fs/nfs/nfs2xdr.c

   1 /*
   2  * linux/fs/nfs/nfs2xdr.c
   3  *
   4  * XDR functions to encode/decode NFS RPC arguments and results.
   5  *
   6  * Copyright (C) 1992, 1993, 1994  Rick Sladkey
   7  * Copyright (C) 1996 Olaf Kirch
   8  * 04 Aug 1998  Ion Badulescu <ionut@cs.columbia.edu>
   9  *              FIFO's need special handling in NFSv2
  10  */
  11
  12 #include <linux/param.h>
  13 #include <linux/time.h>
  14 #include <linux/mm.h>
  15 #include <linux/errno.h>
  16 #include <linux/string.h>
  17 #include <linux/in.h>
  18 #include <linux/pagemap.h>
  19 #include <linux/proc_fs.h>
  20 #include <linux/sunrpc/clnt.h>
  21 #include <linux/nfs.h>
  22 #include <linux/nfs2.h>
  23 #include <linux/nfs_fs.h>
  24 #include "internal.h"
  25
  26 #define NFSDBG_FACILITY         NFSDBG_XDR
  27
  28 /* Mapping from NFS error code to "errno" error code. */
  29 #define errno_NFSERR_IO         EIO
  30
  31 /*
  32  * Declare the space requirements for NFS arguments and replies as
  33  * number of 32bit-words
  34  */
  35 #define NFS_fhandle_sz          (8)
  36 #define NFS_sattr_sz            (8)
  37 #define NFS_filename_sz         (1+(NFS2_MAXNAMLEN>>2))
  38 #define NFS_path_sz             (1+(NFS2_MAXPATHLEN>>2))
  39 #define NFS_fattr_sz            (17)
  40 #define NFS_info_sz             (5)
  41 #define NFS_entry_sz            (NFS_filename_sz+3)
  42
  43 #define NFS_diropargs_sz        (NFS_fhandle_sz+NFS_filename_sz)
  44 #define NFS_removeargs_sz       (NFS_fhandle_sz+NFS_filename_sz)
  45 #define NFS_sattrargs_sz        (NFS_fhandle_sz+NFS_sattr_sz)
  46 #define NFS_readlinkargs_sz     (NFS_fhandle_sz)
  47 #define NFS_readargs_sz         (NFS_fhandle_sz+3)
  48 #define NFS_writeargs_sz        (NFS_fhandle_sz+4)
  49 #define NFS_createargs_sz       (NFS_diropargs_sz+NFS_sattr_sz)
  50 #define NFS_renameargs_sz       (NFS_diropargs_sz+NFS_diropargs_sz)
  51 #define NFS_linkargs_sz         (NFS_fhandle_sz+NFS_diropargs_sz)
  52 #define NFS_symlinkargs_sz      (NFS_diropargs_sz+1+NFS_sattr_sz)
  53 #define NFS_readdirargs_sz      (NFS_fhandle_sz+2)
  54
  55 #define NFS_attrstat_sz         (1+NFS_fattr_sz)
  56 #define NFS_diropres_sz         (1+NFS_fhandle_sz+NFS_fattr_sz)
  57 #define NFS_readlinkres_sz      (2)
  58 #define NFS_readres_sz          (1+NFS_fattr_sz+1)
  59 #define NFS_writeres_sz         (NFS_attrstat_sz)
  60 #define NFS_stat_sz             (1)
  61 #define NFS_readdirres_sz       (1)
  62 #define NFS_statfsres_sz        (1+NFS_info_sz)
  63
  64 /*
  65  * Common NFS XDR functions as inlines
  66  */
  67 static inline __be32 *
  68 xdr_encode_fhandle(__be32 *p, const struct nfs_fh *fhandle)
  69 {
  70         memcpy(p, fhandle->data, NFS2_FHSIZE);
  71         return p + XDR_QUADLEN(NFS2_FHSIZE);
  72 }
  73
  74 static inline __be32 *
  75 xdr_decode_fhandle(__be32 *p, struct nfs_fh *fhandle)
  76 {
  77         /* NFSv2 handles have a fixed length */
  78         fhandle->size = NFS2_FHSIZE;
  79         memcpy(fhandle->data, p, NFS2_FHSIZE);
  80         return p + XDR_QUADLEN(NFS2_FHSIZE);
  81 }
  82
  83 static inline __be32*
  84 xdr_encode_time(__be32 *p, struct timespec *timep)
  85 {
  86         *p++ = htonl(timep->tv_sec);
  87         /* Convert nanoseconds into microseconds */
  88         *p++ = htonl(timep->tv_nsec ? timep->tv_nsec / 1000 : 0);
  89         return p;
  90 }
  91
  92 static inline __be32*
  93 xdr_encode_current_server_time(__be32 *p, struct timespec *timep)
  94 {
  95         /*
  96          * Passing the invalid value useconds=1000000 is a
  97          * Sun convention for "set to current server time".
