qio: add a few block helpers
authorBarret Rhoden <brho@cs.berkeley.edu>
Wed, 5 Jun 2019 20:27:04 +0000 (16:27 -0400)
committerBarret Rhoden <brho@cs.berkeley.edu>
Wed, 5 Jun 2019 22:06:24 +0000 (18:06 -0400)
commit8475b7c6c92951f0a0de131c07b5411b9a45a537
tree0ca3875cec1fa031a642b41386ed17119b869419
parentef632900a8fc19fc65ee4472bf52a2eb1917e6f5
qio: add a few block helpers

These will be used in new versions of qio functions, such as pullupblock
and padblock.  block_transfer_extras() ended up not being used, but I
might in the future.  It's also illustrative of the subtle differences
between transferring extras and block_replace_extras().

Signed-off-by: Barret Rhoden <brho@cs.berkeley.edu>
kern/include/ns.h
kern/src/ns/allocb.c
kern/src/ns/qio.c