9 files changed, 368 insertions, 8 deletions

diff --git a/sys/cddl/compat/opensolaris/sys/kstat.h b/sys/cddl/compat/opensolaris/sys/kstat.h
index 0d199f2acbbf..8757030c7d65 100644
--- a/sys/cddl/compat/opensolaris/sys/kstat.h
+++ b/sys/cddl/compat/opensolaris/sys/kstat.h
@@ -31,7 +31,18 @@
 
 #include <sys/sysctl.h>
 
-#define	KSTAT_TYPE_NAMED	1
+#define	KSTAT_TYPE_RAW		0	/* can be anything */
+					/* ks_ndata >= 1 */
+#define	KSTAT_TYPE_NAMED	1	/* name/value pair */
+					/* ks_ndata >= 1 */
+#define	KSTAT_TYPE_INTR		2	/* interrupt statistics */
+					/* ks_ndata == 1 */
+#define	KSTAT_TYPE_IO		3	/* I/O statistics */
+					/* ks_ndata == 1 */
+#define	KSTAT_TYPE_TIMER	4	/* event timer */
+					/* ks_ndata >= 1 */
+
+#define	KSTAT_NUM_TYPES		5
 
 #define	KSTAT_FLAG_VIRTUAL	0x01
 
diff --git a/sys/cddl/contrib/opensolaris/uts/common/Makefile.files b/sys/cddl/contrib/opensolaris/uts/common/Makefile.files
index 27c5fa6e06d0..a38e1bcebd22 100644
--- a/sys/cddl/contrib/opensolaris/uts/common/Makefile.files
+++ b/sys/cddl/contrib/opensolaris/uts/common/Makefile.files
@@ -72,6 +72,7 @@ ZFS_COMMON_OBJS +=		\
 	bqueue.o		\
 	cityhash.o		\
 	dbuf.o			\
+	dbuf_stats.o		\
 	ddt.o			\
 	ddt_zap.o		\
 	dmu.o			\
diff --git a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/arc.c b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/arc.c
index bb9b55cfee6e..ca4331bccb76 100644
--- a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/arc.c
+++ b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/arc.c
@@ -523,6 +523,10 @@ typedef struct arc_state {
 	 * non-evictable, ARC_BUFC_DATA, and ARC_BUFC_METADATA.
 	 */
 	refcount_t arcs_size;
+	/*
+	 * supports the "dbufs" kstat
+	 */
+	arc_state_type_t arcs_state;
 } arc_state_t;
 
 /*
@@ -1111,6 +1115,11 @@ typedef struct l1arc_buf_hdr {
 
 	/* updated atomically */
 	clock_t			b_arc_access;
+	uint32_t		b_mru_hits;
+	uint32_t		b_mru_ghost_hits;
+	uint32_t		b_mfu_hits;
+	uint32_t		b_mfu_ghost_hits;
+	uint32_t		b_l2_hits;
 
 	/* self protecting */
 	refcount_t		b_refcnt;
@@ -1125,6 +1134,7 @@ typedef struct l2arc_buf_hdr {
 	/* protected by arc_buf_hdr mutex */
 	l2arc_dev_t		*b_dev;		/* L2ARC device */
 	uint64_t		b_daddr;	/* disk address, offset byte */
+	uint32_t		b_hits;
 
 	list_node_t		b_l2node;
 } l2arc_buf_hdr_t;
@@ -2552,6 +2562,55 @@ remove_reference(arc_buf_hdr_t *hdr, kmutex_t *hash_lock, void *tag)
 }
 
