rbd: complete notifies before cleaning up osd_client and rbd_dev

commit 9abc59908e0c5f983aaa91150da32d5b62cf60b7 upstream.

To ensure rbd_dev is not used after it's released, flush all pending
notify callbacks before calling rbd_dev_image_release(). No new
notifies can be added to the queue at this point because the watch has
already be unregistered with the osd_client.

Signed-off-by: Josh Durgin <josh.durgin@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 7 insertions, 0 deletions

diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index 1d29dab42c0a..d9c3326c571f 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -5150,6 +5150,13 @@ static ssize_t rbd_remove(struct bus_type *bus,
         ret = rbd_dev_header_watch_sync(rbd_dev, false);
         if (ret)
                 rbd_warn(rbd_dev, "failed to cancel watch event (%d)\n", ret);
+
+        /*
+         * flush remaining watch callbacks - these must be complete
+         * before the osd_client is shutdown
+         */
+        dout("%s: flushing notifies", __func__);
+        ceph_osdc_flush_notifies(&rbd_dev->rbd_client->client->osdc);
         rbd_dev_image_release(rbd_dev);
         module_put(THIS_MODULE);
         ret = count;