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, Opt_noxattr, Opt_directio, Opt_ignoreqv,
  42         /* Access options */
  43         Opt_access, Opt_posixacl,
  44         /* Lock timeout option */
  45         Opt_locktimeout,
  46         /* Error token */
  47         Opt_err
  48 };
  49
  50 static const match_table_t tokens = {
  51         {Opt_debug, "debug=%x"},
  52         {Opt_dfltuid, "dfltuid=%u"},
  53         {Opt_dfltgid, "dfltgid=%u"},
  54         {Opt_afid, "afid=%u"},
  55         {Opt_uname, "uname=%s"},
  56         {Opt_remotename, "aname=%s"},
  57         {Opt_nodevmap, "nodevmap"},
  58         {Opt_noxattr, "noxattr"},
  59         {Opt_directio, "directio"},
  60         {Opt_ignoreqv, "ignoreqv"},
  61         {Opt_cache, "cache=%s"},
  62         {Opt_cachetag, "cachetag=%s"},
  63         {Opt_access, "access=%s"},
  64         {Opt_posixacl, "posixacl"},
  65         {Opt_locktimeout, "locktimeout=%u"},
  66         {Opt_err, NULL}
  67 };
  68
  69 /* Interpret mount options for cache mode */
  70 static int get_cache_mode(char *s)
  71 {
  72         int version = -EINVAL;
  73
  74         if (!strcmp(s, "loose")) {
  75                 version = CACHE_SC_LOOSE;
  76                 p9_debug(P9_DEBUG_9P, "Cache mode: loose\n");
  77         } else if (!strcmp(s, "fscache")) {
  78                 version = CACHE_SC_FSCACHE;
  79                 p9_debug(P9_DEBUG_9P, "Cache mode: fscache\n");
  80         } else if (!strcmp(s, "mmap")) {
  81                 version = CACHE_SC_MMAP;
  82                 p9_debug(P9_DEBUG_9P, "Cache mode: mmap\n");
  83         } else if (!strcmp(s, "readahead")) {
  84                 version = CACHE_SC_READAHEAD;
  85                 p9_debug(P9_DEBUG_9P, "Cache mode: readahead\n");
  86         } else if (!strcmp(s, "none")) {
  87                 version = CACHE_SC_NONE;
  88                 p9_debug(P9_DEBUG_9P, "Cache mode: none\n");
  89         } else if (kstrtoint(s, 0, &version) != 0) {
  90                 version = -EINVAL;
  91                 pr_info("Unknown Cache mode or invalid value %s\n", s);
  92         }
  93         return version;
  94 }
  95
  96 /*
  97  * Display the mount options in /proc/mounts.
  98  */
  99 int v9fs_show_options(struct seq_file *m, struct dentry *root)
 100 {
 101         struct v9fs_session_info *v9ses = root->d_sb->s_fs_info;
 102
 103         if (v9ses->debug)
 104                 seq_printf(m, ",debug=%x", v9ses->debug);
 105         if (!uid_eq(v9ses->dfltuid, V9FS_DEFUID))
 106                 seq_printf(m, ",dfltuid=%u",
 107                            from_kuid_munged(&init_user_ns, v9ses->dfltuid));
 108         if (!gid_eq(v9ses->dfltgid, V9FS_DEFGID))
 109                 seq_printf(m, ",dfltgid=%u",
 110                            from_kgid_munged(&init_user_ns, v9ses->dfltgid));
 111         if (v9ses->afid != ~0)
 112                 seq_printf(m, ",afid=%u", v9ses->afid);
 113         if (strcmp(v9ses->uname, V9FS_DEFUSER) != 0)
 114                 seq_printf(m, ",uname=%s", v9ses->uname);
 115         if (strcmp(v9ses->aname, V9FS_DEFANAME) != 0)
 116                 seq_printf(m, ",aname=%s", v9ses->aname);
 117         if (v9ses->nodev)
 118                 seq_puts(m, ",nodevmap");
 119         if (v9ses->cache)
 120                 seq_printf(m, ",cache=%x", v9ses->cache);
 121 #ifdef CONFIG_9P_FSCACHE
 122         if (v9ses->cachetag && (v9ses->cache & CACHE_FSCACHE))
 123                 seq_printf(m, ",cachetag=%s", v9ses->cachetag);
 124 #endif
 125
 126         switch (v9ses->flags & V9FS_ACCESS_MASK) {
 127         case V9FS_ACCESS_USER:
 128                 seq_puts(m, ",access=user");
 129                 break;
 130         case V9FS_ACCESS_ANY:
 131                 seq_puts(m, ",access=any");
 132                 break;
 133         case V9FS_ACCESS_CLIENT:
 134                 seq_puts(m, ",access=client");
 135                 break;
 136         case V9FS_ACCESS_SINGLE:
 137                 seq_printf(m, ",access=%u",
 138                            from_kuid_munged(&init_user_ns, v9ses->uid));
 139                 break;
 140         }
 141
 142         if (v9ses->flags & V9FS_IGNORE_QV)
 143                 seq_puts(m, ",ignoreqv");
 144         if (v9ses->flags & V9FS_DIRECT_IO)
 145                 seq_puts(m, ",directio");
 146         if (v9ses->flags & V9FS_POSIX_ACL)
 147                 seq_puts(m, ",posixacl");
 148
 149         if (v9ses->flags & V9FS_NO_XATTR)
 150                 seq_puts(m, ",noxattr");
 151
 152         return p9_show_client_options(m, v9ses->clnt);
 153 }
 154
 155 /**
 156  * v9fs_parse_options - parse mount options into session structure
 157  * @v9ses: existing v9fs session information
 158  * @opts: The mount option string
 159  *
 160  * Return 0 upon success, -ERRNO upon failure.
