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 2010 Sun Microsystems, Inc. All rights reserved. 23 * Use is subject to license terms. 24 */ 25 26 /* 27 * ZFS volume emulation driver. 28 * 29 * Makes a DMU object look like a volume of arbitrary size, up to 2^64 bytes. 30 * Volumes are accessed through the symbolic links named: 31 * 32 * /dev/zvol/dsk/<pool_name>/<dataset_name> 33 * /dev/zvol/rdsk/<pool_name>/<dataset_name> 34 * 35 * These links are created by the /dev filesystem (sdev_zvolops.c). 36 * Volumes are persistent through reboot. No user command needs to be 37 * run before opening and using a device. 38 */ 39 40 #include <sys/types.h> 41 #include <sys/param.h> 42 #include <sys/errno.h> 43 #include <sys/uio.h> 44 #include <sys/buf.h> 45 #include <sys/modctl.h> 46 #include <sys/open.h> 47 #include <sys/kmem.h> 48 #include <sys/conf.h> 49 #include <sys/cmn_err.h> 50 #include <sys/stat.h> 51 #include <sys/zap.h> 52 #include <sys/spa.h> 53 #include <sys/zio.h> 54 #include <sys/dmu_traverse.h> 55 #include <sys/dnode.h> 56 #include <sys/dsl_dataset.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 #include <sys/zfs_znode.h> 73 #include <sys/zfs_rlock.h> 74 #include <sys/vdev_disk.h> 75 #include <sys/vdev_impl.h> 76 #include <sys/zvol.h> 77 #include <sys/dumphdr.h> 78 #include <sys/zil_impl.h> 79 80 #include "zfs_namecheck.h" 81 82 static void *zvol_state; 83 static char *zvol_tag = "zvol_tag"; 84 85 #define ZVOL_DUMPSIZE "dumpsize" 86 87 /* 88 * This lock protects the zvol_state structure from being modified 89 * while it's being used, e.g. an open that comes in before a create 90 * finishes. It also protects temporary opens of the dataset so that, 91 * e.g., an open doesn't get a spurious EBUSY. 92 */ 93 static kmutex_t zvol_state_lock; 94 static uint32_t zvol_minors; 95 96 typedef struct zvol_extent { 97 list_node_t ze_node; 98 dva_t ze_dva; /* dva associated with this extent */ 99 uint64_t ze_nblks; /* number of blocks in extent */ 100 } zvol_extent_t; 101 102 /* 103 * The in-core state of each volume. 104 */ 105 typedef struct zvol_state { 106 char zv_name[MAXPATHLEN]; /* pool/dd name */ 107 uint64_t zv_volsize; /* amount of space we advertise */ 108 uint64_t zv_volblocksize; /* volume block size */ 109 minor_t zv_minor; /* minor number */ 110 uint8_t zv_min_bs; /* minimum addressable block shift */ 111 uint8_t zv_flags; /* readonly, dumpified, etc. */ 112 objset_t *zv_objset; /* objset handle */ 113 uint32_t zv_open_count[OTYPCNT]; /* open counts */ 114 uint32_t zv_total_opens; /* total open count */ 115 zilog_t *zv_zilog; /* ZIL handle */ 116 list_t zv_extents; /* List of extents for dump */ 117 znode_t zv_znode; /* for range locking */ 118 } zvol_state_t; 119 120 /* 121 * zvol specific flags 122 */ 123 #define ZVOL_RDONLY 0x1 124 #define ZVOL_DUMPIFIED 0x2 125 #define ZVOL_EXCL 0x4 126 #define ZVOL_WCE 0x8 127 128 /* 129 * zvol maximum transfer in one DMU tx. 130 */ 131 int zvol_maxphys = DMU_MAX_ACCESS/2; 132 133 extern int zfs_set_prop_nvlist(const char *, zprop_source_t, 134 nvlist_t *, nvlist_t **); 135 static int zvol_remove_zv(zvol_state_t *); 136 static int zvol_get_data(void *arg, lr_write_t *lr, char *buf, zio_t *zio); 137 static int zvol_dumpify(zvol_state_t *zv); 138 static int zvol_dump_fini(zvol_state_t *zv); 139 static int zvol_dump_init(zvol_state_t *zv, boolean_t resize); 140 141 static void 142 zvol_size_changed(uint64_t volsize, major_t maj, minor_t min) 143 { 144 dev_t dev = makedevice(maj, min); 145 146 VERIFY(ddi_prop_update_int64(dev, zfs_dip, 147 "Size", volsize) == DDI_SUCCESS); 148 VERIFY(ddi_prop_update_int64(dev, zfs_dip, 149 "Nblocks", lbtodb(volsize)) == DDI_SUCCESS); 150 151 /* Notify specfs to invalidate the cached size */ 152 spec_size_invalidate(dev, VBLK); 153 spec_size_invalidate(dev, VCHR); 154 } 155 156 int 157 zvol_check_volsize(uint64_t volsize, uint64_t blocksize) 158 { 159 if (volsize == 0) 160 return (EINVAL); 161 162 if (volsize % blocksize != 0) 163 return (EINVAL); 164 165 #ifdef _ILP32 166 if (volsize - 1 > SPEC_MAXOFFSET_T) 167 return (EOVERFLOW); 168 #endif 169 return (0); 170 } 171 172 int 173 zvol_check_volblocksize(uint64_t volblocksize) 174 { 175 if (volblocksize < SPA_MINBLOCKSIZE || 176 volblocksize > SPA_MAXBLOCKSIZE || 177 !ISP2(volblocksize)) 178 return (EDOM); 179 180 return (0); 181 } 182 183 int 184 zvol_get_stats(objset_t *os, nvlist_t *nv) 185 { 186 int error; 187 dmu_object_info_t doi; 188 uint64_t val; 189 190 error = zap_lookup(os, ZVOL_ZAP_OBJ, "size", 8, 1, &val); 191 if (error) 192 return (error); 193 194 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_VOLSIZE, val); 195 196 error = dmu_object_info(os, ZVOL_OBJ, &doi); 197 198 if (error == 0) { 199 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_VOLBLOCKSIZE, 200 doi.doi_data_block_size); 201 } 202 203 return (error); 204 } 205 206 /* 207 * Find a free minor number. 208 */ 209 static minor_t 210 zvol_minor_alloc(void) 211 { 212 minor_t minor; 213 214 ASSERT(MUTEX_HELD(&zvol_state_lock)); 215 216 for (minor = 1; minor <= ZVOL_MAX_MINOR; minor++) 217 if (ddi_get_soft_state(zvol_state, minor) == NULL) 218 return (minor); 219 220 return (0); 221 } 222 223 static zvol_state_t * 224 zvol_minor_lookup(const char *name) 225 { 226 minor_t minor; 227 zvol_state_t *zv; 228 229 ASSERT(MUTEX_HELD(&zvol_state_lock)); 230 231 for (minor = 1; minor <= ZVOL_MAX_MINOR; minor++) { 232 zv = ddi_get_soft_state(zvol_state, minor); 233 if (zv == NULL) 234 continue; 235 if (strcmp(zv->zv_name, name) == 0) 236 break; 237 } 238 239 return (zv); 240 } 241 242 /* extent mapping arg */ 243 struct maparg { 244 zvol_state_t *ma_zv; 245 uint64_t ma_blks; 246 }; 247 248 /*ARGSUSED*/ 249 static int 250 zvol_map_block(spa_t *spa, zilog_t *zilog, const blkptr_t *bp, 251 const zbookmark_t *zb, const dnode_phys_t *dnp, void *arg) 252 { 253 struct maparg *ma = arg; 254 zvol_extent_t *ze; 255 int bs = ma->ma_zv->zv_volblocksize; 256 257 if (bp == NULL || zb->zb_object != ZVOL_OBJ || zb->zb_level != 0) 258 return (0); 259 260 VERIFY3U(ma->ma_blks, ==, zb->zb_blkid); 261 ma->ma_blks++; 262 263 /* Abort immediately if we have encountered gang blocks */ 264 if (BP_IS_GANG(bp)) 265 return (EFRAGS); 266 267 /* 268 * See if the block is at the end of the previous extent. 