block: Catch attempt to attach multiple devices to a blockdev
For instance, -device scsi-disk,drive=foo -device scsi-disk,drive=foo
happily creates two SCSI disks connected to the same block device.
It's all downhill from there.
Device usb-storage deliberately attaches twice to the same blockdev,
which fails with the fix in place. Detach before the second attach
there.
Also catch attempt to delete while a guest device model is attached.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
diff --git a/block.c b/block.c
index 31ca4c5..4c65035 100644
--- a/block.c
+++ b/block.c
@@ -665,6 +665,8 @@
void bdrv_delete(BlockDriverState *bs)
{
+ assert(!bs->peer);
+
/* remove from list, if necessary */
if (bs->device_name[0] != '\0') {
QTAILQ_REMOVE(&bdrv_states, bs, list);
@@ -678,6 +680,26 @@
qemu_free(bs);
}
+int bdrv_attach(BlockDriverState *bs, DeviceState *qdev)
+{
+ if (bs->peer) {
+ return -EBUSY;
+ }
+ bs->peer = qdev;
+ return 0;
+}
+
+void bdrv_detach(BlockDriverState *bs, DeviceState *qdev)
+{
+ assert(bs->peer == qdev);
+ bs->peer = NULL;
+}
+
+DeviceState *bdrv_get_attached(BlockDriverState *bs)
+{
+ return bs->peer;
+}
+
/*
* Run consistency checks on an image
*
diff --git a/block.h b/block.h
index 6a157f4..88ac06e 100644
--- a/block.h
+++ b/block.h
@@ -71,6 +71,9 @@
int bdrv_open(BlockDriverState *bs, const char *filename, int flags,
BlockDriver *drv);
void bdrv_close(BlockDriverState *bs);
+int bdrv_attach(BlockDriverState *bs, DeviceState *qdev);
+void bdrv_detach(BlockDriverState *bs, DeviceState *qdev);
+DeviceState *bdrv_get_attached(BlockDriverState *bs);
int bdrv_check(BlockDriverState *bs);
int bdrv_read(BlockDriverState *bs, int64_t sector_num,
uint8_t *buf, int nb_sectors);
diff --git a/block_int.h b/block_int.h
index e60aed4..a94b801 100644
--- a/block_int.h
+++ b/block_int.h
@@ -148,6 +148,8 @@
BlockDriver *drv; /* NULL means no media */
void *opaque;
+ DeviceState *peer;
+
char filename[1024];
char backing_file[1024]; /* if non zero, the image is a diff of
this file image */
diff --git a/hw/fdc.c b/hw/fdc.c
index 08712bc..1496cfa 100644
--- a/hw/fdc.c
+++ b/hw/fdc.c
@@ -1860,10 +1860,10 @@
dev = isa_create("isa-fdc");
if (fds[0]) {
- qdev_prop_set_drive(&dev->qdev, "driveA", fds[0]->bdrv);
+ qdev_prop_set_drive_nofail(&dev->qdev, "driveA", fds[0]->bdrv);
}
if (fds[1]) {
- qdev_prop_set_drive(&dev->qdev, "driveB", fds[1]->bdrv);
+ qdev_prop_set_drive_nofail(&dev->qdev, "driveB", fds[1]->bdrv);
}
if (qdev_init(&dev->qdev) < 0)
return NULL;
@@ -1882,10 +1882,10 @@
fdctrl = &sys->state;
fdctrl->dma_chann = dma_chann; /* FIXME */
if (fds[0]) {
- qdev_prop_set_drive(dev, "driveA", fds[0]->bdrv);
+ qdev_prop_set_drive_nofail(dev, "driveA", fds[0]->bdrv);
}
if (fds[1]) {
- qdev_prop_set_drive(dev, "driveB", fds[1]->bdrv);
+ qdev_prop_set_drive_nofail(dev, "driveB", fds[1]->bdrv);
}
qdev_init_nofail(dev);
sysbus_connect_irq(&sys->busdev, 0, irq);
@@ -1903,7 +1903,7 @@
dev = qdev_create(NULL, "SUNW,fdtwo");
if (fds[0]) {
- qdev_prop_set_drive(dev, "drive", fds[0]->bdrv);
+ qdev_prop_set_drive_nofail(dev, "drive", fds[0]->bdrv);
}
qdev_init_nofail(dev);
sys = DO_UPCAST(FDCtrlSysBus, busdev.qdev, dev);
diff --git a/hw/ide/qdev.c b/hw/ide/qdev.c
index a5fdab0..b34c473 100644
--- a/hw/ide/qdev.c
+++ b/hw/ide/qdev.c
@@ -83,7 +83,7 @@
dev = qdev_create(&bus->qbus, "ide-drive");
qdev_prop_set_uint32(dev, "unit", unit);
- qdev_prop_set_drive(dev, "drive", drive->bdrv);
+ qdev_prop_set_drive_nofail(dev, "drive", drive->bdrv);
qdev_init_nofail(dev);
return DO_UPCAST(IDEDevice, qdev, dev);
}
diff --git a/hw/pci-hotplug.c b/hw/pci-hotplug.c
index d743192..fe468d6 100644
--- a/hw/pci-hotplug.c
+++ b/hw/pci-hotplug.c
@@ -214,7 +214,11 @@
return NULL;
}
dev = pci_create(bus, devfn, "virtio-blk-pci");
- qdev_prop_set_drive(&dev->qdev, "drive", dinfo->bdrv);
+ if (qdev_prop_set_drive(&dev->qdev, "drive", dinfo->bdrv) < 0) {
+ qdev_free(&dev->qdev);
+ dev = NULL;
+ break;
+ }
