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 unsigned nfs_delegation_watermark = NFS_DEFAULT_DELEGATION_WATERMARK; 31 module_param_named(delegation_watermark, nfs_delegation_watermark, uint, 0644); 32 33 bool directory_delegations = true; 34 module_param(directory_delegations, bool, 0644); 35 MODULE_PARM_DESC(directory_delegations, 36 "Enable the use of directory delegations, defaults to on."); 37 38 static struct hlist_head *nfs_delegation_hash(struct nfs_server *server, 39 const struct nfs_fh *fhandle) 40 { 41 return server->delegation_hash_table + 42 (nfs_fhandle_hash(fhandle) & server->delegation_hash_mask); 43 } 44 45 static void __nfs_free_delegation(struct nfs_delegation *delegation) 46 { 47 put_cred(delegation->cred); 48 delegation->cred = NULL; 49 kfree_rcu(delegation, rcu); 50 } 51 52 static void nfs_mark_delegation_revoked(struct nfs_server *server, 53 struct nfs_delegation *delegation) 54 { 55 if (!test_and_set_bit(NFS_DELEGATION_REVOKED, &delegation->flags)) { 56 delegation->stateid.type = NFS4_INVALID_STATEID_TYPE; 57 atomic_long_dec(&server->nr_active_delegations); 58 if (!test_bit(NFS_DELEGATION_RETURNING, &delegation->flags)) 59 nfs_clear_verifier_delegated(delegation->inode); 60 } 61 } 62 63 static struct nfs_delegation *nfs_get_delegation(struct nfs_delegation *delegation) 64 { 65 refcount_inc(&delegation->refcount); 66 return delegation; 67 } 68 69 static void nfs_put_delegation(struct nfs_delegation *delegation) 70 { 71 if (refcount_dec_and_test(&delegation->refcount)) 72 __nfs_free_delegation(delegation); 73 } 74 75 static void nfs_free_delegation(struct nfs_server *server, 76 struct nfs_delegation *delegation) 77 { 78 nfs_mark_delegation_revoked(server, delegation); 79 nfs_put_delegation(delegation); 80 } 81 82 /** 83 * nfs_mark_delegation_referenced - set delegation's REFERENCED flag 84 * @delegation: delegation to process 85 * 86 */ 87 void nfs_mark_delegation_referenced(struct nfs_delegation *delegation) 88 { 89 set_bit(NFS_DELEGATION_REFERENCED, &delegation->flags); 90 } 91 92 static void nfs_mark_return_delegation(struct nfs_server *server, 93 struct nfs_delegation *delegation) 94 { 95 set_bit(NFS_DELEGATION_RETURN, &delegation->flags); 96 set_bit(NFS4SERV_DELEGRETURN, &server->delegation_flags); 97 set_bit(NFS4CLNT_DELEGRETURN, &server->nfs_client->cl_state); 98 } 99 100 static bool nfs4_is_valid_delegation(const struct nfs_delegation *delegation, 101 fmode_t type) 102 { 103 if (delegation != NULL && (delegation->type & type) == type && 104 !test_bit(NFS_DELEGATION_REVOKED, &delegation->flags) && 105 !test_bit(NFS_DELEGATION_RETURNING, &delegation->flags)) 106 return true; 107 return false; 108 } 109 110 struct nfs_delegation *nfs4_get_valid_delegation(const struct inode *inode) 111 { 112 struct nfs_delegation *delegation; 113 114 delegation = rcu_dereference(NFS_I(inode)->delegation); 115 if (nfs4_is_valid_delegation(delegation, 0)) 116 return delegation; 117 return NULL; 118 } 119 120 static int nfs4_do_check_delegation(struct inode *inode, fmode_t type, 121 int flags, bool mark) 122 { 123 struct nfs_delegation *delegation; 124 int ret = 0; 125 126 type &= FMODE_READ|FMODE_WRITE; 127 rcu_read_lock(); 128 delegation = rcu_dereference(NFS_I(inode)->delegation); 129 if (nfs4_is_valid_delegation(delegation, type)) { 130 if (mark) 131 nfs_mark_delegation_referenced(delegation); 132 ret = 1; 133 if ((flags & NFS_DELEGATION_FLAG_TIME) && 134 !test_bit(NFS_DELEGATION_DELEGTIME, &delegation->flags)) 135 ret = 0; 136 } 137 rcu_read_unlock(); 138 return ret; 139 } 140 /** 141 * nfs4_have_delegation - check if inode has a delegation, mark it 142 * NFS_DELEGATION_REFERENCED if there is one. 143 * @inode: inode to check 144 * @type: delegation types to check for 145 * @flags: various modifiers 146 * 147 * Returns one if inode has the indicated delegation, otherwise zero. 148 */ 149 int nfs4_have_delegation(struct inode *inode, fmode_t type, int flags) 150 { 151 if (S_ISDIR(inode->i_mode) && !directory_delegations) 152 nfs4_inode_set_return_delegation_on_close(inode); 153 return nfs4_do_check_delegation(inode, type, flags, true); 154 } 155 156 /* 157 * nfs4_check_delegation - check if inode has a delegation, do not mark 158 * NFS_DELEGATION_REFERENCED if it has one. 159 */ 160 int nfs4_check_delegation(struct inode *inode, fmode_t type) 161 { 162 return nfs4_do_check_delegation(inode, type, 0, false); 163 } 164 165 static int nfs_delegation_claim_locks(struct nfs4_state *state, const nfs4_stateid *stateid) 166 { 167 struct inode *inode = state->inode; 168 struct file_lock *fl; 169 struct file_lock_context *flctx = locks_inode_context(inode); 170 struct list_head *list; 171 int status = 0; 172 173 if (flctx == NULL) 174 goto out; 175 176 list = &flctx->flc_posix; 177 spin_lock(&flctx->flc_lock); 178 restart: 179 for_each_file_lock(fl, list) { 180 if (nfs_file_open_context(fl->c.flc_file)->state != state) 181 continue; 182 spin_unlock(&flctx->flc_lock); 183 status = nfs4_lock_delegation_recall(fl, state, stateid); 184 if (status < 0) 185 goto out; 186 spin_lock(&flctx->flc_lock); 187 } 188 if (list == &flctx->flc_posix) { 189 list = &flctx->flc_flock; 190 goto restart; 191 } 192 spin_unlock(&flctx->flc_lock); 193 out: 194 return status; 195 } 196 197 static int nfs_delegation_claim_opens(struct inode *inode, 198 const nfs4_stateid *stateid, fmode_t type) 199 { 200 struct nfs_inode *nfsi = NFS_I(inode); 201 struct nfs_open_context *ctx; 202 struct nfs4_state_owner *sp; 203 struct nfs4_state *state; 204 int err; 205 206 again: 207 rcu_read_lock(); 208 list_for_each_entry_rcu(ctx, &nfsi->open_files, list) { 209 state = ctx->state; 210 if (state == NULL) 211 continue; 212 if (!test_bit(NFS_DELEGATED_STATE, &state->flags)) 213 continue; 214 if (!nfs4_valid_open_stateid(state)) 215 continue; 216 if (!nfs4_stateid_match(&state->stateid, stateid)) 217 continue; 218 if (!get_nfs_open_context(ctx)) 219 continue; 220 rcu_read_unlock(); 221 sp = state->owner; 222 /* Block nfs4_proc_unlck */ 223 mutex_lock(&sp->so_delegreturn_mutex); 224 err = nfs4_open_delegation_recall(ctx, state, stateid); 225 if (!err) 226 err = nfs_delegation_claim_locks(state, stateid); 227 mutex_unlock(&sp->so_delegreturn_mutex); 