fs/nfs/callback_xdr.c

   1 /*
   2  * linux/fs/nfs/callback_xdr.c
   3  *
   4  * Copyright (C) 2004 Trond Myklebust
   5  *
   6  * NFSv4 callback encode/decode procedures
   7  */
   8 #include <linux/kernel.h>
   9 #include <linux/sunrpc/svc.h>
  10 #include <linux/nfs4.h>
  11 #include <linux/nfs_fs.h>
  12 #include "nfs4_fs.h"
  13 #include "callback.h"
  14
  15 #define CB_OP_TAGLEN_MAXSZ      (512)
  16 #define CB_OP_HDR_RES_MAXSZ     (2 + CB_OP_TAGLEN_MAXSZ)
  17 #define CB_OP_GETATTR_BITMAP_MAXSZ      (4)
  18 #define CB_OP_GETATTR_RES_MAXSZ (CB_OP_HDR_RES_MAXSZ + \
  19                                 CB_OP_GETATTR_BITMAP_MAXSZ + \
  20                                 2 + 2 + 3 + 3)
  21 #define CB_OP_RECALL_RES_MAXSZ  (CB_OP_HDR_RES_MAXSZ)
  22
  23 #if defined(CONFIG_NFS_V4_1)
  24 #define CB_OP_SEQUENCE_RES_MAXSZ        (CB_OP_HDR_RES_MAXSZ + \
  25                                         4 + 1 + 3)
  26 #endif /* CONFIG_NFS_V4_1 */
  27
  28 #define NFSDBG_FACILITY NFSDBG_CALLBACK
  29
  30 typedef __be32 (*callback_process_op_t)(void *, void *);
  31 typedef __be32 (*callback_decode_arg_t)(struct svc_rqst *, struct xdr_stream *, void *);
  32 typedef __be32 (*callback_encode_res_t)(struct svc_rqst *, struct xdr_stream *, void *);
  33
  34
  35 struct callback_op {
  36         callback_process_op_t process_op;
  37         callback_decode_arg_t decode_args;
  38         callback_encode_res_t encode_res;
  39         long res_maxsize;
  40 };
  41
  42 static struct callback_op callback_ops[];
  43
  44 static __be32 nfs4_callback_null(struct svc_rqst *rqstp, void *argp, void *resp)
  45 {
  46         return htonl(NFS4_OK);
  47 }
  48
  49 static int nfs4_decode_void(struct svc_rqst *rqstp, __be32 *p, void *dummy)
  50 {
  51         return xdr_argsize_check(rqstp, p);
  52 }
  53
  54 static int nfs4_encode_void(struct svc_rqst *rqstp, __be32 *p, void *dummy)
  55 {
  56         return xdr_ressize_check(rqstp, p);
  57 }
  58
  59 static __be32 *read_buf(struct xdr_stream *xdr, int nbytes)
  60 {
  61         __be32 *p;
  62
  63         p = xdr_inline_decode(xdr, nbytes);
  64         if (unlikely(p == NULL))
  65                 printk(KERN_WARNING "NFSv4 callback reply buffer overflowed!\n");
  66         return p;
  67 }
  68
  69 static __be32 decode_string(struct xdr_stream *xdr, unsigned int *len, const char **str)
  70 {
  71         __be32 *p;
  72
  73         p = read_buf(xdr, 4);
  74         if (unlikely(p == NULL))
  75                 return htonl(NFS4ERR_RESOURCE);
  76         *len = ntohl(*p);
  77
  78         if (*len != 0) {
  79                 p = read_buf(xdr, *len);
  80                 if (unlikely(p == NULL))
  81                         return htonl(NFS4ERR_RESOURCE);
  82                 *str = (const char *)p;
  83         } else
  84                 *str = NULL;
  85
  86         return 0;
  87 }
  88
  89 static __be32 decode_fh(struct xdr_stream *xdr, struct nfs_fh *fh)
  90 {
  91         __be32 *p;
  92
  93         p = read_buf(xdr, 4);
  94         if (unlikely(p == NULL))
  95                 return htonl(NFS4ERR_RESOURCE);
  96         fh->size = ntohl(*p);
  97         if (fh->size > NFS4_FHSIZE)
  98                 return htonl(NFS4ERR_BADHANDLE);
  99         p = read_buf(xdr, fh->size);
 100         if (unlikely(p == NULL))
 101                 return htonl(NFS4ERR_RESOURCE);
 102         memcpy(&fh->data[0], p, fh->size);
 103         memset(&fh->data[fh->size], 0, sizeof(fh->data) - fh->size);
 104         return 0;
 105 }
 106
 107 static __be32 decode_bitmap(struct xdr_stream *xdr, uint32_t *bitmap)
 108 {
 109         __be32 *p;
 110         unsigned int attrlen;
 111
 112         p = read_buf(xdr, 4);
 113         if (unlikely(p == NULL))
