udf: Move filling of partition descriptor info into a separate function
[linux-2.6] / fs / 9p / v9fs.c
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 <net/9p/9p.h>
33 #include <net/9p/transport.h>
34 #include <net/9p/client.h>
35 #include "v9fs.h"
36 #include "v9fs_vfs.h"
37
38 /*
39   * Option Parsing (code inspired by NFS code)
40   *  NOTE: each transport will parse its own options
41   */
42
43 enum {
44         /* Options that take integer arguments */
45         Opt_debug, Opt_dfltuid, Opt_dfltgid, Opt_afid,
46         /* String options */
47         Opt_uname, Opt_remotename, Opt_trans,
48         /* Options that take no arguments */
49         Opt_nodevmap,
50         /* Cache options */
51         Opt_cache_loose,
52         /* Access options */
53         Opt_access,
54         /* Error token */
55         Opt_err
56 };
57
58 static match_table_t tokens = {
59         {Opt_debug, "debug=%x"},
60         {Opt_dfltuid, "dfltuid=%u"},
61         {Opt_dfltgid, "dfltgid=%u"},
62         {Opt_afid, "afid=%u"},
63         {Opt_uname, "uname=%s"},
64         {Opt_remotename, "aname=%s"},
65         {Opt_nodevmap, "nodevmap"},
66         {Opt_cache_loose, "cache=loose"},
67         {Opt_cache_loose, "loose"},
68         {Opt_access, "access=%s"},
69         {Opt_err, NULL}
70 };
71
72 /**
73  * v9fs_parse_options - parse mount options into session structure
74  * @options: options string passed from mount
75  * @v9ses: existing v9fs session information
76  *
77  */
78
79 static void v9fs_parse_options(struct v9fs_session_info *v9ses)
80 {
81         char *options;
82         substring_t args[MAX_OPT_ARGS];
83         char *p;
84         int option = 0;
85         char *s, *e;
86         int ret;
87
88         /* setup defaults */
89         v9ses->afid = ~0;
90         v9ses->debug = 0;
91         v9ses->cache = 0;
92
93         if (!v9ses->options)
94                 return;
95
96         options = kstrdup(v9ses->options, GFP_KERNEL);
97         while ((p = strsep(&options, ",")) != NULL) {
98                 int token;
99                 if (!*p)
100                         continue;
101                 token = match_token(p, tokens, args);
102                 if (token < Opt_uname) {
103                         ret = match_int(&args[0], &option);
104                         if (ret < 0) {
105                                 P9_DPRINTK(P9_DEBUG_ERROR,
106                                         "integer field, but no integer?\n");
107                                 continue;
108                         }
109                 }
110                 switch (token) {
111                 case Opt_debug:
112                         v9ses->debug = option;
113 #ifdef CONFIG_NET_9P_DEBUG
114                         p9_debug_level = option;
115 #endif
116                         break;
117
118                 case Opt_dfltuid:
119                         v9ses->dfltuid = option;
120                         break;
121                 case Opt_dfltgid:
122                         v9ses->dfltgid = option;
123                         break;
124                 case Opt_afid:
125                         v9ses->afid = option;
126                         break;
127                 case Opt_uname:
128                         match_strcpy(v9ses->uname, &args[0]);
129                         break;
130                 case Opt_remotename:
131                         match_strcpy(v9ses->aname, &args[0]);
132                         break;
133                 case Opt_nodevmap:
134                         v9ses->nodev = 1;
135                         break;
136                 case Opt_cache_loose:
137                         v9ses->cache = CACHE_LOOSE;
138                         break;
139
140                 case Opt_access:
141                         s = match_strdup(&args[0]);
142                         v9ses->flags &= ~V9FS_ACCESS_MASK;
143                         if (strcmp(s, "user") == 0)
144                                 v9ses->flags |= V9FS_ACCESS_USER;
145                         else if (strcmp(s, "any") == 0)
146                                 v9ses->flags |= V9FS_ACCESS_ANY;
147                         else {
148                                 v9ses->flags |= V9FS_ACCESS_SINGLE;
149                                 v9ses->uid = simple_strtol(s, &e, 10);
150                                 if (*e != '\0')