228 put_nfs_open_context(ctx); 229 if (err != 0) 230 return err; 231 goto again; 232 } 233 rcu_read_unlock(); 234 return 0; 235 } 236 237 /** 238 * nfs_inode_reclaim_delegation - process a delegation reclaim request 239 * @inode: inode to process 240 * @cred: credential to use for request 241 * @type: delegation type 242 * @stateid: delegation stateid 243 * @pagemod_limit: write delegation "space_limit" 244 * @deleg_type: raw delegation type 245 * 246 */ 247 void nfs_inode_reclaim_delegation(struct inode *inode, const struct cred *cred, 248 fmode_t type, const nfs4_stateid *stateid, 249 unsigned long pagemod_limit, u32 deleg_type) 250 { 251 struct nfs_delegation *delegation; 252 const struct cred *oldcred = NULL; 253 254 rcu_read_lock(); 255 delegation = rcu_dereference(NFS_I(inode)->delegation); 256 if (!delegation) { 257 rcu_read_unlock(); 258 nfs_inode_set_delegation(inode, cred, type, stateid, 259 pagemod_limit, deleg_type); 260 return; 261 } 262 263 spin_lock(&delegation->lock); 264 nfs4_stateid_copy(&delegation->stateid, stateid); 265 delegation->type = type; 266 delegation->pagemod_limit = pagemod_limit; 267 oldcred = delegation->cred; 268 delegation->cred = get_cred(cred); 269 switch (deleg_type) { 270 case NFS4_OPEN_DELEGATE_READ_ATTRS_DELEG: 271 case NFS4_OPEN_DELEGATE_WRITE_ATTRS_DELEG: 272 set_bit(NFS_DELEGATION_DELEGTIME, &delegation->flags); 273 break; 274 default: 275 clear_bit(NFS_DELEGATION_DELEGTIME, &delegation->flags); 276 } 277 clear_bit(NFS_DELEGATION_NEED_RECLAIM, &delegation->flags); 278 if (test_and_clear_bit(NFS_DELEGATION_REVOKED, &delegation->flags)) 279 atomic_long_inc(&NFS_SERVER(inode)->nr_active_delegations); 280 spin_unlock(&delegation->lock); 281 rcu_read_unlock(); 282 put_cred(oldcred); 283 trace_nfs4_reclaim_delegation(inode, type); 284 } 285 286 static int nfs_do_return_delegation(struct inode *inode, 287 struct nfs_delegation *delegation, 288 int issync) 289 { 290 const struct cred *cred; 291 int res = 0; 292 293 if (!test_bit(NFS_DELEGATION_REVOKED, &delegation->flags)) { 294 spin_lock(&delegation->lock); 295 cred = get_cred(delegation->cred); 296 spin_unlock(&delegation->lock); 297 res = nfs4_proc_delegreturn(inode, cred, &delegation->stateid, 298 delegation, issync); 299 put_cred(cred); 300 } 301 return res; 302 } 303 304 static struct inode *nfs_delegation_grab_inode(struct nfs_delegation *delegation) 305 { 306 struct inode *inode = NULL; 307 308 spin_lock(&delegation->lock); 309 if (delegation->inode != NULL) 310 inode = igrab(delegation->inode); 311 if (!inode) 312 set_bit(NFS_DELEGATION_INODE_FREEING, &delegation->flags); 313 spin_unlock(&delegation->lock); 314 return inode; 315 } 316 317 static struct nfs_delegation * 318 nfs_start_delegation_return_locked(struct nfs_inode *nfsi) 319 { 320 struct nfs_delegation *ret = NULL; 321 struct nfs_delegation *delegation = rcu_dereference(nfsi->delegation); 322 323 if (delegation == NULL) 324 goto out; 325 spin_lock(&delegation->lock); 326 if (delegation->inode && 327 !test_and_set_bit(NFS_DELEGATION_RETURNING, &delegation->flags)) { 328 clear_bit(NFS_DELEGATION_RETURN_DELAYED, &delegation->flags); 329 /* Refcount matched in nfs_end_delegation_return() */ 330 ret = nfs_get_delegation(delegation); 331 } 332 spin_unlock(&delegation->lock); 333 if (ret) 334 nfs_clear_verifier_delegated(&nfsi->vfs_inode); 335 out: 336 return ret; 337 } 338 339 static struct nfs_delegation * 340 nfs_start_delegation_return(struct nfs_inode *nfsi) 341 { 342 struct nfs_delegation *delegation; 343 344 rcu_read_lock(); 345 delegation = nfs_start_delegation_return_locked(nfsi); 346 rcu_read_unlock(); 347 return delegation; 348 } 349 350 static void nfs_abort_delegation_return(struct nfs_delegation *delegation, 351 struct nfs_server *server, int err) 352 { 353 spin_lock(&delegation->lock); 354 clear_bit(NFS_DELEGATION_RETURNING, &delegation->flags); 355 if (err == -EAGAIN) { 356 set_bit(NFS_DELEGATION_RETURN_DELAYED, &delegation->flags); 357 set_bit(NFS4SERV_DELEGRETURN_DELAYED, 358 &server->delegation_flags); 359 set_bit(NFS4CLNT_DELEGRETURN_DELAYED, 360 &server->nfs_client->cl_state); 361 } 362 spin_unlock(&delegation->lock); 363 } 364 365 static struct nfs_delegation * 366 nfs_detach_delegation_locked(struct nfs_inode *nfsi, 367 struct nfs_delegation *delegation, 368 struct nfs_client *clp) 369 { 370 struct nfs_delegation *deleg_cur = 371 rcu_dereference_protected(nfsi->delegation, 372 lockdep_is_held(&clp->cl_lock)); 373 374 trace_nfs4_detach_delegation(&nfsi->vfs_inode, delegation->type); 375 376 if (deleg_cur == NULL || delegation != deleg_cur) 377 return NULL; 378 379 spin_lock(&delegation->lock); 380 if (!delegation->inode) { 381 spin_unlock(&delegation->lock); 382 return NULL; 383 } 384 hlist_del_init_rcu(&delegation->hash); 385 list_del_rcu(&delegation->super_list); 386 delegation->inode = NULL; 387 rcu_assign_pointer(nfsi->delegation, NULL); 388 spin_unlock(&delegation->lock); 389 clear_bit(NFS_INO_REQ_DIR_DELEG, &nfsi->flags); 390 return delegation; 391 } 392 393 static struct nfs_delegation *nfs_detach_delegation(struct nfs_inode *nfsi, 394 struct nfs_delegation *delegation, 395 struct nfs_server *server) 396 { 397 struct nfs_client *clp = server->nfs_client; 398 399 spin_lock(&clp->cl_lock); 400 delegation = nfs_detach_delegation_locked(nfsi, delegation, clp); 401 spin_unlock(&clp->cl_lock); 402 return delegation; 403 } 404 405 static struct nfs_delegation * 406 nfs_inode_detach_delegation(struct inode *inode) 407 { 408 struct nfs_inode *nfsi = NFS_I(inode); 409 struct nfs_server *server = NFS_SERVER(inode); 410 struct nfs_delegation *delegation; 411 412 rcu_read_lock(); 413 delegation = rcu_dereference(nfsi->delegation); 414 if (delegation != NULL) 415 delegation = nfs_detach_delegation(nfsi, delegation, server); 416 rcu_read_unlock(); 417 return delegation; 418 } 419 420 static void 421 nfs_update_delegation_cred(struct nfs_delegation *delegation, 422 const struct cred *cred) 423 { 424 const struct cred *old; 425 426 if (cred_fscmp(delegation->cred, cred) != 0) { 427 old = xchg(&delegation->cred, get_cred(cred)); 428 put_cred(old); 429 } 430 } 431 432 static void 433 nfs_update_inplace_delegation(struct nfs_server *server, 