fs/9p/conv.c

   1 /*
   2  * linux/fs/9p/conv.c
   3  *
   4  * 9P protocol conversion functions
   5  *
   6  *  Copyright (C) 2004, 2005 by Latchesar Ionkov <lucho@ionkov.net>
   7  *  Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
   8  *  Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
   9  *
  10  *  This program is free software; you can redistribute it and/or modify
  11  *  it under the terms of the GNU General Public License as published by
  12  *  the Free Software Foundation; either version 2 of the License, or
  13  *  (at your option) any later version.
  14  *
  15  *  This program is distributed in the hope that it will be useful,
  16  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  *  GNU General Public License for more details.
  19  *
  20  *  You should have received a copy of the GNU General Public License
  21  *  along with this program; if not, write to:
  22  *  Free Software Foundation
  23  *  51 Franklin Street, Fifth Floor
  24  *  Boston, MA  02111-1301  USA
  25  *
  26  */
  27
  28 #include <linux/config.h>
  29 #include <linux/module.h>
  30 #include <linux/errno.h>
  31 #include <linux/fs.h>
  32 #include <linux/idr.h>
  33 #include <asm/uaccess.h>
  34 #include "debug.h"
  35 #include "v9fs.h"
  36 #include "9p.h"
  37 #include "conv.h"
  38
  39 /*
  40  * Buffer to help with string parsing
  41  */
  42 struct cbuf {
  43         unsigned char *sp;
  44         unsigned char *p;
  45         unsigned char *ep;
  46 };
  47
  48 static inline void buf_init(struct cbuf *buf, void *data, int datalen)
  49 {
  50         buf->sp = buf->p = data;
  51         buf->ep = data + datalen;
  52 }
  53
  54 static inline int buf_check_overflow(struct cbuf *buf)
  55 {
  56         return buf->p > buf->ep;
  57 }
  58
  59 static int buf_check_size(struct cbuf *buf, int len)
  60 {
  61         if (buf->p + len > buf->ep) {
  62                 if (buf->p < buf->ep) {
  63                         eprintk(KERN_ERR, "buffer overflow: want %d has %d\n",
  64                                 len, (int)(buf->ep - buf->p));
  65                         dump_stack();
  66                         buf->p = buf->ep + 1;
  67                 }
  68
  69                 return 0;
  70         }
  71
  72         return 1;
  73 }
  74
  75 static void *buf_alloc(struct cbuf *buf, int len)
  76 {
  77         void *ret = NULL;
  78
  79         if (buf_check_size(buf, len)) {
  80                 ret = buf->p;
  81                 buf->p += len;
  82         }
  83
  84         return ret;
  85 }
  86
  87 static void buf_put_int8(struct cbuf *buf, u8 val)
  88 {
  89         if (buf_check_size(buf, 1)) {
  90                 buf->p[0] = val;
  91                 buf->p++;
  92         }
  93 }
  94
  95 static void buf_put_int16(struct cbuf *buf, u16 val)
  96 {
  97         if (buf_check_size(buf, 2)) {
  98                 *(__le16 *) buf->p = cpu_to_le16(val);
  99                 buf->p += 2;
 100         }
 101 }
 102
 103 static void buf_put_int32(struct cbuf *buf, u32 val)
 104 {
 105         if (buf_check_size(buf, 4)) {
 106                 *(__le32 *)buf->p = cpu_to_le32(val);
 107                 buf->p += 4;
 108         }
 109 }
 110
 111 static void buf_put_int64(struct cbuf *buf, u64 val)
 112 {
 113         if (buf_check_size(buf, 8)) {
 114                 *(__le64 *)buf->p = cpu_to_le64(val);
 115                 buf->p += 8;
 116         }
