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 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 boolean_t zv_issnap; /* is a snapshot (read-only) */ 114 uint32_t zv_open_count[OTYPCNT]; /* open counts */ 115 uint32_t zv_total_opens; /* total open count */ 116 zilog_t *zv_zilog; /* ZIL handle */ 117 list_t zv_extents; /* List of extents for dump */ 118 znode_t zv_znode; /* for range locking */ 119 } zvol_state_t; 120 121 /* 122 * zvol specific flags 123 */ 124 #define ZVOL_RDONLY 0x1 125 #define ZVOL_DUMPIFIED 0x2 126 #define ZVOL_EXCL 0x4 127 #define ZVOL_WCE 0x8 128 129 /* 130 * zvol maximum transfer in one DMU tx. 131 */ 132 int zvol_maxphys = DMU_MAX_ACCESS/2; 133 134 extern int zfs_set_prop_nvlist(const char *, nvlist_t *); 135 static int zvol_get_data(void *arg, lr_write_t *lr, char *buf, zio_t *zio); 136 static int zvol_dumpify(zvol_state_t *zv); 137 static int zvol_dump_fini(zvol_state_t *zv); 138 static int zvol_dump_init(zvol_state_t *zv, boolean_t resize); 139 140 static void 141 zvol_size_changed(zvol_state_t *zv, major_t maj) 142 { 143 dev_t dev = makedevice(maj, zv->zv_minor); 144 145 VERIFY(ddi_prop_update_int64(dev, zfs_dip, 146 "Size", zv->zv_volsize) == DDI_SUCCESS); 147 VERIFY(ddi_prop_update_int64(dev, zfs_dip, 148 "Nblocks", lbtodb(zv->zv_volsize)) == DDI_SUCCESS); 149 150 /* Notify specfs to invalidate the cached size */ 151 spec_size_invalidate(dev, VBLK); 152 spec_size_invalidate(dev, VCHR); 153 } 154 155 int 156 zvol_check_volsize(uint64_t volsize, uint64_t blocksize) 157 { 158 if (volsize == 0) 159 return (EINVAL); 160 161 if (volsize % blocksize != 0) 162 return (EINVAL); 163 164 #ifdef _ILP32 165 if (volsize - 1 > SPEC_MAXOFFSET_T) 166 return (EOVERFLOW); 167 #endif 168 return (0); 169 } 170 171 int 172 zvol_check_volblocksize(uint64_t volblocksize) 173 { 174 if (volblocksize < SPA_MINBLOCKSIZE || 175 volblocksize > SPA_MAXBLOCKSIZE || 176 !ISP2(volblocksize)) 177 return (EDOM); 178 179 return (0); 180 } 181 182 static void 183 zvol_readonly_changed_cb(void *arg, uint64_t newval) 184 { 185 zvol_state_t *zv = arg; 186 187 if (newval) 188 zv->zv_flags |= ZVOL_RDONLY; 189 else 190 zv->zv_flags &= ~ZVOL_RDONLY; 191 } 192 193 int 194 zvol_get_stats(objset_t *os, nvlist_t *nv) 195 { 196 int error; 197 dmu_object_info_t doi; 198 uint64_t val; 199 200 201 error = zap_lookup(os, ZVOL_ZAP_OBJ, "size", 8, 1, &val); 202 if (error) 203 return (error); 204 205 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_VOLSIZE, val); 206 207 error = dmu_object_info(os, ZVOL_OBJ, &doi); 208 209 if (error == 0) { 210 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_VOLBLOCKSIZE, 211 doi.doi_data_block_size); 212 } 213 214 return (error); 215 } 216 217 /* 218 * Find a free minor number. 219 */ 220 static minor_t 221 zvol_minor_alloc(void) 222 { 223 minor_t minor; 224 225 ASSERT(MUTEX_HELD(&zvol_state_lock)); 226 227 for (minor = 1; minor <= ZVOL_MAX_MINOR; minor++) 228 if (ddi_get_soft_state(zvol_state, minor) == NULL) 229 return (minor); 230 231 return (0); 232 } 233 234 static zvol_state_t * 235 zvol_minor_lookup(const char *name) 236 { 237 minor_t minor; 238 zvol_state_t *zv; 239 240 ASSERT(MUTEX_HELD(&zvol_state_lock)); 241 242 for (minor = 1; minor <= ZVOL_MAX_MINOR; minor++) { 243 zv = ddi_get_soft_state(zvol_state, minor); 244 if (zv == NULL) 245 continue; 246 if (strcmp(zv->zv_name, name) == 0) 247 break; 248 } 249 250 return (zv); 251 } 252 253 /* extent mapping arg */ 254 struct maparg { 255 zvol_state_t *ma_zv; 256 uint64_t ma_blks; 257 }; 258 259 /*ARGSUSED*/ 260 static int 261 zvol_map_block(spa_t *spa, blkptr_t *bp, const zbookmark_t *zb, 262 const dnode_phys_t *dnp, void *arg) 263 { 264 struct maparg *ma = arg; 265 zvol_extent_t *ze; 266 int bs = ma->ma_zv->zv_volblocksize; 267 268 if (bp == NULL || zb->zb_object != ZVOL_OBJ || zb->zb_level != 0) 269 return (0); 270 271 VERIFY3U(ma->ma_blks, ==, zb->zb_blkid); 272 ma->ma_blks++; 273 274 /* Abort immediately if we have encountered gang blocks */ 275 if (BP_IS_GANG(bp)) 276 return (EFRAGS); 277 278 /* 279 * See if the block is at the end of the previous extent. 280 */ 281 ze = list_tail(&ma->ma_zv->zv_extents); 282 if (ze && 283 DVA_GET_VDEV(BP_IDENTITY(bp)) == DVA_GET_VDEV(&ze->ze_dva) && 284 DVA_GET_OFFSET(BP_IDENTITY(bp)) == 285 DVA_GET_OFFSET(&ze->ze_dva) + ze->ze_nblks * bs) { 286 ze->ze_nblks++; 287 return (0); 288 } 289 290 dprintf_bp(bp, "%s", "next blkptr:"); 291 292 /* start a new extent */ 293 ze = kmem_zalloc(sizeof (zvol_extent_t), KM_SLEEP); 294 ze->ze_dva = bp->blk_dva[0]; /* structure assignment */ 295 ze->ze_nblks = 1; 296 list_insert_tail(&ma->ma_zv->zv_extents, ze); 297 return (0); 298 } 299 300 static void 301 zvol_free_extents(zvol_state_t *zv) 302 { 303 zvol_extent_t *ze; 304 305 while (ze = list_head(&zv->zv_extents)) { 306 list_remove(&zv->zv_extents, ze); 307 kmem_free(ze, sizeof (zvol_extent_t)); 308 } 309 } 310 311 static int 312 zvol_get_lbas(zvol_state_t *zv) 313 { 314 struct maparg ma; 315 int err; 316 317 ma.ma_zv = zv; 318 ma.ma_blks = 0; 319 zvol_free_extents(zv); 320 321 err = traverse_dataset(dmu_objset_ds(zv->zv_objset), 0, 322 TRAVERSE_PRE | TRAVERSE_PREFETCH_METADATA, zvol_map_block, &ma); 323 if (err || ma.ma_blks != (zv->zv_volsize / zv->zv_volblocksize)) { 324 zvol_free_extents(zv); 325 return (err ? err : EIO); 326 } 327 328 return (0); 329 } 330 331 /* ARGSUSED */ 332 void 333 zvol_create_cb(objset_t *os, void *arg, cred_t *cr, dmu_tx_t *tx) 334 { 335 zfs_creat_t *zct = arg; 336 nvlist_t *nvprops = zct->zct_props; 337 int error; 338 uint64_t volblocksize, volsize; 339 340 VERIFY(nvlist_lookup_uint64(nvprops, 341 zfs_prop_to_name(ZFS_PROP_VOLSIZE), &volsize) == 0); 342 if (nvlist_lookup_uint64(nvprops, 343 zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE), &volblocksize) != 0) 344 volblocksize = zfs_prop_default_numeric(ZFS_PROP_VOLBLOCKSIZE); 345 346 /* 347 * These properties must be removed from the list so the generic 348 * property setting step won't apply to them. 349 */ 350 VERIFY(nvlist_remove_all(nvprops, 351 zfs_prop_to_name(ZFS_PROP_VOLSIZE)) == 0); 352 (void) nvlist_remove_all(nvprops, 353 zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE)); 354 355 error = dmu_object_claim(os, ZVOL_OBJ, DMU_OT_ZVOL, volblocksize, 356 DMU_OT_NONE, 0, tx); 357 ASSERT(error == 0); 358 359 error = zap_create_claim(os, ZVOL_ZAP_OBJ, DMU_OT_ZVOL_PROP, 360 DMU_OT_NONE, 0, tx); 361 ASSERT(error == 0); 362 363 error = zap_update(os, ZVOL_ZAP_OBJ, "size", 8, 1, &volsize, tx); 364 ASSERT(error == 0); 365 } 366 367 /* 368 * Replay a TX_WRITE ZIL transaction that didn't get committed 369 * after a system failure 370 */ 371 static int 372 zvol_replay_write(zvol_state_t *zv, lr_write_t *lr, boolean_t byteswap) 373 { 374 objset_t *os = zv->zv_objset; 375 char *data = (char *)(lr + 1); /* data follows lr_write_t */ 376 uint64_t off = lr->lr_offset; 377 uint64_t len = lr->lr_length; 378 dmu_tx_t *tx; 379 int error; 380 381 if (byteswap) 382 byteswap_uint64_array(lr, sizeof (*lr)); 383 384 tx = dmu_tx_create(os); 385 dmu_tx_hold_write(tx, ZVOL_OBJ, off, len); 386 error = dmu_tx_assign(tx, TXG_WAIT); 387 if (error) { 388 dmu_tx_abort(tx); 389 } else { 390 dmu_write(os, ZVOL_OBJ, off, len, data, tx); 391 dmu_tx_commit(tx); 392 } 393 394 return (error); 395 } 396 397 /* ARGSUSED */ 398 static int 399 zvol_replay_err(zvol_state_t *zv, lr_t *lr, boolean_t byteswap) 400 { 401 return (ENOTSUP); 402 } 403 404 /* 405 * Callback vectors for replaying records. 406 * Only TX_WRITE is needed for zvol. 407 */ 408 zil_replay_func_t *zvol_replay_vector[TX_MAX_TYPE] = { 409 zvol_replay_err, /* 0 no such transaction type */ 410 zvol_replay_err, /* TX_CREATE */ 411 zvol_replay_err, /* TX_MKDIR */ 412 zvol_replay_err, /* TX_MKXATTR */ 413 zvol_replay_err, /* TX_SYMLINK */ 414 zvol_replay_err, /* TX_REMOVE */ 415 zvol_replay_err, /* TX_RMDIR */ 416 zvol_replay_err, /* TX_LINK */ 417 zvol_replay_err, /* TX_RENAME */ 418 zvol_replay_write, /* TX_WRITE */ 419 zvol_replay_err, /* TX_TRUNCATE */ 420 zvol_replay_err, /* TX_SETATTR */ 421 zvol_replay_err, /* TX_ACL */ 422 }; 423 424 /* 425 * Create a minor node (plus a whole lot more) for the specified volume. 426 */ 427 int 428 zvol_create_minor(const char *name, major_t maj) 429 { 430 zvol_state_t *zv; 431 objset_t *os; 432 dmu_object_info_t doi; 433 uint64_t volsize; 434 minor_t minor = 0; 435 struct pathname linkpath; 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 /* lie and say we're read-only */ 449 error = dmu_objset_own(name, DMU_OST_ZVOL, B_TRUE, zvol_tag, &os); 450 451 if (error) { 452 mutex_exit(&zvol_state_lock); 453 return (error); 454 } 455 456 error = zap_lookup(os, ZVOL_ZAP_OBJ, "size", 8, 1, &volsize); 457 458 if (error) { 459 dmu_objset_disown(os, zvol_tag); 460 mutex_exit(&zvol_state_lock); 461 return (error); 462 } 463 464 /* 465 * If there's an existing /dev/zvol symlink, try to use the 466 * same minor number we used last time. 467 */ 468 devpath = kmem_asprintf("%s%s", ZVOL_FULL_DEV_DIR, name); 469 error = lookupname(devpath, UIO_SYSSPACE, NO_FOLLOW, NULL, &vp); 470 strfree(devpath); 471 472 if (error == 0 && vp->v_type != VLNK) 473 error = EINVAL; 474 475 if (error == 0) { 476 pn_alloc(&linkpath); 477 error = pn_getsymlink(vp, &linkpath, kcred); 478 if (error == 0) { 479 char *ms = strstr(linkpath.pn_path, ZVOL_PSEUDO_DEV); 480 if (ms != NULL) { 481 ms += strlen(ZVOL_PSEUDO_DEV); 482 minor = stoi(&ms); 483 } 484 } 485 pn_free(&linkpath); 486 } 487 488 if (vp != NULL) 489 VN_RELE(vp); 490 491 /* 492 * If we found a minor but it's already in use, we must pick a new one. 493 */ 494 if (minor != 0 && ddi_get_soft_state(zvol_state, minor) != NULL) 495 minor = 0; 496 497 if (minor == 0) 498 minor = zvol_minor_alloc(); 499 500 if (minor == 0) { 501 dmu_objset_disown(os, zvol_tag); 502 mutex_exit(&zvol_state_lock); 503 return (ENXIO); 504 } 505 506 if (ddi_soft_state_zalloc(zvol_state, minor) != DDI_SUCCESS) { 507 dmu_objset_disown(os, zvol_tag); 508 mutex_exit(&zvol_state_lock); 509 return (EAGAIN); 510 } 511 512 (void) ddi_prop_update_string(minor, zfs_dip, ZVOL_PROP_NAME, 513 (char *)name); 514 515 (void) sprintf(chrbuf, "%uc,raw", minor); 516 517 if (ddi_create_minor_node(zfs_dip, chrbuf, S_IFCHR, 518 minor, DDI_PSEUDO, 0) == DDI_FAILURE) { 519 ddi_soft_state_free(zvol_state, minor); 520 dmu_objset_disown(os, zvol_tag); 521 mutex_exit(&zvol_state_lock); 522 return (EAGAIN); 523 } 524 525 (void) sprintf(blkbuf, "%uc", minor); 526 527 if (ddi_create_minor_node(zfs_dip, blkbuf, S_IFBLK, 528 minor, DDI_PSEUDO, 0) == DDI_FAILURE) { 529 ddi_remove_minor_node(zfs_dip, chrbuf); 530 ddi_soft_state_free(zvol_state, minor); 531 dmu_objset_disown(os, zvol_tag); 532 mutex_exit(&zvol_state_lock); 533 return (EAGAIN); 534 } 535 536 zv = ddi_get_soft_state(zvol_state, minor); 537 538 (void) strcpy(zv->zv_name, name); 539 zv->zv_min_bs = DEV_BSHIFT; 540 zv->zv_minor = minor; 541 zv->zv_volsize = volsize; 542 zv->zv_objset = os; 543 zv->zv_issnap = dmu_objset_is_snapshot(os); 544 zv->zv_zilog = zil_open(os, zvol_get_data); 545 mutex_init(&zv->zv_znode.z_range_lock, NULL, MUTEX_DEFAULT, NULL); 546 avl_create(&zv->zv_znode.z_range_avl, zfs_range_compare, 547 sizeof (rl_t), offsetof(rl_t, r_node)); 548 list_create(&zv->zv_extents, sizeof (zvol_extent_t), 549 offsetof(zvol_extent_t, ze_node)); 550 /* get and cache the blocksize */ 551 error = dmu_object_info(os, ZVOL_OBJ, &doi); 552 ASSERT(error == 0); 553 zv->zv_volblocksize = doi.doi_data_block_size; 554 555 zil_replay(os, zv, zvol_replay_vector); 556 zvol_size_changed(zv, maj); 557 558 /* XXX this should handle the possible i/o error */ 559 VERIFY(dsl_prop_register(dmu_objset_ds(zv->zv_objset), 560 "readonly", zvol_readonly_changed_cb, zv) == 0); 561 562 zvol_minors++; 563 564 mutex_exit(&zvol_state_lock); 565 566 return (0); 567 } 568 569 /* 570 * Remove minor node for the specified volume. 