434 struct nfs_delegation *delegation, 435 const struct nfs_delegation *update) 436 { 437 if (nfs4_stateid_is_newer(&update->stateid, &delegation->stateid)) { 438 delegation->stateid.seqid = update->stateid.seqid; 439 smp_wmb(); 440 delegation->type = update->type; 441 delegation->pagemod_limit = update->pagemod_limit; 442 if (test_bit(NFS_DELEGATION_REVOKED, &delegation->flags)) { 443 delegation->change_attr = update->change_attr; 444 nfs_update_delegation_cred(delegation, update->cred); 445 /* smp_mb__before_atomic() is implicit due to xchg() */ 446 clear_bit(NFS_DELEGATION_REVOKED, &delegation->flags); 447 atomic_long_inc(&server->nr_active_delegations); 448 } 449 } 450 } 451 452 /** 453 * nfs_inode_set_delegation - set up a delegation on an inode 454 * @inode: inode to which delegation applies 455 * @cred: cred to use for subsequent delegation processing 456 * @type: delegation type 457 * @stateid: delegation stateid 458 * @pagemod_limit: write delegation "space_limit" 459 * @deleg_type: raw delegation type 460 * 461 * Returns zero on success, or a negative errno value. 462 */ 463 int nfs_inode_set_delegation(struct inode *inode, const struct cred *cred, 464 fmode_t type, const nfs4_stateid *stateid, 465 unsigned long pagemod_limit, u32 deleg_type) 466 { 467 struct nfs_server *server = NFS_SERVER(inode); 468 struct nfs_client *clp = server->nfs_client; 469 struct nfs_inode *nfsi = NFS_I(inode); 470 struct nfs_delegation *delegation, *old_delegation; 471 struct nfs_delegation *freeme = NULL; 472 int status = 0; 473 474 delegation = kmalloc(sizeof(*delegation), GFP_KERNEL_ACCOUNT); 475 if (delegation == NULL) 476 return -ENOMEM; 477 nfs4_stateid_copy(&delegation->stateid, stateid); 478 refcount_set(&delegation->refcount, 1); 479 delegation->type = type; 480 delegation->pagemod_limit = pagemod_limit; 481 delegation->change_attr = inode_peek_iversion_raw(inode); 482 delegation->cred = get_cred(cred); 483 delegation->inode = inode; 484 delegation->flags = 1<<NFS_DELEGATION_REFERENCED; 485 switch (deleg_type) { 486 case NFS4_OPEN_DELEGATE_READ_ATTRS_DELEG: 487 case NFS4_OPEN_DELEGATE_WRITE_ATTRS_DELEG: 488 delegation->flags |= BIT(NFS_DELEGATION_DELEGTIME); 489 } 490 delegation->test_gen = 0; 491 spin_lock_init(&delegation->lock); 492 493 spin_lock(&clp->cl_lock); 494 old_delegation = rcu_dereference_protected(nfsi->delegation, 495 lockdep_is_held(&clp->cl_lock)); 496 if (old_delegation == NULL) 497 goto add_new; 498 /* Is this an update of the existing delegation? */ 499 if (nfs4_stateid_match_other(&old_delegation->stateid, 500 &delegation->stateid)) { 501 spin_lock(&old_delegation->lock); 502 nfs_update_inplace_delegation(server, old_delegation, 503 delegation); 504 spin_unlock(&old_delegation->lock); 505 goto out; 506 } 507 if (!test_bit(NFS_DELEGATION_REVOKED, &old_delegation->flags)) { 508 /* 509 * Deal with broken servers that hand out two 510 * delegations for the same file. 511 * Allow for upgrades to a WRITE delegation, but 512 * nothing else. 513 */ 514 dfprintk(FILE, "%s: server %s handed out " 515 "a duplicate delegation!\n", 516 __func__, clp->cl_hostname); 517 if (delegation->type == old_delegation->type || 518 !(delegation->type & FMODE_WRITE)) { 519 freeme = delegation; 520 delegation = NULL; 521 goto out; 522 } 523 if (test_and_set_bit(NFS_DELEGATION_RETURNING, 524 &old_delegation->flags)) 525 goto out; 526 } 527 freeme = nfs_detach_delegation_locked(nfsi, old_delegation, clp); 528 if (freeme == NULL) 529 goto out; 530 add_new: 531 /* 532 * If we didn't revalidate the change attribute before setting 533 * the delegation, then pre-emptively ask for a full attribute 534 * cache revalidation. 535 */ 536 spin_lock(&inode->i_lock); 537 if (NFS_I(inode)->cache_validity & NFS_INO_INVALID_CHANGE) 538 nfs_set_cache_invalid(inode, 539 NFS_INO_INVALID_ATIME | NFS_INO_INVALID_CTIME | 540 NFS_INO_INVALID_MTIME | NFS_INO_INVALID_SIZE | 541 NFS_INO_INVALID_BLOCKS | NFS_INO_INVALID_NLINK | 542 NFS_INO_INVALID_OTHER | NFS_INO_INVALID_DATA | 543 NFS_INO_INVALID_ACCESS | NFS_INO_INVALID_ACL | 544 NFS_INO_INVALID_XATTR); 545 spin_unlock(&inode->i_lock); 546 547 list_add_tail_rcu(&delegation->super_list, &server->delegations); 548 hlist_add_head_rcu(&delegation->hash, 549 nfs_delegation_hash(server, &NFS_I(inode)->fh)); 550 rcu_assign_pointer(nfsi->delegation, delegation); 551 delegation = NULL; 552 553 atomic_long_inc(&server->nr_active_delegations); 554 555 trace_nfs4_set_delegation(inode, type); 556 557 /* If we hold writebacks and have delegated mtime then update */ 558 if (deleg_type == NFS4_OPEN_DELEGATE_WRITE_ATTRS_DELEG && 559 nfs_have_writebacks(inode)) 560 nfs_update_delegated_mtime(inode); 561 out: 562 spin_unlock(&clp->cl_lock); 563 if (delegation != NULL) 564 __nfs_free_delegation(delegation); 565 if (freeme != NULL) { 566 nfs_do_return_delegation(inode, freeme, 0); 567 nfs_free_delegation(server, freeme); 568 } 569 return status; 570 } 571 572 /* 573 * Basic procedure for returning a delegation to the server 574 */ 575 static int nfs_end_delegation_return(struct inode *inode, struct nfs_delegation *delegation, int issync) 576 { 577 struct nfs_server *server = NFS_SERVER(inode); 578 unsigned int mode = O_WRONLY | O_RDWR; 579 int err = 0; 580 581 if (delegation == NULL) 582 return 0; 583 584 /* Directory delegations don't require any state recovery */ 585 if (!S_ISREG(inode->i_mode)) 586 goto out_return; 587 588 if (!issync) 589 mode |= O_NONBLOCK; 590 /* Recall of any remaining application leases */ 591 err = break_lease(inode, mode); 592 593 while (err == 0) { 594 if (test_bit(NFS_DELEGATION_REVOKED, &delegation->flags)) 595 break; 596 err = nfs_delegation_claim_opens(inode, &delegation->stateid, 597 delegation->type); 598 if (!issync || err != -EAGAIN) 599 break; 600 /* 601 * Guard against state recovery 602 */ 603 err = nfs4_wait_clnt_recover(server->nfs_client); 604 } 605 606 if (err) { 607 nfs_abort_delegation_return(delegation, server, err); 608 goto out; 609 } 610 611 out_return: 612 err = nfs_do_return_delegation(inode, delegation, issync); 613 out: 614 /* Refcount matched in nfs_start_delegation_return_locked() */ 615 nfs_put_delegation(delegation); 616 return err; 617 } 618 619 static bool