1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (C) 2006-2010 Red Hat, Inc. All rights reserved. 4 */ 5 6 #include <linux/miscdevice.h> 7 #include <linux/init.h> 8 #include <linux/wait.h> 9 #include <linux/file.h> 10 #include <linux/fs.h> 11 #include <linux/poll.h> 12 #include <linux/signal.h> 13 #include <linux/spinlock.h> 14 #include <linux/dlm.h> 15 #include <linux/dlm_device.h> 16 #include <linux/slab.h> 17 #include <linux/sched/signal.h> 18 19 #include <trace/events/dlm.h> 20 21 #include "dlm_internal.h" 22 #include "lockspace.h" 23 #include "lock.h" 24 #include "user.h" 25 #include "ast.h" 26 #include "config.h" 27 #include "memory.h" 28 29 static const char name_prefix[] = "dlm"; 30 static const struct file_operations device_fops; 31 static atomic_t dlm_monitor_opened; 32 static int dlm_monitor_unused = 1; 33 34 #ifdef CONFIG_COMPAT 35 36 struct dlm_lock_params32 { 37 __u8 mode; 38 __u8 namelen; 39 __u16 unused; 40 __u32 flags; 41 __u32 lkid; 42 __u32 parent; 43 __u64 xid; 44 __u64 timeout; 45 __u32 castparam; 46 __u32 castaddr; 47 __u32 bastparam; 48 __u32 bastaddr; 49 __u32 lksb; 50 char lvb[DLM_USER_LVB_LEN]; 51 char name[]; 52 }; 53 54 struct dlm_write_request32 { 55 __u32 version[3]; 56 __u8 cmd; 57 __u8 is64bit; 58 __u8 unused[2]; 59 60 union { 61 struct dlm_lock_params32 lock; 62 struct dlm_lspace_params lspace; 63 struct dlm_purge_params purge; 64 } i; 65 }; 66 67 struct dlm_lksb32 { 68 __u32 sb_status; 69 __u32 sb_lkid; 70 __u8 sb_flags; 71 __u32 sb_lvbptr; 72 }; 73 74 struct dlm_lock_result32 { 75 __u32 version[3]; 76 __u32 length; 77 __u32 user_astaddr; 78 __u32 user_astparam; 79 __u32 user_lksb; 80 struct dlm_lksb32 lksb; 81 __u8 bast_mode; 82 __u8 unused[3]; 83 /* Offsets may be zero if no data is present */ 84 __u32 lvb_offset; 85 }; 86 87 static void compat_input(struct dlm_write_request *kb, 88 struct dlm_write_request32 *kb32, 89 int namelen) 90 { 91 kb->version[0] = kb32->version[0]; 92 kb->version[1] = kb32->version[1]; 93 kb->version[2] = kb32->version[2]; 94 95 kb->cmd = kb32->cmd; 96 kb->is64bit = kb32->is64bit; 97 if (kb->cmd == DLM_USER_CREATE_LOCKSPACE || 98 kb->cmd == DLM_USER_REMOVE_LOCKSPACE) { 99 kb->i.lspace.flags = kb32->i.lspace.flags; 100 kb->i.lspace.minor = kb32->i.lspace.minor; 101 memcpy(kb->i.lspace.name, kb32->i.lspace.name, namelen); 102 } else if (kb->cmd == DLM_USER_PURGE) { 103 kb->i.purge.nodeid = kb32->i.purge.nodeid; 104 kb->i.purge.pid = kb32->i.purge.pid; 105 } else { 106 kb->i.lock.mode = kb32->i.lock.mode; 107 kb->i.lock.namelen = kb32->i.lock.namelen; 108 kb->i.lock.flags = kb32->i.lock.flags; 109 kb->i.lock.lkid = kb32->i.lock.lkid; 110 kb->i.lock.parent = kb32->i.lock.parent; 111 kb->i.lock.xid = kb32->i.lock.xid; 112 kb->i.lock.timeout = kb32->i.lock.timeout; 113 kb->i.lock.castparam = (__user void *)(long)kb32->i.lock.castparam; 114 kb->i.lock.castaddr = (__user void *)(long)kb32->i.lock.castaddr; 115 kb->i.lock.bastparam = (__user void *)(long)kb32->i.lock.bastparam; 116 kb->i.lock.bastaddr = (__user void *)(long)kb32->i.lock.bastaddr; 117 kb->i.lock.lksb = (__user void *)(long)kb32->i.lock.lksb; 118 memcpy(kb->i.lock.lvb, kb32->i.lock.lvb, DLM_USER_LVB_LEN); 119 memcpy(kb->i.lock.name, kb32->i.lock.name, namelen); 120 } 121 } 122 123 static void compat_output(struct dlm_lock_result *res, 124 struct dlm_lock_result32 *res32) 125 { 126 memset(res32, 0, sizeof(*res32)); 127 128 res32->version[0] = res->version[0]; 129 res32->version[1] = res->version[1]; 130 res32->version[2] = res->version[2]; 131 