[v9,4/7] dm: enable synchronous dax
diff mbox series

Message ID 20190514145422.16923-5-pagupta@redhat.com
State Superseded
Headers show
Series
  • virtio pmem driver
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Commit Message

Pankaj Gupta May 14, 2019, 2:54 p.m. UTC
This patch sets dax device 'DAXDEV_SYNC' flag if all the target
 devices of device mapper support synchrononous DAX. If device
 mapper consists of both synchronous and asynchronous dax devices,
 we don't set 'DAXDEV_SYNC' flag. 

Signed-off-by: Pankaj Gupta <pagupta@redhat.com>
---
 drivers/md/dm-table.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

Comments

Dan Williams May 15, 2019, 8:48 p.m. UTC | #1
[ add Mike and dm-devel ]

Mike, any concerns with the below addition to the device-mapper-dax
implementation?

On Tue, May 14, 2019 at 7:58 AM Pankaj Gupta <pagupta@redhat.com> wrote:
>
>  This patch sets dax device 'DAXDEV_SYNC' flag if all the target
>  devices of device mapper support synchrononous DAX. If device
>  mapper consists of both synchronous and asynchronous dax devices,
>  we don't set 'DAXDEV_SYNC' flag.
>
> Signed-off-by: Pankaj Gupta <pagupta@redhat.com>
> ---
>  drivers/md/dm-table.c | 14 ++++++++++++++
>  1 file changed, 14 insertions(+)
>
> diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
> index cde3b49b2a91..1cce626ff576 100644
> --- a/drivers/md/dm-table.c
> +++ b/drivers/md/dm-table.c
> @@ -886,10 +886,17 @@ static int device_supports_dax(struct dm_target *ti, struct dm_dev *dev,
>         return bdev_dax_supported(dev->bdev, PAGE_SIZE);
>  }
>
> +static int device_synchronous(struct dm_target *ti, struct dm_dev *dev,
> +                              sector_t start, sector_t len, void *data)
> +{
> +       return dax_synchronous(dev->dax_dev);
> +}
> +
>  static bool dm_table_supports_dax(struct dm_table *t)
>  {
>         struct dm_target *ti;
>         unsigned i;
> +       bool dax_sync = true;
>
>         /* Ensure that all targets support DAX. */
>         for (i = 0; i < dm_table_get_num_targets(t); i++) {
> @@ -901,7 +908,14 @@ static bool dm_table_supports_dax(struct dm_table *t)
>                 if (!ti->type->iterate_devices ||
>                     !ti->type->iterate_devices(ti, device_supports_dax, NULL))
>                         return false;
> +
> +               /* Check devices support synchronous DAX */
> +               if (dax_sync &&
> +                   !ti->type->iterate_devices(ti, device_synchronous, NULL))
> +                       dax_sync = false;
>         }
> +       if (dax_sync)
> +               set_dax_synchronous(t->md->dax_dev);
>
>         return true;
>  }
> --
> 2.20.1
>

Patch
diff mbox series

diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
index cde3b49b2a91..1cce626ff576 100644
--- a/drivers/md/dm-table.c
+++ b/drivers/md/dm-table.c
@@ -886,10 +886,17 @@  static int device_supports_dax(struct dm_target *ti, struct dm_dev *dev,
 	return bdev_dax_supported(dev->bdev, PAGE_SIZE);
 }
 
+static int device_synchronous(struct dm_target *ti, struct dm_dev *dev,
+			       sector_t start, sector_t len, void *data)
+{
+	return dax_synchronous(dev->dax_dev);
+}
+
 static bool dm_table_supports_dax(struct dm_table *t)
 {
 	struct dm_target *ti;
 	unsigned i;
+	bool dax_sync = true;
 
 	/* Ensure that all targets support DAX. */
 	for (i = 0; i < dm_table_get_num_targets(t); i++) {
@@ -901,7 +908,14 @@  static bool dm_table_supports_dax(struct dm_table *t)
 		if (!ti->type->iterate_devices ||
 		    !ti->type->iterate_devices(ti, device_supports_dax, NULL))
 			return false;
+
+		/* Check devices support synchronous DAX */
+		if (dax_sync &&
+		    !ti->type->iterate_devices(ti, device_synchronous, NULL))
+			dax_sync = false;
 	}
+	if (dax_sync)
+		set_dax_synchronous(t->md->dax_dev);
 
 	return true;
 }