nfs_delegation_need_return(struct nfs_delegation *delegation) 620 { 621 bool ret = false; 622 623 trace_nfs_delegation_need_return(delegation); 624 625 if (test_and_clear_bit(NFS_DELEGATION_RETURN, &delegation->flags)) 626 ret = true; 627 if (test_bit(NFS_DELEGATION_RETURNING, &delegation->flags) || 628 test_bit(NFS_DELEGATION_RETURN_DELAYED, &delegation->flags) || 629 test_bit(NFS_DELEGATION_REVOKED, &delegation->flags)) 630 ret = false; 631 632 return ret; 633 } 634 635 static int nfs_server_return_marked_delegations(struct nfs_server *server, 636 void __always_unused *data) 637 { 638 struct nfs_delegation *delegation; 639 struct nfs_delegation *prev; 640 struct inode *inode; 641 struct inode *place_holder = NULL; 642 struct nfs_delegation *place_holder_deleg = NULL; 643 int err = 0; 644 645 if (!test_and_clear_bit(NFS4SERV_DELEGRETURN, 646 &server->delegation_flags)) 647 return 0; 648 restart: 649 /* 650 * To avoid quadratic looping we hold a reference 651 * to an inode place_holder. Each time we restart, we 652 * list delegation in the server from the delegations 653 * of that inode. 654 * prev is an RCU-protected pointer to a delegation which 655 * wasn't marked for return and might be a good choice for 656 * the next place_holder. 657 */ 658 prev = NULL; 659 delegation = NULL; 660 rcu_read_lock(); 661 if (place_holder) 662 delegation = rcu_dereference(NFS_I(place_holder)->delegation); 663 if (!delegation || delegation != place_holder_deleg) 664 delegation = list_entry_rcu(server->delegations.next, 665 struct nfs_delegation, super_list); 666 list_for_each_entry_from_rcu(delegation, &server->delegations, super_list) { 667 struct inode *to_put = NULL; 668 669 if (test_bit(NFS_DELEGATION_INODE_FREEING, &delegation->flags)) 670 continue; 671 if (!nfs_delegation_need_return(delegation)) { 672 if (nfs4_is_valid_delegation(delegation, 0)) 673 prev = delegation; 674 continue; 675 } 676 inode = nfs_delegation_grab_inode(delegation); 677 if (inode == NULL) 678 continue; 679 680 if (prev) { 681 struct inode *tmp = nfs_delegation_grab_inode(prev); 682 if (tmp) { 683 to_put = place_holder; 684 place_holder = tmp; 685 place_holder_deleg = prev; 686 } 687 } 688 689 delegation = nfs_start_delegation_return_locked(NFS_I(inode)); 690 rcu_read_unlock(); 691 692 iput(to_put); 693 694 err = nfs_end_delegation_return(inode, delegation, 0); 695 iput(inode); 696 cond_resched(); 697 if (!err) 698 goto restart; 699 set_bit(NFS4SERV_DELEGRETURN, &server->delegation_flags); 700 set_bit(NFS4CLNT_DELEGRETURN, &server->nfs_client->cl_state); 701 goto out; 702 } 703 rcu_read_unlock(); 704 out: 705 iput(place_holder); 706 return err; 707 } 708 709 static bool nfs_server_clear_delayed_delegations(struct nfs_server *server) 710 { 711 struct nfs_delegation *d; 712 bool ret = false; 713 714 if (!test_and_clear_bit(NFS4SERV_DELEGRETURN_DELAYED, 715 &server->delegation_flags)) 716 goto out; 717 list_for_each_entry_rcu (d, &server->delegations, super_list) { 718 if (!test_bit(NFS_DELEGATION_RETURN_DELAYED, &d->flags)) 719 continue; 720 nfs_mark_return_delegation(server, d); 721 clear_bit(NFS_DELEGATION_RETURN_DELAYED, &d->flags); 722 ret = true; 723 } 724 out: 725 return ret; 726 } 727 728 static bool nfs_client_clear_delayed_delegations(struct nfs_client *clp) 729 { 730 struct nfs_server *server; 731 bool ret = false; 732 733 if (!test_and_clear_bit(NFS4CLNT_DELEGRETURN_DELAYED, &clp->cl_state)) 734 goto out; 735 rcu_read_lock(); 736 list_for_each_entry_rcu (server, &clp->cl_superblocks, client_link) { 737 if (nfs_server_clear_delayed_delegations(server)) 738 ret = true; 739 } 740 rcu_read_unlock(); 741 out: 742 return ret; 743 } 744 745 /** 746 * nfs_client_return_marked_delegations - return previously marked delegations 747 * @clp: nfs_client to process 748 * 749 * Note that this function is designed to be called by the state 750 * manager thread. For this reason, it cannot flush the dirty data, 751 * since that could deadlock in case of a state recovery error. 752 * 753 * Returns zero on success, or a negative errno value. 754 */ 755 int nfs_client_return_marked_delegations(struct nfs_client *clp) 756 { 757 int err = nfs_client_for_each_server( 758 clp, nfs_server_return_marked_delegations, NULL); 759 if (err) 760 return err; 761 /* If a return was delayed, sleep to prevent hard looping */ 762 if (nfs_client_clear_delayed_delegations(clp)) 763 ssleep(1); 764 return 0; 765 } 766 767 /** 768 * nfs_inode_evict_delegation - return delegation, don't reclaim opens 769 * @inode: inode to process 770 * 771 * Does not protect against delegation reclaims, therefore really only safe 772 * to be called from nfs4_clear_inode(). Guaranteed to always free 773 * the delegation structure. 774 */ 775 void nfs_inode_evict_delegation(struct inode *inode) 776 { 777 struct nfs_delegation *delegation; 778 779 delegation = nfs_inode_detach_delegation(inode); 780 if (delegation != NULL) { 781 set_bit(NFS_DELEGATION_RETURNING, &delegation->flags); 782 set_bit(NFS_DELEGATION_INODE_FREEING, &delegation->flags); 783 nfs_do_return_delegation(inode, delegation, 1); 784 nfs_free_delegation(NFS_SERVER(inode), delegation); 785 } 786 } 787 788 /** 789 * nfs4_inode_return_delegation - synchronously return a delegation 790 * @inode: inode to process 791 * 792 * This routine will always flush any dirty data to disk on the 793 * assumption that if we need to return the delegation, then 794 * we should stop caching. 795 * 796 * Returns zero on success, or a negative errno value. 797 */ 798 int nfs4_inode_return_delegation(struct inode *inode) 799 { 800 struct nfs_inode *nfsi = NFS_I(inode); 801 struct nfs_delegation *delegation; 802 803 delegation = nfs_start_delegation_return(nfsi); 804 if (delegation != NULL) { 805 /* Synchronous recall of any application leases */ 806 break_lease(inode, O_WRONLY | O_RDWR); 807 if (S_ISREG(inode->i_mode)) 808 nfs_wb_all(inode); 809 return nfs_end_delegation_return(inode, delegation, 1); 810 } 811 return 0; 812 } 813 814 /** 815 * nfs4_inode_set_return_delegation_on_close - asynchronously return a delegation 816 * @inode: inode to process 817 * 818 * This routine is called to request that the delegation be returned as soon 819 * as the file is closed. If the file is already closed, the delegation is 820 * immediately returned. 