1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * linux/fs/nfs/delegation.c 4 * 5 * Copyright (C) 2004 Trond Myklebust 6 * 7 * NFS file delegation management 8 * 9 */ 10 #include <linux/completion.h> 11 #include <linux/kthread.h> 12 #include <linux/module.h> 13 #include <linux/sched.h> 14 #include <linux/slab.h> 15 #include <linux/spinlock.h> 16 #include <linux/iversion.h> 17 18 #include <linux/nfs4.h> 19 #include <linux/nfs_fs.h> 20 #include <linux/nfs_xdr.h> 21 22 #include "nfs4_fs.h" 23 #include "nfs4session.h" 24 #include "delegation.h" 25 #include "internal.h" 26 #include "nfs4trace.h" 27 28 #define NFS_DEFAULT_DELEGATION_WATERMARK (5000U) 29 30 static atomic_long_t nfs_active_delegations; 31 static unsigned nfs_delegation_watermark = NFS_DEFAULT_DELEGATION_WATERMARK; 32 33 static void __nfs_free_delegation(struct nfs_delegation *delegation) 34 { 35 put_cred(delegation->cred); 36 delegation->cred = NULL; 37 kfree_rcu(delegation, rcu); 38 } 39 40 static void nfs_mark_delegation_revoked(struct nfs_delegation *delegation) 41 { 42 if (!test_and_set_bit(NFS_DELEGATION_REVOKED, &delegation->flags)) { 43 delegation->stateid.type = NFS4_INVALID_STATEID_TYPE; 44 atomic_long_dec(&nfs_active_delegations); 45 if (!test_bit(NFS_DELEGATION_RETURNING, &delegation->flags)) 46 nfs_clear_verifier_delegated(delegation->inode); 47 } 48 } 49 50 static struct nfs_delegation *nfs_get_delegation(struct nfs_delegation *delegation) 51 { 52 refcount_inc(&delegation->refcount); 53 return delegation; 54 } 55 56 static void nfs_put_delegation(struct nfs_delegation *delegation) 57 { 58 if (refcount_dec_and_test(&delegation->refcount)) 59 __nfs_free_delegation(delegation); 60 } 61 62 static void nfs_free_delegation(struct nfs_delegation *delegation) 63 { 64 nfs_mark_delegation_revoked(delegation); 65 nfs_put_delegation(delegation); 66 } 67 68 /** 69 * nfs_mark_delegation_referenced - set delegation's REFERENCED flag 70 * @delegation: delegation to process 71 * 72 */ 73 void nfs_mark_delegation_referenced(struct nfs_delegation *delegation) 74 { 75 set_bit(NFS_DELEGATION_REFERENCED, &delegation->flags); 76 } 77 78 static void nfs_mark_return_delegation(struct nfs_server *server, 79 struct nfs_delegation *delegation) 80 { 81 set_bit(NFS_DELEGATION_RETURN, &delegation->flags); 82 set_bit(NFS4CLNT_DELEGRETURN, &server->nfs_client->cl_state); 83 } 84 85 static bool 86 nfs4_is_valid_delegation(const struct nfs_delegation *delegation, 87 fmode_t flags) 88 { 89 if (delegation != NULL && (delegation->type & flags) == flags && 90 !test_bit(NFS_DELEGATION_REVOKED, &delegation->flags) && 91 !test_bit(NFS_DELEGATION_RETURNING, &delegation->flags)) 92 return true; 93 return false; 94 } 95 96 struct nfs_delegation *nfs4_get_valid_delegation(const struct inode *inode) 97 { 98 struct nfs_delegation *delegation; 99 100 delegation = rcu_dereference(NFS_I(inode)->delegation); 101 if (nfs4_is_valid_delegation(delegation, 0)) 102 return delegation; 103 return NULL; 104 } 105 106 static int 107 nfs4_do_check_delegation(struct inode *inode, fmode_t flags, bool mark) 108 { 109 struct nfs_delegation *delegation; 110 int ret = 0; 111 112 flags &= FMODE_READ|FMODE_WRITE; 113 rcu_read_lock(); 114 delegation = rcu_dereference(NFS_I(inode)->delegation); 115 if (nfs4_is_valid_delegation(delegation, flags)) { 116 if (mark) 117 nfs_mark_delegation_referenced(delegation); 118 ret = 1; 119 } 120 rcu_read_unlock(); 121 return ret; 122 } 123 /** 124 * nfs4_have_delegation - check if inode has a delegation, mark it 125 * NFS_DELEGATION_REFERENCED if there is one. 126 * @inode: inode to check 127 * @flags: delegation types to check for 128 * 129 * Returns one if inode has the indicated delegation, otherwise zero. 130 */ 131 int nfs4_have_delegation(struct inode *inode, fmode_t flags) 132 { 133 return nfs4_do_check_delegation(inode, flags, true); 134 } 135 136 /* 137 * nfs4_check_delegation - check if inode has a delegation, do not mark 138 * NFS_DELEGATION_REFERENCED if it has one. 139 */ 140 int nfs4_check_delegation(struct inode *inode, fmode_t flags) 141 { 142 return nfs4_do_check_delegation(inode, flags, false); 143 } 144 145 static int nfs_delegation_claim_locks(struct nfs4_state *state, const nfs4_stateid *stateid) 146 { 147 struct inode *inode = state->inode; 148 struct file_lock *fl; 149 struct file_lock_context *flctx = inode->i_flctx; 150 struct list_head *list; 151 int status = 0; 152 153 if (flctx == NULL) 154 goto out; 155 156 list = &flctx->flc_posix; 157 spin_lock(&flctx->flc_lock); 158 restart: 159 list_for_each_entry(fl, list, fl_list) { 160 if (nfs_file_open_context(fl->fl_file)->state != state) 161 continue; 162 spin_unlock(&flctx->flc_lock); 163 status = nfs4_lock_delegation_recall(fl, state, stateid); 164 if (status < 0) 165 goto out; 166 spin_lock(&flctx->flc_lock); 167 } 168 if (list == &flctx->flc_posix) { 169 list = &flctx->flc_flock; 170 goto restart; 171 } 172 spin_unlock(&flctx->flc_lock); 173 out: 174 return status; 175 } 176 177 static int nfs_delegation_claim_opens(struct inode *inode, 178 const nfs4_stateid *stateid, fmode_t type) 179 { 180 struct nfs_inode *nfsi = NFS_I(inode); 181 struct nfs_open_context *ctx; 182 struct nfs4_state_owner *sp; 183 struct nfs4_state *state; 184 unsigned int seq; 185 int err; 186 187 again: 188 rcu_read_lock(); 189 list_for_each_entry_rcu(ctx, &nfsi->open_files, list) { 190 state = ctx->state; 191 if (state == NULL) 192 continue; 193 if (!test_bit(NFS_DELEGATED_STATE, &state->flags)) 194 continue; 195 if (!nfs4_valid_open_stateid(state)) 196 continue; 197 if (!nfs4_stateid_match(&state->stateid, stateid)) 198 continue; 199 if (!get_nfs_open_context(ctx)) 200 continue; 201 rcu_read_unlock(); 202 sp = state->owner; 203 /* Block nfs4_proc_unlck */ 204 mutex_lock(&sp->so_delegreturn_mutex); 205 seq = raw_seqcount_begin(&sp->so_reclaim_seqcount); 206 err = nfs4_open_delegation_recall(ctx, state, stateid); 207 if (!err) 208 err = nfs_delegation_claim_locks(state, stateid); 209 if (!err && read_seqcount_retry(&sp->so_reclaim_seqcount, seq)) 210 err = -EAGAIN; 211 mutex_unlock(&sp->so_delegreturn_mutex); 212 put_nfs_open_context(ctx); 213 if (err != 0) 214 return err; 215 goto again; 216 } 217 rcu_read_unlock(); 218 return 0; 219 } 220 221 /** 222 * nfs_inode_reclaim_delegation - process a delegation reclaim request 223 * @inode: inode to process 224 * @cred: credential to use for request 225 * @type: delegation type 226 * @stateid: delegation stateid 227 * @pagemod_limit: write delegation "space_limit" 228 * 229 */ 230 void nfs_inode_reclaim_delegation(struct inode *inode, const struct cred *cred, 231 fmode_t type, 232 const nfs4_stateid *stateid, 233 unsigned long pagemod_limit) 234 { 235 struct nfs_delegation *delegation; 236 const struct cred *oldcred = NULL; 237 238 rcu_read_lock(); 239 delegation = rcu_dereference(NFS_I(inode)->delegation); 240 if (delegation != NULL) { 241 spin_lock(&delegation->lock); 242 if (nfs4_is_valid_delegation(delegation, 0)) { 243 nfs4_stateid_copy(&delegation->stateid, stateid); 244 delegation->type = type; 245 delegation->pagemod_limit = pagemod_limit; 246 oldcred = delegation->cred; 247 delegation->cred = get_cred(cred); 248 clear_bit(NFS_DELEGATION_NEED_RECLAIM, 249 &delegation->flags); 250 spin_unlock(&delegation->lock); 251 rcu_read_unlock(); 252 put_cred(oldcred); 253 trace_nfs4_reclaim_delegation(inode, type); 254 return; 255 } 256 /* We appear to have raced with a delegation return. */ 257 spin_unlock(&delegation->lock); 258 } 259 rcu_read_unlock(); 260 nfs_inode_set_delegation(inode, cred, type, stateid, pagemod_limit); 261 } 262 263 static int nfs_do_return_delegation(struct inode *inode, struct nfs_delegation *delegation, int issync) 264 { 265 const struct cred *cred; 266 int res = 0; 267 268 if (!test_bit(NFS_DELEGATION_REVOKED, &delegation->flags)) { 269 spin_lock(&delegation->lock); 270 cred = get_cred(delegation->cred); 271 spin_unlock(&delegation->lock); 272 res = nfs4_proc_delegreturn(inode, cred, 273 &delegation->stateid, 274 issync); 275 put_cred(cred); 276 } 277 return res; 278 } 279 280 static struct inode *nfs_delegation_grab_inode(struct nfs_delegation *delegation) 281 { 282 struct inode *inode = NULL; 283 284 spin_lock(&delegation->lock); 285 if (delegation->inode != NULL) 286 inode = igrab(delegation->inode); 287 if (!inode) 288 set_bit(NFS_DELEGATION_INODE_FREEING, &delegation->flags); 289 spin_unlock(&delegation->lock); 290 return inode; 291 } 292 293 static struct nfs_delegation * 294 nfs_start_delegation_return_locked(struct nfs_inode *nfsi) 295 { 296 struct nfs_delegation *ret = NULL; 297 struct nfs_delegation *delegation = rcu_dereference(nfsi->delegation); 298 299 if (delegation == NULL) 300 goto out; 301 spin_lock(&delegation->lock); 302 if (!test_and_set_bit(NFS_DELEGATION_RETURNING, &delegation->flags)) { 303 clear_bit(NFS_DELEGATION_RETURN_DELAYED, &delegation->flags); 304 /* Refcount matched in nfs_end_delegation_return() */ 305 ret = nfs_get_delegation(delegation); 306 } 307 spin_unlock(&delegation->lock); 308 if (ret) 309 nfs_clear_verifier_delegated(&nfsi->vfs_inode); 310 out: 311 return ret; 312 } 313 314 static struct nfs_delegation * 315 nfs_start_delegation_return(struct nfs_inode *nfsi) 316 { 317 struct nfs_delegation *delegation; 318 319 rcu_read_lock(); 320 delegation = nfs_start_delegation_return_locked(nfsi); 321 rcu_read_unlock(); 322 return delegation; 323 } 324 325 static void nfs_abort_delegation_return(struct nfs_delegation *delegation, 326 struct nfs_client *clp, int err) 327 { 328 329 spin_lock(&delegation->lock); 330 clear_bit(NFS_DELEGATION_RETURNING, &delegation->flags); 331 if (err == -EAGAIN) { 332 set_bit(NFS_DELEGATION_RETURN_DELAYED, &delegation->flags); 333 set_bit(NFS4CLNT_DELEGRETURN_DELAYED, &clp->cl_state); 334 } 335 spin_unlock(&delegation->lock); 336 } 337 338 static struct nfs_delegation * 339 nfs_detach_delegation_locked(struct nfs_inode *nfsi, 340 struct nfs_delegation *delegation, 341 struct nfs_client *clp) 342 { 343 struct nfs_delegation *deleg_cur = 344 rcu_dereference_protected(nfsi->delegation, 345 lockdep_is_held(&clp->cl_lock)); 346 347 if (deleg_cur == NULL || delegation != deleg_cur) 348 return NULL; 349 350 spin_lock(&delegation->lock); 351 if (!delegation->inode) { 352 spin_unlock(&delegation->lock); 353 return NULL; 354 } 355 list_del_rcu(&delegation->super_list); 356 delegation->inode = NULL; 357 rcu_assign_pointer(nfsi->delegation, NULL); 358 spin_unlock(&delegation->lock); 359 return delegation; 360 } 361 362 static struct nfs_delegation *nfs_detach_delegation(struct nfs_inode *nfsi, 363 struct nfs_delegation *delegation, 364 struct nfs_server *server) 365 { 366 struct nfs_client *clp = server->nfs_client; 367 368 spin_lock(&clp->cl_lock); 369 delegation = nfs_detach_delegation_locked(nfsi, delegation, clp); 370 spin_unlock(&clp->cl_lock); 371 return delegation; 372 } 373 374 static struct nfs_delegation * 375 nfs_inode_detach_delegation(struct inode *inode) 376 { 377 struct nfs_inode *nfsi = NFS_I(inode); 378 struct nfs_server *server = NFS_SERVER(inode); 379 struct nfs_delegation *delegation; 380 381 rcu_read_lock(); 382 delegation = rcu_dereference(nfsi->delegation); 383 if (delegation != NULL) 384 delegation = nfs_detach_delegation(nfsi, delegation, server); 385 rcu_read_unlock(); 386 return delegation; 387 } 388 389 static void 390 nfs_update_delegation_cred(struct nfs_delegation *delegation, 391 const struct cred *cred) 392 { 393 const struct cred *old; 394 395 if (cred_fscmp(delegation->cred, cred) != 0) { 396 old = xchg(&delegation->cred, get_cred(cred)); 397 put_cred(old); 398 } 399 } 400 401 static void 402 nfs_update_inplace_delegation(struct nfs_delegation *delegation, 403 const struct nfs_delegation *update) 404 { 405 if (nfs4_stateid_is_newer(&update->stateid, &delegation->stateid)) { 406 delegation->stateid.seqid = update->stateid.seqid; 407 smp_wmb(); 408 delegation->type = update->type; 409 delegation->pagemod_limit = update->pagemod_limit; 410 if (test_bit(NFS_DELEGATION_REVOKED, &delegation->flags)) { 411 delegation->change_attr = update->change_attr; 412 nfs_update_delegation_cred(delegation, update->cred); 413 /* smp_mb__before_atomic() is implicit due to xchg() */ 414 clear_bit(NFS_DELEGATION_REVOKED, &delegation->flags); 415 atomic_long_inc(&nfs_active_delegations); 416 } 417 } 418 } 419 420 /** 421 * nfs_inode_set_delegation - set up a delegation on an inode 422 * @inode: inode to which delegation applies 423 * @cred: cred to use for subsequent delegation processing 424 * @type: delegation type 425 * @stateid: delegation stateid 426 * @pagemod_limit: write delegation "space_limit" 427 * 428 * Returns zero on success, or a negative errno value. 429 */ 430 int nfs_inode_set_delegation(struct inode *inode, const struct cred *cred, 431 fmode_t type, 432 const nfs4_stateid *stateid, 433 unsigned long pagemod_limit) 434 { 435 struct nfs_server *server = NFS_SERVER(inode); 436 struct nfs_client *clp = server->nfs_client; 437 struct nfs_inode *nfsi = NFS_I(inode); 438 struct nfs_delegation *delegation, *old_delegation; 439 struct nfs_delegation *freeme = NULL; 440 int status = 0; 441 442 delegation = kmalloc(sizeof(*delegation), GFP_KERNEL_ACCOUNT); 443 if (delegation == NULL) 444 return -ENOMEM; 445 nfs4_stateid_copy(&delegation->stateid, stateid); 446 refcount_set(&delegation->refcount, 1); 447 delegation->type = type; 448 delegation->pagemod_limit = pagemod_limit; 449 delegation->change_attr = inode_peek_iversion_raw(inode); 450 delegation->cred = get_cred(cred); 451 delegation->inode = inode; 452 delegation->flags = 1<<NFS_DELEGATION_REFERENCED; 453 spin_lock_init(&delegation->lock); 454 455 spin_lock(&clp->cl_lock); 456 old_delegation = rcu_dereference_protected(nfsi->delegation, 457 lockdep_is_held(&clp->cl_lock)); 458 if (old_delegation == NULL) 459 goto add_new; 460 /* Is this an update of the existing delegation? */ 461 if (nfs4_stateid_match_other(&old_delegation->stateid, 462 &delegation->stateid)) { 463 spin_lock(&old_delegation->lock); 464 nfs_update_inplace_delegation(old_delegation, 465 delegation); 466 spin_unlock(&old_delegation->lock); 467 goto out; 468 } 469 if (!test_bit(NFS_DELEGATION_REVOKED, &old_delegation->flags)) { 470 /* 471 * Deal with broken servers that hand out two 472 * delegations for the same file. 473 * Allow for upgrades to a WRITE delegation, but 474 * nothing else. 475 */ 476 dfprintk(FILE, "%s: server %s handed out " 477 "a duplicate delegation!\n", 478 __func__, clp->cl_hostname); 479 if (delegation->type == old_delegation->type || 480 !(delegation->type & FMODE_WRITE)) { 481 freeme = delegation; 482 delegation = NULL; 483 goto out; 484 } 485 if (test_and_set_bit(NFS_DELEGATION_RETURNING, 486 &old_delegation->flags)) 487 goto out; 488 } 489 freeme = nfs_detach_delegation_locked(nfsi, old_delegation, clp); 490 if (freeme == NULL) 491 goto out; 492 add_new: 493 /* 494 * If we didn't revalidate the change attribute before setting 495 * the delegation, then pre-emptively ask for a full attribute 496 * cache revalidation. 497 */ 498 spin_lock(&inode->i_lock); 499 if (NFS_I(inode)->cache_validity & NFS_INO_INVALID_CHANGE) 500 nfs_set_cache_invalid(inode, 501 NFS_INO_INVALID_ATIME | NFS_INO_INVALID_CTIME | 502 NFS_INO_INVALID_MTIME | NFS_INO_INVALID_SIZE | 503 NFS_INO_INVALID_BLOCKS | NFS_INO_INVALID_NLINK | 504 NFS_INO_INVALID_OTHER | NFS_INO_INVALID_DATA | 505 NFS_INO_INVALID_ACCESS | NFS_INO_INVALID_ACL | 506 NFS_INO_INVALID_XATTR); 507 spin_unlock(&inode->i_lock); 508 509 list_add_tail_rcu(&delegation->super_list, &server->delegations); 510 rcu_assign_pointer(nfsi->delegation, delegation); 511 delegation = NULL; 512 513 atomic_long_inc(&nfs_active_delegations); 514 515 trace_nfs4_set_delegation(inode, type); 516 out: 517 spin_unlock(&clp->cl_lock); 518 if (delegation != NULL) 519 __nfs_free_delegation(delegation); 520 if (freeme != NULL) { 521 nfs_do_return_delegation(inode, freeme, 0); 522 nfs_free_delegation(freeme); 523 } 524 return status; 525 } 526 527 /* 528 * Basic procedure for returning a delegation to the server 529 */ 530 static int nfs_end_delegation_return(struct inode *inode, struct nfs_delegation *delegation, int issync) 531 { 532 struct nfs_client *clp = NFS_SERVER(inode)->nfs_client; 533 unsigned int mode = O_WRONLY | O_RDWR; 534 int err = 0; 535 536 if (delegation == NULL) 537 return 0; 538 539 if (!issync) 540 mode |= O_NONBLOCK; 541 /* Recall of any remaining application leases */ 542 err = break_lease(inode, mode); 543 544 while (err == 0) { 545 if (test_bit(NFS_DELEGATION_REVOKED, &delegation->flags)) 546 break; 547 err = nfs_delegation_claim_opens(inode, &delegation->stateid, 548 delegation->type); 549 if (!issync || err != -EAGAIN) 550 break; 551 /* 552 * Guard against state recovery 553 */ 554 err = nfs4_wait_clnt_recover(clp); 555 } 556 557 if (err) { 558 nfs_abort_delegation_return(delegation, clp, err); 