1 files changed, 18 insertions, 48 deletions

diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c
index 797e1ebff2..f24b67c64d 100644
--- a/drivers/dax/bus.c
+++ b/drivers/dax/bus.c
@@ -192,7 +192,7 @@ static u64 dev_dax_size(struct dev_dax *dev_dax)
 	u64 size = 0;
 	int i;
 
-	WARN_ON_ONCE(!rwsem_is_locked(&dax_dev_rwsem));
+	lockdep_assert_held(&dax_dev_rwsem);
 
 	for (i = 0; i < dev_dax->nr_range; i++)
 		size += range_len(&dev_dax->ranges[i].range);
@@ -302,7 +302,7 @@ static unsigned long long dax_region_avail_size(struct dax_region *dax_region)
 	resource_size_t size = resource_size(&dax_region->res);
 	struct resource *res;
 
-	WARN_ON_ONCE(!rwsem_is_locked(&dax_region_rwsem));
+	lockdep_assert_held(&dax_region_rwsem);
 
 	for_each_dax_region_resource(dax_region, res)
 		size -= resource_size(res);
@@ -447,7 +447,7 @@ static void trim_dev_dax_range(struct dev_dax *dev_dax)
 	struct range *range = &dev_dax->ranges[i].range;
 	struct dax_region *dax_region = dev_dax->region;
 
-	WARN_ON_ONCE(!rwsem_is_locked(&dax_region_rwsem));
+	lockdep_assert_held_write(&dax_region_rwsem);
 	dev_dbg(&dev_dax->dev, "delete range[%d]: %#llx:%#llx\n", i,
 		(unsigned long long)range->start,
 		(unsigned long long)range->end);
@@ -465,26 +465,17 @@ static void free_dev_dax_ranges(struct dev_dax *dev_dax)
 		trim_dev_dax_range(dev_dax);
 }
 
-static void __unregister_dev_dax(void *dev)
+static void unregister_dev_dax(void *dev)
 {
 	struct dev_dax *dev_dax = to_dev_dax(dev);
 
 	dev_dbg(dev, "%s\n", __func__);
 
+	down_write(&dax_region_rwsem);
 	kill_dev_dax(dev_dax);
 	device_del(dev);
 	free_dev_dax_ranges(dev_dax);
 	put_device(dev);
-}
-
-static void unregister_dev_dax(void *dev)
-{
-	if (rwsem_is_locked(&dax_region_rwsem))
-		return __unregister_dev_dax(dev);
-
-	if (WARN_ON_ONCE(down_write_killable(&dax_region_rwsem) != 0))
-		return;
-	__unregister_dev_dax(dev);
 	up_write(&dax_region_rwsem);
 }
 
@@ -507,7 +498,7 @@ static int __free_dev_dax_id(struct dev_dax *dev_dax)
 	struct dax_region *dax_region;
 	int rc = dev_dax->id;
 
-	WARN_ON_ONCE(!rwsem_is_locked(&dax_dev_rwsem));
+	lockdep_assert_held_write(&dax_dev_rwsem);
 
 	if (!dev_dax->dyn_id || dev_dax->id < 0)
 		return -1;
@@ -560,15 +551,10 @@ static ssize_t delete_store(struct device *dev, struct device_attribute *attr,
 	if (!victim)
 		return -ENXIO;
 
-	rc = down_write_killable(&dax_region_rwsem);
-	if (rc)
-		return rc;
-	rc = down_write_killable(&dax_dev_rwsem);
-	if (rc) {
-		up_write(&dax_region_rwsem);
-		return rc;
-	}
+	device_lock(dev);
+	device_lock(victim);
 	dev_dax = to_dev_dax(victim);
+	down_write(&dax_dev_rwsem);
 	if (victim->driver || dev_dax_size(dev_dax))
 		rc = -EBUSY;
 	else {
@@ -589,11 +575,12 @@ static ssize_t delete_store(struct device *dev, struct device_attribute *attr,
 			rc = -EBUSY;
 	}
 	up_write(&dax_dev_rwsem);
+	device_unlock(victim);
 
