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 nfs4_is_valid_delegation(const struct nfs_delegation *delegation, 86 fmode_t type) 87 { 88 if (delegation != NULL && (delegation->type & type) == type && 89 !test_bit(NFS_DELEGATION_REVOKED, &delegation->flags) && 90 !test_bit(NFS_DELEGATION_RETURNING, &delegation->flags)) 91 return true; 92 return false; 93 } 94 95 struct nfs_delegation *nfs4_get_valid_delegation(const struct inode *inode) 96 { 97 struct nfs_delegation *delegation; 98 99 delegation = rcu_dereference(NFS_I(inode)->delegation); 100 if (nfs4_is_valid_delegation(delegation, 0)) 101 return delegation; 102 return NULL; 103 } 104 105 static int nfs4_do_check_delegation(struct inode *inode, fmode_t type, 106 int flags, bool mark) 107 { 108 struct nfs_delegation *delegation; 109 int ret = 0; 110 111 type &= FMODE_READ|FMODE_WRITE; 112 rcu_read_lock(); 113 delegation = rcu_dereference(NFS_I(inode)->delegation); 114 if (nfs4_is_valid_delegation(delegation, type)) { 115 if (mark) 116 nfs_mark_delegation_referenced(delegation); 117 ret = 1; 118 if ((flags & NFS_DELEGATION_FLAG_TIME) && 119 !test_bit(NFS_DELEGATION_DELEGTIME, &delegation->flags)) 120 ret = 0; 121 } 122 rcu_read_unlock(); 123 return ret; 124 } 125 /** 126 * nfs4_have_delegation - check if inode has a delegation, mark it 127 * NFS_DELEGATION_REFERENCED if there is one. 128 * @inode: inode to check 129 * @type: delegation types to check for 130 * @flags: various modifiers 131 * 132 * Returns one if inode has the indicated delegation, otherwise zero. 133 */ 134 int nfs4_have_delegation(struct inode *inode, fmode_t type, int flags) 135 { 136 return nfs4_do_check_delegation(inode, type, flags, true); 137 } 138 139 /* 140 * nfs4_check_delegation - check if inode has a delegation, do not mark 141 * NFS_DELEGATION_REFERENCED if it has one. 142 */ 143 int nfs4_check_delegation(struct inode *inode, fmode_t type) 144 { 145 return nfs4_do_check_delegation(inode, type, 0, false); 146 } 147 148 static int nfs_delegation_claim_locks(struct nfs4_state *state, const nfs4_stateid *stateid) 149 { 150 struct inode *inode = state->inode; 151 struct file_lock *fl; 152 struct file_lock_context *flctx = locks_inode_context(inode); 153 struct list_head *list; 154 int status = 0; 155 156 if (flctx == NULL) 157 goto out; 158 159 list = &flctx->flc_posix; 160 spin_lock(&flctx->flc_lock); 161 restart: 162 for_each_file_lock(fl, list) { 163 if (nfs_file_open_context(fl->c.flc_file)->state != state) 164 continue; 165 spin_unlock(&flctx->flc_lock); 166 status = nfs4_lock_delegation_recall(fl, state, stateid); 167 if (status < 0) 168 goto out; 169 spin_lock(&flctx->flc_lock); 170 } 171 if (list == &flctx->flc_posix) { 172 list = &flctx->flc_flock; 173 goto restart; 174 } 175 spin_unlock(&flctx->flc_lock); 176 out: 177 return status; 178 } 179 180 static int nfs_delegation_claim_opens(struct inode *inode, 181 const nfs4_stateid *stateid, fmode_t type) 182 { 183 struct nfs_inode *nfsi = NFS_I(inode); 184 struct nfs_open_context *ctx; 185 struct nfs4_state_owner *sp; 186 struct nfs4_state *state; 187 int err; 188 189 again: 190 rcu_read_lock(); 191 list_for_each_entry_rcu(ctx, &nfsi->open_files, list) { 192 state = ctx->state; 193 if (state == NULL) 194 continue; 195 if (!test_bit(NFS_DELEGATED_STATE, &state->flags)) 196 continue; 197 if (!nfs4_valid_open_stateid(state)) 198 continue; 199 if (!nfs4_stateid_match(&state->stateid, stateid)) 200 continue; 201 if (!get_nfs_open_context(ctx)) 202 continue; 203 rcu_read_unlock(); 204 sp = state->owner; 205 /* Block nfs4_proc_unlck */ 206 mutex_lock(&sp->so_delegreturn_mutex); 207 err = nfs4_open_delegation_recall(ctx, state, stateid); 208 if (!err) 209 err = nfs_delegation_claim_locks(state, stateid); 210 mutex_unlock(&sp->so_delegreturn_mutex); 211 put_nfs_open_context(ctx); 212 if (err != 0) 213 return err; 214 goto again; 215 } 216 rcu_read_unlock(); 217 return 0; 218 } 219 220 /** 221 * nfs_inode_reclaim_delegation - process a delegation reclaim request 222 * @inode: inode to process 223 * @cred: credential to use for request 224 * @type: delegation type 225 * @stateid: delegation stateid 226 * @pagemod_limit: write delegation "space_limit" 227 * @deleg_type: raw delegation type 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, u32 deleg_type) 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 switch (deleg_type) { 247 case NFS4_OPEN_DELEGATE_READ_ATTRS_DELEG: 248 case NFS4_OPEN_DELEGATE_WRITE_ATTRS_DELEG: 249 set_bit(NFS_DELEGATION_DELEGTIME, &delegation->flags); 250 break; 251 default: 252 clear_bit(NFS_DELEGATION_DELEGTIME, &delegation->flags); 253 } 254 clear_bit(NFS_DELEGATION_NEED_RECLAIM, &delegation->flags); 255 if (test_and_clear_bit(NFS_DELEGATION_REVOKED, 256 &delegation->flags)) 257 atomic_long_inc(&nfs_active_delegations); 258 spin_unlock(&delegation->lock); 259 rcu_read_unlock(); 260 put_cred(oldcred); 261 trace_nfs4_reclaim_delegation(inode, type); 262 } else { 263 rcu_read_unlock(); 264 nfs_inode_set_delegation(inode, cred, type, stateid, 265 pagemod_limit, deleg_type); 266 } 267 } 268 269 static int nfs_do_return_delegation(struct inode *inode, 270 struct nfs_delegation *delegation, 271 int issync) 272 { 273 const struct cred *cred; 274 int res = 0; 275 276 if (!test_bit(NFS_DELEGATION_REVOKED, &delegation->flags)) { 277 spin_lock(&delegation->lock); 278 cred = get_cred(delegation->cred); 279 spin_unlock(&delegation->lock); 280 res = nfs4_proc_delegreturn(inode, cred, &delegation->stateid, 281 delegation, issync); 282 put_cred(cred); 283 } 284 return res; 285 } 286 287 static struct inode *nfs_delegation_grab_inode(struct nfs_delegation *delegation) 288 { 289 struct inode *inode = NULL; 290 291 spin_lock(&delegation->lock); 292 if (delegation->inode != NULL) 293 inode = igrab(delegation->inode); 294 if (!inode) 295 set_bit(NFS_DELEGATION_INODE_FREEING, &delegation->flags); 296 spin_unlock(&delegation->lock); 297 return inode; 298 } 299 300 static struct nfs_delegation * 301 nfs_start_delegation_return_locked(struct nfs_inode *nfsi) 302 { 303 struct nfs_delegation *ret = NULL; 304 struct nfs_delegation *delegation = rcu_dereference(nfsi->delegation); 305 306 if (delegation == NULL) 307 goto out; 308 spin_lock(&delegation->lock); 309 if (!test_and_set_bit(NFS_DELEGATION_RETURNING, &delegation->flags)) { 310 clear_bit(NFS_DELEGATION_RETURN_DELAYED, &delegation->flags); 311 /* Refcount matched in nfs_end_delegation_return() */ 312 ret = nfs_get_delegation(delegation); 313 } 314 spin_unlock(&delegation->lock); 315 if (ret) 316 nfs_clear_verifier_delegated(&nfsi->vfs_inode); 317 out: 318 return ret; 319 } 320 321 static struct nfs_delegation * 322 nfs_start_delegation_return(struct nfs_inode *nfsi) 323 { 324 struct nfs_delegation *delegation; 325 326 rcu_read_lock(); 327 delegation = nfs_start_delegation_return_locked(nfsi); 328 rcu_read_unlock(); 329 return delegation; 330 } 331 332 static void nfs_abort_delegation_return(struct nfs_delegation *delegation, 333 struct nfs_client *clp, int err) 334 { 335 336 spin_lock(&delegation->lock); 337 clear_bit(NFS_DELEGATION_RETURNING, &delegation->flags); 338 if (err == -EAGAIN) { 339 set_bit(NFS_DELEGATION_RETURN_DELAYED, &delegation->flags); 340 set_bit(NFS4CLNT_DELEGRETURN_DELAYED, &clp->cl_state); 341 } 342 spin_unlock(&delegation->lock); 343 } 344 345 static struct nfs_delegation * 346 nfs_detach_delegation_locked(struct nfs_inode *nfsi, 347 struct nfs_delegation *delegation, 348 struct nfs_client *clp) 349 { 350 struct nfs_delegation *deleg_cur = 351 rcu_dereference_protected(nfsi->delegation, 352 lockdep_is_held(&clp->cl_lock)); 353 354 if (deleg_cur == NULL || delegation != deleg_cur) 355 return NULL; 356 357 spin_lock(&delegation->lock); 358 if (!delegation->inode) { 359 spin_unlock(&delegation->lock); 360 return NULL; 361 } 362 list_del_rcu(&delegation->super_list); 363 delegation->inode = NULL; 364 rcu_assign_pointer(nfsi->delegation, NULL); 365 spin_unlock(&delegation->lock); 366 return delegation; 367 } 368 369 static struct nfs_delegation *nfs_detach_delegation(struct nfs_inode *nfsi, 370 struct nfs_delegation *delegation, 371 struct nfs_server *server) 372 { 373 struct nfs_client *clp = server->nfs_client; 374 375 spin_lock(&clp->cl_lock); 376 delegation = nfs_detach_delegation_locked(nfsi, delegation, clp); 377 spin_unlock(&clp->cl_lock); 378 return delegation; 379 } 380 381 static struct nfs_delegation * 382 nfs_inode_detach_delegation(struct inode *inode) 383 { 384 struct nfs_inode *nfsi = NFS_I(inode); 385 struct nfs_server *server = NFS_SERVER(inode); 386 struct nfs_delegation *delegation; 387 388 rcu_read_lock(); 389 delegation = rcu_dereference(nfsi->delegation); 390 if (delegation != NULL) 391 delegation = nfs_detach_delegation(nfsi, delegation, server); 392 rcu_read_unlock(); 393 return delegation; 394 } 395 396 static void 397 nfs_update_delegation_cred(struct nfs_delegation *delegation, 398 const struct cred *cred) 399 { 400 const struct cred *old; 401 402 if (cred_fscmp(delegation->cred, cred) != 0) { 403 old = xchg(&delegation->cred, get_cred(cred)); 404 put_cred(old); 405 } 406 } 407 408 static void 409 nfs_update_inplace_delegation(struct nfs_delegation *delegation, 410 const struct nfs_delegation *update) 411 { 412 if (nfs4_stateid_is_newer(&update->stateid, &delegation->stateid)) { 413 delegation->stateid.seqid = update->stateid.seqid; 414 smp_wmb(); 415 delegation->type = update->type; 416 delegation->pagemod_limit = update->pagemod_limit; 417 if (test_bit(NFS_DELEGATION_REVOKED, &delegation->flags)) { 418 delegation->change_attr = update->change_attr; 419 nfs_update_delegation_cred(delegation, update->cred); 420 /* smp_mb__before_atomic() is implicit due to xchg() */ 421 clear_bit(NFS_DELEGATION_REVOKED, &delegation->flags); 422 atomic_long_inc(&nfs_active_delegations); 423 } 424 } 425 } 426 427 /** 428 * nfs_inode_set_delegation - set up a delegation on an inode 429 * @inode: inode to which delegation applies 430 * @cred: cred to use for subsequent delegation processing 431 * @type: delegation type 432 * @stateid: delegation stateid 433 * @pagemod_limit: write delegation "space_limit" 434 * @deleg_type: raw delegation type 435 * 436 * Returns zero on success, or a negative errno value. 