fs/smb/client/cached_dir.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *  Functions to handle the cached directory entries
   4  *
   5  *  Copyright (c) 2022, Ronnie Sahlberg <[email protected]>
   6  */
   7
   8 #include <linux/namei.h>
   9 #include "cifsglob.h"
  10 #include "cifsproto.h"
  11 #include "cifs_debug.h"
  12 #include "smb2proto.h"
  13 #include "cached_dir.h"
  14
  15 static struct cached_fid *init_cached_dir(const char *path);
  16 static void free_cached_dir(struct cached_fid *cfid);
  17 static void smb2_close_cached_fid(struct kref *ref);
  18 static void cfids_laundromat_worker(struct work_struct *work);
  19
  20 struct cached_dir_dentry {
  21         struct list_head entry;
  22         struct dentry *dentry;
  23 };
  24
  25 static struct cached_fid *find_or_create_cached_dir(struct cached_fids *cfids,
  26                                                     const char *path,
  27                                                     bool lookup_only,
  28                                                     __u32 max_cached_dirs)
  29 {
  30         struct cached_fid *cfid;
  31
  32         spin_lock(&cfids->cfid_list_lock);
  33         list_for_each_entry(cfid, &cfids->entries, entry) {
  34                 if (!strcmp(cfid->path, path)) {
  35                         /*
  36                          * If it doesn't have a lease it is either not yet
  37                          * fully cached or it may be in the process of
  38                          * being deleted due to a lease break.
  39                          */
  40                         if (!cfid->time || !cfid->has_lease) {
  41                                 spin_unlock(&cfids->cfid_list_lock);
  42                                 return NULL;
  43                         }
  44                         kref_get(&cfid->refcount);
  45                         spin_unlock(&cfids->cfid_list_lock);
  46                         return cfid;
  47                 }
  48         }
  49         if (lookup_only) {
  50                 spin_unlock(&cfids->cfid_list_lock);
  51                 return NULL;
  52         }
  53         if (cfids->num_entries >= max_cached_dirs) {
  54                 spin_unlock(&cfids->cfid_list_lock);
  55                 return NULL;
  56         }
  57         cfid = init_cached_dir(path);
  58         if (cfid == NULL) {
  59                 spin_unlock(&cfids->cfid_list_lock);
  60                 return NULL;
  61         }
  62         cfid->cfids = cfids;
  63         cfids->num_entries++;
  64         list_add(&cfid->entry, &cfids->entries);
  65         cfid->on_list = true;
  66         kref_get(&cfid->refcount);
  67         /*
  68          * Set @cfid->has_lease to true during construction so that the lease
  69          * reference can be put in cached_dir_lease_break() due to a potential
  70          * lease break right after the request is sent or while @cfid is still
  71          * being cached, or if a reconnection is triggered during construction.
  72          * Concurrent processes won't be to use it yet due to @cfid->time being
  73          * zero.
  74          */
  75         cfid->has_lease = true;
  76
  77         spin_unlock(&cfids->cfid_list_lock);
  78         return cfid;
  79 }
  80
  81 static struct dentry *
  82 path_to_dentry(struct cifs_sb_info *cifs_sb, const char *path)
  83 {
  84         struct dentry *dentry;
  85         const char *s, *p;
  86         char sep;
  87
  88         sep = CIFS_DIR_SEP(cifs_sb);
  89         dentry = dget(cifs_sb->root);
  90         s = path;
  91
  92         do {
  93                 struct inode *dir = d_inode(dentry);
  94                 struct dentry *child;
  95
  96                 if (!S_ISDIR(dir->i_mode)) {
  97                         dput(dentry);
  98                         dentry = ERR_PTR(-ENOTDIR);
  99                         break;
 100                 }
 101
 102                 /* skip separators */
 103                 while (*s == sep)
 104                         s++;
 105                 if (!*s)
 106                         break;
 107                 p = s++;
 108                 /* next separator */
 109                 while (*s && *s != sep)
 110                         s++;
 111
 112                 child = lookup_positive_unlocked(p, dentry, s - p);
 113                 dput(dentry);
 114                 dentry = child;
 115         } while (!IS_ERR(dentry));
 116         return dentry;
 117 }
 118
 119 static const char *path_no_prefix(struct cifs_sb_info *cifs_sb,
 120                                   const char *path)
 121 {
 122         size_t len = 0;
 123
 124         if (!*path)
 125                 return path;
 126
 127         if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH) &&
 128             cifs_sb->prepath) {
 129                 len = strlen(cifs_sb->prepath) + 1;
 130                 if (unlikely(len > strlen(path)))
 131                         return ERR_PTR(-EINVAL);
 132         }
 133         return path + len;
 134 }
 135
 136 /*
 137  * Open the and cache a directory handle.
