mds: MDCache: check validity of mdr requests before dispatching

theanalyst · theanalyst · commit 75cd8c074f37 · 2025-04-02T15:32:32.000+02:00
Ignore null requests

Signed-off-by: Abhishek Lekshmanan &lt;abhishek.lekshmanan@cern.ch&gt;
diff --git a/src/mds/MDCache.cc b/src/mds/MDCache.cc
@@ -10021,6 +10021,10 @@ void MDCache::request_forward(const MDRequestRef& mdr, mds_rank_t who, int port)
 
 void MDCache::dispatch_request(const MDRequestRef& mdr)
 {
+  if (!mdr) {
+    dout(0) << __func__ << ": received a null request!"  << dendl;
+    return;
+  }
   if (mdr->dead) {
     dout(20) << __func__ << ": dead " << *mdr << dendl;
     return;
@@ -13334,7 +13338,9 @@ int MDCache::dump_cache(std::string_view fn, Formatter *f, double timeout)
 void C_MDS_RetryRequest::finish(int r)
 {
   mdr->retry++;
-  cache->dispatch_request(mdr);
+  if (mdr) {
+    cache->dispatch_request(mdr);
+  }
 }
 
 MDSContext *CF_MDS_RetryRequestFactory::build()

Original file line number	Diff line number	Diff line change
`@@ -10021,6 +10021,10 @@ void MDCache::request_forward(const MDRequestRef& mdr, mds_rank_t who, int port)`
`10021`	`10021`
`10022`	`10022`	`void MDCache::dispatch_request(const MDRequestRef& mdr)`
`10023`	`10023`	`{`
	`10024`	`+ if (!mdr) {`
	`10025`	`+ dout(0) << __func__ << ": received a null request!" << dendl;`
	`10026`	`+ return;`
	`10027`	`+ }`
`10024`	`10028`	`if (mdr->dead) {`
`10025`	`10029`	`dout(20) << __func__ << ": dead " << *mdr << dendl;`
`10026`	`10030`	`return;`
`@@ -13334,7 +13338,9 @@ int MDCache::dump_cache(std::string_view fn, Formatter *f, double timeout)`
`13334`	`13338`	`void C_MDS_RetryRequest::finish(int r)`
`13335`	`13339`	`{`
`13336`	`13340`	`mdr->retry++;`
`13337`		`- cache->dispatch_request(mdr);`
	`13341`	`+ if (mdr) {`
	`13342`	`+ cache->dispatch_request(mdr);`
	`13343`	`+ }`
`13338`	`13344`	`}`
`13339`	`13345`
`13340`	`13346`	`MDSContext *CF_MDS_RetryRequestFactory::build()`