this patch adds iscsi_truncate which effectively allows for
online resizing of iscsi volumes. for this to work you have
to resize the volume on your storage and then call
block_resize command in qemu which will issue a
readcapacity16 to update the capacity.
v4:
- factor out complete readcapacity logic into a separate function
- handle capacity change check condition in readcapacity function
(this happens if the block_resize cmd is the first iscsi task
executed after a resize on the storage)
v3:
- remove switch statement in iscsi_open
- create separate patch for brdv_drain_all() in bdrv_truncate()
v2:
- add a general bdrv_drain_all() before bdrv_truncate() to avoid
in-flight AIOs while the device is truncated
- since no AIOs are in flight we can use a sync libiscsi call
to re-read the capacity
- factor out the readcapacity16 logic as it is redundant
to iscsi_open() and iscsi_truncate().
Signed-off-by: Peter Lieven <pl@kamp.de>
[allow any type of unit attention check condition in iscsi_readcapacity_sync(),
as in Message-ID: <51263A2A.6070304@dlhnet.de> - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>