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 #include <linux/module.h> 27 #include <linux/errno.h> 28 #include <linux/fs.h> 29 #include <linux/sched.h> 30 #include <linux/parser.h> 31 #include <linux/idr.h> 32 #include <linux/slab.h> 33 #include <net/9p/9p.h> 34 #include <net/9p/client.h> 35 #include <net/9p/transport.h> 36 #include "v9fs.h" 37 #include "v9fs_vfs.h" 38 #include "cache.h" 39 40 static DEFINE_SPINLOCK(v9fs_sessionlist_lock); 41 static LIST_HEAD(v9fs_sessionlist); 42 43 /* 44 * Option Parsing (code inspired by NFS code) 45 * NOTE: each transport will parse its own options 46 */ 47 48 enum { 49 /* Options that take integer arguments */ 50 Opt_debug, Opt_dfltuid, Opt_dfltgid, Opt_afid, 51 /* String options */ 52 Opt_uname, Opt_remotename, Opt_trans, Opt_cache, Opt_cachetag, 53 /* Options that take no arguments */ 54 Opt_nodevmap, 55 /* Cache options */ 56 Opt_cache_loose, Opt_fscache, 57 /* Access options */ 58 Opt_access, 59 /* Error token */ 60 Opt_err 61 }; 62 63 static const match_table_t tokens = { 64 {Opt_debug, "debug=%x"}, 65 {Opt_dfltuid, "dfltuid=%u"}, 66 {Opt_dfltgid, "dfltgid=%u"}, 67 {Opt_afid, "afid=%u"}, 68 {Opt_uname, "uname=%s"}, 69 {Opt_remotename, "aname=%s"}, 70 {Opt_nodevmap, "nodevmap"}, 71 {Opt_cache, "cache=%s"}, 72 {Opt_cache_loose, "loose"}, 73 {Opt_fscache, "fscache"}, 74 {Opt_cachetag, "cachetag=%s"}, 75 {Opt_access, "access=%s"}, 76 {Opt_err, NULL} 77 }; 78 79 /** 80 * v9fs_parse_options - parse mount options into session structure 81 * @v9ses: existing v9fs session information 82 * 83 * Return 0 upon success, -ERRNO upon failure. 84 */ 85 86 static int v9fs_parse_options(struct v9fs_session_info *v9ses, char *opts) 87 { 88 char *options, *tmp_options; 89 substring_t args[MAX_OPT_ARGS]; 90 char *p; 91 int option = 0; 92 char *s, *e; 93 int ret = 0; 94 95 /* setup defaults */ 96 v9ses->afid = ~0; 97 v9ses->debug = 0; 98 v9ses->cache = 0; 99 #ifdef CONFIG_9P_FSCACHE 100 v9ses->cachetag = NULL; 101 #endif 102 103 if (!opts) 104 return 0; 105 106 tmp_options = kstrdup(opts, GFP_KERNEL); 107 if (!tmp_options) { 108 ret = -ENOMEM; 109 goto fail_option_alloc; 110 } 111 options = tmp_options; 112 113 while ((p = strsep(&options, ",")) != NULL) { 114 int token; 115 if (!*p) 116 continue; 117 token = match_token(p, tokens, args); 118 if (token < Opt_uname) { 119 int r = match_int(&args[0], &option); 120 if (r < 0) { 121 P9_DPRINTK(P9_DEBUG_ERROR, 122 "integer field, but no integer?\n"); 123 ret = r; 124 continue; 125 } 126 } 127 switch (token) { 128 case Opt_debug: 129 v9ses->debug = option; 130 #ifdef CONFIG_NET_9P_DEBUG 131 p9_debug_level = option; 132 #endif 133 break; 134 135 case Opt_dfltuid: 136 v9ses->dfltuid = option; 137 break; 138 case Opt_dfltgid: 139 v9ses->dfltgid = option; 140 break; 141 case Opt_afid: 142 v9ses->afid = option; 143 break; 144 case Opt_uname: 145 match_strlcpy(v9ses->uname, &args[0], PATH_MAX); 146 break; 147 case Opt_remotename: 148 match_strlcpy(v9ses->aname, &args[0], PATH_MAX); 