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 static const char *const v9fs_cache_modes[nr__p9_cache_modes] = {
  70         [CACHE_NONE]            = "none",
  71         [CACHE_READAHEAD]       = "readahead",
  72         [CACHE_WRITEBACK]       = "writeback",
  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, "writeback")) {
  93                 version = CACHE_WRITEBACK;
  94                 p9_debug(P9_DEBUG_9P, "Cache mode: writeback\n");
  95         } else if (!strcmp(s, "readahead")) {
  96                 version = CACHE_READAHEAD;
  97                 p9_debug(P9_DEBUG_9P, "Cache mode: readahead\n");
  98         } else if (!strcmp(s, "none")) {
  99                 version = CACHE_NONE;
 100                 p9_debug(P9_DEBUG_9P, "Cache mode: none\n");
 101         } else
 102                 pr_info("Unknown Cache mode %s\n", s);
 103         return version;
 104 }
 105
 106 /*
 107  * Display the mount options in /proc/mounts.
 108  */
 109 int v9fs_show_options(struct seq_file *m, struct dentry *root)
 110 {
 111         struct v9fs_session_info *v9ses = root->d_sb->s_fs_info;
 112
 113         if (v9ses->debug)
 114                 seq_printf(m, ",debug=%x", v9ses->debug);
 115         if (!uid_eq(v9ses->dfltuid, V9FS_DEFUID))
 116                 seq_printf(m, ",dfltuid=%u",
 117                            from_kuid_munged(&init_user_ns, v9ses->dfltuid));
 118         if (!gid_eq(v9ses->dfltgid, V9FS_DEFGID))
 119                 seq_printf(m, ",dfltgid=%u",
 120                            from_kgid_munged(&init_user_ns, v9ses->dfltgid));
 121         if (v9ses->afid != ~0)
 122                 seq_printf(m, ",afid=%u", v9ses->afid);
 123         if (strcmp(v9ses->uname, V9FS_DEFUSER) != 0)
 124                 seq_printf(m, ",uname=%s", v9ses->uname);
 125         if (strcmp(v9ses->aname, V9FS_DEFANAME) != 0)
 126                 seq_printf(m, ",aname=%s", v9ses->aname);
 127         if (v9ses->nodev)
 128                 seq_puts(m, ",nodevmap");
 129         if (v9ses->cache)
 130                 seq_printf(m, ",cache=%s", v9fs_cache_modes[v9ses->cache]);
 131 #ifdef CONFIG_9P_FSCACHE
 132         if (v9ses->cachetag && v9ses->cache == CACHE_FSCACHE)
 133                 seq_printf(m, ",cachetag=%s", v9ses->cachetag);
 134 #endif
 135
 136         switch (v9ses->flags & V9FS_ACCESS_MASK) {
 137         case V9FS_ACCESS_USER:
 138                 seq_puts(m, ",access=user");
 139                 break;
 140         case V9FS_ACCESS_ANY:
 141                 seq_puts(m, ",access=any");
 142                 break;
 143         case V9FS_ACCESS_CLIENT:
 144                 seq_puts(m, ",access=client");
 145                 break;
 146         case V9FS_ACCESS_SINGLE:
 147                 seq_printf(m, ",access=%u",
 148                            from_kuid_munged(&init_user_ns, v9ses->uid));
 149                 break;
 150         }
 151
 152         if (v9ses->flags & V9FS_IGNORE_QV)
 153                 seq_puts(m, ",ignoreqv");
 154         if (v9ses->flags & V9FS_DIRECT_IO)
 155                 seq_puts(m, ",directio");
 156         if (v9ses->flags & V9FS_POSIX_ACL)
 157                 seq_puts(m, ",posixacl");
 158
 159         if (v9ses->flags & V9FS_NO_XATTR)
 160                 seq_puts(m, ",noxattr");
 161
 162         return p9_show_client_options(m, v9ses->clnt);
 163 }
 164
 165 /**
 166  * v9fs_parse_options - parse mount options into session structure
 167  * @v9ses: existing v9fs session information
 168  * @opts: The mount option string
 169  *
 170  * Return 0 upon success, -ERRNO upon failure.
