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 "lvb_table.h" 25 #include "user.h" 26 #include "ast.h" 27 #include "config.h" 28 #include "memory.h" 29 30 static const char name_prefix[] = "dlm"; 31 static const struct file_operations device_fops; 32 static atomic_t dlm_monitor_opened; 33 static int dlm_monitor_unused = 1; 34 35 #ifdef CONFIG_COMPAT 36 37 struct dlm_lock_params32 { 38 __u8 mode; 39 __u8 namelen; 40 __u16 unused; 41 __u32 flags; 42 __u32 lkid; 43 __u32 parent; 44 __u64 xid; 45 __u64 timeout; 46 __u32 castparam; 47 __u32 castaddr; 48 __u32 bastparam; 49 __u32 bastaddr; 50 __u32 lksb; 51 char lvb[DLM_USER_LVB_LEN]; 52 char name[]; 53 }; 54 55 struct dlm_write_request32 { 56 __u32 version[3]; 57 __u8 cmd; 58 __u8 is64bit; 59 __u8 unused[2]; 60 61 union { 62 struct dlm_lock_params32 lock; 63 struct dlm_lspace_params lspace; 64 struct dlm_purge_params purge; 65 } i; 66 }; 67 68 struct dlm_lksb32 { 69 __u32 sb_status; 70 __u32 sb_lkid; 71 __u8 sb_flags; 72 __u32 sb_lvbptr; 73 }; 74 75 struct dlm_lock_result32 { 76 __u32 version[3]; 77 __u32 length; 78 __u32 user_astaddr; 79 __u32 user_astparam; 80 __u32 user_lksb; 81 struct dlm_lksb32 lksb; 82 __u8 bast_mode; 83 __u8 unused[3]; 84 /* Offsets may be zero if no data is present */ 85 __u32 lvb_offset; 86 }; 87 88 static void compat_input(struct dlm_write_request *kb, 89 struct dlm_write_request32 *kb32, 90 int namelen) 91 { 92 kb->version[0] = kb32->version[0]; 93 kb->version[1] = kb32->version[1]; 94 kb->version[2] = kb32->version[2]; 95 96 kb->cmd = kb32->cmd; 97 kb->is64bit = kb32->is64bit; 98 if (kb->cmd == DLM_USER_CREATE_LOCKSPACE || 99 kb->cmd == DLM_USER_REMOVE_LOCKSPACE) { 100 kb->i.lspace.flags = kb32->i.lspace.flags; 101 kb->i.lspace.minor = kb32->i.lspace.minor; 102 memcpy(kb->i.lspace.name, kb32->i.lspace.name, namelen); 103 } else if (kb->cmd == DLM_USER_PURGE) { 104 kb->i.purge.nodeid = kb32->i.purge.nodeid; 105 kb->i.purge.pid = kb32->i.purge.pid; 106 } else { 107 kb->i.lock.mode = kb32->i.lock.mode; 108 kb->i.lock.namelen = kb32->i.lock.namelen; 109 kb->i.lock.flags = kb32->i.lock.flags; 110 kb->i.lock.lkid = kb32->i.lock.lkid; 111 kb->i.lock.parent = kb32->i.lock.parent; 112 kb->i.lock.xid = kb32->i.lock.xid; 113 kb->i.lock.timeout = kb32->i.lock.timeout; 114 kb->i.lock.castparam = (__user void *)(long)kb32->i.lock.castparam; 115 kb->i.lock.castaddr = (__user void *)(long)kb32->i.lock.castaddr; 116 kb->i.lock.bastparam = (__user void *)(long)kb32->i.lock.bastparam; 117 kb->i.lock.bastaddr = (__user void *)(long)kb32->i.lock.bastaddr; 118 kb->i.lock.lksb = (__user void *)(long)kb32->i.lock.lksb; 119 memcpy(kb->i.lock.lvb, kb32->i.lock.lvb, DLM_USER_LVB_LEN); 120 memcpy(kb->i.lock.name, kb32->i.lock.name, namelen); 121 } 122 } 123 124 static void compat_output(struct dlm_lock_result *res, 125 struct dlm_lock_result32 *res32) 126 { 127 memset(res32, 0, sizeof(*res32)); 128 129 res32->version[0] = res->version[0]; 130 res32->version[1] = res->version[1]; 131 res32->version[2] = res->version[2]; 132 133 res32->user_astaddr = (__u32)(__force long)res->user_astaddr; 134 res32->user_astparam = (__u32)(__force long)res->user_astparam; 135 res32->user_lksb = (__u32)(__force long)res->user_lksb; 136 res32->bast_mode = res->bast_mode; 137 138 res32->lvb_offset = res->lvb_offset; 139 res32->length = res->length; 140 141 res32->lksb.sb_status = res->lksb.sb_status; 142 res32->lksb.sb_flags = res->lksb.sb_flags; 143 res32->lksb.sb_lkid = res->lksb.sb_lkid; 144 res32->lksb.sb_lvbptr = (__u32)(long)res->lksb.sb_lvbptr; 145 } 146 #endif 147 148 /* Figure out if this lock is at the end of its life and no longer 149 available for the application to use. The lkb still exists until 150 the final ast is read. A lock becomes EOL in three situations: 151 1. a noqueue request fails with EAGAIN 152 2. an unlock completes with EUNLOCK 153 3. a cancel of a waiting request completes with ECANCEL/EDEADLK 154 An EOL lock needs to be removed from the process's list of locks. 