fs/9p/v9fs.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  *  This file contains functions assisting in mapping VFS to 9P2000
   4  *
   5  *  Copyright (C) 2004-2008 by Eric Van Hensbergen <ericvh@gmail.com>
   6  *  Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
   7  */
   8
   9 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  10
  11 #include <linux/module.h>
  12 #include <linux/errno.h>
  13 #include <linux/fs.h>
  14 #include <linux/sched.h>
  15 #include <linux/cred.h>
  16 #include <linux/parser.h>
  17 #include <linux/slab.h>
  18 #include <linux/seq_file.h>
  19 #include <net/9p/9p.h>
  20 #include <net/9p/client.h>
  21 #include <net/9p/transport.h>
  22 #include "v9fs.h"
  23 #include "v9fs_vfs.h"
  24 #include "cache.h"
  25
  26 static DEFINE_SPINLOCK(v9fs_sessionlist_lock);
  27 static LIST_HEAD(v9fs_sessionlist);
  28 struct kmem_cache *v9fs_inode_cache;
  29
  30 /*
  31  * Option Parsing (code inspired by NFS code)
  32  *  NOTE: each transport will parse its own options
  33  */
  34
  35 enum {
  36         /* Options that take integer arguments */
  37         Opt_debug, Opt_dfltuid, Opt_dfltgid, Opt_afid,
  38         /* String options */
  39         Opt_uname, Opt_remotename, Opt_cache, Opt_cachetag,
  40         /* Options that take no arguments */
  41         Opt_nodevmap,
  42         /* Cache options */
  43         Opt_cache_loose, Opt_fscache, Opt_mmap,
  44         /* Access options */
  45         Opt_access, Opt_posixacl,
  46         /* Lock timeout option */
  47         Opt_locktimeout,
  48         /* Error token */
  49         Opt_err
  50 };
  51
  52 static const match_table_t tokens = {
  53         {Opt_debug, "debug=%x"},
  54         {Opt_dfltuid, "dfltuid=%u"},
  55         {Opt_dfltgid, "dfltgid=%u"},
  56         {Opt_afid, "afid=%u"},
  57         {Opt_uname, "uname=%s"},
  58         {Opt_remotename, "aname=%s"},
  59         {Opt_nodevmap, "nodevmap"},
  60         {Opt_cache, "cache=%s"},
  61         {Opt_cache_loose, "loose"},
  62         {Opt_fscache, "fscache"},
  63         {Opt_mmap, "mmap"},
  64         {Opt_cachetag, "cachetag=%s"},
  65         {Opt_access, "access=%s"},
  66         {Opt_posixacl, "posixacl"},
  67         {Opt_locktimeout, "locktimeout=%u"},
  68         {Opt_err, NULL}
  69 };
  70
  71 static const char *const v9fs_cache_modes[nr__p9_cache_modes] = {
  72         [CACHE_NONE]    = "none",
  73         [CACHE_MMAP]    = "mmap",
  74         [CACHE_LOOSE]   = "loose",
  75         [CACHE_FSCACHE] = "fscache",
  76 };
  77
  78 /* Interpret mount options for cache mode */
  79 static int get_cache_mode(char *s)
  80 {
  81         int version = -EINVAL;
  82
  83         if (!strcmp(s, "loose")) {
  84                 version = CACHE_LOOSE;
  85                 p9_debug(P9_DEBUG_9P, "Cache mode: loose\n");
  86         } else if (!strcmp(s, "fscache")) {
  87                 version = CACHE_FSCACHE;
  88                 p9_debug(P9_DEBUG_9P, "Cache mode: fscache\n");
  89         } else if (!strcmp(s, "mmap")) {
  90                 version = CACHE_MMAP;
  91                 p9_debug(P9_DEBUG_9P, "Cache mode: mmap\n");
  92         } else if (!strcmp(s, "none")) {
  93                 version = CACHE_NONE;
  94                 p9_debug(P9_DEBUG_9P, "Cache mode: none\n");
  95         } else
  96                 pr_info("Unknown Cache mode %s\n", s);
  97         return version;
  98 }
  99
 100 /*
 101  * Display the mount options in /proc/mounts.
