3741 zfs needs better comments
Submitted by:   Will Andrews <willa@spectralogic.com>
Submitted by:   Justin Gibbs <justing@spectralogic.com>
Submitted by:   Alan Somers <alans@spectralogic.com>
Reviewed by:    Matthew Ahrens <mahrens@delphix.com>

@@ -1012,10 +1012,14 @@
         if (tx->tx_txg == 0)
                 return;
 
         txg_rele_to_quiesce(&tx->tx_txgh);
 
+        /*
+         * Walk the transaction's hold list, removing the hold on the
+         * associated dnode, and notifying waiters if the refcount drops to 0.
+         */
         for (txh = list_head(&tx->tx_holds); txh != tx->tx_needassign_txh;
             txh = list_next(&tx->tx_holds, txh)) {
                 dnode_t *dn = txh->txh_dnode;
 
                 if (dn == NULL)

@@ -1124,10 +1128,14 @@
 {
         dmu_tx_hold_t *txh;
 
         ASSERT(tx->tx_txg != 0);
 
+        /*
+         * Go through the transaction's hold list and remove holds on
+         * associated dnodes, notifying waiters if no holds remain.
+         */
         while (txh = list_head(&tx->tx_holds)) {
                 dnode_t *dn = txh->txh_dnode;
 
                 list_remove(&tx->tx_holds, txh);
                 kmem_free(txh, sizeof (dmu_tx_hold_t));