 114                 return htonl(NFS4ERR_RESOURCE);
 115         attrlen = ntohl(*p);
 116         p = read_buf(xdr, attrlen << 2);
 117         if (unlikely(p == NULL))
 118                 return htonl(NFS4ERR_RESOURCE);
 119         if (likely(attrlen > 0))
 120                 bitmap[0] = ntohl(*p++);
 121         if (attrlen > 1)
 122                 bitmap[1] = ntohl(*p);
 123         return 0;
 124 }
 125
 126 static __be32 decode_stateid(struct xdr_stream *xdr, nfs4_stateid *stateid)
 127 {
 128         __be32 *p;
 129
 130         p = read_buf(xdr, 16);
 131         if (unlikely(p == NULL))
 132                 return htonl(NFS4ERR_RESOURCE);
 133         memcpy(stateid->data, p, 16);
 134         return 0;
 135 }
 136
 137 static __be32 decode_compound_hdr_arg(struct xdr_stream *xdr, struct cb_compound_hdr_arg *hdr)
 138 {
 139         __be32 *p;
 140         __be32 status;
 141
 142         status = decode_string(xdr, &hdr->taglen, &hdr->tag);
 143         if (unlikely(status != 0))
 144                 return status;
 145         /* We do not like overly long tags! */
 146         if (hdr->taglen > CB_OP_TAGLEN_MAXSZ - 12) {
 147                 printk("NFSv4 CALLBACK %s: client sent tag of length %u\n",
 148                                 __func__, hdr->taglen);
 149                 return htonl(NFS4ERR_RESOURCE);
 150         }
 151         p = read_buf(xdr, 12);
 152         if (unlikely(p == NULL))
 153                 return htonl(NFS4ERR_RESOURCE);
 154         hdr->minorversion = ntohl(*p++);
 155         /* Check minor version is zero or one. */
 156         if (hdr->minorversion <= 1) {
 157                 p++;    /* skip callback_ident */
 158         } else {
 159                 printk(KERN_WARNING "%s: NFSv4 server callback with "
 160                         "illegal minor version %u!\n",
 161                         __func__, hdr->minorversion);
 162                 return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
 163         }
 164         hdr->nops = ntohl(*p);
 165         dprintk("%s: minorversion %d nops %d\n", __func__,
 166                 hdr->minorversion, hdr->nops);
 167         return 0;
 168 }
 169
 170 static __be32 decode_op_hdr(struct xdr_stream *xdr, unsigned int *op)
 171 {
 172         __be32 *p;
 173         p = read_buf(xdr, 4);
 174         if (unlikely(p == NULL))
 175                 return htonl(NFS4ERR_RESOURCE);
 176         *op = ntohl(*p);
 177         return 0;
 178 }
 179
 180 static __be32 decode_getattr_args(struct svc_rqst *rqstp, struct xdr_stream *xdr, struct cb_getattrargs *args)
 181 {
 182         __be32 status;
 183
 184         status = decode_fh(xdr, &args->fh);
 185         if (unlikely(status != 0))
 186                 goto out;
 187         args->addr = svc_addr(rqstp);
 188         status = decode_bitmap(xdr, args->bitmap);
 189 out:
 190         dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
 191         return status;
 192 }
 193
 194 static __be32 decode_recall_args(struct svc_rqst *rqstp, struct xdr_stream *xdr, struct cb_recallargs *args)
 195 {
 196         __be32 *p;
 197         __be32 status;
 198
 199         args->addr = svc_addr(rqstp);
 200         status = decode_stateid(xdr, &args->stateid);
 201         if (unlikely(status != 0))
 202                 goto out;
 203         p = read_buf(xdr, 4);
 204         if (unlikely(p == NULL)) {
 205                 status = htonl(NFS4ERR_RESOURCE);
 206                 goto out;
 207         }
 208         args->truncate = ntohl(*p);
 209         status = decode_fh(xdr, &args->fh);
 210 out:
 211         dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
 212         return status;
 213 }
 214
 215 #if defined(CONFIG_NFS_V4_1)
 216