821 */ 822 void nfs4_inode_set_return_delegation_on_close(struct inode *inode) 823 { 824 struct nfs_delegation *delegation; 825 struct nfs_delegation *ret = NULL; 826 827 if (!inode) 828 return; 829 rcu_read_lock(); 830 delegation = nfs4_get_valid_delegation(inode); 831 if (!delegation) 832 goto out; 833 spin_lock(&delegation->lock); 834 if (!delegation->inode) 835 goto out_unlock; 836 if (list_empty(&NFS_I(inode)->open_files) && 837 !test_and_set_bit(NFS_DELEGATION_RETURNING, &delegation->flags)) { 838 /* Refcount matched in nfs_end_delegation_return() */ 839 ret = nfs_get_delegation(delegation); 840 } else 841 set_bit(NFS_DELEGATION_RETURN_IF_CLOSED, &delegation->flags); 842 out_unlock: 843 spin_unlock(&delegation->lock); 844 if (ret) 845 nfs_clear_verifier_delegated(inode); 846 out: 847 rcu_read_unlock(); 848 nfs_end_delegation_return(inode, ret, 0); 849 } 850 851 /** 852 * nfs4_inode_return_delegation_on_close - asynchronously return a delegation 853 * @inode: inode to process 854 * 855 * This routine is called on file close in order to determine if the 856 * inode delegation needs to be returned immediately. 857 */ 858 void nfs4_inode_return_delegation_on_close(struct inode *inode) 859 { 860 struct nfs_delegation *delegation; 861 struct nfs_delegation *ret = NULL; 862 863 if (!inode) 864 return; 865 rcu_read_lock(); 866 delegation = nfs4_get_valid_delegation(inode); 867 if (!delegation) 868 goto out; 869 if (test_bit(NFS_DELEGATION_RETURN_IF_CLOSED, &delegation->flags) || 870 atomic_long_read(&NFS_SERVER(inode)->nr_active_delegations) >= 871 nfs_delegation_watermark) { 872 spin_lock(&delegation->lock); 873 if (delegation->inode && 874 list_empty(&NFS_I(inode)->open_files) && 875 !test_and_set_bit(NFS_DELEGATION_RETURNING, &delegation->flags)) { 876 clear_bit(NFS_DELEGATION_RETURN_IF_CLOSED, &delegation->flags); 877 /* Refcount matched in nfs_end_delegation_return() */ 878 ret = nfs_get_delegation(delegation); 879 } 880 spin_unlock(&delegation->lock); 881 if (ret) 882 nfs_clear_verifier_delegated(inode); 883 } 884 out: 885 rcu_read_unlock(); 886 nfs_end_delegation_return(inode, ret, 0); 887 } 888 889 /** 890 * nfs4_inode_make_writeable 891 * @inode: pointer to inode 892 * 893 * Make the inode writeable by returning the delegation if necessary 894 * 895 * Returns zero on success, or a negative errno value. 896 */ 897 int nfs4_inode_make_writeable(struct inode *inode) 898 { 899 struct nfs_delegation *delegation; 900 901 rcu_read_lock(); 902 delegation = nfs4_get_valid_delegation(inode); 903 if (delegation == NULL || 904 (nfs4_has_session(NFS_SERVER(inode)->nfs_client) && 905 (delegation->type & FMODE_WRITE))) { 906 rcu_read_unlock(); 907 return 0; 908 } 909 rcu_read_unlock(); 910 return nfs4_inode_return_delegation(inode); 911 } 912 913 static void 914 nfs_mark_return_if_closed_delegation(struct nfs_server *server, 915 struct nfs_delegation *delegation) 916 { 917 struct inode *inode; 918 919 if (test_bit(NFS_DELEGATION_RETURN, &delegation->flags) || 920 test_bit(NFS_DELEGATION_RETURN_IF_CLOSED, &delegation->flags)) 921 return; 922 spin_lock(&delegation->lock); 923 inode = delegation->inode; 924 if (!inode) 925 goto out; 926 if (list_empty(&NFS_I(inode)->open_files)) 927 nfs_mark_return_delegation(server, delegation); 928 else 929 set_bit(NFS_DELEGATION_RETURN_IF_CLOSED, &delegation->flags); 930 out: 931 spin_unlock(&delegation->lock); 932 } 933 934 static bool nfs_server_mark_return_all_delegations(struct nfs_server *server) 935 { 936 struct nfs_delegation *delegation; 937 bool ret = false; 938 939 list_for_each_entry_rcu(delegation, &server->delegations, super_list) { 940 nfs_mark_return_delegation(server, delegation); 941 ret = true; 942 } 943 return ret; 944 } 945 946 static void nfs_client_mark_return_all_delegations(struct nfs_client *clp) 947 { 948 struct nfs_server *server; 949 950 rcu_read_lock(); 951 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) 952 nfs_server_mark_return_all_delegations(server); 953 rcu_read_unlock(); 954 } 955 956 static void nfs_delegation_run_state_manager(struct nfs_client *clp) 957 { 958 if (test_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state)) 959 nfs4_schedule_state_manager(clp); 960 } 961 962 /** 963 * nfs_expire_all_delegations 964 * @clp: client to process 965 * 966 */ 967 void nfs_expire_all_delegations(struct nfs_client *clp) 968 { 969 nfs_client_mark_return_all_delegations(clp); 970 nfs_delegation_run_state_manager(clp); 971 } 972 973 /** 974 * nfs_server_return_all_delegations - return delegations for one superblock 975 * @server: pointer to nfs_server to process 976 * 977 */ 978 void nfs_server_return_all_delegations(struct nfs_server *server) 979 { 980 struct nfs_client *clp = server->nfs_client; 981 bool need_wait; 982 983 if (clp == NULL) 984 return; 985 986 rcu_read_lock(); 987 need_wait = nfs_server_mark_return_all_delegations(server); 988 rcu_read_unlock(); 989 990 if (need_wait) { 991 nfs4_schedule_state_manager(clp); 992 nfs4_wait_clnt_recover(clp); 993 } 994 } 995 996 static void nfs_mark_return_unused_delegation_types(struct nfs_server *server, 997 fmode_t flags) 998 { 999 struct nfs_delegation *delegation; 1000 1001 list_for_each_entry_rcu(delegation, &server->delegations, super_list) { 1002 if ((delegation->type == (FMODE_READ|FMODE_WRITE)) && !