xref: /titanic_52/usr/src/uts/common/fs/zfs/dmu_send.c (revision 71be8d8f808a6f8b1a1bbb502fb01c7ccdb8512d)
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 2009 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 #include <sys/dmu.h>
27 #include <sys/dmu_impl.h>
28 #include <sys/dmu_tx.h>
29 #include <sys/dbuf.h>
30 #include <sys/dnode.h>
31 #include <sys/zfs_context.h>
32 #include <sys/dmu_objset.h>
33 #include <sys/dmu_traverse.h>
34 #include <sys/dsl_dataset.h>
35 #include <sys/dsl_dir.h>
36 #include <sys/dsl_pool.h>
37 #include <sys/dsl_synctask.h>
38 #include <sys/zfs_ioctl.h>
39 #include <sys/zap.h>
40 #include <sys/zio_checksum.h>
41 
42 static char *dmu_recv_tag = "dmu_recv_tag";
43 
44 struct backuparg {
45 	dmu_replay_record_t *drr;
46 	vnode_t *vp;
47 	offset_t *off;
48 	objset_t *os;
49 	zio_cksum_t zc;
50 	int err;
51 };
52 
53 static int
54 dump_bytes(struct backuparg *ba, void *buf, int len)
55 {
56 	ssize_t resid; /* have to get resid to get detailed errno */
57 	ASSERT3U(len % 8, ==, 0);
58 
59 	fletcher_4_incremental_native(buf, len, &ba->zc);
60 	ba->err = vn_rdwr(UIO_WRITE, ba->vp,
61 	    (caddr_t)buf, len,
62 	    0, UIO_SYSSPACE, FAPPEND, RLIM64_INFINITY, CRED(), &resid);
63 	*ba->off += len;
64 	return (ba->err);
65 }
66 
67 static int
68 dump_free(struct backuparg *ba, uint64_t object, uint64_t offset,
69     uint64_t length)
70 {
71 	/* write a FREE record */
72 	bzero(ba->drr, sizeof (dmu_replay_record_t));
73 	ba->drr->drr_type = DRR_FREE;
74 	ba->drr->drr_u.drr_free.drr_object = object;
75 	ba->drr->drr_u.drr_free.drr_offset = offset;
76 	ba->drr->drr_u.drr_free.drr_length = length;
77 
78 	if (dump_bytes(ba, ba->drr, sizeof (dmu_replay_record_t)))
79 		return (EINTR);
80 	return (0);
81 }
82 
83 static int
84 dump_data(struct backuparg *ba, dmu_object_type_t type,
85     uint64_t object, uint64_t offset, int blksz, void *data)
86 {
87 	/* write a DATA record */
88 	bzero(ba->drr, sizeof (dmu_replay_record_t));
89 	ba->drr->drr_type = DRR_WRITE;
90 	ba->drr->drr_u.drr_write.drr_object = object;
91 	ba->drr->drr_u.drr_write.drr_type = type;
92 	ba->drr->drr_u.drr_write.drr_offset = offset;
93 	ba->drr->drr_u.drr_write.drr_length = blksz;
94 
95 	if (dump_bytes(ba, ba->drr, sizeof (dmu_replay_record_t)))
96 		return (EINTR);
97 	if (dump_bytes(ba, data, blksz))
98 		return (EINTR);
99 	return (0);
100 }
101 
102 static int
103 dump_freeobjects(struct backuparg *ba, uint64_t firstobj, uint64_t numobjs)
104 {
105 	/* write a FREEOBJECTS record */
106 	bzero(ba->drr, sizeof (dmu_replay_record_t));
107 	ba->drr->drr_type = DRR_FREEOBJECTS;
108 	ba->drr->drr_u.drr_freeobjects.drr_firstobj = firstobj;
109 	ba->drr->drr_u.drr_freeobjects.drr_numobjs = numobjs;
110 
111 	if (dump_bytes(ba, ba->drr, sizeof (dmu_replay_record_t)))
112 		return (EINTR);
113 	return (0);
114 }
115 
116 static int
117 dump_dnode(struct backuparg *ba, uint64_t object, dnode_phys_t *dnp)
118 {
119 	if (dnp == NULL || dnp->dn_type == DMU_OT_NONE)
120 		return (dump_freeobjects(ba, object, 1));
121 
122 	/* write an OBJECT record */
123 	bzero(ba->drr, sizeof (dmu_replay_record_t));
124 	ba->drr->drr_type = DRR_OBJECT;
125 	ba->drr->drr_u.drr_object.drr_object = object;
126 	ba->drr->drr_u.drr_object.drr_type = dnp->dn_type;
127 	ba->drr->drr_u.drr_object.drr_bonustype = dnp->dn_bonustype;
128 	ba->drr->drr_u.drr_object.drr_blksz =
129 	    dnp->dn_datablkszsec << SPA_MINBLOCKSHIFT;
130 	ba->drr->drr_u.drr_object.drr_bonuslen = dnp->dn_bonuslen;
131 	ba->drr->drr_u.drr_object.drr_checksum = dnp->dn_checksum;
132 	ba->drr->drr_u.drr_object.drr_compress = dnp->dn_compress;
133 
134 	if (dump_bytes(ba, ba->drr, sizeof (dmu_replay_record_t)))
135 		return (EINTR);
136 
137 	if (dump_bytes(ba, DN_BONUS(dnp), P2ROUNDUP(dnp->dn_bonuslen, 8)))
138 		return (EINTR);
139 
