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 } 650 651 if (prev) { 652 struct inode *tmp = nfs_delegation_grab_inode(prev); 653 if (tmp) { 654 to_put = place_holder; 655 place_holder = tmp; 656 place_holder_deleg = prev; 657 } 658 } 659 660 inode = nfs_delegation_grab_inode(delegation); 661 if (inode == NULL) { 662 rcu_read_unlock(); 663 iput(to_put); 664 goto restart; 665 } 666 delegation = nfs_start_delegation_return_locked(NFS_I(inode)); 667 rcu_read_unlock(); 668 669 iput(to_put); 670 671 err = nfs_end_delegation_return(inode, delegation, 0); 672 iput(inode); 673 cond_resched(); 674 if (!err) 675 goto restart; 676 set_bit(NFS4CLNT_DELEGRETURN, &server->nfs_client->cl_state); 677 goto out; 678 } 679 rcu_read_unlock(); 680 out: 681 iput(place_holder); 682 return err; 683 } 684 685 static bool nfs_server_clear_delayed_delegations(struct nfs_server *server) 686 { 687 struct nfs_delegation *d; 688 bool ret = false; 689 690 list_for_each_entry_rcu (d, &server->delegations, super_list) { 691 if (!test_bit(NFS_DELEGATION_RETURN_DELAYED, &d->flags)) 692 continue; 693 nfs_mark_return_delegation(server, d); 694 clear_bit(NFS_DELEGATION_RETURN_DELAYED, &d->flags); 695 ret = true; 696 } 697 return ret; 698 } 699 700 static bool nfs_client_clear_delayed_delegations(struct nfs_client *clp) 701 { 702 struct nfs_server *server; 703 bool ret = false; 704 705 if (!test_and_clear_bit(NFS4CLNT_DELEGRETURN_DELAYED, &clp->cl_state)) 706 goto out; 707 rcu_read_lock(); 708 list_for_each_entry_rcu (server, &clp->cl_superblocks, client_link) { 709 if (nfs_server_clear_delayed_delegations(server)) 710 ret = true; 711 } 712 rcu_read_unlock(); 713 out: 714 return ret; 715 } 716 717 /** 718 * nfs_client_return_marked_delegations - return previously marked delegations 719 * @clp: nfs_client to process 720 * 721 * Note that this function is designed to be called by the state 722 * manager thread. For this reason, it cannot flush the dirty data, 723 * since that could deadlock in case of a state recovery error. 724 * 725 * Returns zero on success, or a negative errno value. 726 */ 727 int nfs_client_return_marked_delegations(struct nfs_client *clp) 728 { 729 int err = nfs_client_for_each_server( 730 clp, nfs_server_return_marked_delegations, NULL); 731 if (err) 732 return err; 733 /* If a return was delayed, sleep to prevent hard looping */ 734 if (nfs_client_clear_delayed_delegations(clp)) 735 ssleep(1); 736 return 0; 737 } 738 739 /** 740 * nfs_inode_evict_delegation - return delegation, don't reclaim opens 741 * @inode: inode to process 742 * 743 * Does not protect against delegation reclaims, therefore really only safe 744 * to be called from nfs4_clear_inode(). Guaranteed to always free 745 * the delegation structure. 746 */ 747 void nfs_inode_evict_delegation(struct inode *inode) 748 { 749 struct nfs_delegation *delegation; 750 751 delegation = nfs_inode_detach_delegation(inode); 752 if (delegation != NULL) { 753 set_bit(NFS_DELEGATION_RETURNING, &delegation->flags); 754 set_bit(NFS_DELEGATION_INODE_FREEING, &delegation->flags); 755 nfs_do_return_delegation(inode, delegation, 1); 756 nfs_free_delegation(delegation); 757 } 758 } 759 760 /** 761 * nfs4_inode_return_delegation - synchronously return a delegation 762 * @inode: inode to process 763 * 764 * This routine will always flush any dirty data to disk on the 765 * assumption that if we need to return the delegation, then 766 * we should stop caching. 