diff mbox

[v3,13/16] blk: fix aio context loss on media change

Message ID 20170524025235.32190-14-famz@redhat.com
State New
Headers show

Commit Message

Fam Zheng May 24, 2017, 2:52 a.m. UTC 
From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>

If we have separate iothread for cdrom, we lose connection to it on
qmp_blockdev_change_medium, as aio_context is on bds which is dropped
and switched with new one.

As an example result, after such media change we have crash on
virtio_scsi_ctx_check: Assertion `blk_get_aio_context(d->conf.blk) == s->ctx' failed.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
---
 block/block-backend.c | 6 ++++++
 1 file changed, 6 insertions(+)
diff mbox

Patch

diff --git a/block/block-backend.c b/block/block-backend.c
index 5492f64..dfe577d 100644
--- a/block/block-backend.c
+++ b/block/block-backend.c
@@ -68,6 +68,7 @@  struct BlockBackend {
     NotifierList remove_bs_notifiers, insert_bs_notifiers;
 
     int quiesce_counter;
+    AioContext *aio_context;
 };
 
 typedef struct BlockBackendAIOCB {
@@ -618,6 +619,10 @@  int blk_insert_bs(BlockBackend *blk, BlockDriverState *bs, Error **errp)
     }
     bdrv_ref(bs);
 
+    if (blk->aio_context != NULL) {
+        bdrv_set_aio_context(bs, blk->aio_context);
+    }
+
     notifier_list_notify(&blk->insert_bs_notifiers, blk);
     if (blk->public.throttle_state) {
         throttle_timers_attach_aio_context(
@@ -1692,6 +1697,7 @@  void blk_set_aio_context(BlockBackend *blk, AioContext *new_context)
 {
     BlockDriverState *bs = blk_bs(blk);
 
+    blk->aio_context = new_context;
     if (bs) {
         if (blk->public.throttle_state) {
             throttle_timers_detach_aio_context(&blk->public.throttle_timers);