132 res32->user_astaddr = (__u32)(__force long)res->user_astaddr; 133 res32->user_astparam = (__u32)(__force long)res->user_astparam; 134 res32->user_lksb = (__u32)(__force long)res->user_lksb; 135 res32->bast_mode = res->bast_mode; 136 137 res32->lvb_offset = res->lvb_offset; 138 res32->length = res->length; 139 140 res32->lksb.sb_status = res->lksb.sb_status; 141 res32->lksb.sb_flags = res->lksb.sb_flags; 142 res32->lksb.sb_lkid = res->lksb.sb_lkid; 143 res32->lksb.sb_lvbptr = (__u32)(long)res->lksb.sb_lvbptr; 144 } 145 #endif 146 147 /* should held proc->asts_spin lock */ 148 void dlm_purge_lkb_callbacks(struct dlm_lkb *lkb) 149 { 150 struct dlm_callback *cb, *safe; 151 152 list_for_each_entry_safe(cb, safe, &lkb->lkb_callbacks, list) { 153 list_del(&cb->list); 154 kref_put(&cb->ref, dlm_release_callback); 155 } 156 157 clear_bit(DLM_IFL_CB_PENDING_BIT, &lkb->lkb_iflags); 158 159 /* invalidate */ 160 dlm_callback_set_last_ptr(&lkb->lkb_last_cast, NULL); 161 dlm_callback_set_last_ptr(&lkb->lkb_last_cb, NULL); 162 lkb->lkb_last_bast_mode = -1; 163 } 164 165 /* Figure out if this lock is at the end of its life and no longer 166 available for the application to use. The lkb still exists until 167 the final ast is read. A lock becomes EOL in three situations: 168 1. a noqueue request fails with EAGAIN 169 2. an unlock completes with EUNLOCK 170 3. a cancel of a waiting request completes with ECANCEL/EDEADLK 171 An EOL lock needs to be removed from the process's list of locks. 172 And we can't allow any new operation on an EOL lock. This is 173 not related to the lifetime of the lkb struct which is managed 174 entirely by refcount. */ 175 176 static int lkb_is_endoflife(int mode, int status) 177 { 178 switch (status) { 179 case -DLM_EUNLOCK: 180 return 1; 181 case -DLM_ECANCEL: 182 case -ETIMEDOUT: 183 case -EDEADLK: 184 case -EAGAIN: 185 if (mode == DLM_LOCK_IV) 186 return 1; 187 break; 188 } 189 return 0; 190 } 191 192 /* we could possibly check if the cancel of an orphan has resulted in the lkb 193 being removed and then remove that lkb from the orphans list and free it */ 194 195 void dlm_user_add_ast(struct dlm_lkb *lkb, uint32_t flags, int mode, 196 int status, uint32_t sbflags) 197 { 198 struct dlm_ls *ls; 199 struct dlm_user_args *ua; 200 struct dlm_user_proc *proc; 201 int rv; 202 203 if (test_bit(DLM_DFL_ORPHAN_BIT, &lkb->lkb_dflags) || 204 test_bit(DLM_IFL_DEAD_BIT, &lkb->lkb_iflags)) 205 return; 206 207 ls = lkb->lkb_resource->res_ls; 208 spin_lock(&ls->ls_clear_proc_locks); 209 210 /* If ORPHAN/DEAD flag is set, it means the process is dead so an ast 211 can't be delivered. For ORPHAN's, dlm_clear_proc_locks() freed 212 lkb->ua so we can't try to use it. This second check is necessary 213 for cases where a completion ast is received for an operation that 214 began before clear_proc_locks did its cancel/unlock. */ 215 216 if (test_bit(DLM_DFL_ORPHAN_BIT, &lkb->lkb_dflags) || 217 test_bit(DLM_IFL_DEAD_BIT, &lkb->lkb_iflags)) 218 goto out; 219 220 DLM_ASSERT(lkb->lkb_ua, dlm_print_lkb(lkb);); 221 ua = lkb->lkb_ua; 222 proc = ua->proc; 223 224 if ((flags & DLM_CB_BAST) && ua->bastaddr == NULL) 225 goto out; 226 227 if ((flags & DLM_CB_CAST) && lkb_is_endoflife(mode, status)) 228 set_bit(DLM_IFL_ENDOFLIFE_BIT, &lkb->lkb_iflags); 229 230 spin_lock(&proc->asts_spin); 231 232 rv = dlm_enqueue_lkb_callback(lkb, flags, mode, status, sbflags); 233 switch (rv) { 234 case DLM_ENQUEUE_CALLBACK_FAILURE: 235 spin_unlock(&proc->asts_spin); 236 WARN_ON_ONCE(1); 237 goto