Re: [Qemu-devel] [PATCH v7 14/24] nbd: Switch from close to eject notifier

[Kevin Wolf <kwolf@redhat.com>]

Am 09.11.2015 um 23:39 hat Max Reitz geschrieben:
> The NBD code uses the BDS close notifier to determine when a medium is
> ejected. However, now it should use the BB's BDS removal notifier for
> that instead of the BDS's close notifier.
> 
> Signed-off-by: Max Reitz <mreitz@redhat.com>
> ---
>  blockdev-nbd.c | 37 +------------------------------------
>  nbd.c          | 13 +++++++++++++
>  2 files changed, 14 insertions(+), 36 deletions(-)
> 
> diff --git a/blockdev-nbd.c b/blockdev-nbd.c
> index bcdd18b..b28a55b 100644
> --- a/blockdev-nbd.c
> +++ b/blockdev-nbd.c
> @@ -46,37 +46,11 @@ void qmp_nbd_server_start(SocketAddress *addr, Error **errp)
>      }
>  }
>  
> -/*
> - * Hook into the BlockBackend notifiers to close the export when the
> - * backend is closed.
> - */
> -typedef struct NBDCloseNotifier {
> -    Notifier n;
> -    NBDExport *exp;
> -    QTAILQ_ENTRY(NBDCloseNotifier) next;
> -} NBDCloseNotifier;
> -
> -static QTAILQ_HEAD(, NBDCloseNotifier) close_notifiers =
> -    QTAILQ_HEAD_INITIALIZER(close_notifiers);
> -
> -static void nbd_close_notifier(Notifier *n, void *data)
> -{
> -    NBDCloseNotifier *cn = DO_UPCAST(NBDCloseNotifier, n, n);
> -
> -    notifier_remove(&cn->n);
> -    QTAILQ_REMOVE(&close_notifiers, cn, next);
> -
> -    nbd_export_close(cn->exp);
> -    nbd_export_put(cn->exp);

Here you remove a close/put pair, but in the new code you only add the
close call. Why is this correct?

Kevin