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