grub-0.97/VFS

[Edward Shishkin]

(CC linux-btrfs mailing list)

Hello everyone.

Grub-0.97 filesystem interface (read_func, dir_func)
seems to be poor. Instead of this I would prefer to
have something like the following:

/*
*
* .init_root()           // set index of root dir
* .lookup_begin()        // get index by name
* .lookup_end()          // get inode by index
* .read_file()
* .read_dir()
* .read_symlink()
*
* so that dir_func in grub_open will look like the
* following:
*/
int path_walk()
{
   ops->init_root();
   while (1) {
       int mode;
       ops->lookup_end(&mode, ...);

       switch (type_of_file(mode)) {
       case SYMLINK_FILE:
           follow_symlink(read_symlink, ...);
           ...;
           continue;
       case REGULAR_FILE:
           /*
            * the end of path walk:
            * normally we want to exit here
            */
           ...;
           return 1;
       case DIRECTORY_FILE:
           /*
            * optionally this will
            * print possibilities
            */
           ops->lookup_begin(mode, read_dir, ...);
           ...;
           continue;
       default:
           errnum = ERR_BAD_FILETYPE;
           return 0;
       }
   }
}

Just my 2 cents in the (grub-2?) development process..

Thanks,
Edward.