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_set_return_delegation_on_close - asynchronously return a delegation 785 * @inode: inode to process 786 * 787 * This routine is called to request that the delegation be returned as soon 788 * as the file is closed. If the file is already closed, the delegation is 789 * immediately returned. 790 */ 791 void nfs4_inode_set_return_delegation_on_close(struct inode *inode) 792 { 793 struct nfs_delegation *delegation; 794 struct nfs_delegation *ret = NULL; 795 796 if (!inode) 797 return; 798 rcu_read_lock(); 799 delegation = nfs4_get_valid_delegation(inode); 800 if (!delegation) 801 goto out; 802 spin_lock(&delegation->lock); 803 if (!delegation->inode) 804 goto out_unlock; 805 if (list_empty(&NFS_I(inode)->open_files) && 806 !test_and_set_bit(NFS_DELEGATION_RETURNING, &delegation->flags)) { 807 /* Refcount matched in nfs_end_delegation_return() */ 808 ret = nfs_get_delegation(delegation); 809 } else 810 set_bit(NFS_DELEGATION_RETURN_IF_CLOSED, &delegation->flags); 811 out_unlock: 812 spin_unlock(&delegation->lock); 813 if (ret) 814 nfs_clear_verifier_delegated(inode); 815 out: 816 rcu_read_unlock(); 817 nfs_end_delegation_return(inode, ret, 0); 818 } 819 820 /** 821 * nfs4_inode_return_delegation_on_close - asynchronously return a delegation 822 * @inode: inode to process 823 * 824 * This routine is called on file close in order to determine if the 825 * inode delegation needs to be returned immediately. 826 */ 827 void nfs4_inode_return_delegation_on_close(struct inode *inode) 828 { 829 struct nfs_delegation *delegation; 830 struct nfs_delegation *ret = NULL; 831 832 if (!inode) 833 return; 834 rcu_read_lock(); 835 delegation = nfs4_get_valid_delegation(inode); 836 if (!delegation) 837 goto out; 838 if (test_bit(NFS_DELEGATION_RETURN_IF_CLOSED, &delegation->flags) || 839 atomic_long_read(&nfs_active_delegations) >= nfs_delegation_watermark) { 840 spin_lock(&delegation->lock); 841 if (delegation->inode && 842 list_empty(&NFS_I(inode)->open_files) && 843 !test_and_set_bit(NFS_DELEGATION_RETURNING, &delegation->flags)) { 844 clear_bit(NFS_DELEGATION_RETURN_IF_CLOSED, &delegation->flags); 845 /* Refcount matched in nfs_end_delegation_return() */ 846 ret = nfs_get_delegation(delegation); 847 } 848 spin_unlock(&delegation->lock); 849 if (ret) 850 nfs_clear_verifier_delegated(inode); 851 } 852 out: 853 rcu_read_unlock(); 854 nfs_end_delegation_return(inode, ret, 0); 855 } 856 857 /** 858 * nfs4_inode_make_writeable 859 * @inode: pointer to inode 860 * 861 * Make the inode writeable by returning the delegation if necessary 862 * 863 * Returns zero on success, or a negative errno value. 864 */ 865 int nfs4_inode_make_writeable(struct inode *inode) 866 { 867 struct nfs_delegation *delegation; 868 869 rcu_read_lock(); 870 delegation = nfs4_get_valid_delegation(inode); 871 if (delegation == NULL || 872 (nfs4_has_session(NFS_SERVER(inode)->nfs_client) && 873 (delegation->type & FMODE_WRITE))) { 874 rcu_read_unlock(); 875 return 0; 876 } 877 rcu_read_unlock(); 878 return nfs4_inode_return_delegation(inode); 879 } 880 881 static void nfs_mark_return_if_closed_delegation(struct nfs_server *server, 882 struct nfs_delegation *delegation) 883 { 884 set_bit(NFS_DELEGATION_RETURN_IF_CLOSED, &delegation->flags); 885 set_bit(NFS4CLNT_DELEGRETURN, &server->nfs_client->cl_state); 