[mirror_zfs-debian.git] / module / zfs / dmu_diff.c

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved.
 * Copyright (c) 2012, 2015 by Delphix. All rights reserved.
 */

#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>
#include <sys/zfs_znode.h>

struct diffarg {
	struct vnode *da_vp;		/* file to which we are reporting */
	offset_t *da_offp;
	int da_err;			/* error that stopped diff search */
	dmu_diff_record_t da_ddr;
};

static int
write_record(struct diffarg *da)
{
	ssize_t resid; /* have to get resid to get detailed errno */

	if (da->da_ddr.ddr_type == DDR_NONE) {
		da->da_err = 0;
		return (0);
	}

	da->da_err = vn_rdwr(UIO_WRITE, da->da_vp, (caddr_t)&da->da_ddr,
	    sizeof (da->da_ddr), 0, UIO_SYSSPACE, FAPPEND,
	    RLIM64_INFINITY, CRED(), &resid);
	*da->da_offp += sizeof (da->da_ddr);
	return (da->da_err);
}

static int
report_free_dnode_range(struct diffarg *da, uint64_t first, uint64_t last)
{
	ASSERT(first <= last);
	if (da->da_ddr.ddr_type != DDR_FREE ||
	    first != da->da_ddr.ddr_last + 1) {
		if (write_record(da) != 0)
			return (da->da_err);
		da->da_ddr.ddr_type = DDR_FREE;
		da->da_ddr.ddr_first = first;
		da->da_ddr.ddr_last = last;
		return (0);
	}
	da->da_ddr.ddr_last = last;
	return (0);
}

static int
report_dnode(struct diffarg *da, uint64_t object, dnode_phys_t *dnp)
{
	ASSERT(dnp != NULL);
	if (dnp->dn_type == DMU_OT_NONE)
		return (report_free_dnode_range(da, object, object));

	if (da->da_ddr.ddr_type != DDR_INUSE ||
	    object != da->da_ddr.ddr_last + 1) {
		if (write_record(da) != 0)
			return (da->da_err);
		da->da_ddr.ddr_type = DDR_INUSE;
		da->da_ddr.ddr_first = da->da_ddr.ddr_last = object;
		return (0);
	}
	da->da_ddr.ddr_last = object;
	return (0);
}

#define	DBP_SPAN(dnp, level)				  \
	(((uint64_t)dnp->dn_datablkszsec) << (SPA_MINBLOCKSHIFT + \
	(level) * (dnp->dn_indblkshift - SPA_BLKPTRSHIFT)))

/* ARGSUSED */
static int
diff_cb(spa_t *spa, zilog_t *zilog, const blkptr_t *bp,
    const zbookmark_phys_t *zb, const dnode_phys_t *dnp, void *arg)
{
	struct diffarg *da = arg;
	int err = 0;

	if (issig(JUSTLOOKING) && issig(FORREAL))
		return (SET_ERROR(EINTR));

	if (bp == NULL || zb->zb_object != DMU_META_DNODE_OBJECT)
		return (0);

	if (BP_IS_HOLE(bp)) {
		uint64_t span = DBP_SPAN(dnp, zb->zb_level);
		uint64_t dnobj = (zb->zb_blkid * span) >> DNODE_SHIFT;

		err = report_free_dnode_range(da, dnobj,
		    dnobj + (span >> DNODE_SHIFT) - 1);
		if (err)
			return (err);
	} else if (zb->zb_level == 0) {
		dnode_phys_t *blk;
		arc_buf_t *abuf;
		arc_flags_t aflags = ARC_FLAG_WAIT;
		int blksz = BP_GET_LSIZE(bp);
		int i;

		if (arc_read(NULL, spa, bp, arc_getbuf_func, &abuf,
		    ZIO_PRIORITY_ASYNC_READ, ZIO_FLAG_CANFAIL,
		    &aflags, zb) != 0)
			return (SET_ERROR(EIO));

