1 files changed, 13 insertions, 11 deletions

diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index d050e073e57..66aa4bee80a 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -2552,8 +2552,11 @@ static void atapi_qc_complete(struct ata_queued_cmd *qc)
 		 *
 		 * If door lock fails, always clear sdev->locked to
 		 * avoid this infinite loop.
+		 *
+		 * This may happen before SCSI scan is complete.  Make
+		 * sure qc->dev->sdev isn't NULL before dereferencing.
 		 */
-		if (qc->cdb[0] == ALLOW_MEDIUM_REMOVAL)
+		if (qc->cdb[0] == ALLOW_MEDIUM_REMOVAL && qc->dev->sdev)
 			qc->dev->sdev->locked = 0;
 
 		qc->scsicmd->result = SAM_STAT_CHECK_CONDITION;
@@ -3163,8 +3166,8 @@ static inline int __ata_scsi_queuecmd(struct scsi_cmnd *scmd,
 
 /**
  *	ata_scsi_queuecmd - Issue SCSI cdb to libata-managed device
+ *	@shost: SCSI host of command to be sent
  *	@cmd: SCSI command to be sent
- *	@done: Completion function, called when command is complete
  *
  *	In some cases, this function translates SCSI commands into
  *	ATA taskfiles, and queues the taskfiles to be sent to
@@ -3174,37 +3177,36 @@ static inline int __ata_scsi_queuecmd(struct scsi_cmnd *scmd,
  *	ATA and ATAPI devices appearing as SCSI devices.
  *
  *	LOCKING:
- *	Releases scsi-layer-held lock, and obtains host lock.
+ *	ATA host lock
  *
  *	RETURNS:
  *	Return value from __ata_scsi_queuecmd() if @cmd can be queued,
  *	0 otherwise.
  */
-int ata_scsi_queuecmd(struct scsi_cmnd *cmd, void (*done)(struct scsi_cmnd *))
+int ata_scsi_queuecmd(struct Scsi_Host *shost, struct scsi_cmnd *cmd)
 {
 	struct ata_port *ap;
 	struct ata_device *dev;
 	struct scsi_device *scsidev = cmd->device;
-	struct Scsi_Host *shost = scsidev->host;
 	int rc = 0;
+	unsigned long irq_flags;
 
 	ap = ata_shost_to_port(shost);
 
-	spin_unlock(shost->host_lock);
-	spin_lock(ap->lock);
+	spin_lock_irqsave(ap->lock, irq_flags);
 
 	ata_scsi_dump_cdb(ap, cmd);
 
 	dev = ata_scsi_find_dev(ap, scsidev);
 	if (likely(dev))
-		rc = __ata_scsi_queuecmd(cmd, done, dev);
+		rc = __ata_scsi_queuecmd(cmd, cmd->scsi_done, dev);
 	else {
 		cmd->result = (DID_BAD_TARGET << 16);
-		done(cmd);
+		cmd->scsi_done(cmd);
 	}
 
-	spin_unlock(ap->lock);
-	spin_lock(shost->host_lock);
+	spin_unlock_irqrestore(ap->lock, irq_flags);
+
 	return rc;
 }