 /*
+ * Returns detailed information about a specific arc buffer.  When the
+ * state_index argument is set the function will calculate the arc header
+ * list position for its arc state.  Since this requires a linear traversal
+ * callers are strongly encourage not to do this.  However, it can be helpful
+ * for targeted analysis so the functionality is provided.
+ */
+void
+arc_buf_info(arc_buf_t *ab, arc_buf_info_t *abi, int state_index)
+{
+	arc_buf_hdr_t *hdr = ab->b_hdr;
+	l1arc_buf_hdr_t *l1hdr = NULL;
+	l2arc_buf_hdr_t *l2hdr = NULL;
+	arc_state_t *state = NULL;
+
+	memset(abi, 0, sizeof (arc_buf_info_t));
+
+	if (hdr == NULL)
+		return;
+
+	abi->abi_flags = hdr->b_flags;
+
+	if (HDR_HAS_L1HDR(hdr)) {
+		l1hdr = &hdr->b_l1hdr;
+		state = l1hdr->b_state;
+	}
+	if (HDR_HAS_L2HDR(hdr))
+		l2hdr = &hdr->b_l2hdr;
+
+	if (l1hdr) {
+		abi->abi_bufcnt = l1hdr->b_bufcnt;
+		abi->abi_access = l1hdr->b_arc_access;
+		abi->abi_mru_hits = l1hdr->b_mru_hits;
+		abi->abi_mru_ghost_hits = l1hdr->b_mru_ghost_hits;
+		abi->abi_mfu_hits = l1hdr->b_mfu_hits;
+		abi->abi_mfu_ghost_hits = l1hdr->b_mfu_ghost_hits;
+		abi->abi_holds = refcount_count(&l1hdr->b_refcnt);
+	}
+
+	if (l2hdr) {
+		abi->abi_l2arc_dattr = l2hdr->b_daddr;
+		abi->abi_l2arc_hits = l2hdr->b_hits;
+	}
+
+	abi->abi_state_type = state ? state->arcs_state : ARC_STATE_ANON;
+	abi->abi_state_contents = arc_buf_type(hdr);
+	abi->abi_size = arc_hdr_size(hdr);
+}
+
+/*
  * Move the supplied buffer to the indicated state. The hash lock
  * for the buffer must be held by the caller.
  */
@@ -5258,6 +5317,7 @@ arc_access(arc_buf_hdr_t *hdr, kmutex_t *hash_lock)
 			DTRACE_PROBE1(new_state__mfu, arc_buf_hdr_t *, hdr);
 			arc_change_state(arc_mfu, hdr, hash_lock);
 		}
+		atomic_inc_32(&hdr->b_l1hdr.b_mru_hits);
 		ARCSTAT_BUMP(arcstat_mru_hits);
 	} else if (hdr->b_l1hdr.b_state == arc_mru_ghost) {
 		arc_state_t	*new_state;
@@ -5283,6 +5343,7 @@ arc_access(arc_buf_hdr_t *hdr, kmutex_t *hash_lock)
 		hdr->b_l1hdr.b_arc_access = ddi_get_lbolt();
 		arc_change_state(new_state, hdr, hash_lock);
 
+		atomic_inc_32(&hdr->b_l1hdr.b_mru_ghost_hits);
 		ARCSTAT_BUMP(arcstat_mru_ghost_hits);
 	} else if (hdr->b_l1hdr.b_state == arc_mfu) {
 		/*
@@ -5295,6 +5356,7 @@ arc_access(arc_buf_hdr_t *hdr, kmutex_t *hash_lock)
 		 * the head of the list now.
 		 */
 
+		atomic_inc_32(&hdr->b_l1hdr.b_mfu_hits);
 		ARCSTAT_BUMP(arcstat_mfu_hits);
 		hdr->b_l1hdr.b_arc_access = ddi_get_lbolt();
 	} else if (hdr->b_l1hdr.b_state == arc_mfu_ghost) {
@@ -5317,6 +5379,7 @@ arc_access(arc_buf_hdr_t *hdr, kmutex_t *hash_lock)
 		DTRACE_PROBE1(new_state__mfu, arc_buf_hdr_t *, hdr);
 		arc_change_state(new_state, hdr, hash_lock);
 
+		atomic_inc_32(&hdr->b_l1hdr.b_mfu_ghost_hits);
 		ARCSTAT_BUMP(arcstat_mfu_ghost_hits);
 	} else if (hdr->b_l1hdr.b_state == arc_l2c_only) {
 		/*
@@ -5913,6 +5976,7 @@ top:
 
