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zfs/module/zfs/zvol.c

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/*
* 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 2009 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
/*
* 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/errno.h>
#include <sys/uio.h>
#include <sys/buf.h>
#include <sys/modctl.h>
#include <sys/open.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/dmu_traverse.h>
#include <sys/dnode.h>
#include <sys/dsl_dataset.h>
#include <sys/dsl_prop.h>
#include <sys/dkio.h>
#include <sys/efi_partition.h>
#include <sys/byteorder.h>
#include <sys/pathname.h>
#include <sys/ddi.h>
#include <sys/sunddi.h>
#include <sys/crc32.h>
#include <sys/dirent.h>
#include <sys/policy.h>
#include <sys/fs/zfs.h>
#include <sys/zfs_ioctl.h>
#include <sys/mkdev.h>
#include <sys/zil.h>
#include <sys/refcount.h>
#include <sys/zfs_znode.h>
#include <sys/zfs_rlock.h>
#include <sys/vdev_disk.h>
#include <sys/vdev_impl.h>
#include <sys/zvol.h>
#include <sys/dumphdr.h>
#include <sys/zil_impl.h>
#include "zfs_namecheck.h"
static void *zvol_state;
#define ZVOL_DUMPSIZE "dumpsize"
/*
* This lock protects the zvol_state structure from being modified
* while it's being used, e.g. an open that comes in before a create
* finishes. It also protects temporary opens of the dataset so that,
* e.g., an open doesn't get a spurious EBUSY.
*/
static kmutex_t zvol_state_lock;
static uint32_t zvol_minors;
typedef struct zvol_extent {
list_node_t ze_node;
dva_t ze_dva; /* dva associated with this extent */
uint64_t ze_nblks; /* number of blocks in extent */
} zvol_extent_t;
/*
* 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 */
minor_t zv_minor; /* minor number */
uint8_t zv_min_bs; /* minimum addressable block shift */
uint8_t zv_flags; /* readonly; dumpified */
objset_t *zv_objset; /* objset handle */
uint32_t zv_mode; /* DS_MODE_* flags at open time */
uint32_t zv_open_count[OTYPCNT]; /* open counts */
uint32_t zv_total_opens; /* total open count */
zilog_t *zv_zilog; /* ZIL handle */
list_t zv_extents; /* List of extents for dump */
znode_t zv_znode; /* for range locking */
} zvol_state_t;
/*
* zvol specific flags
*/
#define ZVOL_RDONLY 0x1
#define ZVOL_DUMPIFIED 0x2
#define ZVOL_EXCL 0x4
/*
* zvol maximum transfer in one DMU tx.
*/
int zvol_maxphys = DMU_MAX_ACCESS/2;
extern int zfs_set_prop_nvlist(const char *, nvlist_t *);
static int zvol_get_data(void *arg, lr_write_t *lr, char *buf, zio_t *zio);
static int zvol_dumpify(zvol_state_t *zv);
static int zvol_dump_fini(zvol_state_t *zv);
static int zvol_dump_init(zvol_state_t *zv, boolean_t resize);
static void
zvol_size_changed(zvol_state_t *zv, major_t maj)
{
dev_t dev = makedevice(maj, zv->zv_minor);
VERIFY(ddi_prop_update_int64(dev, zfs_dip,
"Size", zv->zv_volsize) == DDI_SUCCESS);
VERIFY(ddi_prop_update_int64(dev, zfs_dip,
"Nblocks", lbtodb(zv->zv_volsize)) == DDI_SUCCESS);
/* Notify specfs to invalidate the cached size */
spec_size_invalidate(dev, VBLK);
spec_size_invalidate(dev, VCHR);
}
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;
if (newval)
zv->zv_flags |= ZVOL_RDONLY;
else
zv->zv_flags &= ~ZVOL_RDONLY;
}
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);
}
/*
* Find a free minor number.
*/
static minor_t
zvol_minor_alloc(void)
{
minor_t minor;
ASSERT(MUTEX_HELD(&zvol_state_lock));
for (minor = 1; minor <= ZVOL_MAX_MINOR; minor++)
if (ddi_get_soft_state(zvol_state, minor) == NULL)
return (minor);
return (0);
}
static zvol_state_t *
zvol_minor_lookup(const char *name)
{
minor_t minor;
zvol_state_t *zv;
ASSERT(MUTEX_HELD(&zvol_state_lock));
for (minor = 1; minor <= ZVOL_MAX_MINOR; minor++) {
zv = ddi_get_soft_state(zvol_state, minor);
if (zv == NULL)
continue;
if (strcmp(zv->zv_name, name) == 0)
break;
}
return (zv);
}
/* extent mapping arg */
struct maparg {
zvol_state_t *ma_zv;
uint64_t ma_blks;
};
/*ARGSUSED*/
static int
zvol_map_block(spa_t *spa, blkptr_t *bp, const zbookmark_t *zb,
const dnode_phys_t *dnp, void *arg)
{
struct maparg *ma = arg;
zvol_extent_t *ze;
int bs = ma->ma_zv->zv_volblocksize;
if (bp == NULL || zb->zb_object != ZVOL_OBJ || zb->zb_level != 0)
return (0);
VERIFY3U(ma->ma_blks, ==, zb->zb_blkid);
ma->ma_blks++;
/* Abort immediately if we have encountered gang blocks */
if (BP_IS_GANG(bp))
return (EFRAGS);
/*
* See if the block is at the end of the previous extent.
