scsi: add free_request callback
Most device models have a simple lifecycle for the hba_private field
and they can free it when a request is completed or cancelled.
However, in some cases it may be simpler to tie the lifetime
of hba_private to that of the included SCSIRequest. This patch
adds a free_request callback to SCSIBusInfo that lets an HBA
device model do exactly that.
Normally, device models use req->hba_private == NULL to flag requests
that have been completed already. Device models that use free_request
will still need to track this using a flag. This is the reason why
"converting" existing HBAs to use free_request adds complexity and
makes little sense. It is simply an additional convenience that is
provided by the SCSI layer. USB-attached storage will be the first
user.
Signed-off-by: Paolo Bonzini <[email protected]>
Signed-off-by: Gerd Hoffmann <[email protected]>
2 files changed
