| Message ID | 20190116005003.230678-8-bvanassche@acm.org (mailing list archive) |
|---|---|
| State | Mainlined |
| Commit | cd464d838041b3a69464c0dd3938c1f912487bd3 |
| Headers | show |
| Series | sd patches for kernel v5.1 | expand |
On Tue, Jan 15, 2019 at 04:50:03PM -0800, Bart Van Assche wrote: > From scsi_init_command(), a function called by scsi_mq_prep_fn(): > > /* zero out the cmd, except for the embedded scsi_request */ > memset((char *)cmd + sizeof(cmd->req), 0, > sizeof(*cmd) - sizeof(cmd->req) + dev->host->hostt->cmd_size); > > In other words, scsi_mq_prep_fn() clears scsi_cmnd.flags. Hence move > the clear_bit() call into the else branch, the only branch in which > this code is necessary. Right, good call. You can even safely use "cmd->state = 0" in this path instead of clear_bit(), but last time there were objections to it looking inconsistent with the completion+timeout paths that use it atomicly. Anyway, Reviewed-by: Keith Busch <keith.busch@intel.com>
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index b13cc9288ba0..00cd365fb7d2 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -1712,13 +1712,13 @@ static blk_status_t scsi_queue_rq(struct blk_mq_hw_ctx *hctx, if (!scsi_host_queue_ready(q, shost, sdev)) goto out_dec_target_busy; - clear_bit(SCMD_STATE_COMPLETE, &cmd->state); if (!(req->rq_flags & RQF_DONTPREP)) { ret = scsi_mq_prep_fn(req); if (ret != BLK_STS_OK) goto out_dec_host_busy; req->rq_flags |= RQF_DONTPREP; } else { + clear_bit(SCMD_STATE_COMPLETE, &cmd->state); blk_mq_start_request(req); }
From scsi_init_command(), a function called by scsi_mq_prep_fn(): /* zero out the cmd, except for the embedded scsi_request */ memset((char *)cmd + sizeof(cmd->req), 0, sizeof(*cmd) - sizeof(cmd->req) + dev->host->hostt->cmd_size); In other words, scsi_mq_prep_fn() clears scsi_cmnd.flags. Hence move the clear_bit() call into the else branch, the only branch in which this code is necessary. See also commit f1342709d18a ("scsi: Do not rely on blk-mq for double completions"). Cc: Keith Busch <keith.busch@intel.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Hannes Reinecke <hare@suse.com> Signed-off-by: Bart Van Assche <bvanassche@acm.org> --- drivers/scsi/scsi_lib.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)