7 files changed, 56 insertions, 7 deletions

diff --git a/blockdev.c b/blockdev.c
index ba4f66f976..48481120c2 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -17,6 +17,29 @@
 
 static QTAILQ_HEAD(drivelist, DriveInfo) drives = QTAILQ_HEAD_INITIALIZER(drives);
 
+/*
+ * We automatically delete the drive when a device using it gets
+ * unplugged.  Questionable feature, but we can't just drop it.
+ * Device models call blockdev_mark_auto_del() to schedule the
+ * automatic deletion, and generic qdev code calls blockdev_auto_del()
+ * when deletion is actually safe.
+ */
+void blockdev_mark_auto_del(BlockDriverState *bs)
+{
+    DriveInfo *dinfo = drive_get_by_blockdev(bs);
+
+    dinfo->auto_del = 1;
+}
+
+void blockdev_auto_del(BlockDriverState *bs)
+{
+    DriveInfo *dinfo = drive_get_by_blockdev(bs);
+
+    if (dinfo->auto_del) {
+        drive_uninit(dinfo);
+    }
+}
+
 QemuOpts *drive_add(const char *file, const char *fmt, ...)
 {
     va_list ap;
diff --git a/blockdev.h b/blockdev.h
index 6ab592f0fd..32e6979456 100644
--- a/blockdev.h
+++ b/blockdev.h
@@ -13,6 +13,9 @@
 #include "block.h"
 #include "qemu-queue.h"
 
+void blockdev_mark_auto_del(BlockDriverState *bs);
+void blockdev_auto_del(BlockDriverState *bs);
+
 typedef enum {
     IF_NONE,
     IF_IDE, IF_SCSI, IF_FLOPPY, IF_PFLASH, IF_MTD, IF_SD, IF_VIRTIO, IF_XEN,
@@ -28,6 +31,7 @@ typedef struct DriveInfo {
     BlockInterfaceType type;
     int bus;
     int unit;
+    int auto_del;               /* see blockdev_mark_auto_del() */
     QemuOpts *opts;
     char serial[BLOCK_SERIAL_STRLEN + 1];
     QTAILQ_ENTRY(DriveInfo) next;
diff --git a/hw/qdev-properties.c b/hw/qdev-properties.c
index 5b7fd77d44..d7dc234e25 100644
--- a/hw/qdev-properties.c
+++ b/hw/qdev-properties.c
@@ -313,6 +313,15 @@ static int parse_drive(DeviceState *dev, Property *prop, const char *str)
     return 0;
 }
 
+static void free_drive(DeviceState *dev, Property *prop)
+{
+    DriveInfo **ptr = qdev_get_prop_ptr(dev, prop);
+
+    if (*ptr) {
+        blockdev_auto_del((*ptr)->bdrv);
+    }
+}
+
 static int print_drive(DeviceState *dev, Property *prop, char *dest, size_t len)
 {
     DriveInfo **ptr = qdev_get_prop_ptr(dev, prop);
@@ -325,6 +334,7 @@ PropertyInfo qdev_prop_drive = {
     .size  = sizeof(DriveInfo*),
     .parse = parse_drive,
     .print = print_drive,
+    .free  = free_drive,
 };
 
 /* --- character device --- */
diff --git a/hw/scsi-disk.c b/hw/scsi-disk.c
index 2b3898435c..d76e640412 100644
--- a/hw/scsi-disk.c
+++ b/hw/scsi-disk.c
@@ -1043,7 +1043,7 @@ static void scsi_destroy(SCSIDevice *dev)
     SCSIDiskState *s = DO_UPCAST(SCSIDiskState, qdev, dev);
 
     scsi_disk_purge_requests(s);
-    drive_uninit(s->qdev.conf.dinfo);
+    blockdev_mark_auto_del(s->qdev.conf.dinfo->bdrv);
 }
 
 static int scsi_disk_initfn(SCSIDevice *dev)
diff --git a/hw/scsi-generic.c b/hw/scsi-generic.c
index e31060e944..1859c94b7c 100644
--- a/hw/scsi-generic.c
+++ b/hw/scsi-generic.c
@@ -453,7 +453,7 @@ static void scsi_destroy(SCSIDevice *d)
         r = DO_UPCAST(SCSIGenericReq, req, QTAILQ_FIRST(&s->qdev.requests));
         scsi_remove_request(r);
     }
-    drive_uninit(s->qdev.conf.dinfo);
+    blockdev_mark_auto_del(s->qdev.conf.dinfo->bdrv);
 }
 
 static int scsi_generic_initfn(SCSIDevice *dev)
diff --git a/hw/usb-msd.c b/hw/usb-msd.c
index 8e9718c562..3dbfcabeb1 100644
--- a/hw/usb-msd.c
+++ b/hw/usb-msd.c
@@ -522,24 +522,36 @@ static void usb_msd_password_cb(void *opaque, int err)
 static int usb_msd_initfn(USBDevice *dev)
 {
     MSDState *s = DO_UPCAST(MSDState, dev, dev);
+    DriveInfo *dinfo = s->conf.dinfo;
 
-    if (!s->conf.dinfo || !s->conf.dinfo->bdrv) {
+    if (!dinfo || !dinfo->bdrv) {
         error_report("usb-msd: drive property not set");
         return -1;
     }
 
+    /*
+     * 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.
+     *
+     * The hack is probably a bad idea.
+     */
+    s->conf.dinfo = NULL;
+
     s->dev.speed = USB_SPEED_FULL;
     scsi_bus_new(&s->bus, &s->dev.qdev, 0, 1, usb_msd_command_complete);
-    s->scsi_dev = scsi_bus_legacy_add_drive(&s->bus, s->conf.dinfo, 0);
+    s->scsi_dev = scsi_bus_legacy_add_drive(&s->bus, dinfo, 0);
     if (!s->scsi_dev) {
         return -1;
     }
     s->bus.qbus.allow_hotplug = 0;
     usb_msd_handle_reset(dev);
 
-    if (bdrv_key_required(s->conf.dinfo->bdrv)) {
+    if (bdrv_key_required(dinfo->bdrv)) {
         if (cur_mon) {
-            monitor_read_bdrv_key_start(cur_mon, s->conf.dinfo->bdrv,
+            monitor_read_bdrv_key_start(cur_mon, dinfo->bdrv,
                                         usb_msd_password_cb, s);
             s->dev.auto_attach = 0;
         } else {
diff --git a/hw/virtio-pci.c b/hw/virtio-pci.c
index d1303b1a38..31a68fec40 100644
--- a/hw/virtio-pci.c
+++ b/hw/virtio-pci.c
@@ -571,7 +571,7 @@ static int virtio_blk_exit_pci(PCIDevice *pci_dev)
 {
     VirtIOPCIProxy *proxy = DO_UPCAST(VirtIOPCIProxy, pci_dev, pci_dev);
 
-    drive_uninit(proxy->block.dinfo);
+    blockdev_mark_auto_del(proxy->block.dinfo->bdrv);
     return virtio_exit_pci(pci_dev);
 }