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 = locks_inode_context(inode); 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, const nfs4_stateid *stateid, 232 unsigned long pagemod_limit) 233 { 234 struct nfs_delegation *delegation; 235 const struct cred *oldcred = NULL; 236 237 rcu_read_lock(); 238 delegation = rcu_dereference(NFS_I(inode)->delegation); 239 if (delegation != NULL) { 240 spin_lock(&delegation->lock); 241 nfs4_stateid_copy(&delegation->stateid, stateid); 242 delegation->type = type; 243 delegation->pagemod_limit = pagemod_limit; 244 oldcred = delegation->cred; 245 delegation->cred = get_cred(cred); 246 clear_bit(NFS_DELEGATION_NEED_RECLAIM, &delegation->flags); 247 if (test_and_clear_bit(NFS_DELEGATION_REVOKED, 248 &delegation->flags)) 249 atomic_long_inc(&nfs_active_delegations); 250 spin_unlock(&delegation->lock); 251 rcu_read_unlock(); 252 put_cred(oldcred); 253 trace_nfs4_reclaim_delegation(inode, type); 254 } else { 255 rcu_read_unlock(); 256 nfs_inode_set_delegation(inode, cred, type, stateid, 257 pagemod_limit); 258 } 259 } 260 261 static int nfs_do_return_delegation(struct inode *inode, struct nfs_delegation *delegation, int issync) 262 { 263 const struct cred *cred; 264 int res = 0; 265 266 if (!test_bit(NFS_DELEGATION_REVOKED, &delegation->flags)) { 267 spin_lock(&delegation->lock); 268 cred = get_cred(delegation->cred); 269 spin_unlock(&delegation->lock); 270 res = nfs4_proc_delegreturn(inode, cred, 271 &delegation->stateid, 272 issync); 273 put_cred(cred); 274 } 275 return res; 276 } 277 278 static struct inode *nfs_delegation_grab_inode(struct nfs_delegation *delegation) 279 { 280 struct inode *inode = NULL; 281 282 spin_lock(&delegation->lock); 283 if (delegation->inode != NULL) 284 inode = igrab(delegation->inode); 285 if (!inode) 286 set_bit(NFS_DELEGATION_INODE_FREEING, &delegation->flags); 287 spin_unlock(&delegation->lock); 288 return inode; 289 } 290 291 static struct nfs_delegation * 292 nfs_start_delegation_return_locked(struct nfs_inode *nfsi) 293 { 294 struct nfs_delegation *ret = NULL; 295 struct nfs_delegation *delegation = rcu_dereference(nfsi->delegation); 296 297 if (delegation == NULL) 298 goto out; 299 spin_lock(&delegation->lock); 300 if (!test_and_set_bit(NFS_DELEGATION_RETURNING, &delegation->flags)) { 301 clear_bit(NFS_DELEGATION_RETURN_DELAYED, &delegation->flags); 302 /* Refcount matched in nfs_end_delegation_return() */ 303 ret = nfs_get_delegation(delegation); 304 } 305 spin_unlock(&delegation->lock); 306 if (ret) 307 nfs_clear_verifier_delegated(&nfsi->vfs_inode); 308 out: 309 return ret; 310 } 311 312 static struct nfs_delegation * 313 nfs_start_delegation_return(struct nfs_inode *nfsi) 314 { 315 struct nfs_delegation *delegation; 316 317 rcu_read_lock(); 318 delegation = nfs_start_delegation_return_locked(nfsi); 319 rcu_read_unlock(); 320 return delegation; 321 } 322 323 static void nfs_abort_delegation_return(struct nfs_delegation *delegation, 324 struct nfs_client *clp, int err) 325 { 326 327 spin_lock(&delegation->lock); 328 clear_bit(NFS_DELEGATION_RETURNING, &delegation->flags); 329 if (err == -EAGAIN) { 330 set_bit(NFS_DELEGATION_RETURN_DELAYED, &delegation->flags); 331 set_bit(NFS4CLNT_DELEGRETURN_DELAYED, &clp->cl_state); 332 } 333 spin_unlock(&delegation->lock); 334 } 335 336 static struct nfs_delegation * 337 nfs_detach_delegation_locked(struct nfs_inode *nfsi, 338 struct nfs_delegation *delegation, 339 struct nfs_client *clp) 340 { 341 struct nfs_delegation *deleg_cur = 342 rcu_dereference_protected(nfsi->delegation, 343 lockdep_is_held(&clp->cl_lock)); 344 345 if (deleg_cur == NULL || delegation != deleg_cur) 346 return NULL; 347 348 spin_lock(&delegation->lock); 349 if (!delegation->inode) { 350 spin_unlock(&delegation->lock); 351 return NULL; 352 } 353 list_del_rcu(&delegation->super_list); 354 delegation->inode = NULL; 355 rcu_assign_pointer(nfsi->delegation, NULL); 356 spin_unlock(&delegation->lock); 357 return delegation; 358 } 359 360 static struct nfs_delegation *nfs_detach_delegation(struct nfs_inode *nfsi, 361 struct nfs_delegation *delegation, 362 struct nfs_server *server) 363 { 364 struct nfs_client *clp = server->nfs_client; 365 366 spin_lock(&clp->cl_lock); 367 delegation = nfs_detach_delegation_locked(nfsi, delegation, clp); 368 spin_unlock(&clp->cl_lock); 369 return delegation; 370 } 371 372 static struct nfs_delegation * 373 nfs_inode_detach_delegation(struct inode *inode) 374 { 375 struct nfs_inode *nfsi = NFS_I(inode); 376 struct nfs_server *server = NFS_SERVER(inode); 377 struct nfs_delegation *delegation; 378 379 rcu_read_lock(); 380 delegation = rcu_dereference(nfsi->delegation); 381 if (delegation != NULL) 382 delegation = nfs_detach_delegation(nfsi, delegation, server); 383 rcu_read_unlock(); 384 return delegation; 385 } 386 387 static void 