		blk = abuf->b_data;
		for (i = 0; i < blksz >> DNODE_SHIFT; i++) {
			uint64_t dnobj = (zb->zb_blkid <<
			    (DNODE_BLOCK_SHIFT - DNODE_SHIFT)) + i;
			err = report_dnode(da, dnobj, blk+i);
			if (err)
				break;
		}
		arc_buf_destroy(abuf, &abuf);
		if (err)
			return (err);
		/* Don't care about the data blocks */
		return (TRAVERSE_VISIT_NO_CHILDREN);
	}
	return (0);
}

int
dmu_diff(const char *tosnap_name, const char *fromsnap_name,
    struct vnode *vp, offset_t *offp)
{
	struct diffarg da;
	dsl_dataset_t *fromsnap;
	dsl_dataset_t *tosnap;
	dsl_pool_t *dp;
	int error;
	uint64_t fromtxg;

	if (strchr(tosnap_name, '@') == NULL ||
	    strchr(fromsnap_name, '@') == NULL)
		return (SET_ERROR(EINVAL));

	error = dsl_pool_hold(tosnap_name, FTAG, &dp);
	if (error != 0)
		return (error);

	error = dsl_dataset_hold(dp, tosnap_name, FTAG, &tosnap);
	if (error != 0) {
		dsl_pool_rele(dp, FTAG);
		return (error);
	}

	error = dsl_dataset_hold(dp, fromsnap_name, FTAG, &fromsnap);
	if (error != 0) {
		dsl_dataset_rele(tosnap, FTAG);
		dsl_pool_rele(dp, FTAG);
		return (error);
	}

	if (!dsl_dataset_is_before(tosnap, fromsnap, 0)) {
		dsl_dataset_rele(fromsnap, FTAG);
		dsl_dataset_rele(tosnap, FTAG);
		dsl_pool_rele(dp, FTAG);
		return (SET_ERROR(EXDEV));
	}

	fromtxg = dsl_dataset_phys(fromsnap)->ds_creation_txg;
	dsl_dataset_rele(fromsnap, FTAG);

	dsl_dataset_long_hold(tosnap, FTAG);
	dsl_pool_rele(dp, FTAG);

	da.da_vp = vp;
	da.da_offp = offp;
	da.da_ddr.ddr_type = DDR_NONE;
	da.da_ddr.ddr_first = da.da_ddr.ddr_last = 0;
	da.da_err = 0;

	error = traverse_dataset(tosnap, fromtxg,
	    TRAVERSE_PRE | TRAVERSE_PREFETCH_METADATA, diff_cb, &da);

	if (error != 0) {
		da.da_err = error;
	} else {
		/* we set the da.da_err we return as side-effect */
		(void) write_record(&da);
	}

	dsl_dataset_long_rele(tosnap, FTAG);
	dsl_dataset_rele(tosnap, FTAG);