886 } 887 888 static bool nfs_server_mark_return_all_delegations(struct nfs_server *server) 889 { 890 struct nfs_delegation *delegation; 891 bool ret = false; 892 893 list_for_each_entry_rcu(delegation, &server->delegations, super_list) { 894 nfs_mark_return_delegation(server, delegation); 895 ret = true; 896 } 897 return ret; 898 } 899 900 static void nfs_client_mark_return_all_delegations(struct nfs_client *clp) 901 { 902 struct nfs_server *server; 903 904 rcu_read_lock(); 905 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) 906 nfs_server_mark_return_all_delegations(server); 907 rcu_read_unlock(); 908 } 909 910 static void nfs_delegation_run_state_manager(struct nfs_client *clp) 911 { 912 if (test_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state)) 913 nfs4_schedule_state_manager(clp); 914 } 915 916 /** 917 * nfs_expire_all_delegations 918 * @clp: client to process 919 * 920 */ 921 void nfs_expire_all_delegations(struct nfs_client *clp) 922 { 923 nfs_client_mark_return_all_delegations(clp); 924 nfs_delegation_run_state_manager(clp); 925 } 926 927 /** 928 * nfs_server_return_all_delegations - return delegations for one superblock 929 * @server: pointer to nfs_server to process 930 * 931 */ 932 void nfs_server_return_all_delegations(struct nfs_server *server) 933 { 934 struct nfs_client *clp = server->nfs_client; 935 bool need_wait; 936 937 if (clp == NULL) 938 return; 939 940 rcu_read_lock(); 941 need_wait = nfs_server_mark_return_all_delegations(server); 942 rcu_read_unlock(); 943 944 if (need_wait) { 945 nfs4_schedule_state_manager(clp); 946 nfs4_wait_clnt_recover(clp); 947 } 948 } 949 950 static void nfs_mark_return_unused_delegation_types(struct nfs_server *server, 951 fmode_t flags) 952 { 953 struct nfs_delegation *delegation; 954 955 list_for_each_entry_rcu(delegation, &server->delegations, super_list) { 956 if ((delegation->type == (FMODE_READ|FMODE_WRITE)) && !(flags & FMODE_WRITE)) 957 continue; 958 if (delegation->type & flags) 959 nfs_mark_return_if_closed_delegation(server, delegation); 960 } 961 } 962 963 static void nfs_client_mark_return_unused_delegation_types(struct nfs_client *clp, 964 fmode_t flags) 965 { 966 struct nfs_server *server; 967 968 rcu_read_lock(); 969 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) 970 nfs_mark_return_unused_delegation_types(server, flags); 971 rcu_read_unlock(); 972 } 973 974 static void nfs_revoke_delegation(struct inode *inode, 975 const nfs4_stateid *stateid) 976 { 977 struct nfs_delegation *delegation; 978 nfs4_stateid tmp; 979 bool ret = false; 980 981 rcu_read_lock(); 982 delegation = rcu_dereference(NFS_I(inode)->delegation); 983 if (delegation == NULL) 984 goto out; 985 if (stateid == NULL) { 986 nfs4_stateid_copy(&tmp, &delegation->stateid); 987 stateid = &tmp; 988 } else { 989 if (!nfs4_stateid_match_other(stateid, &delegation->stateid)) 990 goto out; 991 spin_lock(&delegation->lock); 992 if (stateid->seqid) { 993 if (nfs4_stateid_is_newer(&delegation->stateid, stateid)) { 994 spin_unlock(&delegation->lock); 995 goto out; 996 } 997 delegation->stateid.seqid = stateid->seqid; 998 } 999 spin_unlock(&delegation->lock); 1000 } 1001 nfs_mark_delegation_revoked(delegation); 1002 ret = true; 1003 out: 1004 rcu_read_unlock(); 1005 if (ret) 1006 nfs_inode_find_state_and_recover(inode, stateid); 