559 goto out; 560 } 561 562 err = nfs_do_return_delegation(inode, delegation, issync); 563 out: 564 /* Refcount matched in nfs_start_delegation_return_locked() */ 565 nfs_put_delegation(delegation); 566 return err; 567 } 568 569 static bool nfs_delegation_need_return(struct nfs_delegation *delegation) 570 { 571 bool ret = false; 572 573 if (test_and_clear_bit(NFS_DELEGATION_RETURN, &delegation->flags)) 574 ret = true; 575 else if (test_bit(NFS_DELEGATION_RETURN_IF_CLOSED, &delegation->flags)) { 576 struct inode *inode; 577 578 spin_lock(&delegation->lock); 579 inode = delegation->inode; 580 if (inode && list_empty(&NFS_I(inode)->open_files)) 581 ret = true; 582 spin_unlock(&delegation->lock); 583 } 584 if (ret) 585 clear_bit(NFS_DELEGATION_RETURN_IF_CLOSED, &delegation->flags); 586 if (test_bit(NFS_DELEGATION_RETURNING, &delegation->flags) || 587 test_bit(NFS_DELEGATION_RETURN_DELAYED, &delegation->flags) || 588 test_bit(NFS_DELEGATION_REVOKED, &delegation->flags)) 589 ret = false; 590 591 return ret; 592 } 593 594 static int nfs_server_return_marked_delegations(struct nfs_server *server, 595 void __always_unused *data) 596 { 597 struct nfs_delegation *delegation; 598 struct nfs_delegation *prev; 599 struct inode *inode; 600 struct inode *place_holder = NULL; 601 struct nfs_delegation *place_holder_deleg = NULL; 602 int err = 0; 603 604 restart: 605 /* 606 * To avoid quadratic looping we hold a reference 607 * to an inode place_holder. Each time we restart, we 608 * list delegation in the server from the delegations 609 * of that inode. 610 * prev is an RCU-protected pointer to a delegation which 611 * wasn't marked for return and might be a good choice for 612 * the next place_holder. 613 */ 614 prev = NULL; 615 delegation = NULL; 616 rcu_read_lock(); 617 if (place_holder) 618 delegation = rcu_dereference(NFS_I(place_holder)->delegation); 619 if (!delegation || delegation != place_holder_deleg) 620 delegation = list_entry_rcu(server->delegations.next, 621 struct nfs_delegation, super_list); 622 list_for_each_entry_from_rcu(delegation, &server->delegations, super_list) { 623 struct inode *to_put = NULL; 624 625 if (test_bit(NFS_DELEGATION_INODE_FREEING, &delegation->flags)) 626 continue; 627 if (!nfs_delegation_need_return(delegation)) { 628 if (nfs4_is_valid_delegation(delegation, 0)) 629 prev = delegation; 630 continue; 631 } 632 633 if (prev) { 634 struct inode *tmp = nfs_delegation_grab_inode(prev); 635 if (tmp) { 636 to_put = place_holder; 637 place_holder = tmp; 638 place_holder_deleg = prev; 639 } 640 } 641 642 inode = nfs_delegation_grab_inode(delegation); 643 if (inode == NULL) { 644 rcu_read_unlock(); 645 iput(to_put); 646 goto restart; 647 } 648 delegation = nfs_start_delegation_return_locked(NFS_I(inode)); 649 rcu_read_unlock(); 650 651 iput(to_put); 652 653 err = nfs_end_delegation_return(inode, delegation, 0); 654 iput(inode); 655 cond_resched(); 656 if (!err) 657 goto restart; 658 set_bit(NFS4CLNT_DELEGRETURN, &server->nfs_client->cl_state); 659 goto out; 660 } 661 rcu_read_unlock(); 662 out: 663 iput(place_holder); 664 return err; 665 } 666 667 static bool nfs_server_clear_delayed_delegations(struct nfs_server *server) 668 { 669 struct nfs_delegation *d; 670 bool ret = false; 671 672 list_for_each_entry_rcu (d, &server->delegations, super_list) { 673 if (!test_bit(NFS_DELEGATION_RETURN_DELAYED, &d->flags)) 674 continue; 675 nfs_mark_return_delegation(server, d); 676 clear_bit(NFS_DELEGATION_RETURN_DELAYED, &d->flags); 677 ret = true; 678 } 679 return ret; 680 } 681 682 static bool nfs_client_clear_delayed_delegations(struct nfs_client *clp) 683 { 684 struct nfs_server *server; 685 bool ret = false; 686 687 if (!test_and_clear_bit(NFS4CLNT_DELEGRETURN_DELAYED, &clp->cl_state)) 688 goto out; 689 rcu_read_lock(); 690 list_for_each_entry_rcu (server, &clp->cl_superblocks, client_link) { 691 if (nfs_server_clear_delayed_delegations(server)) 692 ret = true; 693 } 694 rcu_read_unlock(); 695 out: 696 return ret; 697 } 698 699 /** 700 * nfs_client_return_marked_delegations - return previously marked delegations 701 * @clp: nfs_client to process 702 * 703 * Note that this function is designed to be called by the state 704 * manager thread. For this reason, it cannot flush the dirty data, 705 * since that could deadlock in case of a state recovery error. 706 * 707 * Returns zero on success, or a negative errno value. 708 */ 709 int nfs_client_return_marked_delegations(struct nfs_client *clp) 710 { 711 int err = nfs_client_for_each_server( 712 clp, nfs_server_return_marked_delegations, NULL); 713 if (err) 714 return err; 715 /* If a return was delayed, sleep to prevent hard looping */ 716 if (nfs_client_clear_delayed_delegations(clp)) 717 ssleep(1); 718 return 0; 719 } 720 721 /** 722 * nfs_inode_evict_delegation - return delegation, don't reclaim opens 723 * @inode: inode to process 724 * 725 * Does not protect against delegation reclaims, therefore really only safe 726 * to be called from nfs4_clear_inode(). Guaranteed to always free 727 * the delegation structure. 728 */ 729 void nfs_inode_evict_delegation(struct inode *inode) 730 { 731 struct nfs_delegation *delegation; 732 733 delegation = nfs_inode_detach_delegation(inode); 734 if (delegation != NULL) { 735 set_bit(NFS_DELEGATION_RETURNING, &delegation->flags); 736 set_bit(NFS_DELEGATION_INODE_FREEING, &delegation->flags); 737 nfs_do_return_delegation(inode, delegation, 1); 738 nfs_free_delegation(delegation); 739 } 740 } 741 742 /** 743 * nfs4_inode_return_delegation - synchronously return a delegation 744 * @inode: inode to process 745 * 746 * This routine will always flush any dirty data to disk on the 747 * assumption that if we need to return the delegation, then 748 * we should stop caching. 