 117 }
 118
 119 static char *buf_put_stringn(struct cbuf *buf, const char *s, u16 slen)
 120 {
 121         char *ret;
 122
 123         ret = NULL;
 124         if (buf_check_size(buf, slen + 2)) {
 125                 buf_put_int16(buf, slen);
 126                 ret = buf->p;
 127                 memcpy(buf->p, s, slen);
 128                 buf->p += slen;
 129         }
 130
 131         return ret;
 132 }
 133
 134 static inline void buf_put_string(struct cbuf *buf, const char *s)
 135 {
 136         buf_put_stringn(buf, s, strlen(s));
 137 }
 138
 139 static u8 buf_get_int8(struct cbuf *buf)
 140 {
 141         u8 ret = 0;
 142
 143         if (buf_check_size(buf, 1)) {
 144                 ret = buf->p[0];
 145                 buf->p++;
 146         }
 147
 148         return ret;
 149 }
 150
 151 static u16 buf_get_int16(struct cbuf *buf)
 152 {
 153         u16 ret = 0;
 154
 155         if (buf_check_size(buf, 2)) {
 156                 ret = le16_to_cpu(*(__le16 *)buf->p);
 157                 buf->p += 2;
 158         }
 159
 160         return ret;
 161 }
 162
 163 static u32 buf_get_int32(struct cbuf *buf)
 164 {
 165         u32 ret = 0;
 166
 167         if (buf_check_size(buf, 4)) {
 168                 ret = le32_to_cpu(*(__le32 *)buf->p);
 169                 buf->p += 4;
 170         }
 171
 172         return ret;
 173 }
 174
 175 static u64 buf_get_int64(struct cbuf *buf)
 176 {
 177         u64 ret = 0;
 178
 179         if (buf_check_size(buf, 8)) {
 180                 ret = le64_to_cpu(*(__le64 *)buf->p);
 181                 buf->p += 8;
 182         }
 183
 184         return ret;
 185 }
 186
 187 static void buf_get_str(struct cbuf *buf, struct v9fs_str *vstr)
 188 {
 189         vstr->len = buf_get_int16(buf);
 190         if (!buf_check_overflow(buf) && buf_check_size(buf, vstr->len)) {
 191                 vstr->str = buf->p;
 192                 buf->p += vstr->len;
 193         } else {
 194                 vstr->len = 0;
 195                 vstr->str = NULL;
 196         }
 197 }
 198
 199 static void buf_get_qid(struct cbuf *bufp, struct v9fs_qid *qid)
 200 {
 201         qid->type = buf_get_int8(bufp);
 202         qid->version = buf_get_int32(bufp);
 203         qid->path = buf_get_int64(bufp);
 204 }
 205
 206 /**
 207  * v9fs_size_wstat - calculate the size of a variable length stat struct
 208  * @stat: metadata (stat) structure
 209  * @extended: non-zero if 9P2000.u
 210  *
 211  */
 212
 213 static int v9fs_size_wstat(struct v9fs_wstat *wstat, int extended)
 214 {
 215         int size = 0;
 216
 217         if (wstat == NULL) {
 218                 eprintk(KERN_ERR, "v9fs_size_stat: got a NULL stat pointer\n");
 219                 return 0;
 220         }
 221
 222         size =                  /* 2 + *//* size[2] */
 223             2 +                 /* type[2] */
 224             4 +                 /* dev[4] */
 225             1 +                 /* qid.type[1] */
 226             4 +                 /* qid.vers[4] */
 227             8 +                 /* qid.path[8] */
 228             4 +                 /* mode[4] */
 229             4 +                 /* atime[4] */
 230             4 +                 /* mtime[4] */
 231             8 +                 /* length[8] */
 232             8;                  /* minimum sum of string lengths */
 233
 234         if (wstat->name)
 235                 size += strlen(wstat->name);