out; 238 case DLM_ENQUEUE_CALLBACK_NEED_SCHED: 239 kref_get(&lkb->lkb_ref); 240 list_add_tail(&lkb->lkb_cb_list, &proc->asts); 241 wake_up_interruptible(&proc->wait); 242 break; 243 case DLM_ENQUEUE_CALLBACK_SUCCESS: 244 break; 245 default: 246 WARN_ON_ONCE(1); 247 break; 248 } 249 spin_unlock(&proc->asts_spin); 250 251 if (test_bit(DLM_IFL_ENDOFLIFE_BIT, &lkb->lkb_iflags)) { 252 /* N.B. spin_lock locks_spin, not asts_spin */ 253 spin_lock(&proc->locks_spin); 254 if (!list_empty(&lkb->lkb_ownqueue)) { 255 list_del_init(&lkb->lkb_ownqueue); 256 dlm_put_lkb(lkb); 257 } 258 spin_unlock(&proc->locks_spin); 259 } 260 out: 261 spin_unlock(&ls->ls_clear_proc_locks); 262 } 263 264 static int device_user_lock(struct dlm_user_proc *proc, 265 struct dlm_lock_params *params) 266 { 267 struct dlm_ls *ls; 268 struct dlm_user_args *ua; 269 uint32_t lkid; 270 int error = -ENOMEM; 271 272 ls = dlm_find_lockspace_local(proc->lockspace); 273 if (!ls) 274 return -ENOENT; 275 276 if (!params->castaddr || !params->lksb) { 277 error = -EINVAL; 278 goto out; 279 } 280 281 ua = kzalloc(sizeof(struct dlm_user_args), GFP_NOFS); 282 if (!ua) 283 goto out; 284 ua->proc = proc; 285 ua->user_lksb = params->lksb; 286 ua->castparam = params->castparam; 287 ua->castaddr = params->castaddr; 288 ua->bastparam = params->bastparam; 289 ua->bastaddr = params->bastaddr; 290 ua->xid = params->xid; 291 292 if (params->flags & DLM_LKF_CONVERT) { 293 error = dlm_user_convert(ls, ua, 294 params->mode, params->flags, 295 params->lkid, params->lvb); 296 } else if (params->flags & DLM_LKF_ORPHAN) { 297 error = dlm_user_adopt_orphan(ls, ua, 298 params->mode, params->flags, 299 params->name, params->namelen, 300 &lkid); 301 if (!error) 302 error = lkid; 303 } else { 304 error = dlm_user_request(ls, ua, 305 params->mode, params->flags, 306 params->name, params->namelen); 307 if (!error) 308 error = ua->lksb.sb_lkid; 309 } 310 out: 311 dlm_put_lockspace(ls); 312 return error; 313 } 314 315 static int device_user_unlock(struct dlm_user_proc *proc, 316 struct dlm_lock_params *params) 317 { 318 struct dlm_ls *ls; 319 struct dlm_user_args *ua; 320 int error = -ENOMEM; 321 322 ls = dlm_find_lockspace_local(proc->lockspace); 323 if (!ls) 324 return -ENOENT; 325 326 ua = kzalloc(sizeof(struct dlm_user_args), GFP_NOFS); 327 if (!ua) 328 goto out; 329 ua->proc = proc; 330 ua->user_lksb = params->lksb; 331 ua->castparam = params->castparam; 332 ua->castaddr = params->castaddr; 333 334 if (params->flags & DLM_LKF_CANCEL) 335 error = dlm_user_cancel(ls, ua, params->flags, params->lkid); 336 else 337 error = dlm_user_unlock(ls, ua, params->flags, params->lkid, 338 params->lvb); 339 out: 340 dlm_put_lockspace(ls); 341 return error; 342 } 343 344 static int device_user_deadlock(struct dlm_user_proc *proc, 345 struct dlm_lock_params *params) 346 { 347 struct dlm_ls *ls; 348 int error; 349 350 ls = dlm_find_lockspace_local(proc->lockspace); 351 if (!ls) 352 return -ENOENT; 353 354 error = dlm_user_deadlock(ls, params->flags, params->lkid); 355 356 dlm_put_lockspace(ls); 357 return error; 358 } 359 360 static int dlm_device_register(struct dlm_ls *ls, char *name) 361 { 362 int error, len; 363 364 /* The device is already registered. This happens when the 365 lockspace is created multiple times from userspace. */ 366 if (ls->ls_device.name) 367 return 0; 368 369 error = -ENOMEM; 370 len = strlen(name) + strlen(name_prefix) + 2; 371 ls->ls_device.name = kzalloc(len, GFP_NOFS); 372 if (!ls->ls_device.name) 373 goto fail; 374 375 