From: linbing <hawkerous@gmail.com>
Date: Fri, 21 Dec 2018 00:22:30 +0000 (+0800)
Subject: os/bluestore: fixup access a destroy cond cause deadlock or undefine
X-Git-Tag: v14.1.0~511^2
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=refs%2Fpull%2F25659%2Fhead;p=ceph.git

os/bluestore: fixup access a destroy cond cause deadlock or undefine
              behavior.

Fixes: https://tracker.ceph.com/issues/37733
Signed-off-by: linbing <linbing@t2cloud.net>
---

diff --git a/src/os/bluestore/BlockDevice.h b/src/os/bluestore/BlockDevice.h
index 5faa26073baf..ad60ab32cd44 100644
--- a/src/os/bluestore/BlockDevice.h
+++ b/src/os/bluestore/BlockDevice.h
@@ -95,13 +95,14 @@ public:
 
   void try_aio_wake() {
     assert(num_running >= 1);
+
+    std::lock_guard l(lock);
     if (num_running.fetch_sub(1) == 1) {
 
       // we might have some pending IOs submitted after the check
       // as there is no lock protection for aio_submit.
       // Hence we might have false conditional trigger.
       // aio_wait has to handle that hence do not care here.
-      std::lock_guard l(lock);
       cond.notify_all();
     }
   }