 236         if (wstat->uid)
 237                 size += strlen(wstat->uid);
 238         if (wstat->gid)
 239                 size += strlen(wstat->gid);
 240         if (wstat->muid)
 241                 size += strlen(wstat->muid);
 242
 243         if (extended) {
 244                 size += 4 +     /* n_uid[4] */
 245                     4 +         /* n_gid[4] */
 246                     4 +         /* n_muid[4] */
 247                     2;          /* string length of extension[4] */
 248                 if (wstat->extension)
 249                         size += strlen(wstat->extension);
 250         }
 251
 252         return size;
 253 }
 254
 255 /**
 256  * buf_get_stat - safely decode a recieved metadata (stat) structure
 257  * @bufp: buffer to deserialize
 258  * @stat: metadata (stat) structure
 259  * @extended: non-zero if 9P2000.u
 260  *
 261  */
 262
 263 static void
 264 buf_get_stat(struct cbuf *bufp, struct v9fs_stat *stat, int extended)
 265 {
 266         stat->size = buf_get_int16(bufp);
 267         stat->type = buf_get_int16(bufp);
 268         stat->dev = buf_get_int32(bufp);
 269         stat->qid.type = buf_get_int8(bufp);
 270         stat->qid.version = buf_get_int32(bufp);
 271         stat->qid.path = buf_get_int64(bufp);
 272         stat->mode = buf_get_int32(bufp);
 273         stat->atime = buf_get_int32(bufp);
 274         stat->mtime = buf_get_int32(bufp);
 275         stat->length = buf_get_int64(bufp);
 276         buf_get_str(bufp, &stat->name);
 277         buf_get_str(bufp, &stat->uid);
 278         buf_get_str(bufp, &stat->gid);
 279         buf_get_str(bufp, &stat->muid);
 280
 281         if (extended) {
 282                 buf_get_str(bufp, &stat->extension);
 283                 stat->n_uid = buf_get_int32(bufp);
 284                 stat->n_gid = buf_get_int32(bufp);
 285                 stat->n_muid = buf_get_int32(bufp);
 286         }
 287 }
 288
 289 /**
 290  * v9fs_deserialize_stat - decode a received metadata structure
 291  * @buf: buffer to deserialize
 292  * @buflen: length of received buffer
 293  * @stat: metadata structure to decode into
 294  * @extended: non-zero if 9P2000.u
 295  *
 296  * Note: stat will point to the buf region.
 297  */
 298
 299 int
 300 v9fs_deserialize_stat(void *buf, u32 buflen, struct v9fs_stat *stat,
 301                 int extended)
 302 {
 303         struct cbuf buffer;
 304         struct cbuf *bufp = &buffer;
 305         unsigned char *p;
 306
 307         buf_init(bufp, buf, buflen);
 308         p = bufp->p;
 309         buf_get_stat(bufp, stat, extended);
 310
 311         if (buf_check_overflow(bufp))
 312                 return 0;
 313         else
 314                 return bufp->p - p;
 315 }
 316
 317 /**
 318  * deserialize_fcall - unmarshal a response
 319  * @buf: recieved buffer
 320  * @buflen: length of received buffer
 321  * @rcall: fcall structure to populate
 322  * @rcalllen: length of fcall structure to populate
 323  * @extended: non-zero if 9P2000.u
 324  *
 325  */
 326
 327 int
 328 v9fs_deserialize_fcall(void *buf, u32 buflen, struct v9fs_fcall *rcall,
 329                        int extended)
 330 {
 331
 332         struct cbuf buffer;
 333         struct cbuf *bufp = &buffer;
 334         int i = 0;
 335
 336         buf_init(bufp, buf, buflen);
 337
 338         rcall->size = buf_get_int32(bufp);
 339         rcall->id = buf_get_int8(bufp);
