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, Version 1.0 only 6 * (the "License"). You may not use this file except in compliance 7 * with the License. 8 * 9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 10 * or http://www.opensolaris.org/os/licensing. 11 * See the License for the specific language governing permissions 12 * and limitations under the License. 13 * 14 * When distributing Covered Code, include this CDDL HEADER in each 15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 16 * If applicable, add the following below this CDDL HEADER, with the 17 * fields enclosed by brackets "[]" replaced with your own identifying 18 * information: Portions Copyright [yyyy] [name of copyright owner] 19 * 20 * CDDL HEADER END 21 */ 22 /* 23 * Copyright 2005 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27 #pragma ident "%Z%%M% %I% %E% SMI" 28 29 /* 30 * ZFS volume emulation driver. 31 * 32 * Makes a DMU object look like a volume of arbitrary size, up to 2^64 bytes. 33 * Volumes are accessed through the symbolic links named: 34 * 35 * /dev/zvol/dsk/<pool_name>/<dataset_name> 36 * /dev/zvol/rdsk/<pool_name>/<dataset_name> 37 * 38 * These links are created by the ZFS-specific devfsadm link generator. 39 * Volumes are persistent through reboot. No user command needs to be 40 * run before opening and using a device. 41 */ 42 43 #include <sys/types.h> 44 #include <sys/param.h> 45 #include <sys/errno.h> 46 #include <sys/aio_req.h> 47 #include <sys/uio.h> 48 #include <sys/buf.h> 49 #include <sys/modctl.h> 50 #include <sys/open.h> 51 #include <sys/kmem.h> 52 #include <sys/conf.h> 53 #include <sys/cmn_err.h> 54 #include <sys/stat.h> 55 #include <sys/zap.h> 56 #include <sys/spa.h> 57 #include <sys/zio.h> 58 #include <sys/dsl_prop.h> 59 #include <sys/dkio.h> 60 #include <sys/efi_partition.h> 61 #include <sys/byteorder.h> 62 #include <sys/pathname.h> 63 #include <sys/ddi.h> 64 #include <sys/sunddi.h> 65 #include <sys/crc32.h> 66 #include <sys/dirent.h> 67 #include <sys/policy.h> 68 #include <sys/fs/zfs.h> 69 #include <sys/zfs_ioctl.h> 70 #include <sys/mkdev.h> 71 #include <sys/zil.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 } zvol_state_t; 105 106 static void 107 zvol_size_changed(zvol_state_t *zv, dev_t dev) 108 { 109 dev = makedevice(getmajor(dev), zv->zv_minor); 110 111 VERIFY(ddi_prop_update_int64(dev, zfs_dip, 112 "Size", zv->zv_volsize) == DDI_SUCCESS); 113 VERIFY(ddi_prop_update_int64(dev, zfs_dip, 114 "Nblocks", lbtodb(zv->zv_volsize)) == DDI_SUCCESS); 115 } 116 117 int 118 zvol_check_volsize(zfs_cmd_t *zc, uint64_t blocksize) 119 { 120 if (zc->zc_volsize == 0) 121 return (EINVAL); 122 123 if (zc->zc_volsize % blocksize != 0) 124 return (EINVAL); 125 126 #ifdef _ILP32 127 if (zc->zc_volsize - 1 > SPEC_MAXOFFSET_T) 128 return (EOVERFLOW); 129 #endif 130 return (0); 131 } 132 133 int 134 