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 error = dsl_prop_get_integer(zc->zc_name, "readonly", 169 &zc->zc_zfs_stats.zs_readonly, 170 zc->zc_zfs_stats.zs_readonly_setpoint); 171 172 return (error); 173 } 174 175 /* 176 * Find a free minor number. 177 */ 178 static minor_t 179 zvol_minor_alloc(void) 180 { 181 minor_t minor; 182 183 ASSERT(MUTEX_HELD(&zvol_state_lock)); 184 185 for (minor = 1; minor <= ZVOL_MAX_MINOR; minor++) 186 if (ddi_get_soft_state(zvol_state, minor) == NULL) 187 return (minor); 188 189 return (0); 190 } 191 192 static zvol_state_t * 193 zvol_minor_lookup(char *name) 194 { 195 minor_t minor; 196 zvol_state_t *zv; 197 198 ASSERT(MUTEX_HELD(&zvol_state_lock)); 199 200 for (minor = 1; minor <= ZVOL_MAX_MINOR; minor++) { 201 zv = ddi_get_soft_state(zvol_state, minor); 202 if (zv == NULL) 203 continue; 204 if (strcmp(zv->zv_name, name) == 0) 205 break; 206 } 207 208 return (zv); 209 } 210 211 void 212 zvol_create_cb(objset_t *os, void *arg, dmu_tx_t *tx) 213 { 214 zfs_cmd_t *zc = arg; 215 int error; 216 217 error = dmu_object_claim(os, ZVOL_OBJ, DMU_OT_ZVOL, zc->zc_volblocksize, 218 DMU_OT_NONE, 0, tx); 219 ASSERT(error == 0); 220 221 error = zap_create_claim(os, ZVOL_ZAP_OBJ, DMU_OT_ZVOL_PROP, 222 DMU_OT_NONE, 0, tx); 223 ASSERT(error == 0); 224 225 error = zap_update(os, ZVOL_ZAP_OBJ, "size", 8, 1, &zc->zc_volsize, tx); 226 ASSERT(error == 0); 227 } 228 229 /* 230 * Replay a TX_WRITE ZIL transaction that didn't get committed 231 * after a system failure 232 */ 233 static int 234 zvol_replay_write(zvol_state_t *zv, lr_write_t *lr, boolean_t byteswap) 235 { 236 objset_t *os = zv->zv_objset; 237 char *data = (char *)(lr + 1); /* data follows lr_write_t */ 238 uint64_t off = lr->lr_offset; 239 uint64_t len = lr->lr_length; 240 dmu_tx_t *tx; 241 int error; 242 243 if (byteswap) 244 byteswap_uint64_array(lr, sizeof (*lr)); 245 246 restart: 247 tx = dmu_tx_create(os); 248 dmu_tx_hold_write(tx, ZVOL_OBJ, off, len); 249 error = dmu_tx_assign(tx, zv->zv_txg_assign); 250 if (error) { 251 dmu_tx_abort(tx); 252 if (error == ERESTART && zv->zv_txg_assign == TXG_NOWAIT) { 253 txg_wait_open(dmu_objset_pool(os), 0); 254 goto restart; 255 } 256 } else { 257 dmu_write(os, ZVOL_OBJ, off, len, data, tx); 258 dmu_tx_commit(tx); 259 } 260 261 return (error); 262 } 263 264 /* ARGSUSED */ 265 static int 266 zvol_replay_err(zvol_state_t *zv, lr_t *lr, boolean_t byteswap) 267 { 268 return (ENOTSUP); 269 } 270 271 /* 272 * Callback vectors for replaying records. 