Re: [PATCH] On linux require the libc to have large file support

[Andrei Borzenkov <arvidjaar@gmail.com>]

В Sat, 17 Jan 2015 14:57:07 +0100
Felix Janda <felix.janda@posteo.de> пишет:

> With this, support code in grub-core/osdep/unix/hostdisk.c
> for old glibc releases could be removed.
> ---
> This patch tries to address the issues raised in
> 
> http://lists.gnu.org/archive/html/grub-devel/2014-12/msg00030.html
> ---
>  INSTALL                         |  1 +
>  configure.ac                    |  5 +++++
>  grub-core/osdep/unix/hostdisk.c | 25 -------------------------
>  3 files changed, 6 insertions(+), 25 deletions(-)
> 
> diff --git a/INSTALL b/INSTALL
> index b67cd7f..ac7c2aa 100644
> --- a/INSTALL
> +++ b/INSTALL
> @@ -39,6 +39,7 @@ configuring the GRUB.
>  On GNU/Linux, you also need:
>  
>  * libdevmapper 1.02.34 or later (recommended)
> +* a libc with large file support (e.g. glibc 2.1 or later)
>  
>  For optional grub-emu features, you need:
>  
> diff --git a/configure.ac b/configure.ac
> index 31d2b0b..bdaebb8 100644
> --- a/configure.ac
> +++ b/configure.ac
> @@ -346,6 +346,11 @@ AC_GNU_SOURCE
>  AM_GNU_GETTEXT([external])
>  AC_SYS_LARGEFILE
>  
> +if test x"$host_kernel" = xlinux ; then

I wonder if we should do it unconditionally. Large files support is
really presumed by current code.

Not for now, but something to keep in mind for next version.

> +  AC_CHECK_SIZEOF(off_t)
> +  test x"$ac_cv_sizeof_off_t" = x8 || AC_MSG_ERROR([Large file support is required])
> +fi
> +
>  # Identify characteristics of the host architecture.
>  unset ac_cv_c_bigendian
>  
> diff --git a/grub-core/osdep/unix/hostdisk.c b/grub-core/osdep/unix/hostdisk.c
> index 43b56ff..14cab1c 100644
> --- a/grub-core/osdep/unix/hostdisk.c
> +++ b/grub-core/osdep/unix/hostdisk.c
> @@ -48,11 +48,6 @@
>  #ifdef __linux__
>  # include <sys/ioctl.h>         /* ioctl */
>  # include <sys/mount.h>
> -# if !defined(__GLIBC__) || \
> -        ((__GLIBC__ < 2) || ((__GLIBC__ == 2) && (__GLIBC_MINOR__ < 1)))
> -/* Maybe libc doesn't have large file support.  */
> -#  include <linux/unistd.h>     /* _llseek */
> -# endif /* (GLIBC < 2) || ((__GLIBC__ == 2) && (__GLIBC_MINOR < 1)) */
>  #endif /* __linux__ */
>  
>  grub_uint64_t
> @@ -79,24 +74,6 @@ grub_util_get_fd_size (grub_util_fd_t fd, const char *name, unsigned *log_secsiz
>    return st.st_size;
>  }
>  
> -#if defined(__linux__) && (!defined(__GLIBC__) || \
> -        ((__GLIBC__ < 2) || ((__GLIBC__ == 2) && (__GLIBC_MINOR__ < 1))))
> -  /* Maybe libc doesn't have large file support.  */
> -int
> -grub_util_fd_seek (grub_util_fd_t fd, grub_uint64_t off)
> -{
> -  loff_t offset, result;
> -  static int _llseek (uint filedes, ulong hi, ulong lo,
> -		      loff_t *res, uint wh);
> -  _syscall5 (int, _llseek, uint, filedes, ulong, hi, ulong, lo,
> -	     loff_t *, res, uint, wh);
> -
> -  offset = (loff_t) off;
> -  if (_llseek (fd, offset >> 32, offset & 0xffffffff, &result, SEEK_SET))
> -    return -1;
> -  return GRUB_ERR_NONE;
> -}
> -#else
>  int
>  grub_util_fd_seek (grub_util_fd_t fd, grub_uint64_t off)
>  {
> @@ -107,8 +84,6 @@ grub_util_fd_seek (grub_util_fd_t fd, grub_uint64_t off)
>  
>    return 0;
>  }
> -#endif
> -
>  
>  /* Read LEN bytes from FD in BUF. Return less than or equal to zero if an
>     error occurs, otherwise return LEN.  */