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 #include <sys/refcount.h> 72 73 #include "zfs_namecheck.h" 74 75 #define ZVOL_OBJ 1ULL 76 #define ZVOL_ZAP_OBJ 2ULL 77 78 static void *zvol_state; 79 80 /* 81 * This lock protects the zvol_state structure from being modified 82 * while it's being used, e.g. an open that comes in before a create 83 * finishes. It also protects temporary opens of the dataset so that, 84 * e.g., an open doesn't get a spurious EBUSY. 85 */ 86 static kmutex_t zvol_state_lock; 87 static uint32_t zvol_minors; 88 89 /* 90 * The in-core state of each volume. 91 */ 92 typedef struct zvol_state { 93 char zv_name[MAXPATHLEN]; /* pool/dd name */ 94 uint64_t zv_volsize; /* amount of space we advertise */ 95 minor_t zv_minor; /* minor number */ 96 uint8_t zv_min_bs; /* minimum addressable block shift */ 97 uint8_t zv_readonly; /* hard readonly; like write-protect */ 98 objset_t *zv_objset; /* objset handle */ 99 uint32_t zv_mode; /* DS_MODE_* flags at open time */ 100 uint32_t zv_open_count[OTYPCNT]; /* open counts */ 101 uint32_t zv_total_opens; /* total open count */ 102 zilog_t *zv_zilog; /* ZIL handle */ 103 uint64_t zv_txg_assign; /* txg to assign during ZIL replay */ 104 krwlock_t zv_dslock; /* dmu_sync() rwlock */ 105 } zvol_state_t; 106 107 static void 108 zvol_size_changed(zvol_state_t *zv, dev_t dev) 109 { 110 dev = makedevice(getmajor(dev), zv->zv_minor); 111 112 VERIFY(ddi_prop_update_int64(dev, zfs_dip, 113 "Size", zv->zv_volsize) == DDI_SUCCESS); 114 VERIFY(ddi_prop_update_int64(dev, zfs_dip, 115 "Nblocks", lbtodb(zv->zv_volsize)) == DDI_SUCCESS); 116 } 117 118 int 119 zvol_check_volsize(uint64_t volsize, uint64_t blocksize) 120 { 121 if (volsize == 0) 122 return (EINVAL); 123 124 if (volsize % blocksize != 0) 125 return (EINVAL); 126 127 #ifdef _ILP32 128 if (volsize - 1 > SPEC_MAXOFFSET_T) 129 return (EOVERFLOW); 130 #endif 131 return (0); 132 } 133 134 int 135 zvol_check_volblocksize(uint64_t volblocksize) 136 { 137 if (volblocksize < SPA_MINBLOCKSIZE || 138 volblocksize > SPA_MAXBLOCKSIZE || 139 !ISP2(volblocksize)) 140 return (EDOM); 141 142 return (0); 143 } 144 145 static void 146 zvol_readonly_changed_cb(void *arg, uint64_t newval) 147 { 148 zvol_state_t *zv = arg; 149 150 zv->zv_readonly = (uint8_t)newval; 151 } 152 153 int 154 zvol_get_stats(objset_t *os, nvlist_t *nv) 155 { 156 int error; 157 dmu_object_info_t doi; 158 uint64_t val; 159 160 161 error = zap_lookup(os, ZVOL_ZAP_OBJ, "size", 8, 1, &val); 162 if (error) 163 return (error); 164 165 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_VOLSIZE, val); 166 167 error = dmu_object_info(os, ZVOL_OBJ, &doi); 168 169 if (error == 0) { 170 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_VOLBLOCKSIZE, 171 doi.doi_data_block_size); 172 } 173 174 return (error); 175 } 176 177 /* 178 * Find a free minor number. 