437 */ 438 int nfs_inode_set_delegation(struct inode *inode, const struct cred *cred, 439 fmode_t type, const nfs4_stateid *stateid, 440 unsigned long pagemod_limit, u32 deleg_type) 441 { 442 struct nfs_server *server = NFS_SERVER(inode); 443 struct nfs_client *clp = server->nfs_client; 444 struct nfs_inode *nfsi = NFS_I(inode); 445 struct nfs_delegation *delegation, *old_delegation; 446 struct nfs_delegation *freeme = NULL; 447 int status = 0; 448 449 delegation = kmalloc(sizeof(*delegation), GFP_KERNEL_ACCOUNT); 450 if (delegation == NULL) 451 return -ENOMEM; 452 nfs4_stateid_copy(&delegation->stateid, stateid); 453 refcount_set(&delegation->refcount, 1); 454 delegation->type = type; 455 delegation->pagemod_limit = pagemod_limit; 456 delegation->change_attr = inode_peek_iversion_raw(inode); 457 delegation->cred = get_cred(cred); 458 delegation->inode = inode; 459 delegation->flags = 1<<NFS_DELEGATION_REFERENCED; 460 switch (deleg_type) { 461 case NFS4_OPEN_DELEGATE_READ_ATTRS_DELEG: 462 case NFS4_OPEN_DELEGATE_WRITE_ATTRS_DELEG: 463 delegation->flags |= BIT(NFS_DELEGATION_DELEGTIME); 464 } 465 delegation->test_gen = 0; 466 spin_lock_init(&delegation->lock); 467 468 spin_lock(&clp->cl_lock); 469 old_delegation = rcu_dereference_protected(nfsi->delegation, 470 lockdep_is_held(&clp->cl_lock)); 471 if (old_delegation == NULL) 472 goto add_new; 473 /* Is this an update of the existing delegation? */ 474 if (nfs4_stateid_match_other(&old_delegation->stateid, 475 &delegation->stateid)) { 476 spin_lock(&old_delegation->lock); 477 nfs_update_inplace_delegation(old_delegation, 478 delegation); 479 spin_unlock(&old_delegation->lock); 480 goto out; 481 } 482 if (!test_bit(NFS_DELEGATION_REVOKED, &old_delegation->flags)) { 483 /* 484 * Deal with broken servers that hand out two 485 * delegations for the same file. 486 * Allow for upgrades to a WRITE delegation, but 487 * nothing else. 488 */ 489 dfprintk(FILE, "%s: server %s handed out " 490 "a duplicate delegation!\n", 491 __func__, clp->cl_hostname); 492 if (delegation->type == old_delegation->type || 493 !(delegation->type & FMODE_WRITE)) { 494 freeme = delegation; 495 delegation = NULL; 496 goto out; 497 } 498 if (test_and_set_bit(NFS_DELEGATION_RETURNING, 499 &old_delegation->flags)) 500 goto out; 501 } 502 freeme = nfs_detach_delegation_locked(nfsi, old_delegation, clp); 503 if (freeme == NULL) 504 goto out; 505 add_new: 506 /* 507 * If we didn't revalidate the change attribute before setting 508 * the delegation, then pre-emptively ask for a full attribute 509 * cache revalidation. 510 */ 511 spin_lock(&inode->i_lock); 512 if (NFS_I(inode)->cache_validity & NFS_INO_INVALID_CHANGE) 513 nfs_set_cache_invalid(inode, 514 NFS_INO_INVALID_ATIME | NFS_INO_INVALID_CTIME | 515 NFS_INO_INVALID_MTIME | NFS_INO_INVALID_SIZE | 516 NFS_INO_INVALID_BLOCKS | NFS_INO_INVALID_NLINK | 517 NFS_INO_INVALID_OTHER | NFS_INO_INVALID_DATA | 518 NFS_INO_INVALID_ACCESS | NFS_INO_INVALID_ACL | 519 NFS_INO_INVALID_XATTR); 520 spin_unlock(&inode->i_lock); 521 522 list_add_tail_rcu(&delegation->super_list, &server->delegations); 523 rcu_assign_pointer(nfsi->delegation, delegation); 524 delegation = NULL; 525 526 atomic_long_inc(&nfs_active_delegations); 527 528 trace_nfs4_set_delegation(inode, type); 529 530 /* If we hold writebacks and have delegated mtime then update */ 531 if (deleg_type == NFS4_OPEN_DELEGATE_WRITE_ATTRS_DELEG && 532 nfs_have_writebacks(inode)) 533 nfs_update_delegated_mtime(inode); 534 out: 535 spin_unlock(&clp->cl_lock); 536 if (delegation != NULL) 537 __nfs_free_delegation(delegation); 538 if (freeme != NULL) { 539 nfs_do_return_delegation(inode, freeme, 0); 540 nfs_free_delegation(freeme); 541 } 542 return status; 543 } 544 545 /* 546 * Basic procedure for returning a delegation to the server 547 */ 548 static int nfs_end_delegation_return(struct inode *inode, struct nfs_delegation *delegation, int issync) 549 { 550 struct nfs_client *clp = NFS_SERVER(inode)->nfs_client; 551 unsigned int mode = O_WRONLY | O_RDWR; 552 int err = 0; 553 554 if (delegation == NULL) 555 return 0; 556 557 if (!issync) 558 mode |= O_NONBLOCK; 559 /* Recall of any remaining application leases */ 560 err = break_lease(inode, mode); 561 562 while (err == 0) { 563 if (test_bit(NFS_DELEGATION_REVOKED, &delegation->flags)) 564 break; 565 err = nfs_delegation_claim_opens(inode, &delegation->stateid, 566 delegation->type); 567 if (!issync || err != -EAGAIN) 568 break; 569 /* 570 * Guard against state recovery 571 */ 572 err = nfs4_wait_clnt_recover(clp); 573 } 574 575 if (err) { 576 nfs_abort_delegation_return(delegation, clp, err); 577 goto out; 578 } 579 580 err = nfs_do_return_delegation(inode, delegation, issync); 581 out: 582 /* Refcount matched in nfs_start_delegation_return_locked() */ 583 nfs_put_delegation(delegation); 584 return err; 585 } 586 587 static bool nfs_delegation_need_return(struct nfs_delegation *delegation) 588 { 589 bool ret = false; 590 591 if (test_and_clear_bit(NFS_DELEGATION_RETURN, &delegation->flags)) 592 ret = true; 593 else if (test_bit(NFS_DELEGATION_RETURN_IF_CLOSED, &delegation->flags)) { 594 struct inode *inode; 595 596 spin_lock(&delegation->lock); 597 inode = delegation->inode; 598 if (inode && list_empty(&NFS_I(inode)->open_files)) 599 ret = true; 600 spin_unlock(&delegation->lock); 601 } 602 if (ret) 603 clear_bit(NFS_DELEGATION_RETURN_IF_CLOSED, &delegation->flags); 604 if (test_bit(NFS_DELEGATION_RETURNING, &delegation->flags) || 605 test_bit(NFS_DELEGATION_RETURN_DELAYED, &delegation->flags) || 606 test_bit(NFS_DELEGATION_REVOKED, &delegation->flags)) 607 ret = false; 608 609 return ret; 610 } 611 612 static int nfs_server_return_marked_delegations(struct nfs_server *server, 613 void __always_unused *data) 614 { 615 struct nfs_delegation *delegation; 616 struct nfs_delegation *prev; 617 struct inode *inode; 618 struct inode *place_holder = NULL; 619 struct nfs_delegation *place_holder_deleg = NULL; 620 int err = 0; 621 622 restart: 623 /* 624 * To avoid quadratic looping we hold a reference 625 * to an inode place_holder. Each time we restart, we 626 * list delegation in the server from the delegations 627 * of that inode. 