From 6d9d86cc4e6149d4c0793e8ceb65dab7535a4561 Mon Sep 17 00:00:00 2001

From: Hanna Reitz <hreitz@redhat.com>

Date: Fri, 4 Feb 2022 12:10:11 +0100

Subject: [PATCH 7/8] block/nbd: Move s->ioc on AioContext change

RH-Author: Hanna Reitz <hreitz@redhat.com>

RH-MergeRequest: 74: block/nbd: Handle AioContext changes

RH-Commit: [5/6] b3c1eb21ac70d64fdac6094468a72cfbe50a30a9 (hreitz/qemu-kvm-c-9-s)

RH-Bugzilla: 2033626

RH-Acked-by: Miroslav Rezanina <mrezanin@redhat.com>

RH-Acked-by: Eric Blake <eblake@redhat.com>

RH-Acked-by: Stefan Hajnoczi <stefanha@redhat.com>

s->ioc must always be attached to the NBD node's AioContext.  If that

context changes, s->ioc must be attached to the new context.

Buglink: https://bugzilla.redhat.com/show_bug.cgi?id=2033626

Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>

Signed-off-by: Hanna Reitz <hreitz@redhat.com>

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>

(cherry picked from commit e15f3a66c830e3fce99c9d56c493c2f7078a1225)

Conflict:

- block/nbd.c: open_timer was added after the 6.2 release, so we need

  not (and cannot) assert it is NULL here.

Signed-off-by: Hanna Reitz <hreitz@redhat.com>

---

 block/nbd.c | 41 +++++++++++++++++++++++++++++++++++++++++

 1 file changed, 41 insertions(+)

diff --git a/block/nbd.c b/block/nbd.c

index aab20125d8..a3896c7f5f 100644

--- a/block/nbd.c

+++ b/block/nbd.c

@@ -2003,6 +2003,38 @@ static void nbd_cancel_in_flight(BlockDriverState *bs)

     nbd_co_establish_connection_cancel(s->conn);

 }

+static void nbd_attach_aio_context(BlockDriverState *bs,

+                                   AioContext *new_context)

+{

+    BDRVNBDState *s = bs->opaque;

+

+    /*

+     * The reconnect_delay_timer is scheduled in I/O paths when the

+     * connection is lost, to cancel the reconnection attempt after a

+     * given time.  Once this attempt is done (successfully or not),

+     * nbd_reconnect_attempt() ensures the timer is deleted before the

+     * respective I/O request is resumed.

+     * Since the AioContext can only be changed when a node is drained,

+     * the reconnect_delay_timer cannot be active here.

+     */

+    assert(!s->reconnect_delay_timer);

+

+    if (s->ioc) {

+        qio_channel_attach_aio_context(s->ioc, new_context);

+    }

+}

+

+static void nbd_detach_aio_context(BlockDriverState *bs)

+{

+    BDRVNBDState *s = bs->opaque;

+

+    assert(!s->reconnect_delay_timer);

+

+    if (s->ioc) {

+        qio_channel_detach_aio_context(s->ioc);

+    }

+}

+

 static BlockDriver bdrv_nbd = {

     .format_name                = "nbd",

     .protocol_name              = "nbd",

@@ -2026,6 +2058,9 @@ static BlockDriver bdrv_nbd = {

     .bdrv_dirname               = nbd_dirname,

     .strong_runtime_opts        = nbd_strong_runtime_opts,

     .bdrv_cancel_in_flight      = nbd_cancel_in_flight,

+

+    .bdrv_attach_aio_context    = nbd_attach_aio_context,

+    .bdrv_detach_aio_context    = nbd_detach_aio_context,

 };

 static BlockDriver bdrv_nbd_tcp = {

@@ -2051,6 +2086,9 @@ static BlockDriver bdrv_nbd_tcp = {

     .bdrv_dirname               = nbd_dirname,

     .strong_runtime_opts        = nbd_strong_runtime_opts,

     .bdrv_cancel_in_flight      = nbd_cancel_in_flight,

+

+    .bdrv_attach_aio_context    = nbd_attach_aio_context,

+    .bdrv_detach_aio_context    = nbd_detach_aio_context,

 };

 static BlockDriver bdrv_nbd_unix = {

@@ -2076,6 +2114,9 @@ static BlockDriver bdrv_nbd_unix = {

     .bdrv_dirname               = nbd_dirname,

     .strong_runtime_opts        = nbd_strong_runtime_opts,

     .bdrv_cancel_in_flight      = nbd_cancel_in_flight,

+

+    .bdrv_attach_aio_context    = nbd_attach_aio_context,

+    .bdrv_detach_aio_context    = nbd_detach_aio_context,

 };

 static void bdrv_nbd_init(void)

-- 

2.27.0