diff options
author | Fam Zheng <famz@redhat.com> | 2017-04-05 14:44:24 +0800 |
---|---|---|
committer | Fam Zheng <famz@redhat.com> | 2017-04-11 20:07:15 +0800 |
commit | aabf591007a83dc6520329bce929570115849286 (patch) | |
tree | f951eea607ecebecae95238d0f9e347d01cea572 /block.c | |
parent | 14e9559f4624e704a53d0789124b6f9ea9ebb5ca (diff) | |
download | qemu-aabf591007a83dc6520329bce929570115849286.zip qemu-aabf591007a83dc6520329bce929570115849286.tar.gz qemu-aabf591007a83dc6520329bce929570115849286.tar.bz2 |
block: Quiesce old aio context during bdrv_set_aio_context
The fact that the bs->aio_context is changing can confuse the dataplane
iothread, because of the now fine granularity aio context lock.
bdrv_drain should rather be a bdrv_drained_begin/end pair, but since
bs->aio_context is changing, we can just use aio_disable_external and
bdrv_parent_drained_begin.
Reported-by: Ed Swierk <eswierk@skyportsystems.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Diffstat (limited to 'block.c')
-rw-r--r-- | block.c | 7 |
1 files changed, 5 insertions, 2 deletions
@@ -4396,11 +4396,12 @@ void bdrv_attach_aio_context(BlockDriverState *bs, void bdrv_set_aio_context(BlockDriverState *bs, AioContext *new_context) { - AioContext *ctx; + AioContext *ctx = bdrv_get_aio_context(bs); + aio_disable_external(ctx); + bdrv_parent_drained_begin(bs); bdrv_drain(bs); /* ensure there are no in-flight requests */ - ctx = bdrv_get_aio_context(bs); while (aio_poll(ctx, false)) { /* wait for all bottom halves to execute */ } @@ -4412,6 +4413,8 @@ void bdrv_set_aio_context(BlockDriverState *bs, AioContext *new_context) */ aio_context_acquire(new_context); bdrv_attach_aio_context(bs, new_context); + bdrv_parent_drained_end(bs); + aio_enable_external(ctx); aio_context_release(new_context); } |