1/* 2 * Copyright (c) 2001 The Regents of the University of Michigan. 3 * All rights reserved. 4 * 5 * Kendrick Smith <kmsmith@umich.edu> 6 * Andy Adamson <andros@umich.edu> 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 3. Neither the name of the University nor the names of its 18 * contributors may be used to endorse or promote products derived 19 * from this software without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED 22 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 23 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 24 * DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 26 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 27 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR 28 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF 29 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 30 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 31 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 32 */ 33 34#include <linux/sunrpc/clnt.h> 35#include <linux/sunrpc/svc_xprt.h> 36#include <linux/slab.h> 37#include "nfsd.h" 38#include "state.h" 39 40#define NFSDDBG_FACILITY NFSDDBG_PROC 41 42#define NFSPROC4_CB_NULL 0 43#define NFSPROC4_CB_COMPOUND 1 44#define NFS4_STATEID_SIZE 16 45 46/* Index of predefined Linux callback client operations */ 47 48enum { 49 NFSPROC4_CLNT_CB_NULL = 0, 50 NFSPROC4_CLNT_CB_RECALL, 51 NFSPROC4_CLNT_CB_SEQUENCE, 52}; 53 54enum nfs_cb_opnum4 { 55 OP_CB_RECALL = 4, 56 OP_CB_SEQUENCE = 11, 57}; 58 59#define NFS4_MAXTAGLEN 20 60 61#define NFS4_enc_cb_null_sz 0 62#define NFS4_dec_cb_null_sz 0 63#define cb_compound_enc_hdr_sz 4 64#define cb_compound_dec_hdr_sz (3 + (NFS4_MAXTAGLEN >> 2)) 65#define sessionid_sz (NFS4_MAX_SESSIONID_LEN >> 2) 66#define cb_sequence_enc_sz (sessionid_sz + 4 + \ 67 1 /* no referring calls list yet */) 68#define cb_sequence_dec_sz (op_dec_sz + sessionid_sz + 4) 69 70#define op_enc_sz 1 71#define op_dec_sz 2 72#define enc_nfs4_fh_sz (1 + (NFS4_FHSIZE >> 2)) 73#define enc_stateid_sz (NFS4_STATEID_SIZE >> 2) 74#define NFS4_enc_cb_recall_sz (cb_compound_enc_hdr_sz + \ 75 cb_sequence_enc_sz + \ 76 1 + enc_stateid_sz + \ 77 enc_nfs4_fh_sz) 78 79#define NFS4_dec_cb_recall_sz (cb_compound_dec_hdr_sz + \ 80 cb_sequence_dec_sz + \ 81 op_dec_sz) 82 83/* 84* Generic encode routines from fs/nfs/nfs4xdr.c 85*/ 86static inline __be32 * 87xdr_writemem(__be32 *p, const void *ptr, int nbytes) 88{ 89 int tmp = XDR_QUADLEN(nbytes); 90 if (!tmp) 91 return p; 92 p[tmp-1] = 0; 93 memcpy(p, ptr, nbytes); 94 return p + tmp; 95} 96 97#define WRITE32(n) *p++ = htonl(n) 98#define WRITEMEM(ptr,nbytes) do { \ 99 p = xdr_writemem(p, ptr, nbytes); \ 100} while (0) 101#define RESERVE_SPACE(nbytes) do { \ 102 p = xdr_reserve_space(xdr, nbytes); \ 103 if (!p) dprintk("NFSD: RESERVE_SPACE(%d) failed in function %s\n", (int) (nbytes), __func__); \ 104 BUG_ON(!p); \ 105} while (0) 106 107/* 108 * Generic decode routines from fs/nfs/nfs4xdr.c 109 */ 110#define DECODE_TAIL \ 111 