1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 /* 22 * Copyright 2006 Sun Microsystems, Inc. All rights reserved. 23 * Use is subject to license terms. 24 */ 25 26 #pragma ident "%Z%%M% %I% %E% SMI" 27 28 /* 29 * ZFS volume emulation driver. 30 * 31 * Makes a DMU object look like a volume of arbitrary size, up to 2^64 bytes. 32 * Volumes are accessed through the symbolic links named: 33 * 34 * /dev/zvol/dsk/<pool_name>/<dataset_name> 35 * /dev/zvol/rdsk/<pool_name>/<dataset_name> 36 * 37 * These links are created by the ZFS-specific devfsadm link generator. 38 * Volumes are persistent through reboot. No user command needs to be 39 * run before opening and using a device. 40 */ 41 42 #include <sys/types.h> 43 #include <sys/param.h> 44 #include <sys/errno.h> 45 #include <sys/aio_req.h> 46 #include <sys/uio.h> 47 #include <sys/buf.h> 48 #include <sys/modctl.h> 49 #include <sys/open.h> 50 #include <sys/kmem.h> 51 #include <sys/conf.h> 52 #include <sys/cmn_err.h> 53 #include <sys/stat.h> 54 #include <sys/zap.h> 55 #include <sys/spa.h> 56 #include <sys/zio.h> 57 #include <sys/dsl_prop.h> 58 #include <sys/dkio.h> 59 #include <sys/efi_partition.h> 60 #include <sys/byteorder.h> 61 #include <sys/pathname.h> 62 #include <sys/ddi.h> 63 #include <sys/sunddi.h> 64 #include <sys/crc32.h> 65 #include <sys/dirent.h> 66 #include <sys/policy.h> 67 #include <sys/fs/zfs.h> 68 #include <sys/zfs_ioctl.h> 69 #include <sys/mkdev.h> 70 #include <sys/zil.h> 71 72 #include "zfs_namecheck.h" 73 74 #define ZVOL_OBJ 1ULL 75 #define ZVOL_ZAP_OBJ 2ULL 76 77 static void *zvol_state; 78 79 /* 80 * This lock protects the zvol_state structure from being modified 81 * while it's being used, e.g. an open that comes in before a create 82 * finishes. It also protects temporary opens of the dataset so that, 83 * e.g., an open doesn't get a spurious EBUSY. 84 */ 85 static kmutex_t zvol_state_lock; 86 static uint32_t zvol_minors; 87 88 /* 89 * The in-core state of each volume. 90 */ 91 typedef struct zvol_state { 92 char zv_name[MAXPATHLEN]; /* pool/dd name */ 93 uint64_t zv_volsize; /* amount of space we advertise */ 94 minor_t zv_minor; /* minor number */ 95 uint8_t zv_min_bs; /* minimum addressable block shift */ 96 uint8_t zv_readonly; /* hard readonly; like write-protect */ 97 objset_t *zv_objset; /* objset handle */ 98 uint32_t zv_mode; /* DS_MODE_* flags at open time */ 99 uint32_t zv_open_count[OTYPCNT]; /* open counts */ 100 uint32_t zv_total_opens; /* total open count */ 101 zilog_t *zv_zilog; /* ZIL handle */ 102 uint64_t zv_txg_assign; /* txg to assign during ZIL replay */ 103 } zvol_state_t; 104 105 static void 106 zvol_size_changed(zvol_state_t *zv, dev_t dev) 107 { 108 dev = makedevice(getmajor(dev), zv->zv_minor); 109 110 VERIFY(ddi_prop_update_int64(dev, zfs_dip, 111 "Size", zv->zv_volsize) == DDI_SUCCESS); 112 