 171  */
 172
 173 static int v9fs_parse_options(struct v9fs_session_info *v9ses, char *opts)
 174 {
 175         char *options, *tmp_options;
 176         substring_t args[MAX_OPT_ARGS];
 177         char *p;
 178         int option = 0;
 179         char *s;
 180         int ret = 0;
 181
 182         /* setup defaults */
 183         v9ses->afid = ~0;
 184         v9ses->debug = 0;
 185         v9ses->cache = CACHE_NONE;
 186 #ifdef CONFIG_9P_FSCACHE
 187         v9ses->cachetag = NULL;
 188 #endif
 189         v9ses->session_lock_timeout = P9_LOCK_TIMEOUT;
 190
 191         if (!opts)
 192                 return 0;
 193
 194         tmp_options = kstrdup(opts, GFP_KERNEL);
 195         if (!tmp_options) {
 196                 ret = -ENOMEM;
 197                 goto fail_option_alloc;
 198         }
 199         options = tmp_options;
 200
 201         while ((p = strsep(&options, ",")) != NULL) {
 202                 int token, r;
 203
 204                 if (!*p)
 205                         continue;
 206
 207                 token = match_token(p, tokens, args);
 208                 switch (token) {
 209                 case Opt_debug:
 210                         r = match_int(&args[0], &option);
 211                         if (r < 0) {
 212                                 p9_debug(P9_DEBUG_ERROR,
 213                                          "integer field, but no integer?\n");
 214                                 ret = r;
 215                         } else {
 216                                 v9ses->debug = option;
 217 #ifdef CONFIG_NET_9P_DEBUG
 218                                 p9_debug_level = option;
 219 #endif
 220                         }
 221                         break;
 222
 223                 case Opt_dfltuid:
 224                         r = match_int(&args[0], &option);
 225                         if (r < 0) {
 226                                 p9_debug(P9_DEBUG_ERROR,
 227                                          "integer field, but no integer?\n");
 228                                 ret = r;
 229                                 continue;
 230                         }
 231                         v9ses->dfltuid = make_kuid(current_user_ns(), option);
 232                         if (!uid_valid(v9ses->dfltuid)) {
 233                                 p9_debug(P9_DEBUG_ERROR,
 234                                          "uid field, but not a uid?\n");
 235                                 ret = -EINVAL;
 236                         }
 237                         break;
 238                 case Opt_dfltgid:
 239                         r = match_int(&args[0], &option);
 240                         if (r < 0) {
 241                                 p9_debug(P9_DEBUG_ERROR,
 242                                          "integer field, but no integer?\n");
 243                                 ret = r;
 244                                 continue;
 245                         }
 246                         v9ses->dfltgid = make_kgid(current_user_ns(), option);
 247                         if (!gid_valid(v9ses->dfltgid)) {
 248                                 p9_debug(P9_DEBUG_ERROR,
 249                                          "gid field, but not a gid?\n");
 250                                 ret = -EINVAL;
 251                         }
 252                         break;
 253                 case Opt_afid:
 254                         r = match_int(&args[0], &option);
 255                         if (r < 0) {
 256                                 p9_debug(P9_DEBUG_ERROR,
 257                                          "integer field, but no integer?\n");
 258                                 ret = r;
 259                         } else {
 260                                 v9ses->afid = option;
 261                         }
 262                         break;
 263                 case Opt_uname:
 264                         kfree(v9ses->uname);
 265                         v9ses->uname = match_strdup(&args[0]);