*/
ze = list_tail(&ma->ma_zv->zv_extents);
if (ze &&
DVA_GET_VDEV(BP_IDENTITY(bp)) == DVA_GET_VDEV(&ze->ze_dva) &&
DVA_GET_OFFSET(BP_IDENTITY(bp)) ==
DVA_GET_OFFSET(&ze->ze_dva) + ze->ze_nblks * bs) {
ze->ze_nblks++;
return (0);
}
dprintf_bp(bp, "%s", "next blkptr:");
/* start a new extent */
ze = kmem_zalloc(sizeof (zvol_extent_t), KM_SLEEP);
ze->ze_dva = bp->blk_dva[0]; /* structure assignment */
ze->ze_nblks = 1;
list_insert_tail(&ma->ma_zv->zv_extents, ze);
return (0);
}
static void
zvol_free_extents(zvol_state_t *zv)
{
zvol_extent_t *ze;
while (ze = list_head(&zv->zv_extents)) {
list_remove(&zv->zv_extents, ze);
kmem_free(ze, sizeof (zvol_extent_t));
}
}
static int
zvol_get_lbas(zvol_state_t *zv)
{
struct maparg ma;
int err;
ma.ma_zv = zv;
ma.ma_blks = 0;
zvol_free_extents(zv);
err = traverse_dataset(dmu_objset_ds(zv->zv_objset), 0,
TRAVERSE_PRE | TRAVERSE_PREFETCH_METADATA, zvol_map_block, &ma);
if (err || ma.ma_blks != (zv->zv_volsize / zv->zv_volblocksize)) {
zvol_free_extents(zv);
return (err ? err : EIO);
}
return (0);
}
/* ARGSUSED */
void
zvol_create_cb(objset_t *os, void *arg, cred_t *cr, dmu_tx_t *tx)
{
zfs_creat_t *zct = arg;
nvlist_t *nvprops = zct->zct_props;
int error;
uint64_t volblocksize, volsize;
VERIFY(nvlist_lookup_uint64(nvprops,
zfs_prop_to_name(ZFS_PROP_VOLSIZE), &volsize) == 0);
if (nvlist_lookup_uint64(nvprops,
zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE), &volblocksize) != 0)
volblocksize = zfs_prop_default_numeric(ZFS_PROP_VOLBLOCKSIZE);
/*
* These properties must be removed from the list so the generic
* property setting step won't apply to them.
*/
VERIFY(nvlist_remove_all(nvprops,
zfs_prop_to_name(ZFS_PROP_VOLSIZE)) == 0);
(void) nvlist_remove_all(nvprops,
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, TXG_WAIT);
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 (plus a whole lot more) for the specified volume.
*/
int
zvol_create_minor(const char *name, major_t maj)
{
zvol_state_t *zv;
objset_t *os;
dmu_object_info_t doi;
uint64_t volsize;
minor_t minor = 0;
struct pathname linkpath;
int ds_mode = DS_MODE_OWNER;
vnode_t *vp = NULL;
char *devpath;
size_t devpathlen = strlen(ZVOL_FULL_DEV_DIR) + strlen(name) + 1;
char chrbuf[30], blkbuf[30];
int error;
mutex_enter(&zvol_state_lock);
if ((zv = zvol_minor_lookup(name)) != NULL) {
mutex_exit(&zvol_state_lock);
return (EEXIST);
}
if (strchr(name, '@') != 0)
ds_mode |= DS_MODE_READONLY;
error = dmu_objset_open(name, DMU_OST_ZVOL, ds_mode, &os);
if (error) {
mutex_exit(&zvol_state_lock);
return (error);
}
error = zap_lookup(os, ZVOL_ZAP_OBJ, "size", 8, 1, &volsize);
if (error) {
dmu_objset_close(os);
mutex_exit(&zvol_state_lock);
return (error);
}
/*
* If there's an existing /dev/zvol symlink, try to use the
* same minor number we used last time.
*/
devpath = kmem_alloc(devpathlen, KM_SLEEP);
(void) sprintf(devpath, "%s%s", ZVOL_FULL_DEV_DIR, name);
error = lookupname(devpath, UIO_SYSSPACE, NO_FOLLOW, NULL, &vp);
kmem_free(devpath, devpathlen);
if (error == 0 && vp->v_type != VLNK)
error = EINVAL;
if (error == 0) {
pn_alloc(&linkpath);
error = pn_getsymlink(vp, &linkpath, kcred);
if (error == 0) {
char *ms = strstr(linkpath.pn_path, ZVOL_PSEUDO_DEV);
if (ms != NULL) {
ms += strlen(ZVOL_PSEUDO_DEV);
minor = stoi(&ms);
}
}
pn_free(&linkpath);
}
if (vp != NULL)
VN_RELE(vp);
/*
* If we found a minor but it's already in use, we must pick a new one.
*/
if (minor != 0 && ddi_get_soft_state(zvol_state, minor) != NULL)
minor = 0;
if (minor == 0)
minor = zvol_minor_alloc();
if (minor == 0) {
dmu_objset_close(os);
mutex_exit(&zvol_state_lock);
return (ENXIO);
}
if (ddi_soft_state_zalloc(zvol_state, minor) != DDI_SUCCESS) {
dmu_objset_close(os);
mutex_exit(&zvol_state_lock);
return (EAGAIN);
}
(void) ddi_prop_update_string(minor, zfs_dip, ZVOL_PROP_NAME,
(char *)name);
(void) sprintf(chrbuf, "%uc,raw", minor);
if (ddi_create_minor_node(zfs_dip, chrbuf, S_IFCHR,
minor, DDI_PSEUDO, 0) == DDI_FAILURE) {
ddi_soft_state_free(zvol_state, minor);
dmu_objset_close(os);
mutex_exit(&zvol_state_lock);
return (EAGAIN);
}
(void) sprintf(blkbuf, "%uc", minor);
if (ddi_create_minor_node(zfs_dip, blkbuf, S_IFBLK,
minor, DDI_PSEUDO, 0) == DDI_FAILURE) {
ddi_remove_minor_node(zfs_dip, chrbuf);
ddi_soft_state_free(zvol_state, minor);
dmu_objset_close(os);
mutex_exit(&zvol_state_lock);
return (EAGAIN);
}
zv = ddi_get_soft_state(zvol_state, minor);
(void) strcpy(zv->zv_name, name);
zv->zv_min_bs = DEV_BSHIFT;
zv->zv_minor = minor;
zv->zv_volsize = volsize;
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));
list_create(&zv->zv_extents, sizeof (zvol_extent_t),
offsetof(zvol_extent_t, ze_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, zvol_replay_vector);
zvol_size_changed(zv, maj);
/* 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);
zvol_minors++;
mutex_exit(&zvol_state_lock);
return (0);
}
/*
* Remove minor node for the specified volume.