388 nfs_update_delegation_cred(struct nfs_delegation *delegation, 389 const struct cred *cred) 390 { 391 const struct cred *old; 392 393 if (cred_fscmp(delegation->cred, cred) != 0) { 394 old = xchg(&delegation->cred, get_cred(cred)); 395 put_cred(old); 396 } 397 } 398 399 static void 400 nfs_update_inplace_delegation(struct nfs_delegation *delegation, 401 const struct nfs_delegation *update) 402 { 403 if (nfs4_stateid_is_newer(&update->stateid, &delegation->stateid)) { 404 delegation->stateid.seqid = update->stateid.seqid; 405 smp_wmb(); 406 delegation->type = update->type; 407 delegation->pagemod_limit = update->pagemod_limit; 408 if (test_bit(NFS_DELEGATION_REVOKED, &delegation->flags)) { 409 delegation->change_attr = update->change_attr; 410 nfs_update_delegation_cred(delegation, update->cred); 411 /* smp_mb__before_atomic() is implicit due to xchg() */ 412 clear_bit(NFS_DELEGATION_REVOKED, &delegation->flags); 413 atomic_long_inc(&nfs_active_delegations); 414 } 415 } 416 } 417 418 /** 419 * nfs_inode_set_delegation - set up a delegation on an inode 420 * @inode: inode to which delegation applies 421 * @cred: cred to use for subsequent delegation processing 422 * @type: delegation type 423 * @stateid: delegation stateid 424 * @pagemod_limit: write delegation "space_limit" 425 * 426 * Returns zero on success, or a negative errno value. 427 */ 428 int nfs_inode_set_delegation(struct inode *inode, const struct cred *cred, 429 fmode_t type, 430 const nfs4_stateid *stateid, 431 unsigned long pagemod_limit) 432 { 433 struct nfs_server *server = NFS_SERVER(inode); 434 struct nfs_client *clp = server->nfs_client; 435 struct nfs_inode *nfsi = NFS_I(inode); 436 struct nfs_delegation *delegation, *old_delegation; 437 struct nfs_delegation *freeme = NULL; 438 int status = 0; 439 440 delegation = kmalloc(sizeof(*delegation), GFP_KERNEL_ACCOUNT); 441 if (delegation == NULL) 442 return -ENOMEM; 443 nfs4_stateid_copy(&delegation->stateid, stateid); 444 refcount_set(&delegation->refcount, 1); 445 delegation->type = type; 446 delegation->pagemod_limit = pagemod_limit; 447 delegation->change_attr = inode_peek_iversion_raw(inode); 448 delegation->cred = get_cred(cred); 449 delegation->inode = inode; 450 delegation->flags = 1<<NFS_DELEGATION_REFERENCED; 451 delegation->test_gen = 0; 452 spin_lock_init(&delegation->lock); 453 454 spin_lock(&clp->cl_lock); 455 old_delegation = rcu_dereference_protected(nfsi->delegation, 456 lockdep_is_held(&clp->cl_lock)); 457 if (old_delegation == NULL) 458 goto add_new; 459 /* Is this an update of the existing delegation? */ 460 if (nfs4_stateid_match_other(&old_delegation->stateid, 461 &delegation->stateid)) { 462 spin_lock(&old_delegation->lock); 463 nfs_update_inplace_delegation(old_delegation, 464 delegation); 465 spin_unlock(&old_delegation->lock); 466 goto out; 467 } 468 if (!test_bit(NFS_DELEGATION_REVOKED, &old_delegation->flags)) { 469 /* 470 * Deal with broken servers that hand out two 471 * delegations for the same file. 472 * Allow for upgrades to a WRITE delegation, but 473 * nothing else. 474 */ 475 dfprintk(FILE, "%s: server %s handed out " 476 "a duplicate delegation!\n", 477 __func__, clp->cl_hostname); 478 if (delegation->type == old_delegation->type || 479 !(delegation->type & FMODE_WRITE)) { 480 freeme = delegation; 481 delegation = NULL; 482 goto out; 483 } 484 if (test_and_set_bit(NFS_DELEGATION_RETURNING, 485 &old_delegation->flags)) 486 goto out; 487 } 488 freeme = nfs_detach_delegation_locked(nfsi, old_delegation, clp); 489 if (freeme == NULL) 490 goto out; 491 add_new: 492 /* 493 * If we didn't revalidate the change attribute before setting 494 * the delegation, then pre-emptively ask for a full attribute 495 * cache revalidation. 496 */ 497 spin_lock(&inode->i_lock); 498 if (NFS_I(inode)->cache_validity & NFS_INO_INVALID_CHANGE) 499 nfs_set_cache_invalid(inode, 500 NFS_INO_INVALID_ATIME | NFS_INO_INVALID_CTIME | 501 NFS_INO_INVALID_MTIME | NFS_INO_INVALID_SIZE | 502 NFS_INO_INVALID_BLOCKS | NFS_INO_INVALID_NLINK | 503 NFS_INO_INVALID_OTHER | NFS_INO_INVALID_DATA | 504 NFS_INO_INVALID_ACCESS | NFS_INO_INVALID_ACL | 505 NFS_INO_INVALID_XATTR); 506 spin_unlock(&inode->i_lock); 507 508 list_add_tail_rcu(&delegation->super_list, &server->delegations); 509 rcu_assign_pointer(nfsi->delegation, delegation); 510 delegation = NULL; 511 512 atomic_long_inc(&nfs_active_delegations); 513 514 trace_nfs4_set_delegation(inode, type); 515 out: 516 spin_unlock(&clp->cl_lock); 517 if (delegation != NULL) 518 __nfs_free_delegation(delegation); 519 if (freeme != NULL) { 520 nfs_do_return_delegation(inode, freeme, 0); 521 nfs_free_delegation(freeme); 522 } 523 return status; 524 } 525 526 /* 527 * Basic procedure for returning a delegation to the server 528 */ 529 static int nfs_end_delegation_return(struct inode *inode, struct