if (qdev_init(&dev->qdev) < 0)
dev = NULL;
break;
diff --git a/hw/qdev-properties.c b/hw/qdev-properties.c
index 49b3377..7e3e99e 100644
--- a/hw/qdev-properties.c
+++ b/hw/qdev-properties.c
@@ -311,6 +311,8 @@
bs = bdrv_find(str);
if (bs == NULL)
return -ENOENT;
+ if (bdrv_attach(bs, dev) < 0)
+ return -EEXIST;
*ptr = bs;
return 0;
}
@@ -320,6 +322,7 @@
BlockDriverState **ptr = qdev_get_prop_ptr(dev, prop);
if (*ptr) {
+ bdrv_detach(*ptr, dev);
blockdev_auto_del(*ptr);
}
}
@@ -660,11 +663,28 @@
qdev_prop_set(dev, name, &value, PROP_TYPE_STRING);
}
-void qdev_prop_set_drive(DeviceState *dev, const char *name, BlockDriverState *value)
+int qdev_prop_set_drive(DeviceState *dev, const char *name, BlockDriverState *value)
{
+ int res;
+
+ res = bdrv_attach(value, dev);
+ if (res < 0) {
+ error_report("Can't attach drive %s to %s.%s: %s",
+ bdrv_get_device_name(value),
+ dev->id ? dev->id : dev->info->name,
+ name, strerror(-res));
+ return -1;
+ }
qdev_prop_set(dev, name, &value, PROP_TYPE_DRIVE);
+ return 0;
}
+void qdev_prop_set_drive_nofail(DeviceState *dev, const char *name, BlockDriverState *value)
+{
+ if (qdev_prop_set_drive(dev, name, value) < 0) {
+ exit(1);
+ }
+}
void qdev_prop_set_chr(DeviceState *dev, const char *name, CharDriverState *value)
{
qdev_prop_set(dev, name, &value, PROP_TYPE_CHR);
diff --git a/hw/qdev.h b/hw/qdev.h
index 7a01a81..cbc89f2 100644
--- a/hw/qdev.h
+++ b/hw/qdev.h
@@ -275,7 +275,8 @@
void qdev_prop_set_chr(DeviceState *dev, const char *name, CharDriverState *value);
void qdev_prop_set_netdev(DeviceState *dev, const char *name, VLANClientState *value);
void qdev_prop_set_vlan(DeviceState *dev, const char *name, VLANState *value);
-void qdev_prop_set_drive(DeviceState *dev, const char *name, BlockDriverState *value);
+int qdev_prop_set_drive(DeviceState *dev, const char *name, BlockDriverState *value) QEMU_WARN_UNUSED_RESULT;
+void qdev_prop_set_drive_nofail(DeviceState *dev, const char *name, BlockDriverState *value);
void qdev_prop_set_macaddr(DeviceState *dev, const char *name, uint8_t *value);
/* FIXME: Remove opaque pointer properties. */
void qdev_prop_set_ptr(DeviceState *dev, const char *name, void *value);
diff --git a/hw/s390-virtio.c b/hw/s390-virtio.c
index c7c3fc9..6af58e2 100644
--- a/hw/s390-virtio.c
+++ b/hw/s390-virtio.c
@@ -262,7 +262,7 @@
}
dev = qdev_create((BusState *)s390_bus, "virtio-blk-s390");
- qdev_prop_set_drive(dev, "drive", dinfo->bdrv);
+ qdev_prop_set_drive_nofail(dev, "drive", dinfo->bdrv);
qdev_init_nofail(dev);
}
}
diff --git a/hw/scsi-bus.c b/hw/scsi-bus.c
index 2c58aca..b84b9b9 100644
--- a/hw/scsi-bus.c
+++ b/hw/scsi-bus.c
@@ -91,7 +91,10 @@
driver = bdrv_is_sg(bdrv) ? "scsi-generic" : "scsi-disk";
dev = qdev_create(&bus->qbus, driver);
qdev_prop_set_uint32(dev, "scsi-id", unit);
- qdev_prop_set_drive(dev, "drive", bdrv);
+ if (qdev_prop_set_drive(dev, "drive", bdrv) < 0) {
+ qdev_free(dev);
+ return NULL;
+ }
if (qdev_init(dev) < 0)
return NULL;
return DO_UPCAST(SCSIDevice, qdev, dev);
diff --git a/hw/usb-msd.c b/hw/usb-msd.c
index 19a14b4..65e9624 100644
--- a/hw/usb-msd.c
+++ b/hw/usb-msd.c
@@ -532,12 +532,13 @@
/*
* Hack alert: this pretends to be a block device, but it's really
* a SCSI bus that can serve only a single device, which it
- * creates automatically. Two drive properties pointing to the
- * same drive is not good: free_drive() dies for the second one.
- * Zap the one we're not going to use.
+ * creates automatically. But first it needs to detach from its
+ * blockdev, or else scsi_bus_legacy_add_drive() dies when it
+ * attaches again.
*
* The hack is probably a bad idea.
*/
+ bdrv_detach(bs, &s->dev.qdev);
s->conf.bs = NULL;
s->dev.speed = USB_SPEED_FULL;
@@ -609,7 +610,10 @@
if (!dev) {
return NULL;
}
- qdev_prop_set_drive(&dev->qdev, "drive", dinfo->bdrv);
+ if (qdev_prop_set_drive(&dev->qdev, "drive", dinfo->bdrv) < 0) {
+ qdev_free(&dev->qdev);
+ return NULL;
+ }
if (qdev_init(&dev->qdev) < 0)
return NULL;