	return (da.da_err);
}
Commit	Line	Data
572e2857 BB	1	/*
	2	* CDDL HEADER START
	3	*
	4	* The contents of this file are subject to the terms of the
	5	* Common Development and Distribution License (the "License").
	6	* You may not use this file except in compliance with the License.
	7	*
	8	* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
	9	* or http://www.opensolaris.org/os/licensing.
	10	* See the License for the specific language governing permissions
	11	* and limitations under the License.
	12	*
	13	* When distributing Covered Code, include this CDDL HEADER in each
	14	* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
	15	* If applicable, add the following below this CDDL HEADER, with the
	16	* fields enclosed by brackets "[]" replaced with your own identifying
	17	* information: Portions Copyright [yyyy] [name of copyright owner]
	18	*
	19	* CDDL HEADER END
	20	*/
	21	/*
	22	* Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved.
cae5b340	23	* Copyright (c) 2012, 2015 by Delphix. All rights reserved.
572e2857 BB	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	#include <sys/zfs_znode.h>
	42
	43	struct diffarg {
	44	struct vnode da_vp; / file to which we are reporting */
	45	offset_t *da_offp;
	46	int da_err; /* error that stopped diff search */
	47	dmu_diff_record_t da_ddr;
	48	};
	49
	50	static int
	51	write_record(struct diffarg *da)
	52	{
	53	ssize_t resid; /* have to get resid to get detailed errno */
	54
	55	if (da->da_ddr.ddr_type == DDR_NONE) {
	56	da->da_err = 0;
	57	return (0);
	58	}
	59
	60	da->da_err = vn_rdwr(UIO_WRITE, da->da_vp, (caddr_t)&da->da_ddr,
	61	sizeof (da->da_ddr), 0, UIO_SYSSPACE, FAPPEND,
	62	RLIM64_INFINITY, CRED(), &resid);
	63	*da->da_offp += sizeof (da->da_ddr);
	64	return (da->da_err);
	65	}
	66
	67	static int
	68	report_free_dnode_range(struct diffarg *da, uint64_t first, uint64_t last)
	69	{
	70	ASSERT(first <= last);
	71	if (da->da_ddr.ddr_type != DDR_FREE \|\|
	72	first != da->da_ddr.ddr_last + 1) {
	73	if (write_record(da) != 0)
	74	return (da->da_err);
	75	da->da_ddr.ddr_type = DDR_FREE;
	76	da->da_ddr.ddr_first = first;
	77	da->da_ddr.ddr_last = last;
	78	return (0);
	79	}
	80	da->da_ddr.ddr_last = last;
	81	return (0);
	82	}
	83
	84	static int
	85	report_dnode(struct diffarg da, uint64_t object, dnode_phys_t dnp)
	86	{
	87	ASSERT(dnp != NULL);
88	if (dnp->dn_type == DMU_OT_NONE)
89	return (report_free_dnode_range(da, object, object));
90
91	if (da->da_ddr.ddr_type != DDR_INUSE \|\|
92	object != da->da_ddr.ddr_last + 1) {
93	if (write_record(da) != 0)
94	return (da->da_err);
95	da->da_ddr.ddr_type = DDR_INUSE;
96	da->da_ddr.ddr_first = da->da_ddr.ddr_last = object;
97	return (0);
98	}
99	da->da_ddr.ddr_last = object;
100	return (0);
101	}
102
103	#define DBP_SPAN(dnp, level) \
104	(((uint64_t)dnp->dn_datablkszsec) << (SPA_MINBLOCKSHIFT + \
105	(level) * (dnp->dn_indblkshift - SPA_BLKPTRSHIFT)))
106
107	/* ARGSUSED */
108	static int
c06d4368	109	diff_cb(spa_t spa, zilog_t zilog, const blkptr_t *bp,
ea04106b	110	const zbookmark_phys_t zb, const dnode_phys_t dnp, void *arg)
572e2857 BB	111	{
	112	struct diffarg *da = arg;
	113	int err = 0;
	114
	115	if (issig(JUSTLOOKING) && issig(FORREAL))
a08ee875	116	return (SET_ERROR(EINTR));
