[OpenWrt-Devel] [PATCH] fstools: add a hook before mounting the overlay

[Alin Nastac]

Scripts located in the directory /lib/mount_root will be executed
before mounting the overlay.

Signed-off-by: Alin Nastac <alin.nas...@gmail.com>
---
 libfstools/hook.h    | 51 +++++++++++++++++++++++++++++++++++++++++++++++++++
 libfstools/overlay.c |  3 ++-
 2 files changed, 53 insertions(+), 1 deletion(-)
 create mode 100644 libfstools/hook.h

diff --git a/libfstools/hook.h b/libfstools/hook.h
new file mode 100644
index 0000000..76ee9d0
--- /dev/null
+++ b/libfstools/hook.h
@@ -0,0 +1,51 @@
+#ifndef _HOOK_H
+#define _HOOK_H
+
+#include <sys/types.h>
+#include <sys/wait.h>
+
+static inline int hook_execute(const char *path)
+{
+       DIR *dir;
+       struct dirent *dent;
+       char script[256];
+       pid_t pid;
+
+       ULOG_INFO("executing script in %s\n", path);
+
+       if ((dir = opendir(path)) == NULL) {
+               ULOG_INFO("cannot open %s (%s)\n", path, strerror(errno));
+               return 0;
+       }
+
+       while ((dent = readdir(dir)) != NULL) {
+               struct stat st;
+               int wstatus;
+
+               snprintf(script, sizeof(script), "%s/%s", path, dent->d_name);
+               if (stat(script, &st))
+                       continue;
+               if (!S_ISREG(st.st_mode))
+                       continue;
+               ULOG_INFO("%s\n", script);
+               pid = fork();
+               if (!pid) {
+                       char *cmd[] = {script, NULL};
+
+                       execvp(cmd[0], cmd);
+                       ULOG_ERR("Failed to execute %s\n", script);
+                       exit(-1);
+               }
+               if (pid <= 0) {
+                       ULOG_INFO("Failed to fork() for %s\n", script);
+                       continue;
+               }
+               waitpid(pid, &wstatus, 0);
+       }
+
+       closedir(dir);
+
+       return 0;
+}
+
+#endif
diff --git a/libfstools/overlay.c b/libfstools/overlay.c
index 14214a3..10a16b5 100644
--- a/libfstools/overlay.c
+++ b/libfstools/overlay.c
@@ -29,6 +29,7 @@
 
 #include "libfstools.h"
 #include "volume.h"
+#include "hook.h"
 
 #define SWITCH_JFFS2 "/tmp/.switch_jffs2"
 
@@ -439,7 +440,7 @@ int mount_overlay(struct volume *v)
 
        fs_name = overlay_fs_name(volume_identify(v));
        ULOG_INFO("switching to %s overlay\n", fs_name);
-       if (mount_move("/tmp", "", "/overlay") || fopivot("/overlay", "/rom")) {
+       if (mount_move("/tmp", "", "/overlay") || 
hook_execute("/lib/mount_root") || fopivot("/overlay", "/rom")) {
                ULOG_ERR("switching to %s failed - fallback to ramoverlay\n", 
fs_name);
                return ramoverlay();
        }
-- 
2.7.4


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