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