_ENTRIES 64
26
27 #define IS_INTERLINK_SET(v) ((v) & (DFSREF_REFERRAL_SERVER | \
28 DFSREF_STORAGE_SERVER))
29
30 struct cache_dfs_tgt {
31 char *name;
32 struct list_head list;
33 };
34
35 struct cache_entry {
36 struct hlist_node hlist;
37 const char *path;
38 int ttl;
39 int srvtype;
40 int flags;
41 struct timespec64 etime;
42 int path_consumed;
43 int numtgts;
44 struct list_head tlist;
45 struct cache_dfs_tgt *tgthint;
46 };
47
48 struct vol_info {
49 char *fullpath;
50 spinlock_t smb_vol_lock;
51 struct smb_vol smb_vol;
52 char *mntdata;
53 struct list_head list;
54 struct list_head rlist;
55 struct kref refcnt;
56 };
57
58 static struct kmem_cache *cache_slab __read_mostly;
59 static struct workqueue_struct *dfscache_wq __read_mostly;
60
61 static int cache_ttl;
62 static DEFINE_SPINLOCK(cache_ttl_lock);
63
64 static struct nls_table *cache_nlsc;
65
66 /*
67 * Number of entries in the cache
68 */
69 static atomic_t cache_count;
70
71 static struct hlist_head cache_htable[CACHE_HTABLE_SIZE];
72 static DECLARE_RWSEM(htable_rw_lock);
73
74 static LIST_HEAD(vol_list);
75 static DEFINE_SPINLOCK(vol_list_lock);
76
77 static void refresh_cache_worker(struct work_struct *work);
78
79 static DECLARE_DELAYED_WORK(refresh_task, refresh_cache_worker);
80
81 static int get_normalized_path(const char *path, char **npath)
82 {
83 if (!path || strlen(path) < 3 || (*path != '\\' && *path != '/'))
84 return -EINVAL;
85
86 if (*path == '\\') {
87 *npath = (char *)path;
88 } else {
89 *npath = kstrndup(path, strlen(path), GFP_KERNEL);
90 if (!*npath)
91 return -ENOMEM;
92 convert_delimiter(*npath, '\\');
93 }
94 return 0;
95 }
96
97 static inline void free_normalized_path(const char *path, char *npath)
98 {
99 if (path != npath)
100 kfree(npath);
101 }
102
103 static inline bool cache_entry_expired(const struct cache_entry *ce)
104 {
105 struct timespec64 ts;
106
107 ktime_get_coarse_real_ts64(&ts);
108 return timespec64_compare(&ts, &ce->etime) >= 0;
109 }
110
111 static inline void free_tgts(struct cache_entry *ce)
112 {
113 struct cache_dfs_tgt *t, *n;
114
115 list_for_each_entry_safe(t, n, &ce->tlist, list) {
116 list_del(&t->list);
117 kfree(t->name);
118 kfree(t);
119 }
120 }
121
122 static inline void flush_cache_ent(struct cache_entry *ce)
123 {
124 hlist_del_init(&ce->hlist);
125 kfree(ce->path);
126 free_tgts(ce);
127 atomic_dec(&cache_count);
128 kmem_cache_free(cache_slab, ce);
129 }
130
131 static void flush_cache_ents(void)
132 {
133 int i;
134
135 for (i = 0; i < CACHE_HTABLE_SIZE; i++) {
136 struct hlist_head *l = &cache_htable[i];
137 struct hlist_node *n;
138 struct cache_entry *ce;
139
140 hlist_for_each_entry_safe(ce, n, l, hlist) {
141 if (!hlist_unhashed(&ce->hlist))
142 flush_cache_ent(ce);
143 }
144 }
145 }
146
147 /*
148 * dfs cache /proc file
149 */
150 static int dfscache_proc_show(struct seq_file *m, void *v)
151 {
152 int i;
153 struct cache_entry *ce;
154 struct cache_dfs_tgt *t;
155
156 seq_puts(m, "DFS cache\n---------\n");
157
158 down_read(&htable_rw_lock);
159 for (i = 0; i < CACHE_HTABLE_SIZE; i++) {
160 struct hlist_head *l = &cache_htable[i];
161
162 hlist_for_each_entry(ce, l, hlist) {
163 if (hlist_unhashed(&ce->hlist))
164 continue;
165
166 seq_printf(m,
167 "cache entry: path=%s,type=%s,ttl=%d,etime=%ld,"
168 "interlink=%s,path_consumed=%d,expired=%s\n",
169 ce->path,
170 ce->srvtype == DFS_TYPE_ROOT ? "root" : "link",
171 ce->ttl, ce->etime.tv_nsec,
172 IS_INTERLINK_SET(ce->flags) ? "yes" : "no",
173 ce->path_consumed,
174 cache_entry_expired(ce) ? "yes" : "no");
175
176 list_for_each_entry(t, &ce->tlist, list) {
177 seq_printf(m, " %s%s\n",
178 t->name,
179 ce->tgthint == t ? " (target hint)" : "");
180 }
181 }
182 }
183 up_read(&htable_rw_lock);
184
185 return 0;
186 }
187
188 static ssize_t dfscache_proc_write(struct file *file, const char __user *buffer,
189 size_t count, loff_t *ppos)
190 {
191 char c;
192 int rc;
193
194 rc = get_user(c, buffer);
195 if (rc)
196 return rc;
197
198 if (c != '0')
199 return -EINVAL;
200
201 cifs_dbg(FYI, "clearing dfs cache");
202
203 down_write(&htable_rw_lock);
204 flush_cache_ents();
205 up_write(&htable_rw_lock);
206
207 return count;
208 }
209
210 static int dfscache_proc_open(struct inode *inode, struct file *file)
211 {
212 return single_open(file, dfscache_proc_show, NULL);
213 }
214
215 const struct proc_ops dfscache_proc_ops = {
216 .proc_open = dfscache_proc_open,
217 .proc_read = seq_read,
218 .proc_lseek = seq_lseek,
219 .proc_release = single_release,
220 .proc_write = dfscache_proc_write,
221 };
222
223 #ifdef CONFIG_CIFS_DEBUG2
224 static inline void dump_tgts(const struct cache_entry *ce)
225 {
226 struct cache_dfs_tgt *t;
227
228 cifs_dbg(FYI, "target list:\n");
229 list_for_each_entry(t, &ce->tlist, list) {
230 cifs_dbg(FYI, " %s%s\n", t->name,
231 ce->tgthint == t ? " (target hint)" : "");
232 }
233 }
234
235 static inline void dump_ce(const struct cache_entry *ce)
236 {
237 cifs_dbg(FYI, "cache entry: path=%s,type=%s,ttl=%d,etime=%ld,"
238 "interlink=%s,path_consumed=%d,expired=%s\n", ce->path,
239 ce->srvtype == DFS_TYPE_ROOT ? "root" : "link", ce->ttl,
240 ce->etime.tv_nsec,
241 IS_INTERLINK_SET(ce->flags) ? "yes" : "no",
242 ce->path_consumed,
243 cache_entry_expired(ce) ? "yes" : "no");
244 dump_tgts(ce);
245 }
246
247 static inline void dump_refs(const struct dfs_info3_param *refs, int numrefs)
248 {
249 int i;
250
251 cifs_dbg(FYI, "DFS referrals returned by the server:\n");
252 for (i = 0; i < numrefs; i++) {
253 const struct dfs_info3_param *ref = &refs[i];
254
255 cifs_dbg(FYI,
256 "\n"
257 "flags: 0x%x\n"
258 "path_consumed: %d\n"
259 "server_type: 0x%x\n"
260 "ref_flag: 0x%x\n"
261 "path_name: %s\n"
262 "node_name: %s\n"
263 "ttl: %d (%dm)\n",
264 ref->flags, ref->path_consumed, ref->server_type,
265 ref->ref_flag, ref->path_name, ref->node_name,
266 ref->ttl, ref->ttl / 60);
267 }
268 }
269 #else
270 #define dump_tgts(e)
271 #define dump_ce(e)
272 #define dump_refs(r, n)
273 #endif
274
275 /**
276 * dfs_cache_init - Initialize DFS referral cache.