zvol_check_volblocksize(zfs_cmd_t *zc) 135 { 136 if (zc->zc_volblocksize < SPA_MINBLOCKSIZE || 137 zc->zc_volblocksize > SPA_MAXBLOCKSIZE || 138 !ISP2(zc->zc_volblocksize)) 139 return (EDOM); 140 141 return (0); 142 } 143 144 static void 145 zvol_readonly_changed_cb(void *arg, uint64_t newval) 146 { 147 zvol_state_t *zv = arg; 148 149 zv->zv_readonly = (uint8_t)newval; 150 } 151 152 int 153 zvol_get_stats(zfs_cmd_t *zc, objset_t *os) 154 { 155 int error; 156 dmu_object_info_t doi; 157 158 error = zap_lookup(os, ZVOL_ZAP_OBJ, "size", 8, 1, &zc->zc_volsize); 159 160 if (error) 161 return (error); 162 163 error = dmu_object_info(os, ZVOL_OBJ, &doi); 164 165 if (error == 0) 166 zc->zc_volblocksize = doi.doi_data_block_size; 167 168 return (error); 169 } 170 171 /* 172 * Find a free minor number. 173 */ 174 static minor_t 175 zvol_minor_alloc(void) 176 { 177 minor_t minor; 178 179 ASSERT(MUTEX_HELD(&zvol_state_lock)); 180 181 for (minor = 1; minor <= ZVOL_MAX_MINOR; minor++) 182 if (ddi_get_soft_state(zvol_state, minor) == NULL) 183 return (minor); 184 185 return (0); 186 } 187 188 static zvol_state_t * 189 zvol_minor_lookup(char *name) 190 { 191 minor_t minor; 192 zvol_state_t *zv; 193 194 ASSERT(MUTEX_HELD(&zvol_state_lock)); 195 196 for (minor = 1; minor <= ZVOL_MAX_MINOR; minor++) { 197 zv = ddi_get_soft_state(zvol_state, minor); 198 if (zv == NULL) 199 continue; 200 if (strcmp(zv->zv_name, name) == 0) 201 break; 202 } 203 204 return (zv); 205 } 206 207 void 208 zvol_create_cb(objset_t *os, void *arg, dmu_tx_t *tx) 209 { 210 zfs_cmd_t *zc = arg; 211 int error; 212 213 error = dmu_object_claim(os, ZVOL_OBJ, DMU_OT_ZVOL, zc->zc_volblocksize, 214 DMU_OT_NONE, 0, tx); 215 ASSERT(error == 0); 216 217 error = zap_create_claim(os, ZVOL_ZAP_OBJ, DMU_OT_ZVOL_PROP, 218 DMU_OT_NONE, 0, tx); 219 ASSERT(error == 0); 220 221 error = zap_update(os, ZVOL_ZAP_OBJ, "size", 8, 1, &zc->zc_volsize, tx); 222 ASSERT(error == 0); 223 } 224 225 /* 226 * Replay a TX_WRITE ZIL transaction that didn't get committed 227 * after a system failure 228 */ 229 static int 230 zvol_replay_write(zvol_state_t *zv, lr_write_t *lr, boolean_t byteswap) 231 { 232 objset_t *os = zv->zv_objset; 233 char *data = (char *)(lr + 1); /* data follows lr_write_t */ 234 uint64_t off = lr->lr_offset; 235 uint64_t len = lr->lr_length; 236 dmu_tx_t *tx; 237 int error; 238 239 if (byteswap) 240 byteswap_uint64_array(lr, sizeof (*lr)); 241 242 restart: 243 tx = dmu_tx_create(os); 244 dmu_tx_hold_write(tx, ZVOL_OBJ, off, len); 245 error = dmu_tx_assign(tx, zv->zv_txg_assign); 246 if (error) { 247 dmu_tx_abort(tx); 248 if (error == ERESTART && zv->zv_txg_assign == TXG_NOWAIT) { 249 txg_wait_open(dmu_objset_pool(os), 0); 250 goto restart; 251 } 252 } else { 253 dmu_write(os, ZVOL_OBJ, off, len, data, tx); 254 dmu_tx_commit(tx); 255 } 256 257 return (error); 258 } 259 260 /* ARGSUSED */ 261 static int 262 zvol_replay_err(zvol_state_t *zv, lr_t *lr, boolean_t byteswap) 263 { 264 return (ENOTSUP); 265 } 266 267 /* 268 * Callback vectors for replaying records. 