155 And we can't allow any new operation on an EOL lock. This is 156 not related to the lifetime of the lkb struct which is managed 157 entirely by refcount. */ 158 159 static int lkb_is_endoflife(int mode, int status) 160 { 161 switch (status) { 162 case -DLM_EUNLOCK: 163 return 1; 164 case -DLM_ECANCEL: 165 case -ETIMEDOUT: 166 case -EDEADLK: 167 case -EAGAIN: 168 if (mode == DLM_LOCK_IV) 169 return 1; 170 break; 171 } 172 return 0; 173 } 174 175 /* we could possibly check if the cancel of an orphan has resulted in the lkb 176 being removed and then remove that lkb from the orphans list and free it */ 177 178 void dlm_user_add_ast(struct dlm_lkb *lkb, uint32_t flags, int mode, 179 int status, uint32_t sbflags) 180 { 181 struct dlm_ls *ls; 182 struct dlm_user_args *ua; 183 struct dlm_user_proc *proc; 184 int rv; 185 186 if (lkb->lkb_flags & (DLM_IFL_ORPHAN | DLM_IFL_DEAD)) 187 return; 188 189 ls = lkb->lkb_resource->res_ls; 190 spin_lock(&ls->ls_clear_proc_locks); 191 192 /* If ORPHAN/DEAD flag is set, it means the process is dead so an ast 193 can't be delivered. For ORPHAN's, dlm_clear_proc_locks() freed 194 lkb->ua so we can't try to use it. This second check is necessary 195 for cases where a completion ast is received for an operation that 196 began before clear_proc_locks did its cancel/unlock. */ 197 198 if (lkb->lkb_flags & (DLM_IFL_ORPHAN | DLM_IFL_DEAD)) 199 goto out; 200 201 DLM_ASSERT(lkb->lkb_ua, dlm_print_lkb(lkb);); 202 ua = lkb->lkb_ua; 203 proc = ua->proc; 204 205 if ((flags & DLM_CB_BAST) && ua->bastaddr == NULL) 206 goto out; 207 208 if ((flags & DLM_CB_CAST) && lkb_is_endoflife(mode, status)) 209 lkb->lkb_flags |= DLM_IFL_ENDOFLIFE; 210 211 spin_lock(&proc->asts_spin); 212 213 rv = dlm_enqueue_lkb_callback(lkb, flags, mode, status, sbflags); 214 switch (rv) { 215 case DLM_ENQUEUE_CALLBACK_FAILURE: 216 spin_unlock(&proc->asts_spin); 217 WARN_ON_ONCE(1); 218 goto out; 219 case DLM_ENQUEUE_CALLBACK_NEED_SCHED: 220 kref_get(&lkb->lkb_ref); 221 list_add_tail(&lkb->lkb_cb_list, &proc->asts); 222 wake_up_interruptible(&proc->wait); 223 break; 224 case DLM_ENQUEUE_CALLBACK_SUCCESS: 225 break; 226 default: 227 WARN_ON_ONCE(1); 228 break; 229 } 230 spin_unlock(&proc->asts_spin); 231 232 if (lkb->lkb_flags & DLM_IFL_ENDOFLIFE) { 233 /* N.B. spin_lock locks_spin, not asts_spin */ 234 spin_lock(&proc->locks_spin); 235 if (!list_empty(&lkb->lkb_ownqueue)) { 236 list_del_init(&lkb->lkb_ownqueue); 237 dlm_put_lkb(lkb); 238 } 239 spin_unlock(&proc->locks_spin); 240 } 241 out: 242 spin_unlock(&ls->ls_clear_proc_locks); 243 } 244 245 static int device_user_lock(struct dlm_user_proc *proc, 246 struct dlm_lock_params *params) 247 { 248 struct dlm_ls *ls; 249 struct dlm_user_args *ua; 250 uint32_t lkid; 251 int error = -ENOMEM; 252 253 ls = dlm_find_lockspace_local(proc->lockspace); 254 if (!ls) 255 return -ENOENT; 256 257 if (!params->castaddr || !params->lksb) { 258 error = -EINVAL; 259 goto out; 260 } 261 262 #ifdef CONFIG_DLM_DEPRECATED_API 263 if (params->timeout) 264 pr_warn_once("========================================================\n" 265 "WARNING: the lkb timeout feature is being deprecated and\n" 266 " will be removed in v6.2!