• Benoît Canet's avatar
    qmp: Allow to change password on named block driver states. · 12d3ba82
    Benoît Canet authored
    Signed-off-by: default avatarBenoit Canet <benoit@irqsave.net>
    Reviewed-by: default avatarFam Zheng <famz@redhat.com>
    
    There was two candidate ways to implement named node manipulation:
    
    1)
    { 'command': 'block_passwd', 'data': {'*device': 'str',
                                          '*node-name': 'str', 'password': 'str'}
    }
    
    2)
    
    { 'command': 'block_passwd', 'data': {'device': 'str',
                                          '*device-is-node': 'bool',
                                          'password': 'str'} }
    
    Luiz proposed 1 and says 2 was an abuse of the QMP interface and proposed to
    rewrite the QMP block interface for 2.0.
    
    Luiz does not like in 1 the fact that 2 fields are optional but one of them must
    be specified leading to an abuse of the QMP semantic.
    
    Kevin argumented that 2 what a clear abuse of the device field and would not be
    practical when reading fast some log file because the user would read "device"
    and think that a device is manipulated when it's in fact a node name.
    Documentation of 1 make it pretty clear what to do for the user.
    
    Kevin argued that all bs are node including devices ones so 2 does not make
    sense.
    
    Kevin also argued that rewriting the QMP block interface would not make disapear
    the current one.
    
    Kevin pushed the argument that making the QAPI generator compatible with the
    semantic of the operation would need a rewrite that no one has done yet.
    
    A vote has been done on the list to elect the version to use and 1 won.
    
    For reference the complete thread is:
    "[Qemu-devel] [PATCH V4 4/7] qmp: Allow to change password on names block driver
    states."
    Signed-off-by: default avatarBenoit Canet <benoit@irqsave.net>
    Signed-off-by: default avatarKevin Wolf <kwolf@redhat.com>
    12d3ba82
block.c 142 KB