1007 } 1008 1009 void nfs_remove_bad_delegation(struct inode *inode, 1010 const nfs4_stateid *stateid) 1011 { 1012 nfs_revoke_delegation(inode, stateid); 1013 } 1014 EXPORT_SYMBOL_GPL(nfs_remove_bad_delegation); 1015 1016 void nfs_delegation_mark_returned(struct inode *inode, 1017 const nfs4_stateid *stateid) 1018 { 1019 struct nfs_delegation *delegation; 1020 1021 if (!inode) 1022 return; 1023 1024 rcu_read_lock(); 1025 delegation = rcu_dereference(NFS_I(inode)->delegation); 1026 if (!delegation) 1027 goto out_rcu_unlock; 1028 1029 spin_lock(&delegation->lock); 1030 if (!nfs4_stateid_match_other(stateid, &delegation->stateid)) 1031 goto out_spin_unlock; 1032 if (stateid->seqid) { 1033 /* If delegation->stateid is newer, dont mark as returned */ 1034 if (nfs4_stateid_is_newer(&delegation->stateid, stateid)) 1035 goto out_clear_returning; 1036 if (delegation->stateid.seqid != stateid->seqid) 1037 delegation->stateid.seqid = stateid->seqid; 1038 } 1039 1040 nfs_mark_delegation_revoked(delegation); 1041 clear_bit(NFS_DELEGATION_RETURNING, &delegation->flags); 1042 spin_unlock(&delegation->lock); 1043 if (nfs_detach_delegation(NFS_I(inode), delegation, NFS_SERVER(inode))) 1044 nfs_put_delegation(delegation); 1045 goto out_rcu_unlock; 1046 1047 out_clear_returning: 1048 clear_bit(NFS_DELEGATION_RETURNING, &delegation->flags); 1049 out_spin_unlock: 1050 spin_unlock(&delegation->lock); 1051 out_rcu_unlock: 1052 rcu_read_unlock(); 1053 1054 nfs_inode_find_state_and_recover(inode, stateid); 1055 } 1056 1057 /** 1058 * nfs_expire_unused_delegation_types 1059 * @clp: client to process 1060 * @flags: delegation types to expire 1061 * 1062 */ 1063 void nfs_expire_unused_delegation_types(struct nfs_client *clp, fmode_t flags) 1064 { 1065 nfs_client_mark_return_unused_delegation_types(clp, flags); 1066 nfs_delegation_run_state_manager(clp); 1067 } 1068 1069 static void nfs_mark_return_unreferenced_delegations(struct nfs_server *server) 1070 { 1071 struct nfs_delegation *delegation; 1072 1073 list_for_each_entry_rcu(delegation, &server->delegations, super_list) { 1074 if (test_and_clear_bit(NFS_DELEGATION_REFERENCED, &delegation->flags)) 1075 continue; 1076 nfs_mark_return_if_closed_delegation(server, delegation); 1077 } 1078 } 1079 1080 /** 1081 * nfs_expire_unreferenced_delegations - Eliminate unused delegations 1082 * @clp: nfs_client to process 1083 * 1084 */ 1085 void nfs_expire_unreferenced_delegations(struct nfs_client *clp) 1086 { 1087 struct nfs_server *server; 1088 1089 rcu_read_lock(); 1090 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) 1091 nfs_mark_return_unreferenced_delegations(server); 1092 rcu_read_unlock(); 1093 1094 nfs_delegation_run_state_manager(clp); 1095 } 1096 1097 /** 1098 * nfs_async_inode_return_delegation - asynchronously return a delegation 1099 * @inode: inode to process 1100 * @stateid: state ID information 1101 * 1102 * Returns zero on success, or a negative errno value. 