  98          * It's needed to make permissions checks for the
  99          * "touch" program across v2 mounts to Solaris and
 100          * Irix boxes work correctly. See description of
 101          * sattr in section 6.1 of "NFS Illustrated" by
 102          * Brent Callaghan, Addison-Wesley, ISBN 0-201-32750-5
 103          */
 104         *p++ = htonl(timep->tv_sec);
 105         *p++ = htonl(1000000);
 106         return p;
 107 }
 108
 109 static inline __be32*
 110 xdr_decode_time(__be32 *p, struct timespec *timep)
 111 {
 112         timep->tv_sec = ntohl(*p++);
 113         /* Convert microseconds into nanoseconds */
 114         timep->tv_nsec = ntohl(*p++) * 1000;
 115         return p;
 116 }
 117
 118 static __be32 *
 119 xdr_decode_fattr(__be32 *p, struct nfs_fattr *fattr)
 120 {
 121         u32 rdev, type;
 122         type = ntohl(*p++);
 123         fattr->mode = ntohl(*p++);
 124         fattr->nlink = ntohl(*p++);
 125         fattr->uid = ntohl(*p++);
 126         fattr->gid = ntohl(*p++);
 127         fattr->size = ntohl(*p++);
 128         fattr->du.nfs2.blocksize = ntohl(*p++);
 129         rdev = ntohl(*p++);
 130         fattr->du.nfs2.blocks = ntohl(*p++);
 131         fattr->fsid.major = ntohl(*p++);
 132         fattr->fsid.minor = 0;
 133         fattr->fileid = ntohl(*p++);
 134         p = xdr_decode_time(p, &fattr->atime);
 135         p = xdr_decode_time(p, &fattr->mtime);
 136         p = xdr_decode_time(p, &fattr->ctime);
 137         fattr->valid |= NFS_ATTR_FATTR_V2;
 138         fattr->rdev = new_decode_dev(rdev);
 139         if (type == NFCHR && rdev == NFS2_FIFO_DEV) {
 140                 fattr->mode = (fattr->mode & ~S_IFMT) | S_IFIFO;
 141                 fattr->rdev = 0;
 142         }
 143         return p;
 144 }
 145
 146 static inline __be32 *
 147 xdr_encode_sattr(__be32 *p, struct iattr *attr)
 148 {
 149         const __be32 not_set = __constant_htonl(0xFFFFFFFF);
 150
 151         *p++ = (attr->ia_valid & ATTR_MODE) ? htonl(attr->ia_mode) : not_set;
 152         *p++ = (attr->ia_valid & ATTR_UID) ? htonl(attr->ia_uid) : not_set;
 153         *p++ = (attr->ia_valid & ATTR_GID) ? htonl(attr->ia_gid) : not_set;
 154         *p++ = (attr->ia_valid & ATTR_SIZE) ? htonl(attr->ia_size) : not_set;
 155
 156         if (attr->ia_valid & ATTR_ATIME_SET) {
 157                 p = xdr_encode_time(p, &attr->ia_atime);
 158         } else if (attr->ia_valid & ATTR_ATIME) {
 159                 p = xdr_encode_current_server_time(p, &attr->ia_atime);
 160         } else {
 161                 *p++ = not_set;
 162                 *p++ = not_set;
 163         }
 164
 165         if (attr->ia_valid & ATTR_MTIME_SET) {
 166                 p = xdr_encode_time(p, &attr->ia_mtime);
 167         } else if (attr->ia_valid & ATTR_MTIME) {
 168                 p = xdr_encode_current_server_time(p, &attr->ia_mtime);
 169         } else {
 170                 *p++ = not_set;
 171                 *p++ = not_set;
 172         }
 173         return p;
 174 }
 175
 176 /*
 177  * NFS encode functions
 178  */
 179 /*
 180  * Encode file handle argument
 181  * GETATTR, READLINK, STATFS
 182  */
 183 static int
 184 nfs_xdr_fhandle(struct rpc_rqst *req, __be32 *p, struct nfs_fh *fh)
 185 {
 186         p = xdr_encode_fhandle(p, fh);
 187         req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
 188         return 0;
 189 }
 190
 191 /*
 192  * Encode SETATTR arguments
 193  */
 194 static int
 195 nfs_xdr_sattrargs(struct rpc_rqst *req, __be32 *p, struct nfs_sattrargs *args)
 196 {
