1 /* 2 * Copyright (C) 2006-2008 Red Hat, Inc. All rights reserved. 3 * 4 * This copyrighted material is made available to anyone wishing to use, 5 * modify, copy, or redistribute it subject to the terms and conditions 6 * of the GNU General Public License v.2. 7 */ 8 9 #include <linux/miscdevice.h> 10 #include <linux/init.h> 11 #include <linux/wait.h> 12 #include <linux/module.h> 13 #include <linux/file.h> 14 #include <linux/fs.h> 15 #include <linux/poll.h> 16 #include <linux/signal.h> 17 #include <linux/spinlock.h> 18 #include <linux/dlm.h> 19 #include <linux/dlm_device.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 27 static const char name_prefix[] = "dlm"; 28 static const struct file_operations device_fops; 29 static atomic_t dlm_monitor_opened; 30 static int dlm_monitor_unused = 1; 31 32 #ifdef CONFIG_COMPAT 33 34 struct dlm_lock_params32 { 35 __u8 mode; 36 __u8 namelen; 37 __u16 unused; 38 __u32 flags; 39 __u32 lkid; 40 __u32 parent; 41 __u64 xid; 42 __u64 timeout; 43 __u32 castparam; 44 __u32 castaddr; 45 __u32 bastparam; 46 __u32 bastaddr; 47 __u32 lksb; 48 char lvb[DLM_USER_LVB_LEN]; 49 char name[0]; 50 }; 51 52 struct dlm_write_request32 { 53 __u32 version[3]; 54 __u8 cmd; 55 __u8 is64bit; 56 __u8 unused[2]; 57 58 union { 59 struct dlm_lock_params32 lock; 60 struct dlm_lspace_params lspace; 61 struct dlm_purge_params purge; 62 } i; 63 }; 64 65 struct dlm_lksb32 { 66 __u32 sb_status; 67 __u32 sb_lkid; 68 __u8 sb_flags; 69 __u32 sb_lvbptr; 70 }; 71 72 struct dlm_lock_result32 { 73 __u32 version[3]; 74 __u32 length; 75 __u32 user_astaddr; 76 __u32 user_astparam; 77 __u32 user_lksb; 78 struct dlm_lksb32 lksb; 79 __u8 bast_mode; 80 __u8 unused[3]; 81 /* Offsets may be zero if no data is present */ 82 __u32 lvb_offset; 83 }; 84 85 static void compat_input(struct dlm_write_request *kb, 86 struct dlm_write_request32 *kb32, 87 size_t count) 88 { 89 kb->version[0] = kb32->version[0]; 90 kb->version[1] = kb32->version[1]; 91 kb->version[2] = kb32->version[2]; 92 93 kb->cmd = kb32->cmd; 94 kb->is64bit = kb32->is64bit; 95 if (kb->cmd == DLM_USER_CREATE_LOCKSPACE || 96 kb->cmd == DLM_USER_REMOVE_LOCKSPACE) { 97 kb->i.lspace.flags = kb32->i.lspace.flags; 98 kb->i.lspace.minor = kb32->i.lspace.minor; 99 memcpy(kb->i.lspace.name, kb32->i.lspace.name, count - 100 offsetof(struct dlm_write_request32, i.lspace.name)); 101 } else if (kb->cmd == DLM_USER_PURGE) { 102 kb->i.purge.nodeid = kb32->i.purge.nodeid; 103 kb->i.purge.pid = kb32->i.purge.pid; 104 } else { 105 kb->i.lock.mode = kb32->i.lock.mode; 106 kb->i.lock.namelen = kb32->i.lock.namelen; 107 kb->i.lock.flags = kb32->i.lock.flags; 108 kb->i.lock.lkid = kb32->i.lock.lkid; 109 kb->i.lock.parent = kb32->i.lock.parent; 110 kb->i.lock.xid = kb32->i.lock.xid; 111 kb->i.lock.timeout = kb32->i.lock.timeout; 112 kb->i.lock.castparam = (void *)(long)kb32->i.lock.castparam; 113 kb->i.lock.castaddr = (void *)(long)kb32->i.lock.castaddr; 114 kb->i.lock.bastparam = (void *)(long)kb32->i.lock.bastparam; 115 kb->i.lock.bastaddr = (void *)(long)kb32->i.lock.bastaddr; 116 kb->i.lock.lksb = (void *)(long)kb32->i.lock.lksb; 117 memcpy(kb->i.lock.lvb, kb32->i.lock.lvb, DLM_USER_LVB_LEN); 118 memcpy(kb->i.lock.name, kb32->i.lock.name, count - 119 offsetof(struct dlm_write_request32, i.lock.name)); 120 } 121 } 122 123 static void compat_output(struct