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 #define CB_OP_RECALLANY_RES_MAXSZ       (CB_OP_HDR_RES_MAXSZ)
  27 #endif /* CONFIG_NFS_V4_1 */
  28
  29 #define NFSDBG_FACILITY NFSDBG_CALLBACK
  30
  31 /* Internal error code */
  32 #define NFS4ERR_RESOURCE_HDR    11050
  33
  34 typedef __be32 (*callback_process_op_t)(void *, void *);
  35 typedef __be32 (*callback_decode_arg_t)(struct svc_rqst *, struct xdr_stream *, void *);
  36 typedef __be32 (*callback_encode_res_t)(struct svc_rqst *, struct xdr_stream *, void *);
  37
  38
  39 struct callback_op {
  40         callback_process_op_t process_op;
  41         callback_decode_arg_t decode_args;
  42         callback_encode_res_t encode_res;
  43         long res_maxsize;
  44 };
  45
  46 static struct callback_op callback_ops[];
  47
  48 static __be32 nfs4_callback_null(struct svc_rqst *rqstp, void *argp, void *resp)
  49 {
  50         return htonl(NFS4_OK);
  51 }
  52
  53 static int nfs4_decode_void(struct svc_rqst *rqstp, __be32 *p, void *dummy)
  54 {
  55         return xdr_argsize_check(rqstp, p);
  56 }
  57
  58 static int nfs4_encode_void(struct svc_rqst *rqstp, __be32 *p, void *dummy)
  59 {
  60         return xdr_ressize_check(rqstp, p);
  61 }
  62
  63 static __be32 *read_buf(struct xdr_stream *xdr, int nbytes)
  64 {
  65         __be32 *p;
  66
  67         p = xdr_inline_decode(xdr, nbytes);
  68         if (unlikely(p == NULL))
  69                 printk(KERN_WARNING "NFSv4 callback reply buffer overflowed!\n");
  70         return p;
  71 }
  72
  73 static __be32 decode_string(struct xdr_stream *xdr, unsigned int *len, const char **str)
  74 {
  75         __be32 *p;
  76
  77         p = read_buf(xdr, 4);
  78         if (unlikely(p == NULL))
  79                 return htonl(NFS4ERR_RESOURCE);
  80         *len = ntohl(*p);
  81
  82         if (*len != 0) {
  83                 p = read_buf(xdr, *len);
  84                 if (unlikely(p == NULL))
  85                         return htonl(NFS4ERR_RESOURCE);
  86                 *str = (const char *)p;
  87         } else
  88                 *str = NULL;
  89
  90         return 0;
  91 }
  92
  93 static __be32 decode_fh(struct xdr_stream *xdr, struct nfs_fh *fh)
  94 {
  95         __be32 *p;
  96
  97         p = read_buf(xdr, 4);
  98         if (unlikely(p == NULL))
  99                 return htonl(NFS4ERR_RESOURCE);
 100         fh->size = ntohl(*p);
 101         if (fh->size > NFS4_FHSIZE)
 102                 return htonl(NFS4ERR_BADHANDLE);
 103         p = read_buf(xdr, fh->size);
 104         if (unlikely(p == NULL))
 105                 return htonl(NFS4ERR_RESOURCE);
 106         memcpy(&fh->data[0], p, fh->size);
 107         memset(&fh->data[fh->size], 0, sizeof(fh->data) - fh->size);
 108         return 0;
 109 }
 110
 111 static __be32 decode_bitmap(struct xdr_stream *xdr, uint32_t *bitmap)
 112 {
 113         __be32 *p;
 114         unsigned int attrlen;
 115
 116         p = read_buf(xdr, 4);
 117         if (unlikely(p == NULL))
 118                 return htonl(NFS4ERR_RESOURCE);
 119         attrlen = ntohl(*p);
 120         p = read_buf(xdr, attrlen << 2);
 121         if (unlikely(p == NULL))
 122                 return htonl(NFS4ERR_RESOURCE);
 123         if (likely(attrlen > 0))
 124                 bitmap[0] = ntohl(*p++);
 125         if (attrlen > 1)
 126                 bitmap[1] = ntohl(*p);
 127         return 0;
 128 }
 129