179 */ 180 static minor_t 181 zvol_minor_alloc(void) 182 { 183 minor_t minor; 184 185 ASSERT(MUTEX_HELD(&zvol_state_lock)); 186 187 for (minor = 1; minor <= ZVOL_MAX_MINOR; minor++) 188 if (ddi_get_soft_state(zvol_state, minor) == NULL) 189 return (minor); 190 191 return (0); 192 } 193 194 static zvol_state_t * 195 zvol_minor_lookup(const char *name) 196 { 197 minor_t minor; 198 zvol_state_t *zv; 199 200 ASSERT(MUTEX_HELD(&zvol_state_lock)); 201 202 for (minor = 1; minor <= ZVOL_MAX_MINOR; minor++) { 203 zv = ddi_get_soft_state(zvol_state, minor); 204 if (zv == NULL) 205 continue; 206 if (strcmp(zv->zv_name, name) == 0) 207 break; 208 } 209 210 return (zv); 211 } 212 213 void 214 zvol_create_cb(objset_t *os, void *arg, dmu_tx_t *tx) 215 { 216 zfs_create_data_t *zc = arg; 217 int error; 218 uint64_t volblocksize, volsize; 219 220 VERIFY(nvlist_lookup_uint64(zc->zc_props, 221 zfs_prop_to_name(ZFS_PROP_VOLSIZE), &volsize) == 0); 222 if (nvlist_lookup_uint64(zc->zc_props, 223 zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE), &volblocksize) != 0) 224 volblocksize = zfs_prop_default_numeric(ZFS_PROP_VOLBLOCKSIZE); 225 226 /* 227 * These properites must be removed from the list so the generic 228 * property setting step won't apply to them. 229 */ 230 VERIFY(nvlist_remove_all(zc->zc_props, 231 zfs_prop_to_name(ZFS_PROP_VOLSIZE)) == 0); 232 (void) nvlist_remove_all(zc->zc_props, 233 zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE)); 234 235 error = dmu_object_claim(os, ZVOL_OBJ, DMU_OT_ZVOL, volblocksize, 236 DMU_OT_NONE, 0, tx); 237 ASSERT(error == 0); 238 239 error = zap_create_claim(os, ZVOL_ZAP_OBJ, DMU_OT_ZVOL_PROP, 240 DMU_OT_NONE, 0, tx); 241 ASSERT(error == 0); 242 243 error = zap_update(os, ZVOL_ZAP_OBJ, "size", 8, 1, &volsize, tx); 244 ASSERT(error == 0); 245 } 246 247 /* 248 * Replay a TX_WRITE ZIL transaction that didn't get committed 249 * after a system failure 250 */ 251 static int 252 zvol_replay_write(zvol_state_t *zv, lr_write_t *lr, boolean_t byteswap) 253 { 254 objset_t *os = zv->zv_objset; 255 char *data = (char *)(lr + 1); /* data follows lr_write_t */ 256 uint64_t off = lr->lr_offset; 257 uint64_t len = lr->lr_length; 258 dmu_tx_t *tx; 259 int error; 260 261 if (byteswap) 262 byteswap_uint64_array(lr, sizeof (*lr)); 263 264 tx = dmu_tx_create(os); 265 dmu_tx_hold_write(tx, ZVOL_OBJ, off, len); 266 error = dmu_tx_assign(tx, zv->zv_txg_assign); 267 if (error) { 268 dmu_tx_abort(tx); 269 } else { 270 dmu_write(os, ZVOL_OBJ, off, len, data, tx); 271 dmu_tx_commit(tx); 272 } 273 274 return (error); 275 } 276 277 /* ARGSUSED */ 278 static int 279 zvol_replay_err(zvol_state_t *zv, lr_t *lr, boolean_t byteswap) 280 { 281 return (ENOTSUP); 282 } 283 284 /* 285 * Callback vectors for replaying records. 286 * Only TX_WRITE is needed for zvol. 287 */ 288 zil_replay_func_t *zvol_replay_vector[TX_MAX_TYPE] = { 289 zvol_replay_err, /* 0 no such transaction type */ 290 zvol_replay_err, /* TX_CREATE */ 291 zvol_replay_err, /* TX_MKDIR */ 292 zvol_replay_err, /* TX_MKXATTR */ 293 zvol_replay_err, /* TX_SYMLINK */ 294 zvol_replay_err, /* TX_REMOVE */ 295 zvol_replay_err, /* TX_RMDIR */ 296 zvol_replay_err, /* TX_LINK */ 297 zvol_replay_err, /* TX_RENAME */ 298 zvol_replay_write, /* TX_WRITE */ 299 zvol_replay_err, /* TX_TRUNCATE */ 300 zvol_replay_err, /* TX_SETATTR */ 301 zvol_replay_err, /* TX_ACL */ 302 }; 303 304 /* 305 * Create a minor node for the specified volume. 