dlm_lock_result *res, 124 struct dlm_lock_result32 *res32) 125 { 126 res32->version[0] = res->version[0]; 127 res32->version[1] = res->version[1]; 128 res32->version[2] = res->version[2]; 129 130 res32->user_astaddr = (__u32)(long)res->user_astaddr; 131 res32->user_astparam = (__u32)(long)res->user_astparam; 132 res32->user_lksb = (__u32)(long)res->user_lksb; 133 res32->bast_mode = res->bast_mode; 134 135 res32->lvb_offset = res->lvb_offset; 136 res32->length = res->length; 137 138 res32->lksb.sb_status = res->lksb.sb_status; 139 res32->lksb.sb_flags = res->lksb.sb_flags; 140 res32->lksb.sb_lkid = res->lksb.sb_lkid; 141 res32->lksb.sb_lvbptr = (__u32)(long)res->lksb.sb_lvbptr; 142 } 143 #endif 144 145 /* Figure out if this lock is at the end of its life and no longer 146 available for the application to use. The lkb still exists until 147 the final ast is read. A lock becomes EOL in three situations: 148 1. a noqueue request fails with EAGAIN 149 2. an unlock completes with EUNLOCK 150 3. a cancel of a waiting request completes with ECANCEL/EDEADLK 151 An EOL lock needs to be removed from the process's list of locks. 152 And we can't allow any new operation on an EOL lock. This is 153 not related to the lifetime of the lkb struct which is managed 154 entirely by refcount. */ 155 156 static int lkb_is_endoflife(struct dlm_lkb *lkb, int sb_status, int type) 157 { 158 switch (sb_status) { 159 case -DLM_EUNLOCK: 160 return 1; 161 case -DLM_ECANCEL: 162 case -ETIMEDOUT: 163 case -EDEADLK: 164 if (lkb->lkb_grmode == DLM_LOCK_IV) 165 return 1; 166 break; 167 case -EAGAIN: 168 if (type == AST_COMP && lkb->lkb_grmode == 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, int type, int bastmode) 179 { 180 struct dlm_ls *ls; 181 struct dlm_user_args *ua; 182 struct dlm_user_proc *proc; 183 int eol = 0, ast_type; 184 185 if (lkb->lkb_flags & (DLM_IFL_ORPHAN | DLM_IFL_DEAD)) 186 return; 187 188 ls = lkb->lkb_resource->res_ls; 189 mutex_lock(&ls->ls_clear_proc_locks); 190 191 /* If ORPHAN/DEAD flag is set, it means the process is dead so an ast 192 can't be delivered. For ORPHAN's, dlm_clear_proc_locks() freed 193 lkb->ua so we can't try to use it. This second check is necessary 194 for cases where a completion ast is received for an operation that 195 began before clear_proc_locks did its cancel/unlock. */ 196 197 if (lkb->lkb_flags & (DLM_IFL_ORPHAN | DLM_IFL_DEAD)) 198 goto out; 199 200 DLM_ASSERT(lkb->lkb_ua, dlm_print_lkb(lkb);); 201 ua = lkb->lkb_ua; 202 proc = ua->proc; 203 204 if (type == AST_BAST && ua->bastaddr == NULL) 205 goto out; 206 207 spin_lock(&proc->asts_spin); 208 209 ast_type = lkb->lkb_ast_type; 210 lkb->lkb_ast_type |= type; 211 if (bastmode) 212 lkb->lkb_bastmode = bastmode; 213 214 if (!ast_type) { 215 kref_get(&lkb->lkb_ref); 216 list_add_tail(&lkb->lkb_astqueue, &proc->asts); 217 wake_up_interruptible(&proc->wait); 218 } 219 if (type == AST_COMP && (ast_type & AST_COMP)) 220 log_debug(ls, "ast overlap %x status %x %x", 221 lkb->lkb_id, ua->lksb.sb_status, lkb->lkb_flags); 222 223 eol = lkb_is_endoflife(lkb, ua->lksb.sb_status, type); 224 if (eol) { 225 lkb->lkb_ast_type &= ~AST_BAST; 226 lkb->lkb_flags |= DLM_IFL_ENDOFLIFE; 227 } 228 229 /* We want to copy the lvb to userspace when the completion 230 ast is read if the status is 0, the lock has an lvb and 231 