From: Dan Carpenter <dan.carpenter@oracle.com>
Date: Fri, 23 Oct 2020 11:26:33 +0000 (+0300)
Subject: btrfs: clean up NULL checks in qgroup_unreserve_range()
X-Git-Tag: v5.10.7~1090^2~11
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=f07728d541ebefcf3d2ec7bc99a3bffd052d9f90;p=platform%2Fkernel%2Flinux-rpi.git

btrfs: clean up NULL checks in qgroup_unreserve_range()

Smatch complains that this code dereferences "entry" before checking
whether it's NULL on the next line.  Fortunately, rb_entry() will never
return NULL so it doesn't cause a problem.  We can clean up the NULL
checking a bit to silence the warning and make the code more clear.

Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
---

diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c
index c54ea65..77c5474 100644
--- a/fs/btrfs/qgroup.c
+++ b/fs/btrfs/qgroup.c
@@ -3435,24 +3435,20 @@ static int qgroup_unreserve_range(struct btrfs_inode *inode,
 {
 	struct rb_node *node;
 	struct rb_node *next;
-	struct ulist_node *entry = NULL;
+	struct ulist_node *entry;
 	int ret = 0;
 
 	node = reserved->range_changed.root.rb_node;
+	if (!node)
+		return 0;
 	while (node) {
 		entry = rb_entry(node, struct ulist_node, rb_node);
 		if (entry->val < start)
 			node = node->rb_right;
-		else if (entry)
-			node = node->rb_left;
 		else
-			break;
+			node = node->rb_left;
 	}
 
-	/* Empty changeset */
-	if (!entry)
-		return 0;
-
 	if (entry->val > start && rb_prev(&entry->rb_node))
 		entry = rb_entry(rb_prev(&entry->rb_node), struct ulist_node,
 				 rb_node);