lh | 9ed821d | 2023-04-07 01:36:19 -0700 | [diff] [blame] | 1 | /* |
| 2 | * linux/fs/nfs/delegation.c |
| 3 | * |
| 4 | * Copyright (C) 2004 Trond Myklebust |
| 5 | * |
| 6 | * NFS file delegation management |
| 7 | * |
| 8 | */ |
| 9 | #include <linux/completion.h> |
| 10 | #include <linux/kthread.h> |
| 11 | #include <linux/module.h> |
| 12 | #include <linux/sched.h> |
| 13 | #include <linux/slab.h> |
| 14 | #include <linux/spinlock.h> |
| 15 | |
| 16 | #include <linux/nfs4.h> |
| 17 | #include <linux/nfs_fs.h> |
| 18 | #include <linux/nfs_xdr.h> |
| 19 | |
| 20 | #include "nfs4_fs.h" |
| 21 | #include "delegation.h" |
| 22 | #include "internal.h" |
| 23 | |
| 24 | static void nfs_free_delegation(struct nfs_delegation *delegation) |
| 25 | { |
| 26 | if (delegation->cred) { |
| 27 | put_rpccred(delegation->cred); |
| 28 | delegation->cred = NULL; |
| 29 | } |
| 30 | kfree_rcu(delegation, rcu); |
| 31 | } |
| 32 | |
| 33 | /** |
| 34 | * nfs_mark_delegation_referenced - set delegation's REFERENCED flag |
| 35 | * @delegation: delegation to process |
| 36 | * |
| 37 | */ |
| 38 | void nfs_mark_delegation_referenced(struct nfs_delegation *delegation) |
| 39 | { |
| 40 | set_bit(NFS_DELEGATION_REFERENCED, &delegation->flags); |
| 41 | } |
| 42 | |
| 43 | /** |
| 44 | * nfs_have_delegation - check if inode has a delegation |
| 45 | * @inode: inode to check |
| 46 | * @flags: delegation types to check for |
| 47 | * |
| 48 | * Returns one if inode has the indicated delegation, otherwise zero. |
| 49 | */ |
| 50 | int nfs_have_delegation(struct inode *inode, fmode_t flags) |
| 51 | { |
| 52 | struct nfs_delegation *delegation; |
| 53 | int ret = 0; |
| 54 | |
| 55 | flags &= FMODE_READ|FMODE_WRITE; |
| 56 | rcu_read_lock(); |
| 57 | delegation = rcu_dereference(NFS_I(inode)->delegation); |
| 58 | if (delegation != NULL && (delegation->type & flags) == flags) { |
| 59 | nfs_mark_delegation_referenced(delegation); |
| 60 | ret = 1; |
| 61 | } |
| 62 | rcu_read_unlock(); |
| 63 | return ret; |
| 64 | } |
| 65 | |
| 66 | static int nfs_delegation_claim_locks(struct nfs_open_context *ctx, struct nfs4_state *state) |
| 67 | { |
| 68 | struct inode *inode = state->inode; |
| 69 | struct file_lock *fl; |
| 70 | int status = 0; |
| 71 | |
| 72 | if (inode->i_flock == NULL) |
| 73 | goto out; |
| 74 | |
| 75 | /* Protect inode->i_flock using the file locks lock */ |
| 76 | lock_flocks(); |
| 77 | for (fl = inode->i_flock; fl != NULL; fl = fl->fl_next) { |
| 78 | if (!(fl->fl_flags & (FL_POSIX|FL_FLOCK))) |
| 79 | continue; |
| 80 | if (nfs_file_open_context(fl->fl_file) != ctx) |
| 81 | continue; |
| 82 | unlock_flocks(); |
| 83 | status = nfs4_lock_delegation_recall(state, fl); |
| 84 | if (status < 0) |
| 85 | goto out; |
| 86 | lock_flocks(); |
| 87 | } |
| 88 | unlock_flocks(); |
| 89 | out: |
| 90 | return status; |
| 91 | } |
| 92 | |
| 93 | static int nfs_delegation_claim_opens(struct inode *inode, const nfs4_stateid *stateid) |
| 94 | { |
| 95 | struct nfs_inode *nfsi = NFS_I(inode); |
| 96 | struct nfs_open_context *ctx; |
