fstools: check existing filesystem state before writing the new one

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

diff --git a/libfstools/overlay.c b/libfstools/overlay.c
index 7c9b480ba963818a70c30048ce4e1a1a181a2793..cdac23e0d04bb6c707d9ca873085936a9749c545 100644 (file)
--- a/libfstools/overlay.c
+++ b/libfstools/overlay.c
@@ -67,6 +67,7 @@ handle_rmdir(const char *dir)
 void
 foreachdir(const char *dir, int (*cb)(const char*))
 {
+       struct stat s = { 0 };
        char globdir[256];
        glob_t gl;
        int j;
@@ -77,9 +78,16 @@ foreachdir(const char *dir, int (*cb)(const char*))
                snprintf(globdir, 256, "%s/*", dir); /**/
 
        if (!glob(globdir, GLOB_NOESCAPE | GLOB_MARK | GLOB_ONLYDIR, NULL, &gl))
-               for (j = 0; j < gl.gl_pathc; j++)
-                       foreachdir(gl.gl_pathv[j], cb);
+               for (j = 0; j < gl.gl_pathc; j++) {
+                       char *dir = gl.gl_pathv[j];
+                       int len = strlen(gl.gl_pathv[j]);
 
+                       if (len > 1 && dir[len - 1] == '/')
+                               dir[len - 1] = '\0';
+
+                       if (!lstat(gl.gl_pathv[j], &s) && !S_ISLNK(s.st_mode))
+                               foreachdir(gl.gl_pathv[j], cb);
+       }
        cb(dir);
 }
 
@@ -130,7 +138,10 @@ switch2jffs(struct volume *v)
                return -1;
        }
 
-       system("cp -a /tmp/root/* /rom/overlay"); /**/
+       if (system("cp -a /tmp/root/* /rom/overlay")) {
+               ULOG_ERR("failed - cp -a /tmp/root/* /rom/overlay: %s\n", strerror(errno));
+               return -1;
+       }
 
        if (pivot("/rom", "/mnt")) {
                ULOG_ERR("failed - pivot /rom /mnt: %s\n", strerror(errno));
@@ -235,7 +246,13 @@ jffs2_switch(struct volume *v)
                }
                break;
        }
-       return ret;
+
+       if (ret)
+               return ret;
+
+       sync();
+       fs_state_set("/overlay", FS_STATE_READY);
+       return 0;
 }
 
 static int overlay_mount_fs(struct volume *v)
@@ -266,6 +283,46 @@ static int overlay_mount_fs(struct volume *v)
        return -1;
 }
 
+enum fs_state fs_state_get(const char *dir)
+{
+       char *path;
+       char valstr[16];
+       uint32_t val;
+       ssize_t len;
+
+       path = alloca(strlen(dir) + 1 + sizeof("/.fs_state"));
+       sprintf(path, "%s/.fs_state", dir);
+       len = readlink(path, valstr, sizeof(valstr) - 1);
+       if (len < 0)
+               return FS_STATE_UNKNOWN;
+
+       valstr[len] = 0;
+       val = atoi(valstr);
+
+       if (val > __FS_STATE_LAST)
+               return FS_STATE_UNKNOWN;
+
+       return val;
+}
+
+
+int fs_state_set(const char *dir, enum fs_state state)
+{
+       char valstr[16];
+       char *path;
+
+       if (fs_state_get(dir) == state)
+               return 0;
+
+       path = alloca(strlen(dir) + 1 + sizeof("/.fs_state"));
+       sprintf(path, "%s/.fs_state", dir);
+       unlink(path);
+       snprintf(valstr, sizeof(valstr), "%d", state);
+
+       return symlink(valstr, path);
+}
+
+
 int mount_overlay(struct volume *v)
 {
        char *mp;
@@ -287,6 +344,21 @@ int mount_overlay(struct volume *v)
                return 0;
        }
 
+       switch(fs_state_get("/tmp/overlay")) {
+       case FS_STATE_UNKNOWN:
+               fs_state_set("/tmp/overlay", FS_STATE_PENDING);
+               if (fs_state_get("/tmp/overlay") != FS_STATE_PENDING) {
+                       ULOG_ERR("unable to set filesystem state\n");
+                       break;
+               }
+       case FS_STATE_PENDING:
+               ULOG_INFO("overlay filesystem has not been fully initialized yet\n");
+               overlay_delete("/tmp/overlay", true);
+               break;
+       case FS_STATE_READY:
+               break;
+       }
+
        ULOG_INFO("switching to jffs2 overlay\n");
        if (mount_move("/tmp", "", "/overlay") || fopivot("/overlay", "/rom")) {
                ULOG_ERR("switching to jffs2 failed - fallback to ramoverlay\n");