[PATCH v8 21/27] btrfs: Fix a memory leak in inband dedupe hash

[Qu Wenruo <quwenruo@cn.fujitsu.com>]

We allocate a dedupe hash into async_extent, but forget to free it.
Fix it by freeing the hash before freeing async_extent.

Reported-by: Wang Xiaoguang <wangxg.fnst@cn.fujitsu.com>
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
---
 fs/btrfs/inode.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 979811c..81b19193 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -751,6 +751,7 @@ retry:
 						  WB_SYNC_ALL);
 			else if (ret)
 				unlock_page(async_cow->locked_page);
+			kfree(hash);
 			kfree(async_extent);
 			cond_resched();
 			continue;
@@ -876,6 +877,7 @@ retry:
 			free_async_extent_pages(async_extent);
 		}
 		alloc_hint = ins.objectid + ins.offset;
+		kfree(hash);
 		kfree(async_extent);
 		cond_resched();
 	}
@@ -892,6 +894,7 @@ out_free:
 				     PAGE_SET_WRITEBACK | PAGE_END_WRITEBACK |
 				     PAGE_SET_ERROR);
 	free_async_extent_pages(async_extent);
+	kfree(hash);
 	kfree(async_extent);
 	goto again;
 }
-- 
2.7.3