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(NFS4SERV_DELEGRETURN, &server->delegation_flags); 83 set_bit(NFS4CLNT_DELEGRETURN, &server->nfs_client->cl_state); 84 } 85 86 static bool nfs4_is_valid_delegation(const struct nfs_delegation *delegation, 87 fmode_t type) 88 { 89 if (delegation != NULL && (delegation->type & type) == type && 90 !test_bit(NFS_DELEGATION_REVOKED, &delegation->flags) && 91 !test_bit(NFS_DELEGATION_RETURNING, &delegation->flags)) 92 return true; 93 return false; 94 } 95 96 struct nfs_delegation *nfs4_get_valid_delegation(const struct inode *inode) 97 { 98 struct nfs_delegation *delegation; 99 100 delegation = rcu_dereference(NFS_I(inode)->delegation); 101 if (nfs4_is_valid_delegation(delegation, 0)) 102 return delegation; 103 return NULL; 104 } 105 106 static int nfs4_do_check_delegation(struct inode *inode, fmode_t type, 107 int flags, bool mark) 108 { 109 struct nfs_delegation *delegation; 110 int ret = 0; 111 112 type &= FMODE_READ|FMODE_WRITE; 113 rcu_read_lock(); 114 delegation = rcu_dereference(NFS_I(inode)->delegation); 115 if (nfs4_is_valid_delegation(delegation, type)) { 116 if (mark) 117 nfs_mark_delegation_referenced(delegation); 118 ret = 1; 119 if ((flags & NFS_DELEGATION_FLAG_TIME) && 120 !test_bit(NFS_DELEGATION_DELEGTIME, &delegation->flags)) 121 ret = 0; 122 } 123 rcu_read_unlock(); 124 return ret; 125 } 126 /** 127 * nfs4_have_delegation - check if inode has a delegation, mark it 128 * NFS_DELEGATION_REFERENCED if there is one. 129 * @inode: inode to check 130 * @type: delegation types to check for 131 * @flags: various modifiers 132 * 133 * Returns one if inode has the indicated delegation, otherwise zero. 134 */ 135 int nfs4_have_delegation(struct inode *inode, fmode_t type, int flags) 136 { 137 return nfs4_do_check_delegation(inode, type, flags, true); 138 } 139 140 /* 141 * nfs4_check_delegation - check if inode has a delegation, do not mark 142 * NFS_DELEGATION_REFERENCED if it has one. 143 */ 144 int nfs4_check_delegation(struct inode *inode, fmode_t type) 145 { 146 return nfs4_do_check_delegation(inode, type, 0, false); 147 } 148 149 static int nfs_delegation_claim_locks(struct nfs4_state *state, const nfs4_stateid *stateid) 150 { 151 struct inode *inode = state->inode; 152 struct file_lock *fl; 153 struct file_lock_context *flctx = locks_inode_context(inode); 154 struct list_head *list; 155 int status = 0; 156 157 if (flctx == NULL) 158 goto out; 159 160 list = &flctx->flc_posix; 161 spin_lock(&flctx->flc_lock); 162 restart: 163 for_each_file_lock(fl, list) { 164 if (nfs_file_open_context(fl->c.flc_file)->state != state) 165 continue; 166 spin_unlock(&flctx->flc_lock); 167 status = nfs4_lock_delegation_recall(fl, state, stateid); 168 if (status < 0) 169 goto out; 170 spin_lock(&flctx->flc_lock); 171 } 172 if (list == &flctx->flc_posix) { 173 list = &flctx->flc_flock; 174 goto restart; 175 } 176 spin_unlock(&flctx->flc_lock); 177 out: 178 return status; 179 } 180 181 static int nfs_delegation_claim_opens(struct inode *inode, 182 const nfs4_stateid *stateid, fmode_t type) 183 { 184 struct nfs_inode *nfsi = NFS_I(inode); 185 struct nfs_open_context *ctx; 186 struct nfs4_state_owner *sp; 187 struct nfs4_state *state; 188 int err; 189 190 again: 191 rcu_read_lock(); 192 list_for_each_entry_rcu(ctx, &nfsi->open_files, list) { 193 state = ctx->state; 194 if (state == NULL) 195 continue; 196 if (!test_bit(NFS_DELEGATED_STATE, &state->flags)) 197 continue; 198 if (!nfs4_valid_open_stateid(state)) 199 continue; 200 if (!nfs4_stateid_match(&state->stateid, stateid)) 201 continue; 202 if (!get_nfs_open_context(ctx)) 203 continue; 204 rcu_read_unlock(); 205 sp = state->owner; 206 /* Block nfs4_proc_unlck */ 207 mutex_lock(&sp->so_delegreturn_mutex); 208 err = nfs4_open_delegation_recall(ctx, state, stateid); 209 if (!err) 210 err = nfs_delegation_claim_locks(state, stateid); 211 mutex_unlock(&sp->so_delegreturn_mutex); 212 put_nfs_open_context(ctx); 213 if (err != 0) 214 return err; 215 goto again; 216 } 217 rcu_read_unlock(); 218 return 0; 219 } 220 221 /** 222 * nfs_inode_reclaim_delegation - process a delegation reclaim request 223 * @inode: inode to process 224 * @cred: credential to use for request 225 * @type: delegation type 226 * @stateid: delegation stateid 227 * @pagemod_limit: write delegation "space_limit" 228 * @deleg_type: raw delegation type 229 * 230 */ 231 void nfs_inode_reclaim_delegation(struct inode *inode, const struct cred *cred, 232 fmode_t type, const nfs4_stateid *stateid, 233 unsigned long pagemod_limit, u32 deleg_type) 234 { 235 struct nfs_delegation *delegation; 236 const struct cred *oldcred = NULL; 237 238 rcu_read_lock(); 239 delegation = rcu_dereference(NFS_I(inode)->delegation); 240 if (delegation != NULL) { 241 spin_lock(&delegation->lock); 242 nfs4_stateid_copy(&delegation->stateid, stateid); 243 delegation->type = type; 244 delegation->pagemod_limit = pagemod_limit; 245 oldcred = delegation->cred; 246 delegation->cred = get_cred(cred); 247 switch (deleg_type) { 248 case NFS4_OPEN_DELEGATE_READ_ATTRS_DELEG: 249 case NFS4_OPEN_DELEGATE_WRITE_ATTRS_DELEG: 250 set_bit(NFS_DELEGATION_DELEGTIME, &delegation->flags); 251 break; 252 default: 253 clear_bit(NFS_DELEGATION_DELEGTIME, &delegation->flags); 254 } 255 clear_bit(NFS_DELEGATION_NEED_RECLAIM, &delegation->flags); 256 if (test_and_clear_bit(NFS_DELEGATION_REVOKED, 257 &delegation->flags)) 258 atomic_long_inc(&nfs_active_delegations); 259 spin_unlock(&delegation->lock); 260 rcu_read_unlock(); 261 put_cred(oldcred); 262 trace_nfs4_reclaim_delegation(inode, type); 263 } else { 264 rcu_read_unlock(); 265 nfs_inode_set_delegation(inode, cred, type, stateid, 266 pagemod_limit, deleg_type); 