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 2009 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 ZFS-specific devfsadm link generator. 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 84 #define ZVOL_DUMPSIZE "dumpsize" 85 86 /* 87 * This lock protects the zvol_state structure from being modified 88 * while it's being used, e.g. an open that comes in before a create 89 * finishes. It also protects temporary opens of the dataset so that, 90 * e.g., an open doesn't get a spurious EBUSY. 91 */ 92 static kmutex_t zvol_state_lock; 93 static uint32_t zvol_minors; 94 95 typedef struct zvol_extent { 96 list_node_t ze_node; 97 dva_t ze_dva; /* dva associated with this extent */ 98 uint64_t ze_nblks; /* number of blocks in extent */ 99 } zvol_extent_t; 100 101 /* 102 * The in-core state of each volume. 103 */ 104 typedef struct zvol_state { 105 char zv_name[MAXPATHLEN]; /* pool/dd name */ 106 uint64_t zv_volsize; /* amount of space we advertise */ 107 uint64_t zv_volblocksize; /* volume block size */ 108 minor_t zv_minor; /* minor number */ 109 uint8_t zv_min_bs; /* minimum addressable block shift */ 110 uint8_t zv_flags; /* readonly, dumpified, etc. */ 111 objset_t *zv_objset; /* objset handle */ 112 uint32_t zv_mode; /* DS_MODE_* flags at open time */ 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 *, nvlist_t *); 134 static int zvol_get_data(void *arg, lr_write_t *lr, char *buf, zio_t *zio); 135 static int zvol_dumpify(zvol_state_t *zv); 136 static int zvol_dump_fini(zvol_state_t *zv); 137 static int zvol_dump_init(zvol_state_t *zv, boolean_t resize); 138 139 static void 140 zvol_size_changed(zvol_state_t *zv, major_t maj) 141 { 142 dev_t dev = makedevice(maj, zv->zv_minor); 143 144 VERIFY(ddi_prop_update_int64(dev, zfs_dip, 145 "Size", zv->zv_volsize) == DDI_SUCCESS); 146 VERIFY(ddi_prop_update_int64(dev, zfs_dip, 147 "Nblocks", lbtodb(zv->zv_volsize)) == DDI_SUCCESS); 148 149 /* Notify specfs to invalidate the cached size */ 150 spec_size_invalidate(dev, VBLK); 151 spec_size_invalidate(dev, VCHR); 152 } 153 154 int 155 zvol_check_volsize(uint64_t volsize, uint64_t blocksize) 156 { 157 if (volsize == 0) 158 return (EINVAL); 159 160 if (volsize % blocksize != 0) 161 return (EINVAL); 162 163 #ifdef _ILP32 164 if (volsize - 1 > SPEC_MAXOFFSET_T) 165 return (EOVERFLOW); 166 #endif 167 return (0); 168 } 169 170 int 171 zvol_check_volblocksize(uint64_t volblocksize) 172 { 173 if (volblocksize < SPA_MINBLOCKSIZE || 174 volblocksize > SPA_MAXBLOCKSIZE || 175 !ISP2(volblocksize)) 176 return (EDOM); 177 178 return (0); 179 } 180 181 static void 182 zvol_readonly_changed_cb(void *arg, uint64_t newval) 183 { 184 zvol_state_t *zv = arg; 185 186 if (newval) 187 zv->zv_flags |= ZVOL_RDONLY; 188 else 189 zv->zv_flags &= ~ZVOL_RDONLY; 190 } 191 192 int 193 zvol_get_stats(objset_t *os, nvlist_t *nv) 194 { 195 int error; 196 dmu_object_info_t doi; 197 uint64_t val; 198 199 200 error = zap_lookup(os, ZVOL_ZAP_OBJ, "size", 8, 1, &val); 201 if (error) 202 return (error); 203 204 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_VOLSIZE, val); 205 206 error = dmu_object_info(os, ZVOL_OBJ, &doi); 207 208 if (error == 0) { 209 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_VOLBLOCKSIZE, 210 doi.doi_data_block_size); 211 } 212 213 return (error); 214 } 215 216 /* 217 * Find a free minor number. 218 */ 219 static minor_t 220 zvol_minor_alloc(void) 221 { 222 minor_t minor; 223 224 ASSERT(MUTEX_HELD(&zvol_state_lock)); 225 226 for (minor = 1; minor <= ZVOL_MAX_MINOR; minor++) 227 if (ddi_get_soft_state(zvol_state, minor) == NULL) 228 return (minor); 229 230 return (0); 231 } 232 233 static zvol_state_t * 234 zvol_minor_lookup(const char *name) 235 { 236 minor_t minor; 237 zvol_state_t *zv; 238 239 ASSERT(MUTEX_HELD(&zvol_state_lock)); 240 241 for (minor = 1; minor <= ZVOL_MAX_MINOR; minor++) { 242 zv = ddi_get_soft_state(zvol_state, minor); 243 if (zv == NULL) 244 continue; 245 if (strcmp(zv->zv_name, name) == 0) 246 break; 247 } 248 249 return (zv); 250 } 251 252 /* extent mapping arg */ 253 struct maparg { 254 zvol_state_t *ma_zv; 255 uint64_t ma_blks; 256 }; 257 258 /*ARGSUSED*/ 259 static int 260 zvol_map_block(spa_t *spa, blkptr_t *bp, const zbookmark_t *zb, 261 const dnode_phys_t *dnp, void *arg) 262 { 263 struct maparg *ma = arg; 264 zvol_extent_t *ze; 265 int bs = ma->ma_zv->zv_volblocksize; 266 267 if (bp == NULL || zb->zb_object != ZVOL_OBJ || zb->zb_level != 0) 268 return (0); 269 270 VERIFY3U(ma->ma_blks, ==, zb->zb_blkid); 271 ma->ma_blks++; 272 273 /* Abort immediately if we have encountered gang blocks */ 274 if (BP_IS_GANG(bp)) 275 return (EFRAGS); 276 277 /* 278 * See if the block is at the end of the previous extent. 279 */ 280 ze = list_tail(&ma->ma_zv->zv_extents); 281 if (ze && 282 DVA_GET_VDEV(BP_IDENTITY(bp)) == DVA_GET_VDEV(&ze->ze_dva) && 283 DVA_GET_OFFSET(BP_IDENTITY(bp)) == 284 DVA_GET_OFFSET(&ze->ze_dva) + ze->ze_nblks * bs) { 285 ze->ze_nblks++; 286 return (0); 287 } 288 289 dprintf_bp(bp, "%s", "next blkptr:"); 290 291 /* start a new extent */ 292 ze = kmem_zalloc(sizeof (zvol_extent_t), KM_SLEEP); 293 ze->ze_dva = bp->blk_dva[0]; /* structure assignment */ 294 ze->ze_nblks = 1; 295 list_insert_tail(&ma->ma_zv->zv_extents, ze); 296 return (0); 297 } 298 299 static void 300 zvol_free_extents(zvol_state_t *zv) 301 { 302 zvol_extent_t *ze; 303 304 while (ze = list_head(&zv->zv_extents)) { 305 list_remove(&zv->zv_extents, ze); 306 kmem_free(ze, sizeof (zvol_extent_t)); 307 } 308 } 309 310 static int 311 zvol_get_lbas(zvol_state_t *zv) 312 { 313 struct maparg ma; 314 int err; 315 316 ma.ma_zv = zv; 317 ma.ma_blks = 0; 318 zvol_free_extents(zv); 319 320 err = traverse_dataset(dmu_objset_ds(zv->zv_objset), 0, 321 TRAVERSE_PRE | TRAVERSE_PREFETCH_METADATA, zvol_map_block, &ma); 322 if (err || ma.ma_blks != (zv->zv_volsize / zv->zv_volblocksize)) { 323 zvol_free_extents(zv); 324 return (err ? err : EIO); 325 } 326 327 return (0); 328 } 329 330 /* ARGSUSED */ 331 void 332 zvol_create_cb(objset_t *os, void *arg, cred_t *cr, dmu_tx_t *tx) 333 { 334 zfs_creat_t *zct = arg; 335 nvlist_t *nvprops = zct->zct_props; 336 int error; 337 uint64_t volblocksize, volsize; 338 339 VERIFY(nvlist_lookup_uint64(nvprops, 340 zfs_prop_to_name(ZFS_PROP_VOLSIZE), &volsize) == 0); 341 if (nvlist_lookup_uint64(nvprops, 342 zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE), &volblocksize) != 0) 343 volblocksize = zfs_prop_default_numeric(ZFS_PROP_VOLBLOCKSIZE); 344 345 /* 346 * These properties must be removed from the list so the generic 347 * property setting step won't apply to them. 348 */ 349 VERIFY(nvlist_remove_all(nvprops, 350 zfs_prop_to_name(ZFS_PROP_VOLSIZE)) == 0); 351 (void) nvlist_remove_all(nvprops, 352 zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE)); 353 354 error = dmu_object_claim(os, ZVOL_OBJ, DMU_OT_ZVOL, volblocksize, 355 DMU_OT_NONE, 0, tx); 356 ASSERT(error == 0); 357 358 error = zap_create_claim(os, ZVOL_ZAP_OBJ, DMU_OT_ZVOL_PROP, 359 DMU_OT_NONE, 0, tx); 360 ASSERT(error == 0); 361 362 error = zap_update(os, ZVOL_ZAP_OBJ, "size", 8, 1, &volsize, tx); 363 ASSERT(error == 0); 364 } 365 366 /* 367 * Replay a TX_WRITE ZIL transaction that didn't get committed 368 * after a system failure 369 */ 370 static int 371 zvol_replay_write(zvol_state_t *zv, lr_write_t *lr, boolean_t byteswap) 372 { 373 objset_t *os = zv->zv_objset; 374 char *data = (char *)(lr + 1); /* data follows lr_write_t */ 375 uint64_t off = lr->lr_offset; 376 uint64_t len = lr->lr_length; 377 dmu_tx_t *tx; 378 int error; 379 380 if (byteswap) 381 byteswap_uint64_array(lr, sizeof (*lr)); 382 383 tx = dmu_tx_create(os); 384 dmu_tx_hold_write(tx, ZVOL_OBJ, off, len); 385 error = dmu_tx_assign(tx, TXG_WAIT); 386 if (error) { 387 dmu_tx_abort(tx); 388 } else { 389 dmu_write(os, ZVOL_OBJ, off, len, data, tx); 390 dmu_tx_commit(tx); 391 } 392 393 return (error); 394 } 395 396 /* ARGSUSED */ 397 static int 398 zvol_replay_err(zvol_state_t *zv, lr_t *lr, boolean_t byteswap) 399 { 400 return (ENOTSUP); 401 } 402 403 /* 404 * Callback vectors for replaying records. 405 * Only TX_WRITE is needed for zvol. 406 */ 407 zil_replay_func_t *zvol_replay_vector[TX_MAX_TYPE] = { 408 zvol_replay_err, /* 0 no such transaction type */ 409 zvol_replay_err, /* TX_CREATE */ 410 zvol_replay_err, /* TX_MKDIR */ 411 zvol_replay_err, /* TX_MKXATTR */ 412 zvol_replay_err, /* TX_SYMLINK */ 413 zvol_replay_err, /* TX_REMOVE */ 414 zvol_replay_err, /* TX_RMDIR */ 415 zvol_replay_err, /* TX_LINK */ 416 zvol_replay_err, /* TX_RENAME */ 417 zvol_replay_write, /* TX_WRITE */ 418 zvol_replay_err, /* TX_TRUNCATE */ 419 zvol_replay_err, /* TX_SETATTR */ 420 zvol_replay_err, /* TX_ACL */ 421 }; 422 423 /* 424 * Create a minor node (plus a whole lot more) for the specified volume. 425 */ 426 int 427 zvol_create_minor(const char *name, major_t maj) 428 { 429 zvol_state_t *zv; 430 objset_t *os; 431 dmu_object_info_t doi; 432 uint64_t volsize; 433 minor_t minor = 0; 434 struct pathname linkpath; 435 int ds_mode = DS_MODE_OWNER; 436 vnode_t *vp = NULL; 437 char *devpath; 438 char chrbuf[30], blkbuf[30]; 439 int error; 440 441 mutex_enter(&zvol_state_lock); 442 443 if ((zv = zvol_minor_lookup(name)) != NULL) { 444 mutex_exit(&zvol_state_lock); 445 return (EEXIST); 446 } 447 448 if (strchr(name, '@') != 0) 449 ds_mode |= DS_MODE_READONLY; 450 451 error = dmu_objset_open(name, DMU_OST_ZVOL, ds_mode, &os); 452 453 if (error) { 454 mutex_exit(&zvol_state_lock); 455 return (error); 456 } 457 458 error = zap_lookup(os, ZVOL_ZAP_OBJ, "size", 8, 1, &volsize); 459 460 if (error) { 461 dmu_objset_close(os); 462 mutex_exit(&zvol_state_lock); 463 return (error); 464 } 465 466 /* 467 * If there's an existing /dev/zvol symlink, try to use the 468 * same minor number we used last time. 469 */ 470 devpath = kmem_asprintf("%s%s", ZVOL_FULL_DEV_DIR, name); 471 error = lookupname(devpath, UIO_SYSSPACE, NO_FOLLOW, NULL, &vp); 472 strfree(devpath); 473 474 if (error == 0 && vp->v_type != VLNK) 475 error = EINVAL; 476 477 if (error == 0) { 478 pn_alloc(&linkpath); 479 error = pn_getsymlink(vp, &linkpath, kcred); 480 if (error == 0) { 481 char *ms = strstr(linkpath.pn_path, ZVOL_PSEUDO_DEV); 482 if (ms != NULL) { 483 ms += strlen(ZVOL_PSEUDO_DEV); 484 minor = stoi(&ms); 485 } 486 } 487 pn_free(&linkpath); 488 } 489 490 if (vp != NULL) 491 VN_RELE(vp); 492 493 /* 494 * If we found a minor but it's already in use, we must pick a new one. 495 */ 496 if (minor != 0 && ddi_get_soft_state(zvol_state, minor) != NULL) 497 minor = 0; 498 499 if (minor == 0) 500 minor = zvol_minor_alloc(); 501 502 if (minor == 0) { 503 dmu_objset_close(os); 504 mutex_exit(&zvol_state_lock); 505 return (ENXIO); 506 } 507 508 if (ddi_soft_state_zalloc(zvol_state, minor) != DDI_SUCCESS) { 509 dmu_objset_close(os); 510 mutex_exit(&zvol_state_lock); 511 return (EAGAIN); 512 } 513 514 (void) ddi_prop_update_string(minor, zfs_dip, ZVOL_PROP_NAME, 515 (char *)name); 516 517 (void) sprintf(chrbuf, "%uc,raw", minor); 518 519 if (ddi_create_minor_node(zfs_dip, chrbuf, S_IFCHR, 520 minor, DDI_PSEUDO, 0) == DDI_FAILURE) { 521 ddi_soft_state_free(zvol_state, minor); 522 dmu_objset_close(os); 523 mutex_exit(&zvol_state_lock); 524 return (EAGAIN); 525 } 526 527 (void) sprintf(blkbuf, "%uc", minor); 528 529 if (ddi_create_minor_node(zfs_dip, blkbuf, S_IFBLK, 530 minor, DDI_PSEUDO, 0) == DDI_FAILURE) { 531 ddi_remove_minor_node(zfs_dip, chrbuf); 532 ddi_soft_state_free(zvol_state, minor); 533 dmu_objset_close(os); 534 mutex_exit(&zvol_state_lock); 535 return (EAGAIN); 536 } 537 538 zv = ddi_get_soft_state(zvol_state, minor); 539 540 (void) strcpy(zv->zv_name, name); 541 zv->zv_min_bs = DEV_BSHIFT; 