767 * 768 * Returns zero on success, or a negative errno value. 769 */ 770 int nfs4_inode_return_delegation(struct inode *inode) 771 { 772 struct nfs_inode *nfsi = NFS_I(inode); 773 struct nfs_delegation *delegation; 774 775 delegation = nfs_start_delegation_return(nfsi); 776 if (delegation != NULL) { 777 /* Synchronous recall of any application leases */ 778 break_lease(inode, O_WRONLY | O_RDWR); 779 if (S_ISREG(inode->i_mode)) 780 nfs_wb_all(inode); 781 return nfs_end_delegation_return(inode, delegation, 1); 782 } 783 return 0; 784 } 785 786 /** 787 * nfs4_inode_return_delegation_on_close - asynchronously return a delegation 788 * @inode: inode to process 789 * 790 * This routine is called on file close in order to determine if the 791 * inode delegation needs to be returned immediately. 792 */ 793 void nfs4_inode_return_delegation_on_close(struct inode *inode) 794 { 795 struct nfs_delegation *delegation; 796 struct nfs_delegation *ret = NULL; 797 798 if (!inode) 799 return; 800 rcu_read_lock(); 801 delegation = nfs4_get_valid_delegation(inode); 802 if (!delegation) 803 goto out; 804 if (test_bit(NFS_DELEGATION_RETURN_IF_CLOSED, &delegation->flags) || 805 atomic_long_read(&nfs_active_delegations) >= nfs_delegation_watermark) { 806 spin_lock(&delegation->lock); 807 if (delegation->inode && 808 list_empty(&NFS_I(inode)->open_files) && 809 !test_and_set_bit(NFS_DELEGATION_RETURNING, &delegation->flags)) { 810 clear_bit(NFS_DELEGATION_RETURN_IF_CLOSED, &delegation->flags); 811 /* Refcount matched in nfs_end_delegation_return() */ 812 ret = nfs_get_delegation(delegation); 813 } 814 spin_unlock(&delegation->lock); 815 if (ret) 816 nfs_clear_verifier_delegated(inode); 817 } 818 out: 819 rcu_read_unlock(); 820 nfs_end_delegation_return(inode, ret, 0); 821 } 822 823 /** 824 * nfs4_inode_make_writeable 825 * @inode: pointer to inode 826 * 827 * Make the inode writeable by returning the delegation if necessary 828 * 829 * Returns zero on success, or a negative errno value. 830 */ 831 int nfs4_inode_make_writeable(struct inode *inode) 832 { 833 struct nfs_delegation *delegation; 834 835 rcu_read_lock(); 836 delegation = nfs4_get_valid_delegation(inode); 837 if (delegation == NULL || 838 (nfs4_has_session(NFS_SERVER(inode)->nfs_client) && 839 (delegation->type & FMODE_WRITE))) { 840 rcu_read_unlock(); 841 return 0; 842 } 843 rcu_read_unlock(); 844 return nfs4_inode_return_delegation(inode); 845 } 846 847 static void nfs_mark_return_if_closed_delegation(struct nfs_server *server, 848 struct nfs_delegation *delegation) 849 { 850 set_bit(NFS_DELEGATION_RETURN_IF_CLOSED, &delegation->flags); 851 set_bit(NFS4CLNT_DELEGRETURN, &server->nfs_client->cl_state); 852 } 853 854 static bool nfs_server_mark_return_all_delegations(struct nfs_server *server) 855 { 856 struct nfs_delegation *delegation; 857 bool ret = false; 858 859 list_for_each_entry_rcu(delegation, &server->delegations, super_list) { 860 nfs_mark_return_delegation(server, delegation); 861 ret = true; 862 } 863 return ret; 864 } 865 866 static void