*/
int
zvol_remove_minor(const char *name)
{
zvol_state_t *zv;
char namebuf[30];
mutex_enter(&zvol_state_lock);
if ((zv = zvol_minor_lookup(name)) == NULL) {
mutex_exit(&zvol_state_lock);
return (ENXIO);
}
if (zv->zv_total_opens != 0) {
mutex_exit(&zvol_state_lock);
return (EBUSY);
}
(void) sprintf(namebuf, "%uc,raw", zv->zv_minor);
ddi_remove_minor_node(zfs_dip, namebuf);
(void) sprintf(namebuf, "%uc", zv->zv_minor);
ddi_remove_minor_node(zfs_dip, namebuf);
VERIFY(dsl_prop_unregister(dmu_objset_ds(zv->zv_objset),
"readonly", zvol_readonly_changed_cb, zv) == 0);
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);
ddi_soft_state_free(zvol_state, zv->zv_minor);
zvol_minors--;
mutex_exit(&zvol_state_lock);
return (0);
}
int
zvol_prealloc(zvol_state_t *zv)
{
objset_t *os = zv->zv_objset;
dmu_tx_t *tx;
uint64_t refd, avail, usedobjs, availobjs;
uint64_t resid = zv->zv_volsize;
uint64_t off = 0;
/* Check the space usage before attempting to allocate the space */
dmu_objset_space(os, &refd, &avail, &usedobjs, &availobjs);
if (avail < zv->zv_volsize)
return (ENOSPC);
/* Free old extents if they exist */
zvol_free_extents(zv);
while (resid != 0) {
int error;
uint64_t bytes = MIN(resid, SPA_MAXBLOCKSIZE);
tx = dmu_tx_create(os);
dmu_tx_hold_write(tx, ZVOL_OBJ, off, bytes);
error = dmu_tx_assign(tx, TXG_WAIT);
if (error) {
dmu_tx_abort(tx);
(void) dmu_free_long_range(os, ZVOL_OBJ, 0, off);
return (error);
}
dmu_prealloc(os, ZVOL_OBJ, off, bytes, tx);
dmu_tx_commit(tx);
off += bytes;
resid -= bytes;
}
txg_wait_synced(dmu_objset_pool(os), 0);
return (0);
}
int
zvol_update_volsize(zvol_state_t *zv, major_t maj, uint64_t volsize)
{
dmu_tx_t *tx;
int error;
ASSERT(MUTEX_HELD(&zvol_state_lock));
tx = dmu_tx_create(zv->zv_objset);
dmu_tx_hold_zap(tx, ZVOL_ZAP_OBJ, TRUE, NULL);
error = dmu_tx_assign(tx, TXG_WAIT);
if (error) {
dmu_tx_abort(tx);
return (error);
}
error = zap_update(zv->zv_objset, ZVOL_ZAP_OBJ, "size", 8, 1,
&volsize, tx);
dmu_tx_commit(tx);
if (error == 0)
error = dmu_free_long_range(zv->zv_objset,
ZVOL_OBJ, volsize, DMU_OBJECT_END);
/*
* If we are using a faked-up state (zv_minor == 0) then don't
* try to update the in-core zvol state.
*/
if (error == 0 && zv->zv_minor) {
zv->zv_volsize = volsize;
zvol_size_changed(zv, maj);
}
return (error);
}
int
zvol_set_volsize(const char *name, major_t maj, uint64_t volsize)
{
zvol_state_t *zv;
int error;
dmu_object_info_t doi;
uint64_t old_volsize = 0ULL;
zvol_state_t state = { 0 };
mutex_enter(&zvol_state_lock);
if ((zv = zvol_minor_lookup(name)) == NULL) {
/*
* If we are doing a "zfs clone -o volsize=", then the
* minor node won't exist yet.
*/
error = dmu_objset_open(name, DMU_OST_ZVOL, DS_MODE_OWNER,
&state.zv_objset);
if (error != 0)
goto out;
zv = &state;
}
old_volsize = zv->zv_volsize;
if ((error = dmu_object_info(zv->zv_objset, ZVOL_OBJ, &doi)) != 0 ||
(error = zvol_check_volsize(volsize,
doi.doi_data_block_size)) != 0)
goto out;
if (zv->zv_flags & ZVOL_RDONLY || (zv->zv_mode & DS_MODE_READONLY)) {
error = EROFS;
goto out;
}
error = zvol_update_volsize(zv, maj, volsize);
/*
* Reinitialize the dump area to the new size. If we
* failed to resize the dump area then restore the it back to
* it's original size.
