1 /* 2 * Copyright (C) 2000 Jeff Dike (jdike@karaya.com) 3 * Licensed under the GPL 4 */ 5 6 /* 2001-09-28...2002-04-17 7 * Partition stuff by James_McMechan@hotmail.com 8 * old style ubd by setting UBD_SHIFT to 0 9 * 2002-09-27...2002-10-18 massive tinkering for 2.5 10 * partitions have changed in 2.5 11 * 2003-01-29 more tinkering for 2.5.59-1 12 * This should now address the sysfs problems and has 13 * the symlink for devfs to allow for booting with 14 * the common /dev/ubd/discX/... names rather than 15 * only /dev/ubdN/discN this version also has lots of 16 * clean ups preparing for ubd-many. 17 * James McMechan 18 */ 19 20 #define MAJOR_NR UBD_MAJOR 21 #define UBD_SHIFT 4 22 23 #include "linux/config.h" 24 #include "linux/module.h" 25 #include "linux/blkdev.h" 26 #include "linux/hdreg.h" 27 #include "linux/init.h" 28 #include "linux/devfs_fs_kernel.h" 29 #include "linux/cdrom.h" 30 #include "linux/proc_fs.h" 31 #include "linux/ctype.h" 32 #include "linux/capability.h" 33 #include "linux/mm.h" 34 #include "linux/vmalloc.h" 35 #include "linux/blkpg.h" 36 #include "linux/genhd.h" 37 #include "linux/spinlock.h" 38 #include "linux/platform_device.h" 39 #include "asm/segment.h" 40 #include "asm/uaccess.h" 41 #include "asm/irq.h" 42 #include "asm/types.h" 43 #include "asm/tlbflush.h" 44 #include "user_util.h" 45 #include "mem_user.h" 46 #include "kern_util.h" 47 #include "kern.h" 48 #include "mconsole_kern.h" 49 #include "init.h" 50 #include "irq_user.h" 51 #include "irq_kern.h" 52 #include "ubd_user.h" 53 #include "os.h" 54 #include "mem.h" 55 #include "mem_kern.h" 56 #include "cow.h" 57 58 enum ubd_req { UBD_READ, UBD_WRITE }; 59 60 struct io_thread_req { 61 enum ubd_req op; 62 int fds[2]; 63 unsigned long offsets[2]; 64 unsigned long long offset; 65 unsigned long length; 66 char *buffer; 67 int sectorsize; 68 unsigned long sector_mask; 69 unsigned long long cow_offset; 70 unsigned long bitmap_words[2]; 71 int error; 72 }; 73 74 extern int open_ubd_file(char *file, struct openflags *openflags, 75 char **backing_file_out, int *bitmap_offset_out, 76 unsigned long *bitmap_len_out, int *data_offset_out, 77 int *create_cow_out); 78 extern int create_cow_file(char *cow_file, char *backing_file, 79 struct openflags flags, int sectorsize, 80 int alignment, int *bitmap_offset_out, 81 unsigned long *bitmap_len_out, 82 int *data_offset_out); 83 extern int read_cow_bitmap(int fd, void *buf, int offset, int len); 84 extern void do_io(struct io_thread_req *req); 85 86 static inline int ubd_test_bit(__u64 bit, unsigned char *data) 87 { 88 __u64 n; 89 int bits, off; 90 91 bits = sizeof(data[0]) * 8; 92 n = bit / bits; 93 off = bit % bits; 94 return((data[n] & (1 << off)) != 0); 95 } 96 97 static inline void ubd_set_bit(__u64 bit, unsigned char *data) 98 { 99 __u64 n; 100 int bits, off; 101 102 bits = sizeof(data[0]) * 8; 103 n = bit / bits; 104 off = bit % bits; 105 data[n] |= (1 << off); 106 } 107 /*End stuff from ubd_user.h*/ 108 109 #define DRIVER_NAME "uml-blkdev" 110 111 static DEFINE_SPINLOCK(ubd_io_lock); 112 static DEFINE_SPINLOCK(ubd_lock); 113 114 static void (*do_ubd)(void); 115 116 static int ubd_open(struct inode * inode, struct file * filp); 117 static int ubd_release(struct inode * inode, struct file * file); 118 static int ubd_ioctl(struct inode * inode, struct file * file, 119 unsigned int cmd, unsigned long arg); 120 121 #define MAX_DEV (8) 122 123 static struct block_device_operations ubd_blops = { 124 .owner = THIS_MODULE, 125 .open = ubd_open, 126 .release = ubd_release, 127 .ioctl = ubd_ioctl, 128 }; 129 130 /* Protected by the queue_lock */ 131 static request_queue_t *ubd_queue; 132 133 /* Protected by ubd_lock */ 134 static int fake_major = MAJOR_NR; 135 136 static struct gendisk *ubd_gendisk[MAX_DEV]; 137 static struct gendisk *fake_gendisk[MAX_DEV]; 138 139 #ifdef CONFIG_BLK_DEV_UBD_SYNC 140 #define OPEN_FLAGS ((struct openflags) { .r = 1, .w = 1, .s = 1, .c = 0, \ 141 .cl = 1 }) 142 #else 143 #define OPEN_FLAGS ((struct openflags) { .r = 1, .w = 1, .s = 0, .c = 0, \ 144 .cl = 1 }) 145 #endif 146 147 /* Not protected - changed only in ubd_setup_common and then only to 148 * to enable O_SYNC. 149 */ 150 static struct openflags global_openflags = OPEN_FLAGS; 151 152 struct cow { 153 /* This is the backing file, actually */ 154 char *file; 155 int fd; 156 unsigned long *bitmap; 157 unsigned long bitmap_len; 158 int bitmap_offset; 159 int data_offset; 160 }; 161 162 struct ubd { 163 char *file; 164 int count; 165 int