151                                         v9ses->uid = ~0;
152                         }
153                         kfree(s);
154                         break;
155
156                 default:
157                         continue;
158                 }
159         }
160         kfree(options);
161 }
162
163 /**
164  * v9fs_session_init - initialize session
165  * @v9ses: session information structure
166  * @dev_name: device being mounted
167  * @data: options
168  *
169  */
170
171 struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
172                   const char *dev_name, char *data)
173 {
174         int retval = -EINVAL;
175         struct p9_fid *fid;
176
177         v9ses->uname = __getname();
178         if (!v9ses->uname)
179                 return ERR_PTR(-ENOMEM);
180
181         v9ses->aname = __getname();
182         if (!v9ses->aname) {
183                 __putname(v9ses->uname);
184                 return ERR_PTR(-ENOMEM);
185         }
186
187         v9ses->flags = V9FS_EXTENDED | V9FS_ACCESS_USER;
188         strcpy(v9ses->uname, V9FS_DEFUSER);
189         strcpy(v9ses->aname, V9FS_DEFANAME);
190         v9ses->uid = ~0;
191         v9ses->dfltuid = V9FS_DEFUID;
192         v9ses->dfltgid = V9FS_DEFGID;
193         v9ses->options = kstrdup(data, GFP_KERNEL);
194         v9fs_parse_options(v9ses);
195
196         v9ses->clnt = p9_client_create(dev_name, v9ses->options);
197
198         if (IS_ERR(v9ses->clnt)) {
199                 retval = PTR_ERR(v9ses->clnt);
200                 v9ses->clnt = NULL;
201                 P9_DPRINTK(P9_DEBUG_ERROR, "problem initializing 9p client\n");
202                 goto error;
203         }
204
205         if (!v9ses->clnt->dotu)
206                 v9ses->flags &= ~V9FS_EXTENDED;
207
208         v9ses->maxdata = v9ses->clnt->msize;
209
210         /* for legacy mode, fall back to V9FS_ACCESS_ANY */
211         if (!v9fs_extended(v9ses) &&
212                 ((v9ses->flags&V9FS_ACCESS_MASK) == V9FS_ACCESS_USER)) {
213
214                 v9ses->flags &= ~V9FS_ACCESS_MASK;
215                 v9ses->flags |= V9FS_ACCESS_ANY;
216                 v9ses->uid = ~0;
217         }
218
219         fid = p9_client_attach(v9ses->clnt, NULL, v9ses->uname, ~0,
220                                                         v9ses->aname);
221         if (IS_ERR(fid)) {
222                 retval = PTR_ERR(fid);
223                 fid = NULL;
224                 P9_DPRINTK(P9_DEBUG_ERROR, "cannot attach\n");
225                 goto error;
226         }
227
228         if ((v9ses->flags & V9FS_ACCESS_MASK) == V9FS_ACCESS_SINGLE)
229                 fid->uid = v9ses->uid;
230         else
231                 fid->uid = ~0;
232
233         return fid;
234
235 error:
236         v9fs_session_close(v9ses);
237         return ERR_PTR(retval);
238 }
239
240 /**
241  * v9fs_session_close - shutdown a session
242  * @v9ses: session information structure
243  *
244  */
245
246 void v9fs_session_close(struct v9fs_session_info *v9ses)
247 {
248         if (v9ses->clnt) {
249                 p9_client_destroy(v9ses->clnt);
250                 v9ses->clnt = NULL;
251         }
252
253         __putname(v9ses->uname);
254         __putname(v9ses->aname);
255         kfree(v9ses->options);
256 }
257
258 /**
259  * v9fs_session_cancel - mark transport as disconnected
260  *      and cancel all pending requests.
261  */
262 void v9fs_session_cancel(struct v9fs_session_info *v9ses) {
263         P9_DPRINTK(P9_DEBUG_ERROR, "cancel session %p\n", v9ses);
264         p9_client_disconnect(v9ses->clnt);
265 }
266
267 extern int v9fs_error_init(void);
268
269 /**
270  * v9fs_init - Initialize module
271  *
272  */
273
274 static int __init init_v9fs(void)
275 {
276         printk(KERN_INFO "Installing v9fs 9p2000 file system support\n");
277         /* TODO: Setup list of registered trasnport modules */
278         return register_filesystem(&v9fs_fs_type);
279 }
280
281 /**
282  * v9fs_init - shutdown module
283  *
284  */
285
286 static void __exit exit_v9fs(void)
287 {
288         unregister_filesystem(&v9fs_fs_type);
289 }
290
291 module_init(init_v9fs)
292 module_exit(exit_v9fs)
293
294 MODULE_AUTHOR("Latchesar Ionkov <lucho@ionkov.net>");
295 MODULE_AUTHOR("Eric Van Hensbergen <ericvh@gmail.com>");
296 MODULE_AUTHOR("Ron Minnich <rminnich@lanl.gov>");
297 MODULE_LICENSE("GPL");