1 /* 2 * Network block device - make block devices work over TCP 3 * 4 * Note that you can not swap over this thing, yet. Seems to work but 5 * deadlocks sometimes - you can not swap over TCP in general. 6 * 7 * Copyright 1997-2000 Pavel Machek <pavel@ucw.cz> 8 * Parts copyright 2001 Steven Whitehouse <steve@chygwyn.com> 9 * 10 * This file is released under GPLv2 or later. 11 * 12 * (part of code stolen from loop.c) 13 */ 14 15 #include <linux/major.h> 16 17 #include <linux/blkdev.h> 18 #include <linux/module.h> 19 #include <linux/init.h> 20 #include <linux/sched.h> 21 #include <linux/fs.h> 22 #include <linux/bio.h> 23 #include <linux/stat.h> 24 #include <linux/errno.h> 25 #include <linux/file.h> 26 #include <linux/ioctl.h> 27 #include <linux/compiler.h> 28 #include <linux/err.h> 29 #include <linux/kernel.h> 30 #include <net/sock.h> 31 32 #include <asm/uaccess.h> 33 #include <asm/system.h> 34 #include <asm/types.h> 35 36 #include <linux/nbd.h> 37 38 #define LO_MAGIC 0x68797548 39 40 #ifdef NDEBUG 41 #define dprintk(flags, fmt...) 42 #else /* NDEBUG */ 43 #define dprintk(flags, fmt...) do { \ 44 if (debugflags & (flags)) printk(KERN_DEBUG fmt); \ 45 } while (0) 46 #define DBG_IOCTL 0x0004 47 #define DBG_INIT 0x0010 48 #define DBG_EXIT 0x0020 49 #define DBG_BLKDEV 0x0100 50 #define DBG_RX 0x0200 51 #define DBG_TX 0x0400 52 static unsigned int debugflags; 53 #endif /* NDEBUG */ 54 55 static unsigned int nbds_max = 16; 56 static struct nbd_device nbd_dev[MAX_NBD]; 57 58 /* 59 * Use just one lock (or at most 1 per NIC). Two arguments for this: 60 * 1. Each NIC is essentially a synchronization point for all servers 61 * accessed through that NIC so there's no need to have more locks 62 * than NICs anyway. 63 * 2. More locks lead to more "Dirty cache line bouncing" which will slow 64 * down each lock to the point where they're actually slower than just 65 * a single lock. 66 * Thanks go to Jens Axboe and Al Viro for their LKML emails explaining this! 67 */ 68 static DEFINE_SPINLOCK(nbd_lock); 69 70 #ifndef NDEBUG 71 static const char *ioctl_cmd_to_ascii(int cmd) 72 { 73 switch (cmd) { 74 case NBD_SET_SOCK: return "set-sock"; 75 case NBD_SET_BLKSIZE: return "set-blksize"; 76 case NBD_SET_SIZE: return "set-size"; 77 case NBD_DO_IT: return "do-it"; 78 case NBD_CLEAR_SOCK: return "clear-sock"; 79 case NBD_CLEAR_QUE: return "clear-que"; 80 case NBD_PRINT_DEBUG: return "print-debug"; 81 case NBD_SET_SIZE_BLOCKS: return "set-size-blocks"; 82 case NBD_DISCONNECT: return "disconnect"; 83 case BLKROSET: return "set-read-only"; 84 case BLKFLSBUF: return "flush-buffer-cache"; 85 } 86 return "unknown"; 87 } 88 89 static const char *nbdcmd_to_ascii(int cmd) 90 { 91 switch (cmd) { 92 case NBD_CMD_READ: return "read"; 93 case NBD_CMD_WRITE: return "write"; 94 case NBD_CMD_DISC: return "disconnect"; 95 } 96 return "invalid"; 97 } 98 #endif /* NDEBUG */ 99 100 static void nbd_end_request(struct request *req) 101 { 102 int uptodate = (req->errors == 0) ? 1 : 0; 103 struct request_queue *q = req->q; 104 unsigned long flags; 105 106 dprintk(DBG_BLKDEV, "%s: request %p: %s\n", req->rq_disk->disk_name, 107 req, uptodate? "done": "failed"); 108 109 spin_lock_irqsave(q->queue_lock, flags); 110 if (!end_that_request_first(req, uptodate, req->nr_sectors)) { 111 end_that_request_last(req, uptodate); 112 } 113 spin_unlock_irqrestore(q->queue_lock, flags); 114 } 115 116 /* 117 * Send or receive packet. 