fs/9p/v9fs.c

   1 /*
   2  *  linux/fs/9p/v9fs.c
   3  *
   4  *  This file contains functions assisting in mapping VFS to 9P2000
   5  *
   6  *  Copyright (C) 2004-2008 by Eric Van Hensbergen <ericvh@gmail.com>
   7  *  Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
   8  *
   9  *  This program is free software; you can redistribute it and/or modify
  10  *  it under the terms of the GNU General Public License version 2
  11  *  as published by the Free Software Foundation.
  12  *
  13  *  This program is distributed in the hope that it will be useful,
  14  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  *  GNU General Public License for more details.
  17  *
  18  *  You should have received a copy of the GNU General Public License
  19  *  along with this program; if not, write to:
  20  *  Free Software Foundation
  21  *  51 Franklin Street, Fifth Floor
  22  *  Boston, MA  02111-1301  USA
  23  *
  24  */
  25
  26 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  27
  28 #include <linux/module.h>
  29 #include <linux/errno.h>
  30 #include <linux/fs.h>
  31 #include <linux/sched.h>
  32 #include <linux/cred.h>
  33 #include <linux/parser.h>
  34 #include <linux/idr.h>
  35 #include <linux/slab.h>
  36 #include <linux/seq_file.h>
  37 #include <net/9p/9p.h>
  38 #include <net/9p/client.h>
  39 #include <net/9p/transport.h>
  40 #include "v9fs.h"
  41 #include "v9fs_vfs.h"
  42 #include "cache.h"
  43
  44 static DEFINE_SPINLOCK(v9fs_sessionlist_lock);
  45 static LIST_HEAD(v9fs_sessionlist);
  46 struct kmem_cache *v9fs_inode_cache;
  47
  48 /*
  49  * Option Parsing (code inspired by NFS code)
  50  *  NOTE: each transport will parse its own options
  51  */
  52
  53 enum {
  54         /* Options that take integer arguments */
  55         Opt_debug, Opt_dfltuid, Opt_dfltgid, Opt_afid,
  56         /* String options */
  57         Opt_uname, Opt_remotename, Opt_cache, Opt_cachetag,
  58         /* Options that take no arguments */
  59         Opt_nodevmap,
  60         /* Cache options */
  61         Opt_cache_loose, Opt_fscache, Opt_mmap,
  62         /* Access options */
  63         Opt_access, Opt_posixacl,
  64         /* Lock timeout option */
  65         Opt_locktimeout,
  66         /* Error token */
  67         Opt_err
  68 };
  69
  70 static const match_table_t tokens = {
  71         {Opt_debug, "debug=%x"},
  72         {Opt_dfltuid, "dfltuid=%u"},
  73         {Opt_dfltgid, "dfltgid=%u"},
  74         {Opt_afid, "afid=%u"},
  75         {Opt_uname, "uname=%s"},
  76         {Opt_remotename, "aname=%s"},
  77         {Opt_nodevmap, "nodevmap"},
  78         {Opt_cache, "cache=%s"},
  79         {Opt_cache_loose, "loose"},
  80         {Opt_fscache, "fscache"},
  81         {Opt_mmap, "mmap"},
  82         {Opt_cachetag, "cachetag=%s"},
  83         {Opt_access, "access=%s"},
  84         {Opt_posixacl, "posixacl"},
  85         {Opt_locktimeout, "locktimeout=%u"},
  86         {Opt_err, NULL}
  87 };
  88
  89 static const char *const v9fs_cache_modes[nr__p9_cache_modes] = {
  90         [CACHE_NONE]    = "none",
  91         [CACHE_MMAP]    = "mmap",
  92         [CACHE_LOOSE]   = "loose",
  93         [CACHE_FSCACHE] = "fscache",
  94 };
  95
  96 /* Interpret mount options for cache mode */
  97 static int get_cache_mode(char *s)
  98 {
  99         int version = -EINVAL;
 100
 101         if (!strcmp(s, "loose")) {
 102                 version = CACHE_LOOSE;
 103                 p9_debug(P9_DEBUG_9P, "Cache mode: loose\n");
 104         } else if (!strcmp(s, "fscache")) {
 105                 version = CACHE_FSCACHE;
 106                 p9_debug(P9_DEBUG_9P, "Cache mode: fscache\n");
 107         } else if (!strcmp(s, "mmap")) {
 108                 version = CACHE_MMAP;
 109                 p9_debug(P9_DEBUG_9P, "Cache mode: mmap\n");
 110         } else if (!strcmp(s, "none")) {
 111                 version = CACHE_NONE;
 112                 p9_debug(P9_DEBUG_9P, "Cache mode: none\n");
 113         } else
 114                 pr_info("Unknown Cache mode %s\n", s);
 115         return version;
 116 }
 117
 118 /*
 119  * Display the mount options in /proc/mounts.