 138  * If error then *cfid is not initialized.
 139  */
 140 int open_cached_dir(unsigned int xid, struct cifs_tcon *tcon,
 141                     const char *path,
 142                     struct cifs_sb_info *cifs_sb,
 143                     bool lookup_only, struct cached_fid **ret_cfid)
 144 {
 145         struct cifs_ses *ses;
 146         struct TCP_Server_Info *server;
 147         struct cifs_open_parms oparms;
 148         struct smb2_create_rsp *o_rsp = NULL;
 149         struct smb2_query_info_rsp *qi_rsp = NULL;
 150         int resp_buftype[2];
 151         struct smb_rqst rqst[2];
 152         struct kvec rsp_iov[2];
 153         struct kvec open_iov[SMB2_CREATE_IOV_SIZE];
 154         struct kvec qi_iov[1];
 155         int rc, flags = 0;
 156         __le16 *utf16_path = NULL;
 157         u8 oplock = SMB2_OPLOCK_LEVEL_II;
 158         struct cifs_fid *pfid;
 159         struct dentry *dentry = NULL;
 160         struct cached_fid *cfid;
 161         struct cached_fids *cfids;
 162         const char *npath;
 163         int retries = 0, cur_sleep = 1;
 164
 165         if (cifs_sb->root == NULL)
 166                 return -ENOENT;
 167
 168         if (tcon == NULL)
 169                 return -EOPNOTSUPP;
 170
 171         ses = tcon->ses;
 172         cfids = tcon->cfids;
 173
 174         if (cfids == NULL)
 175                 return -EOPNOTSUPP;
 176
 177 replay_again:
 178         /* reinitialize for possible replay */
 179         flags = 0;
 180         oplock = SMB2_OPLOCK_LEVEL_II;
 181         server = cifs_pick_channel(ses);
 182
 183         if (!server->ops->new_lease_key)
 184                 return -EIO;
 185
 186         utf16_path = cifs_convert_path_to_utf16(path, cifs_sb);
 187         if (!utf16_path)
 188                 return -ENOMEM;
 189
 190         cfid = find_or_create_cached_dir(cfids, path, lookup_only, tcon->max_cached_dirs);
 191         if (cfid == NULL) {
 192                 kfree(utf16_path);
 193                 return -ENOENT;
 194         }
 195         /*
 196          * Return cached fid if it is valid (has a lease and has a time).
 197          * Otherwise, it is either a new entry or laundromat worker removed it
 198          * from @cfids->entries.  Caller will put last reference if the latter.
 199          */
 200         spin_lock(&cfids->cfid_list_lock);
 201         if (cfid->has_lease && cfid->time) {
 202                 spin_unlock(&cfids->cfid_list_lock);
 203                 *ret_cfid = cfid;
 204                 kfree(utf16_path);
 205                 return 0;
 206         }
 207         spin_unlock(&cfids->cfid_list_lock);
 208
 209         /*
 210          * Skip any prefix paths in @path as lookup_positive_unlocked() ends up
 211          * calling ->lookup() which already adds those through
 212          * build_path_from_dentry().  Also, do it earlier as we might reconnect
 213          * below when trying to send compounded request and then potentially
 214          * having a different prefix path (e.g. after DFS failover).
