[CRIU] Re: [PATCH 04/14] eventfd: Add checkpoint/restore support

[Pavel Emelyanov]

On 04/29/2012 05:14 PM, Cyrill Gorcunov wrote:
> 
> Signed-off-by: Cyrill Gorcunov <gorcunov at openvz.org>
> ---
>  Makefile          |    1 +
>  cr-dump.c         |   22 +++++++
>  cr-restore.c      |    4 +
>  cr-show.c         |   23 +++++++
>  crtools.c         |    7 ++
>  eventfs.c         |  165 +++++++++++++++++++++++++++++++++++++++++++++++++++++
>  include/crtools.h |    3 +
>  include/eventfs.h |   20 +++++++
>  include/image.h   |    9 +++
>  9 files changed, 254 insertions(+), 0 deletions(-)
>  create mode 100644 eventfs.c
>  create mode 100644 include/eventfs.h
> 

> diff --git a/eventfs.c b/eventfs.c
> new file mode 100644
> index 0000000..dfea4c9
> --- /dev/null
> +++ b/eventfs.c

Plz, rename to eventfd.c

> @@ -99,6 +100,28 @@ void show_fown_cont(fown_t *fown)
>  	       fown->uid, fown->euid, fown->signum, fown->pid_type, fown->pid);
>  }
>  
> +void show_eventfds(int fd, struct cr_options *o)
> +{
> +	struct eventfd_file_entry efe;
> +
> +	pr_img_head(CR_FD_EVENTFD);


Plz, put this into eventfd.c

> +static int eventfd_open(struct file_desc *d)
> +{
> +	struct eventfd_file_info *info;
> +	size_t size;
> +	int tmp;
> +
> +	info = container_of(d, struct eventfd_file_info, d);
> +
> +	tmp = eventfd(0, 0);
> +	if (tmp < 0) {
> +		pr_perror("Can't create eventfd %#08x",
> +			  info->efe.id);
> +		return -1;
> +	}
> +
> +	if (fcntl(tmp, F_SETFD, info->efe.flags)) {

This is wrong. F_SETFL should be used instead. I've written the rst_file_parms helper for
such cases, please, use one.

BTW, the flags can be pushed to eventfd()'s 2nd arg, if I'm not mistakes, so it's even
better to go this way.

> +		pr_perror("Can't set flags on eventfd %#08x",
> +			  info->efe.id);
> +		goto err_close;
> +	}


> +	size = sizeof(info->efe.counter);
> +	if (write(tmp, &info->efe.counter, size) != size) {
> +		pr_perror("Can't write counter to eventfd %#08x",
> +			  info->efe.id);
> +		goto err_close;
> +	}

Let's avoid this write by passing initial value to eventfd()'s first argument syscall.

Thanks,
Pavel