nfs_client_mark_return_all_delegations(struct nfs_client *clp) 867 { 868 struct nfs_server *server; 869 870 rcu_read_lock(); 871 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) 872 nfs_server_mark_return_all_delegations(server); 873 rcu_read_unlock(); 874 } 875 876 static void nfs_delegation_run_state_manager(struct nfs_client *clp) 877 { 878 if (test_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state)) 879 nfs4_schedule_state_manager(clp); 880 } 881 882 /** 883 * nfs_expire_all_delegations 884 * @clp: client to process 885 * 886 */ 887 void nfs_expire_all_delegations(struct nfs_client *clp) 888 { 889 nfs_client_mark_return_all_delegations(clp); 890 nfs_delegation_run_state_manager(clp); 891 } 892 893 /** 894 * nfs_server_return_all_delegations - return delegations for one superblock 895 * @server: pointer to nfs_server to process 896 * 897 */ 898 void nfs_server_return_all_delegations(struct nfs_server *server) 899 { 900 struct nfs_client *clp = server->nfs_client; 901 bool need_wait; 902 903 if (clp == NULL) 904 return; 905 906 rcu_read_lock(); 907 need_wait = nfs_server_mark_return_all_delegations(server); 908 rcu_read_unlock(); 909 910 if (need_wait) { 911 nfs4_schedule_state_manager(clp); 912 nfs4_wait_clnt_recover(clp); 913 } 914 } 915 916 static void nfs_mark_return_unused_delegation_types(struct nfs_server *server, 917 fmode_t flags) 918 { 919 struct nfs_delegation *delegation; 920 921 list_for_each_entry_rcu(delegation, &server->delegations, super_list) { 922 if ((delegation->type == (FMODE_READ|FMODE_WRITE)) && !(flags & FMODE_WRITE)) 923 continue; 924 if (delegation->type & flags) 925 nfs_mark_return_if_closed_delegation(server, delegation); 926 } 927 } 928 929 static void nfs_client_mark_return_unused_delegation_types(struct nfs_client *clp, 930 fmode_t flags) 931 { 932 struct nfs_server *server; 933 934 rcu_read_lock(); 935 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) 936 nfs_mark_return_unused_delegation_types(server, flags); 937 rcu_read_unlock(); 938 } 939 940 static void nfs_revoke_delegation(struct inode *inode, 941 const nfs4_stateid *stateid) 942 { 943 struct nfs_delegation *delegation; 944 nfs4_stateid tmp; 945 bool ret = false; 946 947 rcu_read_lock(); 948 delegation = rcu_dereference(NFS_I(inode)->delegation); 949 if (delegation == NULL) 950 goto out; 951 if (stateid == NULL) { 952 nfs4_stateid_copy(&tmp, &delegation->stateid); 953 stateid = &tmp; 954 } else { 955 if (!nfs4_stateid_match_other(stateid, &delegation->stateid)) 956 goto out; 957 spin_lock(&delegation->lock); 958 if (stateid->seqid) { 959 if (nfs4_stateid_is_newer(&delegation->stateid, stateid)) { 960 spin_unlock(&delegation->lock); 961 goto out; 962 } 963 delegation->stateid.seqid = stateid->seqid; 964 } 965 spin_unlock(&delegation->lock); 966 } 967 nfs_mark_delegation_revoked(delegation); 968 ret = true; 969 out: 970 rcu_read_unlock(); 971 if (ret) 972 nfs_inode_find_state_and_recover(inode, stateid); 973 } 974 975 void nfs_remove_bad_delegation(struct inode *inode, 976 const nfs4_stateid *stateid) 977 { 978 nfs_revoke_delegation(inode, stateid); 979 } 980 EXPORT_SYMBOL_GPL(nfs_remove_bad_delegation); 981 982 void nfs_delegation_mark_returned(struct inode *inode, 983 const