1103 */ 1104 int nfs_async_inode_return_delegation(struct inode *inode, 1105 const nfs4_stateid *stateid) 1106 { 1107 struct nfs_server *server = NFS_SERVER(inode); 1108 struct nfs_client *clp = server->nfs_client; 1109 struct nfs_delegation *delegation; 1110 1111 rcu_read_lock(); 1112 delegation = nfs4_get_valid_delegation(inode); 1113 if (delegation == NULL) 1114 goto out_enoent; 1115 if (stateid != NULL && 1116 !clp->cl_mvops->match_stateid(&delegation->stateid, stateid)) 1117 goto out_enoent; 1118 nfs_mark_return_delegation(server, delegation); 1119 rcu_read_unlock(); 1120 1121 /* If there are any application leases or delegations, recall them */ 1122 break_lease(inode, O_WRONLY | O_RDWR | O_NONBLOCK); 1123 1124 nfs_delegation_run_state_manager(clp); 1125 return 0; 1126 out_enoent: 1127 rcu_read_unlock(); 1128 return -ENOENT; 1129 } 1130 1131 static struct inode * 1132 nfs_delegation_find_inode_server(struct nfs_server *server, 1133 const struct nfs_fh *fhandle) 1134 { 1135 struct nfs_delegation *delegation; 1136 struct super_block *freeme = NULL; 1137 struct inode *res = NULL; 1138 1139 list_for_each_entry_rcu(delegation, &server->delegations, super_list) { 1140 spin_lock(&delegation->lock); 1141 if (delegation->inode != NULL && 1142 !test_bit(NFS_DELEGATION_REVOKED, &delegation->flags) && 1143 nfs_compare_fh(fhandle, &NFS_I(delegation->inode)->fh) == 0) { 1144 if (nfs_sb_active(server->super)) { 1145 freeme = server->super; 1146 res = igrab(delegation->inode); 1147 } 1148 spin_unlock(&delegation->lock); 1149 if (res != NULL) 1150 return res; 1151 if (freeme) { 1152 rcu_read_unlock(); 1153 nfs_sb_deactive(freeme); 1154 rcu_read_lock(); 1155 } 1156 return ERR_PTR(-EAGAIN); 1157 } 1158 spin_unlock(&delegation->lock); 1159 } 1160 return ERR_PTR(-ENOENT); 1161 } 1162 1163 /** 1164 * nfs_delegation_find_inode - retrieve the inode associated with a delegation 1165 * @clp: client state handle 1166 * @fhandle: filehandle from a delegation recall 1167 * 1168 * Returns pointer to inode matching "fhandle," or NULL if a matching inode 1169 * cannot be found. 1170 */ 1171 struct inode *nfs_delegation_find_inode(struct nfs_client *clp, 1172 const struct nfs_fh *fhandle) 1173 { 1174 struct nfs_server *server; 1175 struct inode *res; 1176 1177 rcu_read_lock(); 1178 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) { 1179 res = nfs_delegation_find_inode_server(server, fhandle); 1180 if (res != ERR_PTR(-ENOENT)) { 1181 rcu_read_unlock(); 1182 return res; 1183 } 1184 } 1185 rcu_read_unlock(); 1186 return ERR_PTR(-ENOENT); 1187 } 1188 1189 static void nfs_delegation_mark_reclaim_server(struct nfs_server *server) 1190 { 1191 struct nfs_delegation *delegation; 1192 1193 list_for_each_entry_rcu(delegation, &server->delegations, super_list) { 1194 /* 1195 * If the delegation may have been admin revoked, then we 1196 * cannot reclaim it. 1197 */ 1198 if (test_bit(NFS_DELEGATION_TEST_EXPIRED, &delegation->flags)) 1199 continue; 1200 set_bit(NFS_DELEGATION_NEED_RECLAIM, &delegation->flags); 1201 } 1202 } 1203 1204 /** 1205 * nfs_delegation_mark_reclaim - mark all delegations as needing to be reclaimed 1206 * @clp: nfs_client to process 1207 * 1208 */ 1209 void nfs_delegation_mark_reclaim(struct nfs_client *clp) 1210 { 1211 struct nfs_server *server; 1212 1213 rcu_read_lock(); 1214 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) 1215 nfs_delegation_mark_reclaim_server(server); 1216 rcu_read_unlock(); 1217 } 1218 1219 static int nfs_server_reap_unclaimed_delegations(struct nfs_server *server, 1220 void __always_unused *data) 1221 { 1222 struct nfs_delegation *delegation; 1223 struct inode *inode; 1224 restart: 1225 rcu_read_lock(); 1226 list_for_each_entry_rcu(delegation, &server->delegations, super_list) { 