749 * 750 * Returns zero on success, or a negative errno value. 751 */ 752 int nfs4_inode_return_delegation(struct inode *inode) 753 { 754 struct nfs_inode *nfsi = NFS_I(inode); 755 struct nfs_delegation *delegation; 756 757 delegation = nfs_start_delegation_return(nfsi); 758 if (delegation != NULL) { 759 /* Synchronous recall of any application leases */ 760 break_lease(inode, O_WRONLY | O_RDWR); 761 if (S_ISREG(inode->i_mode)) 762 nfs_wb_all(inode); 763 return nfs_end_delegation_return(inode, delegation, 1); 764 } 765 return 0; 766 } 767 768 /** 769 * nfs4_inode_return_delegation_on_close - asynchronously return a delegation 770 * @inode: inode to process 771 * 772 * This routine is called on file close in order to determine if the 773 * inode delegation needs to be returned immediately. 774 */ 775 void nfs4_inode_return_delegation_on_close(struct inode *inode) 776 { 777 struct nfs_delegation *delegation; 778 struct nfs_delegation *ret = NULL; 779 780 if (!inode) 781 return; 782 rcu_read_lock(); 783 delegation = nfs4_get_valid_delegation(inode); 784 if (!delegation) 785 goto out; 786 if (test_bit(NFS_DELEGATION_RETURN_IF_CLOSED, &delegation->flags) || 787 atomic_long_read(&nfs_active_delegations) >= nfs_delegation_watermark) { 788 spin_lock(&delegation->lock); 789 if (delegation->inode && 790 list_empty(&NFS_I(inode)->open_files) && 791 !test_and_set_bit(NFS_DELEGATION_RETURNING, &delegation->flags)) { 792 clear_bit(NFS_DELEGATION_RETURN_IF_CLOSED, &delegation->flags); 793 /* Refcount matched in nfs_end_delegation_return() */ 794 ret = nfs_get_delegation(delegation); 795 } 796 spin_unlock(&delegation->lock); 797 if (ret) 798 nfs_clear_verifier_delegated(inode); 799 } 800 out: 801 rcu_read_unlock(); 802 nfs_end_delegation_return(inode, ret, 0); 803 } 804 805 /** 806 * nfs4_inode_make_writeable 807 * @inode: pointer to inode 808 * 809 * Make the inode writeable by returning the delegation if necessary 810 * 811 * Returns zero on success, or a negative errno value. 812 */ 813 int nfs4_inode_make_writeable(struct inode *inode) 814 { 815 struct nfs_delegation *delegation; 816 817 rcu_read_lock(); 818 delegation = nfs4_get_valid_delegation(inode); 819 if (delegation == NULL || 820 (nfs4_has_session(NFS_SERVER(inode)->nfs_client) && 821 (delegation->type & FMODE_WRITE))) { 822 rcu_read_unlock(); 823 return 0; 824 } 825 rcu_read_unlock(); 826 return nfs4_inode_return_delegation(inode); 827 } 828 829 static void nfs_mark_return_if_closed_delegation(struct nfs_server *server, 830 struct nfs_delegation *delegation) 831 { 832 set_bit(NFS_DELEGATION_RETURN_IF_CLOSED, &delegation->flags); 833 set_bit(NFS4CLNT_DELEGRETURN, &server->nfs_client->cl_state); 834 } 835 836 static bool nfs_server_mark_return_all_delegations(struct nfs_server *server) 837 { 838 struct nfs_delegation *delegation; 839 bool ret = false; 840 841 list_for_each_entry_rcu(delegation, &server->delegations, super_list) { 842 nfs_mark_return_delegation(server, delegation); 843 ret = true; 844 } 845 return ret; 846 } 847 848 static void nfs_client_mark_return_all_delegations(struct nfs_client *clp) 849 { 850 struct nfs_server *server; 851 852 rcu_read_lock(); 853 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) 854 nfs_server_mark_return_all_delegations(server); 855 rcu_read_unlock(); 856 } 857 858 static void nfs_delegation_run_state_manager(struct nfs_client *clp) 859 { 860 if (test_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state)) 861 nfs4_schedule_state_manager(clp); 862 } 863 864 /** 865 * nfs_expire_all_delegations 866 * @clp: client to process 867 * 868 */ 869 void nfs_expire_all_delegations(struct nfs_client *clp) 870 { 871 nfs_client_mark_return_all_delegations(clp); 872 nfs_delegation_run_state_manager(clp); 873 } 874 875 /** 876 * nfs_server_return_all_delegations - return delegations for one superblock 877 * @server: pointer to nfs_server to process 878 * 879 */ 880 void nfs_server_return_all_delegations(struct nfs_server *server) 881 { 882 struct nfs_client *clp = server->nfs_client; 883 bool need_wait; 884 885 if (clp == NULL) 886 return; 887 888 rcu_read_lock(); 889 need_wait = nfs_server_mark_return_all_delegations(server); 890 rcu_read_unlock(); 891 892 if (need_wait) { 893 nfs4_schedule_state_manager(clp); 894 nfs4_wait_clnt_recover(clp); 895 } 896 } 897 898 static void nfs_mark_return_unused_delegation_types(struct nfs_server *server, 899 fmode_t flags) 900 { 901 struct nfs_delegation *delegation; 902 903 list_for_each_entry_rcu(delegation, &server->delegations, super_list) { 904 if ((delegation->type == (FMODE_READ|FMODE_WRITE)) && !(flags & FMODE_WRITE)) 905 continue; 906 if (delegation->type & flags) 907 nfs_mark_return_if_closed_delegation(server, delegation); 908 } 909 } 910 911 static void nfs_client_mark_return_unused_delegation_types(struct nfs_client *clp, 912 fmode_t flags) 913 { 914 struct nfs_server *server; 915 916 rcu_read_lock(); 917 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) 918 nfs_mark_return_unused_delegation_types(server, flags); 919 rcu_read_unlock(); 920 } 921 922 static void nfs_revoke_delegation(struct inode *inode, 923 const nfs4_stateid *stateid) 924 { 925 struct nfs_delegation *delegation; 926 nfs4_stateid tmp; 927 bool ret = false; 928 929 rcu_read_lock(); 930 delegation = rcu_dereference(NFS_I(inode)->delegation); 931 if (delegation == NULL) 932 goto out; 933 if (stateid == NULL) { 934 nfs4_stateid_copy(&tmp, &delegation->stateid); 935 stateid = &tmp; 