 130 static __be32 decode_stateid(struct xdr_stream *xdr, nfs4_stateid *stateid)
 131 {
 132         __be32 *p;
 133
 134         p = read_buf(xdr, 16);
 135         if (unlikely(p == NULL))
 136                 return htonl(NFS4ERR_RESOURCE);
 137         memcpy(stateid->data, p, 16);
 138         return 0;
 139 }
 140
 141 static __be32 decode_compound_hdr_arg(struct xdr_stream *xdr, struct cb_compound_hdr_arg *hdr)
 142 {
 143         __be32 *p;
 144         __be32 status;
 145
 146         status = decode_string(xdr, &hdr->taglen, &hdr->tag);
 147         if (unlikely(status != 0))
 148                 return status;
 149         /* We do not like overly long tags! */
 150         if (hdr->taglen > CB_OP_TAGLEN_MAXSZ - 12) {
 151                 printk("NFSv4 CALLBACK %s: client sent tag of length %u\n",
 152                                 __func__, hdr->taglen);
 153                 return htonl(NFS4ERR_RESOURCE);
 154         }
 155         p = read_buf(xdr, 12);
 156         if (unlikely(p == NULL))
 157                 return htonl(NFS4ERR_RESOURCE);
 158         hdr->minorversion = ntohl(*p++);
 159         /* Check minor version is zero or one. */
 160         if (hdr->minorversion <= 1) {
 161                 p++;    /* skip callback_ident */
 162         } else {
 163                 printk(KERN_WARNING "%s: NFSv4 server callback with "
 164                         "illegal minor version %u!\n",
 165                         __func__, hdr->minorversion);
 166                 return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
 167         }
 168         hdr->nops = ntohl(*p);
 169         dprintk("%s: minorversion %d nops %d\n", __func__,
 170                 hdr->minorversion, hdr->nops);
 171         return 0;
 172 }
 173
 174 static __be32 decode_op_hdr(struct xdr_stream *xdr, unsigned int *op)
 175 {
 176         __be32 *p;
 177         p = read_buf(xdr, 4);
 178         if (unlikely(p == NULL))
 179                 return htonl(NFS4ERR_RESOURCE_HDR);
 180         *op = ntohl(*p);
 181         return 0;
 182 }
 183
 184 static __be32 decode_getattr_args(struct svc_rqst *rqstp, struct xdr_stream *xdr, struct cb_getattrargs *args)
 185 {
 186         __be32 status;
 187
 188         status = decode_fh(xdr, &args->fh);
 189         if (unlikely(status != 0))
 190                 goto out;
 191         args->addr = svc_addr(rqstp);
 192         status = decode_bitmap(xdr, args->bitmap);
 193 out:
 194         dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
 195         return status;
 196 }
 197
 198 static __be32 decode_recall_args(struct svc_rqst *rqstp, struct xdr_stream *xdr, struct cb_recallargs *args)
 199 {
 200         __be32 *p;
 201         __be32 status;
 202
 203         args->addr = svc_addr(rqstp);
 204         status = decode_stateid(xdr, &args->stateid);
 205         if (unlikely(status != 0))
 206                 goto out;
 207         p = read_buf(xdr, 4);
 208         if (unlikely(p == NULL)) {
 209                 status = htonl(NFS4ERR_RESOURCE);
 210                 goto out;
 211         }
 212         args->truncate = ntohl(*p);
 213         status = decode_fh(xdr, &args->fh);
 214 out:
 215         dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
 216         return status;
 217 }
 218
 219 #if defined(CONFIG_NFS_V4_1)
 220
 221 static unsigned decode_sessionid(struct xdr_stream *xdr,
 222                                  struct nfs4_sessionid *sid)
 223 {
 224         uint32_t *p;
