1 files changed, 406 insertions, 0 deletions

diff --git a/module/zfs/dmu_traverse.c b/module/zfs/dmu_traverse.c
new file mode 100644
index 000000000..512401470
--- /dev/null
+++ b/module/zfs/dmu_traverse.c
@@ -0,0 +1,406 @@
+/*
+ * 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 2008 Sun Microsystems, Inc.  All rights reserved.
+ * Use is subject to license terms.
+ */
+
+#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/dnode.h>
+#include <sys/spa.h>
+#include <sys/zio.h>
+#include <sys/dmu_impl.h>
+#include <sys/callb.h>
+
+#define	SET_BOOKMARK(zb, objset, object, level, blkid)  \
+{                                                       \
+	(zb)->zb_objset = objset;                       \
+	(zb)->zb_object = object;                       \
+	(zb)->zb_level = level;                         \
+	(zb)->zb_blkid = blkid;                         \
+}
+
+struct prefetch_data {
+	kmutex_t pd_mtx;
+	kcondvar_t pd_cv;
+	int pd_blks_max;
+	int pd_blks_fetched;
+	int pd_flags;
+	boolean_t pd_cancel;
+	boolean_t pd_exited;
+};
+
+struct traverse_data {
+	spa_t *td_spa;
+	uint64_t td_objset;
+	blkptr_t *td_rootbp;
+	uint64_t td_min_txg;
+	int td_flags;
+	struct prefetch_data *td_pfd;
+	blkptr_cb_t *td_func;
+	void *td_arg;
+};
+
+/* ARGSUSED */
+static void
+traverse_zil_block(zilog_t *zilog, blkptr_t *bp, void *arg, uint64_t claim_txg)
+{
+	struct traverse_data *td = arg;
+	zbookmark_t zb;
+
+	if (bp->blk_birth == 0)
+		return;
+
+	if (claim_txg == 0 && bp->blk_birth >= spa_first_txg(td->td_spa))
+		return;
+
+	zb.zb_objset = td->td_objset;
+	zb.zb_object = 0;
+	zb.zb_level = -1;
+	zb.zb_blkid = bp->blk_cksum.zc_word[ZIL_ZC_SEQ];
+	VERIFY(0 == td->td_func(td->td_spa, bp, &zb, NULL, td->td_arg));
+}
+
+/* ARGSUSED */
+static void
+traverse_zil_record(zilog_t *zilog, lr_t *lrc, void *arg, uint64_t claim_txg)
+{
+	struct traverse_data *td = arg;
+
+	if (lrc->lrc_txtype == TX_WRITE) {
+		lr_write_t *lr = (lr_write_t *)lrc;
+		blkptr_t *bp = &lr->lr_blkptr;
+		zbookmark_t zb;
+
+		if (bp->blk_birth == 0)
+			return;
+
+		if (claim_txg == 0 || bp->blk_birth < claim_txg)
+			return;
+
+		zb.zb_objset = td->td_objset;
+		zb.zb_object = lr->lr_foid;
+		zb.zb_level = BP_GET_LEVEL(bp);
+		zb.zb_blkid = lr->lr_offset / BP_GET_LSIZE(bp);
+		VERIFY(0 == td->td_func(td->td_spa, bp, &zb, NULL, td->td_arg));
+	}
+}
+
+static void
+traverse_zil(struct traverse_data *td, zil_header_t *zh)
+{
+	uint64_t claim_txg = zh->zh_claim_txg;
+	zilog_t *zilog;
+
+	/*
+	 * We only want to visit blocks that have been claimed but not yet
+	 * replayed (or, in read-only mode, blocks that *would* be claimed).
