From: George Wilson <george.wilson@delphix.com>
Date: Fri, 4 Oct 2013 22:13:23 +0000 (-0800)
Subject: Illumos #4168, #4169, #4170
X-Git-Tag: zfs-0.7.12~1939
X-Git-Url: https://git.proxmox.com/?a=commitdiff_plain;h=43a696ed38cae25ec2d7b6466ab4a99eb86df7bd;p=mirror_zfs.git

Illumos #4168, #4169, #4170

4168 ztest assertion failure in dbuf_undirty
4169 verbatim import causes zdb to segfault
4170 zhack leaves pool in ACTIVE state
Reviewed by: Adam Leventhal <ahl@delphix.com>
Reviewed by: Eric Schrock <eric.schrock@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Approved by: Dan McDonald <danmcd@nexenta.com>

References:
  https://www.illumos.org/issues/4168
  https://www.illumos.org/issues/4169
  https://www.illumos.org/issues/4170
  illumos/illumos-gate@7fdd916c474ea52896c671bbe7b56ba34a1ca132

Ported-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #1775
---

diff --git a/module/zfs/metaslab.c b/module/zfs/metaslab.c
index f01a8893e..f49a8adc6 100644
--- a/module/zfs/metaslab.c
+++ b/module/zfs/metaslab.c
@@ -117,6 +117,11 @@ int metaslab_prefetch_limit = SPA_DVAS_PER_BP;
  */
 int metaslab_smo_bonus_pct = 150;
 
+/*
+ * Should we be willing to write data to degraded vdevs?
+ */
+boolean_t zfs_write_to_degraded = B_FALSE;
+
 /*
  * ==========================================================================
  * Metaslab classes
@@ -1725,10 +1730,13 @@ top:
 
 		/*
 		 * Avoid writing single-copy data to a failing vdev
+		 * unless the user instructs us that it is okay.
 		 */
 		if ((vd->vdev_stat.vs_write_errors > 0 ||
 		    vd->vdev_state < VDEV_STATE_HEALTHY) &&
-		    d == 0 && dshift == 3) {
+		    d == 0 && dshift == 3 &&
+		    !(zfs_write_to_degraded && vd->vdev_state ==
+		    VDEV_STATE_DEGRADED)) {
 			all_zero = B_FALSE;
 			goto next;
 		}