572e2857	117
cae5b340	118	if (bp == NULL \|\| zb->zb_object != DMU_META_DNODE_OBJECT)
572e2857 BB	119	return (0);
572e2857 BB	120
ea04106b	121	if (BP_IS_HOLE(bp)) {
572e2857 BB	122	uint64_t span = DBP_SPAN(dnp, zb->zb_level);
	123	uint64_t dnobj = (zb->zb_blkid * span) >> DNODE_SHIFT;
	124
	125	err = report_free_dnode_range(da, dnobj,
	126	dnobj + (span >> DNODE_SHIFT) - 1);
	127	if (err)
	128	return (err);
	129	} else if (zb->zb_level == 0) {
	130	dnode_phys_t *blk;
	131	arc_buf_t *abuf;
e10b0808	132	arc_flags_t aflags = ARC_FLAG_WAIT;
572e2857 BB	133	int blksz = BP_GET_LSIZE(bp);
	134	int i;
	135
c06d4368 AX	136	if (arc_read(NULL, spa, bp, arc_getbuf_func, &abuf,
	137	ZIO_PRIORITY_ASYNC_READ, ZIO_FLAG_CANFAIL,
	138	&aflags, zb) != 0)
a08ee875	139	return (SET_ERROR(EIO));
572e2857 BB	140
	141	blk = abuf->b_data;
	142	for (i = 0; i < blksz >> DNODE_SHIFT; i++) {
	143	uint64_t dnobj = (zb->zb_blkid <<
	144	(DNODE_BLOCK_SHIFT - DNODE_SHIFT)) + i;
	145	err = report_dnode(da, dnobj, blk+i);
	146	if (err)
	147	break;
	148	}
cae5b340	149	arc_buf_destroy(abuf, &abuf);
572e2857 BB	150	if (err)
	151	return (err);
	152	/* Don't care about the data blocks */
	153	return (TRAVERSE_VISIT_NO_CHILDREN);
	154	}
	155	return (0);
	156	}
	157
	158	int
a08ee875 LG	159	dmu_diff(const char tosnap_name, const char fromsnap_name,
a08ee875 LG	160	struct vnode vp, offset_t offp)
572e2857 BB	161	{
572e2857 BB	162	struct diffarg da;
a08ee875 LG	163	dsl_dataset_t *fromsnap;
	164	dsl_dataset_t *tosnap;
	165	dsl_pool_t *dp;
	166	int error;
	167	uint64_t fromtxg;
	168
	169	if (strchr(tosnap_name, '@') == NULL \|\|
	170	strchr(fromsnap_name, '@') == NULL)
	171	return (SET_ERROR(EINVAL));
	172
	173	error = dsl_pool_hold(tosnap_name, FTAG, &dp);
	174	if (error != 0)
	175	return (error);
	176
	177	error = dsl_dataset_hold(dp, tosnap_name, FTAG, &tosnap);
	178	if (error != 0) {
	179	dsl_pool_rele(dp, FTAG);
	180	return (error);
	181	}
572e2857	182
a08ee875 LG	183	error = dsl_dataset_hold(dp, fromsnap_name, FTAG, &fromsnap);
	184	if (error != 0) {
	185	dsl_dataset_rele(tosnap, FTAG);
	186	dsl_pool_rele(dp, FTAG);
	187	return (error);
	188	}
572e2857	189
ea04106b	190	if (!dsl_dataset_is_before(tosnap, fromsnap, 0)) {
a08ee875 LG	191	dsl_dataset_rele(fromsnap, FTAG);
	192	dsl_dataset_rele(tosnap, FTAG);
	193	dsl_pool_rele(dp, FTAG);
	194	return (SET_ERROR(EXDEV));
572e2857 BB	195	}
572e2857 BB	196
e10b0808	197	fromtxg = dsl_dataset_phys(fromsnap)->ds_creation_txg;
a08ee875 LG	198	dsl_dataset_rele(fromsnap, FTAG);
	199
	200	dsl_dataset_long_hold(tosnap, FTAG);
	201	dsl_pool_rele(dp, FTAG);
572e2857 BB	202
	203	da.da_vp = vp;
	204	da.da_offp = offp;
	205	da.da_ddr.ddr_type = DDR_NONE;
	206	da.da_ddr.ddr_first = da.da_ddr.ddr_last = 0;
	207	da.da_err = 0;
	208
a08ee875	209	error = traverse_dataset(tosnap, fromtxg,
572e2857 BB	210	TRAVERSE_PRE \| TRAVERSE_PREFETCH_METADATA, diff_cb, &da);
572e2857 BB	211
a08ee875 LG	212	if (error != 0) {
a08ee875 LG	213	da.da_err = error;
572e2857 BB	214	} else {
	215	/* we set the da.da_err we return as side-effect */
	216	(void) write_record(&da);
	217	}
	218
a08ee875 LG	219	dsl_dataset_long_rele(tosnap, FTAG);
	220	dsl_dataset_rele(tosnap, FTAG);
	221
572e2857 BB	222	return (da.da_err);
572e2857 BB	223	}