On 5/4/23 6:50 PM, Bart Van Assche wrote:
> Make scsi_host_block() easier to read by converting it to the widely used
> early-return style. This patch reworks code introduced by commit
> f983622ae605 ("scsi: core: Avoid calling synchronize_rcu() for each device
> in scsi_host_block()").
>
> Cc: Ming Lei <ming.lei@xxxxxxxxxx>
> Cc: Ye Bin <yebin10@xxxxxxxxxx>
> Cc: Hannes Reinecke <hare@xxxxxxx>
> Signed-off-by: Bart Van Assche <bvanassche@xxxxxxx>
> ---
> drivers/scsi/scsi_lib.c | 18 +++++++++++++-----
> 1 file changed, 13 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
> index b7c569a42aa4..758a57616dd3 100644
> --- a/drivers/scsi/scsi_lib.c
> +++ b/drivers/scsi/scsi_lib.c
> @@ -2939,11 +2939,20 @@ scsi_target_unblock(struct device *dev, enum scsi_device_state new_state)
> }
> EXPORT_SYMBOL_GPL(scsi_target_unblock);
>
> +/**
> + * scsi_host_block - Try to transition all logical units to the SDEV_BLOCK state
> + * @shost: device to block
> + *
> + * Pause SCSI command processing for all logical units associated with the SCSI
> + * host and wait until pending scsi_queue_rq() calls have finished.
> + *
> + * Returns zero if successful or a negative error code upon failure.
> + */
> int
> scsi_host_block(struct Scsi_Host *shost)
> {
> struct scsi_device *sdev;
> - int ret = 0;
> + int ret;
>
> /*
> * Call scsi_internal_device_block_nowait so we can avoid
> @@ -2955,7 +2964,7 @@ scsi_host_block(struct Scsi_Host *shost)
> mutex_unlock(&sdev->state_mutex);
> if (ret) {
> scsi_device_put(sdev);
> - break;
> + return ret;
> }
> }
>
> @@ -2965,10 +2974,9 @@ scsi_host_block(struct Scsi_Host *shost)
> */
> WARN_ON_ONCE(shost->tag_set.flags & BLK_MQ_F_BLOCKING);
>
> - if (!ret)
> - synchronize_rcu();
> + synchronize_rcu();
>
> - return ret;
> + return 0;
> }
> EXPORT_SYMBOL_GPL(scsi_host_block);
>
Reviewed-by: Mike Christie <michael.christie@xxxxxxxxxx>
