scsi: sg: update comment for blk_get_request()

The calling convention of blk_get_request() has changed in lk 4.18; update
the comment in sg.c to match.

Fixes: ff005a066240 ("block: sanitize blk_get_request calling conventions")
Signed-off-by: Tony Battersby <tonyb@cybernetics.com>
Acked-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

1 files changed, 5 insertions, 9 deletions

diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index 2962a38c5068..ba9ba0e04f42 100644
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -1741,15 +1741,11 @@ sg_start_req(Sg_request *srp, unsigned char *cmd)
          *
          * With scsi-mq enabled, there are a fixed number of preallocated
          * requests equal in number to shost->can_queue.  If all of the
-         * preallocated requests are already in use, then using GFP_ATOMIC with
-         * blk_get_request() will return -EWOULDBLOCK, whereas using GFP_KERNEL
-         * will cause blk_get_request() to sleep until an active command
-         * completes, freeing up a request.  Neither option is ideal, but
-         * GFP_KERNEL is the better choice to prevent userspace from getting an
-         * unexpected EWOULDBLOCK.
-         *
-         * With scsi-mq disabled, blk_get_request() with GFP_KERNEL usually
-         * does not sleep except under memory pressure.
+         * preallocated requests are already in use, then blk_get_request()
+         * will sleep until an active command completes, freeing up a request.
+         * Although waiting in an asynchronous interface is less than ideal, we
+         * do not want to use BLK_MQ_REQ_NOWAIT here because userspace might
+         * not expect an EWOULDBLOCK from this condition.
          */
         rq = blk_get_request(q, hp->dxfer_direction == SG_DXFER_TO_DEV ?
                         REQ_OP_SCSI_OUT : REQ_OP_SCSI_IN, 0);