 				DTRACE_PROBE1(l2arc__hit, arc_buf_hdr_t *, hdr);
 				ARCSTAT_BUMP(arcstat_l2_hits);
+				atomic_inc_32(&hdr->b_l2hdr.b_hits);
 
 				cb = kmem_zalloc(sizeof (l2arc_read_callback_t),
 				    KM_SLEEP);
diff --git a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dbuf.c b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dbuf.c
index 4ff1dd5d617d..de8a553259fa 100644
--- a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dbuf.c
+++ b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dbuf.c
@@ -649,6 +649,7 @@ retry:
 	for (i = 0; i < DBUF_MUTEXES; i++)
 		mutex_init(&h->hash_mutexes[i], NULL, MUTEX_DEFAULT, NULL);
 
+	dbuf_stats_init(h);
 	/*
 	 * Setup the parameters for the dbuf caches. We set the sizes of the
 	 * dbuf cache and the metadata cache to 1/32nd and 1/16th (default)
@@ -693,6 +694,8 @@ dbuf_fini(void)
 	dbuf_hash_table_t *h = &dbuf_hash_table;
 	int i;
 
+	dbuf_stats_destroy();
+
 	for (i = 0; i < DBUF_MUTEXES; i++)
 		mutex_destroy(&h->hash_mutexes[i]);
 	kmem_free(h->hash_table, (h->hash_table_mask + 1) * sizeof (void *));
diff --git a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dbuf_stats.c b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dbuf_stats.c
new file mode 100644
index 000000000000..1d1ba4edfa07
--- /dev/null
+++ b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dbuf_stats.c
@@ -0,0 +1,242 @@
+/*
+ * 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
+ */
+
+#include <sys/zfs_context.h>
+#include <sys/dbuf.h>
+#include <sys/dmu_objset.h>
+
+/*
+ * Calculate the index of the arc header for the state, disabled by default.
+ */
+int zfs_dbuf_state_index = 0;
+
+/*
+ * ==========================================================================
+ * Dbuf Hash Read Routines
+ * ==========================================================================
+ */
+typedef struct dbuf_stats_t {
+	kmutex_t		lock;
+	kstat_t			*kstat;
+	dbuf_hash_table_t	*hash;
+	int			idx;
+} dbuf_stats_t;
+
+static dbuf_stats_t dbuf_stats_hash_table;
+
+static int
+dbuf_stats_hash_table_headers(char *buf, size_t size)
+{
+	size = snprintf(buf, size - 1,
+	    "%-88s | %-124s | %s\n"
+	    "%-16s %-8s %-8s %-8s %-8s %-8s %-8s %-5s %-5s %5s | "
+	    "%-5s %-5s %-6s %-8s %-6s %-8s %-12s "
+	    "%-6s %-6s %-6s %-6s %-6s %-8s %-8s %-8s %-5s | "
+	    "%-6s %-6s %-8s %-8s %-6s %-6s %-5s %-8s %-8s\n",
+	    "dbuf", "arcbuf", "dnode", "pool", "objset", "object", "level",
+	    "blkid", "offset", "dbsize", "meta", "state", "dbholds", "list",
+	    "atype", "index", "flags", "count", "asize", "access", "mru", "gmru",
+	    "mfu", "gmfu", "l2", "l2_dattr", "l2_asize", "l2_comp", "aholds",
+	    "dtype", "btype", "data_bs", "meta_bs", "bsize",
+	    "lvls", "dholds", "blocks", "dsize");
+        buf[size] = '\0';
+
+	return (0);
+}
+
+int
+__dbuf_stats_hash_table_data(char *buf, size_t size, dmu_buf_impl_t *db)
+{
+	arc_buf_info_t abi = { 0 };
+	dmu_object_info_t doi = { 0 };
+	dnode_t *dn = DB_DNODE(db);
+
+	if (db->db_buf)
+		arc_buf_info(db->db_buf, &abi, zfs_dbuf_state_index);
+
+	if (dn)
+		__dmu_object_info_from_dnode(dn, &doi);
+
+	size = snprintf(buf, size - 1,
+	    "%-16s %-8llu %-8lld %-8lld %-8lld %-8llu %-8llu %-5d %-5d %-5lu | "
+	    "%-5d %-5d %-6lld 0x%-6x %-6lu %-8llu %-12llu "
+	    "%-6lu %-6lu %-6lu %-6lu %-6lu %-8llu %-8llu %-8d %-5lu | "
+	    "%-6d %-6d %-8lu %-8lu %-6llu %-6lu %-5lu %-8llu %-8llu\n",
+	    /* dmu_buf_impl_t */
+	    spa_name(dn->dn_objset->os_spa),
+	    (u_longlong_t)dmu_objset_id(db->db_objset),
+	    (longlong_t)db->db.db_object,
+	    (longlong_t)db->db_level,
+	    (longlong_t)db->db_blkid,
+	    (u_longlong_t)db->db.db_offset,
+	    (u_longlong_t)db->db.db_size,
+	    !!dbuf_is_metadata(db),
+	    db->db_state,
+	    (ulong_t)refcount_count(&db->db_holds),
+	    /* arc_buf_info_t */