267 } 268 } 269 270 static int nfs_do_return_delegation(struct inode *inode, 271 struct nfs_delegation *delegation, 272 int issync) 273 { 274 const struct cred *cred; 275 int res = 0; 276 277 if (!test_bit(NFS_DELEGATION_REVOKED, &delegation->flags)) { 278 spin_lock(&delegation->lock); 279 cred = get_cred(delegation->cred); 280 spin_unlock(&delegation->lock); 281 res = nfs4_proc_delegreturn(inode, cred, &delegation->stateid, 282 delegation, issync); 283 put_cred(cred); 284 } 285 return res; 286 } 287 288 static struct inode *nfs_delegation_grab_inode(struct nfs_delegation *delegation) 289 { 290 struct inode *inode = NULL; 291 292 spin_lock(&delegation->lock); 293 if (delegation->inode != NULL) 294 inode = igrab(delegation->inode); 295 if (!inode) 296 set_bit(NFS_DELEGATION_INODE_FREEING, &delegation->flags); 297 spin_unlock(&delegation->lock); 298 return inode; 299 } 300 301 static struct nfs_delegation * 302 nfs_start_delegation_return_locked(struct nfs_inode *nfsi) 303 { 304 struct nfs_delegation *ret = NULL; 305 struct nfs_delegation *delegation = rcu_dereference(nfsi->delegation); 306 307 if (delegation == NULL) 308 goto out; 309 spin_lock(&delegation->lock); 310 if (delegation->inode && 311 !test_and_set_bit(NFS_DELEGATION_RETURNING, &delegation->flags)) { 312 clear_bit(NFS_DELEGATION_RETURN_DELAYED, &delegation->flags); 313 /* Refcount matched in nfs_end_delegation_return() */ 314 ret = nfs_get_delegation(delegation); 315 } 316 spin_unlock(&delegation->lock); 317 if (ret) 318 nfs_clear_verifier_delegated(&nfsi->vfs_inode); 319 out: 320 return ret; 321 } 322 323 static struct nfs_delegation * 324 nfs_start_delegation_return(struct nfs_inode *nfsi) 325 { 326 struct nfs_delegation *delegation; 327 328 rcu_read_lock(); 329 delegation = nfs_start_delegation_return_locked(nfsi); 330 rcu_read_unlock(); 331 return delegation; 332 } 333 334 static void nfs_abort_delegation_return(struct nfs_delegation *delegation, 335 struct nfs_server *server, int err) 336 { 337 spin_lock(&delegation->lock); 338 clear_bit(NFS_DELEGATION_RETURNING, &delegation->flags); 339 if (err == -EAGAIN) { 340 set_bit(NFS_DELEGATION_RETURN_DELAYED, &delegation->flags); 341 set_bit(NFS4SERV_DELEGRETURN_DELAYED, 342 &server->delegation_flags); 343 set_bit(NFS4CLNT_DELEGRETURN_DELAYED, 344 &server->nfs_client->cl_state); 345 } 346 spin_unlock(&delegation->lock); 347 } 348 349 static struct nfs_delegation * 350 nfs_detach_delegation_locked(struct nfs_inode *nfsi, 351 struct nfs_delegation *delegation, 352 struct nfs_client *clp) 353 { 354 struct nfs_delegation *deleg_cur = 355 rcu_dereference_protected(nfsi->delegation, 356 lockdep_is_held(&clp->cl_lock)); 357 358 if (deleg_cur == NULL || delegation != deleg_cur) 359 return NULL; 360 361 spin_lock(&delegation->lock); 362 if (!delegation->inode) { 363 spin_unlock(&delegation->lock); 364 return NULL; 365 } 366 list_del_rcu(&delegation->super_list); 367 delegation->inode = NULL; 368 rcu_assign_pointer(nfsi->delegation, NULL); 369 spin_unlock(&delegation->lock); 370 return delegation; 371 } 372 373 static struct nfs_delegation *nfs_detach_delegation(struct nfs_inode *nfsi, 374 struct nfs_delegation *delegation, 375 struct nfs_server *server) 376 { 377 struct nfs_client *clp = server->nfs_client; 378 379 spin_lock(&clp->cl_lock); 380 delegation = nfs_detach_delegation_locked(nfsi, delegation, clp); 381 spin_unlock(&clp->cl_lock); 382 return delegation; 383 } 384 385 static struct nfs_delegation * 386 nfs_inode_detach_delegation(struct inode *inode) 387 { 388 struct nfs_inode *nfsi = NFS_I(inode); 389 struct nfs_server *server = NFS_SERVER(inode); 390 struct nfs_delegation *delegation; 391 392 rcu_read_lock(); 393 delegation = rcu_dereference(nfsi->delegation); 394 if (delegation != NULL) 395 delegation = nfs_detach_delegation(nfsi, delegation, server); 396 rcu_read_unlock(); 397 return delegation; 398 } 399 400 static void 401 nfs_update_delegation_cred(struct nfs_delegation *delegation, 402 const struct cred *cred) 403 { 404 const struct cred *old; 405 406 if (cred_fscmp(delegation->cred, cred) != 0) { 407 old = xchg(&delegation->cred, get_cred(cred)); 408 put_cred(old); 409 } 410 } 411 412 static void 413 nfs_update_inplace_delegation(struct nfs_delegation *delegation, 414 const struct nfs_delegation *update) 415 { 416 if (nfs4_stateid_is_newer(&update->stateid, &delegation->stateid)) { 417 delegation->stateid.seqid = update->stateid.seqid; 418 smp_wmb(); 419 delegation->type = update->type; 420 delegation->pagemod_limit = update->pagemod_limit; 421 if (test_bit(NFS_DELEGATION_REVOKED, &delegation->flags)) { 422 delegation->change_attr = update->change_attr; 423 nfs_update_delegation_cred(delegation, update->cred); 424 /* smp_mb__before_atomic() is implicit due to xchg() */ 425 clear_bit(NFS_DELEGATION_REVOKED, &delegation->flags); 426 atomic_long_inc(&nfs_active_delegations); 427 } 428 } 429 } 430 431 /** 432 * nfs_inode_set_delegation - set up a delegation on an inode 433 * @inode: inode to which delegation applies 434 * @cred: cred to use for subsequent delegation processing 435 * @type: delegation type 436 * @stateid: delegation stateid 437 * @pagemod_limit: write delegation "space_limit" 438 * @deleg_type: raw delegation type 439 * 440 * Returns zero on success, or a negative errno value. 