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 (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. 23 */ 24 25 /* Portions Copyright 2010 Robert Milkowski */ 26 27 /* 28 * ZFS volume emulation driver. 29 * 30 * Makes a DMU object look like a volume of arbitrary size, up to 2^64 bytes. 31 * Volumes are accessed through the symbolic links named: 32 * 33 * /dev/zvol/dsk/<pool_name>/<dataset_name> 34 * /dev/zvol/rdsk/<pool_name>/<dataset_name> 35 * 36 * These links are created by the /dev filesystem (sdev_zvolops.c). 37 * Volumes are persistent through reboot. No user command needs to be 38 * run before opening and using a device. 39 */ 40 41 #include <sys/types.h> 42 #include <sys/param.h> 43 #include <sys/errno.h> 44 #include <sys/uio.h> 45 #include <sys/buf.h> 46 #include <sys/modctl.h> 47 #include <sys/open.h> 48 #include <sys/kmem.h> 49 #include <sys/conf.h> 50 #include <sys/cmn_err.h> 51 #include <sys/stat.h> 52 #include <sys/zap.h> 53 #include <sys/spa.h> 54 #include <sys/zio.h> 55 #include <sys/dmu_traverse.h> 56 #include <sys/dnode.h> 57 #include <sys/dsl_dataset.h> 58 #include <sys/dsl_prop.h> 59 #include <sys/dkio.h> 60 #include <sys/efi_partition.h> 61 #include <sys/byteorder.h> 62 #include <sys/pathname.h> 63 #include <sys/ddi.h> 64 #include <sys/sunddi.h> 65 #include <sys/crc32.h> 66 #include <sys/dirent.h> 67 #include <sys/policy.h> 68 #include <sys/fs/zfs.h> 69 #include <sys/zfs_ioctl.h> 70 #include <sys/mkdev.h> 71 #include <sys/zil.h> 72 #include <sys/refcount.h> 73 #include <sys/zfs_znode.h> 74 #include <sys/zfs_rlock.h> 75 #include <sys/vdev_disk.h> 76 #include <sys/vdev_impl.h> 77 #include <sys/zvol.h> 78 #include <sys/dumphdr.h> 79 #include <sys/zil_impl.h> 80 81 #include "zfs_namecheck.h" 82 83 void *zfsdev_state; 84 static char *zvol_tag = "zvol_tag"; 85 86 #define ZVOL_DUMPSIZE "dumpsize" 87 88 /* 89 * This lock protects the zfsdev_state structure from being modified 90 * while it's being used, e.g. an open that comes in before a create 91 * finishes. It also protects temporary opens of the dataset so that, 92 * e.g., an open doesn't get a spurious EBUSY. 93 */ 94 kmutex_t zfsdev_state_lock; 95 static uint32_t zvol_minors; 96 97 typedef struct zvol_extent { 98 list_node_t ze_node; 99 dva_t ze_dva; /* dva associated with this extent */ 100 uint64_t ze_nblks; /* number of blocks in extent */ 101 } zvol_extent_t; 102 103 /* 104 * The in-core state of each volume. 105 */ 106 typedef struct zvol_state { 107 char zv_name[MAXPATHLEN]; /* pool/dd name */ 108 uint64_t zv_volsize; /* amount of space we advertise */ 109 uint64_t zv_volblocksize; /* volume block size */ 110 minor_t zv_minor; /* minor number */ 111 uint8_t zv_min_bs; /* minimum addressable block shift */ 112 uint8_t zv_flags; /* readonly, dumpified, etc. */ 113 objset_t *zv_objset; /* objset handle */ 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 dmu_buf_t *zv_dbuf; /* bonus handle */ 120 } zvol_state_t; 121 122 /* 123 * zvol specific flags 124 */ 125 #define ZVOL_RDONLY 0x1 126 #define ZVOL_DUMPIFIED 0x2 127 #define ZVOL_EXCL 0x4 128 #define ZVOL_WCE 0x8 129 130 /* 131 * zvol maximum transfer in one DMU tx. 132 */ 133 int zvol_maxphys = DMU_MAX_ACCESS/2; 134 135 extern int zfs_set_prop_nvlist(const char *, zprop_source_t, 136 nvlist_t *, nvlist_t **); 137 static int zvol_remove_zv(zvol_state_t *); 138 static int zvol_get_data(void *arg, lr_write_t *lr, char *buf, zio_t *zio); 139 static int zvol_dumpify(zvol_state_t *zv); 140 static int zvol_dump_fini(zvol_state_t *zv); 141 static int zvol_dump_init(zvol_state_t *zv, boolean_t resize); 142 143 static void 144 zvol_size_changed(uint64_t volsize, major_t maj, minor_t min) 145 { 146 dev_t dev = makedevice(maj, min); 147 148 VERIFY(ddi_prop_update_int64(dev, zfs_dip, 149 "Size", volsize) == DDI_SUCCESS); 150 VERIFY(ddi_prop_update_int64(dev, zfs_dip, 151 "Nblocks", lbtodb(volsize)) == DDI_SUCCESS); 152 153 /* Notify specfs to invalidate the cached size */ 154 spec_size_invalidate(dev, VBLK); 155 spec_size_invalidate(dev, VCHR); 156 } 157 158 int 159 zvol_check_volsize(uint64_t volsize, uint64_t blocksize) 160 { 161 if (volsize == 0) 162 return (EINVAL); 163 164 if (volsize % blocksize != 0) 165 return (EINVAL); 166 167 #ifdef _ILP32 168 if (volsize - 1 > SPEC_MAXOFFSET_T) 169 return (EOVERFLOW); 170 #endif 171 return (0); 172 } 173 174 int 175 zvol_check_volblocksize(uint64_t volblocksize) 176 { 177 if (volblocksize < SPA_MINBLOCKSIZE || 178 volblocksize > SPA_MAXBLOCKSIZE || 179 !ISP2(volblocksize)) 180 return (EDOM); 181 182 return (0); 183 } 184 185 int 186 zvol_get_stats(objset_t *os, nvlist_t *nv) 187 { 188 int error; 189 dmu_object_info_t doi; 190 uint64_t val; 191 192 error = zap_lookup(os, ZVOL_ZAP_OBJ, "size", 8, 1, &val); 193 if (error) 194 return (error); 195 196 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_VOLSIZE, val); 197 198 error = dmu_object_info(os, ZVOL_OBJ, &doi); 199 200 if (error == 0) { 201 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_VOLBLOCKSIZE, 202 doi.doi_data_block_size); 203 } 204 205 return (error); 206 } 207 208 static zvol_state_t * 209 zvol_minor_lookup(const char *name) 210 { 211 minor_t minor; 212 zvol_state_t *zv; 213 214 ASSERT(MUTEX_HELD(&zfsdev_state_lock)); 215 216 for (minor = 1; minor <= ZFSDEV_MAX_MINOR; minor++) { 217 zv = zfsdev_get_soft_state(minor, ZSST_ZVOL); 218 if (zv == NULL) 219 continue; 220 if (strcmp(zv->zv_name, name) == 0) 221 return (zv); 222 } 223 224 return (NULL); 225 } 226 227 /* extent mapping arg */ 228 struct maparg { 229 zvol_state_t *ma_zv; 230 uint64_t ma_blks; 231 }; 232 233 /*ARGSUSED*/ 234 static int 235 zvol_map_block(spa_t *spa, zilog_t *zilog, const blkptr_t *bp, arc_buf_t *pbuf, 236 const zbookmark_t *zb, const dnode_phys_t *dnp, void *arg) 237 { 238 struct maparg *ma = arg; 239 zvol_extent_t *ze; 240 int bs = ma->ma_zv->zv_volblocksize; 241 242 if (bp == NULL || zb->zb_object != ZVOL_OBJ || zb->zb_level != 0) 243 return (0); 244 245 VERIFY3U(ma->ma_blks, ==, zb->zb_blkid); 246 ma->ma_blks++; 247 248 /* Abort immediately if we have encountered gang blocks */ 249 if (BP_IS_GANG(bp)) 250 return (EFRAGS); 251 252 /* 253 * See if the block is at the end of the previous extent. 