| 97 | struct nfs4_state *state; |
| 98 | int err; |
| 99 | |
| 100 | again: |
| 101 | spin_lock(&inode->i_lock); |
| 102 | list_for_each_entry(ctx, &nfsi->open_files, list) { |
| 103 | state = ctx->state; |
| 104 | if (state == NULL) |
| 105 | continue; |
| 106 | if (!test_bit(NFS_DELEGATED_STATE, &state->flags)) |
| 107 | continue; |
| 108 | if (!nfs4_stateid_match(&state->stateid, stateid)) |
| 109 | continue; |
| 110 | get_nfs_open_context(ctx); |
| 111 | spin_unlock(&inode->i_lock); |
| 112 | err = nfs4_open_delegation_recall(ctx, state, stateid); |
| 113 | if (err >= 0) |
| 114 | err = nfs_delegation_claim_locks(ctx, state); |
| 115 | put_nfs_open_context(ctx); |
| 116 | if (err != 0) |
| 117 | return err; |
| 118 | goto again; |
| 119 | } |
| 120 | spin_unlock(&inode->i_lock); |
| 121 | return 0; |
| 122 | } |
| 123 | |
| 124 | /** |
| 125 | * nfs_inode_reclaim_delegation - process a delegation reclaim request |
| 126 | * @inode: inode to process |
| 127 | * @cred: credential to use for request |
| 128 | * @res: new delegation state from server |
| 129 | * |
| 130 | */ |
| 131 | void nfs_inode_reclaim_delegation(struct inode *inode, struct rpc_cred *cred, |
| 132 | struct nfs_openres *res) |
| 133 | { |
| 134 | struct nfs_delegation *delegation; |
| 135 | struct rpc_cred *oldcred = NULL; |
| 136 | |
| 137 | rcu_read_lock(); |
| 138 | delegation = rcu_dereference(NFS_I(inode)->delegation); |
| 139 | if (delegation != NULL) { |
| 140 | spin_lock(&delegation->lock); |
| 141 | if (delegation->inode != NULL) { |
| 142 | nfs4_stateid_copy(&delegation->stateid, &res->delegation); |
| 143 | delegation->type = res->delegation_type; |
| 144 | delegation->maxsize = res->maxsize; |
| 145 | oldcred = delegation->cred; |
| 146 | delegation->cred = get_rpccred(cred); |
| 147 | clear_bit(NFS_DELEGATION_NEED_RECLAIM, |
| 148 | &delegation->flags); |
| 149 | NFS_I(inode)->delegation_state = delegation->type; |
| 150 | spin_unlock(&delegation->lock); |
| 151 | rcu_read_unlock(); |
| 152 | put_rpccred(oldcred); |
| 153 | } else { |
| 154 | /* We appear to have raced with a delegation return. */ |
| 155 | spin_unlock(&delegation->lock); |
| 156 | rcu_read_unlock(); |
| 157 | nfs_inode_set_delegation(inode, cred, res); |
| 158 | } |
| 159 | } else { |
| 160 | rcu_read_unlock(); |
| 161 | } |
| 162 | } |
| 163 | |
| 164 | static int nfs_do_return_delegation(struct inode *inode, struct nfs_delegation *delegation, int issync) |
| 165 | { |
| 166 | int res = 0; |
| 167 | |
| 168 | res = nfs4_proc_delegreturn(inode, delegation->cred, &delegation->stateid, issync); |
| 169 | nfs_free_delegation(delegation); |
| 170 | return res; |
| 171 | } |
| 172 | |
| 173 | static struct inode *nfs_delegation_grab_inode(struct nfs_delegation *delegation) |
| 174 | { |
| 175 | struct inode *inode = NULL; |
| 176 | |
| 177 | spin_lock(&delegation->lock); |
| 178 | if (delegation->inode != NULL) |
| 179 | inode = igrab(delegation->inode); |
| 180 | spin_unlock(&delegation->lock); |
| 181 | return inode; |
| 182 | } |
| 183 | |
| 184 | static struct nfs_delegation * |