441 */ 442 int nfs_inode_set_delegation(struct inode *inode, const struct cred *cred, 443 fmode_t type, const nfs4_stateid *stateid, 444 unsigned long pagemod_limit, u32 deleg_type) 445 { 446 struct nfs_server *server = NFS_SERVER(inode); 447 struct nfs_client *clp = server->nfs_client; 448 struct nfs_inode *nfsi = NFS_I(inode); 449 struct nfs_delegation *delegation, *old_delegation; 450 struct nfs_delegation *freeme = NULL; 451 int status = 0; 452 453 delegation = kmalloc(sizeof(*delegation), GFP_KERNEL_ACCOUNT); 454 if (delegation == NULL) 455 return -ENOMEM; 456 nfs4_stateid_copy(&delegation->stateid, stateid); 457 refcount_set(&delegation->refcount, 1); 458 delegation->type = type; 459 delegation->pagemod_limit = pagemod_limit; 460 delegation->change_attr = inode_peek_iversion_raw(inode); 461 delegation->cred = get_cred(cred); 462 delegation->inode = inode; 463 delegation->flags = 1<<NFS_DELEGATION_REFERENCED; 464 switch (deleg_type) { 465 case NFS4_OPEN_DELEGATE_READ_ATTRS_DELEG: 466 case NFS4_OPEN_DELEGATE_WRITE_ATTRS_DELEG: 467 delegation->flags |= BIT(NFS_DELEGATION_DELEGTIME); 468 } 469 delegation->test_gen = 0; 470 spin_lock_init(&delegation->lock); 471 472 spin_lock(&clp->cl_lock); 473 old_delegation = rcu_dereference_protected(nfsi->delegation, 474 lockdep_is_held(&clp->cl_lock)); 475 if (old_delegation == NULL) 476 goto add_new; 477 /* Is this an update of the existing delegation? */ 478 if (nfs4_stateid_match_other(&old_delegation->stateid, 479 &delegation->stateid)) { 480 spin_lock(&old_delegation->lock); 481 nfs_update_inplace_delegation(old_delegation, 482 delegation); 483 spin_unlock(&old_delegation->lock); 484 goto out; 485 } 486 if (!test_bit(NFS_DELEGATION_REVOKED, &old_delegation->flags)) { 487 /* 488 * Deal with broken servers that hand out two 489 * delegations for the same file. 490 * Allow for upgrades to a WRITE delegation, but 491 * nothing else. 492 */ 493 dfprintk(FILE, "%s: server %s handed out " 494 "a duplicate delegation!\n", 495 __func__, clp->cl_hostname); 496 if (delegation->type == old_delegation->type || 497 !(delegation->type & FMODE_WRITE)) { 498 freeme = delegation; 499 delegation = NULL; 500 goto out; 501 } 502 if (test_and_set_bit(NFS_DELEGATION_RETURNING, 503 &old_delegation->flags)) 504 goto out; 505 } 506 freeme = nfs_detach_delegation_locked(nfsi, old_delegation, clp); 507 if (freeme == NULL) 508 goto out; 509 add_new: 510 /* 511 * If we didn't revalidate the change attribute before setting 512 * the delegation, then pre-emptively ask for a full attribute 513 * cache revalidation. 514 */ 515 spin_lock(&inode->i_lock); 516 if (NFS_I(inode)->cache_validity & NFS_INO_INVALID_CHANGE) 517 nfs_set_cache_invalid(inode, 518 NFS_INO_INVALID_ATIME | NFS_INO_INVALID_CTIME | 519 NFS_INO_INVALID_MTIME | NFS_INO_INVALID_SIZE | 520 NFS_INO_INVALID_BLOCKS | NFS_INO_INVALID_NLINK | 521 NFS_INO_INVALID_OTHER | NFS_INO_INVALID_DATA | 522 NFS_INO_INVALID_ACCESS | NFS_INO_INVALID_ACL | 523 NFS_INO_INVALID_XATTR); 524 spin_unlock(&inode->i_lock); 525 526 list_add_tail_rcu(&delegation->super_list, &server->delegations); 527 rcu_assign_pointer(nfsi->delegation, delegation); 528 delegation = NULL; 529 530 atomic_long_inc(&nfs_active_delegations); 531 532 trace_nfs4_set_delegation(inode, type); 533 534 /* If we hold writebacks and have delegated mtime then update */ 535 if (deleg_type == NFS4_OPEN_DELEGATE_WRITE_ATTRS_DELEG && 536 nfs_have_writebacks(inode)) 537 nfs_update_delegated_mtime(inode); 538 out: 539 spin_unlock(&clp->cl_lock); 540 if (delegation != NULL) 541 __nfs_free_delegation(delegation); 542 if (freeme != NULL) { 543 nfs_do_return_delegation(inode, freeme, 0); 544 nfs_free_delegation(freeme); 545 } 546 return status; 547 } 548 549 /* 550 * Basic procedure for returning a delegation to the server 551 */ 552 static int nfs_end_delegation_return(struct inode *inode, struct nfs_delegation *delegation, int issync) 553 { 554 struct nfs_server *server = NFS_SERVER(inode); 555 unsigned int mode = O_WRONLY | O_RDWR; 556 int err = 0; 557 558 if (delegation == NULL) 559 return 0; 560 561 if (!issync) 562 mode |= O_NONBLOCK; 563 /* Recall of any remaining application leases */ 564 err = break_lease(inode, mode); 565 566 while (err == 0) { 567 if (test_bit(NFS_DELEGATION_REVOKED, &delegation->flags)) 568 break; 569 err = nfs_delegation_claim_opens(inode, &delegation->stateid, 570 delegation->type); 571 if (!issync || err != -EAGAIN) 572 break; 573 /* 574 * Guard against state recovery 575 */ 576 err = nfs4_wait_clnt_recover(server->nfs_client); 577 } 578 579 if (err) { 580 nfs_abort_delegation_return(delegation, server, err); 581 goto out; 582 } 583 584 err = nfs_do_return_delegation(inode, delegation, issync); 585 out: 586 /* Refcount matched in nfs_start_delegation_return_locked() */ 587 nfs_put_delegation(delegation); 588 return err; 589 } 590 591 static bool nfs_delegation_need_return(struct nfs_delegation *delegation) 592 { 593 bool ret = false; 594 595 if (test_and_clear_bit(NFS_DELEGATION_RETURN, &delegation->flags)) 596 ret = true; 597 if (test_bit(NFS_DELEGATION_RETURNING, &delegation->flags) || 598 test_bit(NFS_DELEGATION_RETURN_DELAYED, &delegation->flags) || 599 test_bit(NFS_DELEGATION_REVOKED, &delegation->flags)) 600 ret = false; 601 602 return ret; 603 } 604 605 static int nfs_server_return_marked_delegations(struct nfs_server *server, 606 void __always_unused *data) 607 { 608 struct nfs_delegation *delegation; 609 struct nfs_delegation *prev; 610 struct inode *inode; 611 struct inode *place_holder = NULL; 612 struct nfs_delegation *place_holder_deleg = NULL; 613 int err = 0; 614 615 if (!test_and_clear_bit(NFS4SERV_DELEGRETURN, 616 &server->delegation_flags)) 617 return 0; 618 restart: 619 /* 620 * To avoid quadratic looping we hold a reference 621 * to an inode place_holder. Each time we restart, we 622 * list delegation in the server from the delegations 623 * of that inode. 624 * prev is an RCU-protected pointer to a delegation which 625 * wasn't marked for return and might be a good choice for 626 * the next place_holder. 