fd; 166 __u64 size; 167 struct openflags boot_openflags; 168 struct openflags openflags; 169 int no_cow; 170 struct cow cow; 171 struct platform_device pdev; 172 }; 173 174 #define DEFAULT_COW { \ 175 .file = NULL, \ 176 .fd = -1, \ 177 .bitmap = NULL, \ 178 .bitmap_offset = 0, \ 179 .data_offset = 0, \ 180 } 181 182 #define DEFAULT_UBD { \ 183 .file = NULL, \ 184 .count = 0, \ 185 .fd = -1, \ 186 .size = -1, \ 187 .boot_openflags = OPEN_FLAGS, \ 188 .openflags = OPEN_FLAGS, \ 189 .no_cow = 0, \ 190 .cow = DEFAULT_COW, \ 191 } 192 193 struct ubd ubd_dev[MAX_DEV] = { [ 0 ... MAX_DEV - 1 ] = DEFAULT_UBD }; 194 195 static int ubd0_init(void) 196 { 197 struct ubd *dev = &ubd_dev[0]; 198 199 if(dev->file == NULL) 200 dev->file = "root_fs"; 201 return(0); 202 } 203 204 __initcall(ubd0_init); 205 206 /* Only changed by fake_ide_setup which is a setup */ 207 static int fake_ide = 0; 208 static struct proc_dir_entry *proc_ide_root = NULL; 209 static struct proc_dir_entry *proc_ide = NULL; 210 211 static void make_proc_ide(void) 212 { 213 proc_ide_root = proc_mkdir("ide", NULL); 214 proc_ide = proc_mkdir("ide0", proc_ide_root); 215 } 216 217 static int proc_ide_read_media(char *page, char **start, off_t off, int count, 218 int *eof, void *data) 219 { 220 int len; 221 222 strcpy(page, "disk\n"); 223 len = strlen("disk\n"); 224 len -= off; 225 if (len < count){ 226 *eof = 1; 227 if (len <= 0) return 0; 228 } 229 else len = count; 230 *start = page + off; 231 return len; 232 } 233 234 static void make_ide_entries(char *dev_name) 235 { 236 struct proc_dir_entry *dir, *ent; 237 char name[64]; 238 239 if(proc_ide_root == NULL) make_proc_ide(); 240 241 dir = proc_mkdir(dev_name, proc_ide); 242 if(!dir) return; 243 244 ent = create_proc_entry("media", S_IFREG|S_IRUGO, dir); 245 if(!ent) return; 246 ent->nlink = 1; 247 ent->data = NULL; 248 ent->read_proc = proc_ide_read_media; 249 ent->write_proc = NULL; 250 sprintf(name,"ide0/%s", dev_name); 251 proc_symlink(dev_name, proc_ide_root, name); 252 } 253 254 static int fake_ide_setup(char *str) 255 { 256 fake_ide = 1; 257 return(1); 258 } 259 260 __setup("fake_ide", fake_ide_setup); 261 262 __uml_help(fake_ide_setup, 263 "fake_ide\n" 264 " Create ide0 entries that map onto ubd devices.\n\n" 265 ); 266 267 static int parse_unit(char **ptr) 268 { 269 char *str = *ptr, *end; 270 int n = -1; 271 272 if(isdigit(*str)) { 273 n = simple_strtoul(str, &end, 0); 274 if(end == str) 275 return(-1); 276 *ptr = end; 277 } 278 else if (('a' <= *str) && (*str <= 'h')) { 279 n = *str - 'a'; 280 str++; 281 *ptr = str; 282 } 283 return(n); 284 } 285 286 static int ubd_setup_common(char *str, int *index_out) 287 { 288 struct ubd *dev; 289 struct openflags flags = global_openflags; 290 char *backing_file; 291 int n, err, i; 292 293 if(index_out) *index_out = -1; 294 n = *str; 295 if(n == '='){ 296 char *end; 297 int major; 298 299 str++; 300 if(!strcmp(str, "sync")){ 301 global_openflags = of_sync(global_openflags); 302 return(0); 303 } 304 major = simple_strtoul(str, &end, 0); 305 if((*end != '\0') || (end == str)){ 306 printk(KERN_ERR 307 "ubd_setup : didn't parse major number\n"); 308 return(1); 309 } 310 311 err = 1; 312 spin_lock(&ubd_lock); 313 if(fake_major != MAJOR_NR){ 314 printk(KERN_ERR "Can't assign a fake major twice\n"); 315 goto out1; 316 } 317 318 fake_major = major; 319 320 printk(KERN_INFO "Setting extra ubd major number to %d\n", 321 major); 322 err = 0; 323 out1: 324 spin_unlock(&ubd_lock); 325 return(err); 326 } 327 328 n = parse_unit(&str); 329 if(n < 0){ 330 printk(KERN_ERR "ubd_setup : couldn't parse unit number " 331 "'%s'\n", str); 332 return(1); 333 } 334 if(n >= MAX_DEV){ 335 printk(KERN_ERR "ubd_setup : index %d out of range " 336 "(%d devices, from 0 to %d)\n", n, MAX_DEV, MAX_DEV - 1); 337 return(1); 338 } 339 340 err = 1; 341 spin_lock(&ubd_lock); 342 343 dev = &ubd_dev[n]; 344 if(dev->file != NULL){ 345 printk(KERN_ERR "ubd_setup : device already configured\n"); 346 goto out; 347 } 348 349 if (index_out) 350 *index_out = n; 351 352 for (i = 0; i < 4; i++) { 353 switch (*str) { 354 case 'r': 355 flags.w = 0; 356 break; 357 case 's': 358 flags.s = 1; 359 break; 360 case 'd': 361 dev->no_cow = 1; 362 break; 363 case '=': 364 str++; 365 goto break_loop; 366 default: 367 printk(KERN_ERR "ubd_setup : Expected '=' or flag letter (r,s or d)\n"); 368 goto out; 369 } 370 str++; 371 } 372 373 if (*str == '=') 374 printk(KERN_ERR "ubd_setup : Too many flags specified\n"); 375 else 376 printk(KERN_ERR "ubd_setup : Expected '='\n"); 377 goto out; 378 379 break_loop: 380 err = 0; 381 backing_file = strchr(str, ','); 382 383 if (!backing_file) { 384 backing_file = strchr(str, ':'); 385 } 386 387 if(backing_file){ 388 if(dev->no_cow) 389 printk(KERN_ERR "Can't specify both 'd' and a " 390 "cow file\n"); 391 else { 392 *backing_file = '\0'; 393 backing_file++; 394 } 395 } 396 dev->file = str; 397 dev->cow.file = backing_file; 398 dev->boot_openflags = flags; 399 out: 400 spin_unlock(&ubd_lock); 401 return(err); 402 } 403 404 static int ubd_setup(char *str) 405 { 406 ubd_setup_common(str, NULL); 407 return(1); 408 } 409 410 __setup("ubd", ubd_setup); 411 __uml_help(ubd_setup, 412 "ubd<n><flags>=<filename>[(:|,)<filename2>]\n" 413 " This is used to associate a device with a file in the underlying\n" 414 " filesystem. When specifying two filenames, the first one is the\n" 415 " COW name and the second is the backing file name. As separator you can\n" 416 " use either a ':' or a ',': the first one allows writing things like;\n" 417 " ubd0=~/Uml/root_cow:~/Uml/root_backing_file\n" 418 " while with a ',' the shell would not expand the 2nd '~'.\n" 419 " When using only one filename, UML will detect whether to thread it like\n" 420 " a COW file or a backing file. To override this detection, add the 'd'\n" 421 " flag:\n" 422 " ubd0d=BackingFile\n" 423 " Usually, there is a filesystem in the file, but \n" 424 " that's not required. Swap devices containing swap files can be\n" 425 " specified like this. Also, a file which doesn't contain a\n" 426 " filesystem can have its contents read in the virtual \n" 427 " machine by running 'dd' on the device. <n> must be in the range\n" 428 " 0 to 7. Appending an 'r' to the number will cause that device\n" 429 " to be mounted read-only. For example ubd1r=./ext_fs. Appending\n" 430 " an 's' will cause data to be written to disk on the host immediately.\n\n" 431 ); 432 433 static int udb_setup(char *str) 434 { 435 printk("udb%s specified on command line is almost certainly a ubd -> " 436 "udb TYPO\n", str); 437 return(1); 438 } 439 440 __setup("udb", udb_setup); 441 __uml_help(udb_setup, 442 "udb\n" 443 " This option is here solely to catch ubd -> udb typos, which can be\n" 444 " to impossible to catch visually unless you specifically look for\n" 445 " them. The only result of any option starting with 'udb' is an error\n" 446 " in the boot output.\n\n" 447 ); 448 449 static int fakehd_set = 0; 450 static int fakehd(char *str) 451 { 452 printk(KERN_INFO "fakehd : Changing ubd name to \"hd\".\n"); 453 fakehd_set = 1; 454 return 1; 455 } 456 457 __setup("fakehd", fakehd); 458 __uml_help(fakehd, 459 "fakehd\n" 460 " Change the ubd device name to \"hd\".\n\n" 461 ); 462 463 static void do_ubd_request(request_queue_t * q); 464 465 /* Only changed by ubd_init, which is an initcall. */ 466 int thread_fd = -1; 467 468 /* Changed by ubd_handler, which is serialized because interrupts only 469 * happen on CPU 0. 470 */ 471 int intr_count = 0; 472 473 /* call ubd_finish if you need to serialize */ 474 static void __ubd_finish(struct request *req, int error) 475 { 476 int nsect; 477 478 if(error){ 479 end_request(req, 0); 480 return; 481 } 482 nsect = req->current_nr_sectors; 483 req->sector += nsect; 484 req->buffer += nsect << 9; 485 req->errors = 0; 486 req->nr_sectors -= nsect; 487 req->current_nr_sectors = 0; 488 end_request(req, 1); 489 } 490 491 static inline void ubd_finish(struct request *req, int error) 492 { 493 spin_lock(&ubd_io_lock); 494 __ubd_finish(req, error); 495 spin_unlock(&ubd_io_lock); 496 } 497 498 /* Called without ubd_io_lock held */ 499 static void ubd_handler(void) 500 { 501 struct io_thread_req req; 502 struct request *rq = elv_next_request(ubd_queue); 503 int n; 504 505 do_ubd = NULL; 506 intr_count++; 507 n = os_read_file(thread_fd, &req, sizeof(req)); 508 if(n != sizeof(req)){ 509 printk(KERN_ERR "Pid %d - spurious interrupt in ubd_handler, " 510 "err = %d\n", os_getpid(), -n); 511 spin_lock(&ubd_io_lock); 512 end_request(rq, 0); 513 spin_unlock(&ubd_io_lock); 514 return; 515 } 516 517 ubd_finish(rq, req.error); 518 reactivate_fd(thread_fd, UBD_IRQ); 519 do_ubd_request(ubd_queue); 520 } 521 522 static irqreturn_t ubd_intr(int irq, void *dev, struct pt_regs *unused) 523 { 524 ubd_handler(); 525 return(IRQ_HANDLED); 526 } 527 528 /* Only changed by ubd_init, which is an initcall. */ 529 static int io_pid = -1; 530 531 void kill_io_thread(void) 532 { 533 if(io_pid != -1) 534 