From bc0058695a74c0e9aef8bf9582a096ce4924f690 Mon Sep 17 00:00:00 2001 From: Nicholas Bellinger Date: Wed, 2 Apr 2014 14:55:33 -0700 Subject: [PATCH] target: Enable READ_STRIP emulation in target_complete_ok_work This patch enables the use of READ_STRIP software emulation in target_complete_ok_work() code for I/O READs. This is useful when the fabric does not support READ_STRIP hardware offload, but would still like to interact with backend device that have T10 PI enabled. v2 changes: - Move TARGET_PROT_DIN_STRIP check from target_check_read_strip() into target_complete_ok_work() (Sagi) Cc: Martin K. Petersen Cc: Sagi Grimberg Cc: Or Gerlitz Cc: Quinn Tran Cc: Giridhar Malavali Signed-off-by: Nicholas Bellinger --- drivers/target/target_core_transport.c | 31 ++++++++++++++++++++++++++ 1 file changed, 31 insertions(+) diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c index a7a4ef2d589e..d4b98690a736 100644 --- a/drivers/target/target_core_transport.c +++ b/drivers/target/target_core_transport.c @@ -1905,6 +1905,21 @@ static void transport_handle_queue_full( schedule_work(&cmd->se_dev->qf_work_queue); } +static bool target_check_read_strip(struct se_cmd *cmd) +{ + sense_reason_t rc; + + if (!(cmd->se_sess->sup_prot_ops & TARGET_PROT_DIN_STRIP)) { + rc = sbc_dif_read_strip(cmd); + if (rc) { + cmd->pi_err = rc; + return true; + } + } + + return false; +} + static void target_complete_ok_work(struct work_struct *work) { struct se_cmd *cmd = container_of(work, struct se_cmd, work); @@ -1969,6 +1984,22 @@ static void target_complete_ok_work(struct work_struct *work) cmd->data_length; } spin_unlock(&cmd->se_lun->lun_sep_lock); + /* + * Perform READ_STRIP of PI using software emulation when + * backend had PI enabled, if the transport will not be + * performing hardware READ_STRIP offload. + */ + if (cmd->prot_op == TARGET_PROT_DIN_STRIP && + target_check_read_strip(cmd)) { + ret = transport_send_check_condition_and_sense(cmd, + cmd->pi_err, 0); + if (ret == -EAGAIN || ret == -ENOMEM) + goto queue_full; + + transport_lun_remove_cmd(cmd); + transport_cmd_check_stop_to_fabric(cmd); + return; + } trace_target_cmd_complete(cmd); ret = cmd->se_tfo->queue_data_in(cmd);