542 zv->zv_minor = minor; 543 zv->zv_volsize = volsize; 544 zv->zv_objset = os; 545 zv->zv_mode = ds_mode; 546 zv->zv_zilog = zil_open(os, zvol_get_data); 547 mutex_init(&zv->zv_znode.z_range_lock, NULL, MUTEX_DEFAULT, NULL); 548 avl_create(&zv->zv_znode.z_range_avl, zfs_range_compare, 549 sizeof (rl_t), offsetof(rl_t, r_node)); 550 list_create(&zv->zv_extents, sizeof (zvol_extent_t), 551 offsetof(zvol_extent_t, ze_node)); 552 /* get and cache the blocksize */ 553 error = dmu_object_info(os, ZVOL_OBJ, &doi); 554 ASSERT(error == 0); 555 zv->zv_volblocksize = doi.doi_data_block_size; 556 557 zil_replay(os, zv, zvol_replay_vector); 558 zvol_size_changed(zv, maj); 559 560 /* XXX this should handle the possible i/o error */ 561 VERIFY(dsl_prop_register(dmu_objset_ds(zv->zv_objset), 562 "readonly", zvol_readonly_changed_cb, zv) == 0); 563 564 zvol_minors++; 565 566 mutex_exit(&zvol_state_lock); 567 568 return (0); 569 } 570 571 /* 572 * Remove minor node for the specified volume. 573 */ 574 int 575 zvol_remove_minor(const char *name) 576 { 577 zvol_state_t *zv; 578 char namebuf[30]; 579 580 mutex_enter(&zvol_state_lock); 581 582 if ((zv = zvol_minor_lookup(name)) == NULL) { 583 mutex_exit(&zvol_state_lock); 584 return (ENXIO); 585 } 586 587 if (zv->zv_total_opens != 0) { 588 mutex_exit(&zvol_state_lock); 589 return (EBUSY); 590 } 591 592 (void) sprintf(namebuf, "%uc,raw", zv->zv_minor); 593 ddi_remove_minor_node(zfs_dip, namebuf); 594 595 (void) sprintf(namebuf, "%uc", zv->zv_minor); 596 ddi_remove_minor_node(zfs_dip, namebuf); 597 598 VERIFY(dsl_prop_unregister(dmu_objset_ds(zv->zv_objset), 599 "readonly", zvol_readonly_changed_cb, zv) == 0); 600 601 zil_close(zv->zv_zilog); 602 zv->zv_zilog = NULL; 603 dmu_objset_close(zv->zv_objset); 604 zv->zv_objset = NULL; 605 avl_destroy(&zv->zv_znode.z_range_avl); 606 mutex_destroy(&zv->zv_znode.z_range_lock); 607 608 ddi_soft_state_free(zvol_state, zv->zv_minor); 609 610 zvol_minors--; 611 612 mutex_exit(&zvol_state_lock); 613 614 return (0); 615 } 616 617 int 618 zvol_prealloc(zvol_state_t *zv) 619 { 620 objset_t *os = zv->zv_objset; 621 dmu_tx_t *tx; 622 uint64_t refd, avail, usedobjs, availobjs; 623 uint64_t resid = zv->zv_volsize; 624 uint64_t off = 0; 625 626 /* Check the space usage before attempting to allocate the space */ 627 dmu_objset_space(os, &refd, &avail, &usedobjs, &availobjs); 628 if (avail < zv->zv_volsize) 629 return (ENOSPC); 630 631 /* Free old extents if they exist */ 632 zvol_free_extents(zv); 633 634 while (resid != 0) { 635 int error; 636 uint64_t bytes = MIN(resid, SPA_MAXBLOCKSIZE); 637 638 tx = dmu_tx_create(os); 639 dmu_tx_hold_write(tx, ZVOL_OBJ, off, bytes); 640 error = dmu_tx_assign(tx, TXG_WAIT); 641 if (error) { 642 dmu_tx_abort(tx); 643 (void) dmu_free_long_range(os, ZVOL_OBJ, 0, off); 644 return (error); 645 } 646 dmu_prealloc(os, ZVOL_OBJ, off, bytes, tx); 647 dmu_tx_commit(tx); 648 off += bytes; 649 resid -= bytes; 650 } 651 txg_wait_synced(dmu_objset_pool(os), 0); 652 653 return (0); 654 } 655 656 int 657 zvol_update_volsize(zvol_state_t *zv, major_t maj, uint64_t volsize) 658 { 659 dmu_tx_t *tx; 660 int error; 661 662 ASSERT(MUTEX_HELD(&zvol_state_lock)); 663 664 tx = dmu_tx_create(zv->zv_objset); 665 dmu_tx_hold_zap(tx, ZVOL_ZAP_OBJ, TRUE, NULL); 666 error = dmu_tx_assign(tx, TXG_WAIT); 667 if (error) { 668 dmu_tx_abort(tx); 669 return (error); 670 } 671 672 error = zap_update(zv->zv_objset, ZVOL_ZAP_OBJ, "size", 8, 1, 673 &volsize, tx); 674 dmu_tx_commit(tx); 675 676 if (error == 0) 677 error = dmu_free_long_range(zv->zv_objset, 678 ZVOL_OBJ, volsize, DMU_OBJECT_END); 679 680 /* 681 * If we are using a faked-up state (zv_minor == 0) then don't 682 * try to update the in-core zvol state. 683 */ 684 if (error == 0 && zv->zv_minor) { 685 zv->zv_volsize = volsize; 686 zvol_size_changed(zv, maj); 687 } 688 return (error); 689 } 690 691 int 692 zvol_set_volsize(const char *name, major_t maj, uint64_t volsize) 693 { 694 zvol_state_t *zv; 695 int error; 696 dmu_object_info_t doi; 697 uint64_t old_volsize = 0ULL; 698 zvol_state_t state = { 0 }; 699 700 mutex_enter(&zvol_state_lock); 701 702 if ((zv = zvol_minor_lookup(name)) == NULL) { 703 /* 704 * If we are doing a "zfs clone -o volsize=", then the 705 * minor node won't exist yet. 706 */ 707 error = dmu_objset_open(name, DMU_OST_ZVOL, DS_MODE_OWNER, 708 &state.zv_objset); 709 if (error != 0) 710 goto out; 711 zv = &state; 712 } 713 old_volsize = zv->zv_volsize; 714 715 if ((error = dmu_object_info(zv->zv_objset, ZVOL_OBJ, &doi)) != 0 || 716 (error = zvol_check_volsize(volsize, 717 doi.doi_data_block_size)) != 0) 718 goto out; 719 720 if (zv->zv_flags & ZVOL_RDONLY || (zv->zv_mode & DS_MODE_READONLY)) { 721 error = EROFS; 722 goto out; 723 } 724 725 error = zvol_update_volsize(zv, maj, volsize); 726 727 /* 728 * Reinitialize the dump area to the new size. If we 729 * failed to resize the dump area then restore the it back to 730 * it's original size. 731 */ 732 if (error == 0 && zv->zv_flags & ZVOL_DUMPIFIED) { 733 if ((error = zvol_dumpify(zv)) != 0 || 734 (error = dumpvp_resize()) != 0) { 735 (void) zvol_update_volsize(zv, maj, old_volsize); 736 error = zvol_dumpify(zv); 737 } 738 } 739 740 /* 741 * Generate a LUN expansion event. 742 */ 743 if (error == 0) { 744 sysevent_id_t eid; 745 nvlist_t *attr; 746 char *physpath = kmem_zalloc(MAXPATHLEN, KM_SLEEP); 747 748 (void) snprintf(physpath, MAXPATHLEN, "%s%uc", ZVOL_PSEUDO_DEV, 749 zv->zv_minor); 750 751 VERIFY(nvlist_alloc(&attr, NV_UNIQUE_NAME, KM_SLEEP) == 0); 752 VERIFY(nvlist_add_string(attr, DEV_PHYS_PATH, physpath) == 0); 753 754 (void) ddi_log_sysevent(zfs_dip, SUNW_VENDOR, EC_DEV_STATUS, 755 ESC_DEV_DLE, attr, &eid, DDI_SLEEP); 756 757 nvlist_free(attr); 758 kmem_free(physpath, MAXPATHLEN); 759 } 760 761 out: 762 if (state.zv_objset) 763 dmu_objset_close(state.zv_objset); 764 765 mutex_exit(&zvol_state_lock); 766 767 return (error); 768 } 769 770 int 771 zvol_set_volblocksize(const char *name, uint64_t volblocksize) 772 { 773 zvol_state_t *zv; 774 dmu_tx_t *tx; 775 int error; 776 boolean_t needlock; 777 778 /* 779 * The lock may already be held if we are being called from 780 * zvol_dump_init(). 