Retry failed calls to vn_getpath

microsoft · Sep 14, 2018 · 4c38ca0 · 4c38ca0
1 parent efa70da
commit 4c38ca0
Showing 1 changed file with 16 additions and 1 deletion.
diff --git a/ProjFS.Mac/PrjFSKext/PrjFSKext/KauthHandler.cpp b/ProjFS.Mac/PrjFSKext/PrjFSKext/KauthHandler.cpp
@@ -13,6 +13,8 @@
 #include "Locks.hpp"
 #include "PrjFSProviderUserClient.hpp"
 
+static const int MAX_GETPATH_ENOENT_RETRIES = 1024;
+
 // Function prototypes
 static int HandleVnodeOperation(
     kauth_cred_t    credential,
@@ -659,10 +661,23 @@ static bool TrySendRequestAndWaitForResponse(
 
     char vnodePath[PrjFSMaxPath];
     int vnodePathLength = PrjFSMaxPath;
-    if (vn_getpath(vnode, vnodePath, &vnodePathLength))
+
+    // TODO(Mac): Issue #271 - Reduce reliance on vn_getpath
+    int retryCount = 0;
+    int getPathResult = vn_getpath(vnode, vnodePath, &vnodePathLength);
+    while (getPathResult && retryCount < MAX_GETPATH_ENOENT_RETRIES)
+    {
+        getPathResult = vn_getpath(vnode, vnodePath, &vnodePathLength);
+        ++retryCount;
+    }
+
+    if (getPathResult)
     {
         KextLog_Error("Unable to resolve a vnode to its path");
+
+        // Default error code is EACCES. See errno.h for more codes.
         *kauthResult = KAUTH_RESULT_DENY;
+        *kauthError = EAGAIN;
         return false;
     }