[PATCH 07/14] sd: add a sd_disable_write_same helper

[Christoph Hellwig <hch@xxxxxx>]

Add helper to disable WRITE SAME when it is not supported and use it
instead of sd_config_write_same in the I/O completion handler.  This
avoids touching more fields than required in the I/O completion handler
and  prepares for converting sd to use the atomic queue limits API.

Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Reviewed-by: Bart Van Assche <bvanassche@xxxxxxx>
Reviewed-by: Damien Le Moal <dlemoal@xxxxxxxxxx>
---
 drivers/scsi/sd.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index f07d90474e682b..70211d0b187652 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -1004,6 +1004,13 @@ static blk_status_t sd_setup_write_zeroes_cmnd(struct 
scsi_cmnd *cmd)
        return sd_setup_write_same10_cmnd(cmd, false);
 }
 
+static void sd_disable_write_same(struct scsi_disk *sdkp)
+{
+       sdkp->device->no_write_same = 1;
+       sdkp->max_ws_blocks = 0;
+       blk_queue_max_write_zeroes_sectors(sdkp->disk->queue, 0);
+}
+
 static void sd_config_write_same(struct scsi_disk *sdkp)
 {
        struct request_queue *q = sdkp->disk->queue;
@@ -2258,8 +2265,7 @@ static int sd_done(struct scsi_cmnd *SCpnt)
                                if (SCpnt->cmnd[1] & 8) { /* UNMAP */
                                        sd_disable_discard(sdkp);
                                } else {
-                                       sdkp->device->no_write_same = 1;
-                                       sd_config_write_same(sdkp);
+                                       sd_disable_write_same(sdkp);
                                        req->rq_flags |= RQF_QUIET;
                                }
                                break;
-- 
2.43.0