254 */ 255 ze = list_tail(&ma->ma_zv->zv_extents); 256 if (ze && 257 DVA_GET_VDEV(BP_IDENTITY(bp)) == DVA_GET_VDEV(&ze->ze_dva) && 258 DVA_GET_OFFSET(BP_IDENTITY(bp)) == 259 DVA_GET_OFFSET(&ze->ze_dva) + ze->ze_nblks * bs) { 260 ze->ze_nblks++; 261 return (0); 262 } 263 264 dprintf_bp(bp, "%s", "next blkptr:"); 265 266 /* start a new extent */ 267 ze = kmem_zalloc(sizeof (zvol_extent_t), KM_SLEEP); 268 ze->ze_dva = bp->blk_dva[0]; /* structure assignment */ 269 ze->ze_nblks = 1; 270 list_insert_tail(&ma->ma_zv->zv_extents, ze); 271 return (0); 272 } 273 274 static void 275 zvol_free_extents(zvol_state_t *zv) 276 { 277 zvol_extent_t *ze; 278 279 while (ze = list_head(&zv->zv_extents)) { 280 list_remove(&zv->zv_extents, ze); 281 kmem_free(ze, sizeof (zvol_extent_t)); 282 } 283 } 284 285 static int 286 zvol_get_lbas(zvol_state_t *zv) 287 { 288 objset_t *os = zv->zv_objset; 289 struct maparg ma; 290 int err; 291 292 ma.ma_zv = zv; 293 ma.ma_blks = 0; 294 zvol_free_extents(zv); 295 296 /* commit any in-flight changes before traversing the dataset */ 297 txg_wait_synced(dmu_objset_pool(os), 0); 298 err = traverse_dataset(dmu_objset_ds(os), 0, 299 TRAVERSE_PRE | TRAVERSE_PREFETCH_METADATA, zvol_map_block, &ma); 300 if (err || ma.ma_blks != (zv->zv_volsize / zv->zv_volblocksize)) { 301 zvol_free_extents(zv); 302 return (err ? err : EIO); 303 } 304 305 return (0); 306 } 307 308 /* ARGSUSED */ 309 void 310 zvol_create_cb(objset_t *os, void *arg, cred_t *cr, dmu_tx_t *tx) 311 { 312 zfs_creat_t *zct = arg; 313 nvlist_t *nvprops = zct->zct_props; 314 int error; 315 uint64_t volblocksize, volsize; 316 317 VERIFY(nvlist_lookup_uint64(nvprops, 318 zfs_prop_to_name(ZFS_PROP_VOLSIZE), &volsize) == 0); 319 if (nvlist_lookup_uint64(nvprops, 320 zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE), &volblocksize) != 0) 321 volblocksize = zfs_prop_default_numeric(ZFS_PROP_VOLBLOCKSIZE); 322 323 /* 324 * These properties must be removed from the list so the generic 325 * property setting step won't apply to them. 326 */ 327 VERIFY(nvlist_remove_all(nvprops, 328 zfs_prop_to_name(ZFS_PROP_VOLSIZE)) == 0); 329 (void) nvlist_remove_all(nvprops, 330 zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE)); 331 332 error = dmu_object_claim(os, ZVOL_OBJ, DMU_OT_ZVOL, volblocksize, 333 DMU_OT_NONE, 0, tx); 334 ASSERT(error == 0); 335 336 error = zap_create_claim(os, ZVOL_ZAP_OBJ, DMU_OT_ZVOL_PROP, 337 DMU_OT_NONE, 0, tx); 338 ASSERT(error == 0); 339 340 error = zap_update(os, ZVOL_ZAP_OBJ, "size", 8, 1, &volsize, tx); 341 ASSERT(error == 0); 342 } 343 344 /* 345 * Replay a TX_WRITE ZIL transaction that didn't get committed 346 * after a system failure 347 */ 348 static int 349 zvol_replay_write(zvol_state_t *zv, lr_write_t *lr, boolean_t byteswap) 350 { 351 objset_t *os = zv->zv_objset; 352 char *data = (char *)(lr + 1); /* data follows lr_write_t */ 353 uint64_t offset, length; 354 dmu_tx_t *tx; 355 int error; 356 357 if (byteswap) 358 byteswap_uint64_array(lr, sizeof (*lr)); 359 360 offset = lr->lr_offset; 361 length = lr->lr_length; 362 363 /* If it's a dmu_sync() block, write the whole block */ 364 if (lr->lr_common.lrc_reclen == sizeof (lr_write_t)) { 365 uint64_t blocksize = BP_GET_LSIZE(&lr->lr_blkptr); 366 if (length < blocksize) { 367 offset -= offset % blocksize; 368 length = blocksize; 369 } 370 } 371 372 tx = dmu_tx_create(os); 373 dmu_tx_hold_write(tx, ZVOL_OBJ, offset, length); 374 error = dmu_tx_assign(tx, TXG_WAIT); 375 if (error) { 376 dmu_tx_abort(tx); 377 } else { 378 dmu_write(os, ZVOL_OBJ, offset, length, data, tx); 379 dmu_tx_commit(tx); 380 } 381 382 return (error); 383 } 384 385 /* ARGSUSED */ 386 static int 387 zvol_replay_err(zvol_state_t *zv, lr_t *lr, boolean_t byteswap) 388 { 389 return (ENOTSUP); 390 } 391 392 /* 393 * Callback vectors for replaying records. 394 * Only TX_WRITE is needed for zvol. 395 */ 396 zil_replay_func_t *zvol_replay_vector[TX_MAX_TYPE] = { 397 zvol_replay_err, /* 0 no such transaction type */ 398 zvol_replay_err, /* TX_CREATE */ 399 zvol_replay_err, /* TX_MKDIR */ 400 zvol_replay_err, /* TX_MKXATTR */ 401 zvol_replay_err, /* TX_SYMLINK */ 402 zvol_replay_err, /* TX_REMOVE */ 403 zvol_replay_err, /* TX_RMDIR */ 404 zvol_replay_err, /* TX_LINK */ 405 zvol_replay_err, /* TX_RENAME */ 406 zvol_replay_write, /* TX_WRITE */ 407 zvol_replay_err, /* TX_TRUNCATE */ 408 zvol_replay_err, /* TX_SETATTR */ 409 zvol_replay_err, /* TX_ACL */ 410 zvol_replay_err, /* TX_CREATE_ACL */ 411 zvol_replay_err, /* TX_CREATE_ATTR */ 412 zvol_replay_err, /* TX_CREATE_ACL_ATTR */ 413 zvol_replay_err, /* TX_MKDIR_ACL */ 414 zvol_replay_err, /* TX_MKDIR_ATTR */ 415 zvol_replay_err, /* TX_MKDIR_ACL_ATTR */ 416 zvol_replay_err, /* TX_WRITE2 */ 417 }; 418 419 int 420 zvol_name2minor(const char *name, minor_t *minor) 421 { 422 zvol_state_t *zv; 423 424 mutex_enter(&zfsdev_state_lock); 425 zv = zvol_minor_lookup(name); 426 if (minor && zv) 427 *minor = zv->zv_minor; 428 mutex_exit(&zfsdev_state_lock); 429 return (zv ? 0 : -1); 430 } 431 432 /* 433 * Create a minor node (plus a whole lot more) for the specified volume. 434 */ 435 int 436 zvol_create_minor(const char *name) 437 { 438 zfs_soft_state_t *zs; 439 zvol_state_t *zv; 440 objset_t *os; 441 dmu_object_info_t doi; 442 minor_t minor = 0; 443 char chrbuf[30], blkbuf[30]; 444 int error; 445 446 mutex_enter(&zfsdev_state_lock); 447 448 if (zvol_minor_lookup(name) != NULL) { 449 mutex_exit(&zfsdev_state_lock); 450 return (EEXIST); 451 } 452 453 /* lie and say we're read-only */ 454 error = dmu_objset_own(name, DMU_OST_ZVOL, B_TRUE, FTAG, &os); 455 456 if (error) { 457 mutex_exit(&zfsdev_state_lock); 458 return (error); 459 } 460 461 if ((minor = zfsdev_minor_alloc()) == 0) { 462 dmu_objset_disown(os, FTAG); 463 mutex_exit(&zfsdev_state_lock); 464 return (ENXIO); 465 } 466 467 if (ddi_soft_state_zalloc(zfsdev_state, minor) != DDI_SUCCESS) { 468 dmu_objset_disown(os, FTAG); 469 mutex_exit(&zfsdev_state_lock); 470 return (EAGAIN); 471 } 472 (void) ddi_prop_update_string(minor, zfs_dip, ZVOL_PROP_NAME, 473 (char *)name); 474 475 (void) snprintf(chrbuf, sizeof (chrbuf), "%u,raw", minor); 476 477 if (ddi_create_minor_node(zfs_dip, chrbuf, S_IFCHR, 478 minor, DDI_PSEUDO, 0) == DDI_FAILURE) { 479 ddi_soft_state_free(zfsdev_state, minor); 480 dmu_objset_disown(os, FTAG); 481 mutex_exit(&zfsdev_state_lock); 482 return (EAGAIN); 483 } 484 485 (void) snprintf(blkbuf, sizeof (blkbuf), "%u", minor); 486 487 if (ddi_create_minor_node(zfs_dip, blkbuf, S_IFBLK, 488 minor, DDI_PSEUDO, 0) == DDI_FAILURE) { 489 