nfs4_stateid *stateid) 984 { 985 struct nfs_delegation *delegation; 986 987 if (!inode) 988 return; 989 990 rcu_read_lock(); 991 delegation = rcu_dereference(NFS_I(inode)->delegation); 992 if (!delegation) 993 goto out_rcu_unlock; 994 995 spin_lock(&delegation->lock); 996 if (!nfs4_stateid_match_other(stateid, &delegation->stateid)) 997 goto out_spin_unlock; 998 if (stateid->seqid) { 999 /* If delegation->stateid is newer, dont mark as returned */ 1000 if (nfs4_stateid_is_newer(&delegation->stateid, stateid)) 1001 goto out_clear_returning; 1002 if (delegation->stateid.seqid != stateid->seqid) 1003 delegation->stateid.seqid = stateid->seqid; 1004 } 1005 1006 nfs_mark_delegation_revoked(delegation); 1007 1008 out_clear_returning: 1009 clear_bit(NFS_DELEGATION_RETURNING, &delegation->flags); 1010 out_spin_unlock: 1011 spin_unlock(&delegation->lock); 1012 out_rcu_unlock: 1013 rcu_read_unlock(); 1014 1015 nfs_inode_find_state_and_recover(inode, stateid); 1016 } 1017 1018 /** 1019 * nfs_expire_unused_delegation_types 1020 * @clp: client to process 1021 * @flags: delegation types to expire 1022 * 1023 */ 1024 void nfs_expire_unused_delegation_types(struct nfs_client *clp, fmode_t flags) 1025 { 1026 nfs_client_mark_return_unused_delegation_types(clp, flags); 1027 nfs_delegation_run_state_manager(clp); 1028 } 1029 1030 static void nfs_mark_return_unreferenced_delegations(struct nfs_server *server) 1031 { 1032 struct nfs_delegation *delegation; 1033 1034 list_for_each_entry_rcu(delegation, &server->delegations, super_list) { 1035 if (test_and_clear_bit(NFS_DELEGATION_REFERENCED, &delegation->flags)) 1036 continue; 1037 nfs_mark_return_if_closed_delegation(server, delegation); 1038 } 1039 } 1040 1041 /** 1042 * nfs_expire_unreferenced_delegations - Eliminate unused delegations 1043 * @clp: nfs_client to process 1044 * 1045 */ 1046 void nfs_expire_unreferenced_delegations(struct nfs_client *clp) 1047 { 1048 struct nfs_server *server; 1049 1050 rcu_read_lock(); 1051 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) 1052 nfs_mark_return_unreferenced_delegations(server); 1053 rcu_read_unlock(); 1054 1055 nfs_delegation_run_state_manager(clp); 1056 } 1057 1058 /** 1059 * nfs_async_inode_return_delegation - asynchronously return a delegation 1060 * @inode: inode to process 1061 * @stateid: state ID information 1062 * 1063 * Returns zero on success, or a negative errno value. 1064 */ 1065 int nfs_async_inode_return_delegation(struct inode *inode, 1066 const nfs4_stateid *stateid) 1067 { 1068 struct nfs_server *server = NFS_SERVER(inode); 1069 struct nfs_client *clp = server->nfs_client; 1070 struct nfs_delegation *delegation; 1071 1072 rcu_read_lock(); 1073 delegation = nfs4_get_valid_delegation(inode); 1074 if (delegation == NULL) 1075 goto out_enoent; 1076 if (stateid != NULL && 1077 !clp->cl_mvops->match_stateid(&delegation->stateid, stateid)) 1078 goto out_enoent; 1079 nfs_mark_return_delegation(server, delegation); 1080 rcu_read_unlock(); 1081 1082 /* If there are any application leases or delegations, recall them */ 1083 break_lease(inode, O_WRONLY | O_RDWR | O_NONBLOCK); 1084 1085 nfs_delegation_run_state_manager(clp); 1086 return 0; 1087 out_enoent: 1088 rcu_read_unlock(); 1089 return -ENOENT; 