 215          */
 216         npath = path_no_prefix(cifs_sb, path);
 217         if (IS_ERR(npath)) {
 218                 rc = PTR_ERR(npath);
 219                 goto out;
 220         }
 221
 222         if (!npath[0]) {
 223                 dentry = dget(cifs_sb->root);
 224         } else {
 225                 dentry = path_to_dentry(cifs_sb, npath);
 226                 if (IS_ERR(dentry)) {
 227                         rc = -ENOENT;
 228                         goto out;
 229                 }
 230         }
 231         cfid->dentry = dentry;
 232         cfid->tcon = tcon;
 233
 234         /*
 235          * We do not hold the lock for the open because in case
 236          * SMB2_open needs to reconnect.
 237          * This is safe because no other thread will be able to get a ref
 238          * to the cfid until we have finished opening the file and (possibly)
 239          * acquired a lease.
 240          */
 241         if (smb3_encryption_required(tcon))
 242                 flags |= CIFS_TRANSFORM_REQ;
 243
 244         pfid = &cfid->fid;
 245         server->ops->new_lease_key(pfid);
 246
 247         memset(rqst, 0, sizeof(rqst));
 248         resp_buftype[0] = resp_buftype[1] = CIFS_NO_BUFFER;
 249         memset(rsp_iov, 0, sizeof(rsp_iov));
 250
 251         /* Open */
 252         memset(&open_iov, 0, sizeof(open_iov));
 253         rqst[0].rq_iov = open_iov;
 254         rqst[0].rq_nvec = SMB2_CREATE_IOV_SIZE;
 255
 256         oparms = (struct cifs_open_parms) {
 257                 .tcon = tcon,
 258                 .path = path,
 259                 .create_options = cifs_create_options(cifs_sb, CREATE_NOT_FILE),
 260                 .desired_access =  FILE_READ_DATA | FILE_READ_ATTRIBUTES |
 261                                    FILE_READ_EA,
 262                 .disposition = FILE_OPEN,
 263                 .fid = pfid,
 264                 .replay = !!(retries),
 265         };
 266
 267         rc = SMB2_open_init(tcon, server,
 268                             &rqst[0], &oplock, &oparms, utf16_path);
 269         if (rc)
 270                 goto oshr_free;
 271         smb2_set_next_command(tcon, &rqst[0]);
 272
 273         memset(&qi_iov, 0, sizeof(qi_iov));
 274         rqst[1].rq_iov = qi_iov;
 275         rqst[1].rq_nvec = 1;
 276
 277         rc = SMB2_query_info_init(tcon, server,
 278                                   &rqst[1], COMPOUND_FID,
 279                                   COMPOUND_FID, FILE_ALL_INFORMATION,
 280                                   SMB2_O_INFO_FILE, 0,
 281                                   sizeof(struct smb2_file_all_info) +
 282                                   PATH_MAX * 2, 0, NULL);
 283         if (rc)
 284                 goto oshr_free;
 285
 286         smb2_set_related(&rqst[1]);
 287
 288         if (retries) {
 289                 smb2_set_replay(server, &rqst[0]);
 290                 smb2_set_replay(server, &rqst[1]);
 291         }
 292
 293         rc = compound_send_recv(xid, ses, server,
 294                                 flags, 2, rqst,
 295                                 resp_buftype, rsp_iov);
 296         if (rc) {
 297                 if (rc == -EREMCHG) {
 298                         tcon->need_reconnect = true;
 299                         pr_warn_once("server share %s deleted\n",
 300                                      tcon->tree_name);
 301                 }
 302                 goto oshr_free;
 303         }
 304         cfid->is_open = true;
 305
 306         spin_lock(&cfids->cfid_list_lock);
 307
 308         o_rsp = (struct smb2_create_rsp *)rsp_iov[0].iov_base;
 309         oparms.fid->persistent_fid = o_rsp->PersistentFileId;
 310         oparms.fid->volatile_fid = o_rsp->VolatileFileId;
 311 #ifdef CONFIG_CIFS_DEBUG2
 312         oparms.fid->mid = le64_to_cpu(o_rsp->hdr.MessageId);
 313 #endif /* CIFS_DEBUG2 */
 314
 315
 316         if (o_rsp->OplockLevel != SMB2_OPLOCK_LEVEL_LEASE) {
 317                 spin_unlock(&cfids->cfid_list_lock);