 225         int len = NFS4_MAX_SESSIONID_LEN;
 226
 227         p = read_buf(xdr, len);
 228         if (unlikely(p == NULL))
 229                 return htonl(NFS4ERR_RESOURCE);
 230
 231         memcpy(sid->data, p, len);
 232         return 0;
 233 }
 234
 235 static unsigned decode_rc_list(struct xdr_stream *xdr,
 236                                struct referring_call_list *rc_list)
 237 {
 238         uint32_t *p;
 239         int i;
 240         unsigned status;
 241
 242         status = decode_sessionid(xdr, &rc_list->rcl_sessionid);
 243         if (status)
 244                 goto out;
 245
 246         status = htonl(NFS4ERR_RESOURCE);
 247         p = read_buf(xdr, sizeof(uint32_t));
 248         if (unlikely(p == NULL))
 249                 goto out;
 250
 251         rc_list->rcl_nrefcalls = ntohl(*p++);
 252         if (rc_list->rcl_nrefcalls) {
 253                 p = read_buf(xdr,
 254                              rc_list->rcl_nrefcalls * 2 * sizeof(uint32_t));
 255                 if (unlikely(p == NULL))
 256                         goto out;
 257                 rc_list->rcl_refcalls = kmalloc(rc_list->rcl_nrefcalls *
 258                                                 sizeof(*rc_list->rcl_refcalls),
 259                                                 GFP_KERNEL);
 260                 if (unlikely(rc_list->rcl_refcalls == NULL))
 261                         goto out;
 262                 for (i = 0; i < rc_list->rcl_nrefcalls; i++) {
 263                         rc_list->rcl_refcalls[i].rc_sequenceid = ntohl(*p++);
 264                         rc_list->rcl_refcalls[i].rc_slotid = ntohl(*p++);
 265                 }
 266         }
 267         status = 0;
 268
 269 out:
 270         return status;
 271 }
 272
 273 static unsigned decode_cb_sequence_args(struct svc_rqst *rqstp,
 274                                         struct xdr_stream *xdr,
 275                                         struct cb_sequenceargs *args)
 276 {
 277         uint32_t *p;
 278         int i;
 279         unsigned status;
 280
 281         status = decode_sessionid(xdr, &args->csa_sessionid);
 282         if (status)
 283                 goto out;
 284
 285         status = htonl(NFS4ERR_RESOURCE);
 286         p = read_buf(xdr, 5 * sizeof(uint32_t));
 287         if (unlikely(p == NULL))
 288                 goto out;
 289
 290         args->csa_addr = svc_addr(rqstp);
 291         args->csa_sequenceid = ntohl(*p++);
 292         args->csa_slotid = ntohl(*p++);
 293         args->csa_highestslotid = ntohl(*p++);
 294         args->csa_cachethis = ntohl(*p++);
 295         args->csa_nrclists = ntohl(*p++);
 296         args->csa_rclists = NULL;
 297         if (args->csa_nrclists) {
 298                 args->csa_rclists = kmalloc(args->csa_nrclists *
 299                                             sizeof(*args->csa_rclists),
 300                                             GFP_KERNEL);
 301                 if (unlikely(args->csa_rclists == NULL))
 302                         goto out;
 303
 304                 for (i = 0; i < args->csa_nrclists; i++) {
 305                         status = decode_rc_list(xdr, &args->csa_rclists[i]);
 306                         if (status)
 307                                 goto out_free;
 308                 }
 309         }
 310         status = 0;
 311
 312         dprintk("%s: sessionid %x:%x:%x:%x sequenceid %u slotid %u "
 313                 "highestslotid %u cachethis %d nrclists %u\n",
