1 // SPDX-License-Identifier: GPL-2.0
3 * DFS referral cache routines
5 * Copyright (c) 2018-2019 Paulo Alcantara <palcantara@suse.de>
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>
16 #include "smb2proto.h"
17 #include "cifsproto.h"
18 #include "cifs_debug.h"
19 #include "cifs_unicode.h"
22 #include "dfs_cache.h"
24 #define CACHE_HTABLE_SIZE 32
25 #define CACHE_MAX_ENTRIES 64
27 #define IS_INTERLINK_SET(v) ((v) & (DFSREF_REFERRAL_SERVER | \
28 DFSREF_STORAGE_SERVER))
30 struct cache_dfs_tgt {
32 struct list_head list;
36 struct hlist_node hlist;
41 struct timespec64 etime;
44 struct list_head tlist;
45 struct cache_dfs_tgt *tgthint;
50 spinlock_t smb_vol_lock;
51 struct smb_vol smb_vol;
53 struct list_head list;
54 struct list_head rlist;
58 static struct kmem_cache *cache_slab __read_mostly;
59 static struct workqueue_struct *dfscache_wq __read_mostly;
62 static DEFINE_SPINLOCK(cache_ttl_lock);
64 static struct nls_table *cache_nlsc;
67 * Number of entries in the cache
69 static atomic_t cache_count;
71 static struct hlist_head cache_htable[CACHE_HTABLE_SIZE];
72 static DECLARE_RWSEM(htable_rw_lock);
74 static LIST_HEAD(vol_list);
75 static DEFINE_SPINLOCK(vol_list_lock);
77 static void refresh_cache_worker(struct work_struct *work);
79 static DECLARE_DELAYED_WORK(refresh_task, refresh_cache_worker);
81 static int get_normalized_path(const char *path, char **npath)
83 if (!path || strlen(path) < 3 || (*path != '\\' && *path != '/'))
87 *npath = (char *)path;
89 *npath = kstrndup(path, strlen(path), GFP_KERNEL);
92 convert_delimiter(*npath, '\\');
97 static inline void free_normalized_path(const char *path, char *npath)
103 static inline bool cache_entry_expired(const struct cache_entry *ce)
105 struct timespec64 ts;
107 ktime_get_coarse_real_ts64(&ts);
108 return timespec64_compare(&ts, &ce->etime) >= 0;
111 static inline void free_tgts(struct cache_entry *ce)
113 struct cache_dfs_tgt *t, *n;
115 list_for_each_entry_safe(t, n, &ce->tlist, list) {
122 static inline void flush_cache_ent(struct cache_entry *ce)
124 hlist_del_init(&ce->hlist);
127 atomic_dec(&cache_count);
128 kmem_cache_free(cache_slab, ce);
131 static void flush_cache_ents(void)
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;
140 hlist_for_each_entry_safe(ce, n, l, hlist) {
141 if (!hlist_unhashed(&ce->hlist))
148 * dfs cache /proc file
150 static int dfscache_proc_show(struct seq_file *m, void *v)
153 struct cache_entry *ce;
154 struct cache_dfs_tgt *t;
156 seq_puts(m, "DFS cache\n---------\n");
158 down_read(&htable_rw_lock);
159 for (i = 0; i < CACHE_HTABLE_SIZE; i++) {
160 struct hlist_head *l = &cache_htable[i];
162 hlist_for_each_entry(ce, l, hlist) {
163 if (hlist_unhashed(&ce->hlist))
167 "cache entry: path=%s,type=%s,ttl=%d,etime=%ld,"
168 "interlink=%s,path_consumed=%d,expired=%s\n",
170 ce->srvtype == DFS_TYPE_ROOT ? "root" : "link",
171 ce->ttl, ce->etime.tv_nsec,
172 IS_INTERLINK_SET(ce->flags) ? "yes" : "no",
174 cache_entry_expired(ce) ? "yes" : "no");
176 list_for_each_entry(t, &ce->tlist, list) {
177 seq_printf(m, " %s%s\n",
179 ce->tgthint == t ? " (target hint)" : "");
183 up_read(&htable_rw_lock);
188 static ssize_t dfscache_proc_write(struct file *file, const char __user *buffer,
189 size_t count, loff_t *ppos)
194 rc = get_user(c, buffer);
201 cifs_dbg(FYI, "clearing dfs cache");
203 down_write(&htable_rw_lock);
205 up_write(&htable_rw_lock);