628 * prev is an RCU-protected pointer to a delegation which 629 * wasn't marked for return and might be a good choice for 630 * the next place_holder. 631 */ 632 prev = NULL; 633 delegation = NULL; 634 rcu_read_lock(); 635 if (place_holder) 636 delegation = rcu_dereference(NFS_I(place_holder)->delegation); 637 if (!delegation || delegation != place_holder_deleg) 638 delegation = list_entry_rcu(server->delegations.next, 639 struct nfs_delegation, super_list); 640 list_for_each_entry_from_rcu(delegation, &server->delegations, super_list) { 641 struct inode *to_put = NULL; 642 643 if (test_bit(NFS_DELEGATION_INODE_FREEING, &delegation->flags)) 644 continue; 645 if (!nfs_delegation_need_return(delegation)) { 646 if (nfs4_is_valid_delegation(delegation, 0)) 647 prev = delegation; 648 continue; 649 } 650 inode = nfs_delegation_grab_inode(delegation); 651 if (inode == NULL) 652 continue; 653 654 if (prev) { 655 struct inode *tmp = nfs_delegation_grab_inode(prev); 656 if (tmp) { 657 to_put = place_holder; 658 place_holder = tmp; 659 place_holder_deleg = prev; 660 } 661 } 662 663 delegation = nfs_start_delegation_return_locked(NFS_I(inode)); 664 rcu_read_unlock(); 665 666 iput(to_put); 667 668 err = nfs_end_delegation_return(inode, delegation, 0); 669 iput(inode); 670 cond_resched(); 671 if (!err) 672 goto restart; 673 set_bit(NFS4CLNT_DELEGRETURN, &server->nfs_client->cl_state); 674 goto out; 675 } 676 rcu_read_unlock(); 677 out: 678 iput(place_holder); 679 return err; 680 } 681 682 static bool nfs_server_clear_delayed_delegations(struct nfs_server *server) 683 { 684 struct nfs_delegation *d; 685 bool ret = false; 686 687 list_for_each_entry_rcu (d, &server->delegations, super_list) { 688 if (!test_bit(NFS_DELEGATION_RETURN_DELAYED, &d->flags)) 689 continue; 690 nfs_mark_return_delegation(server, d); 691 clear_bit(NFS_DELEGATION_RETURN_DELAYED, &d->flags); 692 ret = true; 693 } 694 return ret; 695 } 696 697 static bool nfs_client_clear_delayed_delegations(struct nfs_client *clp) 698 { 699 struct nfs_server *server; 700 bool ret = false; 701 702 if (!test_and_clear_bit(NFS4CLNT_DELEGRETURN_DELAYED, &clp->cl_state)) 703 goto out; 704 rcu_read_lock(); 705 list_for_each_entry_rcu (server, &clp->cl_superblocks, client_link) { 706 if (nfs_server_clear_delayed_delegations(server)) 707 ret = true; 708 } 709 rcu_read_unlock(); 710 out: 711 return ret; 712 } 713 714 /** 715 * nfs_client_return_marked_delegations - return previously marked delegations 716 * @clp: nfs_client to process 717 * 718 * Note that this function is designed to be called by the state 719 * manager thread. For this reason, it cannot flush the dirty data, 720 * since that could deadlock in case of a state recovery error. 721 * 722 * Returns zero on success, or a negative errno value. 723 */ 724 int nfs_client_return_marked_delegations(struct nfs_client *clp) 725 { 726 int err = nfs_client_for_each_server( 727 clp, nfs_server_return_marked_delegations, NULL); 728 if (err) 729 return err; 730 /* If a return was delayed, sleep to prevent hard looping */ 731 if (nfs_client_clear_delayed_delegations(clp)) 732 ssleep(1); 733 return 0; 734 } 735 736 /** 737 * nfs_inode_evict_delegation - return delegation, don't reclaim opens 738 * @inode: inode to process 739 * 740 * Does not protect against delegation reclaims, therefore really only safe 741 * to be called from nfs4_clear_inode(). Guaranteed to always free 742 * the delegation structure. 743 */ 744 void nfs_inode_evict_delegation(struct inode *inode) 745 { 746 struct nfs_delegation *delegation; 747 748 delegation = nfs_inode_detach_delegation(inode); 749 if (delegation != NULL) { 750 set_bit(NFS_DELEGATION_RETURNING, &delegation->flags); 751 set_bit(NFS_DELEGATION_INODE_FREEING, &delegation->flags); 752 nfs_do_return_delegation(inode, delegation, 1); 753 nfs_free_delegation(delegation); 754 } 755 } 756 757 /** 758 * nfs4_inode_return_delegation - synchronously return a delegation 759 * @inode: inode to process 760 * 761 * This routine will always flush any dirty data to disk on the 762 * assumption that if we need to return the delegation, then 763 * we should stop caching. 764 * 765 * Returns zero on success, or a negative errno value. 766 */ 767 int nfs4_inode_return_delegation(struct inode *inode) 768 { 769 struct nfs_inode *nfsi = NFS_I(inode); 770 struct nfs_delegation *delegation; 771 772 delegation = nfs_start_delegation_return(nfsi); 773 if (delegation != NULL) { 774 /* Synchronous recall of any application leases */ 775 break_lease(inode, O_WRONLY | O_RDWR); 776 if (S_ISREG(inode->i_mode)) 777 nfs_wb_all(inode); 778 return nfs_end_delegation_return(inode, delegation, 1); 779 } 780 return 0; 781 } 782 783 /** 784 * nfs4_inode_return_delegation_on_close - asynchronously return a delegation 785 * @inode: inode to process 786 * 787 * This routine is called on file close in order to determine if the 788 * inode delegation needs to be returned immediately. 