[PATCH RESEND 1/1] ocfs2: fix reflink preserve cleanup issue

[Heming Zhao <heming.zhao@suse.com>]

commit c06c303832ec ("ocfs2: fix xattr array entry __counted_by error")
doesn't handle all cases and the cleanup job for preserved xattr
entries still has bug:
- the 'last' pointer should be shifted by one unit after cleanup
  an array entry.
- current code logic doesn't cleanup the first entry when xh_count is 1.

Note, commit c06c303832ec is also a bug fix for 0fe9b66c65f3.

Fixes: 0fe9b66c65f3 ("ocfs2: Add preserve to reflink.")
Signed-off-by: Heming Zhao <heming.zhao@suse.com>
---
 fs/ocfs2/xattr.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/fs/ocfs2/xattr.c b/fs/ocfs2/xattr.c
index dc1761e84814..31d023f9e2ed 100644
--- a/fs/ocfs2/xattr.c
+++ b/fs/ocfs2/xattr.c
@@ -6364,6 +6364,10 @@ static int ocfs2_reflink_xattr_header(handle_t *handle,
 					(void *)last - (void *)xe);
 				memset(last, 0,
 				       sizeof(struct ocfs2_xattr_entry));
+				last = &new_xh->xh_entries[le16_to_cpu(new_xh->xh_count)] - 1;
+			} else {
+				memset(xe, 0, sizeof(struct ocfs2_xattr_entry));
+				last = NULL;
 			}
 
 			/*
-- 
2.43.0