[CRIU] [PATCH] mnt: Use ns_mountpoint to open a mount point

[Pavel Emelyanov]

On 10/09/2015 06:59 PM, Cyrill Gorcunov wrote:
> From: Andrew Vagin <avagin at openvz.org>
> 
> open_mountpoint helper is called when mount namespace are
> already restored so we have to use local paths.

2 questions from my side:

1. How is this connected with the patch "fsnotify: save mnt_id with path"?
2. Is the test from that set catches this bug?

-- Pavel

> https://jira.sw.ru/browse/PSBM-39957
> 
> Signed-off-by: Andrew Vagin <avagin at openvz.org>
> Signed-off-by: Cyrill Gorcunov <gorcunov at openvz.org>
> ---
>  fsnotify.c   |  4 ++--
>  mount.c      | 10 +++++-----
>  proc_parse.c |  1 +
>  3 files changed, 8 insertions(+), 7 deletions(-)
> 
> diff --git a/fsnotify.c b/fsnotify.c
> index 0d9ec58446b1..3a81a528d7c5 100644
> --- a/fsnotify.c
> +++ b/fsnotify.c
> @@ -526,9 +526,9 @@ static int restore_one_fanotify(int fd, struct fsnotify_mark_info *mark)
>  
>  		mntns_root = mntns_get_root_fd(m->nsid);
>  
> -		target = openat(mntns_root, m->mountpoint, O_PATH);
> +		target = openat(mntns_root, m->ns_mountpoint, O_PATH);
>  		if (target == -1) {
> -			pr_perror("Unable to open %s", m->mountpoint);
> +			pr_perror("Unable to open %s", m->ns_mountpoint);
>  			goto err;
>  		}
>  
> diff --git a/mount.c b/mount.c
> index 2ed061592f86..8936eda59db5 100644
> --- a/mount.c
> +++ b/mount.c
> @@ -1017,23 +1017,23 @@ static int __open_mountpoint(struct mount_info *pm, int mnt_fd)
>  		if (mntns_root < 0)
>  			return -1;
>  
> -		mnt_fd = openat(mntns_root, pm->mountpoint, O_RDONLY);
> +		mnt_fd = openat(mntns_root, pm->ns_mountpoint, O_RDONLY);
>  		if (mnt_fd < 0) {
> -			pr_perror("Can't open %s", pm->mountpoint);
> +			pr_perror("Can't open %s", pm->ns_mountpoint);
>  			return -1;
>  		}
>  	}
>  
>  	ret = fstat(mnt_fd, &st);
>  	if (ret < 0) {
> -		pr_perror("fstat(%s) failed", pm->mountpoint);
> +		pr_perror("fstat(%s) failed", pm->ns_mountpoint);
>  		goto err;
>  	}
>  
> -	dev = phys_stat_resolve_dev(pm->nsid, st.st_dev, pm->mountpoint + 1);
> +	dev = phys_stat_resolve_dev(pm->nsid, st.st_dev, pm->ns_mountpoint + 1);
>  	if (dev != pm->s_dev) {
>  		pr_err("The file system %#x (%#x) %s %s is inaccessible\n",
> -				pm->s_dev, (int)dev, pm->fstype->name, pm->mountpoint);
> +		       pm->s_dev, (int)dev, pm->fstype->name, pm->ns_mountpoint);
>  		goto err;
>  	}
>  
> diff --git a/proc_parse.c b/proc_parse.c
> index 965c7cbc47c0..7cc6b61a93f4 100644
> --- a/proc_parse.c
> +++ b/proc_parse.c
> @@ -1026,6 +1026,7 @@ static int parse_mountinfo_ent(char *str, struct mount_info *new, char **fsname)
>  	new->mountpoint = xmalloc(PATH_MAX);
>  	if (new->mountpoint == NULL)
>  		goto err;
> +	new->ns_mountpoint = new->mountpoint;
>  
>  	new->mountpoint[0] = '.';
>  	ret = sscanf(str, "%i %i %u:%u %ms %s %ms %n",
>