1227 if (test_bit(NFS_DELEGATION_INODE_FREEING, 1228 &delegation->flags) || 1229 test_bit(NFS_DELEGATION_RETURNING, 1230 &delegation->flags) || 1231 test_bit(NFS_DELEGATION_NEED_RECLAIM, 1232 &delegation->flags) == 0) 1233 continue; 1234 inode = nfs_delegation_grab_inode(delegation); 1235 if (inode == NULL) 1236 continue; 1237 delegation = nfs_start_delegation_return_locked(NFS_I(inode)); 1238 rcu_read_unlock(); 1239 if (delegation != NULL) { 1240 if (nfs_detach_delegation(NFS_I(inode), delegation, 1241 server) != NULL) 1242 nfs_free_delegation(delegation); 1243 /* Match nfs_start_delegation_return_locked */ 1244 nfs_put_delegation(delegation); 1245 } 1246 iput(inode); 1247 cond_resched(); 1248 goto restart; 1249 } 1250 rcu_read_unlock(); 1251 return 0; 1252 } 1253 1254 /** 1255 * nfs_delegation_reap_unclaimed - reap unclaimed delegations after reboot recovery is done 1256 * @clp: nfs_client to process 1257 * 1258 */ 1259 void nfs_delegation_reap_unclaimed(struct nfs_client *clp) 1260 { 1261 nfs_client_for_each_server(clp, nfs_server_reap_unclaimed_delegations, 1262 NULL); 1263 } 1264 1265 static inline bool nfs4_server_rebooted(const struct nfs_client *clp) 1266 { 1267 return (clp->cl_state & (BIT(NFS4CLNT_CHECK_LEASE) | 1268 BIT(NFS4CLNT_LEASE_EXPIRED) | 1269 BIT(NFS4CLNT_SESSION_RESET))) != 0; 1270 } 1271 1272 static void nfs_mark_test_expired_delegation(struct nfs_server *server, 1273 struct nfs_delegation *delegation) 1274 { 1275 if (delegation->stateid.type == NFS4_INVALID_STATEID_TYPE) 1276 return; 1277 clear_bit(NFS_DELEGATION_NEED_RECLAIM, &delegation->flags); 1278 set_bit(NFS_DELEGATION_TEST_EXPIRED, &delegation->flags); 1279 set_bit(NFS4CLNT_DELEGATION_EXPIRED, &server->nfs_client->cl_state); 1280 } 1281 1282 static void nfs_inode_mark_test_expired_delegation(struct nfs_server *server, 1283 struct inode *inode) 1284 { 1285 struct nfs_delegation *delegation; 1286 1287 rcu_read_lock(); 1288 delegation = rcu_dereference(NFS_I(inode)->delegation); 1289 if (delegation) 1290 nfs_mark_test_expired_delegation(server, delegation); 1291 rcu_read_unlock(); 1292 1293 } 1294 1295 static void nfs_delegation_mark_test_expired_server(struct nfs_server *server) 1296 { 1297 struct nfs_delegation *delegation; 1298 1299 list_for_each_entry_rcu(delegation, &server->delegations, super_list) 1300 nfs_mark_test_expired_delegation(server, delegation); 1301 } 1302 1303 /** 1304 * nfs_mark_test_expired_all_delegations - mark all delegations for testing 1305 * @clp: nfs_client to process 1306 * 1307 * Iterates through all the delegations associated with this server and 1308 * marks them as needing to be checked for validity. 1309 */ 1310 void nfs_mark_test_expired_all_delegations(struct nfs_client *clp) 1311 { 1312 struct nfs_server *server; 1313 1314 rcu_read_lock(); 1315 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) 1316 nfs_delegation_mark_test_expired_server(server); 1317 rcu_read_unlock(); 1318 } 1319 1320 /** 1321 * nfs_test_expired_all_delegations - test all delegations for a client 1322 * @clp: nfs_client to process 1323 * 1324 * Helper for handling "recallable state revoked" status from server. 