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 * Copyright (c) 2006-2010 Pawel Jakub Dawidek <pjd@FreeBSD.org> 25 * All rights reserved. 26 * 27 * Portions Copyright 2010 Robert Milkowski 28 * 29 * Copyright 2011 Nexenta Systems, Inc. All rights reserved. 30 * Copyright (c) 2012, 2017 by Delphix. All rights reserved. 31 * Copyright (c) 2013, Joyent, Inc. All rights reserved. 32 * Copyright (c) 2014 Integros [integros.com] 33 */ 34 35 /* Portions Copyright 2011 Martin Matuska <mm@FreeBSD.org> */ 36 37 /* 38 * ZFS volume emulation driver. 39 * 40 * Makes a DMU object look like a volume of arbitrary size, up to 2^64 bytes. 41 * Volumes are accessed through the symbolic links named: 42 * 43 * /dev/zvol/<pool_name>/<dataset_name> 44 * 45 * Volumes are persistent through reboot. No user command needs to be 46 * run before opening and using a device. 47 * 48 * On FreeBSD ZVOLs are simply GEOM providers like any other storage device 49 * in the system. Except when they're simply character devices (volmode=dev). 50 */ 51 52 #include <sys/types.h> 53 #include <sys/param.h> 54 #include <sys/kernel.h> 55 #include <sys/errno.h> 56 #include <sys/uio.h> 57 #include <sys/bio.h> 58 #include <sys/buf.h> 59 #include <sys/kmem.h> 60 #include <sys/conf.h> 61 #include <sys/cmn_err.h> 62 #include <sys/stat.h> 63 #include <sys/proc.h> 64 #include <sys/zap.h> 65 #include <sys/spa.h> 66 #include <sys/spa_impl.h> 67 #include <sys/zio.h> 68 #include <sys/disk.h> 69 #include <sys/dmu_traverse.h> 70 #include <sys/dnode.h> 71 #include <sys/dsl_dataset.h> 72 #include <sys/dsl_prop.h> 73 #include <sys/dsl_dir.h> 74 #include <sys/byteorder.h> 75 #include <sys/sunddi.h> 76 #include <sys/dirent.h> 77 #include <sys/policy.h> 78 #include <sys/queue.h> 79 #include <sys/fs/zfs.h> 80 #include <sys/zfs_ioctl.h> 81 #include <sys/zil.h> 82 #include <sys/zfs_znode.h> 83 #include <sys/zfs_rlock.h> 84 #include <sys/vdev_impl.h> 85 #include <sys/vdev_raidz.h> 86 #include <sys/zvol.h> 87 #include <sys/zil_impl.h> 88 #include <sys/dataset_kstats.h> 89 #include <sys/dbuf.h> 90 #include <sys/dmu_tx.h> 91 #include <sys/zfeature.h> 92 #include <sys/zio_checksum.h> 93 #include <sys/zil_impl.h> 94 #include <sys/filio.h> 95 96 #include <geom/geom.h> 97 #include <sys/zvol.h> 98 #include <sys/zvol_impl.h> 99 100 #include "zfs_namecheck.h" 101 102 #define ZVOL_DUMPSIZE "dumpsize" 103 104 #ifdef ZVOL_LOCK_DEBUG 105 #define ZVOL_RW_READER RW_WRITER 106 #define ZVOL_RW_READ_HELD RW_WRITE_HELD 107 #else 108 #define ZVOL_RW_READER RW_READER 109 #define ZVOL_RW_READ_HELD RW_READ_HELD 110 #endif 111 112 enum zvol_geom_state { 113 ZVOL_GEOM_UNINIT, 114 ZVOL_GEOM_STOPPED, 115 ZVOL_GEOM_RUNNING, 116 }; 117 118 struct zvol_state_os { 119 #define zso_dev _zso_state._zso_dev 120 #define zso_geom _zso_state._zso_geom 121 union { 122 /* volmode=dev */ 123 struct zvol_state_dev { 124 struct cdev *zsd_cdev; 125 uint64_t zsd_sync_cnt; 126 } _zso_dev; 127 128 /* volmode=geom */ 129 struct zvol_state_geom { 130 struct g_provider *zsg_provider; 131 struct bio_queue_head zsg_queue; 132 struct mtx zsg_queue_mtx; 133 enum zvol_geom_state zsg_state; 134 } _zso_geom; 135 } _zso_state; 136 int zso_dying; 137 }; 138 139 static uint32_t zvol_minors; 140 141 SYSCTL_DECL(_vfs_zfs); 142 SYSCTL_NODE(_vfs_zfs, OID_AUTO, vol, CTLFLAG_RW, 0, "ZFS VOLUME"); 143 SYSCTL_INT(_vfs_zfs_vol, OID_AUTO, mode, CTLFLAG_RWTUN, &zvol_volmode, 0, 144 "Expose as GEOM providers (1), device files (2) or neither"); 145 static boolean_t zpool_on_zvol = B_FALSE; 146 SYSCTL_INT(_vfs_zfs_vol, OID_AUTO, recursive, CTLFLAG_RWTUN, &zpool_on_zvol, 0, 147 "Allow zpools to use zvols as vdevs (DANGEROUS)"); 148 149 /* 150 * Toggle unmap functionality. 151 */ 152 boolean_t zvol_unmap_enabled = B_TRUE; 153 154 SYSCTL_INT(_vfs_zfs_vol, OID_AUTO, unmap_enabled, CTLFLAG_RWTUN, 155 &zvol_unmap_enabled, 0, "Enable UNMAP functionality"); 156 157 /* 158 * zvol maximum transfer in one DMU tx. 159 */ 160 int zvol_maxphys = DMU_MAX_ACCESS / 2; 161 162 static void zvol_ensure_zilog(zvol_state_t *zv); 163 164 static d_open_t zvol_cdev_open; 165 static d_close_t zvol_cdev_close; 166 static d_ioctl_t zvol_cdev_ioctl; 167 static d_read_t zvol_cdev_read; 168 static d_write_t zvol_cdev_write; 169 static d_strategy_t zvol_geom_bio_strategy; 170 171 static struct cdevsw zvol_cdevsw = { 172 .d_name = "zvol", 173 .d_version = D_VERSION, 174 .d_flags = D_DISK | D_TRACKCLOSE, 175 .d_open = zvol_cdev_open, 176 .d_close = zvol_cdev_close, 177 .d_ioctl = zvol_cdev_ioctl, 178 .d_read = zvol_cdev_read, 179 .d_write = zvol_cdev_write, 180 .d_strategy = zvol_geom_bio_strategy, 181 }; 182 183 extern uint_t zfs_geom_probe_vdev_key; 184 185 struct g_class zfs_zvol_class = { 186 .name = "ZFS::ZVOL", 187 .version = G_VERSION, 188 }; 189 190 DECLARE_GEOM_CLASS(zfs_zvol_class, zfs_zvol); 191 192 static int zvol_geom_open(struct g_provider *pp, int flag, int count); 193 static int zvol_geom_close(struct g_provider *pp, int flag, int count); 194 static void zvol_geom_run(zvol_state_t *zv); 195 static void zvol_geom_destroy(zvol_state_t *zv); 196 static int zvol_geom_access(struct g_provider *pp, int acr, int