dmu_send.c revision 6b4acc8bd9d480535a4d057e291dc7c049f664d9
/*
* 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 2006 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#pragma ident "%Z%%M% %I% %E% SMI"
#include <sys/dmu.h>
#include <sys/dmu_impl.h>
#include <sys/dmu_tx.h>
#include <sys/dbuf.h>
#include <sys/dnode.h>
#include <sys/zfs_context.h>
#include <sys/dmu_objset.h>
#include <sys/dmu_traverse.h>
#include <sys/dsl_dataset.h>
#include <sys/dsl_dir.h>
#include <sys/dsl_pool.h>
#include <sys/dsl_synctask.h>
#include <sys/zfs_ioctl.h>
#include <sys/zap.h>
#include <sys/zio_checksum.h>
struct backuparg {
dmu_replay_record_t *drr;
vnode_t *vp;
objset_t *os;
zio_cksum_t zc;
int err;
};
static int
dump_bytes(struct backuparg *ba, void *buf, int len)
{
ssize_t resid; /* have to get resid to get detailed errno */
ASSERT3U(len % 8, ==, 0);
fletcher_4_incremental_native(buf, len, &ba->zc);
ba->err = vn_rdwr(UIO_WRITE, ba->vp,
(caddr_t)buf, len,
0, UIO_SYSSPACE, FAPPEND, RLIM64_INFINITY, CRED(), &resid);
return (ba->err);
}
static int
dump_free(struct backuparg *ba, uint64_t object, uint64_t offset,
uint64_t length)
{
/* write a FREE record */
bzero(ba->drr, sizeof (dmu_replay_record_t));
ba->drr->drr_type = DRR_FREE;
ba->drr->drr_u.drr_free.drr_object = object;
ba->drr->drr_u.drr_free.drr_offset = offset;
ba->drr->drr_u.drr_free.drr_length = length;
if (dump_bytes(ba, ba->drr, sizeof (dmu_replay_record_t)))
return (EINTR);
return (0);
}
static int
dump_data(struct backuparg *ba, dmu_object_type_t type,
uint64_t object, uint64_t offset, int blksz, void *data)
{
/* write a DATA record */
bzero(ba->drr, sizeof (dmu_replay_record_t));
ba->drr->drr_type = DRR_WRITE;
ba->drr->drr_u.drr_write.drr_object = object;
ba->drr->drr_u.drr_write.drr_type = type;
ba->drr->drr_u.drr_write.drr_offset = offset;
ba->drr->drr_u.drr_write.drr_length = blksz;
if (dump_bytes(ba, ba->drr, sizeof (dmu_replay_record_t)))
return (EINTR);
if (dump_bytes(ba, data, blksz))
return (EINTR);
return (0);
}
static int
dump_freeobjects(struct backuparg *ba, uint64_t firstobj, uint64_t numobjs)
{
/* write a FREEOBJECTS record */
bzero(ba->drr, sizeof (dmu_replay_record_t));
ba->drr->drr_type = DRR_FREEOBJECTS;
ba->drr->drr_u.drr_freeobjects.drr_firstobj = firstobj;
ba->drr->drr_u.drr_freeobjects.drr_numobjs = numobjs;
if (dump_bytes(ba, ba->drr, sizeof (dmu_replay_record_t)))
return (EINTR);
return (0);
}
static int
dump_dnode(struct backuparg *ba, uint64_t object, dnode_phys_t *dnp)
{
if (dnp == NULL || dnp->dn_type == DMU_OT_NONE)
return (dump_freeobjects(ba, object, 1));
/* write an OBJECT record */
bzero(ba->drr, sizeof (dmu_replay_record_t));
ba->drr->drr_type = DRR_OBJECT;
ba->drr->drr_u.drr_object.drr_object = object;
ba->drr->drr_u.drr_object.drr_type = dnp->dn_type;
ba->drr->drr_u.drr_object.drr_bonustype = dnp->dn_bonustype;