\n" 267 "========================================================\n"); 268 #endif 269 270 ua = kzalloc(sizeof(struct dlm_user_args), GFP_NOFS); 271 if (!ua) 272 goto out; 273 ua->proc = proc; 274 ua->user_lksb = params->lksb; 275 ua->castparam = params->castparam; 276 ua->castaddr = params->castaddr; 277 ua->bastparam = params->bastparam; 278 ua->bastaddr = params->bastaddr; 279 ua->xid = params->xid; 280 281 if (params->flags & DLM_LKF_CONVERT) { 282 #ifdef CONFIG_DLM_DEPRECATED_API 283 error = dlm_user_convert(ls, ua, 284 params->mode, params->flags, 285 params->lkid, params->lvb, 286 (unsigned long) params->timeout); 287 #else 288 error = dlm_user_convert(ls, ua, 289 params->mode, params->flags, 290 params->lkid, params->lvb); 291 #endif 292 } else if (params->flags & DLM_LKF_ORPHAN) { 293 error = dlm_user_adopt_orphan(ls, ua, 294 params->mode, params->flags, 295 params->name, params->namelen, 296 &lkid); 297 if (!error) 298 error = lkid; 299 } else { 300 #ifdef CONFIG_DLM_DEPRECATED_API 301 error = dlm_user_request(ls, ua, 302 params->mode, params->flags, 303 params->name, params->namelen, 304 (unsigned long) params->timeout); 305 #else 306 error = dlm_user_request(ls, ua, 307 params->mode, params->flags, 308 params->name, params->namelen); 309 #endif 310 if (!error) 311 error = ua->lksb.sb_lkid; 312 } 313 out: 314 dlm_put_lockspace(ls); 315 return error; 316 } 317 318 static int device_user_unlock(struct dlm_user_proc *proc, 319 struct dlm_lock_params *params) 320 { 321 struct dlm_ls *ls; 322 struct dlm_user_args *ua; 323 int error = -ENOMEM; 324 325 ls = dlm_find_lockspace_local(proc->lockspace); 326 if (!ls) 327 return -ENOENT; 328 329 ua = kzalloc(sizeof(struct dlm_user_args), GFP_NOFS); 330 if (!ua) 331 goto out; 332 ua->proc = proc; 333 ua->user_lksb = params->lksb; 334 ua->castparam = params->castparam; 335 ua->castaddr = params->castaddr; 336 337 if (params->flags & DLM_LKF_CANCEL) 338 error = dlm_user_cancel(ls, ua, params->flags, params->lkid); 339 else 340 error = dlm_user_unlock(ls, ua, params->flags, params->lkid, 341 params->lvb); 342 out: 343 dlm_put_lockspace(ls); 344 return error; 345 } 346 347 static int device_user_deadlock(struct dlm_user_proc *proc, 348 struct dlm_lock_params *params) 349 { 350 struct dlm_ls *ls; 351 int error; 352 353 ls = dlm_find_lockspace_local(proc->lockspace); 354 if (!ls) 355 return -ENOENT; 356 357 error = dlm_user_deadlock(ls, params->flags, params->lkid); 358 359 dlm_put_lockspace(ls); 360 return error; 361 } 362 363 static int dlm_device_register(struct dlm_ls *ls, char *name) 364 { 365 int error, len; 366 367 /* The device is already registered. This happens when the 368 lockspace is created multiple times from userspace. */ 369 if (ls->ls_device.name) 370 return 0; 371 372 error = -ENOMEM; 373 len = strlen(name) + strlen(name_prefix) + 2; 374 ls->ls_device.name = kzalloc(len, GFP_NOFS); 375 if (!ls->ls_device.name) 376 goto fail; 377 378 snprintf((char *)ls->ls_device.name, len, "%s_%s", name_prefix, 379 name); 380 ls->ls_device.fops = &device_fops; 381 ls->ls_device.minor = MISC_DYNAMIC_MINOR; 382 383 error = misc_register(&ls->ls_device); 384 if (error) { 385 kfree(ls->ls_device.name); 386 /* this has to be set to NULL 387 * to avoid a double-free in dlm_device_deregister 388 */ 389 ls->ls_device.name = NULL; 390 } 