Re: [PATCH 2/3] Add post-file deferqueue

[Oren Laadan <orenl-RdfvBDnrOixBDgjK7y7TUQ@public.gmane.org>]

Dan Smith wrote:
> This is the deferq bit of Matt's patch, which is needed by the subsequent
> socket patch.

Hmm... I guess you missed my comments to his post - see below:

> 
> Signed-off-by: Dan Smith <danms-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org>
> Cc: Matt Helsley <matthltc-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org>
> ---
>  checkpoint/files.c               |   28 ++++++++++++++++++++++++++++
>  include/linux/checkpoint_types.h |    1 +
>  2 files changed, 29 insertions(+), 0 deletions(-)
> 
> diff --git a/checkpoint/files.c b/checkpoint/files.c
> index 204055b..784793c 100644
> --- a/checkpoint/files.c
> +++ b/checkpoint/files.c
> @@ -21,6 +21,7 @@
>  #include <linux/syscalls.h>
>  #include <linux/checkpoint.h>
>  #include <linux/checkpoint_hdr.h>
> +#include <linux/deferqueue.h>
>  #include <net/sock.h>
>  
>  
> @@ -289,11 +290,25 @@ static int do_checkpoint_file_table(struct ckpt_ctx *ctx,
>  		goto out;
>  
>  	ckpt_debug("nfds %d\n", nfds);
> +	ctx->files_deferq = deferqueue_create();
> +	if (!ctx->files_deferq) {
> +		ret = -ENOMEM;
> +		goto out;
> +	}

You can create/destroy the deferqueue once, in ckpt_ctx_alloc()
and ckpt_ctx_free(), respectively. It will also simplify the logic
here.

>  	for (n = 0; n < nfds; n++) {
>  		ret = checkpoint_file_desc(ctx, files, fdtable[n]);
>  		if (ret < 0)
>  			break;
>  	}
> +	if (!ret) {
> +		ret = deferqueue_run(ctx->files_deferq);
> +		if (ret > 0) {
> +			pr_warning("c/r: files deferqueue had %d entries\n",
> +				   ret);
> +			ret = 0;
> +		}
> +	}
> +	deferqueue_destroy(ctx->files_deferq);
>   out:
>  	kfree(fdtable);
>  	return ret;
> @@ -692,11 +707,24 @@ static struct files_struct *do_restore_file_table(struct ckpt_ctx *ctx)
>  	if (ret < 0)
>  		goto out;
>  
> +	ret = -ENOMEM;
> +	ctx->files_deferq = deferqueue_create();
> +	if (!ctx->files_deferq)
> +		goto out;

Ditto for alloc/free of ctx->files_deferq.

Oren.

>  	for (i = 0; i < h->fdt_nfds; i++) {
>  		ret = restore_file_desc(ctx);
>  		if (ret < 0)
>  			break;
>  	}
> +	if (!ret) {
> +		ret = deferqueue_run(ctx->files_deferq);
> +		if (ret > 0) {
> +			pr_warning("c/r: files deferqueue had %d entries\n",
> +				   ret);
> +			ret = 0;
> +		}
> +	}
> +	deferqueue_destroy(ctx->files_deferq);
>   out:
>  	ckpt_hdr_put(ctx, h);
>  	if (!ret) {
> diff --git a/include/linux/checkpoint_types.h b/include/linux/checkpoint_types.h
> index a18846f..b6f130c 100644
> --- a/include/linux/checkpoint_types.h
> +++ b/include/linux/checkpoint_types.h
> @@ -48,6 +48,7 @@ struct ckpt_ctx {
>  
>  	struct ckpt_obj_hash *obj_hash;	/* repository for shared objects */
>  	struct deferqueue_head *deferqueue;	/* queue of deferred work */
> +	struct deferqueue_head *files_deferq;
>  
>  	struct path fs_mnt;     /* container root (FIXME) */
>