277 *
278 * Return zero if initialized successfully, otherwise non-zero.
279 */
280 int dfs_cache_init(void)
281 {
282 int rc;
283 int i;
284
285 dfscache_wq = alloc_workqueue("cifs-dfscache",
286 WQ_FREEZABLE | WQ_MEM_RECLAIM, 1);
287 if (!dfscache_wq)
288 return -ENOMEM;
289
290 cache_slab = kmem_cache_create("cifs_dfs_cache",
291 sizeof(struct cache_entry), 0,
292 SLAB_HWCACHE_ALIGN, NULL);
293 if (!cache_slab) {
294 rc = -ENOMEM;
295 goto out_destroy_wq;
296 }
297
298 for (i = 0; i < CACHE_HTABLE_SIZE; i++)
299 INIT_HLIST_HEAD(&cache_htable[i]);
300
301 atomic_set(&cache_count, 0);
302 cache_nlsc = load_nls_default();
303
304 cifs_dbg(FYI, "%s: initialized DFS referral cache\n", __func__);
305 return 0;
306
307 out_destroy_wq:
308 destroy_workqueue(dfscache_wq);
309 return rc;
310 }
311
312 static inline unsigned int cache_entry_hash(const void *data, int size)
313 {
314 unsigned int h;
315
316 h = jhash(data, size, 0);
317 return h & (CACHE_HTABLE_SIZE - 1);
318 }
319
320 /* Check whether second path component of @path is SYSVOL or NETLOGON */
321 static inline bool is_sysvol_or_netlogon(const char *path)
322 {
323 const char *s;
324 char sep = path[0];
325
326 s = strchr(path + 1, sep) + 1;
327 return !strncasecmp(s, "sysvol", strlen("sysvol")) ||
328 !strncasecmp(s, "netlogon", strlen("netlogon"));
329 }
330
331 /* Return target hint of a DFS cache entry */
332 static inline char *get_tgt_name(const struct cache_entry *ce)
333 {
334 struct cache_dfs_tgt *t = ce->tgthint;
335
336 return t ? t->name : ERR_PTR(-ENOENT);
337 }
338
339 /* Return expire time out of a new entry's TTL */
340 static inline struct timespec64 get_expire_time(int ttl)
341 {
342 struct timespec64 ts = {
343 .tv_sec = ttl,
344 .tv_nsec = 0,
345 };
346 struct timespec64 now;
347
348 ktime_get_coarse_real_ts64(&now);
349 return timespec64_add(now, ts);
350 }
351
352 /* Allocate a new DFS target */
353 static struct cache_dfs_tgt *alloc_target(const char *name)
354 {
355 struct cache_dfs_tgt *t;
356
357 t = kmalloc(sizeof(*t), GFP_ATOMIC);
358 if (!t)
359 return ERR_PTR(-ENOMEM);
360 t->name = kstrndup(name, strlen(name), GFP_ATOMIC);
361 if (!t->name) {
362 kfree(t);
363 return ERR_PTR(-ENOMEM);
364 }
365 INIT_LIST_HEAD(&t->list);
366 return t;
367 }
368
369 /*
370 * Copy DFS referral information to a cache entry and conditionally update
371 * target hint.