306 */ 307 int 308 zvol_create_minor(const char *name, dev_t dev) 309 { 310 zvol_state_t *zv; 311 objset_t *os; 312 uint64_t volsize; 313 minor_t minor = 0; 314 struct pathname linkpath; 315 int ds_mode = DS_MODE_PRIMARY; 316 vnode_t *vp = NULL; 317 char *devpath; 318 size_t devpathlen = strlen(ZVOL_FULL_DEV_DIR) + 1 + strlen(name) + 1; 319 char chrbuf[30], blkbuf[30]; 320 int error; 321 322 mutex_enter(&zvol_state_lock); 323 324 if ((zv = zvol_minor_lookup(name)) != NULL) { 325 mutex_exit(&zvol_state_lock); 326 return (EEXIST); 327 } 328 329 if (strchr(name, '@') != 0) 330 ds_mode |= DS_MODE_READONLY; 331 332 error = dmu_objset_open(name, DMU_OST_ZVOL, ds_mode, &os); 333 334 if (error) { 335 mutex_exit(&zvol_state_lock); 336 return (error); 337 } 338 339 error = zap_lookup(os, ZVOL_ZAP_OBJ, "size", 8, 1, &volsize); 340 341 if (error) { 342 dmu_objset_close(os); 343 mutex_exit(&zvol_state_lock); 344 return (error); 345 } 346 347 /* 348 * If there's an existing /dev/zvol symlink, try to use the 349 * same minor number we used last time. 350 */ 351 devpath = kmem_alloc(devpathlen, KM_SLEEP); 352 353 (void) sprintf(devpath, "%s/%s", ZVOL_FULL_DEV_DIR, name); 354 355 error = lookupname(devpath, UIO_SYSSPACE, NO_FOLLOW, NULL, &vp); 356 357 kmem_free(devpath, devpathlen); 358 359 if (error == 0 && vp->v_type != VLNK) 360 error = EINVAL; 361 362 if (error == 0) { 363 pn_alloc(&linkpath); 364 error = pn_getsymlink(vp, &linkpath, kcred); 365 if (error == 0) { 366 char *ms = strstr(linkpath.pn_path, ZVOL_PSEUDO_DEV); 367 if (ms != NULL) { 368 ms += strlen(ZVOL_PSEUDO_DEV); 369 minor = stoi(&ms); 370 } 371 } 372 pn_free(&linkpath); 373 } 374 375 if (vp != NULL) 376 VN_RELE(vp); 377 378 /* 379 * If we found a minor but it's already in use, we must pick a new one. 380 */ 381 if (minor != 0 && ddi_get_soft_state(zvol_state, minor) != NULL) 382 minor = 0; 383 384 if (minor == 0) 385 minor = zvol_minor_alloc(); 386 387 if (minor == 0) { 388 dmu_objset_close(os); 389 mutex_exit(&zvol_state_lock); 390 return (ENXIO); 391 } 392 393 if (ddi_soft_state_zalloc(zvol_state, minor) != DDI_SUCCESS) { 394 dmu_objset_close(os); 395 mutex_exit(&zvol_state_lock); 396 return (EAGAIN); 397 } 398 399 (void) ddi_prop_update_string(minor, zfs_dip, ZVOL_PROP_NAME, 400 (char *)name); 401 402 (void) sprintf(chrbuf, "%uc,raw", minor); 403 404 if (ddi_create_minor_node(zfs_dip, chrbuf, S_IFCHR, 405 minor, DDI_PSEUDO, 0) == DDI_FAILURE) { 406 ddi_soft_state_free(zvol_state, minor); 407 dmu_objset_close(os); 408 mutex_exit(&zvol_state_lock); 409 return (EAGAIN); 410 } 411 412 (void) sprintf(blkbuf, "%uc", minor); 413 414 if (ddi_create_minor_node(zfs_dip, blkbuf, S_IFBLK, 415 