 217 static unsigned decode_sessionid(struct xdr_stream *xdr,
 218                                  struct nfs4_sessionid *sid)
 219 {
 220         uint32_t *p;
 221         int len = NFS4_MAX_SESSIONID_LEN;
 222
 223         p = read_buf(xdr, len);
 224         if (unlikely(p == NULL))
 225                 return htonl(NFS4ERR_RESOURCE);;
 226
 227         memcpy(sid->data, p, len);
 228         return 0;
 229 }
 230
 231 static unsigned decode_rc_list(struct xdr_stream *xdr,
 232                                struct referring_call_list *rc_list)
 233 {
 234         uint32_t *p;
 235         int i;
 236         unsigned status;
 237
 238         status = decode_sessionid(xdr, &rc_list->rcl_sessionid);
 239         if (status)
 240                 goto out;
 241
 242         status = htonl(NFS4ERR_RESOURCE);
 243         p = read_buf(xdr, sizeof(uint32_t));
 244         if (unlikely(p == NULL))
 245                 goto out;
 246
 247         rc_list->rcl_nrefcalls = ntohl(*p++);
 248         if (rc_list->rcl_nrefcalls) {
 249                 p = read_buf(xdr,
 250                              rc_list->rcl_nrefcalls * 2 * sizeof(uint32_t));
 251                 if (unlikely(p == NULL))
 252                         goto out;
 253                 rc_list->rcl_refcalls = kmalloc(rc_list->rcl_nrefcalls *
 254                                                 sizeof(*rc_list->rcl_refcalls),
 255                                                 GFP_KERNEL);
 256                 if (unlikely(rc_list->rcl_refcalls == NULL))
 257                         goto out;
 258                 for (i = 0; i < rc_list->rcl_nrefcalls; i++) {
 259                         rc_list->rcl_refcalls[i].rc_sequenceid = ntohl(*p++);
 260                         rc_list->rcl_refcalls[i].rc_slotid = ntohl(*p++);
 261                 }
 262         }
 263         status = 0;
 264
 265 out:
 266         return status;
 267 }
 268
 269 static unsigned decode_cb_sequence_args(struct svc_rqst *rqstp,
 270                                         struct xdr_stream *xdr,
 271                                         struct cb_sequenceargs *args)
 272 {
 273         uint32_t *p;
 274         int i;
 275         unsigned status;
 276
 277         status = decode_sessionid(xdr, &args->csa_sessionid);
 278         if (status)
 279                 goto out;
 280
 281         status = htonl(NFS4ERR_RESOURCE);
 282         p = read_buf(xdr, 5 * sizeof(uint32_t));
 283         if (unlikely(p == NULL))
 284                 goto out;
 285
 286         args->csa_addr = svc_addr(rqstp);
 287         args->csa_sequenceid = ntohl(*p++);
 288         args->csa_slotid = ntohl(*p++);
 289         args->csa_highestslotid = ntohl(*p++);
 290         args->csa_cachethis = ntohl(*p++);
 291         args->csa_nrclists = ntohl(*p++);
 292         args->csa_rclists = NULL;
 293         if (args->csa_nrclists) {
 294                 args->csa_rclists = kmalloc(args->csa_nrclists *
 295                                             sizeof(*args->csa_rclists),
 296                                             GFP_KERNEL);
 297                 if (unlikely(args->csa_rclists == NULL))
 298                         goto out;
 299
 300                 for (i = 0; i < args->csa_nrclists; i++) {
 301                         status = decode_rc_list(xdr, &args->csa_rclists[i]);
 302                         if (status)
 303                                 goto out_free;
 304                 }
 305         }
 306         status = 0;
 307
 308         dprintk("%s: sessionid %x:%x:%x:%x sequenceid %u slotid %u "
 309                 "highestslotid %u cachethis %d nrclists %u\n",
 310                 __func__,
 311                 ((u32 *)&args->csa_sessionid)[0],
 312                 ((u32 *)&args->csa_sessionid)[1],