372 */
373 static int copy_ref_data(const struct dfs_info3_param *refs, int numrefs,
374 struct cache_entry *ce, const char *tgthint)
375 {
376 int i;
377
378 ce->ttl = refs[0].ttl;
379 ce->etime = get_expire_time(ce->ttl);
380 ce->srvtype = refs[0].server_type;
381 ce->flags = refs[0].ref_flag;
382 ce->path_consumed = refs[0].path_consumed;
383
384 for (i = 0; i < numrefs; i++) {
385 struct cache_dfs_tgt *t;
386
387 t = alloc_target(refs[i].node_name);
388 if (IS_ERR(t)) {
389 free_tgts(ce);
390 return PTR_ERR(t);
391 }
392 if (tgthint && !strcasecmp(t->name, tgthint)) {
393 list_add(&t->list, &ce->tlist);
394 tgthint = NULL;
395 } else {
396 list_add_tail(&t->list, &ce->tlist);
397 }
398 ce->numtgts++;
399 }
400
401 ce->tgthint = list_first_entry_or_null(&ce->tlist,
402 struct cache_dfs_tgt, list);
403
404 return 0;
405 }
406
407 /* Allocate a new cache entry */
408 static struct cache_entry *alloc_cache_entry(const char *path,
409 const struct dfs_info3_param *refs,
410 int numrefs)
411 {
412 struct cache_entry *ce;
413 int rc;
414
415 ce = kmem_cache_zalloc(cache_slab, GFP_KERNEL);
416 if (!ce)
417 return ERR_PTR(-ENOMEM);
418
419 ce->path = kstrndup(path, strlen(path), GFP_KERNEL);
420 if (!ce->path) {
421 kmem_cache_free(cache_slab, ce);
422 return ERR_PTR(-ENOMEM);
423 }
424 INIT_HLIST_NODE(&ce->hlist);
425 INIT_LIST_HEAD(&ce->tlist);
426
427 rc = copy_ref_data(refs, numrefs, ce, NULL);
428 if (rc) {
429 kfree(ce->path);
430 kmem_cache_free(cache_slab, ce);
431 ce = ERR_PTR(rc);
432 }
433 return ce;
434 }
435
436 /* Must be called with htable_rw_lock held */
437 static void remove_oldest_entry(void)
438 {
439 int i;
440 struct cache_entry *ce;
441 struct cache_entry *to_del = NULL;
442
443 for (i = 0; i < CACHE_HTABLE_SIZE; i++) {
444 struct hlist_head *l = &cache_htable[i];
445
446 hlist_for_each_entry(ce, l, hlist) {
447 if (hlist_unhashed(&ce->hlist))
448 continue;
449 if (!to_del || timespec64_compare(&ce->etime,
450 &to_del->etime) < 0)
451 to_del = ce;
452 }
453 }
454
455 if (!to_del) {
456 cifs_dbg(FYI, "%s: no entry to remove", __func__);
457 return;
458 }
459
460 cifs_dbg(FYI, "%s: removing entry", __func__);
461 dump_ce(to_del);
462 flush_cache_ent(to_del);
463 }
464
465 /* Add a new DFS cache entry */
466 static int add_cache_entry(const char *path, unsigned int hash,
467 struct dfs_info3_param *refs, int numrefs)
468 {
469 struct cache_entry *ce;
470
471 ce = alloc_cache_entry(path, refs, numrefs);
472 if (IS_ERR(ce))
473 return PTR_ERR(ce);
474
475 spin_lock(&cache_ttl_lock);
476 if (!cache_ttl) {
477 cache_ttl = ce->ttl;
478 queue_delayed_work(dfscache_wq, &refresh_task, cache_ttl * HZ);
479 } else {
480 cache_ttl = min_t(int, cache_ttl, ce->ttl);
481 mod_delayed_work(dfscache_wq, &refresh_task, cache_ttl * HZ);
482 }
483 spin_unlock(&cache_ttl_lock);
484
485 down_write(&htable_rw_lock);
486 hlist_add_head(&ce->hlist, &cache_htable[hash]);
487 dump_ce(ce);
488 up_write(&htable_rw_lock);
489
490 return 0;
491 }
492
493 /*
494 * Find a DFS cache entry in hash table and optionally check prefix path against
495 * @path.
496 * Use whole path components in the match.
497 * Must be called with htable_rw_lock held.
498 *
499 * Return ERR_PTR(-ENOENT) if the entry is not found.
500 */
501 static struct cache_entry *lookup_cache_entry(const char *path,
502 unsigned int *hash)
503 {
504 struct cache_entry *ce;
505 unsigned int h;
506 bool found = false;
507
508 h = cache_entry_hash(path, strlen(path));
509
510 hlist_for_each_entry(ce, &cache_htable[h], hlist) {
511 if (!strcasecmp(path, ce->path)) {
512 found = true;
513 dump_ce(ce);
514 break;
515 }
516 }
517
518 if (!found)
519 ce = ERR_PTR(-ENOENT);
520 if (hash)
521 *hash = h;
522
523 return ce;
524 }
525
526 static void __vol_release(struct vol_info *vi)
527 {
528 kfree(vi->fullpath);
529 kfree(vi->mntdata);
530 cifs_cleanup_volume_info_contents(&vi->smb_vol);
531 kfree(vi);
532 }
533
534 static void vol_release(struct kref *kref)
535 {
536 struct vol_info *vi = container_of(kref, struct vol_info, refcnt);
537
538 spin_lock(&vol_list_lock);
539 list_del(&vi->list);
540 spin_unlock(&vol_list_lock);
541 __vol_release(vi);
542 }
543
544 static inline void free_vol_list(void)
545 {
546 struct vol_info *vi, *nvi;
547
548 list_for_each_entry_safe(vi, nvi, &vol_list, list) {
549 list_del_init(&vi->list);
550 __vol_release(vi);
551 }
552 }
553
554 /**
555 * dfs_cache_destroy - destroy DFS referral cache
556 */
557 void dfs_cache_destroy(void)
558 {
559 cancel_delayed_work_sync(&refresh_task);
560 unload_nls(cache_nlsc);
561 free_vol_list();
562 flush_cache_ents();
563 kmem_cache_destroy(cache_slab);
564 destroy_workqueue(dfscache_wq);
565
566 cifs_dbg(FYI, "%s: destroyed DFS referral cache\n", __func__);
567 }
568
569 /* Must be called with htable_rw_lock held */
570 static int __update_cache_entry(const char *path,
571 const struct dfs_info3_param *refs,
572 int numrefs)
573 {
574 int rc;
575 struct cache_entry *ce;
576 char *s, *th = NULL;
577
578 ce = lookup_cache_entry(path, NULL);
579 if (IS_ERR(ce))
580 return PTR_ERR(ce);
581
582 if (ce->tgthint) {
583 s = ce->tgthint->name;
584 th = kstrndup(s, strlen(s), GFP_ATOMIC);
585 if (!th)
586 return -ENOMEM;
587 }
588
589 free_tgts(ce);
590 ce->numtgts = 0;
591
592 rc = copy_ref_data(refs, numrefs, ce, th);
593
594 kfree(th);
595
596 return rc;
597 }
598
599 static int get_dfs_referral(const unsigned int xid, struct cifs_ses *ses,
600 const struct nls_table *nls_codepage, int remap,
601 const char *path, struct dfs_info3_param **refs,
602 int *numrefs)
603 {
604 cifs_dbg(FYI, "%s: get an DFS referral for %s\n", __func__, path);
605
606 if (!ses || !ses->server || !ses->server->ops->get_dfs_refer)
607 return -EOPNOTSUPP;
608 if (unlikely(!nls_codepage))
609 return -EINVAL;
610
611 *refs = NULL;
612 *numrefs = 0;
613
614 return ses->server->ops->get_dfs_refer(xid, ses, path, refs, numrefs,
615 nls_codepage, remap);
616 }
617
618 /* Update an expired cache entry by getting a new DFS referral from server */
619 static int update_cache_entry(const char *path,
620 const struct dfs_info3_param *refs,
621 int numrefs)
622 {
623
624 int rc;
625
626 down_write(&htable_rw_lock);
627 rc = __update_cache_entry(path, refs, numrefs);
628 up_write(&htable_rw_lock);
629
630 return rc;
631 }
632
633 /*
634 * Find, create or update a DFS cache entry.