status = 0; \ 112out: \ 113 return status; \ 114xdr_error: \ 115 dprintk("NFSD: xdr error! (%s:%d)\n", __FILE__, __LINE__); \ 116 status = -EIO; \ 117 goto out 118 119#define READ32(x) (x) = ntohl(*p++) 120#define READ64(x) do { \ 121 (x) = (u64)ntohl(*p++) << 32; \ 122 (x) |= ntohl(*p++); \ 123} while (0) 124#define READTIME(x) do { \ 125 p++; \ 126 (x.tv_sec) = ntohl(*p++); \ 127 (x.tv_nsec) = ntohl(*p++); \ 128} while (0) 129#define READ_BUF(nbytes) do { \ 130 p = xdr_inline_decode(xdr, nbytes); \ 131 if (!p) { \ 132 dprintk("NFSD: %s: reply buffer overflowed in line %d.\n", \ 133 __func__, __LINE__); \ 134 return -EIO; \ 135 } \ 136} while (0) 137 138struct nfs4_cb_compound_hdr { 139 /* args */ 140 u32 ident; /* minorversion 0 only */ 141 u32 nops; 142 __be32 *nops_p; 143 u32 minorversion; 144 /* res */ 145 int status; 146}; 147 148static struct { 149int stat; 150int errno; 151} nfs_cb_errtbl[] = { 152 { NFS4_OK, 0 }, 153 { NFS4ERR_PERM, EPERM }, 154 { NFS4ERR_NOENT, ENOENT }, 155 { NFS4ERR_IO, EIO }, 156 { NFS4ERR_NXIO, ENXIO }, 157 { NFS4ERR_ACCESS, EACCES }, 158 { NFS4ERR_EXIST, EEXIST }, 159 { NFS4ERR_XDEV, EXDEV }, 160 { NFS4ERR_NOTDIR, ENOTDIR }, 161 { NFS4ERR_ISDIR, EISDIR }, 162 { NFS4ERR_INVAL, EINVAL }, 163 { NFS4ERR_FBIG, EFBIG }, 164 { NFS4ERR_NOSPC, ENOSPC }, 165 { NFS4ERR_ROFS, EROFS }, 166 { NFS4ERR_MLINK, EMLINK }, 167 { NFS4ERR_NAMETOOLONG, ENAMETOOLONG }, 168 { NFS4ERR_NOTEMPTY, ENOTEMPTY }, 169 { NFS4ERR_DQUOT, EDQUOT }, 170 { NFS4ERR_STALE, ESTALE }, 171 { NFS4ERR_BADHANDLE, EBADHANDLE }, 172 { NFS4ERR_BAD_COOKIE, EBADCOOKIE }, 173 { NFS4ERR_NOTSUPP, ENOTSUPP }, 174 { NFS4ERR_TOOSMALL, ETOOSMALL }, 175 { NFS4ERR_SERVERFAULT, ESERVERFAULT }, 176 { NFS4ERR_BADTYPE, EBADTYPE }, 177 { NFS4ERR_LOCKED, EAGAIN }, 178 { NFS4ERR_RESOURCE, EREMOTEIO }, 179 { NFS4ERR_SYMLINK, ELOOP }, 180 { NFS4ERR_OP_ILLEGAL, EOPNOTSUPP }, 181 { NFS4ERR_DEADLOCK, EDEADLK }, 182 { -1, EIO } 183}; 184 185static int 186nfs_cb_stat_to_errno(int stat) 187{ 188 int i; 189 for (i = 0; nfs_cb_errtbl[i].stat != -1; i++) { 190 if (nfs_cb_errtbl[i].stat == stat) 191 return nfs_cb_errtbl[i].errno; 192 } 193 /* If we cannot translate the error, the recovery routines should 194 * handle it. 195 * Note: remaining NFSv4 error codes have values > 10000, so should 196 * not conflict with native Linux error codes. 197 */ 198 return stat; 199} 200 201/* 202 * XDR encode 203 */ 204 205static void 206encode_stateid(struct xdr_stream *xdr, stateid_t *sid) 207{ 208 __be32 *p; 209 210 RESERVE_SPACE(sizeof(stateid_t)); 211 WRITE32(sid->si_generation); 212 WRITEMEM(&sid->si_opaque, sizeof(stateid_opaque_t)); 213} 214 215static void 216encode_cb_compound_hdr(struct xdr_stream *xdr, struct nfs4_cb_compound_hdr *hdr) 217{ 218 __be32 * p; 219 220 RESERVE_SPACE(16); 221 WRITE32(0); /* tag length is always 0 */ 222 WRITE32(hdr->minorversion); 223 WRITE32(hdr->ident); 224 hdr->nops_p = p; 225 WRITE32(hdr->nops); 226} 227 228static void encode_cb_nops(struct nfs4_cb_compound_hdr *hdr) 229{ 230 *hdr->nops_p = htonl(hdr->nops); 231} 232 233static void 234encode_cb_recall(struct xdr_stream *xdr, struct nfs4_delegation *dp, 235 struct nfs4_cb_compound_hdr *hdr) 236{ 237 __be32 *p; 238 int len = dp->dl_fh.fh_size; 239 240 RESERVE_SPACE(4); 241 WRITE32(OP_CB_RECALL); 242 encode_stateid(xdr, &dp->dl_stateid); 243 RESERVE_SPACE(8 + (XDR_QUADLEN(len) << 2)); 244 WRITE32(0); /* truncate optimization not implemented */ 245 WRITE32(len); 246 WRITEMEM(&dp->dl_fh.fh_base, len); 247 hdr->nops++; 248} 249 250static void 251encode_cb_sequence(struct xdr_stream *xdr, struct nfsd4_cb_sequence *args, 252 struct nfs4_cb_compound_hdr *hdr) 253{ 254 __be32 *p; 255 256 if (hdr->minorversion == 0) 257 return; 258 259 RESERVE_SPACE(1 + NFS4_MAX_SESSIONID_LEN + 20); 260 261 WRITE32(OP_CB_SEQUENCE); 262 WRITEMEM(args->cbs_clp->cl_sessionid.data, NFS4_MAX_SESSIONID_LEN); 263 WRITE32(args->cbs_clp->cl_cb_seq_nr); 264 WRITE32(0); /* slotid, always 0 */ 265 WRITE32(0); /* highest slotid always 0 */ 266 WRITE32(0); /* cachethis always 0 */ 267 WRITE32(0); 268 hdr->nops++; 269} 270 271static int 272nfs4_xdr_enc_cb_null(struct rpc_rqst *req, __be32 *p) 273{ 274 struct xdr_stream xdrs, *xdr = &xdrs; 275 276 xdr_init_encode(&xdrs, &req->rq_snd_buf, p); 277 RESERVE_SPACE(0); 278 return 0; 279} 280 281static int 282nfs4_xdr_enc_cb_recall(struct rpc_rqst *req, __be32 *p, 283 struct nfs4_rpc_args *rpc_args) 284{ 285 struct xdr_stream xdr; 286 struct nfs4_delegation *args = rpc_args->args_op; 287 struct nfs4_cb_compound_hdr hdr = { 288 .ident = args->dl_ident, 289 .minorversion = rpc_args->args_seq.cbs_minorversion, 290 }; 291 292 xdr_init_encode(&xdr, &req->rq_snd_buf, p); 293 encode_cb_compound_hdr(&xdr, &hdr); 294 encode_cb_sequence(&xdr, &rpc_args->args_seq, &hdr); 295 encode_cb_recall(&xdr, args, &hdr); 296 encode_cb_nops(&hdr); 297 return 0; 298} 299 300 301static int 302decode_cb_compound_hdr(struct xdr_stream *xdr, struct nfs4_cb_compound_hdr *hdr){ 303 __be32 *p; 304 u32 taglen; 305 306 READ_BUF(8); 307 READ32(hdr->status); 308 /* We've got no use for the tag; ignore it: */ 309 READ32(taglen); 310 READ_BUF(taglen + 4); 311 p += XDR_QUADLEN(taglen); 312 READ32(hdr->nops); 313 return 0; 314} 315 316static int 317decode_cb_op_hdr(struct xdr_stream *xdr, enum nfs_opnum4 expected) 318{ 319 __be32 *p; 320 u32 op; 321 int32_t nfserr; 322 323 READ_BUF(8); 324 READ32(op); 325 if (op != expected) { 326 dprintk("NFSD: decode_cb_op_hdr: Callback server returned " 327 " operation %d but we issued a request for %d\n", 328 op, expected); 329 return -EIO; 330 } 331 READ32(nfserr); 332 if (nfserr != NFS_OK) 333 return -nfs_cb_stat_to_errno(nfserr); 334 return 0; 335} 336 337/* 338 * Our current back channel implmentation supports a single backchannel 339 * with a single slot. 340 */ 341static int 342decode_cb_sequence(struct xdr_stream *xdr, struct nfsd4_cb_sequence *res, 343 struct rpc_rqst *rqstp) 344{ 345 struct nfs4_sessionid id; 346 int status; 347 u32 dummy; 348 __be32 *p; 349 350 if (res->cbs_minorversion == 0) 351 return 0; 352 353 status = decode_cb_op_hdr(xdr, OP_CB_SEQUENCE); 354 if (status) 355 return status; 356 357 /* 358 * If the server returns different values for sessionID, slotID or 359 * sequence number, the server is looney tunes. 