nfs_delegation *delegation, int issync) 530 { 531 struct nfs_client *clp = NFS_SERVER(inode)->nfs_client; 532 unsigned int mode = O_WRONLY | O_RDWR; 533 int err = 0; 534 535 if (delegation == NULL) 536 return 0; 537 538 if (!issync) 539 mode |= O_NONBLOCK; 540 /* Recall of any remaining application leases */ 541 err = break_lease(inode, mode); 542 543 while (err == 0) { 544 if (test_bit(NFS_DELEGATION_REVOKED, &delegation->flags)) 545 break; 546 err = nfs_delegation_claim_opens(inode, &delegation->stateid, 547 delegation->type); 548 if (!issync || err != -EAGAIN) 549 break; 550 /* 551 * Guard against state recovery 552 */ 553 err = nfs4_wait_clnt_recover(clp); 554 } 555 556 if (err) { 557 nfs_abort_delegation_return(delegation, clp, err); 558 goto out; 559 } 560 561 err = nfs_do_return_delegation(inode, delegation, issync); 562 out: 563 /* Refcount matched in nfs_start_delegation_return_locked() */ 564 nfs_put_delegation(delegation); 565 return err; 566 } 567 568 static bool nfs_delegation_need_return(struct nfs_delegation *delegation) 569 { 570 bool ret = false; 571 572 if (test_and_clear_bit(NFS_DELEGATION_RETURN, &delegation->flags)) 573 ret = true; 574 else if (test_bit(NFS_DELEGATION_RETURN_IF_CLOSED, &delegation->flags)) { 575 struct inode *inode; 576 577 spin_lock(&delegation->lock); 578 inode = delegation->inode; 579 if (inode && list_empty(&NFS_I(inode)->open_files)) 580 ret = true; 581 spin_unlock(&delegation->lock); 582 } 583 if (ret) 584 clear_bit(NFS_DELEGATION_RETURN_IF_CLOSED, &delegation->flags); 585 if (test_bit(NFS_DELEGATION_RETURNING, &delegation->flags) || 586 test_bit(NFS_DELEGATION_RETURN_DELAYED, &delegation->flags) || 587 test_bit(NFS_DELEGATION_REVOKED, &delegation->flags)) 588 ret = false; 589 590 return ret; 591 } 592 593 static int nfs_server_return_marked_delegations(struct nfs_server *server, 594 void __always_unused *data) 595 { 596 struct nfs_delegation *delegation; 597 struct nfs_delegation *prev; 598 struct inode *inode; 599 struct inode *place_holder = NULL; 600 struct nfs_delegation *place_holder_deleg = NULL; 601 int err = 0; 602 603 restart: 604 /* 605 * To avoid quadratic looping we hold a reference 606 * to an inode place_holder. Each time we restart, we 607 * list delegation in the server from the delegations 608 * of that inode. 609 * prev is an RCU-protected pointer to a delegation which 610 * wasn't marked for return and might be a good choice for 611 * the next place_holder. 612 */ 613 prev = NULL; 614 delegation = NULL; 615 rcu_read_lock(); 616 if (place_holder) 617 delegation = rcu_dereference(NFS_I(place_holder)->delegation); 618 if (!delegation || delegation != place_holder_deleg) 619 delegation = list_entry_rcu(server->delegations.next, 620 struct nfs_delegation, super_list); 621 list_for_each_entry_from_rcu(delegation, &server->delegations, super_list) { 622 struct inode *to_put = NULL; 623 624 if (test_bit(NFS_DELEGATION_INODE_FREEING, &delegation->flags)) 625 continue; 626 if (!nfs_delegation_need_return(delegation)) { 627 if (nfs4_is_valid_delegation(delegation, 0)) 628 prev = delegation; 629 continue; 630 } 631 632 if (prev) { 633 struct inode *tmp = nfs_delegation_grab_inode(prev); 634 if (tmp) { 635 to_put = place_holder; 636 place_holder = tmp; 637 place_holder_deleg = prev; 638 } 639 } 640 641 inode = nfs_delegation_grab_inode(delegation); 642 if (inode == NULL) { 643 rcu_read_unlock(); 644 iput(to_put); 645 goto restart; 646 } 647 delegation = nfs_start_delegation_return_locked(NFS_I(inode)); 648 rcu_read_unlock(); 649 650 iput(to_put); 651 652 err = nfs_end_delegation_return(inode, delegation, 0); 653 iput(inode); 654 cond_resched(); 655 if (!err) 656 goto restart; 657 set_bit(NFS4CLNT_DELEGRETURN, &server->nfs_client->cl_state); 658 goto out; 659 } 660 rcu_read_unlock(); 661 out: 662 iput(place_holder); 663 return err; 664 } 665 666 static bool nfs_server_clear_delayed_delegations(struct nfs_server *server) 667 { 668 struct nfs_delegation *d; 669 bool ret = false; 670 671 list_for_each_entry_rcu (d, &server->delegations, super_list) { 672 if (!test_bit(NFS_DELEGATION_RETURN_DELAYED, &d->flags)) 673 continue; 674 nfs_mark_return_delegation(server, d); 675 clear_bit(NFS_DELEGATION_RETURN_DELAYED, &d->flags); 676 ret = true; 677 } 678 return ret; 679 } 680 681 static bool nfs_client_clear_delayed_delegations(struct nfs_client *clp) 682 { 683 struct nfs_server *server; 684 bool ret = false; 685 686 if (!test_and_clear_bit(NFS4CLNT_DELEGRETURN_DELAYED, &clp->cl_state)) 687 goto out; 688 rcu_read_lock(); 689 list_for_each_entry_rcu (server, &clp->cl_superblocks, client_link) { 690 if (nfs_server_clear_delayed_delegations(server)) 691 ret = true; 692 } 693 rcu_read_unlock(); 694 out: 695 return ret; 696 } 697 698 /** 699 * nfs_client_return_marked_delegations - return previously marked delegations 700 * @clp: nfs_client to process 701 * 702 * Note that this function is designed to be called by the state 703 * manager thread. For this reason, it cannot flush the dirty data, 704 * since that could deadlock in case of a state recovery error. 