(flags & FMODE_WRITE)) 1003 continue; 1004 if (delegation->type & flags) 1005 nfs_mark_return_if_closed_delegation(server, delegation); 1006 } 1007 } 1008 1009 static void nfs_client_mark_return_unused_delegation_types(struct nfs_client *clp, 1010 fmode_t flags) 1011 { 1012 struct nfs_server *server; 1013 1014 rcu_read_lock(); 1015 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) 1016 nfs_mark_return_unused_delegation_types(server, flags); 1017 rcu_read_unlock(); 1018 } 1019 1020 static void nfs_revoke_delegation(struct inode *inode, 1021 const nfs4_stateid *stateid) 1022 { 1023 struct nfs_delegation *delegation; 1024 nfs4_stateid tmp; 1025 bool ret = false; 1026 1027 rcu_read_lock(); 1028 delegation = rcu_dereference(NFS_I(inode)->delegation); 1029 if (delegation == NULL) 1030 goto out; 1031 if (stateid == NULL) { 1032 nfs4_stateid_copy(&tmp, &delegation->stateid); 1033 stateid = &tmp; 1034 } else { 1035 if (!nfs4_stateid_match_other(stateid, &delegation->stateid)) 1036 goto out; 1037 spin_lock(&delegation->lock); 1038 if (stateid->seqid) { 1039 if (nfs4_stateid_is_newer(&delegation->stateid, stateid)) { 1040 spin_unlock(&delegation->lock); 1041 goto out; 1042 } 1043 delegation->stateid.seqid = stateid->seqid; 1044 } 1045 spin_unlock(&delegation->lock); 1046 } 1047 nfs_mark_delegation_revoked(NFS_SERVER(inode), delegation); 1048 ret = true; 1049 out: 1050 rcu_read_unlock(); 1051 if (ret) 1052 nfs_inode_find_state_and_recover(inode, stateid); 1053 } 1054 1055 void nfs_delegation_mark_returned(struct inode *inode, 1056 const nfs4_stateid *stateid) 1057 { 1058 struct nfs_delegation *delegation; 1059 1060 if (!inode) 1061 return; 1062 1063 rcu_read_lock(); 1064 delegation = rcu_dereference(NFS_I(inode)->delegation); 1065 if (!delegation) 1066 goto out_rcu_unlock; 1067 1068 spin_lock(&delegation->lock); 1069 if (!nfs4_stateid_match_other(stateid, &delegation->stateid)) 1070 goto out_spin_unlock; 1071 if (stateid->seqid) { 1072 /* If delegation->stateid is newer, dont mark as returned */ 1073 if (nfs4_stateid_is_newer(&delegation->stateid, stateid)) 1074 goto out_clear_returning; 1075 if (delegation->stateid.seqid != stateid->seqid) 1076 delegation->stateid.seqid = stateid->seqid; 1077 } 1078 1079 nfs_mark_delegation_revoked(NFS_SERVER(inode), delegation); 1080 clear_bit(NFS_DELEGATION_RETURNING, &delegation->flags); 1081 spin_unlock(&delegation->lock); 1082 if (nfs_detach_delegation(NFS_I(inode), delegation, NFS_SERVER(inode))) 1083 nfs_put_delegation(delegation); 1084 goto out_rcu_unlock; 1085 1086 out_clear_returning: 1087 clear_bit(NFS_DELEGATION_RETURNING, &delegation->flags); 1088 out_spin_unlock: 1089 spin_unlock(&delegation->lock); 1090 out_rcu_unlock: 1091 rcu_read_unlock(); 1092 1093 nfs_inode_find_state_and_recover(inode, stateid); 1094 } 1095 1096 /** 1097 * nfs_remove_bad_delegation - handle delegations that are unusable 1098 * @inode: inode to process 1099 * @stateid: the delegation's stateid 1100 * 1101 * If the server ACK-ed our FREE_STATEID then clean 1102 * up the delegation, else mark and keep the revoked state. 1103 */ 1104 void nfs_remove_bad_delegation(struct inode *inode, 1105 const nfs4_stateid *stateid) 1106 { 1107 if (stateid && stateid->type == NFS4_FREED_STATEID_TYPE) 1108 nfs_delegation_mark_returned(inode, stateid); 1109 else 1110 nfs_revoke_delegation(inode, stateid); 1111 } 1112 EXPORT_SYMBOL_GPL(nfs_remove_bad_delegation); 1113 1114 /** 1115 * nfs_expire_unused_delegation_types 1116 * @clp: client to process 1117 * @flags: delegation types to expire 1118 * 1119 */ 1120 void nfs_expire_unused_delegation_types(struct nfs_client *clp, fmode_t flags) 1121 { 1122 nfs_client_mark_return_unused_delegation_types(clp, flags); 1123 nfs_delegation_run_state_manager(clp); 1124 } 1125 1126 static void nfs_mark_return_unreferenced_delegations(struct nfs_server *server) 1127 { 1128 struct nfs_delegation *delegation; 1129 1130 list_for_each_entry_rcu(delegation, &server->delegations, super_list) { 1131 if (test_and_clear_bit(NFS_DELEGATION_REFERENCED, &delegation->flags)) 1132 continue; 1133 nfs_mark_return_if_closed_delegation(server, delegation); 1134 } 1135 } 1136 1137 /** 1138 * nfs_expire_unreferenced_delegations - Eliminate unused delegations 1139 * @clp: nfs_client to process 1140 * 1141 */ 1142 void nfs_expire_unreferenced_delegations(struct nfs_client *clp) 1143 { 1144 struct nfs_server *server; 1145 1146 rcu_read_lock(); 1147 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) 1148 nfs_mark_return_unreferenced_delegations(server); 1149 rcu_read_unlock(); 1150 1151 nfs_delegation_run_state_manager(clp); 1152 } 1153 1154 /** 1155 * nfs_async_inode_return_delegation - asynchronously return a delegation 1156 * @inode: inode to process 1157 * @stateid: state ID information 1158 * 1159 * Returns zero on success, or a negative errno value. 1160 */ 1161 int nfs_async_inode_return_delegation(struct inode *inode, 1162 const nfs4_stateid *stateid) 1163 { 1164 struct nfs_server *server = NFS_SERVER(inode); 1165 struct nfs_client *clp = server->nfs_client; 1166 struct nfs_delegation *delegation; 1167 1168 rcu_read_lock(); 1169 delegation = nfs4_get_valid_delegation(inode); 1170 if (delegation == NULL) 1171 goto out_enoent; 1172 if (stateid != NULL && 1173 !clp->cl_mvops->match_stateid(&delegation->stateid, stateid)) 1174 goto out_enoent; 1175 nfs_mark_return_delegation(server, delegation); 1176 rcu_read_unlock(); 1177 1178 /* If there are any application leases or delegations, recall them */ 1179 break_lease(inode, O_WRONLY | O_RDWR | O_NONBLOCK); 1180 1181 nfs_delegation_run_state_manager(clp); 1182 return 0; 1183 out_enoent: 1184 rcu_read_unlock(); 1185 return -ENOENT; 1186 } 1187 1188 static struct inode * 1189 nfs_delegation_find_inode_server(struct nfs_server *server, 1190 const struct nfs_fh *fhandle) 1191 { 1192 struct hlist_head *head = nfs_delegation_hash(server, fhandle); 1193 struct nfs_delegation *delegation; 1194 struct super_block *freeme = NULL; 1195 struct inode *res = NULL; 1196 1197 hlist_for_each_entry_rcu(delegation, head, hash) { 1198 spin_lock(&delegation->lock); 1199 if (delegation->inode != NULL && 1200 !test_bit(NFS_DELEGATION_REVOKED, &delegation->flags) && 1201 nfs_compare_fh(fhandle, &NFS_I(delegation->inode)->fh) == 0) { 1202 if (nfs_sb_active(server->super)) { 1203 freeme = server->super; 1204 res = igrab(delegation->inode); 1205 } 1206 spin_unlock(&delegation->lock); 1207 if (res != NULL) 1208 return res; 1209 if (freeme) { 1210 rcu_read_unlock(); 1211 nfs_sb_deactive(freeme); 1212 rcu_read_lock(); 1213 } 1214 return ERR_PTR(-EAGAIN); 1215 } 1216 spin_unlock(&delegation->lock); 1217 } 1218 return ERR_PTR(-ENOENT); 1219 } 1220 1221 /** 1222 * nfs_delegation_find_inode - retrieve the inode associated with a delegation 1223 * @clp: client state handle 1224 * @fhandle: filehandle from a delegation recall 1225 * 1226 * Returns pointer to inode matching "fhandle," or NULL if a matching inode 1227 * cannot be found. 