360 */ 361 status = -ESERVERFAULT; 362 363 READ_BUF(NFS4_MAX_SESSIONID_LEN + 16); 364 memcpy(id.data, p, NFS4_MAX_SESSIONID_LEN); 365 p += XDR_QUADLEN(NFS4_MAX_SESSIONID_LEN); 366 if (memcmp(id.data, res->cbs_clp->cl_sessionid.data, 367 NFS4_MAX_SESSIONID_LEN)) { 368 dprintk("%s Invalid session id\n", __func__); 369 goto out; 370 } 371 READ32(dummy); 372 if (dummy != res->cbs_clp->cl_cb_seq_nr) { 373 dprintk("%s Invalid sequence number\n", __func__); 374 goto out; 375 } 376 READ32(dummy); /* slotid must be 0 */ 377 if (dummy != 0) { 378 dprintk("%s Invalid slotid\n", __func__); 379 goto out; 380 } 381 status = 0; 382out: 383 return status; 384} 385 386 387static int 388nfs4_xdr_dec_cb_null(struct rpc_rqst *req, __be32 *p) 389{ 390 return 0; 391} 392 393static int 394nfs4_xdr_dec_cb_recall(struct rpc_rqst *rqstp, __be32 *p, 395 struct nfsd4_cb_sequence *seq) 396{ 397 struct xdr_stream xdr; 398 struct nfs4_cb_compound_hdr hdr; 399 int status; 400 401 xdr_init_decode(&xdr, &rqstp->rq_rcv_buf, p); 402 status = decode_cb_compound_hdr(&xdr, &hdr); 403 if (status) 404 goto out; 405 if (seq) { 406 status = decode_cb_sequence(&xdr, seq, rqstp); 407 if (status) 408 goto out; 409 } 410 status = decode_cb_op_hdr(&xdr, OP_CB_RECALL); 411out: 412 return status; 413} 414 415/* 416 * RPC procedure tables 417 */ 418#define PROC(proc, call, argtype, restype) \ 419[NFSPROC4_CLNT_##proc] = { \ 420 .p_proc = NFSPROC4_CB_##call, \ 421 .p_encode = (kxdrproc_t) nfs4_xdr_##argtype, \ 422 .p_decode = (kxdrproc_t) nfs4_xdr_##restype, \ 423 .p_arglen = NFS4_##argtype##_sz, \ 424 .p_replen = NFS4_##restype##_sz, \ 425 .p_statidx = NFSPROC4_CB_##call, \ 426 .p_name = #proc, \ 427} 428 429static struct rpc_procinfo nfs4_cb_procedures[] = { 430 PROC(CB_NULL, NULL, enc_cb_null, dec_cb_null), 431 PROC(CB_RECALL, COMPOUND, enc_cb_recall, dec_cb_recall), 432}; 433 434static struct rpc_version nfs_cb_version4 = { 435/* 436 * Note on the callback rpc program version number: despite language in rfc 437 * 5661 section 18.36.3 requiring servers to use 4 in this field, the 438 * official xdr descriptions for both 4.0 and 4.1 specify version 1, and 439 * in practice that appears to be what implementations use. The section 440 * 18.36.3 language is expected to be fixed in an erratum. 