ddi_remove_minor_node(zfs_dip, chrbuf); 490 ddi_soft_state_free(zfsdev_state, minor); 491 dmu_objset_disown(os, FTAG); 492 mutex_exit(&zfsdev_state_lock); 493 return (EAGAIN); 494 } 495 496 zs = ddi_get_soft_state(zfsdev_state, minor); 497 zs->zss_type = ZSST_ZVOL; 498 zv = zs->zss_data = kmem_zalloc(sizeof (zvol_state_t), KM_SLEEP); 499 (void) strlcpy(zv->zv_name, name, MAXPATHLEN); 500 zv->zv_min_bs = DEV_BSHIFT; 501 zv->zv_minor = minor; 502 zv->zv_objset = os; 503 if (dmu_objset_is_snapshot(os) || !spa_writeable(dmu_objset_spa(os))) 504 zv->zv_flags |= ZVOL_RDONLY; 505 mutex_init(&zv->zv_znode.z_range_lock, NULL, MUTEX_DEFAULT, NULL); 506 avl_create(&zv->zv_znode.z_range_avl, zfs_range_compare, 507 sizeof (rl_t), offsetof(rl_t, r_node)); 508 list_create(&zv->zv_extents, sizeof (zvol_extent_t), 509 offsetof(zvol_extent_t, ze_node)); 510 /* get and cache the blocksize */ 511 error = dmu_object_info(os, ZVOL_OBJ, &doi); 512 ASSERT(error == 0); 513 zv->zv_volblocksize = doi.doi_data_block_size; 514 515 if (spa_writeable(dmu_objset_spa(os))) { 516 if (zil_replay_disable) 517 zil_destroy(dmu_objset_zil(os), B_FALSE); 518 else 519 zil_replay(os, zv, zvol_replay_vector); 520 } 521 dmu_objset_disown(os, FTAG); 522 zv->zv_objset = NULL; 523 524 zvol_minors++; 525 526 mutex_exit(&zfsdev_state_lock); 527 528 return (0); 529 } 530 531 /* 532 * Remove minor node for the specified volume. 533 */ 534 static int 535 zvol_remove_zv(zvol_state_t *zv) 536 { 537 char nmbuf[20]; 538 minor_t minor = zv->zv_minor; 539 540 ASSERT(MUTEX_HELD(&zfsdev_state_lock)); 541 if (zv->zv_total_opens != 0) 542 return (EBUSY); 543 544 (void) snprintf(nmbuf, sizeof (nmbuf), "%u,raw", minor); 545 ddi_remove_minor_node(zfs_dip, nmbuf); 546 547 (void) snprintf(nmbuf, sizeof (nmbuf), "%u", minor); 548 ddi_remove_minor_node(zfs_dip, nmbuf); 549 550 avl_destroy(&zv->zv_znode.z_range_avl); 551 mutex_destroy(&zv->zv_znode.z_range_lock); 552 553 kmem_free(zv, sizeof (zvol_state_t)); 554 555 ddi_soft_state_free(zfsdev_state, minor); 556 557 zvol_minors--; 558 return (0); 559 } 560 561 int 562 zvol_remove_minor(const char *name) 563 { 564 zvol_state_t *zv; 565 int rc; 566 567 mutex_enter(&zfsdev_state_lock); 568 if ((zv = zvol_minor_lookup(name)) == NULL) { 569 mutex_exit(&zfsdev_state_lock); 570 return (ENXIO); 571 } 572 rc = zvol_remove_zv(zv); 573 mutex_exit(&zfsdev_state_lock); 574 return (rc); 575 } 576 577 int 578 zvol_first_open(zvol_state_t *zv) 579 { 580 objset_t *os; 581 uint64_t volsize; 582 int error; 583 uint64_t readonly; 584 585 /* lie and say we're read-only */ 586 error = dmu_objset_own(zv->zv_name, DMU_OST_ZVOL, B_TRUE, 587 zvol_tag, &os); 588 if (error) 589 return (error); 590 591 error = zap_lookup(os, ZVOL_ZAP_OBJ, "size", 8, 1, &volsize); 592 if (error) { 593 ASSERT(error == 0); 594 dmu_objset_disown(os, zvol_tag); 595 return (error); 596 } 597 zv->zv_objset = os; 598 error = dmu_bonus_hold(os, ZVOL_OBJ, zvol_tag, &zv->zv_dbuf); 599 if (error) { 600 dmu_objset_disown(os, zvol_tag); 601 return (error); 602 } 603 zv->zv_volsize = volsize; 604 zv->zv_zilog = zil_open(os, zvol_get_data); 605 zvol_size_changed(zv->zv_volsize, ddi_driver_major(zfs_dip), 606 zv->zv_minor); 607 608 VERIFY(dsl_prop_get_integer(zv->zv_name, "readonly", &readonly, 609 NULL) == 0); 610 if (readonly || dmu_objset_is_snapshot(os) || 611 !spa_writeable(dmu_objset_spa(os))) 612 zv->zv_flags |= ZVOL_RDONLY; 613 else 614 zv->zv_flags &= ~ZVOL_RDONLY; 615 return (error); 616 } 617 618 void 619 zvol_last_close(zvol_state_t *zv) 620 { 621 zil_close(zv->zv_zilog); 622 zv->zv_zilog = NULL; 623 dmu_buf_rele(zv->zv_dbuf, zvol_tag); 624 zv->zv_dbuf = NULL; 625 dmu_objset_disown(zv->zv_objset, zvol_tag); 626 zv->zv_objset = NULL; 627 } 628 629 int 630 zvol_prealloc(zvol_state_t *zv) 631 { 632 objset_t *os = zv->zv_objset; 633 dmu_tx_t *tx; 634 uint64_t refd, avail, usedobjs, availobjs; 635 uint64_t resid = zv->zv_volsize; 636 uint64_t off = 0; 637 638 /* Check the space usage before attempting to allocate the space */ 639 dmu_objset_space(os, &refd, &avail, &usedobjs, &availobjs); 640 if (avail < zv->zv_volsize) 641 return (ENOSPC); 642 643 /* Free old extents if they exist */ 644 zvol_free_extents(zv); 645 646 while (resid != 0) { 647 int error; 648 uint64_t bytes = MIN(resid, SPA_MAXBLOCKSIZE); 649 650 tx = dmu_tx_create(os); 651 dmu_tx_hold_write(tx, ZVOL_OBJ, off, bytes); 652 error = dmu_tx_assign(tx, TXG_WAIT); 653 if (error) { 654 dmu_tx_abort(tx); 655 (void) dmu_free_long_range(os, ZVOL_OBJ, 0, off); 656 return (error); 657 } 658 dmu_prealloc(os, ZVOL_OBJ, off, bytes, tx); 659 dmu_tx_commit(tx); 660 off += bytes; 661 resid -= bytes; 662 } 663 txg_wait_synced(dmu_objset_pool(os), 0); 664 665 return (0); 666 } 667 668 int 669 zvol_update_volsize(objset_t *os, uint64_t volsize) 670 { 671 dmu_tx_t *tx; 672 int error; 673 674 ASSERT(MUTEX_HELD(&zfsdev_state_lock)); 675 676 tx = dmu_tx_create(os); 677 dmu_tx_hold_zap(tx, ZVOL_ZAP_OBJ, TRUE, NULL); 678 error = dmu_tx_assign(tx, TXG_WAIT); 679 if (error) { 680 dmu_tx_abort(tx); 681 return (error); 682 } 683 684 error = zap_update(os, ZVOL_ZAP_OBJ, "size", 8, 1, 685 &volsize, tx); 686 dmu_tx_commit(tx); 687 688 if (error == 0) 689 error = dmu_free_long_range(os, 690 ZVOL_OBJ, volsize, DMU_OBJECT_END); 691 return (error); 692 } 693 694 void 695 zvol_remove_minors(const char *name) 696 { 697 zvol_state_t *zv; 698 char *namebuf; 699 minor_t minor; 700 701 namebuf = kmem_zalloc(strlen(name) + 2, KM_SLEEP); 702 (void) strncpy(namebuf, name, strlen(name)); 703 (void) strcat(namebuf, "/"); 704 mutex_enter(&zfsdev_state_lock); 705 for (minor = 1; minor <= ZFSDEV_MAX_MINOR; minor++) { 706 707 zv = zfsdev_get_soft_state(minor, ZSST_ZVOL); 708 if (zv == NULL) 709 continue; 710 if (strncmp(namebuf, zv->zv_name, strlen(namebuf)) == 0) 711 (void) zvol_remove_zv(zv); 712 } 713 kmem_free(namebuf, strlen(name) + 2); 714 715 mutex_exit(&zfsdev_state_lock); 716 } 717 718 int 719 zvol_set_volsize(const char *name, major_t maj, uint64_t volsize) 720 { 721 zvol_state_t *zv = NULL; 722 objset_t *os; 723 int error; 724 dmu_object_info_t doi; 725 uint64_t old_volsize = 0ULL; 726 uint64_t readonly; 727 728 mutex_enter(&zfsdev_state_lock); 729 zv = zvol_minor_lookup(name); 730 if ((error = dmu_objset_hold(name, FTAG, &os)) != 0) { 731 mutex_exit(&zfsdev_state_lock); 732 return (error); 733 } 734 735 if ((error = dmu_object_info(os, ZVOL_OBJ, &doi)) != 