210 static int dfscache_proc_open(struct inode *inode, struct file *file)
212 return single_open(file, dfscache_proc_show, NULL);
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,
223 #ifdef CONFIG_CIFS_DEBUG2
224 static inline void dump_tgts(const struct cache_entry *ce)
226 struct cache_dfs_tgt *t;
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)" : "");
235 static inline void dump_ce(const struct cache_entry *ce)
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,
241 IS_INTERLINK_SET(ce->flags) ? "yes" : "no",
243 cache_entry_expired(ce) ? "yes" : "no");
247 static inline void dump_refs(const struct dfs_info3_param *refs, int numrefs)
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];
258 "path_consumed: %d\n"
259 "server_type: 0x%x\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);
272 #define dump_refs(r, n)
276 * dfs_cache_init - Initialize DFS referral cache.
278 * Return zero if initialized successfully, otherwise non-zero.
280 int dfs_cache_init(void)
285 dfscache_wq = alloc_workqueue("cifs-dfscache",
286 WQ_FREEZABLE | WQ_MEM_RECLAIM, 1);
290 cache_slab = kmem_cache_create("cifs_dfs_cache",
291 sizeof(struct cache_entry), 0,
292 SLAB_HWCACHE_ALIGN, NULL);
298 for (i = 0; i < CACHE_HTABLE_SIZE; i++)
299 INIT_HLIST_HEAD(&cache_htable[i]);
301 atomic_set(&cache_count, 0);
302 cache_nlsc = load_nls_default();
304 cifs_dbg(FYI, "%s: initialized DFS referral cache\n", __func__);
308 destroy_workqueue(dfscache_wq);
312 static inline unsigned int cache_entry_hash(const void *data, int size)
316 h = jhash(data, size, 0);
317 return h & (CACHE_HTABLE_SIZE - 1);
320 /* Check whether second path component of @path is SYSVOL or NETLOGON */
321 static inline bool is_sysvol_or_netlogon(const char *path)
326 s = strchr(path + 1, sep) + 1;
327 return !strncasecmp(s, "sysvol", strlen("sysvol")) ||
328 !strncasecmp(s, "netlogon", strlen("netlogon"));
331 /* Return target hint of a DFS cache entry */
332 static inline char *get_tgt_name(const struct cache_entry *ce)
334 struct cache_dfs_tgt *t = ce->tgthint;
336 return t ? t->name : ERR_PTR(-ENOENT);
339 /* Return expire time out of a new entry's TTL */
340 static inline struct timespec64 get_expire_time(int ttl)
342 struct timespec64 ts = {
346 struct timespec64 now;
348 ktime_get_coarse_real_ts64(&now);
349 return timespec64_add(now, ts);
352 /* Allocate a new DFS target */
353 static struct cache_dfs_tgt *alloc_target(const char *name)
355 struct cache_dfs_tgt *t;
357 t = kmalloc(sizeof(*t), GFP_ATOMIC);
359 return ERR_PTR(-ENOMEM);
360 t->name = kstrndup(name, strlen(name), GFP_ATOMIC);
363 return ERR_PTR(-ENOMEM);
365 INIT_LIST_HEAD(&t->list);
370 * Copy DFS referral information to a cache entry and conditionally update
373 static int copy_ref_data(const struct dfs_info3_param *refs, int numrefs,
374 struct cache_entry *ce, const char *tgthint)
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;
384 for (i = 0; i < numrefs; i++) {
385 struct cache_dfs_tgt *t;
387 t = alloc_target(refs[i].node_name);
392 if (tgthint && !strcasecmp(t->name, tgthint)) {
393 list_add(&t->list, &ce->tlist);
396 list_add_tail(&t->list, &ce->tlist);
401 ce->tgthint = list_first_entry_or_null(&ce->tlist,
402 struct cache_dfs_tgt, list);
407 /* Allocate a new cache entry */
408 static struct cache_entry *alloc_cache_entry(const char *path,
409 const struct dfs_info3_param *refs,
412 struct cache_entry *ce;
