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