Commit Graph

2 Commits

Author SHA1 Message Date
Vladimir Sementsov-Ogievskiy
9dd003a998 iotests: define group in each iotest
We are going to drop group file. Define group in tests as a preparatory
step.

The patch is generated by

    cd tests/qemu-iotests

    grep '^[0-9]\{3\} ' group | while read line; do
        file=$(awk '{print $1}' <<< "$line");
        groups=$(sed -e 's/^... //' <<< "$line");
        awk "NR==2{print \"# group: $groups\"}1" $file > tmp;
        cat tmp > $file;
    done

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20210116134424.82867-7-vsementsov@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
2021-01-20 14:53:22 -06:00
Eric Blake
dbc7b01492 nbd: Add 'qemu-nbd -A' to expose allocation depth
Allow the server to expose an additional metacontext to be requested
by savvy clients.  qemu-nbd adds a new option -A to expose the
qemu:allocation-depth metacontext through NBD_CMD_BLOCK_STATUS; this
can also be set via QMP when using block-export-add.

qemu as client is hacked into viewing the key aspects of this new
context by abusing the already-experimental x-dirty-bitmap option to
collapse all depths greater than 2, which results in a tri-state value
visible in the output of 'qemu-img map --output=json' (yes, that means
x-dirty-bitmap is now a bit of a misnomer, but I didn't feel like
renaming it as it would introduce a needless break of back-compat,
even though we make no compat guarantees with x- members):

unallocated (depth 0) => "zero":false, "data":true
local (depth 1)       => "zero":false, "data":false
backing (depth 2+)    => "zero":true,  "data":true

libnbd as client is probably a nicer way to get at the information
without having to decipher such hacks in qemu as client. ;)

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20201027050556.269064-11-eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
2020-10-30 15:22:00 -05:00