net/smc: free link group without pending free_work only

Ursula Braun · davem330 · commit 268ffcc4ebfc · 2018-03-14T13:40:44.000-04:00
Make sure there is no pending or running free_work worker for the link
group when freeing the link group.

Signed-off-by: Ursula Braun &lt;ubraun@linux.vnet.ibm.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
@@ -1477,6 +1477,7 @@ static void __exit smc_exit(void)
 	spin_unlock_bh(&smc_lgr_list.lock);
 	list_for_each_entry_safe(lgr, lg, &lgr_freeing_list, list) {
 		list_del_init(&lgr->list);
+		cancel_delayed_work_sync(&lgr->free_work);
 		smc_lgr_free(lgr); /* free link group */
 	}
 	static_branch_disable(&tcp_have_smc);
diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c
@@ -140,7 +140,8 @@ static void smc_lgr_free_work(struct work_struct *work)
 	list_del_init(&lgr->list); /* remove from smc_lgr_list */
 free:
 	spin_unlock_bh(&smc_lgr_list.lock);
-	smc_lgr_free(lgr);
+	if (!delayed_work_pending(&lgr->free_work))
+		smc_lgr_free(lgr);
 }
 
 /* create a new SMC link group */

Original file line number	Diff line number	Diff line change
`@@ -1477,6 +1477,7 @@ static void __exit smc_exit(void)`
`1477`	`1477`	`spin_unlock_bh(&smc_lgr_list.lock);`
`1478`	`1478`	`list_for_each_entry_safe(lgr, lg, &lgr_freeing_list, list) {`
`1479`	`1479`	`list_del_init(&lgr->list);`
	`1480`	`+ cancel_delayed_work_sync(&lgr->free_work);`
`1480`	`1481`	`smc_lgr_free(lgr); /* free link group */`
`1481`	`1482`	`}`
`1482`	`1483`	`static_branch_disable(&tcp_have_smc);`
Original file line number	Diff line number	Diff line change
`@@ -140,7 +140,8 @@ static void smc_lgr_free_work(struct work_struct *work)`
`140`	`140`	`list_del_init(&lgr->list); /* remove from smc_lgr_list */`
`141`	`141`	`free:`
`142`	`142`	`spin_unlock_bh(&smc_lgr_list.lock);`
`143`		`- smc_lgr_free(lgr);`
	`143`	`+ if (!delayed_work_pending(&lgr->free_work))`
	`144`	`+ smc_lgr_free(lgr);`
`144`	`145`	`}`
`145`	`146`
`146`	`147`	`/* create a new SMC link group */`