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libceph: no more kick_requests() race

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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>
This commit is contained in:
Alex Elder 2013-03-25 18:16:11 -05:00 committed by Sage Weil
parent dc4b870c97
commit 92451b4910
1 changed files with 15 additions and 22 deletions
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37
net/ceph/osd_client.c
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@ -1779,31 +1779,24 @@ 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) {
rc = __map_request(osdc, req, 0);
if (rc < 0) {
if (nofail) {
dout("osdc_start_request failed map, "
" will retry %lld\n", req->r_tid);
rc = 0;
}
goto out_unlock;
WARN_ON(req->r_sent);
rc = __map_request(osdc, req, 0);
if (rc < 0) {
if (nofail) {
dout("osdc_start_request failed map, "
" will retry %lld\n", req->r_tid);
rc = 0;
}
if (req->r_osd == NULL) {
dout("send_request %p no up osds in pg\n", req);
ceph_monc_request_next_osdmap(&osdc->client->monc);
} else {
__send_request(osdc, req);
}
rc = 0;
goto out_unlock;
}
if (req->r_osd == NULL) {
dout("send_request %p no up osds in pg\n", req);
ceph_monc_request_next_osdmap(&osdc->client->monc);
} else {
__send_request(osdc, req);
}
rc = 0;
out_unlock:
mutex_unlock(&osdc->request_mutex);
up_read(&osdc->map_sem);