 314                 __func__,
 315                 ((u32 *)&args->csa_sessionid)[0],
 316                 ((u32 *)&args->csa_sessionid)[1],
 317                 ((u32 *)&args->csa_sessionid)[2],
 318                 ((u32 *)&args->csa_sessionid)[3],
 319                 args->csa_sequenceid, args->csa_slotid,
 320                 args->csa_highestslotid, args->csa_cachethis,
 321                 args->csa_nrclists);
 322 out:
 323         dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
 324         return status;
 325
 326 out_free:
 327         for (i = 0; i < args->csa_nrclists; i++)
 328                 kfree(args->csa_rclists[i].rcl_refcalls);
 329         kfree(args->csa_rclists);
 330         goto out;
 331 }
 332
 333 static unsigned decode_recallany_args(struct svc_rqst *rqstp,
 334                                       struct xdr_stream *xdr,
 335                                       struct cb_recallanyargs *args)
 336 {
 337         uint32_t *p;
 338
 339         args->craa_addr = svc_addr(rqstp);
 340         p = read_buf(xdr, 4);
 341         if (unlikely(p == NULL))
 342                 return htonl(NFS4ERR_BADXDR);
 343         args->craa_objs_to_keep = ntohl(*p++);
 344         p = read_buf(xdr, 4);
 345         if (unlikely(p == NULL))
 346                 return htonl(NFS4ERR_BADXDR);
 347         args->craa_type_mask = ntohl(*p);
 348
 349         return 0;
 350 }
 351
 352 #endif /* CONFIG_NFS_V4_1 */
 353
 354 static __be32 encode_string(struct xdr_stream *xdr, unsigned int len, const char *str)
 355 {
 356         __be32 *p;
 357
 358         p = xdr_reserve_space(xdr, 4 + len);
 359         if (unlikely(p == NULL))
 360                 return htonl(NFS4ERR_RESOURCE);
 361         xdr_encode_opaque(p, str, len);
 362         return 0;
 363 }
 364
 365 #define CB_SUPPORTED_ATTR0 (FATTR4_WORD0_CHANGE|FATTR4_WORD0_SIZE)
 366 #define CB_SUPPORTED_ATTR1 (FATTR4_WORD1_TIME_METADATA|FATTR4_WORD1_TIME_MODIFY)
 367 static __be32 encode_attr_bitmap(struct xdr_stream *xdr, const uint32_t *bitmap, __be32 **savep)
 368 {
 369         __be32 bm[2];
 370         __be32 *p;
 371
 372         bm[0] = htonl(bitmap[0] & CB_SUPPORTED_ATTR0);
 373         bm[1] = htonl(bitmap[1] & CB_SUPPORTED_ATTR1);
 374         if (bm[1] != 0) {
 375                 p = xdr_reserve_space(xdr, 16);
 376                 if (unlikely(p == NULL))
 377                         return htonl(NFS4ERR_RESOURCE);
 378                 *p++ = htonl(2);
 379                 *p++ = bm[0];
 380                 *p++ = bm[1];
 381         } else if (bm[0] != 0) {
 382                 p = xdr_reserve_space(xdr, 12);
 383                 if (unlikely(p == NULL))
 384                         return htonl(NFS4ERR_RESOURCE);
 385                 *p++ = htonl(1);
 386                 *p++ = bm[0];
 387         } else {
 388                 p = xdr_reserve_space(xdr, 8);
 389                 if (unlikely(p == NULL))
 390                         return htonl(NFS4ERR_RESOURCE);
 391                 *p++ = htonl(0);
 392         }
 393         *savep = p;
 394         return 0;
 395 }
 396
 397 static __be32 encode_attr_change(struct xdr_stream *xdr, const uint32_t *bitmap, uint64_t change)
 398 {
 399         __be32 *p;
 400
 401         if (!(bitmap[0] & FATTR4_WORD0_CHANGE))
 402                 return 0;
 403         p = xdr_reserve_space(xdr, 8);
 404         if (unlikely(!p))
 405                 return htonl(NFS4ERR_RESOURCE);
 406         p = xdr_encode_hyper(p, change);