 313                 ((u32 *)&args->csa_sessionid)[2],
 314                 ((u32 *)&args->csa_sessionid)[3],
 315                 args->csa_sequenceid, args->csa_slotid,
 316                 args->csa_highestslotid, args->csa_cachethis,
 317                 args->csa_nrclists);
 318 out:
 319         dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
 320         return status;
 321
 322 out_free:
 323         for (i = 0; i < args->csa_nrclists; i++)
 324                 kfree(args->csa_rclists[i].rcl_refcalls);
 325         kfree(args->csa_rclists);
 326         goto out;
 327 }
 328
 329 #endif /* CONFIG_NFS_V4_1 */
 330
 331 static __be32 encode_string(struct xdr_stream *xdr, unsigned int len, const char *str)
 332 {
 333         __be32 *p;
 334
 335         p = xdr_reserve_space(xdr, 4 + len);
 336         if (unlikely(p == NULL))
 337                 return htonl(NFS4ERR_RESOURCE);
 338         xdr_encode_opaque(p, str, len);
 339         return 0;
 340 }
 341
 342 #define CB_SUPPORTED_ATTR0 (FATTR4_WORD0_CHANGE|FATTR4_WORD0_SIZE)
 343 #define CB_SUPPORTED_ATTR1 (FATTR4_WORD1_TIME_METADATA|FATTR4_WORD1_TIME_MODIFY)
 344 static __be32 encode_attr_bitmap(struct xdr_stream *xdr, const uint32_t *bitmap, __be32 **savep)
 345 {
 346         __be32 bm[2];
 347         __be32 *p;
 348
 349         bm[0] = htonl(bitmap[0] & CB_SUPPORTED_ATTR0);
 350         bm[1] = htonl(bitmap[1] & CB_SUPPORTED_ATTR1);
 351         if (bm[1] != 0) {
 352                 p = xdr_reserve_space(xdr, 16);
 353                 if (unlikely(p == NULL))
 354                         return htonl(NFS4ERR_RESOURCE);
 355                 *p++ = htonl(2);
 356                 *p++ = bm[0];
 357                 *p++ = bm[1];
 358         } else if (bm[0] != 0) {
 359                 p = xdr_reserve_space(xdr, 12);
 360                 if (unlikely(p == NULL))
 361                         return htonl(NFS4ERR_RESOURCE);
 362                 *p++ = htonl(1);
 363                 *p++ = bm[0];
 364         } else {
 365                 p = xdr_reserve_space(xdr, 8);
 366                 if (unlikely(p == NULL))
 367                         return htonl(NFS4ERR_RESOURCE);
 368                 *p++ = htonl(0);
 369         }
 370         *savep = p;
 371         return 0;
 372 }
 373
 374 static __be32 encode_attr_change(struct xdr_stream *xdr, const uint32_t *bitmap, uint64_t change)
 375 {
 376         __be32 *p;
 377
 378         if (!(bitmap[0] & FATTR4_WORD0_CHANGE))
 379                 return 0;
 380         p = xdr_reserve_space(xdr, 8);
 381         if (unlikely(!p))
 382                 return htonl(NFS4ERR_RESOURCE);
 383         p = xdr_encode_hyper(p, change);
 384         return 0;
 385 }
 386
 387 static __be32 encode_attr_size(struct xdr_stream *xdr, const uint32_t *bitmap, uint64_t size)
 388 {
 389         __be32 *p;
 390
 391         if (!(bitmap[0] & FATTR4_WORD0_SIZE))
 392                 return 0;
 393         p = xdr_reserve_space(xdr, 8);
 394         if (unlikely(!p))
 395                 return htonl(NFS4ERR_RESOURCE);
 396         p = xdr_encode_hyper(p, size);
 397         return 0;
 398 }
 399
 400 static __be32 encode_attr_time(struct xdr_stream *xdr, const struct timespec *time)
 401 {
 402         __be32 *p;
 403
 404         p = xdr_reserve_space(xdr, 12);
 405         if (unlikely(!p))
 406                 return htonl(NFS4ERR_RESOURCE);
 407         p = xdr_encode_hyper(p, time->tv_sec);
 408         *p = htonl(time->tv_nsec);
 409         return 0;
 410 }
 411
 412 static __be32 encode_attr_ctime(struct xdr_stream *xdr, const uint32_t *bitmap, const struct timespec *time)
 413 {
 414         if (!(bitmap[1] & FATTR4_WORD1_TIME_METADATA))
 415                 return 0;
