overlay: create a common function for deleting all overlay data (optionally excluding...

[project/fstools.git] / libfstools / overlay.c

diff --git a/libfstools/overlay.c b/libfstools/overlay.c
index 21012ba..c535693 100644 (file)
--- a/libfstools/overlay.c
+++ b/libfstools/overlay.c
@@ -32,6 +32,38 @@
 
 #define SWITCH_JFFS2 "/tmp/.switch_jffs2"
 
+static bool keep_sysupgrade;
+
+static int
+handle_rmdir(const char *dir)
+{
+       struct dirent *dt;
+       struct stat st;
+       DIR *d;
+       int fd;
+
+       d = opendir(dir);
+       if (!d)
+               return -1;
+
+       fd = dirfd(d);
+
+       while ((dt = readdir(d)) != NULL) {
+               if (fstatat(fd, dt->d_name, &st, AT_SYMLINK_NOFOLLOW) || S_ISDIR(st.st_mode))
+                       continue;
+
+               if (keep_sysupgrade && !strcmp(dt->d_name, "sysupgrade.tgz"))
+                       continue;
+
+               unlinkat(fd, dt->d_name, 0);
+       }
+
+       closedir(d);
+       rmdir(dir);
+
+       return 0;
+}
+
 void
 foreachdir(const char *dir, int (*cb)(const char*))
 {
@@ -51,6 +83,13 @@ foreachdir(const char *dir, int (*cb)(const char*))
        cb(dir);
 }
 
+void
+overlay_delete(const char *dir, bool _keep_sysupgrade)
+{
+       keep_sysupgrade = _keep_sysupgrade;
+       foreachdir(dir, handle_rmdir);
+}
+
 static int
 overlay_mount(struct volume *v, char *fs)
 {