705 * 706 * Returns zero on success, or a negative errno value. 707 */ 708 int nfs_client_return_marked_delegations(struct nfs_client *clp) 709 { 710 int err = nfs_client_for_each_server( 711 clp, nfs_server_return_marked_delegations, NULL); 712 if (err) 713 return err; 714 /* If a return was delayed, sleep to prevent hard looping */ 715 if (nfs_client_clear_delayed_delegations(clp)) 716 ssleep(1); 717 return 0; 718 } 719 720 /** 721 * nfs_inode_evict_delegation - return delegation, don't reclaim opens 722 * @inode: inode to process 723 * 724 * Does not protect against delegation reclaims, therefore really only safe 725 * to be called from nfs4_clear_inode(). Guaranteed to always free 726 * the delegation structure. 727 */ 728 void nfs_inode_evict_delegation(struct inode *inode) 729 { 730 struct nfs_delegation *delegation; 731 732 delegation = nfs_inode_detach_delegation(inode); 733 if (delegation != NULL) { 734 set_bit(NFS_DELEGATION_RETURNING, &delegation->flags); 735 set_bit(NFS_DELEGATION_INODE_FREEING, &delegation->flags); 736 nfs_do_return_delegation(inode, delegation, 1); 737 nfs_free_delegation(delegation); 738 } 739 } 740 741 /** 742 * nfs4_inode_return_delegation - synchronously return a delegation 743 * @inode: inode to process 744 * 745 * This routine will always flush any dirty data to disk on the 746 * assumption that if we need to return the delegation, then 747 * we should stop caching. 748 * 749 * Returns zero on success, or a negative errno value. 750 */ 751 int nfs4_inode_return_delegation(struct inode *inode) 752 { 753 struct nfs_inode *nfsi = NFS_I(inode); 754 struct nfs_delegation *delegation; 755 756 delegation = nfs_start_delegation_return(nfsi); 757 if (delegation != NULL) { 758 /* Synchronous recall of any application leases */ 759 break_lease(inode, O_WRONLY | O_RDWR); 760 if (S_ISREG(inode->i_mode)) 761 nfs_wb_all(inode); 762 return nfs_end_delegation_return(inode, delegation, 1); 763 } 764 return 0; 765 } 766 767 /** 768 * nfs4_inode_return_delegation_on_close - asynchronously return a delegation 769 * @inode: inode to process 770 * 771 * This routine is called on file close in order to determine if the 772 * inode delegation needs to be returned immediately. 773 */ 774 void nfs4_inode_return_delegation_on_close(struct inode *inode) 775 { 776 struct nfs_delegation *delegation; 777 struct nfs_delegation *ret = NULL; 778 779 if (!inode) 780 return; 781 rcu_read_lock(); 782 delegation = nfs4_get_valid_delegation(inode); 783 if (!delegation) 784 goto out; 785 if (test_bit(NFS_DELEGATION_RETURN_IF_CLOSED, &delegation->flags) || 786 atomic_long_read(&nfs_active_delegations) >= nfs_delegation_watermark) { 787 spin_lock(&delegation->lock); 788 if (delegation->inode && 789 list_empty(&NFS_I(inode)->open_files) && 790 !test_and_set_bit(NFS_DELEGATION_RETURNING, &delegation->flags)) { 791 clear_bit(NFS_DELEGATION_RETURN_IF_CLOSED, &delegation->flags); 792 /* Refcount matched in nfs_end_delegation_return() */ 793 ret = nfs_get_delegation(delegation); 794 } 795 spin_unlock(&delegation->lock); 796 if (ret) 797 nfs_clear_verifier_delegated(inode); 798 } 799 out: 800 rcu_read_unlock(); 801 nfs_end_delegation_return(inode, ret, 0); 802 } 803 804 /** 805 * nfs4_inode_make_writeable 806 * @inode: pointer to inode 807 * 808 * Make the inode writeable by returning the delegation if necessary 809 * 810 * Returns zero on success, or a negative errno value. 811 */ 812 int nfs4_inode_make_writeable(struct inode *inode) 813 { 814 struct nfs_delegation *delegation; 815 816 rcu_read_lock(); 817 delegation = nfs4_get_valid_delegation(inode); 818 if (delegation == NULL || 819 (nfs4_has_session(NFS_SERVER(inode)->nfs_client) && 820 (delegation->type & FMODE_WRITE))) { 821 rcu_read_unlock(); 822 return 0; 823 } 824 rcu_read_unlock(); 825 return nfs4_inode_return_delegation(inode); 826 } 827 828 static void nfs_mark_return_if_closed_delegation(struct nfs_server *server, 829 struct nfs_delegation *delegation) 830 { 831 set_bit(NFS_DELEGATION_RETURN_IF_CLOSED, &delegation->flags); 832 set_bit(NFS4CLNT_DELEGRETURN, &server->nfs_client->cl_state); 833 } 834 835 static bool nfs_server_mark_return_all_delegations(struct nfs_server *server) 836 { 837 struct nfs_delegation *delegation; 838 bool ret = false; 839 840 list_for_each_entry_rcu(delegation, &server->delegations, super_list) { 841 nfs_mark_return_delegation(server, delegation); 842 ret = true; 843 } 844 return ret; 845 } 846 847 static void nfs_client_mark_return_all_delegations(struct nfs_client *clp) 848 { 849 struct nfs_server *server; 850 851 