block: Drop medium lock tracking, ask device models instead

Requires new BlockDevOps member is_medium_locked().  Implement for IDE
and SCSI CD-ROMs.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

block.c

@@ -818,6 +818,14 @@ static void bdrv_dev_resize_cb(BlockDriverState *bs)
     }
 }
 
+bool bdrv_dev_is_medium_locked(BlockDriverState *bs)
+{
+    if (bs->dev_ops && bs->dev_ops->is_medium_locked) {
+        return bs->dev_ops->is_medium_locked(bs->dev_opaque);
+    }
+    return false;
+}
+
 /*
  * Run consistency checks on an image
  *
@@ -1890,7 +1898,7 @@ void bdrv_info(Monitor *mon, QObject **ret_data)
         bs_obj = qobject_from_jsonf("{ 'device': %s, 'type': 'unknown', "
                                     "'removable': %i, 'locked': %i }",
                                     bs->device_name, bs->removable,
-                                    bs->locked);
+                                    bdrv_dev_is_medium_locked(bs));
 
         if (bs->drv) {
             QObject *obj;
@@ -3060,11 +3068,6 @@ void bdrv_eject(BlockDriverState *bs, int eject_flag)
     }
 }
 
-int bdrv_is_locked(BlockDriverState *bs)
-{
-    return bs->locked;
-}
-
 /**
  * Lock or unlock the media (if it is locked, the user won't be able
  * to eject it manually).
@@ -3075,7 +3078,6 @@ void bdrv_set_locked(BlockDriverState *bs, int locked)
 
     trace_bdrv_set_locked(bs, locked);
 
-    bs->locked = locked;
     if (drv && drv->bdrv_set_locked) {
         drv->bdrv_set_locked(bs, locked);
     }

block.h

@@ -36,6 +36,11 @@ typedef struct BlockDevOps {
      * changes.  Sure would be useful if it did.
      */
     void (*change_media_cb)(void *opaque);
+    /*
+     * Is the virtual medium locked into the device?
+     * Device models implement this only when device has such a lock.
+     */
+    bool (*is_medium_locked)(void *opaque);
     /*
      * Runs when the size changed (e.g. monitor command block_resize)
      */
@@ -94,6 +99,7 @@ void bdrv_detach_dev(BlockDriverState *bs, void *dev);
 void *bdrv_get_attached_dev(BlockDriverState *bs);
 void bdrv_set_dev_ops(BlockDriverState *bs, const BlockDevOps *ops,
                       void *opaque);
+bool bdrv_dev_is_medium_locked(BlockDriverState *bs);
 int bdrv_read(BlockDriverState *bs, int64_t sector_num,
               uint8_t *buf, int nb_sectors);
 int bdrv_write(BlockDriverState *bs, int64_t sector_num,
@@ -206,7 +212,6 @@ int bdrv_is_sg(BlockDriverState *bs);
 int bdrv_enable_write_cache(BlockDriverState *bs);
 int bdrv_is_inserted(BlockDriverState *bs);
 int bdrv_media_changed(BlockDriverState *bs);
-int bdrv_is_locked(BlockDriverState *bs);
 void bdrv_set_locked(BlockDriverState *bs, int locked);
 void bdrv_eject(BlockDriverState *bs, int eject_flag);
 void bdrv_get_format(BlockDriverState *bs, char *buf, int buf_size);

block_int.h

@@ -156,7 +156,6 @@ struct BlockDriverState {
     int keep_read_only; /* if true, the media was requested to stay read only */
     int open_flags; /* flags used to open the file, re-used for re-open */
     int removable; /* if true, the media can be removed */
-    int locked;    /* if true, the media cannot temporarily be ejected */
     int encrypted; /* if true, the media is encrypted */
     int valid_key; /* if true, a valid encryption key has been set */
     int sg;        /* if true, the device is a /dev/sg* */

blockdev.c

@@ -640,7 +640,7 @@ static int eject_device(Monitor *mon, BlockDriverState *bs, int force)
         qerror_report(QERR_DEVICE_NOT_REMOVABLE, bdrv_get_device_name(bs));
         return -1;
     }
-    if (!force && bdrv_is_locked(bs)) {
+    if (!force && bdrv_dev_is_medium_locked(bs)) {
         qerror_report(QERR_DEVICE_LOCKED, bdrv_get_device_name(bs));
         return -1;
     }

hw/ide/core.c

@@ -1795,8 +1795,14 @@ void ide_bus_reset(IDEBus *bus)
     bus->dma->ops->reset(bus->dma);
 }
 
+static bool ide_cd_is_medium_locked(void *opaque)
+{
+    return ((IDEState *)opaque)->tray_locked;
+}
+
 static const BlockDevOps ide_cd_block_ops = {
     .change_media_cb = ide_cd_change_cb,
+    .is_medium_locked = ide_cd_is_medium_locked,
 };
 
 int ide_init_drive(IDEState *s, BlockDriverState *bs, IDEDriveKind kind,

hw/scsi-disk.c

@@ -1165,6 +1165,15 @@ static void scsi_destroy(SCSIDevice *dev)
     blockdev_mark_auto_del(s->qdev.conf.bs);
 }
 
+static bool scsi_cd_is_medium_locked(void *opaque)
+{
+    return ((SCSIDiskState *)opaque)->tray_locked;
+}
+
+static const BlockDevOps scsi_cd_block_ops = {
+    .is_medium_locked = scsi_cd_is_medium_locked,
+};
+
 static int scsi_initfn(SCSIDevice *dev, uint8_t scsi_type)
 {
     SCSIDiskState *s = DO_UPCAST(SCSIDiskState, qdev, dev);
@@ -1199,6 +1208,7 @@ static int scsi_initfn(SCSIDevice *dev, uint8_t scsi_type)
     }
 
     if (scsi_type == TYPE_ROM) {
+        bdrv_set_dev_ops(s->bs, &scsi_cd_block_ops, s);
         s->qdev.blocksize = 2048;
     } else if (scsi_type == TYPE_DISK) {
         s->qdev.blocksize = s->qdev.conf.logical_block_size;