+	 */
+	if (claim_txg == 0 && (spa_mode & FWRITE))
+		return;
+
+	zilog = zil_alloc(spa_get_dsl(td->td_spa)->dp_meta_objset, zh);
+
+	(void) zil_parse(zilog, traverse_zil_block, traverse_zil_record, td,
+	    claim_txg);
+
+	zil_free(zilog);
+}
+
+static int
+traverse_visitbp(struct traverse_data *td, const dnode_phys_t *dnp,
+    arc_buf_t *pbuf, blkptr_t *bp, const zbookmark_t *zb)
+{
+	zbookmark_t czb;
+	int err = 0;
+	arc_buf_t *buf = NULL;
+	struct prefetch_data *pd = td->td_pfd;
+
+	if (bp->blk_birth == 0) {
+		err = td->td_func(td->td_spa, NULL, zb, dnp, td->td_arg);
+		return (err);
+	}
+
+	if (bp->blk_birth <= td->td_min_txg)
+		return (0);
+
+	if (pd && !pd->pd_exited &&
+	    ((pd->pd_flags & TRAVERSE_PREFETCH_DATA) ||
+	    BP_GET_TYPE(bp) == DMU_OT_DNODE || BP_GET_LEVEL(bp) > 0)) {
+		mutex_enter(&pd->pd_mtx);
+		ASSERT(pd->pd_blks_fetched >= 0);
+		while (pd->pd_blks_fetched == 0 && !pd->pd_exited)
+			cv_wait(&pd->pd_cv, &pd->pd_mtx);
+		pd->pd_blks_fetched--;
+		cv_broadcast(&pd->pd_cv);
+		mutex_exit(&pd->pd_mtx);
+	}
+
+	if (td->td_flags & TRAVERSE_PRE) {
+		err = td->td_func(td->td_spa, bp, zb, dnp, td->td_arg);
+		if (err)
+			return (err);
+	}
+
+	if (BP_GET_LEVEL(bp) > 0) {
+		uint32_t flags = ARC_WAIT;
+		int i;
+		blkptr_t *cbp;
+		int epb = BP_GET_LSIZE(bp) >> SPA_BLKPTRSHIFT;
+
+		err = arc_read(NULL, td->td_spa, bp, pbuf,
+		    arc_getbuf_func, &buf,
+		    ZIO_PRIORITY_ASYNC_READ, ZIO_FLAG_CANFAIL, &flags, zb);
+		if (err)
+			return (err);
+
+		/* recursively visitbp() blocks below this */
+		cbp = buf->b_data;
+		for (i = 0; i < epb; i++, cbp++) {
+			SET_BOOKMARK(&czb, zb->zb_objset, zb->zb_object,
+			    zb->zb_level - 1,
+			    zb->zb_blkid * epb + i);
+			err = traverse_visitbp(td, dnp, buf, cbp, &czb);
+			if (err)
+				break;
+		}
+	} else if (BP_GET_TYPE(bp) == DMU_OT_DNODE) {
+		uint32_t flags = ARC_WAIT;
+		int i, j;
+		int epb = BP_GET_LSIZE(bp) >> DNODE_SHIFT;
+
+		err = arc_read(NULL, td->td_spa, bp, pbuf,
+		    arc_getbuf_func, &buf,
+		    ZIO_PRIORITY_ASYNC_READ, ZIO_FLAG_CANFAIL, &flags, zb);
+		if (err)
+			return (err);
+
+		/* recursively visitbp() blocks below this */
+		dnp = buf->b_data;
+		for (i = 0; i < epb && err == 0; i++, dnp++) {
+			for (j = 0; j < dnp->dn_nblkptr; j++) {
+				SET_BOOKMARK(&czb, zb->zb_objset,
+				    zb->zb_blkid * epb + i,
+				    dnp->dn_nlevels - 1, j);
+				err = traverse_visitbp(td, dnp, buf,
+				    (blkptr_t *)&dnp->dn_blkptr[j], &czb);
+				if (err)
+					break;
+			}
+		}
+	} else if (BP_GET_TYPE(bp) == DMU_OT_OBJSET) {
+		uint32_t flags = ARC_WAIT;
+		objset_phys_t *osp;
+		int j;
+
+		err = arc_read_nolock(NULL, td->td_spa, bp,
+		    arc_getbuf_func, &buf,
+		    ZIO_PRIORITY_ASYNC_READ, ZIO_FLAG_CANFAIL, &flags, zb);
+		if (err)
+			return (err);
+
+		osp = buf->b_data;
+		/*
+		 * traverse_zil is just here for zdb's leak checking.
+		 * For other consumers, there will be no ZIL blocks.
+		 */
+		traverse_zil(td, &osp->os_zil_header);
+
+		for (j = 0; j < osp->os_meta_dnode.dn_nblkptr; j++) {
+			SET_BOOKMARK(&czb, zb->zb_objset, 0,
+			    osp->os_meta_dnode.dn_nlevels - 1, j);
+			err = traverse_visitbp(td, &osp->os_meta_dnode, buf,
+			    (blkptr_t *)&osp->os_meta_dnode.dn_blkptr[j],
+			    &czb);
+			if (err)
+				break;
+		}
+	}
+
+	if (buf)
+		(void) arc_buf_remove_ref(buf, &buf);
+
+	if (err == 0 && (td->td_flags & TRAVERSE_POST))
+		err = td->td_func(td->td_spa, bp, zb, dnp, td->td_arg);
+
+	return (err);
+}
+
+/* ARGSUSED */
+static int
+traverse_prefetcher(spa_t *spa, blkptr_t *bp, const zbookmark_t *zb,
+    const dnode_phys_t *dnp, void *arg)
+{
+	struct prefetch_data *pfd = arg;
+	uint32_t aflags = ARC_NOWAIT | ARC_PREFETCH;
+
+	ASSERT(pfd->pd_blks_fetched >= 0);
+	if (pfd->pd_cancel)
+		return (EINTR);
+
+	if (bp == NULL || !((pfd->pd_flags & TRAVERSE_PREFETCH_DATA) ||
+	    BP_GET_TYPE(bp) == DMU_OT_DNODE || BP_GET_LEVEL(bp) > 0))
+		return (0);
+
+	mutex_enter(&pfd->pd_mtx);
+	while (!pfd->pd_cancel && pfd->pd_blks_fetched >= pfd->pd_blks_max)
+		cv_wait(&pfd->pd_cv, &pfd->pd_mtx);
+	pfd->pd_blks_fetched++;
+	cv_broadcast(&pfd->pd_cv);
+	mutex_exit(&pfd->pd_mtx);
+
+	(void) arc_read_nolock(NULL, spa, bp, NULL, NULL,
+	    ZIO_PRIORITY_ASYNC_READ,
+	    ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE,
+	    &aflags, zb);
+
+	return (0);
+}
+
+static void
+traverse_prefetch_thread(void *arg)
+{
+	struct traverse_data *td_main = arg;
+	struct traverse_data td = *td_main;
+	zbookmark_t czb;
+
+	td.td_func = traverse_prefetcher;
+	td.td_arg = td_main->td_pfd;
+	td.td_pfd = NULL;
+
+	SET_BOOKMARK(&czb, td.td_objset, 0, -1, 0);
+	(void) traverse_visitbp(&td, NULL, NULL, td.td_rootbp, &czb);
+
+	mutex_enter(&td_main->td_pfd->pd_mtx);
+	td_main->td_pfd->pd_exited = B_TRUE;
+	cv_broadcast(&td_main->td_pfd->pd_cv);
+	mutex_exit(&td_main->td_pfd->pd_mtx);
+}
+
+/*
+ * NB: dataset must not be changing on-disk (eg, is a snapshot or we are
+ * in syncing context).