269 * Only TX_WRITE is needed for zvol. 270 */ 271 zil_replay_func_t *zvol_replay_vector[TX_MAX_TYPE] = { 272 zvol_replay_err, /* 0 no such transaction type */ 273 zvol_replay_err, /* TX_CREATE */ 274 zvol_replay_err, /* TX_MKDIR */ 275 zvol_replay_err, /* TX_MKXATTR */ 276 zvol_replay_err, /* TX_SYMLINK */ 277 zvol_replay_err, /* TX_REMOVE */ 278 zvol_replay_err, /* TX_RMDIR */ 279 zvol_replay_err, /* TX_LINK */ 280 zvol_replay_err, /* TX_RENAME */ 281 zvol_replay_write, /* TX_WRITE */ 282 zvol_replay_err, /* TX_TRUNCATE */ 283 zvol_replay_err, /* TX_SETATTR */ 284 zvol_replay_err, /* TX_ACL */ 285 }; 286 287 /* 288 * Create a minor node for the specified volume. 289 */ 290 int 291 zvol_create_minor(zfs_cmd_t *zc) 292 { 293 char *name = zc->zc_name; 294 dev_t dev = zc->zc_dev; 295 zvol_state_t *zv; 296 objset_t *os; 297 uint64_t volsize; 298 minor_t minor = 0; 299 struct pathname linkpath; 300 int ds_mode = DS_MODE_PRIMARY; 301 vnode_t *vp = NULL; 302 char *devpath; 303 size_t devpathlen = strlen(ZVOL_FULL_DEV_DIR) + 1 + strlen(name) + 1; 304 char chrbuf[30], blkbuf[30]; 305 int error; 306 307 mutex_enter(&zvol_state_lock); 308 309 if ((zv = zvol_minor_lookup(name)) != NULL) { 310 mutex_exit(&zvol_state_lock); 311 return (EEXIST); 312 } 313 314 if (strchr(name, '@') != 0) 315 ds_mode |= DS_MODE_READONLY; 316 317 error = dmu_objset_open(name, DMU_OST_ZVOL, ds_mode, &os); 318 319 if (error) { 320 mutex_exit(&zvol_state_lock); 321 return (error); 322 } 323 324 error = zap_lookup(os, ZVOL_ZAP_OBJ, "size", 8, 1, &volsize); 325 326 if (error) { 327 dmu_objset_close(os); 328 mutex_exit(&zvol_state_lock); 329 return (error); 330 } 331 332 /* 333 * If there's an existing /dev/zvol symlink, try to use the 334 * same minor number we used last time. 335 */ 336 devpath = kmem_alloc(devpathlen, KM_SLEEP); 337 338 (void) sprintf(devpath, "%s/%s", ZVOL_FULL_DEV_DIR, name); 339 340 error = lookupname(devpath, UIO_SYSSPACE, NO_FOLLOW, NULL, &vp); 341 342 kmem_free(devpath, devpathlen); 343 344 if (error == 0 && vp->v_type != VLNK) 345 error = EINVAL; 346 347 if (error == 0) { 348 pn_alloc(&linkpath); 349 error = pn_getsymlink(vp, &linkpath, kcred); 350 if (error == 0) { 351 char *ms = strstr(linkpath.pn_path, ZVOL_PSEUDO_DEV); 352 if (ms != NULL) { 353 ms += strlen(ZVOL_PSEUDO_DEV); 354 minor = stoi(&ms); 355 } 356 } 357 pn_free(&linkpath); 358 } 359 360 if (vp != NULL) 361 VN_RELE(vp); 362 363 /* 364 * If we found a minor but it's already in use, we must pick a new one. 365 */ 366 if (minor != 0 && ddi_get_soft_state(zvol_state, minor) != NULL) 367 minor = 0; 368 369 if (minor == 0) 370 minor = zvol_minor_alloc(); 371 372 if (minor == 0) { 373 dmu_objset_close(os); 374 