269 */ 270 ze = list_tail(&ma->ma_zv->zv_extents); 271 if (ze && 272 DVA_GET_VDEV(BP_IDENTITY(bp)) == DVA_GET_VDEV(&ze->ze_dva) && 273 DVA_GET_OFFSET(BP_IDENTITY(bp)) == 274 DVA_GET_OFFSET(&ze->ze_dva) + ze->ze_nblks * bs) { 275 ze->ze_nblks++; 276 return (0); 277 } 278 279 dprintf_bp(bp, "%s", "next blkptr:"); 280 281 /* start a new extent */ 282 ze = kmem_zalloc(sizeof (zvol_extent_t), KM_SLEEP); 283 ze->ze_dva = bp->blk_dva[0]; /* structure assignment */ 284 ze->ze_nblks = 1; 285 list_insert_tail(&ma->ma_zv->zv_extents, ze); 286 return (0); 287 } 288 289 static void 290 zvol_free_extents(zvol_state_t *zv) 291 { 292 zvol_extent_t *ze; 293 294 while (ze = list_head(&zv->zv_extents)) { 295 list_remove(&zv->zv_extents, ze); 296 kmem_free(ze, sizeof (zvol_extent_t)); 297 } 298 } 299 300 static int 301 zvol_get_lbas(zvol_state_t *zv) 302 { 303 objset_t *os = zv->zv_objset; 304 struct maparg ma; 305 int err; 306 307 ma.ma_zv = zv; 308 ma.ma_blks = 0; 309 zvol_free_extents(zv); 310 311 /* commit any in-flight changes before traversing the dataset */ 312 txg_wait_synced(dmu_objset_pool(os), 0); 313 err = traverse_dataset(dmu_objset_ds(os), 0, 314 TRAVERSE_PRE | TRAVERSE_PREFETCH_METADATA, zvol_map_block, &ma); 315 if (err || ma.ma_blks != (zv->zv_volsize / zv->zv_volblocksize)) { 316 zvol_free_extents(zv); 317 return (err ? err : EIO); 318 } 319 320 return (0); 321 } 322 323 /* ARGSUSED */ 324 void 325 zvol_create_cb(objset_t *os, void *arg, cred_t *cr, dmu_tx_t *tx) 326 { 327 zfs_creat_t *zct = arg; 328 nvlist_t *nvprops = zct->zct_props; 329 int error; 330 uint64_t volblocksize, volsize; 331 332 VERIFY(nvlist_lookup_uint64(nvprops, 333 zfs_prop_to_name(ZFS_PROP_VOLSIZE), &volsize) == 0); 334 if (nvlist_lookup_uint64(nvprops, 335 zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE), &volblocksize) != 0) 336 volblocksize = zfs_prop_default_numeric(ZFS_PROP_VOLBLOCKSIZE); 337 338 /* 339 * These properties must be removed from the list so the generic 340 * property setting step won't apply to them. 341 */ 342 VERIFY(nvlist_remove_all(nvprops, 343 zfs_prop_to_name(ZFS_PROP_VOLSIZE)) == 0); 344 (void) nvlist_remove_all(nvprops, 345 zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE)); 346 347 error = dmu_object_claim(os, ZVOL_OBJ, DMU_OT_ZVOL, volblocksize, 348 DMU_OT_NONE, 0, tx); 349 ASSERT(error == 0); 350 351 error = zap_create_claim(os, ZVOL_ZAP_OBJ, DMU_OT_ZVOL_PROP, 352 DMU_OT_NONE, 0, tx); 353 ASSERT(error == 0); 354 355 error = zap_update(os, ZVOL_ZAP_OBJ, "size", 8, 1, &volsize, tx); 356 ASSERT(error == 0); 357 } 358 359 /* 360 * Replay a TX_WRITE ZIL transaction that didn't get committed 361 * after a system failure 362 */ 363 static int 364 zvol_replay_write(zvol_state_t *zv, lr_write_t *lr, boolean_t byteswap) 365 { 366 objset_t *os = zv->zv_objset; 367 char *data = (char *)(lr + 1); /* data follows lr_write_t */ 368 uint64_t offset, length; 369 dmu_tx_t *tx; 370 int error; 371 372 if (byteswap) 373 byteswap_uint64_array(lr, sizeof (*lr)); 374 375 offset = lr->lr_offset; 376 length = lr->lr_length; 377 378 /* If it's a dmu_sync() block, write the whole block */ 379 if (lr->lr_common.lrc_reclen == sizeof (lr_write_t)) { 380 uint64_t blocksize = BP_GET_LSIZE(&lr->lr_blkptr); 381 if (length < blocksize) { 382 offset -= offset % blocksize; 383 length = blocksize; 384 } 385 } 386 387 tx = dmu_tx_create(os); 388 dmu_tx_hold_write(tx, ZVOL_OBJ, offset, length); 389 error = dmu_tx_assign(tx, TXG_WAIT); 390 if (error) { 391 dmu_tx_abort(tx); 392 } else { 393 dmu_write(os, ZVOL_OBJ, offset, length, data, tx); 394 dmu_tx_commit(tx); 395 } 396 397 return (error); 398 } 399 400 /* ARGSUSED */ 401 static int 402 zvol_replay_err(zvol_state_t *zv, lr_t *lr, boolean_t byteswap) 403 { 404 return (ENOTSUP); 405 } 406 407 /* 408 * Callback vectors for replaying records. 409 * Only TX_WRITE is needed for zvol. 410 */ 411 zil_replay_func_t *zvol_replay_vector[TX_MAX_TYPE] = { 412 zvol_replay_err, /* 0 no such transaction type */ 413 zvol_replay_err, /* TX_CREATE */ 414 zvol_replay_err, /* TX_MKDIR */ 415 zvol_replay_err, /* TX_MKXATTR */ 416 zvol_replay_err, /* TX_SYMLINK */ 417 zvol_replay_err, /* TX_REMOVE */ 418 zvol_replay_err, /* TX_RMDIR */ 419 zvol_replay_err, /* TX_LINK */ 420 zvol_replay_err, /* TX_RENAME */ 421 zvol_replay_write, /* TX_WRITE */ 422 zvol_replay_err, /* TX_TRUNCATE */ 423 zvol_replay_err, /* TX_SETATTR */ 424 zvol_replay_err, /* TX_ACL */ 425 zvol_replay_err, /* TX_CREATE_ACL */ 426 zvol_replay_err, /* TX_CREATE_ATTR */ 427 zvol_replay_err, /* TX_CREATE_ACL_ATTR */ 428 zvol_replay_err, /* TX_MKDIR_ACL */ 429 zvol_replay_err, /* TX_MKDIR_ATTR */ 430 zvol_replay_err, /* TX_MKDIR_ACL_ATTR */ 431 zvol_replay_err, /* TX_WRITE2 */ 432 }; 433 434 int 435 zvol_name2minor(const char *name, minor_t *minor) 436 { 437 zvol_state_t *zv; 438 439 mutex_enter(&zvol_state_lock); 440 zv = zvol_minor_lookup(name); 441 if (minor && zv) 442 *minor = zv->zv_minor; 443 mutex_exit(&zvol_state_lock); 444 return (zv ? 0 : -1); 445 } 446 447 /* 448 * Create a minor node (plus a whole lot more) for the specified volume. 