xfs: zero inode fork buffer at allocation

xfs: zero inode fork buffer at allocation

[ Upstream commit cb512c921639613ce03f87e62c5e93ed9fe8c84d ]

When we first allocate or resize an inline inode fork, we round up
the allocation to 4 byte alingment to make journal alignment
constraints. We don't clear the unused bytes, so we can copy up to
three uninitialised bytes into the journal. Zero those bytes so we
only ever copy zeros into the journal.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Allison Henderson <allison.henderson@oracle.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Leah Rumancik <leah.rumancik@gmail.com>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>