149 break; 150 case Opt_nodevmap: 151 v9ses->nodev = 1; 152 break; 153 case Opt_cache_loose: 154 v9ses->cache = CACHE_LOOSE; 155 break; 156 case Opt_fscache: 157 v9ses->cache = CACHE_FSCACHE; 158 break; 159 case Opt_cachetag: 160 #ifdef CONFIG_9P_FSCACHE 161 v9ses->cachetag = match_strdup(&args[0]); 162 #endif 163 break; 164 case Opt_cache: 165 s = match_strdup(&args[0]); 166 if (!s) { 167 ret = -ENOMEM; 168 P9_DPRINTK(P9_DEBUG_ERROR, 169 "problem allocating copy of cache arg\n"); 170 goto free_and_return; 171 } 172 173 if (strcmp(s, "loose") == 0) 174 v9ses->cache = CACHE_LOOSE; 175 else if (strcmp(s, "fscache") == 0) 176 v9ses->cache = CACHE_FSCACHE; 177 else 178 v9ses->cache = CACHE_NONE; 179 kfree(s); 180 break; 181 182 case Opt_access: 183 s = match_strdup(&args[0]); 184 if (!s) { 185 ret = -ENOMEM; 186 P9_DPRINTK(P9_DEBUG_ERROR, 187 "problem allocating copy of access arg\n"); 188 goto free_and_return; 189 } 190 191 v9ses->flags &= ~V9FS_ACCESS_MASK; 192 if (strcmp(s, "user") == 0) 193 v9ses->flags |= V9FS_ACCESS_USER; 194 else if (strcmp(s, "any") == 0) 195 v9ses->flags |= V9FS_ACCESS_ANY; 196 else if (strcmp(s, "client") == 0) { 197 #ifdef CONFIG_9P_FS_POSIX_ACL 198 v9ses->flags |= V9FS_ACCESS_CLIENT; 199 #else 200 P9_DPRINTK(P9_DEBUG_ERROR, 201 "access=client option not supported\n"); 202 kfree(s); 203 ret = -EINVAL; 204 goto free_and_return; 205 #endif 206 } else { 207 v9ses->flags |= V9FS_ACCESS_SINGLE; 208 v9ses->uid = simple_strtoul(s, &e, 10); 209 if (*e != '\0') 210 v9ses->uid = ~0; 211 } 212 kfree(s); 213 break; 214 215 default: 216 continue; 217 } 218 } 219 220 free_and_return: 221 kfree(tmp_options); 222 fail_option_alloc: 223 return ret; 224 } 225 226 /** 227 * v9fs_session_init - initialize session 228 * @v9ses: session information structure 229 * @dev_name: device being mounted 230 * @data: options 231 * 232 */ 233 234 struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses, 235 const char *dev_name, char *data) 236 { 237 int retval = -EINVAL; 238 struct p9_fid *fid; 239 int rc; 240 241 v9ses->uname = __getname(); 242 if (!v9ses->uname) 243 return ERR_PTR(-ENOMEM); 244 245 v9ses->aname = __getname(); 246 if (!v9ses->aname) { 247 __putname(v9ses->uname); 248 return ERR_PTR(-ENOMEM); 249 } 250 init_rwsem(&v9ses->rename_sem); 251 252 rc = bdi_setup_and_register(&v9ses->bdi, "9p", BDI_CAP_MAP_COPY); 253 if (rc) { 254 __putname(v9ses->aname); 255 __putname(v9ses->uname); 256 return ERR_PTR(rc); 257 } 258 259 spin_lock(&v9fs_sessionlist_lock); 260 list_add(&v9ses->slist, &v9fs_sessionlist); 261 spin_unlock(&v9fs_sessionlist_lock); 262 263 v9ses->flags = V9FS_ACCESS_USER; 264 strcpy(v9ses->uname, V9FS_DEFUSER); 265 strcpy(v9ses->aname, V9FS_DEFANAME); 266 v9ses->uid = ~0; 267 v9ses->dfltuid = V9FS_DEFUID; 268 v9ses->dfltgid = V9FS_DEFGID; 269 270 rc = v9fs_parse_options(v9ses, data); 271 if (rc < 0) { 272 retval = rc; 273 goto error; 274 } 275 276 v9ses->clnt = p9_client_create(dev_name, data); 