ipr: Fix locking for unit attention handling

Make sure we have the host lock held when calling scsi_report_bus_reset. Fixes
a crash seen as the __devices list in the scsi host was changing as we were
iterating through it.

Cc: <stable@vger.kernel.org>
Reviewed-by: Wen Xiong <wenxiong@linux.vnet.ibm.com>
Reviewed-by: Gabriel Krisman Bertazi <krisman@linux.vnet.ibm.com>
Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: James Bottomley <JBottomley@Odin.com>

diff --git a/drivers/scsi/ipr.c b/drivers/scsi/ipr.c
index 8827448..486ffaf 100644 (file)
--- a/drivers/scsi/ipr.c
+++ b/drivers/scsi/ipr.c
@@ -6263,21 +6263,23 @@ static void ipr_scsi_done(struct ipr_cmnd *ipr_cmd)
        struct ipr_ioa_cfg *ioa_cfg = ipr_cmd->ioa_cfg;
        struct scsi_cmnd *scsi_cmd = ipr_cmd->scsi_cmd;
        u32 ioasc = be32_to_cpu(ipr_cmd->s.ioasa.hdr.ioasc);
-       unsigned long hrrq_flags;
+       unsigned long lock_flags;
 
        scsi_set_resid(scsi_cmd, be32_to_cpu(ipr_cmd->s.ioasa.hdr.residual_data_len));
 
        if (likely(IPR_IOASC_SENSE_KEY(ioasc) == 0)) {
                scsi_dma_unmap(scsi_cmd);
 
-               spin_lock_irqsave(ipr_cmd->hrrq->lock, hrrq_flags);
+               spin_lock_irqsave(ipr_cmd->hrrq->lock, lock_flags);
                list_add_tail(&ipr_cmd->queue, &ipr_cmd->hrrq->hrrq_free_q);
                scsi_cmd->scsi_done(scsi_cmd);
-               spin_unlock_irqrestore(ipr_cmd->hrrq->lock, hrrq_flags);
+               spin_unlock_irqrestore(ipr_cmd->hrrq->lock, lock_flags);
        } else {
-               spin_lock_irqsave(ipr_cmd->hrrq->lock, hrrq_flags);
+               spin_lock_irqsave(ioa_cfg->host->host_lock, lock_flags);
+               spin_lock(&ipr_cmd->hrrq->_lock);
                ipr_erp_start(ioa_cfg, ipr_cmd);
-               spin_unlock_irqrestore(ipr_cmd->hrrq->lock, hrrq_flags);
+               spin_unlock(&ipr_cmd->hrrq->_lock);
+               spin_unlock_irqrestore(ioa_cfg->host->host_lock, lock_flags);
        }
 }