diff options
| author | Jeff Garzik <jeff@garzik.org> | 2010-11-16 10:10:29 +0300 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2010-11-17 00:33:23 +0300 |
| commit | f281233d3eba15fb225d21ae2e228fd4553d824a (patch) | |
| tree | 51134454ba8acb558735f90be5540f7d756483e3 /drivers/scsi/libfc | |
| parent | bdbd01ac444bffb3c9aefed3059d12554059b320 (diff) | |
| download | linux-f281233d3eba15fb225d21ae2e228fd4553d824a.tar.xz | |
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 <jgarzik@redhat.com>
Acked-by: James Bottomley <James.Bottomley@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/scsi/libfc')
| -rw-r--r-- | drivers/scsi/libfc/fc_fcp.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/scsi/libfc/fc_fcp.c b/drivers/scsi/libfc/fc_fcp.c index e340373b509b..2924363d142b 100644 --- a/drivers/scsi/libfc/fc_fcp.c +++ b/drivers/scsi/libfc/fc_fcp.c @@ -1753,7 +1753,7 @@ static inline int fc_fcp_lport_queue_ready(struct fc_lport *lport) * This is the i/o strategy routine, called by the SCSI layer. This routine * is called with the host_lock held. */ -int fc_queuecommand(struct scsi_cmnd *sc_cmd, void (*done)(struct scsi_cmnd *)) +static int fc_queuecommand_lck(struct scsi_cmnd *sc_cmd, void (*done)(struct scsi_cmnd *)) { struct fc_lport *lport; struct fc_rport *rport = starget_to_rport(scsi_target(sc_cmd->device)); @@ -1851,6 +1851,8 @@ out: spin_lock_irq(lport->host->host_lock); return rc; } + +DEF_SCSI_QCMD(fc_queuecommand) EXPORT_SYMBOL(fc_queuecommand); /** |