 197         p = xdr_encode_fhandle(p, args->fh);
 198         p = xdr_encode_sattr(p, args->sattr);
 199         req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
 200         return 0;
 201 }
 202
 203 /*
 204  * Encode directory ops argument
 205  * LOOKUP, RMDIR
 206  */
 207 static int
 208 nfs_xdr_diropargs(struct rpc_rqst *req, __be32 *p, struct nfs_diropargs *args)
 209 {
 210         p = xdr_encode_fhandle(p, args->fh);
 211         p = xdr_encode_array(p, args->name, args->len);
 212         req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
 213         return 0;
 214 }
 215
 216 /*
 217  * Encode REMOVE argument
 218  */
 219 static int
 220 nfs_xdr_removeargs(struct rpc_rqst *req, __be32 *p, const struct nfs_removeargs *args)
 221 {
 222         p = xdr_encode_fhandle(p, args->fh);
 223         p = xdr_encode_array(p, args->name.name, args->name.len);
 224         req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
 225         return 0;
 226 }
 227
 228 /*
 229  * Arguments to a READ call. Since we read data directly into the page
 230  * cache, we also set up the reply iovec here so that iov[1] points
 231  * exactly to the page we want to fetch.
 232  */
 233 static int
 234 nfs_xdr_readargs(struct rpc_rqst *req, __be32 *p, struct nfs_readargs *args)
 235 {
 236         struct rpc_auth *auth = req->rq_cred->cr_auth;
 237         unsigned int replen;
 238         u32 offset = (u32)args->offset;
 239         u32 count = args->count;
 240
 241         p = xdr_encode_fhandle(p, args->fh);
 242         *p++ = htonl(offset);
 243         *p++ = htonl(count);
 244         *p++ = htonl(count);
 245         req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
 246
 247         /* Inline the page array */
 248         replen = (RPC_REPHDRSIZE + auth->au_rslack + NFS_readres_sz) << 2;
 249         xdr_inline_pages(&req->rq_rcv_buf, replen,
 250                          args->pages, args->pgbase, count);
 251         req->rq_rcv_buf.flags |= XDRBUF_READ;
 252         return 0;
 253 }
 254
 255 /*
 256  * Decode READ reply
 257  */
 258 static int
 259 nfs_xdr_readres(struct rpc_rqst *req, __be32 *p, struct nfs_readres *res)
 260 {
 261         struct kvec *iov = req->rq_rcv_buf.head;
 262         size_t hdrlen;
 263         u32 count, recvd;
 264         int status;
 265
 266         if ((status = ntohl(*p++)))
 267                 return nfs_stat_to_errno(status);
 268         p = xdr_decode_fattr(p, res->fattr);
 269
 270         count = ntohl(*p++);
 271         res->eof = 0;
 272         hdrlen = (u8 *) p - (u8 *) iov->iov_base;
 273         if (iov->iov_len < hdrlen) {
 274                 dprintk("NFS: READ reply header overflowed:"
 275                                 "length %Zu > %Zu\n", hdrlen, iov->iov_len);
 276                 return -errno_NFSERR_IO;
 277         } else if (iov->iov_len != hdrlen) {
 278                 dprintk("NFS: READ header is short. iovec will be shifted.\n");
 279                 xdr_shift_buf(&req->rq_rcv_buf, iov->iov_len - hdrlen);
 280         }
 281
 282         recvd = req->rq_rcv_buf.len - hdrlen;
 283         if (count > recvd) {
 284                 dprintk("NFS: server cheating in read reply: "
 285                         "count %u > recvd %u\n", count, recvd);
 286                 count = recvd;
 287         }
 288
 289         dprintk("RPC:      readres OK count %u\n", count);
 290         if (count < res->count)
 291                 res->count = count;
 292
 293         return count;
 294 }
 295
 296
 297 /*
 298  * Write arguments. Splice the buffer to be written into the iovec.