 340         rcall->tag = buf_get_int16(bufp);
 341
 342         dprintk(DEBUG_CONV, "size %d id %d tag %d\n", rcall->size, rcall->id,
 343                 rcall->tag);
 344
 345         switch (rcall->id) {
 346         default:
 347                 eprintk(KERN_ERR, "unknown message type: %d\n", rcall->id);
 348                 return -EPROTO;
 349         case RVERSION:
 350                 rcall->params.rversion.msize = buf_get_int32(bufp);
 351                 buf_get_str(bufp, &rcall->params.rversion.version);
 352                 break;
 353         case RFLUSH:
 354                 break;
 355         case RATTACH:
 356                 rcall->params.rattach.qid.type = buf_get_int8(bufp);
 357                 rcall->params.rattach.qid.version = buf_get_int32(bufp);
 358                 rcall->params.rattach.qid.path = buf_get_int64(bufp);
 359                 break;
 360         case RWALK:
 361                 rcall->params.rwalk.nwqid = buf_get_int16(bufp);
 362                 if (rcall->params.rwalk.nwqid > V9FS_MAXWELEM) {
 363                         eprintk(KERN_ERR, "Rwalk with more than %d qids: %d\n",
 364                                 V9FS_MAXWELEM, rcall->params.rwalk.nwqid);
 365                         return -EPROTO;
 366                 }
 367
 368                 for (i = 0; i < rcall->params.rwalk.nwqid; i++)
 369                         buf_get_qid(bufp, &rcall->params.rwalk.wqids[i]);
 370                 break;
 371         case ROPEN:
 372                 buf_get_qid(bufp, &rcall->params.ropen.qid);
 373                 rcall->params.ropen.iounit = buf_get_int32(bufp);
 374                 break;
 375         case RCREATE:
 376                 buf_get_qid(bufp, &rcall->params.rcreate.qid);
 377                 rcall->params.rcreate.iounit = buf_get_int32(bufp);
 378                 break;
 379         case RREAD:
 380                 rcall->params.rread.count = buf_get_int32(bufp);
 381                 rcall->params.rread.data = bufp->p;
 382                 buf_check_size(bufp, rcall->params.rread.count);
 383                 break;
 384         case RWRITE:
 385                 rcall->params.rwrite.count = buf_get_int32(bufp);
 386                 break;
 387         case RCLUNK:
 388                 break;
 389         case RREMOVE:
 390                 break;
 391         case RSTAT:
 392                 buf_get_int16(bufp);
 393                 buf_get_stat(bufp, &rcall->params.rstat.stat, extended);
 394                 break;
 395         case RWSTAT:
 396                 break;
 397         case RERROR:
 398                 buf_get_str(bufp, &rcall->params.rerror.error);
 399                 if (extended)
 400                         rcall->params.rerror.errno = buf_get_int16(bufp);
 401                 break;
 402         }
 403
 404         if (buf_check_overflow(bufp)) {
 405                 dprintk(DEBUG_ERROR, "buffer overflow\n");
 406                 return -EIO;
 407         }
 408
 409         return bufp->p - bufp->sp;
 410 }
 411
 412 static inline void v9fs_put_int8(struct cbuf *bufp, u8 val, u8 * p)
 413 {
 414         *p = val;
 415         buf_put_int8(bufp, val);
 416 }
 417
 418 static inline void v9fs_put_int16(struct cbuf *bufp, u16 val, u16 * p)
 419 {
 420         *p = val;
 421         buf_put_int16(bufp, val);
 422 }
 423
 424 static inline void v9fs_put_int32(struct cbuf *bufp, u32 val, u32 * p)
 425 {
 426         *p = val;
 427         buf_put_int32(bufp, val);
