From 2e215fecbe97167cd5408cea19aa50b80601248c Mon Sep 17 00:00:00 2001 From: Steven Hartland 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 Reviewed by: Matthew Ahrens Reviewed by: George Wilson Approved by: Gordon Ross 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 Ported-by: George Melikov 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 613a9b51e..40293ec1f 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);