 299  */
 300 static int
 301 nfs_xdr_writeargs(struct rpc_rqst *req, __be32 *p, struct nfs_writeargs *args)
 302 {
 303         struct xdr_buf *sndbuf = &req->rq_snd_buf;
 304         u32 offset = (u32)args->offset;
 305         u32 count = args->count;
 306
 307         p = xdr_encode_fhandle(p, args->fh);
 308         *p++ = htonl(offset);
 309         *p++ = htonl(offset);
 310         *p++ = htonl(count);
 311         *p++ = htonl(count);
 312         sndbuf->len = xdr_adjust_iovec(sndbuf->head, p);
 313
 314         /* Copy the page array */
 315         xdr_encode_pages(sndbuf, args->pages, args->pgbase, count);
 316         sndbuf->flags |= XDRBUF_WRITE;
 317         return 0;
 318 }
 319
 320 /*
 321  * Encode create arguments
 322  * CREATE, MKDIR
 323  */
 324 static int
 325 nfs_xdr_createargs(struct rpc_rqst *req, __be32 *p, struct nfs_createargs *args)
 326 {
 327         p = xdr_encode_fhandle(p, args->fh);
 328         p = xdr_encode_array(p, args->name, args->len);
 329         p = xdr_encode_sattr(p, args->sattr);
 330         req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
 331         return 0;
 332 }
 333
 334 /*
 335  * Encode RENAME arguments
 336  */
 337 static int
 338 nfs_xdr_renameargs(struct rpc_rqst *req, __be32 *p, struct nfs_renameargs *args)
 339 {
 340         p = xdr_encode_fhandle(p, args->fromfh);
 341         p = xdr_encode_array(p, args->fromname, args->fromlen);
 342         p = xdr_encode_fhandle(p, args->tofh);
 343         p = xdr_encode_array(p, args->toname, args->tolen);
 344         req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
 345         return 0;
 346 }
 347
 348 /*
 349  * Encode LINK arguments
 350  */
 351 static int
 352 nfs_xdr_linkargs(struct rpc_rqst *req, __be32 *p, struct nfs_linkargs *args)
 353 {
 354         p = xdr_encode_fhandle(p, args->fromfh);
 355         p = xdr_encode_fhandle(p, args->tofh);
 356         p = xdr_encode_array(p, args->toname, args->tolen);
 357         req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
 358         return 0;
 359 }
 360
 361 /*
 362  * Encode SYMLINK arguments
 363  */
 364 static int
 365 nfs_xdr_symlinkargs(struct rpc_rqst *req, __be32 *p, struct nfs_symlinkargs *args)
 366 {
 367         struct xdr_buf *sndbuf = &req->rq_snd_buf;
 368         size_t pad;
 369
 370         p = xdr_encode_fhandle(p, args->fromfh);
 371         p = xdr_encode_array(p, args->fromname, args->fromlen);
 372         *p++ = htonl(args->pathlen);
 373         sndbuf->len = xdr_adjust_iovec(sndbuf->head, p);
 374
 375         xdr_encode_pages(sndbuf, args->pages, 0, args->pathlen);
 376
 377         /*
 378          * xdr_encode_pages may have added a few bytes to ensure the
 379          * pathname ends on a 4-byte boundary.  Start encoding the
 380          * attributes after the pad bytes.
