From a83003decfe501912315a27d93a8d000d11d7f25 Mon Sep 17 00:00:00 2001 From: Nicholas Bellinger Date: Sun, 30 Oct 2016 18:58:39 -0700 Subject: [PATCH] iser-target: Fix queue-full response handling 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 Reviewed-by: Potnuri Bharat Teja Tested-by: Potnuri Bharat Teja Cc: Potnuri Bharat Teja Reported-by: Steve Wise Cc: Steve Wise Cc: Sagi Grimberg Signed-off-by: Nicholas Bellinger --- 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 91cbe86b25c8e..9b33c0c974681 100644 --- a/drivers/infiniband/ulp/isert/ib_isert.c +++ b/drivers/infiniband/ulp/isert/ib_isert.c @@ -1659,10 +1659,23 @@ isert_rdma_write_done(struct ib_cq *cq, struct ib_wc *wc) 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 @@ -1699,13 +1712,15 @@ isert_rdma_read_done(struct ib_cq *cq, struct ib_wc *wc) 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 @@ -2171,26 +2186,28 @@ isert_put_datain(struct iscsi_conn *conn, struct iscsi_cmd *cmd) 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 -- 2.39.5