qemu-nbd: Add --bitmap=NAME option

Having to fire up qemu, then use QMP commands for nbd-server-start
and nbd-server-add, just to expose a persistent dirty bitmap, is
rather tedious.  Make it possible to expose a dirty bitmap using
just qemu-nbd (of course, for now this only works when qemu-nbd is
visiting a BDS formatted as qcow2).

Of course, any good feature also needs unit testing, so expand
iotest 223 to cover it.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20190111194720.15671-9-eblake@redhat.com>
This commit is contained in:
Eric Blake 2019-01-11 13:47:20 -06:00
parent 678ba275c7
commit 636192c4b6
4 changed files with 40 additions and 4 deletions

View file

@ -61,7 +61,7 @@ read 2097152/2097152 bytes at offset 2097152
{ "start": 1024, "length": 2096128, "depth": 0, "zero": false, "data": true},
{ "start": 2097152, "length": 2097152, "depth": 0, "zero": false, "data": false}]
=== End NBD server ===
=== End qemu NBD server ===
{"return": {}}
{"return": {}}
@ -69,4 +69,14 @@ read 2097152/2097152 bytes at offset 2097152
{"return": {}}
{"error": {"class": "GenericError", "desc": "NBD server not running"}}
{"return": {}}
=== Use qemu-nbd as server ===
[{ "start": 0, "length": 65536, "depth": 0, "zero": false, "data": false},
{ "start": 65536, "length": 2031616, "depth": 0, "zero": false, "data": true},
{ "start": 2097152, "length": 2097152, "depth": 0, "zero": false, "data": false}]
[{ "start": 0, "length": 512, "depth": 0, "zero": false, "data": true},
{ "start": 512, "length": 512, "depth": 0, "zero": false, "data": false},
{ "start": 1024, "length": 2096128, "depth": 0, "zero": false, "data": true},
{ "start": 2097152, "length": 2097152, "depth": 0, "zero": false, "data": false}]
*** done