+	    abi.abi_state_type,
+	    abi.abi_state_contents,
+	    (longlong_t)abi.abi_state_index,
+	    abi.abi_flags,
+	    (ulong_t)abi.abi_bufcnt,
+	    (u_longlong_t)abi.abi_size,
+	    (u_longlong_t)abi.abi_access,
+	    (ulong_t)abi.abi_mru_hits,
+	    (ulong_t)abi.abi_mru_ghost_hits,
+	    (ulong_t)abi.abi_mfu_hits,
+	    (ulong_t)abi.abi_mfu_ghost_hits,
+	    (ulong_t)abi.abi_l2arc_hits,
+	    (u_longlong_t)abi.abi_l2arc_dattr,
+	    (u_longlong_t)abi.abi_l2arc_asize,
+	    abi.abi_l2arc_compress,
+	    (ulong_t)abi.abi_holds,
+	    /* dmu_object_info_t */
+	    doi.doi_type,
+	    doi.doi_bonus_type,
+	    (ulong_t)doi.doi_data_block_size,
+	    (ulong_t)doi.doi_metadata_block_size,
+	    (u_longlong_t)doi.doi_bonus_size,
+	    (ulong_t)doi.doi_indirection,
+	    (ulong_t)refcount_count(&dn->dn_holds),
+	    (u_longlong_t)doi.doi_fill_count,
+	    (u_longlong_t)doi.doi_max_offset);
+        buf[size] = '\0';
+
+	return (size);
+}
+
+static int
+dbuf_stats_hash_table_data(char *buf, size_t size, void *data)
+{
+	dbuf_stats_t *dsh = (dbuf_stats_t *)data;
+	dbuf_hash_table_t *h = dsh->hash;
+	dmu_buf_impl_t *db;
+	int length, error = 0;
+
+	ASSERT3S(dsh->idx, >=, 0);
+	ASSERT3S(dsh->idx, <=, h->hash_table_mask);
+	memset(buf, 0, size);
+
+	mutex_enter(DBUF_HASH_MUTEX(h, dsh->idx));
+	for (db = h->hash_table[dsh->idx]; db != NULL; db = db->db_hash_next) {
+		/*
+		 * Returning ENOMEM will cause the data and header functions
+		 * to be called with a larger scratch buffers.
+		 */
+		if (size < 512) {
+			error = ENOMEM;
+			break;
+		}
+
+		mutex_enter(&db->db_mtx);
+		mutex_exit(DBUF_HASH_MUTEX(h, dsh->idx));
+
+		length = __dbuf_stats_hash_table_data(buf, size, db);
+		buf += length;
+		size -= length;
+
+		mutex_exit(&db->db_mtx);
+		mutex_enter(DBUF_HASH_MUTEX(h, dsh->idx));
+	}
+	mutex_exit(DBUF_HASH_MUTEX(h, dsh->idx));
+
+	return (error);
+}
+
+static void *
+dbuf_stats_hash_table_addr(kstat_t *ksp, off_t n)
+{
+	dbuf_stats_t *dsh = ksp->ks_private;
+
+        ASSERT(MUTEX_HELD(&dsh->lock));
+
+	if (n <= dsh->hash->hash_table_mask) {
+		dsh->idx = n;
+		return (dsh);
+	}
+
+	return (NULL);
+}
+
+#ifndef __FreeBSD__
+/*
+ * XXX The FreeBSD SPL is missing support for KSTAT_TYPE_RAW
+ * we can enable this as soon as that's implemented. See the
+ * lindebugfs module for similar callback semantics.
+ */
+static void
+dbuf_stats_hash_table_init(dbuf_hash_table_t *hash)
+{
+	dbuf_stats_t *dsh = &dbuf_stats_hash_table;
+	kstat_t *ksp;
+
+	mutex_init(&dsh->lock, NULL, MUTEX_DEFAULT, NULL);
+	dsh->hash = hash;
+
+	ksp = kstat_create("zfs", 0, "dbufs", "misc",
+	    KSTAT_TYPE_RAW, 0, KSTAT_FLAG_VIRTUAL);
+	dsh->kstat = ksp;
+
+	if (ksp) {
+		ksp->ks_lock = &dsh->lock;
+		ksp->ks_ndata = UINT32_MAX;
+		ksp->ks_private = dsh;
+		kstat_set_raw_ops(ksp, dbuf_stats_hash_table_headers,
+		    dbuf_stats_hash_table_data, dbuf_stats_hash_table_addr);
+		kstat_install(ksp);
+	}
+}
+
+static void
+dbuf_stats_hash_table_destroy(void)
+{
+	dbuf_stats_t *dsh = &dbuf_stats_hash_table;
+	kstat_t *ksp;
+
+	ksp = dsh->kstat;
+	if (ksp)
+		kstat_delete(ksp);
+
+	mutex_destroy(&dsh->lock);
+}
+#else
+static void
+dbuf_stats_hash_table_init(dbuf_hash_table_t *hash)
+{
+}
+
+static void
+dbuf_stats_hash_table_destroy(void)
+{
+}
+#endif
+
+void
+dbuf_stats_init(dbuf_hash_table_t *hash)
+{
+	dbuf_stats_hash_table_init(hash);
+}
+
+void
+dbuf_stats_destroy(void)
+{
+	dbuf_stats_hash_table_destroy();
+}
diff --git a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dmu.c b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dmu.c
index abb27188697c..a0d66a99a3f0 100644
--- a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dmu.c
+++ b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dmu.c
@@ -2509,14 +2509,9 @@ dmu_object_wait_synced(objset_t *os, uint64_t object)
 }
 