391 fail: 392 return error; 393 } 394 395 int dlm_device_deregister(struct dlm_ls *ls) 396 { 397 /* The device is not registered. This happens when the lockspace 398 was never used from userspace, or when device_create_lockspace() 399 calls dlm_release_lockspace() after the register fails. */ 400 if (!ls->ls_device.name) 401 return 0; 402 403 misc_deregister(&ls->ls_device); 404 kfree(ls->ls_device.name); 405 return 0; 406 } 407 408 static int device_user_purge(struct dlm_user_proc *proc, 409 struct dlm_purge_params *params) 410 { 411 struct dlm_ls *ls; 412 int error; 413 414 ls = dlm_find_lockspace_local(proc->lockspace); 415 if (!ls) 416 return -ENOENT; 417 418 error = dlm_user_purge(ls, proc, params->nodeid, params->pid); 419 420 dlm_put_lockspace(ls); 421 return error; 422 } 423 424 static int device_create_lockspace(struct dlm_lspace_params *params) 425 { 426 dlm_lockspace_t *lockspace; 427 struct dlm_ls *ls; 428 int error; 429 430 if (!capable(CAP_SYS_ADMIN)) 431 return -EPERM; 432 433 error = dlm_new_user_lockspace(params->name, dlm_config.ci_cluster_name, 434 params->flags, DLM_USER_LVB_LEN, NULL, 435 NULL, NULL, &lockspace); 436 if (error) 437 return error; 438 439 ls = dlm_find_lockspace_local(lockspace); 440 if (!ls) 441 return -ENOENT; 442 443 error = dlm_device_register(ls, params->name); 444 dlm_put_lockspace(ls); 445 446 if (error) 447 dlm_release_lockspace(lockspace, 0); 448 else 449 error = ls->ls_device.minor; 450 451 return error; 452 } 453 454 static int device_remove_lockspace(struct dlm_lspace_params *params) 455 { 456 dlm_lockspace_t *lockspace; 457 struct dlm_ls *ls; 458 int error, force = 0; 459 460 if (!capable(CAP_SYS_ADMIN)) 461 return -EPERM; 462 463 ls = dlm_find_lockspace_device(params->minor); 464 if (!ls) 465 return -ENOENT; 466 467 if (params->flags & DLM_USER_LSFLG_FORCEFREE) 468 force = 2; 469 470 lockspace = ls->ls_local_handle; 471 dlm_put_lockspace(ls); 472 473 /* The final dlm_release_lockspace waits for references to go to 474 zero, so all processes will need to close their device for the 475 ls before the release will proceed. release also calls the 476 device_deregister above. Converting a positive return value 477 from release to zero means that userspace won't know when its 478 release was the final one, but it shouldn't need to know. */ 479 480 error = dlm_release_lockspace(lockspace, force); 481 if (error > 0) 482 error = 0; 483 return error; 484 } 485 486 /* Check the user's version matches ours */ 487 static int check_version(struct dlm_write_request *req) 488 { 489 if (req->version[0] != DLM_DEVICE_VERSION_MAJOR || 490 (req->version[0] == DLM_DEVICE_VERSION_MAJOR && 491 req->version[1] > DLM_DEVICE_VERSION_MINOR)) { 492 493 printk(KERN_DEBUG "dlm: process %s (%d) version mismatch " 494 "user (%d.%d.%d) kernel (%d.%d.%d)\n", 495 current->comm, 496 task_pid_nr(current), 497 req->version[0], 498 req->version[1], 499 req->version[2], 500 DLM_DEVICE_VERSION_MAJOR, 501 DLM_DEVICE_VERSION_MINOR, 502 DLM_DEVICE_VERSION_PATCH); 503 return -EINVAL; 504 } 505 return 0; 506 } 507 508 /* 509 * device_write 510 * 511 * device_user_lock 512 * dlm_user_request -> request_lock 513 * dlm_user_convert -> convert_lock 514 * 515 * device_user_unlock 516 * dlm_user_unlock -> unlock_lock 517 * dlm_user_cancel -> cancel_lock 518 * 519 * device_create_lockspace 520 * dlm_new_lockspace 521 * 522 * device_remove_lockspace 523 * dlm_release_lockspace 524 */ 525 526 /* a write to a lockspace device is a lock or unlock