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 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   *  NOTE: each transport will parse its own options
  42   */
  43
  44 enum {
  45         /* Options that take integer arguments */
  46         Opt_debug, Opt_msize, Opt_dfltuid, Opt_dfltgid, Opt_afid,
  47         /* String options */
  48         Opt_uname, Opt_remotename, Opt_trans,
  49         /* Options that take no arguments */
  50         Opt_legacy, Opt_nodevmap,
  51         /* Cache options */
  52         Opt_cache_loose,
  53         /* Access options */
  54         Opt_access,
  55         /* Error token */
  56         Opt_err
  57 };
  58
  59 static match_table_t tokens = {
  60         {Opt_debug, "debug=%x"},
  61         {Opt_msize, "msize=%u"},
  62         {Opt_dfltuid, "dfltuid=%u"},
  63         {Opt_dfltgid, "dfltgid=%u"},
  64         {Opt_afid, "afid=%u"},
  65         {Opt_uname, "uname=%s"},
  66         {Opt_remotename, "aname=%s"},
  67         {Opt_trans, "trans=%s"},
  68         {Opt_legacy, "noextend"},
  69         {Opt_nodevmap, "nodevmap"},
  70         {Opt_cache_loose, "cache=loose"},
  71         {Opt_cache_loose, "loose"},
  72         {Opt_access, "access=%s"},
  73         {Opt_err, NULL}
  74 };
  75
  76 /**
  77  * v9fs_parse_options - parse mount options into session structure
  78  * @options: options string passed from mount
  79  * @v9ses: existing v9fs session information
  80  *
  81  */
  82
  83 static void v9fs_parse_options(struct v9fs_session_info *v9ses)
  84 {
  85         char *options;
  86         substring_t args[MAX_OPT_ARGS];
  87         char *p;
  88         int option;
  89         int ret;
  90         char *s, *e;
  91
  92         /* setup defaults */
  93         v9ses->maxdata = 8192;
  94         v9ses->afid = ~0;
  95         v9ses->debug = 0;
  96         v9ses->cache = 0;
  97         v9ses->trans = v9fs_default_trans();
  98
  99         if (!v9ses->options)
 100                 return;
 101
 102         options = kstrdup(v9ses->options, GFP_KERNEL);
 103         while ((p = strsep(&options, ",")) != NULL) {
 104                 int token;
 105                 if (!*p)
 106                         continue;
 107                 token = match_token(p, tokens, args);
 108                 if (token < Opt_uname) {
 109                         if ((ret = match_int(&args[0], &option)) < 0) {
 110                                 P9_DPRINTK(P9_DEBUG_ERROR,
 111                                         "integer field, but no integer?\n");
 112                                 continue;
 113                         }
 114                 }
 115                 switch (token) {
 116                 case Opt_debug:
 117                         v9ses->debug = option;
 118 #ifdef CONFIG_NET_9P_DEBUG
 119                         p9_debug_level = option;
 120 #endif
 121                         break;
 122                 case Opt_msize:
 123                         v9ses->maxdata = option;
 124                         break;
 125                 case Opt_dfltuid:
 126                         v9ses->dfltuid = option;
 127                         break;
 128                 case Opt_dfltgid:
 129                         v9ses->dfltgid = option;
 130                         break;
 131                 case Opt_afid:
 132                         v9ses->afid = option;
 133                         break;
 134                 case Opt_trans:
 135                         v9ses->trans = v9fs_match_trans(&args[0]);
 136                         break;
 137                 case Opt_uname:
 138                         match_strcpy(v9ses->uname, &args[0]);
 139                         break;
 140                 case Opt_remotename:
 141                         match_strcpy(v9ses->aname, &args[0]);
 142                         break;
 143                 case Opt_legacy:
 144                         v9ses->flags &= ~V9FS_EXTENDED;
 145                         break;
 146                 case Opt_nodevmap:
 147                         v9ses->nodev = 1;
 148                         break;
 149                 case Opt_cache_loose:
 150                         v9ses->cache = CACHE_LOOSE;
 151                         break;
 152
 153                 case Opt_access:
 154                         s = match_strdup(&args[0]);
 155                         v9ses->flags &= ~V9FS_ACCESS_MASK;
 156                         if (strcmp(s, "user") == 0)
 157                                 v9ses->flags |= V9FS_ACCESS_USER;
 158                         else if (strcmp(s, "any") == 0)
 159                                 v9ses->flags |= V9FS_ACCESS_ANY;
 160                         else {
 161                                 v9ses->flags |= V9FS_ACCESS_SINGLE;
 162                                 v9ses->uid = simple_strtol(s, &e, 10);
 163                                 if (*e != '\0')
 164                                         v9ses->uid = ~0;
 165                         }
 166                         kfree(s);
 167                         break;