acw, int ace); 197 static void zvol_geom_worker(void *arg); 198 static void zvol_geom_bio_start(struct bio *bp); 199 static int zvol_geom_bio_getattr(struct bio *bp); 200 /* static d_strategy_t zvol_geom_bio_strategy; (declared elsewhere) */ 201 202 /* 203 * GEOM mode implementation 204 */ 205 206 /*ARGSUSED*/ 207 static int 208 zvol_geom_open(struct g_provider *pp, int flag, int count) 209 { 210 zvol_state_t *zv; 211 int err = 0; 212 boolean_t drop_suspend = B_FALSE; 213 boolean_t drop_namespace = B_FALSE; 214 215 if (!zpool_on_zvol && tsd_get(zfs_geom_probe_vdev_key) != NULL) { 216 /* 217 * if zfs_geom_probe_vdev_key is set, that means that zfs is 218 * attempting to probe geom providers while looking for a 219 * replacement for a missing VDEV. In this case, the 220 * spa_namespace_lock will not be held, but it is still illegal 221 * to use a zvol as a vdev. Deadlocks can result if another 222 * thread has spa_namespace_lock 223 */ 224 return (SET_ERROR(EOPNOTSUPP)); 225 } 226 227 retry: 228 rw_enter(&zvol_state_lock, ZVOL_RW_READER); 229 zv = pp->private; 230 if (zv == NULL) { 231 rw_exit(&zvol_state_lock); 232 err = SET_ERROR(ENXIO); 233 goto out_locked; 234 } 235 236 if (zv->zv_open_count == 0 && !mutex_owned(&spa_namespace_lock)) { 237 /* 238 * We need to guarantee that the namespace lock is held 239 * to avoid spurious failures in zvol_first_open. 240 */ 241 drop_namespace = B_TRUE; 242 if (!mutex_tryenter(&spa_namespace_lock)) { 243 rw_exit(&zvol_state_lock); 244 mutex_enter(&spa_namespace_lock); 245 goto retry; 246 } 247 } 248 mutex_enter(&zv->zv_state_lock); 249 if (zv->zv_zso->zso_dying) { 250 rw_exit(&zvol_state_lock); 251 err = SET_ERROR(ENXIO); 252 goto out_zv_locked; 253 } 254 ASSERT3S(zv->zv_volmode, ==, ZFS_VOLMODE_GEOM); 255 256 /* 257 * make sure zvol is not suspended during first open 258 * (hold zv_suspend_lock) and respect proper lock acquisition 259 * ordering - zv_suspend_lock before zv_state_lock 260 */ 261 if (zv->zv_open_count == 0) { 262 drop_suspend = B_TRUE; 263 if (!rw_tryenter(&zv->zv_suspend_lock, ZVOL_RW_READER)) { 264 mutex_exit(&zv->zv_state_lock); 265 rw_enter(&zv->zv_suspend_lock, ZVOL_RW_READER); 266 mutex_enter(&zv->zv_state_lock); 267 /* check to see if zv_suspend_lock is needed */ 268 if (zv->zv_open_count != 0) { 269 rw_exit(&zv->zv_suspend_lock); 270 drop_suspend = B_FALSE; 271 } 272 } 273 } 274 rw_exit(&zvol_state_lock); 275 276 ASSERT(MUTEX_HELD(&zv->zv_state_lock)); 277 278 if (zv->zv_open_count == 0) { 279 ASSERT(ZVOL_RW_READ_HELD(&zv->zv_suspend_lock)); 280 err = zvol_first_open(zv, !(flag & FWRITE)); 281 if (err) 282 goto out_zv_locked; 283 pp->mediasize = zv->zv_volsize; 284 pp->stripeoffset = 0; 285 pp->stripesize = zv->zv_volblocksize; 286 } 287 288 /* 289 * Check for a bad on-disk format version now since we 290 * lied about owning the dataset readonly before. 291 */ 292 if ((flag & FWRITE) && ((zv->zv_flags & ZVOL_RDONLY) || 293 dmu_objset_incompatible_encryption_version(zv->zv_objset))) { 294 err = SET_ERROR(EROFS); 295 goto out_opened; 296 } 297 if (zv->zv_flags & ZVOL_EXCL) { 298 err = SET_ERROR(EBUSY); 299 goto out_opened; 300 } 301 #ifdef FEXCL 302 if (flag & FEXCL) { 303 if (zv->zv_open_count != 0) { 304 err = SET_ERROR(EBUSY); 305 goto out_opened; 306 } 307 zv->zv_flags |= ZVOL_EXCL; 308 } 309 #endif 310 311 zv->zv_open_count += count; 312 out_opened: 313 if (zv->zv_open_count == 0) { 314 zvol_last_close(zv); 315 wakeup(zv); 316 } 317 out_zv_locked: 318 mutex_exit(&zv->zv_state_lock); 319 out_locked: 320 if (drop_namespace) 321 mutex_exit(&spa_namespace_lock); 322 if (drop_suspend) 323 rw_exit(&zv->zv_suspend_lock); 324 return (err); 325 } 326 327 /*ARGSUSED*/ 328 static int 329 zvol_geom_close(struct g_provider *pp, int flag, int count) 330 { 331 zvol_state_t *zv; 332 boolean_t drop_suspend = B_TRUE; 333 int new_open_count; 334 335 rw_enter(&zvol_state_lock, ZVOL_RW_READER); 336 zv = pp->private; 337 if (zv == NULL) { 338 rw_exit(&zvol_state_lock); 339 return (SET_ERROR(ENXIO)); 340 } 341 342 mutex_enter(&zv->zv_state_lock); 343 if (zv->zv_flags & ZVOL_EXCL) { 344 ASSERT3U(zv->zv_open_count, ==, 1); 345 zv->zv_flags &= ~ZVOL_EXCL; 346 } 347 348 ASSERT3S(zv->zv_volmode, ==, ZFS_VOLMODE_GEOM); 349 350 /* 351 * If the open count is zero, this is a spurious close. 352 * That indicates a bug in the kernel / DDI framework. 353 */ 354 ASSERT3U(zv->zv_open_count, >, 0); 355 356 /* 357 * make sure zvol is not suspended during last close 358 * (hold zv_suspend_lock) and respect proper lock acquisition 359 * ordering - zv_suspend_lock before zv_state_lock 360 */ 361 new_open_count = zv->zv_open_count - count; 362 if (new_open_count == 0) { 363 if (!rw_tryenter(&zv->zv_suspend_lock, ZVOL_RW_READER)) { 364 mutex_exit(&zv->zv_state_lock); 365 rw_enter(&zv->zv_suspend_lock, ZVOL_RW_READER); 366 mutex_enter(&zv->zv_state_lock); 367 /* check to see if zv_suspend_lock is needed */ 368 new_open_count = zv->zv_open_count - count; 369 if (new_open_count != 0) { 370 rw_exit(&zv->zv_suspend_lock); 371 drop_suspend = B_FALSE; 372 } 373 } 374 } else { 375 drop_suspend = B_FALSE; 376 } 377 rw_exit(&zvol_state_lock); 378 379 ASSERT(MUTEX_HELD(&zv->zv_state_lock)); 380 381 /* 382 * You may get multiple opens, but only one close. 