From: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Date: Tue, 23 Jun 2020 08:40:07 +0000 (+0900)
Subject: btrfs: use free_root_extent_buffer to free root
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=923eb5236597c90b11114926025e0c04e4c1da32;p=linux.git

btrfs: use free_root_extent_buffer to free root

In btrfs_put_root() we're freeing a btrfs_root's 'node' and 'commit_root'
extent buffers manually via kfree(), while we're using
free_root_extent_buffers() in the free_root_pointers() function above.

free_root_extent_buffers() also NULLs the pointers after freeing, which
mitigates potential double frees.

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
---

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index a9cf6152d175a..b5b7055b79530 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -2001,8 +2001,7 @@ void btrfs_put_root(struct btrfs_root *root)
 		if (root->anon_dev)
 			free_anon_bdev(root->anon_dev);
 		btrfs_drew_lock_destroy(&root->snapshot_lock);
-		free_extent_buffer(root->node);
-		free_extent_buffer(root->commit_root);
+		free_root_extent_buffers(root);
 		kfree(root->free_ino_ctl);
 		kfree(root->free_ino_pinned);
 #ifdef CONFIG_BTRFS_DEBUG