 161  */
 162
 163 static int v9fs_parse_options(struct v9fs_session_info *v9ses, char *opts)
 164 {
 165         char *options, *tmp_options;
 166         substring_t args[MAX_OPT_ARGS];
 167         char *p;
 168         int option = 0;
 169         char *s;
 170         int ret = 0;
 171
 172         /* setup defaults */
 173         v9ses->afid = ~0;
 174         v9ses->debug = 0;
 175         v9ses->cache = CACHE_NONE;
 176 #ifdef CONFIG_9P_FSCACHE
 177         v9ses->cachetag = NULL;
 178 #endif
 179         v9ses->session_lock_timeout = P9_LOCK_TIMEOUT;
 180
 181         if (!opts)
 182                 return 0;
 183
 184         tmp_options = kstrdup(opts, GFP_KERNEL);
 185         if (!tmp_options) {
 186                 ret = -ENOMEM;
 187                 goto fail_option_alloc;
 188         }
 189         options = tmp_options;
 190
 191         while ((p = strsep(&options, ",")) != NULL) {
 192                 int token, r;
 193
 194                 if (!*p)
 195                         continue;
 196
 197                 token = match_token(p, tokens, args);
 198                 switch (token) {
 199                 case Opt_debug:
 200                         r = match_int(&args[0], &option);
 201                         if (r < 0) {
 202                                 p9_debug(P9_DEBUG_ERROR,
 203                                          "integer field, but no integer?\n");
 204                                 ret = r;
 205                         } else {
 206                                 v9ses->debug = option;
 207 #ifdef CONFIG_NET_9P_DEBUG
 208                                 p9_debug_level = option;
 209 #endif
 210                         }
 211                         break;
 212
 213                 case Opt_dfltuid:
 214                         r = match_int(&args[0], &option);
 215                         if (r < 0) {
 216                                 p9_debug(P9_DEBUG_ERROR,
 217                                          "integer field, but no integer?\n");
 218                                 ret = r;
 219                                 continue;
 220                         }
 221                         v9ses->dfltuid = make_kuid(current_user_ns(), option);
 222                         if (!uid_valid(v9ses->dfltuid)) {
 223                                 p9_debug(P9_DEBUG_ERROR,
 224                                          "uid field, but not a uid?\n");
 225                                 ret = -EINVAL;
 226                         }
 227                         break;
 228                 case Opt_dfltgid:
 229                         r = match_int(&args[0], &option);
 230                         if (r < 0) {
 231                                 p9_debug(P9_DEBUG_ERROR,
 232                                          "integer field, but no integer?\n");
 233                                 ret = r;
 234                                 continue;
 235                         }
 236                         v9ses->dfltgid = make_kgid(current_user_ns(), option);
 237                         if (!gid_valid(v9ses->dfltgid)) {
 238                                 p9_debug(P9_DEBUG_ERROR,
 239                                          "gid field, but not a gid?\n");
 240                                 ret = -EINVAL;
 241                         }
 242                         break;
 243                 case Opt_afid:
 244                         r = match_int(&args[0], &option);
 245                         if (r < 0) {
 246                                 p9_debug(P9_DEBUG_ERROR,
 247                                          "integer field, but no integer?\n");
 248                                 ret = r;
 249                         } else {
 250                                 v9ses->afid = option;
 251                         }
 252                         break;
 253                 case Opt_uname:
 254                         kfree(v9ses->uname);
 255                         v9ses->uname = match_strdup(&args[0]);
 256                         if (!v9ses->uname) {
 257                                 ret = -ENOMEM;
 258                                 goto free_and_return;