571 */ 572 int 573 zvol_remove_minor(const char *name) 574 { 575 zvol_state_t *zv; 576 char namebuf[30]; 577 578 mutex_enter(&zvol_state_lock); 579 580 if ((zv = zvol_minor_lookup(name)) == NULL) { 581 mutex_exit(&zvol_state_lock); 582 return (ENXIO); 583 } 584 585 if (zv->zv_total_opens != 0) { 586 mutex_exit(&zvol_state_lock); 587 return (EBUSY); 588 } 589 590 (void) sprintf(namebuf, "%uc,raw", zv->zv_minor); 591 ddi_remove_minor_node(zfs_dip, namebuf); 592 593 (void) sprintf(namebuf, "%uc", zv->zv_minor); 594 ddi_remove_minor_node(zfs_dip, namebuf); 595 596 VERIFY(dsl_prop_unregister(dmu_objset_ds(zv->zv_objset), 597 "readonly", zvol_readonly_changed_cb, zv) == 0); 598 599 zil_close(zv->zv_zilog); 600 zv->zv_zilog = NULL; 601 dmu_objset_disown(zv->zv_objset, zvol_tag); 602 zv->zv_objset = NULL; 603 avl_destroy(&zv->zv_znode.z_range_avl); 604 mutex_destroy(&zv->zv_znode.z_range_lock); 605 606 ddi_soft_state_free(zvol_state, zv->zv_minor); 607 608 zvol_minors--; 609 610 mutex_exit(&zvol_state_lock); 611 612 return (0); 613 } 614 615 int 616 zvol_prealloc(zvol_state_t *zv) 617 { 618 objset_t *os = zv->zv_objset; 619 dmu_tx_t *tx; 620 uint64_t refd, avail, usedobjs, availobjs; 621 uint64_t resid = zv->zv_volsize; 622 uint64_t off = 0; 623 624 /* Check the space usage before attempting to allocate the space */ 625 dmu_objset_space(os, &refd, &avail, &usedobjs, &availobjs); 626 if (avail < zv->zv_volsize) 627 return (ENOSPC); 628 629 /* Free old extents if they exist */ 630 zvol_free_extents(zv); 631 632 while (resid != 0) { 633 int error; 634 uint64_t bytes = MIN(resid, SPA_MAXBLOCKSIZE); 635 636 tx = dmu_tx_create(os); 637 dmu_tx_hold_write(tx, ZVOL_OBJ, off, bytes); 638 error = dmu_tx_assign(tx, TXG_WAIT); 639 if (error) { 640 dmu_tx_abort(tx); 641 (void) dmu_free_long_range(os, ZVOL_OBJ, 0, off); 642 return (error); 643 } 644 dmu_prealloc(os, ZVOL_OBJ, off, bytes, tx); 645 dmu_tx_commit(tx); 646 off += bytes; 647 resid -= bytes; 648 } 649 txg_wait_synced(dmu_objset_pool(os), 0); 650 651 return (0); 652 } 653 654 int 655 zvol_update_volsize(zvol_state_t *zv, major_t maj, uint64_t volsize) 656 { 657 dmu_tx_t *tx; 658 int error; 659 660 ASSERT(MUTEX_HELD(&zvol_state_lock)); 661 662 tx = dmu_tx_create(zv->zv_objset); 663 dmu_tx_hold_zap(tx, ZVOL_ZAP_OBJ, TRUE, NULL); 664 error = dmu_tx_assign(tx, TXG_WAIT); 665 if (error) { 666 dmu_tx_abort(tx); 667 return (error); 668 } 669 670 error = zap_update(zv->zv_objset, ZVOL_ZAP_OBJ, "size", 8, 1, 671 &volsize, tx); 672 dmu_tx_commit(tx); 673 674 if (error == 0) 675 error = dmu_free_long_range(zv->zv_objset, 676 ZVOL_OBJ, volsize, DMU_OBJECT_END); 677 678 /* 679 * If we are using a faked-up state (zv_minor == 0) then don't 680 * try to update the in-core zvol state. 681 */ 682 if (error == 0 && zv->zv_minor) { 683 zv->zv_volsize = volsize; 684 zvol_size_changed(zv, maj); 685 } 686 return (error); 687 } 688 689 int 690 zvol_set_volsize(const char *name, major_t maj, uint64_t volsize) 691 { 692 zvol_state_t *zv; 693 int error; 694 dmu_object_info_t doi; 695 uint64_t old_volsize = 0ULL; 696 zvol_state_t state = { 0 }; 697 698 mutex_enter(&zvol_state_lock); 699 700 if ((zv = zvol_minor_lookup(name)) == NULL) { 701 /* 702 * If we are doing a "zfs clone -o volsize=", then the 703 * minor node won't exist yet. 704 */ 705 error = dmu_objset_own(name, DMU_OST_ZVOL, B_FALSE, FTAG, 706 &state.zv_objset); 707 if (error != 0) 708 goto out; 709 zv = &state; 710 } 711 old_volsize = zv->zv_volsize; 712 713 if ((error = dmu_object_info(zv->zv_objset, ZVOL_OBJ, &doi)) != 0 || 714 (error = zvol_check_volsize(volsize, 715 doi.doi_data_block_size)) != 0) 716 goto out; 717 718 if (zv->zv_flags & ZVOL_RDONLY || zv->zv_issnap) { 719 error = EROFS; 720 goto out; 721 } 722 723 error = zvol_update_volsize(zv, maj, volsize); 724 725 /* 726 * Reinitialize the dump area to the new size. If we 727 * failed to resize the dump area then restore the it back to 728 * it's original size. 729 */ 730 if (error == 0 && zv->zv_flags & ZVOL_DUMPIFIED) { 731 if ((error = zvol_dumpify(zv)) != 0 || 732 (error = dumpvp_resize()) != 0) { 733 (void) zvol_update_volsize(zv, maj, old_volsize); 734 error = zvol_dumpify(zv); 735 } 736 } 737 738 /* 739 * Generate a LUN expansion event. 740 */ 741 if (error == 0) { 742 sysevent_id_t eid; 743 nvlist_t *attr; 744 char *physpath = kmem_zalloc(MAXPATHLEN, KM_SLEEP); 745 746 (void) snprintf(physpath, MAXPATHLEN, "%s%uc", ZVOL_PSEUDO_DEV, 747 zv->zv_minor); 748 749 VERIFY(nvlist_alloc(&attr, NV_UNIQUE_NAME, KM_SLEEP) == 0); 750 VERIFY(nvlist_add_string(attr, DEV_PHYS_PATH, physpath) == 0); 751 752 (void) ddi_log_sysevent(zfs_dip, SUNW_VENDOR, EC_DEV_STATUS, 753 ESC_DEV_DLE, attr, &eid, DDI_SLEEP); 754 755 nvlist_free(attr); 756 kmem_free(physpath, MAXPATHLEN); 757 } 758 759 out: 760 if (state.zv_objset) 761 dmu_objset_disown(state.zv_objset, FTAG); 762 763 mutex_exit(&zvol_state_lock); 764 765 return (error); 766 } 767 768 int 769 zvol_set_volblocksize(const char *name, uint64_t volblocksize) 770 { 771 zvol_state_t *zv; 772 dmu_tx_t *tx; 773 int error; 774 boolean_t needlock; 775 776 /* 777 * The lock may already be held if we are being called from 778 * zvol_dump_init(). 