415 ce = kmem_cache_zalloc(cache_slab, GFP_KERNEL);
417 return ERR_PTR(-ENOMEM);
419 ce->path = kstrndup(path, strlen(path), GFP_KERNEL);
421 kmem_cache_free(cache_slab, ce);
422 return ERR_PTR(-ENOMEM);
424 INIT_HLIST_NODE(&ce->hlist);
425 INIT_LIST_HEAD(&ce->tlist);
427 rc = copy_ref_data(refs, numrefs, ce, NULL);
430 kmem_cache_free(cache_slab, ce);
436 /* Must be called with htable_rw_lock held */
437 static void remove_oldest_entry(void)
440 struct cache_entry *ce;
441 struct cache_entry *to_del = NULL;
443 for (i = 0; i < CACHE_HTABLE_SIZE; i++) {
444 struct hlist_head *l = &cache_htable[i];
446 hlist_for_each_entry(ce, l, hlist) {
447 if (hlist_unhashed(&ce->hlist))
449 if (!to_del || timespec64_compare(&ce->etime,
456 cifs_dbg(FYI, "%s: no entry to remove", __func__);
460 cifs_dbg(FYI, "%s: removing entry", __func__);
462 flush_cache_ent(to_del);
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)
469 struct cache_entry *ce;
471 ce = alloc_cache_entry(path, refs, numrefs);
475 spin_lock(&cache_ttl_lock);
478 queue_delayed_work(dfscache_wq, &refresh_task, cache_ttl * HZ);
480 cache_ttl = min_t(int, cache_ttl, ce->ttl);
481 mod_delayed_work(dfscache_wq, &refresh_task, cache_ttl * HZ);
483 spin_unlock(&cache_ttl_lock);
485 down_write(&htable_rw_lock);
486 hlist_add_head(&ce->hlist, &cache_htable[hash]);
488 up_write(&htable_rw_lock);
494 * Find a DFS cache entry in hash table and optionally check prefix path against
496 * Use whole path components in the match.
497 * Must be called with htable_rw_lock held.
499 * Return ERR_PTR(-ENOENT) if the entry is not found.
501 static struct cache_entry *lookup_cache_entry(const char *path,
504 struct cache_entry *ce;
508 h = cache_entry_hash(path, strlen(path));
510 hlist_for_each_entry(ce, &cache_htable[h], hlist) {
511 if (!strcasecmp(path, ce->path)) {
519 ce = ERR_PTR(-ENOENT);
526 static void __vol_release(struct vol_info *vi)
530 cifs_cleanup_volume_info_contents(&vi->smb_vol);
534 static void vol_release(struct kref *kref)
536 struct vol_info *vi = container_of(kref, struct vol_info, refcnt);
538 spin_lock(&vol_list_lock);
540 spin_unlock(&vol_list_lock);
544 static inline void free_vol_list(void)
546 struct vol_info *vi, *nvi;
548 list_for_each_entry_safe(vi, nvi, &vol_list, list) {
549 list_del_init(&vi->list);
555 * dfs_cache_destroy - destroy DFS referral cache
557 void dfs_cache_destroy(void)
559 cancel_delayed_work_sync(&refresh_task);
560 unload_nls(cache_nlsc);
563 kmem_cache_destroy(cache_slab);
564 destroy_workqueue(dfscache_wq);
566 cifs_dbg(FYI, "%s: destroyed DFS referral cache\n", __func__);
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,
575 struct cache_entry *ce;
578 ce = lookup_cache_entry(path, NULL);
583 s = ce->tgthint->name;
584 th = kstrndup(s, strlen(s), GFP_ATOMIC);
592 rc = copy_ref_data(refs, numrefs, ce, th);
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,
604 cifs_dbg(FYI, "%s: get an DFS referral for %s\n", __func__, path);
606 if (!ses || !ses->server || !ses->server->ops->get_dfs_refer)
608 if (unlikely(!nls_codepage))
614 return ses->server->ops->get_dfs_refer(xid, ses, path, refs, numrefs,
615 nls_codepage, remap);
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,
626 down_write(&htable_rw_lock);
627 rc = __update_cache_entry(path, refs, numrefs);
628 up_write(&htable_rw_lock);
634 * Find, create or update a DFS cache entry.
