From f281233d3eba15fb225d21ae2e228fd4553d824a Mon Sep 17 00:00:00 2001 From: Jeff Garzik Date: Tue, 16 Nov 2010 02:10:29 -0500 Subject: SCSI host lock push-down Move the mid-layer's ->queuecommand() invocation from being locked with the host lock to being unlocked to facilitate speeding up the critical path for drivers who don't need this lock taken anyway. The patch below presents a simple SCSI host lock push-down as an equivalent transformation. No locking or other behavior should change with this patch. All existing bugs and locking orders are preserved. Additionally, add one parameter to queuecommand, struct Scsi_Host * and remove one parameter from queuecommand, void (*done)(struct scsi_cmnd *) Scsi_Host* is a convenient pointer that most host drivers need anyway, and 'done' is redundant to struct scsi_cmnd->scsi_done. Minimal code disturbance was attempted with this change. Most drivers needed only two one-line modifications for their host lock push-down. Signed-off-by: Jeff Garzik Acked-by: James Bottomley Signed-off-by: Linus Torvalds --- drivers/usb/storage/scsiglue.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'drivers/usb/storage/scsiglue.c') diff --git a/drivers/usb/storage/scsiglue.c b/drivers/usb/storage/scsiglue.c index a688b1e686ea..689ee1fb702a 100644 --- a/drivers/usb/storage/scsiglue.c +++ b/drivers/usb/storage/scsiglue.c @@ -285,7 +285,7 @@ static int slave_configure(struct scsi_device *sdev) /* queue a command */ /* This is always called with scsi_lock(host) held */ -static int queuecommand(struct scsi_cmnd *srb, +static int queuecommand_lck(struct scsi_cmnd *srb, void (*done)(struct scsi_cmnd *)) { struct us_data *us = host_to_us(srb->device->host); @@ -315,6 +315,8 @@ static int queuecommand(struct scsi_cmnd *srb, return 0; } +static DEF_SCSI_QCMD(queuecommand) + /*********************************************************************** * Error handling functions ***********************************************************************/ -- cgit v1.2.3