 259                         }
 260                         break;
 261                 case Opt_remotename:
 262                         kfree(v9ses->aname);
 263                         v9ses->aname = match_strdup(&args[0]);
 264                         if (!v9ses->aname) {
 265                                 ret = -ENOMEM;
 266                                 goto free_and_return;
 267                         }
 268                         break;
 269                 case Opt_nodevmap:
 270                         v9ses->nodev = 1;
 271                         break;
 272                 case Opt_noxattr:
 273                         v9ses->flags |= V9FS_NO_XATTR;
 274                         break;
 275                 case Opt_directio:
 276                         v9ses->flags |= V9FS_DIRECT_IO;
 277                         break;
 278                 case Opt_ignoreqv:
 279                         v9ses->flags |= V9FS_IGNORE_QV;
 280                         break;
 281                 case Opt_cachetag:
 282 #ifdef CONFIG_9P_FSCACHE
 283                         kfree(v9ses->cachetag);
 284                         v9ses->cachetag = match_strdup(&args[0]);
 285                         if (!v9ses->cachetag) {
 286                                 ret = -ENOMEM;
 287                                 goto free_and_return;
 288                         }
 289 #endif
 290                         break;
 291                 case Opt_cache:
 292                         s = match_strdup(&args[0]);
 293                         if (!s) {
 294                                 ret = -ENOMEM;
 295                                 p9_debug(P9_DEBUG_ERROR,
 296                                          "problem allocating copy of cache arg\n");
 297                                 goto free_and_return;
 298                         }
 299                         r = get_cache_mode(s);
 300                         if (r < 0)
 301                                 ret = r;
 302                         else
 303                                 v9ses->cache = r;
 304
 305                         kfree(s);
 306                         break;
 307
 308                 case Opt_access:
 309                         s = match_strdup(&args[0]);
 310                         if (!s) {
 311                                 ret = -ENOMEM;
 312                                 p9_debug(P9_DEBUG_ERROR,
 313                                          "problem allocating copy of access arg\n");
 314                                 goto free_and_return;
 315                         }
 316
 317                         v9ses->flags &= ~V9FS_ACCESS_MASK;
 318                         if (strcmp(s, "user") == 0)
 319                                 v9ses->flags |= V9FS_ACCESS_USER;
 320                         else if (strcmp(s, "any") == 0)
 321                                 v9ses->flags |= V9FS_ACCESS_ANY;
 322                         else if (strcmp(s, "client") == 0) {
 323                                 v9ses->flags |= V9FS_ACCESS_CLIENT;
 324                         } else {
 325                                 uid_t uid;
 326
 327                                 v9ses->flags |= V9FS_ACCESS_SINGLE;
 328                                 r = kstrtouint(s, 10, &uid);
 329                                 if (r) {
 330                                         ret = r;
 331                                         pr_info("Unknown access argument %s: %d\n",
 332                                                 s, r);
 333                                         kfree(s);
 334                                         continue;
 335                                 }
 336                                 v9ses->uid = make_kuid(current_user_ns(), uid);
 337                                 if (!uid_valid(v9ses->uid)) {
 338                                         ret = -EINVAL;
 339                                         pr_info("Unknown uid %s\n", s);
 340                                 }
 341                         }
 342
 343                         kfree(s);
 344                         break;
 345
 346                 case Opt_posixacl:
 347 #ifdef CONFIG_9P_FS_POSIX_ACL
 348                         v9ses->flags |= V9FS_POSIX_ACL;
 349 #else
 350                         p9_debug(P9_DEBUG_ERROR,
 351                                  "Not defined CONFIG_9P_FS_POSIX_ACL. Ignoring posixacl option\n");
 352 #endif
 353                         break;
 354
 355                 case Opt_locktimeout:
 356                         r = match_int(&args[0], &option);
 357                         if (r < 0) {
 358                                 p9_debug(P9_DEBUG_ERROR,
 359                                          "integer field, but no integer?\n");
 360                                 ret = r;
 361                                 continue;
 362                         }
 363                         if (option < 1) {
 364                                 p9_debug(P9_DEBUG_ERROR,
 365                                          "locktimeout must be a greater than zero integer.\n");
 366                                 ret = -EINVAL;
 367                                 continue;
 368                         }
 369                         v9ses->session_lock_timeout = (long)option * HZ;
 370                         break;
 371
 372                 default:
 373                         continue;
 374                 }
 375         }
 376
 377 free_and_return:
 378         kfree(tmp_options);
 379 fail_option_alloc:
 380         return ret;
 381 }
 382
 383 /**
 384  * v9fs_session_init - initialize session
 385  * @v9ses: session information structure
 386  * @dev_name: device being mounted
 387  * @data: options
 388  *
 389  */
 390
 391 struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
 392                   const char *dev_name, char *data)
 393 {
 394         struct p9_fid *fid;
 395         int rc = -ENOMEM;
 396
 397         v9ses->uname = kstrdup(V9FS_DEFUSER, GFP_KERNEL);
 398         if (!v9ses->uname)
 399                 goto err_names;
 400
 401         v9ses->aname = kstrdup(V9FS_DEFANAME, GFP_KERNEL);
 402         if (!v9ses->aname)
 403                 goto err_names;
 404         init_rwsem(&v9ses->rename_sem);
 405
 406         v9ses->uid = INVALID_UID;
 407         v9ses->dfltuid = V9FS_DEFUID;
 408         v9ses->dfltgid = V9FS_DEFGID;
 409
 410         v9ses->clnt = p9_client_create(dev_name, data);
 411         if (IS_ERR(v9ses->clnt)) {
 412                 rc = PTR_ERR(v9ses->clnt);
 413                 p9_debug(P9_DEBUG_ERROR, "problem initializing 9p client\n");
 414                 goto err_names;
 415         }
 416
 417         v9ses->flags = V9FS_ACCESS_USER;
 418
 419         if (p9_is_proto_dotl(v9ses->clnt)) {
 420                 v9ses->flags = V9FS_ACCESS_CLIENT;
 421                 v9ses->flags |= V9FS_PROTO_2000L;
 422         } else if (p9_is_proto_dotu(v9ses->clnt)) {
 423                 v9ses->flags |= V9FS_PROTO_2000U;
 424         }
 425
 426         rc = v9fs_parse_options(v9ses, data);
 427         if (rc < 0)
 428                 goto err_clnt;
 429
 430         v9ses->maxdata = v9ses->clnt->msize - P9_IOHDRSZ;
 431
 432         if (!v9fs_proto_dotl(v9ses) &&
 433             ((v9ses->flags & V9FS_ACCESS_MASK) == V9FS_ACCESS_CLIENT)) {
 434                 /*
 435                  * We support ACCESS_CLIENT only for dotl.
 436                  * Fall back to ACCESS_USER
 437                  */
 438                 v9ses->flags &= ~V9FS_ACCESS_MASK;
 439                 v9ses->flags |= V9FS_ACCESS_USER;
 440         }
 441         /*FIXME !! */
 442         /* for legacy mode, fall back to V9FS_ACCESS_ANY */
 443         if (!(v9fs_proto_dotu(v9ses) || v9fs_proto_dotl(v9ses)) &&
 444                 ((v9ses->flags&V9FS_ACCESS_MASK) == V9FS_ACCESS_USER)) {
 445
 446                 v9ses->flags &= ~V9FS_ACCESS_MASK;
 447                 v9ses->flags |= V9FS_ACCESS_ANY;
 448                 v9ses->uid = INVALID_UID;
 449         }
 450         if (!v9fs_proto_dotl(v9ses) ||
 451                 !((v9ses->flags & V9FS_ACCESS_MASK) == V9FS_ACCESS_CLIENT)) {
 452                 /*
 453                  * We support ACL checks on clinet only if the protocol is
 454                  * 9P2000.L and access is V9FS_ACCESS_CLIENT.