441 */ 442 .number = 1, 443 .nrprocs = ARRAY_SIZE(nfs4_cb_procedures), 444 .procs = nfs4_cb_procedures 445}; 446 447static struct rpc_version * nfs_cb_version[] = { 448 &nfs_cb_version4, 449}; 450 451static struct rpc_program cb_program; 452 453static struct rpc_stat cb_stats = { 454 .program = &cb_program 455}; 456 457#define NFS4_CALLBACK 0x40000000 458static struct rpc_program cb_program = { 459 .name = "nfs4_cb", 460 .number = NFS4_CALLBACK, 461 .nrvers = ARRAY_SIZE(nfs_cb_version), 462 .version = nfs_cb_version, 463 .stats = &cb_stats, 464 .pipe_dir_name = "/nfsd4_cb", 465}; 466 467static int max_cb_time(void) 468{ 469 return max(nfsd4_lease/10, (time_t)1) * HZ; 470} 471 472/* Reference counting, callback cleanup, etc., all look racy as heck. 473 * And why is cl_cb_set an atomic? */ 474 475int setup_callback_client(struct nfs4_client *clp, struct nfs4_cb_conn *cb) 476{ 477 struct rpc_timeout timeparms = { 478 .to_initval = max_cb_time(), 479 .to_retries = 0, 480 }; 481 struct rpc_create_args args = { 482 .protocol = XPRT_TRANSPORT_TCP, 483 .address = (struct sockaddr *) &cb->cb_addr, 484 .addrsize = cb->cb_addrlen, 485 .timeout = &timeparms, 486 .program = &cb_program, 487 .prognumber = cb->cb_prog, 488 .version = 0, 489 .authflavor = clp->cl_flavor, 490 .flags = (RPC_CLNT_CREATE_NOPING | RPC_CLNT_CREATE_QUIET), 491 .client_name = clp->cl_principal, 492 }; 493 struct rpc_clnt *client; 494 495 if (!clp->cl_principal && (clp->cl_flavor >= RPC_AUTH_GSS_KRB5)) 496 return -EINVAL; 497 if (cb->cb_minorversion) { 498 args.bc_xprt = cb->cb_xprt; 499 args.protocol = XPRT_TRANSPORT_BC_TCP; 500 } 501 /* Create RPC client */ 502 client = rpc_create(&args); 503 if (IS_ERR(client)) { 504 dprintk("NFSD: couldn't create callback client: %ld\n", 505 PTR_ERR(client)); 506 return PTR_ERR(client); 507 } 508 nfsd4_set_callback_client(clp, client); 509 return 0; 510 511} 512 513static void warn_no_callback_path(struct nfs4_client *clp, int reason) 514{ 515 dprintk("NFSD: warning: no callback path to client %.*s: error %d\n", 516 (int)clp->cl_name.len, clp->cl_name.data, reason); 517} 518 519static void nfsd4_cb_probe_done(struct rpc_task *task, void *calldata) 520{ 521 struct nfs4_client *clp = calldata; 522 523 if (task->tk_status) 524 warn_no_callback_path(clp, task->tk_status); 525 else 526 atomic_set(&clp->cl_cb_set, 1); 527} 528 529static const struct rpc_call_ops nfsd4_cb_probe_ops = { 530 .rpc_call_done = nfsd4_cb_probe_done, 531}; 532 533static struct rpc_cred *callback_cred; 534 535int set_callback_cred(void) 536{ 537 if (callback_cred) 538 return 0; 539 callback_cred = rpc_lookup_machine_cred(); 540 if (!callback_cred) 541 return -ENOMEM; 542 return 0; 543} 544 545 546void do_probe_callback(struct nfs4_client *clp) 547{ 548 struct rpc_message msg = { 549 .rpc_proc = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_NULL], 550 .rpc_argp = clp, 551 .rpc_cred = callback_cred 552 }; 553 int status; 554 555 status = rpc_call_async(clp->cl_cb_client, &msg, 556 RPC_TASK_SOFT | RPC_TASK_SOFTCONN, 557 &nfsd4_cb_probe_ops, (void *)clp); 558 if (status) 559 warn_no_callback_path(clp, status); 560} 561 562/* 563 * Set up the callback client and put a NFSPROC4_CB_NULL on the wire... 564 */ 565void nfsd4_probe_callback(struct nfs4_client *clp, struct nfs4_cb_conn *cb) 566{ 567 int status; 568 569 BUG_ON(atomic_read(&clp->cl_cb_set)); 570 571 status = setup_callback_client(clp, cb); 572 if (status) { 573 warn_no_callback_path(clp, status); 574 return; 575 } 576 do_probe_callback(clp); 577} 578 579/* 580 * There's currently a single callback channel slot. 581 * If the slot is available, then mark it busy. Otherwise, set the 582 * thread for sleeping on the callback RPC wait queue. 