449 */ 450 int 451 zvol_create_minor(const char *name) 452 { 453 zvol_state_t *zv; 454 objset_t *os; 455 dmu_object_info_t doi; 456 minor_t minor = 0; 457 char chrbuf[30], blkbuf[30]; 458 int error; 459 460 mutex_enter(&zvol_state_lock); 461 462 if (zvol_minor_lookup(name) != NULL) { 463 mutex_exit(&zvol_state_lock); 464 return (EEXIST); 465 } 466 467 /* lie and say we're read-only */ 468 error = dmu_objset_own(name, DMU_OST_ZVOL, B_TRUE, zvol_tag, &os); 469 470 if (error) { 471 mutex_exit(&zvol_state_lock); 472 return (error); 473 } 474 475 if ((minor = zvol_minor_alloc()) == 0) { 476 dmu_objset_disown(os, zvol_tag); 477 mutex_exit(&zvol_state_lock); 478 return (ENXIO); 479 } 480 481 if (ddi_soft_state_zalloc(zvol_state, minor) != DDI_SUCCESS) { 482 dmu_objset_disown(os, zvol_tag); 483 mutex_exit(&zvol_state_lock); 484 return (EAGAIN); 485 } 486 (void) ddi_prop_update_string(minor, zfs_dip, ZVOL_PROP_NAME, 487 (char *)name); 488 489 (void) snprintf(chrbuf, sizeof (chrbuf), "%u,raw", minor); 490 491 if (ddi_create_minor_node(zfs_dip, chrbuf, S_IFCHR, 492 minor, DDI_PSEUDO, 0) == DDI_FAILURE) { 493 ddi_soft_state_free(zvol_state, minor); 494 dmu_objset_disown(os, zvol_tag); 495 mutex_exit(&zvol_state_lock); 496 return (EAGAIN); 497 } 498 499 (void) snprintf(blkbuf, sizeof (blkbuf), "%u", minor); 500 501 if (ddi_create_minor_node(zfs_dip, blkbuf, S_IFBLK, 502 minor, DDI_PSEUDO, 0) == DDI_FAILURE) { 503 ddi_remove_minor_node(zfs_dip, chrbuf); 504 ddi_soft_state_free(zvol_state, minor); 505 dmu_objset_disown(os, zvol_tag); 506 mutex_exit(&zvol_state_lock); 507 return (EAGAIN); 508 } 509 510 zv = ddi_get_soft_state(zvol_state, minor); 511 512 (void) strlcpy(zv->zv_name, name, MAXPATHLEN); 513 zv->zv_min_bs = DEV_BSHIFT; 514 zv->zv_minor = minor; 515 zv->zv_objset = os; 516 if (dmu_objset_is_snapshot(os)) 517 zv->zv_flags |= ZVOL_RDONLY; 518 mutex_init(&zv->zv_znode.z_range_lock, NULL, MUTEX_DEFAULT, NULL); 519 avl_create(&zv->zv_znode.z_range_avl, zfs_range_compare, 520 sizeof (rl_t), offsetof(rl_t, r_node)); 521 list_create(&zv->zv_extents, sizeof (zvol_extent_t), 522 offsetof(zvol_extent_t, ze_node)); 523 /* get and cache the blocksize */ 524 error = dmu_object_info(os, ZVOL_OBJ, &doi); 525 ASSERT(error == 0); 526 zv->zv_volblocksize = doi.doi_data_block_size; 527 528 zil_replay(os, zv, zvol_replay_vector); 529 dmu_objset_disown(os, zvol_tag); 530 zv->zv_objset = NULL; 531 532 zvol_minors++; 533 534 mutex_exit(&zvol_state_lock); 535 536 return (0); 537 } 538 539 /* 540 * Remove minor node for the specified volume. 541 */ 542 static int 543 zvol_remove_zv(zvol_state_t *zv) 544 { 545 char nmbuf[20]; 546 547 ASSERT(MUTEX_HELD(&zvol_state_lock)); 548 if (zv->zv_total_opens != 0) 549 return (EBUSY); 550 551 (void) snprintf(nmbuf, sizeof (nmbuf), "%u,raw", zv->zv_minor); 552 ddi_remove_minor_node(zfs_dip, nmbuf); 553 554 (void) snprintf(nmbuf, sizeof (nmbuf), "%u", zv->zv_minor); 555 ddi_remove_minor_node(zfs_dip, nmbuf); 556 557 avl_destroy(&zv->zv_znode.z_range_avl); 558 mutex_destroy(&zv->zv_znode.z_range_lock); 559 560 ddi_soft_state_free(zvol_state, zv->zv_minor); 561 562 zvol_minors--; 563 return (0); 564 } 565 566 int 567 zvol_remove_minor(const char *name) 568 { 569 zvol_state_t *zv; 570 int rc; 571 572 mutex_enter(&zvol_state_lock); 573 if ((zv = zvol_minor_lookup(name)) == NULL) { 574 mutex_exit(&zvol_state_lock); 575 return (ENXIO); 576 } 577 rc = zvol_remove_zv(zv); 578 mutex_exit(&zvol_state_lock); 579 return (rc); 580 } 581 582 int 583 zvol_first_open(zvol_state_t *zv) 584 { 585 objset_t *os; 586 uint64_t volsize; 587 int error; 588 uint64_t readonly; 589 590 /* lie and say we're read-only */ 591 error = dmu_objset_own(zv->zv_name, DMU_OST_ZVOL, B_TRUE, 592 zvol_tag, &os); 593 if (error) 594 return (error); 595 596 error = zap_lookup(os, ZVOL_ZAP_OBJ, "size", 8, 1, &volsize); 597 if (error) { 598 ASSERT(error == 0); 599 dmu_objset_disown(os, zvol_tag); 600 return (error); 601 } 602 zv->zv_objset = os; 603 zv->zv_volsize = volsize; 604 zv->zv_zilog = zil_open(os, zvol_get_data); 605 zvol_size_changed(zv->zv_volsize, ddi_driver_major(zfs_dip), 606 zv->zv_minor); 607 608 VERIFY(dsl_prop_get_integer(zv->zv_name, "readonly", &readonly, 609 NULL) == 0); 610 if (readonly || dmu_objset_is_snapshot(os)) 611 zv->zv_flags |= ZVOL_RDONLY; 612 else 613 zv->zv_flags &= ~ZVOL_RDONLY; 614 return (error); 615 } 616 617 void 618 zvol_last_close(zvol_state_t *zv) 619 { 620 zil_close(zv->zv_zilog); 621 zv->zv_zilog = NULL; 622 dmu_objset_disown(zv->zv_objset, zvol_tag); 623 zv->zv_objset = NULL; 624 } 625 626 int 627 zvol_prealloc(zvol_state_t *zv) 628 { 629 objset_t *os = zv->zv_objset; 630 dmu_tx_t *tx; 631 uint64_t refd, avail, usedobjs, availobjs; 632 uint64_t resid = zv->zv_volsize; 633 uint64_t off = 0; 634 635 /* Check the space usage before attempting to allocate the space */ 636 dmu_objset_space(os, &refd, &avail, &usedobjs, &availobjs); 637 if (avail < zv->zv_volsize) 638 return (ENOSPC); 639 640 /* Free old extents if they exist */ 641 zvol_free_extents(zv); 642 643 while (resid != 0) { 644 int error; 645 uint64_t bytes = MIN(resid, SPA_MAXBLOCKSIZE); 646 647 tx = dmu_tx_create(os); 648 dmu_tx_hold_write(tx, ZVOL_OBJ, off, bytes); 649 error = dmu_tx_assign(tx, TXG_WAIT); 650 if (error) { 651 dmu_tx_abort(tx); 652 (void) dmu_free_long_range(os, ZVOL_OBJ, 0, off); 653 return (error); 654 } 655 dmu_prealloc(os, ZVOL_OBJ, off, bytes, tx); 656 dmu_tx_commit(tx); 657 off += bytes; 658 resid -= bytes; 659 } 660 txg_wait_synced(dmu_objset_pool(os), 0); 661 662 return (0); 663 } 664 665 int 666 zvol_update_volsize(objset_t *os, uint64_t volsize) 667 { 668 dmu_tx_t *tx; 669 int error; 670 671 ASSERT(MUTEX_HELD(&zvol_state_lock)); 672 673 tx = dmu_tx_create(os); 674 dmu_tx_hold_zap(tx, ZVOL_ZAP_OBJ, TRUE, NULL); 675 error = dmu_tx_assign(tx, TXG_WAIT); 676 if (error) { 677 dmu_tx_abort(tx); 678 return (error); 679 } 680 681 error = zap_update(os, ZVOL_ZAP_OBJ, "size", 8, 1, 682 &volsize, tx); 683 dmu_tx_commit(tx); 684 685 if (error == 0) 686 error = dmu_free_long_range(os, 687 ZVOL_OBJ, volsize, DMU_OBJECT_END); 688 return (error); 689 } 690 691 void 692 zvol_remove_minors(const char *name) 693 { 694 zvol_state_t *zv; 695 char *namebuf; 696 minor_t minor; 697 698 namebuf = kmem_zalloc(strlen(name) + 2, KM_SLEEP); 699 (void) strncpy(namebuf, name, strlen(name)); 700 (void) strcat(namebuf, "/"); 701 mutex_enter(&zvol_state_lock); 702 for (minor = 1; minor <= ZVOL_MAX_MINOR; minor++) { 703 704 zv = ddi_get_soft_state(zvol_state, minor); 705 if (zv == NULL) 706 continue; 707 if (strncmp(namebuf, zv->zv_name, strlen(namebuf)) == 0) 708 (void) zvol_remove_zv(zv); 709 } 710 kmem_free(namebuf, strlen(name) + 2); 711 712 mutex_exit(&zvol_state_lock); 713 } 714 715 int 716 zvol_set_volsize(const char *name, major_t maj, uint64_t volsize) 717 { 718 zvol_state_t *zv = NULL; 719 objset_t *os; 720 int error; 721 