block: Leave enforcing tray lock to device models

The device model knows best when to accept the guest's eject command.
No need to detour through the block layer.

bdrv_eject() can't fail anymore.  Make it void.
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

block.c

@@ -3051,18 +3051,13 @@ int bdrv_media_changed(BlockDriverState *bs)
 /**
  * If eject_flag is TRUE, eject the media. Otherwise, close the tray
  */
-int bdrv_eject(BlockDriverState *bs, int eject_flag)
+void bdrv_eject(BlockDriverState *bs, int eject_flag)
 {
     BlockDriver *drv = bs->drv;
 
-    if (eject_flag && bs->locked) {
-        return -EBUSY;
-    }
-
     if (drv && drv->bdrv_eject) {
         drv->bdrv_eject(bs, eject_flag);
     }
-    return 0;
 }
 
 int bdrv_is_locked(BlockDriverState *bs)

block.h

@@ -208,7 +208,7 @@ 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);
-int bdrv_eject(BlockDriverState *bs, int eject_flag);
+void bdrv_eject(BlockDriverState *bs, int eject_flag);
 void bdrv_get_format(BlockDriverState *bs, char *buf, int buf_size);
 BlockDriverState *bdrv_find(const char *name);
 BlockDriverState *bdrv_next(BlockDriverState *bs);

hw/ide/atapi.c

@@ -905,33 +905,22 @@ static void cmd_seek(IDEState *s, uint8_t* buf)
 
 static void cmd_start_stop_unit(IDEState *s, uint8_t* buf)
 {
-    int sense, err = 0;
+    int sense;
     bool start = buf[4] & 1;
     bool loej = buf[4] & 2;     /* load on start, eject on !start */
 
     if (loej) {
-        err = bdrv_eject(s->bs, !start);
-    }
-
-    switch (err) {
-    case 0:
-        ide_atapi_cmd_ok(s);
-        break;
-    case -EBUSY:
-        sense = SENSE_NOT_READY;
-        if (bdrv_is_inserted(s->bs)) {
-            sense = SENSE_ILLEGAL_REQUEST;
+        if (!start && s->tray_locked) {
+            sense = bdrv_is_inserted(s->bs)
+                ? SENSE_NOT_READY : SENSE_ILLEGAL_REQUEST;
+            ide_atapi_cmd_error(s, sense, ASC_MEDIA_REMOVAL_PREVENTED);
+            return;
         }
-        ide_atapi_cmd_error(s, sense, ASC_MEDIA_REMOVAL_PREVENTED);
-        break;
-    default:
-        ide_atapi_cmd_error(s, SENSE_NOT_READY, ASC_MEDIUM_NOT_PRESENT);
-        break;
-    }
-
-    if (loej && !err) {
+        bdrv_eject(s->bs, !start);
         s->tray_open = !start;
     }
+
+    ide_atapi_cmd_ok(s);
 }
 
 static void cmd_mechanism_status(IDEState *s, uint8_t* buf)

hw/scsi-disk.c

@@ -830,6 +830,9 @@ static void scsi_disk_emulate_start_stop(SCSIDiskReq *r)
     bool loej = req->cmd.buf[4] & 2; /* load on start, eject on !start */
 
     if (s->qdev.type == TYPE_ROM && loej) {
+        if (!start && s->tray_locked) {
+            return;
+        }
         bdrv_eject(s->bs, !start);
         s->tray_open = !start;
     }