118 */ 119 static int sock_xmit(struct socket *sock, int send, void *buf, int size, 120 int msg_flags) 121 { 122 int result; 123 struct msghdr msg; 124 struct kvec iov; 125 sigset_t blocked, oldset; 126 127 /* Allow interception of SIGKILL only 128 * Don't allow other signals to interrupt the transmission */ 129 siginitsetinv(&blocked, sigmask(SIGKILL)); 130 sigprocmask(SIG_SETMASK, &blocked, &oldset); 131 132 do { 133 sock->sk->sk_allocation = GFP_NOIO; 134 iov.iov_base = buf; 135 iov.iov_len = size; 136 msg.msg_name = NULL; 137 msg.msg_namelen = 0; 138 msg.msg_control = NULL; 139 msg.msg_controllen = 0; 140 msg.msg_flags = msg_flags | MSG_NOSIGNAL; 141 142 if (send) 143 result = kernel_sendmsg(sock, &msg, &iov, 1, size); 144 else 145 result = kernel_recvmsg(sock, &msg, &iov, 1, size, 0); 146 147 if (signal_pending(current)) { 148 siginfo_t info; 149 printk(KERN_WARNING "nbd (pid %d: %s) got signal %d\n", 150 current->pid, current->comm, 151 dequeue_signal_lock(current, ¤t->blocked, &info)); 152 result = -EINTR; 153 break; 154 } 155 156 if (result <= 0) { 157 if (result == 0) 158 result = -EPIPE; /* short read */ 159 break; 160 } 161 size -= result; 162 buf += result; 163 } while (size > 0); 164 165 sigprocmask(SIG_SETMASK, &oldset, NULL); 166 167 return result; 168 } 169 170 static inline int sock_send_bvec(struct socket *sock, struct bio_vec *bvec, 171 int flags) 172 { 173 int result; 174 void *kaddr = kmap(bvec->bv_page); 175 result = sock_xmit(sock, 1, kaddr + bvec->bv_offset, bvec->bv_len, 176 flags); 177 kunmap(bvec->bv_page); 178 return result; 179 } 180 181 static int nbd_send_req(struct nbd_device *lo, struct request *req) 182 { 183 int result, flags; 184 struct nbd_request request; 185 unsigned long size = req->nr_sectors << 9; 186 struct socket *sock = lo->sock; 187 188 request.magic = htonl(NBD_REQUEST_MAGIC); 189 request.type = htonl(nbd_cmd(req)); 190 request.from = cpu_to_be64((u64) req->sector << 9); 191 request.len = htonl(size); 192 memcpy(request.handle, &req, sizeof(req)); 193 194 dprintk(DBG_TX, "%s: request %p: sending control (%s@%llu,%luB)\n", 195 lo->disk->disk_name, req, 196 nbdcmd_to_ascii(nbd_cmd(req)), 197 (unsigned long long)req->sector << 9, 198 req->nr_sectors << 9); 199 result = sock_xmit(sock, 1, &request, sizeof(request), 200 (nbd_cmd(req) == NBD_CMD_WRITE)? MSG_MORE: 0); 201 if (result <= 0) { 202 printk(KERN_ERR "%s: Send control failed (result %d)\n", 203 lo->disk->disk_name, result); 204 goto error_out; 205 } 206 207 if (nbd_cmd(req) == NBD_CMD_WRITE) { 208 struct req_iterator iter; 209 struct bio_vec *bvec; 210 /* 211 * we are really probing at internals to determine 212 * whether to set MSG_MORE or not... 213 */ 214 rq_for_each_segment(bvec, req, iter) { 215 flags = 0; 216 if (!rq_iter_last(req, iter)) 217 flags = MSG_MORE; 218 dprintk(DBG_TX, "%s: request %p: sending %d bytes data\n", 219 lo->disk->disk_name, req, bvec->bv_len); 220 result = sock_send_bvec(sock, bvec, flags); 221 if (result <= 0) { 