vfs: remove extraneous NULL d_inode check from do_filp_open
[linux-2.6-block.git] / fs / 9p / v9fs.c
CommitLineData
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1/*
2 * linux/fs/9p/v9fs.c
3 *
4 * This file contains functions assisting in mapping VFS to 9P2000
5 *
8a0dc95f 6 * Copyright (C) 2004-2008 by Eric Van Hensbergen <ericvh@gmail.com>
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7 * Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
8 *
9 * This program is free software; you can redistribute it and/or modify
42e8c509
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10 * it under the terms of the GNU General Public License version 2
11 * as published by the Free Software Foundation.
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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
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26#include <linux/module.h>
27#include <linux/errno.h>
28#include <linux/fs.h>
914e2637 29#include <linux/sched.h>
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30#include <linux/parser.h>
31#include <linux/idr.h>
bd238fb4 32#include <net/9p/9p.h>
bd238fb4 33#include <net/9p/client.h>
8b81ef58 34#include <net/9p/transport.h>
9e82cf6a 35#include "v9fs.h"
9e82cf6a 36#include "v9fs_vfs.h"
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37#include "cache.h"
38
39static DEFINE_SPINLOCK(v9fs_sessionlist_lock);
40static LIST_HEAD(v9fs_sessionlist);
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41
42/*
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43 * Option Parsing (code inspired by NFS code)
44 * NOTE: each transport will parse its own options
45 */
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46
47enum {
48 /* Options that take integer arguments */
8a0dc95f 49 Opt_debug, Opt_dfltuid, Opt_dfltgid, Opt_afid,
9e82cf6a 50 /* String options */
60e78d2c 51 Opt_uname, Opt_remotename, Opt_trans, Opt_cache, Opt_cachetag,
9e82cf6a 52 /* Options that take no arguments */
8a0dc95f 53 Opt_nodevmap,
e03abc0c 54 /* Cache options */
60e78d2c 55 Opt_cache_loose, Opt_fscache,
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56 /* Access options */
57 Opt_access,
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58 /* Error token */
59 Opt_err
60};
61
a447c093 62static const match_table_t tokens = {
9e2f6688 63 {Opt_debug, "debug=%x"},
bd32b82d
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64 {Opt_dfltuid, "dfltuid=%u"},
65 {Opt_dfltgid, "dfltgid=%u"},
9e82cf6a 66 {Opt_afid, "afid=%u"},
67543e50 67 {Opt_uname, "uname=%s"},
9e82cf6a 68 {Opt_remotename, "aname=%s"},
9e82cf6a 69 {Opt_nodevmap, "nodevmap"},
60e78d2c 70 {Opt_cache, "cache=%s"},
e03abc0c 71 {Opt_cache_loose, "loose"},
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72 {Opt_fscache, "fscache"},
73 {Opt_cachetag, "cachetag=%s"},
ba17674f 74 {Opt_access, "access=%s"},
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75 {Opt_err, NULL}
76};
77
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78/**
79 * v9fs_parse_options - parse mount options into session structure
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80 * @v9ses: existing v9fs session information
81 *
ab31267d 82 * Return 0 upon success, -ERRNO upon failure.