snprintf((char *)ls->ls_device.name, len, "%s_%s", name_prefix, 376 name); 377 ls->ls_device.fops = &device_fops; 378 ls->ls_device.minor = MISC_DYNAMIC_MINOR; 379 380 error = misc_register(&ls->ls_device); 381 if (error) { 382 kfree(ls->ls_device.name); 383 /* this has to be set to NULL 384 * to avoid a double-free in dlm_device_deregister 385 */ 386 ls->ls_device.name = NULL; 387 } 388 fail: 389 return error; 390 } 391 392 int dlm_device_deregister(struct dlm_ls *ls) 393 { 394 /* The device is not registered. This happens when the lockspace 395 was never used from userspace, or when device_create_lockspace() 396 calls dlm_release_lockspace() after the register fails. */ 397 if (!ls->ls_device.name) 398 return 0; 399 400 misc_deregister(&ls->ls_device); 401 kfree(ls->ls_device.name); 402 return 0; 403 } 404 405 static int device_user_purge(struct dlm_user_proc *proc, 406 struct dlm_purge_params *params) 407 { 408 struct dlm_ls *ls; 409 int error; 410 411 ls = dlm_find_lockspace_local(proc->lockspace); 412 if (!ls) 413 return -ENOENT; 414 415 error = dlm_user_purge(ls, proc, params->nodeid, params->pid); 416 417 dlm_put_lockspace(ls); 418 return error; 419 } 420 421 static int device_create_lockspace(struct dlm_lspace_params *params) 422 { 423 dlm_lockspace_t *lockspace; 424 struct dlm_ls *ls; 425 int error; 426 427 if (!capable(CAP_SYS_ADMIN)) 428 return -EPERM; 429 430 error = dlm_new_user_lockspace(params->name, dlm_config.ci_cluster_name, 431 params->flags, DLM_USER_LVB_LEN, NULL, 432 NULL, NULL, &lockspace); 433 if (error) 434 return error; 435 436 ls = dlm_find_lockspace_local(lockspace); 437 if (!ls) 438 return -ENOENT; 439 440 error = dlm_device_register(ls, params->name); 441 dlm_put_lockspace(ls); 442 443 if (error) 444 dlm_release_lockspace(lockspace, 0); 445 else 446 error = ls->ls_device.minor; 447 448 return error; 449 } 450 451 static int device_remove_lockspace(struct dlm_lspace_params *params) 452 { 453 dlm_lockspace_t *lockspace; 454 struct dlm_ls *ls; 455 int error, force = 0; 456 457 if (!capable(CAP_SYS_ADMIN)) 458 return -EPERM; 459 460 ls = dlm_find_lockspace_device(params->minor); 461 if (!ls) 462 return -ENOENT; 463 464 if (params->flags & DLM_USER_LSFLG_FORCEFREE) 465 force = 2; 466 467 lockspace = ls->ls_local_handle; 468 dlm_put_lockspace(ls); 469 470 /* The final dlm_release_lockspace waits for references to go to 471 zero, so all processes will need to close their device for the 472 ls before the release will proceed. release also calls the 473 device_deregister above. Converting a positive return value 474 from release to zero means that userspace won't know when its 475 release was the final one, but it shouldn't need to know. */ 476 477 error = dlm_release_lockspace(lockspace, force); 478 if (error > 0) 479 error = 0; 480 return error; 481 } 482 483 /* Check the user's version matches ours */ 484 static int check_version(struct dlm_write_request *req) 485 { 486 if (req->version[0] != DLM_DEVICE_VERSION_MAJOR || 487 (req->version[0] == DLM_DEVICE_VERSION_MAJOR && 488 req->version[1] > DLM_DEVICE_VERSION_MINOR)) { 489 490 printk(KERN_DEBUG "dlm: process %s (%d) version mismatch " 491 "user (%d.%d.%d) kernel (%d.%d.