[PATCH AUTOSEL 3.18 29/98] scsi: ->queue_rq can't sleep

From: Sasha Levin
Date: Thu Oct 25 2018 - 10:19:42 EST

From: Christoph Hellwig <hch@xxxxxx>

[ Upstream commit 70a0f2c1898c6abf53670e55642b6e840b003892 ]

The blk-mq ->queue_rq method is always called from process context,
but might have preemption disabled. This means we still always
have to use GFP_ATOMIC for memory allocations, and thus need to
revert part of commit 3c356bde1 ("scsi: stop passing a gfp_mask
argument down the command setup path").

Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Reported-by: Sasha Levin <sasha.levin@xxxxxxxxxx>
Reviewed-by: Bart Van Assche <bart.vanassche@xxxxxxxxxxx>
Tested-by: Alexei Starovoitov <alexei.starovoitov@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
drivers/scsi/scsi_lib.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index a11837054d6c..0d5c218b7ad1 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -616,7 +616,7 @@ static int scsi_alloc_sgtable(struct scsi_data_buffer *sdb, int nents,

ret = __sg_alloc_table(&sdb->table, nents, SCSI_MAX_SG_SEGMENTS,
- first_chunk, gfp_mask, scsi_sg_alloc);
+ first_chunk, GFP_ATOMIC, scsi_sg_alloc);
if (unlikely(ret))
scsi_free_sgtable(sdb, mq);
return ret;