222 printk(KERN_ERR "%s: Send data failed (result %d)\n", 223 lo->disk->disk_name, result); 224 goto error_out; 225 } 226 } 227 } 228 return 0; 229 230 error_out: 231 return 1; 232 } 233 234 static struct request *nbd_find_request(struct nbd_device *lo, 235 struct request *xreq) 236 { 237 struct request *req, *tmp; 238 int err; 239 240 err = wait_event_interruptible(lo->active_wq, lo->active_req != xreq); 241 if (unlikely(err)) 242 goto out; 243 244 spin_lock(&lo->queue_lock); 245 list_for_each_entry_safe(req, tmp, &lo->queue_head, queuelist) { 246 if (req != xreq) 247 continue; 248 list_del_init(&req->queuelist); 249 spin_unlock(&lo->queue_lock); 250 return req; 251 } 252 spin_unlock(&lo->queue_lock); 253 254 err = -ENOENT; 255 256 out: 257 return ERR_PTR(err); 258 } 259 260 static inline int sock_recv_bvec(struct socket *sock, struct bio_vec *bvec) 261 { 262 int result; 263 void *kaddr = kmap(bvec->bv_page); 264 result = sock_xmit(sock, 0, kaddr + bvec->bv_offset, bvec->bv_len, 265 MSG_WAITALL); 266 kunmap(bvec->bv_page); 267 return result; 268 } 269 270 /* NULL returned = something went wrong, inform userspace */ 271 static struct request *nbd_read_stat(struct nbd_device *lo) 272 { 273 int result; 274 struct nbd_reply reply; 275 struct request *req; 276 struct socket *sock = lo->sock; 277 278 reply.magic = 0; 279 result = sock_xmit(sock, 0, &reply, sizeof(reply), MSG_WAITALL); 280 if (result <= 0) { 281 printk(KERN_ERR "%s: Receive control failed (result %d)\n", 282 lo->disk->disk_name, result); 283 goto harderror; 284 } 285 286 if (ntohl(reply.magic) != NBD_REPLY_MAGIC) { 287 printk(KERN_ERR "%s: Wrong magic (0x%lx)\n", 288 lo->disk->disk_name, 289 (unsigned long)ntohl(reply.magic)); 290 result = -EPROTO; 291 goto harderror; 292 } 293 294 req = nbd_find_request(lo, *(struct request **)reply.handle); 295 if (unlikely(IS_ERR(req))) { 296 result = PTR_ERR(req); 297 if (result != -ENOENT) 298 goto harderror; 299 300 printk(KERN_ERR "%s: Unexpected reply (%p)\n", 301 lo->disk->disk_name, reply.handle); 302 result = -EBADR; 303 goto harderror; 304 } 305 306 if (ntohl(reply.error)) { 307 printk(KERN_ERR "%s: Other side returned error (%d)\n", 308 lo->disk->disk_name, ntohl(reply.error)); 309 req->errors++; 310 return req; 311 } 312 313 dprintk(DBG_RX, "%s: request %p: got reply\n", 314 lo->disk->disk_name, req); 315 if (nbd_cmd(req) == NBD_CMD_READ) { 316 struct req_iterator iter; 317 struct bio_vec *bvec; 318 319 rq_for_each_segment(bvec, req, iter) { 320 result = sock_recv_bvec(sock, bvec); 321 if (result <= 0) { 322 printk(KERN_ERR "%s: Receive data failed (result %d)\n", 323 lo->disk->disk_name, result); 324 req->errors++; 325 return req; 326 } 327 dprintk(DBG_RX, "%s: request %p: got %d bytes data\n", 328 lo->disk->disk_name, req, bvec->bv_len); 329 } 330 } 331 return req; 332 harderror: 333 lo->harderror = result; 334 return NULL; 335 } 336 337 static ssize_t pid_show(struct gendisk *disk, char *page) 338 { 339 return sprintf(page, "%ld\n", 340 (long) ((struct nbd_device *)disk->private_data)->pid); 341 } 342 343 static struct disk_attribute pid_attr = { 344 .attr = { .name = "pid", .mode = S_IRUGO }, 345 .show = pid_show, 346 }; 347 348 static int