781 */ 782 needlock = !MUTEX_HELD(&zvol_state_lock); 783 if (needlock) 784 mutex_enter(&zvol_state_lock); 785 786 if ((zv = zvol_minor_lookup(name)) == NULL) { 787 if (needlock) 788 mutex_exit(&zvol_state_lock); 789 return (ENXIO); 790 } 791 if (zv->zv_flags & ZVOL_RDONLY || (zv->zv_mode & DS_MODE_READONLY)) { 792 if (needlock) 793 mutex_exit(&zvol_state_lock); 794 return (EROFS); 795 } 796 797 tx = dmu_tx_create(zv->zv_objset); 798 dmu_tx_hold_bonus(tx, ZVOL_OBJ); 799 error = dmu_tx_assign(tx, TXG_WAIT); 800 if (error) { 801 dmu_tx_abort(tx); 802 } else { 803 error = dmu_object_set_blocksize(zv->zv_objset, ZVOL_OBJ, 804 volblocksize, 0, tx); 805 if (error == ENOTSUP) 806 error = EBUSY; 807 dmu_tx_commit(tx); 808 if (error == 0) 809 zv->zv_volblocksize = volblocksize; 810 } 811 812 if (needlock) 813 mutex_exit(&zvol_state_lock); 814 815 return (error); 816 } 817 818 /*ARGSUSED*/ 819 int 820 zvol_open(dev_t *devp, int flag, int otyp, cred_t *cr) 821 { 822 minor_t minor = getminor(*devp); 823 zvol_state_t *zv; 824 825 if (minor == 0) /* This is the control device */ 826 return (0); 827 828 mutex_enter(&zvol_state_lock); 829 830 zv = ddi_get_soft_state(zvol_state, minor); 831 if (zv == NULL) { 832 mutex_exit(&zvol_state_lock); 833 return (ENXIO); 834 } 835 836 ASSERT(zv->zv_objset != NULL); 837 838 if ((flag & FWRITE) && 839 (zv->zv_flags & ZVOL_RDONLY || (zv->zv_mode & DS_MODE_READONLY))) { 840 mutex_exit(&zvol_state_lock); 841 return (EROFS); 842 } 843 if (zv->zv_flags & ZVOL_EXCL) { 844 mutex_exit(&zvol_state_lock); 845 return (EBUSY); 846 } 847 if (flag & FEXCL) { 848 if (zv->zv_total_opens != 0) { 849 mutex_exit(&zvol_state_lock); 850 return (EBUSY); 851 } 852 zv->zv_flags |= ZVOL_EXCL; 853 } 854 855 if (zv->zv_open_count[otyp] == 0 || otyp == OTYP_LYR) { 856 zv->zv_open_count[otyp]++; 857 zv->zv_total_opens++; 858 } 859 860 mutex_exit(&zvol_state_lock); 861 862 return (0); 863 } 864 865 /*ARGSUSED*/ 866 int 867 zvol_close(dev_t dev, int flag, int otyp, cred_t *cr) 868 { 869 minor_t minor = getminor(dev); 870 zvol_state_t *zv; 871 872 if (minor == 0) /* This is the control device */ 873 return (0); 874 875 mutex_enter(&zvol_state_lock); 876 877 zv = ddi_get_soft_state(zvol_state, minor); 878 if (zv == NULL) { 879 mutex_exit(&zvol_state_lock); 880 return (ENXIO); 881 } 882 883 if (zv->zv_flags & ZVOL_EXCL) { 884 ASSERT(zv->zv_total_opens == 1); 885 zv->zv_flags &= ~ZVOL_EXCL; 886 } 887 888 /* 889 * If the open count is zero, this is a spurious close. 890 * That indicates a bug in the kernel / DDI framework. 891 */ 892 ASSERT(zv->zv_open_count[otyp] != 0); 893 ASSERT(zv->zv_total_opens != 0); 894 895 /* 896 * You may get multiple opens, but only one close. 897 */ 898 zv->zv_open_count[otyp]--; 899 zv->zv_total_opens--; 900 901 mutex_exit(&zvol_state_lock); 902 903 return (0); 904 } 905 906 static void 907 zvol_get_done(dmu_buf_t *db, void *vzgd) 908 { 909 zgd_t *zgd = (zgd_t *)vzgd; 910 rl_t *rl = zgd->zgd_rl; 911 912 dmu_buf_rele(db, vzgd); 913 zfs_range_unlock(rl); 914 zil_add_block(zgd->zgd_zilog, zgd->zgd_bp); 915 kmem_free(zgd, sizeof (zgd_t)); 916 } 917 918 /* 919 * Get data to generate a TX_WRITE intent log record. 920 */ 921 static int 922 zvol_get_data(void *arg, lr_write_t *lr, char *buf, zio_t *zio) 923 { 924 zvol_state_t *zv = arg; 925 objset_t *os = zv->zv_objset; 926 dmu_buf_t *db; 927 rl_t *rl; 928 zgd_t *zgd; 929 uint64_t boff; /* block starting offset */ 930 int dlen = lr->lr_length; /* length of user data */ 931 int error; 932 933 ASSERT(zio); 934 ASSERT(dlen != 0); 935 936 /* 937 * Write records come in two flavors: immediate and indirect. 938 * For small writes it's cheaper to store the data with the 939 * log record (immediate); for large writes it's cheaper to 940 * sync the data and get a pointer to it (indirect) so that 941 * we don't have to write the data twice. 942 */ 943 if (buf != NULL) /* immediate write */ 944 return (dmu_read(os, ZVOL_OBJ, lr->lr_offset, dlen, buf, 945 DMU_READ_NO_PREFETCH)); 946 947 zgd = (zgd_t *)kmem_alloc(sizeof (zgd_t), KM_SLEEP); 948 zgd->zgd_zilog = zv->zv_zilog; 949 zgd->zgd_bp = &lr->lr_blkptr; 950 951 /* 952 * Lock the range of the block to ensure that when the data is 953 * written out and its checksum is being calculated that no other 954 * thread can change the block. 955 */ 956 boff = P2ALIGN_TYPED(lr->lr_offset, zv->zv_volblocksize, uint64_t); 957 rl = zfs_range_lock(&zv->zv_znode, boff, zv->zv_volblocksize, 958 RL_READER); 959 zgd->zgd_rl = rl; 960 961 VERIFY(0 == dmu_buf_hold(os, ZVOL_OBJ, lr->lr_offset, zgd, &db)); 962 error = dmu_sync(zio, db, &lr->lr_blkptr, 963 lr->lr_common.lrc_txg, zvol_get_done, zgd); 964 if (error == 0) 965 zil_add_block(zv->zv_zilog, &lr->lr_blkptr); 966 /* 967 * If we get EINPROGRESS, then we need to wait for a 968 * write IO initiated by dmu_sync() to complete before 969 * we can release this dbuf. We will finish everything 970 * up in the zvol_get_done() callback. 971 */ 972 if (error == EINPROGRESS) 973 return (0); 974 dmu_buf_rele(db, zgd); 975 zfs_range_unlock(rl); 976 kmem_free(zgd, sizeof (zgd_t)); 977 return (error); 978 } 979 980 /* 981 * zvol_log_write() handles synchronous writes using TX_WRITE ZIL transactions. 982 * 983 * We store data in the log buffers if it's small enough. 984 * Otherwise we will later flush the data out via dmu_sync(). 