 416         return encode_attr_time(xdr,time);
 417 }
 418
 419 static __be32 encode_attr_mtime(struct xdr_stream *xdr, const uint32_t *bitmap, const struct timespec *time)
 420 {
 421         if (!(bitmap[1] & FATTR4_WORD1_TIME_MODIFY))
 422                 return 0;
 423         return encode_attr_time(xdr,time);
 424 }
 425
 426 static __be32 encode_compound_hdr_res(struct xdr_stream *xdr, struct cb_compound_hdr_res *hdr)
 427 {
 428         __be32 status;
 429
 430         hdr->status = xdr_reserve_space(xdr, 4);
 431         if (unlikely(hdr->status == NULL))
 432                 return htonl(NFS4ERR_RESOURCE);
 433         status = encode_string(xdr, hdr->taglen, hdr->tag);
 434         if (unlikely(status != 0))
 435                 return status;
 436         hdr->nops = xdr_reserve_space(xdr, 4);
 437         if (unlikely(hdr->nops == NULL))
 438                 return htonl(NFS4ERR_RESOURCE);
 439         return 0;
 440 }
 441
 442 static __be32 encode_op_hdr(struct xdr_stream *xdr, uint32_t op, __be32 res)
 443 {
 444         __be32 *p;
 445
 446         p = xdr_reserve_space(xdr, 8);
 447         if (unlikely(p == NULL))
 448                 return htonl(NFS4ERR_RESOURCE);
 449         *p++ = htonl(op);
 450         *p = res;
 451         return 0;
 452 }
 453
 454 static __be32 encode_getattr_res(struct svc_rqst *rqstp, struct xdr_stream *xdr, const struct cb_getattrres *res)
 455 {
 456         __be32 *savep = NULL;
 457         __be32 status = res->status;
 458
 459         if (unlikely(status != 0))
 460                 goto out;
 461         status = encode_attr_bitmap(xdr, res->bitmap, &savep);
 462         if (unlikely(status != 0))
 463                 goto out;
 464         status = encode_attr_change(xdr, res->bitmap, res->change_attr);
 465         if (unlikely(status != 0))
 466                 goto out;
 467         status = encode_attr_size(xdr, res->bitmap, res->size);
 468         if (unlikely(status != 0))
 469                 goto out;
 470         status = encode_attr_ctime(xdr, res->bitmap, &res->ctime);
 471         if (unlikely(status != 0))
 472                 goto out;
 473         status = encode_attr_mtime(xdr, res->bitmap, &res->mtime);
 474         *savep = htonl((unsigned int)((char *)xdr->p - (char *)(savep+1)));
 475 out:
 476         dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
 477         return status;
 478 }
 479
 480 #if defined(CONFIG_NFS_V4_1)
 481
 482 static unsigned encode_sessionid(struct xdr_stream *xdr,
 483                                  const struct nfs4_sessionid *sid)
 484 {
 485         uint32_t *p;
 486         int len = NFS4_MAX_SESSIONID_LEN;
 487
 488         p = xdr_reserve_space(xdr, len);
 489         if (unlikely(p == NULL))
 490                 return htonl(NFS4ERR_RESOURCE);
 491
 492         memcpy(p, sid, len);
 493         return 0;
 494 }
 495
 496 static unsigned encode_cb_sequence_res(struct svc_rqst *rqstp,
 497                                        struct xdr_stream *xdr,
 498                                        const struct cb_sequenceres *res)
 499 {
 500         uint32_t *p;
 501         unsigned status = res->csr_status;
 502
 503         if (unlikely(status != 0))
 504                 goto out;
 505
 506         encode_sessionid(xdr, &res->csr_sessionid);
 507
 508         p = xdr_reserve_space(xdr, 4 * sizeof(uint32_t));
 509         if (unlikely(p == NULL))
 510                 return htonl(NFS4ERR_RESOURCE);
 511
 512         *p++ = htonl(res->csr_sequenceid);
 513         *p++ = htonl(res->csr_slotid);
 514         *p++ = htonl(res->csr_highestslotid);
 515         *p++ = htonl(res->csr_target_highestslotid);
 516 out:
 517         dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
 518         return status;