lvb_ops says we should. We could probably have set_lvb_lock() 232 set update_user_lvb instead and not need old_mode */ 233 234 if ((lkb->lkb_ast_type & AST_COMP) && 235 (lkb->lkb_lksb->sb_status == 0) && 236 lkb->lkb_lksb->sb_lvbptr && 237 dlm_lvb_operations[ua->old_mode + 1][lkb->lkb_grmode + 1]) 238 ua->update_user_lvb = 1; 239 else 240 ua->update_user_lvb = 0; 241 242 spin_unlock(&proc->asts_spin); 243 244 if (eol) { 245 spin_lock(&proc->locks_spin); 246 if (!list_empty(&lkb->lkb_ownqueue)) { 247 list_del_init(&lkb->lkb_ownqueue); 248 dlm_put_lkb(lkb); 249 } 250 spin_unlock(&proc->locks_spin); 251 } 252 out: 253 mutex_unlock(&ls->ls_clear_proc_locks); 254 } 255 256 static int device_user_lock(struct dlm_user_proc *proc, 257 struct dlm_lock_params *params) 258 { 259 struct dlm_ls *ls; 260 struct dlm_user_args *ua; 261 int error = -ENOMEM; 262 263 ls = dlm_find_lockspace_local(proc->lockspace); 264 if (!ls) 265 return -ENOENT; 266 267 if (!params->castaddr || !params->lksb) { 268 error = -EINVAL; 269 goto out; 270 } 271 272 ua = kzalloc(sizeof(struct dlm_user_args), GFP_KERNEL); 273 if (!ua) 274 goto out; 275 ua->proc = proc; 276 ua->user_lksb = params->lksb; 277 ua->castparam = params->castparam; 278 ua->castaddr = params->castaddr; 279 ua->bastparam = params->bastparam; 280 ua->bastaddr = params->bastaddr; 281 ua->xid = params->xid; 282 283 if (params->flags & DLM_LKF_CONVERT) 284 error = dlm_user_convert(ls, ua, 285 params->mode, params->flags, 286 params->lkid, params->lvb, 287 (unsigned long) params->timeout); 288 else { 289 error = dlm_user_request(ls, ua, 290 params->mode, params->flags, 291 params->name, params->namelen, 292 (unsigned long) params->timeout); 293 if (!error) 294 error = ua->lksb.sb_lkid; 295 } 296 out: 297 dlm_put_lockspace(ls); 298 return error; 299 } 300 301 static int device_user_unlock(struct dlm_user_proc *proc, 302 struct dlm_lock_params *params) 303 { 304 struct dlm_ls *ls; 305 struct dlm_user_args *ua; 306 int error = -ENOMEM; 307 308 ls = dlm_find_lockspace_local(proc->lockspace); 309 if (!ls) 310 return -ENOENT; 311 312 ua = kzalloc(sizeof(struct dlm_user_args), GFP_KERNEL); 313 if (!ua) 314 goto out; 315 ua->proc = proc; 316 ua->user_lksb = params->lksb; 317 ua->castparam = params->castparam; 318 ua->castaddr = params->castaddr; 319 320 if (params->flags & DLM_LKF_CANCEL) 321 error = dlm_user_cancel(ls, ua, params->flags, params->lkid); 322 else 323 error = dlm_user_unlock(ls, ua, params->flags, params->lkid, 324 params->lvb); 325 out: 326 dlm_put_lockspace(ls); 327 return error; 328 } 329 330 static int device_user_deadlock(struct dlm_user_proc *proc, 331 struct dlm_lock_params *params) 332 { 333 struct dlm_ls *ls; 334 int error; 335 336 ls = dlm_find_lockspace_local(proc->lockspace); 337 if (!ls) 338 return -ENOENT; 339 340 error = dlm_user_deadlock(ls, params->flags, params->lkid); 341 342 dlm_put_lockspace(ls); 343 return error; 344 } 345 346 static int dlm_device_register(struct dlm_ls *ls, char *name) 347 { 348 int error, len; 349 350 /* The device is already registered. This happens when the 351 lockspace is created multiple times from userspace. */ 352 if (ls->ls_device.name) 353 return 0; 354 355 error = -ENOMEM; 356 len = strlen(name) + strlen(name_prefix) + 2; 357 ls->ls_device.name = kzalloc(len, GFP_KERNEL); 358 if (!ls->ls_device.name) 