+ */
+static int
+traverse_impl(spa_t *spa, uint64_t objset, blkptr_t *rootbp,
+    uint64_t txg_start, int flags, blkptr_cb_t func, void *arg)
+{
+	struct traverse_data td;
+	struct prefetch_data pd = { 0 };
+	zbookmark_t czb;
+	int err;
+
+	td.td_spa = spa;
+	td.td_objset = objset;
+	td.td_rootbp = rootbp;
+	td.td_min_txg = txg_start;
+	td.td_func = func;
+	td.td_arg = arg;
+	td.td_pfd = &pd;
+	td.td_flags = flags;
+
+	pd.pd_blks_max = 100;
+	pd.pd_flags = flags;
+	mutex_init(&pd.pd_mtx, NULL, MUTEX_DEFAULT, NULL);
+	cv_init(&pd.pd_cv, NULL, CV_DEFAULT, NULL);
+
+	if (!(flags & TRAVERSE_PREFETCH) ||
+	    0 == taskq_dispatch(system_taskq, traverse_prefetch_thread,
+	    &td, TQ_NOQUEUE))
+		pd.pd_exited = B_TRUE;
+
+	SET_BOOKMARK(&czb, objset, 0, -1, 0);
+	err = traverse_visitbp(&td, NULL, NULL, rootbp, &czb);
+
+	mutex_enter(&pd.pd_mtx);
+	pd.pd_cancel = B_TRUE;
+	cv_broadcast(&pd.pd_cv);
+	while (!pd.pd_exited)
+		cv_wait(&pd.pd_cv, &pd.pd_mtx);
+	mutex_exit(&pd.pd_mtx);
+
+	mutex_destroy(&pd.pd_mtx);
+	cv_destroy(&pd.pd_cv);
+
+	return (err);
+}
+
+/*
+ * NB: dataset must not be changing on-disk (eg, is a snapshot or we are
+ * in syncing context).
+ */
+int
+traverse_dataset(dsl_dataset_t *ds, uint64_t txg_start, int flags,
+    blkptr_cb_t func, void *arg)
+{
+	return (traverse_impl(ds->ds_dir->dd_pool->dp_spa, ds->ds_object,
+	    &ds->ds_phys->ds_bp, txg_start, flags, func, arg));
+}
+
+/*
+ * NB: pool must not be changing on-disk (eg, from zdb or sync context).
+ */
+int
+traverse_pool(spa_t *spa, blkptr_cb_t func, void *arg)
+{
+	int err;
+	uint64_t obj;
+	dsl_pool_t *dp = spa_get_dsl(spa);
+	objset_t *mos = dp->dp_meta_objset;
+
+	/* visit the MOS */
+	err = traverse_impl(spa, 0, spa_get_rootblkptr(spa),
+	    0, TRAVERSE_PRE, func, arg);
+	if (err)
+		return (err);
+
+	/* visit each dataset */
+	for (obj = 1; err == 0; err = dmu_object_next(mos, &obj, FALSE, 0)) {
+		dmu_object_info_t doi;
+
+		err = dmu_object_info(mos, obj, &doi);
+		if (err)
+			return (err);
+
+		if (doi.doi_type == DMU_OT_DSL_DATASET) {
+			dsl_dataset_t *ds;
+			rw_enter(&dp->dp_config_rwlock, RW_READER);
+			err = dsl_dataset_hold_obj(dp, obj, FTAG, &ds);
+			rw_exit(&dp->dp_config_rwlock);
+			if (err)
+				return (err);
+			err = traverse_dataset(ds,
+			    ds->ds_phys->ds_prev_snap_txg, TRAVERSE_PRE,
+			    func, arg);
+			dsl_dataset_rele(ds, FTAG);
+			if (err)
+				return (err);
+		}
+	}
+	if (err == ESRCH)
+		err = 0;
+	return (err);
+}