0 || 736 (error = zvol_check_volsize(volsize, 737 doi.doi_data_block_size)) != 0) 738 goto out; 739 740 VERIFY(dsl_prop_get_integer(name, "readonly", &readonly, 741 NULL) == 0); 742 if (readonly) { 743 error = EROFS; 744 goto out; 745 } 746 747 error = zvol_update_volsize(os, volsize); 748 /* 749 * Reinitialize the dump area to the new size. If we 750 * failed to resize the dump area then restore it back to 751 * its original size. 752 */ 753 if (zv && error == 0) { 754 if (zv->zv_flags & ZVOL_DUMPIFIED) { 755 old_volsize = zv->zv_volsize; 756 zv->zv_volsize = volsize; 757 if ((error = zvol_dumpify(zv)) != 0 || 758 (error = dumpvp_resize()) != 0) { 759 (void) zvol_update_volsize(os, old_volsize); 760 zv->zv_volsize = old_volsize; 761 error = zvol_dumpify(zv); 762 } 763 } 764 if (error == 0) { 765 zv->zv_volsize = volsize; 766 zvol_size_changed(volsize, maj, zv->zv_minor); 767 } 768 } 769 770 /* 771 * Generate a LUN expansion event. 772 */ 773 if (zv && error == 0) { 774 sysevent_id_t eid; 775 nvlist_t *attr; 776 char *physpath = kmem_zalloc(MAXPATHLEN, KM_SLEEP); 777 778 (void) snprintf(physpath, MAXPATHLEN, "%s%u", ZVOL_PSEUDO_DEV, 779 zv->zv_minor); 780 781 VERIFY(nvlist_alloc(&attr, NV_UNIQUE_NAME, KM_SLEEP) == 0); 782 VERIFY(nvlist_add_string(attr, DEV_PHYS_PATH, physpath) == 0); 783 784 (void) ddi_log_sysevent(zfs_dip, SUNW_VENDOR, EC_DEV_STATUS, 785 ESC_DEV_DLE, attr, &eid, DDI_SLEEP); 786 787 nvlist_free(attr); 788 kmem_free(physpath, MAXPATHLEN); 789 } 790 791 out: 792 dmu_objset_rele(os, FTAG); 793 794 mutex_exit(&zfsdev_state_lock); 795 796 return (error); 797 } 798 799 /*ARGSUSED*/ 800 int 801 zvol_open(dev_t *devp, int flag, int otyp, cred_t *cr) 802 { 803 zvol_state_t *zv; 804 int err = 0; 805 806 mutex_enter(&zfsdev_state_lock); 807 808 zv = zfsdev_get_soft_state(getminor(*devp), ZSST_ZVOL); 809 if (zv == NULL) { 810 mutex_exit(&zfsdev_state_lock); 811 return (ENXIO); 812 } 813 814 if (zv->zv_total_opens == 0) 815 err = zvol_first_open(zv); 816 if (err) { 817 mutex_exit(&zfsdev_state_lock); 818 return (err); 819 } 820 if ((flag & FWRITE) && (zv->zv_flags & ZVOL_RDONLY)) { 821 err = EROFS; 822 goto out; 823 } 824 if (zv->zv_flags & ZVOL_EXCL) { 825 err = EBUSY; 826 goto out; 827 } 828 if (flag & FEXCL) { 829 if (zv->zv_total_opens != 0) { 830 err = EBUSY; 831 goto out; 832 } 833 zv->zv_flags |= ZVOL_EXCL; 834 } 835 836 if (zv->zv_open_count[otyp] == 0 || otyp == OTYP_LYR) { 837 zv->zv_open_count[otyp]++; 838 zv->zv_total_opens++; 839 } 840 mutex_exit(&zfsdev_state_lock); 841 842 return (err); 843 out: 844 if (zv->zv_total_opens == 0) 845 zvol_last_close(zv); 846 mutex_exit(&zfsdev_state_lock); 847 return (err); 848 } 849 850 /*ARGSUSED*/ 851 int 852 zvol_close(dev_t dev, int flag, int otyp, cred_t *cr) 853 { 854 minor_t minor = getminor(dev); 855 zvol_state_t *zv; 856 int error = 0; 857 858 mutex_enter(&zfsdev_state_lock); 859 860 zv = zfsdev_get_soft_state(minor, ZSST_ZVOL); 861 if (zv == NULL) { 862 mutex_exit(&zfsdev_state_lock); 863 return (ENXIO); 864 } 865 866 if (zv->zv_flags & ZVOL_EXCL) { 867 ASSERT(zv->zv_total_opens == 1); 868 zv->zv_flags &= ~ZVOL_EXCL; 869 } 870 871 /* 872 * If the open count is zero, this is a spurious close. 873 * That indicates a bug in the kernel / DDI framework. 874 */ 875 ASSERT(zv->zv_open_count[otyp] != 0); 876 ASSERT(zv->zv_total_opens != 0); 877 878 /* 879 * You may get multiple opens, but only one close. 880 */ 881 zv->zv_open_count[otyp]--; 882 zv->zv_total_opens--; 883 884 if (zv->zv_total_opens == 0) 885 zvol_last_close(zv); 886 887 mutex_exit(&zfsdev_state_lock); 888 return (error); 889 } 890 891 static void 892 zvol_get_done(zgd_t *zgd, int error) 893 { 894 if (zgd->zgd_db) 895 dmu_buf_rele(zgd->zgd_db, zgd); 896 897 zfs_range_unlock(zgd->zgd_rl); 898 899 if (error == 0 && zgd->zgd_bp) 900 zil_add_block(zgd->zgd_zilog, zgd->zgd_bp); 901 902 kmem_free(zgd, sizeof (zgd_t)); 903 } 904 905 /* 906 * Get data to generate a TX_WRITE intent log record. 907 */ 908 static int 909 zvol_get_data(void *arg, lr_write_t *lr, char *buf, zio_t *zio) 910 { 911 zvol_state_t *zv = arg; 912 objset_t *os = zv->zv_objset; 913 uint64_t object = ZVOL_OBJ; 914 uint64_t offset = lr->lr_offset; 915 uint64_t size = lr->lr_length; /* length of user data */ 916 blkptr_t *bp = &lr->lr_blkptr; 917 dmu_buf_t *db; 918 zgd_t *zgd; 919 int error; 920 921 ASSERT(zio != NULL); 922 ASSERT(size != 0); 923 924 zgd = kmem_zalloc(sizeof (zgd_t), KM_SLEEP); 925 zgd->zgd_zilog = zv->zv_zilog; 926 zgd->zgd_rl = zfs_range_lock(&zv->zv_znode, offset, size, RL_READER); 927 928 /* 929 * Write records come in two flavors: immediate and indirect. 930 * For small writes it's cheaper to store the data with the 931 * log record (immediate); for large writes it's cheaper to 932 * sync the data and get a pointer to it (indirect) so that 933 * we don't have to write the data twice. 934 */ 935 if (buf != NULL) { /* immediate write */ 936 error = dmu_read(os, object, offset, size, buf, 937 DMU_READ_NO_PREFETCH); 938 } else { 939 size = zv->zv_volblocksize; 940 offset = P2ALIGN(offset, size); 941 error = dmu_buf_hold(os, object, offset, zgd, &db, 942 DMU_READ_NO_PREFETCH); 943 if (error == 0) { 944 zgd->zgd_db = db; 945 zgd->zgd_bp = bp; 946 947 ASSERT(db->db_offset == offset); 948 ASSERT(db->db_size == size); 949 950 error = dmu_sync(zio, lr->lr_common.lrc_txg, 951 zvol_get_done, zgd); 952 953 if (error == 0) 954 return (0); 955 } 956 } 957 958 zvol_get_done(zgd, error); 959 960 return (error); 961 } 962 963 /* 964 * zvol_log_write() handles synchronous writes using TX_WRITE ZIL transactions. 965 * 966 * We store data in the log buffers if it's small enough. 967 * Otherwise we will later flush the data out via dmu_sync(). 968 */ 969 ssize_t zvol_immediate_write_sz = 32768; 970 971 static void 972 zvol_log_write(zvol_state_t *zv, dmu_tx_t *tx, offset_t off, ssize_t resid, 973 boolean_t sync) 974 { 975 uint32_t blocksize = zv->zv_volblocksize; 976 zilog_t *zilog = zv->zv_zilog; 977 boolean_t slogging; 978 ssize_t immediate_write_sz; 979 980 if (zil_replaying(zilog, tx)) 981 return; 982 983 immediate_write_sz = (zilog->zl_logbias == ZFS_LOGBIAS_THROUGHPUT) 984 ? 0 : zvol_immediate_write_sz; 985 986 slogging = spa_has_slogs(zilog->zl_spa) && 987 (zilog->zl_logbias == ZFS_LOGBIAS_LATENCY); 988 989 while (resid) { 990 itx_t *itx; 991 lr_write_t *lr; 992 ssize_t len; 993 itx_wr_state_t write_state; 994 995 /* 996 * Unlike zfs_log_write() we can be called with 997 * upto DMU_MAX_ACCESS/2 (5MB) writes. 