minor, DDI_PSEUDO, 0) == DDI_FAILURE) { 416 ddi_remove_minor_node(zfs_dip, chrbuf); 417 ddi_soft_state_free(zvol_state, minor); 418 dmu_objset_close(os); 419 mutex_exit(&zvol_state_lock); 420 return (EAGAIN); 421 } 422 423 zv = ddi_get_soft_state(zvol_state, minor); 424 425 (void) strcpy(zv->zv_name, name); 426 zv->zv_min_bs = DEV_BSHIFT; 427 zv->zv_minor = minor; 428 zv->zv_volsize = volsize; 429 zv->zv_objset = os; 430 zv->zv_mode = ds_mode; 431 zv->zv_zilog = zil_open(os, NULL); 432 433 rw_init(&zv->zv_dslock, NULL, RW_DEFAULT, NULL); 434 435 zil_replay(os, zv, &zv->zv_txg_assign, zvol_replay_vector, NULL); 436 437 zvol_size_changed(zv, dev); 438 439 /* XXX this should handle the possible i/o error */ 440 VERIFY(dsl_prop_register(dmu_objset_ds(zv->zv_objset), 441 "readonly", zvol_readonly_changed_cb, zv) == 0); 442 443 zvol_minors++; 444 445 mutex_exit(&zvol_state_lock); 446 447 return (0); 448 } 449 450 /* 451 * Remove minor node for the specified volume. 452 */ 453 int 454 zvol_remove_minor(const char *name) 455 { 456 zvol_state_t *zv; 457 char namebuf[30]; 458 459 mutex_enter(&zvol_state_lock); 460 461 if ((zv = zvol_minor_lookup(name)) == NULL) { 462 mutex_exit(&zvol_state_lock); 463 return (ENXIO); 464 } 465 466 if (zv->zv_total_opens != 0) { 467 mutex_exit(&zvol_state_lock); 468 return (EBUSY); 469 } 470 471 (void) sprintf(namebuf, "%uc,raw", zv->zv_minor); 472 ddi_remove_minor_node(zfs_dip, namebuf); 473 474 (void) sprintf(namebuf, "%uc", zv->zv_minor); 475 ddi_remove_minor_node(zfs_dip, namebuf); 476 477 VERIFY(dsl_prop_unregister(dmu_objset_ds(zv->zv_objset), 478 "readonly", zvol_readonly_changed_cb, zv) == 0); 479 480 zil_close(zv->zv_zilog); 481 zv->zv_zilog = NULL; 482 dmu_objset_close(zv->zv_objset); 483 zv->zv_objset = NULL; 484 485 ddi_soft_state_free(zvol_state, zv->zv_minor); 486 487 zvol_minors--; 488 489 mutex_exit(&zvol_state_lock); 490 491 return (0); 492 } 493 494 int 495 zvol_set_volsize(const char *name, dev_t dev, uint64_t volsize) 496 { 497 zvol_state_t *zv; 498 dmu_tx_t *tx; 499 int error; 500 dmu_object_info_t doi; 501 502 mutex_enter(&zvol_state_lock); 503 504 if ((zv = zvol_minor_lookup(name)) == NULL) { 505 mutex_exit(&zvol_state_lock); 506 return (ENXIO); 507 } 508 509 if ((error = dmu_object_info(zv->zv_objset, ZVOL_OBJ, &doi)) != 0 || 510 (error = zvol_check_volsize(volsize, 511 doi.doi_data_block_size)) != 0) { 512 mutex_exit(&zvol_state_lock); 513 return (error); 514 } 515 516 if (zv->zv_readonly || (zv->zv_mode & DS_MODE_READONLY)) { 517 mutex_exit(&zvol_state_lock); 518 return (EROFS); 519 } 520 521 tx = dmu_tx_create(zv->zv_objset); 522 dmu_tx_hold_zap(tx, ZVOL_ZAP_OBJ, TRUE, NULL); 523 dmu_tx_hold_free(tx, ZVOL_OBJ, volsize, DMU_OBJECT_END); 524 error = dmu_tx_assign(tx, TXG_WAIT); 525 if (error) { 526 dmu_tx_abort(tx); 527 mutex_exit(&zvol_state_lock); 528 return (error); 529 } 530 531 error = zap_update(zv->zv_objset, ZVOL_ZAP_OBJ, "size", 8, 1, 532 &volsize, tx); 533 if (error == 0) { 534 error = dmu_free_range(zv->zv_objset, ZVOL_OBJ, volsize, 535 DMU_OBJECT_END, tx); 536 } 537 538 dmu_tx_commit(tx); 539 540 if (error == 0) { 541 zv->zv_volsize = volsize; 542 zvol_size_changed(zv, dev); 543 } 544 545 mutex_exit(&zvol_state_lock); 546 547 return (error); 548 } 549 550 int 551 zvol_set_volblocksize(const char *name, uint64_t volblocksize) 552 { 553 zvol_state_t *zv; 554 dmu_tx_t *tx; 555 int error; 556 557 mutex_enter(&zvol_state_lock); 558 559 if ((zv = zvol_minor_lookup(name)) == NULL) { 560 mutex_exit(&zvol_state_lock); 561 return (ENXIO); 562 } 563 564 if (zv->zv_readonly || (zv->zv_mode & DS_MODE_READONLY)) { 565 mutex_exit(&zvol_state_lock); 566 return (EROFS); 567 } 568 569 tx = dmu_tx_create(zv->zv_objset); 570 dmu_tx_hold_bonus(tx, ZVOL_OBJ); 571 error = dmu_tx_assign(tx, TXG_WAIT); 572 if (error) { 573 dmu_tx_abort(tx); 574 } else { 575 error = dmu_object_set_blocksize(zv->zv_objset, ZVOL_OBJ, 576 volblocksize, 0, tx); 577 if (error == ENOTSUP) 578 error = EBUSY; 579 dmu_tx_commit(tx); 580 } 581 582 mutex_exit(&zvol_state_lock); 583 584 return (error); 585 } 586 587 /*ARGSUSED*/ 588 int 589 zvol_open(dev_t *devp, int flag, int otyp, cred_t *cr) 590 { 591 minor_t minor = getminor(*devp); 592 zvol_state_t *zv; 593 594 if (minor == 0) /* This is the control device */ 595 return (0); 596 597 mutex_enter(&zvol_state_lock); 598 599 zv = ddi_get_soft_state(zvol_state, minor); 600 if (zv == NULL) { 601 mutex_exit(&zvol_state_lock); 602 return (ENXIO); 603 } 604 605 ASSERT(zv->zv_objset != NULL); 606 607 if ((flag & FWRITE) && 608 (zv->zv_readonly || (zv->zv_mode & DS_MODE_READONLY))) { 609 mutex_exit(&zvol_state_lock); 610 return (EROFS); 611 } 612 613 if (zv->zv_open_count[otyp] == 0 || otyp == OTYP_LYR) { 614 zv->zv_open_count[otyp]++; 615 zv->zv_total_opens++; 616 } 617 618 mutex_exit(&zvol_state_lock); 619 620 return (0); 621 } 622 623 /*ARGSUSED*/ 624 int 625 zvol_close(dev_t dev, int flag, int otyp, cred_t *cr) 626 { 627 minor_t minor = getminor(dev); 628 zvol_state_t *zv; 629 630 if (minor == 0) /* This is the control device */ 631 return (0); 632 633 mutex_enter(&zvol_state_lock); 634 635 zv = ddi_get_soft_state(zvol_state, minor); 636 if (zv == NULL) { 637 mutex_exit(&zvol_state_lock); 638 return (ENXIO); 639 } 640 641 /* 642 * The next statement is a workaround for the following DDI bug: 643 * 6343604 specfs race: multiple "last-close" of the same device 644 */ 645 if (zv->zv_total_opens == 0) { 646 mutex_exit(&zvol_state_lock); 647 return (0); 648 } 649 650 /* 651 * If the open count is zero, this is a spurious close. 652 * That indicates a bug in the kernel / DDI framework. 653 */ 654 ASSERT(zv->zv_open_count[otyp] != 0); 655 ASSERT(zv->zv_total_opens != 0); 656 657 /* 658 * You may get multiple opens, but only one close. 659 */ 660 zv->zv_open_count[otyp]--; 661 zv->zv_total_opens--; 662 663 mutex_exit(&zvol_state_lock); 664 665 return (0); 666 } 667 668 /* 669 * Create and return an immediate write ZIL transaction. 