359 goto fail; 360 361 snprintf((char *)ls->ls_device.name, len, "%s_%s", name_prefix, 362 name); 363 ls->ls_device.fops = &device_fops; 364 ls->ls_device.minor = MISC_DYNAMIC_MINOR; 365 366 error = misc_register(&ls->ls_device); 367 if (error) { 368 kfree(ls->ls_device.name); 369 } 370 fail: 371 return error; 372 } 373 374 int dlm_device_deregister(struct dlm_ls *ls) 375 { 376 int error; 377 378 /* The device is not registered. This happens when the lockspace 379 was never used from userspace, or when device_create_lockspace() 380 calls dlm_release_lockspace() after the register fails. */ 381 if (!ls->ls_device.name) 382 return 0; 383 384 error = misc_deregister(&ls->ls_device); 385 if (!error) 386 kfree(ls->ls_device.name); 387 return error; 388 } 389 390 static int device_user_purge(struct dlm_user_proc *proc, 391 struct dlm_purge_params *params) 392 { 393 struct dlm_ls *ls; 394 int error; 395 396 ls = dlm_find_lockspace_local(proc->lockspace); 397 if (!ls) 398 return -ENOENT; 399 400 error = dlm_user_purge(ls, proc, params->nodeid, params->pid); 401 402 dlm_put_lockspace(ls); 403 return error; 404 } 405 406 static int device_create_lockspace(struct dlm_lspace_params *params) 407 { 408 dlm_lockspace_t *lockspace; 409 struct dlm_ls *ls; 410 int error; 411 412 if (!capable(CAP_SYS_ADMIN)) 413 return -EPERM; 414 415 error = dlm_new_lockspace(params->name, strlen(params->name), 416 &lockspace, params->flags, DLM_USER_LVB_LEN); 417 if (error) 418 return error; 419 420 ls = dlm_find_lockspace_local(lockspace); 421 if (!ls) 422 return -ENOENT; 423 424 error = dlm_device_register(ls, params->name); 425 dlm_put_lockspace(ls); 426 427 if (error) 428 dlm_release_lockspace(lockspace, 0); 429 else 430 error = ls->ls_device.minor; 431 432 return error; 433 } 434 435 static int device_remove_lockspace(struct dlm_lspace_params *params) 436 { 437 dlm_lockspace_t *lockspace; 438 struct dlm_ls *ls; 439 int error, force = 0; 440 441 if (!capable(CAP_SYS_ADMIN)) 442 return -EPERM; 443 444 ls = dlm_find_lockspace_device(params->minor); 445 if (!ls) 446 return -ENOENT; 447 448 if (params->flags & DLM_USER_LSFLG_FORCEFREE) 449 force = 2; 450 451 lockspace = ls->ls_local_handle; 452 dlm_put_lockspace(ls); 453 454 /* The final dlm_release_lockspace waits for references to go to 455 zero, so all processes will need to close their device for the 456 ls before the release will proceed. release also calls the 457 device_deregister above. Converting a positive return value 458 from release to zero means that userspace won't know when its 459 release was the final one, but it shouldn't need to know. */ 460 461 error = dlm_release_lockspace(lockspace, force); 462 if (error > 0) 463 error = 0; 464 return error; 465 } 466 467 /* Check the user's version matches ours */ 468 static int check_version(struct dlm_write_request *req) 469 { 470 if (req->version[0] != DLM_DEVICE_VERSION_MAJOR || 471 (req->version[0] == DLM_DEVICE_VERSION_MAJOR && 472 req->version[1] > DLM_DEVICE_VERSION_MINOR)) { 473 474 printk(KERN_DEBUG "dlm: process %s (%d) version mismatch " 475 "user (%d.%d.%d) kernel (%d.%d.