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.
639 * For interlinks, __cifs_dfs_mount() and expand_dfs_referral() are supposed to
640 * handle them properly.
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)
648 struct cache_entry *ce;
649 struct dfs_info3_param *refs = NULL;
653 cifs_dbg(FYI, "%s: search path: %s\n", __func__, path);
655 down_read(&htable_rw_lock);
657 ce = lookup_cache_entry(path, &hash);
660 * If @noreq is set, no requests will be sent to the server. Just return
664 up_read(&htable_rw_lock);
665 return PTR_ERR_OR_ZERO(ce);
669 if (!cache_entry_expired(ce)) {
671 up_read(&htable_rw_lock);
678 up_read(&htable_rw_lock);
681 * No entry was found.
683 * Request a new DFS referral in order to create a new cache entry, or
684 * updating an existing one.
686 rc = get_dfs_referral(xid, ses, nls_codepage, remap, path,
691 dump_refs(refs, numrefs);
694 rc = update_cache_entry(path, refs, numrefs);
698 if (atomic_read(&cache_count) >= CACHE_MAX_ENTRIES) {
699 cifs_dbg(FYI, "%s: reached max cache size (%d)", __func__,
701 down_write(&htable_rw_lock);
702 remove_oldest_entry();
703 up_write(&htable_rw_lock);
706 rc = add_cache_entry(path, hash, refs, numrefs);
708 atomic_inc(&cache_count);
711 free_dfs_info_array(refs, numrefs);
716 * Set up a DFS referral from a given cache entry.
718 * Must be called with htable_rw_lock held.
720 static int setup_referral(const char *path, struct cache_entry *ce,
721 struct dfs_info3_param *ref, const char *target)
725 cifs_dbg(FYI, "%s: set up new ref\n", __func__);
727 memset(ref, 0, sizeof(*ref));
729 ref->path_name = kstrndup(path, strlen(path), GFP_ATOMIC);
733 ref->node_name = kstrndup(target, strlen(target), GFP_ATOMIC);
734 if (!ref->node_name) {
739 ref->path_consumed = ce->path_consumed;
741 ref->server_type = ce->srvtype;
742 ref->ref_flag = ce->flags;
747 kfree(ref->path_name);
748 ref->path_name = NULL;
752 /* Return target list of a DFS cache entry */
753 static int get_targets(struct cache_entry *ce, struct dfs_cache_tgt_list *tl)
756 struct list_head *head = &tl->tl_list;
757 struct cache_dfs_tgt *t;
758 struct dfs_cache_tgt_iterator *it, *nit;
760 memset(tl, 0, sizeof(*tl));
761 INIT_LIST_HEAD(head);
763 list_for_each_entry(t, &ce->tlist, list) {
764 it = kzalloc(sizeof(*it), GFP_ATOMIC);
770 it->it_name = kstrndup(t->name, strlen(t->name), GFP_ATOMIC);
777 if (ce->tgthint == t)
778 list_add(&it->it_list, head);
780 list_add_tail(&it->it_list, head);
783 tl->tl_numtgts = ce->numtgts;
788 list_for_each_entry_safe(it, nit, head, it_list) {
796 * dfs_cache_find - find a DFS cache entry
798 * If it doesn't find the cache entry, then it will get a DFS referral
799 * for @path and create a new entry.
