This patch introduces an assertion that can catch pitfalls in
development where there is a mismatch between the size of
reads and writes between a *_phys structure and its respective
in-core structure when bonus buffers are used.
This debugging-aid should be complementary to the verification
done by ztest in ztest_verify_dnode_bt().
A side to this patch is that we now clear out any extra bytes
past a bonus buffer's new size when the buffer is shrinking.
Reviewed-by: Matt Ahrens <matt@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Tom Caputi <tcaputi@datto.com>
Signed-off-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Closes#8348
0e37a0f4f3