998 */ 999 if (blocksize > immediate_write_sz && !slogging && 1000 resid >= blocksize && off % blocksize == 0) { 1001 write_state = WR_INDIRECT; /* uses dmu_sync */ 1002 len = blocksize; 1003 } else if (sync) { 1004 write_state = WR_COPIED; 1005 len = MIN(ZIL_MAX_LOG_DATA, resid); 1006 } else { 1007 write_state = WR_NEED_COPY; 1008 len = MIN(ZIL_MAX_LOG_DATA, resid); 1009 } 1010 1011 itx = zil_itx_create(TX_WRITE, sizeof (*lr) + 1012 (write_state == WR_COPIED ? len : 0)); 1013 lr = (lr_write_t *)&itx->itx_lr; 1014 if (write_state == WR_COPIED && dmu_read(zv->zv_objset, 1015 ZVOL_OBJ, off, len, lr + 1, DMU_READ_NO_PREFETCH) != 0) { 1016 zil_itx_destroy(itx); 1017 itx = zil_itx_create(TX_WRITE, sizeof (*lr)); 1018 lr = (lr_write_t *)&itx->itx_lr; 1019 write_state = WR_NEED_COPY; 1020 } 1021 1022 itx->itx_wr_state = write_state; 1023 if (write_state == WR_NEED_COPY) 1024 itx->itx_sod += len; 1025 lr->lr_foid = ZVOL_OBJ; 1026 lr->lr_offset = off; 1027 lr->lr_length = len; 1028 lr->lr_blkoff = 0; 1029 BP_ZERO(&lr->lr_blkptr); 1030 1031 itx->itx_private = zv; 1032 itx->itx_sync = sync; 1033 1034 zil_itx_assign(zilog, itx, tx); 1035 1036 off += len; 1037 resid -= len; 1038 } 1039 } 1040 1041 static int 1042 zvol_dumpio_vdev(vdev_t *vd, void *addr, uint64_t offset, uint64_t size, 1043 boolean_t doread, boolean_t isdump) 1044 { 1045 vdev_disk_t *dvd; 1046 int c; 1047 int numerrors = 0; 1048 1049 for (c = 0; c < vd->vdev_children; c++) { 1050 ASSERT(vd->vdev_ops == &vdev_mirror_ops || 1051 vd->vdev_ops == &vdev_replacing_ops || 1052 vd->vdev_ops == &vdev_spare_ops); 1053 int err = zvol_dumpio_vdev(vd->vdev_child[c], 1054 addr, offset, size, doread, isdump); 1055 if (err != 0) { 1056 numerrors++; 1057 } else if (doread) { 1058 break; 1059 } 1060 } 1061 1062 if (!vd->vdev_ops->vdev_op_leaf) 1063 return (numerrors < vd->vdev_children ? 0 : EIO); 1064 1065 if (doread && !vdev_readable(vd)) 1066 return (EIO); 1067 else if (!doread && !vdev_writeable(vd)) 1068 return (EIO); 1069 1070 dvd = vd->vdev_tsd; 1071 ASSERT3P(dvd, !=, NULL); 1072 offset += VDEV_LABEL_START_SIZE; 1073 1074 if (ddi_in_panic() || isdump) { 1075 ASSERT(!doread); 1076 if (doread) 1077 return (EIO); 1078 return (ldi_dump(dvd->vd_lh, addr, lbtodb(offset), 1079 lbtodb(size))); 1080 } else { 1081 return (vdev_disk_physio(dvd->vd_lh, addr, size, offset, 1082 doread ? B_READ : B_WRITE)); 1083 } 1084 } 1085 1086 static int 1087 zvol_dumpio(zvol_state_t *zv, void *addr, uint64_t offset, uint64_t size, 1088 boolean_t doread, boolean_t isdump) 1089 { 1090 vdev_t *vd; 1091 int error; 1092 zvol_extent_t *ze; 1093 spa_t *spa = dmu_objset_spa(zv->zv_objset); 1094 1095 /* Must be sector aligned, and not stradle a block boundary. */ 1096 if (P2PHASE(offset, DEV_BSIZE) || P2PHASE(size, DEV_BSIZE) || 1097 P2BOUNDARY(offset, size, zv->zv_volblocksize)) { 1098 return (EINVAL); 1099 } 1100 ASSERT(size <= zv->zv_volblocksize); 1101 1102 /* Locate the extent this belongs to */ 1103 ze = list_head(&zv->zv_extents); 1104 while (offset >= ze->ze_nblks * zv->zv_volblocksize) { 1105 offset -= ze->ze_nblks * zv->zv_volblocksize; 1106 ze = list_next(&zv->zv_extents, ze); 1107 } 1108 1109 if (!ddi_in_panic()) 1110 spa_config_enter(spa, SCL_STATE, FTAG, RW_READER); 1111 1112 vd = vdev_lookup_top(spa, DVA_GET_VDEV(&ze->ze_dva)); 1113 offset += DVA_GET_OFFSET(&ze->ze_dva); 1114 error = zvol_dumpio_vdev(vd, addr, offset, size, doread, isdump); 1115 1116 if (!ddi_in_panic()) 1117 spa_config_exit(spa, SCL_STATE, FTAG); 1118 1119 return (error); 1120 } 1121 1122 int 1123 zvol_strategy(buf_t *bp) 1124 { 1125 zfs_soft_state_t *zs = NULL; 1126 zvol_state_t *zv; 1127 uint64_t off, volsize; 1128 size_t resid; 1129 char *addr; 1130 objset_t *os; 1131 rl_t *rl; 1132 int error = 0; 1133 boolean_t doread = bp->b_flags & B_READ; 1134 boolean_t is_dump; 1135 boolean_t sync; 1136 1137 if (getminor(bp->b_edev) == 0) { 1138 error = EINVAL; 1139 } else { 1140 zs = ddi_get_soft_state(zfsdev_state, getminor(bp->b_edev)); 1141 if (zs == NULL) 1142 error = ENXIO; 1143 else if (zs->zss_type != ZSST_ZVOL) 1144 error = EINVAL; 1145 } 1146 1147 if (error) { 1148 bioerror(bp, error); 1149 biodone(bp); 1150 return (0); 1151 } 1152 1153 zv = zs->zss_data; 1154 1155 if (!(bp->b_flags & B_READ) && (zv->zv_flags & ZVOL_RDONLY)) { 1156 bioerror(bp, EROFS); 1157 biodone(bp); 1158 return (0); 1159 } 1160 1161 off = ldbtob(bp->b_blkno); 1162 volsize = zv->zv_volsize; 1163 1164 os = zv->zv_objset; 1165 ASSERT(os != NULL); 1166 1167 bp_mapin(bp); 1168 addr = bp->b_un.b_addr; 1169 resid = bp->b_bcount; 1170 1171 if (resid > 0 && (off < 0 || off >= volsize)) { 1172 bioerror(bp, EIO); 1173 biodone(bp); 1174 return (0); 1175 } 1176 1177 is_dump = zv->zv_flags & ZVOL_DUMPIFIED; 1178 sync = ((!(bp->b_flags & B_ASYNC) && 1179 !(zv->zv_flags & ZVOL_WCE)) || 1180 (zv->zv_objset->os_sync == ZFS_SYNC_ALWAYS)) && 1181 !doread && !is_dump; 1182 1183 /* 1184 * There must be no buffer changes when doing a dmu_sync() because 1185 * we can't change the data whilst calculating the checksum. 1186 */ 1187 rl = zfs_range_lock(&zv->zv_znode, off, resid, 1188 doread ? RL_READER : RL_WRITER); 1189 1190 while (resid != 0 && off < volsize) { 1191 size_t size = MIN(resid, zvol_maxphys); 1192 if (is_dump) { 1193 size = MIN(size, P2END(off, zv->zv_volblocksize) - off); 1194 error = zvol_dumpio(zv, addr, off, size, 1195 doread, B_FALSE); 1196 } else if (doread) { 1197 error = dmu_read(os, ZVOL_OBJ, off, size, addr, 1198 DMU_READ_PREFETCH); 1199 } else { 1200 dmu_tx_t *tx = dmu_tx_create(os); 1201 dmu_tx_hold_write(tx, ZVOL_OBJ, off, size); 1202 error = dmu_tx_assign(tx, TXG_WAIT); 1203 if (error) { 1204 dmu_tx_abort(tx); 1205 } else { 1206 dmu_write(os, ZVOL_OBJ, off, size, addr, tx); 1207 zvol_log_write(zv, tx, off, size, sync); 1208 dmu_tx_commit(tx); 1209 } 1210 } 1211 if (error) { 1212 /* convert checksum errors into IO errors */ 1213 if (error == ECKSUM) 1214 error = EIO; 1215 break; 1216 } 1217 off += size; 1218 addr += size; 1219 resid -= size; 1220 } 1221 zfs_range_unlock(rl); 1222 1223 if ((bp->b_resid = resid) == bp->b_bcount) 1224 bioerror(bp, off > volsize ? EINVAL : error); 1225 1226 if (sync) 1227 zil_commit(zv->zv_zilog, ZVOL_OBJ); 1228 biodone(bp); 1229 1230 return (0); 1231 } 1232 1233 /* 1234 * Set the buffer count to the zvol maximum transfer. 