diff mbox series

[4/5,v2] ibmvfc: relax locking around ibmvfc_queuecommand

Message ID 20210104221758.981302-1-tyreld@linux.ibm.com (mailing list archive)
State Changes Requested
Headers show
Series None | expand

Commit Message

Tyrel Datwyler Jan. 4, 2021, 10:17 p.m. UTC 
The drivers queuecommand routine is still wrapped to hold the host lock
for the duration of the call. This will become problematic when moving
to multiple queues due to the lock contention preventing asynchronous
submissions to mulitple queues. There is no real legatimate reason to
hold the host lock, and previous patches have insured proper protection
of moving ibmvfc_event objects between free and sent lists.

Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Reviewed-by: Brian King <brking@linux.vnet.ibm.com>
---
 drivers/scsi/ibmvscsi/ibmvfc.c | 12 ++++--------
 1 file changed, 4 insertions(+), 8 deletions(-)

Comments

Tyrel Datwyler Jan. 4, 2021, 10:19 p.m. UTC | #1 
On 1/4/21 2:17 PM, Tyrel Datwyler wrote:
> The drivers queuecommand routine is still wrapped to hold the host lock
> for the duration of the call. This will become problematic when moving
> to multiple queues due to the lock contention preventing asynchronous
> submissions to mulitple queues. There is no real legatimate reason to
> hold the host lock, and previous patches have insured proper protection
> of moving ibmvfc_event objects between free and sent lists.
> 
> Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
> Reviewed-by: Brian King <brking@linux.vnet.ibm.com>
> ---

Ignore. This is the wrong updated patch.

-Tyrel
diff mbox series

Patch

diff --git a/drivers/scsi/ibmvscsi/ibmvfc.c b/drivers/scsi/ibmvscsi/ibmvfc.c
index f680f96d5d06..ff86c43b4b33 100644
--- a/drivers/scsi/ibmvscsi/ibmvfc.c
+++ b/drivers/scsi/ibmvscsi/ibmvfc.c
@@ -1793,10 +1793,9 @@  static struct ibmvfc_cmd *ibmvfc_init_vfc_cmd(struct ibmvfc_event *evt, struct s
  * Returns:
  *	0 on success / other on failure
  **/
-static int ibmvfc_queuecommand_lck(struct scsi_cmnd *cmnd,
-			       void (*done) (struct scsi_cmnd *))
+static int ibmvfc_queuecommand(struct Scsi_Host *shost, struct scsi_cmnd *cmnd)
 {
-	struct ibmvfc_host *vhost = shost_priv(cmnd->device->host);
+	struct ibmvfc_host *vhost = shost_priv(shost);
 	struct fc_rport *rport = starget_to_rport(scsi_target(cmnd->device));
 	struct ibmvfc_cmd *vfc_cmd;
 	struct ibmvfc_fcp_cmd_iu *iu;
@@ -1806,7 +1805,7 @@  static int ibmvfc_queuecommand_lck(struct scsi_cmnd *cmnd,
 	if (unlikely((rc = fc_remote_port_chkready(rport))) ||
 	    unlikely((rc = ibmvfc_host_chkready(vhost)))) {
 		cmnd->result = rc;
-		done(cmnd);
+		cmnd->scsi_done(cmnd);
 		return 0;
 	}
 
@@ -1814,7 +1813,6 @@  static int ibmvfc_queuecommand_lck(struct scsi_cmnd *cmnd,
 	evt = ibmvfc_get_event(&vhost->crq);
 	ibmvfc_init_event(evt, ibmvfc_scsi_done, IBMVFC_CMD_FORMAT);
 	evt->cmnd = cmnd;
-	cmnd->scsi_done = done;
 
 	vfc_cmd = ibmvfc_init_vfc_cmd(evt, cmnd->device);
 	iu = ibmvfc_get_fcp_iu(vhost, vfc_cmd);
@@ -1841,12 +1839,10 @@  static int ibmvfc_queuecommand_lck(struct scsi_cmnd *cmnd,
 			    "Failed to map DMA buffer for command. rc=%d\n", rc);
 
 	cmnd->result = DID_ERROR << 16;
-	done(cmnd);
+	cmnd->scsi_done(cmnd);
 	return 0;
 }
 
-static DEF_SCSI_QCMD(ibmvfc_queuecommand)
-
 /**
  * ibmvfc_sync_completion - Signal that a synchronous command has completed
  * @evt:	ibmvfc event struct