OpenZFS 9187 - racing condition between vdev label and spa_last_synced_txg in vdev_va...

[mirror_zfs.git] / module / zfs / vdev.c

diff --git a/module/zfs/vdev.c b/module/zfs/vdev.c
index 2a28b1c9d6211dbd38b33487d8bf4e449381460c..cebac3bb90007e37971053750e3276369881550f 100644 (file)
--- a/module/zfs/vdev.c
+++ b/module/zfs/vdev.c
@@ -1692,8 +1692,11 @@ vdev_validate(vdev_t *vd)
        /*
         * If we are performing an extreme rewind, we allow for a label that
         * was modified at a point after the current txg.
+        * If config lock is not held do not check for the txg. spa_sync could
+        * be updating the vdev's label before updating spa_last_synced_txg.
         */
-       if (spa->spa_extreme_rewind || spa_last_synced_txg(spa) == 0)
+       if (spa->spa_extreme_rewind || spa_last_synced_txg(spa) == 0 ||
+           spa_config_held(spa, SCL_CONFIG, RW_WRITER) != SCL_CONFIG)
                txg = UINT64_MAX;
        else
                txg = spa_last_synced_txg(spa);