[PATCH 3.10 115/129] rbd: make rbd_obj_notify_ack() synchronous

From: Greg Kroah-Hartman
Date: Mon Jan 06 2014 - 18:04:55 EST

3.10-stable review patch. If anyone has any objections, please let me know.


From: Josh Durgin <josh.durgin@xxxxxxxxxxx>

commit 20e0af67ce88c657d0601977b9941a2256afbdaa upstream.

The only user of rbd_obj_notify_ack() is rbd_watch_cb(). It used
asynchronously with no tracking of when the notify ack completes, so
it may still be in progress when the osd_client is shut down. This
results in a BUG() since the osd client assumes no requests are in
flight when it stops. Since all notifies are flushed before the
osd_client is stopped, waiting for the notify ack to complete before
returning from the watch callback ensures there are no notify acks in
flight during shutdown.

Rename rbd_obj_notify_ack() to rbd_obj_notify_ack_sync() to reflect
its new synchronous nature.

Signed-off-by: Josh Durgin <josh.durgin@xxxxxxxxxxx>
Reviewed-by: Alex Elder <elder@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

drivers/block/rbd.c | 11 ++++++-----
1 file changed, 6 insertions(+), 5 deletions(-)

--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -2819,7 +2819,7 @@ out_err:

-static int rbd_obj_notify_ack(struct rbd_device *rbd_dev, u64 notify_id)
+static int rbd_obj_notify_ack_sync(struct rbd_device *rbd_dev, u64 notify_id)
struct rbd_obj_request *obj_request;
struct ceph_osd_client *osdc = &rbd_dev->rbd_client->client->osdc;
@@ -2834,16 +2834,17 @@ static int rbd_obj_notify_ack(struct rbd
obj_request->osd_req = rbd_osd_req_create(rbd_dev, false, obj_request);
if (!obj_request->osd_req)
goto out;
- obj_request->callback = rbd_obj_request_put;

osd_req_op_watch_init(obj_request->osd_req, 0, CEPH_OSD_OP_NOTIFY_ACK,
notify_id, 0, 0);

ret = rbd_obj_request_submit(osdc, obj_request);
if (ret)
- rbd_obj_request_put(obj_request);
+ goto out;
+ ret = rbd_obj_request_wait(obj_request);
+ rbd_obj_request_put(obj_request);

return ret;
@@ -2863,7 +2864,7 @@ static void rbd_watch_cb(u64 ver, u64 no
if (ret)
rbd_warn(rbd_dev, ": header refresh error (%d)\n", ret);

- rbd_obj_notify_ack(rbd_dev, notify_id);
+ rbd_obj_notify_ack_sync(rbd_dev, notify_id);


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