 455                  */
 456                 v9ses->flags &= ~V9FS_ACL_MASK;
 457         }
 458
 459         fid = p9_client_attach(v9ses->clnt, NULL, v9ses->uname, INVALID_UID,
 460                                                         v9ses->aname);
 461         if (IS_ERR(fid)) {
 462                 rc = PTR_ERR(fid);
 463                 p9_debug(P9_DEBUG_ERROR, "cannot attach\n");
 464                 goto err_clnt;
 465         }
 466
 467         if ((v9ses->flags & V9FS_ACCESS_MASK) == V9FS_ACCESS_SINGLE)
 468                 fid->uid = v9ses->uid;
 469         else
 470                 fid->uid = INVALID_UID;
 471
 472 #ifdef CONFIG_9P_FSCACHE
 473         /* register the session for caching */
 474         if (v9ses->cache & CACHE_FSCACHE) {
 475                 rc = v9fs_cache_session_get_cookie(v9ses, dev_name);
 476                 if (rc < 0)
 477                         goto err_clnt;
 478         }
 479 #endif
 480         spin_lock(&v9fs_sessionlist_lock);
 481         list_add(&v9ses->slist, &v9fs_sessionlist);
 482         spin_unlock(&v9fs_sessionlist_lock);
 483
 484         return fid;
 485
 486 err_clnt:
 487 #ifdef CONFIG_9P_FSCACHE
 488         kfree(v9ses->cachetag);
 489 #endif
 490         p9_client_destroy(v9ses->clnt);
 491 err_names:
 492         kfree(v9ses->uname);
 493         kfree(v9ses->aname);
 494         return ERR_PTR(rc);
 495 }
 496
 497 /**
 498  * v9fs_session_close - shutdown a session
 499  * @v9ses: session information structure
 500  *
 501  */
 502
 503 void v9fs_session_close(struct v9fs_session_info *v9ses)
 504 {
 505         if (v9ses->clnt) {
 506                 p9_client_destroy(v9ses->clnt);
 507                 v9ses->clnt = NULL;
 508         }
 509
 510 #ifdef CONFIG_9P_FSCACHE
 511         fscache_relinquish_volume(v9fs_session_cache(v9ses), NULL, false);
 512         kfree(v9ses->cachetag);
 513 #endif
 514         kfree(v9ses->uname);
 515         kfree(v9ses->aname);
 516
 517         spin_lock(&v9fs_sessionlist_lock);
 518         list_del(&v9ses->slist);
 519         spin_unlock(&v9fs_sessionlist_lock);
 520 }
 521
 522 /**
 523  * v9fs_session_cancel - terminate a session
 524  * @v9ses: session to terminate
 525  *
 526  * mark transport as disconnected and cancel all pending requests.
 527  */
 528
 529 void v9fs_session_cancel(struct v9fs_session_info *v9ses)
 530 {
 531         p9_debug(P9_DEBUG_ERROR, "cancel session %p\n", v9ses);
 532         p9_client_disconnect(v9ses->clnt);
 533 }
 534
 535 /**
 536  * v9fs_session_begin_cancel - Begin terminate of a session
 537  * @v9ses: session to terminate
 538  *
 539  * After this call we don't allow any request other than clunk.
 540  */
 541
 542 void v9fs_session_begin_cancel(struct v9fs_session_info *v9ses)
 543 {
 544         p9_debug(P9_DEBUG_ERROR, "begin cancel session %p\n", v9ses);
 545         p9_client_begin_disconnect(v9ses->clnt);
 546 }
 547
 548 static struct kobject *v9fs_kobj;
 549
 550 #ifdef CONFIG_9P_FSCACHE
 551 /*
 552  * List caches associated with a session
 553  */
 554 static ssize_t caches_show(struct kobject *kobj,
 555                            struct kobj_attribute *attr,
 556                            char *buf)
 557 {
 558         ssize_t n = 0, count = 0, limit = PAGE_SIZE;
 559         struct v9fs_session_info *v9ses;
 560
 561         spin_lock(&v9fs_sessionlist_lock);
 562         list_for_each_entry(v9ses, &v9fs_sessionlist, slist) {
 563                 if (v9ses->cachetag) {
 564                         n = snprintf(buf, limit, "%s\n", v9ses->cachetag);
 565                         if (n < 0) {
 566                                 count = n;
 567                                 break;
 568                         }
 569
 570                         count += n;
 571                         limit -= n;
 572                 }
 573         }
 574
 575         spin_unlock(&v9fs_sessionlist_lock);
 576         return count;
 577 }
 578
 579 static struct kobj_attribute v9fs_attr_cache = __ATTR_RO(caches);
 580 #endif /* CONFIG_9P_FSCACHE */
 581
 582 static struct attribute *v9fs_attrs[] = {
 583 #ifdef CONFIG_9P_FSCACHE
 584         &v9fs_attr_cache.attr,
 585 #endif
 586         NULL,
 587 };
 588
 589 static const struct attribute_group v9fs_attr_group = {
 590         .attrs = v9fs_attrs,
 591 };
 592
 593 /**
 594  * v9fs_sysfs_init - Initialize the v9fs sysfs interface
 595  *
 596  */
 597
 598 static int __init v9fs_sysfs_init(void)
 599 {
 600         v9fs_kobj = kobject_create_and_add("9p", fs_kobj);
 601         if (!v9fs_kobj)
 602                 return -ENOMEM;
 603
 604         if (sysfs_create_group(v9fs_kobj, &v9fs_attr_group)) {
 605                 kobject_put(v9fs_kobj);
 606                 return -ENOMEM;
 607         }
 608
 609         return 0;
 610 }
 611
 612 /**
 613  * v9fs_sysfs_cleanup - Unregister the v9fs sysfs interface
 614  *
 615  */
 616
 617 static void v9fs_sysfs_cleanup(void)
 618 {
 619         sysfs_remove_group(v9fs_kobj, &v9fs_attr_group);
 620         kobject_put(v9fs_kobj);
 621 }
 622
 623 static void v9fs_inode_init_once(void *foo)
 624 {
 625         struct v9fs_inode *v9inode = (struct v9fs_inode *)foo;
 626
 627         memset(&v9inode->qid, 0, sizeof(v9inode->qid));
 628         inode_init_once(&v9inode->netfs.inode);
 629 }
 630
 631 /**
 632  * v9fs_init_inode_cache - initialize a cache for 9P
 633  * Returns 0 on success.