583 */ 584static int nfsd41_cb_setup_sequence(struct nfs4_client *clp, 585 struct rpc_task *task) 586{ 587 struct nfs4_rpc_args *args = task->tk_msg.rpc_argp; 588 u32 *ptr = (u32 *)clp->cl_sessionid.data; 589 int status = 0; 590 591 dprintk("%s: %u:%u:%u:%u\n", __func__, 592 ptr[0], ptr[1], ptr[2], ptr[3]); 593 594 if (test_and_set_bit(0, &clp->cl_cb_slot_busy) != 0) { 595 rpc_sleep_on(&clp->cl_cb_waitq, task, NULL); 596 dprintk("%s slot is busy\n", __func__); 597 status = -EAGAIN; 598 goto out; 599 } 600 601 /* 602 * We'll need the clp during XDR encoding and decoding, 603 * and the sequence during decoding to verify the reply 604 */ 605 args->args_seq.cbs_clp = clp; 606 task->tk_msg.rpc_resp = &args->args_seq; 607 608out: 609 dprintk("%s status=%d\n", __func__, status); 610 return status; 611} 612 613/* 614 * TODO: cb_sequence should support referring call lists, cachethis, multiple 615 * slots, and mark callback channel down on communication errors. 616 */ 617static void nfsd4_cb_prepare(struct rpc_task *task, void *calldata) 618{ 619 struct nfs4_delegation *dp = calldata; 620 struct nfs4_client *clp = dp->dl_client; 621 struct nfs4_rpc_args *args = task->tk_msg.rpc_argp; 622 u32 minorversion = clp->cl_cb_conn.cb_minorversion; 623 int status = 0; 624 625 args->args_seq.cbs_minorversion = minorversion; 626 if (minorversion) { 627 status = nfsd41_cb_setup_sequence(clp, task); 628 if (status) { 629 if (status != -EAGAIN) { 630 /* terminate rpc task */ 631 task->tk_status = status; 632 task->tk_action = NULL; 633 } 634 return; 635 } 636 } 637 rpc_call_start(task); 638} 639 640static void nfsd4_cb_done(struct rpc_task *task, void *calldata) 641{ 642 struct nfs4_delegation *dp = calldata; 643 struct nfs4_client *clp = dp->dl_client; 644 645 dprintk("%s: minorversion=%d\n", __func__, 646 clp->cl_cb_conn.cb_minorversion); 647 648 if (clp->cl_cb_conn.cb_minorversion) { 649 /* No need for lock, access serialized in nfsd4_cb_prepare */ 650 ++clp->cl_cb_seq_nr; 651 clear_bit(0, &clp->cl_cb_slot_busy); 652 rpc_wake_up_next(&clp->cl_cb_waitq); 653 dprintk("%s: freed slot, new seqid=%d\n", __func__, 654 clp->cl_cb_seq_nr); 655 656 /* We're done looking into the sequence information */ 657 task->tk_msg.rpc_resp = NULL; 658 } 659} 660 661 662static void nfsd4_cb_recall_done(struct rpc_task *task, void *calldata) 663{ 664 struct nfs4_delegation *dp = calldata; 665 struct nfs4_client *clp = dp->dl_client; 666 struct rpc_clnt *current_rpc_client = clp->cl_cb_client; 667 668 nfsd4_cb_done(task, calldata); 669 670 if (current_rpc_client == NULL) { 671 /* We're shutting down; give up. */ 672 return; 673 } 674 675 