VERIFY(ddi_prop_update_int64(dev, zfs_dip, 113 "Nblocks", lbtodb(zv->zv_volsize)) == DDI_SUCCESS); 114 } 115 116 int 117 zvol_check_volsize(zfs_cmd_t *zc, uint64_t blocksize) 118 { 119 if (zc->zc_volsize == 0) 120 return (EINVAL); 121 122 if (zc->zc_volsize % blocksize != 0) 123 return (EINVAL); 124 125 #ifdef _ILP32 126 if (zc->zc_volsize - 1 > SPEC_MAXOFFSET_T) 127 return (EOVERFLOW); 128 #endif 129 return (0); 130 } 131 132 int 133 zvol_check_volblocksize(zfs_cmd_t *zc) 134 { 135 if (zc->zc_volblocksize < SPA_MINBLOCKSIZE || 136 zc->zc_volblocksize > SPA_MAXBLOCKSIZE || 137 !ISP2(zc->zc_volblocksize)) 138 return (EDOM); 139 140 return (0); 141 } 142 143 static void 144 zvol_readonly_changed_cb(void *arg, uint64_t newval) 145 { 146 zvol_state_t *zv = arg; 147 148 zv->zv_readonly = (uint8_t)newval; 149 } 150 151 int 152 zvol_get_stats(zfs_cmd_t *zc, objset_t *os) 153 { 154 int error; 155 dmu_object_info_t doi; 156 157 error = zap_lookup(os, ZVOL_ZAP_OBJ, "size", 8, 1, &zc->zc_volsize); 158 159 if (error) 160 return (error); 161 162 error = dmu_object_info(os, ZVOL_OBJ, &doi); 163 164 if (error == 0) 165 zc->zc_volblocksize = doi.doi_data_block_size; 166 167 return (error); 168 } 169 170 /* 171 * Find a free minor number. 172 */ 173 static minor_t 174 zvol_minor_alloc(void) 175 { 176 minor_t minor; 177 178 ASSERT(MUTEX_HELD(&zvol_state_lock)); 179 180 for (minor = 1; minor <= ZVOL_MAX_MINOR; minor++) 181 if (ddi_get_soft_state(zvol_state, minor) == NULL) 182 return (minor); 183 184 return (0); 185 } 186 187 static zvol_state_t * 188 zvol_minor_lookup(char *name) 189 { 190 minor_t minor; 191 zvol_state_t *zv; 192 193 ASSERT(MUTEX_HELD(&zvol_state_lock)); 194 195 for (minor = 1; minor <= ZVOL_MAX_MINOR; minor++) { 196 zv = ddi_get_soft_state(zvol_state, minor); 197 if (zv == NULL) 198 continue; 199 if (strcmp(zv->zv_name, name) == 0) 200 break; 201 } 202 203 return (zv); 204 } 205 206 void 207 zvol_create_cb(objset_t *os, void *arg, dmu_tx_t *tx) 208 { 209 zfs_cmd_t *zc = arg; 210 int error; 211 212 error = dmu_object_claim(os, ZVOL_OBJ, DMU_OT_ZVOL, zc->zc_volblocksize, 213 DMU_OT_NONE, 0, tx); 214 ASSERT(error == 0); 215 216 error = zap_create_claim(os, ZVOL_ZAP_OBJ, DMU_OT_ZVOL_PROP, 217 DMU_OT_NONE, 0, tx); 218 ASSERT(error == 0); 219 220 error = zap_update(os, ZVOL_ZAP_OBJ, "size", 8, 1, &zc->zc_volsize, tx); 221 ASSERT(error == 0); 222 } 223 224 /* 225 * Replay a TX_WRITE ZIL transaction that didn't get committed 226 * after a system failure 227 */ 228 static int 229 zvol_replay_write(zvol_state_t *zv, lr_write_t *lr, boolean_t byteswap) 230 { 231 objset_t *os = zv->zv_objset; 232 char *data = (char *)(lr + 1); /* data follows lr_write_t */ 233 uint64_t off = lr->lr_offset; 234 uint64_t len = lr->lr_length; 235 dmu_tx_t *tx; 236 int error; 237 238 if (byteswap) 239 byteswap_uint64_array(lr, sizeof (*lr)); 240 241 restart: 242 tx = dmu_tx_create(os); 243 dmu_tx_hold_write(tx, ZVOL_OBJ, off, len); 244 error = dmu_tx_assign(tx, zv->zv_txg_assign); 245 if (error) { 246 dmu_tx_abort(tx); 247 if (error == ERESTART && zv->zv_txg_assign == TXG_NOWAIT) { 248 txg_wait_open(dmu_objset_pool(os), 0); 249 goto restart; 250 } 251 } else { 252 dmu_write(os, ZVOL_OBJ, off, len, data, tx); 253 dmu_tx_commit(tx); 254 } 255 256 return (error); 257 } 258 259 /* ARGSUSED */ 260 static int 261 zvol_replay_err(zvol_state_t *zv, lr_t *lr, boolean_t byteswap) 262 { 263 return (ENOTSUP); 264 } 265 266 /* 267 * Callback vectors for replaying records. 268 * Only TX_WRITE is needed for zvol. 269 */ 270 zil_replay_func_t *zvol_replay_vector[TX_MAX_TYPE] = { 271 zvol_replay_err, /* 0 no such transaction type */ 272 zvol_replay_err, /* TX_CREATE */ 273 zvol_replay_err, /* TX_MKDIR */ 274 zvol_replay_err, /* TX_MKXATTR */ 275 zvol_replay_err, /* TX_SYMLINK */ 276 zvol_replay_err, /* TX_REMOVE */ 277 zvol_replay_err, /* TX_RMDIR */ 278 zvol_replay_err, /* TX_LINK */ 279 zvol_replay_err, /* TX_RENAME */ 280 zvol_replay_write, /* TX_WRITE */ 281 zvol_replay_err, /* TX_TRUNCATE */ 282 zvol_replay_err, /* TX_SETATTR */ 283 zvol_replay_err, /* TX_ACL */ 284 }; 285 286 /* 287 * Create a minor node for the specified volume. 288 */ 289 int 290 zvol_create_minor(zfs_cmd_t *zc) 291 { 292 char *name = zc->zc_name; 293 dev_t dev = zc->zc_dev; 294 zvol_state_t *zv; 295 objset_t *os; 296 uint64_t volsize; 297 minor_t minor = 0; 298 struct pathname linkpath; 299 int ds_mode = DS_MODE_PRIMARY; 300 vnode_t *vp = NULL; 301 char *devpath; 302 size_t devpathlen = strlen(ZVOL_FULL_DEV_DIR) + 1 + strlen(name) + 1; 303 char chrbuf[30], blkbuf[30]; 304 int error; 305 306 mutex_enter(&zvol_state_lock); 307 308 if ((zv = zvol_minor_lookup(name)) != NULL) { 309 mutex_exit(&zvol_state_lock); 310 return (EEXIST); 311 } 312 313 if (strchr(name, '@') != 0) 314 ds_mode |= DS_MODE_READONLY; 315 316 error = dmu_objset_open(name, DMU_OST_ZVOL, ds_mode, &os); 317 318 if (error) { 319 mutex_exit(&zvol_state_lock); 320 return (error); 321 } 322 323 error = zap_lookup(os, ZVOL_ZAP_OBJ, "size", 8, 1, &volsize); 324 325 if (error) { 326 dmu_objset_close(os); 327 mutex_exit(&zvol_state_lock); 328 return (error); 329 } 330 331 /* 332 * If there's an existing /dev/zvol symlink, try to use the 333 * same minor number we used last time. 334 */ 335 devpath = kmem_alloc(devpathlen, KM_SLEEP); 336 337 (void) sprintf(devpath, "%s/%s", ZVOL_FULL_DEV_DIR, name); 338 339 error = lookupname(devpath, UIO_SYSSPACE, NO_FOLLOW, NULL, &vp); 340 341 kmem_free(devpath, devpathlen); 342 343 if (error == 0 && vp->v_type != VLNK) 344 error = EINVAL; 345 346 if (error == 0) { 347 pn_alloc(&linkpath); 348 error = pn_getsymlink(vp, &linkpath, kcred); 349 if (error == 0) { 350 char *ms = strstr(linkpath.pn_path, ZVOL_PSEUDO_DEV); 351 if (ms != NULL) { 352 ms += strlen(ZVOL_PSEUDO_DEV); 353 minor = stoi(&ms); 354 } 355 } 356 pn_free(&linkpath); 357 } 358 359 if (vp != NULL) 360 VN_RELE(vp); 361 362 /* 363 * If we found a minor but it's already in use, we must pick a new one. 364 */ 365 if (minor != 0 && ddi_get_soft_state(zvol_state, minor) != NULL) 366 minor = 0; 367 368 if (minor == 0) 369 minor = zvol_minor_alloc(); 370 371 if (minor == 0) { 372 dmu_objset_close(os); 373 mutex_exit(&zvol_state_lock); 374 return (ENXIO); 375 } 376 377 if (ddi_soft_state_zalloc(zvol_state, minor) != DDI_SUCCESS) { 378 dmu_objset_close(os); 379 mutex_exit(&zvol_state_lock); 380 return (EAGAIN); 381 } 382 383 (void) ddi_prop_update_string(minor, zfs_dip, ZVOL_PROP_NAME, name); 384 385 (void) sprintf(chrbuf, "%uc,raw", minor); 386 387 if (ddi_create_minor_node(zfs_dip, chrbuf, S_IFCHR, 388 minor, DDI_PSEUDO, 0) == DDI_FAILURE) { 389 ddi_soft_state_free(zvol_state, minor); 390 dmu_objset_close(os); 391 mutex_exit(&zvol_state_lock); 392 return (EAGAIN); 393 } 394 395 (void) sprintf(blkbuf, "%uc", minor); 396 397 if (ddi_create_minor_node(zfs_dip, blkbuf, S_IFBLK, 398 minor, DDI_PSEUDO, 0) == DDI_FAILURE) { 399 ddi_remove_minor_node(zfs_dip, chrbuf); 400 ddi_soft_state_free(zvol_state, minor); 401 dmu_objset_close(os); 402 mutex_exit(&zvol_state_lock); 403 return (EAGAIN); 404 } 405 406 zv = ddi_get_soft_state(zvol_state, minor); 407 408 (void) strcpy(zv->zv_name, name); 409 zv->zv_min_bs = DEV_BSHIFT; 410 zv->zv_minor = minor; 411 zv->zv_volsize = volsize; 412 zv->zv_objset = os; 413 zv->zv_mode = ds_mode; 414 zv->zv_zilog = zil_open(os, NULL); 415 416 zil_replay(os, zv, &zv->zv_txg_assign, zvol_replay_vector, NULL); 417 418 zvol_size_changed(zv, dev); 419 420 /* XXX this should handle the possible i/o error */ 421 VERIFY(dsl_prop_register(dmu_objset_ds(zv->zv_objset), 422 "readonly", zvol_readonly_changed_cb, zv) == 0); 423 424 zvol_minors++; 425 426 mutex_exit(&zvol_state_lock); 427 428 return (0); 429 } 430 431 /* 432 * Remove minor node for the specified volume. 433 */ 434 int 435 zvol_remove_minor(zfs_cmd_t *zc) 436 { 437 zvol_state_t *zv; 438 char namebuf[30]; 439 440 mutex_enter(&zvol_state_lock); 441 442 if ((zv = zvol_minor_lookup(zc->zc_name)) == NULL) { 443 mutex_exit(&zvol_state_lock); 444 return (ENXIO); 445 } 446 447 if (zv->zv_total_opens != 0) { 448 mutex_exit(&zvol_state_lock); 449 return (EBUSY); 450 } 451 452 (void) sprintf(namebuf, "%uc,raw", zv->zv_minor); 453 ddi_remove_minor_node(zfs_dip, namebuf); 454 455 (void) sprintf(namebuf, "%uc", zv->zv_minor); 456 ddi_remove_minor_node(zfs_dip, namebuf); 457 458 VERIFY(dsl_prop_unregister(dmu_objset_ds(zv->zv_objset), 459 "readonly", zvol_readonly_changed_cb, zv) == 0); 460 461 zil_close(zv->zv_zilog); 462 zv->zv_zilog = NULL; 463 