mutex_exit(&zvol_state_lock); 375 return (ENXIO); 376 } 377 378 if (ddi_soft_state_zalloc(zvol_state, minor) != DDI_SUCCESS) { 379 dmu_objset_close(os); 380 mutex_exit(&zvol_state_lock); 381 return (EAGAIN); 382 } 383 384 (void) ddi_prop_update_string(minor, zfs_dip, ZVOL_PROP_NAME, name); 385 386 (void) sprintf(chrbuf, "%uc,raw", minor); 387 388 if (ddi_create_minor_node(zfs_dip, chrbuf, S_IFCHR, 389 minor, DDI_PSEUDO, 0) == DDI_FAILURE) { 390 ddi_soft_state_free(zvol_state, minor); 391 dmu_objset_close(os); 392 mutex_exit(&zvol_state_lock); 393 return (EAGAIN); 394 } 395 396 (void) sprintf(blkbuf, "%uc", minor); 397 398 if (ddi_create_minor_node(zfs_dip, blkbuf, S_IFBLK, 399 minor, DDI_PSEUDO, 0) == DDI_FAILURE) { 400 ddi_remove_minor_node(zfs_dip, chrbuf); 401 ddi_soft_state_free(zvol_state, minor); 402 dmu_objset_close(os); 403 mutex_exit(&zvol_state_lock); 404 return (EAGAIN); 405 } 406 407 zv = ddi_get_soft_state(zvol_state, minor); 408 409 (void) strcpy(zv->zv_name, name); 410 zv->zv_min_bs = DEV_BSHIFT; 411 zv->zv_minor = minor; 412 zv->zv_volsize = volsize; 413 zv->zv_objset = os; 414 zv->zv_mode = ds_mode; 415 zv->zv_zilog = zil_open(os, NULL); 416 417 zil_replay(os, zv, &zv->zv_txg_assign, zvol_replay_vector, NULL); 418 419 zvol_size_changed(zv, dev); 420 421 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, 1); 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 dmu_free_range(zv->zv_objset, ZVOL_OBJ, zc->zc_volsize, 516 DMU_OBJECT_END, tx); 517 518 dmu_tx_commit(tx); 519 520 if (error == 0) { 521 zv->zv_volsize = zc->zc_volsize; 522 zvol_size_changed(zv, dev); 523 } 524 525 mutex_exit(&zvol_state_lock); 526 527 return (error); 528 } 529 530 int 531 zvol_set_volblocksize(zfs_cmd_t *zc) 532 { 533 zvol_state_t *zv; 534 dmu_tx_t *tx; 535 int error; 536 537 mutex_enter(&zvol_state_lock); 538 539 if ((zv = zvol_minor_lookup(zc->zc_name)) == NULL) { 540 mutex_exit(&zvol_state_lock); 541 return (ENXIO); 542 } 543 544 if (zv->zv_readonly || (zv->zv_mode & DS_MODE_READONLY)) { 545 mutex_exit(&zvol_state_lock); 546 return (EROFS); 547 } 548 549 tx = dmu_tx_create(zv->zv_objset); 550 dmu_tx_hold_bonus(tx, ZVOL_OBJ); 551 error = dmu_tx_assign(tx, TXG_WAIT); 552 if (error) { 553 dmu_tx_abort(tx); 554 } else { 555 error = dmu_object_set_blocksize(zv->zv_objset, ZVOL_OBJ, 556 zc->zc_volblocksize, 0, tx); 557 if (error == ENOTSUP) 558 error = EBUSY; 559 dmu_tx_commit(tx); 560 } 561 562 mutex_exit(&zvol_state_lock); 563 564 return (error); 565 } 566 567 /*ARGSUSED*/ 568 int 569 zvol_open(dev_t *devp, int flag, int otyp, cred_t *cr) 570 { 571 minor_t minor = getminor(*devp); 572 zvol_state_t *zv; 573 574 if (minor == 0) /* This is the control device */ 575 return (0); 576 577 mutex_enter(&zvol_state_lock); 578 579 zv = ddi_get_soft_state(zvol_state, minor); 580 if (zv == NULL) { 581 mutex_exit(&zvol_state_lock); 582 return (ENXIO); 583 } 584 585 ASSERT(zv->zv_objset != NULL); 586 587 if ((flag & FWRITE) && 588 (zv->zv_readonly || (zv->zv_mode & DS_MODE_READONLY))) { 589 mutex_exit(&zvol_state_lock); 590 return (EROFS); 591 } 592 593 if (zv->zv_open_count[otyp] == 0 || otyp == OTYP_LYR) { 594 zv->zv_open_count[otyp]++; 595 zv->zv_total_opens++; 596 } 597 598 mutex_exit(&zvol_state_lock); 599 600 return (0); 601 } 602 603 /*ARGSUSED*/ 604 int 605 zvol_close(dev_t dev, int flag, int otyp, cred_t *cr) 606 { 607 minor_t minor = getminor(dev); 608 zvol_state_t *zv; 609 610 if (minor == 0) /* This is the control device */ 611 return (0); 612 613 mutex_enter(&zvol_state_lock); 614 615 zv = ddi_get_soft_state(zvol_state, minor); 616 if (zv == NULL) { 617 mutex_exit(&zvol_state_lock); 618 return (ENXIO); 619 } 620 621 /* 622 * The next statement is a workaround for the following DDI bug: 623 * 6343604 specfs race: multiple "last-close" of the same device 624 */ 625 if (zv->zv_total_opens == 0) { 626 mutex_exit(&zvol_state_lock); 627 return (0); 628 } 629 630 /* 631 * If the open count is zero, this is a spurious close. 632 * That indicates a bug in the kernel / DDI framework. 633 */ 634 ASSERT(zv->zv_open_count[otyp] != 0); 635 ASSERT(zv->zv_total_opens != 0); 636 637 /* 638 * You may get multiple opens, but only one close. 639 */ 640 zv->zv_open_count[otyp]--; 641 zv->zv_total_opens--; 642 643 mutex_exit(&zvol_state_lock); 644 645 return (0); 646 } 647 648 /* 649 * zvol_log_write() handles synchronous page writes using 650 * TX_WRITE ZIL transactions. 651 * 652 * We store data in the log buffers if it's small enough. 653 * Otherwise we flush the data out via dmu_sync(). 654 */ 655 ssize_t zvol_immediate_write_sz = 65536; 656 657 int 658 zvol_log_write(zvol_state_t *zv, dmu_tx_t *tx, offset_t off, ssize_t len, 659 char *addr) 660 { 661 itx_t *itx; 662 lr_write_t *lr; 663 objset_t *os = zv->zv_objset; 664 int dlen; 665 int error; 666 667 dlen = (len <= zvol_immediate_write_sz ? len : 0); 668 itx = zil_itx_create(TX_WRITE, sizeof (*lr) + dlen); 669 lr = (lr_write_t *)&itx->itx_lr; 670 lr->lr_foid = ZVOL_OBJ; 671 lr->lr_offset = off; 672 lr->lr_length = len; 673 lr->lr_blkoff = 0; 674 BP_ZERO(&lr->lr_blkptr); 675 676 /* 677 * Get the data as we know we'll be writing it immediately 678 */ 679 if (dlen) { /* immediate write */ 680 bcopy(addr, (char *)itx + offsetof(itx_t, itx_lr) + 681 sizeof (*lr), len); 682 } else { 683 txg_suspend(dmu_objset_pool(os)); 684 error = dmu_sync(os, ZVOL_OBJ, off, &lr->lr_blkoff, 685 &lr->lr_blkptr, dmu_tx_get_txg(tx)); 686 txg_resume(dmu_objset_pool(os)); 687 if (error) { 688 kmem_free(itx, offsetof(itx_t, itx_lr)); 689 return (error); 690 } 691 } 692 itx->itx_data_copied = 1; 693 694 (void) zil_itx_assign(zv->zv_zilog, itx, tx); 695 696 return (0); 697 } 698 699 int 700 zvol_strategy(buf_t *bp) 701 { 702 zvol_state_t *zv = ddi_get_soft_state(zvol_state, getminor(bp->b_edev)); 703 uint64_t off, volsize; 704 size_t size, resid; 705 char *addr; 706 objset_t *os; 707 int error = 0; 708 int sync; 709 710 if (zv == NULL) { 711 bioerror(bp, ENXIO); 712 biodone(bp); 713 return (0); 714 } 715 716 if (getminor(bp->b_edev) == 0) { 717 bioerror(bp, EINVAL); 718 biodone(bp); 719 return (0); 720 } 721 722 if (zv->zv_readonly && !