*/
if (error == 0 && zv->zv_flags & ZVOL_DUMPIFIED) {
if ((error = zvol_dumpify(zv)) != 0 ||
(error = dumpvp_resize()) != 0) {
(void) zvol_update_volsize(zv, maj, old_volsize);
error = zvol_dumpify(zv);
}
}
out:
if (state.zv_objset)
dmu_objset_close(state.zv_objset);
mutex_exit(&zvol_state_lock);
return (error);
}
int
zvol_set_volblocksize(const char *name, uint64_t volblocksize)
{
zvol_state_t *zv;
dmu_tx_t *tx;
int error;
boolean_t needlock;
/*
* The lock may already be held if we are being called from
* zvol_dump_init().
*/
needlock = !MUTEX_HELD(&zvol_state_lock);
if (needlock)
mutex_enter(&zvol_state_lock);
if ((zv = zvol_minor_lookup(name)) == NULL) {
if (needlock)
mutex_exit(&zvol_state_lock);
return (ENXIO);
}
if (zv->zv_flags & ZVOL_RDONLY || (zv->zv_mode & DS_MODE_READONLY)) {
if (needlock)
mutex_exit(&zvol_state_lock);
return (EROFS);
}
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);
if (error == 0)
zv->zv_volblocksize = volblocksize;
}
if (needlock)
mutex_exit(&zvol_state_lock);
return (error);
}
/*ARGSUSED*/
int
zvol_open(dev_t *devp, int flag, int otyp, cred_t *cr)
{
minor_t minor = getminor(*devp);
zvol_state_t *zv;
if (minor == 0) /* This is the control device */
return (0);
mutex_enter(&zvol_state_lock);
zv = ddi_get_soft_state(zvol_state, minor);
if (zv == NULL) {
mutex_exit(&zvol_state_lock);
return (ENXIO);
}
ASSERT(zv->zv_objset != NULL);
if ((flag & FWRITE) &&
(zv->zv_flags & ZVOL_RDONLY || (zv->zv_mode & DS_MODE_READONLY))) {
mutex_exit(&zvol_state_lock);
return (EROFS);
}
if (zv->zv_flags & ZVOL_EXCL) {
mutex_exit(&zvol_state_lock);
return (EBUSY);
}
if (flag & FEXCL) {
if (zv->zv_total_opens != 0) {
mutex_exit(&zvol_state_lock);
return (EBUSY);
}
zv->zv_flags |= ZVOL_EXCL;
}
if (zv->zv_open_count[otyp] == 0 || otyp == OTYP_LYR) {
zv->zv_open_count[otyp]++;
zv->zv_total_opens++;
}
mutex_exit(&zvol_state_lock);
return (0);
}
/*ARGSUSED*/
int
zvol_close(dev_t dev, int flag, int otyp, cred_t *cr)
{
minor_t minor = getminor(dev);
zvol_state_t *zv;
if (minor == 0) /* This is the control device */
return (0);
mutex_enter(&zvol_state_lock);
zv = ddi_get_soft_state(zvol_state, minor);
if (zv == NULL) {
mutex_exit(&zvol_state_lock);
return (ENXIO);
}
if (zv->zv_flags & ZVOL_EXCL) {
ASSERT(zv->zv_total_opens == 1);
zv->zv_flags &= ~ZVOL_EXCL;
}
/*
* If the open count is zero, this is a spurious close.
* That indicates a bug in the kernel / DDI framework.
*/
ASSERT(zv->zv_open_count[otyp] != 0);
ASSERT(zv->zv_total_opens != 0);
/*
* You may get multiple opens, but only one close.
*/
zv->zv_open_count[otyp]--;
zv->zv_total_opens--;
mutex_exit(&zvol_state_lock);
return (0);
}
static 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_block(zgd->zgd_zilog, 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 its 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_block(zv->zv_zilog, &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);
}
/*
* 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;
zilog_t *zilog = zv->zv_zilog;
lr_write_t *lr;
if (zilog->zl_replay) {
dsl_dataset_dirty(dmu_objset_ds(zilog->zl_os), tx);
zilog->zl_replayed_seq[dmu_tx_get_txg(tx) & TXG_MASK] =
zilog->zl_replaying_seq;
return;
}
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(zilog, itx, tx);
len -= nbytes;
off += nbytes;
}
}
static int
zvol_dumpio_vdev(vdev_t *vd, void *addr, uint64_t offset, uint64_t size,
boolean_t doread, boolean_t isdump)
{
vdev_disk_t *dvd;
int c;
int numerrors = 0;
for (c = 0; c < vd->vdev_children; c++) {
ASSERT(vd->vdev_ops == &vdev_mirror_ops);
int err = zvol_dumpio_vdev(vd->vdev_child[c],
addr, offset, size, doread, isdump);
if (err != 0) {
numerrors++;
} else if (doread) {
break;
}
}
if (!vd->vdev_ops->vdev_op_leaf)
return (numerrors < vd->vdev_children ? 0 : EIO);
if (doread && !vdev_readable(vd))
return (EIO);
else if (!doread && !vdev_writeable(vd))
return (EIO);
dvd = vd->vdev_tsd;
ASSERT3P(dvd, !=, NULL);
offset += VDEV_LABEL_START_SIZE;
if (ddi_in_panic() || isdump) {