 381          */
 382         pad = sndbuf->tail->iov_len;
 383         if (pad > 0)
 384                 p++;
 385         p = xdr_encode_sattr(p, args->sattr);
 386         sndbuf->len += xdr_adjust_iovec(sndbuf->tail, p) - pad;
 387         return 0;
 388 }
 389
 390 /*
 391  * Encode arguments to readdir call
 392  */
 393 static int
 394 nfs_xdr_readdirargs(struct rpc_rqst *req, __be32 *p, struct nfs_readdirargs *args)
 395 {
 396         struct rpc_auth *auth = req->rq_cred->cr_auth;
 397         unsigned int replen;
 398         u32 count = args->count;
 399
 400         p = xdr_encode_fhandle(p, args->fh);
 401         *p++ = htonl(args->cookie);
 402         *p++ = htonl(count); /* see above */
 403         req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
 404
 405         /* Inline the page array */
 406         replen = (RPC_REPHDRSIZE + auth->au_rslack + NFS_readdirres_sz) << 2;
 407         xdr_inline_pages(&req->rq_rcv_buf, replen, args->pages, 0, count);
 408         return 0;
 409 }
 410
 411 /*
 412  * Decode the result of a readdir call.
 413  * We're not really decoding anymore, we just leave the buffer untouched
 414  * and only check that it is syntactically correct.
 415  * The real decoding happens in nfs_decode_entry below, called directly
 416  * from nfs_readdir for each entry.
 417  */
 418 static int
 419 nfs_xdr_readdirres(struct rpc_rqst *req, __be32 *p, void *dummy)
 420 {
 421         struct xdr_buf *rcvbuf = &req->rq_rcv_buf;
 422         struct kvec *iov = rcvbuf->head;
 423         struct page **page;
 424         size_t hdrlen;
 425         unsigned int pglen, recvd;
 426         u32 len;
 427         int status, nr = 0;
 428         __be32 *end, *entry, *kaddr;
 429
 430         if ((status = ntohl(*p++)))
 431                 return nfs_stat_to_errno(status);
 432
 433         hdrlen = (u8 *) p - (u8 *) iov->iov_base;
 434         if (iov->iov_len < hdrlen) {
 435                 dprintk("NFS: READDIR reply header overflowed:"
 436                                 "length %Zu > %Zu\n", hdrlen, iov->iov_len);
 437                 return -errno_NFSERR_IO;
 438         } else if (iov->iov_len != hdrlen) {
 439                 dprintk("NFS: READDIR header is short. iovec will be shifted.\n");
 440                 xdr_shift_buf(rcvbuf, iov->iov_len - hdrlen);
 441         }
 442
 443         pglen = rcvbuf->page_len;
 444         recvd = rcvbuf->len - hdrlen;
 445         if (pglen > recvd)
 446                 pglen = recvd;
 447         page = rcvbuf->pages;
 448         kaddr = p = kmap_atomic(*page, KM_USER0);
 449         end = (__be32 *)((char *)p + pglen);
 450         entry = p;
 451
 452         /* Make sure the packet actually has a value_follows and EOF entry */
 453         if ((entry + 1) > end)
 454                 goto short_pkt;
 455
 456         for (; *p++; nr++) {
 457                 if (p + 2 > end)
 458                         goto short_pkt;
 459                 p++; /* fileid */
 460                 len = ntohl(*p++);
 461                 p += XDR_QUADLEN(len) + 1;      /* name plus cookie */
 462                 if (len > NFS2_MAXNAMLEN) {
 463                         dprintk("NFS: giant filename in readdir (len 0x%x)!\n",
 464                                                 len);
 465                         goto err_unmap;
 466                 }
 467                 if (p + 2 > end)
 468                         goto short_pkt;
 469                 entry = p;
 470         }
 471
 472         /*
 473          * Apparently some server sends responses that are a valid size, but
 474          * contain no entries, and have value_follows==0 and EOF==0. For
 475          * those, just set the EOF marker.