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.
804 * These parameters are passed down to the get_dfs_refer() call if it
805 * needs to be issued:
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.
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.
815 * Return zero if the target was found, otherwise non-zero.
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)
824 struct cache_entry *ce;
826 rc = get_normalized_path(path, &npath);
830 rc = __dfs_cache_find(xid, ses, nls_codepage, remap, npath, false);
834 down_read(&htable_rw_lock);
836 ce = lookup_cache_entry(npath, NULL);
838 up_read(&htable_rw_lock);
844 rc = setup_referral(path, ce, ref, get_tgt_name(ce));
848 rc = get_targets(ce, tgt_list);
850 up_read(&htable_rw_lock);
853 free_normalized_path(path, npath);
858 * dfs_cache_noreq_find - find a DFS cache entry without sending any requests to
859 * the currently connected server.
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.
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.
869 * Return 0 if successful.
870 * Return -ENOENT if the entry was not found.
871 * Return non-zero for other errors.
873 int dfs_cache_noreq_find(const char *path, struct dfs_info3_param *ref,
874 struct dfs_cache_tgt_list *tgt_list)
878 struct cache_entry *ce;
880 rc = get_normalized_path(path, &npath);
884 cifs_dbg(FYI, "%s: path: %s\n", __func__, npath);
886 down_read(&htable_rw_lock);
888 ce = lookup_cache_entry(npath, NULL);
895 rc = setup_referral(path, ce, ref, get_tgt_name(ce));
899 rc = get_targets(ce, tgt_list);
902 up_read(&htable_rw_lock);
903 free_normalized_path(path, npath);
909 * dfs_cache_update_tgthint - update target hint of a DFS cache entry
911 * If it doesn't find the cache entry, then it will get a DFS referral for @path
912 * and create a new entry.
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.
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
924 * Return zero if the target hint was updated successfully, otherwise non-zero.
926 int dfs_cache_update_tgthint(const unsigned int xid, struct cifs_ses *ses,
927 const struct nls_table *nls_codepage, int remap,
929 const struct dfs_cache_tgt_iterator *it)
933 struct cache_entry *ce;
934 struct cache_dfs_tgt *t;
936 rc = get_normalized_path(path, &npath);
940 cifs_dbg(FYI, "%s: update target hint - path: %s\n", __func__, npath);
942 rc = __dfs_cache_find(xid, ses, nls_codepage, remap, npath, false);
946 down_write(&htable_rw_lock);
948 ce = lookup_cache_entry(npath, NULL);
956 if (likely(!strcasecmp(it->it_name, t->name)))
959 list_for_each_entry(t, &ce->tlist, list) {
960 if (!strcasecmp(t->name, it->it_name)) {
962 cifs_dbg(FYI, "%s: new target hint: %s\n", __func__,
969 up_write(&htable_rw_lock);
971 free_normalized_path(path, npath);
977 * dfs_cache_noreq_update_tgthint - update target hint of a DFS cache entry
978 * without sending any requests to the currently connected server.
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.
984 * @path: path to lookup in DFS referral cache.
985 * @it: target iterator which contains the target hint to update the cache
988 * Return zero if the target hint was updated successfully, otherwise non-zero.
990 int dfs_cache_noreq_update_tgthint(const char *path,
991 const struct dfs_cache_tgt_iterator *it)
995 struct cache_entry *ce;
996 struct cache_dfs_tgt *t;
1001 rc = get_normalized_path(path, &npath);
1005 cifs_dbg(FYI, "%s: path: %s\n", __func__, npath);
1007 down_write(&htable_rw_lock);
1009 ce = lookup_cache_entry(npath, NULL);
1018 if (unlikely(!strcasecmp(it->it_name, t->name)))
1021 list_for_each_entry(t, &ce->tlist, list) {
1022 if (!strcasecmp(t->name, it->it_name)) {
1024 cifs_dbg(FYI, "%s: new target hint: %s\n", __func__,
1031 up_write(&htable_rw_lock);
1032 free_normalized_path(path, npath);
1038 * dfs_cache_get_tgt_referral - returns a DFS referral (@ref) from a given
1039 * target iterator (@it).