dmu_object_info_t doi; 722 uint64_t old_volsize = 0ULL; 723 uint64_t readonly; 724 725 mutex_enter(&zvol_state_lock); 726 zv = zvol_minor_lookup(name); 727 if ((error = dmu_objset_hold(name, FTAG, &os)) != 0) { 728 mutex_exit(&zvol_state_lock); 729 return (error); 730 } 731 732 if ((error = dmu_object_info(os, ZVOL_OBJ, &doi)) != 0 || 733 (error = zvol_check_volsize(volsize, 734 doi.doi_data_block_size)) != 0) 735 goto out; 736 737 VERIFY(dsl_prop_get_integer(name, "readonly", &readonly, 738 NULL) == 0); 739 if (readonly) { 740 error = EROFS; 741 goto out; 742 } 743 744 error = zvol_update_volsize(os, volsize); 745 /* 746 * Reinitialize the dump area to the new size. If we 747 * failed to resize the dump area then restore it back to 748 * its original size. 749 */ 750 if (zv && error == 0) { 751 if (zv->zv_flags & ZVOL_DUMPIFIED) { 752 old_volsize = zv->zv_volsize; 753 zv->zv_volsize = volsize; 754 if ((error = zvol_dumpify(zv)) != 0 || 755 (error = dumpvp_resize()) != 0) { 756 (void) zvol_update_volsize(os, old_volsize); 757 zv->zv_volsize = old_volsize; 758 error = zvol_dumpify(zv); 759 } 760 } 761 if (error == 0) { 762 zv->zv_volsize = volsize; 763 zvol_size_changed(volsize, maj, zv->zv_minor); 764 } 765 } 766 767 /* 768 * Generate a LUN expansion event. 769 */ 770 if (zv && error == 0) { 771 sysevent_id_t eid; 772 nvlist_t *attr; 773 char *physpath = kmem_zalloc(MAXPATHLEN, KM_SLEEP); 774 775 (void) snprintf(physpath, MAXPATHLEN, "%s%u", ZVOL_PSEUDO_DEV, 776 zv->zv_minor); 777 778 VERIFY(nvlist_alloc(&attr, NV_UNIQUE_NAME, KM_SLEEP) == 0); 779 VERIFY(nvlist_add_string(attr, DEV_PHYS_PATH, physpath) == 0); 780 781 (void) ddi_log_sysevent(zfs_dip, SUNW_VENDOR, EC_DEV_STATUS, 782 ESC_DEV_DLE, attr, &eid, DDI_SLEEP); 783 784 nvlist_free(attr); 785 kmem_free(physpath, MAXPATHLEN); 786 } 787 788 out: 789 dmu_objset_rele(os, FTAG); 790 791 mutex_exit(&zvol_state_lock); 792 793 return (error); 794 } 795 796 /*ARGSUSED*/ 797 int 798 zvol_open(dev_t *devp, int flag, int otyp, cred_t *cr) 799 { 800 minor_t minor = getminor(*devp); 801 zvol_state_t *zv; 802 int err = 0; 803 804 if (minor == 0) /* This is the control device */ 805 return (0); 806 807 mutex_enter(&zvol_state_lock); 808 809 zv = ddi_get_soft_state(zvol_state, minor); 810 if (zv == NULL) { 811 mutex_exit(&zvol_state_lock); 812 return (ENXIO); 813 } 814 815 if (zv->zv_total_opens == 0) 816 err = zvol_first_open(zv); 817 if (err) { 818 mutex_exit(&zvol_state_lock); 819 return (err); 820 } 821 if ((flag & FWRITE) && (zv->zv_flags & ZVOL_RDONLY)) { 822 err = EROFS; 823 goto out; 824 } 825 if (zv->zv_flags & ZVOL_EXCL) { 826 err = EBUSY; 827 goto out; 828 } 829 if (flag & FEXCL) { 830 if (zv->zv_total_opens != 0) { 831 err = EBUSY; 832 goto out; 833 } 834 zv->zv_flags |= ZVOL_EXCL; 835 } 836 837 if (zv->zv_open_count[otyp] == 0 || otyp == OTYP_LYR) { 838 zv->zv_open_count[otyp]++; 839 zv->zv_total_opens++; 840 } 841 mutex_exit(&zvol_state_lock); 842 843 return (err); 844 out: 845 if (zv->zv_total_opens == 0) 846 zvol_last_close(zv); 847 mutex_exit(&zvol_state_lock); 848 return (err); 849 } 850 851 /*ARGSUSED*/ 852 int 853 zvol_close(dev_t dev, int flag, int otyp, cred_t *cr) 854 { 855 minor_t minor = getminor(dev); 856 zvol_state_t *zv; 857 int error = 0; 858 859 if (minor == 0) /* This is the control device */ 860 return (0); 861 862 mutex_enter(&zvol_state_lock); 863 864 zv = ddi_get_soft_state(zvol_state, minor); 865 if (zv == NULL) { 866 mutex_exit(&zvol_state_lock); 867 return (ENXIO); 868 } 869 870 if (zv->zv_flags & ZVOL_EXCL) { 871 ASSERT(zv->zv_total_opens == 1); 872 zv->zv_flags &= ~ZVOL_EXCL; 873 } 874 875 /* 876 * If the open count is zero, this is a spurious close. 877 * That indicates a bug in the kernel / DDI framework. 878 */ 879 ASSERT(zv->zv_open_count[otyp] != 0); 880 ASSERT(zv->zv_total_opens != 0); 881 882 /* 883 * You may get multiple opens, but only one close. 884 */ 885 zv->zv_open_count[otyp]--; 886 zv->zv_total_opens--; 887 888 if (zv->zv_total_opens == 0) 889 zvol_last_close(zv); 890 891 mutex_exit(&zvol_state_lock); 892 return (error); 893 } 894 895 static void 896 zvol_get_done(zgd_t *zgd, int error) 897 { 898 if (zgd->zgd_db) 899 dmu_buf_rele(zgd->zgd_db, zgd); 900 901 zfs_range_unlock(zgd->zgd_rl); 902 903 if (error == 0 && zgd->zgd_bp) 904 zil_add_block(zgd->zgd_zilog, zgd->zgd_bp); 905 906 kmem_free(zgd, sizeof (zgd_t)); 907 } 908 909 /* 910 * Get data to generate a TX_WRITE intent log record. 911 */ 912 static int 913 zvol_get_data(void *arg, lr_write_t *lr, char *buf, zio_t *zio) 914 { 915 zvol_state_t *zv = arg; 916 objset_t *os = zv->zv_objset; 917 uint64_t object = ZVOL_OBJ; 918 uint64_t offset = lr->lr_offset; 919 uint64_t size = lr->lr_length; /* length of user data */ 920 blkptr_t *bp = &lr->lr_blkptr; 921 dmu_buf_t *db; 922 zgd_t *zgd; 923 int error; 924 925 ASSERT(zio != NULL); 926 ASSERT(size != 0); 927 928 zgd = kmem_zalloc(sizeof (zgd_t), KM_SLEEP); 929 zgd->zgd_zilog = zv->zv_zilog; 930 zgd->zgd_rl = zfs_range_lock(&zv->zv_znode, offset, size, RL_READER); 931 932 /* 933 * Write records come in two flavors: immediate and indirect. 934 * For small writes it's cheaper to store the data with the 935 * log record (immediate); for large writes it's cheaper to 936 * sync the data and get a pointer to it (indirect) so that 937 * we don't have to write the data twice. 938 */ 939 if (buf != NULL) { /* immediate write */ 940 error = dmu_read(os, object, offset, size, buf, 941 DMU_READ_NO_PREFETCH); 942 } else { 943 size = zv->zv_volblocksize; 944 offset = P2ALIGN(offset, size); 945 error = dmu_buf_hold(os, object, offset, zgd, &db); 946 if (error == 0) { 947 zgd->zgd_db = db; 948 zgd->zgd_bp = bp; 949 950 ASSERT(db->db_offset == offset); 951 ASSERT(db->db_size == size); 952 953 error = dmu_sync(zio, lr->lr_common.lrc_txg, 954 zvol_get_done, zgd); 955 956 if (error == 0) 957 return (0); 958 } 959 } 960 961 zvol_get_done(zgd, error); 962 963 return (error); 964 } 965 966 /* 967 * zvol_log_write() handles synchronous writes using TX_WRITE ZIL transactions. 968 * 969 * We store data in the log buffers if it's small enough. 