[Devel] [PATCH RHEL7 COMMIT] ve/sysfs: relax sanity check for ns_type in sysfs_find_dirent()

[Konstantin Khorenko]

The commit is pushed to "branch-rh7-3.10.0-693.17.1.vz7.45.x-ovz" and will appear at https://src.openvz.org/scm/ovz/vzkernel.git
after rh7-3.10.0-693.17.1.vz7.45.7
------>
commit 54d2b8bbe0edf79c0b35d549261539c9b21eb907
Author: Konstantin Khorenko <khorenko at virtuozzo.com>
Date:   Thu Mar 15 15:04:26 2018 +0300

    ve/sysfs: relax sanity check for ns_type in sysfs_find_dirent()
    
    Don't complain about searching for a non ns specific sysfs entry in ns specific parent dirent.
    
    When we set sysfs permissions for a CT via ve.sysfs_permissions
    we assume the target sysfs entry is non ns specific and call
    sysfs_find_dirent() with NULL ns arg.
    
    This makes sense because ns specific sysfs entries (with s_ns set) are not checked against
    CT specific permissions at all (see sysfs_sd_permission()).
    
    And in case for example we've moved a physical net device from host inside a Container
    we've got ns specific entries (for example devices/pci0000:00/0000:00:1c.2/0000:02:00.0/net)
    and looking for a non ns specific net device name entry inside which triggers a complain.
    Drop the complain.
    
    https://jira.sw.ru/browse/PSBM-82259
    
    Signed-off-by: Konstantin Khorenko <khorenko at virtuozzo.com>
    Reviewed-by: Kirill Tkhai <ktkhai at virtuozzo.com>
---
 fs/sysfs/dir.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c
index dd34b5932ce6..f9294c00b571 100644
--- a/fs/sysfs/dir.c
+++ b/fs/sysfs/dir.c
@@ -643,14 +643,14 @@ struct sysfs_dirent *sysfs_find_dirent(struct sysfs_dirent *parent_sd,
 {
 	struct rb_node *node = parent_sd->s_dir.children.rb_node;
 	unsigned int hash;
-
+#ifndef CONFIG_VE
 	if (!!sysfs_ns_type(parent_sd) != !!ns) {
 		WARN(1, KERN_WARNING "sysfs: ns %s in '%s' for '%s'\n",
 			sysfs_ns_type(parent_sd)? "required": "invalid",
 			parent_sd->s_name, name);
 		return NULL;
 	}
-
+#endif
 	hash = sysfs_name_hash(ns, name);
 	while (node) {
 		struct sysfs_dirent *sd;