[Devel] [PATCH] ploop: Add native ploop support parameter

[Kirill Tkhai]

Please, ignore this

On 09.04.2019 19:21, Kirill Tkhai wrote:
> This adds a possibility to determ whether driver supports
> native discard (without maintaince mode).
> 
> Currently, we show features in module parameters
> and this was started since "large_disk_support".
> The patch continues the way, but the parameter
> is made RW to allow prohibit the feature on flight.
> 
> https://jira.sw.ru/browse/PSBM-93731
> 
> Signed-off-by: Kirill Tkhai <ktkhai at virtuozzo.com>
> ---
>  drivers/block/ploop/dev.c |    6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/drivers/block/ploop/dev.c b/drivers/block/ploop/dev.c
> index 01f70c6abec9..815c74438dd6 100644
> --- a/drivers/block/ploop/dev.c
> +++ b/drivers/block/ploop/dev.c
> @@ -59,6 +59,7 @@ static long root_threshold __read_mostly = 2L * 1024 * 1024; /* 2GB in KB */
>  static long user_threshold __read_mostly = 4L * 1024 * 1024; /* 4GB in KB */
>  
>  static int large_disk_support __read_mostly = 1; /* true */
> +static int native_discard_support __read_mostly = 1;
>  
>  static struct rb_root ploop_devices_tree = RB_ROOT;
>  static DEFINE_MUTEX(ploop_devices_mutex);
> @@ -2184,6 +2185,9 @@ complete_unsupported_discard_req(struct ploop_request * preq)
>  static bool ploop_can_issue_discard(struct ploop_device *plo,
>  				    struct ploop_request *preq)
>  {
> +	if (!native_discard_support)
> +		return false;
> +
>  	if (test_bit(PLOOP_REQ_DISCARD, &preq->state))
>  		return true;
>  
> @@ -5637,6 +5641,8 @@ module_param(user_threshold, long, 0644);
>  MODULE_PARM_DESC(user_threshold, "Disk space reserved for user (in kilobytes)");
>  module_param(large_disk_support, int, 0444);
>  MODULE_PARM_DESC(ploop_large_disk_support, "Support of large disks (>2TB)");
> +module_param(native_discard_support, int, 0644);
> +MODULE_PARM_DESC(native_discard_support, "Native discard support");
>  
>  static int __init ploop_mod_init(void)
>  {
>