 	/* won the race to invalidate the device, clean it up */
 	if (do_del)
 		devm_release_action(dev, unregister_dev_dax, victim);
-	up_write(&dax_region_rwsem);
+	device_unlock(dev);
 	put_device(victim);
 
 	return rc;
@@ -705,7 +692,7 @@ static void dax_mapping_release(struct device *dev)
 	put_device(parent);
 }
 
-static void __unregister_dax_mapping(void *data)
+static void unregister_dax_mapping(void *data)
 {
 	struct device *dev = data;
 	struct dax_mapping *mapping = to_dax_mapping(dev);
@@ -713,25 +700,12 @@ static void __unregister_dax_mapping(void *data)
 
 	dev_dbg(dev, "%s\n", __func__);
 
-	WARN_ON_ONCE(!rwsem_is_locked(&dax_region_rwsem));
-
 	dev_dax->ranges[mapping->range_id].mapping = NULL;
 	mapping->range_id = -1;
 
 	device_unregister(dev);
 }
 
-static void unregister_dax_mapping(void *data)
-{
-	if (rwsem_is_locked(&dax_region_rwsem))
-		return __unregister_dax_mapping(data);
-
-	if (WARN_ON_ONCE(down_write_killable(&dax_region_rwsem) != 0))
-		return;
-	__unregister_dax_mapping(data);
-	up_write(&dax_region_rwsem);
-}
-
 static struct dev_dax_range *get_dax_range(struct device *dev)
 {
 	struct dax_mapping *mapping = to_dax_mapping(dev);
@@ -830,7 +804,7 @@ static int devm_register_dax_mapping(struct dev_dax *dev_dax, int range_id)
 	struct device *dev;
 	int rc;
 
-	WARN_ON_ONCE(!rwsem_is_locked(&dax_region_rwsem));
+	lockdep_assert_held_write(&dax_region_rwsem);
 
 	if (dev_WARN_ONCE(&dev_dax->dev, !dax_region->dev->driver,
 				"region disabled\n"))
@@ -876,7 +850,7 @@ static int alloc_dev_dax_range(struct dev_dax *dev_dax, u64 start,
 	struct resource *alloc;
 	int i, rc;
 
-	WARN_ON_ONCE(!rwsem_is_locked(&dax_region_rwsem));
+	lockdep_assert_held_write(&dax_region_rwsem);
 
 	/* handle the seed alloc special case */
 	if (!size) {
@@ -935,7 +909,7 @@ static int adjust_dev_dax_range(struct dev_dax *dev_dax, struct resource *res, r
 	struct device *dev = &dev_dax->dev;
 	int rc;
 
-	WARN_ON_ONCE(!rwsem_is_locked(&dax_region_rwsem));
+	lockdep_assert_held_write(&dax_region_rwsem);
 
 	if (dev_WARN_ONCE(dev, !size, "deletion is handled by dev_dax_shrink\n"))
 		return -EINVAL;
@@ -963,11 +937,11 @@ static ssize_t size_show(struct device *dev,
 	unsigned long long size;
 	int rc;
 
-	rc = down_write_killable(&dax_dev_rwsem);
+	rc = down_read_interruptible(&dax_dev_rwsem);
 	if (rc)
 		return rc;
 	size = dev_dax_size(dev_dax);
-	up_write(&dax_dev_rwsem);
+	up_read(&dax_dev_rwsem);
 
 	return sysfs_emit(buf, "%llu\n", size);
 }
@@ -1566,12 +1540,8 @@ err_id:
 struct dev_dax *devm_create_dev_dax(struct dev_dax_data *data)
 {
 	struct dev_dax *dev_dax;
-	int rc;
-
-	rc = down_write_killable(&dax_region_rwsem);
-	if (rc)
-		return ERR_PTR(rc);
 
+	down_write(&dax_region_rwsem);
 	dev_dax = __devm_create_dev_dax(data);
 	up_write(&dax_region_rwsem);