On 01/09/2019 08:58 PM, Tyrel Datwyler wrote:
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@vger.kernel.org Signed-off-by: Tyrel Datwyler tyreld@linux.vnet.ibm.com
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);
Reviewed-by: Brian King brking@linux.vnet.ibm.com