970 * Otherwise we will later flush the data out via dmu_sync(). 971 */ 972 ssize_t zvol_immediate_write_sz = 32768; 973 974 static void 975 zvol_log_write(zvol_state_t *zv, dmu_tx_t *tx, offset_t off, ssize_t resid, 976 boolean_t sync) 977 { 978 uint32_t blocksize = zv->zv_volblocksize; 979 zilog_t *zilog = zv->zv_zilog; 980 boolean_t slogging; 981 ssize_t immediate_write_sz; 982 983 if (zil_disable) 984 return; 985 986 if (zil_replaying(zilog, tx)) 987 return; 988 989 immediate_write_sz = (zilog->zl_logbias == ZFS_LOGBIAS_THROUGHPUT) 990 ? 0 : zvol_immediate_write_sz; 991 992 slogging = spa_has_slogs(zilog->zl_spa) && 993 (zilog->zl_logbias == ZFS_LOGBIAS_LATENCY); 994 995 while (resid) { 996 itx_t *itx; 997 lr_write_t *lr; 998 ssize_t len; 999 itx_wr_state_t write_state; 1000 1001 /* 1002 * Unlike zfs_log_write() we can be called with 1003 * upto DMU_MAX_ACCESS/2 (5MB) writes. 1004 */ 1005 if (blocksize > immediate_write_sz && !slogging && 1006 resid >= blocksize && off % blocksize == 0) { 1007 write_state = WR_INDIRECT; /* uses dmu_sync */ 1008 len = blocksize; 1009 } else if (sync) { 1010 write_state = WR_COPIED; 1011 len = MIN(ZIL_MAX_LOG_DATA, resid); 1012 } else { 1013 write_state = WR_NEED_COPY; 1014 len = MIN(ZIL_MAX_LOG_DATA, resid); 1015 } 1016 1017 itx = zil_itx_create(TX_WRITE, sizeof (*lr) + 1018 (write_state == WR_COPIED ? len : 0)); 1019 lr = (lr_write_t *)&itx->itx_lr; 1020 if (write_state == WR_COPIED && dmu_read(zv->zv_objset, 1021 ZVOL_OBJ, off, len, lr + 1, DMU_READ_NO_PREFETCH) != 0) { 1022 zil_itx_destroy(itx); 1023 itx = zil_itx_create(TX_WRITE, sizeof (*lr)); 1024 lr = (lr_write_t *)&itx->itx_lr; 1025 write_state = WR_NEED_COPY; 1026 } 1027 1028 itx->itx_wr_state = write_state; 1029 if (write_state == WR_NEED_COPY) 1030 itx->itx_sod += len; 1031 lr->lr_foid = ZVOL_OBJ; 1032 lr->lr_offset = off; 1033 lr->lr_length = len; 1034 lr->lr_blkoff = 0; 1035 BP_ZERO(&lr->lr_blkptr); 1036 1037 itx->itx_private = zv; 1038 itx->itx_sync = sync; 1039 1040 (void) zil_itx_assign(zilog, itx, tx); 1041 1042 off += len; 1043 resid -= len; 1044 } 1045 } 1046 1047 static int 1048 zvol_dumpio_vdev(vdev_t *vd, void *addr, uint64_t offset, uint64_t size, 1049 boolean_t doread, boolean_t isdump) 1050 { 1051 vdev_disk_t *dvd; 1052 int c; 1053 int numerrors = 0; 1054 1055 for (c = 0; c < vd->vdev_children; c++) { 1056 ASSERT(vd->vdev_ops == &vdev_mirror_ops || 1057 vd->vdev_ops == &vdev_replacing_ops || 1058 vd->vdev_ops == &vdev_spare_ops); 1059 int err = zvol_dumpio_vdev(vd->vdev_child[c], 1060 addr, offset, size, doread, isdump); 1061 if (err != 0) { 1062 numerrors++; 1063 } else if (doread) { 1064 break; 1065 } 1066 } 1067 1068 if (!vd->vdev_ops->vdev_op_leaf) 1069 return (numerrors < vd->vdev_children ? 0 : EIO); 1070 1071 if (doread && !vdev_readable(vd)) 1072 return (EIO); 1073 else if (!doread && !vdev_writeable(vd)) 1074 return (EIO); 1075 1076 dvd = vd->vdev_tsd; 1077 ASSERT3P(dvd, !=, NULL); 1078 offset += VDEV_LABEL_START_SIZE; 1079 1080 if (ddi_in_panic() || isdump) { 1081 ASSERT(!doread); 1082 if (doread) 1083 return (EIO); 1084 return (ldi_dump(dvd->vd_lh, addr, lbtodb(offset), 1085 lbtodb(size))); 1086 } else { 1087 return (vdev_disk_physio(dvd->vd_lh, addr, size, offset, 1088 doread ? B_READ : B_WRITE)); 1089 } 1090 } 1091 1092 static int 1093 zvol_dumpio(zvol_state_t *zv, void *addr, uint64_t offset, uint64_t size, 1094 boolean_t doread, boolean_t isdump) 1095 { 1096 vdev_t *vd; 1097 int error; 1098 zvol_extent_t *ze; 1099 spa_t *spa = dmu_objset_spa(zv->zv_objset); 1100 1101 /* Must be sector aligned, and not stradle a block boundary. */ 1102 if (P2PHASE(offset, DEV_BSIZE) || P2PHASE(size, DEV_BSIZE) || 1103 P2BOUNDARY(offset, size, zv->zv_volblocksize)) { 1104 return (EINVAL); 1105 } 1106 ASSERT(size <= zv->zv_volblocksize); 1107 1108 /* Locate the extent this belongs to */ 1109 ze = list_head(&zv->zv_extents); 1110 while (offset >= ze->ze_nblks * zv->zv_volblocksize) { 1111 offset -= ze->ze_nblks * zv->zv_volblocksize; 1112 ze = list_next(&zv->zv_extents, ze); 1113 } 1114 1115 if (!ddi_in_panic()) 1116 spa_config_enter(spa, SCL_STATE, FTAG, RW_READER); 1117 1118 vd = vdev_lookup_top(spa, DVA_GET_VDEV(&ze->ze_dva)); 1119 offset += DVA_GET_OFFSET(&ze->ze_dva); 1120 error = zvol_dumpio_vdev(vd, addr, offset, size, doread, isdump); 1121 1122 if (!ddi_in_panic()) 1123 spa_config_exit(spa, SCL_STATE, FTAG); 1124 1125 return (error); 1126 } 1127 1128 int 1129 zvol_strategy(buf_t *bp) 1130 { 1131 zvol_state_t *zv = ddi_get_soft_state(zvol_state, getminor(bp->b_edev)); 1132 uint64_t off, volsize; 1133 size_t resid; 1134 char *addr; 1135 objset_t *os; 1136 rl_t *rl; 1137 int error = 0; 1138 boolean_t doread = bp->b_flags & B_READ; 1139 boolean_t is_dump = zv->zv_flags & ZVOL_DUMPIFIED; 1140 boolean_t sync; 1141 1142 if (zv == NULL) { 1143 bioerror(bp, ENXIO); 1144 biodone(bp); 1145 return (0); 1146 } 1147 1148 if (getminor(bp->b_edev) == 0) { 1149 bioerror(bp, EINVAL); 1150 biodone(bp); 1151 return (0); 1152 } 1153 1154 if (!(bp->b_flags & B_READ) && (zv->zv_flags & ZVOL_RDONLY)) { 1155 bioerror(bp, EROFS); 1156 biodone(bp); 1157 return (0); 1158 } 1159 1160 off = ldbtob(bp->b_blkno); 1161 volsize = zv->zv_volsize; 1162 1163 os = zv->zv_objset; 1164 ASSERT(os != NULL); 1165 1166 bp_mapin(bp); 1167 addr = bp->b_un.b_addr; 1168 resid = bp->b_bcount; 1169 1170 if (resid > 0 && (off < 0 || off >= volsize)) { 1171 bioerror(bp, EIO); 1172 biodone(bp); 1173 return (0); 1174 } 1175 1176 sync = !(bp->b_flags & B_ASYNC) && !doread && !is_dump && 1177 !(zv->zv_flags & ZVOL_WCE) && !zil_disable; 1178 1179 /* 1180 * There must be no buffer changes when doing a dmu_sync() because 1181 * we can't change the data whilst calculating the checksum. 