From: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
This patch addresses two queue-full handling bugs in iser-target.
The first is propagating isert_rdma_rw_ctx_post() return back
to target-core via isert_put_datain() + isert_get_dataout()
callbacks, in order to trigger queue-full logic in target-core.
Note target-core expects -EAGAIN or -ENOMEM error to signal
RDMA WRITE/READ data-transfer callbacks should be retried,
after queue-full logic been invoked.
Other types of errors propagated up from RDMA RW API will result
in target-core generating internal CHECK_CONDITION status,
avoiding subsequent isert_put_datain() and isert_get_dataout()
iscsit_transport callback retry attempts.
The second is to use transport_generic_request_failure()
during T10-PI hw-offload errors in isert_rdma_write_done()
and isert_rdma_read_done(), so CHECK_CONDITION queue-full
is handled internally by target-core.
Also add isert_put_response() T10-PI failure case fixme in
isert_rdma_write_done(), which is currently not internally
retried or released until session reinstatement.
Reported-by: Potnuri Bharat Teja <bharat@xxxxxxxxxxx>
Cc: Potnuri Bharat Teja <bharat@xxxxxxxxxxx>
Reported-by: Steve Wise <swise@xxxxxxxxxxxxxxxxxxxxx>
Cc: Steve Wise <swise@xxxxxxxxxxxxxxxxxxxxx>
Cc: Sagi Grimberg <sagi@xxxxxxxxxxx>
Signed-off-by: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
---
drivers/infiniband/ulp/isert/ib_isert.c | 53 ++++++++++++++++++++++-----------
1 file changed, 35 insertions(+), 18 deletions(-)
diff --git a/drivers/infiniband/ulp/isert/ib_isert.c b/drivers/infiniband/ulp/isert/ib_isert.c
index 6dd43f6..e658248 100644
--- a/drivers/infiniband/ulp/isert/ib_isert.c
+++ b/drivers/infiniband/ulp/isert/ib_isert.c
@@ -1666,10 +1666,23 @@
ret = isert_check_pi_status(cmd, isert_cmd->rw.sig->sig_mr);
isert_rdma_rw_ctx_destroy(isert_cmd, isert_conn);
- if (ret)
- transport_send_check_condition_and_sense(cmd, cmd->pi_err, 0);
- else
- isert_put_response(isert_conn->conn, isert_cmd->iscsi_cmd);
+ if (ret) {
+ /*
+ * transport_generic_request_failure() expects to have
+ * plus two references to handle queue-full, so re-add
+ * one here as target-core will have already dropped
+ * it after the first isert_put_datain() callback.
+ */
+ kref_get(&cmd->cmd_kref);
+ transport_generic_request_failure(cmd, cmd->pi_err);
+ } else {
+ /*
+ * XXX: isert_put_response() failure is not retried.
+ */
+ ret = isert_put_response(isert_conn->conn, isert_cmd->iscsi_cmd);
+ if (ret)
+ pr_warn_ratelimited("isert_put_response() ret: %d\n", ret);
+ }
}
static void
@@ -1706,13 +1719,15 @@
cmd->i_state = ISTATE_RECEIVED_LAST_DATAOUT;
spin_unlock_bh(&cmd->istate_lock);
- if (ret) {
- target_put_sess_cmd(se_cmd);
- transport_send_check_condition_and_sense(se_cmd,
- se_cmd->pi_err, 0);
- } else {
+ /*
+ * transport_generic_request_failure() will drop the extra
+ * se_cmd->cmd_kref reference after T10-PI error, and handle
+ * any non-zero ->queue_status() callback error retries.
+ */
+ if (ret)
+ transport_generic_request_failure(se_cmd, se_cmd->pi_err);
+ else
target_execute_cmd(se_cmd);
- }
}
static void
@@ -2172,26 +2187,28 @@
chain_wr = &isert_cmd->tx_desc.send_wr;
}
- isert_rdma_rw_ctx_post(isert_cmd, isert_conn, cqe, chain_wr);
- isert_dbg("Cmd: %p posted RDMA_WRITE for iSER Data READ\n", isert_cmd);
- return 1;
+ rc = isert_rdma_rw_ctx_post(isert_cmd, isert_conn, cqe, chain_wr);
+ isert_dbg("Cmd: %p posted RDMA_WRITE for iSER Data READ rc: %d\n",
+ isert_cmd, rc);
+ return rc;
}
static int
isert_get_dataout(struct iscsi_conn *conn, struct iscsi_cmd *cmd, bool recovery)
{
struct isert_cmd *isert_cmd = iscsit_priv_cmd(cmd);
+ int ret;
isert_dbg("Cmd: %p RDMA_READ data_length: %u write_data_done: %u\n",
isert_cmd, cmd->se_cmd.data_length, cmd->write_data_done);
isert_cmd->tx_desc.tx_cqe.done = isert_rdma_read_done;
- isert_rdma_rw_ctx_post(isert_cmd, conn->context,
- &isert_cmd->tx_desc.tx_cqe, NULL);
+ ret = isert_rdma_rw_ctx_post(isert_cmd, conn->context,
+ &isert_cmd->tx_desc.tx_cqe, NULL);
- isert_dbg("Cmd: %p posted RDMA_READ memory for ISER Data WRITE\n",
- isert_cmd);
- return 0;
+ isert_dbg("Cmd: %p posted RDMA_READ memory for ISER Data WRITE rc: %d\n",
+ isert_cmd, ret);
+ return ret;
}
static int
--
1.9.1
--
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