ba->drr->drr_u.drr_object.drr_blksz =
dnp->dn_datablkszsec << SPA_MINBLOCKSHIFT;
ba->drr->drr_u.drr_object.drr_bonuslen = dnp->dn_bonuslen;
ba->drr->drr_u.drr_object.drr_checksum = dnp->dn_checksum;
ba->drr->drr_u.drr_object.drr_compress = dnp->dn_compress;
if (dump_bytes(ba, ba->drr, sizeof (dmu_replay_record_t)))
return (EINTR);
if (dump_bytes(ba, DN_BONUS(dnp), P2ROUNDUP(dnp->dn_bonuslen, 8)))
return (EINTR);
/* free anything past the end of the file */
if (dump_free(ba, object, (dnp->dn_maxblkid + 1) *
(dnp->dn_datablkszsec << SPA_MINBLOCKSHIFT), -1ULL))
return (EINTR);
if (ba->err)
return (EINTR);
return (0);
}
#define BP_SPAN(dnp, level) \
(((uint64_t)dnp->dn_datablkszsec) << (SPA_MINBLOCKSHIFT + \
(level) * (dnp->dn_indblkshift - SPA_BLKPTRSHIFT)))
static int
backup_cb(traverse_blk_cache_t *bc, spa_t *spa, void *arg)
{
struct backuparg *ba = arg;
uint64_t object = bc->bc_bookmark.zb_object;
int level = bc->bc_bookmark.zb_level;
uint64_t blkid = bc->bc_bookmark.zb_blkid;
blkptr_t *bp = bc->bc_blkptr.blk_birth ? &bc->bc_blkptr : NULL;
dmu_object_type_t type = bp ? BP_GET_TYPE(bp) : DMU_OT_NONE;
void *data = bc->bc_data;
int err = 0;
if (issig(JUSTLOOKING) && issig(FORREAL))
return (EINTR);
ASSERT(data || bp == NULL);
if (bp == NULL && object == 0) {
uint64_t span = BP_SPAN(bc->bc_dnode, level);
uint64_t dnobj = (blkid * span) >> DNODE_SHIFT;
err = dump_freeobjects(ba, dnobj, span >> DNODE_SHIFT);
} else if (bp == NULL) {
uint64_t span = BP_SPAN(bc->bc_dnode, level);
err = dump_free(ba, object, blkid * span, span);
} else if (data && level == 0 && type == DMU_OT_DNODE) {
dnode_phys_t *blk = data;
int i;
int blksz = BP_GET_LSIZE(bp);
for (i = 0; i < blksz >> DNODE_SHIFT; i++) {
uint64_t dnobj =
(blkid << (DNODE_BLOCK_SHIFT - DNODE_SHIFT)) + i;
err = dump_dnode(ba, dnobj, blk+i);
if (err)
break;
}
} else if (level == 0 &&
type != DMU_OT_DNODE && type != DMU_OT_OBJSET) {
int blksz = BP_GET_LSIZE(bp);
if (data == NULL) {
uint32_t aflags = ARC_WAIT;
arc_buf_t *abuf;
zbookmark_t zb;
zb.zb_objset = ba->os->os->os_dsl_dataset->ds_object;
zb.zb_object = object;
zb.zb_level = level;
zb.zb_blkid = blkid;
(void) arc_read(NULL, spa, bp,
dmu_ot[type].ot_byteswap, arc_getbuf_func, &abuf,
ZIO_PRIORITY_ASYNC_READ, ZIO_FLAG_MUSTSUCCEED,
&aflags, &zb);
if (abuf) {
err = dump_data(ba, type, object, blkid * blksz,
blksz, abuf->b_data);
(void) arc_buf_remove_ref(abuf, &abuf);
}
} else {
err = dump_data(ba, type, object, blkid * blksz,
blksz, data);
}
}
ASSERT(err == 0 || err == EINTR);
return (err);
}
int
dmu_sendbackup(objset_t *tosnap, objset_t *fromsnap, vnode_t *vp)
{
dsl_dataset_t *ds = tosnap->os->os_dsl_dataset;
dsl_dataset_t *fromds = fromsnap ? fromsnap->os->os_dsl_dataset : NULL;
dmu_replay_record_t *drr;
struct backuparg ba;
int err;
/* tosnap must be a snapshot */