789 */ 790 void nfs4_inode_return_delegation_on_close(struct inode *inode) 791 { 792 struct nfs_delegation *delegation; 793 struct nfs_delegation *ret = NULL; 794 795 if (!inode) 796 return; 797 rcu_read_lock(); 798 delegation = nfs4_get_valid_delegation(inode); 799 if (!delegation) 800 goto out; 801 if (test_bit(NFS_DELEGATION_RETURN_IF_CLOSED, &delegation->flags) || 802 atomic_long_read(&nfs_active_delegations) >= nfs_delegation_watermark) { 803 spin_lock(&delegation->lock); 804 if (delegation->inode && 805 list_empty(&NFS_I(inode)->open_files) && 806 !test_and_set_bit(NFS_DELEGATION_RETURNING, &delegation->flags)) { 807 clear_bit(NFS_DELEGATION_RETURN_IF_CLOSED, &delegation->flags); 808 /* Refcount matched in nfs_end_delegation_return() */ 809 ret = nfs_get_delegation(delegation); 810 } 811 spin_unlock(&delegation->lock); 812 if (ret) 813 nfs_clear_verifier_delegated(inode); 814 } 815 out: 816 rcu_read_unlock(); 817 nfs_end_delegation_return(inode, ret, 0); 818 } 819 820 /** 821 * nfs4_inode_make_writeable 822 * @inode: pointer to inode 823 * 824 * Make the inode writeable by returning the delegation if necessary 825 * 826 * Returns zero on success, or a negative errno value. 827 */ 828 int nfs4_inode_make_writeable(struct inode *inode) 829 { 830 struct nfs_delegation *delegation; 831 832 rcu_read_lock(); 833 delegation = nfs4_get_valid_delegation(inode); 834 if (delegation == NULL || 835 (nfs4_has_session(NFS_SERVER(inode)->nfs_client) && 836 (delegation->type & FMODE_WRITE))) { 837 rcu_read_unlock(); 838 return 0; 839 } 840 rcu_read_unlock(); 841 return nfs4_inode_return_delegation(inode); 842 } 843 844 static void nfs_mark_return_if_closed_delegation(struct nfs_server *server, 845 struct nfs_delegation *delegation) 846 { 847 set_bit(NFS_DELEGATION_RETURN_IF_CLOSED, &delegation->flags); 848 set_bit(NFS4CLNT_DELEGRETURN, &server->nfs_client->cl_state); 849 } 850 851 static bool nfs_server_mark_return_all_delegations(struct nfs_server *server) 852 { 853 struct nfs_delegation *delegation; 854 bool ret = false; 855 856 list_for_each_entry_rcu(delegation, &server->delegations, super_list) { 857 nfs_mark_return_delegation(server, delegation); 858 ret = true; 859 } 860 return ret; 861 } 862 863 static void nfs_client_mark_return_all_delegations(struct nfs_client *clp) 864 { 865 struct nfs_server *server; 866 867 rcu_read_lock(); 868 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) 869 nfs_server_mark_return_all_delegations(server); 870 rcu_read_unlock(); 871 } 872 873 static void nfs_delegation_run_state_manager(struct nfs_client *clp) 874 { 875 if (test_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state)) 876 nfs4_schedule_state_manager(clp); 877 } 878 879 /** 880 * nfs_expire_all_delegations 881 * @clp: client to process 882 * 883 */ 884 void nfs_expire_all_delegations(struct nfs_client *clp) 885 { 886 nfs_client_mark_return_all_delegations(clp); 887 nfs_delegation_run_state_manager(clp); 888 } 889 890 /** 891 * nfs_server_return_all_delegations - return delegations for one superblock 892 * @server: pointer to nfs_server to process 893 * 894 */ 895 void nfs_server_return_all_delegations(struct nfs_server *server) 896 { 897 struct nfs_client *clp = server->nfs_client; 898 bool need_wait; 899 900 if (clp == NULL) 901 return; 902 903 rcu_read_lock(); 904 need_wait = nfs_server_mark_return_all_delegations(server); 905 rcu_read_unlock(); 906 907 if (need_wait) { 908 nfs4_schedule_state_manager(clp); 909 nfs4_wait_clnt_recover(clp); 910 } 911 } 912 913 static void nfs_mark_return_unused_delegation_types(struct nfs_server *server, 914 fmode_t flags) 915 { 916 struct nfs_delegation *delegation; 917 918 list_for_each_entry_rcu(delegation, &server->delegations, super_list) { 919 if ((delegation->type == (FMODE_READ|FMODE_WRITE)) && !(flags & FMODE_WRITE)) 920 continue; 921 if (delegation->type & flags) 922 nfs_mark_return_if_closed_delegation(server, delegation); 923 } 924 } 925 926 static void nfs_client_mark_return_unused_delegation_types(struct nfs_client *clp, 927 fmode_t flags) 928 { 929 struct nfs_server *server; 930 931 rcu_read_lock(); 932 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) 933 nfs_mark_return_unused_delegation_types(server, flags); 934 rcu_read_unlock(); 935 } 936 937 static void nfs_revoke_delegation(struct inode *inode, 938 const nfs4_stateid *stateid) 939 { 940 struct nfs_delegation *delegation; 941 nfs4_stateid tmp; 942 bool ret = false; 943 944 rcu_read_lock(); 945 delegation = rcu_dereference(NFS_I(inode)->delegation); 946 if (delegation == NULL) 947 goto out; 948 if (stateid == NULL) { 949 nfs4_stateid_copy(&tmp, &delegation->stateid); 950 stateid = &tmp; 951 } else { 952 if (!nfs4_stateid_match_other(stateid, &delegation->stateid)) 953 goto out; 954 spin_lock(&delegation->lock); 955 if (stateid->seqid) { 956 if (nfs4_stateid_is_newer(&delegation->stateid, stateid)) { 957 spin_unlock(&delegation->lock); 958 goto out; 959 } 960 delegation->stateid.seqid = stateid->seqid; 961 } 962 spin_unlock(&delegation->lock); 963 } 964 nfs_mark_delegation_revoked(delegation); 965 ret = true; 966 out: 967 rcu_read_unlock(); 968 if (ret) 969 nfs_inode_find_state_and_recover(inode, stateid); 970 } 971 972 void nfs_remove_bad_delegation(struct inode *inode, 973 const nfs4_stateid *stateid) 974 { 975 nfs_revoke_delegation(inode, stateid); 976 } 977 EXPORT_SYMBOL_GPL(nfs_remove_bad_delegation); 978 979 void nfs_delegation_mark_returned(struct inode *inode, 980 const nfs4_stateid *stateid) 