[RFC PATCH 3/3] scsi, usb: storage: Complete the blk-request directly.
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: 2021-10-15 15:14:33
Also in:
linux-block, linux-mmc, linux-scsi
Subsystem:
scsi subsystem, the rest, usb mass storage driver, usb subsystem · Maintainers:
"James E.J. Bottomley", "Martin K. Petersen", Linus Torvalds, Alan Stern, Greg Kroah-Hartman
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@linutronix.de> --- 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