if (ds->ds_phys->ds_next_snap_obj == 0)
return (EINVAL);
/* fromsnap must be an earlier snapshot from the same fs as tosnap */
if (fromds && (ds->ds_dir != fromds->ds_dir ||
fromds->ds_phys->ds_creation_txg >=
ds->ds_phys->ds_creation_txg))
return (EXDEV);
drr = kmem_zalloc(sizeof (dmu_replay_record_t), KM_SLEEP);
drr->drr_type = DRR_BEGIN;
drr->drr_u.drr_begin.drr_magic = DMU_BACKUP_MAGIC;
drr->drr_u.drr_begin.drr_version = DMU_BACKUP_VERSION;
drr->drr_u.drr_begin.drr_creation_time =
ds->ds_phys->ds_creation_time;
drr->drr_u.drr_begin.drr_type = tosnap->os->os_phys->os_type;
drr->drr_u.drr_begin.drr_toguid = ds->ds_phys->ds_guid;
if (fromds)
drr->drr_u.drr_begin.drr_fromguid = fromds->ds_phys->ds_guid;
dsl_dataset_name(ds, drr->drr_u.drr_begin.drr_toname);
ba.drr = drr;
ba.vp = vp;
ba.os = tosnap;
ZIO_SET_CHECKSUM(&ba.zc, 0, 0, 0, 0);
if (dump_bytes(&ba, drr, sizeof (dmu_replay_record_t))) {
kmem_free(drr, sizeof (dmu_replay_record_t));
return (ba.err);
}
err = traverse_dsl_dataset(ds,
fromds ? fromds->ds_phys->ds_creation_txg : 0,
ADVANCE_PRE | ADVANCE_HOLES | ADVANCE_DATA | ADVANCE_NOLOCK,
backup_cb, &ba);
if (err) {
if (err == EINTR && ba.err)
err = ba.err;
return (err);
}
bzero(drr, sizeof (dmu_replay_record_t));
drr->drr_type = DRR_END;
drr->drr_u.drr_end.drr_checksum = ba.zc;
if (dump_bytes(&ba, drr, sizeof (dmu_replay_record_t)))
return (ba.err);
kmem_free(drr, sizeof (dmu_replay_record_t));
return (0);
}
struct restorearg {
int err;
int byteswap;
vnode_t *vp;
char *buf;
uint64_t voff;
int buflen; /* number of valid bytes in buf */
int bufoff; /* next offset to read */
int bufsize; /* amount of memory allocated for buf */
zio_cksum_t zc;
};
/* ARGSUSED */
static int
replay_incremental_check(void *arg1, void *arg2, dmu_tx_t *tx)
{
dsl_dataset_t *ds = arg1;
struct drr_begin *drrb = arg2;
const char *snapname;
int err;
uint64_t val;
/* must already be a snapshot of this fs */
if (ds->ds_phys->ds_prev_snap_obj == 0)
return (ENODEV);
/* most recent snapshot must match fromguid */
if (ds->ds_prev->ds_phys->ds_guid != drrb->drr_fromguid)
return (ENODEV);
/* must not have any changes since most recent snapshot */
if (ds->ds_phys->ds_bp.blk_birth >
ds->ds_prev->ds_phys->ds_creation_txg)
return (ETXTBSY);
/* new snapshot name must not exist */
snapname = strrchr(drrb->drr_toname, '@');
if (snapname == NULL)
return (EEXIST);
snapname++;
err = zap_lookup(ds->ds_dir->dd_pool->dp_meta_objset,
ds->ds_phys->ds_snapnames_zapobj, snapname, 8, 1, &val);
if (err == 0)
return (EEXIST);
if (err != ENOENT)
return (err);
return (0);
}
/* ARGSUSED */
static void
replay_incremental_sync(void *arg1, void *arg2, dmu_tx_t *tx)
{
dsl_dataset_t *ds = arg1;
dmu_buf_will_dirty(ds->ds_dbuf, tx);
ds->ds_phys->ds_flags |= DS_FLAG_INCONSISTENT;
}
/* ARGSUSED */
static int