rcu_read_lock(); 852 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) 853 nfs_server_mark_return_all_delegations(server); 854 rcu_read_unlock(); 855 } 856 857 static void nfs_delegation_run_state_manager(struct nfs_client *clp) 858 { 859 if (test_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state)) 860 nfs4_schedule_state_manager(clp); 861 } 862 863 /** 864 * nfs_expire_all_delegations 865 * @clp: client to process 866 * 867 */ 868 void nfs_expire_all_delegations(struct nfs_client *clp) 869 { 870 nfs_client_mark_return_all_delegations(clp); 871 nfs_delegation_run_state_manager(clp); 872 } 873 874 /** 875 * nfs_server_return_all_delegations - return delegations for one superblock 876 * @server: pointer to nfs_server to process 877 * 878 */ 879 void nfs_server_return_all_delegations(struct nfs_server *server) 880 { 881 struct nfs_client *clp = server->nfs_client; 882 bool need_wait; 883 884 if (clp == NULL) 885 return; 886 887 rcu_read_lock(); 888 need_wait = nfs_server_mark_return_all_delegations(server); 889 rcu_read_unlock(); 890 891 if (need_wait) { 892 nfs4_schedule_state_manager(clp); 893 nfs4_wait_clnt_recover(clp); 894 } 895 } 896 897 static void nfs_mark_return_unused_delegation_types(struct nfs_server *server, 898 fmode_t flags) 899 { 900 struct nfs_delegation *delegation; 901 902 list_for_each_entry_rcu(delegation, &server->delegations, super_list) { 903 if ((delegation->type == (FMODE_READ|FMODE_WRITE)) && !(flags & FMODE_WRITE)) 904 continue; 905 if (delegation->type & flags) 906 nfs_mark_return_if_closed_delegation(server, delegation); 907 } 908 } 909 910 static void nfs_client_mark_return_unused_delegation_types(struct nfs_client *clp, 911 fmode_t flags) 912 { 913 struct nfs_server *server; 914 915 rcu_read_lock(); 916 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) 917 nfs_mark_return_unused_delegation_types(server, flags); 918 rcu_read_unlock(); 919 } 920 921 static void nfs_revoke_delegation(struct inode *inode, 922 const nfs4_stateid *stateid) 923 { 924 struct nfs_delegation *delegation; 925 nfs4_stateid tmp; 926 bool ret = false; 927 928 rcu_read_lock(); 929 delegation = rcu_dereference(NFS_I(inode)->delegation); 930 if (delegation == NULL) 931 goto out; 932 if (stateid == NULL) { 933 nfs4_stateid_copy(&tmp, &delegation->stateid); 934 stateid = &tmp; 935 } else { 936 if (!nfs4_stateid_match_other(stateid, &delegation->stateid)) 937 goto out; 938 spin_lock(&delegation->lock); 939 if (stateid->seqid) { 940 if (nfs4_stateid_is_newer(&delegation->stateid, stateid)) { 941 spin_unlock(&delegation->lock); 942 goto out; 943 } 944 delegation->stateid.seqid = stateid->seqid; 945 } 946 spin_unlock(&delegation->lock); 947 } 948 nfs_mark_delegation_revoked(delegation); 949 ret = true; 950 out: 951 rcu_read_unlock(); 952 if (ret) 953 nfs_inode_find_state_and_recover(inode, stateid); 954 } 955 956 void nfs_remove_bad_delegation(struct inode *inode, 957 const nfs4_stateid *stateid) 958 { 959 nfs_revoke_delegation(inode, stateid); 960 } 961 EXPORT_SYMBOL_GPL(nfs_remove_bad_delegation); 962 963 void nfs_delegation_mark_returned(struct inode *inode, 964 const nfs4_stateid *stateid) 965 { 966 struct nfs_delegation *delegation; 967 968 if (!inode) 969 return; 970 971 rcu_read_lock(); 972 delegation = rcu_dereference(NFS_I(inode)->delegation); 973 if (!delegation) 974 goto out_rcu_unlock; 975 976 spin_lock(&delegation->lock); 977 if (!nfs4_stateid_match_other(stateid, &delegation->stateid)) 978 goto out_spin_unlock; 979 if (stateid->seqid) { 980 /* If delegation->stateid is newer, dont mark as returned */ 981 if (nfs4_stateid_is_newer(&delegation->stateid, stateid)) 982 goto out_clear_returning; 983 if (delegation->stateid.seqid != stateid->seqid) 984 delegation->stateid.seqid = stateid->seqid; 985 } 986 987 nfs_mark_delegation_revoked(delegation); 988 989 out_clear_returning: 990 clear_bit(NFS_DELEGATION_RETURNING, &delegation->flags); 991 out_spin_unlock: 992 spin_unlock(&delegation->lock); 993 out_rcu_unlock: 994 rcu_read_unlock(); 995 996 nfs_inode_find_state_and_recover(inode, stateid); 997 } 998 999 /** 1000 * nfs_expire_unused_delegation_types 1001 * @clp: client to process 1002 * @flags: delegation types to expire 1003 * 1004 */ 1005 void nfs_expire_unused_delegation_types(struct nfs_client *clp, fmode_t flags) 1006 { 1007 nfs_client_mark_return_unused_delegation_types(clp, flags); 1008 nfs_delegation_run_state_manager(clp); 1009 } 1010 1011 static void nfs_mark_return_unreferenced_delegations(struct nfs_server *server) 1012 { 1013 struct nfs_delegation *delegation; 1014 1015 list_for_each_entry_rcu(delegation, &server->delegations, super_list) { 1016 if (test_and_clear_bit(NFS_DELEGATION_REFERENCED, &delegation->flags)) 1017 continue; 1018 nfs_mark_return_if_closed_delegation(server, delegation); 1019 } 1020 } 1021 1022 /** 1023 * nfs_expire_unreferenced_delegations - Eliminate unused delegations 1024 * @clp: nfs_client to process 1025 * 1026 */ 1027 void nfs_expire_unreferenced_delegations(struct nfs_client *clp) 1028 { 1029 struct nfs_server *server; 1030 1031 rcu_read_lock(); 1032 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) 1033 nfs_mark_return_unreferenced_delegations(server); 1034 rcu_read_unlock(); 1035 1036 nfs_delegation_run_state_manager(clp); 1037 } 1038 1039 /** 1040 * nfs_async_inode_return_delegation - asynchronously return a delegation 1041 * @inode: inode to process 1042 * @stateid: state ID information 1043 * 1044 * Returns zero on success, or a negative errno value. 