1090 } 1091 1092 static struct inode * 1093 nfs_delegation_find_inode_server(struct nfs_server *server, 1094 const struct nfs_fh *fhandle) 1095 { 1096 struct nfs_delegation *delegation; 1097 struct super_block *freeme = NULL; 1098 struct inode *res = NULL; 1099 1100 list_for_each_entry_rcu(delegation, &server->delegations, super_list) { 1101 spin_lock(&delegation->lock); 1102 if (delegation->inode != NULL && 1103 !test_bit(NFS_DELEGATION_REVOKED, &delegation->flags) && 1104 nfs_compare_fh(fhandle, &NFS_I(delegation->inode)->fh) == 0) { 1105 if (nfs_sb_active(server->super)) { 1106 freeme = server->super; 1107 res = igrab(delegation->inode); 1108 } 1109 spin_unlock(&delegation->lock); 1110 if (res != NULL) 1111 return res; 1112 if (freeme) { 1113 rcu_read_unlock(); 1114 nfs_sb_deactive(freeme); 1115 rcu_read_lock(); 1116 } 1117 return ERR_PTR(-EAGAIN); 1118 } 1119 spin_unlock(&delegation->lock); 1120 } 1121 return ERR_PTR(-ENOENT); 1122 } 1123 1124 /** 1125 * nfs_delegation_find_inode - retrieve the inode associated with a delegation 1126 * @clp: client state handle 1127 * @fhandle: filehandle from a delegation recall 1128 * 1129 * Returns pointer to inode matching "fhandle," or NULL if a matching inode 1130 * cannot be found. 1131 */ 1132 struct inode *nfs_delegation_find_inode(struct nfs_client *clp, 1133 const struct nfs_fh *fhandle) 1134 { 1135 struct nfs_server *server; 1136 struct inode *res; 1137 1138 rcu_read_lock(); 1139 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) { 1140 res = nfs_delegation_find_inode_server(server, fhandle); 1141 if (res != ERR_PTR(-ENOENT)) { 1142 rcu_read_unlock(); 1143 return res; 1144 } 1145 } 1146 rcu_read_unlock(); 1147 return ERR_PTR(-ENOENT); 1148 } 1149 1150 static void nfs_delegation_mark_reclaim_server(struct nfs_server *server) 1151 { 1152 struct nfs_delegation *delegation; 1153 1154 list_for_each_entry_rcu(delegation, &server->delegations, super_list) { 1155 /* 1156 * If the delegation may have been admin revoked, then we 1157 * cannot reclaim it. 1158 */ 1159 if (test_bit(NFS_DELEGATION_TEST_EXPIRED, &delegation->flags)) 1160 continue; 1161 set_bit(NFS_DELEGATION_NEED_RECLAIM, &delegation->flags); 1162 } 1163 } 1164 1165 /** 1166 * nfs_delegation_mark_reclaim - mark all delegations as needing to be reclaimed 1167 * @clp: nfs_client to process 1168 * 1169 */ 1170 void nfs_delegation_mark_reclaim(struct nfs_client *clp) 1171 { 1172 struct nfs_server *server; 1173 1174 rcu_read_lock(); 1175 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) 1176 nfs_delegation_mark_reclaim_server(server); 1177 rcu_read_unlock(); 1178 } 1179 1180 static int nfs_server_reap_unclaimed_delegations(struct nfs_server *server, 1181 void __always_unused *data) 1182 { 1183 struct nfs_delegation *delegation; 1184 struct inode *inode; 1185 restart: 1186 rcu_read_lock(); 1187 restart_locked: 1188 list_for_each_entry_rcu(delegation, &server->delegations, super_list) { 1189 if (test_bit(NFS_DELEGATION_INODE_FREEING, 1190 &delegation->flags) || 1191 test_bit(NFS_DELEGATION_RETURNING, 1192 &delegation->flags) || 1193 test_bit(NFS_DELEGATION_NEED_RECLAIM, 1194 &delegation->flags) == 0) 1195 continue; 1196 inode = nfs_delegation_grab_inode(delegation); 1197 if (inode == NULL) 