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83 */
84
4b53e4b5 85static int v9fs_parse_options(struct v9fs_session_info *v9ses, char *opts)
9e82cf6a 86{
8999e04f 87 char *options;
9e82cf6a 88 substring_t args[MAX_OPT_ARGS];
a80d923e 89 char *p;
8a0dc95f 90 int option = 0;
ba17674f 91 char *s, *e;
ab31267d 92 int ret = 0;
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93
94 /* setup defaults */
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95 v9ses->afid = ~0;
96 v9ses->debug = 0;
e03abc0c 97 v9ses->cache = 0;
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98#ifdef CONFIG_9P_FSCACHE
99 v9ses->cachetag = NULL;
100#endif
9e82cf6a 101
4b53e4b5 102 if (!opts)
ab31267d 103 return 0;
9e82cf6a 104
4b53e4b5 105 options = kstrdup(opts, GFP_KERNEL);
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106 if (!options)
107 goto fail_option_alloc;
ab31267d 108
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109 while ((p = strsep(&options, ",")) != NULL) {
110 int token;
111 if (!*p)
112 continue;
113 token = match_token(p, tokens, args);
67543e50 114 if (token < Opt_uname) {
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115 int r = match_int(&args[0], &option);
116 if (r < 0) {
bd238fb4 117 P9_DPRINTK(P9_DEBUG_ERROR,
9e82cf6a 118 "integer field, but no integer?\n");
ab31267d 119 ret = r;
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120 continue;
121 }
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122 }
123 switch (token) {
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124 case Opt_debug:
125 v9ses->debug = option;
10fa16e7 126#ifdef CONFIG_NET_9P_DEBUG
9e2f6688 127 p9_debug_level = option;
10fa16e7 128#endif
9e2f6688 129 break;
8a0dc95f 130
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131 case Opt_dfltuid:
132 v9ses->dfltuid = option;
9e82cf6a 133 break;
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134 case Opt_dfltgid:
135 v9ses->dfltgid = option;
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136 break;
137 case Opt_afid:
138 v9ses->afid = option;
139 break;
67543e50 140 case Opt_uname:
b32a09db 141 match_strlcpy(v9ses->uname, &args[0], PATH_MAX);
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142 break;
143 case Opt_remotename:
b32a09db 144 match_strlcpy(v9ses->aname, &args[0], PATH_MAX);
9e82cf6a 145 break;
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146 case Opt_nodevmap:
147 v9ses->nodev = 1;
148 break;
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149 case Opt_cache_loose:
150 v9ses->cache = CACHE_LOOSE;
151 break;
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152 case Opt_fscache:
153 v9ses->cache = CACHE_FSCACHE;
154 break;
155 case Opt_cachetag:
156#ifdef CONFIG_9P_FSCACHE
157 v9ses->cachetag = match_strdup(&args[0]);
158#endif
159 break;
160 case Opt_cache:
161 s = match_strdup(&args[0]);
162 if (!s)
163 goto fail_option_alloc;
164
165 if (strcmp(s, "loose") == 0)
166 v9ses->cache = CACHE_LOOSE;
167 else if (strcmp(s, "fscache") == 0)
168 v9ses->cache = CACHE_FSCACHE;
169 else
170 v9ses->cache = CACHE_NONE;
171 kfree(s);
172 break;
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173
174 case Opt_access:
175 s = match_strdup(&args[0]);
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176 if (!s)
177 goto fail_option_alloc;
178
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179 v9ses->flags &= ~V9FS_ACCESS_MASK;
180 if (strcmp(s, "user") == 0)
181 v9ses->flags |= V9FS_ACCESS_USER;
182 else if (strcmp(s, "any") == 0)
183 v9ses->flags |= V9FS_ACCESS_ANY;
184 else {
185 v9ses->flags |= V9FS_ACCESS_SINGLE;
f1d9e458 186 v9ses->uid = simple_strtoul(s, &e, 10);
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187 if (*e != '\0')
188 v9ses->uid = ~0;
189 }
0a976297 190 kfree(s);
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191 break;
192
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193 default:
194 continue;
195 }
196 }
8999e04f 197 kfree(options);
ab31267d 198 return ret;
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199
200fail_option_alloc:
201 P9_DPRINTK(P9_DEBUG_ERROR,
202 "failed to allocate copy of option argument\n");
203 return -ENOMEM;
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204}
205
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206/**
207 * v9fs_session_init - initialize session
208 * @v9ses: session information structure
209 * @dev_name: device being mounted
210 * @data: options
211 *
212 */
213
bd238fb4 214struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
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215 const char *dev_name, char *data)
216{
9e82cf6a 217 int retval = -EINVAL;