 476          */
 477         if (!nr && entry[1] == 0) {
 478                 dprintk("NFS: readdir reply truncated!\n");
 479                 entry[1] = 1;
 480         }
 481  out:
 482         kunmap_atomic(kaddr, KM_USER0);
 483         return nr;
 484  short_pkt:
 485         /*
 486          * When we get a short packet there are 2 possibilities. We can
 487          * return an error, or fix up the response to look like a valid
 488          * response and return what we have so far. If there are no
 489          * entries and the packet was short, then return -EIO. If there
 490          * are valid entries in the response, return them and pretend that
 491          * the call was successful, but incomplete. The caller can retry the
 492          * readdir starting at the last cookie.
 493          */
 494         entry[0] = entry[1] = 0;
 495         if (!nr)
 496                 nr = -errno_NFSERR_IO;
 497         goto out;
 498 err_unmap:
 499         nr = -errno_NFSERR_IO;
 500         goto out;
 501 }
 502
 503 __be32 *
 504 nfs_decode_dirent(__be32 *p, struct nfs_entry *entry, int plus)
 505 {
 506         if (!*p++) {
 507                 if (!*p)
 508                         return ERR_PTR(-EAGAIN);
 509                 entry->eof = 1;
 510                 return ERR_PTR(-EBADCOOKIE);
 511         }
 512
 513         entry->ino        = ntohl(*p++);
 514         entry->len        = ntohl(*p++);
 515         entry->name       = (const char *) p;
 516         p                += XDR_QUADLEN(entry->len);
 517         entry->prev_cookie        = entry->cookie;
 518         entry->cookie     = ntohl(*p++);
 519         entry->eof        = !p[0] && p[1];
 520
 521         return p;
 522 }
 523
 524 /*
 525  * NFS XDR decode functions
 526  */
 527 /*
 528  * Decode simple status reply
 529  */
 530 static int
 531 nfs_xdr_stat(struct rpc_rqst *req, __be32 *p, void *dummy)
 532 {
 533         int     status;
 534
 535         if ((status = ntohl(*p++)) != 0)
 536                 status = nfs_stat_to_errno(status);
 537         return status;
 538 }
 539
 540 /*
 541  * Decode attrstat reply
 542  * GETATTR, SETATTR, WRITE
 543  */
 544 static int
 545 nfs_xdr_attrstat(struct rpc_rqst *req, __be32 *p, struct nfs_fattr *fattr)
 546 {
 547         int     status;
 548
 549         if ((status = ntohl(*p++)))
 550                 return nfs_stat_to_errno(status);
 551         xdr_decode_fattr(p, fattr);
 552         return 0;
 553 }
 554
 555 /*
 556  * Decode diropres reply
 557  * LOOKUP, CREATE, MKDIR
 558  */
 559 static int
 560 nfs_xdr_diropres(struct rpc_rqst *req, __be32 *p, struct nfs_diropok *res)
 561 {
 562         int     status;
 563
 564         if ((status = ntohl(*p++)))
 565                 return nfs_stat_to_errno(status);
 566         p = xdr_decode_fhandle(p, res->fh);
 567         xdr_decode_fattr(p, res->fattr);
 568         return 0;
 569 }
 570
 571 /*
 572  * Encode READLINK args
 573  */
 574 static int
 575 nfs_xdr_readlinkargs(struct rpc_rqst *req, __be32 *p, struct nfs_readlinkargs *args)
 576 {
 577         struct rpc_auth *auth = req->rq_cred->cr_auth;