1235 * Using our own routine instead of the default minphys() 1236 * means that for larger writes we write bigger buffers on X86 1237 * (128K instead of 56K) and flush the disk write cache less often 1238 * (every zvol_maxphys - currently 1MB) instead of minphys (currently 1239 * 56K on X86 and 128K on sparc). 1240 */ 1241 void 1242 zvol_minphys(struct buf *bp) 1243 { 1244 if (bp->b_bcount > zvol_maxphys) 1245 bp->b_bcount = zvol_maxphys; 1246 } 1247 1248 int 1249 zvol_dump(dev_t dev, caddr_t addr, daddr_t blkno, int nblocks) 1250 { 1251 minor_t minor = getminor(dev); 1252 zvol_state_t *zv; 1253 int error = 0; 1254 uint64_t size; 1255 uint64_t boff; 1256 uint64_t resid; 1257 1258 zv = zfsdev_get_soft_state(minor, ZSST_ZVOL); 1259 if (zv == NULL) 1260 return (ENXIO); 1261 1262 boff = ldbtob(blkno); 1263 resid = ldbtob(nblocks); 1264 1265 VERIFY3U(boff + resid, <=, zv->zv_volsize); 1266 1267 while (resid) { 1268 size = MIN(resid, P2END(boff, zv->zv_volblocksize) - boff); 1269 error = zvol_dumpio(zv, addr, boff, size, B_FALSE, B_TRUE); 1270 if (error) 1271 break; 1272 boff += size; 1273 addr += size; 1274 resid -= size; 1275 } 1276 1277 return (error); 1278 } 1279 1280 /*ARGSUSED*/ 1281 int 1282 zvol_read(dev_t dev, uio_t *uio, cred_t *cr) 1283 { 1284 minor_t minor = getminor(dev); 1285 zvol_state_t *zv; 1286 uint64_t volsize; 1287 rl_t *rl; 1288 int error = 0; 1289 1290 zv = zfsdev_get_soft_state(minor, ZSST_ZVOL); 1291 if (zv == NULL) 1292 return (ENXIO); 1293 1294 volsize = zv->zv_volsize; 1295 if (uio->uio_resid > 0 && 1296 (uio->uio_loffset < 0 || uio->uio_loffset >= volsize)) 1297 return (EIO); 1298 1299 if (zv->zv_flags & ZVOL_DUMPIFIED) { 1300 error = physio(zvol_strategy, NULL, dev, B_READ, 1301 zvol_minphys, uio); 1302 return (error); 1303 } 1304 1305 rl = zfs_range_lock(&zv->zv_znode, uio->uio_loffset, uio->uio_resid, 1306 RL_READER); 1307 while (uio->uio_resid > 0 && uio->uio_loffset < volsize) { 1308 uint64_t bytes = MIN(uio->uio_resid, DMU_MAX_ACCESS >> 1); 1309 1310 /* don't read past the end */ 1311 if (bytes > volsize - uio->uio_loffset) 1312 bytes = volsize - uio->uio_loffset; 1313 1314 error = dmu_read_uio(zv->zv_objset, ZVOL_OBJ, uio, bytes); 1315 if (error) { 1316 /* convert checksum errors into IO errors */ 1317 if (error == ECKSUM) 1318 error = EIO; 1319 break; 1320 } 1321 } 1322 zfs_range_unlock(rl); 1323 return (error); 1324 } 1325 1326 /*ARGSUSED*/ 1327 int 1328 zvol_write(dev_t dev, uio_t *uio, cred_t *cr) 1329 { 1330 minor_t minor = getminor(dev); 1331 zvol_state_t *zv; 1332 uint64_t volsize; 1333 rl_t *rl; 1334 int error = 0; 1335 boolean_t sync; 1336 1337 zv = zfsdev_get_soft_state(minor, ZSST_ZVOL); 1338 if (zv == NULL) 1339 return (ENXIO); 1340 1341 volsize = zv->zv_volsize; 1342 if (uio->uio_resid > 0 && 1343 (uio->uio_loffset < 0 || uio->uio_loffset >= volsize)) 1344 return (EIO); 1345 1346 if (zv->zv_flags & ZVOL_DUMPIFIED) { 1347 error = physio(zvol_strategy, NULL, dev, B_WRITE, 1348 zvol_minphys, uio); 1349 return (error); 1350 } 1351 1352 sync = !(zv->zv_flags & ZVOL_WCE) || 1353 (zv->zv_objset->os_sync == ZFS_SYNC_ALWAYS); 1354 1355 rl = zfs_range_lock(&zv->zv_znode, uio->uio_loffset, uio->uio_resid, 1356 RL_WRITER); 1357 while (uio->uio_resid > 0 && uio->uio_loffset < volsize) { 1358 uint64_t bytes = MIN(uio->uio_resid, DMU_MAX_ACCESS >> 1); 1359 uint64_t off = uio->uio_loffset; 1360 dmu_tx_t *tx = dmu_tx_create(zv->zv_objset); 1361 1362 if (bytes > volsize - off) /* don't write past the end */ 1363 bytes = volsize - off; 1364 1365 dmu_tx_hold_write(tx, ZVOL_OBJ, off, bytes); 1366 error = dmu_tx_assign(tx, TXG_WAIT); 1367 if (error) { 1368 dmu_tx_abort(tx); 1369 break; 1370 } 1371 error = dmu_write_uio_dbuf(zv->zv_dbuf, uio, bytes, tx); 1372 if (error == 0) 1373 zvol_log_write(zv, tx, off, bytes, sync); 1374 dmu_tx_commit(tx); 1375 1376 if (error) 1377 break; 1378 } 1379 zfs_range_unlock(rl); 1380 if (sync) 1381 zil_commit(zv->zv_zilog, ZVOL_OBJ); 1382 return (error); 1383 } 1384 1385 int 1386 zvol_getefi(void *arg, int flag, uint64_t vs, uint8_t bs) 1387 { 1388 struct uuid uuid = EFI_RESERVED; 1389 efi_gpe_t gpe = { 0 }; 1390 uint32_t crc; 1391 dk_efi_t efi; 1392 int length; 1393 char *ptr; 1394 1395 if (ddi_copyin(arg, &efi, sizeof (dk_efi_t), flag)) 1396 return (EFAULT); 1397 ptr = (char *)(uintptr_t)efi.dki_data_64; 1398 length = efi.dki_length; 1399 /* 1400 * Some clients may attempt to request a PMBR for the 1401 * zvol. Currently this interface will return EINVAL to 1402 * such requests. These requests could be supported by 1403 * adding a check for lba == 0 and consing up an appropriate 1404 * PMBR. 1405 */ 1406 if (efi.dki_lba < 1 || efi.dki_lba > 2 || length <= 0) 1407 return (EINVAL); 1408 1409 gpe.efi_gpe_StartingLBA = LE_64(34ULL); 1410 gpe.efi_gpe_EndingLBA = LE_64((vs >> bs) - 1); 1411 UUID_LE_CONVERT(gpe.efi_gpe_PartitionTypeGUID, uuid); 1412 1413 if (efi.dki_lba == 1) { 1414 efi_gpt_t gpt = { 0 }; 1415 1416 gpt.efi_gpt_Signature = LE_64(EFI_SIGNATURE); 1417 gpt.efi_gpt_Revision = LE_32(EFI_VERSION_CURRENT); 1418 gpt.efi_gpt_HeaderSize = LE_32(sizeof (gpt)); 1419 gpt.efi_gpt_MyLBA = LE_64(1ULL); 1420 gpt.efi_gpt_FirstUsableLBA = LE_64(34ULL); 1421 gpt.efi_gpt_LastUsableLBA = LE_64((vs >> bs) - 1); 1422 gpt.efi_gpt_PartitionEntryLBA = LE_64(2ULL); 1423 gpt.efi_gpt_NumberOfPartitionEntries = LE_32(1); 1424 gpt.efi_gpt_SizeOfPartitionEntry = 1425 LE_32(sizeof (efi_gpe_t)); 1426 CRC32(crc, &gpe, sizeof (gpe), -1U, crc32_table); 1427 gpt.efi_gpt_PartitionEntryArrayCRC32 = LE_32(~crc); 1428 CRC32(crc, &gpt, sizeof (gpt), -1U, crc32_table); 1429 gpt.efi_gpt_HeaderCRC32 = LE_32(~crc); 1430 if (ddi_copyout(&gpt, ptr, MIN(sizeof (gpt), length), 1431 flag)) 1432 return (EFAULT); 1433 ptr += sizeof (gpt); 1434 length -= sizeof (gpt); 1435 } 1436 if (length > 0 && ddi_copyout(&gpe, ptr, MIN(sizeof (gpe), 1437 length), flag)) 1438 return (EFAULT); 1439 return (0); 1440 } 1441 1442 /* 1443 * BEGIN entry points to allow external callers access to the volume. 1444 */ 1445 /* 1446 * Return the volume parameters needed for access from an external caller. 