627 */ 628 prev = NULL; 629 delegation = NULL; 630 rcu_read_lock(); 631 if (place_holder) 632 delegation = rcu_dereference(NFS_I(place_holder)->delegation); 633 if (!delegation || delegation != place_holder_deleg) 634 delegation = list_entry_rcu(server->delegations.next, 635 struct nfs_delegation, super_list); 636 list_for_each_entry_from_rcu(delegation, &server->delegations, super_list) { 637 struct inode *to_put = NULL; 638 639 if (test_bit(NFS_DELEGATION_INODE_FREEING, &delegation->flags)) 640 continue; 641 if (!nfs_delegation_need_return(delegation)) { 642 if (nfs4_is_valid_delegation(delegation, 0)) 643 prev = delegation; 644 continue; 645 } 646 inode = nfs_delegation_grab_inode(delegation); 647 if (inode == NULL) 648 continue; 649 650 if (prev) { 651 struct inode *tmp = nfs_delegation_grab_inode(prev); 652 if (tmp) { 653 to_put = place_holder; 654 place_holder = tmp; 655 place_holder_deleg = prev; 656 } 657 } 658 659 delegation = nfs_start_delegation_return_locked(NFS_I(inode)); 660 rcu_read_unlock(); 661 662 iput(to_put); 663 664 err = nfs_end_delegation_return(inode, delegation, 0); 665 iput(inode); 666 cond_resched(); 667 if (!err) 668 goto restart; 669 set_bit(NFS4SERV_DELEGRETURN, &server->delegation_flags); 670 set_bit(NFS4CLNT_DELEGRETURN, &server->nfs_client->cl_state); 671 goto out; 672 } 673 rcu_read_unlock(); 674 out: 675 iput(place_holder); 676 return err; 677 } 678 679 static bool nfs_server_clear_delayed_delegations(struct nfs_server *server) 680 { 681 struct nfs_delegation *d; 682 bool ret = false; 683 684 if (!test_and_clear_bit(NFS4SERV_DELEGRETURN_DELAYED, 685 &server->delegation_flags)) 686 goto out; 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 out: 695 return ret; 696 } 697 698 static bool nfs_client_clear_delayed_delegations(struct nfs_client *clp) 699 { 700 struct nfs_server *server; 701 bool ret = false; 702 703 if (!test_and_clear_bit(NFS4CLNT_DELEGRETURN_DELAYED, &clp->cl_state)) 704 goto out; 705 rcu_read_lock(); 706 list_for_each_entry_rcu (server, &clp->cl_superblocks, client_link) { 707 if (nfs_server_clear_delayed_delegations(server)) 708 ret = true; 709 } 710 rcu_read_unlock(); 711 out: 712 return ret; 713 } 714 715 /** 716 * nfs_client_return_marked_delegations - return previously marked delegations 717 * @clp: nfs_client to process 718 * 719 * Note that this function is designed to be called by the state 720 * manager thread. For this reason, it cannot flush the dirty data, 721 * since that could deadlock in case of a state recovery error. 722 * 723 * Returns zero on success, or a negative errno value. 724 */ 725 int nfs_client_return_marked_delegations(struct nfs_client *clp) 726 { 727 int err = nfs_client_for_each_server( 728 clp, nfs_server_return_marked_delegations, NULL); 729 if (err) 730 return err; 731 /* If a return was delayed, sleep to prevent hard looping */ 732 if (nfs_client_clear_delayed_delegations(clp)) 733 ssleep(1); 734 return 0; 735 } 736 737 /** 738 * nfs_inode_evict_delegation - return delegation, don't reclaim opens 739 * @inode: inode to process 740 * 741 * Does not protect against delegation reclaims, therefore really only safe 742 * to be called from nfs4_clear_inode(). Guaranteed to always free 743 * the delegation structure. 744 */ 745 void nfs_inode_evict_delegation(struct inode *inode) 746 { 747 struct nfs_delegation *delegation; 748 749 delegation = nfs_inode_detach_delegation(inode); 750 if (delegation != NULL) { 751 set_bit(NFS_DELEGATION_RETURNING, &delegation->flags); 752 set_bit(NFS_DELEGATION_INODE_FREEING, &delegation->flags); 753 nfs_do_return_delegation(inode, delegation, 1); 754 nfs_free_delegation(delegation); 755 } 756 } 757 758 /** 759 * nfs4_inode_return_delegation - synchronously return a delegation 760 * @inode: inode to process 761 * 762 * This routine will always flush any dirty data to disk on the 763 * assumption that if we need to return the delegation, then 764 * we should stop caching. 765 * 766 * Returns zero on success, or a negative errno value. 767 */ 768 int nfs4_inode_return_delegation(struct inode *inode) 769 { 770 struct nfs_inode *nfsi = NFS_I(inode); 771 struct nfs_delegation *delegation; 772 773 delegation = nfs_start_delegation_return(nfsi); 774 if (delegation != NULL) { 775 /* Synchronous recall of any application leases */ 776 break_lease(inode, O_WRONLY | O_RDWR); 777 if (S_ISREG(inode->i_mode)) 778 nfs_wb_all(inode); 779 return nfs_end_delegation_return(inode, delegation, 1); 780 } 781 return 0; 782 } 783 784 /** 785 * nfs4_inode_set_return_delegation_on_close - asynchronously return a delegation 786 * @inode: inode to process 787 * 788 * This routine is called to request that the delegation be returned as soon 789 * as the file is closed. If the file is already closed, the delegation is 790 * immediately returned. 791 */ 792 void nfs4_inode_set_return_delegation_on_close(struct inode *inode) 793 { 794 struct nfs_delegation *delegation; 795 struct nfs_delegation *ret = NULL; 796 797 if (!inode) 798 return; 799 rcu_read_lock(); 800 delegation = nfs4_get_valid_delegation(inode); 801 if (!delegation) 802 goto out; 803 spin_lock(&delegation->lock); 804 if (!delegation->inode) 805 goto out_unlock; 806 if (list_empty(&NFS_I(inode)->open_files) && 807 !test_and_set_bit(NFS_DELEGATION_RETURNING, &delegation->flags)) { 808 /* Refcount matched in nfs_end_delegation_return() */ 809 ret = nfs_get_delegation(delegation); 810 } else 811 set_bit(NFS_DELEGATION_RETURN_IF_CLOSED, &delegation->flags); 812 out_unlock: 813 spin_unlock(&delegation->lock); 814 if (ret) 815 nfs_clear_verifier_delegated(inode); 816 out: 817 rcu_read_unlock(); 818 nfs_end_delegation_return(inode, ret, 0); 819 } 820 821 /** 822 * nfs4_inode_return_delegation_on_close - asynchronously return a delegation 823 * @inode: inode to process 824 * 825 * This routine is called on file close in order to determine if the 826 * inode delegation needs to be returned immediately. 