 428 }
 429
 430 static inline void v9fs_put_int64(struct cbuf *bufp, u64 val, u64 * p)
 431 {
 432         *p = val;
 433         buf_put_int64(bufp, val);
 434 }
 435
 436 static void
 437 v9fs_put_str(struct cbuf *bufp, char *data, struct v9fs_str *str)
 438 {
 439         int len;
 440         char *s;
 441
 442         if (data)
 443                 len = strlen(data);
 444         else
 445                 len = 0;
 446
 447         s = buf_put_stringn(bufp, data, len);
 448         if (str) {
 449                 str->len = len;
 450                 str->str = s;
 451         }
 452 }
 453
 454 static int
 455 v9fs_put_user_data(struct cbuf *bufp, const char __user * data, int count,
 456                    unsigned char **pdata)
 457 {
 458         *pdata = buf_alloc(bufp, count);
 459         return copy_from_user(*pdata, data, count);
 460 }
 461
 462 static void
 463 v9fs_put_wstat(struct cbuf *bufp, struct v9fs_wstat *wstat,
 464                struct v9fs_stat *stat, int statsz, int extended)
 465 {
 466         v9fs_put_int16(bufp, statsz, &stat->size);
 467         v9fs_put_int16(bufp, wstat->type, &stat->type);
 468         v9fs_put_int32(bufp, wstat->dev, &stat->dev);
 469         v9fs_put_int8(bufp, wstat->qid.type, &stat->qid.type);
 470         v9fs_put_int32(bufp, wstat->qid.version, &stat->qid.version);
 471         v9fs_put_int64(bufp, wstat->qid.path, &stat->qid.path);
 472         v9fs_put_int32(bufp, wstat->mode, &stat->mode);
 473         v9fs_put_int32(bufp, wstat->atime, &stat->atime);
 474         v9fs_put_int32(bufp, wstat->mtime, &stat->mtime);
 475         v9fs_put_int64(bufp, wstat->length, &stat->length);
 476
 477         v9fs_put_str(bufp, wstat->name, &stat->name);
 478         v9fs_put_str(bufp, wstat->uid, &stat->uid);
 479         v9fs_put_str(bufp, wstat->gid, &stat->gid);
 480         v9fs_put_str(bufp, wstat->muid, &stat->muid);
 481
 482         if (extended) {
 483                 v9fs_put_str(bufp, wstat->extension, &stat->extension);
 484                 v9fs_put_int32(bufp, wstat->n_uid, &stat->n_uid);
 485                 v9fs_put_int32(bufp, wstat->n_gid, &stat->n_gid);
 486                 v9fs_put_int32(bufp, wstat->n_muid, &stat->n_muid);
 487         }
 488 }
 489
 490 static struct v9fs_fcall *
 491 v9fs_create_common(struct cbuf *bufp, u32 size, u8 id)
 492 {
 493         struct v9fs_fcall *fc;
 494
 495         size += 4 + 1 + 2;      /* size[4] id[1] tag[2] */
 496         fc = kmalloc(sizeof(struct v9fs_fcall) + size, GFP_KERNEL);
 497         if (!fc)
 498                 return ERR_PTR(-ENOMEM);
 499
 500         fc->sdata = (char *)fc + sizeof(*fc);
 501
 502         buf_init(bufp, (char *)fc->sdata, size);
 503         v9fs_put_int32(bufp, size, &fc->size);
 504         v9fs_put_int8(bufp, id, &fc->id);
 505         v9fs_put_int16(bufp, V9FS_NOTAG, &fc->tag);
 506
 507         return fc;
 508 }
 509
 510 void v9fs_set_tag(struct v9fs_fcall *fc, u16 tag)
 511 {
 512         fc->tag = tag;
 513         *(__le16 *) (fc->sdata + 5) = cpu_to_le16(tag);
 514 }
 515
 516 struct v9fs_fcall *v9fs_create_tversion(u32 msize, char *version)
 517 {
 518         int size;
 519         struct v9fs_fcall *fc;
 520         struct cbuf buffer;
 521         struct cbuf *bufp = &buffer;
 522
 523         size = 4 + 2 + strlen(version); /* msize[4] version[s] */
 524         fc = v9fs_create_common(bufp, size, TVERSION);