273 * Only TX_WRITE is needed for zvol. 274 */ 275 zil_replay_func_t *zvol_replay_vector[TX_MAX_TYPE] = { 276 zvol_replay_err, /* 0 no such transaction type */ 277 zvol_replay_err, /* TX_CREATE */ 278 zvol_replay_err, /* TX_MKDIR */ 279 zvol_replay_err, /* TX_MKXATTR */ 280 zvol_replay_err, /* TX_SYMLINK */ 281 zvol_replay_err, /* TX_REMOVE */ 282 zvol_replay_err, /* TX_RMDIR */ 283 zvol_replay_err, /* TX_LINK */ 284 zvol_replay_err, /* TX_RENAME */ 285 zvol_replay_write, /* TX_WRITE */ 286 zvol_replay_err, /* TX_TRUNCATE */ 287 zvol_replay_err, /* TX_SETATTR */ 288 zvol_replay_err, /* TX_ACL */ 289 }; 290 291 /* 292 * Create a minor node for the specified volume. 293 */ 294 int 295 zvol_create_minor(zfs_cmd_t *zc) 296 { 297 char *name = zc->zc_name; 298 dev_t dev = zc->zc_dev; 299 zvol_state_t *zv; 300 objset_t *os; 301 uint64_t volsize; 302 minor_t minor = 0; 303 struct pathname linkpath; 304 int ds_mode = DS_MODE_PRIMARY; 305 vnode_t *vp = NULL; 306 char *devpath; 307 size_t devpathlen = strlen(ZVOL_FULL_DEV_DIR) + 1 + strlen(name) + 1; 308 char chrbuf[30], blkbuf[30]; 309 int error; 310 311 mutex_enter(&zvol_state_lock); 312 313 if ((zv = zvol_minor_lookup(name)) != NULL) { 314 mutex_exit(&zvol_state_lock); 315 return (EEXIST); 316 } 317 318 if (strchr(name, '@') != 0) 319 ds_mode |= DS_MODE_READONLY; 320 321 error = dmu_objset_open(name, DMU_OST_ZVOL, ds_mode, &os); 322 323 if (error) { 324 mutex_exit(&zvol_state_lock); 325 return (error); 326 } 327 328 error = zap_lookup(os, ZVOL_ZAP_OBJ, "size", 8, 1, &volsize); 329 330 if (error) { 331 dmu_objset_close(os); 332 mutex_exit(&zvol_state_lock); 333 return (error); 334 } 335 336 /* 337 * If there's an existing /dev/zvol symlink, try to use the 338 * same minor number we used last time. 339 */ 340 devpath = kmem_alloc(devpathlen, KM_SLEEP); 341 342 (void) sprintf(devpath, "%s/%s", ZVOL_FULL_DEV_DIR, name); 343 344 error = lookupname(devpath, UIO_SYSSPACE, NO_FOLLOW, NULL, &vp); 345 346 kmem_free(devpath, devpathlen); 347 348 if (error == 0 && vp->v_type != VLNK) 349 error = EINVAL; 350 351 if (error == 0) { 352 pn_alloc(&linkpath); 353 error = pn_getsymlink(vp, &linkpath, kcred); 354 if (error == 0) { 355 char *ms = strstr(linkpath.pn_path, ZVOL_PSEUDO_DEV); 356 if (ms != NULL) { 357 ms += strlen(ZVOL_PSEUDO_DEV); 358 minor = stoi(&ms); 359 } 360 } 361 pn_free(&linkpath); 362 } 363 364 if (vp != NULL) 365 VN_RELE(vp); 366 367 /* 368 * If we found a minor but it's already in use, we must pick a new one. 369 */ 370 if (minor != 0 && ddi_get_soft_state(zvol_state, minor) != NULL) 371 minor = 0; 372 373 if (minor == 0) 374 minor = zvol_minor_alloc(); 375 376 if (minor == 0) { 377 dmu_objset_close(os); 378 mutex_exit(&zvol_state_lock); 379 return (ENXIO); 380 } 381 382 if (ddi_soft_state_zalloc(zvol_state, minor) != DDI_SUCCESS) { 383 dmu_objset_close(os); 384 mutex_exit(&zvol_state_lock); 