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 { 197 v9ses->flags |= V9FS_ACCESS_SINGLE; 198 v9ses->uid = simple_strtoul(s, &e, 10); 199 if (*e != '\0') 200 v9ses->uid = ~0; 201 } 202 kfree(s); 203 break; 204 205 default: 206 continue; 207 } 208 } 209 210 free_and_return: 211 kfree(tmp_options); 212 fail_option_alloc: 213 return ret; 214 } 215 216 /** 217 * v9fs_session_init - initialize session 218 * @v9ses: session information structure 219 * @dev_name: device being mounted 220 * @data: options 221 * 222 */ 223 224 struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses, 225 const char *dev_name, char *data) 226 { 227 int retval = -EINVAL; 228 struct p9_fid *fid; 229 int rc; 230 231 v9ses->uname = __getname(); 232 if (!v9ses->uname) 233 return ERR_PTR(-ENOMEM); 234 235 v9ses->aname = __getname(); 236 if (!v9ses->aname) { 237 __putname(v9ses->uname); 238 return ERR_PTR(-ENOMEM); 239 } 240 init_rwsem(&v9ses->rename_sem); 241 242 rc = bdi_setup_and_register(&v9ses->bdi, "9p", BDI_CAP_MAP_COPY); 243 if (rc) { 244 __putname(v9ses->aname); 245 __putname(v9ses->uname); 246 return ERR_PTR(rc); 247 } 248 249 spin_lock(&v9fs_sessionlist_lock); 250 list_add(&v9ses->slist, &v9fs_sessionlist); 251 spin_unlock(&v9fs_sessionlist_lock); 252 253 v9ses->flags = V9FS_ACCESS_USER; 254 strcpy(v9ses->uname, V9FS_DEFUSER); 255 strcpy(v9ses->aname, V9FS_DEFANAME); 256 v9ses->uid = ~0; 257 v9ses->dfltuid = V9FS_DEFUID; 258 v9ses->dfltgid = V9FS_DEFGID; 259 260 rc = v9fs_parse_options(v9ses, data); 261 if (rc < 0) { 262 retval = rc; 263 goto error; 264 } 265 266 v9ses->clnt = p9_client_create(dev_name, data); 267 if (IS_ERR(v9ses->clnt)) { 268 retval = PTR_ERR(v9ses->clnt); 269 v9ses->clnt = NULL; 270 P9_DPRINTK(P9_DEBUG_ERROR, "problem initializing 9p client\n"); 271 goto error; 272 } 273 274 if (p9_is_proto_dotl(v9ses->clnt)) 275 v9ses->flags |= V9FS_PROTO_2000L; 276 else if (p9_is_proto_dotu(v9ses->clnt)) 277 v9ses->flags |= V9FS_PROTO_2000U; 278 279 v9ses->maxdata = v9ses->clnt->msize - P9_IOHDRSZ; 280 281 /* for legacy mode, fall back to V9FS_ACCESS_ANY */ 282 if (!(v9fs_proto_dotu(v9ses) || v9fs_proto_dotl(v9ses)) && 283 ((v9ses->flags&V9FS_ACCESS_MASK) == V9FS_ACCESS_USER)) { 284 285 v9ses->flags &= ~V9FS_ACCESS_MASK; 286 v9ses->flags |= V9FS_ACCESS_ANY; 287 v9ses->uid = ~0; 288 } 289 290 fid = p9_client_attach(v9ses->clnt, NULL, v9ses->uname, ~0, 291 v9ses->aname); 292 if (IS_ERR(fid)) { 293 retval = PTR_ERR(fid); 294 fid = NULL; 295 P9_DPRINTK(P9_DEBUG_ERROR, "cannot attach\n"); 296 goto error; 297 } 298 299 if ((v9ses->flags & V9FS_ACCESS_MASK) == V9FS_ACCESS_SINGLE) 300 fid->uid = v9ses->uid; 301 else 302 fid->uid = ~0; 303 304 #ifdef CONFIG_9P_FSCACHE 305 /* register the session for caching */ 306 v9fs_cache_session_get_cookie(v9ses); 307 #endif 308 309 return fid; 310 311 error: 312 bdi_destroy(&v9ses->bdi); 313 return ERR_PTR(retval); 314 } 315 316 /** 317 * v9fs_session_close - shutdown a session 318 * @v9ses: session information structure 319 * 320 */ 321 322 void v9fs_session_close(struct v9fs_session_info *v9ses) 323 { 324 if (v9ses->clnt) { 325 p9_client_destroy(v9ses->clnt); 326 v9ses->clnt = NULL; 327 } 328 329 #ifdef CONFIG_9P_FSCACHE 330 if (v9ses->fscache) { 331 v9fs_cache_session_put_cookie(v9ses); 332 kfree(v9ses->cachetag); 333 } 334 #endif 335 __putname(v9ses->uname); 336 __putname(v9ses->aname); 337 338 bdi_destroy(&v9ses->bdi); 339 340 spin_lock(&v9fs_sessionlist_lock); 341 list_del(&v9ses->slist); 342 spin_unlock(&v9fs_sessionlist_lock); 343 } 344 345 /** 346 * v9fs_session_cancel - terminate a session 347 * @v9ses: session to terminate 348 * 349 * mark transport as disconnected and cancel all pending requests. 