dmu_objset_close(zv->zv_objset); 464 zv->zv_objset = NULL; 465 466 ddi_soft_state_free(zvol_state, zv->zv_minor); 467 468 zvol_minors--; 469 470 mutex_exit(&zvol_state_lock); 471 472 return (0); 473 } 474 475 int 476 zvol_set_volsize(zfs_cmd_t *zc) 477 { 478 zvol_state_t *zv; 479 dev_t dev = zc->zc_dev; 480 dmu_tx_t *tx; 481 int error; 482 dmu_object_info_t doi; 483 484 mutex_enter(&zvol_state_lock); 485 486 if ((zv = zvol_minor_lookup(zc->zc_name)) == NULL) { 487 mutex_exit(&zvol_state_lock); 488 return (ENXIO); 489 } 490 491 if ((error = dmu_object_info(zv->zv_objset, ZVOL_OBJ, &doi)) != 0 || 492 (error = zvol_check_volsize(zc, doi.doi_data_block_size)) != 0) { 493 mutex_exit(&zvol_state_lock); 494 return (error); 495 } 496 497 if (zv->zv_readonly || (zv->zv_mode & DS_MODE_READONLY)) { 498 mutex_exit(&zvol_state_lock); 499 return (EROFS); 500 } 501 502 tx = dmu_tx_create(zv->zv_objset); 503 dmu_tx_hold_zap(tx, ZVOL_ZAP_OBJ, TRUE, NULL); 504 dmu_tx_hold_free(tx, ZVOL_OBJ, zc->zc_volsize, DMU_OBJECT_END); 505 error = dmu_tx_assign(tx, TXG_WAIT); 506 if (error) { 507 dmu_tx_abort(tx); 508 mutex_exit(&zvol_state_lock); 509 return (error); 510 } 511 512 error = zap_update(zv->zv_objset, ZVOL_ZAP_OBJ, "size", 8, 1, 513 &zc->zc_volsize, tx); 514 if (error == 0) { 515 error = dmu_free_range(zv->zv_objset, ZVOL_OBJ, zc->zc_volsize, 516 DMU_OBJECT_END, tx); 517 } 518 519 dmu_tx_commit(tx); 520 521 if (error == 0) { 522 zv->zv_volsize = zc->zc_volsize; 523 zvol_size_changed(zv, dev); 524 } 525 526 mutex_exit(&zvol_state_lock); 527 528 return (error); 529 } 530 531 int 532 zvol_set_volblocksize(zfs_cmd_t *zc) 533 { 534 zvol_state_t *zv; 535 dmu_tx_t *tx; 536 int error; 537 538 mutex_enter(&zvol_state_lock); 539 540 if ((zv = zvol_minor_lookup(zc->zc_name)) == NULL) { 541 mutex_exit(&zvol_state_lock); 542 return (ENXIO); 543 } 544 545 if (zv->zv_readonly || (zv->zv_mode & DS_MODE_READONLY)) { 546 mutex_exit(&zvol_state_lock); 547 return (EROFS); 548 } 549 550 tx = dmu_tx_create(zv->zv_objset); 551 dmu_tx_hold_bonus(tx, ZVOL_OBJ); 552 error = dmu_tx_assign(tx, TXG_WAIT); 553 if (error) { 554 dmu_tx_abort(tx); 555 } else { 556 error = dmu_object_set_blocksize(zv->zv_objset, ZVOL_OBJ, 557 zc->zc_volblocksize, 0, tx); 558 if (error == ENOTSUP) 559 error = EBUSY; 560 dmu_tx_commit(tx); 561 } 562 563 mutex_exit(&zvol_state_lock); 564 565 return (error); 566 } 567 568 /*ARGSUSED*/ 569 int 570 zvol_open(dev_t *devp, int flag, int otyp, cred_t *cr) 571 { 572 minor_t minor = getminor(*devp); 573 zvol_state_t *zv; 574 575 if (minor == 0) /* This is the control device */ 576 return (0); 577 578 mutex_enter(&zvol_state_lock); 579 580 zv = ddi_get_soft_state(zvol_state, minor); 581 if (zv == NULL) { 582 mutex_exit(&zvol_state_lock); 583 return (ENXIO); 584 } 585 586 ASSERT(zv->zv_objset != NULL); 587 588 if ((flag & FWRITE) && 589 (zv->zv_readonly || (zv->zv_mode & DS_MODE_READONLY))) { 590 mutex_exit(&zvol_state_lock); 591 return (EROFS); 592 } 593 594 if (zv->zv_open_count[otyp] == 0 || otyp == OTYP_LYR) { 595 zv->zv_open_count[otyp]++; 596 zv->zv_total_opens++; 597 } 598 599 mutex_exit(&zvol_state_lock); 600 601 return (0); 602 } 603 604 /*ARGSUSED*/ 605 int 606 zvol_close(dev_t dev, int flag, int otyp, cred_t *cr) 607 { 608 minor_t minor = getminor(dev); 609 zvol_state_t *zv; 610 611 if (minor == 0) /* This is the control device */ 612 return (0); 613 614 mutex_enter(&zvol_state_lock); 615 616 zv = ddi_get_soft_state(zvol_state, minor); 617 if (zv == NULL) { 618 mutex_exit(&zvol_state_lock); 619 return (ENXIO); 620 } 621 622 /* 623 * The next statement is a workaround for the following DDI bug: 624 * 6343604 specfs race: multiple "last-close" of the same device 625 */ 626 if (zv->zv_total_opens == 0) { 627 mutex_exit(&zvol_state_lock); 628 return (0); 629 } 630 631 /* 632 * If the open count is zero, this is a spurious close. 633 * That indicates a bug in the kernel / DDI framework. 634 */ 635 ASSERT(zv->zv_open_count[otyp] != 0); 636 ASSERT(zv->zv_total_opens != 0); 637 638 /* 639 * You may get multiple opens, but only one close. 640 */ 641 zv->zv_open_count[otyp]--; 642 zv->zv_total_opens--; 643 644 mutex_exit(&zvol_state_lock); 645 646 return (0); 647 } 648 649 /* 650 * zvol_log_write() handles synchronous page writes using 651 * TX_WRITE ZIL transactions. 652 * 653 * We store data in the log buffers if it's small enough. 654 * Otherwise we flush the data out via dmu_sync(). 655 */ 656 ssize_t zvol_immediate_write_sz = 65536; 657 658 int 659 zvol_log_write(zvol_state_t *zv, dmu_tx_t *tx, offset_t off, ssize_t len, 660 char *addr) 661 { 662 itx_t *itx; 663 lr_write_t *lr; 664 objset_t *os = zv->zv_objset; 665 int dlen; 666 int error; 667 668 dlen = (len <= zvol_immediate_write_sz ? len : 0); 669 itx = zil_itx_create(TX_WRITE, sizeof (*lr) + dlen); 670 lr = (lr_write_t *)&itx->itx_lr; 671 lr->lr_foid = ZVOL_OBJ; 672 lr->lr_offset = off; 673 lr->lr_length = len; 674 lr->lr_blkoff = 0; 675 BP_ZERO(&lr->lr_blkptr); 676 677 /* 678 * Get the data as we know we'll be writing it immediately 679 */ 680 if (dlen) { /* immediate write */ 681 bcopy(addr, (char *)itx + offsetof(itx_t, itx_lr) + 682 sizeof (*lr), len); 683 } else { 684 txg_suspend(dmu_objset_pool(os)); 685 error = dmu_sync(os, ZVOL_OBJ, off, &lr->lr_blkoff, 686 &lr->lr_blkptr, dmu_tx_get_txg(tx)); 687 txg_resume(dmu_objset_pool(os)); 688 if (error) { 689 kmem_free(itx, offsetof(itx_t, itx_lr)); 690 return (error); 691 } 692 } 693 itx->itx_data_copied = 1; 694 695 (void) zil_itx_assign(zv->zv_zilog, itx, tx); 696 697 return (0); 698 } 699 700 int 701 zvol_strategy(buf_t *bp) 702 { 703 zvol_state_t *zv = ddi_get_soft_state(zvol_state, getminor(bp->b_edev)); 704 uint64_t off, volsize; 705 size_t size, resid; 706 char *addr; 707 objset_t *os; 708 int error = 0; 709 int sync; 710 711 if (zv == NULL) { 712 bioerror(bp, ENXIO); 713 biodone(bp); 714 return (0); 715 } 716 717 if (getminor(bp->b_edev) == 0) { 718 bioerror(bp, EINVAL); 719 biodone(bp); 720 return (0); 721 } 722 723 if (zv->zv_readonly && !