nbd_do_it(struct nbd_device *lo) 349 { 350 struct request *req; 351 int ret; 352 353 BUG_ON(lo->magic != LO_MAGIC); 354 355 lo->pid = current->pid; 356 ret = sysfs_create_file(&lo->disk->kobj, &pid_attr.attr); 357 if (ret) { 358 printk(KERN_ERR "nbd: sysfs_create_file failed!"); 359 return ret; 360 } 361 362 while ((req = nbd_read_stat(lo)) != NULL) 363 nbd_end_request(req); 364 365 sysfs_remove_file(&lo->disk->kobj, &pid_attr.attr); 366 return 0; 367 } 368 369 static void nbd_clear_que(struct nbd_device *lo) 370 { 371 struct request *req; 372 373 BUG_ON(lo->magic != LO_MAGIC); 374 375 /* 376 * Because we have set lo->sock to NULL under the tx_lock, all 377 * modifications to the list must have completed by now. For 378 * the same reason, the active_req must be NULL. 379 * 380 * As a consequence, we don't need to take the spin lock while 381 * purging the list here. 382 */ 383 BUG_ON(lo->sock); 384 BUG_ON(lo->active_req); 385 386 while (!list_empty(&lo->queue_head)) { 387 req = list_entry(lo->queue_head.next, struct request, 388 queuelist); 389 list_del_init(&req->queuelist); 390 req->errors++; 391 nbd_end_request(req); 392 } 393 } 394 395 /* 396 * We always wait for result of write, for now. It would be nice to make it optional 397 * in future 398 * if ((rq_data_dir(req) == WRITE) && (lo->flags & NBD_WRITE_NOCHK)) 399 * { printk( "Warning: Ignoring result!\n"); nbd_end_request( req ); } 400 */ 401 402 static void do_nbd_request(struct request_queue * q) 403 { 404 struct request *req; 405 406 while ((req = elv_next_request(q)) != NULL) { 407 struct nbd_device *lo; 408 409 blkdev_dequeue_request(req); 410 dprintk(DBG_BLKDEV, "%s: request %p: dequeued (flags=%x)\n", 411 req->rq_disk->disk_name, req, req->cmd_type); 412 413 if (!blk_fs_request(req)) 414 goto error_out; 415 416 lo = req->rq_disk->private_data; 417 418 BUG_ON(lo->magic != LO_MAGIC); 419 420 nbd_cmd(req) = NBD_CMD_READ; 421 if (rq_data_dir(req) == WRITE) { 422 nbd_cmd(req) = NBD_CMD_WRITE; 423 if (lo->flags & NBD_READ_ONLY) { 424 printk(KERN_ERR "%s: Write on read-only\n", 425 lo->disk->disk_name); 426 goto error_out; 427 } 428 } 429 430 req->errors = 0; 431 spin_unlock_irq(q->queue_lock); 432 433 mutex_lock(&lo->tx_lock); 434 if (unlikely(!lo->sock)) { 435 mutex_unlock(&lo->tx_lock); 436 printk(KERN_ERR "%s: Attempted send on closed socket\n", 437 lo->disk->disk_name); 438 req->errors++; 439 nbd_end_request(req); 440 spin_lock_irq(q->queue_lock); 441 continue; 442 } 443 444 lo->active_req = req; 445 446 if (nbd_send_req(lo, req) != 0) { 447 printk(KERN_ERR "%s: Request send failed\n", 448 lo->disk->disk_name); 449 req->errors++; 450 nbd_end_request(req); 451 } else { 452 spin_lock(&lo->queue_lock); 453 list_add(&req->queuelist, &lo->queue_head); 454 spin_unlock(&lo->queue_lock); 455 } 456 457 lo->active_req = NULL; 458 mutex_unlock(&lo->tx_lock); 459 wake_up_all(&lo->active_wq); 460 461 spin_lock_irq(q->queue_lock); 462 continue; 463 464 error_out: 465 req->errors++; 466 spin_unlock(q->queue_lock); 467 nbd_end_request(req); 468 spin_lock(q->queue_lock); 469 } 470 return; 471 } 472 473 static int nbd_ioctl(struct inode *inode, struct file *file, 474 unsigned int cmd, unsigned long arg) 475 { 476 struct nbd_device *lo = inode->i_bdev->bd_disk->private_data; 477 int error; 478 struct request sreq ; 479 480 if (!capable(CAP_SYS_ADMIN)) 481 return -EPERM; 482 483 BUG_ON(lo->magic != LO_MAGIC); 484 485 /* Anyone capable of this syscall can do *real bad* things */ 486 dprintk(DBG_IOCTL, "%s: nbd_ioctl cmd=%s(0x%x) arg=%lu\n", 487 lo->disk->disk_name, ioctl_cmd_to_ascii(cmd), cmd, arg); 488 489 switch (cmd) { 490 case NBD_DISCONNECT: 491 printk(KERN_INFO "%s: NBD_DISCONNECT\n", lo->disk->disk_name); 492 sreq.cmd_type = REQ_TYPE_SPECIAL; 493 nbd_cmd(&sreq) = NBD_CMD_DISC; 494 /* 495 * Set these to sane values in case server implementation 496 * fails to check the request type first and also to keep 497 * debugging output cleaner. 498 */ 499 sreq.sector = 0; 500 sreq.nr_sectors = 0; 501 if (!lo->sock) 502 return -EINVAL; 503 nbd_send_req(lo, &sreq); 504 return 0; 505 506 case NBD_CLEAR_SOCK: 507 error = 0; 508 mutex_lock(&lo->tx_lock); 509 lo->sock = NULL; 510 mutex_unlock(&lo->tx_lock); 511 file = lo->file; 512 lo->file = NULL; 513 nbd_clear_que(lo); 514 BUG_ON(!list_empty(&lo->queue_head)); 515 if (file) 516 fput(file); 517 return error; 518 case NBD_SET_SOCK: 519 if (lo->file) 520 return -EBUSY; 521 error = -EINVAL; 522 file = fget(arg); 523 if (file) { 524 inode = file->f_path.dentry->d_inode; 525 if (S_ISSOCK(inode->i_mode)) { 526 lo->file = file; 527 lo->sock = SOCKET_I(inode); 528 error = 0; 529 } else { 530 fput(file); 531 } 532 } 533 return error; 534 case NBD_SET_BLKSIZE: 535 lo->blksize = arg; 536 lo->bytesize &= ~(lo->blksize-1); 537 inode->i_bdev->bd_inode->i_size = lo->bytesize; 538 set_blocksize(inode->i_bdev, lo->blksize); 539 set_capacity(lo->disk, lo->bytesize >> 9); 540 return 0; 541 case NBD_SET_SIZE: 542 lo->bytesize = arg & ~(lo->blksize-1); 543 inode->i_bdev->bd_inode->i_size = lo->bytesize; 544 set_blocksize(inode->i_bdev, lo->blksize); 545 set_capacity(lo->disk, lo->bytesize >> 9); 546 return 0; 547 case NBD_SET_SIZE_BLOCKS: 548 lo->bytesize = ((u64) arg) * lo->blksize; 549 inode->i_bdev->bd_inode->i_size = lo->bytesize; 550 set_blocksize(inode->i_bdev, lo->blksize); 551 set_capacity(lo->disk, lo->bytesize >> 9); 552 return 0; 553 case NBD_DO_IT: 554 if (!lo->file) 555 return -EINVAL; 556 error = nbd_do_it(lo); 557 if (error) 558 return error; 559 /* on return tidy up in case we have a signal */ 560 /* Forcibly shutdown the socket causing all listeners 561 * to error 562 * 563 * FIXME: This code is duplicated from sys_shutdown, but 564 * there should be a more generic interface rather than 565 * calling socket ops directly here */ 566 mutex_lock(&lo->tx_lock); 567 if (lo->sock) { 568 printk(KERN_WARNING "%s: shutting down socket\n", 569 lo->disk->disk_name); 570 lo->sock->ops->shutdown(lo->sock, 571 SEND_SHUTDOWN|RCV_SHUTDOWN); 572 lo->sock = NULL; 573 } 574 mutex_unlock(&lo->tx_lock); 575 file = lo->file; 576 lo->file = NULL; 577 nbd_clear_que(lo); 578 printk(KERN_WARNING "%s: queue cleared\n", lo->disk->disk_name); 579 if (file) 580 fput(file); 581 return lo->harderror; 582 case NBD_CLEAR_QUE: 583 /* 584 * This is for compatibility only. The queue is always cleared 585 * by NBD_DO_IT or NBD_CLEAR_SOCK. 586 */ 587 