635 *
636 * If the entry wasn't found, it will create a new one. Or if it was found but
637 * expired, then it will update the entry accordingly.
638 *
639 * For interlinks, __cifs_dfs_mount() and expand_dfs_referral() are supposed to
640 * handle them properly.
641 */
642 static int __dfs_cache_find(const unsigned int xid, struct cifs_ses *ses,
643 const struct nls_table *nls_codepage, int remap,
644 const char *path, bool noreq)
645 {
646 int rc;
647 unsigned int hash;
648 struct cache_entry *ce;
649 struct dfs_info3_param *refs = NULL;
650 int numrefs = 0;
651 bool newent = false;
652
653 cifs_dbg(FYI, "%s: search path: %s\n", __func__, path);
654
655 down_read(&htable_rw_lock);
656
657 ce = lookup_cache_entry(path, &hash);
658
659 /*
660 * If @noreq is set, no requests will be sent to the server. Just return
661 * the cache entry.
662 */
663 if (noreq) {
664 up_read(&htable_rw_lock);
665 return PTR_ERR_OR_ZERO(ce);
666 }
667
668 if (!IS_ERR(ce)) {
669 if (!cache_entry_expired(ce)) {
670 dump_ce(ce);
671 up_read(&htable_rw_lock);
672 return 0;
673 }
674 } else {
675 newent = true;
676 }
677
678 up_read(&htable_rw_lock);
679
680 /*
681 * No entry was found.
682 *
683 * Request a new DFS referral in order to create a new cache entry, or
684 * updating an existing one.
685 */
686 rc = get_dfs_referral(xid, ses, nls_codepage, remap, path,
687 &refs, &numrefs);
688 if (rc)
689 return rc;
690
691 dump_refs(refs, numrefs);
692
693 if (!newent) {
694 rc = update_cache_entry(path, refs, numrefs);
695 goto out_free_refs;
696 }
697
698 if (atomic_read(&cache_count) >= CACHE_MAX_ENTRIES) {
699 cifs_dbg(FYI, "%s: reached max cache size (%d)", __func__,
700 CACHE_MAX_ENTRIES);
701 down_write(&htable_rw_lock);
702 remove_oldest_entry();
703 up_write(&htable_rw_lock);
704 }
705
706 rc = add_cache_entry(path, hash, refs, numrefs);
707 if (!rc)
708 atomic_inc(&cache_count);
709
710 out_free_refs:
711 free_dfs_info_array(refs, numrefs);
712 return rc;
713 }
714
715 /*
716 * Set up a DFS referral from a given cache entry.
717 *
718 * Must be called with htable_rw_lock held.
719 */
720 static int setup_referral(const char *path, struct cache_entry *ce,
721 struct dfs_info3_param *ref, const char *target)
722 {
723 int rc;
724
725 cifs_dbg(FYI, "%s: set up new ref\n", __func__);
726
727 memset(ref, 0, sizeof(*ref));
728
729 ref->path_name = kstrndup(path, strlen(path), GFP_ATOMIC);
730 if (!ref->path_name)
731 return -ENOMEM;
732
733 ref->node_name = kstrndup(target, strlen(target), GFP_ATOMIC);
734 if (!ref->node_name) {
735 rc = -ENOMEM;
736 goto err_free_path;
737 }
738
739 ref->path_consumed = ce->path_consumed;
740 ref->ttl = ce->ttl;
741 ref->server_type = ce->srvtype;
742 ref->ref_flag = ce->flags;
743
744 return 0;
745
746 err_free_path:
747 kfree(ref->path_name);
748 ref->path_name = NULL;
749 return rc;
750 }
751
752 /* Return target list of a DFS cache entry */
753 static int get_targets(struct cache_entry *ce, struct dfs_cache_tgt_list *tl)
754 {
755 int rc;
756 struct list_head *head = &tl->tl_list;
757 struct cache_dfs_tgt *t;
758 struct dfs_cache_tgt_iterator *it, *nit;
759
760 memset(tl, 0, sizeof(*tl));
761 INIT_LIST_HEAD(head);
762
763 list_for_each_entry(t, &ce->tlist, list) {
764 it = kzalloc(sizeof(*it), GFP_ATOMIC);
765 if (!it) {
766 rc = -ENOMEM;
767 goto err_free_it;
768 }
769
770 it->it_name = kstrndup(t->name, strlen(t->name), GFP_ATOMIC);
771 if (!it->it_name) {
772 kfree(it);
773 rc = -ENOMEM;
774 goto err_free_it;
775 }
776
777 if (ce->tgthint == t)
778 list_add(&it->it_list, head);
779 else
780 list_add_tail(&it->it_list, head);
781 }
782
783 tl->tl_numtgts = ce->numtgts;
784
785 return 0;
786
787 err_free_it:
788 list_for_each_entry_safe(it, nit, head, it_list) {
789 kfree(it->it_name);
790 kfree(it);
791 }
792 return rc;
793 }
794
795 /**
796 * dfs_cache_find - find a DFS cache entry
797 *
798 * If it doesn't find the cache entry, then it will get a DFS referral
799 * for @path and create a new entry.
800 *
801 * In case the cache entry exists but expired, it will get a DFS referral
802 * for @path and then update the respective cache entry.
803 *
804 * These parameters are passed down to the get_dfs_refer() call if it
805 * needs to be issued:
806 * @xid: syscall xid
807 * @ses: smb session to issue the request on
808 * @nls_codepage: charset conversion
809 * @remap: path character remapping type
810 * @path: path to lookup in DFS referral cache.
811 *
812 * @ref: when non-NULL, store single DFS referral result in it.
813 * @tgt_list: when non-NULL, store complete DFS target list in it.
814 *
815 * Return zero if the target was found, otherwise non-zero.