383 */ 384 zv->zv_open_count = new_open_count; 385 if (zv->zv_open_count == 0) { 386 ASSERT(ZVOL_RW_READ_HELD(&zv->zv_suspend_lock)); 387 zvol_last_close(zv); 388 wakeup(zv); 389 } 390 391 mutex_exit(&zv->zv_state_lock); 392 393 if (drop_suspend) 394 rw_exit(&zv->zv_suspend_lock); 395 return (0); 396 } 397 398 static void 399 zvol_geom_run(zvol_state_t *zv) 400 { 401 struct zvol_state_geom *zsg = &zv->zv_zso->zso_geom; 402 struct g_provider *pp = zsg->zsg_provider; 403 404 ASSERT3S(zv->zv_volmode, ==, ZFS_VOLMODE_GEOM); 405 406 g_error_provider(pp, 0); 407 408 kproc_kthread_add(zvol_geom_worker, zv, &system_proc, NULL, 0, 0, 409 "zfskern", "zvol %s", pp->name + sizeof (ZVOL_DRIVER)); 410 } 411 412 static void 413 zvol_geom_destroy(zvol_state_t *zv) 414 { 415 struct zvol_state_geom *zsg = &zv->zv_zso->zso_geom; 416 struct g_provider *pp = zsg->zsg_provider; 417 418 ASSERT3S(zv->zv_volmode, ==, ZFS_VOLMODE_GEOM); 419 420 g_topology_assert(); 421 422 mutex_enter(&zv->zv_state_lock); 423 VERIFY(zsg->zsg_state == ZVOL_GEOM_RUNNING); 424 mutex_exit(&zv->zv_state_lock); 425 zsg->zsg_provider = NULL; 426 g_wither_geom(pp->geom, ENXIO); 427 } 428 429 void 430 zvol_wait_close(zvol_state_t *zv) 431 { 432 433 if (zv->zv_volmode != ZFS_VOLMODE_GEOM) 434 return; 435 mutex_enter(&zv->zv_state_lock); 436 zv->zv_zso->zso_dying = B_TRUE; 437 438 if (zv->zv_open_count) 439 msleep(zv, &zv->zv_state_lock, 440 PRIBIO, "zvol:dying", 10*hz); 441 mutex_exit(&zv->zv_state_lock); 442 } 443 444 445 static int 446 zvol_geom_access(struct g_provider *pp, int acr, int acw, int ace) 447 { 448 int count, error, flags; 449 450 g_topology_assert(); 451 452 /* 453 * To make it easier we expect either open or close, but not both 454 * at the same time. 455 */ 456 KASSERT((acr >= 0 && acw >= 0 && ace >= 0) || 457 (acr <= 0 && acw <= 0 && ace <= 0), 458 ("Unsupported access request to %s (acr=%d, acw=%d, ace=%d).", 459 pp->name, acr, acw, ace)); 460 461 if (pp->private == NULL) { 462 if (acr <= 0 && acw <= 0 && ace <= 0) 463 return (0); 464 return (pp->error); 465 } 466 467 /* 468 * We don't pass FEXCL flag to zvol_geom_open()/zvol_geom_close() if 469 * ace != 0, because GEOM already handles that and handles it a bit 470 * differently. GEOM allows for multiple read/exclusive consumers and 471 * ZFS allows only one exclusive consumer, no matter if it is reader or 472 * writer. I like better the way GEOM works so I'll leave it for GEOM 473 * to decide what to do. 474 */ 475 476 count = acr + acw + ace; 477 if (count == 0) 478 return (0); 479 480 flags = 0; 481 if (acr != 0 || ace != 0) 482 flags |= FREAD; 483 if (acw != 0) 484 flags |= FWRITE; 485 486 g_topology_unlock(); 487 if (count > 0) 488 error = zvol_geom_open(pp, flags, count); 489 else 490 error = zvol_geom_close(pp, flags, -count); 491 g_topology_lock(); 492 return (error); 493 } 494 495 static void 496 zvol_geom_worker(void *arg) 497 { 498 zvol_state_t *zv = arg; 499 struct zvol_state_geom *zsg = &zv->zv_zso->zso_geom; 500 struct bio *bp; 501 502 ASSERT3S(zv->zv_volmode, ==, ZFS_VOLMODE_GEOM); 503 504 thread_lock(curthread); 505 sched_prio(curthread, PRIBIO); 506 thread_unlock(curthread); 507 508 for (;;) { 509 mtx_lock(&zsg->zsg_queue_mtx); 510 bp = bioq_takefirst(&zsg->zsg_queue); 511 if (bp == NULL) { 512 if (zsg->zsg_state == ZVOL_GEOM_STOPPED) { 513 zsg->zsg_state = ZVOL_GEOM_RUNNING; 514 wakeup(&zsg->zsg_state); 515 mtx_unlock(&zsg->zsg_queue_mtx); 516 kthread_exit(); 517 } 518 msleep(&zsg->zsg_queue, &zsg->zsg_queue_mtx, 519 PRIBIO | PDROP, "zvol:io", 0); 520 continue; 521 } 522 mtx_unlock(&zsg->zsg_queue_mtx); 523 zvol_geom_bio_strategy(bp); 524 } 525 } 526 527 static void 528 zvol_geom_bio_start(struct bio *bp) 529 { 530 zvol_state_t *zv = bp->bio_to->private; 531 struct zvol_state_geom *zsg; 532 boolean_t first; 533 534 if (zv == NULL) { 535 g_io_deliver(bp, ENXIO); 536 return; 537 } 538 if (bp->bio_cmd == BIO_GETATTR) { 539 if (zvol_geom_bio_getattr(bp)) 540 g_io_deliver(bp, EOPNOTSUPP); 541 return; 542 } 543 544 if (!THREAD_CAN_SLEEP()) { 545 zsg = &zv->zv_zso->zso_geom; 546 mtx_lock(&zsg->zsg_queue_mtx); 547 first = (bioq_first(&zsg->zsg_queue) == NULL); 548 bioq_insert_tail(&zsg->zsg_queue, bp); 549 mtx_unlock(&zsg->zsg_queue_mtx); 550 if (first) 551 wakeup_one(&zsg->zsg_queue); 552 return; 553 } 554 555 zvol_geom_bio_strategy(bp); 556 } 557 558 static int 559 zvol_geom_bio_getattr(struct bio *bp) 560 { 561 zvol_state_t *zv; 562 563 zv = bp->bio_to->private; 564 ASSERT3P(zv, !