 525         if (IS_ERR(fc))
 526                 goto error;
 527
 528         v9fs_put_int32(bufp, msize, &fc->params.tversion.msize);
 529         v9fs_put_str(bufp, version, &fc->params.tversion.version);
 530
 531         if (buf_check_overflow(bufp)) {
 532                 kfree(fc);
 533                 fc = ERR_PTR(-ENOMEM);
 534         }
 535       error:
 536         return fc;
 537 }
 538
 539 #if 0
 540 struct v9fs_fcall *v9fs_create_tauth(u32 afid, char *uname, char *aname)
 541 {
 542         int size;
 543         struct v9fs_fcall *fc;
 544         struct cbuf buffer;
 545         struct cbuf *bufp = &buffer;
 546
 547         size = 4 + 2 + strlen(uname) + 2 + strlen(aname);       /* afid[4] uname[s] aname[s] */
 548         fc = v9fs_create_common(bufp, size, TAUTH);
 549         if (IS_ERR(fc))
 550                 goto error;
 551
 552         v9fs_put_int32(bufp, afid, &fc->params.tauth.afid);
 553         v9fs_put_str(bufp, uname, &fc->params.tauth.uname);
 554         v9fs_put_str(bufp, aname, &fc->params.tauth.aname);
 555
 556         if (buf_check_overflow(bufp)) {
 557                 kfree(fc);
 558                 fc = ERR_PTR(-ENOMEM);
 559         }
 560       error:
 561         return fc;
 562 }
 563 #endif  /*  0  */
 564
 565 struct v9fs_fcall *
 566 v9fs_create_tattach(u32 fid, u32 afid, char *uname, char *aname)
 567 {
 568         int size;
 569         struct v9fs_fcall *fc;
 570         struct cbuf buffer;
 571         struct cbuf *bufp = &buffer;
 572
 573         size = 4 + 4 + 2 + strlen(uname) + 2 + strlen(aname);   /* fid[4] afid[4] uname[s] aname[s] */
 574         fc = v9fs_create_common(bufp, size, TATTACH);
 575         if (IS_ERR(fc))
 576                 goto error;
 577
 578         v9fs_put_int32(bufp, fid, &fc->params.tattach.fid);
 579         v9fs_put_int32(bufp, afid, &fc->params.tattach.afid);
 580         v9fs_put_str(bufp, uname, &fc->params.tattach.uname);
 581         v9fs_put_str(bufp, aname, &fc->params.tattach.aname);
 582
 583       error:
 584         return fc;
 585 }
 586
 587 struct v9fs_fcall *v9fs_create_tflush(u16 oldtag)
 588 {
 589         int size;
 590         struct v9fs_fcall *fc;
 591         struct cbuf buffer;
 592         struct cbuf *bufp = &buffer;
 593
 594         size = 2;               /* oldtag[2] */
 595         fc = v9fs_create_common(bufp, size, TFLUSH);
 596         if (IS_ERR(fc))
 597                 goto error;
 598
 599         v9fs_put_int16(bufp, oldtag, &fc->params.tflush.oldtag);
 600
 601         if (buf_check_overflow(bufp)) {
 602                 kfree(fc);
 603                 fc = ERR_PTR(-ENOMEM);
 604         }
 605       error:
 606         return fc;
 607 }
 608
 609 struct v9fs_fcall *v9fs_create_twalk(u32 fid, u32 newfid, u16 nwname,
 610                                      char **wnames)
 611 {
 612         int i, size;
 613         struct v9fs_fcall *fc;
 614         struct cbuf buffer;
 615         struct cbuf *bufp = &buffer;
 616
 617         if (nwname > V9FS_MAXWELEM) {
 618                 dprintk(DEBUG_ERROR, "nwname > %d\n", V9FS_MAXWELEM);
 619                 return NULL;
 620         }
 621
 622         size = 4 + 4 + 2;       /* fid[4] newfid[4] nwname[2] ... */
 623         for (i = 0; i < nwname; i++) {
 624                 size += 2 + strlen(wnames[i]);  /* wname[s] */
 625         }
 626
 627         fc = v9fs_create_common(bufp, size, TWALK);
 628         if (IS_ERR(fc))