350 */ 351 352 void v9fs_session_cancel(struct v9fs_session_info *v9ses) { 353 P9_DPRINTK(P9_DEBUG_ERROR, "cancel session %p\n", v9ses); 354 p9_client_disconnect(v9ses->clnt); 355 } 356 357 /** 358 * v9fs_session_begin_cancel - Begin terminate of a session 359 * @v9ses: session to terminate 360 * 361 * After this call we don't allow any request other than clunk. 362 */ 363 364 void v9fs_session_begin_cancel(struct v9fs_session_info *v9ses) 365 { 366 P9_DPRINTK(P9_DEBUG_ERROR, "begin cancel session %p\n", v9ses); 367 p9_client_begin_disconnect(v9ses->clnt); 368 } 369 370 extern int v9fs_error_init(void); 371 372 static struct kobject *v9fs_kobj; 373 374 #ifdef CONFIG_9P_FSCACHE 375 /** 376 * caches_show - list caches associated with a session 377 * 378 * Returns the size of buffer written. 379 */ 380 381 static ssize_t caches_show(struct kobject *kobj, 382 struct kobj_attribute *attr, 383 char *buf) 384 { 385 ssize_t n = 0, count = 0, limit = PAGE_SIZE; 386 struct v9fs_session_info *v9ses; 387 388 spin_lock(&v9fs_sessionlist_lock); 389 list_for_each_entry(v9ses, &v9fs_sessionlist, slist) { 390 if (v9ses->cachetag) { 391 n = snprintf(buf, limit, "%s\n", v9ses->cachetag); 392 if (n < 0) { 393 count = n; 394 break; 395 } 396 397 count += n; 398 limit -= n; 399 } 400 } 401 402 spin_unlock(&v9fs_sessionlist_lock); 403 return count; 404 } 405 406 static struct kobj_attribute v9fs_attr_cache = __ATTR_RO(caches); 407 #endif /* CONFIG_9P_FSCACHE */ 408 409 static struct attribute *v9fs_attrs[] = { 410 #ifdef CONFIG_9P_FSCACHE 411 &v9fs_attr_cache.attr, 412 #endif 413 NULL, 414 }; 415 416 static struct attribute_group v9fs_attr_group = { 417 .attrs = v9fs_attrs, 418 }; 419 420 /** 421 * v9fs_sysfs_init - Initialize the v9fs sysfs interface 422 * 423 */ 424 425 static int v9fs_sysfs_init(void) 426 { 427 v9fs_kobj = kobject_create_and_add("9p", fs_kobj); 428 if (!v9fs_kobj) 429 return -ENOMEM; 430 431 if (sysfs_create_group(v9fs_kobj, &v9fs_attr_group)) { 432 kobject_put(v9fs_kobj); 433 return -ENOMEM; 434 } 435 436 return 0; 437 } 438 439 /** 440 * v9fs_sysfs_cleanup - Unregister the v9fs sysfs interface 441 * 442 */ 443 444 static void v9fs_sysfs_cleanup(void) 445 { 446 sysfs_remove_group(v9fs_kobj, &v9fs_attr_group); 447 kobject_put(v9fs_kobj); 448 } 449 450 /** 451 * init_v9fs - Initialize module 452 * 453 */ 454 455 static int __init init_v9fs(void) 456 { 457 int err; 458 printk(KERN_INFO "Installing v9fs 9p2000 file system support\n"); 459 /* TODO: Setup list of registered trasnport modules */ 460 err = register_filesystem(&v9fs_fs_type); 461 if (err < 0) { 462 printk(KERN_ERR "Failed to register filesystem\n"); 463 return err; 464 } 465 466 err = v9fs_cache_register(); 467 if (err < 0) { 468 printk(KERN_ERR "Failed to register v9fs for caching\n"); 469 goto out_fs_unreg; 470 } 471 472 err = v9fs_sysfs_init(); 473 if (err < 0) { 474 printk(KERN_ERR "Failed to register with sysfs\n"); 475 goto out_sysfs_cleanup; 476 } 477 478 return 0; 479 480 out_sysfs_cleanup: 481 v9fs_sysfs_cleanup(); 482 483 out_fs_unreg: 484 unregister_filesystem(&v9fs_fs_type); 485 486 return err; 487 } 488 489 /** 490 * exit_v9fs - shutdown module 491 * 492 */ 493 494 static void __exit exit_v9fs(void) 495 { 496 v9fs_sysfs_cleanup(); 497 v9fs_cache_unregister(); 498 unregister_filesystem(&v9fs_fs_type); 499 } 500 501 module_init(init_v9fs) 502 module_exit(exit_v9fs) 503 504 MODULE_AUTHOR("Latchesar Ionkov <lucho@ionkov.net>"); 505 MODULE_AUTHOR("Eric Van Hensbergen <ericvh@gmail.com>"); 506 MODULE_AUTHOR("Ron Minnich <rminnich@lanl.gov>"); 507 MODULE_LICENSE("GPL"); 508