 102  */
 103 int v9fs_show_options(struct seq_file *m, struct dentry *root)
 104 {
 105         struct v9fs_session_info *v9ses = root->d_sb->s_fs_info;
 106
 107         if (v9ses->debug)
 108                 seq_printf(m, ",debug=%x", v9ses->debug);
 109         if (!uid_eq(v9ses->dfltuid, V9FS_DEFUID))
 110                 seq_printf(m, ",dfltuid=%u",
 111                            from_kuid_munged(&init_user_ns, v9ses->dfltuid));
 112         if (!gid_eq(v9ses->dfltgid, V9FS_DEFGID))
 113                 seq_printf(m, ",dfltgid=%u",
 114                            from_kgid_munged(&init_user_ns, v9ses->dfltgid));
 115         if (v9ses->afid != ~0)
 116                 seq_printf(m, ",afid=%u", v9ses->afid);
 117         if (strcmp(v9ses->uname, V9FS_DEFUSER) != 0)
 118                 seq_printf(m, ",uname=%s", v9ses->uname);
 119         if (strcmp(v9ses->aname, V9FS_DEFANAME) != 0)
 120                 seq_printf(m, ",aname=%s", v9ses->aname);
 121         if (v9ses->nodev)
 122                 seq_puts(m, ",nodevmap");
 123         if (v9ses->cache)
 124                 seq_printf(m, ",%s", v9fs_cache_modes[v9ses->cache]);
 125 #ifdef CONFIG_9P_FSCACHE
 126         if (v9ses->cachetag && v9ses->cache == CACHE_FSCACHE)
 127                 seq_printf(m, ",cachetag=%s", v9ses->cachetag);
 128 #endif
 129
 130         switch (v9ses->flags & V9FS_ACCESS_MASK) {
 131         case V9FS_ACCESS_USER:
 132                 seq_puts(m, ",access=user");
 133                 break;
 134         case V9FS_ACCESS_ANY:
 135                 seq_puts(m, ",access=any");
 136                 break;
 137         case V9FS_ACCESS_CLIENT:
 138                 seq_puts(m, ",access=client");
 139                 break;
 140         case V9FS_ACCESS_SINGLE:
 141                 seq_printf(m, ",access=%u",
 142                            from_kuid_munged(&init_user_ns, v9ses->uid));
 143                 break;
 144         }
 145
 146         if (v9ses->flags & V9FS_POSIX_ACL)
 147                 seq_puts(m, ",posixacl");
 148
 149         return p9_show_client_options(m, v9ses->clnt);
 150 }
 151
 152 /**
 153  * v9fs_parse_options - parse mount options into session structure
 154  * @v9ses: existing v9fs session information
 155  * @opts: The mount option string
 156  *
 157  * Return 0 upon success, -ERRNO upon failure.