 266                         if (!v9ses->uname) {
 267                                 ret = -ENOMEM;
 268                                 goto free_and_return;
 269                         }
 270                         break;
 271                 case Opt_remotename:
 272                         kfree(v9ses->aname);
 273                         v9ses->aname = match_strdup(&args[0]);
 274                         if (!v9ses->aname) {
 275                                 ret = -ENOMEM;
 276                                 goto free_and_return;
 277                         }
 278                         break;
 279                 case Opt_nodevmap:
 280                         v9ses->nodev = 1;
 281                         break;
 282                 case Opt_noxattr:
 283                         v9ses->flags |= V9FS_NO_XATTR;
 284                         break;
 285                 case Opt_directio:
 286                         v9ses->flags |= V9FS_DIRECT_IO;
 287                         break;
 288                 case Opt_ignoreqv:
 289                         v9ses->flags |= V9FS_IGNORE_QV;
 290                         break;
 291                 case Opt_cachetag:
 292 #ifdef CONFIG_9P_FSCACHE
 293                         kfree(v9ses->cachetag);
 294                         v9ses->cachetag = match_strdup(&args[0]);
 295                         if (!v9ses->cachetag) {
 296                                 ret = -ENOMEM;
 297                                 goto free_and_return;
 298                         }
 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                         r = get_cache_mode(s);
 310                         if (r < 0)
 311                                 ret = r;
 312                         else
 313                                 v9ses->cache = r;
 314
 315                         kfree(s);
 316                         break;
 317
 318                 case Opt_access:
 319                         s = match_strdup(&args[0]);
 320                         if (!s) {
 321                                 ret = -ENOMEM;
 322                                 p9_debug(P9_DEBUG_ERROR,
 323                                          "problem allocating copy of access arg\n");
 324                                 goto free_and_return;
 325                         }
 326
 327                         v9ses->flags &= ~V9FS_ACCESS_MASK;
 328                         if (strcmp(s, "user") == 0)
 329                                 v9ses->flags |= V9FS_ACCESS_USER;
 330                         else if (strcmp(s, "any") == 0)
 331                                 v9ses->flags |= V9FS_ACCESS_ANY;
 332                         else if (strcmp(s, "client") == 0) {
 333                                 v9ses->flags |= V9FS_ACCESS_CLIENT;
 334                         } else {
 335                                 uid_t uid;
 336
 337                                 v9ses->flags |= V9FS_ACCESS_SINGLE;
 338                                 r = kstrtouint(s, 10, &uid);
 339                                 if (r) {
 340                                         ret = r;
 341                                         pr_info("Unknown access argument %s: %d\n",
 342                                                 s, r);
 343                                         kfree(s);
 344                                         continue;
 345                                 }
 346                                 v9ses->uid = make_kuid(current_user_ns(), uid);
 347                                 if (!uid_valid(v9ses->uid)) {
 348                                         ret = -EINVAL;
 349                                         pr_info("Unknown uid %s\n", s);
 350                                 }
 351                         }
 352
 353                         kfree(s);
 354                         break;
 355
 356                 case Opt_posixacl:
 357 #ifdef CONFIG_9P_FS_POSIX_ACL
 358                         v9ses->flags |= V9FS_POSIX_ACL;
 359 #else
 360                         p9_debug(P9_DEBUG_ERROR,