1447 * These values are invariant as long as the volume is held open. 1448 */ 1449 int 1450 zvol_get_volume_params(minor_t minor, uint64_t *blksize, 1451 uint64_t *max_xfer_len, void **minor_hdl, void **objset_hdl, void **zil_hdl, 1452 void **rl_hdl, void **bonus_hdl) 1453 { 1454 zvol_state_t *zv; 1455 1456 zv = zfsdev_get_soft_state(minor, ZSST_ZVOL); 1457 if (zv == NULL) 1458 return (ENXIO); 1459 if (zv->zv_flags & ZVOL_DUMPIFIED) 1460 return (ENXIO); 1461 1462 ASSERT(blksize && max_xfer_len && minor_hdl && 1463 objset_hdl && zil_hdl && rl_hdl && bonus_hdl); 1464 1465 *blksize = zv->zv_volblocksize; 1466 *max_xfer_len = (uint64_t)zvol_maxphys; 1467 *minor_hdl = zv; 1468 *objset_hdl = zv->zv_objset; 1469 *zil_hdl = zv->zv_zilog; 1470 *rl_hdl = &zv->zv_znode; 1471 *bonus_hdl = zv->zv_dbuf; 1472 return (0); 1473 } 1474 1475 /* 1476 * Return the current volume size to an external caller. 1477 * The size can change while the volume is open. 1478 */ 1479 uint64_t 1480 zvol_get_volume_size(void *minor_hdl) 1481 { 1482 zvol_state_t *zv = minor_hdl; 1483 1484 return (zv->zv_volsize); 1485 } 1486 1487 /* 1488 * Return the current WCE setting to an external caller. 1489 * The WCE setting can change while the volume is open. 1490 */ 1491 int 1492 zvol_get_volume_wce(void *minor_hdl) 1493 { 1494 zvol_state_t *zv = minor_hdl; 1495 1496 return ((zv->zv_flags & ZVOL_WCE) ? 1 : 0); 1497 } 1498 1499 /* 1500 * Entry point for external callers to zvol_log_write 1501 */ 1502 void 1503 zvol_log_write_minor(void *minor_hdl, dmu_tx_t *tx, offset_t off, ssize_t resid, 1504 boolean_t sync) 1505 { 1506 zvol_state_t *zv = minor_hdl; 1507 1508 zvol_log_write(zv, tx, off, resid, sync); 1509 } 1510 /* 1511 * END entry points to allow external callers access to the volume. 1512 */ 1513 1514 /* 1515 * Dirtbag ioctls to support mkfs(1M) for UFS filesystems. See dkio(7I). 1516 */ 1517 /*ARGSUSED*/ 1518 int 1519 zvol_ioctl(dev_t dev, int cmd, intptr_t arg, int flag, cred_t *cr, int *rvalp) 1520 { 1521 zvol_state_t *zv; 1522 struct dk_cinfo dki; 1523 struct dk_minfo dkm; 1524 struct dk_callback *dkc; 1525 int error = 0; 1526 rl_t *rl; 1527 1528 mutex_enter(&zfsdev_state_lock); 1529 1530 zv = zfsdev_get_soft_state(getminor(dev), ZSST_ZVOL); 1531 1532 if (zv == NULL) { 1533 mutex_exit(&zfsdev_state_lock); 1534 return (ENXIO); 1535 } 1536 ASSERT(zv->zv_total_opens > 0); 1537 1538 switch (cmd) { 1539 1540 case DKIOCINFO: 1541 bzero(&dki, sizeof (dki)); 1542 (void) strcpy(dki.dki_cname, "zvol"); 1543 (void) strcpy(dki.dki_dname, "zvol"); 1544 dki.dki_ctype = DKC_UNKNOWN; 1545 dki.dki_unit = getminor(dev); 1546 dki.dki_maxtransfer = 1 << (SPA_MAXBLOCKSHIFT - zv->zv_min_bs); 1547 mutex_exit(&zfsdev_state_lock); 1548 if (ddi_copyout(&dki, (void *)arg, sizeof (dki), flag)) 1549 error = EFAULT; 1550 return (error); 1551 1552 case DKIOCGMEDIAINFO: 1553 bzero(&dkm, sizeof (dkm)); 1554 dkm.dki_lbsize = 1U << zv->zv_min_bs; 1555 dkm.dki_capacity = zv->zv_volsize >> zv->zv_min_bs; 1556 dkm.dki_media_type = DK_UNKNOWN; 1557 mutex_exit(&zfsdev_state_lock); 1558 if (ddi_copyout(&dkm, (void *)arg, sizeof (dkm), flag)) 1559 error = EFAULT; 1560 return (error); 1561 1562 case DKIOCGETEFI: 1563 { 1564 uint64_t vs = zv->zv_volsize; 1565 uint8_t bs = zv->zv_min_bs; 1566 1567 mutex_exit(&zfsdev_state_lock); 1568 error = zvol_getefi((void *)arg, flag, vs, bs); 1569 return (error); 1570 } 1571 1572 case DKIOCFLUSHWRITECACHE: 1573 dkc = (struct dk_callback *)arg; 1574 mutex_exit(&zfsdev_state_lock); 1575 zil_commit(zv->zv_zilog, ZVOL_OBJ); 1576 if ((flag & FKIOCTL) && dkc != NULL && dkc->dkc_callback) { 1577 (*dkc->dkc_callback)(dkc->dkc_cookie, error); 1578 error = 0; 1579 } 1580 return (error); 1581 1582 case DKIOCGETWCE: 1583 { 1584 int wce = (zv->zv_flags & ZVOL_WCE) ? 1 : 0; 1585 if (ddi_copyout(&wce, (void *)arg, sizeof (int), 1586 flag)) 1587 error = EFAULT; 1588 break; 1589 } 1590 case DKIOCSETWCE: 1591 { 1592 int wce; 1593 if (ddi_copyin((void *)arg, &wce, sizeof (int), 1594 flag)) { 1595 error = EFAULT; 1596 break; 1597 } 1598 if (wce) { 1599 zv->zv_flags |= ZVOL_WCE; 1600 mutex_exit(&zfsdev_state_lock); 1601 } else { 1602 zv->zv_flags &= ~ZVOL_WCE; 1603 mutex_exit(&zfsdev_state_lock); 1604 zil_commit(zv->zv_zilog, ZVOL_OBJ); 1605 } 1606 return (0); 1607 } 1608 1609 case DKIOCGGEOM: 1610 case DKIOCGVTOC: 1611 /* 1612 * commands using these (like prtvtoc) expect ENOTSUP 1613 * since we're emulating an EFI label 1614 */ 1615 error = ENOTSUP; 1616 break; 1617 1618 case DKIOCDUMPINIT: 1619 rl = zfs_range_lock(&zv->zv_znode, 0, zv->zv_volsize, 1620 RL_WRITER); 1621 error = zvol_dumpify(zv); 1622 zfs_range_unlock(rl); 1623 break; 1624 1625 case DKIOCDUMPFINI: 1626 if (!(zv->zv_flags & ZVOL_DUMPIFIED)) 1627 break; 1628 rl = zfs_range_lock(&zv->zv_znode, 0, zv->zv_volsize, 1629 RL_WRITER); 1630 error = zvol_dump_fini(zv); 1631 zfs_range_unlock(rl); 1632 break; 1633 1634 default: 1635 error = ENOTTY; 1636 break; 1637 1638 } 1639 mutex_exit(&zfsdev_state_lock); 1640 return (error); 1641 } 1642 1643 int 1644 zvol_busy(void) 1645 { 1646 return (zvol_minors != 0); 1647 } 1648 1649 void 1650 zvol_init(void) 1651 { 1652 VERIFY(ddi_soft_state_init(&zfsdev_state, sizeof (zfs_soft_state_t), 1653 1) == 0); 1654 mutex_init(&zfsdev_state_lock, NULL, MUTEX_DEFAULT, NULL); 1655 } 1656 1657 void 1658 zvol_fini(void) 1659 { 1660 mutex_destroy(&zfsdev_state_lock); 1661 ddi_soft_state_fini(&zfsdev_state); 1662 } 1663 1664 static int 1665 zvol_dump_init(zvol_state_t *zv, boolean_t resize) 1666 { 1667 dmu_tx_t *tx; 1668 int error = 0; 1669 objset_t *os = zv->zv_objset; 1670 nvlist_t *nv = NULL; 1671 uint64_t version = spa_version(dmu_objset_spa(zv->zv_objset)); 1672 1673 ASSERT(MUTEX_HELD(&zfsdev_state_lock)); 1674 error = dmu_free_long_range(zv->zv_objset, ZVOL_OBJ, 0, 1675 DMU_OBJECT_END); 1676 /* wait for dmu_free_long_range to actually free the blocks */ 1677 txg_wait_synced(dmu_objset_pool(zv->zv_objset), 0); 1678 1679 tx = dmu_tx_create(os); 1680 dmu_tx_hold_zap(tx, ZVOL_ZAP_OBJ, TRUE, NULL); 1681 dmu_tx_hold_bonus(tx, ZVOL_OBJ); 1682 error = dmu_tx_assign(tx, TXG_WAIT); 1683 if (error) { 1684 dmu_tx_abort(tx); 1685 return (error); 1686 } 1687 1688 /* 1689 * If we are resizing the dump device then we only need to 1690 * update the refreservation to match the newly updated 1691 * zvolsize. Otherwise, we save off the original state of the 1692 * zvol so that we can restore them if the zvol is ever undumpified. 