 318                 rc = -EINVAL;
 319                 goto oshr_free;
 320         }
 321
 322         rc = smb2_parse_contexts(server, rsp_iov,
 323                                  &oparms.fid->epoch,
 324                                  oparms.fid->lease_key,
 325                                  &oplock, NULL, NULL);
 326         if (rc) {
 327                 spin_unlock(&cfids->cfid_list_lock);
 328                 goto oshr_free;
 329         }
 330
 331         rc = -EINVAL;
 332         if (!(oplock & SMB2_LEASE_READ_CACHING_HE)) {
 333                 spin_unlock(&cfids->cfid_list_lock);
 334                 goto oshr_free;
 335         }
 336         qi_rsp = (struct smb2_query_info_rsp *)rsp_iov[1].iov_base;
 337         if (le32_to_cpu(qi_rsp->OutputBufferLength) < sizeof(struct smb2_file_all_info)) {
 338                 spin_unlock(&cfids->cfid_list_lock);
 339                 goto oshr_free;
 340         }
 341         if (!smb2_validate_and_copy_iov(
 342                                 le16_to_cpu(qi_rsp->OutputBufferOffset),
 343                                 sizeof(struct smb2_file_all_info),
 344                                 &rsp_iov[1], sizeof(struct smb2_file_all_info),
 345                                 (char *)&cfid->file_all_info))
 346                 cfid->file_all_info_is_valid = true;
 347
 348         cfid->time = jiffies;
 349         spin_unlock(&cfids->cfid_list_lock);
 350         /* At this point the directory handle is fully cached */
 351         rc = 0;
 352
 353 oshr_free:
 354         SMB2_open_free(&rqst[0]);
 355         SMB2_query_info_free(&rqst[1]);
 356         free_rsp_buf(resp_buftype[0], rsp_iov[0].iov_base);
 357         free_rsp_buf(resp_buftype[1], rsp_iov[1].iov_base);
 358 out:
 359         if (rc) {
 360                 spin_lock(&cfids->cfid_list_lock);
 361                 if (cfid->on_list) {
 362                         list_del(&cfid->entry);
 363                         cfid->on_list = false;
 364                         cfids->num_entries--;
 365                 }
 366                 if (cfid->has_lease) {
 367                         /*
 368                          * We are guaranteed to have two references at this
 369                          * point. One for the caller and one for a potential
 370                          * lease. Release one here, and the second below.
 371                          */
 372                         cfid->has_lease = false;
 373                         kref_put(&cfid->refcount, smb2_close_cached_fid);
 374                 }
 375                 spin_unlock(&cfids->cfid_list_lock);
 376
 377                 kref_put(&cfid->refcount, smb2_close_cached_fid);
 378         } else {
 379                 *ret_cfid = cfid;
 380                 atomic_inc(&tcon->num_remote_opens);
 381         }
 382         kfree(utf16_path);
 383
 384         if (is_replayable_error(rc) &&
 385             smb2_should_replay(tcon, &retries, &cur_sleep))
 386                 goto replay_again;
 387
 388         return rc;
 389 }
 390
 391 int open_cached_dir_by_dentry(struct cifs_tcon *tcon,
 392                               struct dentry *dentry,
 393                               struct cached_fid **ret_cfid)
 394 {
 395         struct cached_fid *cfid;
 396         struct cached_fids *cfids = tcon->cfids;
 397
 398         if (cfids == NULL)
 399                 return -EOPNOTSUPP;
 400
 401         spin_lock(&cfids->cfid_list_lock);
 402         list_for_each_entry(cfid, &cfids->entries, entry) {
 403                 if (dentry && cfid->dentry == dentry) {
 404                         cifs_dbg(FYI, "found a cached file handle by dentry\n");
 405                         kref_get(&cfid->refcount);
 406                         *ret_cfid = cfid;
 407                         spin_unlock(&cfids->cfid_list_lock);
 408                         return 0;
 409                 }
 410         }
 411         spin_unlock(&cfids->cfid_list_lock);
 412         return -ENOENT;
 413 }
 414
 415 static void
