fs/smb/client/dfs.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (c) 2022 Paulo Alcantara <palcantara@suse.de>
   4  */
   5
   6 #include <linux/namei.h>
   7 #include "cifsproto.h"
   8 #include "cifs_debug.h"
   9 #include "dns_resolve.h"
  10 #include "fs_context.h"
  11 #include "dfs.h"
  12
  13 /**
  14  * dfs_parse_target_referral - set fs context for dfs target referral
  15  *
  16  * @full_path: full path in UNC format.
  17  * @ref: dfs referral pointer.
  18  * @ctx: smb3 fs context pointer.
  19  *
  20  * Return zero if dfs referral was parsed correctly, otherwise non-zero.
  21  */
  22 int dfs_parse_target_referral(const char *full_path, const struct dfs_info3_param *ref,
  23                               struct smb3_fs_context *ctx)
  24 {
  25         int rc;
  26         const char *prepath = NULL;
  27         char *path;
  28
  29         if (!full_path || !*full_path || !ref || !ctx)
  30                 return -EINVAL;
  31
  32         if (WARN_ON_ONCE(!ref->node_name || ref->path_consumed < 0))
  33                 return -EINVAL;
  34
  35         if (strlen(full_path) - ref->path_consumed) {
  36                 prepath = full_path + ref->path_consumed;
  37                 /* skip initial delimiter */
  38                 if (*prepath == '/' || *prepath == '\\')
  39                         prepath++;
  40         }
  41
  42         path = cifs_build_devname(ref->node_name, prepath);
  43         if (IS_ERR(path))
  44                 return PTR_ERR(path);
  45
  46         rc = smb3_parse_devname(path, ctx);
  47         if (rc)
  48                 goto out;
  49
  50         rc = dns_resolve_server_name_to_ip(path, (struct sockaddr *)&ctx->dstaddr, NULL);
  51
  52 out:
  53         kfree(path);
  54         return rc;
  55 }
  56
  57 /*
  58  * cifs_build_path_to_root returns full path to root when we do not have an
  59  * existing connection (tcon)
  60  */
  61 static char *build_unc_path_to_root(const struct smb3_fs_context *ctx,
  62                                     const struct cifs_sb_info *cifs_sb, bool useppath)
  63 {
  64         char *full_path, *pos;
  65         unsigned int pplen = useppath && ctx->prepath ? strlen(ctx->prepath) + 1 : 0;
  66         unsigned int unc_len = strnlen(ctx->UNC, MAX_TREE_SIZE + 1);
  67
  68         if (unc_len > MAX_TREE_SIZE)
  69                 return ERR_PTR(-EINVAL);
  70
  71         full_path = kmalloc(unc_len + pplen + 1, GFP_KERNEL);
  72         if (full_path == NULL)
  73                 return ERR_PTR(-ENOMEM);
  74
  75         memcpy(full_path, ctx->UNC, unc_len);
  76         pos = full_path + unc_len;
  77
  78         if (pplen) {
  79                 *pos = CIFS_DIR_SEP(cifs_sb);
  80                 memcpy(pos + 1, ctx->prepath, pplen);
  81                 pos += pplen;
  82         }
  83
  84         *pos = '\0'; /* add trailing null */
  85         convert_delimiter(full_path, CIFS_DIR_SEP(cifs_sb));
  86         cifs_dbg(FYI, "%s: full_path=%s\n", __func__, full_path);
  87         return full_path;
  88 }
  89
  90 static int get_session(struct cifs_mount_ctx *mnt_ctx, const char *full_path)
  91 {
  92         struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
  93         int rc;
  94
  95         ctx->leaf_fullpath = (char *)full_path;
  96         rc = cifs_mount_get_session(mnt_ctx);
  97         ctx->leaf_fullpath = NULL;
  98
  99         return rc;
 100 }
 101
 102 static int add_root_smb_session(struct cifs_mount_ctx *mnt_ctx)
 103 {
 104         struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
 105         struct dfs_root_ses *root_ses;
 106         struct cifs_ses *ses = mnt_ctx->ses;
 107
 108         if (ses) {
 109                 root_ses = kmalloc(sizeof(*root_ses), GFP_KERNEL);
 110                 if (!root_ses)
 111                         return -ENOMEM;
 112
 113                 INIT_LIST_HEAD(&root_ses->list);
 114
 115                 spin_lock(&cifs_tcp_ses_lock);
 116                 ses->ses_count++;
 117                 spin_unlock(&cifs_tcp_ses_lock);
 118                 root_ses->ses = ses;
 119                 list_add_tail(&root_ses->list, &mnt_ctx->dfs_ses_list);
 120         }
 121         ctx->dfs_root_ses = ses;
 122         return 0;
 123 }
 124
