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