 416 smb2_close_cached_fid(struct kref *ref)
 417 {
 418         struct cached_fid *cfid = container_of(ref, struct cached_fid,
 419                                                refcount);
 420         int rc;
 421
 422         spin_lock(&cfid->cfids->cfid_list_lock);
 423         if (cfid->on_list) {
 424                 list_del(&cfid->entry);
 425                 cfid->on_list = false;
 426                 cfid->cfids->num_entries--;
 427         }
 428         spin_unlock(&cfid->cfids->cfid_list_lock);
 429
 430         dput(cfid->dentry);
 431         cfid->dentry = NULL;
 432
 433         if (cfid->is_open) {
 434                 rc = SMB2_close(0, cfid->tcon, cfid->fid.persistent_fid,
 435                            cfid->fid.volatile_fid);
 436                 if (rc) /* should we retry on -EBUSY or -EAGAIN? */
 437                         cifs_dbg(VFS, "close cached dir rc %d\n", rc);
 438         }
 439
 440         free_cached_dir(cfid);
 441 }
 442
 443 void drop_cached_dir_by_name(const unsigned int xid, struct cifs_tcon *tcon,
 444                              const char *name, struct cifs_sb_info *cifs_sb)
 445 {
 446         struct cached_fid *cfid = NULL;
 447         int rc;
 448
 449         rc = open_cached_dir(xid, tcon, name, cifs_sb, true, &cfid);
 450         if (rc) {
 451                 cifs_dbg(FYI, "no cached dir found for rmdir(%s)\n", name);
 452                 return;
 453         }
 454         spin_lock(&cfid->cfids->cfid_list_lock);
 455         if (cfid->has_lease) {
 456                 cfid->has_lease = false;
 457                 kref_put(&cfid->refcount, smb2_close_cached_fid);
 458         }
 459         spin_unlock(&cfid->cfids->cfid_list_lock);
 460         close_cached_dir(cfid);
 461 }
 462
 463
 464 void close_cached_dir(struct cached_fid *cfid)
 465 {
 466         kref_put(&cfid->refcount, smb2_close_cached_fid);
 467 }
 468
 469 /*
 470  * Called from cifs_kill_sb when we unmount a share
 471  */
 472 void close_all_cached_dirs(struct cifs_sb_info *cifs_sb)
 473 {
 474         struct rb_root *root = &cifs_sb->tlink_tree;
 475         struct rb_node *node;
 476         struct cached_fid *cfid;
 477         struct cifs_tcon *tcon;
 478         struct tcon_link *tlink;
 479         struct cached_fids *cfids;
 480         struct cached_dir_dentry *tmp_list, *q;
 481         LIST_HEAD(entry);
 482
 483         spin_lock(&cifs_sb->tlink_tree_lock);
 484         for (node = rb_first(root); node; node = rb_next(node)) {
 485                 tlink = rb_entry(node, struct tcon_link, tl_rbnode);
 486                 tcon = tlink_tcon(tlink);
 487                 if (IS_ERR(tcon))
 488                         continue;
 489                 cfids = tcon->cfids;
 490                 if (cfids == NULL)
 491                         continue;
 492                 spin_lock(&cfids->cfid_list_lock);
 493                 list_for_each_entry(cfid, &cfids->entries, entry) {
 494                         tmp_list = kmalloc(sizeof(*tmp_list), GFP_ATOMIC);
 495                         if (tmp_list == NULL)
 496                                 break;
 497                         spin_lock(&cfid->fid_lock);
 498                         tmp_list->dentry = cfid->dentry;
 499                         cfid->dentry = NULL;
 500                         spin_unlock(&cfid->fid_lock);
 501
 502                         list_add_tail(&tmp_list->entry, &entry);
 503                 }
 504                 spin_unlock(&cfids->cfid_list_lock);
 505         }
 506         spin_unlock(&cifs_sb->tlink_tree_lock);
 507
 508         list_for_each_entry_safe(tmp_list, q, &entry, entry) {
 509                 list_del(&tmp_list->entry);
 510                 dput(tmp_list->dentry);
 511                 kfree(tmp_list);
 512         }
 513
 514         /* Flush any pending work that will drop dentries */
 515         flush_workqueue(cfid_put_wq);
 516 }
 517
 518 /*
 519  * Invalidate all cached dirs when a TCON has been reset
 520  * due to a session loss.
