diff options
Diffstat (limited to 'drivers/scsi/scsi.c')
| -rw-r--r-- | drivers/scsi/scsi.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c index 18185133d..eeff3d5fd 100644 --- a/drivers/scsi/scsi.c +++ b/drivers/scsi/scsi.c @@ -1768,14 +1768,24 @@ void scsi_finish_command(Scsi_Cmnd * SCpnt) { struct Scsi_Host *host; Scsi_Device *device; + unsigned long flags; ASSERT_LOCK(&io_request_lock, 0); host = SCpnt->host; device = SCpnt->device; + /* + * We need to protect the decrement, as otherwise a race condition + * would exist. Fiddling with SCpnt isn't a problem as the + * design only allows a single SCpnt to be active in only + * one execution context, but the device and host structures are + * shared. + */ + spin_lock_irqsave(&io_request_lock, flags); host->host_busy--; /* Indicate that we are free */ device->device_busy--; /* Decrement device usage counter. */ + spin_unlock_irqrestore(&io_request_lock, flags); /* * Clear the flags which say that the device/host is no longer |