816 */
817 int dfs_cache_find(const unsigned int xid, struct cifs_ses *ses,
818 const struct nls_table *nls_codepage, int remap,
819 const char *path, struct dfs_info3_param *ref,
820 struct dfs_cache_tgt_list *tgt_list)
821 {
822 int rc;
823 char *npath;
824 struct cache_entry *ce;
825
826 rc = get_normalized_path(path, &npath);
827 if (rc)
828 return rc;
829
830 rc = __dfs_cache_find(xid, ses, nls_codepage, remap, npath, false);
831 if (rc)
832 goto out_free_path;
833
834 down_read(&htable_rw_lock);
835
836 ce = lookup_cache_entry(npath, NULL);
837 if (IS_ERR(ce)) {
838 up_read(&htable_rw_lock);
839 rc = PTR_ERR(ce);
840 goto out_free_path;
841 }
842
843 if (ref)
844 rc = setup_referral(path, ce, ref, get_tgt_name(ce));
845 else
846 rc = 0;
847 if (!rc && tgt_list)
848 rc = get_targets(ce, tgt_list);
849
850 up_read(&htable_rw_lock);
851
852 out_free_path:
853 free_normalized_path(path, npath);
854 return rc;
855 }
856
857 /**
858 * dfs_cache_noreq_find - find a DFS cache entry without sending any requests to
859 * the currently connected server.
860 *
861 * NOTE: This function will neither update a cache entry in case it was
862 * expired, nor create a new cache entry if @path hasn't been found. It heavily
863 * relies on an existing cache entry.
864 *
865 * @path: path to lookup in the DFS referral cache.
866 * @ref: when non-NULL, store single DFS referral result in it.
867 * @tgt_list: when non-NULL, store complete DFS target list in it.
868 *
869 * Return 0 if successful.
870 * Return -ENOENT if the entry was not found.
871 * Return non-zero for other errors.
872 */
873 int dfs_cache_noreq_find(const char *path, struct dfs_info3_param *ref,
874 struct dfs_cache_tgt_list *tgt_list)
875 {
876 int rc;
877 char *npath;
878 struct cache_entry *ce;
879
880 rc = get_normalized_path(path, &npath);
881 if (rc)
882 return rc;
883
884 cifs_dbg(FYI, "%s: path: %s\n", __func__, npath);
885
886 down_read(&htable_rw_lock);
887
888 ce = lookup_cache_entry(npath, NULL);
889 if (IS_ERR(ce)) {
890 rc = PTR_ERR(ce);
891 goto out_unlock;
892 }
893
894 if (ref)
895 rc = setup_referral(path, ce, ref, get_tgt_name(ce));
896 else
897 rc = 0;
898 if (!rc && tgt_list)
899 rc = get_targets(ce, tgt_list);
900
901 out_unlock:
902 up_read(&htable_rw_lock);
903 free_normalized_path(path, npath);
904
905 return rc;
906 }
907
908 /**
909 * dfs_cache_update_tgthint - update target hint of a DFS cache entry
910 *
911 * If it doesn't find the cache entry, then it will get a DFS referral for @path
912 * and create a new entry.
913 *
914 * In case the cache entry exists but expired, it will get a DFS referral
915 * for @path and then update the respective cache entry.
916 *
917 * @xid: syscall id
918 * @ses: smb session
919 * @nls_codepage: charset conversion
920 * @remap: type of character remapping for paths
921 * @path: path to lookup in DFS referral cache.
922 * @it: DFS target iterator
923 *
924 * Return zero if the target hint was updated successfully, otherwise non-zero.
925 */
926 int dfs_cache_update_tgthint(const unsigned int xid, struct cifs_ses *ses,
927 const struct nls_table *nls_codepage, int remap,
928 const char *path,
929 const struct dfs_cache_tgt_iterator *it)
930 {
931 int rc;
932 char *npath;
933 struct cache_entry *ce;
934 struct cache_dfs_tgt *t;
935
936 rc = get_normalized_path(path, &npath);
937 if (rc)
938 return rc;
939
940 cifs_dbg(FYI, "%s: update target hint - path: %s\n", __func__, npath);
941
942 rc = __dfs_cache_find(xid, ses, nls_codepage, remap, npath, false);
943 if (rc)
944 goto out_free_path;
945
946 down_write(&htable_rw_lock);
947
948 ce = lookup_cache_entry(npath, NULL);
949 if (IS_ERR(ce)) {
950 rc = PTR_ERR(ce);
951 goto out_unlock;
952 }
953
954 t = ce->tgthint;
955
956 if (likely(!strcasecmp(it->it_name, t->name)))
957 goto out_unlock;
958
959 list_for_each_entry(t, &ce->tlist, list) {
960 if (!strcasecmp(t->name, it->it_name)) {
961 ce->tgthint = t;
962 cifs_dbg(FYI, "%s: new target hint: %s\n", __func__,
963 it->it_name);
964 break;
965 }
966 }
967
968 out_unlock:
969 up_write(&htable_rw_lock);
970 out_free_path:
971 free_normalized_path(path, npath);
972
973 return rc;
974 }
975
976 /**
977 * dfs_cache_noreq_update_tgthint - update target hint of a DFS cache entry
978 * without sending any requests to the currently connected server.
979 *
980 * NOTE: This function will neither update a cache entry in case it was
981 * expired, nor create a new cache entry if @path hasn't been found. It heavily
982 * relies on an existing cache entry.
983 *
984 * @path: path to lookup in DFS referral cache.
985 * @it: target iterator which contains the target hint to update the cache
986 * entry with.
987 *
988 * Return zero if the target hint was updated successfully, otherwise non-zero.
989 */
990 int dfs_cache_noreq_update_tgthint(const char *path,
991 const struct dfs_cache_tgt_iterator *it)
992 {
993 int rc;
994 char *npath;
995 struct cache_entry *ce;
996 struct cache_dfs_tgt *t;
997
998 if (!it)
999 return -EINVAL;
1000
1001 rc = get_normalized_path(path, &npath);
1002 if (rc)
1003 return rc;
1004
1005 cifs_dbg(FYI, "%s: path: %s\n", __func__, npath);
1006
1007 down_write(&htable_rw_lock);
1008
1009 ce = lookup_cache_entry(npath, NULL);
1010 if (IS_ERR(ce)) {
1011 rc = PTR_ERR(ce);
1012 goto out_unlock;
1013 }
1014
1015 rc = 0;
1016 t = ce->tgthint;
1017
1018 if (unlikely(!strcasecmp(it->it_name, t->name)))
1019 goto out_unlock;
1020
1021 list_for_each_entry(t, &ce->tlist, list) {
1022 if (!strcasecmp(t->name, it->it_name)) {
1023 ce->tgthint = t;
1024 cifs_dbg(FYI, "%s: new target hint: %s\n", __func__,
1025 it->it_name);
1026 break;
1027 }
1028 }
1029
1030 out_unlock:
1031 up_write(&htable_rw_lock);
1032 free_normalized_path(path, npath);
1033
1034 return rc;
1035 }
1036
1037 /**
1038 * dfs_cache_get_tgt_referral - returns a DFS referral (@ref) from a given
1039 * target iterator (@it).
