If one of the MD raid participating target dax device supports
DAXDEV_RECOVERY, then it'll be declared on the whole that the
MD device is capable of DAXDEV_RECOVERY.
And only when the recovery process reaches to the target driver,
it becomes deterministic whether a certain dax address range
maybe recovered, or not.

Signed-off-by: Jane Chu <[email protected]>
---
 drivers/md/dm-table.c | 33 +++++++++++++++++++++++++++++++++
 1 file changed, 33 insertions(+)

diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
index e43096cfe9e2..8af8a81b6172 100644
--- a/drivers/md/dm-table.c
+++ b/drivers/md/dm-table.c
@@ -844,6 +844,36 @@ static bool dm_table_supports_dax(struct dm_table *t,
        return true;
 }
 
+/* Check whether device is capable of dax poison recovery */
+static int device_poison_recovery_capable(struct dm_target *ti,
+       struct dm_dev *dev, sector_t start, sector_t len, void *data)
+{
+       if (!dev->dax_dev)
+               return false;
+       return dax_recovery_capable(dev->dax_dev);
+}
+
+static bool dm_table_supports_poison_recovery(struct dm_table *t,
+       iterate_devices_callout_fn func)
+{
+       struct dm_target *ti;
+       unsigned int i;
+
+       /* Check if any DAX target supports poison recovery */
+       for (i = 0; i < dm_table_get_num_targets(t); i++) {
+               ti = dm_table_get_target(t, i);
+
+               if (!ti->type->direct_access)
+                       return false;
+
+               if (ti->type->iterate_devices &&
+                   ti->type->iterate_devices(ti, func, NULL))
+                       return true;
+       }
+
+       return false;
+}
+
 static int device_is_rq_stackable(struct dm_target *ti, struct dm_dev *dev,
                                  sector_t start, sector_t len, void *data)
 {
@@ -2014,6 +2044,9 @@ int dm_table_set_restrictions(struct dm_table *t, struct 
request_queue *q,
                blk_queue_flag_set(QUEUE_FLAG_DAX, q);
                if (dm_table_supports_dax(t, 
device_not_dax_synchronous_capable))
                        set_dax_synchronous(t->md->dax_dev);
+               if (dm_table_supports_poison_recovery(t,
+                                       device_poison_recovery_capable))
+                       set_dax_recovery(t->md->dax_dev);
        }
        else
                blk_queue_flag_clear(QUEUE_FLAG_DAX, q);
-- 
2.18.4


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