ASSERT(!doread);
if (doread)
return (EIO);
return (ldi_dump(dvd->vd_lh, addr, lbtodb(offset),
lbtodb(size)));
} else {
return (vdev_disk_physio(dvd->vd_lh, addr, size, offset,
doread ? B_READ : B_WRITE));
}
}
static int
zvol_dumpio(zvol_state_t *zv, void *addr, uint64_t offset, uint64_t size,
boolean_t doread, boolean_t isdump)
{
vdev_t *vd;
int error;
zvol_extent_t *ze;
spa_t *spa = dmu_objset_spa(zv->zv_objset);
/* Must be sector aligned, and not stradle a block boundary. */
if (P2PHASE(offset, DEV_BSIZE) || P2PHASE(size, DEV_BSIZE) ||
P2BOUNDARY(offset, size, zv->zv_volblocksize)) {
return (EINVAL);
}
ASSERT(size <= zv->zv_volblocksize);
/* Locate the extent this belongs to */
ze = list_head(&zv->zv_extents);
while (offset >= ze->ze_nblks * zv->zv_volblocksize) {
offset -= ze->ze_nblks * zv->zv_volblocksize;
ze = list_next(&zv->zv_extents, ze);
}
spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
vd = vdev_lookup_top(spa, DVA_GET_VDEV(&ze->ze_dva));
offset += DVA_GET_OFFSET(&ze->ze_dva);
error = zvol_dumpio_vdev(vd, addr, offset, size, doread, isdump);
spa_config_exit(spa, SCL_STATE, FTAG);
return (error);
}
int
zvol_strategy(buf_t *bp)
{
zvol_state_t *zv = ddi_get_soft_state(zvol_state, getminor(bp->b_edev));
uint64_t off, volsize;
size_t resid;
char *addr;
objset_t *os;
rl_t *rl;
int error = 0;
boolean_t doread = bp->b_flags & B_READ;
boolean_t is_dump = zv->zv_flags & ZVOL_DUMPIFIED;
if (zv == NULL) {
bioerror(bp, ENXIO);
biodone(bp);
return (0);
}
if (getminor(bp->b_edev) == 0) {
bioerror(bp, EINVAL);
biodone(bp);
return (0);
}
if (!(bp->b_flags & B_READ) &&
(zv->zv_flags & ZVOL_RDONLY ||
zv->zv_mode & DS_MODE_READONLY)) {
bioerror(bp, EROFS);
biodone(bp);
return (0);
}
off = ldbtob(bp->b_blkno);
volsize = zv->zv_volsize;
os = zv->zv_objset;
ASSERT(os != NULL);
bp_mapin(bp);
addr = bp->b_un.b_addr;
resid = bp->b_bcount;
if (resid > 0 && (off < 0 || off >= volsize)) {
bioerror(bp, EIO);
biodone(bp);
return (0);
}
/*
* There must be no buffer changes when doing a dmu_sync() because
* we can't change the data whilst calculating the checksum.
*/
rl = zfs_range_lock(&zv->zv_znode, off, resid,
doread ? RL_READER : RL_WRITER);
while (resid != 0 && off < volsize) {
size_t size = MIN(resid, zvol_maxphys);
if (is_dump) {
size = MIN(size, P2END(off, zv->zv_volblocksize) - off);
error = zvol_dumpio(zv, addr, off, size,
doread, B_FALSE);
} else if (doread) {
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) {
/* convert checksum errors into IO errors */
if (error == ECKSUM)
error = EIO;
break;
}
off += size;
addr += size;
resid -= size;
}
zfs_range_unlock(rl);
if ((bp->b_resid = resid) == bp->b_bcount)
bioerror(bp, off > volsize ? EINVAL : error);
if (!(bp->b_flags & B_ASYNC) && !doread && !zil_disable && !is_dump)
zil_commit(zv->zv_zilog, UINT64_MAX, ZVOL_OBJ);
biodone(bp);
return (0);
}
/*
* Set the buffer count to the zvol maximum transfer.
* Using our own routine instead of the default minphys()
* means that for larger writes we write bigger buffers on X86
* (128K instead of 56K) and flush the disk write cache less often
* (every zvol_maxphys - currently 1MB) instead of minphys (currently
* 56K on X86 and 128K on sparc).
*/
void
zvol_minphys(struct buf *bp)
{
if (bp->b_bcount > zvol_maxphys)
bp->b_bcount = zvol_maxphys;
}
int
zvol_dump(dev_t dev, caddr_t addr, daddr_t blkno, int nblocks)
{
minor_t minor = getminor(dev);
zvol_state_t *zv;
int error = 0;
uint64_t size;
uint64_t boff;
uint64_t resid;
if (minor == 0) /* This is the control device */
return (ENXIO);
zv = ddi_get_soft_state(zvol_state, minor);
if (zv == NULL)
return (ENXIO);
boff = ldbtob(blkno);
resid = ldbtob(nblocks);
VERIFY3U(boff + resid, <=, zv->zv_volsize);
while (resid) {
size = MIN(resid, P2END(boff, zv->zv_volblocksize) - boff);
error = zvol_dumpio(zv, addr, boff, size, B_FALSE, B_TRUE);
if (error)
break;
boff += size;
addr += size;
resid -= size;
}
return (error);
}
/*ARGSUSED*/
int
zvol_read(dev_t dev, uio_t *uio, cred_t *cr)
{