779 */ 780 needlock = !MUTEX_HELD(&zvol_state_lock); 781 if (needlock) 782 mutex_enter(&zvol_state_lock); 783 784 if ((zv = zvol_minor_lookup(name)) == NULL) { 785 if (needlock) 786 mutex_exit(&zvol_state_lock); 787 return (ENXIO); 788 } 789 if (zv->zv_flags & ZVOL_RDONLY || zv->zv_issnap) { 790 if (needlock) 791 mutex_exit(&zvol_state_lock); 792 return (EROFS); 793 } 794 795 tx = dmu_tx_create(zv->zv_objset); 796 dmu_tx_hold_bonus(tx, ZVOL_OBJ); 797 error = dmu_tx_assign(tx, TXG_WAIT); 798 if (error) { 799 dmu_tx_abort(tx); 800 } else { 801 error = dmu_object_set_blocksize(zv->zv_objset, ZVOL_OBJ, 802 volblocksize, 0, tx); 803 if (error == ENOTSUP) 804 error = EBUSY; 805 dmu_tx_commit(tx); 806 if (error == 0) 807 zv->zv_volblocksize = volblocksize; 808 } 809 810 if (needlock) 811 mutex_exit(&zvol_state_lock); 812 813 return (error); 814 } 815 816 /*ARGSUSED*/ 817 int 818 zvol_open(dev_t *devp, int flag, int otyp, cred_t *cr) 819 { 820 minor_t minor = getminor(*devp); 821 zvol_state_t *zv; 822 823 if (minor == 0) /* This is the control device */ 824 return (0); 825 826 mutex_enter(&zvol_state_lock); 827 828 zv = ddi_get_soft_state(zvol_state, minor); 829 if (zv == NULL) { 830 mutex_exit(&zvol_state_lock); 831 return (ENXIO); 832 } 833 834 ASSERT(zv->zv_objset != NULL); 835 836 if ((flag & FWRITE) && 837 (zv->zv_flags & ZVOL_RDONLY || zv->zv_issnap)) { 838 mutex_exit(&zvol_state_lock); 839 return (EROFS); 840 } 841 if (zv->zv_flags & ZVOL_EXCL) { 842 mutex_exit(&zvol_state_lock); 843 return (EBUSY); 844 } 845 if (flag & FEXCL) { 846 if (zv->zv_total_opens != 0) { 847 mutex_exit(&zvol_state_lock); 848 return (EBUSY); 849 } 850 zv->zv_flags |= ZVOL_EXCL; 851 } 852 853 if (zv->zv_open_count[otyp] == 0 || otyp == OTYP_LYR) { 854 zv->zv_open_count[otyp]++; 855 zv->zv_total_opens++; 856 } 857 858 mutex_exit(&zvol_state_lock); 859 860 return (0); 861 } 862 863 /*ARGSUSED*/ 864 int 865 zvol_close(dev_t dev, int flag, int otyp, cred_t *cr) 866 { 867 minor_t minor = getminor(dev); 868 zvol_state_t *zv; 869 870 if (minor == 0) /* This is the control device */ 871 return (0); 872 873 mutex_enter(&zvol_state_lock); 874 875 zv = ddi_get_soft_state(zvol_state, minor); 876 if (zv == NULL) { 877 mutex_exit(&zvol_state_lock); 878 return (ENXIO); 879 } 880 881 if (zv->zv_flags & ZVOL_EXCL) { 882 ASSERT(zv->zv_total_opens == 1); 883 zv->zv_flags &= ~ZVOL_EXCL; 884 } 885 886 /* 887 * If the open count is zero, this is a spurious close. 888 * That indicates a bug in the kernel / DDI framework. 889 */ 890 ASSERT(zv->zv_open_count[otyp] != 0); 891 ASSERT(zv->zv_total_opens != 0); 892 893 /* 894 * You may get multiple opens, but only one close. 895 */ 896 zv->zv_open_count[otyp]--; 897 zv->zv_total_opens--; 898 899 mutex_exit(&zvol_state_lock); 900 901 return (0); 902 } 903 904 static void 905 zvol_get_done(dmu_buf_t *db, void *vzgd) 906 { 907 zgd_t *zgd = (zgd_t *)vzgd; 908 rl_t *rl = zgd->zgd_rl; 909 910 dmu_buf_rele(db, vzgd); 911 zfs_range_unlock(rl); 912 zil_add_block(zgd->zgd_zilog, zgd->zgd_bp); 913 kmem_free(zgd, sizeof (zgd_t)); 914 } 915 916 /* 917 * Get data to generate a TX_WRITE intent log record. 918 */ 919 static int 920 zvol_get_data(void *arg, lr_write_t *lr, char *buf, zio_t *zio) 921 { 922 zvol_state_t *zv = arg; 923 objset_t *os = zv->zv_objset; 924 dmu_buf_t *db; 925 rl_t *rl; 926 zgd_t *zgd; 927 uint64_t boff; /* block starting offset */ 928 int dlen = lr->lr_length; /* length of user data */ 929 int error; 930 931 ASSERT(zio); 932 ASSERT(dlen != 0); 933 934 /* 935 * Write records come in two flavors: immediate and indirect. 936 * For small writes it's cheaper to store the data with the 937 * log record (immediate); for large writes it's cheaper to 938 * sync the data and get a pointer to it (indirect) so that 939 * we don't have to write the data twice. 940 */ 941 if (buf != NULL) /* immediate write */ 942 return (dmu_read(os, ZVOL_OBJ, lr->lr_offset, dlen, buf, 943 DMU_READ_NO_PREFETCH)); 944 945 zgd = (zgd_t *)kmem_alloc(sizeof (zgd_t), KM_SLEEP); 946 zgd->zgd_zilog = zv->zv_zilog; 947 zgd->zgd_bp = &lr->lr_blkptr; 948 949 /* 950 * Lock the range of the block to ensure that when the data is 951 * written out and its checksum is being calculated that no other 952 * thread can change the block. 953 */ 954 boff = P2ALIGN_TYPED(lr->lr_offset, zv->zv_volblocksize, uint64_t); 955 rl = zfs_range_lock(&zv->zv_znode, boff, zv->zv_volblocksize, 956 RL_READER); 957 zgd->zgd_rl = rl; 958 959 VERIFY(0 == dmu_buf_hold(os, ZVOL_OBJ, lr->lr_offset, zgd, &db)); 960 error = dmu_sync(zio, db, &lr->lr_blkptr, 961 lr->lr_common.lrc_txg, zvol_get_done, zgd); 962 if (error == 0) 963 zil_add_block(zv->zv_zilog, &lr->lr_blkptr); 964 /* 965 * If we get EINPROGRESS, then we need to wait for a 966 * write IO initiated by dmu_sync() to complete before 967 * we can release this dbuf. We will finish everything 968 * up in the zvol_get_done() callback. 969 */ 970 if (error == EINPROGRESS) 971 return (0); 972 dmu_buf_rele(db, zgd); 973 zfs_range_unlock(rl); 974 kmem_free(zgd, sizeof (zgd_t)); 975 return (error); 976 } 977 978 /* 979 * zvol_log_write() handles synchronous writes using TX_WRITE ZIL transactions. 980 * 981 * We store data in the log buffers if it's small enough. 982 * Otherwise we will later flush the data out via dmu_sync(). 983 */ 984 ssize_t zvol_immediate_write_sz = 32768; 985 986 static void 987 zvol_log_write(zvol_state_t *zv, dmu_tx_t *tx, offset_t off, ssize_t resid, 988 boolean_t sync) 989 { 990 uint32_t blocksize = zv->zv_volblocksize; 991 zilog_t *zilog = zv->zv_zilog; 992 boolean_t slogging; 993 ssize_t immediate_write_sz; 994 995 if (zil_disable) 996 return; 997 998 if (zilog->zl_replay) { 999 dsl_dataset_dirty(dmu_objset_ds(zilog->zl_os), tx); 1000 zilog->zl_replayed_seq[dmu_tx_get_txg(tx) & TXG_MASK] = 1001 zilog->zl_replaying_seq; 1002 return; 1003 } 1004 1005 immediate_write_sz = (zilog->zl_logbias == ZFS_LOGBIAS_THROUGHPUT) 1006 ? 