On Wed, Aug 09, 2017 at 03:09:18PM +0200, Hannes Reinecke wrote:
> While the 'state' attribute can (and will) change occasionally,
> calling 'poll()' or 'select()' on it fails as sysfs is never
> notified that the state has changed.
> With this patch calling 'poll()' or 'select()' will work
> properly.
>
> Signed-off-by: Hannes Reinecke <h...@suse.com>
> ---
> drivers/scsi/scsi_lib.c | 7 +++++--
> drivers/scsi/scsi_transport_srp.c | 5 ++++-
> 2 files changed, 9 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
> index 41c19c7..2101cfd 100644
> --- a/drivers/scsi/scsi_lib.c
> +++ b/drivers/scsi/scsi_lib.c
> @@ -2654,6 +2654,7 @@ void scsi_exit_queue(void)
>
> }
> sdev->sdev_state = state;
> + sysfs_notify(&sdev->sdev_gendev.kobj, NULL, "state");
> return 0;
>
> illegal:
> @@ -3074,14 +3075,16 @@ int scsi_internal_device_unblock_nowait(struct
> scsi_device *sdev,
> * offlined states and goose the device queue if successful.
> */
> if ((sdev->sdev_state == SDEV_BLOCK) ||
> - (sdev->sdev_state == SDEV_TRANSPORT_OFFLINE))
> + (sdev->sdev_state == SDEV_TRANSPORT_OFFLINE)) {
> sdev->sdev_state = new_state;
> - else if (sdev->sdev_state == SDEV_CREATED_BLOCK) {
> + sysfs_notify(&sdev->sdev_gendev.kobj, NULL, "state");
> + } else if (sdev->sdev_state == SDEV_CREATED_BLOCK) {
> if (new_state == SDEV_TRANSPORT_OFFLINE ||
> new_state == SDEV_OFFLINE)
> sdev->sdev_state = new_state;
> else
> sdev->sdev_state = SDEV_CREATED;
> + sysfs_notify(&sdev->sdev_gendev.kobj, NULL, "state");
> } else if (sdev->sdev_state != SDEV_CANCEL &&
> sdev->sdev_state != SDEV_OFFLINE)
> return -EINVAL;
This would be a lot more readable using switch statements:
switch (sdev->sdev_state) {
case SDEV_BLOCK:
case SDEV_TRANSPORT_OFFLINE:
sdev->sdev_state = new_state;
sysfs_notify(&sdev->sdev_gendev.kobj, NULL, "state");
break;
case SDEV_CREATED_BLOCK:
switch (new_state) {
case SDEV_TRANSPORT_OFFLINE:
case SDEV_OFFLINE:
sdev->sdev_state = new_state;
break;
default:
sdev->sdev_state = SDEV_CREATED;
break;
}
sysfs_notify(&sdev->sdev_gendev.kobj, NULL, "state");
break;
case SDEV_CANCEL:
case SDEV_OFFLINE:
break;
default:
return -EINVAL;
}
Otherwise it looks fine to me.