=, NULL); 565 566 spa_t *spa = dmu_objset_spa(zv->zv_objset); 567 uint64_t refd, avail, usedobjs, availobjs; 568 569 if (g_handleattr_int(bp, "GEOM::candelete", 1)) 570 return (0); 571 if (strcmp(bp->bio_attribute, "blocksavail") == 0) { 572 dmu_objset_space(zv->zv_objset, &refd, &avail, 573 &usedobjs, &availobjs); 574 if (g_handleattr_off_t(bp, "blocksavail", avail / DEV_BSIZE)) 575 return (0); 576 } else if (strcmp(bp->bio_attribute, "blocksused") == 0) { 577 dmu_objset_space(zv->zv_objset, &refd, &avail, 578 &usedobjs, &availobjs); 579 if (g_handleattr_off_t(bp, "blocksused", refd / DEV_BSIZE)) 580 return (0); 581 } else if (strcmp(bp->bio_attribute, "poolblocksavail") == 0) { 582 avail = metaslab_class_get_space(spa_normal_class(spa)); 583 avail -= metaslab_class_get_alloc(spa_normal_class(spa)); 584 if (g_handleattr_off_t(bp, "poolblocksavail", 585 avail / DEV_BSIZE)) 586 return (0); 587 } else if (strcmp(bp->bio_attribute, "poolblocksused") == 0) { 588 refd = metaslab_class_get_alloc(spa_normal_class(spa)); 589 if (g_handleattr_off_t(bp, "poolblocksused", refd / DEV_BSIZE)) 590 return (0); 591 } 592 return (1); 593 } 594 595 static void 596 zvol_geom_bio_strategy(struct bio *bp) 597 { 598 zvol_state_t *zv; 599 uint64_t off, volsize; 600 size_t resid; 601 char *addr; 602 objset_t *os; 603 zfs_locked_range_t *lr; 604 int error = 0; 605 boolean_t doread = B_FALSE; 606 boolean_t is_dumpified; 607 boolean_t sync; 608 609 if (bp->bio_to) 610 zv = bp->bio_to->private; 611 else 612 zv = bp->bio_dev->si_drv2; 613 614 if (zv == NULL) { 615 error = SET_ERROR(ENXIO); 616 goto out; 617 } 618 619 rw_enter(&zv->zv_suspend_lock, ZVOL_RW_READER); 620 621 switch (bp->bio_cmd) { 622 case BIO_READ: 623 doread = B_TRUE; 624 break; 625 case BIO_WRITE: 626 case BIO_FLUSH: 627 case BIO_DELETE: 628 if (zv->zv_flags & ZVOL_RDONLY) { 629 error = SET_ERROR(EROFS); 630 goto resume; 631 } 632 zvol_ensure_zilog(zv); 633 if (bp->bio_cmd == BIO_FLUSH) 634 goto sync; 635 break; 636 default: 637 error = SET_ERROR(EOPNOTSUPP); 638 goto resume; 639 } 640 641 off = bp->bio_offset; 642 volsize = zv->zv_volsize; 643 644 os = zv->zv_objset; 645 ASSERT3P(os, !=, NULL); 646 647 addr = bp->bio_data; 648 resid = bp->bio_length; 649 650 if (resid > 0 && off >= volsize) { 651 error = SET_ERROR(EIO); 652 goto resume; 653 } 654 655 is_dumpified = B_FALSE; 656 sync = !doread && !is_dumpified && 657 zv->zv_objset->os_sync == ZFS_SYNC_ALWAYS; 658 659 /* 660 * There must be no buffer changes when doing a dmu_sync() because 661 * we can't change the data whilst calculating the checksum. 662 */ 663 lr = zfs_rangelock_enter(&zv->zv_rangelock, off, resid, 664 doread ? RL_READER : RL_WRITER); 665 666 if (bp->bio_cmd == BIO_DELETE) { 667 dmu_tx_t *tx = dmu_tx_create(zv->zv_objset); 668 error = dmu_tx_assign(tx, TXG_WAIT); 669 if (error != 0) { 670 dmu_tx_abort(tx); 671 } else { 672 zvol_log_truncate(zv, tx, off, resid, sync); 673 dmu_tx_commit(tx); 674 error = dmu_free_long_range(zv->zv_objset, ZVOL_OBJ, 675 off, resid); 676 resid = 0; 677 } 678 goto unlock; 679 } 680 while (resid != 0 && off < volsize) { 681 size_t size = MIN(resid, zvol_maxphys); 682 if (doread) { 683 error = dmu_read(os, ZVOL_OBJ, off, size, addr, 684 DMU_READ_PREFETCH); 685 } else { 686 dmu_tx_t *tx = dmu_tx_create(os); 687 dmu_tx_hold_write_by_dnode(tx, zv->zv_dn, off, size); 688 error = dmu_tx_assign(tx, TXG_WAIT); 689 if (error) { 690 dmu_tx_abort(tx); 691 } else { 692 dmu_write(os, ZVOL_OBJ, off, size, addr, tx); 693 zvol_log_write(zv, tx, off, size, sync); 694 dmu_tx_commit(tx); 695 } 696 } 697 if (error) { 698 /* convert checksum errors into IO errors */ 699 if (error == ECKSUM) 700 error = SET_ERROR(EIO); 701 break; 702 } 703 off += size; 704 addr += size; 705 resid -= size; 706 } 707 unlock: 708 zfs_rangelock_exit(lr); 709 710 bp->bio_completed = bp->bio_length - resid; 711 if (bp->bio_completed < bp->bio_length && off > volsize) 712 error = SET_ERROR(EINVAL); 713 714 switch (bp->bio_cmd) { 715 case BIO_FLUSH: 716 break; 717 case BIO_READ: 718 dataset_kstats_update_read_kstats(&zv->zv_kstat, 719 bp->bio_completed); 720 break; 721 case BIO_WRITE: 722 dataset_kstats_update_write_kstats(&zv->zv_kstat, 723 bp->bio_completed); 724 break; 725 case BIO_DELETE: 726 break; 727 default: 728 break; 729 } 730 731 if (sync) { 732 sync: 733 zil_commit(zv->zv_zilog, ZVOL_OBJ); 734 } 735 resume: 736 rw_exit(&zv->zv_suspend_lock); 737 out: 738 if (bp->bio_to) 739 g_io_deliver(bp, error); 740 else 741 biofinish(bp, NULL, error); 742 } 743 744 /* 745 * Character device mode implementation 746 */ 747 748 static int 749 zvol_cdev_read(struct cdev *dev, struct uio *uio, int ioflag) 750 { 751 zvol_state_t *zv; 752 uint64_t volsize; 753 zfs_locked_range_t *lr; 754 int error = 0; 755 756 zv = dev->si_drv2; 757 758 volsize = zv->zv_volsize; 759 /* 760 * uio_loffset == volsize isn't an error as 761 * its required for EOF processing. 