 120  */
 121 int v9fs_show_options(struct seq_file *m, struct dentry *root)
 122 {
 123         struct v9fs_session_info *v9ses = root->d_sb->s_fs_info;
 124
 125         if (v9ses->debug)
 126                 seq_printf(m, ",debug=%x", v9ses->debug);
 127         if (!uid_eq(v9ses->dfltuid, V9FS_DEFUID))
 128                 seq_printf(m, ",dfltuid=%u",
 129                            from_kuid_munged(&init_user_ns, v9ses->dfltuid));
 130         if (!gid_eq(v9ses->dfltgid, V9FS_DEFGID))
 131                 seq_printf(m, ",dfltgid=%u",
 132                            from_kgid_munged(&init_user_ns, v9ses->dfltgid));
 133         if (v9ses->afid != ~0)
 134                 seq_printf(m, ",afid=%u", v9ses->afid);
 135         if (strcmp(v9ses->uname, V9FS_DEFUSER) != 0)
 136                 seq_printf(m, ",uname=%s", v9ses->uname);
 137         if (strcmp(v9ses->aname, V9FS_DEFANAME) != 0)
 138                 seq_printf(m, ",aname=%s", v9ses->aname);
 139         if (v9ses->nodev)
 140                 seq_puts(m, ",nodevmap");
 141         if (v9ses->cache)
 142                 seq_printf(m, ",%s", v9fs_cache_modes[v9ses->cache]);
 143 #ifdef CONFIG_9P_FSCACHE
 144         if (v9ses->cachetag && v9ses->cache == CACHE_FSCACHE)
 145                 seq_printf(m, ",cachetag=%s", v9ses->cachetag);
 146 #endif
 147
 148         switch (v9ses->flags & V9FS_ACCESS_MASK) {
 149         case V9FS_ACCESS_USER:
 150                 seq_puts(m, ",access=user");
 151                 break;
 152         case V9FS_ACCESS_ANY:
 153                 seq_puts(m, ",access=any");
 154                 break;
 155         case V9FS_ACCESS_CLIENT:
 156                 seq_puts(m, ",access=client");
 157                 break;
 158         case V9FS_ACCESS_SINGLE:
 159                 seq_printf(m, ",access=%u",
 160                            from_kuid_munged(&init_user_ns, v9ses->uid));
 161                 break;
 162         }
 163
 164         if (v9ses->flags & V9FS_POSIX_ACL)
 165                 seq_puts(m, ",posixacl");
 166
 167         return p9_show_client_options(m, v9ses->clnt);
 168 }
 169
 170 /**
 171  * v9fs_parse_options - parse mount options into session structure
 172  * @v9ses: existing v9fs session information
 173  *
 174  * Return 0 upon success, -ERRNO upon failure.