 407         return 0;
 408 }
 409
 410 static __be32 encode_attr_size(struct xdr_stream *xdr, const uint32_t *bitmap, uint64_t size)
 411 {
 412         __be32 *p;
 413
 414         if (!(bitmap[0] & FATTR4_WORD0_SIZE))
 415                 return 0;
 416         p = xdr_reserve_space(xdr, 8);
 417         if (unlikely(!p))
 418                 return htonl(NFS4ERR_RESOURCE);
 419         p = xdr_encode_hyper(p, size);
 420         return 0;
 421 }
 422
 423 static __be32 encode_attr_time(struct xdr_stream *xdr, const struct timespec *time)
 424 {
 425         __be32 *p;
 426
 427         p = xdr_reserve_space(xdr, 12);
 428         if (unlikely(!p))
 429                 return htonl(NFS4ERR_RESOURCE);
 430         p = xdr_encode_hyper(p, time->tv_sec);
 431         *p = htonl(time->tv_nsec);
 432         return 0;
 433 }
 434
 435 static __be32 encode_attr_ctime(struct xdr_stream *xdr, const uint32_t *bitmap, const struct timespec *time)
 436 {
 437         if (!(bitmap[1] & FATTR4_WORD1_TIME_METADATA))
 438                 return 0;
 439         return encode_attr_time(xdr,time);
 440 }
 441
 442 static __be32 encode_attr_mtime(struct xdr_stream *xdr, const uint32_t *bitmap, const struct timespec *time)
 443 {
 444         if (!(bitmap[1] & FATTR4_WORD1_TIME_MODIFY))
 445                 return 0;
 446         return encode_attr_time(xdr,time);
 447 }
 448
 449 static __be32 encode_compound_hdr_res(struct xdr_stream *xdr, struct cb_compound_hdr_res *hdr)
 450 {
 451         __be32 status;
 452
 453         hdr->status = xdr_reserve_space(xdr, 4);
 454         if (unlikely(hdr->status == NULL))
 455                 return htonl(NFS4ERR_RESOURCE);
 456         status = encode_string(xdr, hdr->taglen, hdr->tag);
 457         if (unlikely(status != 0))
 458                 return status;
 459         hdr->nops = xdr_reserve_space(xdr, 4);
 460         if (unlikely(hdr->nops == NULL))
 461                 return htonl(NFS4ERR_RESOURCE);
 462         return 0;
 463 }
 464
 465 static __be32 encode_op_hdr(struct xdr_stream *xdr, uint32_t op, __be32 res)
 466 {
 467         __be32 *p;
 468
 469         p = xdr_reserve_space(xdr, 8);
 470         if (unlikely(p == NULL))
 471                 return htonl(NFS4ERR_RESOURCE_HDR);
 472         *p++ = htonl(op);
 473         *p = res;
 474         return 0;
 475 }
 476
 477 static __be32 encode_getattr_res(struct svc_rqst *rqstp, struct xdr_stream *xdr, const struct cb_getattrres *res)
 478 {
 479         __be32 *savep = NULL;
 480         __be32 status = res->status;
 481
 482         if (unlikely(status != 0))
 483                 goto out;
 484         status = encode_attr_bitmap(xdr, res->bitmap, &savep);
 485         if (unlikely(status != 0))
 486                 goto out;
 487         status = encode_attr_change(xdr, res->bitmap, res->change_attr);
 488         if (unlikely(status != 0))
 489                 goto out;
 490         status = encode_attr_size(xdr, res->bitmap, res->size);
 491         if (unlikely(status != 0))
 492                 goto out;
 493         status = encode_attr_ctime(xdr, res->bitmap, &res->ctime);
 494         if (unlikely(status != 0))
 495                 goto out;
 496         status = encode_attr_mtime(xdr, res->bitmap, &res->mtime);
 497         *savep = htonl((unsigned int)((char *)xdr->p - (char *)(savep+1)));
 498 out:
 499         dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
 500         return status;
 501 }
 502