140 	/* free anything past the end of the file */
141 	if (dump_free(ba, object, (dnp->dn_maxblkid + 1) *
142 	    (dnp->dn_datablkszsec << SPA_MINBLOCKSHIFT), -1ULL))
143 		return (EINTR);
144 	if (ba->err)
145 		return (EINTR);
146 	return (0);
147 }
148 
149 #define	BP_SPAN(dnp, level) \
150 	(((uint64_t)dnp->dn_datablkszsec) << (SPA_MINBLOCKSHIFT + \
151 	(level) * (dnp->dn_indblkshift - SPA_BLKPTRSHIFT)))
152 
153 static int
154 backup_cb(spa_t *spa, blkptr_t *bp, const zbookmark_t *zb,
155     const dnode_phys_t *dnp, void *arg)
156 {
157 	struct backuparg *ba = arg;
158 	dmu_object_type_t type = bp ? BP_GET_TYPE(bp) : DMU_OT_NONE;
159 	int err = 0;
160 
161 	if (issig(JUSTLOOKING) && issig(FORREAL))
162 		return (EINTR);
163 
164 	if (zb->zb_object != 0 && DMU_OBJECT_IS_SPECIAL(zb->zb_object)) {
165 		return (0);
166 	} else if (bp == NULL && zb->zb_object == 0) {
167 		uint64_t span = BP_SPAN(dnp, zb->zb_level);
168 		uint64_t dnobj = (zb->zb_blkid * span) >> DNODE_SHIFT;
169 		err = dump_freeobjects(ba, dnobj, span >> DNODE_SHIFT);
170 	} else if (bp == NULL) {
171 		uint64_t span = BP_SPAN(dnp, zb->zb_level);
172 		err = dump_free(ba, zb->zb_object, zb->zb_blkid * span, span);
173 	} else if (zb->zb_level > 0 || type == DMU_OT_OBJSET) {
174 		return (0);
175 	} else if (type == DMU_OT_DNODE) {
176 		dnode_phys_t *blk;
177 		int i;
178 		int blksz = BP_GET_LSIZE(bp);
179 		uint32_t aflags = ARC_WAIT;
180 		arc_buf_t *abuf;
181 
182 		if (arc_read_nolock(NULL, spa, bp,
183 		    arc_getbuf_func, &abuf, ZIO_PRIORITY_ASYNC_READ,
184 		    ZIO_FLAG_CANFAIL, &aflags, zb) != 0)
185 			return (EIO);
186 
187 		blk = abuf->b_data;
188 		for (i = 0; i < blksz >> DNODE_SHIFT; i++) {
189 			uint64_t dnobj = (zb->zb_blkid <<
190 			    (DNODE_BLOCK_SHIFT - DNODE_SHIFT)) + i;
191 			err = dump_dnode(ba, dnobj, blk+i);
192 			if (err)
193 				break;
194 		}
195 		(void) arc_buf_remove_ref(abuf, &abuf);
196 	} else { /* it's a level-0 block of a regular object */
197 		uint32_t aflags = ARC_WAIT;
198 		arc_buf_t *abuf;
199 		int blksz = BP_GET_LSIZE(bp);
200 
201 		if (arc_read_nolock(NULL, spa, bp,
202 		    arc_getbuf_func, &abuf, ZIO_PRIORITY_ASYNC_READ,
203 		    ZIO_FLAG_CANFAIL, &aflags, zb) != 0)
204 			return (EIO);
205 
206 		err = dump_data(ba, type, zb->zb_object, zb->zb_blkid * blksz,
207 		    blksz, abuf->b_data);
208 		(void) arc_buf_remove_ref(abuf, &abuf);
209 	}
210 
211 	ASSERT(err == 0 || err == EINTR);
212 	return (err);
213 }
214 
215 int
216 dmu_sendbackup(objset_t *tosnap, objset_t *fromsnap, boolean_t fromorigin,
217     vnode_t *vp, offset_t *off)
218 {
219 	dsl_dataset_t *ds = tosnap->os_dsl_dataset;
220 	dsl_dataset_t *fromds = fromsnap ? fromsnap->os_dsl_dataset : NULL;
221 	dmu_replay_record_t *drr;
222 	struct backuparg ba;
223 	int err;
224 	uint64_t fromtxg = 0;
225 
226 	/* tosnap must be a snapshot */
227 	if (ds->ds_phys->ds_next_snap_obj == 0)
228 		return (EINVAL);
229 
230 	/* fromsnap must be an earlier snapshot from the same fs as tosnap */
231 	if (fromds && (ds->ds_dir != fromds->ds_dir ||
232 	    fromds->ds_phys->ds_creation_txg >= ds->ds_phys->ds_creation_txg))
233 		return (EXDEV);
234 
235 	if (fromorigin) {
236 		dsl_pool_t *dp = ds->ds_dir->dd_pool;
237 
238 		if (fromsnap)
239 			return (EINVAL);
240 
241 		if (dsl_dir_is_clone(ds->ds_dir)) {
242 			rw_enter(&dp->dp_config_rwlock, RW_READER);
243 			err = dsl_dataset_hold_obj(dp,
244 			    ds->ds_dir->dd_phys->dd_origin_obj, FTAG, &fromds);
245 			rw_exit(&dp->dp_config_rwlock);
246 			if (err)
247 				return (err);
248 		} else {
249 			fromorigin = B_FALSE;
250 		}
251 	}
252 
253 
254 	drr = kmem_zalloc(sizeof (dmu_replay_record_t), KM_SLEEP);
255 	drr->drr_type = DRR_BEGIN;
256 	drr->drr_u.drr_begin.drr_magic = DMU_BACKUP_MAGIC;
257 	drr->drr_u.drr_begin.drr_version = DMU_BACKUP_STREAM_VERSION;