1040 *
1041 * @path: path to lookup in DFS referral cache.
1042 * @it: DFS target iterator.
1043 * @ref: DFS referral pointer to set up the gathered information.
1044 *
1045 * Return zero if the DFS referral was set up correctly, otherwise non-zero.
1046 */
1047 int dfs_cache_get_tgt_referral(const char *path,
1048 const struct dfs_cache_tgt_iterator *it,
1049 struct dfs_info3_param *ref)
1050 {
1051 int rc;
1052 char *npath;
1053 struct cache_entry *ce;
1054
1055 if (!it || !ref)
1056 return -EINVAL;
1057
1058 rc = get_normalized_path(path, &npath);
1059 if (rc)
1060 return rc;
1061
1062 cifs_dbg(FYI, "%s: path: %s\n", __func__, npath);
1063
1064 down_read(&htable_rw_lock);
1065
1066 ce = lookup_cache_entry(npath, NULL);
1067 if (IS_ERR(ce)) {
1068 rc = PTR_ERR(ce);
1069 goto out_unlock;
1070 }
1071
1072 cifs_dbg(FYI, "%s: target name: %s\n", __func__, it->it_name);
1073
1074 rc = setup_referral(path, ce, ref, it->it_name);
1075
1076 out_unlock:
1077 up_read(&htable_rw_lock);
1078 free_normalized_path(path, npath);
1079
1080 return rc;
1081 }
1082
1083 static int dup_vol(struct smb_vol *vol, struct smb_vol *new)
1084 {
1085 memcpy(new, vol, sizeof(*new));
1086
1087 if (vol->username) {
1088 new->username = kstrndup(vol->username, strlen(vol->username),
1089 GFP_KERNEL);
1090 if (!new->username)
1091 return -ENOMEM;
1092 }
1093 if (vol->password) {
1094 new->password = kstrndup(vol->password, strlen(vol->password),
1095 GFP_KERNEL);
1096 if (!new->password)
1097 goto err_free_username;
1098 }
1099 if (vol->UNC) {
1100 cifs_dbg(FYI, "%s: vol->UNC: %s\n", __func__, vol->UNC);
1101 new->UNC = kstrndup(vol->UNC, strlen(vol->UNC), GFP_KERNEL);
1102 if (!new->UNC)
1103 goto err_free_password;
1104 }
1105 if (vol->domainname) {
1106 new->domainname = kstrndup(vol->domainname,
1107 strlen(vol->domainname), GFP_KERNEL);
1108 if (!new->domainname)
1109 goto err_free_unc;
1110 }
1111 if (vol->iocharset) {
1112 new->iocharset = kstrndup(vol->iocharset,
1113 strlen(vol->iocharset), GFP_KERNEL);
1114 if (!new->iocharset)
1115 goto err_free_domainname;
1116 }
1117 if (vol->prepath) {
1118 cifs_dbg(FYI, "%s: vol->prepath: %s\n", __func__, vol->prepath);
1119 new->prepath = kstrndup(vol->prepath, strlen(vol->prepath),
1120 GFP_KERNEL);
1121 if (!new->prepath)
1122 goto err_free_iocharset;
1123 }
1124
1125 return 0;
1126
1127 err_free_iocharset:
1128 kfree(new->iocharset);
1129 err_free_domainname:
1130 kfree(new->domainname);
1131 err_free_unc:
1132 kfree(new->UNC);
1133 err_free_password:
1134 kzfree(new->password);
1135 err_free_username:
1136 kfree(new->username);
1137 kfree(new);
1138 return -ENOMEM;
1139 }
1140
1141 /**
1142 * dfs_cache_add_vol - add a cifs volume during mount() that will be handled by
1143 * DFS cache refresh worker.
1144 *
1145 * @mntdata: mount data.
1146 * @vol: cifs volume.
1147 * @fullpath: origin full path.
1148 *
1149 * Return zero if volume was set up correctly, otherwise non-zero.
1150 */
1151 int dfs_cache_add_vol(char *mntdata, struct smb_vol *vol, const char *fullpath)
1152 {
1153 int rc;
1154 struct vol_info *vi;
1155
1156 if (!vol || !fullpath || !mntdata)
1157 return -EINVAL;
1158
1159 cifs_dbg(FYI, "%s: fullpath: %s\n", __func__, fullpath);
1160
1161 vi = kzalloc(sizeof(*vi), GFP_KERNEL);
1162 if (!vi)
1163 return -ENOMEM;
1164
1165 vi->fullpath = kstrndup(fullpath, strlen(fullpath), GFP_KERNEL);
1166 if (!vi->fullpath) {
1167 rc = -ENOMEM;
1168 goto err_free_vi;
1169 }
1170
1171 rc = dup_vol(vol, &vi->smb_vol);
1172 if (rc)
1173 goto err_free_fullpath;
1174
1175 vi->mntdata = mntdata;
1176 spin_lock_init(&vi->smb_vol_lock);
1177 kref_init(&vi->refcnt);
1178
1179 spin_lock(&vol_list_lock);
1180 list_add_tail(&vi->list, &vol_list);
1181 spin_unlock(&vol_list_lock);
1182
1183 return 0;
1184
1185 err_free_fullpath:
1186 kfree(vi->fullpath);
1187 err_free_vi:
1188 kfree(vi);
1189 return rc;
1190 }
1191
1192 /* Must be called with vol_list_lock held */
1193 static struct vol_info *find_vol(const char *fullpath)
1194 {
1195 struct vol_info *vi;
1196
1197 list_for_each_entry(vi, &vol_list, list) {
1198 cifs_dbg(FYI, "%s: vi->fullpath: %s\n", __func__, vi->fullpath);
1199 if (!strcasecmp(vi->fullpath, fullpath))
1200 return vi;
1201 }
1202 return ERR_PTR(-ENOENT);
1203 }
1204
1205 /**
1206 * dfs_cache_update_vol - update vol info in DFS cache after failover
1207 *
1208 * @fullpath: fullpath to look up in volume list.