385 return (EAGAIN); 386 } 387 388 (void) ddi_prop_update_string(minor, zfs_dip, ZVOL_PROP_NAME, name); 389 390 (void) sprintf(chrbuf, "%uc,raw", minor); 391 392 if (ddi_create_minor_node(zfs_dip, chrbuf, S_IFCHR, 393 minor, DDI_PSEUDO, 0) == DDI_FAILURE) { 394 ddi_soft_state_free(zvol_state, minor); 395 dmu_objset_close(os); 396 mutex_exit(&zvol_state_lock); 397 return (EAGAIN); 398 } 399 400 (void) sprintf(blkbuf, "%uc", minor); 401 402 if (ddi_create_minor_node(zfs_dip, blkbuf, S_IFBLK, 403 minor, DDI_PSEUDO, 0) == DDI_FAILURE) { 404 ddi_remove_minor_node(zfs_dip, chrbuf); 405 ddi_soft_state_free(zvol_state, minor); 406 dmu_objset_close(os); 407 mutex_exit(&zvol_state_lock); 408 return (EAGAIN); 409 } 410 411 zv = ddi_get_soft_state(zvol_state, minor); 412 413 (void) strcpy(zv->zv_name, name); 414 zv->zv_min_bs = DEV_BSHIFT; 415 zv->zv_minor = minor; 416 zv->zv_volsize = volsize; 417 zv->zv_objset = os; 418 zv->zv_mode = ds_mode; 419 zv->zv_zilog = zil_open(os, NULL); 420 421 zil_replay(os, zv, &zv->zv_txg_assign, zvol_replay_vector, NULL); 422 423 zvol_size_changed(zv, dev); 424 425 VERIFY(dsl_prop_register(dmu_objset_ds(zv->zv_objset), 426 "readonly", zvol_readonly_changed_cb, zv) == 0); 427 428 zvol_minors++; 429 430 mutex_exit(&zvol_state_lock); 431 432 return (0); 433 } 434 435 /* 436 * Remove minor node for the specified volume. 437 */ 438 int 439 zvol_remove_minor(zfs_cmd_t *zc) 440 { 441 zvol_state_t *zv; 442 char namebuf[30]; 443 444 mutex_enter(&zvol_state_lock); 445 446 if ((zv = zvol_minor_lookup(zc->zc_name)) == NULL) { 447 mutex_exit(&zvol_state_lock); 448 return (ENXIO); 449 } 450 451 if (zv->zv_total_opens != 0) { 452 mutex_exit(&zvol_state_lock); 453 return (EBUSY); 454 } 455 456 (void) sprintf(namebuf, "%uc,raw", zv->zv_minor); 457 ddi_remove_minor_node(zfs_dip, namebuf); 458 459 (void) sprintf(namebuf, "%uc", zv->zv_minor); 460 ddi_remove_minor_node(zfs_dip, namebuf); 461 462 VERIFY(dsl_prop_unregister(dmu_objset_ds(zv->zv_objset), 463 "readonly", zvol_readonly_changed_cb, zv) == 0); 464 465 zil_close(zv->zv_zilog); 466 zv->zv_zilog = NULL; 467 dmu_objset_close(zv->zv_objset); 468 zv->zv_objset = NULL; 469 470 ddi_soft_state_free(zvol_state, zv->zv_minor); 471 472 zvol_minors--; 473 474 mutex_exit(&zvol_state_lock); 475 476 return (0); 477 } 478 479 int 480 zvol_set_volsize(zfs_cmd_t *zc) 481 { 482 zvol_state_t *zv; 483 dev_t dev = zc->zc_dev; 484 dmu_tx_t *tx; 485 int error; 486 dmu_object_info_t doi; 487 488 mutex_enter(&zvol_state_lock); 489 490 if ((zv = zvol_minor_lookup(zc->zc_name)) == NULL) { 491 mutex_exit(&zvol_state_lock); 492 return (ENXIO); 493 } 494 495 if ((error = dmu_object_info(zv->zv_objset, ZVOL_OBJ, &doi)) != 