 361                                  "Not defined CONFIG_9P_FS_POSIX_ACL. Ignoring posixacl option\n");
 362 #endif
 363                         break;
 364
 365                 case Opt_locktimeout:
 366                         r = match_int(&args[0], &option);
 367                         if (r < 0) {
 368                                 p9_debug(P9_DEBUG_ERROR,
 369                                          "integer field, but no integer?\n");
 370                                 ret = r;
 371                                 continue;
 372                         }
 373                         if (option < 1) {
 374                                 p9_debug(P9_DEBUG_ERROR,
 375                                          "locktimeout must be a greater than zero integer.\n");
 376                                 ret = -EINVAL;
 377                                 continue;
 378                         }
 379                         v9ses->session_lock_timeout = (long)option * HZ;
 380                         break;
 381
 382                 default:
 383                         continue;
 384                 }
 385         }
 386
 387 free_and_return:
 388         kfree(tmp_options);
 389 fail_option_alloc:
 390         return ret;
 391 }
 392
 393 /**
 394  * v9fs_session_init - initialize session
 395  * @v9ses: session information structure
 396  * @dev_name: device being mounted
 397  * @data: options
 398  *
 399  */
 400
 401 struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
 402                   const char *dev_name, char *data)
 403 {
 404         struct p9_fid *fid;
 405         int rc = -ENOMEM;
 406
 407         v9ses->uname = kstrdup(V9FS_DEFUSER, GFP_KERNEL);
 408         if (!v9ses->uname)
 409                 goto err_names;
 410
 411         v9ses->aname = kstrdup(V9FS_DEFANAME, GFP_KERNEL);
 412         if (!v9ses->aname)
 413                 goto err_names;
 414         init_rwsem(&v9ses->rename_sem);
 415
 416         v9ses->uid = INVALID_UID;
 417         v9ses->dfltuid = V9FS_DEFUID;
 418         v9ses->dfltgid = V9FS_DEFGID;
 419
 420         v9ses->clnt = p9_client_create(dev_name, data);
 421         if (IS_ERR(v9ses->clnt)) {
 422                 rc = PTR_ERR(v9ses->clnt);
 423                 p9_debug(P9_DEBUG_ERROR, "problem initializing 9p client\n");
 424                 goto err_names;
 425         }
 426
 427         v9ses->flags = V9FS_ACCESS_USER;
 428
 429         if (p9_is_proto_dotl(v9ses->clnt)) {
 430                 v9ses->flags = V9FS_ACCESS_CLIENT;
 431                 v9ses->flags |= V9FS_PROTO_2000L;
 432         } else if (p9_is_proto_dotu(v9ses->clnt)) {
 433                 v9ses->flags |= V9FS_PROTO_2000U;
 434         }
 435
 436         rc = v9fs_parse_options(v9ses, data);
 437         if (rc < 0)
 438                 goto err_clnt;
 439
 440         v9ses->maxdata = v9ses->clnt->msize - P9_IOHDRSZ;
 441
 442         if (!v9fs_proto_dotl(v9ses) &&
 443             ((v9ses->flags & V9FS_ACCESS_MASK) == V9FS_ACCESS_CLIENT)) {
 444                 /*
 445                  * We support ACCESS_CLIENT only for dotl.
 446                  * Fall back to ACCESS_USER
 447                  */
 448                 v9ses->flags &= ~V9FS_ACCESS_MASK;
 449                 v9ses->flags |= V9FS_ACCESS_USER;
 450         }
 451         /*FIXME !! */
 452         /* for legacy mode, fall back to V9FS_ACCESS_ANY */
 453         if (!(v9fs_proto_dotu(v9ses) || v9fs_proto_dotl(v9ses)) &&
 454                 ((v9ses->flags&V9FS_ACCESS_MASK) == V9FS_ACCESS_USER)) {
 455
 456                 v9ses->flags &= ~V9FS_ACCESS_MASK;
 457                 v9ses->flags |= V9FS_ACCESS_ANY;
 458                 v9ses->uid = INVALID_UID;
 459         }
 460         if (!v9fs_proto_dotl(v9ses) ||
 461                 !((v9ses->flags & V9FS_ACCESS_MASK) == V9FS_ACCESS_CLIENT)) {
 462                 /*
 463                  * We support ACL checks on clinet only if the protocol is
 464                  * 9P2000.L and access is V9FS_ACCESS_CLIENT.