request, a write 527 to the control device is to create/remove a lockspace */ 528 529 static ssize_t device_write(struct file *file, const char __user *buf, 530 size_t count, loff_t *ppos) 531 { 532 struct dlm_user_proc *proc = file->private_data; 533 struct dlm_write_request *kbuf; 534 int error; 535 536 #ifdef CONFIG_COMPAT 537 if (count < sizeof(struct dlm_write_request32)) 538 #else 539 if (count < sizeof(struct dlm_write_request)) 540 #endif 541 return -EINVAL; 542 543 /* 544 * can't compare against COMPAT/dlm_write_request32 because 545 * we don't yet know if is64bit is zero 546 */ 547 if (count > sizeof(struct dlm_write_request) + DLM_RESNAME_MAXLEN) 548 return -EINVAL; 549 550 kbuf = memdup_user_nul(buf, count); 551 if (IS_ERR(kbuf)) 552 return PTR_ERR(kbuf); 553 554 if (check_version(kbuf)) { 555 error = -EBADE; 556 goto out_free; 557 } 558 559 #ifdef CONFIG_COMPAT 560 if (!kbuf->is64bit) { 561 struct dlm_write_request32 *k32buf; 562 int namelen = 0; 563 564 if (count > sizeof(struct dlm_write_request32)) 565 namelen = count - sizeof(struct dlm_write_request32); 566 567 k32buf = (struct dlm_write_request32 *)kbuf; 568 569 /* add 1 after namelen so that the name string is terminated */ 570 kbuf = kzalloc(sizeof(struct dlm_write_request) + namelen + 1, 571 GFP_NOFS); 572 if (!kbuf) { 573 kfree(k32buf); 574 return -ENOMEM; 575 } 576 577 if (proc) 578 set_bit(DLM_PROC_FLAGS_COMPAT, &proc->flags); 579 580 compat_input(kbuf, k32buf, namelen); 581 kfree(k32buf); 582 } 583 #endif 584 585 /* do we really need this? can a write happen after a close? */ 586 if ((kbuf->cmd == DLM_USER_LOCK || kbuf->cmd == DLM_USER_UNLOCK) && 587 (proc && test_bit(DLM_PROC_FLAGS_CLOSING, &proc->flags))) { 588 error = -EINVAL; 589 goto out_free; 590 } 591 592 error = -EINVAL; 593 594 switch (kbuf->cmd) 595 { 596 case DLM_USER_LOCK: 597 if (!proc) { 598 log_print("no locking on control device"); 599 goto out_free; 600 } 601 error = device_user_lock(proc, &kbuf->i.lock); 602 break; 603 604 case DLM_USER_UNLOCK: 605 if (!proc) { 606 log_print("no locking on control device"); 607 goto out_free; 608 } 609 error = device_user_unlock(proc, &kbuf->i.lock); 610 break; 611 612 case DLM_USER_DEADLOCK: 613 if (!proc) { 614 log_print("no locking on control device"); 615 goto out_free; 616 } 617 error = device_user_deadlock(proc, &kbuf->i.lock); 618 break; 619 620 case DLM_USER_CREATE_LOCKSPACE: 621 if (proc) { 622 log_print("create/remove only on control device"); 623 goto out_free; 624 } 625 error = device_create_lockspace(&kbuf->i.lspace); 626 break; 627 628 case DLM_USER_REMOVE_LOCKSPACE: 629 if (proc) { 630 log_print("create/remove only on control device"); 631 goto out_free; 632 } 633 error = device_remove_lockspace(&kbuf->i.lspace); 634 break; 635 636 case DLM_USER_PURGE: 637 if (!proc) { 638 log_print("no locking on control device"); 639 goto out_free; 640 } 641 error = device_user_purge(proc, &kbuf->i.purge); 642 break; 643 644 default: 645 log_print("Unknown command passed to DLM device : %d\n", 646 kbuf->cmd); 647 } 648 649 out_free: 650 kfree(kbuf); 651 return error; 652 } 653 654 /* Every process that opens the lockspace device has its own "proc" structure 655 hanging off the open file that's used to keep track of locks owned by the 656 process and asts that need to be delivered to the process. */ 657 658 static int device_open(struct inode *inode, struct file *file) 659 { 660 struct dlm_user_proc *proc; 661 struct dlm_ls *ls; 662 663 ls = dlm_find_lockspace_device(iminor(inode)); 