While mapping DMA for scatter list when a scsi command is queued the
existing call to dma_alloc_coherent() in our map_sg_data() function
passes zero for the gfp_flags parameter. We are most definitly in atomic
context at this point as queue_command() is called in softirq context
and further we have a spinlock holding the scsi host lock.
Fix this by passing GFP_ATOMIC to dma_alloc_coherent() to prevent any
sort of sleeping in atomic context deadlock.
Fixes: 4dddbc26c389 ("[SCSI] ibmvscsi: handle large scatter/gather lists")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Tyrel Datwyler <tyreld@xxxxxxxxxxxxxxxxxx>
---
drivers/scsi/ibmvscsi/ibmvscsi.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/scsi/ibmvscsi/ibmvscsi.c b/drivers/scsi/ibmvscsi/ibmvscsi.c
index 1135e74..cb8535e 100644
--- a/drivers/scsi/ibmvscsi/ibmvscsi.c
+++ b/drivers/scsi/ibmvscsi/ibmvscsi.c
@@ -731,7 +731,7 @@ static int map_sg_data(struct scsi_cmnd *cmd,
evt_struct->ext_list = (struct srp_direct_buf *)
dma_alloc_coherent(dev,
SG_ALL * sizeof(struct srp_direct_buf),
- &evt_struct->ext_list_token, 0);
+ &evt_struct->ext_list_token, GFP_ATOMIC);
if (!evt_struct->ext_list) {
if (!firmware_has_feature(FW_FEATURE_CMO))
sdev_printk(KERN_ERR, cmd->device,
--
1.8.3.1