| 185 | nfs_detach_delegation_locked(struct nfs_inode *nfsi, |
| 186 | struct nfs_server *server) |
| 187 | { |
| 188 | struct nfs_delegation *delegation = |
| 189 | rcu_dereference_protected(nfsi->delegation, |
| 190 | lockdep_is_held(&server->nfs_client->cl_lock)); |
| 191 | |
| 192 | if (delegation == NULL) |
| 193 | goto nomatch; |
| 194 | |
| 195 | spin_lock(&delegation->lock); |
| 196 | list_del_rcu(&delegation->super_list); |
| 197 | delegation->inode = NULL; |
| 198 | nfsi->delegation_state = 0; |
| 199 | rcu_assign_pointer(nfsi->delegation, NULL); |
| 200 | spin_unlock(&delegation->lock); |
| 201 | return delegation; |
| 202 | nomatch: |
| 203 | return NULL; |
| 204 | } |
| 205 | |
| 206 | static struct nfs_delegation *nfs_detach_delegation(struct nfs_inode *nfsi, |
| 207 | struct nfs_server *server) |
| 208 | { |
| 209 | struct nfs_client *clp = server->nfs_client; |
| 210 | struct nfs_delegation *delegation; |
| 211 | |
| 212 | spin_lock(&clp->cl_lock); |
| 213 | delegation = nfs_detach_delegation_locked(nfsi, server); |
| 214 | spin_unlock(&clp->cl_lock); |
| 215 | return delegation; |
| 216 | } |
| 217 | |
| 218 | /** |
| 219 | * nfs_inode_set_delegation - set up a delegation on an inode |
| 220 | * @inode: inode to which delegation applies |
| 221 | * @cred: cred to use for subsequent delegation processing |
| 222 | * @res: new delegation state from server |
| 223 | * |
| 224 | * Returns zero on success, or a negative errno value. |
| 225 | */ |
| 226 | int nfs_inode_set_delegation(struct inode *inode, struct rpc_cred *cred, struct nfs_openres *res) |
| 227 | { |
| 228 | struct nfs_server *server = NFS_SERVER(inode); |
| 229 | struct nfs_client *clp = server->nfs_client; |
| 230 | struct nfs_inode *nfsi = NFS_I(inode); |
| 231 | struct nfs_delegation *delegation, *old_delegation; |
| 232 | struct nfs_delegation *freeme = NULL; |
| 233 | int status = 0; |
| 234 | |
| 235 | delegation = kmalloc(sizeof(*delegation), GFP_NOFS); |
| 236 | if (delegation == NULL) |
| 237 | return -ENOMEM; |
| 238 | nfs4_stateid_copy(&delegation->stateid, &res->delegation); |
| 239 | delegation->type = res->delegation_type; |
| 240 | delegation->maxsize = res->maxsize; |
| 241 | delegation->change_attr = inode->i_version; |
| 242 | delegation->cred = get_rpccred(cred); |
| 243 | delegation->inode = inode; |
| 244 | delegation->flags = 1<<NFS_DELEGATION_REFERENCED; |
| 245 | spin_lock_init(&delegation->lock); |
| 246 | |
| 247 | spin_lock(&clp->cl_lock); |
| 248 | old_delegation = rcu_dereference_protected(nfsi->delegation, |
| 249 | lockdep_is_held(&clp->cl_lock)); |
| 250 | if (old_delegation != NULL) { |
| 251 | if (nfs4_stateid_match(&delegation->stateid, |
| 252 | &old_delegation->stateid) && |
| 253 | delegation->type == old_delegation->type) { |
| 254 | goto out; |
| 255 | } |
| 256 | /* |
| 257 | * Deal with broken servers that hand out two |
| 258 | * delegations for the same file. |
| 259 | * Allow for upgrades to a WRITE delegation, but |
| 260 | * nothing else. |
| 261 | */ |
| 262 | dfprintk(FILE, "%s: server %s handed out " |
| 263 | "a duplicate delegation!\n", |