762 */ 763 if (uio->uio_resid > 0 && 764 (uio->uio_loffset < 0 || uio->uio_loffset > volsize)) 765 return (SET_ERROR(EIO)); 766 767 lr = zfs_rangelock_enter(&zv->zv_rangelock, uio->uio_loffset, 768 uio->uio_resid, RL_READER); 769 while (uio->uio_resid > 0 && uio->uio_loffset < volsize) { 770 uint64_t bytes = MIN(uio->uio_resid, DMU_MAX_ACCESS >> 1); 771 772 /* don't read past the end */ 773 if (bytes > volsize - uio->uio_loffset) 774 bytes = volsize - uio->uio_loffset; 775 776 error = dmu_read_uio_dnode(zv->zv_dn, uio, bytes); 777 if (error) { 778 /* convert checksum errors into IO errors */ 779 if (error == ECKSUM) 780 error = SET_ERROR(EIO); 781 break; 782 } 783 } 784 zfs_rangelock_exit(lr); 785 786 return (error); 787 } 788 789 static int 790 zvol_cdev_write(struct cdev *dev, struct uio *uio, int ioflag) 791 { 792 zvol_state_t *zv; 793 uint64_t volsize; 794 zfs_locked_range_t *lr; 795 int error = 0; 796 boolean_t sync; 797 798 zv = dev->si_drv2; 799 800 volsize = zv->zv_volsize; 801 802 if (uio->uio_resid > 0 && 803 (uio->uio_loffset < 0 || uio->uio_loffset > volsize)) 804 return (SET_ERROR(EIO)); 805 806 sync = (ioflag & IO_SYNC) || 807 (zv->zv_objset->os_sync == ZFS_SYNC_ALWAYS); 808 809 rw_enter(&zv->zv_suspend_lock, ZVOL_RW_READER); 810 zvol_ensure_zilog(zv); 811 812 lr = zfs_rangelock_enter(&zv->zv_rangelock, uio->uio_loffset, 813 uio->uio_resid, RL_WRITER); 814 while (uio->uio_resid > 0 && uio->uio_loffset < volsize) { 815 uint64_t bytes = MIN(uio->uio_resid, DMU_MAX_ACCESS >> 1); 816 uint64_t off = uio->uio_loffset; 817 dmu_tx_t *tx = dmu_tx_create(zv->zv_objset); 818 819 if (bytes > volsize - off) /* don't write past the end */ 820 bytes = volsize - off; 821 822 dmu_tx_hold_write_by_dnode(tx, zv->zv_dn, off, bytes); 823 error = dmu_tx_assign(tx, TXG_WAIT); 824 if (error) { 825 dmu_tx_abort(tx); 826 break; 827 } 828 error = dmu_write_uio_dnode(zv->zv_dn, uio, bytes, tx); 829 if (error == 0) 830 zvol_log_write(zv, tx, off, bytes, sync); 831 dmu_tx_commit(tx); 832 833 if (error) 834 break; 835 } 836 zfs_rangelock_exit(lr); 837 if (sync) 838 zil_commit(zv->zv_zilog, ZVOL_OBJ); 839 rw_exit(&zv->zv_suspend_lock); 840 return (error); 841 } 842 843 static int 844 zvol_cdev_open(struct cdev *dev, int flags, int fmt, struct thread *td) 845 { 846 zvol_state_t *zv; 847 struct zvol_state_dev *zsd; 848 int err = 0; 849 boolean_t drop_suspend = B_FALSE; 850 boolean_t drop_namespace = B_FALSE; 851 852 retry: 853 rw_enter(&zvol_state_lock, ZVOL_RW_READER); 854 zv = dev->si_drv2; 855 if (zv == NULL) { 856 rw_exit(&zvol_state_lock); 857 err = SET_ERROR(ENXIO); 858 goto out_locked; 859 } 860 861 if (zv->zv_open_count == 0 && !mutex_owned(&spa_namespace_lock)) { 862 /* 863 * We need to guarantee that the namespace lock is held 864 * to avoid spurious failures in zvol_first_open. 865 */ 866 drop_namespace = B_TRUE; 867 if (!mutex_tryenter(&spa_namespace_lock)) { 868 rw_exit(&zvol_state_lock); 869 mutex_enter(&spa_namespace_lock); 870 goto retry; 871 } 872 } 873 mutex_enter(&zv->zv_state_lock); 874 875 ASSERT3S(zv->zv_volmode, ==, ZFS_VOLMODE_DEV); 876 877 /* 878 * make sure zvol is not suspended during first open 879 * (hold zv_suspend_lock) and respect proper lock acquisition 880 * ordering - zv_suspend_lock before zv_state_lock 881 */ 882 if (zv->zv_open_count == 0) { 883 drop_suspend = B_TRUE; 884 if (!rw_tryenter(&zv->zv_suspend_lock, ZVOL_RW_READER)) { 885 mutex_exit(&zv->zv_state_lock); 886 rw_enter(&zv->zv_suspend_lock, ZVOL_RW_READER); 887 mutex_enter(&zv->zv_state_lock); 888 /* check to see if zv_suspend_lock is needed */ 889 if (zv->zv_open_count != 0) { 890 rw_exit(&zv->zv_suspend_lock); 891 drop_suspend = B_FALSE; 892 } 893 } 894 } 895 rw_exit(&zvol_state_lock); 896 897 ASSERT(MUTEX_HELD(&zv->zv_state_lock)); 898 899 if (zv->zv_open_count == 0) { 900 ASSERT(ZVOL_RW_READ_HELD(&zv->zv_suspend_lock)); 901 err = zvol_first_open(zv, !(flags & FWRITE)); 902 if (err) 903 goto out_zv_locked; 904 } 905 906 if ((flags & FWRITE) && (zv->zv_flags & ZVOL_RDONLY)) { 907 err = SET_ERROR(EROFS); 908 goto out_opened; 909 } 910 if (zv->zv_flags & ZVOL_EXCL) { 911 err = SET_ERROR(EBUSY); 912 goto out_opened; 913 } 914 #ifdef FEXCL 915 if (flags & FEXCL) { 916 if (zv->zv_open_count != 0) { 917 err = SET_ERROR(EBUSY); 918 goto out_opened; 919 } 920 zv->zv_flags |= ZVOL_EXCL; 921 } 922 #endif 923 924 zv->zv_open_count++; 925 if (flags & (FSYNC | FDSYNC)) { 926 zsd = &zv->zv_zso->zso_dev; 927 zsd->zsd_sync_cnt++; 928 if (zsd->zsd_sync_cnt == 1 && 929 (zv->zv_flags & ZVOL_WRITTEN_TO) != 0) 930 zil_async_to_sync(zv->zv_zilog, ZVOL_OBJ); 931 } 932 out_opened: 933 if (zv->zv_open_count == 0) { 934 zvol_last_close(zv); 935 wakeup(zv); 936 } 937 out_zv_locked: 938 mutex_exit(&zv->zv_state_lock); 939 out_locked: 940 if (drop_namespace) 941 mutex_exit(&spa_namespace_lock); 942 if (drop_suspend) 943 rw_exit(&zv->zv_suspend_lock); 944 return (err); 945 } 946 947 static int 948 zvol_cdev_close(struct cdev *dev, int flags, int fmt, struct thread *td) 949 { 950 zvol_state_t *zv; 951 struct zvol_state_dev *zsd; 952 boolean_t drop_suspend = B_TRUE; 953 954 rw_enter(&zvol_state_lock, ZVOL_RW_READER); 955 zv = dev->si_drv2; 956 if (zv == NULL) { 957 rw_exit(&zvol_state_lock); 958 return (SET_ERROR(ENXIO)); 959 } 960 961 mutex_enter(&zv->zv_state_lock); 962 if (zv->zv_flags & ZVOL_EXCL) { 963 ASSERT3U(zv->zv_open_count, ==, 1); 964 zv->zv_flags &= ~ZVOL_EXCL; 965 } 966 967 ASSERT3S(zv->zv_volmode, ==, ZFS_VOLMODE_DEV); 968 969 /* 970 * If the open count is zero, this is a spurious close. 971 * That indicates a bug in the kernel / DDI framework. 