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authorJeff Garzik <jeff@garzik.org>2010-11-16 02:10:29 -0500
committerLinus Torvalds <torvalds@linux-foundation.org>2010-11-16 16:33:23 -0500
commitf281233d3eba15fb225d21ae2e228fd4553d824a (patch)
tree51134454ba8acb558735f90be5540f7d756483e3 /include/scsi/libiscsi.h
parentbdbd01ac444bffb3c9aefed3059d12554059b320 (diff)
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 'include/scsi/libiscsi.h')
-rw-r--r--include/scsi/libiscsi.h3
1 files changed, 1 insertions, 2 deletions
diff --git a/include/scsi/libiscsi.h b/include/scsi/libiscsi.h
index ae5196aae1a5..b81d969ddc67 100644
--- a/include/scsi/libiscsi.h
+++ b/include/scsi/libiscsi.h
@@ -341,8 +341,7 @@ extern int iscsi_eh_abort(struct scsi_cmnd *sc);
341extern int iscsi_eh_recover_target(struct scsi_cmnd *sc); 341extern int iscsi_eh_recover_target(struct scsi_cmnd *sc);
342extern int iscsi_eh_session_reset(struct scsi_cmnd *sc); 342extern int iscsi_eh_session_reset(struct scsi_cmnd *sc);
343extern int iscsi_eh_device_reset(struct scsi_cmnd *sc); 343extern int iscsi_eh_device_reset(struct scsi_cmnd *sc);
344extern int iscsi_queuecommand(struct scsi_cmnd *sc, 344extern int iscsi_queuecommand(struct Scsi_Host *h, struct scsi_cmnd *sc);
345 void (*done)(struct scsi_cmnd *));
346 345
347/* 346/*
348 * iSCSI host helpers. 347 * iSCSI host helpers.