670 */ 671 itx_t * 672 zvol_immediate_itx(offset_t off, ssize_t len, char *addr) 673 { 674 itx_t *itx; 675 lr_write_t *lr; 676 677 itx = zil_itx_create(TX_WRITE, sizeof (*lr) + len); 678 lr = (lr_write_t *)&itx->itx_lr; 679 lr->lr_foid = ZVOL_OBJ; 680 lr->lr_offset = off; 681 lr->lr_length = len; 682 lr->lr_blkoff = 0; 683 BP_ZERO(&lr->lr_blkptr); 684 bcopy(addr, (char *)itx + offsetof(itx_t, itx_lr) + 685 sizeof (*lr), len); 686 itx->itx_wr_state = WR_COPIED; 687 return (itx); 688 } 689 690 /* 691 * zvol_log_write() handles synchronous writes using TX_WRITE ZIL transactions. 692 * 693 * We store data in the log buffers if it's small enough. 694 * Otherwise we flush the data out via dmu_sync(). 695 */ 696 ssize_t zvol_immediate_write_sz = 65536; 697 698 int 699 zvol_log_write(zvol_state_t *zv, dmu_tx_t *tx, offset_t off, ssize_t len, 700 char *addr) 701 { 702 dmu_object_info_t doi; 703 ssize_t nbytes; 704 itx_t *itx; 705 lr_write_t *lr; 706 objset_t *os; 707 dmu_buf_t *db; 708 uint64_t txg; 709 uint64_t boff; 710 int error; 711 uint32_t blocksize; 712 713 /* handle common case */ 714 if (len <= zvol_immediate_write_sz) { 715 itx = zvol_immediate_itx(off, len, addr); 716 (void) zil_itx_assign(zv->zv_zilog, itx, tx); 717 return (0); 718 } 719 720 txg = dmu_tx_get_txg(tx); 721 os = zv->zv_objset; 722 723 /* 724 * We need to dmu_sync() each block in the range. 725 * For this we need the blocksize. 726 */ 727 error = dmu_object_info(os, ZVOL_OBJ, &doi); 728 if (error) 729 return (error); 730 blocksize = doi.doi_data_block_size; 731 732 /* 733 * We need to immediate write or dmu_sync() each block in the range. 734 */ 735 while (len) { 736 nbytes = MIN(len, blocksize - P2PHASE(off, blocksize)); 737 if (nbytes <= zvol_immediate_write_sz) { 738 itx = zvol_immediate_itx(off, nbytes, addr); 739 } else { 740 boff = P2ALIGN_TYPED(off, blocksize, uint64_t); 741 itx = zil_itx_create(TX_WRITE, sizeof (*lr)); 742 lr = (lr_write_t *)&itx->itx_lr; 743 lr->lr_foid = ZVOL_OBJ; 744 lr->lr_offset = off; 745 lr->lr_length = nbytes; 746 lr->lr_blkoff = off - boff; 747 BP_ZERO(&lr->lr_blkptr); 748 749 /* XXX - we should do these IOs in parallel */ 750 VERIFY(0 == dmu_buf_hold(os, ZVOL_OBJ, boff, 751 FTAG, &db)); 752 ASSERT(boff == db->db_offset); 753 error = dmu_sync(NULL, db, &lr->lr_blkptr, 754 txg, NULL, NULL); 755 dmu_buf_rele(db, FTAG); 756 if (error) { 757 kmem_free(itx, offsetof(itx_t, itx_lr)); 758 return (error); 759 } 760 itx->itx_wr_state = WR_COPIED; 761 } 762 (void) zil_itx_assign(zv->zv_zilog, itx, tx); 763 len -= nbytes; 764 off += nbytes; 765 } 766 return (0); 767 } 768 769 int 770 zvol_strategy(buf_t *bp) 771 { 772 zvol_state_t *zv = ddi_get_soft_state(zvol_state, getminor(bp->b_edev)); 773 uint64_t off, volsize; 774 size_t size, resid; 775 char *addr; 776 objset_t *os; 777 int error = 0; 778 int sync; 779 int reading; 780 int txg_sync_needed = B_FALSE; 781 782 if (zv == NULL) { 783 bioerror(bp, ENXIO); 784 biodone(bp); 785 return (0); 786 } 787 788 if (getminor(bp->b_edev) == 0) { 789 bioerror(bp, EINVAL); 790 biodone(bp); 791 return (0); 792 } 793 794 if ((zv->zv_readonly || (zv->zv_mode & DS_MODE_READONLY)) && 795 !