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