%d)\n", 492 current->comm, 493 task_pid_nr(current), 494 req->version[0], 495 req->version[1], 496 req->version[2], 497 DLM_DEVICE_VERSION_MAJOR, 498 DLM_DEVICE_VERSION_MINOR, 499 DLM_DEVICE_VERSION_PATCH); 500 return -EINVAL; 501 } 502 return 0; 503 } 504 505 /* 506 * device_write 507 * 508 * device_user_lock 509 * dlm_user_request -> request_lock 510 * dlm_user_convert -> convert_lock 511 * 512 * device_user_unlock 513 * dlm_user_unlock -> unlock_lock 514 * dlm_user_cancel -> cancel_lock 515 * 516 * device_create_lockspace 517 * dlm_new_lockspace 518 * 519 * device_remove_lockspace 520 * dlm_release_lockspace 521 */ 522 523 /* a write to a lockspace device is a lock or unlock request, a write 524 to the control device is to create/remove a lockspace */ 525 526 static ssize_t device_write(struct file *file, const char __user *buf, 527 size_t count, loff_t *ppos) 528 { 529 struct dlm_user_proc *proc = file->private_data; 530 struct dlm_write_request *kbuf; 531 int error; 532 533 #ifdef CONFIG_COMPAT 534 if (count < sizeof(struct dlm_write_request32)) 535 #else 536 if (count < sizeof(struct dlm_write_request)) 537 #endif 538 return -EINVAL; 539 540 /* 541 * can't compare against COMPAT/dlm_write_request32 because 542 * we don't yet know if is64bit is zero 543 */ 544 if (count > sizeof(struct dlm_write_request) + DLM_RESNAME_MAXLEN) 545 return -EINVAL; 546 547 kbuf = memdup_user_nul(buf, count); 548 if (IS_ERR(kbuf)) 549 return PTR_ERR(kbuf); 550 551 if (check_version(kbuf)) { 552 error = -EBADE; 553 goto out_free; 554 } 555 556 #ifdef CONFIG_COMPAT 557 if (!kbuf->is64bit) { 558 struct dlm_write_request32 *k32buf; 559 int namelen = 0; 560 561 if (count > sizeof(struct dlm_write_request32)) 562 namelen = count - sizeof(struct dlm_write_request32); 563 564 k32buf = (struct dlm_write_request32 *)kbuf; 565 566 /* add 1 after namelen so that the name string is terminated */ 567 kbuf = kzalloc(sizeof(struct dlm_write_request) + namelen + 1, 568 GFP_NOFS); 569 if (!kbuf) { 570 kfree(k32buf); 571 return -ENOMEM; 572 } 573 574 if (proc) 575 set_bit(DLM_PROC_FLAGS_COMPAT, &proc->flags); 576 577 compat_input(kbuf, k32buf, namelen); 578 kfree(k32buf); 579 } 580 #endif 581 582 /* do we really need this? can a write happen after a close? */ 583 if ((kbuf->cmd == DLM_USER_LOCK || kbuf->cmd == DLM_USER_UNLOCK) && 584 (proc && test_bit(DLM_PROC_FLAGS_CLOSING, &proc->flags))) { 585 error = -EINVAL; 586 goto out_free; 587 } 588 589 error = -EINVAL; 590 591 switch (kbuf->cmd) 592 { 593 case DLM_USER_LOCK: 594 if (!proc) { 595 log_print("no locking on control device"); 596 goto out_free; 597 } 598 error = device_user_lock(proc, &kbuf->i.lock); 599 break; 600 601 case DLM_USER_UNLOCK: 602 if (!proc) { 603 log_print("no locking on control device"); 604 goto out_free; 605 } 606 error = device_user_unlock(proc, &kbuf->i.lock); 607 break; 608 609 case DLM_USER_DEADLOCK: 610 if (!proc) { 611 log_print("no locking on control device"); 612 goto out_free; 613 } 614 error = device_user_deadlock(proc, &kbuf->i.lock); 615 break; 616 617 case DLM_USER_CREATE_LOCKSPACE: 618 if (proc) { 619 log_print("create/remove only on control device"); 620 goto out_free; 621 } 622 error = device_create_lockspace(&kbuf->i.lspace); 623 break; 624 625 case DLM_USER_REMOVE_LOCKSPACE: 626 if (proc) { 627 log_print("create/remove only on control device"); 628 goto out_free; 629 } 630 error = device_remove_lockspace(&kbuf->i.lspace); 631 break; 632 633 case DLM_USER_PURGE: 634 if (!proc) { 635 log_print("no locking on control device"); 636 goto out_free; 637 } 638 error = device_user_purge(proc, &kbuf->i.purge); 639 break; 640 641 default: 642 log_print("Unknown command passed to DLM device : %d\n", 643 kbuf->cmd); 644 } 645 646 out_free: 647 kfree(kbuf); 648 return error; 649 } 650 651 /* Every process that opens the lockspace device has its