1693 */ 1694 if (resize) { 1695 error = zap_update(os, ZVOL_ZAP_OBJ, 1696 zfs_prop_to_name(ZFS_PROP_REFRESERVATION), 8, 1, 1697 &zv->zv_volsize, tx); 1698 } else { 1699 uint64_t checksum, compress, refresrv, vbs, dedup; 1700 1701 error = dsl_prop_get_integer(zv->zv_name, 1702 zfs_prop_to_name(ZFS_PROP_COMPRESSION), &compress, NULL); 1703 error = error ? error : dsl_prop_get_integer(zv->zv_name, 1704 zfs_prop_to_name(ZFS_PROP_CHECKSUM), &checksum, NULL); 1705 error = error ? error : dsl_prop_get_integer(zv->zv_name, 1706 zfs_prop_to_name(ZFS_PROP_REFRESERVATION), &refresrv, NULL); 1707 error = error ? error : dsl_prop_get_integer(zv->zv_name, 1708 zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE), &vbs, NULL); 1709 if (version >= SPA_VERSION_DEDUP) { 1710 error = error ? error : 1711 dsl_prop_get_integer(zv->zv_name, 1712 zfs_prop_to_name(ZFS_PROP_DEDUP), &dedup, NULL); 1713 } 1714 1715 error = error ? error : zap_update(os, ZVOL_ZAP_OBJ, 1716 zfs_prop_to_name(ZFS_PROP_COMPRESSION), 8, 1, 1717 &compress, tx); 1718 error = error ? error : zap_update(os, ZVOL_ZAP_OBJ, 1719 zfs_prop_to_name(ZFS_PROP_CHECKSUM), 8, 1, &checksum, tx); 1720 error = error ? error : zap_update(os, ZVOL_ZAP_OBJ, 1721 zfs_prop_to_name(ZFS_PROP_REFRESERVATION), 8, 1, 1722 &refresrv, tx); 1723 error = error ? error : zap_update(os, ZVOL_ZAP_OBJ, 1724 zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE), 8, 1, 1725 &vbs, tx); 1726 error = error ? error : dmu_object_set_blocksize( 1727 os, ZVOL_OBJ, SPA_MAXBLOCKSIZE, 0, tx); 1728 if (version >= SPA_VERSION_DEDUP) { 1729 error = error ? error : zap_update(os, ZVOL_ZAP_OBJ, 1730 zfs_prop_to_name(ZFS_PROP_DEDUP), 8, 1, 1731 &dedup, tx); 1732 } 1733 if (error == 0) 1734 zv->zv_volblocksize = SPA_MAXBLOCKSIZE; 1735 } 1736 dmu_tx_commit(tx); 1737 1738 /* 1739 * We only need update the zvol's property if we are initializing 1740 * the dump area for the first time. 1741 */ 1742 if (!resize) { 1743 VERIFY(nvlist_alloc(&nv, NV_UNIQUE_NAME, KM_SLEEP) == 0); 1744 VERIFY(nvlist_add_uint64(nv, 1745 zfs_prop_to_name(ZFS_PROP_REFRESERVATION), 0) == 0); 1746 VERIFY(nvlist_add_uint64(nv, 1747 zfs_prop_to_name(ZFS_PROP_COMPRESSION), 1748 ZIO_COMPRESS_OFF) == 0); 1749 VERIFY(nvlist_add_uint64(nv, 1750 zfs_prop_to_name(ZFS_PROP_CHECKSUM), 1751 ZIO_CHECKSUM_OFF) == 0); 1752 if (version >= SPA_VERSION_DEDUP) { 1753 VERIFY(nvlist_add_uint64(nv, 1754 zfs_prop_to_name(ZFS_PROP_DEDUP), 1755 ZIO_CHECKSUM_OFF) == 0); 1756 } 1757 1758 error = zfs_set_prop_nvlist(zv->zv_name, ZPROP_SRC_LOCAL, 1759 nv, NULL); 1760 nvlist_free(nv); 1761 1762 if (error) 1763 return (error); 1764 } 1765 1766 /* Allocate the space for the dump */ 1767 error = zvol_prealloc(zv); 1768 return (error); 1769 } 1770 1771 static int 1772 zvol_dumpify(zvol_state_t *zv) 1773 { 1774 int error = 0; 1775 uint64_t dumpsize = 0; 1776 dmu_tx_t *tx; 1777 objset_t *os = zv->zv_objset; 1778 1779 if (zv->zv_flags & ZVOL_RDONLY) 1780 return (EROFS); 1781 1782 if (zap_lookup(zv->zv_objset, ZVOL_ZAP_OBJ, ZVOL_DUMPSIZE, 1783 8, 1, &dumpsize) != 0 || dumpsize != zv->zv_volsize) { 1784 boolean_t resize = (dumpsize > 0) ? B_TRUE : B_FALSE; 1785 1786 if ((error = zvol_dump_init(zv, resize)) != 0) { 1787 (void) zvol_dump_fini(zv); 1788 return (error); 1789 } 1790 } 1791 1792 /* 1793 * Build up our lba mapping. 1794 */ 1795 error = zvol_get_lbas(zv); 1796 if (error) { 1797 (void) zvol_dump_fini(zv); 1798 return (error); 1799 } 1800 1801 tx = dmu_tx_create(os); 1802 dmu_tx_hold_zap(tx, ZVOL_ZAP_OBJ, TRUE, NULL); 1803 error = dmu_tx_assign(tx, TXG_WAIT); 1804 if (error) { 1805 dmu_tx_abort(tx); 1806 (void) zvol_dump_fini(zv); 1807 return (error); 1808 } 1809 1810 zv->zv_flags |= ZVOL_DUMPIFIED; 1811 error = zap_update(os, ZVOL_ZAP_OBJ, ZVOL_DUMPSIZE, 8, 1, 1812 &zv->zv_volsize, tx); 1813 dmu_tx_commit(tx); 1814 1815 if (error) { 1816 (void) zvol_dump_fini(zv); 1817 return (error); 1818 } 1819 1820 txg_wait_synced(dmu_objset_pool(os), 0); 1821 return (0); 1822 } 1823 1824 static int 1825 zvol_dump_fini(zvol_state_t *zv) 1826 { 1827 dmu_tx_t *tx; 1828 objset_t *os = zv->zv_objset; 1829 nvlist_t *nv; 1830 int error = 0; 1831 uint64_t checksum, compress, refresrv, vbs, dedup; 1832 uint64_t version = spa_version(dmu_objset_spa(zv->zv_objset)); 1833 1834 /* 1835 * Attempt to restore the zvol back to its pre-dumpified state. 1836 * This is a best-effort attempt as it's possible that not all 1837 * of these properties were initialized during the dumpify process 1838 * (i.e. error during zvol_dump_init). 1839 */ 1840 1841 tx = dmu_tx_create(os); 1842 dmu_tx_hold_zap(tx, ZVOL_ZAP_OBJ, TRUE, NULL); 1843 error = dmu_tx_assign(tx, TXG_WAIT); 1844 if (error) { 1845 dmu_tx_abort(tx); 1846 return (error); 1847 } 1848 (void) zap_remove(os, ZVOL_ZAP_OBJ, ZVOL_DUMPSIZE, tx); 1849 dmu_tx_commit(tx); 1850 1851 (void) zap_lookup(zv->zv_objset, ZVOL_ZAP_OBJ, 1852 zfs_prop_to_name(ZFS_PROP_CHECKSUM), 8, 1, &checksum); 1853 (void) zap_lookup(zv->zv_objset, ZVOL_ZAP_OBJ, 1854 zfs_prop_to_name(ZFS_PROP_COMPRESSION), 8, 1, &compress); 1855 (void) zap_lookup(zv->zv_objset, ZVOL_ZAP_OBJ, 1856 zfs_prop_to_name(ZFS_PROP_REFRESERVATION), 8, 1, &refresrv); 1857 (void) zap_lookup(zv->zv_objset, ZVOL_ZAP_OBJ, 1858 zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE), 8, 1, &vbs); 1859 1860 VERIFY(nvlist_alloc(&nv, NV_UNIQUE_NAME, KM_SLEEP) == 0); 1861 (void) nvlist_add_uint64(nv, 1862 zfs_prop_to_name(ZFS_PROP_CHECKSUM), checksum); 1863 (void) nvlist_add_uint64(nv, 1864 zfs_prop_to_name(ZFS_PROP_COMPRESSION), compress); 1865 (void) nvlist_add_uint64(nv, 1866 zfs_prop_to_name(ZFS_PROP_REFRESERVATION), refresrv); 1867 if (version >= SPA_VERSION_DEDUP && 1868 zap_lookup(zv->zv_objset, ZVOL_ZAP_OBJ, 1869 zfs_prop_to_name(ZFS_PROP_DEDUP), 8, 1, &dedup) == 0) { 1870 (void) nvlist_add_uint64(nv, 1871 zfs_prop_to_name(ZFS_PROP_DEDUP), dedup); 1872 } 1873 (void) zfs_set_prop_nvlist(zv->zv_name, ZPROP_SRC_LOCAL, 1874 nv, NULL); 1875 nvlist_free(nv); 1876 1877 zvol_free_extents(zv); 1878 zv->zv_flags &= ~ZVOL_DUMPIFIED; 1879 (void) dmu_free_long_range(os, ZVOL_OBJ, 0, DMU_OBJECT_END); 1880 /* wait for dmu_free_long_range to actually free the blocks */ 1881 txg_wait_synced(dmu_objset_pool(zv->zv_objset), 0); 1882 tx = dmu_tx_create(os); 1883 dmu_tx_hold_bonus(tx, ZVOL_OBJ); 1884 error = dmu_tx_assign(tx, TXG_WAIT); 1885 if (error) { 1886 dmu_tx_abort(tx); 1887 return (error); 1888 } 1889 if (dmu_object_set_blocksize(os, ZVOL_OBJ, vbs, 0, tx) == 0) 1890 zv->zv_volblocksize = vbs; 1891 dmu_tx_commit(tx); 1892 1893 return (0); 1894 } 1895