1198 goto restart_locked; 1199 delegation = nfs_start_delegation_return_locked(NFS_I(inode)); 1200 rcu_read_unlock(); 1201 if (delegation != NULL) { 1202 if (nfs_detach_delegation(NFS_I(inode), delegation, 1203 server) != NULL) 1204 nfs_free_delegation(delegation); 1205 /* Match nfs_start_delegation_return_locked */ 1206 nfs_put_delegation(delegation); 1207 } 1208 iput(inode); 1209 cond_resched(); 1210 goto restart; 1211 } 1212 rcu_read_unlock(); 1213 return 0; 1214 } 1215 1216 /** 1217 * nfs_delegation_reap_unclaimed - reap unclaimed delegations after reboot recovery is done 1218 * @clp: nfs_client to process 1219 * 1220 */ 1221 void nfs_delegation_reap_unclaimed(struct nfs_client *clp) 1222 { 1223 nfs_client_for_each_server(clp, nfs_server_reap_unclaimed_delegations, 1224 NULL); 1225 } 1226 1227 static inline bool nfs4_server_rebooted(const struct nfs_client *clp) 1228 { 1229 return (clp->cl_state & (BIT(NFS4CLNT_CHECK_LEASE) | 1230 BIT(NFS4CLNT_LEASE_EXPIRED) | 1231 BIT(NFS4CLNT_SESSION_RESET))) != 0; 1232 } 1233 1234 static void nfs_mark_test_expired_delegation(struct nfs_server *server, 1235 struct nfs_delegation *delegation) 1236 { 1237 if (delegation->stateid.type == NFS4_INVALID_STATEID_TYPE) 1238 return; 1239 clear_bit(NFS_DELEGATION_NEED_RECLAIM, &delegation->flags); 1240 set_bit(NFS_DELEGATION_TEST_EXPIRED, &delegation->flags); 1241 set_bit(NFS4CLNT_DELEGATION_EXPIRED, &server->nfs_client->cl_state); 1242 } 1243 1244 static void nfs_inode_mark_test_expired_delegation(struct nfs_server *server, 1245 struct inode *inode) 1246 { 1247 struct nfs_delegation *delegation; 1248 1249 rcu_read_lock(); 1250 delegation = rcu_dereference(NFS_I(inode)->delegation); 1251 if (delegation) 1252 nfs_mark_test_expired_delegation(server, delegation); 1253 rcu_read_unlock(); 1254 1255 } 1256 1257 static void nfs_delegation_mark_test_expired_server(struct nfs_server *server) 1258 { 1259 struct nfs_delegation *delegation; 1260 1261 list_for_each_entry_rcu(delegation, &server->delegations, super_list) 1262 nfs_mark_test_expired_delegation(server, delegation); 1263 } 1264 1265 /** 1266 * nfs_mark_test_expired_all_delegations - mark all delegations for testing 1267 * @clp: nfs_client to process 1268 * 1269 * Iterates through all the delegations associated with this server and 1270 * marks them as needing to be checked for validity. 1271 */ 1272 void nfs_mark_test_expired_all_delegations(struct nfs_client *clp) 1273 { 1274 struct nfs_server *server; 1275 1276 rcu_read_lock(); 1277 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) 1278 nfs_delegation_mark_test_expired_server(server); 1279 rcu_read_unlock(); 1280 } 1281 1282 /** 1283 * nfs_test_expired_all_delegations - test all delegations for a client 1284 * @clp: nfs_client to process 1285 * 1286 * Helper for handling "recallable state revoked" status from server. 