(bp->b_flags & B_READ)) { 724 bioerror(bp, EROFS); 725 biodone(bp); 726 return (0); 727 } 728 729 off = ldbtob(bp->b_blkno); 730 volsize = zv->zv_volsize; 731 732 os = zv->zv_objset; 733 ASSERT(os != NULL); 734 sync = !(bp->b_flags & B_ASYNC) && !(zil_disable); 735 736 bp_mapin(bp); 737 addr = bp->b_un.b_addr; 738 resid = bp->b_bcount; 739 740 while (resid != 0 && off < volsize) { 741 742 size = MIN(resid, 1UL << 20); /* cap at 1MB per tx */ 743 744 if (size > volsize - off) /* don't write past the end */ 745 size = volsize - off; 746 747 if (bp->b_flags & B_READ) { 748 error = dmu_read(os, ZVOL_OBJ, 749 off, size, addr); 750 } else { 751 dmu_tx_t *tx = dmu_tx_create(os); 752 dmu_tx_hold_write(tx, ZVOL_OBJ, off, size); 753 error = dmu_tx_assign(tx, TXG_WAIT); 754 if (error) { 755 dmu_tx_abort(tx); 756 } else { 757 dmu_write(os, ZVOL_OBJ, off, size, addr, tx); 758 if (sync) { 759 /* use the ZIL to commit this write */ 760 error = zvol_log_write(zv, tx, off, 761 size, addr); 762 if (error) { 763 txg_wait_synced( 764 dmu_objset_pool(os), 0); 765 sync = B_FALSE; 766 } 767 } 768 dmu_tx_commit(tx); 769 } 770 } 771 if (error) 772 break; 773 off += size; 774 addr += size; 775 resid -= size; 776 } 777 778 if ((bp->b_resid = resid) == bp->b_bcount) 779 bioerror(bp, off > volsize ? EINVAL : error); 780 781 biodone(bp); 782 783 if (sync) 784 zil_commit(zv->zv_zilog, UINT64_MAX, FDSYNC); 785 786 return (0); 787 } 788 789 /*ARGSUSED*/ 790 int 791 zvol_read(dev_t dev, uio_t *uiop, cred_t *cr) 792 { 793 return (physio(zvol_strategy, NULL, dev, B_READ, minphys, uiop)); 794 } 795 796 /*ARGSUSED*/ 797 int 798 zvol_write(dev_t dev, uio_t *uiop, cred_t *cr) 799 { 800 return (physio(zvol_strategy, NULL, dev, B_WRITE, minphys, uiop)); 801 } 802 803 /*ARGSUSED*/ 804 int 805 zvol_aread(dev_t dev, struct aio_req *aio, cred_t *cr) 806 { 807 return (aphysio(zvol_strategy, anocancel, dev, B_READ, minphys, aio)); 808 } 809 810 /*ARGSUSED*/ 811 int 812 zvol_awrite(dev_t dev, struct aio_req *aio, cred_t *cr) 813 { 814 return (aphysio(zvol_strategy, anocancel, dev, B_WRITE, minphys, aio)); 815 } 816 817 /* 818 * Dirtbag ioctls to support mkfs(1M) for UFS filesystems. See dkio(7I). 