 465                  */
 466                 v9ses->flags &= ~V9FS_ACL_MASK;
 467         }
 468
 469         fid = p9_client_attach(v9ses->clnt, NULL, v9ses->uname, INVALID_UID,
 470                                                         v9ses->aname);
 471         if (IS_ERR(fid)) {
 472                 rc = PTR_ERR(fid);
 473                 p9_debug(P9_DEBUG_ERROR, "cannot attach\n");
 474                 goto err_clnt;
 475         }
 476
 477         if ((v9ses->flags & V9FS_ACCESS_MASK) == V9FS_ACCESS_SINGLE)
 478                 fid->uid = v9ses->uid;
 479         else
 480                 fid->uid = INVALID_UID;
 481
 482 #ifdef CONFIG_9P_FSCACHE
 483         /* register the session for caching */
 484         if (v9ses->cache == CACHE_FSCACHE) {
 485                 rc = v9fs_cache_session_get_cookie(v9ses, dev_name);
 486                 if (rc < 0)
 487                         goto err_clnt;
 488         }
 489 #endif
 490         spin_lock(&v9fs_sessionlist_lock);
 491         list_add(&v9ses->slist, &v9fs_sessionlist);
 492         spin_unlock(&v9fs_sessionlist_lock);
 493
 494         return fid;
 495
 496 err_clnt:
 497 #ifdef CONFIG_9P_FSCACHE
 498         kfree(v9ses->cachetag);
 499 #endif
 500         p9_client_destroy(v9ses->clnt);
 501 err_names:
 502         kfree(v9ses->uname);
 503         kfree(v9ses->aname);
 504         return ERR_PTR(rc);
 505 }
 506
 507 /**
 508  * v9fs_session_close - shutdown a session
 509  * @v9ses: session information structure
 510  *
 511  */
 512
 513 void v9fs_session_close(struct v9fs_session_info *v9ses)
 514 {
 515         if (v9ses->clnt) {
 516                 p9_client_destroy(v9ses->clnt);
 517                 v9ses->clnt = NULL;
 518         }
 519
 520 #ifdef CONFIG_9P_FSCACHE
 521         fscache_relinquish_volume(v9fs_session_cache(v9ses), NULL, false);
 522         kfree(v9ses->cachetag);
 523 #endif
 524         kfree(v9ses->uname);
 525         kfree(v9ses->aname);
 526
 527         spin_lock(&v9fs_sessionlist_lock);
 528         list_del(&v9ses->slist);
 529         spin_unlock(&v9fs_sessionlist_lock);
 530 }
 531
 532 /**
 533  * v9fs_session_cancel - terminate a session
 534  * @v9ses: session to terminate
 535  *
 536  * mark transport as disconnected and cancel all pending requests.
 537  */
 538
 539 void v9fs_session_cancel(struct v9fs_session_info *v9ses)
 540 {
 541         p9_debug(P9_DEBUG_ERROR, "cancel session %p\n", v9ses);
 542         p9_client_disconnect(v9ses->clnt);
 543 }
 544
 545 /**
 546  * v9fs_session_begin_cancel - Begin terminate of a session
 547  * @v9ses: session to terminate
 548  *
 549  * After this call we don't allow any request other than clunk.
 550  */
 551
 552 void v9fs_session_begin_cancel(struct v9fs_session_info *v9ses)
 553 {
 554         p9_debug(P9_DEBUG_ERROR, "begin cancel session %p\n", v9ses);
 555         p9_client_begin_disconnect(v9ses->clnt);
 556 }
 557
 558 extern int v9fs_error_init(void);
 559
 560 static struct kobject *v9fs_kobj;
 561
 562 #ifdef CONFIG_9P_FSCACHE
 563 /*
 564  * List caches associated with a session
 565  */
 566 static ssize_t caches_show(struct kobject *kobj,
 567                            struct kobj_attribute *attr,
 568                            char *buf)
 569 {
 570         ssize_t n = 0, count = 0, limit = PAGE_SIZE;
 571         struct v9fs_session_info *v9ses;
 572
 573         spin_lock(&v9fs_sessionlist_lock);
 574         list_for_each_entry(v9ses, &v9fs_sessionlist, slist) {
 575                 if (v9ses->cachetag) {
 576                         n = snprintf(buf, limit, "%s\n", v9ses->cachetag);