bd238fb4 218 struct p9_fid *fid;
ab31267d 219 int rc;
9e82cf6a 220
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221 v9ses->uname = __getname();
222 if (!v9ses->uname)
bd238fb4 223 return ERR_PTR(-ENOMEM);
9e82cf6a 224
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225 v9ses->aname = __getname();
226 if (!v9ses->aname) {
227 __putname(v9ses->uname);
bd238fb4 228 return ERR_PTR(-ENOMEM);
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229 }
230
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231 spin_lock(&v9fs_sessionlist_lock);
232 list_add(&v9ses->slist, &v9fs_sessionlist);
233 spin_unlock(&v9fs_sessionlist_lock);
234
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235 v9ses->flags = V9FS_EXTENDED | V9FS_ACCESS_USER;
236 strcpy(v9ses->uname, V9FS_DEFUSER);
237 strcpy(v9ses->aname, V9FS_DEFANAME);
238 v9ses->uid = ~0;
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239 v9ses->dfltuid = V9FS_DEFUID;
240 v9ses->dfltgid = V9FS_DEFGID;
ab31267d 241
4b53e4b5 242 rc = v9fs_parse_options(v9ses, data);
ab31267d
JM
243 if (rc < 0) {
244 retval = rc;
245 goto error;
246 }
a80d923e 247
4b53e4b5 248 v9ses->clnt = p9_client_create(dev_name, data);
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LI
249 if (IS_ERR(v9ses->clnt)) {
250 retval = PTR_ERR(v9ses->clnt);
251 v9ses->clnt = NULL;
252 P9_DPRINTK(P9_DEBUG_ERROR, "problem initializing 9p client\n");
253 goto error;
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254 }
255
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256 if (!v9ses->clnt->dotu)
257 v9ses->flags &= ~V9FS_EXTENDED;
258
fbedadc1 259 v9ses->maxdata = v9ses->clnt->msize - P9_IOHDRSZ;
8a0dc95f 260
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261 /* for legacy mode, fall back to V9FS_ACCESS_ANY */
262 if (!v9fs_extended(v9ses) &&
263 ((v9ses->flags&V9FS_ACCESS_MASK) == V9FS_ACCESS_USER)) {
264
265 v9ses->flags &= ~V9FS_ACCESS_MASK;
266 v9ses->flags |= V9FS_ACCESS_ANY;
267 v9ses->uid = ~0;
268 }
269
270 fid = p9_client_attach(v9ses->clnt, NULL, v9ses->uname, ~0,
271 v9ses->aname);
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272 if (IS_ERR(fid)) {
273 retval = PTR_ERR(fid);
274 fid = NULL;
275 P9_DPRINTK(P9_DEBUG_ERROR, "cannot attach\n");
276 goto error;
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277 }
278
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279 if ((v9ses->flags & V9FS_ACCESS_MASK) == V9FS_ACCESS_SINGLE)
280 fid->uid = v9ses->uid;
281 else
282 fid->uid = ~0;
283
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284#ifdef CONFIG_9P_FSCACHE
285 /* register the session for caching */
286 v9fs_cache_session_get_cookie(v9ses);
287#endif
288
bd238fb4 289 return fid;
9e82cf6a 290
bd238fb4 291error:
bd238fb4 292 return ERR_PTR(retval);
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293}
294
295/**
296 * v9fs_session_close - shutdown a session
297 * @v9ses: session information structure
298 *
299 */
300
301void v9fs_session_close(struct v9fs_session_info *v9ses)
302{
bd238fb4
LI
303 if (v9ses->clnt) {
304 p9_client_destroy(v9ses->clnt);
305 v9ses->clnt = NULL;
3cf6429a 306 }
9e82cf6a 307
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308#ifdef CONFIG_9P_FSCACHE
309 if (v9ses->fscache) {
310 v9fs_cache_session_put_cookie(v9ses);
311 kfree(v9ses->cachetag);
312 }
313#endif
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314 __putname(v9ses->uname);
315 __putname(v9ses->aname);
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316
317 spin_lock(&v9fs_sessionlist_lock);
318 list_del(&v9ses->slist);
319 spin_unlock(&v9fs_sessionlist_lock);
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320}
321
322b329a 322/**
ee443996
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323 * v9fs_session_cancel - terminate a session
324 * @v9ses: session to terminate
325 *
326 * mark transport as disconnected and cancel all pending requests.
322b329a 327 */
ee443996 328
322b329a 329void v9fs_session_cancel(struct v9fs_session_info *v9ses) {
bd238fb4
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330 P9_DPRINTK(P9_DEBUG_ERROR, "cancel session %p\n", v9ses);
331 p9_client_disconnect(v9ses->clnt);
322b329a
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332}
333
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334extern int v9fs_error_init(void);
335
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336static struct kobject *v9fs_kobj;
337
338#ifdef CONFIG_9P_FSCACHE
9e82cf6a 339/**
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340 * caches_show - list caches associated with a session
341 *
342 * Returns the size of buffer written.
