The usb-storage driver runs in a thread and completes its request from
that thread. Since it is a single queued device it always schedules
ksoftirqd for its completion.
The completion is performed in the SCSI stack. Add
scsi_done_preemptible() which inlines most of scsi_mq_done() and
completes the request directly via blk_mq_complete_request_direct().
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
---
drivers/scsi/scsi_lib.c | 17 ++++++++++++++++-
drivers/usb/storage/usb.c | 2 +-
include/scsi/scsi_cmnd.h | 7 +++++++
3 files changed, 24 insertions(+), 2 deletions(-)
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 572673873ddf8..f0eeedce6b081 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -1575,16 +1575,31 @@ static blk_status_t scsi_prepare_cmd(struct request *req)
return scsi_cmd_to_driver(cmd)->init_command(cmd);
}
-static void scsi_mq_done(struct scsi_cmnd *cmd)
+static void _scsi_mq_done(struct scsi_cmnd *cmd)
{
if (unlikely(blk_should_fake_timeout(scsi_cmd_to_rq(cmd)->q)))
return;
if (unlikely(test_and_set_bit(SCMD_STATE_COMPLETE, &cmd->state)))
return;
trace_scsi_dispatch_cmd_done(cmd);
+}
+
+static void scsi_mq_done(struct scsi_cmnd *cmd)
+{
+ _scsi_mq_done(cmd);
blk_mq_complete_request(scsi_cmd_to_rq(cmd));
}
+void scsi_done_preemptible(struct scsi_cmnd *scmd)
+{
+ if (scmd->scsi_done != scsi_mq_done) {
+ scmd->scsi_done(scmd);
+ return;
+ }
+ _scsi_mq_done(scmd);
+ blk_mq_complete_request_direct(scsi_cmd_to_rq(scmd));
+}
+
static void scsi_mq_put_budget(struct request_queue *q, int budget_token)
{
struct scsi_device *sdev = q->queuedata;
diff --git a/drivers/usb/storage/usb.c b/drivers/usb/storage/usb.c
index 90aa9c12ffac5..6ceedd1e14ce7 100644
--- a/drivers/usb/storage/usb.c
+++ b/drivers/usb/storage/usb.c
@@ -417,7 +417,7 @@ static int usb_stor_control_thread(void * __us)
if (srb) {
usb_stor_dbg(us, "scsi cmd done, result=0x%x\n",
srb->result);
- srb->scsi_done(srb);
+ scsi_done_preemptible(srb);
}
} /* for (;;) */
diff --git a/include/scsi/scsi_cmnd.h b/include/scsi/scsi_cmnd.h
index eaf04c9a1dfcb..e992f2f74dd69 100644
--- a/include/scsi/scsi_cmnd.h
+++ b/include/scsi/scsi_cmnd.h
@@ -396,4 +396,11 @@ static inline unsigned scsi_transfer_length(struct scsi_cmnd *scmd)
extern void scsi_build_sense(struct scsi_cmnd *scmd, int desc,
u8 key, u8 asc, u8 ascq);
+static inline void scsi_done(struct scsi_cmnd *scmd)
+{
+ scmd->scsi_done(scmd);
+}
+
+extern void scsi_done_preemptible(struct scsi_cmnd *scmd);
+
#endif /* _SCSI_SCSI_CMND_H */
--
2.33.0
