OpenZFS 3821 - Race in rollback, zil close, and zil flush

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

diff --git a/module/zfs/dsl_pool.c b/module/zfs/dsl_pool.c
index 2386484c80918e8ec44232508d52fc50e3ced58e..1bc73ebc7a0e5af3dc18e77e9c8c8099e3d0adfe 100644 (file)
--- a/module/zfs/dsl_pool.c
+++ b/module/zfs/dsl_pool.c
@@ -615,9 +615,16 @@ dsl_pool_sync_done(dsl_pool_t *dp, uint64_t txg)
 {
        zilog_t *zilog;
 
-       while ((zilog = txg_list_remove(&dp->dp_dirty_zilogs, txg))) {
+       while ((zilog = txg_list_head(&dp->dp_dirty_zilogs, txg))) {
                dsl_dataset_t *ds = dmu_objset_ds(zilog->zl_os);
+               /*
+                * We don't remove the zilog from the dp_dirty_zilogs
+                * list until after we've cleaned it. This ensures that
+                * callers of zilog_is_dirty() receive an accurate
+                * answer when they are racing with the spa sync thread.
+                */
                zil_clean(zilog, txg);
+               (void) txg_list_remove_this(&dp->dp_dirty_zilogs, zilog, txg);
                ASSERT(!dmu_objset_is_dirty(zilog->zl_os, txg));
                dmu_buf_rele(ds->ds_dbuf, zilog);
        }