0 || 496 (error = zvol_check_volsize(zc, doi.doi_data_block_size)) != 0) { 497 mutex_exit(&zvol_state_lock); 498 return (error); 499 } 500 501 if (zv->zv_readonly || (zv->zv_mode & DS_MODE_READONLY)) { 502 mutex_exit(&zvol_state_lock); 503 return (EROFS); 504 } 505 506 tx = dmu_tx_create(zv->zv_objset); 507 dmu_tx_hold_zap(tx, ZVOL_ZAP_OBJ, 1); 508 dmu_tx_hold_free(tx, ZVOL_OBJ, zc->zc_volsize, DMU_OBJECT_END); 509 error = dmu_tx_assign(tx, TXG_WAIT); 510 if (error) { 511 dmu_tx_abort(tx); 512 mutex_exit(&zvol_state_lock); 513 return (error); 514 } 515 516 error = zap_update(zv->zv_objset, ZVOL_ZAP_OBJ, "size", 8, 1, 517 &zc->zc_volsize, tx); 518 if (error == 0) 519 dmu_free_range(zv->zv_objset, ZVOL_OBJ, zc->zc_volsize, 520 DMU_OBJECT_END, tx); 521 522 dmu_tx_commit(tx); 523 524 if (error == 0) { 525 zv->zv_volsize = zc->zc_volsize; 526 zvol_size_changed(zv, dev); 527 } 528 529 mutex_exit(&zvol_state_lock); 530 531 return (error); 532 } 533 534 int 535 zvol_set_volblocksize(zfs_cmd_t *zc) 536 { 537 zvol_state_t *zv; 538 dmu_tx_t *tx; 539 int error; 540 541 mutex_enter(&zvol_state_lock); 542 543 if ((zv = zvol_minor_lookup(zc->zc_name)) == NULL) { 544 mutex_exit(&zvol_state_lock); 545 return (ENXIO); 546 } 547 548 if (zv->zv_readonly || (zv->zv_mode & DS_MODE_READONLY)) { 549 mutex_exit(&zvol_state_lock); 550 return (EROFS); 551 } 552 553 tx = dmu_tx_create(zv->zv_objset); 554 dmu_tx_hold_bonus(tx, ZVOL_OBJ); 555 error = dmu_tx_assign(tx, TXG_WAIT); 556 if (error) { 557 dmu_tx_abort(tx); 558 } else { 559 error = dmu_object_set_blocksize(zv->zv_objset, ZVOL_OBJ, 560 zc->zc_volblocksize, 0, tx); 561 if (error == ENOTSUP) 562 error = EBUSY; 563 dmu_tx_commit(tx); 564 } 565 566 mutex_exit(&zvol_state_lock); 567 568 return (error); 569 } 570 571 /*ARGSUSED*/ 572 int 573 zvol_open(dev_t *devp, int flag, int otyp, cred_t *cr) 574 { 575 minor_t minor = getminor(*devp); 576 zvol_state_t *zv; 577 578 if (minor == 0) /* This is the control device */ 579 return (0); 580 581 mutex_enter(&zvol_state_lock); 582 583 zv = ddi_get_soft_state(zvol_state, minor); 584 if (zv == NULL) { 585 mutex_exit(&zvol_state_lock); 586 return (ENXIO); 587 } 588 589 ASSERT(zv->zv_objset != NULL); 590 591 if ((flag & FWRITE) && 592 (zv->zv_readonly || (zv->zv_mode & DS_MODE_READONLY))) { 593 mutex_exit(&zvol_state_lock); 594 return (EROFS); 595 } 596 597 if (zv->zv_open_count[otyp] == 0 || otyp == OTYP_LYR) { 598 zv->zv_open_count[otyp]++; 599 zv->zv_total_opens++; 600 } 601 602 mutex_exit(&zvol_state_lock); 603 604 return (0); 605 } 606 607 /*ARGSUSED*/ 608 int 609 zvol_close(dev_t dev, int flag, int otyp, cred_t *cr) 610 { 611 minor_t minor = getminor(dev); 612 