From b077fd4c4e16d372ef81035199e132687dbcf0e3 Mon Sep 17 00:00:00 2001
From: Christopher Siden <chris.siden@delphix.com>
Date: Mon, 14 Jan 2013 10:29:55 -0800
Subject: [PATCH] Illumos #3189 kernel panic in test hotspare_onoffline_004_neg

3189 kernel panic in ZFS test suite during hotspare_onoffline_004_neg

Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Arne Jansen <sensille@gmx.net>
Approved by: Dan McDonald <danmcd@nexenta.com>

References:
  illumos/illumos-gate@8f0b538d1dc99df23a6a89cfd9ffddc1b9804a00
  changeset: 13818:e9ad0a945d45
  https://www.illumos.org/issues/3189

Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>
---
 module/zfs/dmu_tx.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/module/zfs/dmu_tx.c b/module/zfs/dmu_tx.c
index 044349c34..e47d858dd 100644
--- a/module/zfs/dmu_tx.c
+++ b/module/zfs/dmu_tx.c
@@ -589,7 +589,7 @@ dmu_tx_count_free(dmu_tx_hold_t *txh, uint64_t off, uint64_t len)
 		    (dn->dn_indblkshift - SPA_BLKPTRSHIFT);
 
 		while (level++ < maxlevel) {
-			txh->txh_memory_tohold += MIN(blkcnt, (nl1blks >> epbs))
+			txh->txh_memory_tohold += MAX(MIN(blkcnt, nl1blks), 1)
 			    << dn->dn_indblkshift;
 			blkcnt = 1 + (blkcnt >> epbs);
 		}