827 */ 828 void nfs4_inode_return_delegation_on_close(struct inode *inode) 829 { 830 struct nfs_delegation *delegation; 831 struct nfs_delegation *ret = NULL; 832 833 if (!inode) 834 return; 835 rcu_read_lock(); 836 delegation = nfs4_get_valid_delegation(inode); 837 if (!delegation) 838 goto out; 839 if (test_bit(NFS_DELEGATION_RETURN_IF_CLOSED, &delegation->flags) || 840 atomic_long_read(&nfs_active_delegations) >= nfs_delegation_watermark) { 841 spin_lock(&delegation->lock); 842 if (delegation->inode && 843 list_empty(&NFS_I(inode)->open_files) && 844 !test_and_set_bit(NFS_DELEGATION_RETURNING, &delegation->flags)) { 845 clear_bit(NFS_DELEGATION_RETURN_IF_CLOSED, &delegation->flags); 846 /* Refcount matched in nfs_end_delegation_return() */ 847 ret = nfs_get_delegation(delegation); 848 } 849 spin_unlock(&delegation->lock); 850 if (ret) 851 nfs_clear_verifier_delegated(inode); 852 } 853 out: 854 rcu_read_unlock(); 855 nfs_end_delegation_return(inode, ret, 0); 856 } 857 858 /** 859 * nfs4_inode_make_writeable 860 * @inode: pointer to inode 861 * 862 * Make the inode writeable by returning the delegation if necessary 863 * 864 * Returns zero on success, or a negative errno value. 865 */ 866 int nfs4_inode_make_writeable(struct inode *inode) 867 { 868 struct nfs_delegation *delegation; 869 870 rcu_read_lock(); 871 delegation = nfs4_get_valid_delegation(inode); 872 if (delegation == NULL || 873 (nfs4_has_session(NFS_SERVER(inode)->nfs_client) && 874 (delegation->type & FMODE_WRITE))) { 875 rcu_read_unlock(); 876 return 0; 877 } 878 rcu_read_unlock(); 879 return nfs4_inode_return_delegation(inode); 880 } 881 882 static void 883 nfs_mark_return_if_closed_delegation(struct nfs_server *server, 884 struct nfs_delegation *delegation) 885 { 886 struct inode *inode; 887 888 if (test_bit(NFS_DELEGATION_RETURN, &delegation->flags) || 889 test_bit(NFS_DELEGATION_RETURN_IF_CLOSED, &delegation->flags)) 890 return; 891 spin_lock(&delegation->lock); 892 inode = delegation->inode; 893 if (!inode) 894 goto out; 895 if (list_empty(&NFS_I(inode)->open_files)) 896 nfs_mark_return_delegation(server, delegation); 897 else 898 set_bit(NFS_DELEGATION_RETURN_IF_CLOSED, &delegation->flags); 899 out: 900 spin_unlock(&delegation->lock); 901 } 902 903 static bool nfs_server_mark_return_all_delegations(struct nfs_server *server) 904 { 905 struct nfs_delegation *delegation; 906 bool ret = false; 907 908 list_for_each_entry_rcu(delegation, &server->delegations, super_list) { 909 nfs_mark_return_delegation(server, delegation); 910 ret = true; 911 } 912 return ret; 913 } 914 915 static void nfs_client_mark_return_all_delegations(struct nfs_client *clp) 916 { 917 struct nfs_server *server; 918 919 rcu_read_lock(); 920 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) 921 nfs_server_mark_return_all_delegations(server); 922 rcu_read_unlock(); 923 } 924 925 static void nfs_delegation_run_state_manager(struct nfs_client *clp) 926 { 927 if (test_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state)) 928 nfs4_schedule_state_manager(clp); 929 } 930 931 /** 932 * nfs_expire_all_delegations 933 * @clp: client to process 934 * 935 */ 936 void nfs_expire_all_delegations(struct nfs_client *clp) 937 { 938 nfs_client_mark_return_all_delegations(clp); 939 nfs_delegation_run_state_manager(clp); 940 } 941 942 /** 943 * nfs_server_return_all_delegations - return delegations for one superblock 944 * @server: pointer to nfs_server to process 945 * 946 */ 947 void nfs_server_return_all_delegations(struct nfs_server *server) 948 { 949 struct nfs_client *clp = server->nfs_client; 950 bool need_wait; 951 952 if (clp == NULL) 953 return; 954 955 rcu_read_lock(); 956 need_wait = nfs_server_mark_return_all_delegations(server); 957 rcu_read_unlock(); 958 959 if (need_wait) { 960 nfs4_schedule_state_manager(clp); 961 nfs4_wait_clnt_recover(clp); 962 } 963 } 964 965 static void nfs_mark_return_unused_delegation_types(struct nfs_server *server, 966 fmode_t flags) 967 { 968 struct nfs_delegation *delegation; 969 970 list_for_each_entry_rcu(delegation, &server->delegations, super_list) { 971 if ((delegation->type == (FMODE_READ|FMODE_WRITE)) && !(flags & FMODE_WRITE)) 972 continue; 973 if (delegation->type & flags) 974 nfs_mark_return_if_closed_delegation(server, delegation); 975 } 976 } 977 978 static void nfs_client_mark_return_unused_delegation_types(struct nfs_client *clp, 979 fmode_t flags) 980 { 981 struct nfs_server *server; 982 983 rcu_read_lock(); 984 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) 985 nfs_mark_return_unused_delegation_types(server, flags); 986 rcu_read_unlock(); 987 } 988 989 static void nfs_revoke_delegation(struct inode *inode, 990 const nfs4_stateid *stateid) 991 { 992 struct nfs_delegation *delegation; 993 nfs4_stateid tmp; 994 bool ret = false; 995 996 rcu_read_lock(); 997 delegation = rcu_dereference(NFS_I(inode)->delegation); 998 if (delegation == NULL) 999 goto out; 1000 if (stateid == NULL) { 1001 nfs4_stateid_copy(&tmp, &delegation->stateid); 1002 stateid = &tmp; 1003 } else { 1004 if (!nfs4_stateid_match_other(stateid, &delegation->stateid)) 1005 goto out; 1006 spin_lock(&delegation->lock); 1007 if (stateid->seqid) { 1008 if (nfs4_stateid_is_newer(&delegation->stateid, stateid)) { 1009 spin_unlock(&delegation->lock); 1010 goto out; 1011 } 1012 delegation->stateid.seqid = stateid->seqid; 1013 } 1014 spin_unlock(&delegation->lock); 1015 } 1016 nfs_mark_delegation_revoked(delegation); 1017 ret = true; 1018 out: 1019 