block/null-{co,aio}: Allow reading zeroes
commitcd219eb1e55a5bf9eab4193cafaf6ab188fc2752
authorMax Reitz <mreitz@redhat.com>
Thu, 24 Mar 2016 22:33:58 +0000 (24 23:33 +0100)
committerKevin Wolf <kwolf@redhat.com>
Wed, 30 Mar 2016 10:16:03 +0000 (30 12:16 +0200)
treee5e415c1096468eef2eb77d14c15dd992122bdbb
parentaad15de4275d2fc90acdf6101493dfee4e39b803
block/null-{co,aio}: Allow reading zeroes

This is optional so that it does not impede the null block driver's
performance unless this behavior is desired.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
block/null.c