258 	drr->drr_u.drr_begin.drr_creation_time =
259 	    ds->ds_phys->ds_creation_time;
260 	drr->drr_u.drr_begin.drr_type = tosnap->os_phys->os_type;
261 	if (fromorigin)
262 		drr->drr_u.drr_begin.drr_flags |= DRR_FLAG_CLONE;
263 	drr->drr_u.drr_begin.drr_toguid = ds->ds_phys->ds_guid;
264 	if (ds->ds_phys->ds_flags & DS_FLAG_CI_DATASET)
265 		drr->drr_u.drr_begin.drr_flags |= DRR_FLAG_CI_DATA;
266 
267 	if (fromds)
268 		drr->drr_u.drr_begin.drr_fromguid = fromds->ds_phys->ds_guid;
269 	dsl_dataset_name(ds, drr->drr_u.drr_begin.drr_toname);
270 
271 	if (fromds)
272 		fromtxg = fromds->ds_phys->ds_creation_txg;
273 	if (fromorigin)
274 		dsl_dataset_rele(fromds, FTAG);
275 
276 	ba.drr = drr;
277 	ba.vp = vp;
278 	ba.os = tosnap;
279 	ba.off = off;
280 	ZIO_SET_CHECKSUM(&ba.zc, 0, 0, 0, 0);
281 
282 	if (dump_bytes(&ba, drr, sizeof (dmu_replay_record_t))) {
283 		kmem_free(drr, sizeof (dmu_replay_record_t));
284 		return (ba.err);
285 	}
286 
287 	err = traverse_dataset(ds, fromtxg, TRAVERSE_PRE | TRAVERSE_PREFETCH,
288 	    backup_cb, &ba);
289 
290 	if (err) {
291 		if (err == EINTR && ba.err)
292 			err = ba.err;
293 		kmem_free(drr, sizeof (dmu_replay_record_t));
294 		return (err);
295 	}
296 
297 	bzero(drr, sizeof (dmu_replay_record_t));
298 	drr->drr_type = DRR_END;
299 	drr->drr_u.drr_end.drr_checksum = ba.zc;
300 
301 	if (dump_bytes(&ba, drr, sizeof (dmu_replay_record_t))) {
302 		kmem_free(drr, sizeof (dmu_replay_record_t));
303 		return (ba.err);
304 	}
305 
306 	kmem_free(drr, sizeof (dmu_replay_record_t));
307 
308 	return (0);
309 }
310 
311 struct recvbeginsyncarg {
312 	const char *tofs;
313 	const char *tosnap;
314 	dsl_dataset_t *origin;
315 	uint64_t fromguid;
316 	dmu_objset_type_t type;
317 	void *tag;
318 	boolean_t force;
319 	uint64_t dsflags;
320 	char clonelastname[MAXNAMELEN];
321 	dsl_dataset_t *ds; /* the ds to recv into; returned from the syncfunc */
322 };
323 
324 /* ARGSUSED */
325 static int
326 recv_new_check(void *arg1, void *arg2, dmu_tx_t *tx)
327 {
328 	dsl_dir_t *dd = arg1;
329 	struct recvbeginsyncarg *rbsa = arg2;
330 	objset_t *mos = dd->dd_pool->dp_meta_objset;
331 	uint64_t val;
332 	int err;
333 
334 	err = zap_lookup(mos, dd->dd_phys->dd_child_dir_zapobj,
335 	    strrchr(rbsa->tofs, '/') + 1, sizeof (uint64_t), 1, &val);
336 
337 	if (err != ENOENT)
338 		return (err ? err : EEXIST);
339 
340 	if (rbsa->origin) {
341 		/* make sure it's a snap in the same pool */
342 		if (rbsa->origin->ds_dir->dd_pool != dd->dd_pool)
343 			return (EXDEV);
344 		if (!dsl_dataset_is_snapshot(rbsa->origin))
345 			return (EINVAL);
346 		if (rbsa->origin->ds_phys->ds_guid != rbsa->fromguid)
347 			return (ENODEV);
348 	}
349 
350 	return (0);
351 }
352 
353 static void
354 recv_new_sync(void *arg1, void *arg2, cred_t *cr, dmu_tx_t *tx)
355 {
356 	dsl_dir_t *dd = arg1;
357 	struct recvbeginsyncarg *rbsa = arg2;
358 	uint64_t flags = DS_FLAG_INCONSISTENT | rbsa->dsflags;
359 	uint64_t dsobj;
360 
361 	/* Create and open new dataset. */
362 	dsobj = dsl_dataset_create_sync(dd, strrchr(rbsa->tofs, '/') + 1,
363 	    rbsa->origin, flags, cr, tx);
364 	VERIFY(0 == dsl_dataset_own_obj(dd->dd_pool, dsobj,
365 	    B_TRUE, dmu_recv_tag, &rbsa->ds));
366 
367 	if (rbsa->origin == NULL) {
368 		(void) dmu_objset_create_impl(dd->dd_pool->dp_spa,
369 		    rbsa->ds, &rbsa->ds->ds_phys->ds_bp, rbsa->type, tx);
370 	}
371 
372 	spa_history_internal_log(LOG_DS_REPLAY_FULL_SYNC,
373 	    dd->dd_pool->dp_spa, tx, cr, "dataset = %lld", dsobj);
374 }
375 
376 /* ARGSUSED */
377 static int
378 recv_existing_check(void *arg1, void *arg2, dmu_tx_t *tx)
379 {
380 	dsl_dataset_t *ds = arg1;
381 	struct recvbeginsyncarg *rbsa = arg2;
382 	int err;
383 	uint64_t val;
384 
385 	/* must not have any changes since most recent snapshot */
