[PATCH v3 14/25] devdax: Fix sparse lock imbalance warning

[Dan Williams <dan.j.williams@xxxxxxxxx>]

Annotate dax_read_{lock,unlock} with their locking expectations to fix
this sparse report:

drivers/dax/super.c:45:5: sparse: warning: context imbalance in 'dax_read_lock' - wrong count at exit
drivers/dax/super.c: note: in included file (through include/linux/notifier.h, include/linux/memory_hotplug.h, include/linux/mmzone.h, include/linux/gfp.h, include/linux/mm.h, include/linux/pagemap.h):
./include/linux/srcu.h:189:9: sparse: warning: context imbalance in 'dax_read_unlock' - unexpected unlock

Reported-by: kernel test robot <lkp@xxxxxxxxx>
Link: http://lore.kernel.org/r/202210091141.cHaQEuCs-lkp@xxxxxxxxx
Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
---
 drivers/dax/super.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/dax/super.c b/drivers/dax/super.c
index 4909ad945a49..41342e47662d 100644
--- a/drivers/dax/super.c
+++ b/drivers/dax/super.c
@@ -42,13 +42,13 @@ static DEFINE_IDA(dax_minor_ida);
 static struct kmem_cache *dax_cache __read_mostly;
 static struct super_block *dax_superblock __read_mostly;
 
-int dax_read_lock(void)
+int dax_read_lock(void) __acquires(&dax_srcu)
 {
 	return srcu_read_lock(&dax_srcu);
 }
 EXPORT_SYMBOL_GPL(dax_read_lock);
 
-void dax_read_unlock(int id)
+void dax_read_unlock(int id) __releases(&dax_srcu)
 {
 	srcu_read_unlock(&dax_srcu, id);
 }