[PATCH 04/62] dax/bus.c: Fix a locking bug

[Bart Van Assche]

From: Bart Van Assche <bvanassche@xxxxxxx>

Only unlock dax_dev_rwsem if it has been locked. This locking bug was
detected by the Clang thread-safety analyzer.

Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
Cc: Vishal Verma <vishal.l.verma@xxxxxxxxx>
Cc: Dave Jiang <dave.jiang@xxxxxxxxx>
Cc: Alison Schofield <alison.schofield@xxxxxxxxx>
Cc: nvdimm@xxxxxxxxxxxxxxx
Cc: linux-cxl@xxxxxxxxxxxxxxx
Fixes: c05ae9d85b47 ("dax/bus.c: replace driver-core lock usage by a local rwsem")
Signed-off-by: Bart Van Assche <bvanassche@xxxxxxx>
---
 drivers/dax/bus.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c
index c94c09622516..ebd3806c34e5 100644
--- a/drivers/dax/bus.c
+++ b/drivers/dax/bus.c
@@ -1117,11 +1117,10 @@ static ssize_t size_store(struct device *dev, struct device_attribute *attr,
 	}
 	rc = down_write_killable(&dax_dev_rwsem);
 	if (rc)
-		goto err_dev;
+		goto err_region;
 
 	rc = dev_dax_resize(dax_region, dev_dax, val);
 
-err_dev:
 	up_write(&dax_dev_rwsem);
 err_region:
 	up_write(&dax_region_rwsem);