libceph: no more kick_requests() race (92451b49) · Commits · 戴 / test

Since we no longer drop the request mutex between registering and mapping an osd request in ceph_osdc_start_request(), there is no chance of a race with kick_requests(). We can now therefore map and send the new request unconditionally (but we'll issue a warning should it ever occur). Signed-off-by:

Alex Elder <elder@inktank.com> Reviewed-off-by:

Sage Weil <sage@inktank.com>

net/ceph/osd_client.c

+15 −22

Original line number	Diff line number	Diff line
		@@ -1779,13 +1779,8 @@ int ceph_osdc_start_request(struct ceph_osd_client *osdc,

		down_read(&osdc->map_sem);
		mutex_lock(&osdc->request_mutex);
		/*
		* a racing kick_requests() may have sent the message for us
		* while we dropped request_mutex above, so only send now if
		* the request still han't been touched yet.
		*/
		__register_request(osdc, req);
		if (req->r_sent == 0) {
		WARN_ON(req->r_sent);
		rc = __map_request(osdc, req, 0);
		if (rc < 0) {
		if (nofail) {
		@@ -1802,8 +1797,6 @@ int ceph_osdc_start_request(struct ceph_osd_client *osdc,
		__send_request(osdc, req);
		}
		rc = 0;
		}

		out_unlock:
		mutex_unlock(&osdc->request_mutex);
		up_read(&osdc->map_sem);

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