minor_t minor = getminor(dev);
zvol_state_t *zv;
uint64_t volsize;
rl_t *rl;
int error = 0;
if (minor == 0) /* This is the control device */
return (ENXIO);
zv = ddi_get_soft_state(zvol_state, minor);
if (zv == NULL)
return (ENXIO);
volsize = zv->zv_volsize;
if (uio->uio_resid > 0 &&
(uio->uio_loffset < 0 || uio->uio_loffset >= volsize))
return (EIO);
if (zv->zv_flags & ZVOL_DUMPIFIED) {
error = physio(zvol_strategy, NULL, dev, B_READ,
zvol_minphys, uio);
return (error);
}
rl = zfs_range_lock(&zv->zv_znode, uio->uio_loffset, uio->uio_resid,
RL_READER);
while (uio->uio_resid > 0 && uio->uio_loffset < volsize) {
uint64_t bytes = MIN(uio->uio_resid, DMU_MAX_ACCESS >> 1);
/* don't read past the end */
if (bytes > volsize - uio->uio_loffset)
bytes = volsize - uio->uio_loffset;
error = dmu_read_uio(zv->zv_objset, ZVOL_OBJ, uio, bytes);
if (error) {
/* convert checksum errors into IO errors */
if (error == ECKSUM)
error = EIO;
break;
}
}
zfs_range_unlock(rl);
return (error);
}
/*ARGSUSED*/
int
zvol_write(dev_t dev, uio_t *uio, cred_t *cr)
{
minor_t minor = getminor(dev);
zvol_state_t *zv;
uint64_t volsize;
rl_t *rl;
int error = 0;
if (minor == 0) /* This is the control device */
return (ENXIO);
zv = ddi_get_soft_state(zvol_state, minor);
if (zv == NULL)
return (ENXIO);
volsize = zv->zv_volsize;
if (uio->uio_resid > 0 &&
(uio->uio_loffset < 0 || uio->uio_loffset >= volsize))
return (EIO);
if (zv->zv_flags & ZVOL_DUMPIFIED) {
error = physio(zvol_strategy, NULL, dev, B_WRITE,
zvol_minphys, uio);
return (error);
}
rl = zfs_range_lock(&zv->zv_znode, uio->uio_loffset, uio->uio_resid,
RL_WRITER);
while (uio->uio_resid > 0 && uio->uio_loffset < volsize) {
uint64_t bytes = MIN(uio->uio_resid, DMU_MAX_ACCESS >> 1);
uint64_t off = uio->uio_loffset;
dmu_tx_t *tx = dmu_tx_create(zv->zv_objset);
if (bytes > volsize - off) /* don't write past the end */
bytes = volsize - off;
dmu_tx_hold_write(tx, ZVOL_OBJ, off, bytes);
error = dmu_tx_assign(tx, TXG_WAIT);
if (error) {
dmu_tx_abort(tx);
break;
}
error = dmu_write_uio(zv->zv_objset, ZVOL_OBJ, uio, bytes, tx);
if (error == 0)
zvol_log_write(zv, tx, off, bytes);
dmu_tx_commit(tx);
if (error)
break;
}
zfs_range_unlock(rl);
if (!zil_disable)
zil_commit(zv->zv_zilog, UINT64_MAX, ZVOL_OBJ);
return (error);
}
int
zvol_getefi(void *arg, int flag, uint64_t vs, uint8_t bs)
{
struct uuid uuid = EFI_RESERVED;
efi_gpe_t gpe = { 0 };
uint32_t crc;
dk_efi_t efi;
int length;
char *ptr;
if (ddi_copyin(arg, &efi, sizeof (dk_efi_t), flag))
return (EFAULT);
ptr = (char *)(uintptr_t)efi.dki_data_64;
length = efi.dki_length;
/*
* Some clients may attempt to request a PMBR for the
* zvol. Currently this interface will return EINVAL to
* such requests. These requests could be supported by
* adding a check for lba == 0 and consing up an appropriate
* PMBR.
*/
if (efi.dki_lba < 1 || efi.dki_lba > 2 || length <= 0)
return (EINVAL);
gpe.efi_gpe_StartingLBA = LE_64(34ULL);
gpe.efi_gpe_EndingLBA = LE_64((vs >> bs) - 1);
UUID_LE_CONVERT(gpe.efi_gpe_PartitionTypeGUID, uuid);
if (efi.dki_lba == 1) {
efi_gpt_t gpt = { 0 };
gpt.efi_gpt_Signature = LE_64(EFI_SIGNATURE);
gpt.efi_gpt_Revision = LE_32(EFI_VERSION_CURRENT);
gpt.efi_gpt_HeaderSize = LE_32(sizeof (gpt));
gpt.efi_gpt_MyLBA = LE_64(1ULL);
gpt.efi_gpt_FirstUsableLBA = LE_64(34ULL);
gpt.efi_gpt_LastUsableLBA = LE_64((vs >> bs) - 1);
gpt.efi_gpt_PartitionEntryLBA = LE_64(2ULL);
gpt.efi_gpt_NumberOfPartitionEntries = LE_32(1);
gpt.efi_gpt_SizeOfPartitionEntry =
LE_32(sizeof (efi_gpe_t));
CRC32(crc, &gpe, sizeof (gpe), -1U, crc32_table);
gpt.efi_gpt_PartitionEntryArrayCRC32 = LE_32(~crc);
CRC32(crc, &gpt, sizeof (gpt), -1U, crc32_table);
gpt.efi_gpt_HeaderCRC32 = LE_32(~crc);
if (ddi_copyout(&gpt, ptr, MIN(sizeof (gpt), length),
flag))
return (EFAULT);
ptr += sizeof (gpt);
length -= sizeof (gpt);
}
if (length > 0 && ddi_copyout(&gpe, ptr, MIN(sizeof (gpe),
length), flag))
return (EFAULT);
return (0);
}
/*
* Dirtbag ioctls to support mkfs(1M) for UFS filesystems. See dkio(7I).