rcu_read_unlock(); 1020 if (ret) 1021 nfs_inode_find_state_and_recover(inode, stateid); 1022 } 1023 1024 void nfs_remove_bad_delegation(struct inode *inode, 1025 const nfs4_stateid *stateid) 1026 { 1027 nfs_revoke_delegation(inode, stateid); 1028 } 1029 EXPORT_SYMBOL_GPL(nfs_remove_bad_delegation); 1030 1031 void nfs_delegation_mark_returned(struct inode *inode, 1032 const nfs4_stateid *stateid) 1033 { 1034 struct nfs_delegation *delegation; 1035 1036 if (!inode) 1037 return; 1038 1039 rcu_read_lock(); 1040 delegation = rcu_dereference(NFS_I(inode)->delegation); 1041 if (!delegation) 1042 goto out_rcu_unlock; 1043 1044 spin_lock(&delegation->lock); 1045 if (!nfs4_stateid_match_other(stateid, &delegation->stateid)) 1046 goto out_spin_unlock; 1047 if (stateid->seqid) { 1048 /* If delegation->stateid is newer, dont mark as returned */ 1049 if (nfs4_stateid_is_newer(&delegation->stateid, stateid)) 1050 goto out_clear_returning; 1051 if (delegation->stateid.seqid != stateid->seqid) 1052 delegation->stateid.seqid = stateid->seqid; 1053 } 1054 1055 nfs_mark_delegation_revoked(delegation); 1056 clear_bit(NFS_DELEGATION_RETURNING, &delegation->flags); 1057 spin_unlock(&delegation->lock); 1058 if (nfs_detach_delegation(NFS_I(inode), delegation, NFS_SERVER(inode))) 1059 nfs_put_delegation(delegation); 1060 goto out_rcu_unlock; 1061 1062 out_clear_returning: 1063 clear_bit(NFS_DELEGATION_RETURNING, &delegation->flags); 1064 out_spin_unlock: 1065 spin_unlock(&delegation->lock); 1066 out_rcu_unlock: 1067 rcu_read_unlock(); 1068 1069 nfs_inode_find_state_and_recover(inode, stateid); 1070 } 1071 1072 /** 1073 * nfs_expire_unused_delegation_types 1074 * @clp: client to process 1075 * @flags: delegation types to expire 1076 * 1077 */ 1078 void nfs_expire_unused_delegation_types(struct nfs_client *clp, fmode_t flags) 1079 { 1080 nfs_client_mark_return_unused_delegation_types(clp, flags); 1081 nfs_delegation_run_state_manager(clp); 1082 } 1083 1084 static void nfs_mark_return_unreferenced_delegations(struct nfs_server *server) 1085 { 1086 struct nfs_delegation *delegation; 1087 1088 list_for_each_entry_rcu(delegation, &server->delegations, super_list) { 1089 if (test_and_clear_bit(NFS_DELEGATION_REFERENCED, &delegation->flags)) 1090 continue; 1091 nfs_mark_return_if_closed_delegation(server, delegation); 1092 } 1093 } 1094 1095 /** 1096 * nfs_expire_unreferenced_delegations - Eliminate unused delegations 1097 * @clp: nfs_client to process 1098 * 1099 */ 1100 void nfs_expire_unreferenced_delegations(struct nfs_client *clp) 1101 { 1102 struct nfs_server *server; 1103 1104 rcu_read_lock(); 1105 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) 1106 nfs_mark_return_unreferenced_delegations(server); 1107 rcu_read_unlock(); 1108 1109 nfs_delegation_run_state_manager(clp); 1110 } 1111 1112 /** 1113 * nfs_async_inode_return_delegation - asynchronously return a delegation 1114 * @inode: inode to process 1115 * @stateid: state ID information 1116 * 1117 * Returns zero on success, or a negative errno value. 1118 */ 1119 int nfs_async_inode_return_delegation(struct inode *inode, 1120 const nfs4_stateid *stateid) 1121 { 1122 struct nfs_server *server = NFS_SERVER(inode); 1123 struct nfs_client *clp = server->nfs_client; 1124 struct nfs_delegation *delegation; 1125 1126 rcu_read_lock(); 1127 delegation = nfs4_get_valid_delegation(inode); 1128 if (delegation == NULL) 1129 goto out_enoent; 1130 if (stateid != NULL && 1131 !clp->cl_mvops->match_stateid(&delegation->stateid, stateid)) 1132 goto out_enoent; 1133 nfs_mark_return_delegation(server, delegation); 1134 rcu_read_unlock(); 1135 1136 /* If there are any application leases or delegations, recall them */ 1137 break_lease(inode, O_WRONLY | O_RDWR | O_NONBLOCK); 1138 1139 nfs_delegation_run_state_manager(clp); 1140 return 0; 1141 out_enoent: 1142 rcu_read_unlock(); 1143 return -ENOENT; 1144 } 1145 1146 static struct inode * 1147 nfs_delegation_find_inode_server(struct nfs_server *server, 1148 const struct nfs_fh *fhandle) 1149 { 1150 struct nfs_delegation *delegation; 1151 struct super_block *freeme = NULL; 1152 struct inode *res = NULL; 1153 1154 list_for_each_entry_rcu(delegation, &server->delegations, super_list) { 1155 spin_lock(&delegation->lock); 1156 if (delegation->inode != NULL && 1157 !test_bit(NFS_DELEGATION_REVOKED, &delegation->flags) && 1158 nfs_compare_fh(fhandle, &NFS_I(delegation->inode)->fh) == 0) { 1159 if (nfs_sb_active(server->super)) { 1160 freeme = server->super; 1161 res = igrab(delegation->inode); 1162 } 1163 spin_unlock(&delegation->lock); 1164 if (res != NULL) 1165 return res; 1166 if (freeme) { 1167 rcu_read_unlock(); 1168 nfs_sb_deactive(freeme); 1169 rcu_read_lock(); 1170 } 1171 return ERR_PTR(-EAGAIN); 1172 } 1173 spin_unlock(&delegation->lock); 1174 } 1175 return ERR_PTR(-ENOENT); 1176 } 1177 1178 /** 1179 * nfs_delegation_find_inode - retrieve the inode associated with a delegation 1180 * @clp: client state handle 1181 * @fhandle: filehandle from a delegation recall 1182 * 1183 * Returns pointer to inode matching "fhandle," or NULL if a matching inode 1184 * cannot be found. 