972 */ 973 ASSERT3U(zv->zv_open_count, >, 0); 974 /* 975 * make sure zvol is not suspended during last close 976 * (hold zv_suspend_lock) and respect proper lock acquisition 977 * ordering - zv_suspend_lock before zv_state_lock 978 */ 979 if (zv->zv_open_count == 1) { 980 if (!rw_tryenter(&zv->zv_suspend_lock, ZVOL_RW_READER)) { 981 mutex_exit(&zv->zv_state_lock); 982 rw_enter(&zv->zv_suspend_lock, ZVOL_RW_READER); 983 mutex_enter(&zv->zv_state_lock); 984 /* check to see if zv_suspend_lock is needed */ 985 if (zv->zv_open_count != 1) { 986 rw_exit(&zv->zv_suspend_lock); 987 drop_suspend = B_FALSE; 988 } 989 } 990 } else { 991 drop_suspend = B_FALSE; 992 } 993 rw_exit(&zvol_state_lock); 994 995 ASSERT(MUTEX_HELD(&zv->zv_state_lock)); 996 997 /* 998 * You may get multiple opens, but only one close. 999 */ 1000 zv->zv_open_count--; 1001 if (flags & (FSYNC | FDSYNC)) { 1002 zsd = &zv->zv_zso->zso_dev; 1003 zsd->zsd_sync_cnt--; 1004 } 1005 1006 if (zv->zv_open_count == 0) { 1007 ASSERT(ZVOL_RW_READ_HELD(&zv->zv_suspend_lock)); 1008 zvol_last_close(zv); 1009 wakeup(zv); 1010 } 1011 1012 mutex_exit(&zv->zv_state_lock); 1013 1014 if (drop_suspend) 1015 rw_exit(&zv->zv_suspend_lock); 1016 return (0); 1017 } 1018 1019 static int 1020 zvol_cdev_ioctl(struct cdev *dev, ulong_t cmd, caddr_t data, 1021 int fflag, struct thread *td) 1022 { 1023 zvol_state_t *zv; 1024 zfs_locked_range_t *lr; 1025 off_t offset, length; 1026 int i, error; 1027 boolean_t sync; 1028 1029 zv = dev->si_drv2; 1030 1031 error = 0; 1032 KASSERT(zv->zv_open_count > 0, 1033 ("Device with zero access count in %s", __func__)); 1034 1035 i = IOCPARM_LEN(cmd); 1036 switch (cmd) { 1037 case DIOCGSECTORSIZE: 1038 *(uint32_t *)data = DEV_BSIZE; 1039 break; 1040 case DIOCGMEDIASIZE: 1041 *(off_t *)data = zv->zv_volsize; 1042 break; 1043 case DIOCGFLUSH: 1044 rw_enter(&zv->zv_suspend_lock, ZVOL_RW_READER); 1045 if (zv->zv_zilog != NULL) 1046 zil_commit(zv->zv_zilog, ZVOL_OBJ); 1047 rw_exit(&zv->zv_suspend_lock); 1048 break; 1049 case DIOCGDELETE: 1050 if (!zvol_unmap_enabled) 1051 break; 1052 1053 offset = ((off_t *)data)[0]; 1054 length = ((off_t *)data)[1]; 1055 if ((offset % DEV_BSIZE) != 0 || (length % DEV_BSIZE) != 0 || 1056 offset < 0 || offset >= zv->zv_volsize || 1057 length <= 0) { 1058 printf("%s: offset=%jd length=%jd\n", __func__, offset, 1059 length); 1060 error = SET_ERROR(EINVAL); 1061 break; 1062 } 1063 rw_enter(&zv->zv_suspend_lock, ZVOL_RW_READER); 1064 zvol_ensure_zilog(zv); 1065 lr = zfs_rangelock_enter(&zv->zv_rangelock, offset, length, 1066 RL_WRITER); 1067 dmu_tx_t *tx = dmu_tx_create(zv->zv_objset); 1068 error = dmu_tx_assign(tx, TXG_WAIT); 1069 if (error != 0) { 1070 sync = FALSE; 1071 dmu_tx_abort(tx); 1072 } else { 1073 sync = (zv->zv_objset->os_sync == ZFS_SYNC_ALWAYS); 1074 zvol_log_truncate(zv, tx, offset, length, sync); 1075 dmu_tx_commit(tx); 1076 error = dmu_free_long_range(zv->zv_objset, ZVOL_OBJ, 1077 offset, length); 1078 } 1079 zfs_rangelock_exit(lr); 1080 if (sync) 1081 zil_commit(zv->zv_zilog, ZVOL_OBJ); 1082 rw_exit(&zv->zv_suspend_lock); 1083 break; 1084 case DIOCGSTRIPESIZE: 1085 *(off_t *)data = zv->zv_volblocksize; 1086 break; 1087 case DIOCGSTRIPEOFFSET: 1088 *(off_t *)data = 0; 1089 break; 1090 case DIOCGATTR: { 1091 spa_t *spa = dmu_objset_spa(zv->zv_objset); 1092 struct diocgattr_arg *arg = (struct diocgattr_arg *)data; 1093 uint64_t refd, avail, usedobjs, availobjs; 1094 1095 if (strcmp(arg->name, "GEOM::candelete") == 0) 1096 arg->value.i = 1; 1097 else if (strcmp(arg->name, "blocksavail") == 0) { 1098 dmu_objset_space(zv->zv_objset, &refd, &avail, 1099 &usedobjs, &availobjs); 1100 arg->value.off = avail / DEV_BSIZE; 1101 } else if (strcmp(arg->name, "blocksused") == 0) { 1102 dmu_objset_space(zv->zv_objset, &refd, &avail, 1103 &usedobjs, &availobjs); 1104 arg->value.off = refd / DEV_BSIZE; 1105 } else if (strcmp(arg->name, "poolblocksavail") == 0) { 1106 avail = metaslab_class_get_space(spa_normal_class(spa)); 1107 avail -= metaslab_class_get_alloc( 1108 spa_normal_class(spa)); 1109 arg->value.off = avail / DEV_BSIZE; 1110 } else if (strcmp(arg->name, "poolblocksused") == 0) { 1111 refd = metaslab_class_get_alloc(spa_normal_class(spa)); 1112 arg->value.off = refd / DEV_BSIZE; 1113 } else 1114 error = SET_ERROR(ENOIOCTL); 1115 break; 1116 } 1117 case FIOSEEKHOLE: 1118 case FIOSEEKDATA: { 1119 off_t *off = (off_t *)data; 1120 uint64_t noff; 1121 boolean_t hole; 1122 1123 hole = (cmd == FIOSEEKHOLE); 1124 noff = *off; 1125 error = dmu_offset_next(zv->zv_objset, ZVOL_OBJ, hole, &noff); 1126 *off = noff; 1127 break; 1128 } 1129 default: 1130 error = SET_ERROR(ENOIOCTL); 1131 } 1132 1133 return (error); 1134 } 1135 1136 /* 1137 * Misc. helpers 1138 */ 1139 1140 static void 1141 zvol_ensure_zilog(zvol_state_t *zv) 1142 { 1143 ASSERT(ZVOL_RW_READ_HELD(&zv->zv_suspend_lock)); 1144 1145 /* 1146 * Open a ZIL if this is the first time we have written to this 1147 * zvol. We protect zv->zv_zilog with zv_suspend_lock rather 1148 * than zv_state_lock so that we don't need to acquire an 1149 * additional lock in this path. 1150 */ 1151 if (zv->zv_zilog == NULL) { 1152 if (!rw_tryupgrade(&zv->zv_suspend_lock)) { 1153 rw_exit(&zv->zv_suspend_lock); 1154 rw_enter(&zv->zv_suspend_lock, RW_WRITER); 1155 } 1156 if (zv->zv_zilog == NULL) { 1157 zv->zv_zilog = zil_open(zv->zv_objset, 1158 zvol_get_data); 1159 zv->zv_flags |= ZVOL_WRITTEN_TO; 1160 } 1161 rw_downgrade(&zv->zv_suspend_lock); 