 634  */
 635 static int v9fs_init_inode_cache(void)
 636 {
 637         v9fs_inode_cache = kmem_cache_create("v9fs_inode_cache",
 638                                           sizeof(struct v9fs_inode),
 639                                           0, (SLAB_RECLAIM_ACCOUNT|
 640                                               SLAB_MEM_SPREAD|SLAB_ACCOUNT),
 641                                           v9fs_inode_init_once);
 642         if (!v9fs_inode_cache)
 643                 return -ENOMEM;
 644
 645         return 0;
 646 }
 647
 648 /**
 649  * v9fs_destroy_inode_cache - destroy the cache of 9P inode
 650  *
 651  */
 652 static void v9fs_destroy_inode_cache(void)
 653 {
 654         /*
 655          * Make sure all delayed rcu free inodes are flushed before we
 656          * destroy cache.
 657          */
 658         rcu_barrier();
 659         kmem_cache_destroy(v9fs_inode_cache);
 660 }
 661
 662 static int v9fs_cache_register(void)
 663 {
 664         int ret;
 665
 666         ret = v9fs_init_inode_cache();
 667         if (ret < 0)
 668                 return ret;
 669         return ret;
 670 }
 671
 672 static void v9fs_cache_unregister(void)
 673 {
 674         v9fs_destroy_inode_cache();
 675 }
 676
 677 /**
 678  * init_v9fs - Initialize module
 679  *
 680  */
 681
 682 static int __init init_v9fs(void)
 683 {
 684         int err;
 685
 686         pr_info("Installing v9fs 9p2000 file system support\n");
 687         /* TODO: Setup list of registered trasnport modules */
 688
 689         err = v9fs_cache_register();
 690         if (err < 0) {
 691                 pr_err("Failed to register v9fs for caching\n");
 692                 return err;
 693         }
 694
 695         err = v9fs_sysfs_init();
 696         if (err < 0) {
 697                 pr_err("Failed to register with sysfs\n");
 698                 goto out_cache;
 699         }
 700         err = register_filesystem(&v9fs_fs_type);
 701         if (err < 0) {
 702                 pr_err("Failed to register filesystem\n");
 703                 goto out_sysfs_cleanup;
 704         }
 705
 706         return 0;
 707
 708 out_sysfs_cleanup:
 709         v9fs_sysfs_cleanup();
 710
 711 out_cache:
 712         v9fs_cache_unregister();
 713
 714         return err;
 715 }
 716
 717 /**
 718  * exit_v9fs - shutdown module
 719  *
 720  */
 721
 722 static void __exit exit_v9fs(void)
 723 {
 724         v9fs_sysfs_cleanup();
 725         v9fs_cache_unregister();
 726         unregister_filesystem(&v9fs_fs_type);
 727 }
 728
 729 module_init(init_v9fs)
 730 module_exit(exit_v9fs)
 731
 732 MODULE_AUTHOR("Latchesar Ionkov <lucho@ionkov.net>");
 733 MODULE_AUTHOR("Eric Van Hensbergen <ericvh@gmail.com>");
 734 MODULE_AUTHOR("Ron Minnich <rminnich@lanl.gov>");
 735 MODULE_LICENSE("GPL");