 503 #if defined(CONFIG_NFS_V4_1)
 504
 505 static unsigned encode_sessionid(struct xdr_stream *xdr,
 506                                  const struct nfs4_sessionid *sid)
 507 {
 508         uint32_t *p;
 509         int len = NFS4_MAX_SESSIONID_LEN;
 510
 511         p = xdr_reserve_space(xdr, len);
 512         if (unlikely(p == NULL))
 513                 return htonl(NFS4ERR_RESOURCE);
 514
 515         memcpy(p, sid, len);
 516         return 0;
 517 }
 518
 519 static unsigned encode_cb_sequence_res(struct svc_rqst *rqstp,
 520                                        struct xdr_stream *xdr,
 521                                        const struct cb_sequenceres *res)
 522 {
 523         uint32_t *p;
 524         unsigned status = res->csr_status;
 525
 526         if (unlikely(status != 0))
 527                 goto out;
 528
 529         encode_sessionid(xdr, &res->csr_sessionid);
 530
 531         p = xdr_reserve_space(xdr, 4 * sizeof(uint32_t));
 532         if (unlikely(p == NULL))
 533                 return htonl(NFS4ERR_RESOURCE);
 534
 535         *p++ = htonl(res->csr_sequenceid);
 536         *p++ = htonl(res->csr_slotid);
 537         *p++ = htonl(res->csr_highestslotid);
 538         *p++ = htonl(res->csr_target_highestslotid);
 539 out:
 540         dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
 541         return status;
 542 }
 543
 544 static __be32
 545 preprocess_nfs41_op(int nop, unsigned int op_nr, struct callback_op **op)
 546 {
 547         if (op_nr == OP_CB_SEQUENCE) {
 548                 if (nop != 0)
 549                         return htonl(NFS4ERR_SEQUENCE_POS);
 550         } else {
 551                 if (nop == 0)
 552                         return htonl(NFS4ERR_OP_NOT_IN_SESSION);
 553         }
 554
 555         switch (op_nr) {
 556         case OP_CB_GETATTR:
 557         case OP_CB_RECALL:
 558         case OP_CB_SEQUENCE:
 559         case OP_CB_RECALL_ANY:
 560                 *op = &callback_ops[op_nr];
 561                 break;
 562
 563         case OP_CB_LAYOUTRECALL:
 564         case OP_CB_NOTIFY_DEVICEID:
 565         case OP_CB_NOTIFY:
 566         case OP_CB_PUSH_DELEG:
 567         case OP_CB_RECALLABLE_OBJ_AVAIL:
 568         case OP_CB_RECALL_SLOT:
 569         case OP_CB_WANTS_CANCELLED:
 570         case OP_CB_NOTIFY_LOCK:
 571                 return htonl(NFS4ERR_NOTSUPP);
 572
 573         default:
 574                 return htonl(NFS4ERR_OP_ILLEGAL);
 575         }
 576
 577         return htonl(NFS_OK);
 578 }
 579
 580 #else /* CONFIG_NFS_V4_1 */
 581
 582 static __be32
 583 preprocess_nfs41_op(int nop, unsigned int op_nr, struct callback_op **op)
 584 {
 585         return htonl(NFS4ERR_MINOR_VERS_MISMATCH);
 586 }
 587
 588 #endif /* CONFIG_NFS_V4_1 */
 589
 590 static __be32
 591 preprocess_nfs4_op(unsigned int op_nr, struct callback_op **op)
 592 {
 593         switch (op_nr) {
 594         case OP_CB_GETATTR:
 595         case OP_CB_RECALL:
 596                 *op = &callback_ops[op_nr];
 597                 break;
 598         default:
 599                 return htonl(NFS4ERR_OP_ILLEGAL);
 600         }
 601
 602         return htonl(NFS_OK);
 603 }
 604
 605 static __be32 process_op(uint32_t minorversion, int nop,
 606                 struct svc_rqst *rqstp,
 607                 struct xdr_stream *xdr_in, void *argp,
 608                 struct xdr_stream *xdr_out, void *resp)
 609 {
 610         struct callback_op *op = &callback_ops[0];