1185 */ 1186 struct inode *nfs_delegation_find_inode(struct nfs_client *clp, 1187 const struct nfs_fh *fhandle) 1188 { 1189 struct nfs_server *server; 1190 struct inode *res; 1191 1192 rcu_read_lock(); 1193 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) { 1194 res = nfs_delegation_find_inode_server(server, fhandle); 1195 if (res != ERR_PTR(-ENOENT)) { 1196 rcu_read_unlock(); 1197 return res; 1198 } 1199 } 1200 rcu_read_unlock(); 1201 return ERR_PTR(-ENOENT); 1202 } 1203 1204 static void nfs_delegation_mark_reclaim_server(struct nfs_server *server) 1205 { 1206 struct nfs_delegation *delegation; 1207 1208 list_for_each_entry_rcu(delegation, &server->delegations, super_list) { 1209 /* 1210 * If the delegation may have been admin revoked, then we 1211 * cannot reclaim it. 1212 */ 1213 if (test_bit(NFS_DELEGATION_TEST_EXPIRED, &delegation->flags)) 1214 continue; 1215 set_bit(NFS_DELEGATION_NEED_RECLAIM, &delegation->flags); 1216 } 1217 } 1218 1219 /** 1220 * nfs_delegation_mark_reclaim - mark all delegations as needing to be reclaimed 1221 * @clp: nfs_client to process 1222 * 1223 */ 1224 void nfs_delegation_mark_reclaim(struct nfs_client *clp) 1225 { 1226 struct nfs_server *server; 1227 1228 rcu_read_lock(); 1229 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) 1230 nfs_delegation_mark_reclaim_server(server); 1231 rcu_read_unlock(); 1232 } 1233 1234 static int nfs_server_reap_unclaimed_delegations(struct nfs_server *server, 1235 void __always_unused *data) 1236 { 1237 struct nfs_delegation *delegation; 1238 struct inode *inode; 1239 restart: 1240 rcu_read_lock(); 1241 list_for_each_entry_rcu(delegation, &server->delegations, super_list) { 1242 if (test_bit(NFS_DELEGATION_INODE_FREEING, 1243 &delegation->flags) || 1244 test_bit(NFS_DELEGATION_RETURNING, 1245 &delegation->flags) || 1246 test_bit(NFS_DELEGATION_NEED_RECLAIM, 1247 &delegation->flags) == 0) 1248 continue; 1249 inode = nfs_delegation_grab_inode(delegation); 1250 if (inode == NULL) 1251 continue; 1252 delegation = nfs_start_delegation_return_locked(NFS_I(inode)); 1253 rcu_read_unlock(); 1254 if (delegation != NULL) { 1255 if (nfs_detach_delegation(NFS_I(inode), delegation, 1256 server) != NULL) 1257 nfs_free_delegation(delegation); 1258 /* Match nfs_start_delegation_return_locked */ 1259 nfs_put_delegation(delegation); 1260 } 1261 iput(inode); 1262 cond_resched(); 1263 goto restart; 1264 } 1265 rcu_read_unlock(); 1266 return 0; 1267 } 1268 1269 /** 1270 * nfs_delegation_reap_unclaimed - reap unclaimed delegations after reboot recovery is done 1271 * @clp: nfs_client to process 1272 * 1273 */ 1274 void nfs_delegation_reap_unclaimed(struct nfs_client *clp) 1275 { 1276 nfs_client_for_each_server(clp, nfs_server_reap_unclaimed_delegations, 1277 NULL); 1278 } 1279 1280 static inline bool nfs4_server_rebooted(const struct nfs_client *clp) 1281 { 1282 return (clp->cl_state & (BIT(NFS4CLNT_CHECK_LEASE) | 1283 BIT(NFS4CLNT_LEASE_EXPIRED) | 1284 BIT(NFS4CLNT_SESSION_RESET))) != 0; 1285 } 1286 1287 static void nfs_mark_test_expired_delegation(struct nfs_server *server, 1288 struct nfs_delegation *delegation) 1289 { 1290 if (delegation->stateid.type == NFS4_INVALID_STATEID_TYPE) 1291 return; 1292 clear_bit(NFS_DELEGATION_NEED_RECLAIM, &delegation->flags); 1293 set_bit(NFS_DELEGATION_TEST_EXPIRED, &delegation->flags); 1294 set_bit(NFS4SERV_DELEGATION_EXPIRED, &server->delegation_flags); 1295 set_bit(NFS4CLNT_DELEGATION_EXPIRED, &server->nfs_client->cl_state); 1296 } 1297 1298 static void nfs_inode_mark_test_expired_delegation(struct nfs_server *server, 1299 struct inode *inode) 1300 { 1301 struct nfs_delegation *delegation; 1302 1303 rcu_read_lock(); 1304 delegation = rcu_dereference(NFS_I(inode)->delegation); 1305 if (delegation) 1306 nfs_mark_test_expired_delegation(server, delegation); 1307 rcu_read_unlock(); 1308 1309 } 1310 1311 static void nfs_delegation_mark_test_expired_server(struct nfs_server *server) 1312 { 1313 struct nfs_delegation *delegation; 1314 1315 list_for_each_entry_rcu(delegation, &server->delegations, super_list) 1316 nfs_mark_test_expired_delegation(server, delegation); 1317 } 1318 1319 /** 1320 * nfs_mark_test_expired_all_delegations - mark all delegations for testing 1321 * @clp: nfs_client to process 1322 * 1323 * Iterates through all the delegations associated with this server and 1324 * marks them as needing to be checked for validity. 1325 */ 1326 void nfs_mark_test_expired_all_delegations(struct nfs_client *clp) 1327 { 1328 struct nfs_server *server; 1329 1330 rcu_read_lock(); 1331 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) 1332 nfs_delegation_mark_test_expired_server(server); 1333 rcu_read_unlock(); 1334 } 1335 1336 /** 1337 * nfs_test_expired_all_delegations - test all delegations for a client 1338 * @clp: nfs_client to process 1339 * 1340 * Helper for handling "recallable state revoked" status from server. 1341 */ 1342 void nfs_test_expired_all_delegations(struct nfs_client *clp) 1343 { 1344 nfs_mark_test_expired_all_delegations(clp); 1345 nfs4_schedule_state_manager(clp); 1346 } 1347 1348 static void 1349 nfs_delegation_test_free_expired(struct inode *inode, 1350 nfs4_stateid *stateid, 1351 const struct cred *cred) 1352 { 1353 struct nfs_server *server = NFS_SERVER(inode); 1354 const struct nfs4_minor_version_ops *ops = server->nfs_client->cl_mvops; 1355 int status; 1356 1357 if (!cred) 1358 return; 1359 status = ops->test_and_free_expired(server, stateid, cred); 1360 if (status == -NFS4ERR_EXPIRED || status == -NFS4ERR_BAD_STATEID) 1361 nfs_remove_bad_delegation(inode, stateid); 1362 } 1363 1364 static int nfs_server_reap_expired_delegations(struct nfs_server *server, 1365 void __always_unused *data) 1366 { 1367 struct nfs_delegation *delegation; 1368 struct inode *inode; 1369 const struct cred *cred; 1370 nfs4_stateid stateid; 1371 unsigned long gen = ++server->delegation_gen; 1372 1373 if (!test_and_clear_bit(NFS4SERV_DELEGATION_EXPIRED, 1374 &server->delegation_flags)) 1375 return 0; 1376 restart: 1377 rcu_read_lock(); 1378 list_for_each_entry_rcu(delegation, &server->delegations, super_list) { 1379 if (test_bit(NFS_DELEGATION_INODE_FREEING, 1380 &delegation->flags) || 1381 test_bit(NFS_DELEGATION_RETURNING, 1382 &delegation->flags) || 1383 test_bit(NFS_DELEGATION_TEST_EXPIRED, 