 158  */
 159
 160 static int v9fs_parse_options(struct v9fs_session_info *v9ses, char *opts)
 161 {
 162         char *options, *tmp_options;
 163         substring_t args[MAX_OPT_ARGS];
 164         char *p;
 165         int option = 0;
 166         char *s;
 167         int ret = 0;
 168
 169         /* setup defaults */
 170         v9ses->afid = ~0;
 171         v9ses->debug = 0;
 172         v9ses->cache = CACHE_NONE;
 173 #ifdef CONFIG_9P_FSCACHE
 174         v9ses->cachetag = NULL;
 175 #endif
 176         v9ses->session_lock_timeout = P9_LOCK_TIMEOUT;
 177
 178         if (!opts)
 179                 return 0;
 180
 181         tmp_options = kstrdup(opts, GFP_KERNEL);
 182         if (!tmp_options) {
 183                 ret = -ENOMEM;
 184                 goto fail_option_alloc;
 185         }
 186         options = tmp_options;
 187
 188         while ((p = strsep(&options, ",")) != NULL) {
 189                 int token, r;
 190
 191                 if (!*p)
 192                         continue;
 193
 194                 token = match_token(p, tokens, args);
 195                 switch (token) {
 196                 case Opt_debug:
 197                         r = match_int(&args[0], &option);
 198                         if (r < 0) {
 199                                 p9_debug(P9_DEBUG_ERROR,
 200                                          "integer field, but no integer?\n");
 201                                 ret = r;
 202                         } else {
 203                                 v9ses->debug = option;
 204 #ifdef CONFIG_NET_9P_DEBUG
 205                                 p9_debug_level = option;
 206 #endif
 207                         }
 208                         break;
 209
 210                 case Opt_dfltuid:
 211                         r = match_int(&args[0], &option);
 212                         if (r < 0) {
 213                                 p9_debug(P9_DEBUG_ERROR,
 214                                          "integer field, but no integer?\n");
 215                                 ret = r;
 216                                 continue;
 217                         }
 218                         v9ses->dfltuid = make_kuid(current_user_ns(), option);
 219                         if (!uid_valid(v9ses->dfltuid)) {
 220                                 p9_debug(P9_DEBUG_ERROR,
 221                                          "uid field, but not a uid?\n");
 222                                 ret = -EINVAL;
 223                         }
 224                         break;
 225                 case Opt_dfltgid:
 226                         r = match_int(&args[0], &option);
 227                         if (r < 0) {
 228                                 p9_debug(P9_DEBUG_ERROR,
 229                                          "integer field, but no integer?\n");
 230                                 ret = r;
 231                                 continue;
 232                         }
 233                         v9ses->dfltgid = make_kgid(current_user_ns(), option);
 234                         if (!gid_valid(v9ses->dfltgid)) {
 235                                 p9_debug(P9_DEBUG_ERROR,
 236                                          "gid field, but not a gid?\n");
 237                                 ret = -EINVAL;
 238                         }
 239                         break;
 240                 case Opt_afid:
 241                         r = match_int(&args[0], &option);
 242                         if (r < 0) {
 243                                 p9_debug(P9_DEBUG_ERROR,
 244                                          "integer field, but no integer?\n");
 245                                 ret = r;
 246                         } else {
 247                                 v9ses->afid = option;
 248                         }
 249                         break;
 250                 case Opt_uname:
 251                         kfree(v9ses->uname);
 252                         v9ses->uname = match_strdup(&args[0]);
 253                         if (!v9ses->uname) {
 254                                 ret = -ENOMEM;
 255                                 goto free_and_return;
 256                         }
 257                         break;
 258                 case Opt_remotename:
 259                         kfree(v9ses->aname);
 260                         v9ses->aname = match_strdup(&args[0]);
 261                         if (!v9ses->aname) {
 262                                 ret = -ENOMEM;
 263                                 goto free_and_return;
 264                         }
 265                         break;
 266                 case Opt_nodevmap:
 267                         v9ses->nodev = 1;
 268                         break;
 269                 case Opt_cache_loose:
 270                         v9ses->cache = CACHE_LOOSE;
 271                         break;
 272                 case Opt_fscache:
 273                         v9ses->cache = CACHE_FSCACHE;
 274                         break;
 275                 case Opt_mmap:
 276                         v9ses->cache = CACHE_MMAP;
 277                         break;
 278                 case Opt_cachetag:
 279 #ifdef CONFIG_9P_FSCACHE
 280                         kfree(v9ses->cachetag);
 281                         v9ses->cachetag = match_strdup(&args[0]);
 282                         if (!v9ses->cachetag) {
 283                                 ret = -ENOMEM;
 284                                 goto free_and_return;
 285                         }
 286 #endif
 287                         break;
 288                 case Opt_cache:
 289                         s = match_strdup(&args[0]);
 290                         if (!s) {
 291                                 ret = -ENOMEM;