 168
 169                 default:
 170                         continue;
 171                 }
 172         }
 173         kfree(options);
 174 }
 175
 176 /**
 177  * v9fs_session_init - initialize session
 178  * @v9ses: session information structure
 179  * @dev_name: device being mounted
 180  * @data: options
 181  *
 182  */
 183
 184 struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
 185                   const char *dev_name, char *data)
 186 {
 187         int retval = -EINVAL;
 188         struct p9_trans *trans = NULL;
 189         struct p9_fid *fid;
 190
 191         v9ses->uname = __getname();
 192         if (!v9ses->uname)
 193                 return ERR_PTR(-ENOMEM);
 194
 195         v9ses->aname = __getname();
 196         if (!v9ses->aname) {
 197                 __putname(v9ses->uname);
 198                 return ERR_PTR(-ENOMEM);
 199         }
 200
 201         v9ses->flags = V9FS_EXTENDED | V9FS_ACCESS_USER;
 202         strcpy(v9ses->uname, V9FS_DEFUSER);
 203         strcpy(v9ses->aname, V9FS_DEFANAME);
 204         v9ses->uid = ~0;
 205         v9ses->dfltuid = V9FS_DEFUID;
 206         v9ses->dfltgid = V9FS_DEFGID;
 207         v9ses->options = kstrdup(data, GFP_KERNEL);
 208         v9fs_parse_options(v9ses);
 209
 210         if (v9ses->trans == NULL) {
 211                 retval = -EPROTONOSUPPORT;
 212                 P9_DPRINTK(P9_DEBUG_ERROR,
 213                                 "No transport defined or default transport\n");
 214                 goto error;
 215         }
 216
 217         trans = v9ses->trans->create(dev_name, v9ses->options);
 218         if (IS_ERR(trans)) {
 219                 retval = PTR_ERR(trans);
 220                 trans = NULL;
 221                 goto error;
 222         }
 223         if ((v9ses->maxdata+P9_IOHDRSZ) > v9ses->trans->maxsize)
 224                 v9ses->maxdata = v9ses->trans->maxsize-P9_IOHDRSZ;
 225
 226         v9ses->clnt = p9_client_create(trans, v9ses->maxdata+P9_IOHDRSZ,
 227                 v9fs_extended(v9ses));
 228
 229         if (IS_ERR(v9ses->clnt)) {
 230                 retval = PTR_ERR(v9ses->clnt);
 231                 v9ses->clnt = NULL;
 232                 P9_DPRINTK(P9_DEBUG_ERROR, "problem initializing 9p client\n");
 233                 goto error;
 234         }
 235
 236         if (!v9ses->clnt->dotu)
 237                 v9ses->flags &= ~V9FS_EXTENDED;
 238
 239         /* for legacy mode, fall back to V9FS_ACCESS_ANY */
 240         if (!v9fs_extended(v9ses) &&
 241                 ((v9ses->flags&V9FS_ACCESS_MASK) == V9FS_ACCESS_USER)) {
 242
 243                 v9ses->flags &= ~V9FS_ACCESS_MASK;
 244                 v9ses->flags |= V9FS_ACCESS_ANY;
 245                 v9ses->uid = ~0;
 246         }
 247
 248         fid = p9_client_attach(v9ses->clnt, NULL, v9ses->uname, ~0,
 249                                                         v9ses->aname);
 250         if (IS_ERR(fid)) {
 251                 retval = PTR_ERR(fid);
 252                 fid = NULL;
 253                 P9_DPRINTK(P9_DEBUG_ERROR, "cannot attach\n");
 254                 goto error;
 255         }
 256
 257         if ((v9ses->flags & V9FS_ACCESS_MASK) == V9FS_ACCESS_SINGLE)
 258                 fid->uid = v9ses->uid;
 259         else
 260                 fid->uid = ~0;
 261
 262         return fid;
 263
 264 error:
 265         v9fs_session_close(v9ses);
 266         return ERR_PTR(retval);
 267 }
 268
 269 /**
 270  * v9fs_session_close - shutdown a session
 271  * @v9ses: session information structure
 272  *
 273  */
 274
 275 void v9fs_session_close(struct v9fs_session_info *v9ses)
 276 {
 277         if (v9ses->clnt) {
 278                 p9_client_destroy(v9ses->clnt);
 279                 v9ses->clnt = NULL;
 280         }
 281
 282         __putname(v9ses->uname);
 283         __putname(v9ses->aname);
 284         kfree(v9ses->options);
 285 }
 286
 287 /**
 288  * v9fs_session_cancel - mark transport as disconnected
 289  *      and cancel all pending requests.
 290  */
 291 void v9fs_session_cancel(struct v9fs_session_info *v9ses) {
 292         P9_DPRINTK(P9_DEBUG_ERROR, "cancel session %p\n", v9ses);
 293         p9_client_disconnect(v9ses->clnt);
 294 }
 295
 296 extern int v9fs_error_init(void);
 297
 298 /**
 299  * v9fs_init - Initialize module
 300  *
 301  */
 302
 303 static int __init init_v9fs(void)
 304 {
 305         printk(KERN_INFO "Installing v9fs 9p2000 file system support\n");
 306         /* TODO: Setup list of registered trasnport modules */
 307         return register_filesystem(&v9fs_fs_type);
 308 }
 309
 310 /**
 311  * v9fs_init - shutdown module
 312  *
 313  */
 314
 315 static void __exit exit_v9fs(void)
 316 {
 317         unregister_filesystem(&v9fs_fs_type);
 318 }
 319
 320 module_init(init_v9fs)
 321 module_exit(exit_v9fs)
 322
 323 MODULE_AUTHOR("Latchesar Ionkov <lucho@ionkov.net>");
 324 MODULE_AUTHOR("Eric Van Hensbergen <ericvh@gmail.com>");
 325 MODULE_AUTHOR("Ron Minnich <rminnich@lanl.gov>");
 326 MODULE_LICENSE("GPL");