From 8e86b93c2b69a7369aa62a6daec203fe5e757497 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Mon, 9 Jul 2012 12:06:28 +0200 Subject: [PATCH] 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 Signed-off-by: Gerd Hoffmann --- hw/scsi-bus.c | 5 +++++ hw/scsi.h | 1 + 2 files changed, 6 insertions(+) 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); } diff --git a/hw/scsi.h b/hw/scsi.h index 76f06d41de..367a346020 100644 --- a/hw/scsi.h +++ b/hw/scsi.h @@ -134,6 +134,7 @@ struct SCSIBusInfo { void (*save_request)(QEMUFile *f, SCSIRequest *req); void *(*load_request)(QEMUFile *f, SCSIRequest *req); + void (*free_request)(SCSIBus *bus, void *priv); }; #define TYPE_SCSI_BUS "SCSI"