 521  */
 522 void invalidate_all_cached_dirs(struct cifs_tcon *tcon)
 523 {
 524         struct cached_fids *cfids = tcon->cfids;
 525         struct cached_fid *cfid, *q;
 526
 527         if (cfids == NULL)
 528                 return;
 529
 530         /*
 531          * Mark all the cfids as closed, and move them to the cfids->dying list.
 532          * They'll be cleaned up later by cfids_invalidation_worker. Take
 533          * a reference to each cfid during this process.
 534          */
 535         spin_lock(&cfids->cfid_list_lock);
 536         list_for_each_entry_safe(cfid, q, &cfids->entries, entry) {
 537                 list_move(&cfid->entry, &cfids->dying);
 538                 cfids->num_entries--;
 539                 cfid->is_open = false;
 540                 cfid->on_list = false;
 541                 if (cfid->has_lease) {
 542                         /*
 543                          * The lease was never cancelled from the server,
 544                          * so steal that reference.
 545                          */
 546                         cfid->has_lease = false;
 547                 } else
 548                         kref_get(&cfid->refcount);
 549         }
 550         /*
 551          * Queue dropping of the dentries once locks have been dropped
 552          */
 553         if (!list_empty(&cfids->dying))
 554                 queue_work(cfid_put_wq, &cfids->invalidation_work);
 555         spin_unlock(&cfids->cfid_list_lock);
 556 }
 557
 558 static void
 559 cached_dir_offload_close(struct work_struct *work)
 560 {
 561         struct cached_fid *cfid = container_of(work,
 562                                 struct cached_fid, close_work);
 563         struct cifs_tcon *tcon = cfid->tcon;
 564
 565         WARN_ON(cfid->on_list);
 566
 567         kref_put(&cfid->refcount, smb2_close_cached_fid);
 568         cifs_put_tcon(tcon, netfs_trace_tcon_ref_put_cached_close);
 569 }
 570
 571 /*
 572  * Release the cached directory's dentry, and then queue work to drop cached
 573  * directory itself (closing on server if needed).
 574  *
 575  * Must be called with a reference to the cached_fid and a reference to the
 576  * tcon.
 577  */
 578 static void cached_dir_put_work(struct work_struct *work)
 579 {
 580         struct cached_fid *cfid = container_of(work, struct cached_fid,
 581                                                put_work);
 582         struct dentry *dentry;
 583
 584         spin_lock(&cfid->fid_lock);
 585         dentry = cfid->dentry;
 586         cfid->dentry = NULL;
 587         spin_unlock(&cfid->fid_lock);
 588
 589         dput(dentry);
 590         queue_work(serverclose_wq, &cfid->close_work);
 591 }
 592
 593 int cached_dir_lease_break(struct cifs_tcon *tcon, __u8 lease_key[16])
 594 {
 595         struct cached_fids *cfids = tcon->cfids;
 596         struct cached_fid *cfid;
 597
 598         if (cfids == NULL)
 599                 return false;
 600
 601         spin_lock(&cfids->cfid_list_lock);
 602         list_for_each_entry(cfid, &cfids->entries, entry) {
 603                 if (cfid->has_lease &&
 604                     !memcmp(lease_key,
 605                             cfid->fid.lease_key,
 606                             SMB2_LEASE_KEY_SIZE)) {
 607                         cfid->has_lease = false;
 608                         cfid->time = 0;
 609                         /*
 610                          * We found a lease remove it from the list
 611                          * so no threads can access it.