1162 } 1163 } 1164 1165 static boolean_t 1166 zvol_is_zvol_impl(const char *device) 1167 { 1168 return (device && strncmp(device, ZVOL_DIR, strlen(ZVOL_DIR)) == 0); 1169 } 1170 1171 static void 1172 zvol_rename_minor(zvol_state_t *zv, const char *newname) 1173 { 1174 ASSERT(RW_LOCK_HELD(&zvol_state_lock)); 1175 ASSERT(MUTEX_HELD(&zv->zv_state_lock)); 1176 1177 /* move to new hashtable entry */ 1178 zv->zv_hash = zvol_name_hash(zv->zv_name); 1179 hlist_del(&zv->zv_hlink); 1180 hlist_add_head(&zv->zv_hlink, ZVOL_HT_HEAD(zv->zv_hash)); 1181 1182 if (zv->zv_volmode == ZFS_VOLMODE_GEOM) { 1183 struct zvol_state_geom *zsg = &zv->zv_zso->zso_geom; 1184 struct g_provider *pp = zsg->zsg_provider; 1185 struct g_geom *gp; 1186 1187 g_topology_lock(); 1188 gp = pp->geom; 1189 ASSERT3P(gp, !=, NULL); 1190 1191 zsg->zsg_provider = NULL; 1192 g_wither_provider(pp, ENXIO); 1193 1194 pp = g_new_providerf(gp, "%s/%s", ZVOL_DRIVER, newname); 1195 pp->flags |= G_PF_DIRECT_RECEIVE | G_PF_DIRECT_SEND; 1196 pp->sectorsize = DEV_BSIZE; 1197 pp->mediasize = zv->zv_volsize; 1198 pp->private = zv; 1199 zsg->zsg_provider = pp; 1200 g_error_provider(pp, 0); 1201 g_topology_unlock(); 1202 } else if (zv->zv_volmode == ZFS_VOLMODE_DEV) { 1203 struct zvol_state_dev *zsd = &zv->zv_zso->zso_dev; 1204 struct cdev *dev; 1205 struct make_dev_args args; 1206 1207 dev = zsd->zsd_cdev; 1208 if (dev != NULL) { 1209 destroy_dev(dev); 1210 dev = zsd->zsd_cdev = NULL; 1211 if (zv->zv_open_count > 0) { 1212 zv->zv_flags &= ~ZVOL_EXCL; 1213 zv->zv_open_count = 0; 1214 /* XXX need suspend lock but lock order */ 1215 zvol_last_close(zv); 1216 } 1217 } 1218 1219 make_dev_args_init(&args); 1220 args.mda_flags = MAKEDEV_CHECKNAME | MAKEDEV_WAITOK; 1221 args.mda_devsw = &zvol_cdevsw; 1222 args.mda_cr = NULL; 1223 args.mda_uid = UID_ROOT; 1224 args.mda_gid = GID_OPERATOR; 1225 args.mda_mode = 0640; 1226 args.mda_si_drv2 = zv; 1227 if (make_dev_s(&args, &dev, "%s/%s", ZVOL_DRIVER, newname) 1228 == 0) { 1229 dev->si_iosize_max = maxphys; 1230 zsd->zsd_cdev = dev; 1231 } 1232 } 1233 strlcpy(zv->zv_name, newname, sizeof (zv->zv_name)); 1234 } 1235 1236 /* 1237 * Remove minor node for the specified volume. 1238 */ 1239 static void 1240 zvol_free(zvol_state_t *zv) 1241 { 1242 ASSERT(!RW_LOCK_HELD(&zv->zv_suspend_lock)); 1243 ASSERT(!MUTEX_HELD(&zv->zv_state_lock)); 1244 ASSERT0(zv->zv_open_count); 1245 1246 ZFS_LOG(1, "ZVOL %s destroyed.", zv->zv_name); 1247 1248 rw_destroy(&zv->zv_suspend_lock); 1249 zfs_rangelock_fini(&zv->zv_rangelock); 1250 1251 if (zv->zv_volmode == ZFS_VOLMODE_GEOM) { 1252 struct zvol_state_geom *zsg = &zv->zv_zso->zso_geom; 1253 struct g_provider *pp __maybe_unused = zsg->zsg_provider; 1254 1255 ASSERT3P(pp->private, ==, NULL); 1256 1257 g_topology_lock(); 1258 zvol_geom_destroy(zv); 1259 g_topology_unlock(); 1260 mtx_destroy(&zsg->zsg_queue_mtx); 1261 } else if (zv->zv_volmode == ZFS_VOLMODE_DEV) { 1262 struct zvol_state_dev *zsd = &zv->zv_zso->zso_dev; 1263 struct cdev *dev = zsd->zsd_cdev; 1264 1265 ASSERT3P(dev->si_drv2, ==, NULL); 1266 1267 destroy_dev(dev); 1268 } 1269 1270 mutex_destroy(&zv->zv_state_lock); 1271 dataset_kstats_destroy(&zv->zv_kstat); 1272 kmem_free(zv->zv_zso, sizeof (struct zvol_state_os)); 1273 kmem_free(zv, sizeof (zvol_state_t)); 1274 zvol_minors--; 1275 } 1276 1277 /* 1278 * Create a minor node (plus a whole lot more) for the specified volume. 1279 */ 1280 static int 1281 zvol_create_minor_impl(const char *name) 1282 { 1283 zvol_state_t *zv; 1284 objset_t *os; 1285 dmu_object_info_t *doi; 1286 uint64_t volsize; 1287 uint64_t volmode, hash; 1288 int error; 1289 1290 ZFS_LOG(1, "Creating ZVOL %s...", name); 1291 hash = zvol_name_hash(name); 1292 if ((zv = zvol_find_by_name_hash(name, hash, RW_NONE)) != NULL) { 1293 ASSERT(MUTEX_HELD(&zv->zv_state_lock)); 1294 mutex_exit(&zv->zv_state_lock); 1295 return (SET_ERROR(EEXIST)); 1296 } 1297 1298 DROP_GIANT(); 1299 1300 doi = kmem_alloc(sizeof (dmu_object_info_t), KM_SLEEP); 1301 1302 /* lie and say we're read-only */ 1303 error = dmu_objset_own(name, DMU_OST_ZVOL, B_TRUE, B_TRUE, FTAG, &os); 1304 if (error) 1305 goto out_doi; 1306 1307 error = dmu_object_info(os, ZVOL_OBJ, doi); 1308 if (error) 1309 goto out_dmu_objset_disown; 1310 1311 error = zap_lookup(os, ZVOL_ZAP_OBJ, "size", 8, 1, &volsize); 1312 if (error) 1313 goto out_dmu_objset_disown; 1314 1315 error = dsl_prop_get_integer(name, 1316 zfs_prop_to_name(ZFS_PROP_VOLMODE), &volmode, NULL); 1317 if (error || volmode == ZFS_VOLMODE_DEFAULT) 1318 volmode = zvol_volmode; 1319 error = 0; 1320 1321 /* 1322 * zvol_alloc equivalent ... 