1 files changed, 53 insertions, 0 deletions

diff --git a/libbb/find_mount_point.c b/libbb/find_mount_point.c
new file mode 100644
index 000000000..cb00b9806
--- /dev/null
+++ b/libbb/find_mount_point.c
@@ -0,0 +1,53 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * Utility routines.
+ *
+ * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
+ *
+ * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
+ */
+
+#include "libbb.h"
+#include <mntent.h>
+
+/*
+ * Given a block device, find the mount table entry if that block device
+ * is mounted.
+ *
+ * Given any other file (or directory), find the mount table entry for its
+ * filesystem.
+ */
+struct mntent *find_mount_point(const char *name, const char *table)
+{
+        struct stat s;
+        dev_t mountDevice;
+        FILE *mountTable;
+        struct mntent *mountEntry;
+
+        if (stat(name, &s) != 0)
+                return 0;
+
+        if ((s.st_mode & S_IFMT) == S_IFBLK)
+                mountDevice = s.st_rdev;
+        else
+                mountDevice = s.st_dev;
+
+
+        mountTable = setmntent(table ? table : bb_path_mtab_file, "r");
+        if (!mountTable)
+                return 0;
+
+        while ((mountEntry = getmntent(mountTable)) != 0) {
+                if (strcmp(name, mountEntry->mnt_dir) == 0
+                 || strcmp(name, mountEntry->mnt_fsname) == 0
+                ) { /* String match. */
+                        break;
+                }
+                if (stat(mountEntry->mnt_fsname, &s) == 0 && s.st_rdev == mountDevice)  /* Match the device. */
+                        break;
+                if (stat(mountEntry->mnt_dir, &s) == 0 && s.st_dev == mountDevice)      /* Match the directory's mount point. */
+                        break;
+        }
+        endmntent(mountTable);
+        return mountEntry;
+}