 125 static int get_dfs_conn(struct cifs_mount_ctx *mnt_ctx, const char *ref_path, const char *full_path,
 126                         const struct dfs_cache_tgt_iterator *tit)
 127 {
 128         struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
 129         struct dfs_info3_param ref = {};
 130         bool is_refsrv;
 131         int rc, rc2;
 132
 133         rc = dfs_cache_get_tgt_referral(ref_path + 1, tit, &ref);
 134         if (rc)
 135                 return rc;
 136
 137         rc = dfs_parse_target_referral(full_path + 1, &ref, ctx);
 138         if (rc)
 139                 goto out;
 140
 141         cifs_mount_put_conns(mnt_ctx);
 142         rc = get_session(mnt_ctx, ref_path);
 143         if (rc)
 144                 goto out;
 145
 146         is_refsrv = !!(ref.flags & DFSREF_REFERRAL_SERVER);
 147
 148         rc = -EREMOTE;
 149         if (ref.flags & DFSREF_STORAGE_SERVER) {
 150                 rc = cifs_mount_get_tcon(mnt_ctx);
 151                 if (rc)
 152                         goto out;
 153
 154                 /* some servers may not advertise referral capability under ref.flags */
 155                 is_refsrv |= is_tcon_dfs(mnt_ctx->tcon);
 156
 157                 rc = cifs_is_path_remote(mnt_ctx);
 158         }
 159
 160         dfs_cache_noreq_update_tgthint(ref_path + 1, tit);
 161
 162         if (rc == -EREMOTE && is_refsrv) {
 163                 rc2 = add_root_smb_session(mnt_ctx);
 164                 if (rc2)
 165                         rc = rc2;
 166         }
 167
 168 out:
 169         free_dfs_info_param(&ref);
 170         return rc;
 171 }
 172
 173 static int __dfs_mount_share(struct cifs_mount_ctx *mnt_ctx)
 174 {
 175         struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
 176         struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
 177         char *ref_path = NULL, *full_path = NULL;
 178         struct dfs_cache_tgt_iterator *tit;
 179         struct TCP_Server_Info *server;
 180         struct cifs_tcon *tcon;
 181         char *origin_fullpath = NULL;
 182         int num_links = 0;
 183         int rc;
 184
 185         ref_path = dfs_get_path(cifs_sb, ctx->UNC);
 186         if (IS_ERR(ref_path))
 187                 return PTR_ERR(ref_path);
 188
 189         full_path = build_unc_path_to_root(ctx, cifs_sb, true);
 190         if (IS_ERR(full_path)) {
 191                 rc = PTR_ERR(full_path);
 192                 full_path = NULL;
 193                 goto out;
 194         }
 195
 196         origin_fullpath = kstrdup(full_path, GFP_KERNEL);
 197         if (!origin_fullpath) {
 198                 rc = -ENOMEM;
 199                 goto out;
 200         }
 201
 202         do {
 203                 struct dfs_cache_tgt_list tl = DFS_CACHE_TGT_LIST_INIT(tl);
 204
 205                 rc = dfs_get_referral(mnt_ctx, ref_path + 1, NULL, &tl);
 206                 if (rc)
 207                         break;
 208
 209                 tit = dfs_cache_get_tgt_iterator(&tl);
 210                 if (!tit) {
 211                         cifs_dbg(VFS, "%s: dfs referral (%s) with no targets\n", __func__,
 212                                  ref_path + 1);
 213                         rc = -ENOENT;
 214                         dfs_cache_free_tgts(&tl);
 215                         break;
 216                 }
 217
 218                 do {
 219                         rc = get_dfs_conn(mnt_ctx, ref_path, full_path, tit);
 220                         if (!rc)
 221                                 break;
 222                         if (rc == -EREMOTE) {
 223                                 if (++num_links > MAX_NESTED_LINKS) {
 224                                         rc = -ELOOP;
 225                                         break;
 226                                 }
 227                                 kfree(ref_path);
 228                                 kfree(full_path);
 229                                 ref_path = full_path = NULL;
 230
 231                                 full_path = build_unc_path_to_root(ctx, cifs_sb, true);
 232                                 if (IS_ERR(full_path)) {
 233                                         rc = PTR_ERR(full_path);
 234                                         full_path = NULL;
