MFV r246392:

Import vendor ZFS bugfix fixing a possible deadlock in arc_read().

Illumos ZFS issues:
  3498 panic in arc_read(): !refcount_is_zero(&pbuf->b_hdr->b_refcnt)

References:
  https://www.illumos.org/issues/3498

MFC after:	2 weeks

1 files changed, 3 insertions, 4 deletions

diff --git a/cddl/contrib/opensolaris/cmd/zdb/zdb.c b/cddl/contrib/opensolaris/cmd/zdb/zdb.c
index 82941af..bbaefaf 100644
--- a/cddl/contrib/opensolaris/cmd/zdb/zdb.c
+++ b/cddl/contrib/opensolaris/cmd/zdb/zdb.c
@@ -983,7 +983,7 @@ visit_indirect(spa_t *spa, const dnode_phys_t *dnp,
 		arc_buf_t *buf;
 		uint64_t fill = 0;
 
-		err = arc_read_nolock(NULL, spa, bp, arc_getbuf_func, &buf,
+		err = arc_read(NULL, spa, bp, arc_getbuf_func, &buf,
 		    ZIO_PRIORITY_ASYNC_READ, ZIO_FLAG_CANFAIL, &flags, zb);
 		if (err)
 			return (err);
@@ -2001,9 +2001,8 @@ zdb_count_block(zdb_cb_t *zcb, zilog_t *zilog, const blkptr_t *bp,
 	    bp, NULL, NULL, ZIO_FLAG_CANFAIL)), ==, 0);
 }
 
-/* ARGSUSED */
 static int
-zdb_blkptr_cb(spa_t *spa, zilog_t *zilog, const blkptr_t *bp, arc_buf_t *pbuf,
+zdb_blkptr_cb(spa_t *spa, zilog_t *zilog, const blkptr_t *bp,
     const zbookmark_t *zb, const dnode_phys_t *dnp, void *arg)
 {
 	zdb_cb_t *zcb = arg;
@@ -2410,7 +2409,7 @@ typedef struct zdb_ddt_entry {
 /* ARGSUSED */
 static int
 zdb_ddt_add_cb(spa_t *spa, zilog_t *zilog, const blkptr_t *bp,
-    arc_buf_t *pbuf, const zbookmark_t *zb, const dnode_phys_t *dnp, void *arg)
+    const zbookmark_t *zb, const dnode_phys_t *dnp, void *arg)
 {
 	avl_tree_t *t = arg;
 	avl_index_t where;