Re: [Qemu-devel] [PATCH 3/7] linux-user: Implement FS_IOC_FIEMAP ioctl

[Blue Swirl]

On Fri, Jan 7, 2011 at 8:52 PM, Riku Voipio <address@hidden> wrote:
> From: Peter Maydell <address@hidden>
>
> Implement the FS_IOC_FIEMAP ioctl using the new support for
> custom handling of ioctls; this is needed because the struct
> that is passed includes a variable-length array.
>
> Signed-off-by: Peter Maydell <address@hidden>
> Signed-off-by: Riku Voipio <address@hidden>
> ---
>  linux-user/ioctls.h        |    4 ++
>  linux-user/syscall.c       |   88 
> ++++++++++++++++++++++++++++++++++++++++++++
>  linux-user/syscall_defs.h  |    1 +
>  linux-user/syscall_types.h |   16 ++++++++
>  4 files changed, 109 insertions(+), 0 deletions(-)
>
> diff --git a/linux-user/ioctls.h b/linux-user/ioctls.h
> index 769e1bc..538e257 100644
> --- a/linux-user/ioctls.h
> +++ b/linux-user/ioctls.h
> @@ -76,6 +76,10 @@
>  #ifdef FIGETBSZ
>      IOCTL(FIGETBSZ, IOC_R, MK_PTR(TYPE_LONG))
>  #endif
> +#ifdef FS_IOC_FIEMAP
> +     IOCTL_SPECIAL(FS_IOC_FIEMAP, IOC_W | IOC_R, do_ioctl_fs_ioc_fiemap,
> +                   MK_PTR(MK_STRUCT(STRUCT_fiemap)))
> +#endif
>
>   IOCTL(SIOCATMARK, 0, TYPE_NULL)
>   IOCTL(SIOCADDRT, IOC_W, MK_PTR(MK_STRUCT(STRUCT_rtentry)))
> diff --git a/linux-user/syscall.c b/linux-user/syscall.c
> index 970efe3..f10e17a 100644
> --- a/linux-user/syscall.c
> +++ b/linux-user/syscall.c
> @@ -83,6 +83,7 @@ int __clone2(int (*fn)(void *), void *child_stack_base,
>  #include <linux/kd.h>
>  #include <linux/mtio.h>
>  #include <linux/fs.h>
> +#include <linux/fiemap.h>

This fails if the file doesn't exist:
  CC    i386-linux-user/syscall.o
/src/qemu/linux-user/syscall.c:86:26: error: linux/fiemap.h: No such
file or directory
/src/qemu/linux-user/syscall.c: In function 'do_ioctl_fs_ioc_fiemap':
/src/qemu/linux-user/syscall.c:3025: error: dereferencing pointer to
incomplete type
/src/qemu/linux-user/syscall.c:3025: error: invalid application of
'sizeof' to incomplete type 'struct fiemap'
/src/qemu/linux-user/syscall.c:3025: error: invalid application of
'sizeof' to incomplete type 'struct fiemap_extent'
cc1: warnings being treated as errors
/src/qemu/linux-user/syscall.c:3025: error: division by zero
/src/qemu/linux-user/syscall.c:3029: error: dereferencing pointer to
incomplete type
/src/qemu/linux-user/syscall.c:3030: error: invalid application of
'sizeof' to incomplete type 'struct fiemap_extent'
/src/qemu/linux-user/syscall.c:3030: error: dereferencing pointer to
incomplete type
/src/qemu/linux-user/syscall.c:3040: error: invalid application of
'sizeof' to incomplete type 'struct fiemap'
/src/qemu/linux-user/syscall.c:3049: error: dereferencing pointer to
incomplete type
/src/qemu/linux-user/syscall.c:3050: error: dereferencing pointer to
incomplete type
/src/qemu/linux-user/syscall.c:3058: error: dereferencing pointer to
incomplete type
/src/qemu/linux-user/syscall.c:3061: error: dereferencing pointer to
incomplete type
/src/qemu/linux-user/syscall.c:3062: error: dereferencing pointer to
incomplete type

The fix is to introduce a feature check in configure.