[CRIU] [PATCH 4/6] mnt: add --enable-external-masters option

[Andrew Vagin]

On Tue, Apr 07, 2015 at 11:37:19PM +0000, Tycho Andersen wrote:
> This option enables external (slave) bind mounts to be resolved.
> 
> Signed-off-by: Tycho Andersen <tycho.andersen at canonical.com>
> ---
>  crtools.c            | 11 +++++++++++
>  include/cr_options.h |  1 +
>  mount.c              |  3 +++
>  3 files changed, 15 insertions(+)
> 
> diff --git a/crtools.c b/crtools.c
> index fe77f39..095c86e 100644
> --- a/crtools.c
> +++ b/crtools.c
> @@ -205,6 +205,7 @@ int main(int argc, char *argv[], char *envp[])
>  		{ "feature",		required_argument,	0, 1063	},
>  		{ "skip-mnt",		required_argument,	0, 1064},
>  		{ "enable-external-sharing", no_argument, 	0, 1065 },
> +		{ "enable-external-masters", no_argument, 	0, 1066 },
>  		{ },
>  	};
>  
> @@ -425,6 +426,9 @@ int main(int argc, char *argv[], char *envp[])
>  		case 1065:
>  			opts.enable_external_sharing = true;
>  			break;
> +		case 1066:
> +			opts.enable_external_masters = true;
> +			break;
>  		case 'M':
>  			{
>  				char *aux;
> @@ -461,6 +465,11 @@ int main(int argc, char *argv[], char *envp[])
>  		return 1;
>  	}
>  
> +	if (!opts.autodetect_ext_mounts && (opts.enable_external_masters || opts.enable_external_sharing)) {
> +		pr_msg("must specify --ext-mount-map auto with --enable-external-{sharing|masters}");
> +		return 1;
> +	}
> +
>  	if (work_dir == NULL)
>  		work_dir = imgs_dir;
>  
> @@ -655,6 +664,8 @@ usage:
>  "                        attempt to autodetect external mount mapings\n"
>  "  --enable-external-sharing\n"
>  "                        allow autoresolving mounts with external sharing\n"
> +"  --enable-external-masters\n"
> +"                        allow autoresolving mounts with external masters\n"
>  "  --manage-cgroups      dump or restore cgroups the process is in\n"
>  "  --cgroup-root [controller:]/newroot\n"
>  "                        change the root cgroup the controller will be\n"
> diff --git a/include/cr_options.h b/include/cr_options.h
> index 29be2c8..28bed45 100644
> --- a/include/cr_options.h
> +++ b/include/cr_options.h
> @@ -64,6 +64,7 @@ struct cr_options {
>  	struct list_head	new_cgroup_roots;
>  	bool			autodetect_ext_mounts;
>  	bool			enable_external_sharing;
> +	bool			enable_external_masters;
>  	bool			aufs;		/* auto-deteced, not via cli */
>  };
>  
> diff --git a/mount.c b/mount.c
> index 8835a81..7d565d8 100644
> --- a/mount.c
> +++ b/mount.c
> @@ -691,6 +691,9 @@ static int resolve_external_mounts(struct mount_info *info)
>  			if (opts.enable_external_sharing && pm->shared_id == m->shared_id)
>  				match = true;
>  
> +			if (opts.enable_external_masters && pm->shared_id == m->master_id)
> +				match = true;

if think this code should be inverted:
			if (!opts.enable_external_masters || pm->shared_id != m->master_id)
				match = false.

In your case, we can meet pm with another shared_id and set it as
external, but it looks wrong. Do I miss something?

> +
>  			if (!match)
>  				continue;
>  
> -- 
> 2.1.4
> 
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