(bp->b_flags & B_READ)) { 723 bioerror(bp, EROFS); 724 biodone(bp); 725 return (0); 726 } 727 728 off = ldbtob(bp->b_blkno); 729 volsize = zv->zv_volsize; 730 731 os = zv->zv_objset; 732 ASSERT(os != NULL); 733 sync = !(bp->b_flags & B_ASYNC) && !(zil_disable); 734 735 bp_mapin(bp); 736 addr = bp->b_un.b_addr; 737 resid = bp->b_bcount; 738 739 while (resid != 0 && off < volsize) { 740 741 size = MIN(resid, 1UL << 20); /* cap at 1MB per tx */ 742 743 if (size > volsize - off) /* don't write past the end */ 744 size = volsize - off; 745 746 if (bp->b_flags & B_READ) { 747 error = dmu_read_canfail(os, ZVOL_OBJ, 748 off, size, addr); 749 } else { 750 dmu_tx_t *tx = dmu_tx_create(os); 751 dmu_tx_hold_write(tx, ZVOL_OBJ, off, size); 752 error = dmu_tx_assign(tx, TXG_WAIT); 753 if (error) { 754 dmu_tx_abort(tx); 755 } else { 756 dmu_write(os, ZVOL_OBJ, off, size, addr, tx); 757 if (sync) { 758 /* use the ZIL to commit this write */ 759 error = zvol_log_write(zv, tx, off, 760 size, addr); 761 if (error) { 762 txg_wait_synced( 763 dmu_objset_pool(os), 0); 764 sync = B_FALSE; 765 } 766 } 767 dmu_tx_commit(tx); 768 } 769 } 770 if (error) 771 break; 772 off += size; 773 addr += size; 774 resid -= size; 775 } 776 777 if ((bp->b_resid = resid) == bp->b_bcount) 778 bioerror(bp, off > volsize ? EINVAL : error); 779 780 biodone(bp); 781 782 if (sync) 783 zil_commit(zv->zv_zilog, UINT64_MAX, FDSYNC); 784 785 return (0); 786 } 787 788 /*ARGSUSED*/ 789 int 790 zvol_read(dev_t dev, uio_t *uiop, cred_t *cr) 791 { 792 return (physio(zvol_strategy, NULL, dev, B_READ, minphys, uiop)); 793 } 794 795 /*ARGSUSED*/ 796 int 797 zvol_write(dev_t dev, uio_t *uiop, cred_t *cr) 798 { 799 return (physio(zvol_strategy, NULL, dev, B_WRITE, minphys, uiop)); 800 } 801 802 /*ARGSUSED*/ 803 int 804 zvol_aread(dev_t dev, struct aio_req *aio, cred_t *cr) 805 { 806 return (aphysio(zvol_strategy, anocancel, dev, B_READ, minphys, aio)); 807 } 808 809 /*ARGSUSED*/ 810 int 811 zvol_awrite(dev_t dev, struct aio_req *aio, cred_t *cr) 812 { 813 return (aphysio(zvol_strategy, anocancel, dev, B_WRITE, minphys, aio)); 814 } 815 816 /* 817 * Dirtbag ioctls to support mkfs(1M) for UFS filesystems. See dkio(7I). 