os_kill_process(io_pid, 1); 535 } 536 537 __uml_exitcall(kill_io_thread); 538 539 static int ubd_file_size(struct ubd *dev, __u64 *size_out) 540 { 541 char *file; 542 543 file = dev->cow.file ? dev->cow.file : dev->file; 544 return(os_file_size(file, size_out)); 545 } 546 547 static void ubd_close(struct ubd *dev) 548 { 549 os_close_file(dev->fd); 550 if(dev->cow.file == NULL) 551 return; 552 553 os_close_file(dev->cow.fd); 554 vfree(dev->cow.bitmap); 555 dev->cow.bitmap = NULL; 556 } 557 558 static int ubd_open_dev(struct ubd *dev) 559 { 560 struct openflags flags; 561 char **back_ptr; 562 int err, create_cow, *create_ptr; 563 564 dev->openflags = dev->boot_openflags; 565 create_cow = 0; 566 create_ptr = (dev->cow.file != NULL) ? &create_cow : NULL; 567 back_ptr = dev->no_cow ? NULL : &dev->cow.file; 568 dev->fd = open_ubd_file(dev->file, &dev->openflags, back_ptr, 569 &dev->cow.bitmap_offset, &dev->cow.bitmap_len, 570 &dev->cow.data_offset, create_ptr); 571 572 if((dev->fd == -ENOENT) && create_cow){ 573 dev->fd = create_cow_file(dev->file, dev->cow.file, 574 dev->openflags, 1 << 9, PAGE_SIZE, 575 &dev->cow.bitmap_offset, 576 &dev->cow.bitmap_len, 577 &dev->cow.data_offset); 578 if(dev->fd >= 0){ 579 printk(KERN_INFO "Creating \"%s\" as COW file for " 580 "\"%s\"\n", dev->file, dev->cow.file); 581 } 582 } 583 584 if(dev->fd < 0){ 585 printk("Failed to open '%s', errno = %d\n", dev->file, 586 -dev->fd); 587 return(dev->fd); 588 } 589 590 if(dev->cow.file != NULL){ 591 err = -ENOMEM; 592 dev->cow.bitmap = (void *) vmalloc(dev->cow.bitmap_len); 593 if(dev->cow.bitmap == NULL){ 594 printk(KERN_ERR "Failed to vmalloc COW bitmap\n"); 595 goto error; 596 } 597 flush_tlb_kernel_vm(); 598 599 err = read_cow_bitmap(dev->fd, dev->cow.bitmap, 600 dev->cow.bitmap_offset, 601 dev->cow.bitmap_len); 602 if(err < 0) 603 goto error; 604 605 flags = dev->openflags; 606 flags.w = 0; 607 err = open_ubd_file(dev->cow.file, &flags, NULL, NULL, NULL, 608 NULL, NULL); 609 if(err < 0) goto error; 610 dev->cow.fd = err; 611 } 612 return(0); 613 error: 614 os_close_file(dev->fd); 615 return(err); 616 } 617 618 static int ubd_new_disk(int major, u64 size, int unit, 619 struct gendisk **disk_out) 620 621 { 622 struct gendisk *disk; 623 char from[sizeof("ubd/nnnnn\0")], to[sizeof("discnnnnn/disc\0")]; 624 int err; 625 626 disk = alloc_disk(1 << UBD_SHIFT); 627 if(disk == NULL) 628 return(-ENOMEM); 629 630 disk->major = major; 631 disk->first_minor = unit << UBD_SHIFT; 632 disk->fops = &ubd_blops; 633 set_capacity(disk, size / 512); 634 if(major == MAJOR_NR){ 635 sprintf(disk->disk_name, "ubd%c", 'a' + unit); 636 sprintf(disk->devfs_name, "ubd/disc%d", unit); 637 sprintf(from, "ubd/%d", unit); 638 sprintf(to, "disc%d/disc", unit); 639 err = devfs_mk_symlink(from, to); 640 if(err) 641 printk("ubd_new_disk failed to make link from %s to " 642 "%s, error = %d\n", from, to, err); 643 } 644 else { 645 sprintf(disk->disk_name, "ubd_fake%d", unit); 646 sprintf(disk->devfs_name, "ubd_fake/disc%d", unit); 647 } 648 649 /* sysfs register (not for ide fake devices) */ 650 if (major == MAJOR_NR) { 651 ubd_dev[unit].pdev.id = unit; 652 ubd_dev[unit].pdev.name = DRIVER_NAME; 653 platform_device_register(&ubd_dev[unit].pdev); 654 disk->driverfs_dev = &ubd_dev[unit].pdev.dev; 655 } 656 657 disk->private_data = &ubd_dev[unit]; 658 disk->queue = ubd_queue; 659 add_disk(disk); 660 661 *disk_out = disk; 662 return 0; 663 } 664 665 #define ROUND_BLOCK(n) ((n + ((1 << 9) - 1)) & (-1 << 9)) 666 667 static int ubd_add(int n) 668 { 669 struct ubd *dev = &ubd_dev[n]; 670 int err; 671 672 err = -ENODEV; 673 if(dev->file == NULL) 674 goto out; 675 676 if (ubd_open_dev(dev)) 677 goto out; 678 679 err = ubd_file_size(dev, &dev->size); 680 if(err < 0) 681 goto out_close; 682 683 dev->size = ROUND_BLOCK(dev->size); 684 685 err = ubd_new_disk(MAJOR_NR, dev->size, n, &ubd_gendisk[n]); 686 if(err) 687 goto out_close; 688 689 if(fake_major != MAJOR_NR) 690 ubd_new_disk(fake_major, dev->size, n, 691 &fake_gendisk[n]); 692 693 /* perhaps this should also be under the "if (fake_major)" above */ 694 /* using the fake_disk->disk_name and also the fakehd_set name */ 695 if (fake_ide) 696 make_ide_entries(ubd_gendisk[n]->disk_name); 697 698 err = 0; 699 out_close: 700 ubd_close(dev); 701 out: 702 return err; 703 } 704 705 static int ubd_config(char *str) 706 { 707 int n, err; 708 709 str = uml_strdup(str); 710 if(str == NULL){ 711 printk(KERN_ERR "ubd_config failed to strdup string\n"); 712 return(1); 