936 } else { 937 if (!nfs4_stateid_match_other(stateid, &delegation->stateid)) 938 goto out; 939 spin_lock(&delegation->lock); 940 if (stateid->seqid) { 941 if (nfs4_stateid_is_newer(&delegation->stateid, stateid)) { 942 spin_unlock(&delegation->lock); 943 goto out; 944 } 945 delegation->stateid.seqid = stateid->seqid; 946 } 947 spin_unlock(&delegation->lock); 948 } 949 nfs_mark_delegation_revoked(delegation); 950 ret = true; 951 out: 952 rcu_read_unlock(); 953 if (ret) 954 nfs_inode_find_state_and_recover(inode, stateid); 955 } 956 957 void nfs_remove_bad_delegation(struct inode *inode, 958 const nfs4_stateid *stateid) 959 { 960 nfs_revoke_delegation(inode, stateid); 961 } 962 EXPORT_SYMBOL_GPL(nfs_remove_bad_delegation); 963 964 void nfs_delegation_mark_returned(struct inode *inode, 965 const nfs4_stateid *stateid) 966 { 967 struct nfs_delegation *delegation; 968 969 if (!inode) 970 return; 971 972 rcu_read_lock(); 973 delegation = rcu_dereference(NFS_I(inode)->delegation); 974 if (!delegation) 975 goto out_rcu_unlock; 976 977 spin_lock(&delegation->lock); 978 if (!nfs4_stateid_match_other(stateid, &delegation->stateid)) 979 goto out_spin_unlock; 980 if (stateid->seqid) { 981 /* If delegation->stateid is newer, dont mark as returned */ 982 if (nfs4_stateid_is_newer(&delegation->stateid, stateid)) 983 goto out_clear_returning; 984 if (delegation->stateid.seqid != stateid->seqid) 985 delegation->stateid.seqid = stateid->seqid; 986 } 987 988 nfs_mark_delegation_revoked(delegation); 989 990 out_clear_returning: 991 clear_bit(NFS_DELEGATION_RETURNING, &delegation->flags); 992 out_spin_unlock: 993 spin_unlock(&delegation->lock); 994 out_rcu_unlock: 995 rcu_read_unlock(); 996 997 nfs_inode_find_state_and_recover(inode, stateid); 998 } 999 1000 /** 1001 * nfs_expire_unused_delegation_types 1002 * @clp: client to process 1003 * @flags: delegation types to expire 1004 * 1005 */ 1006 void nfs_expire_unused_delegation_types(struct nfs_client *clp, fmode_t flags) 1007 { 1008 nfs_client_mark_return_unused_delegation_types(clp, flags); 1009 nfs_delegation_run_state_manager(clp); 1010 } 1011 1012 static void nfs_mark_return_unreferenced_delegations(struct nfs_server *server) 1013 { 1014 struct nfs_delegation *delegation; 1015 1016 list_for_each_entry_rcu(delegation, &server->delegations, super_list) { 1017 if (test_and_clear_bit(NFS_DELEGATION_REFERENCED, &delegation->flags)) 1018 continue; 1019 nfs_mark_return_if_closed_delegation(server, delegation); 1020 } 1021 } 1022 1023 /** 1024 * nfs_expire_unreferenced_delegations - Eliminate unused delegations 1025 * @clp: nfs_client to process 1026 * 1027 */ 1028 void nfs_expire_unreferenced_delegations(struct nfs_client *clp) 1029 { 1030 struct nfs_server *server; 1031 1032 rcu_read_lock(); 1033 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) 1034 nfs_mark_return_unreferenced_delegations(server); 1035 rcu_read_unlock(); 1036 1037 nfs_delegation_run_state_manager(clp); 1038 } 1039 1040 /** 1041 * nfs_async_inode_return_delegation - asynchronously return a delegation 1042 * @inode: inode to process 1043 * @stateid: state ID information 1044 * 1045 * Returns zero on success, or a negative errno value. 1046 */ 1047 int nfs_async_inode_return_delegation(struct inode *inode, 1048 const nfs4_stateid *stateid) 1049 { 1050 struct nfs_server *server = NFS_SERVER(inode); 1051 struct nfs_client *clp = server->nfs_client; 1052 struct nfs_delegation *delegation; 1053 1054 rcu_read_lock(); 1055 delegation = nfs4_get_valid_delegation(inode); 1056 if (delegation == NULL) 1057 goto out_enoent; 1058 if (stateid != NULL && 1059 !clp->cl_mvops->match_stateid(&delegation->stateid, stateid)) 1060 goto out_enoent; 1061 nfs_mark_return_delegation(server, delegation); 1062 rcu_read_unlock(); 1063 1064 /* If there are any application leases or delegations, recall them */ 1065 break_lease(inode, O_WRONLY | O_RDWR | O_NONBLOCK); 1066 1067 nfs_delegation_run_state_manager(clp); 1068 return 0; 1069 out_enoent: 1070 rcu_read_unlock(); 1071 return -ENOENT; 1072 } 1073 1074 static struct inode * 1075 nfs_delegation_find_inode_server(struct nfs_server *server, 1076 const struct nfs_fh *fhandle) 1077 { 1078 struct nfs_delegation *delegation; 1079 struct super_block *freeme = NULL; 1080 struct inode *res = NULL; 1081 1082 list_for_each_entry_rcu(delegation, &server->delegations, super_list) { 1083 spin_lock(&delegation->lock); 1084 if (delegation->inode != NULL && 1085 !test_bit(NFS_DELEGATION_REVOKED, &delegation->flags) && 1086 nfs_compare_fh(fhandle, &NFS_I(delegation->inode)->fh) == 0) { 1087 if (nfs_sb_active(server->super)) { 1088 freeme = server->super; 1089 res = igrab(delegation->inode); 1090 } 1091 spin_unlock(&delegation->lock); 1092 if (res != NULL) 1093 return res; 1094 if (freeme) { 1095 rcu_read_unlock(); 1096 nfs_sb_deactive(freeme); 1097 rcu_read_lock(); 1098 } 1099 return ERR_PTR(-EAGAIN); 1100 } 1101 spin_unlock(&delegation->lock); 1102 } 1103 return ERR_PTR(-ENOENT); 1104 } 1105 1106 /** 1107 * nfs_delegation_find_inode - retrieve the inode associated with a delegation 1108 * @clp: client state handle 1109 * @fhandle: filehandle from a delegation recall 1110 * 1111 * Returns pointer to inode matching "fhandle," or NULL if a matching inode 1112 * cannot be found. 