*/
/*ARGSUSED*/
int
zvol_ioctl(dev_t dev, int cmd, intptr_t arg, int flag, cred_t *cr, int *rvalp)
{
zvol_state_t *zv;
struct dk_cinfo dki;
struct dk_minfo dkm;
struct dk_callback *dkc;
int error = 0;
rl_t *rl;
mutex_enter(&zvol_state_lock);
zv = ddi_get_soft_state(zvol_state, getminor(dev));
if (zv == NULL) {
mutex_exit(&zvol_state_lock);
return (ENXIO);
}
switch (cmd) {
case DKIOCINFO:
bzero(&dki, sizeof (dki));
(void) strcpy(dki.dki_cname, "zvol");
(void) strcpy(dki.dki_dname, "zvol");
dki.dki_ctype = DKC_UNKNOWN;
dki.dki_maxtransfer = 1 << (SPA_MAXBLOCKSHIFT - zv->zv_min_bs);
mutex_exit(&zvol_state_lock);
if (ddi_copyout(&dki, (void *)arg, sizeof (dki), flag))
error = EFAULT;
return (error);
case DKIOCGMEDIAINFO:
bzero(&dkm, sizeof (dkm));
dkm.dki_lbsize = 1U << zv->zv_min_bs;
dkm.dki_capacity = zv->zv_volsize >> zv->zv_min_bs;
dkm.dki_media_type = DK_UNKNOWN;
mutex_exit(&zvol_state_lock);
if (ddi_copyout(&dkm, (void *)arg, sizeof (dkm), flag))
error = EFAULT;
return (error);
case DKIOCGETEFI:
{
uint64_t vs = zv->zv_volsize;
uint8_t bs = zv->zv_min_bs;
mutex_exit(&zvol_state_lock);
error = zvol_getefi((void *)arg, flag, vs, bs);
return (error);
}
case DKIOCFLUSHWRITECACHE:
dkc = (struct dk_callback *)arg;
zil_commit(zv->zv_zilog, UINT64_MAX, ZVOL_OBJ);
if ((flag & FKIOCTL) && dkc != NULL && dkc->dkc_callback) {
(*dkc->dkc_callback)(dkc->dkc_cookie, error);
error = 0;
}
break;
case DKIOCGGEOM:
case DKIOCGVTOC:
/*
* commands using these (like prtvtoc) expect ENOTSUP
* since we're emulating an EFI label
*/
error = ENOTSUP;
break;
case DKIOCDUMPINIT:
rl = zfs_range_lock(&zv->zv_znode, 0, zv->zv_volsize,
RL_WRITER);
error = zvol_dumpify(zv);
zfs_range_unlock(rl);
break;
case DKIOCDUMPFINI:
rl = zfs_range_lock(&zv->zv_znode, 0, zv->zv_volsize,
RL_WRITER);
error = zvol_dump_fini(zv);
zfs_range_unlock(rl);
break;
default:
error = ENOTTY;
break;
}
mutex_exit(&zvol_state_lock);
return (error);
}
int
zvol_busy(void)
{
return (zvol_minors != 0);
}
void
zvol_init(void)
{
VERIFY(ddi_soft_state_init(&zvol_state, sizeof (zvol_state_t), 1) == 0);
mutex_init(&zvol_state_lock, NULL, MUTEX_DEFAULT, NULL);
}
void
zvol_fini(void)
{
mutex_destroy(&zvol_state_lock);
ddi_soft_state_fini(&zvol_state);
}
static boolean_t
zvol_is_swap(zvol_state_t *zv)
{
vnode_t *vp;
boolean_t ret = B_FALSE;
char *devpath;
size_t devpathlen;
int error;
devpathlen = strlen(ZVOL_FULL_DEV_DIR) + strlen(zv->zv_name) + 1;
devpath = kmem_alloc(devpathlen, KM_SLEEP);
(void) sprintf(devpath, "%s%s", ZVOL_FULL_DEV_DIR, zv->zv_name);
error = lookupname(devpath, UIO_SYSSPACE, FOLLOW, NULLVPP, &vp);
kmem_free(devpath, devpathlen);
ret = !error && IS_SWAPVP(common_specvp(vp));
if (vp != NULL)
VN_RELE(vp);
return (ret);
}
static int
zvol_dump_init(zvol_state_t *zv, boolean_t resize)
{
dmu_tx_t *tx;
int error = 0;
objset_t *os = zv->zv_objset;
nvlist_t *nv = NULL;
ASSERT(MUTEX_HELD(&zvol_state_lock));
tx = dmu_tx_create(os);
dmu_tx_hold_zap(tx, ZVOL_ZAP_OBJ, TRUE, NULL);
error = dmu_tx_assign(tx, TXG_WAIT);
if (error) {
dmu_tx_abort(tx);
return (error);
}
/*
* If we are resizing the dump device then we only need to
* update the refreservation to match the newly updated
* zvolsize. Otherwise, we save off the original state of the
* zvol so that we can restore them if the zvol is ever undumpified.
*/
if (resize) {
error = zap_update(os, ZVOL_ZAP_OBJ,
zfs_prop_to_name(ZFS_PROP_REFRESERVATION), 8, 1,
&zv->zv_volsize, tx);
} else {
uint64_t checksum, compress, refresrv, vbs;
error = dsl_prop_get_integer(zv->zv_name,
zfs_prop_to_name(ZFS_PROP_COMPRESSION), &compress, NULL);
error = error ? error : dsl_prop_get_integer(zv->zv_name,
zfs_prop_to_name(ZFS_PROP_CHECKSUM), &checksum, NULL);
error = error ? error : dsl_prop_get_integer(zv->zv_name,
zfs_prop_to_name(ZFS_PROP_REFRESERVATION), &refresrv, NULL);
error = error ? error : dsl_prop_get_integer(zv->zv_name,
zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE), &vbs, NULL);
error = error ? error : zap_update(os, ZVOL_ZAP_OBJ,
zfs_prop_to_name(ZFS_PROP_COMPRESSION), 8, 1,
&compress, tx);
error = error ? error : zap_update(os, ZVOL_ZAP_OBJ,
zfs_prop_to_name(ZFS_PROP_CHECKSUM), 8, 1, &checksum, tx);
error = error ? error : zap_update(os, ZVOL_ZAP_OBJ,
zfs_prop_to_name(ZFS_PROP_REFRESERVATION), 8, 1,
&refresrv, tx);
error = error ? error : zap_update(os, ZVOL_ZAP_OBJ,
zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE), 8, 1,
&vbs, tx);
}
dmu_tx_commit(tx);
/* Truncate the file */
if (!error)
error = dmu_free_long_range(zv->zv_objset,
ZVOL_OBJ, 0, DMU_OBJECT_END);
if (error)
return (error);
/*
* We only need update the zvol's property if we are initializing
* the dump area for the first time.