981 { 982 struct nfs_delegation *delegation; 983 984 if (!inode) 985 return; 986 987 rcu_read_lock(); 988 delegation = rcu_dereference(NFS_I(inode)->delegation); 989 if (!delegation) 990 goto out_rcu_unlock; 991 992 spin_lock(&delegation->lock); 993 if (!nfs4_stateid_match_other(stateid, &delegation->stateid)) 994 goto out_spin_unlock; 995 if (stateid->seqid) { 996 /* If delegation->stateid is newer, dont mark as returned */ 997 if (nfs4_stateid_is_newer(&delegation->stateid, stateid)) 998 goto out_clear_returning; 999 if (delegation->stateid.seqid != stateid->seqid) 1000 delegation->stateid.seqid = stateid->seqid; 1001 } 1002 1003 nfs_mark_delegation_revoked(delegation); 1004 1005 out_clear_returning: 1006 clear_bit(NFS_DELEGATION_RETURNING, &delegation->flags); 1007 out_spin_unlock: 1008 spin_unlock(&delegation->lock); 1009 out_rcu_unlock: 1010 rcu_read_unlock(); 1011 1012 nfs_inode_find_state_and_recover(inode, stateid); 1013 } 1014 1015 /** 1016 * nfs_expire_unused_delegation_types 1017 * @clp: client to process 1018 * @flags: delegation types to expire 1019 * 1020 */ 1021 void nfs_expire_unused_delegation_types(struct nfs_client *clp, fmode_t flags) 1022 { 1023 nfs_client_mark_return_unused_delegation_types(clp, flags); 1024 nfs_delegation_run_state_manager(clp); 1025 } 1026 1027 static void nfs_mark_return_unreferenced_delegations(struct nfs_server *server) 1028 { 1029 struct nfs_delegation *delegation; 1030 1031 list_for_each_entry_rcu(delegation, &server->delegations, super_list) { 1032 if (test_and_clear_bit(NFS_DELEGATION_REFERENCED, &delegation->flags)) 1033 continue; 1034 nfs_mark_return_if_closed_delegation(server, delegation); 1035 } 1036 } 1037 1038 /** 1039 * nfs_expire_unreferenced_delegations - Eliminate unused delegations 1040 * @clp: nfs_client to process 1041 * 1042 */ 1043 void nfs_expire_unreferenced_delegations(struct nfs_client *clp) 1044 { 1045 struct nfs_server *server; 1046 1047 rcu_read_lock(); 1048 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) 1049 nfs_mark_return_unreferenced_delegations(server); 1050 rcu_read_unlock(); 1051 1052 nfs_delegation_run_state_manager(clp); 1053 } 1054 1055 /** 1056 * nfs_async_inode_return_delegation - asynchronously return a delegation 1057 * @inode: inode to process 1058 * @stateid: state ID information 1059 * 1060 * Returns zero on success, or a negative errno value. 1061 */ 1062 int nfs_async_inode_return_delegation(struct inode *inode, 1063 const nfs4_stateid *stateid) 1064 { 1065 struct nfs_server *server = NFS_SERVER(inode); 1066 struct nfs_client *clp = server->nfs_client; 1067 struct nfs_delegation *delegation; 1068 1069 rcu_read_lock(); 1070 delegation = nfs4_get_valid_delegation(inode); 1071 if (delegation == NULL) 1072 goto out_enoent; 1073 if (stateid != NULL && 1074 !clp->cl_mvops->match_stateid(&delegation->stateid, stateid)) 1075 goto out_enoent; 1076 nfs_mark_return_delegation(server, delegation); 1077 rcu_read_unlock(); 1078 1079 /* If there are any application leases or delegations, recall them */ 1080 break_lease(inode, O_WRONLY | O_RDWR | O_NONBLOCK); 1081 1082 nfs_delegation_run_state_manager(clp); 1083 return 0; 1084 out_enoent: 1085 rcu_read_unlock(); 1086 return -ENOENT; 1087 } 1088 1089 static struct inode * 1090 nfs_delegation_find_inode_server(struct nfs_server *server, 1091 const struct nfs_fh *fhandle) 1092 { 1093 struct nfs_delegation *delegation; 1094 struct super_block *freeme = NULL; 1095 struct inode *res = NULL; 1096 1097 list_for_each_entry_rcu(delegation, &server->delegations, super_list) { 1098 spin_lock(&delegation->lock); 1099 if (delegation->inode != NULL && 1100 !test_bit(NFS_DELEGATION_REVOKED, &delegation->flags) && 1101 nfs_compare_fh(fhandle, &NFS_I(delegation->inode)->fh) == 0) { 1102 if (nfs_sb_active(server->super)) { 1103 freeme = server->super; 1104 res = igrab(delegation->inode); 1105 } 1106 spin_unlock(&delegation->lock); 1107 if (res != NULL) 1108 return res; 1109 if (freeme) { 1110 rcu_read_unlock(); 1111 nfs_sb_deactive(freeme); 1112 rcu_read_lock(); 1113 } 1114 return ERR_PTR(-EAGAIN); 1115 } 1116 spin_unlock(&delegation->lock); 1117 } 1118 return ERR_PTR(-ENOENT); 1119 } 1120 1121 /** 1122 * nfs_delegation_find_inode - retrieve the inode associated with a delegation 1123 * @clp: client state handle 1124 * @fhandle: filehandle from a delegation recall 1125 * 1126 * Returns pointer to inode matching "fhandle," or NULL if a matching inode 1127 * cannot be found. 1128 */ 1129 struct inode *nfs_delegation_find_inode(struct nfs_client *clp, 1130 const struct nfs_fh *fhandle) 1131 { 1132 struct nfs_server *server; 1133 struct inode *res; 1134 1135 rcu_read_lock(); 1136 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) { 1137 res = nfs_delegation_find_inode_server(server, fhandle); 1138 if (res != ERR_PTR(-ENOENT)) { 1139 rcu_read_unlock(); 1140 return res; 1141 } 1142 } 1143 rcu_read_unlock(); 1144 return ERR_PTR(-ENOENT); 1145 } 1146 1147 static void nfs_delegation_mark_reclaim_server(struct nfs_server *server) 1148 { 1149 struct nfs_delegation *delegation; 1150 1151 list_for_each_entry_rcu(delegation, &server->delegations, super_list) { 1152 /* 1153 * If the delegation may have been admin revoked, then we 1154 * cannot reclaim it. 1155 */ 1156 if (test_bit(NFS_DELEGATION_TEST_EXPIRED, &delegation->flags)) 1157 continue; 1158 set_bit(NFS_DELEGATION_NEED_RECLAIM, &delegation->flags); 