own "proc" structure 652 hanging off the open file that's used to keep track of locks owned by the 653 process and asts that need to be delivered to the process. */ 654 655 static int device_open(struct inode *inode, struct file *file) 656 { 657 struct dlm_user_proc *proc; 658 struct dlm_ls *ls; 659 660 ls = dlm_find_lockspace_device(iminor(inode)); 661 if (!ls) 662 return -ENOENT; 663 664 proc = kzalloc(sizeof(struct dlm_user_proc), GFP_NOFS); 665 if (!proc) { 666 dlm_put_lockspace(ls); 667 return -ENOMEM; 668 } 669 670 proc->lockspace = ls->ls_local_handle; 671 INIT_LIST_HEAD(&proc->asts); 672 INIT_LIST_HEAD(&proc->locks); 673 INIT_LIST_HEAD(&proc->unlocking); 674 spin_lock_init(&proc->asts_spin); 675 spin_lock_init(&proc->locks_spin); 676 init_waitqueue_head(&proc->wait); 677 file->private_data = proc; 678 679 return 0; 680 } 681 682 static int device_close(struct inode *inode, struct file *file) 683 { 684 struct dlm_user_proc *proc = file->private_data; 685 struct dlm_ls *ls; 686 687 ls = dlm_find_lockspace_local(proc->lockspace); 688 if (!ls) 689 return -ENOENT; 690 691 set_bit(DLM_PROC_FLAGS_CLOSING, &proc->flags); 692 693 dlm_clear_proc_locks(ls, proc); 694 695 /* at this point no more lkb's should exist for this lockspace, 696 so there's no chance of dlm_user_add_ast() being called and 697 looking for lkb->ua->proc */ 698 699 kfree(proc); 700 file->private_data = NULL; 701 702 dlm_put_lockspace(ls); 703 dlm_put_lockspace(ls); /* for the find in device_open() */ 704 705 /* FIXME: AUTOFREE: if this ls is no longer used do 706 device_remove_lockspace() */ 707 708 return 0; 709 } 710 711 static int copy_result_to_user(struct dlm_user_args *ua, int compat, 712 uint32_t flags, int mode, int copy_lvb, 713 char __user *buf, size_t count) 714 { 715 #ifdef CONFIG_COMPAT 716 struct dlm_lock_result32 result32; 717 #endif 718 struct dlm_lock_result result; 719 void *resultptr; 720 int error=0; 721 int len; 722 int struct_len; 723 724 memset(&result, 0, sizeof(struct dlm_lock_result)); 725 result.version[0] = DLM_DEVICE_VERSION_MAJOR; 726 result.version[1] = DLM_DEVICE_VERSION_MINOR; 727 result.version[2] = DLM_DEVICE_VERSION_PATCH; 728 memcpy(&result.lksb, &ua->lksb, offsetof(struct dlm_lksb, sb_lvbptr)); 729 result.user_lksb = ua->user_lksb; 730 731 /* FIXME: dlm1 provides for the user's bastparam/addr to not be updated 732 in a conversion unless the conversion is successful. See code 733 in dlm_user_convert() for updating ua from ua_tmp. OpenVMS, though, 734 notes that a new blocking AST address and parameter are set even if 735 the conversion fails, so maybe we should just do that. */ 736 737 if (flags & DLM_CB_BAST) { 738 result.user_astaddr = ua->bastaddr; 739 result.user_astparam = ua->bastparam; 740 result.bast_mode = mode; 741 } else { 742 result.user_astaddr = ua->castaddr; 743 result.user_astparam = ua->castparam; 744 } 745 746 #ifdef CONFIG_COMPAT 747 if (compat) 748 len = sizeof(struct dlm_lock_result32); 749 else 750 #endif 751 len = sizeof(struct dlm_lock_result); 752 struct_len = len; 753 754 /* copy lvb to userspace if there is one, it's been updated, and 755 the user buffer has space for it */ 756 757 if (copy_lvb && ua->lksb.sb_lvbptr && count >= len + DLM_USER_LVB_LEN) { 758 if (copy_to_user(buf+len, ua->lksb.sb_lvbptr, 759 DLM_USER_LVB_LEN)) { 760 error = -EFAULT; 761 goto out; 762 } 763 764 result.lvb_offset = len; 765 len += DLM_USER_LVB_LEN; 766 } 767 768 result.length = len; 769 resultptr = &result; 770 #ifdef CONFIG_COMPAT 771 if (compat) { 