 175  */
 176
 177 static int v9fs_parse_options(struct v9fs_session_info *v9ses, char *opts)
 178 {
 179         char *options, *tmp_options;
 180         substring_t args[MAX_OPT_ARGS];
 181         char *p;
 182         int option = 0;
 183         char *s, *e;
 184         int ret = 0;
 185
 186         /* setup defaults */
 187         v9ses->afid = ~0;
 188         v9ses->debug = 0;
 189         v9ses->cache = CACHE_NONE;
 190 #ifdef CONFIG_9P_FSCACHE
 191         v9ses->cachetag = NULL;
 192 #endif
 193         v9ses->session_lock_timeout = P9_LOCK_TIMEOUT;
 194
 195         if (!opts)
 196                 return 0;
 197
 198         tmp_options = kstrdup(opts, GFP_KERNEL);
 199         if (!tmp_options) {
 200                 ret = -ENOMEM;
 201                 goto fail_option_alloc;
 202         }
 203         options = tmp_options;
 204
 205         while ((p = strsep(&options, ",")) != NULL) {
 206                 int token, r;
 207                 if (!*p)
 208                         continue;
 209                 token = match_token(p, tokens, args);
 210                 switch (token) {
 211                 case Opt_debug:
 212                         r = match_int(&args[0], &option);
 213                         if (r < 0) {
 214                                 p9_debug(P9_DEBUG_ERROR,
 215                                          "integer field, but no integer?\n");
 216                                 ret = r;
 217                                 continue;
 218                         }
 219                         v9ses->debug = option;
 220 #ifdef CONFIG_NET_9P_DEBUG
 221                         p9_debug_level = option;
 222 #endif
 223                         break;
 224
 225                 case Opt_dfltuid:
 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->dfltuid = make_kuid(current_user_ns(), option);
 234                         if (!uid_valid(v9ses->dfltuid)) {
 235                                 p9_debug(P9_DEBUG_ERROR,
 236                                          "uid field, but not a uid?\n");
 237                                 ret = -EINVAL;
 238                                 continue;
 239                         }
 240                         break;
 241                 case Opt_dfltgid:
 242                         r = match_int(&args[0], &option);
 243                         if (r < 0) {
 244                                 p9_debug(P9_DEBUG_ERROR,
 245                                          "integer field, but no integer?\n");
 246                                 ret = r;
 247                                 continue;
 248                         }
 249                         v9ses->dfltgid = make_kgid(current_user_ns(), option);
 250                         if (!gid_valid(v9ses->dfltgid)) {
 251                                 p9_debug(P9_DEBUG_ERROR,
 252                                          "gid field, but not a gid?\n");
 253                                 ret = -EINVAL;
 254                                 continue;
 255                         }
 256                         break;
 257                 case Opt_afid:
 258                         r = match_int(&args[0], &option);
 259                         if (r < 0) {
 260                                 p9_debug(P9_DEBUG_ERROR,
 261                                          "integer field, but no integer?\n");
 262                                 ret = r;
 263                                 continue;
 264                         }
 265                         v9ses->afid = option;
 266                         break;
 267                 case Opt_uname:
 268                         kfree(v9ses->uname);
 269                         v9ses->uname = match_strdup(&args[0]);
 270                         if (!v9ses->uname) {
 271                                 ret = -ENOMEM;
 272                                 goto free_and_return;
 273                         }
 274                         break;
 275                 case Opt_remotename:
 276                         kfree(v9ses->aname);
 277                         v9ses->aname = match_strdup(&args[0]);
 278                         if (!v9ses->aname) {
 279                                 ret = -ENOMEM;
 280                                 goto free_and_return;
 281                         }
 282                         break;
 283                 case Opt_nodevmap:
 284                         v9ses->nodev = 1;
 285                         break;
 286                 case Opt_cache_loose:
 287                         v9ses->cache = CACHE_LOOSE;
 288                         break;
 289                 case Opt_fscache:
 290                         v9ses->cache = CACHE_FSCACHE;
 291                         break;
 292                 case Opt_mmap:
 293                         v9ses->cache = CACHE_MMAP;
 294                         break;
 295                 case Opt_cachetag:
 296 #ifdef CONFIG_9P_FSCACHE
 297                         kfree(v9ses->cachetag);
 298                         v9ses->cachetag = match_strdup(&args[0]);
 299 #endif
 300                         break;
 301                 case Opt_cache:
 302                         s = match_strdup(&args[0]);
 303                         if (!s) {
 304                                 ret = -ENOMEM;
 305                                 p9_debug(P9_DEBUG_ERROR,
 306                                          "problem allocating copy of cache arg\n");
 307                                 goto free_and_return;
 308                         }
 309                         ret = get_cache_mode(s);
 310                         if (ret == -EINVAL) {