1113 */ 1114 struct inode *nfs_delegation_find_inode(struct nfs_client *clp, 1115 const struct nfs_fh *fhandle) 1116 { 1117 struct nfs_server *server; 1118 struct inode *res; 1119 1120 rcu_read_lock(); 1121 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) { 1122 res = nfs_delegation_find_inode_server(server, fhandle); 1123 if (res != ERR_PTR(-ENOENT)) { 1124 rcu_read_unlock(); 1125 return res; 1126 } 1127 } 1128 rcu_read_unlock(); 1129 return ERR_PTR(-ENOENT); 1130 } 1131 1132 static void nfs_delegation_mark_reclaim_server(struct nfs_server *server) 1133 { 1134 struct nfs_delegation *delegation; 1135 1136 list_for_each_entry_rcu(delegation, &server->delegations, super_list) { 1137 /* 1138 * If the delegation may have been admin revoked, then we 1139 * cannot reclaim it. 1140 */ 1141 if (test_bit(NFS_DELEGATION_TEST_EXPIRED, &delegation->flags)) 1142 continue; 1143 set_bit(NFS_DELEGATION_NEED_RECLAIM, &delegation->flags); 1144 } 1145 } 1146 1147 /** 1148 * nfs_delegation_mark_reclaim - mark all delegations as needing to be reclaimed 1149 * @clp: nfs_client to process 1150 * 1151 */ 1152 void nfs_delegation_mark_reclaim(struct nfs_client *clp) 1153 { 1154 struct nfs_server *server; 1155 1156 rcu_read_lock(); 1157 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) 1158 nfs_delegation_mark_reclaim_server(server); 1159 rcu_read_unlock(); 1160 } 1161 1162 static int nfs_server_reap_unclaimed_delegations(struct nfs_server *server, 1163 void __always_unused *data) 1164 { 1165 struct nfs_delegation *delegation; 1166 struct inode *inode; 1167 restart: 1168 rcu_read_lock(); 1169 restart_locked: 1170 list_for_each_entry_rcu(delegation, &server->delegations, super_list) { 1171 if (test_bit(NFS_DELEGATION_INODE_FREEING, 1172 &delegation->flags) || 1173 test_bit(NFS_DELEGATION_RETURNING, 1174 &delegation->flags) || 1175 test_bit(NFS_DELEGATION_NEED_RECLAIM, 1176 &delegation->flags) == 0) 1177 continue; 1178 inode = nfs_delegation_grab_inode(delegation); 1179 if (inode == NULL) 1180 goto restart_locked; 1181 delegation = nfs_start_delegation_return_locked(NFS_I(inode)); 1182 rcu_read_unlock(); 1183 if (delegation != NULL) { 1184 if (nfs_detach_delegation(NFS_I(inode), delegation, 1185 server) != NULL) 1186 nfs_free_delegation(delegation); 1187 /* Match nfs_start_delegation_return_locked */ 1188 nfs_put_delegation(delegation); 1189 } 1190 iput(inode); 1191 cond_resched(); 1192 goto restart; 1193 } 1194 rcu_read_unlock(); 1195 return 0; 1196 } 1197 1198 /** 1199 * nfs_delegation_reap_unclaimed - reap unclaimed delegations after reboot recovery is done 1200 * @clp: nfs_client to process 1201 * 1202 */ 1203 void nfs_delegation_reap_unclaimed(struct nfs_client *clp) 1204 { 1205 nfs_client_for_each_server(clp, nfs_server_reap_unclaimed_delegations, 1206 NULL); 1207 } 1208 1209 static inline bool nfs4_server_rebooted(const struct nfs_client *clp) 1210 { 1211 return (clp->cl_state & (BIT(NFS4CLNT_CHECK_LEASE) | 1212 BIT(NFS4CLNT_LEASE_EXPIRED) | 1213 BIT(NFS4CLNT_SESSION_RESET))) != 0; 1214 } 1215 1216 static void nfs_mark_test_expired_delegation(struct nfs_server *server, 1217 struct nfs_delegation *delegation) 1218 { 1219 if (delegation->stateid.type == NFS4_INVALID_STATEID_TYPE) 1220 return; 1221 clear_bit(NFS_DELEGATION_NEED_RECLAIM, &delegation->flags); 1222 set_bit(NFS_DELEGATION_TEST_EXPIRED, &delegation->flags); 1223 set_bit(NFS4CLNT_DELEGATION_EXPIRED, &server->nfs_client->cl_state); 1224 } 1225 1226 static void nfs_inode_mark_test_expired_delegation(struct nfs_server *server, 1227 struct inode *inode) 1228 { 1229 struct nfs_delegation *delegation; 1230 1231 rcu_read_lock(); 1232 delegation = rcu_dereference(NFS_I(inode)->delegation); 1233 if (delegation) 1234 nfs_mark_test_expired_delegation(server, delegation); 1235 rcu_read_unlock(); 1236 1237 } 1238 1239 static void nfs_delegation_mark_test_expired_server(struct nfs_server *server) 1240 { 1241 struct nfs_delegation *delegation; 1242 1243 list_for_each_entry_rcu(delegation, &server->delegations, super_list) 1244 nfs_mark_test_expired_delegation(server, delegation); 1245 } 1246 1247 /** 1248 * nfs_mark_test_expired_all_delegations - mark all delegations for testing 1249 * @clp: nfs_client to process 1250 * 1251 * Iterates through all the delegations associated with this server and 1252 * marks them as needing to be checked for validity. 1253 */ 1254 void nfs_mark_test_expired_all_delegations(struct nfs_client *clp) 1255 { 1256 struct nfs_server *server; 1257 1258 rcu_read_lock(); 1259 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) 1260 nfs_delegation_mark_test_expired_server(server); 1261 rcu_read_unlock(); 1262 } 1263 1264 /** 1265 * nfs_test_expired_all_delegations - test all delegations for a client 1266 * @clp: nfs_client to process 1267 * 1268 * Helper for handling "recallable state revoked" status from server. 1269 */ 1270 void nfs_test_expired_all_delegations(struct nfs_client *clp) 1271 { 1272 nfs_mark_test_expired_all_delegations(clp); 1273 nfs4_schedule_state_manager(clp); 1274 } 1275 1276 static void 1277 nfs_delegation_test_free_expired(struct inode *inode, 1278 nfs4_stateid *stateid, 1279 const struct cred *cred) 1280 { 1281 struct nfs_server *server = NFS_SERVER(inode); 1282 const struct nfs4_minor_version_ops *ops = server->nfs_client->cl_mvops; 1283 int status; 1284 1285 if (!cred) 1286 return; 1287 status = ops->test_and_free_expired(server, stateid, cred); 1288 if (status == -NFS4ERR_EXPIRED || status == -NFS4ERR_BAD_STATEID) 1289 nfs_remove_bad_delegation(inode, stateid); 1290 } 1291 1292 static int nfs_server_reap_expired_delegations(struct nfs_server *server, 1293 void __always_unused *data) 1294 { 1295 struct nfs_delegation *delegation; 1296 struct inode *inode; 1297 const struct cred *cred; 1298 nfs4_stateid stateid; 1299 restart: 1300 rcu_read_lock(); 1301 restart_locked: 1302 list_for_each_entry_rcu(delegation, &server->delegations, super_list) { 1303 if (test_bit(NFS_DELEGATION_INODE_FREEING, 