664 if (!ls) 665 return -ENOENT; 666 667 proc = kzalloc(sizeof(struct dlm_user_proc), GFP_NOFS); 668 if (!proc) { 669 dlm_put_lockspace(ls); 670 return -ENOMEM; 671 } 672 673 proc->lockspace = ls->ls_local_handle; 674 INIT_LIST_HEAD(&proc->asts); 675 INIT_LIST_HEAD(&proc->locks); 676 INIT_LIST_HEAD(&proc->unlocking); 677 spin_lock_init(&proc->asts_spin); 678 spin_lock_init(&proc->locks_spin); 679 init_waitqueue_head(&proc->wait); 680 file->private_data = proc; 681 682 return 0; 683 } 684 685 static int device_close(struct inode *inode, struct file *file) 686 { 687 struct dlm_user_proc *proc = file->private_data; 688 struct dlm_ls *ls; 689 690 ls = dlm_find_lockspace_local(proc->lockspace); 691 if (!ls) 692 return -ENOENT; 693 694 set_bit(DLM_PROC_FLAGS_CLOSING, &proc->flags); 695 696 dlm_clear_proc_locks(ls, proc); 697 698 /* at this point no more lkb's should exist for this lockspace, 699 so there's no chance of dlm_user_add_ast() being called and 700 looking for lkb->ua->proc */ 701 702 kfree(proc); 703 file->private_data = NULL; 704 705 dlm_put_lockspace(ls); 706 dlm_put_lockspace(ls); /* for the find in device_open() */ 707 708 /* FIXME: AUTOFREE: if this ls is no longer used do 709 device_remove_lockspace() */ 710 711 return 0; 712 } 713 714 static int copy_result_to_user(struct dlm_user_args *ua, int compat, 715 uint32_t flags, int mode, int copy_lvb, 716 char __user *buf, size_t count) 717 { 718 #ifdef CONFIG_COMPAT 719 struct dlm_lock_result32 result32; 720 #endif 721 struct dlm_lock_result result; 722 void *resultptr; 723 int error=0; 724 int len; 725 int struct_len; 726 727 memset(&result, 0, sizeof(struct dlm_lock_result)); 728 result.version[0] = DLM_DEVICE_VERSION_MAJOR; 729 result.version[1] = DLM_DEVICE_VERSION_MINOR; 730 result.version[2] = DLM_DEVICE_VERSION_PATCH; 731 memcpy(&result.lksb, &ua->lksb, offsetof(struct dlm_lksb, sb_lvbptr)); 732 result.user_lksb = ua->user_lksb; 733 734 /* FIXME: dlm1 provides for the user's bastparam/addr to not be updated 735 in a conversion unless the conversion is successful. See code 736 in dlm_user_convert() for updating ua from ua_tmp. OpenVMS, though, 737 notes that a new blocking AST address and parameter are set even if 738 the conversion fails, so maybe we should just do that. */ 739 740 if (flags & DLM_CB_BAST) { 741 result.user_astaddr = ua->bastaddr; 742 result.user_astparam = ua->bastparam; 743 result.bast_mode = mode; 744 } else { 745 result.user_astaddr = ua->castaddr; 746 result.user_astparam = ua->castparam; 747 } 748 749 #ifdef CONFIG_COMPAT 750 if (compat) 751 len = sizeof(struct dlm_lock_result32); 752 else 753 #endif 754 len = sizeof(struct dlm_lock_result); 755 struct_len = len; 756 757 /* copy lvb to userspace if there is one, it's been updated, and 758 the user buffer has space for it */ 759 760 if (copy_lvb && ua->lksb.sb_lvbptr && count >= len + DLM_USER_LVB_LEN) { 761 if (copy_to_user(buf+len, ua->lksb.sb_lvbptr, 762 DLM_USER_LVB_LEN)) { 763 error = -EFAULT; 764 goto out; 765 } 766 767 result.lvb_offset = len; 768 len += DLM_USER_LVB_LEN; 769 } 770 771 result.length = len; 772 resultptr = &result; 773 #ifdef CONFIG_COMPAT 774 if (compat) { 775 compat_output(&result, &result32); 776 resultptr = &result32; 777 } 778 #endif 779 780 if (copy_to_user(buf, resultptr, struct_len)) 781 error = -EFAULT; 782 else 783 error = len; 784 out: 785 return error; 786 } 787 788 static int copy_version_to_user(char __user *buf, size_t count) 789 { 790 struct dlm_device_version