replay_full_check(void *arg1, void *arg2, dmu_tx_t *tx)
{
dsl_dir_t *dd = arg1;
struct drr_begin *drrb = arg2;
objset_t *mos = dd->dd_pool->dp_meta_objset;
char *cp;
uint64_t val;
int err;
cp = strchr(drrb->drr_toname, '@');
*cp = '\0';
err = zap_lookup(mos, dd->dd_phys->dd_child_dir_zapobj,
strrchr(drrb->drr_toname, '/') + 1,
sizeof (uint64_t), 1, &val);
*cp = '@';
if (err != ENOENT)
return (err ? err : EEXIST);
return (0);
}
static void
replay_full_sync(void *arg1, void *arg2, dmu_tx_t *tx)
{
dsl_dir_t *dd = arg1;
struct drr_begin *drrb = arg2;
char *cp;
dsl_dataset_t *ds;
uint64_t dsobj;
cp = strchr(drrb->drr_toname, '@');
*cp = '\0';
dsobj = dsl_dataset_create_sync(dd, strrchr(drrb->drr_toname, '/') + 1,
NULL, tx);
*cp = '@';
VERIFY(0 == dsl_dataset_open_obj(dd->dd_pool, dsobj, NULL,
DS_MODE_EXCLUSIVE, FTAG, &ds));
(void) dmu_objset_create_impl(dsl_dataset_get_spa(ds),
ds, drrb->drr_type, tx);
dmu_buf_will_dirty(ds->ds_dbuf, tx);
ds->ds_phys->ds_flags |= DS_FLAG_INCONSISTENT;
dsl_dataset_close(ds, DS_MODE_EXCLUSIVE, FTAG);
}
static int
replay_end_check(void *arg1, void *arg2, dmu_tx_t *tx)
{
objset_t *os = arg1;
struct drr_begin *drrb = arg2;
char *snapname;
/* XXX verify that drr_toname is in dd */
snapname = strchr(drrb->drr_toname, '@');
if (snapname == NULL)
return (EINVAL);
snapname++;
return (dsl_dataset_snapshot_check(os, snapname, tx));
}
static void
replay_end_sync(void *arg1, void *arg2, dmu_tx_t *tx)
{
objset_t *os = arg1;
struct drr_begin *drrb = arg2;
char *snapname;
dsl_dataset_t *ds, *hds;
snapname = strchr(drrb->drr_toname, '@') + 1;
dsl_dataset_snapshot_sync(os, snapname, tx);
/* set snapshot's creation time and guid */
hds = os->os->os_dsl_dataset;
VERIFY(0 == dsl_dataset_open_obj(hds->ds_dir->dd_pool,
hds->ds_phys->ds_prev_snap_obj, NULL,
DS_MODE_PRIMARY | DS_MODE_READONLY | DS_MODE_INCONSISTENT,
FTAG, &ds));
dmu_buf_will_dirty(ds->ds_dbuf, tx);
ds->ds_phys->ds_creation_time = drrb->drr_creation_time;
ds->ds_phys->ds_guid = drrb->drr_toguid;
ds->ds_phys->ds_flags &= ~DS_FLAG_INCONSISTENT;
dsl_dataset_close(ds, DS_MODE_PRIMARY, FTAG);
dmu_buf_will_dirty(hds->ds_dbuf, tx);
hds->ds_phys->ds_flags &= ~DS_FLAG_INCONSISTENT;
}
static void *
restore_read(struct restorearg *ra, int len)
{
void *rv;
/* some things will require 8-byte alignment, so everything must */
ASSERT3U(len % 8, ==, 0);
while (ra->buflen - ra->bufoff < len) {
ssize_t resid;
int leftover = ra->buflen - ra->bufoff;
(void) memmove(ra->buf, ra->buf + ra->bufoff, leftover);
ra->err = vn_rdwr(UIO_READ, ra->vp,
(caddr_t)ra->buf + leftover, ra->bufsize - leftover,
ra->voff, UIO_SYSSPACE, FAPPEND,
RLIM64_INFINITY, CRED(), &resid);
ra->voff += ra->bufsize - leftover - resid;
ra->buflen = ra->bufsize - resid;
ra->bufoff = 0;
if (resid == ra->bufsize - leftover)
ra->err = EINVAL;
if (ra->err)
return (NULL);