 235                                 } else {
 236                                         ref_path = dfs_get_path(cifs_sb, full_path);
 237                                         if (IS_ERR(ref_path)) {
 238                                                 rc = PTR_ERR(ref_path);
 239                                                 ref_path = NULL;
 240                                         }
 241                                 }
 242                                 break;
 243                         }
 244                 } while ((tit = dfs_cache_get_next_tgt(&tl, tit)));
 245                 dfs_cache_free_tgts(&tl);
 246         } while (rc == -EREMOTE);
 247
 248         if (!rc) {
 249                 server = mnt_ctx->server;
 250                 tcon = mnt_ctx->tcon;
 251
 252                 mutex_lock(&server->refpath_lock);
 253                 spin_lock(&server->srv_lock);
 254                 if (!server->origin_fullpath) {
 255                         server->origin_fullpath = origin_fullpath;
 256                         origin_fullpath = NULL;
 257                 }
 258                 spin_unlock(&server->srv_lock);
 259                 mutex_unlock(&server->refpath_lock);
 260
 261                 if (list_empty(&tcon->dfs_ses_list)) {
 262                         list_replace_init(&mnt_ctx->dfs_ses_list,
 263                                           &tcon->dfs_ses_list);
 264                         queue_delayed_work(dfscache_wq, &tcon->dfs_cache_work,
 265                                            dfs_cache_get_ttl() * HZ);
 266                 } else {
 267                         dfs_put_root_smb_sessions(&mnt_ctx->dfs_ses_list);
 268                 }
 269         }
 270
 271 out:
 272         kfree(origin_fullpath);
 273         kfree(ref_path);
 274         kfree(full_path);
 275         return rc;
 276 }
 277
 278 int dfs_mount_share(struct cifs_mount_ctx *mnt_ctx, bool *isdfs)
 279 {
 280         struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
 281         struct cifs_ses *ses;
 282         char *source = ctx->source;
 283         bool nodfs = ctx->nodfs;
 284         int rc;
 285
 286         *isdfs = false;
 287         /* Temporarily set @ctx->source to NULL as we're not matching DFS
 288          * superblocks yet.  See cifs_match_super() and match_server().
 289          */
 290         ctx->source = NULL;
 291         rc = get_session(mnt_ctx, NULL);
 292         if (rc)
 293                 goto out;
 294
 295         ctx->dfs_root_ses = mnt_ctx->ses;
 296         /*
 297          * If called with 'nodfs' mount option, then skip DFS resolving.  Otherwise unconditionally
 298          * try to get an DFS referral (even cached) to determine whether it is an DFS mount.
 299          *
 300          * Skip prefix path to provide support for DFS referrals from w2k8 servers which don't seem
 301          * to respond with PATH_NOT_COVERED to requests that include the prefix.
 302          */
 303         if (!nodfs) {
 304                 rc = dfs_get_referral(mnt_ctx, ctx->UNC + 1, NULL, NULL);
 305                 if (rc) {
 306                         if (rc != -ENOENT && rc != -EOPNOTSUPP && rc != -EIO)
 307                                 goto out;
 308                         nodfs = true;
 309                 }
 310         }
 311         if (nodfs) {
 312                 rc = cifs_mount_get_tcon(mnt_ctx);
 313                 if (!rc)
 314                         rc = cifs_is_path_remote(mnt_ctx);
 315                 goto out;
 316         }
 317
 318         *isdfs = true;
 319         /*
 320          * Prevent DFS root session of being put in the first call to
 321          * cifs_mount_put_conns().  If another DFS root server was not found
 322          * while chasing the referrals (@ctx->dfs_root_ses == @ses), then we
 323          * can safely put extra refcount of @ses.
 324          */
 325         ses = mnt_ctx->ses;
 326         mnt_ctx->ses = NULL;
 327         mnt_ctx->server = NULL;
 328         rc = __dfs_mount_share(mnt_ctx);
 329         if (ses == ctx->dfs_root_ses)
 330                 cifs_put_smb_ses(ses);
 331 out:
 332         /*
 333          * Restore previous value of @ctx->source so DFS superblock can be
 334          * matched in cifs_match_super().