 292                                 p9_debug(P9_DEBUG_ERROR,
 293                                          "problem allocating copy of cache arg\n");
 294                                 goto free_and_return;
 295                         }
 296                         r = get_cache_mode(s);
 297                         if (r < 0)
 298                                 ret = r;
 299                         else
 300                                 v9ses->cache = r;
 301
 302                         kfree(s);
 303                         break;
 304
 305                 case Opt_access:
 306                         s = match_strdup(&args[0]);
 307                         if (!s) {
 308                                 ret = -ENOMEM;
 309                                 p9_debug(P9_DEBUG_ERROR,
 310                                          "problem allocating copy of access arg\n");
 311                                 goto free_and_return;
 312                         }
 313
 314                         v9ses->flags &= ~V9FS_ACCESS_MASK;
 315                         if (strcmp(s, "user") == 0)
 316                                 v9ses->flags |= V9FS_ACCESS_USER;
 317                         else if (strcmp(s, "any") == 0)
 318                                 v9ses->flags |= V9FS_ACCESS_ANY;
 319                         else if (strcmp(s, "client") == 0) {
 320                                 v9ses->flags |= V9FS_ACCESS_CLIENT;
 321                         } else {
 322                                 uid_t uid;
 323
 324                                 v9ses->flags |= V9FS_ACCESS_SINGLE;
 325                                 r = kstrtouint(s, 10, &uid);
 326                                 if (r) {
 327                                         ret = r;
 328                                         pr_info("Unknown access argument %s: %d\n",
 329                                                 s, r);
 330                                         kfree(s);
 331                                         continue;
 332                                 }
 333                                 v9ses->uid = make_kuid(current_user_ns(), uid);
 334                                 if (!uid_valid(v9ses->uid)) {
 335                                         ret = -EINVAL;
 336                                         pr_info("Unknown uid %s\n", s);
 337                                 }
 338                         }
 339
 340                         kfree(s);
 341                         break;
 342
 343                 case Opt_posixacl:
 344 #ifdef CONFIG_9P_FS_POSIX_ACL
 345                         v9ses->flags |= V9FS_POSIX_ACL;
 346 #else
 347                         p9_debug(P9_DEBUG_ERROR,
 348                                  "Not defined CONFIG_9P_FS_POSIX_ACL. Ignoring posixacl option\n");
 349 #endif
 350                         break;
 351
 352                 case Opt_locktimeout:
 353                         r = match_int(&args[0], &option);
 354                         if (r < 0) {
 355                                 p9_debug(P9_DEBUG_ERROR,
 356                                          "integer field, but no integer?\n");
 357                                 ret = r;
 358                                 continue;
 359                         }
 360                         if (option < 1) {
 361                                 p9_debug(P9_DEBUG_ERROR,
 362                                          "locktimeout must be a greater than zero integer.\n");
 363                                 ret = -EINVAL;
 364                                 continue;
 365                         }
 366                         v9ses->session_lock_timeout = (long)option * HZ;
 367                         break;
 368
 369                 default:
 370                         continue;
 371                 }
 372         }
 373
 374 free_and_return:
 375         kfree(tmp_options);
 376 fail_option_alloc:
 377         return ret;
 378 }
 379
 380 /**
 381  * v9fs_session_init - initialize session
 382  * @v9ses: session information structure
 383  * @dev_name: device being mounted
 384  * @data: options
 385  *
 386  */
 387
 388 struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
 389                   const char *dev_name, char *data)
 390 {
 391         struct p9_fid *fid;
 392         int rc = -ENOMEM;
 393
 394         v9ses->uname = kstrdup(V9FS_DEFUSER, GFP_KERNEL);
 395         if (!v9ses->uname)
 396                 goto err_names;
 397
 398         v9ses->aname = kstrdup(V9FS_DEFANAME, GFP_KERNEL);
 399         if (!v9ses->aname)
 400                 goto err_names;
 401         init_rwsem(&v9ses->rename_sem);
 402
 403         v9ses->uid = INVALID_UID;
 404         v9ses->dfltuid = V9FS_DEFUID;
 405         v9ses->dfltgid = V9FS_DEFGID;
 406
 407         v9ses->clnt = p9_client_create(dev_name, data);
 408         if (IS_ERR(v9ses->clnt)) {
 409                 rc = PTR_ERR(v9ses->clnt);
 410                 p9_debug(P9_DEBUG_ERROR, "problem initializing 9p client\n");
 411                 goto err_names;
 412         }
 413
 414         v9ses->flags = V9FS_ACCESS_USER;
 415
 416         if (p9_is_proto_dotl(v9ses->clnt)) {
 417                 v9ses->flags = V9FS_ACCESS_CLIENT;
 418                 v9ses->flags |= V9FS_PROTO_2000L;
 419         } else if (p9_is_proto_dotu(v9ses->clnt)) {
 420                 v9ses->flags |= V9FS_PROTO_2000U;
 421         }
 422
 423         rc = v9fs_parse_options(v9ses, data);
 424         if (rc < 0)
 425                 goto err_clnt;
 426
 427         v9ses->maxdata = v9ses->clnt->msize - P9_IOHDRSZ;
 428
 429         if (!v9fs_proto_dotl(v9ses) &&
 430             ((v9ses->flags & V9FS_ACCESS_MASK) == V9FS_ACCESS_CLIENT)) {
 431                 /*
 432                  * We support ACCESS_CLIENT only for dotl.