 629                 goto error;
 630
 631         v9fs_put_int32(bufp, fid, &fc->params.twalk.fid);
 632         v9fs_put_int32(bufp, newfid, &fc->params.twalk.newfid);
 633         v9fs_put_int16(bufp, nwname, &fc->params.twalk.nwname);
 634         for (i = 0; i < nwname; i++) {
 635                 v9fs_put_str(bufp, wnames[i], &fc->params.twalk.wnames[i]);
 636         }
 637
 638         if (buf_check_overflow(bufp)) {
 639                 kfree(fc);
 640                 fc = ERR_PTR(-ENOMEM);
 641         }
 642       error:
 643         return fc;
 644 }
 645
 646 struct v9fs_fcall *v9fs_create_topen(u32 fid, u8 mode)
 647 {
 648         int size;
 649         struct v9fs_fcall *fc;
 650         struct cbuf buffer;
 651         struct cbuf *bufp = &buffer;
 652
 653         size = 4 + 1;           /* fid[4] mode[1] */
 654         fc = v9fs_create_common(bufp, size, TOPEN);
 655         if (IS_ERR(fc))
 656                 goto error;
 657
 658         v9fs_put_int32(bufp, fid, &fc->params.topen.fid);
 659         v9fs_put_int8(bufp, mode, &fc->params.topen.mode);
 660
 661         if (buf_check_overflow(bufp)) {
 662                 kfree(fc);
 663                 fc = ERR_PTR(-ENOMEM);
 664         }
 665       error:
 666         return fc;
 667 }
 668
 669 struct v9fs_fcall *v9fs_create_tcreate(u32 fid, char *name, u32 perm, u8 mode)
 670 {
 671         int size;
 672         struct v9fs_fcall *fc;
 673         struct cbuf buffer;
 674         struct cbuf *bufp = &buffer;
 675
 676         size = 4 + 2 + strlen(name) + 4 + 1;    /* fid[4] name[s] perm[4] mode[1] */
 677         fc = v9fs_create_common(bufp, size, TCREATE);
 678         if (IS_ERR(fc))
 679                 goto error;
 680
 681         v9fs_put_int32(bufp, fid, &fc->params.tcreate.fid);
 682         v9fs_put_str(bufp, name, &fc->params.tcreate.name);
 683         v9fs_put_int32(bufp, perm, &fc->params.tcreate.perm);
 684         v9fs_put_int8(bufp, mode, &fc->params.tcreate.mode);
 685
 686         if (buf_check_overflow(bufp)) {
 687                 kfree(fc);
 688                 fc = ERR_PTR(-ENOMEM);
 689         }
 690       error:
 691         return fc;
 692 }
 693
 694 struct v9fs_fcall *v9fs_create_tread(u32 fid, u64 offset, u32 count)
 695 {
 696         int size;
 697         struct v9fs_fcall *fc;
 698         struct cbuf buffer;
 699         struct cbuf *bufp = &buffer;
 700
 701         size = 4 + 8 + 4;       /* fid[4] offset[8] count[4] */
 702         fc = v9fs_create_common(bufp, size, TREAD);
 703         if (IS_ERR(fc))
 704                 goto error;
 705
 706         v9fs_put_int32(bufp, fid, &fc->params.tread.fid);
 707         v9fs_put_int64(bufp, offset, &fc->params.tread.offset);
 708         v9fs_put_int32(bufp, count, &fc->params.tread.count);
 709
 710         if (buf_check_overflow(bufp)) {
 711                 kfree(fc);
 712                 fc = ERR_PTR(-ENOMEM);
 713         }
 714       error:
 715         return fc;
 716 }
 717
 718 struct v9fs_fcall *v9fs_create_twrite(u32 fid, u64 offset, u32 count,
 719                                       const char __user * data)
 720 {
 721         int size, err;
 722         struct v9fs_fcall *fc;
 723         struct cbuf buffer;
 724         struct cbuf *bufp = &buffer;
 725
 726         size = 4 + 8 + 4 + count;       /* fid[4] offset[8] count[4] data[count] */
 727         fc = v9fs_create_common(bufp, size, TWRITE);
 728         if (IS_ERR(fc))