| 264 | __func__, clp->cl_hostname); |
| 265 | if (delegation->type == old_delegation->type || |
| 266 | !(delegation->type & FMODE_WRITE)) { |
| 267 | freeme = delegation; |
| 268 | delegation = NULL; |
| 269 | goto out; |
| 270 | } |
| 271 | freeme = nfs_detach_delegation_locked(nfsi, server); |
| 272 | } |
| 273 | list_add_rcu(&delegation->super_list, &server->delegations); |
| 274 | nfsi->delegation_state = delegation->type; |
| 275 | rcu_assign_pointer(nfsi->delegation, delegation); |
| 276 | delegation = NULL; |
| 277 | |
| 278 | /* Ensure we revalidate the attributes and page cache! */ |
| 279 | spin_lock(&inode->i_lock); |
| 280 | nfsi->cache_validity |= NFS_INO_REVAL_FORCED; |
| 281 | spin_unlock(&inode->i_lock); |
| 282 | |
| 283 | out: |
| 284 | spin_unlock(&clp->cl_lock); |
| 285 | if (delegation != NULL) |
| 286 | nfs_free_delegation(delegation); |
| 287 | if (freeme != NULL) |
| 288 | nfs_do_return_delegation(inode, freeme, 0); |
| 289 | return status; |
| 290 | } |
| 291 | |
| 292 | /* |
| 293 | * Basic procedure for returning a delegation to the server |
| 294 | */ |
| 295 | static int __nfs_inode_return_delegation(struct inode *inode, struct nfs_delegation *delegation, int issync) |
| 296 | { |
| 297 | struct nfs_inode *nfsi = NFS_I(inode); |
| 298 | int err; |
| 299 | |
| 300 | /* |
| 301 | * Guard against new delegated open/lock/unlock calls and against |
| 302 | * state recovery |
| 303 | */ |
| 304 | down_write(&nfsi->rwsem); |
| 305 | err = nfs_delegation_claim_opens(inode, &delegation->stateid); |
| 306 | up_write(&nfsi->rwsem); |
| 307 | if (err) |
| 308 | goto out; |
| 309 | |
| 310 | err = nfs_do_return_delegation(inode, delegation, issync); |
| 311 | out: |
| 312 | return err; |
| 313 | } |
| 314 | |
| 315 | /** |
| 316 | * nfs_client_return_marked_delegations - return previously marked delegations |
| 317 | * @clp: nfs_client to process |
| 318 | * |
| 319 | * Returns zero on success, or a negative errno value. |
| 320 | */ |
| 321 | int nfs_client_return_marked_delegations(struct nfs_client *clp) |
| 322 | { |
| 323 | struct nfs_delegation *delegation; |
| 324 | struct nfs_server *server; |
| 325 | struct inode *inode; |
| 326 | int err = 0; |
| 327 | |
| 328 | restart: |
| 329 | rcu_read_lock(); |
| 330 | list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) { |
| 331 | list_for_each_entry_rcu(delegation, &server->delegations, |
| 332 | super_list) { |
| 333 | if (!test_and_clear_bit(NFS_DELEGATION_RETURN, |
| 334 | &delegation->flags)) |
| 335 | continue; |
| 336 | inode = nfs_delegation_grab_inode(delegation); |
| 337 | if (inode == NULL) |
| 338 | continue; |
| 339 | delegation = nfs_detach_delegation(NFS_I(inode), |
| 340 | server); |
| 341 | rcu_read_unlock(); |
| 342 | |
| 343 | if (delegation != NULL) { |
| 344 | filemap_flush(inode->i_mapping); |
| 345 | err = __nfs_inode_return_delegation(inode, |
| 346 | delegation, 0); |
| 347 | } |
| 348 | iput(inode); |
| 349 | if (!err) |
| 350 | goto restart; |
| 351 | set_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state); |
