| Message ID | 20220308002747.122682-13-michael.christie@oracle.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | misc iscsi patches | expand |
On 3/7/22 16:27, Mike Christie wrote: > set_bit doesn't provide a barrier, so we can hit race where we've called > iscsi_suspend_tx and didn't see a work queued, and then a work is queued > and run and doesn't see the suspend bit is set. We will then call into the > driver when they might have already cleaned up their xmit related code. > > Signed-off-by: Mike Christie <michael.christie@oracle.com> > --- > drivers/scsi/libiscsi.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c > index a165d4d10cea..b79739b41b10 100644 > --- a/drivers/scsi/libiscsi.c > +++ b/drivers/scsi/libiscsi.c > @@ -2020,10 +2020,14 @@ EXPORT_SYMBOL_GPL(iscsi_suspend_queue); > */ > void iscsi_suspend_tx(struct iscsi_conn *conn) > { > - struct Scsi_Host *shost = conn->session->host; > + struct iscsi_session *session = conn->session; > + struct Scsi_Host *shost = session->host; > struct iscsi_host *ihost = shost_priv(shost); > > + spin_lock_bh(&session->frwd_lock); > set_bit(ISCSI_CONN_FLAG_SUSPEND_TX, &conn->flags); > + spin_unlock_bh(&session->frwd_lock); > + > if (ihost->workq) > flush_work(&conn->xmitwork); > } Reviewed-by: Lee Duncan <lduncan@suse.com>
diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c index a165d4d10cea..b79739b41b10 100644 --- a/drivers/scsi/libiscsi.c +++ b/drivers/scsi/libiscsi.c @@ -2020,10 +2020,14 @@ EXPORT_SYMBOL_GPL(iscsi_suspend_queue); */ void iscsi_suspend_tx(struct iscsi_conn *conn) { - struct Scsi_Host *shost = conn->session->host; + struct iscsi_session *session = conn->session; + struct Scsi_Host *shost = session->host; struct iscsi_host *ihost = shost_priv(shost); + spin_lock_bh(&session->frwd_lock); set_bit(ISCSI_CONN_FLAG_SUSPEND_TX, &conn->flags); + spin_unlock_bh(&session->frwd_lock); + if (ihost->workq) flush_work(&conn->xmitwork); }
set_bit doesn't provide a barrier, so we can hit race where we've called iscsi_suspend_tx and didn't see a work queued, and then a work is queued and run and doesn't see the suspend bit is set. We will then call into the driver when they might have already cleaned up their xmit related code. Signed-off-by: Mike Christie <michael.christie@oracle.com> --- drivers/scsi/libiscsi.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)