1159 } 1160 } 1161 1162 /** 1163 * nfs_delegation_mark_reclaim - mark all delegations as needing to be reclaimed 1164 * @clp: nfs_client to process 1165 * 1166 */ 1167 void nfs_delegation_mark_reclaim(struct nfs_client *clp) 1168 { 1169 struct nfs_server *server; 1170 1171 rcu_read_lock(); 1172 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) 1173 nfs_delegation_mark_reclaim_server(server); 1174 rcu_read_unlock(); 1175 } 1176 1177 static int nfs_server_reap_unclaimed_delegations(struct nfs_server *server, 1178 void __always_unused *data) 1179 { 1180 struct nfs_delegation *delegation; 1181 struct inode *inode; 1182 restart: 1183 rcu_read_lock(); 1184 list_for_each_entry_rcu(delegation, &server->delegations, super_list) { 1185 if (test_bit(NFS_DELEGATION_INODE_FREEING, 1186 &delegation->flags) || 1187 test_bit(NFS_DELEGATION_RETURNING, 1188 &delegation->flags) || 1189 test_bit(NFS_DELEGATION_NEED_RECLAIM, 1190 &delegation->flags) == 0) 1191 continue; 1192 inode = nfs_delegation_grab_inode(delegation); 1193 if (inode == NULL) 1194 continue; 1195 delegation = nfs_start_delegation_return_locked(NFS_I(inode)); 1196 rcu_read_unlock(); 1197 if (delegation != NULL) { 1198 if (nfs_detach_delegation(NFS_I(inode), delegation, 1199 server) != NULL) 1200 nfs_free_delegation(delegation); 1201 /* Match nfs_start_delegation_return_locked */ 1202 nfs_put_delegation(delegation); 1203 } 1204 iput(inode); 1205 cond_resched(); 1206 goto restart; 1207 } 1208 rcu_read_unlock(); 1209 return 0; 1210 } 1211 1212 /** 1213 * nfs_delegation_reap_unclaimed - reap unclaimed delegations after reboot recovery is done 1214 * @clp: nfs_client to process 1215 * 1216 */ 1217 void nfs_delegation_reap_unclaimed(struct nfs_client *clp) 1218 { 1219 nfs_client_for_each_server(clp, nfs_server_reap_unclaimed_delegations, 1220 NULL); 1221 } 1222 1223 static inline bool nfs4_server_rebooted(const struct nfs_client *clp) 1224 { 1225 return (clp->cl_state & (BIT(NFS4CLNT_CHECK_LEASE) | 1226 BIT(NFS4CLNT_LEASE_EXPIRED) | 1227 BIT(NFS4CLNT_SESSION_RESET))) != 0; 1228 } 1229 1230 static void nfs_mark_test_expired_delegation(struct nfs_server *server, 1231 struct nfs_delegation *delegation) 1232 { 1233 if (delegation->stateid.type == NFS4_INVALID_STATEID_TYPE) 1234 return; 1235 clear_bit(NFS_DELEGATION_NEED_RECLAIM, &delegation->flags); 1236 set_bit(NFS_DELEGATION_TEST_EXPIRED, &delegation->flags); 1237 set_bit(NFS4CLNT_DELEGATION_EXPIRED, &server->nfs_client->cl_state); 1238 } 1239 1240 static void nfs_inode_mark_test_expired_delegation(struct nfs_server *server, 1241 struct inode *inode) 1242 { 1243 struct nfs_delegation *delegation; 1244 1245 rcu_read_lock(); 1246 delegation = rcu_dereference(NFS_I(inode)->delegation); 1247 if (delegation) 1248 nfs_mark_test_expired_delegation(server, delegation); 1249 rcu_read_unlock(); 1250 1251 } 1252 1253 static void nfs_delegation_mark_test_expired_server(struct nfs_server *server) 1254 { 1255 struct nfs_delegation *delegation; 1256 1257 list_for_each_entry_rcu(delegation, &server->delegations, super_list) 1258 nfs_mark_test_expired_delegation(server, delegation); 1259 } 1260 1261 /** 1262 * nfs_mark_test_expired_all_delegations - mark all delegations for testing 1263 * @clp: nfs_client to process 1264 * 1265 * Iterates through all the delegations associated with this server and 1266 * marks them as needing to be checked for validity. 1267 */ 1268 void nfs_mark_test_expired_all_delegations(struct nfs_client *clp) 1269 { 1270 struct nfs_server *server; 1271 1272 rcu_read_lock(); 1273 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) 1274 nfs_delegation_mark_test_expired_server(server); 1275 rcu_read_unlock(); 1276 } 1277 1278 /** 1279 * nfs_test_expired_all_delegations - test all delegations for a client 1280 * @clp: nfs_client to process 1281 * 1282 * Helper for handling "recallable state revoked" status from server. 1283 */ 1284 void nfs_test_expired_all_delegations(struct nfs_client *clp) 1285 { 1286 nfs_mark_test_expired_all_delegations(clp); 1287 nfs4_schedule_state_manager(clp); 1288 } 1289 1290 static void 1291 nfs_delegation_test_free_expired(struct inode *inode, 1292 nfs4_stateid *stateid, 1293 const struct cred *cred) 1294 { 1295 struct nfs_server *server = NFS_SERVER(inode); 1296 const struct nfs4_minor_version_ops *ops = server->nfs_client->cl_mvops; 1297 int status; 1298 1299 if (!cred) 1300 return; 1301 status = ops->test_and_free_expired(server, stateid, cred); 1302 if (status == -NFS4ERR_EXPIRED || status == -NFS4ERR_BAD_STATEID) 1303 nfs_remove_bad_delegation(inode, stateid); 1304 } 1305 1306 static int nfs_server_reap_expired_delegations(struct nfs_server *server, 1307 void __always_unused *data) 1308 { 1309 struct nfs_delegation *delegation; 1310 struct inode *inode; 1311 const struct cred *cred; 1312 nfs4_stateid stateid; 1313 unsigned long gen = ++server->delegation_gen; 1314 1315 restart: 1316 rcu_read_lock(); 1317 list_for_each_entry_rcu(delegation, &server->delegations, super_list) { 1318 if (test_bit(NFS_DELEGATION_INODE_FREEING, 1319 &delegation->flags) || 1320 test_bit(NFS_DELEGATION_RETURNING, 1321 &delegation->flags) || 1322 test_bit(NFS_DELEGATION_TEST_EXPIRED, 1323 &delegation->flags) == 0 || 1324 delegation->test_gen == gen) 1325 continue; 1326 inode = nfs_delegation_grab_inode(delegation); 1327 if (inode == NULL) 1328 continue; 