 335          */
 336         ctx->source = source;
 337         return rc;
 338 }
 339
 340 /* Update dfs referral path of superblock */
 341 static int update_server_fullpath(struct TCP_Server_Info *server, struct cifs_sb_info *cifs_sb,
 342                                   const char *target)
 343 {
 344         int rc = 0;
 345         size_t len = strlen(target);
 346         char *refpath, *npath;
 347
 348         if (unlikely(len < 2 || *target != '\\'))
 349                 return -EINVAL;
 350
 351         if (target[1] == '\\') {
 352                 len += 1;
 353                 refpath = kmalloc(len, GFP_KERNEL);
 354                 if (!refpath)
 355                         return -ENOMEM;
 356
 357                 scnprintf(refpath, len, "%s", target);
 358         } else {
 359                 len += sizeof("\\");
 360                 refpath = kmalloc(len, GFP_KERNEL);
 361                 if (!refpath)
 362                         return -ENOMEM;
 363
 364                 scnprintf(refpath, len, "\\%s", target);
 365         }
 366
 367         npath = dfs_cache_canonical_path(refpath, cifs_sb->local_nls, cifs_remap(cifs_sb));
 368         kfree(refpath);
 369
 370         if (IS_ERR(npath)) {
 371                 rc = PTR_ERR(npath);
 372         } else {
 373                 mutex_lock(&server->refpath_lock);
 374                 spin_lock(&server->srv_lock);
 375                 kfree(server->leaf_fullpath);
 376                 server->leaf_fullpath = npath;
 377                 spin_unlock(&server->srv_lock);
 378                 mutex_unlock(&server->refpath_lock);
 379         }
 380         return rc;
 381 }
 382
 383 static int target_share_matches_server(struct TCP_Server_Info *server, char *share,
 384                                        bool *target_match)
 385 {
 386         int rc = 0;
 387         const char *dfs_host;
 388         size_t dfs_host_len;
 389
 390         *target_match = true;
 391         extract_unc_hostname(share, &dfs_host, &dfs_host_len);
 392
 393         /* Check if hostnames or addresses match */
 394         cifs_server_lock(server);
 395         if (dfs_host_len != strlen(server->hostname) ||
 396             strncasecmp(dfs_host, server->hostname, dfs_host_len)) {
 397                 cifs_dbg(FYI, "%s: %.*s doesn't match %s\n", __func__,
 398                          (int)dfs_host_len, dfs_host, server->hostname);
 399                 rc = match_target_ip(server, dfs_host, dfs_host_len, target_match);
 400                 if (rc)
 401                         cifs_dbg(VFS, "%s: failed to match target ip: %d\n", __func__, rc);
 402         }
 403         cifs_server_unlock(server);
 404         return rc;
 405 }
 406
 407 static void __tree_connect_ipc(const unsigned int xid, char *tree,
 408                                struct cifs_sb_info *cifs_sb,
 409                                struct cifs_ses *ses)
 410 {
 411         struct TCP_Server_Info *server = ses->server;
 412         struct cifs_tcon *tcon = ses->tcon_ipc;
 413         int rc;
 414
 415         spin_lock(&ses->ses_lock);
 416         spin_lock(&ses->chan_lock);
 417         if (cifs_chan_needs_reconnect(ses, server) ||
 418             ses->ses_status != SES_GOOD) {
 419                 spin_unlock(&ses->chan_lock);
 420                 spin_unlock(&ses->ses_lock);
 421                 cifs_server_dbg(FYI, "%s: skipping ipc reconnect due to disconnected ses\n",
 422                                 __func__);
 423                 return;
 424         }
 425         spin_unlock(&ses->chan_lock);
 426         spin_unlock(&ses->ses_lock);
 427
 428         cifs_server_lock(server);
 429         scnprintf(tree, MAX_TREE_SIZE, "\\\\%s\\IPC$", server->hostname);
 430         cifs_server_unlock(server);
 431
 432         rc = server->ops->tree_connect(xid, ses, tree, tcon,
 433                                        cifs_sb->local_nls);
 434         cifs_server_dbg(FYI, "%s: tree_reconnect %s: %d\n", __func__, tree, rc);
 435         spin_lock(&tcon->tc_lock);
 436         if (rc) {
 437                 tcon->status = TID_NEED_TCON;
 438         } else {
 439                 tcon->status = TID_GOOD;
 440                 tcon->need_reconnect = false;
 441         }
 442         spin_unlock(&tcon->tc_lock);
 443 }
 444
 445 static void tree_connect_ipc(const unsigned int xid, char *tree,
 446                              struct cifs_sb_info *cifs_sb,
 447                              struct cifs_tcon *tcon)
 448 {
 449         struct cifs_ses *ses = tcon->ses;
 450
 451         __tree_connect_ipc(xid, tree, cifs_sb, ses);
 452         __tree_connect_ipc(xid, tree, cifs_sb, CIFS_DFS_ROOT_SES(ses));