386 	if (!rbsa->force && dsl_dataset_modified_since_lastsnap(ds))
387 		return (ETXTBSY);
388 
389 	if (rbsa->fromguid) {
390 		/* if incremental, most recent snapshot must match fromguid */
391 		if (ds->ds_prev == NULL)
392 			return (ENODEV);
393 		if (ds->ds_prev->ds_phys->ds_guid != rbsa->fromguid)
394 			return (ENODEV);
395 	} else {
396 		/* if full, most recent snapshot must be $ORIGIN */
397 		if (ds->ds_phys->ds_prev_snap_txg >= TXG_INITIAL)
398 			return (ENODEV);
399 	}
400 
401 	/* temporary clone name must not exist */
402 	err = zap_lookup(ds->ds_dir->dd_pool->dp_meta_objset,
403 	    ds->ds_dir->dd_phys->dd_child_dir_zapobj,
404 	    rbsa->clonelastname, 8, 1, &val);
405 	if (err == 0)
406 		return (EEXIST);
407 	if (err != ENOENT)
408 		return (err);
409 
410 	/* new snapshot name must not exist */
411 	err = zap_lookup(ds->ds_dir->dd_pool->dp_meta_objset,
412 	    ds->ds_phys->ds_snapnames_zapobj, rbsa->tosnap, 8, 1, &val);
413 	if (err == 0)
414 		return (EEXIST);
415 	if (err != ENOENT)
416 		return (err);
417 	return (0);
418 }
419 
420 /* ARGSUSED */
421 static void
422 recv_existing_sync(void *arg1, void *arg2, cred_t *cr, dmu_tx_t *tx)
423 {
424 	dsl_dataset_t *ohds = arg1;
425 	struct recvbeginsyncarg *rbsa = arg2;
426 	dsl_pool_t *dp = ohds->ds_dir->dd_pool;
427 	dsl_dataset_t *cds;
428 	uint64_t flags = DS_FLAG_INCONSISTENT | rbsa->dsflags;
429 	uint64_t dsobj;
430 
431 	/* create and open the temporary clone */
432 	dsobj = dsl_dataset_create_sync(ohds->ds_dir, rbsa->clonelastname,
433 	    ohds->ds_prev, flags, cr, tx);
434 	VERIFY(0 == dsl_dataset_own_obj(dp, dsobj, B_TRUE, dmu_recv_tag, &cds));
435 
436 	/*
437 	 * If we actually created a non-clone, we need to create the
438 	 * objset in our new dataset.
439 	 */
440 	if (BP_IS_HOLE(dsl_dataset_get_blkptr(cds))) {
441 		(void) dmu_objset_create_impl(dp->dp_spa,
442 		    cds, dsl_dataset_get_blkptr(cds), rbsa->type, tx);
443 	}
444 
445 	/* copy the refquota from the target fs to the clone */
446 	if (ohds->ds_quota > 0)
447 		dsl_dataset_set_quota_sync(cds, &ohds->ds_quota, cr, tx);
448 
449 	rbsa->ds = cds;
450 
451 	spa_history_internal_log(LOG_DS_REPLAY_INC_SYNC,
452 	    dp->dp_spa, tx, cr, "dataset = %lld", dsobj);
453 }
454 
455 /*
456  * NB: callers *MUST* call dmu_recv_stream() if dmu_recv_begin()
457  * succeeds; otherwise we will leak the holds on the datasets.
458  */
459 int
460 dmu_recv_begin(char *tofs, char *tosnap, struct drr_begin *drrb,
461     boolean_t force, objset_t *origin, dmu_recv_cookie_t *drc)
462 {
463 	int err = 0;
464 	boolean_t byteswap;
465 	struct recvbeginsyncarg rbsa = { 0 };
466 	uint64_t version;
467 	int flags;
468 	dsl_dataset_t *ds;
469 
470 	if (drrb->drr_magic == DMU_BACKUP_MAGIC)
471 		byteswap = FALSE;
472 	else if (drrb->drr_magic == BSWAP_64(DMU_BACKUP_MAGIC))
473 		byteswap = TRUE;
474 	else
475 		return (EINVAL);
476 
477 	rbsa.tofs = tofs;
478 	rbsa.tosnap = tosnap;
479 	rbsa.origin = origin ? origin->os_dsl_dataset : NULL;
480 	rbsa.fromguid = drrb->drr_fromguid;
481 	rbsa.type = drrb->drr_type;
482 	rbsa.tag = FTAG;
483 	rbsa.dsflags = 0;
484 	version = drrb->drr_version;
485 	flags = drrb->drr_flags;
486 
487 	if (byteswap) {
488 		rbsa.type = BSWAP_32(rbsa.type);
489 		rbsa.fromguid = BSWAP_64(rbsa.fromguid);
490 		version = BSWAP_64(version);
491 		flags = BSWAP_32(flags);
492 	}
493 
494 	if (version != DMU_BACKUP_STREAM_VERSION ||
495 	    rbsa.type >= DMU_OST_NUMTYPES ||
496 	    ((flags & DRR_FLAG_CLONE) && origin == NULL))
497 		return (EINVAL);
498 
499 	if (flags & DRR_FLAG_CI_DATA)
500 		rbsa.dsflags = DS_FLAG_CI_DATASET;
501 
502 	bzero(drc, sizeof (dmu_recv_cookie_t));
503 	drc->drc_drrb = drrb;
504 	drc->drc_tosnap = tosnap;
505 	drc->drc_force = force;
506 
507 	/*
508 	 * Process the begin in syncing context.
