From: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
This patch changes target core to also check for -ENOMEM from fabric callbacks
to signal QUEUE_FULL status, instead of just -EAGAIN in order to catch a
larger set of fabric failure cases that want to trigger QUEUE_FULL logic.
This includes the callbacks for ->write_pending(), ->queue_data_in() and
->queue_status().
It also makes transport_generic_write_pending() return zero upon QUEUE_FULL,
and removes two unnecessary -EAGAIN checks to catch write pending QUEUE_FULL
cases from transport_generic_new_cmd() failures in transport_handle_cdb_direct()
and transport_processing_thread():TRANSPORT_NEW_CMD_MAP state.
Reported-by: Bart Van Assche <bvanassche@xxxxxxx>
Cc: Bart Van Assche <bvanassche@xxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: Roland Dreier <roland@xxxxxxxxxxxxxxx>
Signed-off-by: Nicholas A. Bellinger <nab@xxxxxxxxxxxxxxx>
---
drivers/target/target_core_transport.c | 31 +++++++++++++++----------------
1 files changed, 15 insertions(+), 16 deletions(-)
diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c
index bfd420c..1821606 100644
--- a/drivers/target/target_core_transport.c
+++ b/drivers/target/target_core_transport.c
@@ -911,7 +911,7 @@ void transport_remove_task_from_execute_queue(
}
/*
- * Handle QUEUE_FULL / -EAGAIN status
+ * Handle QUEUE_FULL / -EAGAIN and -ENOMEM status
*/
static void target_qf_do_work(struct work_struct *work)
@@ -1647,9 +1647,7 @@ int transport_handle_cdb_direct(
* and call transport_generic_request_failure() if necessary..
*/
ret = transport_generic_new_cmd(cmd);
- if (ret == -EAGAIN)
- return 0;
- else if (ret < 0) {
+ if (ret < 0) {
cmd->transport_error_status = ret;
transport_generic_request_failure(cmd, 0,
(cmd->data_direction != DMA_TO_DEVICE));
@@ -1888,7 +1886,7 @@ static void transport_generic_request_failure(
ASCQ_2CH_PREVIOUS_RESERVATION_CONFLICT_STATUS);
ret = cmd->se_tfo->queue_status(cmd);
- if (ret == -EAGAIN)
+ if (ret == -EAGAIN || ret == -ENOMEM)
goto queue_full;
goto check_stop;
case PYX_TRANSPORT_USE_SENSE_REASON:
@@ -1915,7 +1913,7 @@ static void transport_generic_request_failure(
else {
ret = transport_send_check_condition_and_sense(cmd,
cmd->scsi_sense_reason, 0);
- if (ret == -EAGAIN)
+ if (ret == -EAGAIN || ret == -ENOMEM)
goto queue_full;
}
@@ -3310,7 +3308,7 @@ static void target_complete_ok_work(struct work_struct *work)
if (cmd->scsi_status) {
ret = transport_send_check_condition_and_sense(
cmd, reason, 1);
- if (ret == -EAGAIN)
+ if (ret == -EAGAIN || ret == -ENOMEM)
goto queue_full;
transport_lun_remove_cmd(cmd);
@@ -3335,7 +3333,7 @@ static void target_complete_ok_work(struct work_struct *work)
spin_unlock(&cmd->se_lun->lun_sep_lock);
ret = cmd->se_tfo->queue_data_in(cmd);
- if (ret == -EAGAIN)
+ if (ret == -EAGAIN || ret == -ENOMEM)
goto queue_full;
break;
case DMA_TO_DEVICE:
@@ -3356,14 +3354,14 @@ static void target_complete_ok_work(struct work_struct *work)
}
spin_unlock(&cmd->se_lun->lun_sep_lock);
ret = cmd->se_tfo->queue_data_in(cmd);
- if (ret == -EAGAIN)
+ if (ret == -EAGAIN || ret == -ENOMEM)
goto queue_full;
break;
}
/* Fall through for DMA_TO_DEVICE */
case DMA_NONE:
ret = cmd->se_tfo->queue_status(cmd);
- if (ret == -EAGAIN)
+ if (ret == -EAGAIN || ret == -ENOMEM)
goto queue_full;
break;
default:
@@ -3892,7 +3890,10 @@ EXPORT_SYMBOL(transport_generic_process_write);
static void transport_write_pending_qf(struct se_cmd *cmd)
{
- if (cmd->se_tfo->write_pending(cmd) == -EAGAIN) {
+ int ret;
+
+ ret = cmd->se_tfo->write_pending(cmd);
+ if (ret == -EAGAIN || ret == -ENOMEM) {
pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n",
cmd);
transport_handle_queue_full(cmd, cmd->se_dev);
@@ -3922,7 +3923,7 @@ static int transport_generic_write_pending(struct se_cmd *cmd)
* frontend know that WRITE buffers are ready.
*/
ret = cmd->se_tfo->write_pending(cmd);
- if (ret == -EAGAIN)
+ if (ret == -EAGAIN || ret == -ENOMEM)
goto queue_full;
else if (ret < 0)
return ret;
@@ -3933,7 +3934,7 @@ queue_full:
pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n", cmd);
cmd->t_state = TRANSPORT_COMPLETE_QF_WP;
transport_handle_queue_full(cmd, cmd->se_dev);
- return ret;
+ return 0;
}
/**
@@ -4585,9 +4586,7 @@ get_cmd:
break;
}
ret = transport_generic_new_cmd(cmd);
- if (ret == -EAGAIN)
- break;
- else if (ret < 0) {
+ if (ret < 0) {
cmd->transport_error_status = ret;
transport_generic_request_failure(cmd,
0, (cmd->data_direction !=
--
1.7.2.5
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