 311                                 kfree(s);
 312                                 goto free_and_return;
 313                         }
 314
 315                         v9ses->cache = ret;
 316                         kfree(s);
 317                         break;
 318
 319                 case Opt_access:
 320                         s = match_strdup(&args[0]);
 321                         if (!s) {
 322                                 ret = -ENOMEM;
 323                                 p9_debug(P9_DEBUG_ERROR,
 324                                          "problem allocating copy of access arg\n");
 325                                 goto free_and_return;
 326                         }
 327
 328                         v9ses->flags &= ~V9FS_ACCESS_MASK;
 329                         if (strcmp(s, "user") == 0)
 330                                 v9ses->flags |= V9FS_ACCESS_USER;
 331                         else if (strcmp(s, "any") == 0)
 332                                 v9ses->flags |= V9FS_ACCESS_ANY;
 333                         else if (strcmp(s, "client") == 0) {
 334                                 v9ses->flags |= V9FS_ACCESS_CLIENT;
 335                         } else {
 336                                 uid_t uid;
 337                                 v9ses->flags |= V9FS_ACCESS_SINGLE;
 338                                 uid = simple_strtoul(s, &e, 10);
 339                                 if (*e != '\0') {
 340                                         ret = -EINVAL;
 341                                         pr_info("Unknown access argument %s\n",
 342                                                 s);
 343                                         kfree(s);
 344                                         goto free_and_return;
 345                                 }
 346                                 v9ses->uid = make_kuid(current_user_ns(), uid);
 347                                 if (!uid_valid(v9ses->uid)) {
 348                                         ret = -EINVAL;
 349                                         pr_info("Uknown uid %s\n", s);
 350                                         kfree(s);
 351                                         goto free_and_return;
 352                                 }
 353                         }
 354
 355                         kfree(s);
 356                         break;
 357
 358                 case Opt_posixacl:
 359 #ifdef CONFIG_9P_FS_POSIX_ACL
 360                         v9ses->flags |= V9FS_POSIX_ACL;
 361 #else
 362                         p9_debug(P9_DEBUG_ERROR,
 363                                  "Not defined CONFIG_9P_FS_POSIX_ACL. Ignoring posixacl option\n");
 364 #endif
 365                         break;
 366
 367                 case Opt_locktimeout:
 368                         r = match_int(&args[0], &option);
 369                         if (r < 0) {
 370                                 p9_debug(P9_DEBUG_ERROR,
 371                                          "integer field, but no integer?\n");
 372                                 ret = r;
 373                                 continue;
 374                         }
 375                         if (option < 1) {
 376                                 p9_debug(P9_DEBUG_ERROR,
 377                                          "locktimeout must be a greater than zero integer.\n");
 378                                 ret = -EINVAL;
 379                                 continue;
 380                         }
 381                         v9ses->session_lock_timeout = (long)option * HZ;
 382                         break;
 383
 384                 default:
 385                         continue;
 386                 }
 387         }
 388
 389 free_and_return:
 390         kfree(tmp_options);
 391 fail_option_alloc:
 392         return ret;
 393 }
 394
 395 /**
 396  * v9fs_session_init - initialize session
 397  * @v9ses: session information structure
 398  * @dev_name: device being mounted
 399  * @data: options
 400  *
 401  */
 402
 403 struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
 404                   const char *dev_name, char *data)
 405 {
 406         struct p9_fid *fid;
 407         int rc = -ENOMEM;
 408
 409         v9ses->uname = kstrdup(V9FS_DEFUSER, GFP_KERNEL);
 410         if (!v9ses->uname)
 411                 goto err_names;
 412
 413         v9ses->aname = kstrdup(V9FS_DEFANAME, GFP_KERNEL);
 414         if (!v9ses->aname)
 415                 goto err_names;
 416         init_rwsem(&v9ses->rename_sem);
 417
 418         v9ses->uid = INVALID_UID;
 419         v9ses->dfltuid = V9FS_DEFUID;
 420         v9ses->dfltgid = V9FS_DEFGID;
 421
 422         v9ses->clnt = p9_client_create(dev_name, data);
 423         if (IS_ERR(v9ses->clnt)) {
 424                 rc = PTR_ERR(v9ses->clnt);
 425                 p9_debug(P9_DEBUG_ERROR, "problem initializing 9p client\n");
 426                 goto err_names;
 427         }
 428
 429         v9ses->flags = V9FS_ACCESS_USER;
 430
 431         if (p9_is_proto_dotl(v9ses->clnt)) {
 432                 v9ses->flags = V9FS_ACCESS_CLIENT;
 433                 v9ses->flags |= V9FS_PROTO_2000L;
 434         } else if (p9_is_proto_dotu(v9ses->clnt)) {
 435                 v9ses->flags |= V9FS_PROTO_2000U;
 436         }
 437
 438         rc = v9fs_parse_options(v9ses, data);
 439         if (rc < 0)
 440                 goto err_clnt;
 441
 442         v9ses->maxdata = v9ses->clnt->msize - P9_IOHDRSZ;
 443
 444         if (!v9fs_proto_dotl(v9ses) &&
 445             ((v9ses->flags & V9FS_ACCESS_MASK) == V9FS_ACCESS_CLIENT)) {
 446                 /*
 447                  * We support ACCESS_CLIENT only for dotl.