1209 * @server: TCP ses pointer.
1210 *
1211 * Return zero if volume was updated, otherwise non-zero.
1212 */
1213 int dfs_cache_update_vol(const char *fullpath, struct TCP_Server_Info *server)
1214 {
1215 struct vol_info *vi;
1216
1217 if (!fullpath || !server)
1218 return -EINVAL;
1219
1220 cifs_dbg(FYI, "%s: fullpath: %s\n", __func__, fullpath);
1221
1222 spin_lock(&vol_list_lock);
1223 vi = find_vol(fullpath);
1224 if (IS_ERR(vi)) {
1225 spin_unlock(&vol_list_lock);
1226 return PTR_ERR(vi);
1227 }
1228 kref_get(&vi->refcnt);
1229 spin_unlock(&vol_list_lock);
1230
1231 cifs_dbg(FYI, "%s: updating volume info\n", __func__);
1232 spin_lock(&vi->smb_vol_lock);
1233 memcpy(&vi->smb_vol.dstaddr, &server->dstaddr,
1234 sizeof(vi->smb_vol.dstaddr));
1235 spin_unlock(&vi->smb_vol_lock);
1236
1237 kref_put(&vi->refcnt, vol_release);
1238
1239 return 0;
1240 }
1241
1242 /**
1243 * dfs_cache_del_vol - remove volume info in DFS cache during umount()
1244 *
1245 * @fullpath: fullpath to look up in volume list.
1246 */
1247 void dfs_cache_del_vol(const char *fullpath)
1248 {
1249 struct vol_info *vi;
1250
1251 if (!fullpath || !*fullpath)
1252 return;
1253
1254 cifs_dbg(FYI, "%s: fullpath: %s\n", __func__, fullpath);
1255
1256 spin_lock(&vol_list_lock);
1257 vi = find_vol(fullpath);
1258 spin_unlock(&vol_list_lock);
1259
1260 kref_put(&vi->refcnt, vol_release);
1261 }
1262
1263 /**
1264 * dfs_cache_get_tgt_share - parse a DFS target
1265 *
1266 * @it: DFS target iterator.
1267 * @share: tree name.
1268 * @share_len: length of tree name.
1269 * @prefix: prefix path.
1270 * @prefix_len: length of prefix path.
1271 *
1272 * Return zero if target was parsed correctly, otherwise non-zero.
1273 */
1274 int dfs_cache_get_tgt_share(const struct dfs_cache_tgt_iterator *it,
1275 const char **share, size_t *share_len,
1276 const char **prefix, size_t *prefix_len)
1277 {
1278 char *s, sep;
1279
1280 if (!it || !share || !share_len || !prefix || !prefix_len)
1281 return -EINVAL;
1282
1283 sep = it->it_name[0];
1284 if (sep != '\\' && sep != '/')
1285 return -EINVAL;
1286
1287 s = strchr(it->it_name + 1, sep);
1288 if (!s)
1289 return -EINVAL;
1290
1291 s = strchrnul(s + 1, sep);
1292
1293 *share = it->it_name;
1294 *share_len = s - it->it_name;
1295 *prefix = *s ? s + 1 : s;
1296 *prefix_len = &it->it_name[strlen(it->it_name)] - *prefix;
1297
1298 return 0;
1299 }
1300
1301 /* Get all tcons that are within a DFS namespace and can be refreshed */
1302 static void get_tcons(struct TCP_Server_Info *server, struct list_head *head)
1303 {
1304 struct cifs_ses *ses;
1305 struct cifs_tcon *tcon;
1306
1307 INIT_LIST_HEAD(head);
1308
1309 spin_lock(&cifs_tcp_ses_lock);
1310 list_for_each_entry(ses, &server->smb_ses_list, smb_ses_list) {
1311 list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
1312 if (!tcon->need_reconnect && !tcon->need_reopen_files &&
1313 tcon->dfs_path) {
1314 tcon->tc_count++;
1315 list_add_tail(&tcon->ulist, head);
1316 }
1317 }
1318 if (ses->tcon_ipc && !ses->tcon_ipc->need_reconnect &&
1319 ses->tcon_ipc->dfs_path) {
1320 list_add_tail(&ses->tcon_ipc->ulist, head);
1321 }
1322 }
1323 spin_unlock(&cifs_tcp_ses_lock);
1324 }
1325
1326 static bool is_dfs_link(const char *path)
1327 {
1328 char *s;
1329
1330 s = strchr(path + 1, '\\');
1331 if (!s)
1332 return false;
1333 return !!strchr(s + 1, '\\');
1334 }
1335
1336 static char *get_dfs_root(const char *path)
1337 {
1338 char *s, *npath;
1339
1340 s = strchr(path + 1, '\\');
1341 if (!s)
1342 return ERR_PTR(-EINVAL);
1343
1344 s = strchr(s + 1, '\\');
1345 if (!s)
1346 return ERR_PTR(-EINVAL);
1347
1348 npath = kstrndup(path, s - path, GFP_KERNEL);
1349 if (!npath)
1350 return ERR_PTR(-ENOMEM);
1351
1352 return npath;
1353 }
1354
1355 static inline void put_tcp_server(struct TCP_Server_Info *server)
1356 {
1357 cifs_put_tcp_session(server, 0);
1358 }
1359
1360 static struct TCP_Server_Info *get_tcp_server(struct smb_vol *vol)
1361 {
1362 struct TCP_Server_Info *server;
1363
1364 server = cifs_find_tcp_session(vol);
1365 if (IS_ERR_OR_NULL(server))
1366 return NULL;
1367
1368 spin_lock(&GlobalMid_Lock);
1369 if (server->tcpStatus != CifsGood) {
1370 spin_unlock(&GlobalMid_Lock);
1371 put_tcp_server(server);
1372 return NULL;
1373 }
1374 spin_unlock(&GlobalMid_Lock);
1375
1376 return server;
1377 }
1378
1379 /* Find root SMB session out of a DFS link path */
1380 static struct cifs_ses *find_root_ses(struct vol_info *vi,
1381 struct cifs_tcon *tcon,
1382 const char *path)
1383 {
1384 char *rpath;
1385 int rc;
1386 struct cache_entry *ce;
1387 struct dfs_info3_param ref = {0};
