diff --git a/block/blk-mq-debugfs.c b/block/blk-mq-debugfs.c
index f8120832ca7b..7921573aebbc 100644
--- a/block/blk-mq-debugfs.c
+++ b/block/blk-mq-debugfs.c
@@ -839,6 +839,9 @@ static const struct blk_mq_debugfs_attr blk_mq_debugfs_ctx_attrs[] = {
 static bool debugfs_create_files(struct dentry *parent, void *data,
 				 const struct blk_mq_debugfs_attr *attr)
 {
+	if (IS_ERR_OR_NULL(parent))
+		return false;
+
 	d_inode(parent)->i_private = data;
 
 	for (; attr->name; attr++) {
diff --git a/drivers/base/cacheinfo.c b/drivers/base/cacheinfo.c
index cf78fa6d470d..a7359535caf5 100644
--- a/drivers/base/cacheinfo.c
+++ b/drivers/base/cacheinfo.c
@@ -79,8 +79,7 @@ static void cache_size(struct cacheinfo *this_leaf, struct device_node *np)
 	ct_idx = get_cacheinfo_idx(this_leaf->type);
 	propname = cache_type_info[ct_idx].size_prop;
 
-	if (of_property_read_u32(np, propname, &this_leaf->size))
-		this_leaf->size = 0;
+	of_property_read_u32(np, propname, &this_leaf->size);
 }
 
 /* not cache_line_size() because that's a macro in include/linux/cache.h */
@@ -114,8 +113,7 @@ static void cache_nr_sets(struct cacheinfo *this_leaf, struct device_node *np)
 	ct_idx = get_cacheinfo_idx(this_leaf->type);
 	propname = cache_type_info[ct_idx].nr_sets_prop;
 
-	if (of_property_read_u32(np, propname, &this_leaf->number_of_sets))
-		this_leaf->number_of_sets = 0;
+	of_property_read_u32(np, propname, &this_leaf->number_of_sets);
 }
 
 static void cache_associativity(struct cacheinfo *this_leaf)
diff --git a/fs/debugfs/inode.c b/fs/debugfs/inode.c
index 13b01351dd1c..29c68c5d44d5 100644
--- a/fs/debugfs/inode.c
+++ b/fs/debugfs/inode.c
@@ -324,7 +324,7 @@ static struct dentry *failed_creating(struct dentry *dentry)
 	inode_unlock(d_inode(dentry->d_parent));
 	dput(dentry);
 	simple_release_fs(&debugfs_mount, &debugfs_mount_count);
-	return NULL;
+	return ERR_PTR(-ENOMEM);
 }
 
 static struct dentry *end_creating(struct dentry *dentry)
@@ -347,7 +347,7 @@ static struct dentry *__debugfs_create_file(const char *name, umode_t mode,
 	dentry = start_creating(name, parent);
 
 	if (IS_ERR(dentry))
-		return NULL;
+		return dentry;
 
 	inode = debugfs_get_inode(dentry->d_sb);
 	if (unlikely(!inode))
@@ -386,7 +386,8 @@ static struct dentry *__debugfs_create_file(const char *name, umode_t mode,
  * This function will return a pointer to a dentry if it succeeds.  This
  * pointer must be passed to the debugfs_remove() function when the file is
  * to be removed (no automatic cleanup happens if your module is unloaded,
- * you are responsible here.)  If an error occurs, %NULL will be returned.
+ * you are responsible here.)  If an error occurs, %ERR_PTR(-ERROR) will be
+ * returned.
  *
  * If debugfs is not enabled in the kernel, the value -%ENODEV will be
  * returned.
@@ -464,7 +465,8 @@ EXPORT_SYMBOL_GPL(debugfs_create_file_unsafe);
  * This function will return a pointer to a dentry if it succeeds.  This
  * pointer must be passed to the debugfs_remove() function when the file is
  * to be removed (no automatic cleanup happens if your module is unloaded,
- * you are responsible here.)  If an error occurs, %NULL will be returned.
+ * you are responsible here.)  If an error occurs, %ERR_PTR(-ERROR) will be
+ * returned.
  *
  * If debugfs is not enabled in the kernel, the value -%ENODEV will be
  * returned.
@@ -495,7 +497,8 @@ EXPORT_SYMBOL_GPL(debugfs_create_file_size);
  * This function will return a pointer to a dentry if it succeeds.  This
  * pointer must be passed to the debugfs_remove() function when the file is
  * to be removed (no automatic cleanup happens if your module is unloaded,
- * you are responsible here.)  If an error occurs, %NULL will be returned.
+ * you are responsible here.)  If an error occurs, %ERR_PTR(-ERROR) will be
+ * returned.
  *
  * If debugfs is not enabled in the kernel, the value -%ENODEV will be
  * returned.
@@ -506,7 +509,7 @@ struct dentry *debugfs_create_dir(const char *name, struct dentry *parent)
 	struct inode *inode;
 