| 352 | return err; |
| 353 | } |
| 354 | } |
| 355 | rcu_read_unlock(); |
| 356 | return 0; |
| 357 | } |
| 358 | |
| 359 | /** |
| 360 | * nfs_inode_return_delegation_noreclaim - return delegation, don't reclaim opens |
| 361 | * @inode: inode to process |
| 362 | * |
| 363 | * Does not protect against delegation reclaims, therefore really only safe |
| 364 | * to be called from nfs4_clear_inode(). |
| 365 | */ |
| 366 | void nfs_inode_return_delegation_noreclaim(struct inode *inode) |
| 367 | { |
| 368 | struct nfs_server *server = NFS_SERVER(inode); |
| 369 | struct nfs_inode *nfsi = NFS_I(inode); |
| 370 | struct nfs_delegation *delegation; |
| 371 | |
| 372 | if (rcu_access_pointer(nfsi->delegation) != NULL) { |
| 373 | delegation = nfs_detach_delegation(nfsi, server); |
| 374 | if (delegation != NULL) |
| 375 | nfs_do_return_delegation(inode, delegation, 0); |
| 376 | } |
| 377 | } |
| 378 | |
| 379 | /** |
| 380 | * nfs_inode_return_delegation - synchronously return a delegation |
| 381 | * @inode: inode to process |
| 382 | * |
| 383 | * Returns zero on success, or a negative errno value. |
| 384 | */ |
| 385 | int nfs_inode_return_delegation(struct inode *inode) |
| 386 | { |
| 387 | struct nfs_server *server = NFS_SERVER(inode); |
| 388 | struct nfs_inode *nfsi = NFS_I(inode); |
| 389 | struct nfs_delegation *delegation; |
| 390 | int err = 0; |
| 391 | |
| 392 | if (rcu_access_pointer(nfsi->delegation) != NULL) { |
| 393 | delegation = nfs_detach_delegation(nfsi, server); |
| 394 | if (delegation != NULL) { |
| 395 | nfs_wb_all(inode); |
| 396 | err = __nfs_inode_return_delegation(inode, delegation, 1); |
| 397 | } |
| 398 | } |
| 399 | return err; |
| 400 | } |
| 401 | |
| 402 | static void nfs_mark_return_delegation(struct nfs_server *server, |
| 403 | struct nfs_delegation *delegation) |
| 404 | { |
| 405 | set_bit(NFS_DELEGATION_RETURN, &delegation->flags); |
| 406 | set_bit(NFS4CLNT_DELEGRETURN, &server->nfs_client->cl_state); |
| 407 | } |
| 408 | |
| 409 | /** |
| 410 | * nfs_super_return_all_delegations - return delegations for one superblock |
| 411 | * @sb: sb to process |
| 412 | * |
| 413 | */ |
| 414 | void nfs_super_return_all_delegations(struct super_block *sb) |
| 415 | { |
| 416 | struct nfs_server *server = NFS_SB(sb); |
| 417 | struct nfs_client *clp = server->nfs_client; |
| 418 | struct nfs_delegation *delegation; |
| 419 | |
| 420 | if (clp == NULL) |
| 421 | return; |
| 422 | |
| 423 | rcu_read_lock(); |
| 424 | list_for_each_entry_rcu(delegation, &server->delegations, super_list) { |
| 425 | spin_lock(&delegation->lock); |
| 426 | set_bit(NFS_DELEGATION_RETURN, &delegation->flags); |
| 427 | spin_unlock(&delegation->lock); |
| 428 | } |
| 429 | rcu_read_unlock(); |
| 430 | |
| 431 | if (nfs_client_return_marked_delegations(clp) != 0) |
| 432 | nfs4_schedule_state_manager(clp); |
| 433 | } |
| 434 | |
| 435 | static void nfs_mark_return_all_delegation_types(struct nfs_server *server, |
| 436 | fmode_t flags) |
| 437 | { |
| 438 | struct nfs_delegation *delegation; |
| 439 | |