1182 */ 1183 rl = zfs_range_lock(&zv->zv_znode, off, resid, 1184 doread ? RL_READER : RL_WRITER); 1185 1186 while (resid != 0 && off < volsize) { 1187 size_t size = MIN(resid, zvol_maxphys); 1188 if (is_dump) { 1189 size = MIN(size, P2END(off, zv->zv_volblocksize) - off); 1190 error = zvol_dumpio(zv, addr, off, size, 1191 doread, B_FALSE); 1192 } else if (doread) { 1193 error = dmu_read(os, ZVOL_OBJ, off, size, addr, 1194 DMU_READ_PREFETCH); 1195 } else { 1196 dmu_tx_t *tx = dmu_tx_create(os); 1197 dmu_tx_hold_write(tx, ZVOL_OBJ, off, size); 1198 error = dmu_tx_assign(tx, TXG_WAIT); 1199 if (error) { 1200 dmu_tx_abort(tx); 1201 } else { 1202 dmu_write(os, ZVOL_OBJ, off, size, addr, tx); 1203 zvol_log_write(zv, tx, off, size, sync); 1204 dmu_tx_commit(tx); 1205 } 1206 } 1207 if (error) { 1208 /* convert checksum errors into IO errors */ 1209 if (error == ECKSUM) 1210 error = EIO; 1211 break; 1212 } 1213 off += size; 1214 addr += size; 1215 resid -= size; 1216 } 1217 zfs_range_unlock(rl); 1218 1219 if ((bp->b_resid = resid) == bp->b_bcount) 1220 bioerror(bp, off > volsize ? EINVAL : error); 1221 1222 if (sync) 1223 zil_commit(zv->zv_zilog, UINT64_MAX, ZVOL_OBJ); 1224 biodone(bp); 1225 1226 return (0); 1227 } 1228 1229 /* 1230 * Set the buffer count to the zvol maximum transfer. 1231 * Using our own routine instead of the default minphys() 1232 * means that for larger writes we write bigger buffers on X86 1233 * (128K instead of 56K) and flush the disk write cache less often 1234 * (every zvol_maxphys - currently 1MB) instead of minphys (currently 1235 * 56K on X86 and 128K on sparc). 1236 */ 1237 void 1238 zvol_minphys(struct buf *bp) 1239 { 1240 if (bp->b_bcount > zvol_maxphys) 1241 bp->b_bcount = zvol_maxphys; 1242 } 1243 1244 int 1245 zvol_dump(dev_t dev, caddr_t addr, daddr_t blkno, int nblocks) 1246 { 1247 minor_t minor = getminor(dev); 1248 zvol_state_t *zv; 1249 int error = 0; 1250 uint64_t size; 1251 uint64_t boff; 1252 uint64_t resid; 1253 1254 if (minor == 0) /* This is the control device */ 1255 return (ENXIO); 1256 1257 zv = ddi_get_soft_state(zvol_state, minor); 1258 if (zv == NULL) 1259 return (ENXIO); 1260 1261 boff = ldbtob(blkno); 1262 resid = ldbtob(nblocks); 1263 1264 VERIFY3U(boff + resid, <=, zv->zv_volsize); 1265 1266 while (resid) { 1267 size = MIN(resid, P2END(boff, zv->zv_volblocksize) - boff); 1268 error = zvol_dumpio(zv, addr, boff, size, B_FALSE, B_TRUE); 1269 if (error) 1270 break; 1271 boff += size; 1272 addr += size; 1273 resid -= size; 1274 } 1275 1276 return (error); 1277 } 1278 1279 /*ARGSUSED*/ 1280 int 1281 zvol_read(dev_t dev, uio_t *uio, cred_t *cr) 1282 { 1283 minor_t minor = getminor(dev); 1284 zvol_state_t *zv; 1285 uint64_t volsize; 1286 rl_t *rl; 1287 int error = 0; 1288 1289 if (minor == 0) /* This is the control device */ 1290 return (ENXIO); 1291 1292 zv = ddi_get_soft_state(zvol_state, minor); 1293 if (zv == NULL) 1294 return (ENXIO); 1295 1296 volsize = zv->zv_volsize; 1297 if (uio->uio_resid > 0 && 1298 (uio->uio_loffset < 0 || uio->uio_loffset >= volsize)) 1299 return (EIO); 1300 1301 if (zv->zv_flags & ZVOL_DUMPIFIED) { 1302 error = physio(zvol_strategy, NULL, dev, B_READ, 1303 zvol_minphys, uio); 1304 return (error); 1305 } 1306 1307 rl = zfs_range_lock(&zv->zv_znode, uio->uio_loffset, uio->uio_resid, 1308 RL_READER); 1309 while (uio->uio_resid > 0 && uio->uio_loffset < volsize) { 1310 uint64_t bytes = MIN(uio->uio_resid, DMU_MAX_ACCESS >> 1); 1311 1312 /* don't read past the end */ 1313 if (bytes > volsize - uio->uio_loffset) 1314 bytes = volsize - uio->uio_loffset; 1315 1316 error = dmu_read_uio(zv->zv_objset, ZVOL_OBJ, uio, bytes); 1317 if (error) { 1318 /* convert checksum errors into IO errors */ 1319 if (error == ECKSUM) 1320 error = EIO; 1321 break; 1322 } 1323 } 1324 zfs_range_unlock(rl); 1325 return (error); 1326 } 1327 1328 /*ARGSUSED*/ 1329 int 1330 zvol_write(dev_t dev, uio_t *uio, cred_t *cr) 1331 { 1332 minor_t minor = getminor(dev); 1333 zvol_state_t *zv; 1334 uint64_t volsize; 1335 rl_t *rl; 1336 int error = 0; 1337 boolean_t sync; 1338 1339 if (minor == 0) /* This is the control device */ 1340 return (ENXIO); 1341 1342 zv = ddi_get_soft_state(zvol_state, minor); 1343 if (zv == NULL) 1344 return (ENXIO); 1345 1346 volsize = zv->zv_volsize; 1347 if (uio->uio_resid > 0 && 1348 (uio->uio_loffset < 0 || uio->uio_loffset >= volsize)) 1349 return (EIO); 1350 1351 if (zv->zv_flags & ZVOL_DUMPIFIED) { 1352 error = physio(zvol_strategy, NULL, dev, B_WRITE, 1353 zvol_minphys, uio); 1354 return (error); 1355 } 1356 1357 sync = !(zv->zv_flags & ZVOL_WCE) && !zil_disable; 1358 1359 rl = zfs_range_lock(&zv->zv_znode, uio->uio_loffset, uio->uio_resid, 1360 RL_WRITER); 1361 while (uio->uio_resid > 0 && uio->uio_loffset < volsize) { 1362 uint64_t bytes = MIN(uio->uio_resid, DMU_MAX_ACCESS >> 1); 1363 uint64_t off = uio->uio_loffset; 1364 dmu_tx_t *tx = dmu_tx_create(zv->zv_objset); 1365 1366 if (bytes > volsize - off) /* don't write past the end */ 1367 bytes = volsize - off; 1368 1369 dmu_tx_hold_write(tx, ZVOL_OBJ, off, bytes); 1370 error = dmu_tx_assign(tx, TXG_WAIT); 1371 if (error) { 1372 dmu_tx_abort(tx); 1373 break; 1374 } 1375 error = dmu_write_uio(zv->zv_objset, ZVOL_OBJ, uio, bytes, tx); 1376 if (error == 0) 1377 zvol_log_write(zv, tx, off, bytes, sync); 1378 dmu_tx_commit(tx); 1379 1380 if (error) 1381 break; 1382 } 1383 zfs_range_unlock(rl); 1384 if (sync) 1385 zil_commit(zv->zv_zilog, UINT64_MAX, ZVOL_OBJ); 1386 return (error); 1387 } 1388 1389 int 1390 zvol_getefi(void *arg, int flag, uint64_t vs, uint8_t bs) 1391 { 1392 struct uuid uuid = EFI_RESERVED; 1393 efi_gpe_t gpe = { 0 }; 1394 uint32_t crc; 1395 dk_efi_t efi; 1396 int length; 1397 char *ptr; 1398 1399 if (ddi_copyin(arg, &efi, sizeof (dk_efi_t), flag)) 1400 return (EFAULT); 1401 ptr = (char *)(uintptr_t)efi.dki_data_64; 1402 length = efi.dki_length; 1403 /* 1404 * Some clients may attempt to request a PMBR for the 1405 * zvol. Currently this interface will return EINVAL to 1406 * such requests. These requests could be supported by 1407 * adding a check for lba == 0 and consing up an appropriate 1408 * PMBR. 1409 */ 1410 if (efi.dki_lba < 1 || efi.dki_lba > 2 || length <= 0) 1411 return (EINVAL); 1412 1413 gpe.efi_gpe_StartingLBA = LE_64(34ULL); 1414 gpe.efi_gpe_EndingLBA = LE_64((vs >> bs) - 1); 1415 UUID_LE_CONVERT(gpe.efi_gpe_PartitionTypeGUID, uuid); 1416 1417 if (efi.dki_lba == 1) { 1418 efi_gpt_t gpt = { 0 }; 1419 1420 gpt.efi_gpt_Signature = LE_64(EFI_SIGNATURE); 1421 gpt.efi_gpt_Revision = LE_32(EFI_VERSION_CURRENT); 1422 gpt.efi_gpt_HeaderSize = LE_32(sizeof (gpt)); 1423 gpt.efi_gpt_MyLBA = LE_64(1ULL); 1424 gpt.efi_gpt_FirstUsableLBA = LE_64(34ULL); 1425 gpt.efi_gpt_LastUsableLBA = LE_64((vs >> bs) - 1); 1426 gpt.efi_gpt_PartitionEntryLBA = LE_64(2ULL); 1427 gpt.efi_gpt_NumberOfPartitionEntries = LE_32(1); 1428 gpt.efi_gpt_SizeOfPartitionEntry = 1429 LE_32(sizeof (efi_gpe_t)); 1430 CRC32(crc, &gpe, sizeof (gpe), -1U, crc32_table); 1431 gpt.efi_gpt_PartitionEntryArrayCRC32 = LE_32(~crc); 1432 CRC32(crc, &gpt, sizeof (gpt), -1U, crc32_table); 1433 gpt.efi_gpt_HeaderCRC32 = LE_32(~crc); 1434 if (ddi_copyout(&gpt, ptr, MIN(sizeof (gpt), length), 1435 flag)) 1436 return (EFAULT); 1437 ptr += sizeof (gpt); 1438 length -= sizeof (gpt); 1439 } 1440 if (length > 0 && ddi_copyout(&gpe, ptr, MIN(sizeof (gpe), 1441 length), flag)) 1442 return (EFAULT); 1443 return (0); 1444 } 1445 1446 /* 1447 * Dirtbag ioctls to support mkfs(1M) for UFS filesystems. See dkio(7I). 1448 */ 1449 /*ARGSUSED*/ 1450 int 1451 zvol_ioctl(dev_t dev, int cmd, intptr_t arg, int flag, cred_t *cr, int *rvalp) 1452 { 1453 zvol_state_t *zv; 1454 struct dk_cinfo dki; 1455 struct dk_minfo dkm; 1456 struct dk_callback *dkc; 1457 int error = 0; 1458 rl_t *rl; 1459 1460 mutex_enter(&zvol_state_lock); 1461 1462 zv = ddi_get_soft_state(zvol_state, getminor(dev)); 1463 1464 if (zv == NULL) { 1465 mutex_exit(&zvol_state_lock); 1466 return (ENXIO); 1467 } 1468 ASSERT(zv->zv_total_opens > 0); 1469 1470 switch (cmd) { 1471 1472 case DKIOCINFO: 1473 bzero(&dki, sizeof (dki)); 1474 (void) strcpy(dki.dki_cname, "zvol"); 1475 (void) strcpy(dki.dki_dname, "zvol"); 1476 dki.dki_ctype = DKC_UNKNOWN; 1477 dki.dki_unit = getminor(dev); 1478 dki.dki_maxtransfer = 1 << (SPA_MAXBLOCKSHIFT - zv->zv_min_bs); 1479 mutex_exit(&zvol_state_lock); 1480 if (ddi_copyout(&dki, (void *)arg, sizeof (dki), flag)) 1481 error = EFAULT; 1482 return (error); 1483 1484 case DKIOCGMEDIAINFO: 1485 bzero(&dkm, sizeof (dkm)); 1486 dkm.dki_lbsize = 1U << zv->zv_min_bs; 1487 dkm.dki_capacity = zv->zv_volsize >> zv->zv_min_bs; 1488 dkm.dki_media_type = DK_UNKNOWN; 1489 mutex_exit(&zvol_state_lock); 1490 if (ddi_copyout(&dkm, (void *)arg, sizeof (dkm), flag)) 1491 error = EFAULT; 1492 return (error); 1493 1494 case DKIOCGETEFI: 1495 { 1496 uint64_t vs = zv->zv_volsize; 1497 uint8_t bs = zv->zv_min_bs; 1498 1499 mutex_exit(&zvol_state_lock); 1500 error = zvol_getefi((void *)arg, flag, vs, bs); 1501 return (error); 1502 } 1503 1504 case DKIOCFLUSHWRITECACHE: 1505 dkc = (struct dk_callback *)arg; 1506 mutex_exit(&zvol_state_lock); 1507 zil_commit(zv->zv_zilog, UINT64_MAX, ZVOL_OBJ); 1508 if ((flag & FKIOCTL) && dkc != NULL && dkc->dkc_callback) { 1509 (*dkc->dkc_callback)(dkc->dkc_cookie, error); 1510 error = 0; 1511 } 1512 return (error); 1513 1514 case DKIOCGETWCE: 1515 { 1516 int wce = (zv->zv_flags & ZVOL_WCE) ? 1 : 0; 1517 if (ddi_copyout(&wce, (void *)arg, sizeof (int), 1518 flag)) 1519 error = EFAULT; 1520 break; 1521 } 1522 case DKIOCSETWCE: 1523 { 1524 int wce; 1525 if (ddi_copyin((void *)arg, &wce, sizeof (int), 1526 flag)) { 1527 error = EFAULT; 1528 break; 1529 } 1530 if (wce) { 1531 zv->zv_flags |= ZVOL_WCE; 1532 mutex_exit(&zvol_state_lock); 1533 } else { 1534 zv->zv_flags &= ~ZVOL_WCE; 1535 mutex_exit(&zvol_state_lock); 1536 zil_commit(zv->zv_zilog, UINT64_MAX, ZVOL_OBJ); 1537 } 1538 return (0); 1539 } 1540 1541 case DKIOCGGEOM: 1542 case DKIOCGVTOC: 1543 /* 1544 * commands using these (like prtvtoc) expect ENOTSUP 1545 * since we're emulating an EFI label 1546 */ 1547 error = ENOTSUP; 1548 break; 1549 1550 case DKIOCDUMPINIT: 1551 rl = zfs_range_lock(&zv->zv_znode, 0, zv->zv_volsize, 1552 RL_WRITER); 1553 error = zvol_dumpify(zv); 1554 zfs_range_unlock(rl); 1555 break; 1556 1557 case DKIOCDUMPFINI: 1558 if (!(zv->zv_flags & ZVOL_DUMPIFIED)) 1559 break; 1560 rl = zfs_range_lock(&zv->zv_znode, 0, zv->zv_volsize, 1561 RL_WRITER); 1562 error = zvol_dump_fini(zv); 1563 zfs_range_unlock(rl); 1564 break; 1565 1566 default: 1567 error = ENOTTY; 1568 break; 1569 1570 } 1571 mutex_exit(&zvol_state_lock); 1572 return (error); 1573 } 1574 1575 int 1576 zvol_busy(void) 1577 { 1578 return (zvol_minors != 0); 1579 } 1580 1581 void 1582 zvol_init(void) 1583 { 1584 VERIFY(ddi_soft_state_init(&zvol_state, sizeof (zvol_state_t), 1) == 0); 1585 mutex_init(&zvol_state_lock, NULL, MUTEX_DEFAULT, NULL); 1586 } 1587 1588 void 1589 zvol_fini(void) 1590 { 1591 mutex_destroy(&zvol_state_lock); 1592 ddi_soft_state_fini(&zvol_state); 1593 } 1594 1595 static int 1596 zvol_dump_init(zvol_state_t *zv, boolean_t resize) 1597 { 1598 dmu_tx_t *tx; 1599 int error = 0; 1600 objset_t *os = zv->zv_objset; 1601 nvlist_t *nv = NULL; 1602 uint64_t version = spa_version(dmu_objset_spa(zv->zv_objset)); 1603 1604 ASSERT(MUTEX_HELD(&zvol_state_lock)); 1605 error = dmu_free_long_range(zv->zv_objset, ZVOL_OBJ, 0, 1606 DMU_OBJECT_END); 1607 /* wait for dmu_free_long_range to actually free the blocks */ 1608 txg_wait_synced(dmu_objset_pool(zv->zv_objset), 0); 1609 1610 tx = dmu_tx_create(os); 1611 dmu_tx_hold_zap(tx, ZVOL_ZAP_OBJ, TRUE, NULL); 1612 dmu_tx_hold_bonus(tx, ZVOL_OBJ); 1613 error = dmu_tx_assign(tx, TXG_WAIT); 1614 if (error) { 1615 dmu_tx_abort(tx); 1616 return (error); 1617 } 1618 1619 /* 1620 * If we are resizing the dump device then we only need to 1621 * update the refreservation to match the newly updated 1622 * zvolsize. Otherwise, we save off the original state of the 1623 * zvol so that we can restore them if the zvol is ever undumpified. 