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");