Fix error handling of vdev_top_zap

In `vdev_load()`, we look up several entries in the `vdev_top_zap`
object.  In most cases, if we encounter an i/o error, it will be
returned to the caller.  However, when handling
`VDEV_TOP_ZAP_ALLOCATION_BIAS`, if we get an i/o error, we may continue
on, which in theory could cause us to not realize that a vdev should be
used only for `special` allocations.

In practice, if we encountered an i/o error while looking for
`VDEV_TOP_ZAP_ALLOCATION_BIAS` in the `vdev_top_zap`, we'd also get an
i/o error while looking for other entries in the same object, and thus
the zpool open/import would fail.  Therefore the impact of this problem
is negligible.

This commit adds error handling for i/o errors while accessing the
`vdev_top_zap`, so that we aren't relying on unrelated code to fail for
us.

Reviewed-by: Don Brady <don.brady@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes #10637
This commit is contained in:
Matthew Ahrens 2020-07-29 17:04:34 -07:00 committed by GitHub
parent ae12b02308
commit 3a92552f75
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@ -3127,11 +3127,18 @@ vdev_load(vdev_t *vd)
spa_t *spa = vd->vdev_spa;
char bias_str[64];
if (zap_lookup(spa->spa_meta_objset, vd->vdev_top_zap,
error = zap_lookup(spa->spa_meta_objset, vd->vdev_top_zap,
VDEV_TOP_ZAP_ALLOCATION_BIAS, 1, sizeof (bias_str),
bias_str) == 0) {
bias_str);
if (error == 0) {
ASSERT(vd->vdev_alloc_bias == VDEV_BIAS_NONE);
vd->vdev_alloc_bias = vdev_derive_alloc_bias(bias_str);
} else if (error != ENOENT) {
vdev_set_state(vd, B_FALSE, VDEV_STATE_CANT_OPEN,
VDEV_AUX_CORRUPT_DATA);
vdev_dbgmsg(vd, "vdev_load: zap_lookup(top_zap=%llu) "
"failed [error=%d]", vd->vdev_top_zap, error);
return (error);
}
}
@ -3301,6 +3308,7 @@ vdev_destroy_ms_flush_data(vdev_t *vd, dmu_tx_t *tx)
VDEV_TOP_ZAP_MS_UNFLUSHED_PHYS_TXGS, sizeof (uint64_t), 1, &object);
if (err == ENOENT)
return;
VERIFY0(err);
VERIFY0(dmu_object_free(mos, object, tx));
VERIFY0(zap_remove(mos, vd->vdev_top_zap,