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authorNicholas Bellinger <nab@linux-iscsi.org>2014-06-05 16:27:53 -0700
committerNicholas Bellinger <nab@linux-iscsi.org>2014-06-06 14:20:23 -0700
commitb3e5fe1688b998ba5287a68667ef7cc568739e44 (patch)
tree5d7a9999d5cfc92ff4cd4ccc50d1ebea95f41334 /drivers/target/tcm_fc
parent1d2b60a5545942b1376cb48c1d55843d71e3a08f (diff)
tcm_fc: Generate TASK_SET_FULL status for DataIN failures
This patch changes ft_queue_data_in() to set SAM_STAT_TASK_SET_FULL status upon a lport->tt.seq_send() failure, where it will now stop sending subsequent DataIN, and immediately attempt to send the response with exception status. Sending a response with SAM_STAT_TASK_SET_FULL status is useful in order to signal the initiator that it should try to reduce it's current queue_depth, to lower the number of outstanding I/Os on the wire. Also, add a check to skip sending DataIN if TASK_SET_FULL status has already been set due to a response lport->tt.seq_send() failure, that has asked target-core to requeue a response. Reported-by: Vasu Dev <vasu.dev@linux.intel.com> Reviewed-by: Vasu Dev <vasu.dev@linux.intel.com> Cc: Jun Wu <jwu@stormojo.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Diffstat (limited to 'drivers/target/tcm_fc')
-rw-r--r--drivers/target/tcm_fc/tfc_io.c17
1 files changed, 15 insertions, 2 deletions
diff --git a/drivers/target/tcm_fc/tfc_io.c b/drivers/target/tcm_fc/tfc_io.c
index e415af32115a..97b486c3dda1 100644
--- a/drivers/target/tcm_fc/tfc_io.c
+++ b/drivers/target/tcm_fc/tfc_io.c
@@ -82,6 +82,10 @@ int ft_queue_data_in(struct se_cmd *se_cmd)
if (cmd->aborted)
return 0;
+
+ if (se_cmd->scsi_status == SAM_STAT_TASK_SET_FULL)
+ goto queue_status;
+
ep = fc_seq_exch(cmd->seq);
lport = ep->lp;
cmd->seq = lport->tt.seq_start_next(cmd->seq);
@@ -178,14 +182,23 @@ int ft_queue_data_in(struct se_cmd *se_cmd)
FC_TYPE_FCP, f_ctl, fh_off);
error = lport->tt.seq_send(lport, seq, fp);
if (error) {
- /* XXX For now, initiator will retry */
- pr_err_ratelimited("%s: Failed to send frame %p, "
+ pr_info_ratelimited("%s: Failed to send frame %p, "
"xid <0x%x>, remaining %zu, "
"lso_max <0x%x>\n",
__func__, fp, ep->xid,
remaining, lport->lso_max);
+ /*
+ * Go ahead and set TASK_SET_FULL status ignoring the
+ * rest of the DataIN, and immediately attempt to
+ * send the response via ft_queue_status() in order
+ * to notify the initiator that it should reduce it's
+ * per LUN queue_depth.
+ */
+ se_cmd->scsi_status = SAM_STAT_TASK_SET_FULL;
+ break;
}
}
+queue_status:
return ft_queue_status(se_cmd);
}

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