[PATCH 10/19] libfc: Avoid that sending after an abort triggers a kernel warning

Robert Love
2013-10-21T18:01:20Z

Calling fc_seq_send() after an ABTS message has been received triggers
a kernel warning (WARN_ON(!(ep->esb_stat & ESB_ST_SEQ_INIT))). Avoid
this by returning -ENXIO to the caller if fc_seq_send() is invoked after
an ABTS message has been received.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Cc: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
---
drivers/scsi/libfc/fc_exch.c | 59 ++++++++++++++++++++++++++----------------
1 file changed, 37 insertions(+), 22 deletions(-)

diff --git a/drivers/scsi/libfc/fc_exch.c b/drivers/scsi/libfc/fc_exch.c
index bc0aba4..2a7fd5a 100644
--- a/drivers/scsi/libfc/fc_exch.c
+++ b/drivers/scsi/libfc/fc_exch.c
@@ -463,15 +463,21 @@ static void fc_exch_delete(struct fc_exch *ep)
}

static int fc_seq_send_locked(struct fc_lport *lport, struct fc_seq *sp,
- struct fc_frame *fp)
+ struct fc_frame *fp)
{
struct fc_exch *ep;
struct fc_frame_header *fh = fc_frame_header_get(fp);
- int error;
+ int error = -ENXIO;
u32 f_ctl;
u8 fh_type = fh->fh_type;

ep = fc_seq_exch(sp);
+
+ if (ep->esb_stat & (ESB_ST_COMPLETE | ESB_ST_ABNORMAL)) {
+ fc_frame_free(fp);
+ goto out;
+ }
+
WARN_ON(!(ep->esb_stat & ESB_ST_SEQ_INIT));

f_ctl = ntoh24(fh->fh_f_ctl);
@@ -514,6 +520,9 @@ out:
* @lport: The local port that the exchange will be sent on
* @sp: The sequence to be sent
* @fp: The frame to be sent on the exchange
+ *
+ * Note: The frame will be freed either by a direct call to fc_frame_free(fp)
+ * or indirectly by calling libfc_function_template.frame_send().
*/
static int fc_seq_send(struct fc_lport *lport, struct fc_seq *sp,
struct fc_frame *fp)
@@ -621,27 +630,31 @@ static int fc_exch_abort_locked(struct fc_exch *ep,
if (!sp)
return -ENOMEM;

- ep->esb_stat |= ESB_ST_SEQ_INIT | ESB_ST_ABNORMAL;
if (timer_msec)
fc_exch_timer_set_locked(ep, timer_msec);

- /*
- * If not logged into the fabric, don't send ABTS but leave
- * sequence active until next timeout.
- */
- if (!ep->sid)
- return 0;
-
- /*
- * Send an abort for the sequence that timed out.
- */
- fp = fc_frame_alloc(ep->lp, 0);
- if (fp) {
- fc_fill_fc_hdr(fp, FC_RCTL_BA_ABTS, ep->did, ep->sid,
- FC_TYPE_BLS, FC_FC_END_SEQ | FC_FC_SEQ_INIT, 0);
- error = fc_seq_send_locked(ep->lp, sp, fp);
- } else
- error = -ENOBUFS;
+ if (ep->sid) {
+ /*
+ * Send an abort for the sequence that timed out.
+ */
+ fp = fc_frame_alloc(ep->lp, 0);
+ if (fp) {
+ ep->esb_stat |= ESB_ST_SEQ_INIT;
+ fc_fill_fc_hdr(fp, FC_RCTL_BA_ABTS, ep->did, ep->sid,
+ FC_TYPE_BLS, FC_FC_END_SEQ |
+ FC_FC_SEQ_INIT, 0);
+ error = fc_seq_send_locked(ep->lp, sp, fp);
+ } else {
+ error = -ENOBUFS;
+ }
+ } else {
+ /*
+ * If not logged into the fabric, don't send ABTS but leave
+ * sequence active until next timeout.
+ */
+ error = 0;
+ }
+ ep->esb_stat |= ESB_ST_ABNORMAL;
return error;
}

@@ -1299,9 +1312,10 @@ static void fc_exch_recv_abts(struct fc_exch *ep, struct fc_frame *rx_fp)
spin_unlock_bh(&ep->ex_lock);
goto reject;
}
- if (!(ep->esb_stat & ESB_ST_REC_QUAL))
+ if (!(ep->esb_stat & ESB_ST_REC_QUAL)) {
+ ep->esb_stat |= ESB_ST_REC_QUAL;
fc_exch_hold(ep); /* hold for REC_QUAL */
- ep->esb_stat |= ESB_ST_ABNORMAL | ESB_ST_REC_QUAL;
+ }
fc_exch_timer_set_locked(ep, ep->r_a_tov);

fp = fc_frame_alloc(ep->lp, sizeof(*ap));
@@ -1322,6 +1336,7 @@ static void fc_exch_recv_abts(struct fc_exch *ep, struct fc_frame *rx_fp)
}
sp = fc_seq_start_next_locked(sp);
fc_seq_send_last(sp, fp, FC_RCTL_BA_ACC, FC_TYPE_BLS);
+ ep->esb_stat |= ESB_ST_ABNORMAL;
spin_unlock_bh(&ep->ex_lock);
fc_frame_free(rx_fp);
return;