From: Sage Weil <sage@redhat.com>
Date: Mon, 1 May 2017 20:10:44 +0000 (-0500)
Subject: osdc/Objecter: fix pool dne corner case
X-Git-Tag: v12.0.3~146^2
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=d60c1c40ce7a4eb7806b748b0738de39c11d6781;p=ceph.git

osdc/Objecter: fix pool dne corner case

We have a request that is queued before a pool exists, there is one
epoch where it exists, and then the pool disappears again.  The two maps
are processed at the same time.  For the first we set needs_resend, map to
an osd, and remove from the homeless sessin.  For the second, the pool
dne, we set osd back to -1, and send a map check request.  Finally,
handle_osd_maps scans need_resend, sees the pool dne, and removes from
need_resend.  The difference from the "usual" case is that we are neither
on the need_resend list nor on the homeless session.

Fix this by concluding immediately that the pool existed (briefly) and
then no longer exists.

Fixes: http://tracker.ceph.com/issues/19552
Signed-off-by: Sage Weil <sage@redhat.com>
---

diff --git a/src/osdc/Objecter.cc b/src/osdc/Objecter.cc
index dc102d52943..0ce319a352d 100644
--- a/src/osdc/Objecter.cc
+++ b/src/osdc/Objecter.cc
@@ -1458,9 +1458,9 @@ void Objecter::_check_op_pool_dne(Op *op, unique_lock *sl)
 {
   // rwlock is locked unique
 
-  if (op->attempts) {
-    // we send a reply earlier, which means that previously the pool
-    // existed, and now it does not (i.e., it was deleted).
+  if (op->target.pool_ever_existed) {
+    // the pool previously existed and now it does not, which means it
+    // was deleted.
     op->map_dne_bound = osdmap->get_epoch();
     ldout(cct, 10) << "check_op_pool_dne tid " << op->tid
 		   << " pool previously exists but now does not"
@@ -2749,6 +2749,7 @@ int Objecter::_calc_target(op_target_t *t, Connection *con, bool any_change)
 		<< t->target_oloc << " -> pgid " << pgid << dendl;
   ldout(cct,30) << __func__ << "  target pi " << pi
 		<< " pg_num " << pi->get_pg_num() << dendl;
+  t->pool_ever_existed = true;
 
   int size = pi->size;
   int min_size = pi->min_size;
diff --git a/src/osdc/Objecter.h b/src/osdc/Objecter.h
index 980cdc7e0e8..abbc8d8116c 100644
--- a/src/osdc/Objecter.h
+++ b/src/osdc/Objecter.h
@@ -1240,6 +1240,9 @@ public:
     ///< true if we are directed at base_pgid, not base_oid
     bool precalc_pgid = false;
 
+    ///< true if we have ever mapped to a valid pool
+    bool pool_ever_existed = false;
+
     ///< explcit pg target, if any
     pg_t base_pgid;