1304 &delegation->flags) || 1305 test_bit(NFS_DELEGATION_RETURNING, 1306 &delegation->flags) || 1307 test_bit(NFS_DELEGATION_TEST_EXPIRED, 1308 &delegation->flags) == 0) 1309 continue; 1310 inode = nfs_delegation_grab_inode(delegation); 1311 if (inode == NULL) 1312 goto restart_locked; 1313 spin_lock(&delegation->lock); 1314 cred = get_cred_rcu(delegation->cred); 1315 nfs4_stateid_copy(&stateid, &delegation->stateid); 1316 spin_unlock(&delegation->lock); 1317 clear_bit(NFS_DELEGATION_TEST_EXPIRED, &delegation->flags); 1318 rcu_read_unlock(); 1319 nfs_delegation_test_free_expired(inode, &stateid, cred); 1320 put_cred(cred); 1321 if (!nfs4_server_rebooted(server->nfs_client)) { 1322 iput(inode); 1323 cond_resched(); 1324 goto restart; 1325 } 1326 nfs_inode_mark_test_expired_delegation(server,inode); 1327 iput(inode); 1328 return -EAGAIN; 1329 } 1330 rcu_read_unlock(); 1331 return 0; 1332 } 1333 1334 /** 1335 * nfs_reap_expired_delegations - reap expired delegations 1336 * @clp: nfs_client to process 1337 * 1338 * Iterates through all the delegations associated with this server and 1339 * checks if they have may have been revoked. This function is usually 1340 * expected to be called in cases where the server may have lost its 1341 * lease. 1342 */ 1343 void nfs_reap_expired_delegations(struct nfs_client *clp) 1344 { 1345 nfs_client_for_each_server(clp, nfs_server_reap_expired_delegations, 1346 NULL); 1347 } 1348 1349 void nfs_inode_find_delegation_state_and_recover(struct inode *inode, 1350 const nfs4_stateid *stateid) 1351 { 1352 struct nfs_client *clp = NFS_SERVER(inode)->nfs_client; 1353 struct nfs_delegation *delegation; 1354 bool found = false; 1355 1356 rcu_read_lock(); 1357 delegation = rcu_dereference(NFS_I(inode)->delegation); 1358 if (delegation && 1359 nfs4_stateid_match_or_older(&delegation->stateid, stateid) && 1360 !test_bit(NFS_DELEGATION_REVOKED, &delegation->flags)) { 1361 nfs_mark_test_expired_delegation(NFS_SERVER(inode), delegation); 1362 found = true; 1363 } 1364 rcu_read_unlock(); 1365 if (found) 1366 nfs4_schedule_state_manager(clp); 1367 } 1368 1369 /** 1370 * nfs_delegations_present - check for existence of delegations 1371 * @clp: client state handle 1372 * 1373 * Returns one if there are any nfs_delegation structures attached 1374 * to this nfs_client. 1375 */ 1376 int nfs_delegations_present(struct nfs_client *clp) 1377 { 1378 struct nfs_server *server; 1379 int ret = 0; 1380 1381 rcu_read_lock(); 1382 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) 1383 if (!list_empty(&server->delegations)) { 1384 ret = 1; 1385 break; 1386 } 1387 rcu_read_unlock(); 1388 return ret; 1389 } 1390 1391 /** 1392 * nfs4_refresh_delegation_stateid - Update delegation stateid seqid 1393 * @dst: stateid to refresh 1394 * @inode: inode to check 1395 * 1396 * Returns "true" and updates "dst->seqid" * if inode had a delegation 1397 * that matches our delegation stateid. Otherwise "false" is returned. 1398 */ 1399 bool nfs4_refresh_delegation_stateid(nfs4_stateid *dst, struct inode *inode) 1400 { 1401 struct nfs_delegation *delegation; 1402 bool ret = false; 1403 if (!inode) 1404 goto out; 1405 1406 rcu_read_lock(); 1407 delegation = rcu_dereference(NFS_I(inode)->delegation); 1408 if (delegation != NULL && 1409 nfs4_stateid_match_other(dst, &delegation->stateid) && 1410 nfs4_stateid_is_newer(&delegation->stateid, dst) && 1411 !test_bit(NFS_DELEGATION_REVOKED, &delegation->flags)) { 1412 dst->seqid = delegation->stateid.seqid; 1413 ret = true; 1414 } 1415 rcu_read_unlock(); 1416 out: 1417 return ret; 1418 } 1419 1420 /** 1421 * nfs4_copy_delegation_stateid - Copy inode's state ID information 1422 * @inode: inode to check 1423 * @flags: delegation type requirement 1424 * @dst: stateid data structure to fill in 1425 * @cred: optional argument to retrieve credential 1426 * 1427 * Returns "true" and fills in "dst->data" * if inode had a delegation, 1428 * otherwise "false" is returned. 1429 */ 1430 bool nfs4_copy_delegation_stateid(struct inode *inode, fmode_t flags, 1431 nfs4_stateid *dst, const struct cred **cred) 1432 { 1433 struct nfs_inode *nfsi = NFS_I(inode); 1434 struct nfs_delegation *delegation; 1435 bool ret = false; 1436 1437 flags &= FMODE_READ|FMODE_WRITE; 1438 rcu_read_lock(); 1439 delegation = rcu_dereference(nfsi->delegation); 1440 if (!delegation) 1441 goto out; 1442 spin_lock(&delegation->lock); 1443 ret = nfs4_is_valid_delegation(delegation, flags); 1444 if (ret) { 1445 nfs4_stateid_copy(dst, &delegation->stateid); 1446 nfs_mark_delegation_referenced(delegation); 1447 if (cred) 1448 *cred = get_cred(delegation->cred); 1449 } 1450 spin_unlock(&delegation->lock); 1451 out: 1452 rcu_read_unlock(); 1453 return ret; 1454 } 1455 1456 /** 1457 * nfs4_delegation_flush_on_close - Check if we must flush file on close 1458 * @inode: inode to check 1459 * 1460 * This function checks the number of outstanding writes to the file 1461 * against the delegation 'space_limit' field to see if 1462 * the spec requires us to flush the file on close. 1463 */ 1464 bool nfs4_delegation_flush_on_close(const struct inode *inode) 1465 { 1466 struct nfs_inode *nfsi = NFS_I(inode); 1467 struct nfs_delegation *delegation; 1468 bool ret = true; 1469 1470 rcu_read_lock(); 1471 delegation = rcu_dereference(nfsi->delegation); 1472 if (delegation == NULL || !(delegation->type & FMODE_WRITE)) 1473 goto out; 1474 if (atomic_long_read(&nfsi->nrequests) < delegation->pagemod_limit) 1475 ret = false; 1476 out: 1477 rcu_read_unlock(); 1478 return ret; 1479 } 1480 1481 module_param_named(delegation_watermark, nfs_delegation_watermark, uint, 0644); 1482