 448                  * Fall back to ACCESS_USER
 449                  */
 450                 v9ses->flags &= ~V9FS_ACCESS_MASK;
 451                 v9ses->flags |= V9FS_ACCESS_USER;
 452         }
 453         /*FIXME !! */
 454         /* for legacy mode, fall back to V9FS_ACCESS_ANY */
 455         if (!(v9fs_proto_dotu(v9ses) || v9fs_proto_dotl(v9ses)) &&
 456                 ((v9ses->flags&V9FS_ACCESS_MASK) == V9FS_ACCESS_USER)) {
 457
 458                 v9ses->flags &= ~V9FS_ACCESS_MASK;
 459                 v9ses->flags |= V9FS_ACCESS_ANY;
 460                 v9ses->uid = INVALID_UID;
 461         }
 462         if (!v9fs_proto_dotl(v9ses) ||
 463                 !((v9ses->flags & V9FS_ACCESS_MASK) == V9FS_ACCESS_CLIENT)) {
 464                 /*
 465                  * We support ACL checks on clinet only if the protocol is
 466                  * 9P2000.L and access is V9FS_ACCESS_CLIENT.
 467                  */
 468                 v9ses->flags &= ~V9FS_ACL_MASK;
 469         }
 470
 471         fid = p9_client_attach(v9ses->clnt, NULL, v9ses->uname, INVALID_UID,
 472                                                         v9ses->aname);
 473         if (IS_ERR(fid)) {
 474                 rc = PTR_ERR(fid);
 475                 p9_debug(P9_DEBUG_ERROR, "cannot attach\n");
 476                 goto err_clnt;
 477         }
 478
 479         if ((v9ses->flags & V9FS_ACCESS_MASK) == V9FS_ACCESS_SINGLE)
 480                 fid->uid = v9ses->uid;
 481         else
 482                 fid->uid = INVALID_UID;
 483
 484 #ifdef CONFIG_9P_FSCACHE
 485         /* register the session for caching */
 486         v9fs_cache_session_get_cookie(v9ses);
 487 #endif
 488         spin_lock(&v9fs_sessionlist_lock);
 489         list_add(&v9ses->slist, &v9fs_sessionlist);
 490         spin_unlock(&v9fs_sessionlist_lock);
 491
 492         return fid;
 493
 494 err_clnt:
 495         p9_client_destroy(v9ses->clnt);
 496 err_names:
 497         kfree(v9ses->uname);
 498         kfree(v9ses->aname);
 499         return ERR_PTR(rc);
 500 }
 501
 502 /**
 503  * v9fs_session_close - shutdown a session
 504  * @v9ses: session information structure
 505  *
 506  */
 507
 508 void v9fs_session_close(struct v9fs_session_info *v9ses)
 509 {
 510         if (v9ses->clnt) {
 511                 p9_client_destroy(v9ses->clnt);
 512                 v9ses->clnt = NULL;
 513         }
 514
 515 #ifdef CONFIG_9P_FSCACHE
 516         if (v9ses->fscache)
 517                 v9fs_cache_session_put_cookie(v9ses);
 518         kfree(v9ses->cachetag);
 519 #endif
 520         kfree(v9ses->uname);
 521         kfree(v9ses->aname);
 522
 523         spin_lock(&v9fs_sessionlist_lock);
 524         list_del(&v9ses->slist);
 525         spin_unlock(&v9fs_sessionlist_lock);
 526 }
 527
 528 /**
 529  * v9fs_session_cancel - terminate a session
 530  * @v9ses: session to terminate
 531  *
 532  * mark transport as disconnected and cancel all pending requests.