985 */ 986 ssize_t zvol_immediate_write_sz = 32768; 987 988 static void 989 zvol_log_write(zvol_state_t *zv, dmu_tx_t *tx, offset_t off, ssize_t resid, 990 boolean_t sync) 991 { 992 uint32_t blocksize = zv->zv_volblocksize; 993 zilog_t *zilog = zv->zv_zilog; 994 boolean_t slogging; 995 996 if (zil_disable) 997 return; 998 999 if (zilog->zl_replay) { 1000 dsl_dataset_dirty(dmu_objset_ds(zilog->zl_os), tx); 1001 zilog->zl_replayed_seq[dmu_tx_get_txg(tx) & TXG_MASK] = 1002 zilog->zl_replaying_seq; 1003 return; 1004 } 1005 1006 slogging = spa_has_slogs(zilog->zl_spa); 1007 1008 while (resid) { 1009 itx_t *itx; 1010 lr_write_t *lr; 1011 ssize_t len; 1012 itx_wr_state_t write_state; 1013 1014 /* 1015 * Unlike zfs_log_write() we can be called with 1016 * upto DMU_MAX_ACCESS/2 (5MB) writes. 1017 */ 1018 if (blocksize > zvol_immediate_write_sz && !slogging && 1019 resid >= blocksize && off % blocksize == 0) { 1020 write_state = WR_INDIRECT; /* uses dmu_sync */ 1021 len = blocksize; 1022 } else if (sync) { 1023 write_state = WR_COPIED; 1024 len = MIN(ZIL_MAX_LOG_DATA, resid); 1025 } else { 1026 write_state = WR_NEED_COPY; 1027 len = MIN(ZIL_MAX_LOG_DATA, resid); 1028 } 1029 1030 itx = zil_itx_create(TX_WRITE, sizeof (*lr) + 1031 (write_state == WR_COPIED ? len : 0)); 1032 lr = (lr_write_t *)&itx->itx_lr; 1033 if (write_state == WR_COPIED && dmu_read(zv->zv_objset, 1034 ZVOL_OBJ, off, len, lr + 1, DMU_READ_NO_PREFETCH) != 0) { 1035 kmem_free(itx, offsetof(itx_t, itx_lr) + 1036 itx->itx_lr.lrc_reclen); 1037 itx = zil_itx_create(TX_WRITE, sizeof (*lr)); 1038 lr = (lr_write_t *)&itx->itx_lr; 1039 write_state = WR_NEED_COPY; 1040 } 1041 1042 itx->itx_wr_state = write_state; 1043 if (write_state == WR_NEED_COPY) 1044 itx->itx_sod += len; 1045 lr->lr_foid = ZVOL_OBJ; 1046 lr->lr_offset = off; 1047 lr->lr_length = len; 1048 lr->lr_blkoff = off - P2ALIGN_TYPED(off, blocksize, uint64_t); 1049 BP_ZERO(&lr->lr_blkptr); 1050 1051 itx->itx_private = zv; 1052 itx->itx_sync = sync; 1053 1054 (void) zil_itx_assign(zilog, itx, tx); 1055 1056 off += len; 1057 resid -= len; 1058 } 1059 } 1060 1061 static int 1062 zvol_dumpio_vdev(vdev_t *vd, void *addr, uint64_t offset, uint64_t size, 1063 boolean_t doread, boolean_t isdump) 1064 { 1065 vdev_disk_t *dvd; 1066 int c; 1067 int numerrors = 0; 1068 1069 for (c = 0; c < vd->vdev_children; c++) { 1070 ASSERT(vd->vdev_ops == &vdev_mirror_ops || 1071 vd->vdev_ops == &vdev_replacing_ops || 1072 vd->vdev_ops == &vdev_spare_ops); 1073 int err = zvol_dumpio_vdev(vd->vdev_child[c], 1074 addr, offset, size, doread, isdump); 1075 if (err != 0) { 1076 numerrors++; 1077 } else if (doread) { 1078 break; 1079 } 1080 } 1081 1082 if (!vd->vdev_ops->vdev_op_leaf) 1083 return (numerrors < vd->vdev_children ? 0 : EIO); 1084 1085 if (doread && !vdev_readable(vd)) 1086 return (EIO); 1087 else if (!doread && !vdev_writeable(vd)) 1088 return (EIO); 1089 1090 dvd = vd->vdev_tsd; 1091 ASSERT3P(dvd, !=, NULL); 1092 offset += VDEV_LABEL_START_SIZE; 1093 1094 if (ddi_in_panic() || isdump) { 1095 ASSERT(!doread); 1096 if (doread) 1097 return (EIO); 1098 return (ldi_dump(dvd->vd_lh, addr, lbtodb(offset), 1099 lbtodb(size))); 1100 } else { 1101 return (vdev_disk_physio(dvd->vd_lh, addr, size, offset, 1102 doread ? B_READ : B_WRITE)); 1103 } 1104 } 1105 1106 static int 1107 zvol_dumpio(zvol_state_t *zv, void *addr, uint64_t offset, uint64_t size, 1108 boolean_t doread, boolean_t isdump) 1109 { 1110 vdev_t *vd; 1111 int error; 1112 zvol_extent_t *ze; 1113 spa_t *spa = dmu_objset_spa(zv->zv_objset); 1114 1115 /* Must be sector aligned, and not stradle a block boundary. */ 1116 if (P2PHASE(offset, DEV_BSIZE) || P2PHASE(size, DEV_BSIZE) || 1117 P2BOUNDARY(offset, size, zv->zv_volblocksize)) { 1118 return (EINVAL); 1119 } 1120 ASSERT(size <= zv->zv_volblocksize); 1121 1122 /* Locate the extent this belongs to */ 1123 ze = list_head(&zv->zv_extents); 1124 while (offset >= ze->ze_nblks * zv->zv_volblocksize) { 1125 offset -= ze->ze_nblks * zv->zv_volblocksize; 1126 ze = list_next(&zv->zv_extents, ze); 1127 } 1128 spa_config_enter(spa, SCL_STATE, FTAG, RW_READER); 1129 vd = vdev_lookup_top(spa, DVA_GET_VDEV(&ze->ze_dva)); 1130 offset += DVA_GET_OFFSET(&ze->ze_dva); 1131 error = zvol_dumpio_vdev(vd, addr, offset, size, doread, isdump); 1132 spa_config_exit(spa, SCL_STATE, FTAG); 1133 return (error); 1134 } 1135 1136 int 1137 zvol_strategy(buf_t *bp) 1138 { 1139 zvol_state_t *zv = ddi_get_soft_state(zvol_state, getminor(bp->b_edev)); 1140 uint64_t off, volsize; 1141 size_t resid; 1142 char *addr; 1143 objset_t *os; 1144 rl_t *rl; 1145 int error = 0; 1146 boolean_t doread = bp->b_flags & B_READ; 1147 boolean_t is_dump = zv->zv_flags & ZVOL_DUMPIFIED; 1148 boolean_t sync; 1149 1150 if (zv == NULL) { 1151 bioerror(bp, ENXIO); 1152 biodone(bp); 1153 return (0); 1154 } 1155 1156 if (getminor(bp->b_edev) == 0) { 1157 bioerror(bp, EINVAL); 1158 biodone(bp); 1159 return (0); 1160 } 1161 1162 if (!(bp->b_flags & B_READ) && 1163 (zv->zv_flags & ZVOL_RDONLY || 1164 zv->zv_mode & DS_MODE_READONLY)) { 1165 bioerror(bp, EROFS); 1166 biodone(bp); 1167 return (0); 1168 } 1169 1170 off = ldbtob(bp->b_blkno); 1171 volsize = zv->zv_volsize; 1172 1173 os = zv->zv_objset; 1174 ASSERT(os != NULL); 1175 1176 bp_mapin(bp); 1177 addr = bp->b_un.b_addr; 1178 resid = bp->b_bcount; 1179 1180 if (resid > 0 && (off < 0 || off >= volsize)) { 1181 bioerror(bp, EIO); 1182 biodone(bp); 1183 return (0); 1184 } 1185 1186 sync = !(bp->b_flags & B_ASYNC) && !doread && !is_dump && 1187 !(zv->zv_flags & ZVOL_WCE) && !zil_disable; 1188 1189 /* 1190 * There must be no buffer changes when doing a dmu_sync() because 1191 * we can't change the data whilst calculating the checksum. 