0 : zvol_immediate_write_sz; 1007 1008 slogging = spa_has_slogs(zilog->zl_spa) && 1009 (zilog->zl_logbias == ZFS_LOGBIAS_LATENCY); 1010 1011 while (resid) { 1012 itx_t *itx; 1013 lr_write_t *lr; 1014 ssize_t len; 1015 itx_wr_state_t write_state; 1016 1017 /* 1018 * Unlike zfs_log_write() we can be called with 1019 * upto DMU_MAX_ACCESS/2 (5MB) writes. 1020 */ 1021 if (blocksize > immediate_write_sz && !slogging && 1022 resid >= blocksize && off % blocksize == 0) { 1023 write_state = WR_INDIRECT; /* uses dmu_sync */ 1024 len = blocksize; 1025 } else if (sync) { 1026 write_state = WR_COPIED; 1027 len = MIN(ZIL_MAX_LOG_DATA, resid); 1028 } else { 1029 write_state = WR_NEED_COPY; 1030 len = MIN(ZIL_MAX_LOG_DATA, resid); 1031 } 1032 1033 itx = zil_itx_create(TX_WRITE, sizeof (*lr) + 1034 (write_state == WR_COPIED ? len : 0)); 1035 lr = (lr_write_t *)&itx->itx_lr; 1036 if (write_state == WR_COPIED && dmu_read(zv->zv_objset, 1037 ZVOL_OBJ, off, len, lr + 1, DMU_READ_NO_PREFETCH) != 0) { 1038 kmem_free(itx, offsetof(itx_t, itx_lr) + 1039 itx->itx_lr.lrc_reclen); 1040 itx = zil_itx_create(TX_WRITE, sizeof (*lr)); 1041 lr = (lr_write_t *)&itx->itx_lr; 1042 write_state = WR_NEED_COPY; 1043 } 1044 1045 itx->itx_wr_state = write_state; 1046 if (write_state == WR_NEED_COPY) 1047 itx->itx_sod += len; 1048 lr->lr_foid = ZVOL_OBJ; 1049 lr->lr_offset = off; 1050 lr->lr_length = len; 1051 lr->lr_blkoff = off - P2ALIGN_TYPED(off, blocksize, uint64_t); 1052 BP_ZERO(&lr->lr_blkptr); 1053 1054 itx->itx_private = zv; 1055 itx->itx_sync = sync; 1056 1057 (void) zil_itx_assign(zilog, itx, tx); 1058 1059 off += len; 1060 resid -= len; 1061 } 1062 } 1063 1064 static int 1065 zvol_dumpio_vdev(vdev_t *vd, void *addr, uint64_t offset, uint64_t size, 1066 boolean_t doread, boolean_t isdump) 1067 { 1068 vdev_disk_t *dvd; 1069 int c; 1070 int numerrors = 0; 1071 1072 for (c = 0; c < vd->vdev_children; c++) { 1073 ASSERT(vd->vdev_ops == &vdev_mirror_ops || 1074 vd->vdev_ops == &vdev_replacing_ops || 1075 vd->vdev_ops == &vdev_spare_ops); 1076 int err = zvol_dumpio_vdev(vd->vdev_child[c], 1077 addr, offset, size, doread, isdump); 1078 if (err != 0) { 1079 numerrors++; 1080 } else if (doread) { 1081 break; 1082 } 1083 } 1084 1085 if (!vd->vdev_ops->vdev_op_leaf) 1086 return (numerrors < vd->vdev_children ? 0 : EIO); 1087 1088 if (doread && !vdev_readable(vd)) 1089 return (EIO); 1090 else if (!doread && !vdev_writeable(vd)) 1091 return (EIO); 1092 1093 dvd = vd->vdev_tsd; 1094 ASSERT3P(dvd, !=, NULL); 1095 offset += VDEV_LABEL_START_SIZE; 1096 1097 if (ddi_in_panic() || isdump) { 1098 ASSERT(!doread); 1099 if (doread) 1100 return (EIO); 1101 return (ldi_dump(dvd->vd_lh, addr, lbtodb(offset), 1102 lbtodb(size))); 1103 } else { 1104 return (vdev_disk_physio(dvd->vd_lh, addr, size, offset, 1105 doread ? B_READ : B_WRITE)); 1106 } 1107 } 1108 1109 static int 1110 zvol_dumpio(zvol_state_t *zv, void *addr, uint64_t offset, uint64_t size, 1111 boolean_t doread, boolean_t isdump) 1112 { 1113 vdev_t *vd; 1114 int error; 1115 zvol_extent_t *ze; 1116 spa_t *spa = dmu_objset_spa(zv->zv_objset); 1117 1118 /* Must be sector aligned, and not stradle a block boundary. */ 1119 if (P2PHASE(offset, DEV_BSIZE) || P2PHASE(size, DEV_BSIZE) || 1120 P2BOUNDARY(offset, size, zv->zv_volblocksize)) { 1121 return (EINVAL); 1122 } 1123 ASSERT(size <= zv->zv_volblocksize); 1124 1125 /* Locate the extent this belongs to */ 1126 ze = list_head(&zv->zv_extents); 1127 while (offset >= ze->ze_nblks * zv->zv_volblocksize) { 1128 offset -= ze->ze_nblks * zv->zv_volblocksize; 1129 ze = list_next(&zv->zv_extents, ze); 1130 } 1131 spa_config_enter(spa, SCL_STATE, FTAG, RW_READER); 1132 vd = vdev_lookup_top(spa, DVA_GET_VDEV(&ze->ze_dva)); 1133 offset += DVA_GET_OFFSET(&ze->ze_dva); 1134 error = zvol_dumpio_vdev(vd, addr, offset, size, doread, isdump); 1135 spa_config_exit(spa, SCL_STATE, FTAG); 1136 return (error); 1137 } 1138 1139 int 1140 zvol_strategy(buf_t *bp) 1141 { 1142 zvol_state_t *zv = ddi_get_soft_state(zvol_state, getminor(bp->b_edev)); 1143 uint64_t off, volsize; 1144 size_t resid; 1145 char *addr; 1146 objset_t *os; 1147 rl_t *rl; 1148 int error = 0; 1149 boolean_t doread = bp->b_flags & B_READ; 1150 boolean_t is_dump = zv->zv_flags & ZVOL_DUMPIFIED; 1151 boolean_t sync; 1152 1153 if (zv == NULL) { 1154 bioerror(bp, ENXIO); 1155 biodone(bp); 1156 return (0); 1157 } 1158 1159 if (getminor(bp->b_edev) == 0) { 1160 bioerror(bp, EINVAL); 1161 biodone(bp); 1162 return (0); 1163 } 1164 1165 if (!(bp->b_flags & B_READ) && 1166 (zv->zv_flags & ZVOL_RDONLY || zv->zv_issnap)) { 1167 bioerror(bp, EROFS); 1168 biodone(bp); 1169 return (0); 1170 } 1171 1172 off = ldbtob(bp->b_blkno); 1173 volsize = zv->zv_volsize; 1174 1175 os = zv->zv_objset; 1176 ASSERT(os != NULL); 1177 1178 bp_mapin(bp); 1179 addr = bp->b_un.b_addr; 1180 resid = bp->b_bcount; 1181 1182 if (resid > 0 && (off < 0 || off >= volsize)) { 1183 bioerror(bp, EIO); 1184 biodone(bp); 1185 return (0); 1186 } 1187 1188 sync = !(bp->b_flags & B_ASYNC) && !doread && !is_dump && 1189 !(zv->zv_flags & ZVOL_WCE) && !zil_disable; 1190 1191 /* 1192 * There must be no buffer changes when doing a dmu_sync() because 1193 * we can't change the data whilst calculating the checksum. 