277 if (IS_ERR(v9ses->clnt)) { 278 retval = PTR_ERR(v9ses->clnt); 279 v9ses->clnt = NULL; 280 P9_DPRINTK(P9_DEBUG_ERROR, "problem initializing 9p client\n"); 281 goto error; 282 } 283 284 if (p9_is_proto_dotl(v9ses->clnt)) 285 v9ses->flags |= V9FS_PROTO_2000L; 286 else if (p9_is_proto_dotu(v9ses->clnt)) 287 v9ses->flags |= V9FS_PROTO_2000U; 288 289 v9ses->maxdata = v9ses->clnt->msize - P9_IOHDRSZ; 290 291 if (!v9fs_proto_dotl(v9ses) && 292 ((v9ses->flags & V9FS_ACCESS_MASK) == V9FS_ACCESS_CLIENT)) { 293 /* 294 * We support ACCESS_CLIENT only for dotl. 295 * Fall back to ACCESS_USER 296 */ 297 v9ses->flags &= ~V9FS_ACCESS_MASK; 298 v9ses->flags |= V9FS_ACCESS_USER; 299 } 300 /*FIXME !! */ 301 /* for legacy mode, fall back to V9FS_ACCESS_ANY */ 302 if (!(v9fs_proto_dotu(v9ses) || v9fs_proto_dotl(v9ses)) && 303 ((v9ses->flags&V9FS_ACCESS_MASK) == V9FS_ACCESS_USER)) { 304 305 v9ses->flags &= ~V9FS_ACCESS_MASK; 306 v9ses->flags |= V9FS_ACCESS_ANY; 307 v9ses->uid = ~0; 308 } 309 310 fid = p9_client_attach(v9ses->clnt, NULL, v9ses->uname, ~0, 311 v9ses->aname); 312 if (IS_ERR(fid)) { 313 retval = PTR_ERR(fid); 314 fid = NULL; 315 P9_DPRINTK(P9_DEBUG_ERROR, "cannot attach\n"); 316 goto error; 317 } 318 319 if ((v9ses->flags & V9FS_ACCESS_MASK) == V9FS_ACCESS_SINGLE) 320 fid->uid = v9ses->uid; 321 else 322 fid->uid = ~0; 323 324 #ifdef CONFIG_9P_FSCACHE 325 /* register the session for caching */ 326 v9fs_cache_session_get_cookie(v9ses); 327 #endif 328 329 return fid; 330 331 error: 332 bdi_destroy(&v9ses->bdi); 333 return ERR_PTR(retval); 334 } 335 336 /** 337 * v9fs_session_close - shutdown a session 338 * @v9ses: session information structure 339 * 340 */ 341 342 void v9fs_session_close(struct v9fs_session_info *v9ses) 343 { 344 if (v9ses->clnt) { 345 p9_client_destroy(v9ses->clnt); 346 v9ses->clnt = NULL; 347 } 348 349 #ifdef CONFIG_9P_FSCACHE 350 if (v9ses->fscache) { 351 v9fs_cache_session_put_cookie(v9ses); 352 kfree(v9ses->cachetag); 353 } 354 #endif 355 __putname(v9ses->uname); 356 __putname(v9ses->aname); 357 358 bdi_destroy(&v9ses->bdi); 359 360 spin_lock(&v9fs_sessionlist_lock); 361 list_del(&v9ses->slist); 362 spin_unlock(&v9fs_sessionlist_lock); 363 } 364 365 /** 366 * v9fs_session_cancel - terminate a session 367 * @v9ses: session to terminate 368 * 369 * mark transport as disconnected and cancel all pending requests. 370 */ 371 372 void v9fs_session_cancel(struct v9fs_session_info *v9ses) { 373 P9_DPRINTK(P9_DEBUG_ERROR, "cancel session %p\n", v9ses); 374 p9_client_disconnect(v9ses->clnt); 375 } 376 377 /** 378 * v9fs_session_begin_cancel - Begin terminate of a session 379 * @v9ses: session to terminate 380 * 381 * After this call we don't allow any request other than clunk. 382 */ 383 384 void v9fs_session_begin_cancel(struct v9fs_session_info *v9ses) 385 { 386 P9_DPRINTK(P9_DEBUG_ERROR, "begin cancel session %p\n", v9ses); 387 p9_client_begin_disconnect(v9ses->clnt); 388 } 389 390 extern int v9fs_error_init(void); 391 392 static struct kobject *v9fs_kobj; 393 394 #ifdef CONFIG_9P_FSCACHE 395 /** 396 * caches_show - list caches associated with a session 397 * 398 * Returns the size of buffer written. 