[CRIU] [PATCH 2/4] mounts: use relative paths for mountpoints (v2)

[Andrew Vagin]

On Fri, Feb 28, 2014 at 04:29:50PM +0400, Andrew Vagin wrote:
> On Fri, Feb 28, 2014 at 02:39:45PM +0400, Pavel Emelyanov wrote:
> > On 02/24/2014 12:04 PM, Andrey Vagin wrote:
> > > v2: don't use snprintf
> > 
> > Some comment would be nice.
> > 
> > > Signed-off-by: Andrey Vagin <avagin at openvz.org>
> > > ---
> > >  mount.c | 13 +++++++++----
> > >  1 file changed, 9 insertions(+), 4 deletions(-)
> > > 
> > > diff --git a/mount.c b/mount.c
> > > index a5436a6..795f947 100644
> > > --- a/mount.c
> > > +++ b/mount.c
> > > @@ -45,9 +45,10 @@ static int close_mountpoint(DIR *dfd);
> > >  static struct mount_info *mnt_build_tree(struct mount_info *list);
> > >  static int validate_mounts(struct mount_info *info, bool call_plugins);
> > >  
> > > +/* Asolute paths are used on dump and relative paths are used on restore */
> > >  static inline int is_root(char *p)
> > >  {
> > > -	return p[0] == '/' && p[1] == '\0';
> > > +	return (!strcmp(p, "/") || !strcmp(p, "./"));
> > >  }
> > >  
> > >  /* True for the root mount (the topmost one) */
> > > @@ -78,7 +79,7 @@ int open_mount(unsigned int s_dev)
> > >  			if (mntns_root == -1) {
> > >  				pr_debug("mpopen %s\n", i->mountpoint);
> > >  				return open(i->mountpoint, O_RDONLY);
> > > -			} else if (i->mountpoint[1] == '\0') {
> > > +			} else if (is_root_mount(i)) {
> > >  				pr_debug("mpopen root\n");
> > >  				return dup(mntns_root);
> > >  			} else {
> > > @@ -1359,6 +1360,7 @@ static struct mount_info *read_mnt_ns_img(int ns_pid)
> > >  
> > >  	while (1) {
> > >  		struct mount_info *pm;
> > > +		int len;
> > >  
> > >  		ret = pb_read_one_eof(img, &me, PB_MNT);
> > >  		if (ret <= 0)
> > > @@ -1387,10 +1389,13 @@ static struct mount_info *read_mnt_ns_img(int ns_pid)
> > >  		if (!pm->root)
> > >  			goto err;
> > >  
> > > -		pr_debug("\t\tGetting mpt for %d\n", pm->mnt_id);
> > > -		pm->mountpoint = xstrdup(me->mountpoint);
> > > +		pr_debug("\t\tGetting mpt for %d:%s\n", pm->mnt_id, me->mountpoint);
> > > +		len  = strlen(me->mountpoint) + 2;
> > > +		pm->mountpoint = xmalloc(len);
> > >  		if (!pm->mountpoint)
> > >  			goto err;
> > > +		pm->mountpoint[0] = '.';
> > > +		strcpy(pm->mountpoint + 1, me->mountpoint);
> > 
> > How about bind mount's source? Don't we change the code from
> > 
> > # chroot /new-root
> > # mount /foo /bar --bind
> > 
> > into
> > 
> > # chdir /new-root
> > # mount /foo ./bar --bind
> > 
> > ?
> 
> Good question. Will check.

snprintf(rpath, sizeof(rpath), "%s%s", mi->bind->mountpoint, mi->root);

so this patch does nothing wrong with bind mounts

> > 
> > >  
> > >  		pr_debug("\t\tGetting source for %d\n", pm->mnt_id);
> > >  		pm->source = xstrdup(me->source);
> > > 
> > 
> >