 433                  * Fall back to ACCESS_USER
 434                  */
 435                 v9ses->flags &= ~V9FS_ACCESS_MASK;
 436                 v9ses->flags |= V9FS_ACCESS_USER;
 437         }
 438         /*FIXME !! */
 439         /* for legacy mode, fall back to V9FS_ACCESS_ANY */
 440         if (!(v9fs_proto_dotu(v9ses) || v9fs_proto_dotl(v9ses)) &&
 441                 ((v9ses->flags&V9FS_ACCESS_MASK) == V9FS_ACCESS_USER)) {
 442
 443                 v9ses->flags &= ~V9FS_ACCESS_MASK;
 444                 v9ses->flags |= V9FS_ACCESS_ANY;
 445                 v9ses->uid = INVALID_UID;
 446         }
 447         if (!v9fs_proto_dotl(v9ses) ||
 448                 !((v9ses->flags & V9FS_ACCESS_MASK) == V9FS_ACCESS_CLIENT)) {
 449                 /*
 450                  * We support ACL checks on clinet only if the protocol is
 451                  * 9P2000.L and access is V9FS_ACCESS_CLIENT.
 452                  */
 453                 v9ses->flags &= ~V9FS_ACL_MASK;
 454         }
 455
 456         fid = p9_client_attach(v9ses->clnt, NULL, v9ses->uname, INVALID_UID,
 457                                                         v9ses->aname);
 458         if (IS_ERR(fid)) {
 459                 rc = PTR_ERR(fid);
 460                 p9_debug(P9_DEBUG_ERROR, "cannot attach\n");
 461                 goto err_clnt;
 462         }
 463
 464         if ((v9ses->flags & V9FS_ACCESS_MASK) == V9FS_ACCESS_SINGLE)
 465                 fid->uid = v9ses->uid;
 466         else
 467                 fid->uid = INVALID_UID;
 468
 469 #ifdef CONFIG_9P_FSCACHE
 470         /* register the session for caching */
 471         if (v9ses->cache == CACHE_FSCACHE) {
 472                 rc = v9fs_cache_session_get_cookie(v9ses, dev_name);
 473                 if (rc < 0)
 474                         goto err_clnt;
 475         }
 476 #endif
 477         spin_lock(&v9fs_sessionlist_lock);
 478         list_add(&v9ses->slist, &v9fs_sessionlist);
 479         spin_unlock(&v9fs_sessionlist_lock);
 480
 481         return fid;
 482
 483 err_clnt:
 484 #ifdef CONFIG_9P_FSCACHE
 485         kfree(v9ses->cachetag);
 486 #endif
 487         p9_client_destroy(v9ses->clnt);
 488 err_names:
 489         kfree(v9ses->uname);
 490         kfree(v9ses->aname);
 491         return ERR_PTR(rc);
 492 }
 493
 494 /**
 495  * v9fs_session_close - shutdown a session
 496  * @v9ses: session information structure
 497  *
 498  */
 499
 500 void v9fs_session_close(struct v9fs_session_info *v9ses)
 501 {
 502         if (v9ses->clnt) {
 503                 p9_client_destroy(v9ses->clnt);
 504                 v9ses->clnt = NULL;
 505         }
 506
 507 #ifdef CONFIG_9P_FSCACHE
 508         fscache_relinquish_volume(v9fs_session_cache(v9ses), NULL, false);
 509         kfree(v9ses->cachetag);
 510 #endif
 511         kfree(v9ses->uname);
 512         kfree(v9ses->aname);
 513
 514         spin_lock(&v9fs_sessionlist_lock);
 515         list_del(&v9ses->slist);
 516         spin_unlock(&v9fs_sessionlist_lock);
 517 }
 518
 519 /**
 520  * v9fs_session_cancel - terminate a session
 521  * @v9ses: session to terminate
 522  *
 523  * mark transport as disconnected and cancel all pending requests.