1194 */ 1195 rl = zfs_range_lock(&zv->zv_znode, off, resid, 1196 doread ? RL_READER : RL_WRITER); 1197 1198 while (resid != 0 && off < volsize) { 1199 size_t size = MIN(resid, zvol_maxphys); 1200 if (is_dump) { 1201 size = MIN(size, P2END(off, zv->zv_volblocksize) - off); 1202 error = zvol_dumpio(zv, addr, off, size, 1203 doread, B_FALSE); 1204 } else if (doread) { 1205 error = dmu_read(os, ZVOL_OBJ, off, size, addr, 1206 DMU_READ_PREFETCH); 1207 } else { 1208 dmu_tx_t *tx = dmu_tx_create(os); 1209 dmu_tx_hold_write(tx, ZVOL_OBJ, off, size); 1210 error = dmu_tx_assign(tx, TXG_WAIT); 1211 if (error) { 1212 dmu_tx_abort(tx); 1213 } else { 1214 dmu_write(os, ZVOL_OBJ, off, size, addr, tx); 1215 zvol_log_write(zv, tx, off, size, sync); 1216 dmu_tx_commit(tx); 1217 } 1218 } 1219 if (error) { 1220 /* convert checksum errors into IO errors */ 1221 if (error == ECKSUM) 1222 error = EIO; 1223 break; 1224 } 1225 off += size; 1226 addr += size; 1227 resid -= size; 1228 } 1229 zfs_range_unlock(rl); 1230 1231 if ((bp->b_resid = resid) == bp->b_bcount) 1232 bioerror(bp, off > volsize ? EINVAL : error); 1233 1234 if (sync) 1235 zil_commit(zv->zv_zilog, UINT64_MAX, ZVOL_OBJ); 1236 biodone(bp); 1237 1238 return (0); 1239 } 1240 1241 /* 1242 * Set the buffer count to the zvol maximum transfer. 1243 * Using our own routine instead of the default minphys() 1244 * means that for larger writes we write bigger buffers on X86 1245 * (128K instead of 56K) and flush the disk write cache less often 1246 * (every zvol_maxphys - currently 1MB) instead of minphys (currently 1247 * 56K on X86 and 128K on sparc). 1248 */ 1249 void 1250 zvol_minphys(struct buf *bp) 1251 { 1252 if (bp->b_bcount > zvol_maxphys) 1253 bp->b_bcount = zvol_maxphys; 1254 } 1255 1256 int 1257 zvol_dump(dev_t dev, caddr_t addr, daddr_t blkno, int nblocks) 1258 { 1259 minor_t minor = getminor(dev); 1260 zvol_state_t *zv; 1261 int error = 0; 1262 uint64_t size; 1263 uint64_t boff; 1264 uint64_t resid; 1265 1266 if (minor == 0) /* This is the control device */ 1267 return (ENXIO); 1268 1269 zv = ddi_get_soft_state(zvol_state, minor); 1270 if (zv == NULL) 1271 return (ENXIO); 1272 1273 boff = ldbtob(blkno); 1274 resid = ldbtob(nblocks); 1275 1276 VERIFY3U(boff + resid, <=, zv->zv_volsize); 1277 1278 while (resid) { 1279 size = MIN(resid, P2END(boff, zv->zv_volblocksize) - boff); 1280 error = zvol_dumpio(zv, addr, boff, size, B_FALSE, B_TRUE); 1281 if (error) 1282 break; 1283 boff += size; 1284 addr += size; 1285 resid -= size; 1286 } 1287 1288 return (error); 1289 } 1290 1291 /*ARGSUSED*/ 1292 int 1293 zvol_read(dev_t dev, uio_t *uio, cred_t *cr) 1294 { 1295 minor_t minor = getminor(dev); 1296 zvol_state_t *zv; 1297 uint64_t volsize; 1298 rl_t *rl; 1299 int error = 0; 1300 1301 if (minor == 0) /* This is the control device */ 1302 return (ENXIO); 1303 1304 zv = ddi_get_soft_state(zvol_state, minor); 1305 if (zv == NULL) 1306 return (ENXIO); 1307 1308 volsize = zv->zv_volsize; 1309 if (uio->uio_resid > 0 && 1310 (uio->uio_loffset < 0 || uio->uio_loffset >= volsize)) 1311 return (EIO); 1312 1313 if (zv->zv_flags & ZVOL_DUMPIFIED) { 1314 error = physio(zvol_strategy, NULL, dev, B_READ, 1315 zvol_minphys, uio); 1316 return (error); 1317 } 1318 1319 rl = zfs_range_lock(&zv->zv_znode, uio->uio_loffset, uio->uio_resid, 1320 RL_READER); 1321 while (uio->uio_resid > 0 && uio->uio_loffset < volsize) { 1322 uint64_t bytes = MIN(uio->uio_resid, DMU_MAX_ACCESS >> 1); 1323 1324 /* don't read past the end */ 1325 if (bytes > volsize - uio->uio_loffset) 1326 bytes = volsize - uio->uio_loffset; 1327 1328 error = dmu_read_uio(zv->zv_objset, ZVOL_OBJ, uio, bytes); 1329 if (error) { 1330 /* convert checksum errors into IO errors */ 1331 if (error == ECKSUM) 1332 error = EIO; 1333 break; 1334 } 1335 } 1336 zfs_range_unlock(rl); 1337 return (error); 1338 } 1339 1340 /*ARGSUSED*/ 1341 int 1342 zvol_write(dev_t dev, uio_t *uio, cred_t *cr) 1343 { 1344 minor_t minor = getminor(dev); 1345 zvol_state_t *zv; 1346 uint64_t volsize; 1347 rl_t *rl; 1348 int error = 0; 1349 boolean_t sync; 1350 1351 if (minor == 0) /* This is the control device */ 1352 return (ENXIO); 1353 1354 zv = ddi_get_soft_state(zvol_state, minor); 1355 if (zv == NULL) 1356 return (ENXIO); 1357 1358 volsize = zv->zv_volsize; 1359 if (uio->uio_resid > 0 && 1360 (uio->uio_loffset < 0 || uio->uio_loffset >= volsize)) 1361 return (EIO); 1362 1363 if (zv->zv_flags & ZVOL_DUMPIFIED) { 1364 error = physio(zvol_strategy, NULL, dev, B_WRITE, 1365 zvol_minphys, uio); 1366 return (error); 1367 } 1368 1369 sync = !(zv->zv_flags & ZVOL_WCE) && !zil_disable; 1370 1371 rl = zfs_range_lock(&zv->zv_znode, uio->uio_loffset, uio->uio_resid, 1372 RL_WRITER); 1373 while (uio->uio_resid > 0 && uio->uio_loffset < volsize) { 1374 uint64_t bytes = MIN(uio->uio_resid, DMU_MAX_ACCESS >> 1); 1375 uint64_t off = uio->uio_loffset; 1376 dmu_tx_t *tx = dmu_tx_create(zv->zv_objset); 1377 1378 if (bytes > volsize - off) /* don't write past the end */ 1379 bytes = volsize - off; 1380 1381 dmu_tx_hold_write(tx, ZVOL_OBJ, off, bytes); 1382 error = dmu_tx_assign(tx, TXG_WAIT); 1383 if (error) { 1384 dmu_tx_abort(tx); 1385 break; 1386 } 1387 error = dmu_write_uio(zv->zv_objset, ZVOL_OBJ, uio, bytes, tx); 1388 if (error == 0) 1389 zvol_log_write(zv, tx, off, bytes, sync); 1390 dmu_tx_commit(tx); 1391 1392 if (error) 1393 break; 1394 } 1395 zfs_range_unlock(rl); 1396 if (sync) 1397 zil_commit(zv->zv_zilog, UINT64_MAX, ZVOL_OBJ); 1398 return (error); 1399 } 1400 1401 int 1402 zvol_getefi(void *arg, int flag, uint64_t vs, uint8_t bs) 1403 { 1404 struct uuid uuid = EFI_RESERVED; 1405 efi_gpe_t gpe = { 0 }; 1406 uint32_t crc; 1407 dk_efi_t efi; 1408 int length; 1409 char *ptr; 1410 1411 if (ddi_copyin(arg, &efi, sizeof (dk_efi_t), flag)) 1412 return (EFAULT); 1413 ptr = (char *)(uintptr_t)efi.dki_data_64; 1414 length = efi.dki_length; 1415 /* 1416 * Some clients may attempt to request a PMBR for the 1417 * zvol. Currently this interface will return EINVAL to 1418 * such requests. These requests could be supported by 1419 * adding a check for lba == 0 and consing up an appropriate 1420 * PMBR. 1421 */ 1422 if (efi.dki_lba < 1 || efi.dki_lba > 2 || length <= 0) 1423 return (EINVAL); 1424 1425 gpe.efi_gpe_StartingLBA = LE_64(34ULL); 1426 gpe.efi_gpe_EndingLBA = LE_64((vs >> bs) - 1); 1427 UUID_LE_CONVERT(gpe.efi_gpe_PartitionTypeGUID, uuid); 1428 1429 if (efi.dki_lba == 1) { 1430 efi_gpt_t gpt = { 0 }; 1431 1432 gpt.efi_gpt_Signature = LE_64(EFI_SIGNATURE); 1433 gpt.efi_gpt_Revision = LE_32(EFI_VERSION_CURRENT); 1434 gpt.efi_gpt_HeaderSize = LE_32(sizeof (gpt)); 1435 gpt.efi_gpt_MyLBA = LE_64(1ULL); 1436 gpt.efi_gpt_FirstUsableLBA = LE_64(34ULL); 1437 gpt.efi_gpt_LastUsableLBA = LE_64((vs >> bs) - 1); 1438 gpt.efi_gpt_PartitionEntryLBA = LE_64(2ULL); 1439 gpt.efi_gpt_NumberOfPartitionEntries = LE_32(1); 1440 gpt.efi_gpt_SizeOfPartitionEntry = 1441 LE_32(sizeof (efi_gpe_t)); 1442 CRC32(crc, &gpe, sizeof (gpe), -1U, crc32_table); 1443 gpt.efi_gpt_PartitionEntryArrayCRC32 = LE_32(~crc); 1444 CRC32(crc, &gpt, sizeof (gpt), -1U, crc32_table); 1445 gpt.efi_gpt_HeaderCRC32 = LE_32(~crc); 1446 if (ddi_copyout(&gpt, ptr, MIN(sizeof (gpt), length), 1447 flag)) 1448 return (EFAULT); 1449 ptr += sizeof (gpt); 1450 length -= sizeof (gpt); 1451 } 1452 if (length > 0 && ddi_copyout(&gpe, ptr, MIN(sizeof (gpe), 1453 length), flag)) 1454 return (EFAULT); 1455 return (0); 1456 } 1457 1458 /* 1459 * Dirtbag ioctls to support mkfs(1M) for UFS filesystems. See dkio(7I). 1460 */ 1461 /*ARGSUSED*/ 1462 int 1463 zvol_ioctl(dev_t dev, int cmd, intptr_t arg, int flag, cred_t *cr, int *rvalp) 1464 { 1465 zvol_state_t *zv; 1466 struct dk_cinfo dki; 1467 struct dk_minfo dkm; 1468 struct dk_callback *dkc; 1469 int error = 0; 1470 rl_t *rl; 1471 1472 mutex_enter(&zvol_state_lock); 1473 1474 zv = ddi_get_soft_state(zvol_state, getminor(dev)); 1475 1476 if (zv == NULL) { 1477 mutex_exit(&zvol_state_lock); 1478 return (ENXIO); 1479 } 1480 ASSERT(zv->zv_total_opens > 0); 1481 1482 switch (cmd) { 1483 1484 case DKIOCINFO: 1485 bzero(&dki, sizeof (dki)); 1486 (void) strcpy(dki.dki_cname, "zvol"); 1487 (void) strcpy(dki.dki_dname, "zvol"); 1488 dki.dki_ctype = DKC_UNKNOWN; 1489 dki.dki_maxtransfer = 1 << (SPA_MAXBLOCKSHIFT - zv->zv_min_bs); 1490 mutex_exit(&zvol_state_lock); 1491 if (ddi_copyout(&dki, (void *)arg, sizeof (dki), flag)) 1492 error = EFAULT; 1493 return (error); 1494 1495 case DKIOCGMEDIAINFO: 1496 bzero(&dkm, sizeof (dkm)); 1497 dkm.dki_lbsize = 1U << zv->zv_min_bs; 1498 dkm.dki_capacity = zv->zv_volsize >> zv->zv_min_bs; 1499 dkm.dki_media_type = DK_UNKNOWN; 1500 mutex_exit(&zvol_state_lock); 1501 if (ddi_copyout(&dkm, (void *)arg, sizeof (dkm), flag)) 1502 error = EFAULT; 1503 return (error); 1504 1505 case DKIOCGETEFI: 1506 { 1507 uint64_t vs = zv->zv_volsize; 1508 uint8_t bs = zv->zv_min_bs; 1509 1510 mutex_exit(&zvol_state_lock); 1511 error = zvol_getefi((void *)arg, flag, vs, bs); 1512 return (error); 1513 } 1514 1515 case DKIOCFLUSHWRITECACHE: 1516 dkc = (struct dk_callback *)arg; 1517 mutex_exit(&zvol_state_lock); 1518 zil_commit(zv->zv_zilog, UINT64_MAX, ZVOL_OBJ); 1519 if ((flag & FKIOCTL) && dkc != NULL && dkc->dkc_callback) { 1520 (*dkc->dkc_callback)(dkc->dkc_cookie, error); 1521 error = 0; 1522 } 1523 return (error); 1524 1525 case DKIOCGETWCE: 1526 { 1527 int wce = (zv->zv_flags & ZVOL_WCE) ? 1 : 0; 1528 if (ddi_copyout(&wce, (void *)arg, sizeof (int), 1529 flag)) 1530 error = EFAULT; 1531 break; 1532 } 1533 case DKIOCSETWCE: 1534 { 1535 int wce; 1536 if (ddi_copyin((void *)arg, &wce, sizeof (int), 1537 flag)) { 1538 error = EFAULT; 1539 break; 1540 } 1541 if (wce) { 1542 zv->zv_flags |= ZVOL_WCE; 1543 mutex_exit(&zvol_state_lock); 1544 } else { 1545 zv->zv_flags &= ~ZVOL_WCE; 1546 mutex_exit(&zvol_state_lock); 1547 zil_commit(zv->zv_zilog, UINT64_MAX, ZVOL_OBJ); 1548 } 1549 return (0); 1550 } 1551 1552 case DKIOCGGEOM: 1553 case DKIOCGVTOC: 1554 /* 1555 * commands using these (like prtvtoc) expect ENOTSUP 1556 * since we're emulating an EFI label 1557 */ 1558 error = ENOTSUP; 1559 break; 1560 1561 case DKIOCDUMPINIT: 1562 rl = zfs_range_lock(&zv->zv_znode, 0, zv->zv_volsize, 1563 RL_WRITER); 1564 error = zvol_dumpify(zv); 1565 zfs_range_unlock(rl); 1566 break; 1567 1568 case DKIOCDUMPFINI: 1569 if (!(zv->zv_flags & ZVOL_DUMPIFIED)) 1570 break; 1571 rl = zfs_range_lock(&zv->zv_znode, 0, zv->zv_volsize, 1572 RL_WRITER); 1573 error = zvol_dump_fini(zv); 1574 zfs_range_unlock(rl); 1575 break; 1576 1577 default: 1578 error = ENOTTY; 1579 break; 1580 1581 } 1582 mutex_exit(&zvol_state_lock); 1583 return (error); 1584 } 1585 1586 int 1587 zvol_busy(void) 1588 { 1589 return (zvol_minors != 0); 1590 } 1591 1592 void 1593 zvol_init(void) 1594 { 1595 VERIFY(ddi_soft_state_init(&zvol_state, sizeof (zvol_state_t), 1) == 0); 1596 mutex_init(&zvol_state_lock, NULL, MUTEX_DEFAULT, NULL); 1597 } 1598 1599 void 1600 zvol_fini(void) 1601 { 1602 mutex_destroy(&zvol_state_lock); 1603 ddi_soft_state_fini(&zvol_state); 1604 } 1605 1606 static boolean_t 1607 zvol_is_swap(zvol_state_t *zv) 1608 { 1609 vnode_t *vp; 1610 boolean_t ret = B_FALSE; 1611 char *devpath; 1612 int error; 1613 1614 devpath = kmem_asprintf("%s%s", ZVOL_FULL_DEV_DIR, zv->zv_name); 1615 error = lookupname(devpath, UIO_SYSSPACE, FOLLOW, NULLVPP, &vp); 1616 strfree(devpath); 1617 1618 ret = !error && IS_SWAPVP(common_specvp(vp)); 1619 1620 if (vp != NULL) 1621 VN_RELE(vp); 1622 1623 return (ret); 1624 } 1625 1626 static int 1627 zvol_dump_init(zvol_state_t *zv, boolean_t resize) 1628 { 1629 dmu_tx_t *tx; 1630 int error = 0; 1631 objset_t *os = zv->zv_objset; 1632 nvlist_t *nv = NULL; 1633 1634 ASSERT(MUTEX_HELD(&zvol_state_lock)); 1635 1636 tx = dmu_tx_create(os); 1637 dmu_tx_hold_zap(tx, ZVOL_ZAP_OBJ, TRUE, NULL); 1638 error = dmu_tx_assign(tx, TXG_WAIT); 1639 if (error) { 1640 dmu_tx_abort(tx); 1641 return (error); 1642 } 1643 1644 /* 1645 * If we are resizing the dump device then we only need to 1646 * update the refreservation to match the newly updated 1647 * zvolsize. Otherwise, we save off the original state of the 1648 * zvol so that we can restore them if the zvol is ever undumpified. 