1045 */ 1046 int nfs_async_inode_return_delegation(struct inode *inode, 1047 const nfs4_stateid *stateid) 1048 { 1049 struct nfs_server *server = NFS_SERVER(inode); 1050 struct nfs_client *clp = server->nfs_client; 1051 struct nfs_delegation *delegation; 1052 1053 rcu_read_lock(); 1054 delegation = nfs4_get_valid_delegation(inode); 1055 if (delegation == NULL) 1056 goto out_enoent; 1057 if (stateid != NULL && 1058 !clp->cl_mvops->match_stateid(&delegation->stateid, stateid)) 1059 goto out_enoent; 1060 nfs_mark_return_delegation(server, delegation); 1061 rcu_read_unlock(); 1062 1063 /* If there are any application leases or delegations, recall them */ 1064 break_lease(inode, O_WRONLY | O_RDWR | O_NONBLOCK); 1065 1066 nfs_delegation_run_state_manager(clp); 1067 return 0; 1068 out_enoent: 1069 rcu_read_unlock(); 1070 return -ENOENT; 1071 } 1072 1073 static struct inode * 1074 nfs_delegation_find_inode_server(struct nfs_server *server, 1075 const struct nfs_fh *fhandle) 1076 { 1077 struct nfs_delegation *delegation; 1078 struct super_block *freeme = NULL; 1079 struct inode *res = NULL; 1080 1081 list_for_each_entry_rcu(delegation, &server->delegations, super_list) { 1082 spin_lock(&delegation->lock); 1083 if (delegation->inode != NULL && 1084 !test_bit(NFS_DELEGATION_REVOKED, &delegation->flags) && 1085 nfs_compare_fh(fhandle, &NFS_I(delegation->inode)->fh) == 0) { 1086 if (nfs_sb_active(server->super)) { 1087 freeme = server->super; 1088 res = igrab(delegation->inode); 1089 } 1090 spin_unlock(&delegation->lock); 1091 if (res != NULL) 1092 return res; 1093 if (freeme) { 1094 rcu_read_unlock(); 1095 nfs_sb_deactive(freeme); 1096 rcu_read_lock(); 1097 } 1098 return ERR_PTR(-EAGAIN); 1099 } 1100 spin_unlock(&delegation->lock); 1101 } 1102 return ERR_PTR(-ENOENT); 1103 } 1104 1105 /** 1106 * nfs_delegation_find_inode - retrieve the inode associated with a delegation 1107 * @clp: client state handle 1108 * @fhandle: filehandle from a delegation recall 1109 * 1110 * Returns pointer to inode matching "fhandle," or NULL if a matching inode 1111 * cannot be found. 1112 */ 1113 struct inode *nfs_delegation_find_inode(struct nfs_client *clp, 1114 const struct nfs_fh *fhandle) 1115 { 1116 struct nfs_server *server; 1117 struct inode *res; 1118 1119 rcu_read_lock(); 1120 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) { 1121 res = nfs_delegation_find_inode_server(server, fhandle); 1122 if (res != ERR_PTR(-ENOENT)) { 1123 rcu_read_unlock(); 1124 return res; 1125 } 1126 } 1127 rcu_read_unlock(); 1128 return ERR_PTR(-ENOENT); 1129 } 1130 1131 static void nfs_delegation_mark_reclaim_server(struct nfs_server *server) 1132 { 1133 struct nfs_delegation *delegation; 1134 1135 list_for_each_entry_rcu(delegation, &server->delegations, super_list) { 1136 /* 1137 * If the delegation may have been admin revoked, then we 1138 * cannot reclaim it. 1139 */ 1140 if (test_bit(NFS_DELEGATION_TEST_EXPIRED, &delegation->flags)) 1141 continue; 1142 set_bit(NFS_DELEGATION_NEED_RECLAIM, &delegation->flags); 1143 } 1144 } 1145 1146 /** 1147 * nfs_delegation_mark_reclaim - mark all delegations as needing to be reclaimed 1148 * @clp: nfs_client to process 1149 * 1150 */ 1151 void nfs_delegation_mark_reclaim(struct nfs_client *clp) 1152 { 1153 struct nfs_server *server; 1154 1155 rcu_read_lock(); 1156 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) 1157 nfs_delegation_mark_reclaim_server(server); 1158 rcu_read_unlock(); 1159 } 1160 1161 static int nfs_server_reap_unclaimed_delegations(struct nfs_server *server, 1162 void __always_unused *data) 1163 { 1164 struct nfs_delegation *delegation; 1165 struct inode *inode; 1166 restart: 1167 rcu_read_lock(); 1168 restart_locked: 1169 list_for_each_entry_rcu(delegation, &server->delegations, super_list) { 1170 if (test_bit(NFS_DELEGATION_INODE_FREEING, 1171 &delegation->flags) || 1172 test_bit(NFS_DELEGATION_RETURNING, 1173 &delegation->flags) || 1174 test_bit(NFS_DELEGATION_NEED_RECLAIM, 1175 &delegation->flags) == 0) 1176 continue; 1177 inode = nfs_delegation_grab_inode(delegation); 1178 if (inode == NULL) 1179 goto restart_locked; 1180 delegation = nfs_start_delegation_return_locked(NFS_I(inode)); 1181 rcu_read_unlock(); 1182 if (delegation != NULL) { 1183 if (nfs_detach_delegation(NFS_I(inode), delegation, 1184 server) != NULL) 1185 nfs_free_delegation(delegation); 1186 /* Match nfs_start_delegation_return_locked */ 1187 nfs_put_delegation(delegation); 1188 } 1189 iput(inode); 1190 cond_resched(); 1191 goto restart; 1192 } 1193 rcu_read_unlock(); 1194 return 0; 1195 } 1196 1197 /** 1198 * nfs_delegation_reap_unclaimed - reap unclaimed delegations after reboot recovery is done 1199 * @clp: nfs_client to process 1200 * 1201 */ 1202 void nfs_delegation_reap_unclaimed(struct nfs_client *clp) 1203 { 1204 nfs_client_for_each_server(clp, nfs_server_reap_unclaimed_delegations, 1205 NULL); 1206 } 1207 1208 static inline bool nfs4_server_rebooted(const struct nfs_client *clp) 1209 { 1210 return (clp->cl_state & (BIT(NFS4CLNT_CHECK_LEASE) | 1211 BIT(NFS4CLNT_LEASE_EXPIRED) | 1212 BIT(NFS4CLNT_SESSION_RESET))) != 0; 1213 } 1214 1215 static void nfs_mark_test_expired_delegation(struct nfs_server *server, 1216 struct nfs_delegation *delegation) 1217 { 1218 if (delegation->stateid.type == NFS4_INVALID_STATEID_TYPE) 1219 return; 1220 clear_bit(NFS_DELEGATION_NEED_RECLAIM, &delegation->flags); 1221 set_bit(NFS_DELEGATION_TEST_EXPIRED, &delegation->flags); 1222 set_bit(NFS4CLNT_DELEGATION_EXPIRED, &server->nfs_client->cl_state); 1223 } 1224 1225 static void nfs_inode_mark_test_expired_delegation(struct nfs_server *server, 1226 struct inode *inode) 1227 { 1228 struct nfs_delegation *delegation; 1229 1230 rcu_read_lock(); 1231 delegation = rcu_dereference(NFS_I(inode)->delegation); 1232 if (delegation) 1233 nfs_mark_test_expired_delegation(server, delegation); 1234 rcu_read_unlock(); 1235 1236 } 1237 1238 static void nfs_delegation_mark_test_expired_server(struct nfs_server *server) 1239 { 1240 struct nfs_delegation *delegation; 1241 1242 list_for_each_entry_rcu(delegation, &server->delegations, super_list) 1243 nfs_mark_test_expired_delegation(server, delegation); 1244 } 1245 1246 /** 1247 * nfs_mark_test_expired_all_delegations - mark all delegations for testing 1248 * @clp: nfs_client to process 1249 * 1250 * Iterates through all the delegations associated with this server and 1251 * marks them as needing to be checked for validity. 1252 */ 1253 void nfs_mark_test_expired_all_delegations(struct nfs_client *clp) 1254 { 1255 struct nfs_server *server; 1256 1257 rcu_read_lock(); 1258 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) 1259 nfs_delegation_mark_test_expired_server(server); 1260 rcu_read_unlock(); 1261 } 1262 1263 /** 1264 * nfs_test_expired_all_delegations - test all delegations for a client 1265 * @clp: nfs_client to process 1266 * 1267 * Helper for handling "recallable state revoked" status from server. 1268 */ 1269 void nfs_test_expired_all_delegations(struct nfs_client *clp) 1270 { 1271 nfs_mark_test_expired_all_delegations(clp); 1272 nfs4_schedule_state_manager(clp); 1273 } 1274 1275 static void 1276 nfs_delegation_test_free_expired(struct inode *inode, 1277 nfs4_stateid *stateid, 1278 const struct cred *cred) 1279 { 1280 struct nfs_server *server = NFS_SERVER(inode); 1281 const struct nfs4_minor_version_ops *ops = server->nfs_client->cl_mvops; 1282 int status; 1283 1284 if (!cred) 1285 return; 1286 status = ops->test_and_free_expired(server, stateid, cred); 1287 if (status == -NFS4ERR_EXPIRED || status == -NFS4ERR_BAD_STATEID) 1288 nfs_remove_bad_delegation(inode, stateid); 1289 } 1290 1291 static int nfs_server_reap_expired_delegations(struct nfs_server *server, 1292 void __always_unused *data) 1293 { 1294 struct nfs_delegation *delegation; 1295 struct inode *inode; 1296 const struct cred *cred; 1297 nfs4_stateid stateid; 1298 unsigned long gen = ++server->delegation_gen; 1299 1300 restart: 1301 rcu_read_lock(); 1302 restart_locked: 1303 list_for_each_entry_rcu(delegation, &server->delegations, super_list) { 1304 if (test_bit(NFS_DELEGATION_INODE_FREEING, 1305 &delegation->flags) || 1306 test_bit(NFS_DELEGATION_RETURNING, 1307 &delegation->flags) || 1308 test_bit(NFS_DELEGATION_TEST_EXPIRED, 1309 &delegation->flags) == 0 || 1310 delegation->test_gen == gen) 1311 continue; 1312 inode = nfs_delegation_grab_inode(delegation); 1313 if (inode == NULL) 1314 goto restart_locked; 1315 spin_lock(&delegation->lock); 1316 cred = get_cred_rcu(delegation->cred); 1317 nfs4_stateid_copy(&stateid, &delegation->stateid); 1318 spin_unlock(&delegation->lock); 1319 delegation->test_gen = gen; 1320 clear_bit(NFS_DELEGATION_TEST_EXPIRED, &delegation->flags); 1321 rcu_read_unlock(); 1322 nfs_delegation_test_free_expired(inode, &stateid, cred); 1323 put_cred(cred); 1324 if (!nfs4_server_rebooted(server->nfs_client)) { 1325 iput(inode); 1326 cond_resched(); 1327 goto restart; 1328 } 1329 nfs_inode_mark_test_expired_delegation(server,inode); 1330 iput(inode); 1331 return -EAGAIN; 1332 } 1333 rcu_read_unlock(); 1334 return 0; 1335 } 1336 1337 /** 1338 * nfs_reap_expired_delegations - reap expired delegations 1339 * @clp: nfs_client to process 1340 * 1341 * Iterates through all the delegations associated with this server and 1342 * checks if they have may have been revoked. This function is usually 1343 * expected to be called in cases where the server may have lost its 1344 * lease. 