git.maemo.org Git - h-e-n/blob - 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  * Dynamic Transport Registration Routines
  41  *
  42  */
  43
  44 static LIST_HEAD(v9fs_trans_list);
  45 static struct p9_trans_module *v9fs_default_trans;
  46
  47 /**
  48  * v9fs_register_trans - register a new transport with 9p
  49  * @m - structure describing the transport module and entry points
  50  *
  51  */
  52 void v9fs_register_trans(struct p9_trans_module *m)
  53 {
  54         list_add_tail(&m->list, &v9fs_trans_list);
  55         if (m->def)
  56                 v9fs_default_trans = m;
  57 }
  58 EXPORT_SYMBOL(v9fs_register_trans);
  59
  60 /**
  61  * v9fs_match_trans - match transport versus registered transports
  62  * @arg: string identifying transport
  63  *
  64  */
  65 static struct p9_trans_module *v9fs_match_trans(const substring_t *name)
  66 {
  67         struct list_head *p;
  68         struct p9_trans_module *t = NULL;
  69
  70         list_for_each(p, &v9fs_trans_list) {
  71                 t = list_entry(p, struct p9_trans_module, list);
  72                 if (strncmp(t->name, name->from, name->to-name->from) == 0) {
  73                         P9_DPRINTK(P9_DEBUG_TRANS, "trans=%s\n", t->name);
  74                         break;
  75                 }
  76         }
  77         return t;
  78 }
  79
  80 /*
  81   * Option Parsing (code inspired by NFS code)
  82   *  NOTE: each transport will parse its own options
  83   */
  84
  85 enum {
  86         /* Options that take integer arguments */
  87         Opt_debug, Opt_msize, Opt_dfltuid, Opt_dfltgid, Opt_afid,
  88         /* String options */
  89         Opt_uname, Opt_remotename, Opt_trans,
  90         /* Options that take no arguments */
  91         Opt_legacy, Opt_nodevmap,
  92         /* Cache options */
  93         Opt_cache_loose,
  94         /* Access options */
  95         Opt_access,
  96         /* Error token */
  97         Opt_err
  98 };
  99
 100 static match_table_t tokens = {
 101         {Opt_debug, "debug=%x"},
 102         {Opt_msize, "msize=%u"},
 103         {Opt_dfltuid, "dfltuid=%u"},
 104         {Opt_dfltgid, "dfltgid=%u"},
 105         {Opt_afid, "afid=%u"},
 106         {Opt_uname, "uname=%s"},
 107         {Opt_remotename, "aname=%s"},
 108         {Opt_trans, "trans=%s"},
 109         {Opt_legacy, "noextend"},
 110         {Opt_nodevmap, "nodevmap"},
 111         {Opt_cache_loose, "cache=loose"},
 112         {Opt_cache_loose, "loose"},
 113         {Opt_access, "access=%s"},
 114         {Opt_err, NULL}
 115 };
 116
 117 /**
 118  * v9fs_parse_options - parse mount options into session structure
 119  * @options: options string passed from mount
 120  * @v9ses: existing v9fs session information
 121  *
 122  */
 123
 124 static void v9fs_parse_options(struct v9fs_session_info *v9ses)
 125 {
 126         char *options = v9ses->options;
 127         substring_t args[MAX_OPT_ARGS];
 128         char *p;
 129         int option;
 130         int ret;
 131         char *s, *e;
 132
 133         /* setup defaults */
 134         v9ses->maxdata = 8192;
 135         v9ses->afid = ~0;
 136         v9ses->debug = 0;
 137         v9ses->cache = 0;
 138         v9ses->trans = v9fs_default_trans;
 139
 140         if (!options)
 141                 return;
 142
 143         while ((p = strsep(&options, ",")) != NULL) {
 144                 int token;
 145                 if (!*p)
 146                         continue;
 147                 token = match_token(p, tokens, args);
 148                 if (token < Opt_uname) {
 149                         if ((ret = match_int(&args[0], &option)) < 0) {
 150                                 P9_DPRINTK(P9_DEBUG_ERROR,
 151                                         "integer field, but no integer?\n");
