[PATCH v6] ntdll: Add support for EXT4 case folding per directory

[Huw Davies]

On Thu, Jun 13, 2019 at 06:53:59PM +0300, Gabriel Ivăncescu wrote:
> +    if ((fd = open( dir, O_RDONLY | O_NONBLOCK | O_LARGEFILE )) == -1)
>          return TRUE;
> -    /* Normally, we'd have to parse the mtab to find out exactly what
> -     * kind of FUSE FS this is. But, someone on wine-devel suggested
> -     * a shortcut. We'll stat a special file in the directory. If it's
> -     * there, we'll assume it's a CIOPFS, else not.
> -     * This will break if somebody puts a file named ".ciopfs" in a non-
> -     * CIOPFS directory.
> -     */
> -    cifile = RtlAllocateHeap( GetProcessHeap(), 0, strlen( dir )+sizeof("/.ciopfs") );
> -    if (!cifile) return TRUE;
> -    strcpy( cifile, dir );
> -    strcat( cifile, "/.ciopfs" );
> -    if (stat( cifile, &st ) == 0)
> +
> +    if (ioctl( fd, EXT2_IOC_GETFLAGS, &flags ) != -1 && (flags & EXT4_CASEFOLD_FL))
>      {
> -        RtlFreeHeap( GetProcessHeap(), 0, cifile );
> -        return FALSE;
> +        sens = FALSE;
>      }
> -    RtlFreeHeap( GetProcessHeap(), 0, cifile );
> -    return TRUE;
> +    else
> +    {
> +        /* Assume CIOPFS is case insensitive. Normally, we'd have to parse
> +         * the mtab to find out exactly what kind of FUSE FS this is. But,
> +         * someone on wine-devel suggested a shortcut. We'll stat a special
> +         * file in the directory. If it's there, we'll assume it's a CIOPFS,
> +         * else not. This will break if somebody puts a file named ".ciopfs"
> +         * in a non-CIOPFS directory.
> +         */
> +        if (fstatfs( fd, &stfs ) != -1 && stfs.f_type == 0x65735546 /* FUSE_SUPER_MAGIC */ &&
> +            fstatat( fd, ".ciopfs", &st, AT_NO_AUTOMOUNT ) == 0)
> +            sens = FALSE;
> +    }
> +    close( fd );
> +    return sens;
>  #else
>      return TRUE;
>  #endif

I've sent in a new version with a few changes.  Most notably I've
trimmed the CIOPFS comment right down.  I've also inverted the
return value check of fstatfs() to match that of fstatat().

Huw.