772 compat_output(&result, &result32); 773 resultptr = &result32; 774 } 775 #endif 776 777 if (copy_to_user(buf, resultptr, struct_len)) 778 error = -EFAULT; 779 else 780 error = len; 781 out: 782 return error; 783 } 784 785 static int copy_version_to_user(char __user *buf, size_t count) 786 { 787 struct dlm_device_version ver; 788 789 memset(&ver, 0, sizeof(struct dlm_device_version)); 790 ver.version[0] = DLM_DEVICE_VERSION_MAJOR; 791 ver.version[1] = DLM_DEVICE_VERSION_MINOR; 792 ver.version[2] = DLM_DEVICE_VERSION_PATCH; 793 794 if (copy_to_user(buf, &ver, sizeof(struct dlm_device_version))) 795 return -EFAULT; 796 return sizeof(struct dlm_device_version); 797 } 798 799 /* a read returns a single ast described in a struct dlm_lock_result */ 800 801 static ssize_t device_read(struct file *file, char __user *buf, size_t count, 802 loff_t *ppos) 803 { 804 struct dlm_user_proc *proc = file->private_data; 805 struct dlm_lkb *lkb; 806 DECLARE_WAITQUEUE(wait, current); 807 struct dlm_callback *cb; 808 int rv, ret; 809 810 if (count == sizeof(struct dlm_device_version)) { 811 rv = copy_version_to_user(buf, count); 812 return rv; 813 } 814 815 if (!proc) { 816 log_print("non-version read from control device %zu", count); 817 return -EINVAL; 818 } 819 820 #ifdef CONFIG_COMPAT 821 if (count < sizeof(struct dlm_lock_result32)) 822 #else 823 if (count < sizeof(struct dlm_lock_result)) 824 #endif 825 return -EINVAL; 826 827 try_another: 828 829 /* do we really need this? can a read happen after a close? */ 830 if (test_bit(DLM_PROC_FLAGS_CLOSING, &proc->flags)) 831 return -EINVAL; 832 833 spin_lock(&proc->asts_spin); 834 if (list_empty(&proc->asts)) { 835 if (file->f_flags & O_NONBLOCK) { 836 spin_unlock(&proc->asts_spin); 837 return -EAGAIN; 838 } 839 840 add_wait_queue(&proc->wait, &wait); 841 842 repeat: 843 set_current_state(TASK_INTERRUPTIBLE); 844 if (list_empty(&proc->asts) && !signal_pending(current)) { 845 spin_unlock(&proc->asts_spin); 846 schedule(); 847 spin_lock(&proc->asts_spin); 848 goto repeat; 849 } 850 set_current_state(TASK_RUNNING); 851 remove_wait_queue(&proc->wait, &wait); 852 853 if (signal_pending(current)) { 854 spin_unlock(&proc->asts_spin); 855 return -ERESTARTSYS; 856 } 857 } 858 859 /* if we empty lkb_callbacks, we don't want to unlock the spinlock 860 without removing lkb_cb_list; so empty lkb_cb_list is always 861 consistent with empty lkb_callbacks */ 862 863 lkb = list_first_entry(&proc->asts, struct dlm_lkb, lkb_cb_list); 864 865 rv = dlm_dequeue_lkb_callback(lkb, &cb); 866 switch (rv) { 867 case DLM_DEQUEUE_CALLBACK_EMPTY: 868 /* this shouldn't happen; lkb should have been removed from 869 * list when last item was dequeued 870 */ 871 log_print("dlm_rem_lkb_callback empty %x", lkb->lkb_id); 872 list_del_init(&lkb->lkb_cb_list); 873 spin_unlock(&proc->asts_spin); 874 /* removes ref for proc->asts, may cause lkb to be freed */ 875 dlm_put_lkb(lkb); 876 WARN_ON_ONCE(1); 877 goto try_another; 878 case DLM_DEQUEUE_CALLBACK_LAST: 879 list_del_init(&lkb->lkb_cb_list); 880 clear_bit(DLM_IFL_CB_PENDING_BIT, &lkb->lkb_iflags); 881 break; 882 case DLM_DEQUEUE_CALLBACK_SUCCESS: 883 break; 884 default: 885 WARN_ON_ONCE(1); 886 break; 887 } 888 spin_unlock(&proc->asts_spin); 889 890 if (cb->flags & DLM_CB_BAST) { 891 trace_dlm_bast(lkb->lkb_resource->res_ls, lkb, cb->mode); 892 } else if (cb->flags & DLM_CB_CAST) { 893 lkb->lkb_lksb->sb_status = cb->sb_status; 894 lkb->lkb_lksb->sb_flags = cb->sb_flags; 895 trace_dlm_ast(lkb->lkb_resource->res_ls, lkb); 