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authorIlya Dryomov <idryomov@gmail.com>2015-05-11 17:53:10 +0300
committerIlya Dryomov <idryomov@gmail.com>2015-05-20 21:02:14 +0300
commitb0494532214bdfbf241e94fabab5dd46f7b82631 (patch)
tree0e0a3057667e958118daf8ef835cb7f996b8ad8a /net
parente26081808edadfd257c6c9d81014e3b25e9a6118 (diff)
downloadkernel-b0494532214bdfbf241e94fabab5dd46f7b82631.tar.gz
libceph: request a new osdmap if lingering request maps to no osd
This commit does two things. First, if there are any homeless lingering requests, we now request a new osdmap even if the osdmap that is being processed brought no changes, i.e. if a given lingering request turned homeless in one of the previous epochs and remained homeless in the current epoch. Not doing so leaves us with a stale osdmap and as a result we may miss our window for reestablishing the watch and lose notifies. MON=1 OSD=1: # cat linger-needmap.sh #!/bin/bash rbd create --size 1 test DEV=$(rbd map test) ceph osd out 0 rbd map dne/dne # obtain a new osdmap as a side effect (!) sleep 1 ceph osd in 0 rbd resize --size 2 test # rbd info test | grep size -> 2M # blockdev --getsize $DEV -> 1M N.B.: Not obtaining a new osdmap in between "osd out" and "osd in" above is enough to make it miss that resize notify, but that is a bug^Wlimitation of ceph watch/notify v1. Second, homeless lingering requests are now kicked just like those lingering requests whose mapping has changed. This is mainly to recognize that a homeless lingering request makes no sense and to preserve the invariant that a registered lingering request is not sitting on any of r_req_lru_item lists. This spares us a WARN_ON, which commit ba9d114ec557 ("libceph: clear r_req_lru_item in __unregister_linger_request()") tried to fix the _wrong_ way. Cc: stable@vger.kernel.org # 3.10+ Signed-off-by: Ilya Dryomov <idryomov@gmail.com> Reviewed-by: Sage Weil <sage@redhat.com>
Diffstat (limited to 'net')
-rw-r--r--net/ceph/osd_client.c31
1 files changed, 20 insertions, 11 deletions
diff --git a/net/ceph/osd_client.c b/net/ceph/osd_client.c
index 41a4abc7e98e..31d4b1ebff01 100644
--- a/net/ceph/osd_client.c
+++ b/net/ceph/osd_client.c
@@ -2017,20 +2017,29 @@ static void kick_requests(struct ceph_osd_client *osdc, bool force_resend,
err = __map_request(osdc, req,
force_resend || force_resend_writes);
dout("__map_request returned %d\n", err);
- if (err == 0)
- continue; /* no change and no osd was specified */
if (err < 0)
continue; /* hrm! */
- if (req->r_osd == NULL) {
- dout("tid %llu maps to no valid osd\n", req->r_tid);
- needmap++; /* request a newer map */
- continue;
- }
+ if (req->r_osd == NULL || err > 0) {
+ if (req->r_osd == NULL) {
+ dout("lingering %p tid %llu maps to no osd\n",
+ req, req->r_tid);
+ /*
+ * A homeless lingering request makes
+ * no sense, as it's job is to keep
+ * a particular OSD connection open.
+ * Request a newer map and kick the
+ * request, knowing that it won't be
+ * resent until we actually get a map
+ * that can tell us where to send it.
+ */
+ needmap++;
+ }
- dout("kicking lingering %p tid %llu osd%d\n", req, req->r_tid,
- req->r_osd ? req->r_osd->o_osd : -1);
- __register_request(osdc, req);
- __unregister_linger_request(osdc, req);
+ dout("kicking lingering %p tid %llu osd%d\n", req,
+ req->r_tid, req->r_osd ? req->r_osd->o_osd : -1);
+ __register_request(osdc, req);
+ __unregister_linger_request(osdc, req);
+ }
}
reset_changed_osds(osdc);
mutex_unlock(&osdc->request_mutex);