 612                          */
 613                         list_del(&cfid->entry);
 614                         cfid->on_list = false;
 615                         cfids->num_entries--;
 616
 617                         ++tcon->tc_count;
 618                         trace_smb3_tcon_ref(tcon->debug_id, tcon->tc_count,
 619                                             netfs_trace_tcon_ref_get_cached_lease_break);
 620                         queue_work(cfid_put_wq, &cfid->put_work);
 621                         spin_unlock(&cfids->cfid_list_lock);
 622                         return true;
 623                 }
 624         }
 625         spin_unlock(&cfids->cfid_list_lock);
 626         return false;
 627 }
 628
 629 static struct cached_fid *init_cached_dir(const char *path)
 630 {
 631         struct cached_fid *cfid;
 632
 633         cfid = kzalloc(sizeof(*cfid), GFP_ATOMIC);
 634         if (!cfid)
 635                 return NULL;
 636         cfid->path = kstrdup(path, GFP_ATOMIC);
 637         if (!cfid->path) {
 638                 kfree(cfid);
 639                 return NULL;
 640         }
 641
 642         INIT_WORK(&cfid->close_work, cached_dir_offload_close);
 643         INIT_WORK(&cfid->put_work, cached_dir_put_work);
 644         INIT_LIST_HEAD(&cfid->entry);
 645         INIT_LIST_HEAD(&cfid->dirents.entries);
 646         mutex_init(&cfid->dirents.de_mutex);
 647         spin_lock_init(&cfid->fid_lock);
 648         kref_init(&cfid->refcount);
 649         return cfid;
 650 }
 651
 652 static void free_cached_dir(struct cached_fid *cfid)
 653 {
 654         struct cached_dirent *dirent, *q;
 655
 656         WARN_ON(work_pending(&cfid->close_work));
 657         WARN_ON(work_pending(&cfid->put_work));
 658
 659         dput(cfid->dentry);
 660         cfid->dentry = NULL;
 661
 662         /*
 663          * Delete all cached dirent names
 664          */
 665         list_for_each_entry_safe(dirent, q, &cfid->dirents.entries, entry) {
 666                 list_del(&dirent->entry);
 667                 kfree(dirent->name);
 668                 kfree(dirent);
 669         }
 670
 671         kfree(cfid->path);
 672         cfid->path = NULL;
 673         kfree(cfid);
 674 }
 675
 676 static void cfids_invalidation_worker(struct work_struct *work)
 677 {
 678         struct cached_fids *cfids = container_of(work, struct cached_fids,
 679                                                  invalidation_work);
 680         struct cached_fid *cfid, *q;
 681         LIST_HEAD(entry);
 682
 683         spin_lock(&cfids->cfid_list_lock);
 684         /* move cfids->dying to the local list */
 685         list_cut_before(&entry, &cfids->dying, &cfids->dying);
 686         spin_unlock(&cfids->cfid_list_lock);
 687
 688         list_for_each_entry_safe(cfid, q, &entry, entry) {
 689                 list_del(&cfid->entry);
 690                 /* Drop the ref-count acquired in invalidate_all_cached_dirs */
 691                 kref_put(&cfid->refcount, smb2_close_cached_fid);
 692         }
 693 }
 694
 695 static void cfids_laundromat_worker(struct work_struct *work)
 696 {
 697         struct cached_fids *cfids;
 698         struct cached_fid *cfid, *q;
 699         struct dentry *dentry;
 700         LIST_HEAD(entry);
 701
 702         cfids = container_of(work, struct cached_fids, laundromat_work.work);
 703
 704         spin_lock(&cfids->cfid_list_lock);
 705         list_for_each_entry_safe(cfid, q, &cfids->entries, entry) {
 706                 if (cfid->time &&
 707                     time_after(jiffies, cfid->time + HZ * dir_cache_timeout)) {
 708                         cfid->on_list = false;
 709                         list_move(&cfid->entry, &entry);
 710                         cfids->num_entries--;
 711                         if (cfid->has_lease) {
 712                                 /*
 713                                  * Our lease has not yet been cancelled from the
 714                                  * server. Steal that reference.
