Move close_all_open_fds() in oslib-posix, rename it
qemu_close_all_open_fds() and export it.

Signed-off-by: Clément Léger <cleger@rivosinc.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
---
 include/qemu/osdep.h    |  7 +++++++
 system/async-teardown.c | 37 +------------------------------------
 util/oslib-posix.c      | 34 ++++++++++++++++++++++++++++++++++
 3 files changed, 42 insertions(+), 36 deletions(-)

diff --git a/include/qemu/osdep.h b/include/qemu/osdep.h
index 191916f38e..5cd8517380 100644
--- a/include/qemu/osdep.h
+++ b/include/qemu/osdep.h
@@ -757,6 +757,13 @@ static inline void qemu_reset_optind(void)
 
 int qemu_fdatasync(int fd);
 
+/**
+ * qemu_close_all_open_fd:
+ *
+ * Close all open file descriptors
+ */
+void qemu_close_all_open_fd(void);
+
 /**
  * Sync changes made to the memory mapped file back to the backing
  * storage. For POSIX compliant systems this will fallback
diff --git a/system/async-teardown.c b/system/async-teardown.c
index 396963c091..edf49e1007 100644
--- a/system/async-teardown.c
+++ b/system/async-teardown.c
@@ -26,40 +26,6 @@
 
 static pid_t the_ppid;
 
-/*
- * Close all open file descriptors.
- */
-static void close_all_open_fd(void)
-{
-    struct dirent *de;
-    int fd, dfd;
-    DIR *dir;
-
-#ifdef CONFIG_CLOSE_RANGE
-    int r = close_range(0, ~0U, 0);
-    if (!r) {
-        /* Success, no need to try other ways. */
-        return;
-    }
-#endif
-
-    dir = opendir("/proc/self/fd");
-    if (!dir) {
-        /* If /proc is not mounted, there is nothing that can be done. */
-        return;
-    }
-    /* Avoid closing the directory. */
-    dfd = dirfd(dir);
-
-    for (de = readdir(dir); de; de = readdir(dir)) {
-        fd = atoi(de->d_name);
-        if (fd != dfd) {
-            close(fd);
-        }
-    }
-    closedir(dir);
-}
-
 static void hup_handler(int signal)
 {
     /* Check every second if this process has been reparented. */
@@ -85,9 +51,8 @@ static int async_teardown_fn(void *arg)
     /*
      * Close all file descriptors that might have been inherited from the
      * main qemu process when doing clone, needed to make libvirt happy.
-     * Not using close_range for increased compatibility with older kernels.
      */
-    close_all_open_fd();
+    qemu_close_all_open_fd();
 
     /* Set up a handler for SIGHUP and unblock SIGHUP. */
     sigaction(SIGHUP, &sa, NULL);
diff --git a/util/oslib-posix.c b/util/oslib-posix.c
index b090fe0eed..1e867efa47 100644
--- a/util/oslib-posix.c
+++ b/util/oslib-posix.c
@@ -807,3 +807,37 @@ int qemu_msync(void *addr, size_t length, int fd)
 
     return msync(addr, length, MS_SYNC);
 }
+
+/*
+ * Close all open file descriptors.
+ */
+void qemu_close_all_open_fd(void)
+{
+    struct dirent *de;
+    int fd, dfd;
+    DIR *dir;
+
+#ifdef CONFIG_CLOSE_RANGE
+    int r = close_range(0, ~0U, 0);
+    if (!r) {
+        /* Success, no need to try other ways. */
+        return;
+    }
+#endif
+
+    dir = opendir("/proc/self/fd");
+    if (!dir) {
+        /* If /proc is not mounted, there is nothing that can be done. */
+        return;
+    }
+    /* Avoid closing the directory. */
+    dfd = dirfd(dir);
+
+    for (de = readdir(dir); de; de = readdir(dir)) {
+        fd = atoi(de->d_name);
+        if (fd != dfd) {
+            close(fd);
+        }
+    }
+    closedir(dir);
+}
-- 
2.45.2