Implement .free_request() callback for freeing driver private part
of the request. Then we can avoid to leak this part if the request isn't
completed by SCSI, and freed by blk-mq finally.
One use case is that for handling CPU hotplug when the current
hctx is down, but some requests allocated from this hctx are still
in queue.
Cc: Bart Van Assche <bvanassche@xxxxxxx>
Cc: Hannes Reinecke <hare@xxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Keith Busch <keith.busch@xxxxxxxxx>
Signed-off-by: Ming Lei <ming.lei@xxxxxxxxxx>
---
drivers/scsi/scsi_lib.c | 13 +++++++++++++
1 file changed, 13 insertions(+)
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 65d0a10c76ad..e07a376a8c38 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -1073,6 +1073,18 @@ static void scsi_initialize_rq(struct request *rq)
cmd->retries = 0;
}
+/*
+ * Only called when the request isn't completed by SCSI, and freed by
+ * blk-mq
+ */
+static void scsi_free_rq(struct request *rq)
+{
+ struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq);
+
+ if (rq->rq_flags & RQF_DONTPREP)
+ scsi_mq_uninit_cmd(cmd);
+}
+
/* Add a command to the list used by the aacraid and dpt_i2o drivers */
void scsi_add_cmd_to_list(struct scsi_cmnd *cmd)
{
@@ -1800,6 +1812,7 @@ static const struct blk_mq_ops scsi_mq_ops = {
.init_request = scsi_mq_init_request,
.exit_request = scsi_mq_exit_request,
.initialize_rq_fn = scsi_initialize_rq,
+ .free_request = scsi_free_rq,
.busy = scsi_mq_lld_busy,
.map_queues = scsi_map_queues,
};
--
2.20.1
