[CRIU] [PATCH 10/16] restore: look up root for each file

[Pavel Emelyanov]

On 04/09/2014 03:35 AM, Andrey Vagin wrote:
> Signed-off-by: Andrey Vagin <avagin at openvz.org>
> ---
>  files-reg.c          | 16 +++++++++++++++-
>  include/proc_parse.h |  1 +
>  mount.c              |  1 +
>  3 files changed, 17 insertions(+), 1 deletion(-)
> 
> diff --git a/files-reg.c b/files-reg.c
> index 750b356..81736d5 100644
> --- a/files-reg.c
> +++ b/files-reg.c
> @@ -23,6 +23,7 @@
>  #include "fs-magic.h"
>  #include "asm/atomic.h"
>  #include "namespaces.h"
> +#include "proc_parse.h"
>  
>  #include "protobuf.h"
>  #include "protobuf/regfile.pb-c.h"
> @@ -608,9 +609,22 @@ int open_path(struct file_desc *d,
>  	struct reg_file_info *rfi;
>  	int tmp;
>  	char *orig_path = NULL;
> +	struct mount_info *m;
>  
>  	rfi = container_of(d, struct reg_file_info, d);
>  
> +	if (rfi->rfe->mnt_id >= 0) {
> +		m = lookup_mnt_id(rfi->rfe->mnt_id);
> +		if (m == NULL) {
> +			pr_err("Unable to look up the %d mntns: %s\n",
> +						rfi->rfe->mnt_id, rfi->path);
> +			return -1;
> +		}
> +
> +		if (mntns_collect_root(m->nsid->pid))

We perform root lookup every single fd? Shouldn't it be per-task?

> +			return -1;
> +	}
> +
>  	if (rfi->remap) {
>  		mutex_lock(ghost_file_mutex);
>  		if (rfi_remap(rfi) < 0) {
> @@ -674,7 +688,7 @@ static int do_open_reg_noseek_flags(struct reg_file_info *rfi, void *arg)
>  	u32 flags = *(u32 *)arg;
>  	int fd;
>  
> -	fd = open(rfi->path, flags);
> +	fd = openat(mntns_root, rfi->path, flags);

This should be the respective service fd, isn't it?

>  	if (fd < 0) {
>  		pr_perror("Can't open file %s on restore", rfi->path);
>  		return fd;
> diff --git a/include/proc_parse.h b/include/proc_parse.h
> index c42a48c..423b490 100644
> --- a/include/proc_parse.h
> +++ b/include/proc_parse.h
> @@ -116,6 +116,7 @@ struct mount_info {
>  	int		is_file;
>  	bool		is_root;
>  	struct mount_info *next;
> +	struct ns_id	*nsid;
>  
>  	/* tree linkage */
>  	struct mount_info *parent;
> diff --git a/mount.c b/mount.c
> index 9b40903..57f9d5f 100644
> --- a/mount.c
> +++ b/mount.c
> @@ -1445,6 +1445,7 @@ static int collect_mnt_from_image(struct mount_info **pms, struct ns_id *nsid)
>  		if (!pm)
>  			goto err;
>  
> +		pm->nsid = nsid;
>  		pm->next = *pms;
>  		*pms = pm;
>  
>