(bp->b_flags & B_READ)) { 796 bioerror(bp, EROFS); 797 biodone(bp); 798 return (0); 799 } 800 801 off = ldbtob(bp->b_blkno); 802 volsize = zv->zv_volsize; 803 804 os = zv->zv_objset; 805 ASSERT(os != NULL); 806 sync = !(bp->b_flags & B_ASYNC) && !(zil_disable); 807 808 bp_mapin(bp); 809 addr = bp->b_un.b_addr; 810 resid = bp->b_bcount; 811 812 /* 813 * There must be no buffer changes when doing a dmu_sync() because 814 * we can't change the data whilst calculating the checksum. 815 * A better approach than a per zvol rwlock would be to lock ranges. 816 */ 817 reading = bp->b_flags & B_READ; 818 if (reading || resid <= zvol_immediate_write_sz) 819 rw_enter(&zv->zv_dslock, RW_READER); 820 else 821 rw_enter(&zv->zv_dslock, RW_WRITER); 822 823 while (resid != 0 && off < volsize) { 824 825 size = MIN(resid, 1UL << 20); /* cap at 1MB per tx */ 826 827 if (size > volsize - off) /* don't write past the end */ 828 size = volsize - off; 829 830 if (reading) { 831 error = dmu_read(os, ZVOL_OBJ, off, size, addr); 832 } else { 833 dmu_tx_t *tx = dmu_tx_create(os); 834 dmu_tx_hold_write(tx, ZVOL_OBJ, off, size); 835 error = dmu_tx_assign(tx, TXG_WAIT); 836 if (error) { 837 dmu_tx_abort(tx); 838 } else { 839 dmu_write(os, ZVOL_OBJ, off, size, addr, tx); 840 if (sync) { 841 /* use the ZIL to commit this write */ 842 if (zvol_log_write(zv, tx, off, size, 843 addr) != 0) { 844 txg_sync_needed = B_TRUE; 845 } 846 } 847 dmu_tx_commit(tx); 848 } 849 } 850 if (error) 851 break; 852 off += size; 853 addr += size; 854 resid -= size; 855 } 856 rw_exit(&zv->zv_dslock); 857 858 if ((bp->b_resid = resid) == bp->b_bcount) 859 bioerror(bp, off > volsize ? EINVAL : error); 860 861 biodone(bp); 862 863 if (sync) { 864 if (txg_sync_needed) 865 txg_wait_synced(dmu_objset_pool(os), 0); 866 else 867 zil_commit(zv->zv_zilog, UINT64_MAX, 0); 868 } 869 870 return (0); 871 } 872 873 /*ARGSUSED*/ 874 int 875 zvol_read(dev_t dev, uio_t *uiop, cred_t *cr) 876 { 877 return (physio(zvol_strategy, NULL, dev, B_READ, minphys, uiop)); 878 } 879 880 /*ARGSUSED*/ 881 int 882 zvol_write(dev_t dev, uio_t *uiop, cred_t *cr) 883 { 884 return (physio(zvol_strategy, NULL, dev, B_WRITE, minphys, uiop)); 885 } 886 887 /*ARGSUSED*/ 888 int 889 zvol_aread(dev_t dev, struct aio_req *aio, cred_t *cr) 890 { 891 return (aphysio(zvol_strategy, anocancel, dev, B_READ, minphys, aio)); 892 } 893 894 /*ARGSUSED*/ 895 int 896 zvol_awrite(dev_t dev, struct aio_req *aio, cred_t *cr) 897 { 898 return (aphysio(zvol_strategy, anocancel, dev, B_WRITE, minphys, aio)); 899 } 900 901 /* 902 * Dirtbag ioctls to support mkfs(1M) for UFS filesystems. See dkio(7I). 