%d)\n", 476 current->comm, 477 task_pid_nr(current), 478 req->version[0], 479 req->version[1], 480 req->version[2], 481 DLM_DEVICE_VERSION_MAJOR, 482 DLM_DEVICE_VERSION_MINOR, 483 DLM_DEVICE_VERSION_PATCH); 484 return -EINVAL; 485 } 486 return 0; 487 } 488 489 /* 490 * device_write 491 * 492 * device_user_lock 493 * dlm_user_request -> request_lock 494 * dlm_user_convert -> convert_lock 495 * 496 * device_user_unlock 497 * dlm_user_unlock -> unlock_lock 498 * dlm_user_cancel -> cancel_lock 499 * 500 * device_create_lockspace 501 * dlm_new_lockspace 502 * 503 * device_remove_lockspace 504 * dlm_release_lockspace 505 */ 506 507 /* a write to a lockspace device is a lock or unlock request, a write 508 to the control device is to create/remove a lockspace */ 509 510 static ssize_t device_write(struct file *file, const char __user *buf, 511 size_t count, loff_t *ppos) 512 { 513 struct dlm_user_proc *proc = file->private_data; 514 struct dlm_write_request *kbuf; 515 sigset_t tmpsig, allsigs; 516 int error; 517 518 #ifdef CONFIG_COMPAT 519 if (count < sizeof(struct dlm_write_request32)) 520 #else 521 if (count < sizeof(struct dlm_write_request)) 522 #endif 523 return -EINVAL; 524 525 kbuf = kzalloc(count + 1, GFP_KERNEL); 526 if (!kbuf) 527 return -ENOMEM; 528 529 if (copy_from_user(kbuf, buf, count)) { 530 error = -EFAULT; 531 goto out_free; 532 } 533 534 if (check_version(kbuf)) { 535 error = -EBADE; 536 goto out_free; 537 } 538 539 #ifdef CONFIG_COMPAT 540 if (!kbuf->is64bit) { 541 struct dlm_write_request32 *k32buf; 542 k32buf = (struct dlm_write_request32 *)kbuf; 543 kbuf = kmalloc(count + 1 + (sizeof(struct dlm_write_request) - 544 sizeof(struct dlm_write_request32)), GFP_KERNEL); 545 if (!kbuf) { 546 kfree(k32buf); 547 return -ENOMEM; 548 } 549 550 if (proc) 551 set_bit(DLM_PROC_FLAGS_COMPAT, &proc->flags); 552 compat_input(kbuf, k32buf, count + 1); 553 kfree(k32buf); 554 } 555 #endif 556 557 /* do we really need this? can a write happen after a close? */ 558 if ((kbuf->cmd == DLM_USER_LOCK || kbuf->cmd == DLM_USER_UNLOCK) && 559 (proc && test_bit(DLM_PROC_FLAGS_CLOSING, &proc->flags))) { 560 error = -EINVAL; 561 goto out_free; 562 } 563 564 sigfillset(&allsigs); 565 sigprocmask(SIG_BLOCK, &allsigs, &tmpsig); 566 567 error = -EINVAL; 568 569 switch (kbuf->cmd) 570 { 571 case DLM_USER_LOCK: 572 if (!proc) { 573 log_print("no locking on control device"); 574 goto out_sig; 575 } 576 error = device_user_lock(proc, &kbuf->i.lock); 577 break; 578 579 case DLM_USER_UNLOCK: 580 if (!proc) { 581 log_print("no locking on control device"); 582 goto out_sig; 583 } 584 error = device_user_unlock(proc, &kbuf->i.lock); 585 break; 586 587 case DLM_USER_DEADLOCK: 588 if (!proc) { 589 log_print("no locking on control device"); 590 goto out_sig; 591 } 592 error = device_user_deadlock(proc, &kbuf->i.lock); 593 break; 594 595 case DLM_USER_CREATE_LOCKSPACE: 596 if (proc) { 597 log_print("create/remove only on control device"); 598 goto out_sig; 599 } 600 error = device_create_lockspace(&kbuf->i.lspace); 601 break; 602 603 case DLM_USER_REMOVE_LOCKSPACE: 604 if (proc) { 605 log_print("create/remove only on control device"); 606 goto out_sig; 607 } 608 error = device_remove_lockspace(&kbuf->i.lspace); 609 break; 610 611 case DLM_USER_PURGE: 612 if (!proc) { 613 log_print("no locking on control device"); 614 goto out_sig; 615 } 616 error = device_user_purge(proc, &kbuf->i.purge); 617 break; 618 619 default: 620 log_print("Unknown command passed to DLM device : %d\n", 621 kbuf->cmd); 622 } 623 624 out_sig: 625 