 524  */
 525
 526 void v9fs_session_cancel(struct v9fs_session_info *v9ses)
 527 {
 528         p9_debug(P9_DEBUG_ERROR, "cancel session %p\n", v9ses);
 529         p9_client_disconnect(v9ses->clnt);
 530 }
 531
 532 /**
 533  * v9fs_session_begin_cancel - Begin terminate of a session
 534  * @v9ses: session to terminate
 535  *
 536  * After this call we don't allow any request other than clunk.
 537  */
 538
 539 void v9fs_session_begin_cancel(struct v9fs_session_info *v9ses)
 540 {
 541         p9_debug(P9_DEBUG_ERROR, "begin cancel session %p\n", v9ses);
 542         p9_client_begin_disconnect(v9ses->clnt);
 543 }
 544
 545 extern int v9fs_error_init(void);
 546
 547 static struct kobject *v9fs_kobj;
 548
 549 #ifdef CONFIG_9P_FSCACHE
 550 /*
 551  * List caches associated with a session
 552  */
 553 static ssize_t caches_show(struct kobject *kobj,
 554                            struct kobj_attribute *attr,
 555                            char *buf)
 556 {
 557         ssize_t n = 0, count = 0, limit = PAGE_SIZE;
 558         struct v9fs_session_info *v9ses;
 559
 560         spin_lock(&v9fs_sessionlist_lock);
 561         list_for_each_entry(v9ses, &v9fs_sessionlist, slist) {
 562                 if (v9ses->cachetag) {
 563                         n = snprintf(buf, limit, "%s\n", v9ses->cachetag);
 564                         if (n < 0) {
 565                                 count = n;
 566                                 break;
 567                         }
 568
 569                         count += n;
 570                         limit -= n;
 571                 }
 572         }
 573
 574         spin_unlock(&v9fs_sessionlist_lock);
 575         return count;
 576 }
 577
 578 static struct kobj_attribute v9fs_attr_cache = __ATTR_RO(caches);
 579 #endif /* CONFIG_9P_FSCACHE */
 580
 581 static struct attribute *v9fs_attrs[] = {
 582 #ifdef CONFIG_9P_FSCACHE
 583         &v9fs_attr_cache.attr,
 584 #endif
 585         NULL,
 586 };
 587
 588 static const struct attribute_group v9fs_attr_group = {
 589         .attrs = v9fs_attrs,
 590 };
 591
 592 /**
 593  * v9fs_sysfs_init - Initialize the v9fs sysfs interface
 594  *
 595  */
 596
 597 static int __init v9fs_sysfs_init(void)
 598 {
 599         v9fs_kobj = kobject_create_and_add("9p", fs_kobj);
 600         if (!v9fs_kobj)
 601                 return -ENOMEM;
 602
 603         if (sysfs_create_group(v9fs_kobj, &v9fs_attr_group)) {
 604                 kobject_put(v9fs_kobj);
 605                 return -ENOMEM;
 606         }
 607
 608         return 0;
 609 }
 610
 611 /**
 612  * v9fs_sysfs_cleanup - Unregister the v9fs sysfs interface
 613  *
 614  */
 615
 616 static void v9fs_sysfs_cleanup(void)
 617 {
 618         sysfs_remove_group(v9fs_kobj, &v9fs_attr_group);
 619         kobject_put(v9fs_kobj);
 620 }
 621
 622 static void v9fs_inode_init_once(void *foo)
 623 {
 624         struct v9fs_inode *v9inode = (struct v9fs_inode *)foo;
 625
 626         memset(&v9inode->qid, 0, sizeof(v9inode->qid));
 627         inode_init_once(&v9inode->netfs.inode);
 628 }
 629
 630 /**
 631  * v9fs_init_inode_cache - initialize a cache for 9P
 632  * Returns 0 on success.
