Btrfs: zero unused bytes in inode item
The otime field is not zeroed, so users will see random otime in an old
filesystem with a new kernel which has otime support in the future.
The reserved bytes are also not zeroed, and we'll have compatibility
issue if we make use of those bytes.
Signed-off-by: Li Zefan <lizefan@huawei.com>
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index ee45ebf..144f464 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -4693,6 +4693,8 @@
inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
struct btrfs_inode_item);
+ memset_extent_buffer(path->nodes[0], 0, (unsigned long)inode_item,
+ sizeof(*inode_item));
fill_inode_item(trans, path->nodes[0], inode_item, inode);
ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,