/* Could compute checksum here? */
}
ASSERT3U(ra->bufoff % 8, ==, 0);
ASSERT3U(ra->buflen - ra->bufoff, >=, len);
rv = ra->buf + ra->bufoff;
ra->bufoff += len;
if (ra->byteswap)
fletcher_4_incremental_byteswap(rv, len, &ra->zc);
else
fletcher_4_incremental_native(rv, len, &ra->zc);
return (rv);
}
static void
backup_byteswap(dmu_replay_record_t *drr)
{
#define DO64(X) (drr->drr_u.X = BSWAP_64(drr->drr_u.X))
#define DO32(X) (drr->drr_u.X = BSWAP_32(drr->drr_u.X))
drr->drr_type = BSWAP_32(drr->drr_type);
switch (drr->drr_type) {
case DRR_BEGIN:
DO64(drr_begin.drr_magic);
DO64(drr_begin.drr_version);
DO64(drr_begin.drr_creation_time);
DO32(drr_begin.drr_type);
DO64(drr_begin.drr_toguid);
DO64(drr_begin.drr_fromguid);
break;
case DRR_OBJECT:
DO64(drr_object.drr_object);
/* DO64(drr_object.drr_allocation_txg); */
DO32(drr_object.drr_type);
DO32(drr_object.drr_bonustype);
DO32(drr_object.drr_blksz);
DO32(drr_object.drr_bonuslen);
break;
case DRR_FREEOBJECTS:
DO64(drr_freeobjects.drr_firstobj);
DO64(drr_freeobjects.drr_numobjs);
break;
case DRR_WRITE:
DO64(drr_write.drr_object);
DO32(drr_write.drr_type);
DO64(drr_write.drr_offset);
DO64(drr_write.drr_length);
break;
case DRR_FREE:
DO64(drr_free.drr_object);
DO64(drr_free.drr_offset);
DO64(drr_free.drr_length);
break;
case DRR_END:
DO64(drr_end.drr_checksum.zc_word[0]);
DO64(drr_end.drr_checksum.zc_word[1]);
DO64(drr_end.drr_checksum.zc_word[2]);
DO64(drr_end.drr_checksum.zc_word[3]);
break;
}
#undef DO64
#undef DO32
}
static int
restore_object(struct restorearg *ra, objset_t *os, struct drr_object *drro)
{
int err;
dmu_tx_t *tx;
err = dmu_object_info(os, drro->drr_object, NULL);
if (err != 0 && err != ENOENT)
return (EINVAL);
if (drro->drr_type == DMU_OT_NONE ||
drro->drr_type >= DMU_OT_NUMTYPES ||
drro->drr_bonustype >= DMU_OT_NUMTYPES ||
drro->drr_checksum >= ZIO_CHECKSUM_FUNCTIONS ||
drro->drr_compress >= ZIO_COMPRESS_FUNCTIONS ||
P2PHASE(drro->drr_blksz, SPA_MINBLOCKSIZE) ||
drro->drr_blksz < SPA_MINBLOCKSIZE ||
drro->drr_blksz > SPA_MAXBLOCKSIZE ||
drro->drr_bonuslen > DN_MAX_BONUSLEN) {
return (EINVAL);
}
tx = dmu_tx_create(os);
if (err == ENOENT) {
/* currently free, want to be allocated */
dmu_tx_hold_bonus(tx, DMU_NEW_OBJECT);
dmu_tx_hold_write(tx, DMU_NEW_OBJECT, 0, 1);
err = dmu_tx_assign(tx, TXG_WAIT);
if (err) {
dmu_tx_abort(tx);
return (err);
}
err = dmu_object_claim(os, drro->drr_object,
drro->drr_type, drro->drr_blksz,
drro->drr_bonustype, drro->drr_bonuslen, tx);
} else {
/* currently allocated, want to be allocated */
dmu_tx_hold_bonus(tx, drro->drr_object);
/*
* We may change blocksize, so need to
* hold_write
*/
dmu_tx_hold_write(tx, drro->drr_object, 0, 1);
err = dmu_tx_assign(tx, TXG_WAIT);
if (err) {
dmu_tx_abort(tx);
return (err);
}
err = dmu_object_reclaim(os, drro->drr_object,
drro->drr_type, drro->drr_blksz,
