From 2e215fecbe97167cd5408cea19aa50b80601248c Mon Sep 17 00:00:00 2001
From: Steven Hartland <steven.hartland@multiplay.co.uk>
Date: Mon, 3 Apr 2017 16:38:51 -0700
Subject: [PATCH] OpenZFS 7885 - zpool list can report 16.0e for expandsz
Authored by: Steven Hartland <steven.hartland@multiplay.co.uk>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Approved by: Gordon Ross <gordon.w.ross@gmail.com>
When a member of a RAIDZ has been replaced with a device smaller than
the original, then the top level vdev can report its expand size as
16.0E.
The reduced child asize causes the RAIDZ to have a vdev_asize lower than
its vdev_max_asize which then results in an underflow during the
calculation of the parents expand size.
Fix this by updating the vdev_asize if it shrinks, which is already
protected by a check against vdev_min_asize so should always be safe.
Also for RAIDZ vdevs, ensure that the sum of their child vdev_min_asize
is always greater than the parents vdev_min_size.
Reviewed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Ported-by: George Melikov <mail@gmelikov.ru>
OpenZFS-issue: https://www.illumos.org/issues/7885
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/bb0dbaa
Closes #5963
---
module/zfs/vdev.c | 24 +++++++++++++++++-------
1 file changed, 17 insertions(+), 7 deletions(-)
diff --git a/module/zfs/vdev.c b/module/zfs/vdev.c
index 613a9b51ec..40293ec1fc 100644
--- a/module/zfs/vdev.c
+++ b/module/zfs/vdev.c
@@ -134,7 +134,8 @@ vdev_get_min_asize(vdev_t *vd)
* so each child must provide at least 1/Nth of its asize.
*/
if (pvd->vdev_ops == &vdev_raidz_ops)
- return (pvd->vdev_min_asize / pvd->vdev_children);
+ return ((pvd->vdev_min_asize + pvd->vdev_children - 1) /
+ pvd->vdev_children);
return (pvd->vdev_min_asize);
}
@@ -1330,7 +1331,7 @@ vdev_open(vdev_t *vd)
vd->vdev_psize = psize;
/*
- * Make sure the allocatable size hasn't shrunk.
+ * Make sure the allocatable size hasn't shrunk too much.
*/
if (asize < vd->vdev_min_asize) {
vdev_set_state(vd, B_TRUE, VDEV_STATE_CANT_OPEN,
@@ -1370,12 +1371,21 @@ vdev_open(vdev_t *vd)
}
/*
- * If all children are healthy and the asize has increased,
- * then we've experienced dynamic LUN growth. If automatic
- * expansion is enabled then use the additional space.
+ * If all children are healthy we update asize if either:
+ * The asize has increased, due to a device expansion caused by dynamic
+ * LUN growth or vdev replacement, and automatic expansion is enabled;
+ * making the additional space available.
+ *
+ * The asize has decreased, due to a device shrink usually caused by a
+ * vdev replace with a smaller device. This ensures that calculations
+ * based of max_asize and asize e.g. esize are always valid. It's safe
+ * to do this as we've already validated that asize is greater than
+ * vdev_min_asize.
*/
- if (vd->vdev_state == VDEV_STATE_HEALTHY && asize > vd->vdev_asize &&
- (vd->vdev_expanding || spa->spa_autoexpand))
+ if (vd->vdev_state == VDEV_STATE_HEALTHY &&
+ ((asize > vd->vdev_asize &&
+ (vd->vdev_expanding || spa->spa_autoexpand)) ||
+ (asize < vd->vdev_asize)))
vd->vdev_asize = asize;
vdev_set_min_asize(vd);