 729                 goto error;
 730
 731         v9fs_put_int32(bufp, fid, &fc->params.twrite.fid);
 732         v9fs_put_int64(bufp, offset, &fc->params.twrite.offset);
 733         v9fs_put_int32(bufp, count, &fc->params.twrite.count);
 734         err = v9fs_put_user_data(bufp, data, count, &fc->params.twrite.data);
 735         if (err) {
 736                 kfree(fc);
 737                 fc = ERR_PTR(err);
 738         }
 739
 740         if (buf_check_overflow(bufp)) {
 741                 kfree(fc);
 742                 fc = ERR_PTR(-ENOMEM);
 743         }
 744       error:
 745         return fc;
 746 }
 747
 748 struct v9fs_fcall *v9fs_create_tclunk(u32 fid)
 749 {
 750         int size;
 751         struct v9fs_fcall *fc;
 752         struct cbuf buffer;
 753         struct cbuf *bufp = &buffer;
 754
 755         size = 4;               /* fid[4] */
 756         fc = v9fs_create_common(bufp, size, TCLUNK);
 757         if (IS_ERR(fc))
 758                 goto error;
 759
 760         v9fs_put_int32(bufp, fid, &fc->params.tclunk.fid);
 761
 762         if (buf_check_overflow(bufp)) {
 763                 kfree(fc);
 764                 fc = ERR_PTR(-ENOMEM);
 765         }
 766       error:
 767         return fc;
 768 }
 769
 770 struct v9fs_fcall *v9fs_create_tremove(u32 fid)
 771 {
 772         int size;
 773         struct v9fs_fcall *fc;
 774         struct cbuf buffer;
 775         struct cbuf *bufp = &buffer;
 776
 777         size = 4;               /* fid[4] */
 778         fc = v9fs_create_common(bufp, size, TREMOVE);
 779         if (IS_ERR(fc))
 780                 goto error;
 781
 782         v9fs_put_int32(bufp, fid, &fc->params.tremove.fid);
 783
 784         if (buf_check_overflow(bufp)) {
 785                 kfree(fc);
 786                 fc = ERR_PTR(-ENOMEM);
 787         }
 788       error:
 789         return fc;
 790 }
 791
 792 struct v9fs_fcall *v9fs_create_tstat(u32 fid)
 793 {
 794         int size;
 795         struct v9fs_fcall *fc;
 796         struct cbuf buffer;
 797         struct cbuf *bufp = &buffer;
 798
 799         size = 4;               /* fid[4] */
 800         fc = v9fs_create_common(bufp, size, TSTAT);
 801         if (IS_ERR(fc))
 802                 goto error;
 803
 804         v9fs_put_int32(bufp, fid, &fc->params.tstat.fid);
 805
 806         if (buf_check_overflow(bufp)) {
 807                 kfree(fc);
 808                 fc = ERR_PTR(-ENOMEM);
 809         }
 810       error:
 811         return fc;
 812 }
 813
 814 struct v9fs_fcall *v9fs_create_twstat(u32 fid, struct v9fs_wstat *wstat,
 815                                       int extended)
 816 {
 817         int size, statsz;
 818         struct v9fs_fcall *fc;
 819         struct cbuf buffer;
 820         struct cbuf *bufp = &buffer;
 821
 822         statsz = v9fs_size_wstat(wstat, extended);
 823         size = 4 + 2 + 2 + statsz;      /* fid[4] stat[n] */
 824         fc = v9fs_create_common(bufp, size, TWSTAT);
 825         if (IS_ERR(fc))
 826                 goto error;
 827
 828         v9fs_put_int32(bufp, fid, &fc->params.twstat.fid);
 829         buf_put_int16(bufp, statsz + 2);
 830         v9fs_put_wstat(bufp, wstat, &fc->params.twstat.stat, statsz, extended);
 831
 832         if (buf_check_overflow(bufp)) {
 833                 kfree(fc);
 834                 fc = ERR_PTR(-ENOMEM);
 835         }
 836       error:
 837         return fc;
 838 }