903 */ 904 /*ARGSUSED*/ 905 int 906 zvol_ioctl(dev_t dev, int cmd, intptr_t arg, int flag, cred_t *cr, int *rvalp) 907 { 908 zvol_state_t *zv; 909 struct dk_cinfo dkc; 910 struct dk_minfo dkm; 911 dk_efi_t efi; 912 efi_gpt_t gpt; 913 efi_gpe_t gpe; 914 struct uuid uuid = EFI_RESERVED; 915 uint32_t crc; 916 int error = 0; 917 918 mutex_enter(&zvol_state_lock); 919 920 zv = ddi_get_soft_state(zvol_state, getminor(dev)); 921 922 if (zv == NULL) { 923 mutex_exit(&zvol_state_lock); 924 return (ENXIO); 925 } 926 927 switch (cmd) { 928 929 case DKIOCINFO: 930 bzero(&dkc, sizeof (dkc)); 931 (void) strcpy(dkc.dki_cname, "zvol"); 932 (void) strcpy(dkc.dki_dname, "zvol"); 933 dkc.dki_ctype = DKC_UNKNOWN; 934 dkc.dki_maxtransfer = 1 << (SPA_MAXBLOCKSHIFT - zv->zv_min_bs); 935 mutex_exit(&zvol_state_lock); 936 if (ddi_copyout(&dkc, (void *)arg, sizeof (dkc), flag)) 937 error = EFAULT; 938 return (error); 939 940 case DKIOCGMEDIAINFO: 941 bzero(&dkm, sizeof (dkm)); 942 dkm.dki_lbsize = 1U << zv->zv_min_bs; 943 dkm.dki_capacity = zv->zv_volsize >> zv->zv_min_bs; 944 dkm.dki_media_type = DK_UNKNOWN; 945 mutex_exit(&zvol_state_lock); 946 if (ddi_copyout(&dkm, (void *)arg, sizeof (dkm), flag)) 947 error = EFAULT; 948 return (error); 949 950 case DKIOCGETEFI: 951 if (ddi_copyin((void *)arg, &efi, sizeof (dk_efi_t), flag)) { 952 mutex_exit(&zvol_state_lock); 953 return (EFAULT); 954 } 955 956 bzero(&gpt, sizeof (gpt)); 957 bzero(&gpe, sizeof (gpe)); 958 959 efi.dki_data = (void *)(uintptr_t)efi.dki_data_64; 960 961 if (efi.dki_length < sizeof (gpt) + sizeof (gpe)) { 962 mutex_exit(&zvol_state_lock); 963 return (EINVAL); 964 } 965 966 efi.dki_length = sizeof (gpt) + sizeof (gpe); 967 968 gpt.efi_gpt_Signature = LE_64(EFI_SIGNATURE); 969 gpt.efi_gpt_Revision = LE_32(EFI_VERSION_CURRENT); 970 gpt.efi_gpt_HeaderSize = LE_32(sizeof (gpt)); 971 gpt.efi_gpt_FirstUsableLBA = LE_64(0ULL); 972 gpt.efi_gpt_LastUsableLBA = 973 LE_64((zv->zv_volsize >> zv->zv_min_bs) - 1); 974 gpt.efi_gpt_NumberOfPartitionEntries = LE_32(1); 975 gpt.efi_gpt_SizeOfPartitionEntry = LE_32(sizeof (gpe)); 976 977 UUID_LE_CONVERT(gpe.efi_gpe_PartitionTypeGUID, uuid); 978 gpe.efi_gpe_StartingLBA = gpt.efi_gpt_FirstUsableLBA; 979 gpe.efi_gpe_EndingLBA = gpt.efi_gpt_LastUsableLBA; 980 981 CRC32(crc, &gpe, sizeof (gpe), -1U, crc32_table); 982 gpt.efi_gpt_PartitionEntryArrayCRC32 = LE_32(~crc); 983 984 CRC32(crc, &gpt, sizeof (gpt), -1U, crc32_table); 985 gpt.efi_gpt_HeaderCRC32 = LE_32(~crc); 986 987 mutex_exit(&zvol_state_lock); 988 if (ddi_copyout(&gpt, efi.dki_data, sizeof (gpt), flag) || 989 ddi_copyout(&gpe, efi.dki_data + 1, sizeof (gpe), flag)) 990 error = EFAULT; 991 return (error); 992 993 default: 994 error = ENOTSUP; 995 break; 996 997 } 998 mutex_exit(&zvol_state_lock); 999 return (error); 1000 } 1001 1002 int 1003 zvol_busy(void) 1004 { 1005 return (zvol_minors != 0); 1006 } 1007 1008 void 1009 zvol_init(void) 1010 { 1011 VERIFY(ddi_soft_state_init(&zvol_state, sizeof (zvol_state_t), 1) == 0); 1012 mutex_init(&zvol_state_lock, NULL, MUTEX_DEFAULT, NULL); 1013 } 1014 1015 void 1016 zvol_fini(void) 1017 { 1018 mutex_destroy(&zvol_state_lock); 1019 ddi_soft_state_fini(&zvol_state); 1020 } 1021