1228 */ 1229 struct inode *nfs_delegation_find_inode(struct nfs_client *clp, 1230 const struct nfs_fh *fhandle) 1231 { 1232 struct nfs_server *server; 1233 struct inode *res; 1234 1235 rcu_read_lock(); 1236 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) { 1237 res = nfs_delegation_find_inode_server(server, fhandle); 1238 if (res != ERR_PTR(-ENOENT)) { 1239 rcu_read_unlock(); 1240 return res; 1241 } 1242 } 1243 rcu_read_unlock(); 1244 return ERR_PTR(-ENOENT); 1245 } 1246 1247 static void nfs_delegation_mark_reclaim_server(struct nfs_server *server) 1248 { 1249 struct nfs_delegation *delegation; 1250 1251 list_for_each_entry_rcu(delegation, &server->delegations, super_list) { 1252 /* 1253 * If the delegation may have been admin revoked, then we 1254 * cannot reclaim it. 1255 */ 1256 if (test_bit(NFS_DELEGATION_TEST_EXPIRED, &delegation->flags)) 1257 continue; 1258 set_bit(NFS_DELEGATION_NEED_RECLAIM, &delegation->flags); 1259 } 1260 } 1261 1262 /** 1263 * nfs_delegation_mark_reclaim - mark all delegations as needing to be reclaimed 1264 * @clp: nfs_client to process 1265 * 1266 */ 1267 void nfs_delegation_mark_reclaim(struct nfs_client *clp) 1268 { 1269 struct nfs_server *server; 1270 1271 rcu_read_lock(); 1272 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) 1273 nfs_delegation_mark_reclaim_server(server); 1274 rcu_read_unlock(); 1275 } 1276 1277 static int nfs_server_reap_unclaimed_delegations(struct nfs_server *server, 1278 void __always_unused *data) 1279 { 1280 struct nfs_delegation *delegation; 1281 struct inode *inode; 1282 restart: 1283 rcu_read_lock(); 1284 list_for_each_entry_rcu(delegation, &server->delegations, super_list) { 1285 if (test_bit(NFS_DELEGATION_INODE_FREEING, 1286 &delegation->flags) || 1287 test_bit(NFS_DELEGATION_RETURNING, 1288 &delegation->flags) || 1289 test_bit(NFS_DELEGATION_NEED_RECLAIM, 1290 &delegation->flags) == 0) 1291 continue; 1292 inode = nfs_delegation_grab_inode(delegation); 1293 if (inode == NULL) 1294 continue; 1295 delegation = nfs_start_delegation_return_locked(NFS_I(inode)); 1296 rcu_read_unlock(); 1297 if (delegation != NULL) { 1298 if (nfs_detach_delegation(NFS_I(inode), delegation, 1299 server) != NULL) 1300 nfs_free_delegation(server, delegation); 1301 /* Match nfs_start_delegation_return_locked */ 1302 nfs_put_delegation(delegation); 1303 } 1304 iput(inode); 1305 cond_resched(); 1306 goto restart; 1307 } 1308 rcu_read_unlock(); 1309 return 0; 1310 } 1311 1312 /** 1313 * nfs_delegation_reap_unclaimed - reap unclaimed delegations after reboot recovery is done 1314 * @clp: nfs_client to process 1315 * 1316 */ 1317 void nfs_delegation_reap_unclaimed(struct nfs_client *clp) 1318 { 1319 nfs_client_for_each_server(clp, nfs_server_reap_unclaimed_delegations, 1320 NULL); 1321 } 1322 1323 static inline bool nfs4_server_rebooted(const struct nfs_client *clp) 1324 { 1325 return (clp->cl_state & (BIT(NFS4CLNT_CHECK_LEASE) | 1326 BIT(NFS4CLNT_LEASE_EXPIRED) | 1327 BIT(NFS4CLNT_SESSION_RESET))) != 0; 1328 } 1329 1330 static void nfs_mark_test_expired_delegation(struct nfs_server *server, 1331 struct nfs_delegation *delegation) 1332 { 1333 if (delegation->stateid.type == NFS4_INVALID_STATEID_TYPE) 1334 return; 1335 clear_bit(NFS_DELEGATION_NEED_RECLAIM, &delegation->flags); 1336 set_bit(NFS_DELEGATION_TEST_EXPIRED, &delegation->flags); 1337 set_bit(NFS4SERV_DELEGATION_EXPIRED, &server->delegation_flags); 1338 set_bit(NFS4CLNT_DELEGATION_EXPIRED, &server->nfs_client->cl_state); 1339 } 1340 1341 static void nfs_inode_mark_test_expired_delegation(struct nfs_server *server, 1342 struct inode *inode) 1343 { 1344 struct nfs_delegation *delegation; 1345 1346 rcu_read_lock(); 1347 delegation = rcu_dereference(NFS_I(inode)->delegation); 1348 if (delegation) 1349 nfs_mark_test_expired_delegation(server, delegation); 1350 rcu_read_unlock(); 1351 1352 } 1353 1354 static void nfs_delegation_mark_test_expired_server(struct nfs_server *server) 1355 { 1356 struct nfs_delegation *delegation; 1357 1358 list_for_each_entry_rcu(delegation, &server->delegations, super_list) 1359 nfs_mark_test_expired_delegation(server, delegation); 1360 } 1361 1362 /** 1363 * nfs_mark_test_expired_all_delegations - mark all delegations for testing 1364 * @clp: nfs_client to process 1365 * 1366 * Iterates through all the delegations associated with this server and 1367 * marks them as needing to be checked for validity. 1368 */ 1369 void nfs_mark_test_expired_all_delegations(struct nfs_client *clp) 1370 { 1371 struct nfs_server *server; 1372 1373 rcu_read_lock(); 1374 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) 1375 nfs_delegation_mark_test_expired_server(server); 1376 rcu_read_unlock(); 1377 } 1378 1379 /** 1380 * nfs_test_expired_all_delegations - test all delegations for a client 1381 * @clp: nfs_client to process 1382 * 1383 * Helper for handling "recallable state revoked" status from server. 1384 */ 1385 void nfs_test_expired_all_delegations(struct nfs_client *clp) 1386 { 1387 nfs_mark_test_expired_all_delegations(clp); 1388 nfs4_schedule_state_manager(clp); 1389 } 1390 1391 static void 1392 nfs_delegation_test_free_expired(struct inode *inode, 1393 nfs4_stateid *stateid, 1394 const struct cred *cred) 1395 { 1396 struct nfs_server *server = NFS_SERVER(inode); 1397 const struct nfs4_minor_version_ops *ops = server->nfs_client->cl_mvops; 1398 int status; 1399 1400 if (!cred) 1401 return; 1402 status = ops->test_and_free_expired(server, stateid, cred); 1403 if (status == -NFS4ERR_EXPIRED || status == -NFS4ERR_BAD_STATEID) 1404 nfs_remove_bad_delegation(inode, stateid); 1405 } 1406 1407 static int nfs_server_reap_expired_delegations(struct nfs_server *server, 1408 void __always_unused *data) 1409 { 1410 struct nfs_delegation *delegation; 1411 struct inode *inode; 1412 const struct cred *cred; 1413 nfs4_stateid stateid; 1414 unsigned long gen = ++server->delegation_gen; 1415 1416 if (!test_and_clear_bit(NFS4SERV_DELEGATION_EXPIRED, 1417 &server->delegation_flags)) 1418 return 0; 1419 restart: 1420 rcu_read_lock(); 1421 list_for_each_entry_rcu(delegation, &server->delegations, super_list) { 1422 if (test_bit(NFS_DELEGATION_INODE_FREEING, 1423 &delegation->flags) || 1424 test_bit(NFS_DELEGATION_RETURNING, 1425 &delegation->flags) || 