* [PATCH net 1/1] net/smc: save link group ptr before calling smc_buf_unuse
@ 2018-10-23 13:48 Ursula Braun
2018-10-23 18:00 ` David Miller
0 siblings, 1 reply; 2+ messages in thread
From: Ursula Braun @ 2018-10-23 13:48 UTC (permalink / raw)
To: davem; +Cc: netdev, linux-s390, schwidefsky, heiko.carstens, raspl, ubraun
From: Karsten Graul <kgraul@linux.ibm.com>
The pointer to the link group is unset in the smc connection structure
right before the call to smc_buf_unuse. Save the pointer and provide it
to smc_buf_unuse.
Fixes: a6920d1d130c ("net/smc: handle unregistered buffers")
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
---
net/smc/smc_core.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c
index e871368500e3..12d8493f72f4 100644
--- a/net/smc/smc_core.c
+++ b/net/smc/smc_core.c
@@ -291,7 +291,8 @@ static int smc_lgr_create(struct smc_sock *smc, bool is_smcd,
return rc;
}
-static void smc_buf_unuse(struct smc_connection *conn)
+static void smc_buf_unuse(struct smc_connection *conn,
+ struct smc_link_group *lgr)
{
if (conn->sndbuf_desc)
conn->sndbuf_desc->used = 0;
@@ -301,8 +302,6 @@ static void smc_buf_unuse(struct smc_connection *conn)
conn->rmb_desc->used = 0;
} else {
/* buf registration failed, reuse not possible */
- struct smc_link_group *lgr = conn->lgr;
-
write_lock_bh(&lgr->rmbs_lock);
list_del(&conn->rmb_desc->list);
write_unlock_bh(&lgr->rmbs_lock);
@@ -315,6 +314,8 @@ static void smc_buf_unuse(struct smc_connection *conn)
/* remove a finished connection from its link group */
void smc_conn_free(struct smc_connection *conn)
{
+ struct smc_link_group *lgr;
+
if (!conn->lgr)
return;
if (conn->lgr->is_smcd) {
@@ -323,8 +324,9 @@ void smc_conn_free(struct smc_connection *conn)
} else {
smc_cdc_tx_dismiss_slots(conn);
}
+ lgr = conn->lgr; /* smc_lgr_unregister_conn() unsets lgr */
smc_lgr_unregister_conn(conn);
- smc_buf_unuse(conn);
+ smc_buf_unuse(conn, lgr);
}
static void smc_link_clear(struct smc_link *lnk)
--
2.16.4
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH net 1/1] net/smc: save link group ptr before calling smc_buf_unuse
2018-10-23 13:48 [PATCH net 1/1] net/smc: save link group ptr before calling smc_buf_unuse Ursula Braun
@ 2018-10-23 18:00 ` David Miller
0 siblings, 0 replies; 2+ messages in thread
From: David Miller @ 2018-10-23 18:00 UTC (permalink / raw)
To: ubraun; +Cc: netdev, linux-s390, schwidefsky, heiko.carstens, raspl
From: Ursula Braun <ubraun@linux.ibm.com>
Date: Tue, 23 Oct 2018 15:48:05 +0200
> @@ -315,6 +314,8 @@ static void smc_buf_unuse(struct smc_connection *conn)
> /* remove a finished connection from its link group */
> void smc_conn_free(struct smc_connection *conn)
> {
> + struct smc_link_group *lgr;
> +
> if (!conn->lgr)
> return;
> if (conn->lgr->is_smcd) {
> @@ -323,8 +324,9 @@ void smc_conn_free(struct smc_connection *conn)
> } else {
> smc_cdc_tx_dismiss_slots(conn);
> }
> + lgr = conn->lgr; /* smc_lgr_unregister_conn() unsets lgr */
> smc_lgr_unregister_conn(conn);
> - smc_buf_unuse(conn);
> + smc_buf_unuse(conn, lgr);
> }
This doesn't make any sense.
smc_lgr_unregister_conn() can free the memory and release the object,
albeit sometimes asynchronously via a workqueue.
It is not safe, therefore, to refrence the lgr object after that
function call.
I'm not applying this, sorry.
^ permalink raw reply [flat|nested] 2+ messages in thread
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