53 lines
2.0 KiB
Diff
53 lines
2.0 KiB
Diff
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From: Eryu Guan <eguan@linux.alibaba.com>
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Date: Mon, 27 Jan 2020 19:02:25 +0000
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Subject: [PATCH] virtiofsd: stop all queue threads on exit in virtio_loop()
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On guest graceful shutdown, virtiofsd receives VHOST_USER_GET_VRING_BASE
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request from VMM and shuts down virtqueues by calling fv_set_started(),
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which joins fv_queue_thread() threads. So when virtio_loop() returns,
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there should be no thread is still accessing data in fuse session and/or
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virtio dev.
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But on abnormal exit, e.g. guest got killed for whatever reason,
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vhost-user socket is closed and virtio_loop() breaks out the main loop
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and returns to main(). But it's possible fv_queue_worker()s are still
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working and accessing fuse session and virtio dev, which results in
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crash or use-after-free.
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Fix it by stopping fv_queue_thread()s before virtio_loop() returns,
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to make sure there's no-one could access fuse session and virtio dev.
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Reported-by: Qingming Su <qingming.su@linux.alibaba.com>
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Signed-off-by: Eryu Guan <eguan@linux.alibaba.com>
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Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
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Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
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(cherry picked from commit 9883df8ccae6d744a0c8d9cbf9d62b1797d70ebd)
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---
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tools/virtiofsd/fuse_virtio.c | 13 +++++++++++++
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1 file changed, 13 insertions(+)
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diff --git a/tools/virtiofsd/fuse_virtio.c b/tools/virtiofsd/fuse_virtio.c
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index 9f6582343c..80a6e929df 100644
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--- a/tools/virtiofsd/fuse_virtio.c
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+++ b/tools/virtiofsd/fuse_virtio.c
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@@ -815,6 +815,19 @@ int virtio_loop(struct fuse_session *se)
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}
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}
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+ /*
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+ * Make sure all fv_queue_thread()s quit on exit, as we're about to
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+ * free virtio dev and fuse session, no one should access them anymore.
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+ */
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+ for (int i = 0; i < se->virtio_dev->nqueues; i++) {
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+ if (!se->virtio_dev->qi[i]) {
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+ continue;
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+ }
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+
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+ fuse_log(FUSE_LOG_INFO, "%s: Stopping queue %d thread\n", __func__, i);
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+ fv_queue_cleanup_thread(se->virtio_dev, i);
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+ }
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+
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fuse_log(FUSE_LOG_INFO, "%s: Exit\n", __func__);
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return 0;
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