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.
1045 * Return zero if the DFS referral was set up correctly, otherwise non-zero.
1047 int dfs_cache_get_tgt_referral(const char *path,
1048 const struct dfs_cache_tgt_iterator *it,
1049 struct dfs_info3_param *ref)
1053 struct cache_entry *ce;
1058 rc = get_normalized_path(path, &npath);
1062 cifs_dbg(FYI, "%s: path: %s\n", __func__, npath);
1064 down_read(&htable_rw_lock);
1066 ce = lookup_cache_entry(npath, NULL);
1072 cifs_dbg(FYI, "%s: target name: %s\n", __func__, it->it_name);
1074 rc = setup_referral(path, ce, ref, it->it_name);
1077 up_read(&htable_rw_lock);
1078 free_normalized_path(path, npath);
1083 static int dup_vol(struct smb_vol *vol, struct smb_vol *new)
1085 memcpy(new, vol, sizeof(*new));
1087 if (vol->username) {
1088 new->username = kstrndup(vol->username, strlen(vol->username),
1093 if (vol->password) {
1094 new->password = kstrndup(vol->password, strlen(vol->password),
1097 goto err_free_username;
1100 cifs_dbg(FYI, "%s: vol->UNC: %s\n", __func__, vol->UNC);
1101 new->UNC = kstrndup(vol->UNC, strlen(vol->UNC), GFP_KERNEL);
1103 goto err_free_password;
1105 if (vol->domainname) {
1106 new->domainname = kstrndup(vol->domainname,
1107 strlen(vol->domainname), GFP_KERNEL);
1108 if (!new->domainname)
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;
1118 cifs_dbg(FYI, "%s: vol->prepath: %s\n", __func__, vol->prepath);
1119 new->prepath = kstrndup(vol->prepath, strlen(vol->prepath),
1122 goto err_free_iocharset;
1128 kfree(new->iocharset);
1129 err_free_domainname:
1130 kfree(new->domainname);
1134 kzfree(new->password);
1136 kfree(new->username);
1142 * dfs_cache_add_vol - add a cifs volume during mount() that will be handled by
1143 * DFS cache refresh worker.
1145 * @mntdata: mount data.
1146 * @vol: cifs volume.
1147 * @fullpath: origin full path.
1149 * Return zero if volume was set up correctly, otherwise non-zero.
1151 int dfs_cache_add_vol(char *mntdata, struct smb_vol *vol, const char *fullpath)
1154 struct vol_info *vi;
1156 if (!vol || !fullpath || !mntdata)
1159 cifs_dbg(FYI, "%s: fullpath: %s\n", __func__, fullpath);
1161 vi = kzalloc(sizeof(*vi), GFP_KERNEL);
1165 vi->fullpath = kstrndup(fullpath, strlen(fullpath), GFP_KERNEL);
1166 if (!vi->fullpath) {
1171 rc = dup_vol(vol, &vi->smb_vol);
1173 goto err_free_fullpath;
1175 vi->mntdata = mntdata;
1176 spin_lock_init(&vi->smb_vol_lock);
1177 kref_init(&vi->refcnt);
1179 spin_lock(&vol_list_lock);
1180 list_add_tail(&vi->list, &vol_list);
1181 spin_unlock(&vol_list_lock);
1186 kfree(vi->fullpath);
1192 /* Must be called with vol_list_lock held */
1193 static struct vol_info *find_vol(const char *fullpath)
1195 struct vol_info *vi;
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))
1202 return ERR_PTR(-ENOENT);
1206 * dfs_cache_update_vol - update vol info in DFS cache after failover
1208 * @fullpath: fullpath to look up in volume list.