drro->drr_bonustype, drro->drr_bonuslen, tx);
}
if (err) {
dmu_tx_commit(tx);
return (EINVAL);
}
dmu_object_set_checksum(os, drro->drr_object, drro->drr_checksum, tx);
dmu_object_set_compress(os, drro->drr_object, drro->drr_compress, tx);
if (drro->drr_bonuslen) {
dmu_buf_t *db;
void *data;
VERIFY(0 == dmu_bonus_hold(os, drro->drr_object, FTAG, &db));
dmu_buf_will_dirty(db, tx);
ASSERT3U(db->db_size, ==, drro->drr_bonuslen);
data = restore_read(ra, P2ROUNDUP(db->db_size, 8));
if (data == NULL) {
dmu_tx_commit(tx);
return (ra->err);
}
bcopy(data, db->db_data, db->db_size);
if (ra->byteswap) {
dmu_ot[drro->drr_bonustype].ot_byteswap(db->db_data,
drro->drr_bonuslen);
}
dmu_buf_rele(db, FTAG);
}
dmu_tx_commit(tx);
return (0);
}
/* ARGSUSED */
static int
restore_freeobjects(struct restorearg *ra, objset_t *os,
struct drr_freeobjects *drrfo)
{
uint64_t obj;
if (drrfo->drr_firstobj + drrfo->drr_numobjs < drrfo->drr_firstobj)
return (EINVAL);
for (obj = drrfo->drr_firstobj;
obj < drrfo->drr_firstobj + drrfo->drr_numobjs;
(void) dmu_object_next(os, &obj, FALSE, 0)) {
dmu_tx_t *tx;
int err;
if (dmu_object_info(os, obj, NULL) != 0)
continue;
tx = dmu_tx_create(os);
dmu_tx_hold_bonus(tx, obj);
err = dmu_tx_assign(tx, TXG_WAIT);
if (err) {
dmu_tx_abort(tx);
return (err);
}
err = dmu_object_free(os, obj, tx);
dmu_tx_commit(tx);
if (err && err != ENOENT)
return (EINVAL);
}
return (0);
}
static int
restore_write(struct restorearg *ra, objset_t *os,
struct drr_write *drrw)
{
dmu_tx_t *tx;
void *data;
int err;
if (drrw->drr_offset + drrw->drr_length < drrw->drr_offset ||
drrw->drr_type >= DMU_OT_NUMTYPES)
return (EINVAL);
data = restore_read(ra, drrw->drr_length);
if (data == NULL)
return (ra->err);
if (dmu_object_info(os, drrw->drr_object, NULL) != 0)
return (EINVAL);
tx = dmu_tx_create(os);
dmu_tx_hold_write(tx, drrw->drr_object,
drrw->drr_offset, drrw->drr_length);
err = dmu_tx_assign(tx, TXG_WAIT);
if (err) {
dmu_tx_abort(tx);
return (err);
}
if (ra->byteswap)
dmu_ot[drrw->drr_type].ot_byteswap(data, drrw->drr_length);
dmu_write(os, drrw->drr_object,
drrw->drr_offset, drrw->drr_length, data, tx);
dmu_tx_commit(tx);
return (0);
}
/* ARGSUSED */
static int
restore_free(struct restorearg *ra, objset_t *os,
struct drr_free *drrf)
{
dmu_tx_t *tx;
int err;
if (drrf->drr_length != -1ULL &&
drrf->drr_offset + drrf->drr_length < drrf->drr_offset)
return (EINVAL);
if (dmu_object_info(os, drrf->drr_object, NULL) != 0)
return (EINVAL);
tx = dmu_tx_create(os);
dmu_tx_hold_free(tx, drrf->drr_object,
drrf->drr_offset, drrf->drr_length);
err = dmu_tx_assign(tx, TXG_WAIT);
if (err) {
dmu_tx_abort(tx);
return (err);
}
err = dmu_free_range(os, drrf->drr_object,
drrf->drr_offset, drrf->drr_length, tx);
dmu_tx_commit(tx);
return (err);
}
int
dmu_recvbackup(char *tosnap, struct drr_begin *drrb, uint64_t *sizep,