ver; 791 792 memset(&ver, 0, sizeof(struct dlm_device_version)); 793 ver.version[0] = DLM_DEVICE_VERSION_MAJOR; 794 ver.version[1] = DLM_DEVICE_VERSION_MINOR; 795 ver.version[2] = DLM_DEVICE_VERSION_PATCH; 796 797 if (copy_to_user(buf, &ver, sizeof(struct dlm_device_version))) 798 return -EFAULT; 799 return sizeof(struct dlm_device_version); 800 } 801 802 /* a read returns a single ast described in a struct dlm_lock_result */ 803 804 static ssize_t device_read(struct file *file, char __user *buf, size_t count, 805 loff_t *ppos) 806 { 807 struct dlm_user_proc *proc = file->private_data; 808 struct dlm_lkb *lkb; 809 DECLARE_WAITQUEUE(wait, current); 810 struct dlm_callback *cb; 811 int rv, copy_lvb = 0; 812 int old_mode, new_mode; 813 814 if (count == sizeof(struct dlm_device_version)) { 815 rv = copy_version_to_user(buf, count); 816 return rv; 817 } 818 819 if (!proc) { 820 log_print("non-version read from control device %zu", count); 821 return -EINVAL; 822 } 823 824 #ifdef CONFIG_COMPAT 825 if (count < sizeof(struct dlm_lock_result32)) 826 #else 827 if (count < sizeof(struct dlm_lock_result)) 828 #endif 829 return -EINVAL; 830 831 try_another: 832 833 /* do we really need this? can a read happen after a close? */ 834 if (test_bit(DLM_PROC_FLAGS_CLOSING, &proc->flags)) 835 return -EINVAL; 836 837 spin_lock(&proc->asts_spin); 838 if (list_empty(&proc->asts)) { 839 if (file->f_flags & O_NONBLOCK) { 840 spin_unlock(&proc->asts_spin); 841 return -EAGAIN; 842 } 843 844 add_wait_queue(&proc->wait, &wait); 845 846 repeat: 847 set_current_state(TASK_INTERRUPTIBLE); 848 if (list_empty(&proc->asts) && !signal_pending(current)) { 849 spin_unlock(&proc->asts_spin); 850 schedule(); 851 spin_lock(&proc->asts_spin); 852 goto repeat; 853 } 854 set_current_state(TASK_RUNNING); 855 remove_wait_queue(&proc->wait, &wait); 856 857 if (signal_pending(current)) { 858 spin_unlock(&proc->asts_spin); 859 return -ERESTARTSYS; 860 } 861 } 862 863 /* if we empty lkb_callbacks, we don't want to unlock the spinlock 864 without removing lkb_cb_list; so empty lkb_cb_list is always 865 consistent with empty lkb_callbacks */ 866 867 lkb = list_first_entry(&proc->asts, struct dlm_lkb, lkb_cb_list); 868 869 /* rem_lkb_callback sets a new lkb_last_cast */ 870 old_mode = lkb->lkb_last_cast->mode; 871 872 rv = dlm_dequeue_lkb_callback(lkb, &cb); 873 switch (rv) { 874 case DLM_DEQUEUE_CALLBACK_EMPTY: 875 /* this shouldn't happen; lkb should have been removed from 876 * list when last item was dequeued 877 */ 878 log_print("dlm_rem_lkb_callback empty %x", lkb->lkb_id); 879 list_del_init(&lkb->lkb_cb_list); 880 spin_unlock(&proc->asts_spin); 881 /* removes ref for proc->asts, may cause lkb to be freed */ 882 dlm_put_lkb(lkb); 883 WARN_ON_ONCE(1); 884 goto try_another; 885 case DLM_DEQUEUE_CALLBACK_LAST: 886 list_del_init(&lkb->lkb_cb_list); 887 lkb->lkb_flags &= ~DLM_IFL_CB_PENDING; 888 break; 889 case DLM_DEQUEUE_CALLBACK_SUCCESS: 890 break; 891 default: 892 WARN_ON_ONCE(1); 893 break; 894 } 895 spin_unlock(&proc->asts_spin); 896 897 if (cb->flags & DLM_CB_BAST) { 898 trace_dlm_bast(lkb->lkb_resource->res_ls, lkb, cb->mode); 899 } else if (cb->flags & DLM_CB_CAST) { 900 new_mode = cb->mode; 901 902 if (!cb->sb_status && lkb->lkb_lksb->sb_lvbptr && 903 dlm_lvb_operations[old_mode + 1][new_mode + 1]) 904 copy_lvb = 1; 905 906 lkb->lkb_lksb->sb_status = cb->sb_status; 907 lkb->lkb_lksb->sb_flags = cb->sb_flags; 908 trace_dlm_ast(lkb->lkb_resource->res_ls, lkb); 909 } 910 911 rv = copy_result_to_user(lkb->lkb_ua, 912 test_bit(DLM_PROC_FLAGS_COMPAT, &proc->flags), 913 cb->flags, cb->mode, copy_lvb, buf, count); 914 915 kref_put(&cb->ref, dlm_release_callback); 916 917 /* removes ref for proc->asts, may cause lkb to be freed */ 918 if (rv == DLM_DEQUEUE_CALLBACK_LAST) 919 dlm_put_lkb(lkb); 920 921 return rv; 922 } 923 924 static __poll_t device_poll(struct file *file, poll_table *wait) 925 { 926 struct dlm_user_proc *proc = file->private_data; 927 928 poll_wait(file, &proc->wait, wait); 929 930 spin_lock(&proc->asts_spin); 931 if (!list_empty(&proc->asts)) { 932 spin_unlock(&proc->asts_spin); 933 return EPOLLIN | EPOLLRDNORM; 934 } 935 spin_unlock(&proc->asts_spin); 936 return 0; 937 } 938 939 int dlm_user_daemon_available(void) 940 { 941 /* dlm_controld hasn't started (or, has started, but not 942 properly populated configfs) */ 943 944 if (!dlm_our_nodeid()) 945 return 0; 946 947 /* This is to deal with versions of dlm_controld that don't 948 know about the monitor device. We assume that if the 949 dlm_controld was started (above), but the monitor device 950 was never opened, that it's an old version. dlm_controld 951 should open the monitor device before populating configfs. */ 952 953 if (dlm_monitor_unused) 954 return 1; 955 956 return atomic_read(&dlm_monitor_opened) ? 1 : 0; 957 } 958 959 static int ctl_device_open(struct inode *inode, struct file *file) 960 { 961 file->private_data = NULL; 962 return 0; 963 } 964 965 static int ctl_device_close(struct inode *inode, struct file *file) 966 { 967 return 0; 968 } 969 970 static int monitor_device_open(struct inode *inode, struct file *file) 971 { 972 atomic_inc(&dlm_monitor_opened); 973 dlm_monitor_unused = 0; 974 return 0; 975 } 976 977 static int monitor_device_close(struct inode *inode, struct file *file) 978 { 979 if (atomic_dec_and_test(&dlm_monitor_opened)) 980 dlm_stop_lockspaces(); 981 return 0; 982 } 983 984 static const struct file_operations device_fops = { 985 .open = device_open, 986 .release = device_close, 987 .read = device_read, 988 .write = device_write, 989 .poll = device_poll, 990 .owner = THIS_MODULE, 991 .llseek = noop_llseek, 992 }; 993 994 static const struct file_operations ctl_device_fops = { 995 .open = ctl_device_open, 996 .release = ctl_device_close, 997 .read = device_read, 998 .write = device_write, 999 .owner = THIS_MODULE, 1000 .llseek = noop_llseek, 1001 }; 1002 1003 static struct miscdevice ctl_device = { 1004 .name = "dlm-control", 1005 .fops = &ctl_device_fops, 1006 .minor = MISC_DYNAMIC_MINOR, 1007 }; 1008 1009 static const struct file_operations monitor_device_fops = { 1010 .open = monitor_device_open, 1011 .release = monitor_device_close, 1012 .owner = THIS_MODULE, 1013 .llseek = noop_llseek, 1014 }; 1015 1016 static struct miscdevice monitor_device = { 1017 .name = "dlm-monitor", 1018 .fops = &monitor_device_fops, 1019 .minor = MISC_DYNAMIC_MINOR, 1020 }; 1021 1022 int __init dlm_user_init(void) 1023 { 1024 int error; 1025 1026 atomic_set(&dlm_monitor_opened, 0); 1027 1028 error = misc_register(&ctl_device); 1029 if (error) { 1030 log_print("misc_register failed for control device"); 1031 goto out; 1032 } 1033 1034 error = misc_register(&monitor_device); 1035 if (error) { 1036 log_print("misc_register failed for monitor device"); 1037 misc_deregister(&ctl_device); 1038 } 1039 out: 1040 return error; 1041 } 1042 1043 void dlm_user_exit(void) 1044 { 1045 misc_deregister(&ctl_device); 1046 misc_deregister(&monitor_device); 1047 } 1048 1049