[SCSI] libfc: Enhanced exchange ID selection mechanism and fix related EMA selection logic.
Problem:
In case of exchange responder case, EMA selection was defaulted to the
last EMA from EMA list (lport.ema_list). If exchange ID is selected
from offload pool and not setup DDP, resulting into incorrect
selection of EMA, and eventually dropping the packet because unable to
find exchange.
Fix:
Enhanced the exchange ID selection (depending upon request type and
exchange responder) Made necessary enhancement in EMA selection
algorithm.
Signed-off-by: Kiran Patil <kiran.patil@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
diff --git a/drivers/scsi/libfc/fc_exch.c b/drivers/scsi/libfc/fc_exch.c
index a3d6402..08bf5fa 100644
--- a/drivers/scsi/libfc/fc_exch.c
+++ b/drivers/scsi/libfc/fc_exch.c
@@ -2281,16 +2281,45 @@
EXPORT_SYMBOL(fc_exch_mgr_free);
/**
+ * fc_find_ema() - Lookup and return appropriate Exchange Manager Anchor depending
+ * upon 'xid'.
+ * @f_ctl: f_ctl
+ * @lport: The local port the frame was received on
+ * @fh: The received frame header
+ */
+static struct fc_exch_mgr_anchor *fc_find_ema(u32 f_ctl,
+ struct fc_lport *lport,
+ struct fc_frame_header *fh)
+{
+ struct fc_exch_mgr_anchor *ema;
+ u16 xid;
+
+ if (f_ctl & FC_FC_EX_CTX)
+ xid = ntohs(fh->fh_ox_id);
+ else {
+ xid = ntohs(fh->fh_rx_id);
+ if (xid == FC_XID_UNKNOWN)
+ return list_entry(lport->ema_list.prev,
+ typeof(*ema), ema_list);
+ }
+
+ list_for_each_entry(ema, &lport->ema_list, ema_list) {
+ if ((xid >= ema->mp->min_xid) &&
+ (xid <= ema->mp->max_xid))
+ return ema;
+ }
+ return NULL;
+}
+/**
* fc_exch_recv() - Handler for received frames
* @lport: The local port the frame was received on
- * @fp: The received frame
+ * @fp: The received frame
*/
void fc_exch_recv(struct fc_lport *lport, struct fc_frame *fp)
{
struct fc_frame_header *fh = fc_frame_header_get(fp);
struct fc_exch_mgr_anchor *ema;
- u32 f_ctl, found = 0;
- u16 oxid;
+ u32 f_ctl;
/* lport lock ? */
if (!lport || lport->state == LPORT_ST_DISABLED) {
@@ -2301,24 +2330,17 @@
}
f_ctl = ntoh24(fh->fh_f_ctl);
- oxid = ntohs(fh->fh_ox_id);
- if (f_ctl & FC_FC_EX_CTX) {
- list_for_each_entry(ema, &lport->ema_list, ema_list) {
- if ((oxid >= ema->mp->min_xid) &&
- (oxid <= ema->mp->max_xid)) {
- found = 1;
- break;
- }
- }
-
- if (!found) {
- FC_LPORT_DBG(lport, "Received response for out "
- "of range oxid:%hx\n", oxid);
- fc_frame_free(fp);
- return;
- }
- } else
- ema = list_entry(lport->ema_list.prev, typeof(*ema), ema_list);
+ ema = fc_find_ema(f_ctl, lport, fh);
+ if (!ema) {
+ FC_LPORT_DBG(lport, "Unable to find Exchange Manager Anchor,"
+ "fc_ctl <0x%x>, xid <0x%x>\n",
+ f_ctl,
+ (f_ctl & FC_FC_EX_CTX) ?
+ ntohs(fh->fh_ox_id) :
+ ntohs(fh->fh_rx_id));
+ fc_frame_free(fp);
+ return;
+ }
/*
* If frame is marked invalid, just drop it.