boolean_t force, vnode_t *vp, uint64_t voffset)
{
struct restorearg ra;
dmu_replay_record_t *drr;
char *cp;
objset_t *os = NULL;
zio_cksum_t pzc;
bzero(&ra, sizeof (ra));
ra.vp = vp;
ra.voff = voffset;
ra.bufsize = 1<<20;
ra.buf = kmem_alloc(ra.bufsize, KM_SLEEP);
if (drrb->drr_magic == DMU_BACKUP_MAGIC) {
ra.byteswap = FALSE;
} else if (drrb->drr_magic == BSWAP_64(DMU_BACKUP_MAGIC)) {
ra.byteswap = TRUE;
} else {
ra.err = EINVAL;
goto out;
}
/*
* NB: this assumes that struct drr_begin will be the largest in
* dmu_replay_record_t's drr_u, and thus we don't need to pad it
* with zeros to make it the same length as we wrote out.
*/
((dmu_replay_record_t *)ra.buf)->drr_type = DRR_BEGIN;
((dmu_replay_record_t *)ra.buf)->drr_pad = 0;
((dmu_replay_record_t *)ra.buf)->drr_u.drr_begin = *drrb;
if (ra.byteswap) {
fletcher_4_incremental_byteswap(ra.buf,
sizeof (dmu_replay_record_t), &ra.zc);
} else {
fletcher_4_incremental_native(ra.buf,
sizeof (dmu_replay_record_t), &ra.zc);
}
(void) strcpy(drrb->drr_toname, tosnap); /* for the sync funcs */
if (ra.byteswap) {
drrb->drr_magic = BSWAP_64(drrb->drr_magic);
drrb->drr_version = BSWAP_64(drrb->drr_version);
drrb->drr_creation_time = BSWAP_64(drrb->drr_creation_time);
drrb->drr_type = BSWAP_32(drrb->drr_type);
drrb->drr_toguid = BSWAP_64(drrb->drr_toguid);
drrb->drr_fromguid = BSWAP_64(drrb->drr_fromguid);
}
ASSERT3U(drrb->drr_magic, ==, DMU_BACKUP_MAGIC);
if (drrb->drr_version != DMU_BACKUP_VERSION ||
drrb->drr_type >= DMU_OST_NUMTYPES ||
strchr(drrb->drr_toname, '@') == NULL) {
ra.err = EINVAL;
goto out;
}
/*
* Process the begin in syncing context.
*/
if (drrb->drr_fromguid) {
/* incremental backup */
dsl_dataset_t *ds = NULL;
cp = strchr(tosnap, '@');
*cp = '\0';
ra.err = dsl_dataset_open(tosnap, DS_MODE_EXCLUSIVE, FTAG, &ds);
*cp = '@';
if (ra.err)
goto out;
/*
* Only do the rollback if the most recent snapshot
* matches the incremental source
*/
if (force) {
if (ds->ds_prev == NULL ||
ds->ds_prev->ds_phys->ds_guid !=
drrb->drr_fromguid) {
dsl_dataset_close(ds, DS_MODE_EXCLUSIVE, FTAG);
return (ENODEV);
}
(void) dsl_dataset_rollback(ds);
}
ra.err = dsl_sync_task_do(ds->ds_dir->dd_pool,
replay_incremental_check, replay_incremental_sync,
ds, drrb, 1);
dsl_dataset_close(ds, DS_MODE_EXCLUSIVE, FTAG);
} else {
/* full backup */
dsl_dir_t *dd = NULL;
const char *tail;
/* can't restore full backup into topmost fs, for now */
if (strrchr(drrb->drr_toname, '/') == NULL) {
ra.err = EINVAL;
goto out;
}
cp = strchr(tosnap, '@');
*cp = '\0';
ra.err = dsl_dir_open(tosnap, FTAG, &dd, &tail);
*cp = '@';
if (ra.err)
goto out;
if (tail == NULL) {
ra.err = EEXIST;
goto out;
}
ra.err = dsl_sync_task_do(dd->dd_pool, replay_full_check,
replay_full_sync, dd, drrb, 5);
dsl_dir_close(dd, FTAG);
}
if (ra.err)
goto out;
/*
* Open the objset we are modifying.