 577                         if (n < 0) {
 578                                 count = n;
 579                                 break;
 580                         }
 581
 582                         count += n;
 583                         limit -= n;
 584                 }
 585         }
 586
 587         spin_unlock(&v9fs_sessionlist_lock);
 588         return count;
 589 }
 590
 591 static struct kobj_attribute v9fs_attr_cache = __ATTR_RO(caches);
 592 #endif /* CONFIG_9P_FSCACHE */
 593
 594 static struct attribute *v9fs_attrs[] = {
 595 #ifdef CONFIG_9P_FSCACHE
 596         &v9fs_attr_cache.attr,
 597 #endif
 598         NULL,
 599 };
 600
 601 static const struct attribute_group v9fs_attr_group = {
 602         .attrs = v9fs_attrs,
 603 };
 604
 605 /**
 606  * v9fs_sysfs_init - Initialize the v9fs sysfs interface
 607  *
 608  */
 609
 610 static int __init v9fs_sysfs_init(void)
 611 {
 612         v9fs_kobj = kobject_create_and_add("9p", fs_kobj);
 613         if (!v9fs_kobj)
 614                 return -ENOMEM;
 615
 616         if (sysfs_create_group(v9fs_kobj, &v9fs_attr_group)) {
 617                 kobject_put(v9fs_kobj);
 618                 return -ENOMEM;
 619         }
 620
 621         return 0;
 622 }
 623
 624 /**
 625  * v9fs_sysfs_cleanup - Unregister the v9fs sysfs interface
 626  *
 627  */
 628
 629 static void v9fs_sysfs_cleanup(void)
 630 {
 631         sysfs_remove_group(v9fs_kobj, &v9fs_attr_group);
 632         kobject_put(v9fs_kobj);
 633 }
 634
 635 static void v9fs_inode_init_once(void *foo)
 636 {
 637         struct v9fs_inode *v9inode = (struct v9fs_inode *)foo;
 638
 639         memset(&v9inode->qid, 0, sizeof(v9inode->qid));
 640         inode_init_once(&v9inode->netfs.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
 678         ret = v9fs_init_inode_cache();
 679         if (ret < 0)
 680                 return ret;
 681         return ret;
 682 }
 683
 684 static void v9fs_cache_unregister(void)
 685 {
 686         v9fs_destroy_inode_cache();
 687 }
 688
 689 /**
 690  * init_v9fs - Initialize module
 691  *
 692  */
 693
 694 static int __init init_v9fs(void)
 695 {
 696         int err;
 697
 698         pr_info("Installing v9fs 9p2000 file system support\n");
 699         /* TODO: Setup list of registered trasnport modules */
 700
 701         err = v9fs_cache_register();
 702         if (err < 0) {
 703                 pr_err("Failed to register v9fs for caching\n");
 704                 return err;
 705         }
 706
 707         err = v9fs_sysfs_init();
 708         if (err < 0) {
 709                 pr_err("Failed to register with sysfs\n");
 710                 goto out_cache;
 711         }
 712         err = register_filesystem(&v9fs_fs_type);
 713         if (err < 0) {
 714                 pr_err("Failed to register filesystem\n");
 715                 goto out_sysfs_cleanup;
 716         }
 717
 718         return 0;
 719
 720 out_sysfs_cleanup:
 721         v9fs_sysfs_cleanup();
 722
 723 out_cache:
 724         v9fs_cache_unregister();
 725
 726         return err;
 727 }
 728
 729 /**
 730  * exit_v9fs - shutdown module
 731  *
 732  */
 733
 734 static void __exit exit_v9fs(void)
 735 {
 736         v9fs_sysfs_cleanup();
 737         v9fs_cache_unregister();
 738         unregister_filesystem(&v9fs_fs_type);
 739 }
 740
 741 module_init(init_v9fs)
 742 module_exit(exit_v9fs)
 743
 744 MODULE_AUTHOR("Latchesar Ionkov <lucho@ionkov.net>");
 745 MODULE_AUTHOR("Eric Van Hensbergen <ericvh@gmail.com>");
 746 MODULE_AUTHOR("Ron Minnich <rminnich@lanl.gov>");
 747 MODULE_LICENSE("GPL");