 void
-dmu_object_info_from_dnode(dnode_t *dn, dmu_object_info_t *doi)
+__dmu_object_info_from_dnode(dnode_t *dn, dmu_object_info_t *doi)
 {
-	dnode_phys_t *dnp;
-
-	rw_enter(&dn->dn_struct_rwlock, RW_READER);
-	mutex_enter(&dn->dn_mtx);
-
-	dnp = dn->dn_phys;
+	dnode_phys_t *dnp = dn->dn_phys;
 
 	doi->doi_data_block_size = dn->dn_datablksz;
 	doi->doi_metadata_block_size = dn->dn_indblkshift ?
@@ -2534,6 +2529,15 @@ dmu_object_info_from_dnode(dnode_t *dn, dmu_object_info_t *doi)
 	doi->doi_fill_count = 0;
 	for (int i = 0; i < dnp->dn_nblkptr; i++)
 		doi->doi_fill_count += BP_GET_FILL(&dnp->dn_blkptr[i]);
+}
+
+void
+dmu_object_info_from_dnode(dnode_t *dn, dmu_object_info_t *doi)
+{
+	rw_enter(&dn->dn_struct_rwlock, RW_READER);
+	mutex_enter(&dn->dn_mtx);
+
+	__dmu_object_info_from_dnode(dn, doi);
 
 	mutex_exit(&dn->dn_mtx);
 	rw_exit(&dn->dn_struct_rwlock);
diff --git a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/arc.h b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/arc.h
index c7d7e523f2f3..7be5f9037dd3 100644
--- a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/arc.h
+++ b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/arc.h
@@ -185,6 +185,36 @@ typedef enum arc_space_type {
 	ARC_SPACE_NUMTYPES
 } arc_space_type_t;
 