sigprocmask(SIG_SETMASK, &tmpsig, NULL); 626 recalc_sigpending(); 627 out_free: 628 kfree(kbuf); 629 return error; 630 } 631 632 /* Every process that opens the lockspace device has its own "proc" structure 633 hanging off the open file that's used to keep track of locks owned by the 634 process and asts that need to be delivered to the process. */ 635 636 static int device_open(struct inode *inode, struct file *file) 637 { 638 struct dlm_user_proc *proc; 639 struct dlm_ls *ls; 640 641 ls = dlm_find_lockspace_device(iminor(inode)); 642 if (!ls) 643 return -ENOENT; 644 645 proc = kzalloc(sizeof(struct dlm_user_proc), GFP_KERNEL); 646 if (!proc) { 647 dlm_put_lockspace(ls); 648 return -ENOMEM; 649 } 650 651 proc->lockspace = ls->ls_local_handle; 652 INIT_LIST_HEAD(&proc->asts); 653 INIT_LIST_HEAD(&proc->locks); 654 INIT_LIST_HEAD(&proc->unlocking); 655 spin_lock_init(&proc->asts_spin); 656 spin_lock_init(&proc->locks_spin); 657 init_waitqueue_head(&proc->wait); 658 file->private_data = proc; 659 660 return 0; 661 } 662 663 static int device_close(struct inode *inode, struct file *file) 664 { 665 struct dlm_user_proc *proc = file->private_data; 666 struct dlm_ls *ls; 667 sigset_t tmpsig, allsigs; 668 669 ls = dlm_find_lockspace_local(proc->lockspace); 670 if (!ls) 671 return -ENOENT; 672 673 sigfillset(&allsigs); 674 sigprocmask(SIG_BLOCK, &allsigs, &tmpsig); 675 676 set_bit(DLM_PROC_FLAGS_CLOSING, &proc->flags); 677 678 dlm_clear_proc_locks(ls, proc); 679 680 /* at this point no more lkb's should exist for this lockspace, 681 so there's no chance of dlm_user_add_ast() being called and 682 looking for lkb->ua->proc */ 683 684 kfree(proc); 685 file->private_data = NULL; 686 687 dlm_put_lockspace(ls); 688 dlm_put_lockspace(ls); /* for the find in device_open() */ 689 690 /* FIXME: AUTOFREE: if this ls is no longer used do 691 device_remove_lockspace() */ 692 693 sigprocmask(SIG_SETMASK, &tmpsig, NULL); 694 recalc_sigpending(); 695 696 return 0; 697 } 698 699 static int copy_result_to_user(struct dlm_user_args *ua, int compat, int type, 700 int bmode, char __user *buf, size_t count) 701 { 702 #ifdef CONFIG_COMPAT 703 struct dlm_lock_result32 result32; 704 #endif 705 struct dlm_lock_result result; 706 void *resultptr; 707 int error=0; 708 int len; 709 int struct_len; 710 711 memset(&result, 0, sizeof(struct dlm_lock_result)); 712 result.version[0] = DLM_DEVICE_VERSION_MAJOR; 713 result.version[1] = DLM_DEVICE_VERSION_MINOR; 714 result.version[2] = DLM_DEVICE_VERSION_PATCH; 715 memcpy(&result.lksb, &ua->lksb, sizeof(struct dlm_lksb)); 716 result.user_lksb = ua->user_lksb; 717 718 /* FIXME: dlm1 provides for the user's bastparam/addr to not be updated 719 in a conversion unless the conversion is successful. See code 720 in dlm_user_convert() for updating ua from ua_tmp. OpenVMS, though, 721 notes that a new blocking AST address and parameter are set even if 722 the conversion fails, so maybe we should just do that. */ 723 724 if (type == AST_BAST) { 725 result.user_astaddr = ua->bastaddr; 726 result.user_astparam = ua->bastparam; 727 result.bast_mode = bmode; 728 } else { 729 result.user_astaddr = ua->castaddr; 730 result.user_astparam = ua->castparam; 731 } 732 733 #ifdef CONFIG_COMPAT 734 if (compat) 735 len = sizeof(struct dlm_lock_result32); 736 else 737 #endif 738 len = sizeof(struct dlm_lock_result); 