zvol_state_t *zv; 613 614 if (minor == 0) /* This is the control device */ 615 return (0); 616 617 mutex_enter(&zvol_state_lock); 618 619 zv = ddi_get_soft_state(zvol_state, minor); 620 if (zv == NULL) { 621 mutex_exit(&zvol_state_lock); 622 return (ENXIO); 623 } 624 625 /* 626 * The next statement is a workaround for the following DDI bug: 627 * 6343604 specfs race: multiple "last-close" of the same device 628 */ 629 if (zv->zv_total_opens == 0) { 630 mutex_exit(&zvol_state_lock); 631 return (0); 632 } 633 634 /* 635 * If the open count is zero, this is a spurious close. 636 * That indicates a bug in the kernel / DDI framework. 637 */ 638 ASSERT(zv->zv_open_count[otyp] != 0); 639 ASSERT(zv->zv_total_opens != 0); 640 641 /* 642 * You may get multiple opens, but only one close. 643 */ 644 zv->zv_open_count[otyp]--; 645 zv->zv_total_opens--; 646 647 mutex_exit(&zvol_state_lock); 648 649 return (0); 650 } 651 652 /* 653 * zvol_log_write() handles synchronous page writes using 654 * TX_WRITE ZIL transactions. 655 * 656 * We store data in the log buffers if it's small enough. 657 * Otherwise we flush the data out via dmu_sync(). 658 */ 659 ssize_t zvol_immediate_write_sz = 65536; 660 661 int 662 zvol_log_write(zvol_state_t *zv, dmu_tx_t *tx, offset_t off, ssize_t len, 663 char *addr) 664 { 665 itx_t *itx; 666 lr_write_t *lr; 667 objset_t *os = zv->zv_objset; 668 int dlen; 669 int error; 670 671 dlen = (len <= zvol_immediate_write_sz ? len : 0); 672 itx = zil_itx_create(TX_WRITE, sizeof (*lr) + dlen); 673 lr = (lr_write_t *)&itx->itx_lr; 674 lr->lr_foid = ZVOL_OBJ; 675 lr->lr_offset = off; 676 lr->lr_length = len; 677 lr->lr_blkoff = 0; 678 BP_ZERO(&lr->lr_blkptr); 679 680 /* 681 * Get the data as we know we'll be writing it immediately 682 */ 683 if (dlen) { /* immediate write */ 684 bcopy(addr, (char *)itx + offsetof(itx_t, itx_lr) + 685 sizeof (*lr), len); 686 } else { 687 txg_suspend(dmu_objset_pool(os)); 688 error = dmu_sync(os, ZVOL_OBJ, off, &lr->lr_blkoff, 689 &lr->lr_blkptr, dmu_tx_get_txg(tx)); 690 txg_resume(dmu_objset_pool(os)); 691 if (error) { 692 kmem_free(itx, offsetof(itx_t, itx_lr)); 693 return (error); 694 } 695 } 696 itx->itx_data_copied = 1; 697 698 (void) zil_itx_assign(zv->zv_zilog, itx, tx); 699 700 return (0); 701 } 702 703 int 704 zvol_strategy(buf_t *bp) 705 { 706 zvol_state_t *zv = ddi_get_soft_state(zvol_state, getminor(bp->b_edev)); 707 uint64_t off, volsize; 708 size_t size, resid; 709 char *addr; 710 objset_t *os; 711 int error = 0; 712 int sync; 713 714 if (zv == NULL) { 715 bioerror(bp, ENXIO); 716 biodone(bp); 717 return (0); 718 } 719 720 if (getminor(bp->b_edev) == 0) { 721 bioerror(bp, EINVAL); 722 biodone(bp); 723 return (0); 724 } 725 726 if (zv->zv_readonly && !