1192 */ 1193 rl = zfs_range_lock(&zv->zv_znode, off, resid, 1194 doread ? RL_READER : RL_WRITER); 1195 1196 while (resid != 0 && off < volsize) { 1197 size_t size = MIN(resid, zvol_maxphys); 1198 if (is_dump) { 1199 size = MIN(size, P2END(off, zv->zv_volblocksize) - off); 1200 error = zvol_dumpio(zv, addr, off, size, 1201 doread, B_FALSE); 1202 } else if (doread) { 1203 error = dmu_read(os, ZVOL_OBJ, off, size, addr, 1204 DMU_READ_PREFETCH); 1205 } else { 1206 dmu_tx_t *tx = dmu_tx_create(os); 1207 dmu_tx_hold_write(tx, ZVOL_OBJ, off, size); 1208 error = dmu_tx_assign(tx, TXG_WAIT); 1209 if (error) { 1210 dmu_tx_abort(tx); 1211 } else { 1212 dmu_write(os, ZVOL_OBJ, off, size, addr, tx); 1213 zvol_log_write(zv, tx, off, size, sync); 1214 dmu_tx_commit(tx); 1215 } 1216 } 1217 if (error) { 1218 /* convert checksum errors into IO errors */ 1219 if (error == ECKSUM) 1220 error = EIO; 1221 break; 1222 } 1223 off += size; 1224 addr += size; 1225 resid -= size; 1226 } 1227 zfs_range_unlock(rl); 1228 1229 if ((bp->b_resid = resid) == bp->b_bcount) 1230 bioerror(bp, off > volsize ? EINVAL : error); 1231 1232 if (sync) 1233 zil_commit(zv->zv_zilog, UINT64_MAX, ZVOL_OBJ); 1234 biodone(bp); 1235 1236 return (0); 1237 } 1238 1239 /* 1240 * Set the buffer count to the zvol maximum transfer. 1241 * Using our own routine instead of the default minphys() 1242 * means that for larger writes we write bigger buffers on X86 1243 * (128K instead of 56K) and flush the disk write cache less often 1244 * (every zvol_maxphys - currently 1MB) instead of minphys (currently 1245 * 56K on X86 and 128K on sparc). 1246 */ 1247 void 1248 zvol_minphys(struct buf *bp) 1249 { 1250 if (bp->b_bcount > zvol_maxphys) 1251 bp->b_bcount = zvol_maxphys; 1252 } 1253 1254 int 1255 zvol_dump(dev_t dev, caddr_t addr, daddr_t blkno, int nblocks) 1256 { 1257 minor_t minor = getminor(dev); 1258 zvol_state_t *zv; 1259 int error = 0; 1260 uint64_t size; 1261 uint64_t boff; 1262 uint64_t resid; 1263 1264 if (minor == 0) /* This is the control device */ 1265 return (ENXIO); 1266 1267 zv = ddi_get_soft_state(zvol_state, minor); 1268 if (zv == NULL) 1269 return (ENXIO); 1270 1271 boff = ldbtob(blkno); 1272 resid = ldbtob(nblocks); 1273 1274 VERIFY3U(boff + resid, <=, zv->zv_volsize); 1275 1276 while (resid) { 1277 size = MIN(resid, P2END(boff, zv->zv_volblocksize) - boff); 1278 error = zvol_dumpio(zv, addr, boff, size, B_FALSE, B_TRUE); 1279 if (error) 1280 break; 1281 boff += size; 1282 addr += size; 1283 resid -= size; 1284 } 1285 1286 return (error); 1287 } 1288 1289 /*ARGSUSED*/ 1290 int 1291 zvol_read(dev_t dev, uio_t *uio, cred_t *cr) 1292 { 1293 minor_t minor = getminor(dev); 1294 zvol_state_t *zv; 1295 uint64_t volsize; 1296 rl_t *rl; 1297 int error = 0; 1298 1299 if (minor == 0) /* This is the control device */ 1300 return (ENXIO); 1301 1302 zv = ddi_get_soft_state(zvol_state, minor); 1303 if (zv == NULL) 1304 return (ENXIO); 1305 1306 volsize = zv->zv_volsize; 1307 if (uio->uio_resid > 0 && 1308 (uio->uio_loffset < 0 || uio->uio_loffset >= volsize)) 1309 return (EIO); 1310 1311 if (zv->zv_flags & ZVOL_DUMPIFIED) { 1312 error = physio(zvol_strategy, NULL, dev, B_READ, 1313 zvol_minphys, uio); 1314 return (error); 1315 } 1316 1317 rl = zfs_range_lock(&zv->zv_znode, uio->uio_loffset, uio->uio_resid, 1318 RL_READER); 1319 while (uio->uio_resid > 0 && uio->uio_loffset < volsize) { 1320 uint64_t bytes = MIN(uio->uio_resid, DMU_MAX_ACCESS >> 1); 1321 1322 /* don't read past the end */ 1323 if (bytes > volsize - uio->uio_loffset) 1324 bytes = volsize - uio->uio_loffset; 1325 1326 error = dmu_read_uio(zv->zv_objset, ZVOL_OBJ, uio, bytes); 1327 if (error) { 1328 /* convert checksum errors into IO errors */ 1329 if (error == ECKSUM) 1330 error = EIO; 1331 break; 1332 } 1333 } 1334 zfs_range_unlock(rl); 1335 return (error); 1336 } 1337 1338 /*ARGSUSED*/ 1339 int 1340 zvol_write(dev_t dev, uio_t *uio, cred_t *cr) 1341 { 1342 minor_t minor = getminor(dev); 1343 zvol_state_t *zv; 1344 uint64_t volsize; 1345 rl_t *rl; 1346 int error = 0; 1347 boolean_t sync; 1348 1349 if (minor == 0) /* This is the control device */ 1350 return (ENXIO); 1351 1352 zv = ddi_get_soft_state(zvol_state, minor); 1353 if (zv == NULL) 1354 return (ENXIO); 1355 1356 volsize = zv->zv_volsize; 1357 if (uio->uio_resid > 0 && 1358 (uio->uio_loffset < 0 || uio->uio_loffset >= volsize)) 1359 return (EIO); 1360 1361 if (zv->zv_flags & ZVOL_DUMPIFIED) { 1362 error = physio(zvol_strategy, NULL, dev, B_WRITE, 1363 zvol_minphys, uio); 1364 return (error); 1365 } 1366 1367 sync = !(zv->zv_flags & ZVOL_WCE) && !zil_disable; 1368 1369 rl = zfs_range_lock(&zv->zv_znode, uio->uio_loffset, uio->uio_resid, 1370 RL_WRITER); 1371 while (uio->uio_resid > 0 && uio->uio_loffset < volsize) { 1372 uint64_t bytes = MIN(uio->uio_resid, DMU_MAX_ACCESS >> 1); 1373 uint64_t off = uio->uio_loffset; 1374 dmu_tx_t *tx = dmu_tx_create(zv->zv_objset); 1375 1376 if (bytes > volsize - off) /* don't write past the end */ 1377 bytes = volsize - off; 1378 1379 dmu_tx_hold_write(tx, ZVOL_OBJ, off, bytes); 1380 error = dmu_tx_assign(tx, TXG_WAIT); 1381 if (error) { 1382 dmu_tx_abort(tx); 1383 break; 1384 } 1385 error = dmu_write_uio(zv->zv_objset, ZVOL_OBJ, uio, bytes, tx); 1386 if (error == 0) 1387 zvol_log_write(zv, tx, off, bytes, sync); 1388 dmu_tx_commit(tx); 1389 1390 if (error) 1391 break; 1392 } 1393 zfs_range_unlock(rl); 1394 if (sync) 1395 zil_commit(zv->zv_zilog, UINT64_MAX, ZVOL_OBJ); 1396 return (error); 1397 } 1398 1399 int 1400 zvol_getefi(void *arg, int flag, uint64_t vs, uint8_t bs) 1401 { 1402 struct uuid uuid = EFI_RESERVED; 1403 efi_gpe_t gpe = { 0 }; 1404 uint32_t crc; 1405 dk_efi_t efi; 1406 int length; 1407 char *ptr; 1408 1409 if (ddi_copyin(arg, &efi, sizeof (dk_efi_t), flag)) 1410 return (EFAULT); 1411 ptr = (char *)(uintptr_t)efi.dki_data_64; 1412 length = efi.dki_length; 1413 /* 1414 * Some clients may attempt to request a PMBR for the 1415 * zvol. Currently this interface will return EINVAL to 1416 * such requests. These requests could be supported by 1417 * adding a check for lba == 0 and consing up an appropriate 1418 * PMBR. 1419 */ 1420 if (efi.dki_lba < 1 || efi.dki_lba > 2 || length <= 0) 1421 return (EINVAL); 1422 1423 gpe.efi_gpe_StartingLBA = LE_64(34ULL); 1424 gpe.efi_gpe_EndingLBA = LE_64((vs >> bs) - 1); 1425 UUID_LE_CONVERT(gpe.efi_gpe_PartitionTypeGUID, uuid); 1426 1427 if (efi.dki_lba == 1) { 1428 efi_gpt_t gpt = { 0 }; 1429 1430 gpt.efi_gpt_Signature = LE_64(EFI_SIGNATURE); 1431 gpt.efi_gpt_Revision = LE_32(EFI_VERSION_CURRENT); 1432 gpt.efi_gpt_HeaderSize = LE_32(sizeof (gpt)); 1433 gpt.efi_gpt_MyLBA = LE_64(1ULL); 1434 gpt.efi_gpt_FirstUsableLBA = LE_64(34ULL); 1435 gpt.efi_gpt_LastUsableLBA = LE_64((vs >> bs) - 1); 1436 gpt.efi_gpt_PartitionEntryLBA = LE_64(2ULL); 1437 gpt.efi_gpt_NumberOfPartitionEntries = LE_32(1); 1438 gpt.efi_gpt_SizeOfPartitionEntry = 1439 LE_32(sizeof (efi_gpe_t)); 1440 CRC32(crc, &gpe, sizeof (gpe), -1U, crc32_table); 1441 gpt.efi_gpt_PartitionEntryArrayCRC32 = LE_32(~crc); 1442 CRC32(crc, &gpt, sizeof (gpt), -1U, crc32_table); 1443 gpt.efi_gpt_HeaderCRC32 = LE_32(~crc); 1444 if (ddi_copyout(&gpt, ptr, MIN(sizeof (gpt), length), 1445 flag)) 1446 return (EFAULT); 1447 ptr += sizeof (gpt); 1448 length -= sizeof (gpt); 1449 } 1450 if (length > 0 && ddi_copyout(&gpe, ptr, MIN(sizeof (gpe), 1451 length), flag)) 1452 return (EFAULT); 1453 return (0); 1454 } 1455 1456 /* 1457 * Dirtbag ioctls to support mkfs(1M) for UFS filesystems. See dkio(7I). 1458 */ 1459 /*ARGSUSED*/ 1460 int 1461 zvol_ioctl(dev_t dev, int cmd, intptr_t arg, int flag, cred_t *cr, int *rvalp) 1462 { 1463 zvol_state_t *zv; 1464 struct dk_cinfo dki; 1465 struct dk_minfo dkm; 1466 struct dk_callback *dkc; 1467 int error = 0; 1468 rl_t *rl; 1469 1470 mutex_enter(&zvol_state_lock); 1471 1472 zv = ddi_get_soft_state(zvol_state, getminor(dev)); 1473 1474 if (zv == NULL) { 1475 mutex_exit(&zvol_state_lock); 1476 return (ENXIO); 1477 } 1478 ASSERT(zv->zv_total_opens > 0); 1479 1480 switch (cmd) { 1481 1482 case DKIOCINFO: 1483 bzero(&dki, sizeof (dki)); 1484 (void) strcpy(dki.dki_cname, "zvol"); 1485 (void) strcpy(dki.dki_dname, "zvol"); 1486 dki.dki_ctype = DKC_UNKNOWN; 1487 dki.dki_maxtransfer = 1 << (SPA_MAXBLOCKSHIFT - zv->zv_min_bs); 1488 mutex_exit(&zvol_state_lock); 1489 if (ddi_copyout(&dki, (void *)arg, sizeof (dki), flag)) 1490 error = EFAULT; 1491 return (error); 1492 1493 case DKIOCGMEDIAINFO: 1494 bzero(&dkm, sizeof (dkm)); 1495 dkm.dki_lbsize = 1U << zv->zv_min_bs; 1496 dkm.dki_capacity = zv->zv_volsize >> zv->zv_min_bs; 1497 dkm.dki_media_type = DK_UNKNOWN; 1498 mutex_exit(&zvol_state_lock); 1499 if (ddi_copyout(&dkm, (void *)arg, sizeof (dkm), flag)) 1500 error = EFAULT; 1501 return (error); 1502 1503 case DKIOCGETEFI: 1504 { 1505 uint64_t vs = zv->zv_volsize; 1506 uint8_t bs = zv->zv_min_bs; 1507 1508 mutex_exit(&zvol_state_lock); 1509 error = zvol_getefi((void *)arg, flag, vs, bs); 1510 return (error); 1511 } 1512 1513 case DKIOCFLUSHWRITECACHE: 1514 dkc = (struct dk_callback *)arg; 1515 mutex_exit(&zvol_state_lock); 1516 zil_commit(zv->zv_zilog, UINT64_MAX, ZVOL_OBJ); 1517 if ((flag & FKIOCTL) && dkc != NULL && dkc->dkc_callback) { 1518 (*dkc->dkc_callback)(dkc->dkc_cookie, error); 1519 error = 0; 1520 } 1521 return (error); 1522 1523 case DKIOCGETWCE: 1524 { 1525 int wce = (zv->zv_flags & ZVOL_WCE) ? 1 : 0; 1526 if (ddi_copyout(&wce, (void *)arg, sizeof (int), 1527 flag)) 1528 error = EFAULT; 1529 break; 1530 } 1531 case DKIOCSETWCE: 1532 { 1533 int wce; 1534 if (ddi_copyin((void *)arg, &wce, sizeof (int), 1535 flag)) { 1536 error = EFAULT; 1537 break; 1538 } 1539 if (wce) { 1540 zv->zv_flags |= ZVOL_WCE; 1541 mutex_exit(&zvol_state_lock); 1542 } else { 1543 zv->zv_flags &= ~ZVOL_WCE; 1544 mutex_exit(&zvol_state_lock); 1545 zil_commit(zv->zv_zilog, UINT64_MAX, ZVOL_OBJ); 1546 } 1547 return (0); 1548 } 1549 1550 case DKIOCGGEOM: 1551 case DKIOCGVTOC: 1552 /* 1553 * commands using these (like prtvtoc) expect ENOTSUP 1554 * since we're emulating an EFI label 1555 */ 1556 error = ENOTSUP; 1557 break; 1558 1559 case DKIOCDUMPINIT: 1560 rl = zfs_range_lock(&zv->zv_znode, 0, zv->zv_volsize, 1561 RL_WRITER); 1562 error = zvol_dumpify(zv); 1563 zfs_range_unlock(rl); 1564 break; 1565 1566 case DKIOCDUMPFINI: 1567 if (!(zv->zv_flags & ZVOL_DUMPIFIED)) 1568 break; 1569 rl = zfs_range_lock(&zv->zv_znode, 0, zv->zv_volsize, 1570 RL_WRITER); 1571 error = zvol_dump_fini(zv); 1572 zfs_range_unlock(rl); 1573 break; 1574 1575 default: 1576 error = ENOTTY; 1577 break; 1578 1579 } 1580 mutex_exit(&zvol_state_lock); 1581 return (error); 1582 } 1583 1584 int 1585 zvol_busy(void) 1586 { 1587 return (zvol_minors != 0); 1588 } 1589 1590 void 1591 zvol_init(void) 1592 { 1593 VERIFY(ddi_soft_state_init(&zvol_state, sizeof (zvol_state_t), 1) == 0); 1594 mutex_init(&zvol_state_lock, NULL, MUTEX_DEFAULT, NULL); 1595 } 1596 1597 void 1598 zvol_fini(void) 1599 { 1600 mutex_destroy(&zvol_state_lock); 1601 ddi_soft_state_fini(&zvol_state); 1602 } 1603 1604 static boolean_t 1605 zvol_is_swap(zvol_state_t *zv) 1606 { 1607 vnode_t *vp; 1608 boolean_t ret = B_FALSE; 1609 char *devpath; 1610 int error; 1611 1612 devpath = kmem_asprintf("%s%s", ZVOL_FULL_DEV_DIR, zv->zv_name); 1613 error = lookupname(devpath, UIO_SYSSPACE, FOLLOW, NULLVPP, &vp); 1614 strfree(devpath); 1615 1616 ret = !error && IS_SWAPVP(common_specvp(vp)); 1617 1618 if (vp != NULL) 1619 VN_RELE(vp); 1620 1621 return (ret); 1622 } 1623 1624 static int 1625 zvol_dump_init(zvol_state_t *zv, boolean_t resize) 1626 { 1627 dmu_tx_t *tx; 1628 int error = 0; 1629 objset_t *os = zv->zv_objset; 1630 nvlist_t *nv = NULL; 1631 1632 ASSERT(MUTEX_HELD(&zvol_state_lock)); 1633 1634 tx = dmu_tx_create(os); 1635 dmu_tx_hold_zap(tx, ZVOL_ZAP_OBJ, TRUE, NULL); 1636 error = dmu_tx_assign(tx, TXG_WAIT); 1637 if (error) { 1638 dmu_tx_abort(tx); 1639 return (error); 1640 } 1641 1642 /* 1643 * If we are resizing the dump device then we only need to 1644 * update the refreservation to match the newly updated 1645 * zvolsize. Otherwise, we save off the original state of the 1646 * zvol so that we can restore them if the zvol is ever undumpified. 