[PATCH] fix megaraid.c locking

This fixes locking in megaraid.c, namely:

 (1) make sure megaraid_queue release the adapter lock by changing the
     code to have a single return
 (2) remove the errornous scsi_assign_lock call

Testing by Burton Windle.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Burton Windle <bwindle@fint.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 14 insertions, 15 deletions

diff --git a/drivers/scsi/megaraid.c b/drivers/scsi/megaraid.c
index dfea346b00a5..f9792528e33f 100644
--- a/drivers/scsi/megaraid.c
+++ b/drivers/scsi/megaraid.c
@@ -380,23 +380,23 @@ megaraid_queue(Scsi_Cmnd *scmd, void (*done)(Scsi_Cmnd *))
 
         spin_lock_irqsave(&adapter->lock, flags);
         scb = mega_build_cmd(adapter, scmd, &busy);
+        if (!scb)
+                goto out;
 
-        if(scb) {
-                scb->state |= SCB_PENDQ;
-                list_add_tail(&scb->list, &adapter->pending_list);
+        scb->state |= SCB_PENDQ;
+        list_add_tail(&scb->list, &adapter->pending_list);
 
-                /*
-                 * Check if the HBA is in quiescent state, e.g., during a
-                 * delete logical drive opertion. If it is, don't run
-                 * the pending_list.
-                 */
-                if(atomic_read(&adapter->quiescent) == 0) {
-                        mega_runpendq(adapter);
-                }
-                return 0;
-        }
-        spin_unlock_irqrestore(&adapter->lock, flags);
+        /*
+         * Check if the HBA is in quiescent state, e.g., during a
+         * delete logical drive opertion. If it is, don't run
+         * the pending_list.
+         */
+        if (atomic_read(&adapter->quiescent) == 0)
+                mega_runpendq(adapter);
 
+        busy = 0;
+ out:
+        spin_unlock_irqrestore(&adapter->lock, flags);
         return busy;
 }
 
@@ -4677,7 +4677,6 @@ megaraid_probe_one(struct pci_dev *pdev, const struct pci_device_id *id)
 
         adapter->flag = flag;
         spin_lock_init(&adapter->lock);
-        scsi_assign_lock(host, &adapter->lock);
 
         host->cmd_per_lun = max_cmd_per_lun;
         host->max_sectors = max_sectors_per_io;