713 } 714 err = ubd_setup_common(str, &n); 715 if(err){ 716 kfree(str); 717 return(-1); 718 } 719 if(n == -1) return(0); 720 721 spin_lock(&ubd_lock); 722 err = ubd_add(n); 723 if(err) 724 ubd_dev[n].file = NULL; 725 spin_unlock(&ubd_lock); 726 727 return(err); 728 } 729 730 static int ubd_get_config(char *name, char *str, int size, char **error_out) 731 { 732 struct ubd *dev; 733 int n, len = 0; 734 735 n = parse_unit(&name); 736 if((n >= MAX_DEV) || (n < 0)){ 737 *error_out = "ubd_get_config : device number out of range"; 738 return(-1); 739 } 740 741 dev = &ubd_dev[n]; 742 spin_lock(&ubd_lock); 743 744 if(dev->file == NULL){ 745 CONFIG_CHUNK(str, size, len, "", 1); 746 goto out; 747 } 748 749 CONFIG_CHUNK(str, size, len, dev->file, 0); 750 751 if(dev->cow.file != NULL){ 752 CONFIG_CHUNK(str, size, len, ",", 0); 753 CONFIG_CHUNK(str, size, len, dev->cow.file, 1); 754 } 755 else CONFIG_CHUNK(str, size, len, "", 1); 756 757 out: 758 spin_unlock(&ubd_lock); 759 return(len); 760 } 761 762 static int ubd_id(char **str, int *start_out, int *end_out) 763 { 764 int n; 765 766 n = parse_unit(str); 767 *start_out = 0; 768 *end_out = MAX_DEV - 1; 769 return n; 770 } 771 772 static int ubd_remove(int n) 773 { 774 struct ubd *dev; 775 int err = -ENODEV; 776 777 spin_lock(&ubd_lock); 778 779 if(ubd_gendisk[n] == NULL) 780 goto out; 781 782 dev = &ubd_dev[n]; 783 784 if(dev->file == NULL) 785 goto out; 786 787 /* you cannot remove a open disk */ 788 err = -EBUSY; 789 if(dev->count > 0) 790 goto out; 791 792 del_gendisk(ubd_gendisk[n]); 793 put_disk(ubd_gendisk[n]); 794 ubd_gendisk[n] = NULL; 795 796 if(fake_gendisk[n] != NULL){ 797 del_gendisk(fake_gendisk[n]); 798 put_disk(fake_gendisk[n]); 799 fake_gendisk[n] = NULL; 800 } 801 802 platform_device_unregister(&dev->pdev); 803 *dev = ((struct ubd) DEFAULT_UBD); 804 err = 0; 805 out: 806 spin_unlock(&ubd_lock); 807 return err; 808 } 809 810 static struct mc_device ubd_mc = { 811 .name = "ubd", 812 .config = ubd_config, 813 .get_config = ubd_get_config, 814 .id = ubd_id, 815 .remove = ubd_remove, 816 }; 817 818 static int ubd_mc_init(void) 819 { 820 mconsole_register_dev(&ubd_mc); 821 return 0; 822 } 823 824 __initcall(ubd_mc_init); 825 826 static struct platform_driver ubd_driver = { 827 .driver = { 828 .name = DRIVER_NAME, 829 }, 830 }; 831 832 int ubd_init(void) 833 { 834 int i; 835 836 devfs_mk_dir("ubd"); 837 if (register_blkdev(MAJOR_NR, "ubd")) 838 return -1; 839 840 ubd_queue = blk_init_queue(do_ubd_request, &ubd_io_lock); 841 if (!ubd_queue) { 842 unregister_blkdev(MAJOR_NR, "ubd"); 843 return -1; 844 } 845 846 if (fake_major != MAJOR_NR) { 847 char name[sizeof("ubd_nnn\0")]; 848 849 snprintf(name, sizeof(name), "ubd_%d", fake_major); 850 devfs_mk_dir(name); 851 if (register_blkdev(fake_major, "ubd")) 852 return -1; 853 } 854 platform_driver_register(&ubd_driver); 855 for (i = 0; i < MAX_DEV; i++) 856 ubd_add(i); 857 return 0; 858 } 859 860 late_initcall(ubd_init); 861 862 int ubd_driver_init(void){ 863 unsigned long stack; 864 int err; 865 866 /* Set by CONFIG_BLK_DEV_UBD_SYNC or ubd=sync.*/ 867 if(global_openflags.s){ 868 printk(KERN_INFO "ubd: Synchronous mode\n"); 869 /* Letting ubd=sync be like using ubd#s= instead of ubd#= is 870 * enough. So use anyway the io thread. */ 871 } 872 stack = alloc_stack(0, 0); 873 io_pid = start_io_thread(stack + PAGE_SIZE - sizeof(void *), 874 &thread_fd); 875 if(io_pid < 0){ 876 printk(KERN_ERR 877 "ubd : Failed to start I/O thread (errno = %d) - " 878 "falling back to synchronous I/O\n", -io_pid); 879 io_pid = -1; 880 return(0); 881 } 882 err = um_request_irq(UBD_IRQ, thread_fd, IRQ_READ, ubd_intr, 883 SA_INTERRUPT, "ubd", ubd_dev); 884 if(err != 0) 885 printk(KERN_ERR "um_request_irq failed - errno = %d\n", -err); 886 return(err); 887 } 888 889 device_initcall(ubd_driver_init); 890 891 static int ubd_open(struct inode *inode, struct file *filp) 892 { 893 struct gendisk *disk = inode->i_bdev->bd_disk; 894 struct ubd *dev = disk->private_data; 895 int err = 0; 896 897 if(dev->count == 0){ 898 err = ubd_open_dev(dev); 899 if(err){ 900 printk(KERN_ERR "%s: Can't open \"%s\": errno = %d\n", 901 disk->disk_name, dev->file, -err); 902 goto out; 903 } 904 } 905 dev->count++; 906 set_disk_ro(disk, !dev->openflags.w); 907 908 /* This should no more be needed. And it didn't work anyway to exclude 909 * read-write remounting of filesystems.