1325 */ 1326 void nfs_test_expired_all_delegations(struct nfs_client *clp) 1327 { 1328 nfs_mark_test_expired_all_delegations(clp); 1329 nfs4_schedule_state_manager(clp); 1330 } 1331 1332 static void 1333 nfs_delegation_test_free_expired(struct inode *inode, 1334 nfs4_stateid *stateid, 1335 const struct cred *cred) 1336 { 1337 struct nfs_server *server = NFS_SERVER(inode); 1338 const struct nfs4_minor_version_ops *ops = server->nfs_client->cl_mvops; 1339 int status; 1340 1341 if (!cred) 1342 return; 1343 status = ops->test_and_free_expired(server, stateid, cred); 1344 if (status == -NFS4ERR_EXPIRED || status == -NFS4ERR_BAD_STATEID) 1345 nfs_remove_bad_delegation(inode, stateid); 1346 } 1347 1348 static int nfs_server_reap_expired_delegations(struct nfs_server *server, 1349 void __always_unused *data) 1350 { 1351 struct nfs_delegation *delegation; 1352 struct inode *inode; 1353 const struct cred *cred; 1354 nfs4_stateid stateid; 1355 unsigned long gen = ++server->delegation_gen; 1356 1357 restart: 1358 rcu_read_lock(); 1359 list_for_each_entry_rcu(delegation, &server->delegations, super_list) { 1360 if (test_bit(NFS_DELEGATION_INODE_FREEING, 1361 &delegation->flags) || 1362 test_bit(NFS_DELEGATION_RETURNING, 1363 &delegation->flags) || 1364 test_bit(NFS_DELEGATION_TEST_EXPIRED, 1365 &delegation->flags) == 0 || 1366 delegation->test_gen == gen) 1367 continue; 1368 inode = nfs_delegation_grab_inode(delegation); 1369 if (inode == NULL) 1370 continue; 1371 spin_lock(&delegation->lock); 1372 cred = get_cred_rcu(delegation->cred); 1373 nfs4_stateid_copy(&stateid, &delegation->stateid); 1374 spin_unlock(&delegation->lock); 1375 delegation->test_gen = gen; 1376 clear_bit(NFS_DELEGATION_TEST_EXPIRED, &delegation->flags); 1377 rcu_read_unlock(); 1378 nfs_delegation_test_free_expired(inode, &stateid, cred); 1379 put_cred(cred); 1380 if (!nfs4_server_rebooted(server->nfs_client)) { 1381 iput(inode); 1382 cond_resched(); 1383 goto restart; 1384 } 1385 nfs_inode_mark_test_expired_delegation(server,inode); 1386 iput(inode); 1387 return -EAGAIN; 1388 } 1389 rcu_read_unlock(); 1390 return 0; 1391 } 1392 1393 /** 1394 * nfs_reap_expired_delegations - reap expired delegations 1395 * @clp: nfs_client to process 1396 * 1397 * Iterates through all the delegations associated with this server and 1398 * checks if they have may have been revoked. This function is usually 1399 * expected to be called in cases where the server may have lost its 1400 * lease. 1401 */ 1402 void nfs_reap_expired_delegations(struct nfs_client *clp) 1403 { 1404 nfs_client_for_each_server(clp, nfs_server_reap_expired_delegations, 1405 NULL); 1406 } 1407 1408 void nfs_inode_find_delegation_state_and_recover(struct inode *inode, 1409 const nfs4_stateid *stateid) 1410 { 1411 struct nfs_client *clp = NFS_SERVER(inode)->nfs_client; 1412 struct nfs_delegation *delegation; 1413 bool found = false; 1414 1415 rcu_read_lock(); 1416 delegation = rcu_dereference(NFS_I(inode)->delegation); 1417 if (delegation && 1418 nfs4_stateid_match_or_older(&delegation->stateid, stateid) && 1419 !test_bit(NFS_DELEGATION_REVOKED, &delegation->flags)) { 1420 nfs_mark_test_expired_delegation(NFS_SERVER(inode), delegation); 1421 found = true; 1422 } 1423 rcu_read_unlock(); 1424 if (found) 1425 nfs4_schedule_state_manager(clp); 1426 } 1427 1428 /** 1429 * nfs_delegations_present - check for existence of delegations 1430 * @clp: client state handle 1431 * 1432 * Returns one if there are any nfs_delegation structures attached 1433 * to this nfs_client. 