diff mbox

[v2,3/3] nbd: Follow the BDS' AIO context

Message ID 1403118403-14397-4-git-send-email-mreitz@redhat.com
State New
Headers show

Commit Message

Max Reitz June 18, 2014, 7:06 p.m. UTC 
Keep the NBD server always in the same AIO context as the exported BDS
by calling bdrv_add_aio_context_notifier() and implementing the required
callbacks.

Signed-off-by: Max Reitz <mreitz@redhat.com>
---
 nbd.c | 31 +++++++++++++++++++++++++++++++
 1 file changed, 31 insertions(+)

Comments

Stefan Hajnoczi June 19, 2014, 4:01 a.m. UTC | #1 
On Wed, Jun 18, 2014 at 09:06:43PM +0200, Max Reitz wrote:
> Keep the NBD server always in the same AIO context as the exported BDS
> by calling bdrv_add_aio_context_notifier() and implementing the required
> callbacks.
> 
> Signed-off-by: Max Reitz <mreitz@redhat.com>
> ---
>  nbd.c | 31 +++++++++++++++++++++++++++++++
>  1 file changed, 31 insertions(+)

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
diff mbox

Patch

diff --git a/nbd.c b/nbd.c
index 2715acc..cd92f88 100644
--- a/nbd.c
+++ b/nbd.c
@@ -811,6 +811,34 @@  static void nbd_request_put(NBDRequest *req)
     nbd_client_put(client);
 }
 
+static void bs_aio_attached(AioContext *ctx, void *opaque)
+{
+    NBDExport *exp = opaque;
+    NBDClient *client;
+
+    TRACE("Export %s: Attaching clients to AIO context %p\n", exp->name, ctx);
+
+    exp->ctx = ctx;
+
+    QTAILQ_FOREACH(client, &exp->clients, next) {
+        nbd_set_handlers(client);
+    }
+}
+
+static void bs_aio_detach(void *opaque)
+{
+    NBDExport *exp = opaque;
+    NBDClient *client;
+
+    TRACE("Export %s: Detaching clients from AIO context %p\n", exp->name, exp->ctx);
+
+    QTAILQ_FOREACH(client, &exp->clients, next) {
+        nbd_unset_handlers(client);
+    }
+
+    exp->ctx = NULL;
+}
+
 NBDExport *nbd_export_new(BlockDriverState *bs, off_t dev_offset,
                           off_t size, uint32_t nbdflags,
                           void (*close)(NBDExport *))
@@ -825,6 +853,7 @@  NBDExport *nbd_export_new(BlockDriverState *bs, off_t dev_offset,
     exp->close = close;
     exp->ctx = bdrv_get_aio_context(bs);
     bdrv_ref(bs);
+    bdrv_add_aio_context_notifier(bs, bs_aio_attached, bs_aio_detach, exp);
     return exp;
 }
 
@@ -872,6 +901,8 @@  void nbd_export_close(NBDExport *exp)
     nbd_export_set_name(exp, NULL);
     nbd_export_put(exp);
     if (exp->bs) {
+        bdrv_remove_aio_context_notifier(exp->bs, bs_aio_attached,
+                                         bs_aio_detach, exp);
         bdrv_unref(exp->bs);
         exp->bs = NULL;
     }