| 440 | list_for_each_entry_rcu(delegation, &server->delegations, super_list) { |
| 441 | if ((delegation->type == (FMODE_READ|FMODE_WRITE)) && !(flags & FMODE_WRITE)) |
| 442 | continue; |
| 443 | if (delegation->type & flags) |
| 444 | nfs_mark_return_delegation(server, delegation); |
| 445 | } |
| 446 | } |
| 447 | |
| 448 | static void nfs_client_mark_return_all_delegation_types(struct nfs_client *clp, |
| 449 | fmode_t flags) |
| 450 | { |
| 451 | struct nfs_server *server; |
| 452 | |
| 453 | rcu_read_lock(); |
| 454 | list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) |
| 455 | nfs_mark_return_all_delegation_types(server, flags); |
| 456 | rcu_read_unlock(); |
| 457 | } |
| 458 | |
| 459 | static void nfs_delegation_run_state_manager(struct nfs_client *clp) |
| 460 | { |
| 461 | if (test_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state)) |
| 462 | nfs4_schedule_state_manager(clp); |
| 463 | } |
| 464 | |
| 465 | void nfs_remove_bad_delegation(struct inode *inode) |
| 466 | { |
| 467 | struct nfs_delegation *delegation; |
| 468 | |
| 469 | delegation = nfs_detach_delegation(NFS_I(inode), NFS_SERVER(inode)); |
| 470 | if (delegation) { |
| 471 | nfs_inode_find_state_and_recover(inode, &delegation->stateid); |
| 472 | nfs_free_delegation(delegation); |
| 473 | } |
| 474 | } |
| 475 | EXPORT_SYMBOL_GPL(nfs_remove_bad_delegation); |
| 476 | |
| 477 | /** |
| 478 | * nfs_expire_all_delegation_types |
| 479 | * @clp: client to process |
| 480 | * @flags: delegation types to expire |
| 481 | * |
| 482 | */ |
| 483 | void nfs_expire_all_delegation_types(struct nfs_client *clp, fmode_t flags) |
| 484 | { |
| 485 | nfs_client_mark_return_all_delegation_types(clp, flags); |
| 486 | nfs_delegation_run_state_manager(clp); |
| 487 | } |
| 488 | |
| 489 | /** |
| 490 | * nfs_expire_all_delegations |
| 491 | * @clp: client to process |
| 492 | * |
| 493 | */ |
| 494 | void nfs_expire_all_delegations(struct nfs_client *clp) |
| 495 | { |
| 496 | nfs_expire_all_delegation_types(clp, FMODE_READ|FMODE_WRITE); |
| 497 | } |
| 498 | |
| 499 | static void nfs_mark_return_unreferenced_delegations(struct nfs_server *server) |
| 500 | { |
| 501 | struct nfs_delegation *delegation; |
| 502 | |
| 503 | list_for_each_entry_rcu(delegation, &server->delegations, super_list) { |
| 504 | if (test_and_clear_bit(NFS_DELEGATION_REFERENCED, &delegation->flags)) |
| 505 | continue; |
| 506 | nfs_mark_return_delegation(server, delegation); |
| 507 | } |
| 508 | } |
| 509 | |
| 510 | /** |
| 511 | * nfs_expire_unreferenced_delegations - Eliminate unused delegations |
| 512 | * @clp: nfs_client to process |
| 513 | * |
| 514 | */ |
| 515 | void nfs_expire_unreferenced_delegations(struct nfs_client *clp) |
| 516 | { |
| 517 | struct nfs_server *server; |
| 518 | |
| 519 | rcu_read_lock(); |
| 520 | list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) |
| 521 | nfs_mark_return_unreferenced_delegations(server); |
| 522 | rcu_read_unlock(); |
| 523 | |
| 524 | nfs_delegation_run_state_manager(clp); |
| 525 | } |
| 526 | |
| 527 | /** |
| 528 | * nfs_async_inode_return_delegation - asynchronously return a delegation |