1649 */ 1650 if (resize) { 1651 error = zap_update(os, ZVOL_ZAP_OBJ, 1652 zfs_prop_to_name(ZFS_PROP_REFRESERVATION), 8, 1, 1653 &zv->zv_volsize, tx); 1654 } else { 1655 uint64_t checksum, compress, refresrv, vbs; 1656 1657 error = dsl_prop_get_integer(zv->zv_name, 1658 zfs_prop_to_name(ZFS_PROP_COMPRESSION), &compress, NULL); 1659 error = error ? error : dsl_prop_get_integer(zv->zv_name, 1660 zfs_prop_to_name(ZFS_PROP_CHECKSUM), &checksum, NULL); 1661 error = error ? error : dsl_prop_get_integer(zv->zv_name, 1662 zfs_prop_to_name(ZFS_PROP_REFRESERVATION), &refresrv, NULL); 1663 error = error ? error : dsl_prop_get_integer(zv->zv_name, 1664 zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE), &vbs, NULL); 1665 1666 error = error ? error : zap_update(os, ZVOL_ZAP_OBJ, 1667 zfs_prop_to_name(ZFS_PROP_COMPRESSION), 8, 1, 1668 &compress, tx); 1669 error = error ? error : zap_update(os, ZVOL_ZAP_OBJ, 1670 zfs_prop_to_name(ZFS_PROP_CHECKSUM), 8, 1, &checksum, tx); 1671 error = error ? error : zap_update(os, ZVOL_ZAP_OBJ, 1672 zfs_prop_to_name(ZFS_PROP_REFRESERVATION), 8, 1, 1673 &refresrv, tx); 1674 error = error ? error : zap_update(os, ZVOL_ZAP_OBJ, 1675 zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE), 8, 1, 1676 &vbs, tx); 1677 } 1678 dmu_tx_commit(tx); 1679 1680 /* Truncate the file */ 1681 if (!error) 1682 error = dmu_free_long_range(zv->zv_objset, 1683 ZVOL_OBJ, 0, DMU_OBJECT_END); 1684 1685 if (error) 1686 return (error); 1687 1688 /* 1689 * We only need update the zvol's property if we are initializing 1690 * the dump area for the first time. 1691 */ 1692 if (!resize) { 1693 VERIFY(nvlist_alloc(&nv, NV_UNIQUE_NAME, KM_SLEEP) == 0); 1694 VERIFY(nvlist_add_uint64(nv, 1695 zfs_prop_to_name(ZFS_PROP_REFRESERVATION), 0) == 0); 1696 VERIFY(nvlist_add_uint64(nv, 1697 zfs_prop_to_name(ZFS_PROP_COMPRESSION), 1698 ZIO_COMPRESS_OFF) == 0); 1699 VERIFY(nvlist_add_uint64(nv, 1700 zfs_prop_to_name(ZFS_PROP_CHECKSUM), 1701 ZIO_CHECKSUM_OFF) == 0); 1702 VERIFY(nvlist_add_uint64(nv, 1703 zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE), 1704 SPA_MAXBLOCKSIZE) == 0); 1705 1706 error = zfs_set_prop_nvlist(zv->zv_name, nv); 1707 nvlist_free(nv); 1708 1709 if (error) 1710 return (error); 1711 } 1712 1713 /* Allocate the space for the dump */ 1714 error = zvol_prealloc(zv); 1715 return (error); 1716 } 1717 1718 static int 1719 zvol_dumpify(zvol_state_t *zv) 1720 { 1721 int error = 0; 1722 uint64_t dumpsize = 0; 1723 dmu_tx_t *tx; 1724 objset_t *os = zv->zv_objset; 1725 1726 if (zv->zv_flags & ZVOL_RDONLY || zv->zv_issnap) 1727 return (EROFS); 1728 1729 /* 1730 * We do not support swap devices acting as dump devices. 1731 */ 1732 if (zvol_is_swap(zv)) 1733 return (ENOTSUP); 1734 1735 if (zap_lookup(zv->zv_objset, ZVOL_ZAP_OBJ, ZVOL_DUMPSIZE, 1736 8, 1, &dumpsize) != 0 || dumpsize != zv->zv_volsize) { 1737 boolean_t resize = (dumpsize > 0) ? B_TRUE : B_FALSE; 1738 1739 if ((error = zvol_dump_init(zv, resize)) != 0) { 1740 (void) zvol_dump_fini(zv); 1741 return (error); 1742 } 1743 } 1744 1745 /* 1746 * Build up our lba mapping. 1747 */ 1748 error = zvol_get_lbas(zv); 1749 if (error) { 1750 (void) zvol_dump_fini(zv); 1751 return (error); 1752 } 1753 1754 tx = dmu_tx_create(os); 1755 dmu_tx_hold_zap(tx, ZVOL_ZAP_OBJ, TRUE, NULL); 1756 error = dmu_tx_assign(tx, TXG_WAIT); 1757 if (error) { 1758 dmu_tx_abort(tx); 1759 (void) zvol_dump_fini(zv); 1760 return (error); 1761 } 1762 1763 zv->zv_flags |= ZVOL_DUMPIFIED; 1764 error = zap_update(os, ZVOL_ZAP_OBJ, ZVOL_DUMPSIZE, 8, 1, 1765 &zv->zv_volsize, tx); 1766 dmu_tx_commit(tx); 1767 1768 if (error) { 1769 (void) zvol_dump_fini(zv); 1770 return (error); 1771 } 1772 1773 txg_wait_synced(dmu_objset_pool(os), 0); 1774 return (0); 1775 } 1776 1777 static int 1778 zvol_dump_fini(zvol_state_t *zv) 1779 { 1780 dmu_tx_t *tx; 1781 objset_t *os = zv->zv_objset; 1782 nvlist_t *nv; 1783 int error = 0; 1784 uint64_t checksum, compress, refresrv, vbs; 1785 1786 /* 1787 * Attempt to restore the zvol back to its pre-dumpified state. 1788 * This is a best-effort attempt as it's possible that not all 1789 * of these properties were initialized during the dumpify process 1790 * (i.e. error during zvol_dump_init). 1791 */ 1792 1793 tx = dmu_tx_create(os); 1794 dmu_tx_hold_zap(tx, ZVOL_ZAP_OBJ, TRUE, NULL); 1795 error = dmu_tx_assign(tx, TXG_WAIT); 1796 if (error) { 1797 dmu_tx_abort(tx); 1798 return (error); 1799 } 1800 (void) zap_remove(os, ZVOL_ZAP_OBJ, ZVOL_DUMPSIZE, tx); 1801 dmu_tx_commit(tx); 1802 1803 (void) zap_lookup(zv->zv_objset, ZVOL_ZAP_OBJ, 1804 zfs_prop_to_name(ZFS_PROP_CHECKSUM), 8, 1, &checksum); 1805 (void) zap_lookup(zv->zv_objset, ZVOL_ZAP_OBJ, 1806 zfs_prop_to_name(ZFS_PROP_COMPRESSION), 8, 1, &compress); 1807 (void) zap_lookup(zv->zv_objset, ZVOL_ZAP_OBJ, 1808 zfs_prop_to_name(ZFS_PROP_REFRESERVATION), 8, 1, &refresrv); 1809 (void) zap_lookup(zv->zv_objset, ZVOL_ZAP_OBJ, 1810 zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE), 8, 1, &vbs); 1811 1812 VERIFY(nvlist_alloc(&nv, NV_UNIQUE_NAME, KM_SLEEP) == 0); 1813 (void) nvlist_add_uint64(nv, 1814 zfs_prop_to_name(ZFS_PROP_CHECKSUM), checksum); 1815 (void) nvlist_add_uint64(nv, 1816 zfs_prop_to_name(ZFS_PROP_COMPRESSION), compress); 1817 (void) nvlist_add_uint64(nv, 1818 zfs_prop_to_name(ZFS_PROP_REFRESERVATION), refresrv); 1819 (void) nvlist_add_uint64(nv, 1820 zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE), vbs); 1821 (void) zfs_set_prop_nvlist(zv->zv_name, nv); 1822 nvlist_free(nv); 1823 1824 zvol_free_extents(zv); 1825 zv->zv_flags &= ~ZVOL_DUMPIFIED; 1826 (void) dmu_free_long_range(os, ZVOL_OBJ, 0, DMU_OBJECT_END); 1827 1828 return (0); 1829 } 1830