 152                                 continue;
 153                         }
 154                 }
 155                 switch (token) {
 156                 case Opt_debug:
 157                         v9ses->debug = option;
 158 #ifdef CONFIG_NET_9P_DEBUG
 159                         p9_debug_level = option;
 160 #endif
 161                         break;
 162                 case Opt_msize:
 163                         v9ses->maxdata = option;
 164                         break;
 165                 case Opt_dfltuid:
 166                         v9ses->dfltuid = option;
 167                         break;
 168                 case Opt_dfltgid:
 169                         v9ses->dfltgid = option;
 170                         break;
 171                 case Opt_afid:
 172                         v9ses->afid = option;
 173                         break;
 174                 case Opt_trans:
 175                         v9ses->trans = v9fs_match_trans(&args[0]);
 176                         break;
 177                 case Opt_uname:
 178                         match_strcpy(v9ses->uname, &args[0]);
 179                         break;
 180                 case Opt_remotename:
 181                         match_strcpy(v9ses->aname, &args[0]);
 182                         break;
 183                 case Opt_legacy:
 184                         v9ses->flags &= ~V9FS_EXTENDED;
 185                         break;
 186                 case Opt_nodevmap:
 187                         v9ses->nodev = 1;
 188                         break;
 189                 case Opt_cache_loose:
 190                         v9ses->cache = CACHE_LOOSE;
 191                         break;
 192
 193                 case Opt_access:
 194                         s = match_strdup(&args[0]);
 195                         v9ses->flags &= ~V9FS_ACCESS_MASK;
 196                         if (strcmp(s, "user") == 0)
 197                                 v9ses->flags |= V9FS_ACCESS_USER;
 198                         else if (strcmp(s, "any") == 0)
 199                                 v9ses->flags |= V9FS_ACCESS_ANY;
 200                         else {
 201                                 v9ses->flags |= V9FS_ACCESS_SINGLE;
 202                                 v9ses->uid = simple_strtol(s, &e, 10);
 203                                 if (*e != '\0')
 204                                         v9ses->uid = ~0;
 205                         }
 206                         break;
 207
 208                 default:
 209                         continue;
 210                 }
 211         }
 212 }
 213
 214 /**
 215  * v9fs_session_init - initialize session
 216  * @v9ses: session information structure
 217  * @dev_name: device being mounted
 218  * @data: options
 219  *
 220  */
 221
 222 struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
 223                   const char *dev_name, char *data)
 224 {
 225         int retval = -EINVAL;
 226         struct p9_trans *trans = NULL;
 227         struct p9_fid *fid;
 228
 229         v9ses->uname = __getname();
 230         if (!v9ses->uname)
 231                 return ERR_PTR(-ENOMEM);
 232
 233         v9ses->aname = __getname();
 234         if (!v9ses->aname) {
 235                 __putname(v9ses->uname);
 236                 return ERR_PTR(-ENOMEM);
 237         }
 238
 239         v9ses->flags = V9FS_EXTENDED | V9FS_ACCESS_USER;
 240         strcpy(v9ses->uname, V9FS_DEFUSER);
 241         strcpy(v9ses->aname, V9FS_DEFANAME);
 242         v9ses->uid = ~0;
 243         v9ses->dfltuid = V9FS_DEFUID;
 244         v9ses->dfltgid = V9FS_DEFGID;
 245         v9ses->options = kstrdup(data, GFP_KERNEL);
 246         v9fs_parse_options(v9ses);
 247
 248         if ((v9ses->trans == NULL) && !list_empty(&v9fs_trans_list))
 249                 v9ses->trans = list_first_entry(&v9fs_trans_list,
