Merge branch 'lukas/erts/etoomanyrefs_forker/OTP-15210' into maint

* lukas/erts/etoomanyrefs_forker/OTP-15210:
  erts: Handle EMFILE errors in forker_driver for write

1 files changed, 12 insertions, 1 deletions

diff --git a/erts/emulator/sys/unix/sys_uds.c b/erts/emulator/sys/unix/sys_uds.c
index c328fd00bb..39a4866065 100644
--- a/erts/emulator/sys/unix/sys_uds.c
+++ b/erts/emulator/sys/unix/sys_uds.c
@@ -132,7 +132,7 @@ sys_uds_writev(int fd, struct iovec *iov, size_t iov_len,
 
     struct msghdr msg;
     struct cmsghdr *cmsg = NULL;
-    int res, i;
+    int res, i, error;
 
     /* initialize socket message */
     memset(&msg, 0, sizeof(struct msghdr));
@@ -173,11 +173,22 @@ sys_uds_writev(int fd, struct iovec *iov, size_t iov_len,
 
     res = sendmsg(fd, &msg, flags);
 
+#ifdef ETOOMANYREFS
+    /* Linux may give ETOOMANYREFS when there are too many fds in transit.
+       We map this to EMFILE as bsd and other use this error code and we want
+       the behaviour to be the same on all OSs */
+    if (errno == ETOOMANYREFS)
+        errno = EMFILE;
+#endif
+    error = errno;
+
     if (iov_len > MAXIOV)
         free(iov[0].iov_base);
 
     free(msg.msg_control);
 
+    errno = error;
+
     return res;
 }