818 */ 819 /*ARGSUSED*/ 820 int 821 zvol_ioctl(dev_t dev, int cmd, intptr_t arg, int flag, cred_t *cr, int *rvalp) 822 { 823 zvol_state_t *zv; 824 struct dk_cinfo dkc; 825 struct dk_minfo dkm; 826 dk_efi_t efi; 827 efi_gpt_t gpt; 828 efi_gpe_t gpe; 829 struct uuid uuid = EFI_RESERVED; 830 uint32_t crc; 831 int error = 0; 832 833 mutex_enter(&zvol_state_lock); 834 835 zv = ddi_get_soft_state(zvol_state, getminor(dev)); 836 837 if (zv == NULL) { 838 mutex_exit(&zvol_state_lock); 839 return (ENXIO); 840 } 841 842 switch (cmd) { 843 844 case DKIOCINFO: 845 bzero(&dkc, sizeof (dkc)); 846 (void) strcpy(dkc.dki_cname, "zvol"); 847 (void) strcpy(dkc.dki_dname, "zvol"); 848 dkc.dki_ctype = DKC_UNKNOWN; 849 dkc.dki_maxtransfer = 1 << 15; 850 mutex_exit(&zvol_state_lock); 851 if (ddi_copyout(&dkc, (void *)arg, sizeof (dkc), flag)) 852 error = EFAULT; 853 return (error); 854 855 case DKIOCGMEDIAINFO: 856 bzero(&dkm, sizeof (dkm)); 857 dkm.dki_lbsize = 1U << zv->zv_min_bs; 858 dkm.dki_capacity = zv->zv_volsize >> zv->zv_min_bs; 859 dkm.dki_media_type = DK_UNKNOWN; 860 mutex_exit(&zvol_state_lock); 861 if (ddi_copyout(&dkm, (void *)arg, sizeof (dkm), flag)) 862 error = EFAULT; 863 return (error); 864 865 case DKIOCGETEFI: 866 if (ddi_copyin((void *)arg, &efi, sizeof (dk_efi_t), flag)) { 867 mutex_exit(&zvol_state_lock); 868 return (EFAULT); 869 } 870 871 bzero(&gpt, sizeof (gpt)); 872 bzero(&gpe, sizeof (gpe)); 873 874 efi.dki_data = (void *)(uintptr_t)efi.dki_data_64; 875 876 if (efi.dki_length < sizeof (gpt) + sizeof (gpe)) { 877 mutex_exit(&zvol_state_lock); 878 return (EINVAL); 879 } 880 881 efi.dki_length = sizeof (gpt) + sizeof (gpe); 882 883 gpt.efi_gpt_Signature = LE_64(EFI_SIGNATURE); 884 gpt.efi_gpt_Revision = LE_32(EFI_VERSION_CURRENT); 885 gpt.efi_gpt_HeaderSize = LE_32(sizeof (gpt)); 886 gpt.efi_gpt_FirstUsableLBA = LE_64(0ULL); 887 gpt.efi_gpt_LastUsableLBA = 888 LE_64((zv->zv_volsize >> zv->zv_min_bs) - 1); 889 gpt.efi_gpt_NumberOfPartitionEntries = LE_32(1); 890 gpt.efi_gpt_SizeOfPartitionEntry = LE_32(sizeof (gpe)); 891 892 UUID_LE_CONVERT(gpe.efi_gpe_PartitionTypeGUID, uuid); 893 gpe.efi_gpe_StartingLBA = gpt.efi_gpt_FirstUsableLBA; 894 gpe.efi_gpe_EndingLBA = gpt.efi_gpt_LastUsableLBA; 895 896 CRC32(crc, &gpe, sizeof (gpe), -1U, crc32_table); 897 gpt.efi_gpt_PartitionEntryArrayCRC32 = LE_32(~crc); 898 899 CRC32(crc, &gpt, sizeof (gpt), -1U, crc32_table); 900 gpt.efi_gpt_HeaderCRC32 = LE_32(~crc); 901 902 mutex_exit(&zvol_state_lock); 903 if (ddi_copyout(&gpt, efi.dki_data, sizeof (gpt), flag) || 904 ddi_copyout(&gpe, efi.dki_data + 1, sizeof (gpe), flag)) 905 error = EFAULT; 906 return (error); 907 908 default: 909 error = ENOTSUP; 910 break; 911 912 } 913 mutex_exit(&zvol_state_lock); 914 return (error); 915 } 916 917 int 918 zvol_busy(void) 919 { 920 return (zvol_minors != 0); 921 } 922 923 void 924 zvol_init(void) 925 { 926 VERIFY(ddi_soft_state_init(&zvol_state, sizeof (zvol_state_t), 1) == 0); 927 mutex_init(&zvol_state_lock, NULL, MUTEX_DEFAULT, NULL); 928 } 929 930 void 931 zvol_fini(void) 932 { 933 mutex_destroy(&zvol_state_lock); 934 ddi_soft_state_fini(&zvol_state); 935 } 936