 250                  struct p9_trans_module, list);
 251
 252         if (v9ses->trans == NULL) {
 253                 retval = -EPROTONOSUPPORT;
 254                 P9_DPRINTK(P9_DEBUG_ERROR,
 255                                 "No transport defined or default transport\n");
 256                 goto error;
 257         }
 258
 259         trans = v9ses->trans->create(dev_name, v9ses->options);
 260         if (IS_ERR(trans)) {
 261                 retval = PTR_ERR(trans);
 262                 trans = NULL;
 263                 goto error;
 264         }
 265         if ((v9ses->maxdata+P9_IOHDRSZ) > v9ses->trans->maxsize)
 266                 v9ses->maxdata = v9ses->trans->maxsize-P9_IOHDRSZ;
 267
 268         v9ses->clnt = p9_client_create(trans, v9ses->maxdata+P9_IOHDRSZ,
 269                 v9fs_extended(v9ses));
 270
 271         if (IS_ERR(v9ses->clnt)) {
 272                 retval = PTR_ERR(v9ses->clnt);
 273                 v9ses->clnt = NULL;
 274                 P9_DPRINTK(P9_DEBUG_ERROR, "problem initializing 9p client\n");
 275                 goto error;
 276         }
 277
 278         if (!v9ses->clnt->dotu)
 279                 v9ses->flags &= ~V9FS_EXTENDED;
 280
 281         /* for legacy mode, fall back to V9FS_ACCESS_ANY */
 282         if (!v9fs_extended(v9ses) &&
 283                 ((v9ses->flags&V9FS_ACCESS_MASK) == V9FS_ACCESS_USER)) {
 284
 285                 v9ses->flags &= ~V9FS_ACCESS_MASK;
 286                 v9ses->flags |= V9FS_ACCESS_ANY;
 287                 v9ses->uid = ~0;
 288         }
 289
 290         fid = p9_client_attach(v9ses->clnt, NULL, v9ses->uname, ~0,
 291                                                         v9ses->aname);
 292         if (IS_ERR(fid)) {
 293                 retval = PTR_ERR(fid);
 294                 fid = NULL;
 295                 P9_DPRINTK(P9_DEBUG_ERROR, "cannot attach\n");
 296                 goto error;
 297         }
 298
 299         if ((v9ses->flags & V9FS_ACCESS_MASK) == V9FS_ACCESS_SINGLE)
 300                 fid->uid = v9ses->uid;
 301         else
 302                 fid->uid = ~0;
 303
 304         return fid;
 305
 306 error:
 307         v9fs_session_close(v9ses);
 308         return ERR_PTR(retval);
 309 }
 310
 311 /**
 312  * v9fs_session_close - shutdown a session
 313  * @v9ses: session information structure
 314  *
 315  */
 316
 317 void v9fs_session_close(struct v9fs_session_info *v9ses)
 318 {
 319         if (v9ses->clnt) {
 320                 p9_client_destroy(v9ses->clnt);
 321                 v9ses->clnt = NULL;
 322         }
 323
 324         __putname(v9ses->uname);
 325         __putname(v9ses->aname);
 326         kfree(v9ses->options);
 327 }
 328
 329 /**
 330  * v9fs_session_cancel - mark transport as disconnected
 331  *      and cancel all pending requests.
 332  */
 333 void v9fs_session_cancel(struct v9fs_session_info *v9ses) {
 334         P9_DPRINTK(P9_DEBUG_ERROR, "cancel session %p\n", v9ses);
 335         p9_client_disconnect(v9ses->clnt);
 336 }
 337
 338 extern int v9fs_error_init(void);
 339
 340 /**
 341  * v9fs_init - Initialize module
 342  *
 343  */
 344
 345 static int __init init_v9fs(void)
 346 {
 347         printk(KERN_INFO "Installing v9fs 9p2000 file system support\n");
 348         /* TODO: Setup list of registered trasnport modules */
 349         return register_filesystem(&v9fs_fs_type);
 350 }
 351
 352 /**
 353  * v9fs_init - shutdown module
 354  *
 355  */
 356
 357 static void __exit exit_v9fs(void)
 358 {
 359         unregister_filesystem(&v9fs_fs_type);
 360 }
 361
 362 module_init(init_v9fs)
 363 module_exit(exit_v9fs)
 364
 365 MODULE_AUTHOR("Latchesar Ionkov <lucho@ionkov.net>");
 366 MODULE_AUTHOR("Eric Van Hensbergen <ericvh@gmail.com>");
 367 MODULE_AUTHOR("Ron Minnich <rminnich@lanl.gov>");
 368 MODULE_LICENSE("GPL");