509 	 */
510 
511 	/* open the dataset we are logically receiving into */
512 	err = dsl_dataset_hold(tofs, dmu_recv_tag, &ds);
513 	if (err == 0) {
514 		/* target fs already exists; recv into temp clone */
515 
516 		/* Can't recv a clone into an existing fs */
517 		if (flags & DRR_FLAG_CLONE) {
518 			dsl_dataset_rele(ds, dmu_recv_tag);
519 			return (EINVAL);
520 		}
521 
522 		/* must not have an incremental recv already in progress */
523 		if (!mutex_tryenter(&ds->ds_recvlock)) {
524 			dsl_dataset_rele(ds, dmu_recv_tag);
525 			return (EBUSY);
526 		}
527 
528 		/* tmp clone name is: tofs/%tosnap" */
529 		(void) snprintf(rbsa.clonelastname, sizeof (rbsa.clonelastname),
530 		    "%%%s", tosnap);
531 		rbsa.force = force;
532 		err = dsl_sync_task_do(ds->ds_dir->dd_pool,
533 		    recv_existing_check, recv_existing_sync, ds, &rbsa, 5);
534 		if (err) {
535 			mutex_exit(&ds->ds_recvlock);
536 			dsl_dataset_rele(ds, dmu_recv_tag);
537 			return (err);
538 		}
539 		drc->drc_logical_ds = ds;
540 		drc->drc_real_ds = rbsa.ds;
541 	} else if (err == ENOENT) {
542 		/* target fs does not exist; must be a full backup or clone */
543 		char *cp;
544 
545 		/*
546 		 * If it's a non-clone incremental, we are missing the
547 		 * target fs, so fail the recv.
548 		 */
549 		if (rbsa.fromguid && !(flags & DRR_FLAG_CLONE))
550 			return (ENOENT);
551 
552 		/* Open the parent of tofs */
553 		cp = strrchr(tofs, '/');
554 		*cp = '\0';
555 		err = dsl_dataset_hold(tofs, FTAG, &ds);
556 		*cp = '/';
557 		if (err)
558 			return (err);
559 
560 		err = dsl_sync_task_do(ds->ds_dir->dd_pool,
561 		    recv_new_check, recv_new_sync, ds->ds_dir, &rbsa, 5);
562 		dsl_dataset_rele(ds, FTAG);
563 		if (err)
564 			return (err);
565 		drc->drc_logical_ds = drc->drc_real_ds = rbsa.ds;
566 		drc->drc_newfs = B_TRUE;
567 	}
568 
569 	return (err);
570 }
571 
572 struct restorearg {
573 	int err;
574 	int byteswap;
575 	vnode_t *vp;
576 	char *buf;
577 	uint64_t voff;
578 	int bufsize; /* amount of memory allocated for buf */
579 	zio_cksum_t cksum;
580 };
581 
582 static void *
583 restore_read(struct restorearg *ra, int len)
584 {
585 	void *rv;
586 	int done = 0;
587 
588 	/* some things will require 8-byte alignment, so everything must */
589 	ASSERT3U(len % 8, ==, 0);
590 
591 	while (done < len) {
592 		ssize_t resid;
593 
594 		ra->err = vn_rdwr(UIO_READ, ra->vp,
595 		    (caddr_t)ra->buf + done, len - done,
596 		    ra->voff, UIO_SYSSPACE, FAPPEND,
597 		    RLIM64_INFINITY, CRED(), &resid);
598 
599 		if (resid == len - done)
600 			ra->err = EINVAL;
601 		ra->voff += len - done - resid;
602 		done = len - resid;
603 		if (ra->err)
604 			return (NULL);
605 	}
606 
607 	ASSERT3U(done, ==, len);
608 	rv = ra->buf;
609 	if (ra->byteswap)
610 		fletcher_4_incremental_byteswap(rv, len, &ra->cksum);
611 	else
612 		fletcher_4_incremental_native(rv, len, &ra->cksum);
613 	return (rv);
614 }
615 
616 static void
617 backup_byteswap(dmu_replay_record_t *drr)
618 {
619 #define	DO64(X) (drr->drr_u.X = BSWAP_64(drr->drr_u.X))
620 #define	DO32(X) (drr->drr_u.X = BSWAP_32(drr->drr_u.X))
621 	drr->drr_type = BSWAP_32(drr->drr_type);
622 	drr->drr_payloadlen = BSWAP_32(drr->drr_payloadlen);
623 	switch (drr->drr_type) {
624 	case DRR_BEGIN:
625 		DO64(drr_begin.drr_magic);
626 		DO64(drr_begin.drr_version);
627 		DO64(drr_begin.drr_creation_time);
628 		DO32(drr_begin.drr_type);
629 		DO32(drr_begin.drr_flags);
630 		DO64(drr_begin.drr_toguid);
631 		DO64(drr_begin.drr_fromguid);
632 		break;
633 	case DRR_OBJECT:
634 		DO64(drr_object.drr_object);
635 		/* DO64(drr_object.drr_allocation_txg); */
636 		DO32(drr_object.drr_type);
637 		DO32(drr_object.drr_bonustype);
638 		DO32(drr_object.drr_blksz);
639 		DO32(drr_object.drr_bonuslen);
640 		break;
641 	case DRR_FREEOBJECTS:
642 		DO64(drr_freeobjects.drr_firstobj);
643 		DO64(drr_freeobjects.drr_numobjs);
644 		break;
645 	case DRR_WRITE:
646 		DO64(drr_write.drr_object);
647 		DO32(drr_write.drr_type);
648 		DO64(drr_write.drr_offset);
649 		DO64(drr_write.drr_length);
650 		break;
651 	case DRR_FREE:
652 		DO64(drr_free.drr_object);
653 		DO64(drr_free.drr_offset);
654 		DO64(drr_free.drr_length);
655 		break;
656 	case DRR_END:
657 		DO64(drr_end.drr_checksum.zc_word[0]);
658 		DO64(drr_end.drr_checksum.zc_word[1]);
659 		DO64(drr_end.drr_checksum.zc_word[2]);
660 		DO64(drr_end.drr_checksum.zc_word[3]);
661 		break;
662 	}
663 #undef DO64
664 #undef DO32
665 }
666 
667 static int