343 */
344
345static ssize_t caches_show(struct kobject *kobj,
346 struct kobj_attribute *attr,
347 char *buf)
348{
349 ssize_t n = 0, count = 0, limit = PAGE_SIZE;
350 struct v9fs_session_info *v9ses;
351
352 spin_lock(&v9fs_sessionlist_lock);
353 list_for_each_entry(v9ses, &v9fs_sessionlist, slist) {
354 if (v9ses->cachetag) {
355 n = snprintf(buf, limit, "%s\n", v9ses->cachetag);
356 if (n < 0) {
357 count = n;
358 break;
359 }
360
361 count += n;
362 limit -= n;
363 }
364 }
365
366 spin_unlock(&v9fs_sessionlist_lock);
367 return count;
368}
369
370static struct kobj_attribute v9fs_attr_cache = __ATTR_RO(caches);
371#endif /* CONFIG_9P_FSCACHE */
372
373static struct attribute *v9fs_attrs[] = {
374#ifdef CONFIG_9P_FSCACHE
375 &v9fs_attr_cache.attr,
376#endif
377 NULL,
378};
379
380static struct attribute_group v9fs_attr_group = {
381 .attrs = v9fs_attrs,
382};
383
384/**
385 * v9fs_sysfs_init - Initialize the v9fs sysfs interface
386 *
387 */
388
389static int v9fs_sysfs_init(void)
390{
391 v9fs_kobj = kobject_create_and_add("9p", fs_kobj);
392 if (!v9fs_kobj)
393 return -ENOMEM;
394
395 if (sysfs_create_group(v9fs_kobj, &v9fs_attr_group)) {
396 kobject_put(v9fs_kobj);
397 return -ENOMEM;
398 }
399
400 return 0;
401}
402
403/**
404 * v9fs_sysfs_cleanup - Unregister the v9fs sysfs interface
405 *
406 */
407
408static void v9fs_sysfs_cleanup(void)
409{
410 sysfs_remove_group(v9fs_kobj, &v9fs_attr_group);
411 kobject_put(v9fs_kobj);
412}
413
414/**
415 * init_v9fs - Initialize module
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EVH
416 *
417 */
418
419static int __init init_v9fs(void)
420{
60e78d2c 421 int err;
f94b3470 422 printk(KERN_INFO "Installing v9fs 9p2000 file system support\n");
a80d923e 423 /* TODO: Setup list of registered trasnport modules */
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424 err = register_filesystem(&v9fs_fs_type);
425 if (err < 0) {
426 printk(KERN_ERR "Failed to register filesystem\n");
427 return err;
428 }
429
430 err = v9fs_cache_register();
431 if (err < 0) {
432 printk(KERN_ERR "Failed to register v9fs for caching\n");
433 goto out_fs_unreg;
434 }
435
436 err = v9fs_sysfs_init();
437 if (err < 0) {
438 printk(KERN_ERR "Failed to register with sysfs\n");
439 goto out_sysfs_cleanup;
440 }
441
442 return 0;
443
444out_sysfs_cleanup:
445 v9fs_sysfs_cleanup();
446
447out_fs_unreg:
448 unregister_filesystem(&v9fs_fs_type);
449
450 return err;
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451}
452
453/**
60e78d2c 454 * exit_v9fs - shutdown module
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455 *
456 */
457
458static void __exit exit_v9fs(void)
459{
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460 v9fs_sysfs_cleanup();
461 v9fs_cache_unregister();
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462 unregister_filesystem(&v9fs_fs_type);
463}
464
465module_init(init_v9fs)
466module_exit(exit_v9fs)
467
bd238fb4 468MODULE_AUTHOR("Latchesar Ionkov <lucho@ionkov.net>");
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469MODULE_AUTHOR("Eric Van Hensbergen <ericvh@gmail.com>");
470MODULE_AUTHOR("Ron Minnich <rminnich@lanl.gov>");
471MODULE_LICENSE("GPL");