1624 */ 1625 if (resize) { 1626 error = zap_update(os, ZVOL_ZAP_OBJ, 1627 zfs_prop_to_name(ZFS_PROP_REFRESERVATION), 8, 1, 1628 &zv->zv_volsize, tx); 1629 } else { 1630 uint64_t checksum, compress, refresrv, vbs, dedup; 1631 1632 error = dsl_prop_get_integer(zv->zv_name, 1633 zfs_prop_to_name(ZFS_PROP_COMPRESSION), &compress, NULL); 1634 error = error ? error : dsl_prop_get_integer(zv->zv_name, 1635 zfs_prop_to_name(ZFS_PROP_CHECKSUM), &checksum, NULL); 1636 error = error ? error : dsl_prop_get_integer(zv->zv_name, 1637 zfs_prop_to_name(ZFS_PROP_REFRESERVATION), &refresrv, NULL); 1638 error = error ? error : dsl_prop_get_integer(zv->zv_name, 1639 zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE), &vbs, NULL); 1640 if (version >= SPA_VERSION_DEDUP) { 1641 error = error ? error : 1642 dsl_prop_get_integer(zv->zv_name, 1643 zfs_prop_to_name(ZFS_PROP_DEDUP), &dedup, NULL); 1644 } 1645 1646 error = error ? error : zap_update(os, ZVOL_ZAP_OBJ, 1647 zfs_prop_to_name(ZFS_PROP_COMPRESSION), 8, 1, 1648 &compress, tx); 1649 error = error ? error : zap_update(os, ZVOL_ZAP_OBJ, 1650 zfs_prop_to_name(ZFS_PROP_CHECKSUM), 8, 1, &checksum, tx); 1651 error = error ? error : zap_update(os, ZVOL_ZAP_OBJ, 1652 zfs_prop_to_name(ZFS_PROP_REFRESERVATION), 8, 1, 1653 &refresrv, tx); 1654 error = error ? error : zap_update(os, ZVOL_ZAP_OBJ, 1655 zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE), 8, 1, 1656 &vbs, tx); 1657 error = error ? error : dmu_object_set_blocksize( 1658 os, ZVOL_OBJ, SPA_MAXBLOCKSIZE, 0, tx); 1659 if (version >= SPA_VERSION_DEDUP) { 1660 error = error ? error : zap_update(os, ZVOL_ZAP_OBJ, 1661 zfs_prop_to_name(ZFS_PROP_DEDUP), 8, 1, 1662 &dedup, tx); 1663 } 1664 if (error == 0) 1665 zv->zv_volblocksize = SPA_MAXBLOCKSIZE; 1666 } 1667 dmu_tx_commit(tx); 1668 1669 /* 1670 * We only need update the zvol's property if we are initializing 1671 * the dump area for the first time. 1672 */ 1673 if (!resize) { 1674 VERIFY(nvlist_alloc(&nv, NV_UNIQUE_NAME, KM_SLEEP) == 0); 1675 VERIFY(nvlist_add_uint64(nv, 1676 zfs_prop_to_name(ZFS_PROP_REFRESERVATION), 0) == 0); 1677 VERIFY(nvlist_add_uint64(nv, 1678 zfs_prop_to_name(ZFS_PROP_COMPRESSION), 1679 ZIO_COMPRESS_OFF) == 0); 1680 VERIFY(nvlist_add_uint64(nv, 1681 zfs_prop_to_name(ZFS_PROP_CHECKSUM), 1682 ZIO_CHECKSUM_OFF) == 0); 1683 if (version >= SPA_VERSION_DEDUP) { 1684 VERIFY(nvlist_add_uint64(nv, 1685 zfs_prop_to_name(ZFS_PROP_DEDUP), 1686 ZIO_CHECKSUM_OFF) == 0); 1687 } 1688 1689 error = zfs_set_prop_nvlist(zv->zv_name, ZPROP_SRC_LOCAL, 1690 nv, NULL); 1691 nvlist_free(nv); 1692 1693 if (error) 1694 return (error); 1695 } 1696 1697 /* Allocate the space for the dump */ 1698 error = zvol_prealloc(zv); 1699 return (error); 1700 } 1701 1702 static int 1703 zvol_dumpify(zvol_state_t *zv) 1704 { 1705 int error = 0; 1706 uint64_t dumpsize = 0; 1707 dmu_tx_t *tx; 1708 objset_t *os = zv->zv_objset; 1709 1710 if (zv->zv_flags & ZVOL_RDONLY) 1711 return (EROFS); 1712 1713 if (zap_lookup(zv->zv_objset, ZVOL_ZAP_OBJ, ZVOL_DUMPSIZE, 1714 8, 1, &dumpsize) != 0 || dumpsize != zv->zv_volsize) { 1715 boolean_t resize = (dumpsize > 0) ? B_TRUE : B_FALSE; 1716 1717 if ((error = zvol_dump_init(zv, resize)) != 0) { 1718 (void) zvol_dump_fini(zv); 1719 return (error); 1720 } 1721 } 1722 1723 /* 1724 * Build up our lba mapping. 1725 */ 1726 error = zvol_get_lbas(zv); 1727 if (error) { 1728 (void) zvol_dump_fini(zv); 1729 return (error); 1730 } 1731 1732 tx = dmu_tx_create(os); 1733 dmu_tx_hold_zap(tx, ZVOL_ZAP_OBJ, TRUE, NULL); 1734 error = dmu_tx_assign(tx, TXG_WAIT); 1735 if (error) { 1736 dmu_tx_abort(tx); 1737 (void) zvol_dump_fini(zv); 1738 return (error); 1739 } 1740 1741 zv->zv_flags |= ZVOL_DUMPIFIED; 1742 error = zap_update(os, ZVOL_ZAP_OBJ, ZVOL_DUMPSIZE, 8, 1, 1743 &zv->zv_volsize, tx); 1744 dmu_tx_commit(tx); 1745 1746 if (error) { 1747 (void) zvol_dump_fini(zv); 1748 return (error); 1749 } 1750 1751 txg_wait_synced(dmu_objset_pool(os), 0); 1752 return (0); 1753 } 1754 1755 static int 1756 zvol_dump_fini(zvol_state_t *zv) 1757 { 1758 dmu_tx_t *tx; 1759 objset_t *os = zv->zv_objset; 1760 nvlist_t *nv; 1761 int error = 0; 1762 uint64_t checksum, compress, refresrv, vbs, dedup; 1763 uint64_t version = spa_version(dmu_objset_spa(zv->zv_objset)); 1764 1765 /* 1766 * Attempt to restore the zvol back to its pre-dumpified state. 1767 * This is a best-effort attempt as it's possible that not all 1768 * of these properties were initialized during the dumpify process 1769 * (i.e. error during zvol_dump_init). 1770 */ 1771 1772 tx = dmu_tx_create(os); 1773 dmu_tx_hold_zap(tx, ZVOL_ZAP_OBJ, TRUE, NULL); 1774 error = dmu_tx_assign(tx, TXG_WAIT); 1775 if (error) { 1776 dmu_tx_abort(tx); 1777 return (error); 1778 } 1779 (void) zap_remove(os, ZVOL_ZAP_OBJ, ZVOL_DUMPSIZE, tx); 1780 dmu_tx_commit(tx); 1781 1782 (void) zap_lookup(zv->zv_objset, ZVOL_ZAP_OBJ, 1783 zfs_prop_to_name(ZFS_PROP_CHECKSUM), 8, 1, &checksum); 1784 (void) zap_lookup(zv->zv_objset, ZVOL_ZAP_OBJ, 1785 zfs_prop_to_name(ZFS_PROP_COMPRESSION), 8, 1, &compress); 1786 (void) zap_lookup(zv->zv_objset, ZVOL_ZAP_OBJ, 1787 zfs_prop_to_name(ZFS_PROP_REFRESERVATION), 8, 1, &refresrv); 1788 (void) zap_lookup(zv->zv_objset, ZVOL_ZAP_OBJ, 1789 zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE), 8, 1, &vbs); 1790 1791 VERIFY(nvlist_alloc(&nv, NV_UNIQUE_NAME, KM_SLEEP) == 0); 1792 (void) nvlist_add_uint64(nv, 1793 zfs_prop_to_name(ZFS_PROP_CHECKSUM), checksum); 1794 (void) nvlist_add_uint64(nv, 1795 zfs_prop_to_name(ZFS_PROP_COMPRESSION), compress); 1796 (void) nvlist_add_uint64(nv, 1797 zfs_prop_to_name(ZFS_PROP_REFRESERVATION), refresrv); 1798 if (version >= SPA_VERSION_DEDUP && 1799 zap_lookup(zv->zv_objset, ZVOL_ZAP_OBJ, 1800 zfs_prop_to_name(ZFS_PROP_DEDUP), 8, 1, &dedup) == 0) { 1801 (void) nvlist_add_uint64(nv, 1802 zfs_prop_to_name(ZFS_PROP_DEDUP), dedup); 1803 } 1804 (void) zfs_set_prop_nvlist(zv->zv_name, ZPROP_SRC_LOCAL, 1805 nv, NULL); 1806 nvlist_free(nv); 1807 1808 zvol_free_extents(zv); 1809 zv->zv_flags &= ~ZVOL_DUMPIFIED; 1810 (void) dmu_free_long_range(os, ZVOL_OBJ, 0, DMU_OBJECT_END); 1811 /* wait for dmu_free_long_range to actually free the blocks */ 1812 txg_wait_synced(dmu_objset_pool(zv->zv_objset), 0); 1813 tx = dmu_tx_create(os); 1814 dmu_tx_hold_bonus(tx, ZVOL_OBJ); 1815 error = dmu_tx_assign(tx, TXG_WAIT); 1816 if (error) { 1817 dmu_tx_abort(tx); 1818 return (error); 1819 } 1820 if (dmu_object_set_blocksize(os, ZVOL_OBJ, vbs, 0, tx) == 0) 1821 zv->zv_volblocksize = vbs; 1822 dmu_tx_commit(tx); 1823 1824 return (0); 1825 } 1826