+typedef enum arc_state_type {
+	ARC_STATE_ANON,
+	ARC_STATE_MRU,
+	ARC_STATE_MRU_GHOST,
+	ARC_STATE_MFU,
+	ARC_STATE_MFU_GHOST,
+	ARC_STATE_L2C_ONLY,
+	ARC_STATE_NUMTYPES
+} arc_state_type_t;
+
+typedef struct arc_buf_info {
+	arc_state_type_t	abi_state_type;
+	arc_buf_contents_t	abi_state_contents;
+	uint64_t		abi_state_index;
+	uint32_t		abi_flags;
+	uint32_t		abi_bufcnt;
+	uint64_t		abi_size;
+	uint64_t		abi_spa;
+	uint64_t		abi_access;
+	uint32_t		abi_mru_hits;
+	uint32_t		abi_mru_ghost_hits;
+	uint32_t		abi_mfu_hits;
+	uint32_t		abi_mfu_ghost_hits;
+	uint32_t		abi_l2arc_hits;
+	uint32_t		abi_holds;
+	uint64_t		abi_l2arc_dattr;
+	uint64_t		abi_l2arc_asize;
+	enum zio_compress	abi_l2arc_compress;
+} arc_buf_info_t;
+
 void arc_space_consume(uint64_t space, arc_space_type_t type);
 void arc_space_return(uint64_t space, arc_space_type_t type);
 boolean_t arc_is_metadata(arc_buf_t *buf);
@@ -200,6 +230,7 @@ arc_buf_t *arc_loan_compressed_buf(spa_t *spa, uint64_t psize, uint64_t lsize,
 void arc_return_buf(arc_buf_t *buf, void *tag);
 void arc_loan_inuse_buf(arc_buf_t *buf, void *tag);
 void arc_buf_destroy(arc_buf_t *buf, void *tag);
+void arc_buf_info(arc_buf_t *buf, arc_buf_info_t *abi, int state_index);
 int arc_buf_size(arc_buf_t *buf);
 int arc_buf_lsize(arc_buf_t *buf);
 void arc_buf_access(arc_buf_t *buf);
diff --git a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/dbuf.h b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/dbuf.h
index ec966432f2ac..af9a0a72159b 100644
--- a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/dbuf.h
+++ b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/dbuf.h
@@ -333,6 +333,9 @@ void dbuf_free_range(struct dnode *dn, uint64_t start, uint64_t end,
 
 void dbuf_new_size(dmu_buf_impl_t *db, int size, dmu_tx_t *tx);
 
+void dbuf_stats_init(dbuf_hash_table_t *hash);
+void dbuf_stats_destroy(void);
+
 #define	DB_DNODE(_db)		((_db)->db_dnode_handle->dnh_dnode)
 #define	DB_DNODE_LOCK(_db)	((_db)->db_dnode_handle->dnh_zrlock)
 #define	DB_DNODE_ENTER(_db)	(zrl_add(&DB_DNODE_LOCK(_db)))
diff --git a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/dmu.h b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/dmu.h
index 90b7a5b263c1..b23ce0194378 100644
--- a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/dmu.h
+++ b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/dmu.h
@@ -855,6 +855,7 @@ extern const dmu_object_byteswap_info_t dmu_ot_byteswap[DMU_BSWAP_NUMFUNCS];
  * If doi is NULL, just indicates whether the object exists.
  */
 int dmu_object_info(objset_t *os, uint64_t object, dmu_object_info_t *doi);
+void __dmu_object_info_from_dnode(struct dnode *dn, dmu_object_info_t *doi);
 /* Like dmu_object_info, but faster if you have a held dnode in hand. */
 void dmu_object_info_from_dnode(dnode_t *dn, dmu_object_info_t *doi);
 /* Like dmu_object_info, but faster if you have a held dbuf in hand. */