autofs-5.1.4 - fix deadlock in dumpmaps

From: Ian Kent <raven@themaw.net>

Commit a223d11fa8e (autofs-5.1.3 - serialize calls to open_xxxx()
functions) introduces a deadlock when using the dumpmaps function.

In this case the open fd mutex needs to be unlocked in the forked
child process of the do_spawn() function.

Signed-off-by: Ian Kent <raven@themaw.net>
---
 CHANGELOG      |    1 +
 daemon/spawn.c |    1 +
 2 files changed, 2 insertions(+)

diff --git a/CHANGELOG b/CHANGELOG
index 2747327b..0f30596f 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -2,6 +2,7 @@ xx/xx/2018 autofs-5.1.5
 - fix flag file permission.
 - fix directory create permission.
 - fix use after free in do_master_list_reset().
+- fix deadlock in dumpmaps.
 
 19/12/2017 autofs-5.1.4
 - fix spec file url.
diff --git a/daemon/spawn.c b/daemon/spawn.c
index fabe577e..dbbca7fa 100644
--- a/daemon/spawn.c
+++ b/daemon/spawn.c
@@ -338,6 +338,7 @@ static int do_spawn(unsigned logopt, unsigned int wait,
 		dup2(pipefd[1], STDOUT_FILENO);
 		dup2(pipefd[1], STDERR_FILENO);
 		close(pipefd[1]);
+		open_mutex_unlock();
 
 		/* what to mount must always be second last */
 		while (*pargv++)