| 529 | * @inode: inode to process |
| 530 | * @stateid: state ID information |
| 531 | * |
| 532 | * Returns zero on success, or a negative errno value. |
| 533 | */ |
| 534 | int nfs_async_inode_return_delegation(struct inode *inode, |
| 535 | const nfs4_stateid *stateid) |
| 536 | { |
| 537 | struct nfs_server *server = NFS_SERVER(inode); |
| 538 | struct nfs_client *clp = server->nfs_client; |
| 539 | struct nfs_delegation *delegation; |
| 540 | |
| 541 | rcu_read_lock(); |
| 542 | delegation = rcu_dereference(NFS_I(inode)->delegation); |
| 543 | if (delegation == NULL) |
| 544 | goto out_enoent; |
| 545 | |
| 546 | if (!clp->cl_mvops->match_stateid(&delegation->stateid, stateid)) |
| 547 | goto out_enoent; |
| 548 | nfs_mark_return_delegation(server, delegation); |
| 549 | rcu_read_unlock(); |
| 550 | |
| 551 | nfs_delegation_run_state_manager(clp); |
| 552 | return 0; |
| 553 | out_enoent: |
| 554 | rcu_read_unlock(); |
| 555 | return -ENOENT; |
| 556 | } |
| 557 | |
| 558 | static struct inode * |
| 559 | nfs_delegation_find_inode_server(struct nfs_server *server, |
| 560 | const struct nfs_fh *fhandle) |
| 561 | { |
| 562 | struct nfs_delegation *delegation; |
| 563 | struct inode *res = NULL; |
| 564 | |
| 565 | list_for_each_entry_rcu(delegation, &server->delegations, super_list) { |
| 566 | spin_lock(&delegation->lock); |
| 567 | if (delegation->inode != NULL && |
| 568 | nfs_compare_fh(fhandle, &NFS_I(delegation->inode)->fh) == 0) { |
| 569 | res = igrab(delegation->inode); |
| 570 | } |
| 571 | spin_unlock(&delegation->lock); |
| 572 | if (res != NULL) |
| 573 | break; |
| 574 | } |
| 575 | return res; |
| 576 | } |
| 577 | |
| 578 | /** |
| 579 | * nfs_delegation_find_inode - retrieve the inode associated with a delegation |
| 580 | * @clp: client state handle |
| 581 | * @fhandle: filehandle from a delegation recall |
| 582 | * |
| 583 | * Returns pointer to inode matching "fhandle," or NULL if a matching inode |
| 584 | * cannot be found. |
| 585 | */ |
| 586 | struct inode *nfs_delegation_find_inode(struct nfs_client *clp, |
| 587 | const struct nfs_fh *fhandle) |
| 588 | { |
| 589 | struct nfs_server *server; |
| 590 | struct inode *res = NULL; |
| 591 | |
| 592 | rcu_read_lock(); |
| 593 | list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) { |
| 594 | res = nfs_delegation_find_inode_server(server, fhandle); |
| 595 | if (res != NULL) |
| 596 | break; |
| 597 | } |
| 598 | rcu_read_unlock(); |
| 599 | return res; |
| 600 | } |
| 601 | |
| 602 | static void nfs_delegation_mark_reclaim_server(struct nfs_server *server) |
| 603 | { |
| 604 | struct nfs_delegation *delegation; |
| 605 | |
| 606 | list_for_each_entry_rcu(delegation, &server->delegations, super_list) |
| 607 | set_bit(NFS_DELEGATION_NEED_RECLAIM, &delegation->flags); |
| 608 | } |
| 609 | |
| 610 | /** |
| 611 | * nfs_delegation_mark_reclaim - mark all delegations as needing to be reclaimed |
| 612 | * @clp: nfs_client to process |
| 613 | * |
| 614 | */ |
| 615 | void nfs_delegation_mark_reclaim(struct nfs_client *clp) |