668 restore_object(struct restorearg *ra, objset_t *os, struct drr_object *drro)
669 {
670 	int err;
671 	dmu_tx_t *tx;
672 	void *data = NULL;
673 
674 	if (drro->drr_type == DMU_OT_NONE ||
675 	    drro->drr_type >= DMU_OT_NUMTYPES ||
676 	    drro->drr_bonustype >= DMU_OT_NUMTYPES ||
677 	    drro->drr_checksum >= ZIO_CHECKSUM_FUNCTIONS ||
678 	    drro->drr_compress >= ZIO_COMPRESS_FUNCTIONS ||
679 	    P2PHASE(drro->drr_blksz, SPA_MINBLOCKSIZE) ||
680 	    drro->drr_blksz < SPA_MINBLOCKSIZE ||
681 	    drro->drr_blksz > SPA_MAXBLOCKSIZE ||
682 	    drro->drr_bonuslen > DN_MAX_BONUSLEN) {
683 		return (EINVAL);
684 	}
685 
686 	err = dmu_object_info(os, drro->drr_object, NULL);
687 
688 	if (err != 0 && err != ENOENT)
689 		return (EINVAL);
690 
691 	if (drro->drr_bonuslen) {
692 		data = restore_read(ra, P2ROUNDUP(drro->drr_bonuslen, 8));
693 		if (ra->err)
694 			return (ra->err);
695 	}
696 
697 	if (err == ENOENT) {
698 		/* currently free, want to be allocated */
699 		tx = dmu_tx_create(os);
700 		dmu_tx_hold_bonus(tx, DMU_NEW_OBJECT);
701 		err = dmu_tx_assign(tx, TXG_WAIT);
702 		if (err) {
703 			dmu_tx_abort(tx);
704 			return (err);
705 		}
706 		err = dmu_object_claim(os, drro->drr_object,
707 		    drro->drr_type, drro->drr_blksz,
708 		    drro->drr_bonustype, drro->drr_bonuslen, tx);
709 		dmu_tx_commit(tx);
710 	} else {
711 		/* currently allocated, want to be allocated */
712 		err = dmu_object_reclaim(os, drro->drr_object,
713 		    drro->drr_type, drro->drr_blksz,
714 		    drro->drr_bonustype, drro->drr_bonuslen);
715 	}
716 	if (err)
717 		return (EINVAL);
718 
719 	tx = dmu_tx_create(os);
720 	dmu_tx_hold_bonus(tx, drro->drr_object);
721 	err = dmu_tx_assign(tx, TXG_WAIT);
722 	if (err) {
723 		dmu_tx_abort(tx);
724 		return (err);
725 	}
726 
727 	dmu_object_set_checksum(os, drro->drr_object, drro->drr_checksum, tx);
728 	dmu_object_set_compress(os, drro->drr_object, drro->drr_compress, tx);
729 
730 	if (data != NULL) {
731 		dmu_buf_t *db;
732 
733 		VERIFY(0 == dmu_bonus_hold(os, drro->drr_object, FTAG, &db));
734 		dmu_buf_will_dirty(db, tx);
735 
736 		ASSERT3U(db->db_size, >=, drro->drr_bonuslen);
737 		bcopy(data, db->db_data, drro->drr_bonuslen);
738 		if (ra->byteswap) {
739 			dmu_ot[drro->drr_bonustype].ot_byteswap(db->db_data,
740 			    drro->drr_bonuslen);
741 		}
742 		dmu_buf_rele(db, FTAG);
743 	}
744 	dmu_tx_commit(tx);
745 	return (0);
746 }
747 
748 /* ARGSUSED */
749 static int
750 restore_freeobjects(struct restorearg *ra, objset_t *os,
751     struct drr_freeobjects *drrfo)
752 {
753 	uint64_t obj;
754 
755 	if (drrfo->drr_firstobj + drrfo->drr_numobjs < drrfo->drr_firstobj)
756 		return (EINVAL);
757 
758 	for (obj = drrfo->drr_firstobj;
759 	    obj < drrfo->drr_firstobj + drrfo->drr_numobjs;
760 	    (void) dmu_object_next(os, &obj, FALSE, 0)) {
761 		int err;
762 
763 		if (dmu_object_info(os, obj, NULL) != 0)
764 			continue;
765 
766 		err = dmu_free_object(os, obj);
767 		if (err)
768 			return (err);
769 	}
770 	return (0);
771 }
772 
773 static int
774 restore_write(struct restorearg *ra, objset_t *os,
775     struct drr_write *drrw)
776 {
777 	dmu_tx_t *tx;
778 	void *data;
779 	int err;
780 
781 	if (drrw->drr_offset + drrw->drr_length < drrw->drr_offset ||
782 	    drrw->drr_type >= DMU_OT_NUMTYPES)
783 		return (EINVAL);
784 
785 	data = restore_read(ra, drrw->drr_length);
786 	if (data == NULL)
787 		return (ra->err);
788 
789 	if (dmu_object_info(os, drrw->drr_object, NULL) != 0)
790 		return (EINVAL);
791 
792 	tx = dmu_tx_create(os);
793 
794 	dmu_tx_hold_write(tx, drrw->drr_object,
795 	    drrw->drr_offset, drrw->drr_length);
796 	err = dmu_tx_assign(tx, TXG_WAIT);
797 	if (err) {
798 		dmu_tx_abort(tx);
799 		return (err);
800 	}
801 	if (ra->byteswap)
802 		dmu_ot[drrw->drr_type].ot_byteswap(data, drrw->drr_length);
803 	dmu_write(os, drrw->drr_object,
804 	    drrw->drr_offset, drrw->drr_length, data, tx);
805 	dmu_tx_commit(tx);
806 	return (0);
807 }
808 
809 /* ARGSUSED */
810 static int
811 restore_free(struct restorearg *ra, objset_t *os,
812     struct drr_free *drrf)
813 {
814 	int err;
815 
816 	if (drrf->drr_length != -1ULL &&
817 	    drrf->drr_offset + drrf->drr_length < drrf->drr_offset)
818 		return (EINVAL);
819 
820 	if (dmu_object_info(os, drrf->drr_object, NULL) != 0)
821 		return (EINVAL);
822 
823 	err = dmu_free_long_range(os, drrf->drr_object,
824 	    drrf->drr_offset, drrf->drr_length);
825 	return (err);
826 }
827 
828 /*
829  * NB: callers *must* call dmu_recv_end() if this succeeds.
