From 4bf9078286d58c2cd4e85cb8b31411220a377092 Mon Sep 17 00:00:00 2001
From: Sage Weil <sage@inktank.com>
Date: Sat, 15 Dec 2012 17:45:25 -0800
Subject: [PATCH] osdc/Objecter: prevent pool dne check from invalidating
 scan_requests iterator

We iterate over ops and, if the pool dne and other conditions are true,
we will immediately return ENOENT and cancel an op.  Increment the
iterator at the top of the loop to avoid invalidating it.

We also need to switch to a map<>, because hash_map<> mutations may
invalidate any/all iterators.

Fixes: #3613
Signed-off-by: Sage Weil <sage@inktank.com>
---
 src/osdc/Objecter.cc | 14 +++++++-------
 src/osdc/Objecter.h  |  3 +--
 2 files changed, 8 insertions(+), 9 deletions(-)

diff --git a/src/osdc/Objecter.cc b/src/osdc/Objecter.cc
index 9d7fe67cf9d2e..e29d879133b42 100644
--- a/src/osdc/Objecter.cc
+++ b/src/osdc/Objecter.cc
@@ -439,10 +439,10 @@ void Objecter::scan_requests(bool skipped_map,
   }
 
   // check for changed request mappings
-  for (hash_map<tid_t,Op*>::iterator p = ops.begin();
-       p != ops.end();
-       ++p) {
+  map<tid_t,Op*>::iterator p = ops.begin();
+  while (p != ops.end()) {
     Op *op = p->second;
+    ++p;   // check_op_pool_dne() may touch ops; prevent iterator invalidation
     ldout(cct, 10) << " checking op " << op->tid << dendl;
     int r = recalc_op_target(op);
     switch (r) {
@@ -568,7 +568,7 @@ void Objecter::handle_osd_map(MOSDMap *m)
   // unpause requests?
   if ((was_pauserd && !pauserd) ||
       (was_pausewr && !pausewr))
-    for (hash_map<tid_t,Op*>::iterator p = ops.begin();
+    for (map<tid_t,Op*>::iterator p = ops.begin();
 	 p != ops.end();
 	 p++) {
       Op *op = p->second;
@@ -900,7 +900,7 @@ void Objecter::tick()
   cutoff -= cct->_conf->objecter_timeout;  // timeout
 
   unsigned laggy_ops = 0;
-  for (hash_map<tid_t,Op*>::iterator p = ops.begin();
+  for (map<tid_t,Op*>::iterator p = ops.begin();
        p != ops.end();
        p++) {
     Op *op = p->second;
@@ -2010,7 +2010,7 @@ void Objecter::ms_handle_remote_reset(Connection *con)
 void Objecter::dump_active()
 {
   ldout(cct, 20) << "dump_active .. " << num_homeless_ops << " homeless" << dendl;
-  for (hash_map<tid_t,Op*>::iterator p = ops.begin(); p != ops.end(); p++) {
+  for (map<tid_t,Op*>::iterator p = ops.begin(); p != ops.end(); p++) {
     Op *op = p->second;
     ldout(cct, 20) << op->tid << "\t" << op->pgid << "\tosd." << (op->session ? op->session->osd : -1)
 	    << "\t" << op->oid << "\t" << op->ops << dendl;
@@ -2033,7 +2033,7 @@ void Objecter::dump_requests(Formatter& fmt) const
 void Objecter::dump_ops(Formatter& fmt) const
 {
   fmt.open_array_section("ops");
-  for (hash_map<tid_t,Op*>::const_iterator p = ops.begin();
+  for (map<tid_t,Op*>::const_iterator p = ops.begin();
        p != ops.end();
        ++p) {
     Op *op = p->second;
diff --git a/src/osdc/Objecter.h b/src/osdc/Objecter.h
index e23f32a8d0f08..bba7e9944c213 100644
--- a/src/osdc/Objecter.h
+++ b/src/osdc/Objecter.h
@@ -28,7 +28,6 @@
 #include <list>
 #include <map>
 #include <memory>
-#include <ext/hash_map>
 using namespace std;
 using namespace __gnu_cxx;
 
@@ -884,7 +883,7 @@ public:
 
  private:
   // pending ops
-  hash_map<tid_t,Op*>       ops;
+  map<tid_t,Op*>            ops;
   int                       num_homeless_ops;
   map<uint64_t, LingerOp*>  linger_ops;
   map<tid_t,PoolStatOp*>    poolstat_ops;
-- 
2.39.5