 715                                  */
 716                                 cfid->has_lease = false;
 717                         } else
 718                                 kref_get(&cfid->refcount);
 719                 }
 720         }
 721         spin_unlock(&cfids->cfid_list_lock);
 722
 723         list_for_each_entry_safe(cfid, q, &entry, entry) {
 724                 list_del(&cfid->entry);
 725
 726                 spin_lock(&cfid->fid_lock);
 727                 dentry = cfid->dentry;
 728                 cfid->dentry = NULL;
 729                 spin_unlock(&cfid->fid_lock);
 730
 731                 dput(dentry);
 732                 if (cfid->is_open) {
 733                         spin_lock(&cifs_tcp_ses_lock);
 734                         ++cfid->tcon->tc_count;
 735                         trace_smb3_tcon_ref(cfid->tcon->debug_id, cfid->tcon->tc_count,
 736                                             netfs_trace_tcon_ref_get_cached_laundromat);
 737                         spin_unlock(&cifs_tcp_ses_lock);
 738                         queue_work(serverclose_wq, &cfid->close_work);
 739                 } else
 740                         /*
 741                          * Drop the ref-count from above, either the lease-ref (if there
 742                          * was one) or the extra one acquired.
 743                          */
 744                         kref_put(&cfid->refcount, smb2_close_cached_fid);
 745         }
 746         queue_delayed_work(cfid_put_wq, &cfids->laundromat_work,
 747                            dir_cache_timeout * HZ);
 748 }
 749
 750 struct cached_fids *init_cached_dirs(void)
 751 {
 752         struct cached_fids *cfids;
 753
 754         cfids = kzalloc(sizeof(*cfids), GFP_KERNEL);
 755         if (!cfids)
 756                 return NULL;
 757         spin_lock_init(&cfids->cfid_list_lock);
 758         INIT_LIST_HEAD(&cfids->entries);
 759         INIT_LIST_HEAD(&cfids->dying);
 760
 761         INIT_WORK(&cfids->invalidation_work, cfids_invalidation_worker);
 762         INIT_DELAYED_WORK(&cfids->laundromat_work, cfids_laundromat_worker);
 763         queue_delayed_work(cfid_put_wq, &cfids->laundromat_work,
 764                            dir_cache_timeout * HZ);
 765
 766         return cfids;
 767 }
 768
 769 /*
 770  * Called from tconInfoFree when we are tearing down the tcon.
 771  * There are no active users or open files/directories at this point.
 772  */
 773 void free_cached_dirs(struct cached_fids *cfids)
 774 {
 775         struct cached_fid *cfid, *q;
 776         LIST_HEAD(entry);
 777
 778         if (cfids == NULL)
 779                 return;
 780
 781         cancel_delayed_work_sync(&cfids->laundromat_work);
 782         cancel_work_sync(&cfids->invalidation_work);
 783
 784         spin_lock(&cfids->cfid_list_lock);
 785         list_for_each_entry_safe(cfid, q, &cfids->entries, entry) {
 786                 cfid->on_list = false;
 787                 cfid->is_open = false;
 788                 list_move(&cfid->entry, &entry);
 789         }
 790         list_for_each_entry_safe(cfid, q, &cfids->dying, entry) {
 791                 cfid->on_list = false;
 792                 cfid->is_open = false;
 793                 list_move(&cfid->entry, &entry);
 794         }
 795         spin_unlock(&cfids->cfid_list_lock);
 796
 797         list_for_each_entry_safe(cfid, q, &entry, entry) {
 798                 list_del(&cfid->entry);
 799                 free_cached_dir(cfid);
 800         }
 801
 802         kfree(cfids);
 803 }