switch (task->tk_status) { 676 case 0: 677 return; 678 case -EBADHANDLE: 679 case -NFS4ERR_BAD_STATEID: 680 /* Race: client probably got cb_recall 681 * before open reply granting delegation */ 682 break; 683 default: 684 /* Network partition? */ 685 atomic_set(&clp->cl_cb_set, 0); 686 warn_no_callback_path(clp, task->tk_status); 687 if (current_rpc_client != task->tk_client) { 688 /* queue a callback on the new connection: */ 689 atomic_inc(&dp->dl_count); 690 nfsd4_cb_recall(dp); 691 return; 692 } 693 } 694 if (dp->dl_retries--) { 695 rpc_delay(task, 2*HZ); 696 task->tk_status = 0; 697 rpc_restart_call_prepare(task); 698 return; 699 } else { 700 atomic_set(&clp->cl_cb_set, 0); 701 warn_no_callback_path(clp, task->tk_status); 702 } 703} 704 705static void nfsd4_cb_recall_release(void *calldata) 706{ 707 struct nfs4_delegation *dp = calldata; 708 709 nfs4_put_delegation(dp); 710} 711 712static const struct rpc_call_ops nfsd4_cb_recall_ops = { 713 .rpc_call_prepare = nfsd4_cb_prepare, 714 .rpc_call_done = nfsd4_cb_recall_done, 715 .rpc_release = nfsd4_cb_recall_release, 716}; 717 718static struct workqueue_struct *callback_wq; 719 720int nfsd4_create_callback_queue(void) 721{ 722 callback_wq = create_singlethread_workqueue("nfsd4_callbacks"); 723 if (!callback_wq) 724 return -ENOMEM; 725 return 0; 726} 727 728void nfsd4_destroy_callback_queue(void) 729{ 730 destroy_workqueue(callback_wq); 731} 732 733/* must be called under the state lock */ 734void nfsd4_set_callback_client(struct nfs4_client *clp, struct rpc_clnt *new) 735{ 736 struct rpc_clnt *old = clp->cl_cb_client; 737 738 clp->cl_cb_client = new; 739 /* 740 * After this, any work that saw the old value of cl_cb_client will 741 * be gone: 742 */ 743 flush_workqueue(callback_wq); 744 /* So we can safely shut it down: */ 745 if (old) 746 rpc_shutdown_client(old); 747} 748 749/* 750 * called with dp->dl_count inc'ed. 751 */ 752static void _nfsd4_cb_recall(struct nfs4_delegation *dp) 753{ 754 struct nfs4_client *clp = dp->dl_client; 755 struct rpc_clnt *clnt = clp->cl_cb_client; 756 struct nfs4_rpc_args *args = &dp->dl_recall.cb_args; 757 struct rpc_message msg = { 758 .rpc_proc = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_RECALL], 759 .rpc_cred = callback_cred 760 }; 761 762 if (clnt == NULL) { 763 nfs4_put_delegation(dp); 764 return; /* Client is shutting down; give up. */ 765 } 766 767 args->args_op = dp; 768 msg.rpc_argp = args; 769 dp->dl_retries = 1; 770 rpc_call_async(clnt, &msg, RPC_TASK_SOFT, &nfsd4_cb_recall_ops, dp); 771} 772 773void nfsd4_do_callback_rpc(struct work_struct *w) 774{ 775 /* In future, generalize to handle any sort of callback. */ 776 struct nfsd4_callback *c = container_of(w, struct nfsd4_callback, cb_work); 777 struct nfs4_delegation *dp = container_of(c, struct nfs4_delegation, dl_recall); 778 779 _nfsd4_cb_recall(dp); 780} 781 782 783void nfsd4_cb_recall(struct nfs4_delegation *dp) 784{ 785 queue_work(callback_wq, &dp->dl_recall.cb_work); 786} 787