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>

diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index 2962a38..ba9ba0e 100644 (file)
--- 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);