 453 }
 454
 455 static int __tree_connect_dfs_target(const unsigned int xid, struct cifs_tcon *tcon,
 456                                      struct cifs_sb_info *cifs_sb, char *tree, bool islink,
 457                                      struct dfs_cache_tgt_list *tl)
 458 {
 459         int rc;
 460         struct TCP_Server_Info *server = tcon->ses->server;
 461         const struct smb_version_operations *ops = server->ops;
 462         struct cifs_ses *root_ses = CIFS_DFS_ROOT_SES(tcon->ses);
 463         char *share = NULL, *prefix = NULL;
 464         struct dfs_cache_tgt_iterator *tit;
 465         bool target_match;
 466
 467         tit = dfs_cache_get_tgt_iterator(tl);
 468         if (!tit) {
 469                 rc = -ENOENT;
 470                 goto out;
 471         }
 472
 473         /* Try to tree connect to all dfs targets */
 474         for (; tit; tit = dfs_cache_get_next_tgt(tl, tit)) {
 475                 const char *target = dfs_cache_get_tgt_name(tit);
 476                 struct dfs_cache_tgt_list ntl = DFS_CACHE_TGT_LIST_INIT(ntl);
 477
 478                 kfree(share);
 479                 kfree(prefix);
 480                 share = prefix = NULL;
 481
 482                 /* Check if share matches with tcp ses */
 483                 rc = dfs_cache_get_tgt_share(server->leaf_fullpath + 1, tit, &share, &prefix);
 484                 if (rc) {
 485                         cifs_dbg(VFS, "%s: failed to parse target share: %d\n", __func__, rc);
 486                         break;
 487                 }
 488
 489                 rc = target_share_matches_server(server, share, &target_match);
 490                 if (rc)
 491                         break;
 492                 if (!target_match) {
 493                         rc = -EHOSTUNREACH;
 494                         continue;
 495                 }
 496
 497                 dfs_cache_noreq_update_tgthint(server->leaf_fullpath + 1, tit);
 498                 tree_connect_ipc(xid, tree, cifs_sb, tcon);
 499
 500                 scnprintf(tree, MAX_TREE_SIZE, "\\%s", share);
 501                 if (!islink) {
 502                         rc = ops->tree_connect(xid, tcon->ses, tree, tcon, cifs_sb->local_nls);
 503                         break;
 504                 }
 505
 506                 /*
 507                  * If no dfs referrals were returned from link target, then just do a TREE_CONNECT
 508                  * to it.  Otherwise, cache the dfs referral and then mark current tcp ses for
 509                  * reconnect so either the demultiplex thread or the echo worker will reconnect to
 510                  * newly resolved target.
 511                  */
 512                 if (dfs_cache_find(xid, root_ses, cifs_sb->local_nls, cifs_remap(cifs_sb), target,
 513                                    NULL, &ntl)) {
 514                         rc = ops->tree_connect(xid, tcon->ses, tree, tcon, cifs_sb->local_nls);
 515                         if (rc)
 516                                 continue;
 517
 518                         rc = cifs_update_super_prepath(cifs_sb, prefix);
 519                 } else {
 520                         /* Target is another dfs share */
 521                         rc = update_server_fullpath(server, cifs_sb, target);
 522                         dfs_cache_free_tgts(tl);
 523
 524                         if (!rc) {
 525                                 rc = -EREMOTE;
 526                                 list_replace_init(&ntl.tl_list, &tl->tl_list);
 527                         } else
 528                                 dfs_cache_free_tgts(&ntl);
 529                 }
 530                 break;
 531         }
 532
 533 out:
 534         kfree(share);
 535         kfree(prefix);
 536
 537         return rc;
 538 }
 539
 540 static int tree_connect_dfs_target(const unsigned int xid, struct cifs_tcon *tcon,
 541                                    struct cifs_sb_info *cifs_sb, char *tree, bool islink,
 542                                    struct dfs_cache_tgt_list *tl)
 543 {
 544         int rc;
 545         int num_links = 0;
 546         struct TCP_Server_Info *server = tcon->ses->server;
 547         char *old_fullpath = server->leaf_fullpath;
 548
 549         do {
 550                 rc = __tree_connect_dfs_target(xid, tcon, cifs_sb, tree, islink, tl);
 551                 if (!rc || rc != -EREMOTE)
 552                         break;
 553         } while (rc = -ELOOP, ++num_links < MAX_NESTED_LINKS);
 554         /*
 555          * If we couldn't tree connect to any targets from last referral path, then
 556          * retry it from newly resolved dfs referral.