*/ 910 /*if((filp->f_mode & FMODE_WRITE) && !dev->openflags.w){ 911 if(--dev->count == 0) ubd_close(dev); 912 err = -EROFS; 913 }*/ 914 out: 915 return(err); 916 } 917 918 static int ubd_release(struct inode * inode, struct file * file) 919 { 920 struct gendisk *disk = inode->i_bdev->bd_disk; 921 struct ubd *dev = disk->private_data; 922 923 if(--dev->count == 0) 924 ubd_close(dev); 925 return(0); 926 } 927 928 static void cowify_bitmap(__u64 io_offset, int length, unsigned long *cow_mask, 929 __u64 *cow_offset, unsigned long *bitmap, 930 __u64 bitmap_offset, unsigned long *bitmap_words, 931 __u64 bitmap_len) 932 { 933 __u64 sector = io_offset >> 9; 934 int i, update_bitmap = 0; 935 936 for(i = 0; i < length >> 9; i++){ 937 if(cow_mask != NULL) 938 ubd_set_bit(i, (unsigned char *) cow_mask); 939 if(ubd_test_bit(sector + i, (unsigned char *) bitmap)) 940 continue; 941 942 update_bitmap = 1; 943 ubd_set_bit(sector + i, (unsigned char *) bitmap); 944 } 945 946 if(!update_bitmap) 947 return; 948 949 *cow_offset = sector / (sizeof(unsigned long) * 8); 950 951 /* This takes care of the case where we're exactly at the end of the 952 * device, and *cow_offset + 1 is off the end. So, just back it up 953 * by one word. Thanks to Lynn Kerby for the fix and James McMechan 954 * for the original diagnosis. 955 */ 956 if(*cow_offset == ((bitmap_len + sizeof(unsigned long) - 1) / 957 sizeof(unsigned long) - 1)) 958 (*cow_offset)--; 959 960 bitmap_words[0] = bitmap[*cow_offset]; 961 bitmap_words[1] = bitmap[*cow_offset + 1]; 962 963 *cow_offset *= sizeof(unsigned long); 964 *cow_offset += bitmap_offset; 965 } 966 967 static void cowify_req(struct io_thread_req *req, unsigned long *bitmap, 968 __u64 bitmap_offset, __u64 bitmap_len) 969 { 970 __u64 sector = req->offset >> 9; 971 int i; 972 973 if(req->length > (sizeof(req->sector_mask) * 8) << 9) 974 panic("Operation too long"); 975 976 if(req->op == UBD_READ) { 977 for(i = 0; i < req->length >> 9; i++){ 978 if(ubd_test_bit(sector + i, (unsigned char *) bitmap)) 979 ubd_set_bit(i, (unsigned char *) 980 &req->sector_mask); 981 } 982 } 983 else cowify_bitmap(req->offset, req->length, &req->sector_mask, 984 &req->cow_offset, bitmap, bitmap_offset, 985 req->bitmap_words, bitmap_len); 986 } 987 988 /* Called with ubd_io_lock held */ 989 static int prepare_request(struct request *req, struct io_thread_req *io_req) 990 { 991 struct gendisk *disk = req->rq_disk; 992 struct ubd *dev = disk->private_data; 993 __u64 offset; 994 int len; 995 996 if(req->rq_status == RQ_INACTIVE) return(1); 997 998 /* This should be impossible now */ 999 if((rq_data_dir(req) == WRITE) && !dev->openflags.w){ 1000 printk("Write attempted on readonly ubd device %s\n", 1001 disk->disk_name); 1002 end_request(req, 0); 1003 return(1); 1004 } 1005 1006 offset = ((__u64) req->sector) << 9; 1007 len = req->current_nr_sectors << 9; 1008 1009 io_req->fds[0] = (dev->cow.file != NULL) ? dev->cow.fd : dev->fd; 1010 io_req->fds[1] = dev->fd; 1011 io_req->cow_offset = -1; 1012 io_req->offset = offset; 1013 io_req->length = len; 1014 io_req->error = 0; 1015 io_req->sector_mask = 0; 1016 1017 io_req->op = (rq_data_dir(req) == READ) ? UBD_READ : UBD_WRITE; 1018 io_req->offsets[0] = 0; 1019 io_req->offsets[1] = dev->cow.data_offset; 1020 io_req->buffer = req->buffer; 1021 io_req->sectorsize = 1 << 9; 1022 1023 if(dev->cow.file != NULL) 1024 cowify_req(io_req, dev->cow.bitmap, dev->cow.bitmap_offset, 1025 dev->cow.bitmap_len); 1026 1027 return(0); 1028 } 1029 1030 /* Called with ubd_io_lock held */ 1031 static void do_ubd_request(request_queue_t *q) 1032 { 1033 struct io_thread_req io_req; 1034 struct request *req; 1035 int err, n; 1036 1037 if(thread_fd == -1){ 1038 while((req = elv_next_request(q)) != NULL){ 1039 err = prepare_request(req, &io_req); 1040 if(!err){ 1041 do_io(&io_req); 1042 __ubd_finish(req, io_req.error); 1043 } 1044 } 1045 } 1046 else { 1047 if(do_ubd || (req = elv_next_request(q)) == NULL) 1048 return; 1049 err = prepare_request(req, &io_req); 1050 if(!err){ 1051 do_ubd = ubd_handler; 1052 n = os_write_file(thread_fd, (char *) &io_req, 1053 sizeof(io_req)); 1054 if(n != sizeof(io_req)) 1055 printk("write to io thread failed, " 1056 "errno = %d\n", -n); 1057 } 1058 } 1059 } 1060 1061 static int ubd_ioctl(struct inode * inode, struct file * file, 1062 unsigned int cmd, unsigned long arg) 1063 { 1064 struct hd_geometry __user *loc = (struct hd_geometry __user *) arg; 1065 struct ubd *dev = inode->i_bdev->bd_disk->private_data; 1066 struct hd_driveid ubd_id = { 1067 .cyls = 0, 1068 .heads = 128, 1069 .sectors = 32, 1070 }; 1071 1072 switch (cmd) { 1073 struct hd_geometry g; 1074 struct cdrom_volctrl volume; 1075 case HDIO_GETGEO: 1076 if(!loc) return(-EINVAL); 1077 g.heads = 128; 1078 g.sectors = 32; 1079 g.cylinders = dev->size / (128 * 32 * 512); 1080 g.start = get_start_sect(inode->i_bdev); 1081 return(copy_to_user(loc, &g, sizeof(g)) ? -EFAULT : 0); 1082 1083 case HDIO_GET_IDENTITY: 1084 ubd_id.cyls = dev->size / (128 * 32 * 512); 1085 if(copy_to_user((char __user *) arg, (char *) &ubd_id, 1086 sizeof(ubd_id))) 1087 return(-EFAULT); 1088 return(0); 1089 1090 case CDROMVOLREAD: 1091 if(copy_from_user(&volume, (char __user *) arg, sizeof(volume))) 1092 return(-EFAULT); 1093 volume.channel0 = 255; 1094 volume.channel1 = 255; 1095 volume.channel2 = 255; 1096 volume.channel3 = 255; 1097 if(copy_to_user((char __user *) arg, &volume, sizeof(volume))) 1098 return(-EFAULT); 1099 return(0); 1100 } 1101 return(-EINVAL); 1102 } 1103 1104 static int same_backing_files(char *from_cmdline, char *from_cow, char *cow) 1105 { 1106 struct uml_stat buf1, buf2; 1107 int err; 1108 1109 if(from_cmdline == NULL) return(1); 1110 if(!strcmp(from_cmdline, from_cow)) return(1); 1111 1112 err = os_stat_file(from_cmdline, &buf1); 1113 if(err < 0){ 1114 printk("Couldn't stat '%s', err = %d\n", from_cmdline, -err); 1115 return(1); 1116 } 1117 err = os_stat_file(from_cow, &buf2); 1118 if(err < 0){ 1119 printk("Couldn't stat '%s', err = %d\n", from_cow, -err); 1120 return(1); 1121 } 1122 if((buf1.ust_dev == buf2.ust_dev) && (buf1.ust_ino == buf2.ust_ino)) 1123 return(1); 1124 1125 printk("Backing file mismatch - \"%s\" requested,\n" 1126 "\"%s\" specified in COW header of \"%s\"\n", 1127 from_cmdline, from_cow, cow); 1128 return(0); 1129 } 1130 1131 static int backing_file_mismatch(char *file, __u64 size, time_t mtime) 1132 { 1133 unsigned long modtime; 1134 long long actual; 1135 int err; 1136 1137 err = os_file_modtime(file, &modtime); 1138 if(err < 0){ 1139 printk("Failed to get modification time of backing file " 1140 "\"%s\", err = %d\n", file, -err); 1141 return(err); 1142 } 1143 1144 err = os_file_size(file, &actual); 1145 if(err < 0){ 1146 printk("Failed to get size of backing file \"%s\", " 1147 "err = %d\n", file, -err); 1148 return(err); 1149 } 1150 1151 if(actual != size){ 1152 /*__u64 can be a long on AMD64 and with %lu GCC complains; so 1153 * the typecast.*/ 1154 printk("Size mismatch (%llu vs %llu) of COW header vs backing " 1155 "file\n", (unsigned long long) size, actual); 1156 return(-EINVAL); 1157 } 1158 if(modtime != mtime){ 1159 printk("mtime mismatch (%ld vs %ld) of COW header vs backing " 1160 "file\n", mtime, modtime); 1161 return(-EINVAL); 1162 } 1163 return(0); 1164 } 1165 1166 int read_cow_bitmap(int fd, void *buf, int offset, int len) 1167 { 1168 int err; 1169 1170 err = os_seek_file(fd, offset); 1171 if(err < 0) 1172 return(err); 1173 1174 err = os_read_file(fd, buf, len); 1175 if(err < 0) 1176 return(err); 1177 1178 return(0); 1179 } 1180 1181 int open_ubd_file(char *file, struct openflags *openflags, 1182 char **backing_file_out, int *bitmap_offset_out, 1183 unsigned long *bitmap_len_out, int *data_offset_out, 1184 int *create_cow_out) 1185 { 1186 time_t mtime; 1187 unsigned long long size; 1188 __u32 version, align; 1189 char *backing_file; 1190 int fd, err, sectorsize, same, mode = 0644; 1191 1192 fd = os_open_file(file, *openflags, mode); 1193 if(fd < 0){ 1194 if((fd == -ENOENT) && (create_cow_out != NULL)) 1195 *create_cow_out = 1; 1196 if(!openflags->w || 1197 ((fd != -EROFS) && (fd != -EACCES))) return(fd); 1198 openflags->w = 0; 1199 fd = os_open_file(file, *openflags, mode); 1200 if(fd < 0) 1201 return(fd); 1202 } 1203 1204 err = os_lock_file(fd, openflags->w); 1205 if(err < 0){ 1206 printk("Failed to lock '%s', err = %d\n", file, -err); 1207 goto out_close; 1208 } 1209 1210 if(backing_file_out == NULL) return(fd); 1211 1212 err = read_cow_header(file_reader, &fd, &version, &backing_file, &mtime, 1213 &size, §orsize, &align, bitmap_offset_out); 1214 if(err && (*backing_file_out != NULL)){ 1215 printk("Failed to read COW header from COW file \"%s\", " 1216 "errno = %d\n", file, -err); 1217 goto out_close; 1218 } 1219 if(err) return(fd); 1220 1221 if(backing_file_out == NULL) return(fd); 1222 1223 same = same_backing_files(*backing_file_out, backing_file, file); 1224 1225 if(!same && !backing_file_mismatch(*backing_file_out, size, mtime)){ 1226 printk("Switching backing file to '%s'\n", *backing_file_out); 1227 err = write_cow_header(file, fd, *backing_file_out, 