 633  */
 634 static int v9fs_init_inode_cache(void)
 635 {
 636         v9fs_inode_cache = kmem_cache_create("v9fs_inode_cache",
 637                                           sizeof(struct v9fs_inode),
 638                                           0, (SLAB_RECLAIM_ACCOUNT|
 639                                               SLAB_MEM_SPREAD|SLAB_ACCOUNT),
 640                                           v9fs_inode_init_once);
 641         if (!v9fs_inode_cache)
 642                 return -ENOMEM;
 643
 644         return 0;
 645 }
 646
 647 /**
 648  * v9fs_destroy_inode_cache - destroy the cache of 9P inode
 649  *
 650  */
 651 static void v9fs_destroy_inode_cache(void)
 652 {
 653         /*
 654          * Make sure all delayed rcu free inodes are flushed before we
 655          * destroy cache.
 656          */
 657         rcu_barrier();
 658         kmem_cache_destroy(v9fs_inode_cache);
 659 }
 660
 661 static int v9fs_cache_register(void)
 662 {
 663         int ret;
 664
 665         ret = v9fs_init_inode_cache();
 666         if (ret < 0)
 667                 return ret;
 668         return ret;
 669 }
 670
 671 static void v9fs_cache_unregister(void)
 672 {
 673         v9fs_destroy_inode_cache();
 674 }
 675
 676 /**
 677  * init_v9fs - Initialize module
 678  *
 679  */
 680
 681 static int __init init_v9fs(void)
 682 {
 683         int err;
 684
 685         pr_info("Installing v9fs 9p2000 file system support\n");
 686         /* TODO: Setup list of registered trasnport modules */
 687
 688         err = v9fs_cache_register();
 689         if (err < 0) {
 690                 pr_err("Failed to register v9fs for caching\n");
 691                 return err;
 692         }
 693
 694         err = v9fs_sysfs_init();
 695         if (err < 0) {
 696                 pr_err("Failed to register with sysfs\n");
 697                 goto out_cache;
 698         }
 699         err = register_filesystem(&v9fs_fs_type);
 700         if (err < 0) {
 701                 pr_err("Failed to register filesystem\n");
 702                 goto out_sysfs_cleanup;
 703         }
 704
 705         return 0;
 706
 707 out_sysfs_cleanup:
 708         v9fs_sysfs_cleanup();
 709
 710 out_cache:
 711         v9fs_cache_unregister();
 712
 713         return err;
 714 }
 715
 716 /**
 717  * exit_v9fs - shutdown module
 718  *
 719  */
 720
 721 static void __exit exit_v9fs(void)
 722 {
 723         v9fs_sysfs_cleanup();
 724         v9fs_cache_unregister();
 725         unregister_filesystem(&v9fs_fs_type);
 726 }
 727
 728 module_init(init_v9fs)
 729 module_exit(exit_v9fs)
 730
 731 MODULE_AUTHOR("Latchesar Ionkov <lucho@ionkov.net>");
 732 MODULE_AUTHOR("Eric Van Hensbergen <ericvh@gmail.com>");
 733 MODULE_AUTHOR("Ron Minnich <rminnich@lanl.gov>");
 734 MODULE_LICENSE("GPL");