BUG_ON(!lo->sock && !list_empty(&lo->queue_head)); 588 return 0; 589 case NBD_PRINT_DEBUG: 590 printk(KERN_INFO "%s: next = %p, prev = %p, head = %p\n", 591 inode->i_bdev->bd_disk->disk_name, 592 lo->queue_head.next, lo->queue_head.prev, 593 &lo->queue_head); 594 return 0; 595 } 596 return -EINVAL; 597 } 598 599 static struct block_device_operations nbd_fops = 600 { 601 .owner = THIS_MODULE, 602 .ioctl = nbd_ioctl, 603 }; 604 605 /* 606 * And here should be modules and kernel interface 607 * (Just smiley confuses emacs :-) 608 */ 609 610 static int __init nbd_init(void) 611 { 612 int err = -ENOMEM; 613 int i; 614 615 BUILD_BUG_ON(sizeof(struct nbd_request) != 28); 616 617 if (nbds_max > MAX_NBD) { 618 printk(KERN_CRIT "nbd: cannot allocate more than %u nbds; %u requested.\n", MAX_NBD, 619 nbds_max); 620 return -EINVAL; 621 } 622 623 for (i = 0; i < nbds_max; i++) { 624 struct gendisk *disk = alloc_disk(1); 625 if (!disk) 626 goto out; 627 nbd_dev[i].disk = disk; 628 /* 629 * The new linux 2.5 block layer implementation requires 630 * every gendisk to have its very own request_queue struct. 631 * These structs are big so we dynamically allocate them. 632 */ 633 disk->queue = blk_init_queue(do_nbd_request, &nbd_lock); 634 if (!disk->queue) { 635 put_disk(disk); 636 goto out; 637 } 638 } 639 640 if (register_blkdev(NBD_MAJOR, "nbd")) { 641 err = -EIO; 642 goto out; 643 } 644 645 printk(KERN_INFO "nbd: registered device at major %d\n", NBD_MAJOR); 646 dprintk(DBG_INIT, "nbd: debugflags=0x%x\n", debugflags); 647 648 for (i = 0; i < nbds_max; i++) { 649 struct gendisk *disk = nbd_dev[i].disk; 650 nbd_dev[i].file = NULL; 651 nbd_dev[i].magic = LO_MAGIC; 652 nbd_dev[i].flags = 0; 653 spin_lock_init(&nbd_dev[i].queue_lock); 654 INIT_LIST_HEAD(&nbd_dev[i].queue_head); 655 mutex_init(&nbd_dev[i].tx_lock); 656 init_waitqueue_head(&nbd_dev[i].active_wq); 657 nbd_dev[i].blksize = 1024; 658 nbd_dev[i].bytesize = 0x7ffffc00ULL << 10; /* 2TB */ 659 disk->major = NBD_MAJOR; 660 disk->first_minor = i; 661 disk->fops = &nbd_fops; 662 disk->private_data = &nbd_dev[i]; 663 disk->flags |= GENHD_FL_SUPPRESS_PARTITION_INFO; 664 sprintf(disk->disk_name, "nbd%d", i); 665 set_capacity(disk, 0x7ffffc00ULL << 1); /* 2 TB */ 666 add_disk(disk); 667 } 668 669 return 0; 670 out: 671 while (i--) { 672 blk_cleanup_queue(nbd_dev[i].disk->queue); 673 put_disk(nbd_dev[i].disk); 674 } 675 return err; 676 } 677 678 static void __exit nbd_cleanup(void) 679 { 680 int i; 681 for (i = 0; i < nbds_max; i++) { 682 struct gendisk *disk = nbd_dev[i].disk; 683 nbd_dev[i].magic = 0; 684 if (disk) { 685 del_gendisk(disk); 686 blk_cleanup_queue(disk->queue); 687 put_disk(disk); 688 } 689 } 690 unregister_blkdev(NBD_MAJOR, "nbd"); 691 printk(KERN_INFO "nbd: unregistered device at major %d\n", NBD_MAJOR); 692 } 693 694 module_init(nbd_init); 695 module_exit(nbd_cleanup); 696 697 MODULE_DESCRIPTION("Network Block Device"); 698 MODULE_LICENSE("GPL"); 699 700 module_param(nbds_max, int, 0444); 701 MODULE_PARM_DESC(nbds_max, "How many network block devices to initialize."); 702 #ifndef NDEBUG 703 module_param(debugflags, int, 0644); 704 MODULE_PARM_DESC(debugflags, "flags for controlling debug output"); 705 #endif 706