1228 sectorsize, align, &size); 1229 if(err){ 1230 printk("Switch failed, errno = %d\n", -err); 1231 return(err); 1232 } 1233 } 1234 else { 1235 *backing_file_out = backing_file; 1236 err = backing_file_mismatch(*backing_file_out, size, mtime); 1237 if(err) goto out_close; 1238 } 1239 1240 cow_sizes(version, size, sectorsize, align, *bitmap_offset_out, 1241 bitmap_len_out, data_offset_out); 1242 1243 return(fd); 1244 out_close: 1245 os_close_file(fd); 1246 return(err); 1247 } 1248 1249 int create_cow_file(char *cow_file, char *backing_file, struct openflags flags, 1250 int sectorsize, int alignment, int *bitmap_offset_out, 1251 unsigned long *bitmap_len_out, int *data_offset_out) 1252 { 1253 int err, fd; 1254 1255 flags.c = 1; 1256 fd = open_ubd_file(cow_file, &flags, NULL, NULL, NULL, NULL, NULL); 1257 if(fd < 0){ 1258 err = fd; 1259 printk("Open of COW file '%s' failed, errno = %d\n", cow_file, 1260 -err); 1261 goto out; 1262 } 1263 1264 err = init_cow_file(fd, cow_file, backing_file, sectorsize, alignment, 1265 bitmap_offset_out, bitmap_len_out, 1266 data_offset_out); 1267 if(!err) 1268 return(fd); 1269 os_close_file(fd); 1270 out: 1271 return(err); 1272 } 1273 1274 static int update_bitmap(struct io_thread_req *req) 1275 { 1276 int n; 1277 1278 if(req->cow_offset == -1) 1279 return(0); 1280 1281 n = os_seek_file(req->fds[1], req->cow_offset); 1282 if(n < 0){ 1283 printk("do_io - bitmap lseek failed : err = %d\n", -n); 1284 return(1); 1285 } 1286 1287 n = os_write_file(req->fds[1], &req->bitmap_words, 1288 sizeof(req->bitmap_words)); 1289 if(n != sizeof(req->bitmap_words)){ 1290 printk("do_io - bitmap update failed, err = %d fd = %d\n", -n, 1291 req->fds[1]); 1292 return(1); 1293 } 1294 1295 return(0); 1296 } 1297 1298 void do_io(struct io_thread_req *req) 1299 { 1300 char *buf; 1301 unsigned long len; 1302 int n, nsectors, start, end, bit; 1303 int err; 1304 __u64 off; 1305 1306 nsectors = req->length / req->sectorsize; 1307 start = 0; 1308 do { 1309 bit = ubd_test_bit(start, (unsigned char *) &req->sector_mask); 1310 end = start; 1311 while((end < nsectors) && 1312 (ubd_test_bit(end, (unsigned char *) 1313 &req->sector_mask) == bit)) 1314 end++; 1315 1316 off = req->offset + req->offsets[bit] + 1317 start * req->sectorsize; 1318 len = (end - start) * req->sectorsize; 1319 buf = &req->buffer[start * req->sectorsize]; 1320 1321 err = os_seek_file(req->fds[bit], off); 1322 if(err < 0){ 1323 printk("do_io - lseek failed : err = %d\n", -err); 1324 req->error = 1; 1325 return; 1326 } 1327 if(req->op == UBD_READ){ 1328 n = 0; 1329 do { 1330 buf = &buf[n]; 1331 len -= n; 1332 n = os_read_file(req->fds[bit], buf, len); 1333 if (n < 0) { 1334 printk("do_io - read failed, err = %d " 1335 "fd = %d\n", -n, req->fds[bit]); 1336 req->error = 1; 1337 return; 1338 } 1339 } while((n < len) && (n != 0)); 1340 if (n < len) memset(&buf[n], 0, len - n); 1341 } else { 1342 n = os_write_file(req->fds[bit], buf, len); 1343 if(n != len){ 1344 printk("do_io - write failed err = %d " 1345 "fd = %d\n", -n, req->fds[bit]); 1346 req->error = 1; 1347 return; 1348 } 1349 } 1350 1351 start = end; 1352 } while(start < nsectors); 1353 1354 req->error = update_bitmap(req); 1355 } 1356 1357 /* Changed in start_io_thread, which is serialized by being called only 1358 * from ubd_init, which is an initcall. 1359 */ 1360 int kernel_fd = -1; 1361 1362 /* Only changed by the io thread */ 1363 int io_count = 0; 1364 1365 int io_thread(void *arg) 1366 { 1367 struct io_thread_req req; 1368 int n; 1369 1370 ignore_sigwinch_sig(); 1371 while(1){ 1372 n = os_read_file(kernel_fd, &req, sizeof(req)); 1373 if(n != sizeof(req)){ 1374 if(n < 0) 1375 printk("io_thread - read failed, fd = %d, " 1376 "err = %d\n", kernel_fd, -n); 1377 else { 1378 printk("io_thread - short read, fd = %d, " 1379 "length = %d\n", kernel_fd, n); 1380 } 1381 continue; 1382 } 1383 io_count++; 1384 do_io(&req); 1385 n = os_write_file(kernel_fd, &req, sizeof(req)); 1386 if(n != sizeof(req)) 1387 printk("io_thread - write failed, fd = %d, err = %d\n", 1388 kernel_fd, -n); 1389 } 1390 } 1391 1392 /* 1393 * Overrides for Emacs so that we follow Linus's tabbing style. 1394 * Emacs will notice this stuff at the end of the file and automatically 1395 * adjust the settings for this buffer only. This must remain at the end 1396 * of the file. 1397 * --------------------------------------------------------------------------- 1398 * Local variables: 1399 * c-file-style: "linux" 1400 * End: 1401 */ 1402