 	if (IS_ERR(dentry))
-		return NULL;
+		return dentry;
 
 	inode = debugfs_get_inode(dentry->d_sb);
 	if (unlikely(!inode))
@@ -545,7 +548,7 @@ struct dentry *debugfs_create_automount(const char *name,
 	struct inode *inode;
 
 	if (IS_ERR(dentry))
-		return NULL;
+		return dentry;
 
 	inode = debugfs_get_inode(dentry->d_sb);
 	if (unlikely(!inode))
@@ -581,8 +584,8 @@ EXPORT_SYMBOL(debugfs_create_automount);
  * This function will return a pointer to a dentry if it succeeds.  This
  * pointer must be passed to the debugfs_remove() function when the symbolic
  * link is to be removed (no automatic cleanup happens if your module is
- * unloaded, you are responsible here.)  If an error occurs, %NULL will be
- * returned.
+ * unloaded, you are responsible here.)  If an error occurs, %ERR_PTR(-ERROR)
+ * will be returned.
  *
  * If debugfs is not enabled in the kernel, the value -%ENODEV will be
  * returned.
@@ -594,12 +597,12 @@ struct dentry *debugfs_create_symlink(const char *name, struct dentry *parent,
 	struct inode *inode;
 	char *link = kstrdup(target, GFP_KERNEL);
 	if (!link)
-		return NULL;
+		return ERR_PTR(-ENOMEM);
 
 	dentry = start_creating(name, parent);
 	if (IS_ERR(dentry)) {
 		kfree(link);
-		return NULL;
+		return dentry;
 	}
 
 	inode = debugfs_get_inode(dentry->d_sb);
@@ -787,6 +790,13 @@ struct dentry *debugfs_rename(struct dentry *old_dir, struct dentry *old_dentry,
 	struct dentry *dentry = NULL, *trap;
 	struct name_snapshot old_name;
 
+	if (IS_ERR(old_dir))
+		return old_dir;
+	if (IS_ERR(new_dir))
+		return new_dir;
+	if (IS_ERR_OR_NULL(old_dentry))
+		return old_dentry;
+
 	trap = lock_rename(new_dir, old_dir);
 	/* Source or destination directories don't exist? */
 	if (d_really_is_negative(old_dir) || d_really_is_negative(new_dir))
@@ -820,7 +830,9 @@ exit:
 	if (dentry && !IS_ERR(dentry))
 		dput(dentry);
 	unlock_rename(new_dir, old_dir);
-	return NULL;
+	if (IS_ERR(dentry))
+		return dentry;
+	return ERR_PTR(-EINVAL);
 }
 EXPORT_SYMBOL_GPL(debugfs_rename);
 
diff --git a/kernel/relay.c b/kernel/relay.c
index 04f248644e06..9e0f52375487 100644
--- a/kernel/relay.c
+++ b/kernel/relay.c
@@ -428,6 +428,8 @@ static struct dentry *relay_create_buf_file(struct rchan *chan,
 	dentry = chan->cb->create_buf_file(tmpname, chan->parent,
 					   S_IRUSR, buf,
 					   &chan->is_global);
+	if (IS_ERR(dentry))
+		dentry = NULL;
 
 	kfree(tmpname);
 
@@ -461,7 +463,7 @@ static struct rchan_buf *relay_open_buf(struct rchan *chan, unsigned int cpu)
 		dentry = chan->cb->create_buf_file(NULL, NULL,
 						   S_IRUSR, buf,
 						   &chan->is_global);
-		if (WARN_ON(dentry))
+		if (IS_ERR_OR_NULL(dentry))
 			goto free_buf;
 	}