| 616 | { |
| 617 | struct nfs_server *server; |
| 618 | |
| 619 | rcu_read_lock(); |
| 620 | list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) |
| 621 | nfs_delegation_mark_reclaim_server(server); |
| 622 | rcu_read_unlock(); |
| 623 | } |
| 624 | |
| 625 | /** |
| 626 | * nfs_delegation_reap_unclaimed - reap unclaimed delegations after reboot recovery is done |
| 627 | * @clp: nfs_client to process |
| 628 | * |
| 629 | */ |
| 630 | void nfs_delegation_reap_unclaimed(struct nfs_client *clp) |
| 631 | { |
| 632 | struct nfs_delegation *delegation; |
| 633 | struct nfs_server *server; |
| 634 | struct inode *inode; |
| 635 | |
| 636 | restart: |
| 637 | rcu_read_lock(); |
| 638 | list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) { |
| 639 | list_for_each_entry_rcu(delegation, &server->delegations, |
| 640 | super_list) { |
| 641 | if (test_bit(NFS_DELEGATION_NEED_RECLAIM, |
| 642 | &delegation->flags) == 0) |
| 643 | continue; |
| 644 | inode = nfs_delegation_grab_inode(delegation); |
| 645 | if (inode == NULL) |
| 646 | continue; |
| 647 | delegation = nfs_detach_delegation(NFS_I(inode), |
| 648 | server); |
| 649 | rcu_read_unlock(); |
| 650 | |
| 651 | if (delegation != NULL) |
| 652 | nfs_free_delegation(delegation); |
| 653 | iput(inode); |
| 654 | goto restart; |
| 655 | } |
| 656 | } |
| 657 | rcu_read_unlock(); |
| 658 | } |
| 659 | |
| 660 | /** |
| 661 | * nfs_delegations_present - check for existence of delegations |
| 662 | * @clp: client state handle |
| 663 | * |
| 664 | * Returns one if there are any nfs_delegation structures attached |
| 665 | * to this nfs_client. |
| 666 | */ |
| 667 | int nfs_delegations_present(struct nfs_client *clp) |
| 668 | { |
| 669 | struct nfs_server *server; |
| 670 | int ret = 0; |
| 671 | |
| 672 | rcu_read_lock(); |
| 673 | list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) |
| 674 | if (!list_empty(&server->delegations)) { |
| 675 | ret = 1; |
| 676 | break; |
| 677 | } |
| 678 | rcu_read_unlock(); |
| 679 | return ret; |
| 680 | } |
| 681 | |
| 682 | /** |
| 683 | * nfs4_copy_delegation_stateid - Copy inode's state ID information |
| 684 | * @dst: stateid data structure to fill in |
| 685 | * @inode: inode to check |
| 686 | * @flags: delegation type requirement |
| 687 | * |
| 688 | * Returns "true" and fills in "dst->data" * if inode had a delegation, |
| 689 | * otherwise "false" is returned. |
| 690 | */ |
| 691 | bool nfs4_copy_delegation_stateid(nfs4_stateid *dst, struct inode *inode, |
| 692 | fmode_t flags) |
| 693 | { |
| 694 | struct nfs_inode *nfsi = NFS_I(inode); |
| 695 | struct nfs_delegation *delegation; |
| 696 | bool ret; |
| 697 | |
| 698 | flags &= FMODE_READ|FMODE_WRITE; |
| 699 | rcu_read_lock(); |
| 700 | delegation = rcu_dereference(nfsi->delegation); |
| 701 | ret = (delegation != NULL && (delegation->type & flags) == flags); |
| 702 | if (ret) { |
| 703 | nfs4_stateid_copy(dst, &delegation->stateid); |
| 704 | nfs_mark_delegation_referenced(delegation); |
| 705 | } |
| 706 | rcu_read_unlock(); |
| 707 | return ret; |
| 708 | } |