1209 * @server: TCP ses pointer.
1211 * Return zero if volume was updated, otherwise non-zero.
1213 int dfs_cache_update_vol(const char *fullpath, struct TCP_Server_Info *server)
1215 struct vol_info *vi;
1217 if (!fullpath || !server)
1220 cifs_dbg(FYI, "%s: fullpath: %s\n", __func__, fullpath);
1222 spin_lock(&vol_list_lock);
1223 vi = find_vol(fullpath);
1225 spin_unlock(&vol_list_lock);
1228 kref_get(&vi->refcnt);
1229 spin_unlock(&vol_list_lock);
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);
1237 kref_put(&vi->refcnt, vol_release);
1243 * dfs_cache_del_vol - remove volume info in DFS cache during umount()
1245 * @fullpath: fullpath to look up in volume list.
1247 void dfs_cache_del_vol(const char *fullpath)
1249 struct vol_info *vi;
1251 if (!fullpath || !*fullpath)
1254 cifs_dbg(FYI, "%s: fullpath: %s\n", __func__, fullpath);
1256 spin_lock(&vol_list_lock);
1257 vi = find_vol(fullpath);
1258 spin_unlock(&vol_list_lock);
1260 kref_put(&vi->refcnt, vol_release);
1263 /* Get all tcons that are within a DFS namespace and can be refreshed */
1264 static void get_tcons(struct TCP_Server_Info *server, struct list_head *head)
1266 struct cifs_ses *ses;
1267 struct cifs_tcon *tcon;
1269 INIT_LIST_HEAD(head);
1271 spin_lock(&cifs_tcp_ses_lock);
1272 list_for_each_entry(ses, &server->smb_ses_list, smb_ses_list) {
1273 list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
1274 if (!tcon->need_reconnect && !tcon->need_reopen_files &&
1277 list_add_tail(&tcon->ulist, head);
1280 if (ses->tcon_ipc && !ses->tcon_ipc->need_reconnect &&
1281 ses->tcon_ipc->dfs_path) {
1282 list_add_tail(&ses->tcon_ipc->ulist, head);
1285 spin_unlock(&cifs_tcp_ses_lock);
1288 static bool is_dfs_link(const char *path)
1292 s = strchr(path + 1, '\\');
1295 return !!strchr(s + 1, '\\');
1298 static char *get_dfs_root(const char *path)
1302 s = strchr(path + 1, '\\');
1304 return ERR_PTR(-EINVAL);
1306 s = strchr(s + 1, '\\');
1308 return ERR_PTR(-EINVAL);
1310 npath = kstrndup(path, s - path, GFP_KERNEL);
1312 return ERR_PTR(-ENOMEM);
1317 static inline void put_tcp_server(struct TCP_Server_Info *server)
1319 cifs_put_tcp_session(server, 0);
1322 static struct TCP_Server_Info *get_tcp_server(struct smb_vol *vol)
1324 struct TCP_Server_Info *server;
1326 server = cifs_find_tcp_session(vol);
1327 if (IS_ERR_OR_NULL(server))
1330 spin_lock(&GlobalMid_Lock);
1331 if (server->tcpStatus != CifsGood) {
1332 spin_unlock(&GlobalMid_Lock);
1333 put_tcp_server(server);
1336 spin_unlock(&GlobalMid_Lock);
1341 /* Find root SMB session out of a DFS link path */
1342 static struct cifs_ses *find_root_ses(struct vol_info *vi,
1343 struct cifs_tcon *tcon,
1348 struct cache_entry *ce;
1349 struct dfs_info3_param ref = {0};
1350 char *mdata = NULL, *devname = NULL;
1351 struct TCP_Server_Info *server;
1352 struct cifs_ses *ses;
1353 struct smb_vol vol = {NULL};
1355 rpath = get_dfs_root(path);
