[Devel] [PATCH rh7] ve/fs: namespace -- Ignore device permissions during restore

[Cyrill Gorcunov]

To support several storage backends (ploops) inside container
we've hacks in libvzctl which setup "old" permissions when
restore procedure initiated. But the former idea was simply
allow CRIU to do all the works and restore ploops mounts
by its own (since CRIU fetches all mount options and such).

For this sake we turn off mount options filtering provisionally
if @is_pseudosuper is set, and CRIU restore mounts as regular
ones.

https://jira.sw.ru/browse/PSBM-48188

Signed-off-by: Cyrill Gorcunov <gorcunov at virtuozzo.com>
CC: Igor Sukhih <igor at virtuozzo.com>
CC: Vladimir Davydov <vdavydov at virtuozzo.com>
CC: Konstantin Khorenko <khorenko at virtuozzo.com>
---
 fs/namespace.c |    7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

Index: linux-pcs7.git/fs/namespace.c
===================================================================
--- linux-pcs7.git.orig/fs/namespace.c
+++ linux-pcs7.git/fs/namespace.c
@@ -1933,7 +1933,12 @@ again:
 		if (devmnt->dev == dev) {
 			err = ve_devmnt_check(data, devmnt->allowed_options);
 
-			if (!err && !remount)
+			/*
+			 * In case of @is_pseudouser set, ie restore procedure,
+			 * we don't check for allowed options filtering, since
+			 * restore mode is special.
+			 */
+			if ((ve->is_pseudosuper || !err) && !remount)
 				err = ve_devmnt_insert(data, devmnt->hidden_options);
 
 			break;