 533  */
 534
 535 void v9fs_session_cancel(struct v9fs_session_info *v9ses) {
 536         p9_debug(P9_DEBUG_ERROR, "cancel session %p\n", v9ses);
 537         p9_client_disconnect(v9ses->clnt);
 538 }
 539
 540 /**
 541  * v9fs_session_begin_cancel - Begin terminate of a session
 542  * @v9ses: session to terminate
 543  *
 544  * After this call we don't allow any request other than clunk.
 545  */
 546
 547 void v9fs_session_begin_cancel(struct v9fs_session_info *v9ses)
 548 {
 549         p9_debug(P9_DEBUG_ERROR, "begin cancel session %p\n", v9ses);
 550         p9_client_begin_disconnect(v9ses->clnt);
 551 }
 552
 553 extern int v9fs_error_init(void);
 554
 555 static struct kobject *v9fs_kobj;
 556
 557 #ifdef CONFIG_9P_FSCACHE
 558 /**
 559  * caches_show - list caches associated with a session
 560  *
 561  * Returns the size of buffer written.
 562  */
 563
 564 static ssize_t caches_show(struct kobject *kobj,
 565                            struct kobj_attribute *attr,
 566                            char *buf)
 567 {
 568         ssize_t n = 0, count = 0, limit = PAGE_SIZE;
 569         struct v9fs_session_info *v9ses;
 570
 571         spin_lock(&v9fs_sessionlist_lock);
 572         list_for_each_entry(v9ses, &v9fs_sessionlist, slist) {
 573                 if (v9ses->cachetag) {
 574                         n = snprintf(buf, limit, "%s\n", v9ses->cachetag);
 575                         if (n < 0) {
 576                                 count = n;
 577                                 break;
 578                         }
 579
 580                         count += n;
 581                         limit -= n;
 582                 }
 583         }
 584
 585         spin_unlock(&v9fs_sessionlist_lock);
 586         return count;
 587 }
 588
 589 static struct kobj_attribute v9fs_attr_cache = __ATTR_RO(caches);
 590 #endif /* CONFIG_9P_FSCACHE */
 591
 592 static struct attribute *v9fs_attrs[] = {
 593 #ifdef CONFIG_9P_FSCACHE
 594         &v9fs_attr_cache.attr,
 595 #endif
 596         NULL,
 597 };
 598
 599 static struct attribute_group v9fs_attr_group = {
 600         .attrs = v9fs_attrs,
 601 };
 602
 603 /**
 604  * v9fs_sysfs_init - Initialize the v9fs sysfs interface
 605  *
 606  */
 607
 608 static int __init v9fs_sysfs_init(void)
 609 {
 610         v9fs_kobj = kobject_create_and_add("9p", fs_kobj);
 611         if (!v9fs_kobj)
 612                 return -ENOMEM;
 613
 614         if (sysfs_create_group(v9fs_kobj, &v9fs_attr_group)) {
 615                 kobject_put(v9fs_kobj);
 616                 return -ENOMEM;
 617         }
 618
 619         return 0;
 620 }
 621
 622 /**
 623  * v9fs_sysfs_cleanup - Unregister the v9fs sysfs interface
 624  *
 625  */
 626
 627 static void v9fs_sysfs_cleanup(void)
 628 {
 629         sysfs_remove_group(v9fs_kobj, &v9fs_attr_group);
 630         kobject_put(v9fs_kobj);
 631 }
 632
 633 static void v9fs_inode_init_once(void *foo)
 634 {
 635         struct v9fs_inode *v9inode = (struct v9fs_inode *)foo;
 636 #ifdef CONFIG_9P_FSCACHE
 637         v9inode->fscache = NULL;
 638 #endif
 639         memset(&v9inode->qid, 0, sizeof(v9inode->qid));
 640         inode_init_once(&v9inode->vfs_inode);
 641 }
 642
 643 /**
 644  * v9fs_init_inode_cache - initialize a cache for 9P
 645  * Returns 0 on success.
