(main): If the lock call fails with EBUSY or

EAGAIN, retry a few times.

1 files changed, 38 insertions, 4 deletions

diff --git a/lib-src/movemail.c b/lib-src/movemail.c
index 80f6afd3616..79ea6dcabab 100644
--- a/lib-src/movemail.c
+++ b/lib-src/movemail.c
@@ -295,6 +295,9 @@ main (argc, argv)
 
   if (fork () == 0)
     {
+      int lockcount = 0;
+      int status;
+
       setuid (getuid ());
 
 #ifndef MAIL_USE_MMDF
@@ -320,22 +323,53 @@ main (argc, argv)
       outdesc = open (outname, O_WRONLY | O_CREAT | O_EXCL, 0666);
       if (outdesc < 0)
         pfatal_with_name (outname);
+
+      /* This label exists so we can retry locking
+         after a delay, if it got EAGAIN or EBUSY.  */
+    retry_lock:
+
+      /* Try to lock it.  */
 #ifdef MAIL_USE_SYSTEM_LOCK
 #ifdef MAIL_USE_LOCKF
-      if (lockf (indesc, F_LOCK, 0) < 0) pfatal_with_name (inname);
+      status = lockf (indesc, F_LOCK, 0);
 #else /* not MAIL_USE_LOCKF */
 #ifdef XENIX
-      if (locking (indesc, LK_RLCK, 0L) < 0) pfatal_with_name (inname);
+      status = locking (indesc, LK_RLCK, 0L);
 #else
 #ifdef WINDOWSNT
-      if (locking (indesc, LK_RLCK, -1L) < 0) pfatal_with_name (inname);
+      status = locking (indesc, LK_RLCK, -1L);
 #else
-      if (flock (indesc, LOCK_EX) < 0) pfatal_with_name (inname);
+      status = flock (indesc, LOCK_EX);
 #endif
 #endif
 #endif /* not MAIL_USE_LOCKF */
 #endif /* MAIL_USE_SYSTEM_LOCK */
 
+      /* If it fails, retry up to 5 times
+         for certain failure codes.  */
+      if (status < 0)
+        {
+          if (++lockcount <= 5)
+            {
+#ifdef EAGAIN
+              if (errno == EAGAIN)
+                {
+                  sleep (1);
+                  goto retry_lock;
+                }
+#endif
+#ifdef EBUSY
+              if (errno == EBUSY)
+                {
+                  sleep (1);
+                  goto retry_lock;
+                }
+#endif
+            }
+
+          pfatal_with_name (inname);
+        }
+  
       {
         char buf[1024];