 611         unsigned int op_nr;
 612         __be32 status;
 613         long maxlen;
 614         __be32 res;
 615
 616         dprintk("%s: start\n", __func__);
 617         status = decode_op_hdr(xdr_in, &op_nr);
 618         if (unlikely(status))
 619                 return status;
 620
 621         dprintk("%s: minorversion=%d nop=%d op_nr=%u\n",
 622                 __func__, minorversion, nop, op_nr);
 623
 624         status = minorversion ? preprocess_nfs41_op(nop, op_nr, &op) :
 625                                 preprocess_nfs4_op(op_nr, &op);
 626         if (status == htonl(NFS4ERR_OP_ILLEGAL))
 627                 op_nr = OP_CB_ILLEGAL;
 628         if (status)
 629                 goto encode_hdr;
 630
 631         maxlen = xdr_out->end - xdr_out->p;
 632         if (maxlen > 0 && maxlen < PAGE_SIZE) {
 633                 if (likely(op->decode_args != NULL))
 634                         status = op->decode_args(rqstp, xdr_in, argp);
 635                 if (likely(status == 0 && op->process_op != NULL))
 636                         status = op->process_op(argp, resp);
 637         } else
 638                 status = htonl(NFS4ERR_RESOURCE);
 639
 640 encode_hdr:
 641         res = encode_op_hdr(xdr_out, op_nr, status);
 642         if (unlikely(res))
 643                 return res;
 644         if (op->encode_res != NULL && status == 0)
 645                 status = op->encode_res(rqstp, xdr_out, resp);
 646         dprintk("%s: done, status = %d\n", __func__, ntohl(status));
 647         return status;
 648 }
 649
 650 /*
 651  * Decode, process and encode a COMPOUND
 652  */
 653 static __be32 nfs4_callback_compound(struct svc_rqst *rqstp, void *argp, void *resp)
 654 {
 655         struct cb_compound_hdr_arg hdr_arg = { 0 };
 656         struct cb_compound_hdr_res hdr_res = { NULL };
 657         struct xdr_stream xdr_in, xdr_out;
 658         __be32 *p;
 659         __be32 status;
 660         unsigned int nops = 0;
 661
 662         dprintk("%s: start\n", __func__);
 663
 664         xdr_init_decode(&xdr_in, &rqstp->rq_arg, rqstp->rq_arg.head[0].iov_base);
 665
 666         p = (__be32*)((char *)rqstp->rq_res.head[0].iov_base + rqstp->rq_res.head[0].iov_len);
 667         xdr_init_encode(&xdr_out, &rqstp->rq_res, p);
 668
 669         status = decode_compound_hdr_arg(&xdr_in, &hdr_arg);
 670         if (status == __constant_htonl(NFS4ERR_RESOURCE))
 671                 return rpc_garbage_args;
 672
 673         hdr_res.taglen = hdr_arg.taglen;
 674         hdr_res.tag = hdr_arg.tag;
 675         if (encode_compound_hdr_res(&xdr_out, &hdr_res) != 0)
 676                 return rpc_system_err;
 677
 678         while (status == 0 && nops != hdr_arg.nops) {
 679                 status = process_op(hdr_arg.minorversion, nops,
 680                                     rqstp, &xdr_in, argp, &xdr_out, resp);
 681                 nops++;
 682         }
 683
 684         /* Buffer overflow in decode_ops_hdr or encode_ops_hdr. Return
 685         * resource error in cb_compound status without returning op */
 686         if (unlikely(status == htonl(NFS4ERR_RESOURCE_HDR))) {
 687                 status = htonl(NFS4ERR_RESOURCE);
 688                 nops--;
 689         }
 690
 691         *hdr_res.status = status;
 692         *hdr_res.nops = htonl(nops);
 693         dprintk("%s: done, status = %u\n", __func__, ntohl(status));
 694         return rpc_success;
 695 }
 696
 697 /*
 698  * Define NFS4 callback COMPOUND ops.