1426 test_bit(NFS_DELEGATION_TEST_EXPIRED, 1427 &delegation->flags) == 0 || 1428 delegation->test_gen == gen) 1429 continue; 1430 inode = nfs_delegation_grab_inode(delegation); 1431 if (inode == NULL) 1432 continue; 1433 spin_lock(&delegation->lock); 1434 cred = get_cred_rcu(delegation->cred); 1435 nfs4_stateid_copy(&stateid, &delegation->stateid); 1436 spin_unlock(&delegation->lock); 1437 delegation->test_gen = gen; 1438 clear_bit(NFS_DELEGATION_TEST_EXPIRED, &delegation->flags); 1439 rcu_read_unlock(); 1440 nfs_delegation_test_free_expired(inode, &stateid, cred); 1441 put_cred(cred); 1442 if (!nfs4_server_rebooted(server->nfs_client)) { 1443 iput(inode); 1444 cond_resched(); 1445 goto restart; 1446 } 1447 nfs_inode_mark_test_expired_delegation(server,inode); 1448 set_bit(NFS4SERV_DELEGATION_EXPIRED, &server->delegation_flags); 1449 set_bit(NFS4CLNT_DELEGATION_EXPIRED, 1450 &server->nfs_client->cl_state); 1451 iput(inode); 1452 return -EAGAIN; 1453 } 1454 rcu_read_unlock(); 1455 return 0; 1456 } 1457 1458 /** 1459 * nfs_reap_expired_delegations - reap expired delegations 1460 * @clp: nfs_client to process 1461 * 1462 * Iterates through all the delegations associated with this server and 1463 * checks if they have may have been revoked. This function is usually 1464 * expected to be called in cases where the server may have lost its 1465 * lease. 1466 */ 1467 void nfs_reap_expired_delegations(struct nfs_client *clp) 1468 { 1469 nfs_client_for_each_server(clp, nfs_server_reap_expired_delegations, 1470 NULL); 1471 } 1472 1473 void nfs_inode_find_delegation_state_and_recover(struct inode *inode, 1474 const nfs4_stateid *stateid) 1475 { 1476 struct nfs_client *clp = NFS_SERVER(inode)->nfs_client; 1477 struct nfs_delegation *delegation; 1478 bool found = false; 1479 1480 rcu_read_lock(); 1481 delegation = rcu_dereference(NFS_I(inode)->delegation); 1482 if (delegation && 1483 nfs4_stateid_match_or_older(&delegation->stateid, stateid) && 1484 !test_bit(NFS_DELEGATION_REVOKED, &delegation->flags)) { 1485 nfs_mark_test_expired_delegation(NFS_SERVER(inode), delegation); 1486 found = true; 1487 } 1488 rcu_read_unlock(); 1489 if (found) 1490 nfs4_schedule_state_manager(clp); 1491 } 1492 1493 /** 1494 * nfs_delegations_present - check for existence of delegations 1495 * @clp: client state handle 1496 * 1497 * Returns one if there are any nfs_delegation structures attached 1498 * to this nfs_client. 1499 */ 1500 int nfs_delegations_present(struct nfs_client *clp) 1501 { 1502 struct nfs_server *server; 1503 int ret = 0; 1504 1505 rcu_read_lock(); 1506 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) 1507 if (!list_empty(&server->delegations)) { 1508 ret = 1; 1509 break; 1510 } 1511 rcu_read_unlock(); 1512 return ret; 1513 } 1514 1515 /** 1516 * nfs4_refresh_delegation_stateid - Update delegation stateid seqid 1517 * @dst: stateid to refresh 1518 * @inode: inode to check 1519 * 1520 * Returns "true" and updates "dst->seqid" * if inode had a delegation 1521 * that matches our delegation stateid. Otherwise "false" is returned. 1522 */ 1523 bool nfs4_refresh_delegation_stateid(nfs4_stateid *dst, struct inode *inode) 1524 { 1525 struct nfs_delegation *delegation; 1526 bool ret = false; 1527 if (!inode) 1528 goto out; 1529 1530 rcu_read_lock(); 1531 delegation = rcu_dereference(NFS_I(inode)->delegation); 1532 if (delegation != NULL && 1533 nfs4_stateid_match_other(dst, &delegation->stateid) && 1534 nfs4_stateid_is_newer(&delegation->stateid, dst) && 1535 !test_bit(NFS_DELEGATION_REVOKED, &delegation->flags)) { 1536 dst->seqid = delegation->stateid.seqid; 1537 ret = true; 1538 } 1539 rcu_read_unlock(); 1540 out: 1541 return ret; 1542 } 1543 1544 /** 1545 * nfs4_copy_delegation_stateid - Copy inode's state ID information 1546 * @inode: inode to check 1547 * @flags: delegation type requirement 1548 * @dst: stateid data structure to fill in 1549 * @cred: optional argument to retrieve credential 1550 * 1551 * Returns "true" and fills in "dst->data" * if inode had a delegation, 1552 * otherwise "false" is returned. 1553 */ 1554 bool nfs4_copy_delegation_stateid(struct inode *inode, fmode_t flags, 1555 nfs4_stateid *dst, const struct cred **cred) 1556 { 1557 struct nfs_inode *nfsi = NFS_I(inode); 1558 struct nfs_delegation *delegation; 1559 bool ret = false; 1560 1561 flags &= FMODE_READ|FMODE_WRITE; 1562 rcu_read_lock(); 1563 delegation = rcu_dereference(nfsi->delegation); 1564 if (!delegation) 1565 goto out; 1566 spin_lock(&delegation->lock); 1567 ret = nfs4_is_valid_delegation(delegation, flags); 1568 if (ret) { 1569 nfs4_stateid_copy(dst, &delegation->stateid); 1570 nfs_mark_delegation_referenced(delegation); 1571 if (cred) 1572 *cred = get_cred(delegation->cred); 1573 } 1574 spin_unlock(&delegation->lock); 1575 out: 1576 rcu_read_unlock(); 1577 return ret; 1578 } 1579 1580 /** 1581 * nfs4_delegation_flush_on_close - Check if we must flush file on close 1582 * @inode: inode to check 1583 * 1584 * This function checks the number of outstanding writes to the file 1585 * against the delegation 'space_limit' field to see if 1586 * the spec requires us to flush the file on close. 1587 */ 1588 bool nfs4_delegation_flush_on_close(const struct inode *inode) 1589 { 1590 struct nfs_inode *nfsi = NFS_I(inode); 1591 struct nfs_delegation *delegation; 1592 bool ret = true; 1593 1594 rcu_read_lock(); 1595 delegation = rcu_dereference(nfsi->delegation); 1596 if (delegation == NULL || !(delegation->type & FMODE_WRITE)) 1597 goto out; 1598 if (atomic_long_read(&nfsi->nrequests) < delegation->pagemod_limit) 1599 ret = false; 1600 out: 1601 rcu_read_unlock(); 1602 return ret; 1603 } 1604 1605 int nfs4_delegation_hash_alloc(struct nfs_server *server) 1606 { 1607 int delegation_buckets, i; 1608 1609 delegation_buckets = roundup_pow_of_two(nfs_delegation_watermark / 16); 1610 server->delegation_hash_mask = delegation_buckets - 1; 1611 server->delegation_hash_table = kmalloc_array(delegation_buckets, 1612 sizeof(*server->delegation_hash_table), GFP_KERNEL); 1613 if (!server->delegation_hash_table) 1614 return -ENOMEM; 1615 for (i = 0; i < delegation_buckets; i++) 1616 INIT_HLIST_HEAD(&server->delegation_hash_table[i]); 1617 return 0; 1618 } 1619