From: Sage Weil <sage@inktank.com>
Date: Sat, 15 Mar 2014 03:26:04 +0000 (-0700)
Subject: common/PrioritizedQueue: fix remove_by_class() corner case
X-Git-Tag: v0.79~109^2~4
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=8bd89442aeb6f9fa7c2dea80b793aae4d70d50c9;p=ceph.git

common/PrioritizedQueue: fix remove_by_class() corner case

If i is the first entry, then setting cur = begin() sets us up to point at
something that we are about to delete.  Move the check to the end to avoid
this.

Backport: emperor, dumpling
Signed-off-by: Sage Weil <sage@inktank.com>
---

diff --git a/src/common/PrioritizedQueue.h b/src/common/PrioritizedQueue.h
index d936d5d86c4f..28a9f7a4cd7f 100644
--- a/src/common/PrioritizedQueue.h
+++ b/src/common/PrioritizedQueue.h
@@ -171,11 +171,8 @@ class PrioritizedQueue {
       if (i == q.end())
 	return;
       size -= i->second.size();
-      if (i == cur) {
+      if (i == cur)
 	++cur;
-	if (cur == q.end())
-	  cur = q.begin();
-      }
       if (out) {
 	for (typename list<pair<unsigned, T> >::reverse_iterator j =
 	       i->second.rbegin();
@@ -185,6 +182,8 @@ class PrioritizedQueue {
 	}
       }
       q.erase(i);
+      if (cur == q.end())
+	cur = q.begin();
     }
 
     void dump(Formatter *f) const {