diff options
Diffstat (limited to 'sys/contrib/opensolaris/uts/common/fs/zfs/zvol.c')
-rw-r--r-- | sys/contrib/opensolaris/uts/common/fs/zfs/zvol.c | 801 |
1 files changed, 801 insertions, 0 deletions
diff --git a/sys/contrib/opensolaris/uts/common/fs/zfs/zvol.c b/sys/contrib/opensolaris/uts/common/fs/zfs/zvol.c new file mode 100644 index 0000000..c6aa07b --- /dev/null +++ b/sys/contrib/opensolaris/uts/common/fs/zfs/zvol.c @@ -0,0 +1,801 @@ +/* + * CDDL HEADER START + * + * The contents of this file are subject to the terms of the + * Common Development and Distribution License (the "License"). + * You may not use this file except in compliance with the License. + * + * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE + * or http://www.opensolaris.org/os/licensing. + * See the License for the specific language governing permissions + * and limitations under the License. + * + * When distributing Covered Code, include this CDDL HEADER in each + * file and include the License file at usr/src/OPENSOLARIS.LICENSE. + * If applicable, add the following below this CDDL HEADER, with the + * fields enclosed by brackets "[]" replaced with your own identifying + * information: Portions Copyright [yyyy] [name of copyright owner] + * + * CDDL HEADER END + */ +/* + * Copyright (c) 2006 Pawel Jakub Dawidek <pjd@FreeBSD.org> + * All rights reserved. + */ +/* + * Copyright 2007 Sun Microsystems, Inc. All rights reserved. + * Use is subject to license terms. + */ + +#pragma ident "%Z%%M% %I% %E% SMI" + +/* + * ZFS volume emulation driver. + * + * Makes a DMU object look like a volume of arbitrary size, up to 2^64 bytes. + * Volumes are accessed through the symbolic links named: + * + * /dev/zvol/dsk/<pool_name>/<dataset_name> + * /dev/zvol/rdsk/<pool_name>/<dataset_name> + * + * These links are created by the ZFS-specific devfsadm link generator. + * Volumes are persistent through reboot. No user command needs to be + * run before opening and using a device. + */ + +#include <sys/types.h> +#include <sys/param.h> +#include <sys/kernel.h> +#include <sys/errno.h> +#include <sys/uio.h> +#include <sys/bio.h> +#include <sys/buf.h> +#include <sys/kmem.h> +#include <sys/conf.h> +#include <sys/cmn_err.h> +#include <sys/stat.h> +#include <sys/zap.h> +#include <sys/spa.h> +#include <sys/zio.h> +#include <sys/dsl_prop.h> +#include <sys/dkio.h> +#include <sys/byteorder.h> +#include <sys/sunddi.h> +#include <sys/dirent.h> +#include <sys/policy.h> +#include <sys/fs/zfs.h> +#include <sys/zfs_ioctl.h> +#include <sys/zil.h> +#include <sys/refcount.h> +#include <sys/zfs_znode.h> +#include <sys/zfs_rlock.h> +#include <geom/geom.h> + +#include "zfs_namecheck.h" + +struct g_class zfs_zvol_class = { + .name = "ZFS::ZVOL", + .version = G_VERSION, +}; + +DECLARE_GEOM_CLASS(zfs_zvol_class, zfs_zvol); + +#define ZVOL_OBJ 1ULL +#define ZVOL_ZAP_OBJ 2ULL + +static uint32_t zvol_minors; + +/* + * The in-core state of each volume. + */ +typedef struct zvol_state { + char zv_name[MAXPATHLEN]; /* pool/dd name */ + uint64_t zv_volsize; /* amount of space we advertise */ + uint64_t zv_volblocksize; /* volume block size */ + struct g_provider *zv_provider; /* GEOM provider */ + uint8_t zv_min_bs; /* minimum addressable block shift */ + uint8_t zv_readonly; /* hard readonly; like write-protect */ + objset_t *zv_objset; /* objset handle */ + uint32_t zv_mode; /* DS_MODE_* flags at open time */ + uint32_t zv_total_opens; /* total open count */ + zilog_t *zv_zilog; /* ZIL handle */ + uint64_t zv_txg_assign; /* txg to assign during ZIL replay */ + znode_t zv_znode; /* for range locking */ + int zv_state; + struct bio_queue_head zv_queue; + struct mtx zv_queue_mtx; /* zv_queue mutex */ +} zvol_state_t; + +/* + * zvol maximum transfer in one DMU tx. + */ +int zvol_maxphys = DMU_MAX_ACCESS/2; + +static int zvol_get_data(void *arg, lr_write_t *lr, char *buf, zio_t *zio); + +int +zvol_check_volsize(uint64_t volsize, uint64_t blocksize) +{ + if (volsize == 0) + return (EINVAL); + + if (volsize % blocksize != 0) + return (EINVAL); + +#ifdef _ILP32 + if (volsize - 1 > SPEC_MAXOFFSET_T) + return (EOVERFLOW); +#endif + return (0); +} + +int +zvol_check_volblocksize(uint64_t volblocksize) +{ + if (volblocksize < SPA_MINBLOCKSIZE || + volblocksize > SPA_MAXBLOCKSIZE || + !ISP2(volblocksize)) + return (EDOM); + + return (0); +} + +static void +zvol_readonly_changed_cb(void *arg, uint64_t newval) +{ + zvol_state_t *zv = arg; + + zv->zv_readonly = (uint8_t)newval; +} + +int +zvol_get_stats(objset_t *os, nvlist_t *nv) +{ + int error; + dmu_object_info_t doi; + uint64_t val; + + + error = zap_lookup(os, ZVOL_ZAP_OBJ, "size", 8, 1, &val); + if (error) + return (error); + + dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_VOLSIZE, val); + + error = dmu_object_info(os, ZVOL_OBJ, &doi); + + if (error == 0) { + dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_VOLBLOCKSIZE, + doi.doi_data_block_size); + } + + return (error); +} + +static zvol_state_t * +zvol_minor_lookup(const char *name) +{ + struct g_provider *pp; + struct g_geom *gp; + + g_topology_assert(); + + LIST_FOREACH(gp, &zfs_zvol_class.geom, geom) { + LIST_FOREACH(pp, &gp->provider, provider) { + if (strcmp(pp->name + sizeof(ZVOL_DEV_DIR), name) == 0) + return (pp->private); + } + } + + return (NULL); +} + +static int +zvol_access(struct g_provider *pp, int acr, int acw, int ace) +{ + zvol_state_t *zv; + + g_topology_assert(); + + zv = pp->private; + if (zv == NULL) { + if (acr <= 0 && acw <= 0 && ace <= 0) + return (0); + return (pp->error); + } + + ASSERT(zv->zv_objset != NULL); + + if (acw > 0 && (zv->zv_readonly || (zv->zv_mode & DS_MODE_READONLY))) + return (EROFS); + + zv->zv_total_opens += acr + acw + ace; + + return (0); +} + +/* + * zvol_log_write() handles synchronous writes using TX_WRITE ZIL transactions. + * + * We store data in the log buffers if it's small enough. + * Otherwise we will later flush the data out via dmu_sync(). + */ +ssize_t zvol_immediate_write_sz = 32768; + +static void +zvol_log_write(zvol_state_t *zv, dmu_tx_t *tx, offset_t off, ssize_t len) +{ + uint32_t blocksize = zv->zv_volblocksize; + lr_write_t *lr; + + while (len) { + ssize_t nbytes = MIN(len, blocksize - P2PHASE(off, blocksize)); + itx_t *itx = zil_itx_create(TX_WRITE, sizeof (*lr)); + + itx->itx_wr_state = + len > zvol_immediate_write_sz ? WR_INDIRECT : WR_NEED_COPY; + itx->itx_private = zv; + lr = (lr_write_t *)&itx->itx_lr; + lr->lr_foid = ZVOL_OBJ; + lr->lr_offset = off; + lr->lr_length = nbytes; + lr->lr_blkoff = off - P2ALIGN_TYPED(off, blocksize, uint64_t); + BP_ZERO(&lr->lr_blkptr); + + (void) zil_itx_assign(zv->zv_zilog, itx, tx); + len -= nbytes; + off += nbytes; + } +} + +static void +zvol_start(struct bio *bp) +{ + zvol_state_t *zv; + + switch (bp->bio_cmd) { + case BIO_READ: + case BIO_WRITE: + case BIO_FLUSH: + zv = bp->bio_to->private; + ASSERT(zv != NULL); + mtx_lock(&zv->zv_queue_mtx); + bioq_insert_tail(&zv->zv_queue, bp); + wakeup_one(&zv->zv_queue); + mtx_unlock(&zv->zv_queue_mtx); + break; + case BIO_DELETE: + case BIO_GETATTR: + default: + g_io_deliver(bp, EOPNOTSUPP); + break; + } +} + +static void +zvol_serve_one(zvol_state_t *zv, struct bio *bp) +{ + uint64_t off, volsize; + size_t size, resid; + char *addr; + objset_t *os; + rl_t *rl; + int error = 0; + boolean_t reading; + + off = bp->bio_offset; + volsize = zv->zv_volsize; + + os = zv->zv_objset; + ASSERT(os != NULL); + + addr = bp->bio_data; + resid = bp->bio_length; + + error = 0; + + /* + * There must be no buffer changes when doing a dmu_sync() because + * we can't change the data whilst calculating the checksum. + * A better approach than a per zvol rwlock would be to lock ranges. + */ + reading = (bp->bio_cmd == BIO_READ); + rl = zfs_range_lock(&zv->zv_znode, off, resid, + reading ? RL_READER : RL_WRITER); + + while (resid != 0 && off < volsize) { + + size = MIN(resid, zvol_maxphys); /* zvol_maxphys per tx */ + + if (size > volsize - off) /* don't write past the end */ + size = volsize - off; + + if (reading) { + error = dmu_read(os, ZVOL_OBJ, off, size, addr); + } else { + dmu_tx_t *tx = dmu_tx_create(os); + dmu_tx_hold_write(tx, ZVOL_OBJ, off, size); + error = dmu_tx_assign(tx, TXG_WAIT); + if (error) { + dmu_tx_abort(tx); + } else { + dmu_write(os, ZVOL_OBJ, off, size, addr, tx); + zvol_log_write(zv, tx, off, size); + dmu_tx_commit(tx); + } + } + if (error) + break; + off += size; + addr += size; + resid -= size; + } + zfs_range_unlock(rl); + + bp->bio_completed = bp->bio_length - resid; + if (bp->bio_completed < bp->bio_length) + bp->bio_error = (off > volsize ? EINVAL : error); + + /* + * XXX: We are devilering here? + * Looks like I don't understand something here, but I was sure it was + * an async request. + */ + g_io_deliver(bp, bp->bio_error); +} + +static void +zvol_worker(void *arg) +{ + zvol_state_t *zv; + struct bio *bp; + + zv = arg; + for (;;) { + mtx_lock(&zv->zv_queue_mtx); + bp = bioq_takefirst(&zv->zv_queue); + if (bp == NULL) { + if (zv->zv_state == 1) { + zv->zv_state = 2; + wakeup(&zv->zv_state); + mtx_unlock(&zv->zv_queue_mtx); + kthread_exit(0); + } + msleep(&zv->zv_queue, &zv->zv_queue_mtx, PRIBIO | PDROP, + "zvol:io", 0); + continue; + } + mtx_unlock(&zv->zv_queue_mtx); + if (bp->bio_cmd == BIO_FLUSH) { + zil_commit(zv->zv_zilog, UINT64_MAX, ZVOL_OBJ); + g_io_deliver(bp, 0); + } else { + zvol_serve_one(zv, bp); + } + } +} + +void +zvol_create_cb(objset_t *os, void *arg, dmu_tx_t *tx) +{ + zfs_create_data_t *zc = arg; + int error; + uint64_t volblocksize, volsize; + + VERIFY(nvlist_lookup_uint64(zc->zc_props, + zfs_prop_to_name(ZFS_PROP_VOLSIZE), &volsize) == 0); + if (nvlist_lookup_uint64(zc->zc_props, + zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE), &volblocksize) != 