 646  */
 647 static int v9fs_init_inode_cache(void)
 648 {
 649         v9fs_inode_cache = kmem_cache_create("v9fs_inode_cache",
 650                                           sizeof(struct v9fs_inode),
 651                                           0, (SLAB_RECLAIM_ACCOUNT|
 652                                               SLAB_MEM_SPREAD|SLAB_ACCOUNT),
 653                                           v9fs_inode_init_once);
 654         if (!v9fs_inode_cache)
 655                 return -ENOMEM;
 656
 657         return 0;
 658 }
 659
 660 /**
 661  * v9fs_destroy_inode_cache - destroy the cache of 9P inode
 662  *
 663  */
 664 static void v9fs_destroy_inode_cache(void)
 665 {
 666         /*
 667          * Make sure all delayed rcu free inodes are flushed before we
 668          * destroy cache.
 669          */
 670         rcu_barrier();
 671         kmem_cache_destroy(v9fs_inode_cache);
 672 }
 673
 674 static int v9fs_cache_register(void)
 675 {
 676         int ret;
 677         ret = v9fs_init_inode_cache();
 678         if (ret < 0)
 679                 return ret;
 680 #ifdef CONFIG_9P_FSCACHE
 681         ret = fscache_register_netfs(&v9fs_cache_netfs);
 682         if (ret < 0)
 683                 v9fs_destroy_inode_cache();
 684 #endif
 685         return ret;
 686 }
 687
 688 static void v9fs_cache_unregister(void)
 689 {
 690         v9fs_destroy_inode_cache();
 691 #ifdef CONFIG_9P_FSCACHE
 692         fscache_unregister_netfs(&v9fs_cache_netfs);
 693 #endif
 694 }
 695
 696 /**
 697  * init_v9fs - Initialize module
 698  *
 699  */
 700
 701 static int __init init_v9fs(void)
 702 {
 703         int err;
 704         pr_info("Installing v9fs 9p2000 file system support\n");
 705         /* TODO: Setup list of registered trasnport modules */
 706
 707         err = v9fs_cache_register();
 708         if (err < 0) {
 709                 pr_err("Failed to register v9fs for caching\n");
 710                 return err;
 711         }
 712
 713         err = v9fs_sysfs_init();
 714         if (err < 0) {
 715                 pr_err("Failed to register with sysfs\n");
 716                 goto out_cache;
 717         }
 718         err = register_filesystem(&v9fs_fs_type);
 719         if (err < 0) {
 720                 pr_err("Failed to register filesystem\n");
 721                 goto out_sysfs_cleanup;
 722         }
 723
 724         return 0;
 725
 726 out_sysfs_cleanup:
 727         v9fs_sysfs_cleanup();
 728
 729 out_cache:
 730         v9fs_cache_unregister();
 731
 732         return err;
 733 }
 734
 735 /**
 736  * exit_v9fs - shutdown module
 737  *
 738  */
 739
 740 static void __exit exit_v9fs(void)
 741 {
 742         v9fs_sysfs_cleanup();
 743         v9fs_cache_unregister();
 744         unregister_filesystem(&v9fs_fs_type);
 745 }
 746
 747 module_init(init_v9fs)
 748 module_exit(exit_v9fs)
 749
 750 MODULE_AUTHOR("Latchesar Ionkov <lucho@ionkov.net>");
 751 MODULE_AUTHOR("Eric Van Hensbergen <ericvh@gmail.com>");
 752 MODULE_AUTHOR("Ron Minnich <rminnich@lanl.gov>");
 753 MODULE_LICENSE("GPL");