lib: Error out on too many FDs in mtio-select.

diff --git a/lib/mtio-select.c b/lib/mtio-select.c
index eb84a45..63f4e8b 100644 (file)
--- a/lib/mtio-select.c
+++ b/lib/mtio-select.c
@@ -44,6 +44,11 @@ int block(int fd, int ev, time_t to)
     struct blocker *bl;
     int rv;
     
+    if(fd >= FD_SETSIZE) {
+       flog(LOG_ERR, "tried to use more file descriptors than select() can handle: fd %i", fd);
+       errno = EMFILE;
+       return(-1);
+    }
     omalloc(bl);
     bl->fd = fd;
     bl->ev = ev;