830  */
831 int
832 dmu_recv_stream(dmu_recv_cookie_t *drc, vnode_t *vp, offset_t *voffp)
833 {
834 	struct restorearg ra = { 0 };
835 	dmu_replay_record_t *drr;
836 	objset_t *os;
837 	zio_cksum_t pcksum;
838 
839 	if (drc->drc_drrb->drr_magic == BSWAP_64(DMU_BACKUP_MAGIC))
840 		ra.byteswap = TRUE;
841 
842 	{
843 		/* compute checksum of drr_begin record */
844 		dmu_replay_record_t *drr;
845 		drr = kmem_zalloc(sizeof (dmu_replay_record_t), KM_SLEEP);
846 
847 		drr->drr_type = DRR_BEGIN;
848 		drr->drr_u.drr_begin = *drc->drc_drrb;
849 		if (ra.byteswap) {
850 			fletcher_4_incremental_byteswap(drr,
851 			    sizeof (dmu_replay_record_t), &ra.cksum);
852 		} else {
853 			fletcher_4_incremental_native(drr,
854 			    sizeof (dmu_replay_record_t), &ra.cksum);
855 		}
856 		kmem_free(drr, sizeof (dmu_replay_record_t));
857 	}
858 
859 	if (ra.byteswap) {
860 		struct drr_begin *drrb = drc->drc_drrb;
861 		drrb->drr_magic = BSWAP_64(drrb->drr_magic);
862 		drrb->drr_version = BSWAP_64(drrb->drr_version);
863 		drrb->drr_creation_time = BSWAP_64(drrb->drr_creation_time);
864 		drrb->drr_type = BSWAP_32(drrb->drr_type);
865 		drrb->drr_toguid = BSWAP_64(drrb->drr_toguid);
866 		drrb->drr_fromguid = BSWAP_64(drrb->drr_fromguid);
867 	}
868 
869 	ra.vp = vp;
870 	ra.voff = *voffp;
871 	ra.bufsize = 1<<20;
872 	ra.buf = kmem_alloc(ra.bufsize, KM_SLEEP);
873 
874 	/* these were verified in dmu_recv_begin */
875 	ASSERT(drc->drc_drrb->drr_version == DMU_BACKUP_STREAM_VERSION);
876 	ASSERT(drc->drc_drrb->drr_type < DMU_OST_NUMTYPES);
877 
878 	/*
879 	 * Open the objset we are modifying.
880 	 */
881 	VERIFY(dmu_objset_from_ds(drc->drc_real_ds, &os) == 0);
882 
883 	ASSERT(drc->drc_real_ds->ds_phys->ds_flags & DS_FLAG_INCONSISTENT);
884 
885 	/*
886 	 * Read records and process them.
887 	 */
888 	pcksum = ra.cksum;
889 	while (ra.err == 0 &&
890 	    NULL != (drr = restore_read(&ra, sizeof (*drr)))) {
891 		if (issig(JUSTLOOKING) && issig(FORREAL)) {
892 			ra.err = EINTR;
893 			goto out;
894 		}
895 
896 		if (ra.byteswap)
897 			backup_byteswap(drr);
898 
899 		switch (drr->drr_type) {
900 		case DRR_OBJECT:
901 		{
902 			/*
903 			 * We need to make a copy of the record header,
904 			 * because restore_{object,write} may need to
905 			 * restore_read(), which will invalidate drr.
906 			 */
907 			struct drr_object drro = drr->drr_u.drr_object;
908 			ra.err = restore_object(&ra, os, &drro);
909 			break;
910 		}
911 		case DRR_FREEOBJECTS:
912 		{
913 			struct drr_freeobjects drrfo =
914 			    drr->drr_u.drr_freeobjects;
915 			ra.err = restore_freeobjects(&ra, os, &drrfo);
916 			break;
917 		}
918 		case DRR_WRITE:
919 		{
920 			struct drr_write drrw = drr->drr_u.drr_write;
921 			ra.err = restore_write(&ra, os, &drrw);
922 			break;
923 		}
924 		case DRR_FREE:
925 		{
926 			struct drr_free drrf = drr->drr_u.drr_free;
927 			ra.err = restore_free(&ra, os, &drrf);
928 			break;
929 		}
930 		case DRR_END:
931 		{
932 			struct drr_end drre = drr->drr_u.drr_end;
933 			/*
934 			 * We compare against the *previous* checksum
935 			 * value, because the stored checksum is of
936 			 * everything before the DRR_END record.
937 			 */
938 			if (!ZIO_CHECKSUM_EQUAL(drre.drr_checksum, pcksum))
939 				ra.err = ECKSUM;
940 			goto out;
941 		}
942 		default:
943 			ra.err = EINVAL;
944 			goto out;
945 		}
946 		pcksum = ra.cksum;
947 	}
948 	ASSERT(ra.err != 0);
949 
950 out:
951 	if (ra.err != 0) {
952 		/*
953 		 * destroy what we created, so we don't leave it in the
954 		 * inconsistent restoring state.