*/
if (!resize) {
VERIFY(nvlist_alloc(&nv, NV_UNIQUE_NAME, KM_SLEEP) == 0);
VERIFY(nvlist_add_uint64(nv,
zfs_prop_to_name(ZFS_PROP_REFRESERVATION), 0) == 0);
VERIFY(nvlist_add_uint64(nv,
zfs_prop_to_name(ZFS_PROP_COMPRESSION),
ZIO_COMPRESS_OFF) == 0);
VERIFY(nvlist_add_uint64(nv,
zfs_prop_to_name(ZFS_PROP_CHECKSUM),
ZIO_CHECKSUM_OFF) == 0);
VERIFY(nvlist_add_uint64(nv,
zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE),
SPA_MAXBLOCKSIZE) == 0);
error = zfs_set_prop_nvlist(zv->zv_name, nv);
nvlist_free(nv);
if (error)
return (error);
}
/* Allocate the space for the dump */
error = zvol_prealloc(zv);
return (error);
}
static int
zvol_dumpify(zvol_state_t *zv)
{
int error = 0;
uint64_t dumpsize = 0;
dmu_tx_t *tx;
objset_t *os = zv->zv_objset;
if (zv->zv_flags & ZVOL_RDONLY || (zv->zv_mode & DS_MODE_READONLY))
return (EROFS);
/*
* We do not support swap devices acting as dump devices.
*/
if (zvol_is_swap(zv))
return (ENOTSUP);
if (zap_lookup(zv->zv_objset, ZVOL_ZAP_OBJ, ZVOL_DUMPSIZE,
8, 1, &dumpsize) != 0 || dumpsize != zv->zv_volsize) {
boolean_t resize = (dumpsize > 0) ? B_TRUE : B_FALSE;
if ((error = zvol_dump_init(zv, resize)) != 0) {
(void) zvol_dump_fini(zv);
return (error);
}
}
/*
* Build up our lba mapping.
*/
error = zvol_get_lbas(zv);
if (error) {
(void) zvol_dump_fini(zv);
return (error);
}
tx = dmu_tx_create(os);
dmu_tx_hold_zap(tx, ZVOL_ZAP_OBJ, TRUE, NULL);
error = dmu_tx_assign(tx, TXG_WAIT);
if (error) {
dmu_tx_abort(tx);
(void) zvol_dump_fini(zv);
return (error);
}
zv->zv_flags |= ZVOL_DUMPIFIED;
error = zap_update(os, ZVOL_ZAP_OBJ, ZVOL_DUMPSIZE, 8, 1,
&zv->zv_volsize, tx);
dmu_tx_commit(tx);
if (error) {
(void) zvol_dump_fini(zv);
return (error);
}
txg_wait_synced(dmu_objset_pool(os), 0);
return (0);
}
static int
zvol_dump_fini(zvol_state_t *zv)
{
dmu_tx_t *tx;
objset_t *os = zv->zv_objset;
nvlist_t *nv;
int error = 0;
uint64_t checksum, compress, refresrv, vbs;
/*
* Attempt to restore the zvol back to its pre-dumpified state.
* This is a best-effort attempt as it's possible that not all
* of these properties were initialized during the dumpify process
* (i.e. error during zvol_dump_init).
*/
tx = dmu_tx_create(os);
dmu_tx_hold_zap(tx, ZVOL_ZAP_OBJ, TRUE, NULL);
error = dmu_tx_assign(tx, TXG_WAIT);
if (error) {
dmu_tx_abort(tx);
return (error);
}
(void) zap_remove(os, ZVOL_ZAP_OBJ, ZVOL_DUMPSIZE, tx);
dmu_tx_commit(tx);
(void) zap_lookup(zv->zv_objset, ZVOL_ZAP_OBJ,
zfs_prop_to_name(ZFS_PROP_CHECKSUM), 8, 1, &checksum);
(void) zap_lookup(zv->zv_objset, ZVOL_ZAP_OBJ,
zfs_prop_to_name(ZFS_PROP_COMPRESSION), 8, 1, &compress);
(void) zap_lookup(zv->zv_objset, ZVOL_ZAP_OBJ,
zfs_prop_to_name(ZFS_PROP_REFRESERVATION), 8, 1, &refresrv);
(void) zap_lookup(zv->zv_objset, ZVOL_ZAP_OBJ,
zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE), 8, 1, &vbs);
VERIFY(nvlist_alloc(&nv, NV_UNIQUE_NAME, KM_SLEEP) == 0);
(void) nvlist_add_uint64(nv,
zfs_prop_to_name(ZFS_PROP_CHECKSUM), checksum);
(void) nvlist_add_uint64(nv,
zfs_prop_to_name(ZFS_PROP_COMPRESSION), compress);
(void) nvlist_add_uint64(nv,
zfs_prop_to_name(ZFS_PROP_REFRESERVATION), refresrv);
(void) nvlist_add_uint64(nv,
zfs_prop_to_name(ZFS_PROP_VOLBLOCKSIZE), vbs);
(void) zfs_set_prop_nvlist(zv->zv_name, nv);
nvlist_free(nv);
zvol_free_extents(zv);
zv->zv_flags &= ~ZVOL_DUMPIFIED;
(void) dmu_free_long_range(os, ZVOL_OBJ, 0, DMU_OBJECT_END);
return (0);
}
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