 519 }
 520
 521 static __be32
 522 preprocess_nfs41_op(int nop, unsigned int op_nr, struct callback_op **op)
 523 {
 524         if (op_nr == OP_CB_SEQUENCE) {
 525                 if (nop != 0)
 526                         return htonl(NFS4ERR_SEQUENCE_POS);
 527         } else {
 528                 if (nop == 0)
 529                         return htonl(NFS4ERR_OP_NOT_IN_SESSION);
 530         }
 531
 532         switch (op_nr) {
 533         case OP_CB_GETATTR:
 534         case OP_CB_RECALL:
 535         case OP_CB_SEQUENCE:
 536                 *op = &callback_ops[op_nr];
 537                 break;
 538
 539         case OP_CB_LAYOUTRECALL:
 540         case OP_CB_NOTIFY_DEVICEID:
 541         case OP_CB_NOTIFY:
 542         case OP_CB_PUSH_DELEG:
 543         case OP_CB_RECALL_ANY:
 544         case OP_CB_RECALLABLE_OBJ_AVAIL:
 545         case OP_CB_RECALL_SLOT:
 546         case OP_CB_WANTS_CANCELLED:
 547         case OP_CB_NOTIFY_LOCK:
 548                 return htonl(NFS4ERR_NOTSUPP);
 549
 550         default:
 551                 return htonl(NFS4ERR_OP_ILLEGAL);
 552         }
 553
 554         return htonl(NFS_OK);
 555 }
 556
 557 #else /* CONFIG_NFS_V4_1 */
 558
 559 static __be32
 560 preprocess_nfs41_op(int nop, unsigned int op_nr, struct callback_op **op)
 561 {
 562         return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
 563 }
 564
 565 #endif /* CONFIG_NFS_V4_1 */
 566
 567 static __be32
 568 preprocess_nfs4_op(unsigned int op_nr, struct callback_op **op)
 569 {
 570         switch (op_nr) {
 571         case OP_CB_GETATTR:
 572         case OP_CB_RECALL:
 573                 *op = &callback_ops[op_nr];
 574                 break;
 575         default:
 576                 return htonl(NFS4ERR_OP_ILLEGAL);
 577         }
 578
 579         return htonl(NFS_OK);
 580 }
 581
 582 static __be32 process_op(uint32_t minorversion, int nop,
 583                 struct svc_rqst *rqstp,
 584                 struct xdr_stream *xdr_in, void *argp,
 585                 struct xdr_stream *xdr_out, void *resp)
 586 {
 587         struct callback_op *op = &callback_ops[0];
 588         unsigned int op_nr = OP_CB_ILLEGAL;
 589         __be32 status;
 590         long maxlen;
 591         __be32 res;
 592
 593         dprintk("%s: start\n", __func__);
 594         status = decode_op_hdr(xdr_in, &op_nr);
 595         if (unlikely(status)) {
 596                 status = htonl(NFS4ERR_OP_ILLEGAL);
 597                 goto out;
 598         }
 599
 600         dprintk("%s: minorversion=%d nop=%d op_nr=%u\n",
 601                 __func__, minorversion, nop, op_nr);
 602
 603         status = minorversion ? preprocess_nfs41_op(nop, op_nr, &op) :
 604                                 preprocess_nfs4_op(op_nr, &op);
 605         if (status == htonl(NFS4ERR_OP_ILLEGAL))
 606                 op_nr = OP_CB_ILLEGAL;
 607 out:
 608         maxlen = xdr_out->end - xdr_out->p;
 609         if (maxlen > 0 && maxlen < PAGE_SIZE) {
 610                 if (likely(status == 0 && op->decode_args != NULL))
 611                         status = op->decode_args(rqstp, xdr_in, argp);
 612                 if (likely(status == 0 && op->process_op != NULL))
 613                         status = op->process_op(argp, resp);
 614         } else
 615                 status = htonl(NFS4ERR_RESOURCE);
 616
 617         res = encode_op_hdr(xdr_out, op_nr, status);
 618         if (status == 0)
 619                 status = res;
 620         if (op->encode_res != NULL && status == 0)
 621                 status = op->encode_res(rqstp, xdr_out, resp);
 622         dprintk("%s: done, status = %d\n", __func__, ntohl(status));
 623         return status;
 624 }
 625
 626 /*
 627  * Decode, process and encode a COMPOUND
