diff options
| author | Paolo Bonzini <pbonzini@redhat.com> | 2012-07-09 12:06:28 +0200 |
|---|---|---|
| committer | Gerd Hoffmann <kraxel@redhat.com> | 2012-07-10 13:35:05 +0200 |
| commit | 8e86b93c2b69a7369aa62a6daec203fe5e757497 (patch) | |
| tree | 15625220161591ccea5b760795cd1a2f6450fed5 /hw/scsi-bus.c | |
| parent | 92336855975805d88c7979f53bc05c2d47abab04 (diff) | |
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 <pbonzini@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Diffstat (limited to 'hw/scsi-bus.c')
| -rw-r--r-- | hw/scsi-bus.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/hw/scsi-bus.c b/hw/scsi-bus.c index 5ad1013be1..dc7406389d 100644 --- a/hw/scsi-bus.c +++ b/hw/scsi-bus.c @@ -1354,6 +1354,7 @@ static const char *scsi_command_name(uint8_t cmd) SCSIRequest *scsi_req_ref(SCSIRequest *req) { + assert(req->refcount > 0); req->refcount++; return req; } @@ -1362,6 +1363,10 @@ void scsi_req_unref(SCSIRequest *req) { assert(req->refcount > 0); if (--req->refcount == 0) { + SCSIBus *bus = DO_UPCAST(SCSIBus, qbus, req->dev->qdev.parent_bus); + if (bus->info->free_request && req->hba_private) { + bus->info->free_request(bus, req->hba_private); + } if (req->ops->free_req) { req->ops->free_req(req); } |