955 		 */
956 		txg_wait_synced(drc->drc_real_ds->ds_dir->dd_pool, 0);
957 
958 		(void) dsl_dataset_destroy(drc->drc_real_ds, dmu_recv_tag,
959 		    B_FALSE);
960 		if (drc->drc_real_ds != drc->drc_logical_ds) {
961 			mutex_exit(&drc->drc_logical_ds->ds_recvlock);
962 			dsl_dataset_rele(drc->drc_logical_ds, dmu_recv_tag);
963 		}
964 	}
965 
966 	kmem_free(ra.buf, ra.bufsize);
967 	*voffp = ra.voff;
968 	return (ra.err);
969 }
970 
971 struct recvendsyncarg {
972 	char *tosnap;
973 	uint64_t creation_time;
974 	uint64_t toguid;
975 };
976 
977 static int
978 recv_end_check(void *arg1, void *arg2, dmu_tx_t *tx)
979 {
980 	dsl_dataset_t *ds = arg1;
981 	struct recvendsyncarg *resa = arg2;
982 
983 	return (dsl_dataset_snapshot_check(ds, resa->tosnap, tx));
984 }
985 
986 static void
987 recv_end_sync(void *arg1, void *arg2, cred_t *cr, dmu_tx_t *tx)
988 {
989 	dsl_dataset_t *ds = arg1;
990 	struct recvendsyncarg *resa = arg2;
991 
992 	dsl_dataset_snapshot_sync(ds, resa->tosnap, cr, tx);
993 
994 	/* set snapshot's creation time and guid */
995 	dmu_buf_will_dirty(ds->ds_prev->ds_dbuf, tx);
996 	ds->ds_prev->ds_phys->ds_creation_time = resa->creation_time;
997 	ds->ds_prev->ds_phys->ds_guid = resa->toguid;
998 	ds->ds_prev->ds_phys->ds_flags &= ~DS_FLAG_INCONSISTENT;
999 
1000 	dmu_buf_will_dirty(ds->ds_dbuf, tx);
1001 	ds->ds_phys->ds_flags &= ~DS_FLAG_INCONSISTENT;
1002 }
1003 
1004 static int
1005 dmu_recv_existing_end(dmu_recv_cookie_t *drc)
1006 {
1007 	struct recvendsyncarg resa;
1008 	dsl_dataset_t *ds = drc->drc_logical_ds;
1009 	int err;
1010 
1011 	/*
1012 	 * XXX hack; seems the ds is still dirty and dsl_pool_zil_clean()
1013 	 * expects it to have a ds_user_ptr (and zil), but clone_swap()
1014 	 * can close it.
1015 	 */
1016 	txg_wait_synced(ds->ds_dir->dd_pool, 0);
1017 
1018 	if (dsl_dataset_tryown(ds, FALSE, dmu_recv_tag)) {
1019 		err = dsl_dataset_clone_swap(drc->drc_real_ds, ds,
1020 		    drc->drc_force);
1021 		if (err)
1022 			goto out;
1023 	} else {
1024 		mutex_exit(&ds->ds_recvlock);
1025 		dsl_dataset_rele(ds, dmu_recv_tag);
1026 		(void) dsl_dataset_destroy(drc->drc_real_ds, dmu_recv_tag,
1027 		    B_FALSE);
1028 		return (EBUSY);
1029 	}
1030 
1031 	resa.creation_time = drc->drc_drrb->drr_creation_time;
1032 	resa.toguid = drc->drc_drrb->drr_toguid;
1033 	resa.tosnap = drc->drc_tosnap;
1034 
1035 	err = dsl_sync_task_do(ds->ds_dir->dd_pool,
1036 	    recv_end_check, recv_end_sync, ds, &resa, 3);
1037 	if (err) {
1038 		/* swap back */
1039 		(void) dsl_dataset_clone_swap(drc->drc_real_ds, ds, B_TRUE);
1040 	}
1041 
1042 out:
1043 	mutex_exit(&ds->ds_recvlock);
1044 	dsl_dataset_disown(ds, dmu_recv_tag);
1045 	(void) dsl_dataset_destroy(drc->drc_real_ds, dmu_recv_tag, B_FALSE);
1046 	return (err);
1047 }
1048 
1049 static int
1050 dmu_recv_new_end(dmu_recv_cookie_t *drc)
1051 {
1052 	struct recvendsyncarg resa;
1053 	dsl_dataset_t *ds = drc->drc_logical_ds;
1054 	int err;
1055 
1056 	/*
1057 	 * XXX hack; seems the ds is still dirty and dsl_pool_zil_clean()
1058 	 * expects it to have a ds_user_ptr (and zil), but clone_swap()
1059 	 * can close it.
1060 	 */
1061 	txg_wait_synced(ds->ds_dir->dd_pool, 0);
1062 
1063 	resa.creation_time = drc->drc_drrb->drr_creation_time;
1064 	resa.toguid = drc->drc_drrb->drr_toguid;
1065 	resa.tosnap = drc->drc_tosnap;
1066 
1067 	err = dsl_sync_task_do(ds->ds_dir->dd_pool,
1068 	    recv_end_check, recv_end_sync, ds, &resa, 3);
1069 	if (err) {
1070 		/* clean up the fs we just recv'd into */
1071 		(void) dsl_dataset_destroy(ds, dmu_recv_tag, B_FALSE);
1072 	} else {
1073 		/* release the hold from dmu_recv_begin */
1074 		dsl_dataset_disown(ds, dmu_recv_tag);
1075 	}
1076 	return (err);
1077 }
1078 
1079 int
1080 dmu_recv_end(dmu_recv_cookie_t *drc)
1081 {
1082 	if (drc->drc_logical_ds != drc->drc_real_ds)
1083 		return (dmu_recv_existing_end(drc));
1084 	else
1085 		return (dmu_recv_new_end(drc));
1086 }
1087