 699  */
 700 static struct callback_op callback_ops[] = {
 701         [0] = {
 702                 .res_maxsize = CB_OP_HDR_RES_MAXSZ,
 703         },
 704         [OP_CB_GETATTR] = {
 705                 .process_op = (callback_process_op_t)nfs4_callback_getattr,
 706                 .decode_args = (callback_decode_arg_t)decode_getattr_args,
 707                 .encode_res = (callback_encode_res_t)encode_getattr_res,
 708                 .res_maxsize = CB_OP_GETATTR_RES_MAXSZ,
 709         },
 710         [OP_CB_RECALL] = {
 711                 .process_op = (callback_process_op_t)nfs4_callback_recall,
 712                 .decode_args = (callback_decode_arg_t)decode_recall_args,
 713                 .res_maxsize = CB_OP_RECALL_RES_MAXSZ,
 714         },
 715 #if defined(CONFIG_NFS_V4_1)
 716         [OP_CB_SEQUENCE] = {
 717                 .process_op = (callback_process_op_t)nfs4_callback_sequence,
 718                 .decode_args = (callback_decode_arg_t)decode_cb_sequence_args,
 719                 .encode_res = (callback_encode_res_t)encode_cb_sequence_res,
 720                 .res_maxsize = CB_OP_SEQUENCE_RES_MAXSZ,
 721         },
 722         [OP_CB_RECALL_ANY] = {
 723                 .process_op = (callback_process_op_t)nfs4_callback_recallany,
 724                 .decode_args = (callback_decode_arg_t)decode_recallany_args,
 725                 .res_maxsize = CB_OP_RECALLANY_RES_MAXSZ,
 726         },
 727 #endif /* CONFIG_NFS_V4_1 */
 728 };
 729
 730 /*
 731  * Define NFS4 callback procedures
 732  */
 733 static struct svc_procedure nfs4_callback_procedures1[] = {
 734         [CB_NULL] = {
 735                 .pc_func = nfs4_callback_null,
 736                 .pc_decode = (kxdrproc_t)nfs4_decode_void,
 737                 .pc_encode = (kxdrproc_t)nfs4_encode_void,
 738                 .pc_xdrressize = 1,
 739         },
 740         [CB_COMPOUND] = {
 741                 .pc_func = nfs4_callback_compound,
 742                 .pc_encode = (kxdrproc_t)nfs4_encode_void,
 743                 .pc_argsize = 256,
 744                 .pc_ressize = 256,
 745                 .pc_xdrressize = NFS4_CALLBACK_BUFSIZE,
 746         }
 747 };
 748
 749 struct svc_version nfs4_callback_version1 = {
 750         .vs_vers = 1,
 751         .vs_nproc = ARRAY_SIZE(nfs4_callback_procedures1),
 752         .vs_proc = nfs4_callback_procedures1,
 753         .vs_xdrsize = NFS4_CALLBACK_XDRSIZE,
 754         .vs_dispatch = NULL,
 755 };
 756
 757 struct svc_version nfs4_callback_version4 = {
 758         .vs_vers = 4,
 759         .vs_nproc = ARRAY_SIZE(nfs4_callback_procedures1),
 760         .vs_proc = nfs4_callback_procedures1,
 761         .vs_xdrsize = NFS4_CALLBACK_XDRSIZE,
 762         .vs_dispatch = NULL,
 763 };