399 */ 400 401 static ssize_t caches_show(struct kobject *kobj, 402 struct kobj_attribute *attr, 403 char *buf) 404 { 405 ssize_t n = 0, count = 0, limit = PAGE_SIZE; 406 struct v9fs_session_info *v9ses; 407 408 spin_lock(&v9fs_sessionlist_lock); 409 list_for_each_entry(v9ses, &v9fs_sessionlist, slist) { 410 if (v9ses->cachetag) { 411 n = snprintf(buf, limit, "%s\n", v9ses->cachetag); 412 if (n < 0) { 413 count = n; 414 break; 415 } 416 417 count += n; 418 limit -= n; 419 } 420 } 421 422 spin_unlock(&v9fs_sessionlist_lock); 423 return count; 424 } 425 426 static struct kobj_attribute v9fs_attr_cache = __ATTR_RO(caches); 427 #endif /* CONFIG_9P_FSCACHE */ 428 429 static struct attribute *v9fs_attrs[] = { 430 #ifdef CONFIG_9P_FSCACHE 431 &v9fs_attr_cache.attr, 432 #endif 433 NULL, 434 }; 435 436 static struct attribute_group v9fs_attr_group = { 437 .attrs = v9fs_attrs, 438 }; 439 440 /** 441 * v9fs_sysfs_init - Initialize the v9fs sysfs interface 442 * 443 */ 444 445 static int v9fs_sysfs_init(void) 446 { 447 v9fs_kobj = kobject_create_and_add("9p", fs_kobj); 448 if (!v9fs_kobj) 449 return -ENOMEM; 450 451 if (sysfs_create_group(v9fs_kobj, &v9fs_attr_group)) { 452 kobject_put(v9fs_kobj); 453 return -ENOMEM; 454 } 455 456 return 0; 457 } 458 459 /** 460 * v9fs_sysfs_cleanup - Unregister the v9fs sysfs interface 461 * 462 */ 463 464 static void v9fs_sysfs_cleanup(void) 465 { 466 sysfs_remove_group(v9fs_kobj, &v9fs_attr_group); 467 kobject_put(v9fs_kobj); 468 } 469 470 /** 471 * init_v9fs - Initialize module 472 * 473 */ 474 475 static int __init init_v9fs(void) 476 { 477 int err; 478 printk(KERN_INFO "Installing v9fs 9p2000 file system support\n"); 479 /* TODO: Setup list of registered trasnport modules */ 480 err = register_filesystem(&v9fs_fs_type); 481 if (err < 0) { 482 printk(KERN_ERR "Failed to register filesystem\n"); 483 return err; 484 } 485 486 err = v9fs_cache_register(); 487 if (err < 0) { 488 printk(KERN_ERR "Failed to register v9fs for caching\n"); 489 goto out_fs_unreg; 490 } 491 492 err = v9fs_sysfs_init(); 493 if (err < 0) { 494 printk(KERN_ERR "Failed to register with sysfs\n"); 495 goto out_sysfs_cleanup; 496 } 497 498 return 0; 499 500 out_sysfs_cleanup: 501 v9fs_sysfs_cleanup(); 502 503 out_fs_unreg: 504 unregister_filesystem(&v9fs_fs_type); 505 506 return err; 507 } 508 509 /** 510 * exit_v9fs - shutdown module 511 * 512 */ 513 514 static void __exit exit_v9fs(void) 515 { 516 v9fs_sysfs_cleanup(); 517 v9fs_cache_unregister(); 518 unregister_filesystem(&v9fs_fs_type); 519 } 520 521 module_init(init_v9fs) 522 module_exit(exit_v9fs) 523 524 MODULE_AUTHOR("Latchesar Ionkov <lucho@ionkov.net>"); 525 MODULE_AUTHOR("Eric Van Hensbergen <ericvh@gmail.com>"); 526 MODULE_AUTHOR("Ron Minnich <rminnich@lanl.gov>"); 527 MODULE_LICENSE("GPL"); 528