From: Ira Weiny <ira.weiny@xxxxxxxxx>
dax_direct_access() is a special case of accessing pmem via a page
offset and without a struct page.
Because the dax driver is well aware of the special protections it has
mapped memory with, call dev_access_[en|dis]able() directly instead of
the unnecessary overhead of trying to get a page to kmap.
Similar to kmap, we leverage existing functions, dax_read_[un]lock(),
because they are already required to surround the use of the memory
returned from dax_direct_access().
Signed-off-by: Ira Weiny <ira.weiny@xxxxxxxxx>
---
drivers/dax/super.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/dax/super.c b/drivers/dax/super.c
index e84070b55463..0ddb3ee73e36 100644
--- a/drivers/dax/super.c
+++ b/drivers/dax/super.c
@@ -30,6 +30,7 @@ static DEFINE_SPINLOCK(dax_host_lock);
int dax_read_lock(void)
{
+ dev_access_enable(false);
return srcu_read_lock(&dax_srcu);
}
EXPORT_SYMBOL_GPL(dax_read_lock);
@@ -37,6 +38,7 @@ EXPORT_SYMBOL_GPL(dax_read_lock);
void dax_read_unlock(int id)
{
srcu_read_unlock(&dax_srcu, id);
+ dev_access_disable(false);
}
EXPORT_SYMBOL_GPL(dax_read_unlock);
--
2.28.0.rc0.12.gb6a658bd00c9
