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| author | Stefan Hajnoczi <stefanha@redhat.com> | 2023-04-04 11:33:07 -0400 |
|---|---|---|
| committer | Kevin Wolf <kwolf@redhat.com> | 2023-05-10 14:15:13 +0200 |
| commit | 3edf660a9155848d1d7bc6ad2586ceb0285105e3 (patch) | |
| tree | 0c2d12be814859368da9f478aa300b20fb7cae0f /hw/block | |
| parent | 17ac39c3e726173f737bb6cd898c160b406532d4 (diff) | |
| download | qemu-3edf660a9155848d1d7bc6ad2586ceb0285105e3.zip qemu-3edf660a9155848d1d7bc6ad2586ceb0285105e3.tar.gz qemu-3edf660a9155848d1d7bc6ad2586ceb0285105e3.tar.bz2 | |
aio-wait: avoid AioContext lock in aio_wait_bh_oneshot()
There is no need for the AioContext lock in aio_wait_bh_oneshot().
It's easy to remove the lock from existing callers and then switch from
AIO_WAIT_WHILE() to AIO_WAIT_WHILE_UNLOCKED() in aio_wait_bh_oneshot().
Document that the AioContext lock should not be held across
aio_wait_bh_oneshot(). Holding a lock across aio_poll() can cause
deadlock so we don't want callers to do that.
This is a step towards getting rid of the AioContext lock.
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20230404153307.458883-1-stefanha@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Diffstat (limited to 'hw/block')
| -rw-r--r-- | hw/block/dataplane/virtio-blk.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/hw/block/dataplane/virtio-blk.c b/hw/block/dataplane/virtio-blk.c index a620299..af1c24c 100644 --- a/hw/block/dataplane/virtio-blk.c +++ b/hw/block/dataplane/virtio-blk.c @@ -315,9 +315,10 @@ void virtio_blk_data_plane_stop(VirtIODevice *vdev) s->stopping = true; trace_virtio_blk_data_plane_stop(s); - aio_context_acquire(s->ctx); aio_wait_bh_oneshot(s->ctx, virtio_blk_data_plane_stop_bh, s); + aio_context_acquire(s->ctx); + /* Wait for virtio_blk_dma_restart_bh() and in flight I/O to complete */ blk_drain(s->conf->conf.blk); |