819 */ 820 /*ARGSUSED*/ 821 int 822 zvol_ioctl(dev_t dev, int cmd, intptr_t arg, int flag, cred_t *cr, int *rvalp) 823 { 824 zvol_state_t *zv; 825 struct dk_cinfo dkc; 826 struct dk_minfo dkm; 827 dk_efi_t efi; 828 efi_gpt_t gpt; 829 efi_gpe_t gpe; 830 struct uuid uuid = EFI_RESERVED; 831 uint32_t crc; 832 int error = 0; 833 834 mutex_enter(&zvol_state_lock); 835 836 zv = ddi_get_soft_state(zvol_state, getminor(dev)); 837 838 if (zv == NULL) { 839 mutex_exit(&zvol_state_lock); 840 return (ENXIO); 841 } 842 843 switch (cmd) { 844 845 case DKIOCINFO: 846 bzero(&dkc, sizeof (dkc)); 847 (void) strcpy(dkc.dki_cname, "zvol"); 848 (void) strcpy(dkc.dki_dname, "zvol"); 849 dkc.dki_ctype = DKC_UNKNOWN; 850 dkc.dki_maxtransfer = 1 << (SPA_MAXBLOCKSHIFT - zv->zv_min_bs); 851 mutex_exit(&zvol_state_lock); 852 if (ddi_copyout(&dkc, (void *)arg, sizeof (dkc), flag)) 853 error = EFAULT; 854 return (error); 855 856 case DKIOCGMEDIAINFO: 857 bzero(&dkm, sizeof (dkm)); 858 dkm.dki_lbsize = 1U << zv->zv_min_bs; 859 dkm.dki_capacity = zv->zv_volsize >> zv->zv_min_bs; 860 dkm.dki_media_type = DK_UNKNOWN; 861 mutex_exit(&zvol_state_lock); 862 if (ddi_copyout(&dkm, (void *)arg, sizeof (dkm), flag)) 863 error = EFAULT; 864 return (error); 865 866 case DKIOCGETEFI: 867 if (ddi_copyin((void *)arg, &efi, sizeof (dk_efi_t), flag)) { 868 mutex_exit(&zvol_state_lock); 869 return (EFAULT); 870 } 871 872 bzero(&gpt, sizeof (gpt)); 873 bzero(&gpe, sizeof (gpe)); 874 875 efi.dki_data = (void *)(uintptr_t)efi.dki_data_64; 876 877 if (efi.dki_length < sizeof (gpt) + sizeof (gpe)) { 878 mutex_exit(&zvol_state_lock); 879 return (EINVAL); 880 } 881 882 efi.dki_length = sizeof (gpt) + sizeof (gpe); 883 884 gpt.efi_gpt_Signature = LE_64(EFI_SIGNATURE); 885 gpt.efi_gpt_Revision = LE_32(EFI_VERSION_CURRENT); 886 gpt.efi_gpt_HeaderSize = LE_32(sizeof (gpt)); 887 gpt.efi_gpt_FirstUsableLBA = LE_64(0ULL); 888 gpt.efi_gpt_LastUsableLBA = 889 LE_64((zv->zv_volsize >> zv->zv_min_bs) - 1); 890 gpt.efi_gpt_NumberOfPartitionEntries = LE_32(1); 891 gpt.efi_gpt_SizeOfPartitionEntry = LE_32(sizeof (gpe)); 892 893 UUID_LE_CONVERT(gpe.efi_gpe_PartitionTypeGUID, uuid); 894 gpe.efi_gpe_StartingLBA = gpt.efi_gpt_FirstUsableLBA; 895 gpe.efi_gpe_EndingLBA = gpt.efi_gpt_LastUsableLBA; 896 897 CRC32(crc, &gpe, sizeof (gpe), -1U, crc32_table); 898 gpt.efi_gpt_PartitionEntryArrayCRC32 = LE_32(~crc); 899 900 CRC32(crc, &gpt, sizeof (gpt), -1U, crc32_table); 901 gpt.efi_gpt_HeaderCRC32 = LE_32(~crc); 902 903 mutex_exit(&zvol_state_lock); 904 if (ddi_copyout(&gpt, efi.dki_data, sizeof (gpt), flag) || 905 ddi_copyout(&gpe, efi.dki_data + 1, sizeof (gpe), flag)) 906 error = EFAULT; 907 return (error); 908 909 default: 910 error = ENOTSUP; 911 break; 912 913 } 914 mutex_exit(&zvol_state_lock); 915 return (error); 916 } 917 918 int 919 zvol_busy(void) 920 { 921 return (zvol_minors != 0); 922 } 923 924 void 925 zvol_init(void) 926 { 927 VERIFY(ddi_soft_state_init(&zvol_state, sizeof (zvol_state_t), 1) == 0); 928 mutex_init(&zvol_state_lock, NULL, MUTEX_DEFAULT, NULL); 929 } 930 931 void 932 zvol_fini(void) 933 { 934 mutex_destroy(&zvol_state_lock); 935 ddi_soft_state_fini(&zvol_state); 936 } 937