(bp->b_flags & B_READ)) { 727 bioerror(bp, EROFS); 728 biodone(bp); 729 return (0); 730 } 731 732 off = ldbtob(bp->b_blkno); 733 volsize = zv->zv_volsize; 734 735 os = zv->zv_objset; 736 ASSERT(os != NULL); 737 sync = !(bp->b_flags & B_ASYNC) && !(zil_disable); 738 739 bp_mapin(bp); 740 addr = bp->b_un.b_addr; 741 resid = bp->b_bcount; 742 743 while (resid != 0 && off < volsize) { 744 745 size = MIN(resid, 1UL << 20); /* cap at 1MB per tx */ 746 747 if (size > volsize - off) /* don't write past the end */ 748 size = volsize - off; 749 750 if (bp->b_flags & B_READ) { 751 error = dmu_read_canfail(os, ZVOL_OBJ, 752 off, size, addr); 753 } else { 754 dmu_tx_t *tx = dmu_tx_create(os); 755 dmu_tx_hold_write(tx, ZVOL_OBJ, off, size); 756 error = dmu_tx_assign(tx, TXG_WAIT); 757 if (error) { 758 dmu_tx_abort(tx); 759 } else { 760 dmu_write(os, ZVOL_OBJ, off, size, addr, tx); 761 if (sync) { 762 /* use the ZIL to commit this write */ 763 error = zvol_log_write(zv, tx, off, 764 size, addr); 765 if (error) { 766 txg_wait_synced( 767 dmu_objset_pool(os), 0); 768 sync = B_FALSE; 769 } 770 } 771 dmu_tx_commit(tx); 772 } 773 } 774 if (error) 775 break; 776 off += size; 777 addr += size; 778 resid -= size; 779 } 780 781 if ((bp->b_resid = resid) == bp->b_bcount) 782 bioerror(bp, off > volsize ? EINVAL : error); 783 784 biodone(bp); 785 786 if (sync) 787 zil_commit(zv->zv_zilog, UINT64_MAX, FDSYNC); 788 789 return (0); 790 } 791 792 /*ARGSUSED*/ 793 int 794 zvol_read(dev_t dev, uio_t *uiop, cred_t *cr) 795 { 796 return (physio(zvol_strategy, NULL, dev, B_READ, minphys, uiop)); 797 } 798 799 /*ARGSUSED*/ 800 int 801 zvol_write(dev_t dev, uio_t *uiop, cred_t *cr) 802 { 803 return (physio(zvol_strategy, NULL, dev, B_WRITE, minphys, uiop)); 804 } 805 806 /*ARGSUSED*/ 807 int 808 zvol_aread(dev_t dev, struct aio_req *aio, cred_t *cr) 809 { 810 return (aphysio(zvol_strategy, anocancel, dev, B_READ, minphys, aio)); 811 } 812 813 /*ARGSUSED*/ 814 int 815 zvol_awrite(dev_t dev, struct aio_req *aio, cred_t *cr) 816 { 817 return (aphysio(zvol_strategy, anocancel, dev, B_WRITE, minphys, aio)); 818 } 819 820 /* 821 * Dirtbag ioctls to support mkfs(1M) for UFS filesystems. See dkio(7I). 822 */ 823 /*ARGSUSED*/ 824 int 825 zvol_ioctl(dev_t dev, int cmd, intptr_t arg, int flag, cred_t *cr, int *rvalp) 826 { 827 zvol_state_t *zv; 828 struct dk_cinfo dkc; 829 struct dk_minfo dkm; 830 dk_efi_t efi; 831 efi_gpt_t gpt; 832 efi_gpe_t gpe; 833 struct uuid uuid = EFI_RESERVED; 834 uint32_t crc; 835 int error = 0; 836 837 mutex_enter(&zvol_state_lock); 838 839 zv = ddi_get_soft_state(zvol_state, getminor(dev)); 840 841 if (zv == NULL) { 842 