*/
cp = strchr(tosnap, '@');
*cp = '\0';
ra.err = dmu_objset_open(tosnap, DMU_OST_ANY,
DS_MODE_PRIMARY | DS_MODE_INCONSISTENT, &os);
*cp = '@';
ASSERT3U(ra.err, ==, 0);
/*
* Read records and process them.
*/
pzc = ra.zc;
while (ra.err == 0 &&
NULL != (drr = restore_read(&ra, sizeof (*drr)))) {
if (issig(JUSTLOOKING) && issig(FORREAL)) {
ra.err = EINTR;
goto out;
}
if (ra.byteswap)
backup_byteswap(drr);
switch (drr->drr_type) {
case DRR_OBJECT:
{
/*
* We need to make a copy of the record header,
* because restore_{object,write} may need to
* restore_read(), which will invalidate drr.
*/
struct drr_object drro = drr->drr_u.drr_object;
ra.err = restore_object(&ra, os, &drro);
break;
}
case DRR_FREEOBJECTS:
{
struct drr_freeobjects drrfo =
drr->drr_u.drr_freeobjects;
ra.err = restore_freeobjects(&ra, os, &drrfo);
break;
}
case DRR_WRITE:
{
struct drr_write drrw = drr->drr_u.drr_write;
ra.err = restore_write(&ra, os, &drrw);
break;
}
case DRR_FREE:
{
struct drr_free drrf = drr->drr_u.drr_free;
ra.err = restore_free(&ra, os, &drrf);
break;
}
case DRR_END:
{
struct drr_end drre = drr->drr_u.drr_end;
/*
* We compare against the *previous* checksum
* value, because the stored checksum is of
* everything before the DRR_END record.
*/
if (drre.drr_checksum.zc_word[0] != 0 &&
!ZIO_CHECKSUM_EQUAL(drre.drr_checksum, pzc)) {
ra.err = ECKSUM;
goto out;
}
ra.err = dsl_sync_task_do(dmu_objset_ds(os)->
ds_dir->dd_pool, replay_end_check, replay_end_sync,
os, drrb, 3);
goto out;
}
default:
ra.err = EINVAL;
goto out;
}
pzc = ra.zc;
}
out:
if (os)
dmu_objset_close(os);
/*
* Make sure we don't rollback/destroy unless we actually
* processed the begin properly. 'os' will only be set if this
* is the case.
*/
if (ra.err && os && tosnap && strchr(tosnap, '@')) {
/*
* rollback or destroy what we created, so we don't
* leave it in the restoring state.
*/
dsl_dataset_t *ds;
int err;
cp = strchr(tosnap, '@');
*cp = '\0';
err = dsl_dataset_open(tosnap,
DS_MODE_EXCLUSIVE | DS_MODE_INCONSISTENT,
FTAG, &ds);
if (err == 0) {
txg_wait_synced(ds->ds_dir->dd_pool, 0);
if (drrb->drr_fromguid) {
/* incremental: rollback to most recent snap */
(void) dsl_dataset_rollback(ds);
dsl_dataset_close(ds, DS_MODE_EXCLUSIVE, FTAG);
} else {
/* full: destroy whole fs */
dsl_dataset_close(ds, DS_MODE_EXCLUSIVE, FTAG);
(void) dsl_dataset_destroy(tosnap);
}
}
*cp = '@';
}
kmem_free(ra.buf, ra.bufsize);
if (sizep)
*sizep = ra.voff;
return (ra.err);
}