virtio-scsi: use scsi_device_get

This will help us to avoid the scsi device disappearing
after we took a reference to it.

It doesn't by itself forbid case when we try to access
an unrealized device

Suggested-by: Stefan Hajnoczi <stefanha@gmail.com>
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20200913160259.32145-9-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20201006123904.610658-13-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Maxim Levitsky 2020-10-06 15:39:03 +03:00 committed by Paolo Bonzini
parent 8ff3449560
commit 07a47d4a18

View file

@ -33,7 +33,7 @@ static inline int virtio_scsi_get_lun(uint8_t *lun)
return ((lun[2] << 8) | lun[3]) & 0x3FFF;
}
static inline SCSIDevice *virtio_scsi_device_find(VirtIOSCSI *s, uint8_t *lun)
static inline SCSIDevice *virtio_scsi_device_get(VirtIOSCSI *s, uint8_t *lun)
{
if (lun[0] != 1) {
return NULL;
@ -41,7 +41,7 @@ static inline SCSIDevice *virtio_scsi_device_find(VirtIOSCSI *s, uint8_t *lun)
if (lun[2] != 0 && !(lun[2] >= 0x40 && lun[2] < 0x80)) {
return NULL;
}
return scsi_device_find(&s->bus, 0, lun[1], virtio_scsi_get_lun(lun));
return scsi_device_get(&s->bus, 0, lun[1], virtio_scsi_get_lun(lun));
}
void virtio_scsi_init_req(VirtIOSCSI *s, VirtQueue *vq, VirtIOSCSIReq *req)
@ -256,7 +256,7 @@ static inline void virtio_scsi_ctx_check(VirtIOSCSI *s, SCSIDevice *d)
* case of async cancellation. */
static int virtio_scsi_do_tmf(VirtIOSCSI *s, VirtIOSCSIReq *req)
{
SCSIDevice *d = virtio_scsi_device_find(s, req->req.tmf.lun);
SCSIDevice *d = virtio_scsi_device_get(s, req->req.tmf.lun);
SCSIRequest *r, *next;
BusChild *kid;
int target;
@ -370,10 +370,10 @@ static int virtio_scsi_do_tmf(VirtIOSCSI *s, VirtIOSCSIReq *req)
rcu_read_lock();
QTAILQ_FOREACH_RCU(kid, &s->bus.qbus.children, sibling) {
d = SCSI_DEVICE(kid->child);
if (d->channel == 0 && d->id == target) {
qdev_reset_all(&d->qdev);
}
SCSIDevice *d1 = SCSI_DEVICE(kid->child);
if (d1->channel == 0 && d1->id == target) {
qdev_reset_all(&d1->qdev);
}
}
rcu_read_unlock();
@ -386,14 +386,17 @@ static int virtio_scsi_do_tmf(VirtIOSCSI *s, VirtIOSCSIReq *req)
break;
}
object_unref(OBJECT(d));
return ret;
incorrect_lun:
req->resp.tmf.response = VIRTIO_SCSI_S_INCORRECT_LUN;
object_unref(OBJECT(d));
return ret;
fail:
req->resp.tmf.response = VIRTIO_SCSI_S_BAD_TARGET;
object_unref(OBJECT(d));
return ret;
}
@ -564,7 +567,7 @@ static int virtio_scsi_handle_cmd_req_prepare(VirtIOSCSI *s, VirtIOSCSIReq *req)
}
}
d = virtio_scsi_device_find(s, req->req.cmd.lun);
d = virtio_scsi_device_get(s, req->req.cmd.lun);
if (!d) {
req->resp.cmd.response = VIRTIO_SCSI_S_BAD_TARGET;
virtio_scsi_complete_cmd_req(req);
@ -580,10 +583,12 @@ static int virtio_scsi_handle_cmd_req_prepare(VirtIOSCSI *s, VirtIOSCSIReq *req)
req->sreq->cmd.xfer > req->qsgl.size)) {
req->resp.cmd.response = VIRTIO_SCSI_S_OVERRUN;
virtio_scsi_complete_cmd_req(req);
object_unref(OBJECT(d));
return -ENOBUFS;
}
scsi_req_ref(req->sreq);
blk_io_plug(d->conf.blk);
object_unref(OBJECT(d));
return 0;
}