 578         unsigned int replen;
 579
 580         p = xdr_encode_fhandle(p, args->fh);
 581         req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
 582
 583         /* Inline the page array */
 584         replen = (RPC_REPHDRSIZE + auth->au_rslack + NFS_readlinkres_sz) << 2;
 585         xdr_inline_pages(&req->rq_rcv_buf, replen, args->pages, args->pgbase, args->pglen);
 586         return 0;
 587 }
 588
 589 /*
 590  * Decode READLINK reply
 591  */
 592 static int
 593 nfs_xdr_readlinkres(struct rpc_rqst *req, __be32 *p, void *dummy)
 594 {
 595         struct xdr_buf *rcvbuf = &req->rq_rcv_buf;
 596         struct kvec *iov = rcvbuf->head;
 597         size_t hdrlen;
 598         u32 len, recvd;
 599         char    *kaddr;
 600         int     status;
 601
 602         if ((status = ntohl(*p++)))
 603                 return nfs_stat_to_errno(status);
 604         /* Convert length of symlink */
 605         len = ntohl(*p++);
 606         if (len >= rcvbuf->page_len) {
 607                 dprintk("nfs: server returned giant symlink!\n");
 608                 return -ENAMETOOLONG;
 609         }
 610         hdrlen = (u8 *) p - (u8 *) iov->iov_base;
 611         if (iov->iov_len < hdrlen) {
 612                 dprintk("NFS: READLINK reply header overflowed:"
 613                                 "length %Zu > %Zu\n", hdrlen, iov->iov_len);
 614                 return -errno_NFSERR_IO;
 615         } else if (iov->iov_len != hdrlen) {
 616                 dprintk("NFS: READLINK header is short. iovec will be shifted.\n");
 617                 xdr_shift_buf(rcvbuf, iov->iov_len - hdrlen);
 618         }
 619         recvd = req->rq_rcv_buf.len - hdrlen;
 620         if (recvd < len) {
 621                 dprintk("NFS: server cheating in readlink reply: "
 622                                 "count %u > recvd %u\n", len, recvd);
 623                 return -EIO;
 624         }
 625
 626         /* NULL terminate the string we got */
 627         kaddr = (char *)kmap_atomic(rcvbuf->pages[0], KM_USER0);
 628         kaddr[len+rcvbuf->page_base] = '\0';
 629         kunmap_atomic(kaddr, KM_USER0);
 630         return 0;
 631 }
 632
 633 /*
 634  * Decode WRITE reply
 635  */
 636 static int
 637 nfs_xdr_writeres(struct rpc_rqst *req, __be32 *p, struct nfs_writeres *res)
 638 {
 639         res->verf->committed = NFS_FILE_SYNC;
 640         return nfs_xdr_attrstat(req, p, res->fattr);
 641 }
 642
 643 /*
 644  * Decode STATFS reply
 645  */
 646 static int
 647 nfs_xdr_statfsres(struct rpc_rqst *req, __be32 *p, struct nfs2_fsstat *res)
 648 {
 649         int     status;
 650
 651         if ((status = ntohl(*p++)))
 652                 return nfs_stat_to_errno(status);
 653
 654         res->tsize  = ntohl(*p++);
 655         res->bsize  = ntohl(*p++);
 656         res->blocks = ntohl(*p++);
 657         res->bfree  = ntohl(*p++);
 658         res->bavail = ntohl(*p++);
 659         return 0;
 660 }
 661
 662 /*
 663  * We need to translate between nfs status return values and
 664  * the local errno values which may not be the same.