896 } 897 898 ret = copy_result_to_user(lkb->lkb_ua, 899 test_bit(DLM_PROC_FLAGS_COMPAT, &proc->flags), 900 cb->flags, cb->mode, cb->copy_lvb, buf, count); 901 902 kref_put(&cb->ref, dlm_release_callback); 903 904 /* removes ref for proc->asts, may cause lkb to be freed */ 905 if (rv == DLM_DEQUEUE_CALLBACK_LAST) 906 dlm_put_lkb(lkb); 907 908 return ret; 909 } 910 911 static __poll_t device_poll(struct file *file, poll_table *wait) 912 { 913 struct dlm_user_proc *proc = file->private_data; 914 915 poll_wait(file, &proc->wait, wait); 916 917 spin_lock(&proc->asts_spin); 918 if (!list_empty(&proc->asts)) { 919 spin_unlock(&proc->asts_spin); 920 return EPOLLIN | EPOLLRDNORM; 921 } 922 spin_unlock(&proc->asts_spin); 923 return 0; 924 } 925 926 int dlm_user_daemon_available(void) 927 { 928 /* dlm_controld hasn't started (or, has started, but not 929 properly populated configfs) */ 930 931 if (!dlm_our_nodeid()) 932 return 0; 933 934 /* This is to deal with versions of dlm_controld that don't 935 know about the monitor device. We assume that if the 936 dlm_controld was started (above), but the monitor device 937 was never opened, that it's an old version. dlm_controld 938 should open the monitor device before populating configfs. */ 939 940 if (dlm_monitor_unused) 941 return 1; 942 943 return atomic_read(&dlm_monitor_opened) ? 1 : 0; 944 } 945 946 static int ctl_device_open(struct inode *inode, struct file *file) 947 { 948 file->private_data = NULL; 949 return 0; 950 } 951 952 static int ctl_device_close(struct inode *inode, struct file *file) 953 { 954 return 0; 955 } 956 957 static int monitor_device_open(struct inode *inode, struct file *file) 958 { 959 atomic_inc(&dlm_monitor_opened); 960 dlm_monitor_unused = 0; 961 return 0; 962 } 963 964 static int monitor_device_close(struct inode *inode, struct file *file) 965 { 966 if (atomic_dec_and_test(&dlm_monitor_opened)) 967 dlm_stop_lockspaces(); 968 return 0; 969 } 970 971 static const struct file_operations device_fops = { 972 .open = device_open, 973 .release = device_close, 974 .read = device_read, 975 .write = device_write, 976 .poll = device_poll, 977 .owner = THIS_MODULE, 978 .llseek = noop_llseek, 979 }; 980 981 static const struct file_operations ctl_device_fops = { 982 .open = ctl_device_open, 983 .release = ctl_device_close, 984 .read = device_read, 985 .write = device_write, 986 .owner = THIS_MODULE, 987 .llseek = noop_llseek, 988 }; 989 990 static struct miscdevice ctl_device = { 991 .name = "dlm-control", 992 .fops = &ctl_device_fops, 993 .minor = MISC_DYNAMIC_MINOR, 994 }; 995 996 static const struct file_operations monitor_device_fops = { 997 .open = monitor_device_open, 998 .release = monitor_device_close, 999 .owner = THIS_MODULE, 1000 .llseek = noop_llseek, 1001 }; 1002 1003 static struct miscdevice monitor_device = { 1004 .name = "dlm-monitor", 1005 .fops = &monitor_device_fops, 1006 .minor = MISC_DYNAMIC_MINOR, 1007 }; 1008 1009 int __init dlm_user_init(void) 1010 { 1011 int error; 1012 1013 atomic_set(&dlm_monitor_opened, 0); 1014 1015 error = misc_register(&ctl_device); 1016 if (error) { 1017 log_print("misc_register failed for control device"); 1018 goto out; 1019 } 1020 1021 error = misc_register(&monitor_device); 1022 if (error) { 1023 log_print("misc_register failed for monitor device"); 1024 misc_deregister(&ctl_device); 1025 } 1026 out: 1027 return error; 1028 } 1029 1030 void dlm_user_exit(void) 1031 { 1032 misc_deregister(&ctl_device); 1033 misc_deregister(&monitor_device); 1034 } 1035 1036