1287 */ 1288 void nfs_test_expired_all_delegations(struct nfs_client *clp) 1289 { 1290 nfs_mark_test_expired_all_delegations(clp); 1291 nfs4_schedule_state_manager(clp); 1292 } 1293 1294 static void 1295 nfs_delegation_test_free_expired(struct inode *inode, 1296 nfs4_stateid *stateid, 1297 const struct cred *cred) 1298 { 1299 struct nfs_server *server = NFS_SERVER(inode); 1300 const struct nfs4_minor_version_ops *ops = server->nfs_client->cl_mvops; 1301 int status; 1302 1303 if (!cred) 1304 return; 1305 status = ops->test_and_free_expired(server, stateid, cred); 1306 if (status == -NFS4ERR_EXPIRED || status == -NFS4ERR_BAD_STATEID) 1307 nfs_remove_bad_delegation(inode, stateid); 1308 } 1309 1310 static int nfs_server_reap_expired_delegations(struct nfs_server *server, 1311 void __always_unused *data) 1312 { 1313 struct nfs_delegation *delegation; 1314 struct inode *inode; 1315 const struct cred *cred; 1316 nfs4_stateid stateid; 1317 unsigned long gen = ++server->delegation_gen; 1318 1319 restart: 1320 rcu_read_lock(); 1321 restart_locked: 1322 list_for_each_entry_rcu(delegation, &server->delegations, super_list) { 1323 if (test_bit(NFS_DELEGATION_INODE_FREEING, 1324 &delegation->flags) || 1325 test_bit(NFS_DELEGATION_RETURNING, 1326 &delegation->flags) || 1327 test_bit(NFS_DELEGATION_TEST_EXPIRED, 1328 &delegation->flags) == 0 || 1329 delegation->test_gen == gen) 1330 continue; 1331 inode = nfs_delegation_grab_inode(delegation); 1332 if (inode == NULL) 1333 goto restart_locked; 1334 spin_lock(&delegation->lock); 1335 cred = get_cred_rcu(delegation->cred); 1336 nfs4_stateid_copy(&stateid, &delegation->stateid); 1337 spin_unlock(&delegation->lock); 1338 delegation->test_gen = gen; 1339 clear_bit(NFS_DELEGATION_TEST_EXPIRED, &delegation->flags); 1340 rcu_read_unlock(); 1341 nfs_delegation_test_free_expired(inode, &stateid, cred); 1342 put_cred(cred); 1343 if (!nfs4_server_rebooted(server->nfs_client)) { 1344 iput(inode); 1345 cond_resched(); 1346 goto restart; 1347 } 1348 nfs_inode_mark_test_expired_delegation(server,inode); 1349 iput(inode); 1350 return -EAGAIN; 1351 } 1352 rcu_read_unlock(); 1353 return 0; 1354 } 1355 1356 /** 1357 * nfs_reap_expired_delegations - reap expired delegations 1358 * @clp: nfs_client to process 1359 * 1360 * Iterates through all the delegations associated with this server and 1361 * checks if they have may have been revoked. This function is usually 1362 * expected to be called in cases where the server may have lost its 1363 * lease. 1364 */ 1365 void nfs_reap_expired_delegations(struct nfs_client *clp) 1366 { 1367 nfs_client_for_each_server(clp, nfs_server_reap_expired_delegations, 1368 NULL); 1369 } 1370 1371 void nfs_inode_find_delegation_state_and_recover(struct inode *inode, 1372 const nfs4_stateid *stateid) 1373 { 1374 struct nfs_client *clp = NFS_SERVER(inode)->nfs_client; 1375 struct nfs_delegation *delegation; 1376 bool found = false; 1377 1378 rcu_read_lock(); 1379 delegation = rcu_dereference(NFS_I(inode)->delegation); 1380 if (delegation && 1381 nfs4_stateid_match_or_older(&delegation->stateid, stateid) && 1382 !test_bit(NFS_DELEGATION_REVOKED, &delegation->flags)) { 1383 nfs_mark_test_expired_delegation(NFS_SERVER(inode), delegation); 1384 found = true; 1385 } 1386 rcu_read_unlock(); 1387 if (found) 1388 nfs4_schedule_state_manager(clp); 1389 } 1390 1391 /** 1392 * nfs_delegations_present - check for existence of delegations 1393 * @clp: client state handle 1394 * 1395 * Returns one if there are any nfs_delegation structures attached 1396 * to this nfs_client. 