1329 spin_lock(&delegation->lock); 1330 cred = get_cred_rcu(delegation->cred); 1331 nfs4_stateid_copy(&stateid, &delegation->stateid); 1332 spin_unlock(&delegation->lock); 1333 delegation->test_gen = gen; 1334 clear_bit(NFS_DELEGATION_TEST_EXPIRED, &delegation->flags); 1335 rcu_read_unlock(); 1336 nfs_delegation_test_free_expired(inode, &stateid, cred); 1337 put_cred(cred); 1338 if (!nfs4_server_rebooted(server->nfs_client)) { 1339 iput(inode); 1340 cond_resched(); 1341 goto restart; 1342 } 1343 nfs_inode_mark_test_expired_delegation(server,inode); 1344 iput(inode); 1345 return -EAGAIN; 1346 } 1347 rcu_read_unlock(); 1348 return 0; 1349 } 1350 1351 /** 1352 * nfs_reap_expired_delegations - reap expired delegations 1353 * @clp: nfs_client to process 1354 * 1355 * Iterates through all the delegations associated with this server and 1356 * checks if they have may have been revoked. This function is usually 1357 * expected to be called in cases where the server may have lost its 1358 * lease. 1359 */ 1360 void nfs_reap_expired_delegations(struct nfs_client *clp) 1361 { 1362 nfs_client_for_each_server(clp, nfs_server_reap_expired_delegations, 1363 NULL); 1364 } 1365 1366 void nfs_inode_find_delegation_state_and_recover(struct inode *inode, 1367 const nfs4_stateid *stateid) 1368 { 1369 struct nfs_client *clp = NFS_SERVER(inode)->nfs_client; 1370 struct nfs_delegation *delegation; 1371 bool found = false; 1372 1373 rcu_read_lock(); 1374 delegation = rcu_dereference(NFS_I(inode)->delegation); 1375 if (delegation && 1376 nfs4_stateid_match_or_older(&delegation->stateid, stateid) && 1377 !test_bit(NFS_DELEGATION_REVOKED, &delegation->flags)) { 1378 nfs_mark_test_expired_delegation(NFS_SERVER(inode), delegation); 1379 found = true; 1380 } 1381 rcu_read_unlock(); 1382 if (found) 1383 nfs4_schedule_state_manager(clp); 1384 } 1385 1386 /** 1387 * nfs_delegations_present - check for existence of delegations 1388 * @clp: client state handle 1389 * 1390 * Returns one if there are any nfs_delegation structures attached 1391 * to this nfs_client. 1392 */ 1393 int nfs_delegations_present(struct nfs_client *clp) 1394 { 1395 struct nfs_server *server; 1396 int ret = 0; 1397 1398 rcu_read_lock(); 1399 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) 1400 if (!list_empty(&server->delegations)) { 1401 ret = 1; 1402 break; 1403 } 1404 rcu_read_unlock(); 1405 return ret; 1406 } 1407 1408 /** 1409 * nfs4_refresh_delegation_stateid - Update delegation stateid seqid 1410 * @dst: stateid to refresh 1411 * @inode: inode to check 1412 * 1413 * Returns "true" and updates "dst->seqid" * if inode had a delegation 1414 * that matches our delegation stateid. Otherwise "false" is returned. 1415 */ 1416 bool nfs4_refresh_delegation_stateid(nfs4_stateid *dst, struct inode *inode) 1417 { 1418 struct nfs_delegation *delegation; 1419 bool ret = false; 1420 if (!inode) 1421 goto out; 1422 1423 rcu_read_lock(); 1424 delegation = rcu_dereference(NFS_I(inode)->delegation); 1425 if (delegation != NULL && 1426 nfs4_stateid_match_other(dst, &delegation->stateid) && 1427 nfs4_stateid_is_newer(&delegation->stateid, dst) && 1428 !test_bit(NFS_DELEGATION_REVOKED, &delegation->flags)) { 1429 dst->seqid = delegation->stateid.seqid; 1430 ret = true; 1431 } 1432 rcu_read_unlock(); 1433 out: 1434 return ret; 1435 } 1436 1437 /** 1438 * nfs4_copy_delegation_stateid - Copy inode's state ID information 1439 * @inode: inode to check 1440 * @flags: delegation type requirement 1441 * @dst: stateid data structure to fill in 1442 * @cred: optional argument to retrieve credential 1443 * 1444 * Returns "true" and fills in "dst->data" * if inode had a delegation, 1445 * otherwise "false" is returned. 1446 */ 1447 bool nfs4_copy_delegation_stateid(struct inode *inode, fmode_t flags, 1448 nfs4_stateid *dst, const struct cred **cred) 1449 { 1450 struct nfs_inode *nfsi = NFS_I(inode); 1451 struct nfs_delegation *delegation; 1452 bool ret = false; 1453 1454 flags &= FMODE_READ|FMODE_WRITE; 1455 rcu_read_lock(); 1456 delegation = rcu_dereference(nfsi->delegation); 1457 if (!delegation) 1458 goto out; 1459 spin_lock(&delegation->lock); 1460 ret = nfs4_is_valid_delegation(delegation, flags); 1461 if (ret) { 1462 nfs4_stateid_copy(dst, &delegation->stateid); 1463 nfs_mark_delegation_referenced(delegation); 1464 if (cred) 1465 *cred = get_cred(delegation->cred); 1466 } 1467 spin_unlock(&delegation->lock); 1468 out: 1469 rcu_read_unlock(); 1470 return ret; 1471 } 1472 1473 /** 1474 * nfs4_delegation_flush_on_close - Check if we must flush file on close 1475 * @inode: inode to check 1476 * 1477 * This function checks the number of outstanding writes to the file 1478 * against the delegation 'space_limit' field to see if 1479 * the spec requires us to flush the file on close. 1480 */ 1481 bool nfs4_delegation_flush_on_close(const struct inode *inode) 1482 { 1483 struct nfs_inode *nfsi = NFS_I(inode); 1484 struct nfs_delegation *delegation; 1485 bool ret = true; 1486 1487 rcu_read_lock(); 1488 delegation = rcu_dereference(nfsi->delegation); 1489 if (delegation == NULL || !(delegation->type & FMODE_WRITE)) 1490 goto out; 1491 if (atomic_long_read(&nfsi->nrequests) < delegation->pagemod_limit) 1492 ret = false; 1493 out: 1494 rcu_read_unlock(); 1495 return ret; 1496 } 1497 1498 module_param_named(delegation_watermark, nfs_delegation_watermark, uint, 0644); 1499