xref: /openbmc/linux/fs/9p/v9fs.c (revision c21b37f6)
1 /*
2  *  linux/fs/9p/v9fs.c
3  *
4  *  This file contains functions assisting in mapping VFS to 9P2000
5  *
6  *  Copyright (C) 2004 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/conn.h>
35 #include <net/9p/client.h>
36 #include "v9fs.h"
37 #include "v9fs_vfs.h"
38 
39 /*
40   * Option Parsing (code inspired by NFS code)
41   *
42   */
43 
44 enum {
45 	/* Options that take integer arguments */
46 	Opt_debug, Opt_port, Opt_msize, Opt_uid, Opt_gid, Opt_afid,
47 	Opt_rfdno, Opt_wfdno,
48 	/* String options */
49 	Opt_uname, Opt_remotename,
50 	/* Options that take no arguments */
51 	Opt_legacy, Opt_nodevmap, Opt_unix, Opt_tcp, Opt_fd, Opt_pci,
52 	/* Cache options */
53 	Opt_cache_loose,
54 	/* Error token */
55 	Opt_err
56 };
57 
58 static match_table_t tokens = {
59 	{Opt_debug, "debug=%x"},
60 	{Opt_port, "port=%u"},
61 	{Opt_msize, "msize=%u"},
62 	{Opt_uid, "uid=%u"},
63 	{Opt_gid, "gid=%u"},
64 	{Opt_afid, "afid=%u"},
65 	{Opt_rfdno, "rfdno=%u"},
66 	{Opt_wfdno, "wfdno=%u"},
67 	{Opt_uname, "uname=%s"},
68 	{Opt_remotename, "aname=%s"},
69 	{Opt_unix, "proto=unix"},
70 	{Opt_tcp, "proto=tcp"},
71 	{Opt_fd, "proto=fd"},
72 #ifdef CONFIG_PCI_9P
73 	{Opt_pci, "proto=pci"},
74 #endif
75 	{Opt_tcp, "tcp"},
76 	{Opt_unix, "unix"},
77 	{Opt_fd, "fd"},
78 	{Opt_legacy, "noextend"},
79 	{Opt_nodevmap, "nodevmap"},
80 	{Opt_cache_loose, "cache=loose"},
81 	{Opt_cache_loose, "loose"},
82 	{Opt_err, NULL}
83 };
84 
85 extern struct p9_transport *p9pci_trans_create(void);
86 
87 /*
88  *  Parse option string.
89  */
90 
91 /**
92  * v9fs_parse_options - parse mount options into session structure
93  * @options: options string passed from mount
94  * @v9ses: existing v9fs session information
95  *
96  */
97 
98 static void v9fs_parse_options(char *options, struct v9fs_session_info *v9ses)
99 {
100 	char *p;
101 	substring_t args[MAX_OPT_ARGS];
102 	int option;
103 	int ret;
104 
105 	/* setup defaults */
106 	v9ses->port = V9FS_PORT;
107 	v9ses->maxdata = 9000;
108 	v9ses->proto = PROTO_TCP;
109 	v9ses->extended = 1;
110 	v9ses->afid = ~0;
111 	v9ses->debug = 0;
112 	v9ses->rfdno = ~0;
113 	v9ses->wfdno = ~0;
114 	v9ses->cache = 0;
115 
116 	if (!options)
117 		return;
118 
119 	while ((p = strsep(&options, ",")) != NULL) {
120 		int token;
121 		if (!*p)
122 			continue;
123 		token = match_token(p, tokens, args);
124 		if (token < Opt_uname) {
125 			if ((ret = match_int(&args[0], &option)) < 0) {
126 				P9_DPRINTK(P9_DEBUG_ERROR,
127 					"integer field, but no integer?\n");
128 				continue;
129 			}
130 		}
131 		switch (token) {
132 		case Opt_debug:
133 			v9ses->debug = option;
134 #ifdef CONFIG_NET_9P_DEBUG
135 			p9_debug_level = option;
136 #endif
137 			break;
138 		case Opt_port:
139 			v9ses->port = option;
140 			break;
141 		case Opt_msize:
142 			v9ses->maxdata = option;
143 			break;
144 		case Opt_uid:
145 			v9ses->uid = option;
146 			break;
147 		case Opt_gid:
148 			v9ses->gid = option;
149 			break;
150 		case Opt_afid:
151 			v9ses->afid = option;
152 			break;
153 		case Opt_rfdno:
154 			v9ses->rfdno = option;
155 			break;
156 		case Opt_wfdno:
157 			v9ses->wfdno = option;
158 			break;
159 		case Opt_tcp:
160 			v9ses->proto = PROTO_TCP;
161 			break;
162 		case Opt_unix:
163 			v9ses->proto = PROTO_UNIX;
164 			break;
165 		case Opt_pci:
166 			v9ses->proto = PROTO_PCI;
167 			break;
168 		case Opt_fd:
169 			v9ses->proto = PROTO_FD;
170 			break;
171 		case Opt_uname:
172 			match_strcpy(v9ses->name, &args[0]);
173 			break;
174 		case Opt_remotename:
175 			match_strcpy(v9ses->remotename, &args[0]);
176 			break;
177 		case Opt_legacy:
178 			v9ses->extended = 0;
