[PATCH 1/8] scsi: Drop struct Scsi_Host->host_lock around SHT->queuecommand()

From: Nicholas A. Bellinger
Date: Thu Sep 16 2010 - 18:35:41 EST


From: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>

This patch converts scsi_dispatch_cmd() to only hold struct Scsi_Host->host_lock
for scsi_cmd_get_serial(), and drops the lock because the call into
the LLD with host->hostt->queuecommand().

Signed-off-by: Nicholas A. Bellinger <nab@xxxxxxxxxxxxxxx>
---
drivers/scsi/scsi.c | 3 ++-
1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c
index ad0ed21..06e5b3a 100644
--- a/drivers/scsi/scsi.c
+++ b/drivers/scsi/scsi.c
@@ -745,6 +745,7 @@ int scsi_dispatch_cmd(struct scsi_cmnd *cmd)
* TODO: kill serial or move to blk layer
*/
scsi_cmd_get_serial(host, cmd);
+ spin_unlock_irqrestore(host->host_lock, flags);

if (unlikely(host->shost_state == SHOST_DEL)) {
cmd->result = (DID_NO_CONNECT << 16);
@@ -753,7 +754,7 @@ int scsi_dispatch_cmd(struct scsi_cmnd *cmd)
trace_scsi_dispatch_cmd_start(cmd);
rtn = host->hostt->queuecommand(cmd, scsi_done);
}
- spin_unlock_irqrestore(host->host_lock, flags);
+
if (rtn) {
trace_scsi_dispatch_cmd_error(cmd, rtn);
if (rtn != SCSI_MLQUEUE_DEVICE_BUSY &&
--
1.7.2.3

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