0) + volblocksize = zfs_prop_default_numeric(ZFS_PROP_VOLBLOCKSIZE); + + /* + * These properites must be removed from the list so the generic + * property setting step won't apply to them. + */ + VERIFY(nvlist_remove_all(zc->zc_props, + zfs_prop_to_name(ZFS_PROP_VOLSIZE)) == 0); + (void) nvlist_remove_all(zc->zc_props, + zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE)); + + error = dmu_object_claim(os, ZVOL_OBJ, DMU_OT_ZVOL, volblocksize, + DMU_OT_NONE, 0, tx); + ASSERT(error == 0); + + error = zap_create_claim(os, ZVOL_ZAP_OBJ, DMU_OT_ZVOL_PROP, + DMU_OT_NONE, 0, tx); + ASSERT(error == 0); + + error = zap_update(os, ZVOL_ZAP_OBJ, "size", 8, 1, &volsize, tx); + ASSERT(error == 0); +} + +/* + * Replay a TX_WRITE ZIL transaction that didn't get committed + * after a system failure + */ +static int +zvol_replay_write(zvol_state_t *zv, lr_write_t *lr, boolean_t byteswap) +{ + objset_t *os = zv->zv_objset; + char *data = (char *)(lr + 1); /* data follows lr_write_t */ + uint64_t off = lr->lr_offset; + uint64_t len = lr->lr_length; + dmu_tx_t *tx; + int error; + + if (byteswap) + byteswap_uint64_array(lr, sizeof (*lr)); + + tx = dmu_tx_create(os); + dmu_tx_hold_write(tx, ZVOL_OBJ, off, len); + error = dmu_tx_assign(tx, zv->zv_txg_assign); + if (error) { + dmu_tx_abort(tx); + } else { + dmu_write(os, ZVOL_OBJ, off, len, data, tx); + dmu_tx_commit(tx); + } + + return (error); +} + +/* ARGSUSED */ +static int +zvol_replay_err(zvol_state_t *zv, lr_t *lr, boolean_t byteswap) +{ + return (ENOTSUP); +} + +/* + * Callback vectors for replaying records. + * Only TX_WRITE is needed for zvol. + */ +zil_replay_func_t *zvol_replay_vector[TX_MAX_TYPE] = { + zvol_replay_err, /* 0 no such transaction type */ + zvol_replay_err, /* TX_CREATE */ + zvol_replay_err, /* TX_MKDIR */ + zvol_replay_err, /* TX_MKXATTR */ + zvol_replay_err, /* TX_SYMLINK */ + zvol_replay_err, /* TX_REMOVE */ + zvol_replay_err, /* TX_RMDIR */ + zvol_replay_err, /* TX_LINK */ + zvol_replay_err, /* TX_RENAME */ + zvol_replay_write, /* TX_WRITE */ + zvol_replay_err, /* TX_TRUNCATE */ + zvol_replay_err, /* TX_SETATTR */ + zvol_replay_err, /* TX_ACL */ +}; + +/* + * Create a minor node for the specified volume. + */ +int +zvol_create_minor(const char *name, dev_t dev) +{ + struct g_provider *pp; + struct g_geom *gp; + zvol_state_t *zv; + objset_t *os; + dmu_object_info_t doi; + uint64_t volsize; + int ds_mode = DS_MODE_PRIMARY; + int error; + + DROP_GIANT(); + g_topology_lock(); + + if ((zv = zvol_minor_lookup(name)) != NULL) { + error = EEXIST; + goto end; + } + + if (strchr(name, '@') != 0) + ds_mode |= DS_MODE_READONLY; + + error = dmu_objset_open(name, DMU_OST_ZVOL, ds_mode, &os); + if (error) + goto end; + + g_topology_unlock(); + PICKUP_GIANT(); + error = zap_lookup(os, ZVOL_ZAP_OBJ, "size", 8, 1, &volsize); + DROP_GIANT(); + g_topology_lock(); + if (error) { + dmu_objset_close(os); + goto end; + } + + gp = g_new_geomf(&zfs_zvol_class, "zfs::zvol::%s", name); + gp->start = zvol_start; + gp->access = zvol_access; + pp = g_new_providerf(gp, "%s/%s", ZVOL_DEV_DIR, name); + pp->mediasize = volsize; + pp->sectorsize = DEV_BSIZE; + + zv = kmem_zalloc(sizeof(*zv), KM_SLEEP); + (void) strcpy(zv->zv_name, name); + zv->zv_min_bs = DEV_BSHIFT; + zv->zv_provider = pp; + zv->zv_volsize = pp->mediasize; + zv->zv_objset = os; + zv->zv_mode = ds_mode; + zv->zv_zilog = zil_open(os, zvol_get_data); + mutex_init(&zv->zv_znode.z_range_lock, NULL, MUTEX_DEFAULT, NULL); + avl_create(&zv->zv_znode.z_range_avl, zfs_range_compare, + sizeof (rl_t), offsetof(rl_t, r_node)); + + + /* get and cache the blocksize */ + error = dmu_object_info(os, ZVOL_OBJ, &doi); + ASSERT(error == 0); + zv->zv_volblocksize = doi.doi_data_block_size; + + zil_replay(os, zv, &zv->zv_txg_assign, zvol_replay_vector); + + /* XXX this should handle the possible i/o error */ + VERIFY(dsl_prop_register(dmu_objset_ds(zv->zv_objset), + "readonly", zvol_readonly_changed_cb, zv) == 0); + + pp->private = zv; + g_error_provider(pp, 0); + + bioq_init(&zv->zv_queue); + mtx_init(&zv->zv_queue_mtx, "zvol", NULL, MTX_DEF); + zv->zv_state = 0; + kthread_create(zvol_worker, zv, NULL, 0, 0, "zvol:worker %s", pp->name); + + zvol_minors++; +end: + g_topology_unlock(); + PICKUP_GIANT(); + + return (error); +} + +/* + * Remove minor node for the specified volume. + */ +int +zvol_remove_minor(const char *name) +{ + struct g_provider *pp; + zvol_state_t *zv; + int error = 0; + + DROP_GIANT(); + g_topology_lock(); + + if ((zv = zvol_minor_lookup(name)) == NULL) { + error = ENXIO; + goto end; + } + + if (zv->zv_total_opens != 0) { + error = EBUSY; + goto end; + } + + VERIFY(dsl_prop_unregister(dmu_objset_ds(zv->zv_objset), + "readonly", zvol_readonly_changed_cb, zv) == 0); + + mtx_lock(&zv->zv_queue_mtx); + zv->zv_state = 1; + wakeup_one(&zv->zv_queue); + while (zv->zv_state != 2) + msleep(&zv->zv_state, &zv->zv_queue_mtx, 0, "zvol:w", 0); + mtx_unlock(&zv->zv_queue_mtx); + mtx_destroy(&zv->zv_queue_mtx); + + pp = zv->zv_provider; + pp->private = NULL; + g_wither_geom(pp->geom, ENXIO); + + zil_close(zv->zv_zilog); + zv->zv_zilog = NULL; + dmu_objset_close(zv->zv_objset); + zv->zv_objset = NULL; + avl_destroy(&zv->zv_znode.z_range_avl); + mutex_destroy(&zv->zv_znode.z_range_lock); + + kmem_free(zv, sizeof(*zv)); + + zvol_minors--; +end: + g_topology_unlock(); + PICKUP_GIANT(); + + return (error); +} + +int +zvol_set_volsize(const char *name, dev_t dev, uint64_t volsize) +{ + zvol_state_t *zv; + dmu_tx_t *tx; + int error; + dmu_object_info_t doi; + + DROP_GIANT(); + g_topology_lock(); + + if ((zv = zvol_minor_lookup(name)) == NULL) { + error = ENXIO; + goto end; + } + + if ((error = dmu_object_info(zv->zv_objset, ZVOL_OBJ, &doi)) != 0 || + (error = zvol_check_volsize(volsize, + doi.doi_data_block_size)) != 0) { + goto end; + } + + if (zv->zv_readonly || (zv->zv_mode & DS_MODE_READONLY)) { + error = EROFS; + goto end; + } + + tx = dmu_tx_create(zv->zv_objset); + dmu_tx_hold_zap(tx, ZVOL_ZAP_OBJ, TRUE, NULL); + dmu_tx_hold_free(tx, ZVOL_OBJ, volsize, DMU_OBJECT_END); + error = dmu_tx_assign(tx, TXG_WAIT); + if (error) { + dmu_tx_abort(tx); + goto end; + } + + error = zap_update(zv->zv_objset, ZVOL_ZAP_OBJ, "size", 8, 1, + &volsize, tx); + if (error == 0) { + error = dmu_free_range(zv->zv_objset, ZVOL_OBJ, volsize, + DMU_OBJECT_END, tx); + } + + dmu_tx_commit(tx); + + if (error == 0) { + zv->zv_volsize = volsize; + zv->zv_provider->mediasize = volsize; /* XXX: Not supported. */ + } +end: + g_topology_unlock(); + PICKUP_GIANT(); + + return (error); +} + +int +zvol_set_volblocksize(const char *name, uint64_t volblocksize) +{ + zvol_state_t *zv; + dmu_tx_t *tx; + int error; + + DROP_GIANT(); + g_topology_lock(); + + if ((zv = zvol_minor_lookup(name)) == NULL) { + error = ENXIO; + goto end; + } + + if (zv->zv_readonly || (zv->zv_mode & DS_MODE_READONLY)) { + error = EROFS; + goto end; + } + + tx = dmu_tx_create(zv->zv_objset); + dmu_tx_hold_bonus(tx, ZVOL_OBJ); + error = dmu_tx_assign(tx, TXG_WAIT); + if (error) { + dmu_tx_abort(tx); + } else { + error = dmu_object_set_blocksize(zv->zv_objset, ZVOL_OBJ, + volblocksize, 0, tx); + if (error == ENOTSUP) + error = EBUSY; + dmu_tx_commit(tx); + /* XXX: Not supported. */ +#if 0 + if (error == 0) + zv->zv_provider->sectorsize = zc->zc_volblocksize; +#endif + } +end: + g_topology_unlock(); + PICKUP_GIANT(); + + return (error); +} + +void +zvol_get_done(dmu_buf_t *db, void *vzgd) +{ + zgd_t *zgd = (zgd_t *)vzgd; + rl_t *rl = zgd->zgd_rl; + + dmu_buf_rele(db, vzgd); + zfs_range_unlock(rl); + zil_add_vdev(zgd->zgd_zilog, DVA_GET_VDEV(BP_IDENTITY(zgd->zgd_bp))); + kmem_free(zgd, sizeof (zgd_t)); +} + +/* + * Get data to generate a TX_WRITE intent log record. + */ +static int +zvol_get_data(void *arg, lr_write_t *lr, char *buf, zio_t *zio) +{ + zvol_state_t *zv = arg; + objset_t *os = zv->zv_objset; + dmu_buf_t *db; + rl_t *rl; + zgd_t *zgd; + uint64_t boff; /* block starting offset */ + int dlen = lr->lr_length; /* length of user data */ + int error; + + ASSERT(zio); + ASSERT(dlen != 0); + + /* + * Write records come in two flavors: immediate and indirect. + * For small writes it's cheaper to store the data with the + * log record (immediate); for large writes it's cheaper to + * sync the data and get a pointer to it (indirect) so that + * we don't have to write the data twice. + */ + if (buf != NULL) /* immediate write */ + return (dmu_read(os, ZVOL_OBJ, lr->lr_offset, dlen, buf)); + + zgd = (zgd_t *)kmem_alloc(sizeof (zgd_t), KM_SLEEP); + zgd->zgd_zilog = zv->zv_zilog; + zgd->zgd_bp = &lr->lr_blkptr; + + /* + * Lock the range of the block to ensure that when the data is + * written out and it's checksum is being calculated that no other + * thread can change the block. + */ + boff = P2ALIGN_TYPED(lr->lr_offset, zv->zv_volblocksize, uint64_t); + rl = zfs_range_lock(&zv->zv_znode, boff, zv->zv_volblocksize, + RL_READER); + zgd->zgd_rl = rl; + + VERIFY(0 == dmu_buf_hold(os, ZVOL_OBJ, lr->lr_offset, zgd, &db)); + error = dmu_sync(zio, db, &lr->lr_blkptr, + lr->lr_common.lrc_txg, zvol_get_done, zgd); + if (error == 0) + zil_add_vdev(zv->zv_zilog, + DVA_GET_VDEV(BP_IDENTITY(&lr->lr_blkptr))); + /* + * If we get EINPROGRESS, then we need to wait for a + * write IO initiated by dmu_sync() to complete before + * we can release this dbuf. We will finish everything + * up in the zvol_get_done() callback. + */ + if (error == EINPROGRESS) + return (0); + dmu_buf_rele(db, zgd); + zfs_range_unlock(rl); + kmem_free(zgd, sizeof (zgd_t)); + return (error); +} + +int +zvol_busy(void) +{ + return (zvol_minors != 0); +} + +void +zvol_init(void) +{ + ZFS_LOG(1, "ZVOL Initialized."); +} + +void +zvol_fini(void) +{ + ZFS_LOG(1, "ZVOL Deinitialized."); +} |