179 			break;
180 		case Opt_nodevmap:
181 			v9ses->nodev = 1;
182 			break;
183 		case Opt_cache_loose:
184 			v9ses->cache = CACHE_LOOSE;
185 			break;
186 		default:
187 			continue;
188 		}
189 	}
190 }
191 
192 /**
193  * v9fs_session_init - initialize session
194  * @v9ses: session information structure
195  * @dev_name: device being mounted
196  * @data: options
197  *
198  */
199 
200 struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
201 		  const char *dev_name, char *data)
202 {
203 	int retval = -EINVAL;
204 	struct p9_transport *trans;
205 	struct p9_fid *fid;
206 
207 	v9ses->name = __getname();
208 	if (!v9ses->name)
209 		return ERR_PTR(-ENOMEM);
210 
211 	v9ses->remotename = __getname();
212 	if (!v9ses->remotename) {
213 		__putname(v9ses->name);
214 		return ERR_PTR(-ENOMEM);
215 	}
216 
217 	strcpy(v9ses->name, V9FS_DEFUSER);
218 	strcpy(v9ses->remotename, V9FS_DEFANAME);
219 
220 	v9fs_parse_options(data, v9ses);
221 
222 	switch (v9ses->proto) {
223 	case PROTO_TCP:
224 		trans = p9_trans_create_tcp(dev_name, v9ses->port);
225 		break;
226 	case PROTO_UNIX:
227 		trans = p9_trans_create_unix(dev_name);
228 		*v9ses->remotename = 0;
229 		break;
230 	case PROTO_FD:
231 		trans = p9_trans_create_fd(v9ses->rfdno, v9ses->wfdno);
232 		*v9ses->remotename = 0;
233 		break;
234 #ifdef CONFIG_PCI_9P
235 	case PROTO_PCI:
236 		trans = p9pci_trans_create();
237 		*v9ses->remotename = 0;
238 		break;
239 #endif
240 	default:
241 		printk(KERN_ERR "v9fs: Bad mount protocol %d\n", v9ses->proto);
242 		retval = -ENOPROTOOPT;
243 		goto error;
244 	};
245 
246 	if (IS_ERR(trans)) {
247 		retval = PTR_ERR(trans);
248 		trans = NULL;
249 		goto error;
250 	}
251 
252 	v9ses->clnt = p9_client_create(trans, v9ses->maxdata + P9_IOHDRSZ,
253 		v9ses->extended);
254 
255 	if (IS_ERR(v9ses->clnt)) {
256 		retval = PTR_ERR(v9ses->clnt);
257 		v9ses->clnt = NULL;
258 		P9_DPRINTK(P9_DEBUG_ERROR, "problem initializing 9p client\n");
259 		goto error;
260 	}
261 
262 	fid = p9_client_attach(v9ses->clnt, NULL, v9ses->name,
263 							v9ses->remotename);
264 	if (IS_ERR(fid)) {
265 		retval = PTR_ERR(fid);
266 		fid = NULL;
267 		P9_DPRINTK(P9_DEBUG_ERROR, "cannot attach\n");
268 		goto error;
269 	}
270 
271 	return fid;
272 
273 error:
274 	v9fs_session_close(v9ses);
275 	return ERR_PTR(retval);
276 }
277 
278 /**
279  * v9fs_session_close - shutdown a session
280  * @v9ses: session information structure
281  *
282  */
283 
284 void v9fs_session_close(struct v9fs_session_info *v9ses)
285 {
286 	if (v9ses->clnt) {
287 		p9_client_destroy(v9ses->clnt);
288 		v9ses->clnt = NULL;
289 	}
290 
291 	__putname(v9ses->name);
292 	__putname(v9ses->remotename);
293 }
294 
295 /**
296  * v9fs_session_cancel - mark transport as disconnected
297  * 	and cancel all pending requests.
298  */
299 void v9fs_session_cancel(struct v9fs_session_info *v9ses) {
300 	P9_DPRINTK(P9_DEBUG_ERROR, "cancel session %p\n", v9ses);
301 	p9_client_disconnect(v9ses->clnt);
302 }
303 
304 extern int v9fs_error_init(void);
305 
306 /**
307  * v9fs_init - Initialize module
308  *
309  */
310 
311 static int __init init_v9fs(void)
312 {
313 	printk(KERN_INFO "Installing v9fs 9p2000 file system support\n");
314 
315 	return register_filesystem(&v9fs_fs_type);
316 }
317 
318 /**
319  * v9fs_init - shutdown module
320  *
321  */
322 
323 static void __exit exit_v9fs(void)
324 {
325 	unregister_filesystem(&v9fs_fs_type);
326 }
327 
328 module_init(init_v9fs)
329 module_exit(exit_v9fs)
330 
331 MODULE_AUTHOR("Latchesar Ionkov <lucho@ionkov.net>");
332 MODULE_AUTHOR("Eric Van Hensbergen <ericvh@gmail.com>");
333 MODULE_AUTHOR("Ron Minnich <rminnich@lanl.gov>");
334 MODULE_LICENSE("GPL");
335