1384 &delegation->flags) == 0 || 1385 delegation->test_gen == gen) 1386 continue; 1387 inode = nfs_delegation_grab_inode(delegation); 1388 if (inode == NULL) 1389 continue; 1390 spin_lock(&delegation->lock); 1391 cred = get_cred_rcu(delegation->cred); 1392 nfs4_stateid_copy(&stateid, &delegation->stateid); 1393 spin_unlock(&delegation->lock); 1394 delegation->test_gen = gen; 1395 clear_bit(NFS_DELEGATION_TEST_EXPIRED, &delegation->flags); 1396 rcu_read_unlock(); 1397 nfs_delegation_test_free_expired(inode, &stateid, cred); 1398 put_cred(cred); 1399 if (!nfs4_server_rebooted(server->nfs_client)) { 1400 iput(inode); 1401 cond_resched(); 1402 goto restart; 1403 } 1404 nfs_inode_mark_test_expired_delegation(server,inode); 1405 set_bit(NFS4SERV_DELEGATION_EXPIRED, &server->delegation_flags); 1406 set_bit(NFS4CLNT_DELEGATION_EXPIRED, 1407 &server->nfs_client->cl_state); 1408 iput(inode); 1409 return -EAGAIN; 1410 } 1411 rcu_read_unlock(); 1412 return 0; 1413 } 1414 1415 /** 1416 * nfs_reap_expired_delegations - reap expired delegations 1417 * @clp: nfs_client to process 1418 * 1419 * Iterates through all the delegations associated with this server and 1420 * checks if they have may have been revoked. This function is usually 1421 * expected to be called in cases where the server may have lost its 1422 * lease. 1423 */ 1424 void nfs_reap_expired_delegations(struct nfs_client *clp) 1425 { 1426 nfs_client_for_each_server(clp, nfs_server_reap_expired_delegations, 1427 NULL); 1428 } 1429 1430 void nfs_inode_find_delegation_state_and_recover(struct inode *inode, 1431 const nfs4_stateid *stateid) 1432 { 1433 struct nfs_client *clp = NFS_SERVER(inode)->nfs_client; 1434 struct nfs_delegation *delegation; 1435 bool found = false; 1436 1437 rcu_read_lock(); 1438 delegation = rcu_dereference(NFS_I(inode)->delegation); 1439 if (delegation && 1440 nfs4_stateid_match_or_older(&delegation->stateid, stateid) && 1441 !test_bit(NFS_DELEGATION_REVOKED, &delegation->flags)) { 1442 nfs_mark_test_expired_delegation(NFS_SERVER(inode), delegation); 1443 found = true; 1444 } 1445 rcu_read_unlock(); 1446 if (found) 1447 nfs4_schedule_state_manager(clp); 1448 } 1449 1450 /** 1451 * nfs_delegations_present - check for existence of delegations 1452 * @clp: client state handle 1453 * 1454 * Returns one if there are any nfs_delegation structures attached 1455 * to this nfs_client. 1456 */ 1457 int nfs_delegations_present(struct nfs_client *clp) 1458 { 1459 struct nfs_server *server; 1460 int ret = 0; 1461 1462 rcu_read_lock(); 1463 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) 1464 if (!list_empty(&server->delegations)) { 1465 ret = 1; 1466 break; 1467 } 1468 rcu_read_unlock(); 1469 return ret; 1470 } 1471 1472 /** 1473 * nfs4_refresh_delegation_stateid - Update delegation stateid seqid 1474 * @dst: stateid to refresh 1475 * @inode: inode to check 1476 * 1477 * Returns "true" and updates "dst->seqid" * if inode had a delegation 1478 * that matches our delegation stateid. Otherwise "false" is returned. 1479 */ 1480 bool nfs4_refresh_delegation_stateid(nfs4_stateid *dst, struct inode *inode) 1481 { 1482 struct nfs_delegation *delegation; 1483 bool ret = false; 1484 if (!inode) 1485 goto out; 1486 1487 rcu_read_lock(); 1488 delegation = rcu_dereference(NFS_I(inode)->delegation); 1489 if (delegation != NULL && 1490 nfs4_stateid_match_other(dst, &delegation->stateid) && 1491 nfs4_stateid_is_newer(&delegation->stateid, dst) && 1492 !test_bit(NFS_DELEGATION_REVOKED, &delegation->flags)) { 1493 dst->seqid = delegation->stateid.seqid; 1494 ret = true; 1495 } 1496 rcu_read_unlock(); 1497 out: 1498 return ret; 1499 } 1500 1501 /** 1502 * nfs4_copy_delegation_stateid - Copy inode's state ID information 1503 * @inode: inode to check 1504 * @flags: delegation type requirement 1505 * @dst: stateid data structure to fill in 1506 * @cred: optional argument to retrieve credential 1507 * 1508 * Returns "true" and fills in "dst->data" * if inode had a delegation, 1509 * otherwise "false" is returned. 1510 */ 1511 bool nfs4_copy_delegation_stateid(struct inode *inode, fmode_t flags, 1512 nfs4_stateid *dst, const struct cred **cred) 1513 { 1514 struct nfs_inode *nfsi = NFS_I(inode); 1515 struct nfs_delegation *delegation; 1516 bool ret = false; 1517 1518 flags &= FMODE_READ|FMODE_WRITE; 1519 rcu_read_lock(); 1520 delegation = rcu_dereference(nfsi->delegation); 1521 if (!delegation) 1522 goto out; 1523 spin_lock(&delegation->lock); 1524 ret = nfs4_is_valid_delegation(delegation, flags); 1525 if (ret) { 1526 nfs4_stateid_copy(dst, &delegation->stateid); 1527 nfs_mark_delegation_referenced(delegation); 1528 if (cred) 1529 *cred = get_cred(delegation->cred); 1530 } 1531 spin_unlock(&delegation->lock); 1532 out: 1533 rcu_read_unlock(); 1534 return ret; 1535 } 1536 1537 /** 1538 * nfs4_delegation_flush_on_close - Check if we must flush file on close 1539 * @inode: inode to check 1540 * 1541 * This function checks the number of outstanding writes to the file 1542 * against the delegation 'space_limit' field to see if 1543 * the spec requires us to flush the file on close. 1544 */ 1545 bool nfs4_delegation_flush_on_close(const struct inode *inode) 1546 { 1547 struct nfs_inode *nfsi = NFS_I(inode); 1548 struct nfs_delegation *delegation; 1549 bool ret = true; 1550 1551 rcu_read_lock(); 1552 delegation = rcu_dereference(nfsi->delegation); 1553 if (delegation == NULL || !(delegation->type & FMODE_WRITE)) 1554 goto out; 1555 if (atomic_long_read(&nfsi->nrequests) < delegation->pagemod_limit) 1556 ret = false; 1557 out: 1558 rcu_read_unlock(); 1559 return ret; 1560 } 1561 1562 module_param_named(delegation_watermark, nfs_delegation_watermark, uint, 0644); 1563