failtest: don't assume FD_SETSIZE is maximum runtime fd.

This breaks when rlimit is less.  Unfortunately, valgrind (32 bit x86,
3.7.0.SVN, Ubuntu) fails to set the file limit properly on the test:
reducing it to the obvious getrlimit/setrlimit/getrlimit works fine,
so leaving diagnostics for another day.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
(Imported from CCAN commit a85a809bb17af6b6cf6fa31b300c6622f64ee700)

Autobuild-User: Rusty Russell <rusty@rustcorp.com.au>
Autobuild-Date: Thu Mar  8 06:30:48 CET 2012 on sn-devel-104

diff --git a/lib/ccan/failtest/_info b/lib/ccan/failtest/_info
index 14dcb783be08b0ebc0c13465d7d4de2834ecc48c..4a5b97c9313e337df1f9e9155fb2526f4974cf2d 100644 (file)
--- a/lib/ccan/failtest/_info
+++ b/lib/ccan/failtest/_info
@@ -54,6 +54,9 @@
  *
  * License: LGPL
  * Author: Rusty Russell <rusty@rustcorp.com.au>
+ * Ccanlint:
+ *     // valgrind seems to mess up rlimit.
+ *     tests_pass_valgrind test/run-with-fdlimit.c:FAIL
  */
 int main(int argc, char *argv[])
 {

diff --git a/lib/ccan/failtest/failtest.c b/lib/ccan/failtest/failtest.c
index 701586e9b884607afa4f1267eba4c2caa763cff3..5f68394518f412a06d77c56e0c62a482d39223ad 100644 (file)
--- a/lib/ccan/failtest/failtest.c
+++ b/lib/ccan/failtest/failtest.c
@@ -14,6 +14,7 @@
 #include <sys/stat.h>
 #include <sys/time.h>
 #include <sys/mman.h>
+#include <sys/resource.h>
 #include <signal.h>
 #include <assert.h>
 #include <ccan/time/time.h>
@@ -194,11 +195,21 @@ static struct failtest_call *add_history_(enum failtest_call_type type,
 static int move_fd_to_high(int fd)
 {
        int i;
+       struct rlimit lim;
+       int max;
 
-       for (i = FD_SETSIZE - 1; i >= 0; i--) {
+       if (getrlimit(RLIMIT_NOFILE, &lim) == 0) {
+               max = lim.rlim_cur;
+               printf("Max is %i\n", max);
+       } else
+               max = FD_SETSIZE;
+
+       for (i = max - 1; i > fd; i--) {
                if (fcntl(i, F_GETFL) == -1 && errno == EBADF) {
-                       if (dup2(fd, i) == -1)
-                               err(1, "Failed to dup fd %i to %i", fd, i);
+                       if (dup2(fd, i) == -1) {
+                               warn("Failed to dup fd %i to %i", fd, i);
+                               continue;
+                       }
                        close(fd);
                        return i;
                }

diff --git a/lib/ccan/failtest/test/run-with-fdlimit.c b/lib/ccan/failtest/test/run-with-fdlimit.c
new file mode 100644 (file)
index 0000000..6b4483f
--- /dev/null
+++ b/lib/ccan/failtest/test/run-with-fdlimit.c
@@ -0,0 +1,51 @@
+/* Include the C files directly. */
+#include <ccan/failtest/failtest.c>
+#include <stdlib.h>
+#include <err.h>
+#include <ccan/tap/tap.h>
+
+int main(void)
+{
+       int fd, pfd[2], ecode;
+       struct rlimit lim;
+
+       if (getrlimit(RLIMIT_NOFILE, &lim) != 0)
+               err(1, "getrlimit RLIMIT_NOFILE fail?");
+
+       printf("rlimit = %lu/%lu (inf=%lu)\n",
+              (long)lim.rlim_cur, (long)lim.rlim_max,
+              (long)RLIM_INFINITY);
+       lim.rlim_cur /= 2;
+       if (lim.rlim_cur < 8)
+               errx(1, "getrlimit limit %li too low", (long)lim.rlim_cur);
+       if (setrlimit(RLIMIT_NOFILE, &lim) != 0)
+               err(1, "setrlimit RLIMIT_NOFILE (%li/%li)",
+                   (long)lim.rlim_cur, (long)lim.rlim_max);
+
+       plan_tests(2);
+       failtest_init(0, NULL);
+
+       if (pipe(pfd))
+               abort();
+
+       fd = failtest_open("run-with-fdlimit-scratch", "run-with_fdlimit.c", 1,
+                          O_RDWR|O_CREAT, 0600);
+       if (fd == -1) {
+               /* We are the child: write error code for parent to check. */
+               ecode = errno;
+               if (write(pfd[1], &ecode, sizeof(ecode)) != sizeof(ecode))
+                       abort();
+               failtest_exit(0);
+       }
+
+       /* Check child got correct errno. */
+       ok1(read(pfd[0], &ecode, sizeof(ecode)) == sizeof(ecode));
+       ok1(ecode == EACCES);
+
+       /* Clean up. */
+       failtest_close(fd, "run-open.c", 1);
+       close(pfd[0]);
+       close(pfd[1]);
+
+       return exit_status();
+}