1357 return ERR_CAST(rpath);
1359 down_read(&htable_rw_lock);
1361 ce = lookup_cache_entry(rpath, NULL);
1363 up_read(&htable_rw_lock);
1368 rc = setup_referral(path, ce, &ref, get_tgt_name(ce));
1370 up_read(&htable_rw_lock);
1375 up_read(&htable_rw_lock);
1377 mdata = cifs_compose_mount_options(vi->mntdata, rpath, &ref,
1379 free_dfs_info_param(&ref);
1381 if (IS_ERR(mdata)) {
1382 ses = ERR_CAST(mdata);
1387 rc = cifs_setup_volume_info(&vol, mdata, devname, false);
1395 server = get_tcp_server(&vol);
1397 ses = ERR_PTR(-EHOSTDOWN);
1401 ses = cifs_get_smb_ses(server, &vol);
1404 cifs_cleanup_volume_info_contents(&vol);
1411 /* Refresh DFS cache entry from a given tcon */
1412 static int refresh_tcon(struct vol_info *vi, struct cifs_tcon *tcon)
1417 struct cache_entry *ce;
1418 struct cifs_ses *root_ses = NULL, *ses;
1419 struct dfs_info3_param *refs = NULL;
1424 path = tcon->dfs_path + 1;
1426 rc = get_normalized_path(path, &npath);
1430 down_read(&htable_rw_lock);
1432 ce = lookup_cache_entry(npath, NULL);
1435 up_read(&htable_rw_lock);
1439 if (!cache_entry_expired(ce)) {
1440 up_read(&htable_rw_lock);
1444 up_read(&htable_rw_lock);
1446 /* If it's a DFS Link, then use root SMB session for refreshing it */
1447 if (is_dfs_link(npath)) {
1448 ses = root_ses = find_root_ses(vi, tcon, npath);
1458 rc = get_dfs_referral(xid, ses, cache_nlsc, tcon->remap, npath, &refs,
1461 dump_refs(refs, numrefs);
1462 rc = update_cache_entry(npath, refs, numrefs);
1463 free_dfs_info_array(refs, numrefs);
1467 cifs_put_smb_ses(root_ses);
1470 free_normalized_path(path, npath);
1478 * Worker that will refresh DFS cache based on lowest TTL value from a DFS
1481 static void refresh_cache_worker(struct work_struct *work)
1483 struct vol_info *vi, *nvi;
1484 struct TCP_Server_Info *server;
1487 struct cifs_tcon *tcon, *ntcon;
1491 * Find SMB volumes that are eligible (server->tcpStatus == CifsGood)
1494 spin_lock(&vol_list_lock);
1495 list_for_each_entry(vi, &vol_list, list) {
1496 server = get_tcp_server(&vi->smb_vol);
1500 kref_get(&vi->refcnt);
1501 list_add_tail(&vi->rlist, &vols);
1502 put_tcp_server(server);
1504 spin_unlock(&vol_list_lock);
1506 /* Walk through all TCONs and refresh any expired cache entry */
1507 list_for_each_entry_safe(vi, nvi, &vols, rlist) {
1508 spin_lock(&vi->smb_vol_lock);
1509 server = get_tcp_server(&vi->smb_vol);
1510 spin_unlock(&vi->smb_vol_lock);
1515 get_tcons(server, &tcons);
1518 list_for_each_entry_safe(tcon, ntcon, &tcons, ulist) {
1520 * Skip tcp server if any of its tcons failed to refresh
1521 * (possibily due to reconnects).
1524 rc = refresh_tcon(vi, tcon);
1526 list_del_init(&tcon->ulist);
1527 cifs_put_tcon(tcon);
1530 put_tcp_server(server);
1533 list_del_init(&vi->rlist);
1534 kref_put(&vi->refcnt, vol_release);
1537 spin_lock(&cache_ttl_lock);
1538 queue_delayed_work(dfscache_wq, &refresh_task, cache_ttl * HZ);
1539 spin_unlock(&cache_ttl_lock);