 665  */
 666 static struct {
 667         int stat;
 668         int errno;
 669 } nfs_errtbl[] = {
 670         { NFS_OK,               0               },
 671         { NFSERR_PERM,          -EPERM          },
 672         { NFSERR_NOENT,         -ENOENT         },
 673         { NFSERR_IO,            -errno_NFSERR_IO},
 674         { NFSERR_NXIO,          -ENXIO          },
 675 /*      { NFSERR_EAGAIN,        -EAGAIN         }, */
 676         { NFSERR_ACCES,         -EACCES         },
 677         { NFSERR_EXIST,         -EEXIST         },
 678         { NFSERR_XDEV,          -EXDEV          },
 679         { NFSERR_NODEV,         -ENODEV         },
 680         { NFSERR_NOTDIR,        -ENOTDIR        },
 681         { NFSERR_ISDIR,         -EISDIR         },
 682         { NFSERR_INVAL,         -EINVAL         },
 683         { NFSERR_FBIG,          -EFBIG          },
 684         { NFSERR_NOSPC,         -ENOSPC         },
 685         { NFSERR_ROFS,          -EROFS          },
 686         { NFSERR_MLINK,         -EMLINK         },
 687         { NFSERR_NAMETOOLONG,   -ENAMETOOLONG   },
 688         { NFSERR_NOTEMPTY,      -ENOTEMPTY      },
 689         { NFSERR_DQUOT,         -EDQUOT         },
 690         { NFSERR_STALE,         -ESTALE         },
 691         { NFSERR_REMOTE,        -EREMOTE        },
 692 #ifdef EWFLUSH
 693         { NFSERR_WFLUSH,        -EWFLUSH        },
 694 #endif
 695         { NFSERR_BADHANDLE,     -EBADHANDLE     },
 696         { NFSERR_NOT_SYNC,      -ENOTSYNC       },
 697         { NFSERR_BAD_COOKIE,    -EBADCOOKIE     },
 698         { NFSERR_NOTSUPP,       -ENOTSUPP       },
 699         { NFSERR_TOOSMALL,      -ETOOSMALL      },
 700         { NFSERR_SERVERFAULT,   -EREMOTEIO      },
 701         { NFSERR_BADTYPE,       -EBADTYPE       },
 702         { NFSERR_JUKEBOX,       -EJUKEBOX       },
 703         { -1,                   -EIO            }
 704 };
 705
 706 /*
 707  * Convert an NFS error code to a local one.
 708  * This one is used jointly by NFSv2 and NFSv3.
 709  */
 710 int
 711 nfs_stat_to_errno(int stat)
 712 {
 713         int i;
 714
 715         for (i = 0; nfs_errtbl[i].stat != -1; i++) {
 716                 if (nfs_errtbl[i].stat == stat)
 717                         return nfs_errtbl[i].errno;
 718         }
 719         dprintk("nfs_stat_to_errno: bad nfs status return value: %d\n", stat);
 720         return nfs_errtbl[i].errno;
 721 }
 722
 723 #define PROC(proc, argtype, restype, timer)                             \
 724 [NFSPROC_##proc] = {                                                    \
 725         .p_proc     =  NFSPROC_##proc,                                  \
 726         .p_encode   =  (kxdrproc_t) nfs_xdr_##argtype,                  \
 727         .p_decode   =  (kxdrproc_t) nfs_xdr_##restype,                  \
 728         .p_arglen   =  NFS_##argtype##_sz,                              \
 729         .p_replen   =  NFS_##restype##_sz,                              \
 730         .p_timer    =  timer,                                           \
 731         .p_statidx  =  NFSPROC_##proc,                                  \
 732         .p_name     =  #proc,                                           \
 733         }
 734 struct rpc_procinfo     nfs_procedures[] = {
 735     PROC(GETATTR,       fhandle,        attrstat, 1),
 736     PROC(SETATTR,       sattrargs,      attrstat, 0),
 737     PROC(LOOKUP,        diropargs,      diropres, 2),
 738     PROC(READLINK,      readlinkargs,   readlinkres, 3),
 739     PROC(READ,          readargs,       readres, 3),
 740     PROC(WRITE,         writeargs,      writeres, 4),
 741     PROC(CREATE,        createargs,     diropres, 0),
 742     PROC(REMOVE,        removeargs,     stat, 0),
 743     PROC(RENAME,        renameargs,     stat, 0),
 744     PROC(LINK,          linkargs,       stat, 0),
 745     PROC(SYMLINK,       symlinkargs,    stat, 0),
 746     PROC(MKDIR,         createargs,     diropres, 0),
 747     PROC(RMDIR,         diropargs,      stat, 0),
 748     PROC(READDIR,       readdirargs,    readdirres, 3),
 749     PROC(STATFS,        fhandle,        statfsres, 0),
 750 };
 751
 752 struct rpc_version              nfs_version2 = {
 753         .number                 = 2,
 754         .nrprocs                = ARRAY_SIZE(nfs_procedures),
 755         .procs                  = nfs_procedures
 756 };