 557          */
 558         if (rc && server->leaf_fullpath != old_fullpath)
 559                 cifs_signal_cifsd_for_reconnect(server, true);
 560
 561         dfs_cache_free_tgts(tl);
 562         return rc;
 563 }
 564
 565 int cifs_tree_connect(const unsigned int xid, struct cifs_tcon *tcon, const struct nls_table *nlsc)
 566 {
 567         int rc;
 568         struct TCP_Server_Info *server = tcon->ses->server;
 569         const struct smb_version_operations *ops = server->ops;
 570         struct super_block *sb = NULL;
 571         struct cifs_sb_info *cifs_sb;
 572         struct dfs_cache_tgt_list tl = DFS_CACHE_TGT_LIST_INIT(tl);
 573         char *tree;
 574         struct dfs_info3_param ref = {0};
 575
 576         /* only send once per connect */
 577         spin_lock(&tcon->tc_lock);
 578         if (tcon->status != TID_NEW &&
 579             tcon->status != TID_NEED_TCON) {
 580                 spin_unlock(&tcon->tc_lock);
 581                 return -EHOSTDOWN;
 582         }
 583
 584         if (tcon->status == TID_GOOD) {
 585                 spin_unlock(&tcon->tc_lock);
 586                 return 0;
 587         }
 588         tcon->status = TID_IN_TCON;
 589         spin_unlock(&tcon->tc_lock);
 590
 591         tree = kzalloc(MAX_TREE_SIZE, GFP_KERNEL);
 592         if (!tree) {
 593                 rc = -ENOMEM;
 594                 goto out;
 595         }
 596
 597         if (tcon->ipc) {
 598                 cifs_server_lock(server);
 599                 scnprintf(tree, MAX_TREE_SIZE, "\\\\%s\\IPC$", server->hostname);
 600                 cifs_server_unlock(server);
 601                 rc = ops->tree_connect(xid, tcon->ses, tree, tcon, nlsc);
 602                 goto out;
 603         }
 604
 605         sb = cifs_get_tcp_super(server);
 606         if (IS_ERR(sb)) {
 607                 rc = PTR_ERR(sb);
 608                 cifs_dbg(VFS, "%s: could not find superblock: %d\n", __func__, rc);
 609                 goto out;
 610         }
 611
 612         cifs_sb = CIFS_SB(sb);
 613
 614         /* If it is not dfs or there was no cached dfs referral, then reconnect to same share */
 615         if (!server->leaf_fullpath ||
 616             dfs_cache_noreq_find(server->leaf_fullpath + 1, &ref, &tl)) {
 617                 rc = ops->tree_connect(xid, tcon->ses, tcon->tree_name, tcon, cifs_sb->local_nls);
 618                 goto out;
 619         }
 620
 621         rc = tree_connect_dfs_target(xid, tcon, cifs_sb, tree, ref.server_type == DFS_TYPE_LINK,
 622                                      &tl);
 623         free_dfs_info_param(&ref);
 624
 625 out:
 626         kfree(tree);
 627         cifs_put_tcp_super(sb);
 628
 629         if (rc) {
 630                 spin_lock(&tcon->tc_lock);
 631                 if (tcon->status == TID_IN_TCON)
 632                         tcon->status = TID_NEED_TCON;
 633                 spin_unlock(&tcon->tc_lock);
 634         } else {
 635                 spin_lock(&tcon->tc_lock);
 636                 if (tcon->status == TID_IN_TCON)
 637                         tcon->status = TID_GOOD;
 638                 spin_unlock(&tcon->tc_lock);
 639                 tcon->need_reconnect = false;
 640         }
 641
 642         return rc;
 643 }