blockdev: Introduce DriveInfo.enable_auto_del

BlockDriverStates shouldn't be affected by an unplugged guest device,
except if created with the legacy -drive command line option or the
drive_add HMP command.

Make the automatic deletion as well as cancelling of jobs conditional on
an enable_auto_del boolean that is only set in drive_init().

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Wenchao Xia <xiawenc@linux.vnet.ibm.com>

blockdev.c

@@ -89,6 +89,10 @@ void blockdev_mark_auto_del(BlockDriverState *bs)
 {
     DriveInfo *dinfo = drive_get_by_blockdev(bs);
 
+    if (dinfo && !dinfo->enable_auto_del) {
+        return;
+    }
+
     if (bs->job) {
         block_job_cancel(bs->job);
     }
@@ -746,6 +750,7 @@ static void qemu_opt_rename(QemuOpts *opts, const char *from, const char *to)
 DriveInfo *drive_init(QemuOpts *all_opts, BlockInterfaceType block_default_type)
 {
     const char *value;
+    DriveInfo *dinfo;
 
     /* Change legacy command line options into QMP ones */
     qemu_opt_rename(all_opts, "iops", "throttling.iops-total");
@@ -794,7 +799,17 @@ DriveInfo *drive_init(QemuOpts *all_opts, BlockInterfaceType block_default_type)
         qemu_opt_unset(all_opts, "cache");
     }
 
-    return blockdev_init(all_opts, block_default_type);
+    /* Actual block device init: Functionality shared with blockdev-add */
+    dinfo = blockdev_init(all_opts, block_default_type);
+    if (dinfo == NULL) {
+        goto fail;
+    }
+
+    /* Set legacy DriveInfo fields */
+    dinfo->enable_auto_del = true;
+
+fail:
+    return dinfo;
 }
 
 void do_commit(Monitor *mon, const QDict *qdict)

include/sysemu/blockdev.h

@@ -37,6 +37,7 @@ struct DriveInfo {
     int bus;
     int unit;
     int auto_del;               /* see blockdev_mark_auto_del() */
+    bool enable_auto_del; /* Only for legacy drive_init() */
     int media_cd;
     int cyls, heads, secs, trans;
     QemuOpts *opts;