1323 */ 1324 zv = kmem_zalloc(sizeof (*zv), KM_SLEEP); 1325 zv->zv_hash = hash; 1326 mutex_init(&zv->zv_state_lock, NULL, MUTEX_DEFAULT, NULL); 1327 zv->zv_zso = kmem_zalloc(sizeof (struct zvol_state_os), KM_SLEEP); 1328 zv->zv_volmode = volmode; 1329 if (zv->zv_volmode == ZFS_VOLMODE_GEOM) { 1330 struct zvol_state_geom *zsg = &zv->zv_zso->zso_geom; 1331 struct g_provider *pp; 1332 struct g_geom *gp; 1333 1334 zsg->zsg_state = ZVOL_GEOM_UNINIT; 1335 mtx_init(&zsg->zsg_queue_mtx, "zvol", NULL, MTX_DEF); 1336 1337 g_topology_lock(); 1338 gp = g_new_geomf(&zfs_zvol_class, "zfs::zvol::%s", name); 1339 gp->start = zvol_geom_bio_start; 1340 gp->access = zvol_geom_access; 1341 pp = g_new_providerf(gp, "%s/%s", ZVOL_DRIVER, name); 1342 pp->flags |= G_PF_DIRECT_RECEIVE | G_PF_DIRECT_SEND; 1343 pp->sectorsize = DEV_BSIZE; 1344 pp->mediasize = 0; 1345 pp->private = zv; 1346 1347 zsg->zsg_provider = pp; 1348 bioq_init(&zsg->zsg_queue); 1349 } else if (zv->zv_volmode == ZFS_VOLMODE_DEV) { 1350 struct zvol_state_dev *zsd = &zv->zv_zso->zso_dev; 1351 struct cdev *dev; 1352 struct make_dev_args args; 1353 1354 make_dev_args_init(&args); 1355 args.mda_flags = MAKEDEV_CHECKNAME | MAKEDEV_WAITOK; 1356 args.mda_devsw = &zvol_cdevsw; 1357 args.mda_cr = NULL; 1358 args.mda_uid = UID_ROOT; 1359 args.mda_gid = GID_OPERATOR; 1360 args.mda_mode = 0640; 1361 args.mda_si_drv2 = zv; 1362 error = make_dev_s(&args, &dev, "%s/%s", ZVOL_DRIVER, name); 1363 if (error) { 1364 kmem_free(zv->zv_zso, sizeof (struct zvol_state_os)); 1365 mutex_destroy(&zv->zv_state_lock); 1366 kmem_free(zv, sizeof (*zv)); 1367 dmu_objset_disown(os, B_TRUE, FTAG); 1368 goto out_doi; 1369 } 1370 dev->si_iosize_max = maxphys; 1371 zsd->zsd_cdev = dev; 1372 } 1373 (void) strlcpy(zv->zv_name, name, MAXPATHLEN); 1374 rw_init(&zv->zv_suspend_lock, NULL, RW_DEFAULT, NULL); 1375 zfs_rangelock_init(&zv->zv_rangelock, NULL, NULL); 1376 1377 if (dmu_objset_is_snapshot(os) || !spa_writeable(dmu_objset_spa(os))) 1378 zv->zv_flags |= ZVOL_RDONLY; 1379 1380 zv->zv_volblocksize = doi->doi_data_block_size; 1381 zv->zv_volsize = volsize; 1382 zv->zv_objset = os; 1383 1384 if (spa_writeable(dmu_objset_spa(os))) { 1385 if (zil_replay_disable) 1386 zil_destroy(dmu_objset_zil(os), B_FALSE); 1387 else 1388 zil_replay(os, zv, zvol_replay_vector); 1389 } 1390 ASSERT3P(zv->zv_kstat.dk_kstats, ==, NULL); 1391 dataset_kstats_create(&zv->zv_kstat, zv->zv_objset); 1392 1393 /* TODO: prefetch for geom tasting */ 1394 1395 zv->zv_objset = NULL; 1396 out_dmu_objset_disown: 1397 dmu_objset_disown(os, B_TRUE, FTAG); 1398 1399 if (error == 0 && volmode == ZFS_VOLMODE_GEOM) { 1400 zvol_geom_run(zv); 1401 g_topology_unlock(); 1402 } 1403 out_doi: 1404 kmem_free(doi, sizeof (dmu_object_info_t)); 1405 if (error == 0) { 1406 rw_enter(&zvol_state_lock, RW_WRITER); 1407 zvol_insert(zv); 1408 zvol_minors++; 1409 rw_exit(&zvol_state_lock); 1410 ZFS_LOG(1, "ZVOL %s created.", name); 1411 } 1412 PICKUP_GIANT(); 1413 return (error); 1414 } 1415 1416 static void 1417 zvol_clear_private(zvol_state_t *zv) 1418 { 1419 ASSERT(RW_LOCK_HELD(&zvol_state_lock)); 1420 if (zv->zv_volmode == ZFS_VOLMODE_GEOM) { 1421 struct zvol_state_geom *zsg = &zv->zv_zso->zso_geom; 1422 struct g_provider *pp = zsg->zsg_provider; 1423 1424 if (pp->private == NULL) /* already cleared */ 1425 return; 1426 1427 mtx_lock(&zsg->zsg_queue_mtx); 1428 zsg->zsg_state = ZVOL_GEOM_STOPPED; 1429 pp->private = NULL; 1430 wakeup_one(&zsg->zsg_queue); 1431 while (zsg->zsg_state != ZVOL_GEOM_RUNNING) 1432 msleep(&zsg->zsg_state, &zsg->zsg_queue_mtx, 1433 0, "zvol:w", 0); 1434 mtx_unlock(&zsg->zsg_queue_mtx); 1435 ASSERT(!RW_LOCK_HELD(&zv->zv_suspend_lock)); 1436 } else if (zv->zv_volmode == ZFS_VOLMODE_DEV) { 1437 struct zvol_state_dev *zsd = &zv->zv_zso->zso_dev; 1438 struct cdev *dev = zsd->zsd_cdev; 1439 1440 dev->si_drv2 = NULL; 1441 } 1442 } 1443 1444 static int 1445 zvol_update_volsize(zvol_state_t *zv, uint64_t volsize) 1446 { 1447 zv->zv_volsize = volsize; 1448 if (zv->zv_volmode == ZFS_VOLMODE_GEOM) { 1449 struct zvol_state_geom *zsg = &zv->zv_zso->zso_geom; 1450 struct g_provider *pp = zsg->zsg_provider; 1451 1452 g_topology_lock(); 1453 1454 if (pp->private == NULL) { 1455 g_topology_unlock(); 1456 return (SET_ERROR(ENXIO)); 1457 } 1458 1459 /* 1460 * Do not invoke resize event when initial size was zero. 1461 * ZVOL initializes the size on first open, this is not 1462 * real resizing. 1463 */ 1464 if (pp->mediasize == 0) 1465 pp->mediasize = zv->zv_volsize; 1466 else 1467 g_resize_provider(pp, zv->zv_volsize); 1468 1469 g_topology_unlock(); 1470 } 1471 return (0); 1472 } 1473 1474 static void 1475 zvol_set_disk_ro_impl(zvol_state_t *zv, int flags) 1476 { 1477 // XXX? set_disk_ro(zv->zv_zso->zvo_disk, flags); 1478 } 1479 1480 static void 1481 zvol_set_capacity_impl(zvol_state_t *zv, uint64_t capacity) 1482 { 1483 // XXX? set_capacity(zv->zv_zso->zvo_disk, capacity); 1484 } 1485 1486 const static zvol_platform_ops_t zvol_freebsd_ops = { 1487 .zv_free = zvol_free, 1488 .zv_rename_minor = zvol_rename_minor, 1489 .zv_create_minor = zvol_create_minor_impl, 1490 .zv_update_volsize = zvol_update_volsize, 1491 .zv_clear_private = zvol_clear_private, 1492 .zv_is_zvol = zvol_is_zvol_impl, 1493 .zv_set_disk_ro = zvol_set_disk_ro_impl, 1494 .zv_set_capacity = zvol_set_capacity_impl, 1495 }; 1496 1497 /* 1498 * Public interfaces 1499 */ 1500 1501 int 1502 zvol_busy(void) 1503 { 1504 return (zvol_minors != 0); 1505 } 1506 1507 int 1508 zvol_init(void) 1509 { 1510 zvol_init_impl(); 1511 zvol_register_ops(&zvol_freebsd_ops); 1512 return (0); 1513 } 1514 1515 void 1516 zvol_fini(void) 1517 { 1518 zvol_fini_impl(); 1519 } 1520