1388 char *mdata = NULL, *devname = NULL;
1389 struct TCP_Server_Info *server;
1390 struct cifs_ses *ses;
1391 struct smb_vol vol = {NULL};
1392
1393 rpath = get_dfs_root(path);
1394 if (IS_ERR(rpath))
1395 return ERR_CAST(rpath);
1396
1397 down_read(&htable_rw_lock);
1398
1399 ce = lookup_cache_entry(rpath, NULL);
1400 if (IS_ERR(ce)) {
1401 up_read(&htable_rw_lock);
1402 ses = ERR_CAST(ce);
1403 goto out;
1404 }
1405
1406 rc = setup_referral(path, ce, &ref, get_tgt_name(ce));
1407 if (rc) {
1408 up_read(&htable_rw_lock);
1409 ses = ERR_PTR(rc);
1410 goto out;
1411 }
1412
1413 up_read(&htable_rw_lock);
1414
1415 mdata = cifs_compose_mount_options(vi->mntdata, rpath, &ref,
1416 &devname);
1417 free_dfs_info_param(&ref);
1418
1419 if (IS_ERR(mdata)) {
1420 ses = ERR_CAST(mdata);
1421 mdata = NULL;
1422 goto out;
1423 }
1424
1425 rc = cifs_setup_volume_info(&vol, mdata, devname, false);
1426 kfree(devname);
1427
1428 if (rc) {
1429 ses = ERR_PTR(rc);
1430 goto out;
1431 }
1432
1433 server = get_tcp_server(&vol);
1434 if (!server) {
1435 ses = ERR_PTR(-EHOSTDOWN);
1436 goto out;
1437 }
1438
1439 ses = cifs_get_smb_ses(server, &vol);
1440
1441 out:
1442 cifs_cleanup_volume_info_contents(&vol);
1443 kfree(mdata);
1444 kfree(rpath);
1445
1446 return ses;
1447 }
1448
1449 /* Refresh DFS cache entry from a given tcon */
1450 static int refresh_tcon(struct vol_info *vi, struct cifs_tcon *tcon)
1451 {
1452 int rc = 0;
1453 unsigned int xid;
1454 char *path, *npath;
1455 struct cache_entry *ce;
1456 struct cifs_ses *root_ses = NULL, *ses;
1457 struct dfs_info3_param *refs = NULL;
1458 int numrefs = 0;
1459
1460 xid = get_xid();
1461
1462 path = tcon->dfs_path + 1;
1463
1464 rc = get_normalized_path(path, &npath);
1465 if (rc)
1466 goto out_free_xid;
1467
1468 down_read(&htable_rw_lock);
1469
1470 ce = lookup_cache_entry(npath, NULL);
1471 if (IS_ERR(ce)) {
1472 rc = PTR_ERR(ce);
1473 up_read(&htable_rw_lock);
1474 goto out_free_path;
1475 }
1476
1477 if (!cache_entry_expired(ce)) {
1478 up_read(&htable_rw_lock);
1479 goto out_free_path;
1480 }
1481
1482 up_read(&htable_rw_lock);
1483
1484 /* If it's a DFS Link, then use root SMB session for refreshing it */
1485 if (is_dfs_link(npath)) {
1486 ses = root_ses = find_root_ses(vi, tcon, npath);
1487 if (IS_ERR(ses)) {
1488 rc = PTR_ERR(ses);
1489 root_ses = NULL;
1490 goto out_free_path;
1491 }
1492 } else {
1493 ses = tcon->ses;
1494 }
1495
1496 rc = get_dfs_referral(xid, ses, cache_nlsc, tcon->remap, npath, &refs,
1497 &numrefs);
1498 if (!rc) {
1499 dump_refs(refs, numrefs);
1500 rc = update_cache_entry(npath, refs, numrefs);
1501 free_dfs_info_array(refs, numrefs);
1502 }
1503
1504 if (root_ses)
1505 cifs_put_smb_ses(root_ses);
1506
1507 out_free_path:
1508 free_normalized_path(path, npath);
1509
1510 out_free_xid:
1511 free_xid(xid);
1512 return rc;
1513 }
1514
1515 /*
1516 * Worker that will refresh DFS cache based on lowest TTL value from a DFS
1517 * referral.
1518 */
1519 static void refresh_cache_worker(struct work_struct *work)
1520 {
1521 struct vol_info *vi, *nvi;
1522 struct TCP_Server_Info *server;
1523 LIST_HEAD(vols);
1524 LIST_HEAD(tcons);
1525 struct cifs_tcon *tcon, *ntcon;
1526 int rc;
1527
1528 /*
1529 * Find SMB volumes that are eligible (server->tcpStatus == CifsGood)
1530 * for refreshing.
1531 */
1532 spin_lock(&vol_list_lock);
1533 list_for_each_entry(vi, &vol_list, list) {
1534 server = get_tcp_server(&vi->smb_vol);
1535 if (!server)
1536 continue;
1537
1538 kref_get(&vi->refcnt);
1539 list_add_tail(&vi->rlist, &vols);
1540 put_tcp_server(server);
1541 }
1542 spin_unlock(&vol_list_lock);
1543
1544 /* Walk through all TCONs and refresh any expired cache entry */
1545 list_for_each_entry_safe(vi, nvi, &vols, rlist) {
1546 spin_lock(&vi->smb_vol_lock);
1547 server = get_tcp_server(&vi->smb_vol);
1548 spin_unlock(&vi->smb_vol_lock);
1549
1550 if (!server)
1551 goto next_vol;
1552
1553 get_tcons(server, &tcons);
1554 rc = 0;
1555
1556 list_for_each_entry_safe(tcon, ntcon, &tcons, ulist) {
1557 /*
1558 * Skip tcp server if any of its tcons failed to refresh
1559 * (possibily due to reconnects).
1560 */
1561 if (!rc)
1562 rc = refresh_tcon(vi, tcon);
1563
1564 list_del_init(&tcon->ulist);
1565 cifs_put_tcon(tcon);
1566 }
1567
1568 put_tcp_server(server);
1569
1570 next_vol:
1571 list_del_init(&vi->rlist);
1572 kref_put(&vi->refcnt, vol_release);
1573 }
1574
1575 spin_lock(&cache_ttl_lock);
1576 queue_delayed_work(dfscache_wq, &refresh_task, cache_ttl * HZ);
1577 spin_unlock(&cache_ttl_lock);
1578 }
Linux with added FPC-III support