1345 */ 1346 void nfs_reap_expired_delegations(struct nfs_client *clp) 1347 { 1348 nfs_client_for_each_server(clp, nfs_server_reap_expired_delegations, 1349 NULL); 1350 } 1351 1352 void nfs_inode_find_delegation_state_and_recover(struct inode *inode, 1353 const nfs4_stateid *stateid) 1354 { 1355 struct nfs_client *clp = NFS_SERVER(inode)->nfs_client; 1356 struct nfs_delegation *delegation; 1357 bool found = false; 1358 1359 rcu_read_lock(); 1360 delegation = rcu_dereference(NFS_I(inode)->delegation); 1361 if (delegation && 1362 nfs4_stateid_match_or_older(&delegation->stateid, stateid) && 1363 !test_bit(NFS_DELEGATION_REVOKED, &delegation->flags)) { 1364 nfs_mark_test_expired_delegation(NFS_SERVER(inode), delegation); 1365 found = true; 1366 } 1367 rcu_read_unlock(); 1368 if (found) 1369 nfs4_schedule_state_manager(clp); 1370 } 1371 1372 /** 1373 * nfs_delegations_present - check for existence of delegations 1374 * @clp: client state handle 1375 * 1376 * Returns one if there are any nfs_delegation structures attached 1377 * to this nfs_client. 1378 */ 1379 int nfs_delegations_present(struct nfs_client *clp) 1380 { 1381 struct nfs_server *server; 1382 int ret = 0; 1383 1384 rcu_read_lock(); 1385 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) 1386 if (!list_empty(&server->delegations)) { 1387 ret = 1; 1388 break; 1389 } 1390 rcu_read_unlock(); 1391 return ret; 1392 } 1393 1394 /** 1395 * nfs4_refresh_delegation_stateid - Update delegation stateid seqid 1396 * @dst: stateid to refresh 1397 * @inode: inode to check 1398 * 1399 * Returns "true" and updates "dst->seqid" * if inode had a delegation 1400 * that matches our delegation stateid. Otherwise "false" is returned. 1401 */ 1402 bool nfs4_refresh_delegation_stateid(nfs4_stateid *dst, struct inode *inode) 1403 { 1404 struct nfs_delegation *delegation; 1405 bool ret = false; 1406 if (!inode) 1407 goto out; 1408 1409 rcu_read_lock(); 1410 delegation = rcu_dereference(NFS_I(inode)->delegation); 1411 if (delegation != NULL && 1412 nfs4_stateid_match_other(dst, &delegation->stateid) && 1413 nfs4_stateid_is_newer(&delegation->stateid, dst) && 1414 !test_bit(NFS_DELEGATION_REVOKED, &delegation->flags)) { 1415 dst->seqid = delegation->stateid.seqid; 1416 ret = true; 1417 } 1418 rcu_read_unlock(); 1419 out: 1420 return ret; 1421 } 1422 1423 /** 1424 * nfs4_copy_delegation_stateid - Copy inode's state ID information 1425 * @inode: inode to check 1426 * @flags: delegation type requirement 1427 * @dst: stateid data structure to fill in 1428 * @cred: optional argument to retrieve credential 1429 * 1430 * Returns "true" and fills in "dst->data" * if inode had a delegation, 1431 * otherwise "false" is returned. 1432 */ 1433 bool nfs4_copy_delegation_stateid(struct inode *inode, fmode_t flags, 1434 nfs4_stateid *dst, const struct cred **cred) 1435 { 1436 struct nfs_inode *nfsi = NFS_I(inode); 1437 struct nfs_delegation *delegation; 1438 bool ret = false; 1439 1440 flags &= FMODE_READ|FMODE_WRITE; 1441 rcu_read_lock(); 1442 delegation = rcu_dereference(nfsi->delegation); 1443 if (!delegation) 1444 goto out; 1445 spin_lock(&delegation->lock); 1446 ret = nfs4_is_valid_delegation(delegation, flags); 1447 if (ret) { 1448 nfs4_stateid_copy(dst, &delegation->stateid); 1449 nfs_mark_delegation_referenced(delegation); 1450 if (cred) 1451 *cred = get_cred(delegation->cred); 1452 } 1453 spin_unlock(&delegation->lock); 1454 out: 1455 rcu_read_unlock(); 1456 return ret; 1457 } 1458 1459 /** 1460 * nfs4_delegation_flush_on_close - Check if we must flush file on close 1461 * @inode: inode to check 1462 * 1463 * This function checks the number of outstanding writes to the file 1464 * against the delegation 'space_limit' field to see if 1465 * the spec requires us to flush the file on close. 1466 */ 1467 bool nfs4_delegation_flush_on_close(const struct inode *inode) 1468 { 1469 struct nfs_inode *nfsi = NFS_I(inode); 1470 struct nfs_delegation *delegation; 1471 bool ret = true; 1472 1473 rcu_read_lock(); 1474 delegation = rcu_dereference(nfsi->delegation); 1475 if (delegation == NULL || !(delegation->type & FMODE_WRITE)) 1476 goto out; 1477 if (atomic_long_read(&nfsi->nrequests) < delegation->pagemod_limit) 1478 ret = false; 1479 out: 1480 rcu_read_unlock(); 1481 return ret; 1482 } 1483 1484 module_param_named(delegation_watermark, nfs_delegation_watermark, uint, 0644); 1485