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