ocfs2: Wrap extent block reads in a dedicated function.

We weren't consistently checking extent blocks after we read them.
Most places checked the signature, but none checked h_blkno or
h_fs_signature.  Create a toplevel ocfs2_read_extent_block() that does
the read and the validation.

Signed-off-by: Joel Becker <[email protected]>
Signed-off-by: Mark Fasheh <[email protected]>
4 files changed