1647 */ 1648 if (resize) { 1649 error = zap_update(os, ZVOL_ZAP_OBJ, 1650 zfs_prop_to_name(ZFS_PROP_REFRESERVATION), 8, 1, 1651 &zv->zv_volsize, tx); 1652 } else { 1653 uint64_t checksum, compress, refresrv, vbs; 1654 1655 error = dsl_prop_get_integer(zv->zv_name, 1656 zfs_prop_to_name(ZFS_PROP_COMPRESSION), &compress, NULL); 1657 error = error ? error : dsl_prop_get_integer(zv->zv_name, 1658 zfs_prop_to_name(ZFS_PROP_CHECKSUM), &checksum, NULL); 1659 error = error ? error : dsl_prop_get_integer(zv->zv_name, 1660 zfs_prop_to_name(ZFS_PROP_REFRESERVATION), &refresrv, NULL); 1661 error = error ? error : dsl_prop_get_integer(zv->zv_name, 1662 zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE), &vbs, NULL); 1663 1664 error = error ? error : zap_update(os, ZVOL_ZAP_OBJ, 1665 zfs_prop_to_name(ZFS_PROP_COMPRESSION), 8, 1, 1666 &compress, tx); 1667 error = error ? error : zap_update(os, ZVOL_ZAP_OBJ, 1668 zfs_prop_to_name(ZFS_PROP_CHECKSUM), 8, 1, &checksum, tx); 1669 error = error ? error : zap_update(os, ZVOL_ZAP_OBJ, 1670 zfs_prop_to_name(ZFS_PROP_REFRESERVATION), 8, 1, 1671 &refresrv, tx); 1672 error = error ? error : zap_update(os, ZVOL_ZAP_OBJ, 1673 zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE), 8, 1, 1674 &vbs, tx); 1675 } 1676 dmu_tx_commit(tx); 1677 1678 /* Truncate the file */ 1679 if (!error) 1680 error = dmu_free_long_range(zv->zv_objset, 1681 ZVOL_OBJ, 0, DMU_OBJECT_END); 1682 1683 if (error) 1684 return (error); 1685 1686 /* 1687 * We only need update the zvol's property if we are initializing 1688 * the dump area for the first time. 1689 */ 1690 if (!resize) { 1691 VERIFY(nvlist_alloc(&nv, NV_UNIQUE_NAME, KM_SLEEP) == 0); 1692 VERIFY(nvlist_add_uint64(nv, 1693 zfs_prop_to_name(ZFS_PROP_REFRESERVATION), 0) == 0); 1694 VERIFY(nvlist_add_uint64(nv, 1695 zfs_prop_to_name(ZFS_PROP_COMPRESSION), 1696 ZIO_COMPRESS_OFF) == 0); 1697 VERIFY(nvlist_add_uint64(nv, 1698 zfs_prop_to_name(ZFS_PROP_CHECKSUM), 1699 ZIO_CHECKSUM_OFF) == 0); 1700 VERIFY(nvlist_add_uint64(nv, 1701 zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE), 1702 SPA_MAXBLOCKSIZE) == 0); 1703 1704 error = zfs_set_prop_nvlist(zv->zv_name, nv); 1705 nvlist_free(nv); 1706 1707 if (error) 1708 return (error); 1709 } 1710 1711 /* Allocate the space for the dump */ 1712 error = zvol_prealloc(zv); 1713 return (error); 1714 } 1715 1716 static int 1717 zvol_dumpify(zvol_state_t *zv) 1718 { 1719 int error = 0; 1720 uint64_t dumpsize = 0; 1721 dmu_tx_t *tx; 1722 objset_t *os = zv->zv_objset; 1723 1724 if (zv->zv_flags & ZVOL_RDONLY || (zv->zv_mode & DS_MODE_READONLY)) 1725 return (EROFS); 1726 1727 /* 1728 * We do not support swap devices acting as dump devices. 1729 */ 1730 if (zvol_is_swap(zv)) 1731 return (ENOTSUP); 1732 1733 if (zap_lookup(zv->zv_objset, ZVOL_ZAP_OBJ, ZVOL_DUMPSIZE, 1734 8, 1, &dumpsize) != 0 || dumpsize != zv->zv_volsize) { 1735 boolean_t resize = (dumpsize > 0) ? B_TRUE : B_FALSE; 1736 1737 if ((error = zvol_dump_init(zv, resize)) != 0) { 1738 (void) zvol_dump_fini(zv); 1739 return (error); 1740 } 1741 } 1742 1743 /* 1744 * Build up our lba mapping. 1745 */ 1746 error = zvol_get_lbas(zv); 1747 if (error) { 1748 (void) zvol_dump_fini(zv); 1749 return (error); 1750 } 1751 1752 tx = dmu_tx_create(os); 1753 dmu_tx_hold_zap(tx, ZVOL_ZAP_OBJ, TRUE, NULL); 1754 error = dmu_tx_assign(tx, TXG_WAIT); 1755 if (error) { 1756 dmu_tx_abort(tx); 1757 (void) zvol_dump_fini(zv); 1758 return (error); 1759 } 1760 1761 zv->zv_flags |= ZVOL_DUMPIFIED; 1762 error = zap_update(os, ZVOL_ZAP_OBJ, ZVOL_DUMPSIZE, 8, 1, 1763 &zv->zv_volsize, tx); 1764 dmu_tx_commit(tx); 1765 1766 if (error) { 1767 (void) zvol_dump_fini(zv); 1768 return (error); 1769 } 1770 1771 txg_wait_synced(dmu_objset_pool(os), 0); 1772 return (0); 1773 } 1774 1775 static int 1776 zvol_dump_fini(zvol_state_t *zv) 1777 { 1778 dmu_tx_t *tx; 1779 objset_t *os = zv->zv_objset; 1780 nvlist_t *nv; 1781 int error = 0; 1782 uint64_t checksum, compress, refresrv, vbs; 1783 1784 /* 1785 * Attempt to restore the zvol back to its pre-dumpified state. 1786 * This is a best-effort attempt as it's possible that not all 1787 * of these properties were initialized during the dumpify process 1788 * (i.e. error during zvol_dump_init). 1789 */ 1790 1791 tx = dmu_tx_create(os); 1792 dmu_tx_hold_zap(tx, ZVOL_ZAP_OBJ, TRUE, NULL); 1793 error = dmu_tx_assign(tx, TXG_WAIT); 1794 if (error) { 1795 dmu_tx_abort(tx); 1796 return (error); 1797 } 1798 (void) zap_remove(os, ZVOL_ZAP_OBJ, ZVOL_DUMPSIZE, tx); 1799 dmu_tx_commit(tx); 1800 1801 (void) zap_lookup(zv->zv_objset, ZVOL_ZAP_OBJ, 1802 zfs_prop_to_name(ZFS_PROP_CHECKSUM), 8, 1, &checksum); 1803 (void) zap_lookup(zv->zv_objset, ZVOL_ZAP_OBJ, 1804 zfs_prop_to_name(ZFS_PROP_COMPRESSION), 8, 1, &compress); 1805 (void) zap_lookup(zv->zv_objset, ZVOL_ZAP_OBJ, 1806 zfs_prop_to_name(ZFS_PROP_REFRESERVATION), 8, 1, &refresrv); 1807 (void) zap_lookup(zv->zv_objset, ZVOL_ZAP_OBJ, 1808 zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE), 8, 1, &vbs); 1809 1810 VERIFY(nvlist_alloc(&nv, NV_UNIQUE_NAME, KM_SLEEP) == 0); 1811 (void) nvlist_add_uint64(nv, 1812 zfs_prop_to_name(ZFS_PROP_CHECKSUM), checksum); 1813 (void) nvlist_add_uint64(nv, 1814 zfs_prop_to_name(ZFS_PROP_COMPRESSION), compress); 1815 (void) nvlist_add_uint64(nv, 1816 zfs_prop_to_name(ZFS_PROP_REFRESERVATION), refresrv); 1817 (void) nvlist_add_uint64(nv, 1818 zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE), vbs); 1819 (void) zfs_set_prop_nvlist(zv->zv_name, nv); 1820 nvlist_free(nv); 1821 1822 zvol_free_extents(zv); 1823 zv->zv_flags &= ~ZVOL_DUMPIFIED; 1824 (void) dmu_free_long_range(os, ZVOL_OBJ, 0, DMU_OBJECT_END); 1825 1826 return (0); 1827 } 1828