Commit 38b54b6d authored by Fam Zheng's avatar Fam Zheng Committed by Stefan Hajnoczi
Browse files

nbd: use BlockDriverState refcnt 



Previously, nbd calls drive_get_ref() on the drive of bs. A BDS doesn't
always have associated dinfo, which nbd doesn't care either. We already
have BDS ref count, so use it to make it safe for a BDS w/o blockdev.

Signed-off-by: default avatarFam Zheng <famz@redhat.com>
Signed-off-by: default avatarStefan Hajnoczi <stefanha@redhat.com>
parent c0777fe1

blockdev-nbd.c

+1 −9
Original line number Diff line number Diff line
@@ -69,12 +69,6 @@ static void nbd_close_notifier(Notifier *n, void *data) 
    g_free(cn);

}



static void nbd_server_put_ref(NBDExport *exp)

{

    BlockDriverState *bs = nbd_export_get_blockdev(exp);

    drive_put_ref(drive_get_by_blockdev(bs));

}



void qmp_nbd_server_add(const char *device, bool has_writable, bool writable,

                        Error **errp)

{
@@ -105,11 +99,9 @@ void qmp_nbd_server_add(const char *device, bool has_writable, bool writable, 
        writable = false;

    }



    exp = nbd_export_new(bs, 0, -1, writable ? 0 : NBD_FLAG_READ_ONLY,

                         nbd_server_put_ref);

    exp = nbd_export_new(bs, 0, -1, writable ? 0 : NBD_FLAG_READ_ONLY, NULL);



    nbd_export_set_name(exp, device);

    drive_get_ref(drive_get_by_blockdev(bs));



    n = g_malloc0(sizeof(NBDCloseNotifier));

    n->n.notify = nbd_close_notifier;

nbd.c

+5 −0
Original line number Diff line number Diff line
@@ -882,6 +882,7 @@ NBDExport *nbd_export_new(BlockDriverState *bs, off_t dev_offset, 
    exp->nbdflags = nbdflags;

    exp->size = size == -1 ? bdrv_getlength(bs) : size;

    exp->close = close;

    bdrv_ref(bs);

    return exp;

}
@@ -928,6 +929,10 @@ void nbd_export_close(NBDExport *exp) 
    }

    nbd_export_set_name(exp, NULL);

    nbd_export_put(exp);

    if (exp->bs) {

        bdrv_unref(exp->bs);

        exp->bs = NULL;

    }

}



void nbd_export_get(NBDExport *exp)