mutex_exit(&zvol_state_lock); 843 return (ENXIO); 844 } 845 846 switch (cmd) { 847 848 case DKIOCINFO: 849 bzero(&dkc, sizeof (dkc)); 850 (void) strcpy(dkc.dki_cname, "zvol"); 851 (void) strcpy(dkc.dki_dname, "zvol"); 852 dkc.dki_ctype = DKC_UNKNOWN; 853 dkc.dki_maxtransfer = 1 << 15; 854 mutex_exit(&zvol_state_lock); 855 if (ddi_copyout(&dkc, (void *)arg, sizeof (dkc), flag)) 856 error = EFAULT; 857 return (error); 858 859 case DKIOCGMEDIAINFO: 860 bzero(&dkm, sizeof (dkm)); 861 dkm.dki_lbsize = 1U << zv->zv_min_bs; 862 dkm.dki_capacity = zv->zv_volsize >> zv->zv_min_bs; 863 dkm.dki_media_type = DK_UNKNOWN; 864 mutex_exit(&zvol_state_lock); 865 if (ddi_copyout(&dkm, (void *)arg, sizeof (dkm), flag)) 866 error = EFAULT; 867 return (error); 868 869 case DKIOCGETEFI: 870 if (ddi_copyin((void *)arg, &efi, sizeof (dk_efi_t), flag)) { 871 mutex_exit(&zvol_state_lock); 872 return (EFAULT); 873 } 874 875 bzero(&gpt, sizeof (gpt)); 876 bzero(&gpe, sizeof (gpe)); 877 878 efi.dki_data = (void *)(uintptr_t)efi.dki_data_64; 879 880 if (efi.dki_length < sizeof (gpt) + sizeof (gpe)) { 881 mutex_exit(&zvol_state_lock); 882 return (EINVAL); 883 } 884 885 efi.dki_length = sizeof (gpt) + sizeof (gpe); 886 887 gpt.efi_gpt_Signature = LE_64(EFI_SIGNATURE); 888 gpt.efi_gpt_Revision = LE_32(EFI_VERSION_CURRENT); 889 gpt.efi_gpt_HeaderSize = LE_32(sizeof (gpt)); 890 gpt.efi_gpt_FirstUsableLBA = LE_64(0ULL); 891 gpt.efi_gpt_LastUsableLBA = 892 LE_64((zv->zv_volsize >> zv->zv_min_bs) - 1); 893 gpt.efi_gpt_NumberOfPartitionEntries = LE_32(1); 894 gpt.efi_gpt_SizeOfPartitionEntry = LE_32(sizeof (gpe)); 895 896 UUID_LE_CONVERT(gpe.efi_gpe_PartitionTypeGUID, uuid); 897 gpe.efi_gpe_StartingLBA = gpt.efi_gpt_FirstUsableLBA; 898 gpe.efi_gpe_EndingLBA = gpt.efi_gpt_LastUsableLBA; 899 900 CRC32(crc, &gpe, sizeof (gpe), -1U, crc32_table); 901 gpt.efi_gpt_PartitionEntryArrayCRC32 = LE_32(~crc); 902 903 CRC32(crc, &gpt, sizeof (gpt), -1U, crc32_table); 904 gpt.efi_gpt_HeaderCRC32 = LE_32(~crc); 905 906 mutex_exit(&zvol_state_lock); 907 if (ddi_copyout(&gpt, efi.dki_data, sizeof (gpt), flag) || 908 ddi_copyout(&gpe, efi.dki_data + 1, sizeof (gpe), flag)) 909 error = EFAULT; 910 return (error); 911 912 default: 913 error = ENOTSUP; 914 break; 915 916 } 917 mutex_exit(&zvol_state_lock); 918 return (error); 919 } 920 921 int 922 zvol_busy(void) 923 { 924 return (zvol_minors != 0); 925 } 926 927 void 928 zvol_init(void) 929 { 930 VERIFY(ddi_soft_state_init(&zvol_state, sizeof (zvol_state_t), 1) == 0); 931 mutex_init(&zvol_state_lock, NULL, MUTEX_DEFAULT, NULL); 932 } 933 934 void 935 zvol_fini(void) 936 { 937 mutex_destroy(&zvol_state_lock); 938 ddi_soft_state_fini(&zvol_state); 939 } 940