1397 */ 1398 int nfs_delegations_present(struct nfs_client *clp) 1399 { 1400 struct nfs_server *server; 1401 int ret = 0; 1402 1403 rcu_read_lock(); 1404 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) 1405 if (!list_empty(&server->delegations)) { 1406 ret = 1; 1407 break; 1408 } 1409 rcu_read_unlock(); 1410 return ret; 1411 } 1412 1413 /** 1414 * nfs4_refresh_delegation_stateid - Update delegation stateid seqid 1415 * @dst: stateid to refresh 1416 * @inode: inode to check 1417 * 1418 * Returns "true" and updates "dst->seqid" * if inode had a delegation 1419 * that matches our delegation stateid. Otherwise "false" is returned. 1420 */ 1421 bool nfs4_refresh_delegation_stateid(nfs4_stateid *dst, struct inode *inode) 1422 { 1423 struct nfs_delegation *delegation; 1424 bool ret = false; 1425 if (!inode) 1426 goto out; 1427 1428 rcu_read_lock(); 1429 delegation = rcu_dereference(NFS_I(inode)->delegation); 1430 if (delegation != NULL && 1431 nfs4_stateid_match_other(dst, &delegation->stateid) && 1432 nfs4_stateid_is_newer(&delegation->stateid, dst) && 1433 !test_bit(NFS_DELEGATION_REVOKED, &delegation->flags)) { 1434 dst->seqid = delegation->stateid.seqid; 1435 ret = true; 1436 } 1437 rcu_read_unlock(); 1438 out: 1439 return ret; 1440 } 1441 1442 /** 1443 * nfs4_copy_delegation_stateid - Copy inode's state ID information 1444 * @inode: inode to check 1445 * @flags: delegation type requirement 1446 * @dst: stateid data structure to fill in 1447 * @cred: optional argument to retrieve credential 1448 * 1449 * Returns "true" and fills in "dst->data" * if inode had a delegation, 1450 * otherwise "false" is returned. 1451 */ 1452 bool nfs4_copy_delegation_stateid(struct inode *inode, fmode_t flags, 1453 nfs4_stateid *dst, const struct cred **cred) 1454 { 1455 struct nfs_inode *nfsi = NFS_I(inode); 1456 struct nfs_delegation *delegation; 1457 bool ret = false; 1458 1459 flags &= FMODE_READ|FMODE_WRITE; 1460 rcu_read_lock(); 1461 delegation = rcu_dereference(nfsi->delegation); 1462 if (!delegation) 1463 goto out; 1464 spin_lock(&delegation->lock); 1465 ret = nfs4_is_valid_delegation(delegation, flags); 1466 if (ret) { 1467 nfs4_stateid_copy(dst, &delegation->stateid); 1468 nfs_mark_delegation_referenced(delegation); 1469 if (cred) 1470 *cred = get_cred(delegation->cred); 1471 } 1472 spin_unlock(&delegation->lock); 1473 out: 1474 rcu_read_unlock(); 1475 return ret; 1476 } 1477 1478 /** 1479 * nfs4_delegation_flush_on_close - Check if we must flush file on close 1480 * @inode: inode to check 1481 * 1482 * This function checks the number of outstanding writes to the file 1483 * against the delegation 'space_limit' field to see if 1484 * the spec requires us to flush the file on close. 1485 */ 1486 bool nfs4_delegation_flush_on_close(const struct inode *inode) 1487 { 1488 struct nfs_inode *nfsi = NFS_I(inode); 1489 struct nfs_delegation *delegation; 1490 bool ret = true; 1491 1492 rcu_read_lock(); 1493 delegation = rcu_dereference(nfsi->delegation); 1494 if (delegation == NULL || !(delegation->type & FMODE_WRITE)) 1495 goto out; 1496 if (atomic_long_read(&nfsi->nrequests) < delegation->pagemod_limit) 1497 ret = false; 1498 out: 1499 rcu_read_unlock(); 1500 return ret; 1501 } 1502 1503 module_param_named(delegation_watermark, nfs_delegation_watermark, uint, 0644); 1504