Re: [PATCH 1/2] libata: Expose trim capability in sysfs

[Marc MERLIN <marc@merlins.org>]

On Tue, Apr 01, 2014 at 08:42:36PM -0400, Martin K. Petersen wrote:
> From: "Martin K. Petersen" <martin.petersen@oracle.com>
> 
> Now that drives with support for queued trim are starting to appear, it
> would be helpful to expose the chosen trim mode to userland. Create a
> sysfs "trim" attribute for each ata_device that displays whether trim is
> "unsupported", "unqueued" or "queued".
 
Ok, I'm going to sound stupid, but which sysfs property is this in?
Or more simply what file do I have to cat see this?

Thanks,
Marc

> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
> Cc: Chris Samuel <chris@csamuel.org>
> Cc: Marc MERLIN <marc@merlins.org>
> ---
>  drivers/ata/libata-transport.c | 32 ++++++++++++++++++++++++++++++++
>  1 file changed, 32 insertions(+)
> 
> diff --git a/drivers/ata/libata-transport.c b/drivers/ata/libata-transport.c
> index e37413228228..a9a1a9055a3a 100644
> --- a/drivers/ata/libata-transport.c
> +++ b/drivers/ata/libata-transport.c
> @@ -559,6 +559,37 @@ show_ata_dev_gscr(struct device *dev,
>  
>  static DEVICE_ATTR(gscr, S_IRUGO, show_ata_dev_gscr, NULL);
>  
> +enum {
> +	ATA_TRIM_UNSUPPORTED = 0,
> +	ATA_TRIM_UNQUEUED = 1,
> +	ATA_TRIM_QUEUED = 2,
> +};
> +
> +static const char *trim_mode[] = {
> +	[ATA_TRIM_UNSUPPORTED] = "unsupported",
> +	[ATA_TRIM_UNQUEUED] = "unqueued",
> +	[ATA_TRIM_QUEUED] = "queued",
> +};
> +
> +static ssize_t
> +show_ata_dev_trim(struct device *dev,
> +		  struct device_attribute *attr, char *buf)
> +{
> +	struct ata_device *ata_dev = transport_class_to_dev(dev);
> +	unsigned int mode;
> +
> +	if (!ata_id_has_trim(ata_dev->id))
> +		mode = ATA_TRIM_UNSUPPORTED;
> +	else if (ata_fpdma_dsm_supported(ata_dev))
> +		mode = ATA_TRIM_QUEUED;
> +	else
> +		mode = ATA_TRIM_UNQUEUED;
> +
> +	return snprintf(buf, 20, "%s\n", trim_mode[mode]);
> +}
> +
> +static DEVICE_ATTR(trim, S_IRUGO, show_ata_dev_trim, NULL);
> +
>  static DECLARE_TRANSPORT_CLASS(ata_dev_class,
>  			       "ata_device", NULL, NULL, NULL);
>  
> @@ -732,6 +763,7 @@ struct scsi_transport_template *ata_attach_transport(void)
>  	SETUP_DEV_ATTRIBUTE(ering);
>  	SETUP_DEV_ATTRIBUTE(id);
>  	SETUP_DEV_ATTRIBUTE(gscr);
> +	SETUP_DEV_ATTRIBUTE(trim);
>  	BUG_ON(count > ATA_DEV_ATTRS);
>  	i->dev_attrs[count] = NULL;
>  
> -- 
> 1.8.3.1
> 
> 

-- 
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