1434 */ 1435 int nfs_delegations_present(struct nfs_client *clp) 1436 { 1437 struct nfs_server *server; 1438 int ret = 0; 1439 1440 rcu_read_lock(); 1441 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) 1442 if (!list_empty(&server->delegations)) { 1443 ret = 1; 1444 break; 1445 } 1446 rcu_read_unlock(); 1447 return ret; 1448 } 1449 1450 /** 1451 * nfs4_refresh_delegation_stateid - Update delegation stateid seqid 1452 * @dst: stateid to refresh 1453 * @inode: inode to check 1454 * 1455 * Returns "true" and updates "dst->seqid" * if inode had a delegation 1456 * that matches our delegation stateid. Otherwise "false" is returned. 1457 */ 1458 bool nfs4_refresh_delegation_stateid(nfs4_stateid *dst, struct inode *inode) 1459 { 1460 struct nfs_delegation *delegation; 1461 bool ret = false; 1462 if (!inode) 1463 goto out; 1464 1465 rcu_read_lock(); 1466 delegation = rcu_dereference(NFS_I(inode)->delegation); 1467 if (delegation != NULL && 1468 nfs4_stateid_match_other(dst, &delegation->stateid) && 1469 nfs4_stateid_is_newer(&delegation->stateid, dst) && 1470 !test_bit(NFS_DELEGATION_REVOKED, &delegation->flags)) { 1471 dst->seqid = delegation->stateid.seqid; 1472 ret = true; 1473 } 1474 rcu_read_unlock(); 1475 out: 1476 return ret; 1477 } 1478 1479 /** 1480 * nfs4_copy_delegation_stateid - Copy inode's state ID information 1481 * @inode: inode to check 1482 * @flags: delegation type requirement 1483 * @dst: stateid data structure to fill in 1484 * @cred: optional argument to retrieve credential 1485 * 1486 * Returns "true" and fills in "dst->data" * if inode had a delegation, 1487 * otherwise "false" is returned. 1488 */ 1489 bool nfs4_copy_delegation_stateid(struct inode *inode, fmode_t flags, 1490 nfs4_stateid *dst, const struct cred **cred) 1491 { 1492 struct nfs_inode *nfsi = NFS_I(inode); 1493 struct nfs_delegation *delegation; 1494 bool ret = false; 1495 1496 flags &= FMODE_READ|FMODE_WRITE; 1497 rcu_read_lock(); 1498 delegation = rcu_dereference(nfsi->delegation); 1499 if (!delegation) 1500 goto out; 1501 spin_lock(&delegation->lock); 1502 ret = nfs4_is_valid_delegation(delegation, flags); 1503 if (ret) { 1504 nfs4_stateid_copy(dst, &delegation->stateid); 1505 nfs_mark_delegation_referenced(delegation); 1506 if (cred) 1507 *cred = get_cred(delegation->cred); 1508 } 1509 spin_unlock(&delegation->lock); 1510 out: 1511 rcu_read_unlock(); 1512 return ret; 1513 } 1514 1515 /** 1516 * nfs4_delegation_flush_on_close - Check if we must flush file on close 1517 * @inode: inode to check 1518 * 1519 * This function checks the number of outstanding writes to the file 1520 * against the delegation 'space_limit' field to see if 1521 * the spec requires us to flush the file on close. 1522 */ 1523 bool nfs4_delegation_flush_on_close(const struct inode *inode) 1524 { 1525 struct nfs_inode *nfsi = NFS_I(inode); 1526 struct nfs_delegation *delegation; 1527 bool ret = true; 1528 1529 rcu_read_lock(); 1530 delegation = rcu_dereference(nfsi->delegation); 1531 if (delegation == NULL || !(delegation->type & FMODE_WRITE)) 1532 goto out; 1533 if (atomic_long_read(&nfsi->nrequests) < delegation->pagemod_limit) 1534 ret = false; 1535 out: 1536 rcu_read_unlock(); 1537 return ret; 1538 } 1539 1540 module_param_named(delegation_watermark, nfs_delegation_watermark, uint, 0644); 1541