739 struct_len = len; 740 741 /* copy lvb to userspace if there is one, it's been updated, and 742 the user buffer has space for it */ 743 744 if (ua->update_user_lvb && ua->lksb.sb_lvbptr && 745 count >= len + DLM_USER_LVB_LEN) { 746 if (copy_to_user(buf+len, ua->lksb.sb_lvbptr, 747 DLM_USER_LVB_LEN)) { 748 error = -EFAULT; 749 goto out; 750 } 751 752 result.lvb_offset = len; 753 len += DLM_USER_LVB_LEN; 754 } 755 756 result.length = len; 757 resultptr = &result; 758 #ifdef CONFIG_COMPAT 759 if (compat) { 760 compat_output(&result, &result32); 761 resultptr = &result32; 762 } 763 #endif 764 765 if (copy_to_user(buf, resultptr, struct_len)) 766 error = -EFAULT; 767 else 768 error = len; 769 out: 770 return error; 771 } 772 773 static int copy_version_to_user(char __user *buf, size_t count) 774 { 775 struct dlm_device_version ver; 776 777 memset(&ver, 0, sizeof(struct dlm_device_version)); 778 ver.version[0] = DLM_DEVICE_VERSION_MAJOR; 779 ver.version[1] = DLM_DEVICE_VERSION_MINOR; 780 ver.version[2] = DLM_DEVICE_VERSION_PATCH; 781 782 if (copy_to_user(buf, &ver, sizeof(struct dlm_device_version))) 783 return -EFAULT; 784 return sizeof(struct dlm_device_version); 785 } 786 787 /* a read returns a single ast described in a struct dlm_lock_result */ 788 789 static ssize_t device_read(struct file *file, char __user *buf, size_t count, 790 loff_t *ppos) 791 { 792 struct dlm_user_proc *proc = file->private_data; 793 struct dlm_lkb *lkb; 794 DECLARE_WAITQUEUE(wait, current); 795 int error, type=0, bmode=0, removed = 0; 796 797 if (count == sizeof(struct dlm_device_version)) { 798 error = copy_version_to_user(buf, count); 799 return error; 800 } 801 802 if (!proc) { 803 log_print("non-version read from control device %zu", count); 804 return -EINVAL; 805 } 806 807 #ifdef CONFIG_COMPAT 808 if (count < sizeof(struct dlm_lock_result32)) 809 #else 810 if (count < sizeof(struct dlm_lock_result)) 811 #endif 812 return -EINVAL; 813 814 /* do we really need this? can a read happen after a close? */ 815 if (test_bit(DLM_PROC_FLAGS_CLOSING, &proc->flags)) 816 return -EINVAL; 817 818 spin_lock(&proc->asts_spin); 819 if (list_empty(&proc->asts)) { 820 if (file->f_flags & O_NONBLOCK) { 821 spin_unlock(&proc->asts_spin); 822 return -EAGAIN; 823 } 824 825 add_wait_queue(&proc->wait, &wait); 826 827 repeat: 828 set_current_state(TASK_INTERRUPTIBLE); 829 if (list_empty(&proc->asts) && !signal_pending(current)) { 830 spin_unlock(&proc->asts_spin); 831 schedule(); 832 spin_lock(&proc->asts_spin); 833 goto repeat; 834 } 835 set_current_state(TASK_RUNNING); 836 remove_wait_queue(&proc->wait, &wait); 837 838 if (signal_pending(current)) { 839 spin_unlock(&proc->asts_spin); 840 return -ERESTARTSYS; 841 } 842 } 843 844 /* there may be both completion and blocking asts to return for 845 the lkb, don't remove lkb from asts list unless no asts remain */ 846 847 lkb = list_entry(proc->asts.next, struct dlm_lkb, lkb_astqueue); 848 849 if (lkb->lkb_ast_type & AST_COMP) { 850 lkb->lkb_ast_type &= ~AST_COMP; 851 type = AST_COMP; 852 } else if (lkb->lkb_ast_type & AST_BAST) { 853 lkb->lkb_ast_type &= ~AST_BAST; 854 type = AST_BAST; 855 bmode = lkb->lkb_bastmode; 856 } 857 858 if (!lkb->lkb_ast_type) { 859 list_del(&lkb->lkb_astqueue); 860 removed = 1; 861 } 862 spin_unlock(&proc->asts_spin); 863 864 error = copy_result_to_user(lkb->lkb_ua, 865 test_bit(DLM_PROC_FLAGS_COMPAT, &proc->flags), 866 type, bmode, buf, count); 867 868 /* removes reference for the proc->asts lists added by 869 dlm_user_add_ast() and may result in the lkb being freed */ 870 if (removed) 871 dlm_put_lkb(lkb); 872 873 return error; 874 } 875 876 static unsigned int device_poll(struct file *file, poll_table *wait) 877 { 878 struct dlm_user_proc *proc = file->private_data; 879 880 poll_wait(file, &proc->wait, wait); 881 882 spin_lock(&proc->asts_spin); 883 if (!list_empty(&proc->asts)) { 884 spin_unlock(&proc->asts_spin); 885 return POLLIN | POLLRDNORM; 886 } 887 spin_unlock(&proc->asts_spin); 888 return 0; 889 } 890 891 int dlm_user_daemon_available(void) 892 { 893 /* dlm_controld hasn't started (or, has started, but not 894 properly populated configfs) */ 895 896 if (!dlm_our_nodeid()) 897 return 0; 898 899 /* This is to deal with versions of dlm_controld that don't 900 know about the monitor device. We assume that if the 901 dlm_controld was started (above), but the monitor device 902 was never opened, that it's an old version. dlm_controld 903 should open the monitor device before populating configfs. */ 904 905 if (dlm_monitor_unused) 906 return 1; 907 908 return atomic_read(&dlm_monitor_opened) ? 1 : 0; 909 } 910 911 static int ctl_device_open(struct inode *inode, struct file *file) 912 { 913 file->private_data = NULL; 914 return 0; 915 } 916 917 static int ctl_device_close(struct inode *inode, struct file *file) 918 { 919 return 0; 920 } 921 922 static int monitor_device_open(struct inode *inode, struct file *file) 923 { 924 atomic_inc(&dlm_monitor_opened); 925 dlm_monitor_unused = 0; 926 return 0; 927 } 928 929 static int monitor_device_close(struct inode *inode, struct file *file) 930 { 931 if (atomic_dec_and_test(&dlm_monitor_opened)) 932 dlm_stop_lockspaces(); 933 return 0; 934 } 935 936 static const struct file_operations device_fops = { 937 .open = device_open, 938 .release = device_close, 939 .read = device_read, 940 .write = device_write, 941 .poll = device_poll, 942 .owner = THIS_MODULE, 943 }; 944 945 static const struct file_operations ctl_device_fops = { 946 .open = ctl_device_open, 947 .release = ctl_device_close, 948 .read = device_read, 949 .write = device_write, 950 .owner = THIS_MODULE, 951 }; 952 953 static struct miscdevice ctl_device = { 954 .name = "dlm-control", 955 .fops = &ctl_device_fops, 956 .minor = MISC_DYNAMIC_MINOR, 957 }; 958 959 static const struct file_operations monitor_device_fops = { 960 .open = monitor_device_open, 961 .release = monitor_device_close, 962 .owner = THIS_MODULE, 963 }; 964 965 static struct miscdevice monitor_device = { 966 .name = "dlm-monitor", 967 .fops = &monitor_device_fops, 968 .minor = MISC_DYNAMIC_MINOR, 969 }; 970 971 int __init dlm_user_init(void) 972 { 973 int error; 974 975 atomic_set(&dlm_monitor_opened, 0); 976 977 error = misc_register(&ctl_device); 978 if (error) { 979 log_print("misc_register failed for control device"); 980 goto out; 981 } 982 983 error = misc_register(&monitor_device); 984 if (error) { 985 log_print("misc_register failed for monitor device"); 986 misc_deregister(&ctl_device); 987 } 988 out: 989 return error; 990 } 991 992 void dlm_user_exit(void) 993 { 994 misc_deregister(&ctl_device); 995 misc_deregister(&monitor_device); 996 } 997 998