 628  */
 629 static __be32 nfs4_callback_compound(struct svc_rqst *rqstp, void *argp, void *resp)
 630 {
 631         struct cb_compound_hdr_arg hdr_arg = { 0 };
 632         struct cb_compound_hdr_res hdr_res = { NULL };
 633         struct xdr_stream xdr_in, xdr_out;
 634         __be32 *p;
 635         __be32 status;
 636         unsigned int nops = 0;
 637
 638         dprintk("%s: start\n", __func__);
 639
 640         xdr_init_decode(&xdr_in, &rqstp->rq_arg, rqstp->rq_arg.head[0].iov_base);
 641
 642         p = (__be32*)((char *)rqstp->rq_res.head[0].iov_base + rqstp->rq_res.head[0].iov_len);
 643         xdr_init_encode(&xdr_out, &rqstp->rq_res, p);
 644
 645         status = decode_compound_hdr_arg(&xdr_in, &hdr_arg);
 646         if (status == __constant_htonl(NFS4ERR_RESOURCE))
 647                 return rpc_garbage_args;
 648
 649         hdr_res.taglen = hdr_arg.taglen;
 650         hdr_res.tag = hdr_arg.tag;
 651         if (encode_compound_hdr_res(&xdr_out, &hdr_res) != 0)
 652                 return rpc_system_err;
 653
 654         while (status == 0 && nops != hdr_arg.nops) {
 655                 status = process_op(hdr_arg.minorversion, nops,
 656                                     rqstp, &xdr_in, argp, &xdr_out, resp);
 657                 nops++;
 658         }
 659
 660         *hdr_res.status = status;
 661         *hdr_res.nops = htonl(nops);
 662         dprintk("%s: done, status = %u\n", __func__, ntohl(status));
 663         return rpc_success;
 664 }
 665
 666 /*
 667  * Define NFS4 callback COMPOUND ops.
 668  */
 669 static struct callback_op callback_ops[] = {
 670         [0] = {
 671                 .res_maxsize = CB_OP_HDR_RES_MAXSZ,
 672         },
 673         [OP_CB_GETATTR] = {
 674                 .process_op = (callback_process_op_t)nfs4_callback_getattr,
 675                 .decode_args = (callback_decode_arg_t)decode_getattr_args,
 676                 .encode_res = (callback_encode_res_t)encode_getattr_res,
 677                 .res_maxsize = CB_OP_GETATTR_RES_MAXSZ,
 678         },
 679         [OP_CB_RECALL] = {
 680                 .process_op = (callback_process_op_t)nfs4_callback_recall,
 681                 .decode_args = (callback_decode_arg_t)decode_recall_args,
 682                 .res_maxsize = CB_OP_RECALL_RES_MAXSZ,
 683         },
 684 #if defined(CONFIG_NFS_V4_1)
 685         [OP_CB_SEQUENCE] = {
 686                 .process_op = (callback_process_op_t)nfs4_callback_sequence,
 687                 .decode_args = (callback_decode_arg_t)decode_cb_sequence_args,
 688                 .encode_res = (callback_encode_res_t)encode_cb_sequence_res,
 689                 .res_maxsize = CB_OP_SEQUENCE_RES_MAXSZ,
 690         },
 691 #endif /* CONFIG_NFS_V4_1 */
 692 };
 693
 694 /*
 695  * Define NFS4 callback procedures
 696  */
 697 static struct svc_procedure nfs4_callback_procedures1[] = {
 698         [CB_NULL] = {
 699                 .pc_func = nfs4_callback_null,
 700                 .pc_decode = (kxdrproc_t)nfs4_decode_void,
 701                 .pc_encode = (kxdrproc_t)nfs4_encode_void,
 702                 .pc_xdrressize = 1,
 703         },
 704         [CB_COMPOUND] = {
 705                 .pc_func = nfs4_callback_compound,
 706                 .pc_encode = (kxdrproc_t)nfs4_encode_void,
 707                 .pc_argsize = 256,
 708                 .pc_ressize = 256,
 709                 .pc_xdrressize = NFS4_CALLBACK_BUFSIZE,
 710         }
 711 };
 712
 713 struct svc_version nfs4_callback_version1 = {
 714         .vs_vers = 1,
 715         .vs_nproc = ARRAY_SIZE(nfs4_callback_procedures1),
 716         .vs_proc = nfs4_callback_procedures1,
 717         .vs_xdrsize = NFS4_CALLBACK_XDRSIZE,
 718         .vs_dispatch = NULL,
 719 };
 720