From: 胡玮文 <huww98@outlook.com>
Date: Thu, 6 Jan 2022 07:43:29 +0000 (+0800)
Subject: mds: fix seg fault in expire_recursive
X-Git-Tag: v15.2.17~36^2
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=3ffc8882710ce47dc9f8cba3a4f8f4b629b5614d;p=ceph.git

mds: fix seg fault in expire_recursive

Range-based for should not be used when we are altering the container.
Use iterator explicitly instead.

Fixes: https://tracker.ceph.com/issues/53805
Signed-off-by: 胡玮文 <huww98@outlook.com>
(cherry picked from commit d48a2cf7e2481cf9758f2934464ec6d9c35d898b)
---

diff --git a/src/mds/MDCache.cc b/src/mds/MDCache.cc
index adf46a839e61..88d2b648d02a 100644
--- a/src/mds/MDCache.cc
+++ b/src/mds/MDCache.cc
@@ -3733,8 +3733,9 @@ bool MDCache::expire_recursive(CInode *in, expiremap &expiremap)
       return true;
     }
 
-    for (auto &it : subdir->items) {
-      CDentry *dn = it.second;
+    for (auto it = subdir->items.begin(); it != subdir->items.end();) {
+      CDentry *dn = it->second;
+      it++;
       CDentry::linkage_t *dnl = dn->get_linkage();
       if (dnl->is_primary()) {
 	CInode *tin = dnl->get_inode();