[PATCH 3.10 06/35] ipr: Fix locking for unit attention handling

From: Greg Kroah-Hartman
Date: Fri Aug 14 2015 - 14:08:59 EST

3.10-stable review patch. If anyone has any objections, please let me know.


From: Brian King <brking@xxxxxxxxxxxxxxxxxx>

commit 36b8e180e1e929e00b351c3b72aab3147fc14116 upstream.

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.

Reviewed-by: Wen Xiong <wenxiong@xxxxxxxxxxxxxxxxxx>
Reviewed-by: Gabriel Krisman Bertazi <krisman@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Brian King <brking@xxxxxxxxxxxxxxxxxx>
Reviewed-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
Signed-off-by: James Bottomley <JBottomley@xxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

drivers/scsi/ipr.c | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)

--- a/drivers/scsi/ipr.c
+++ b/drivers/scsi/ipr.c
@@ -6141,21 +6141,23 @@ static void ipr_scsi_done(struct ipr_cmn
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)) {

- 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);
- 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);

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