[Devel] [PATCH RHEL8 COMMIT] sync: sync_collect_filesystems: fix possible infinite loop

[Konstantin Khorenko]

The commit is pushed to "branch-rh8-4.18.0-240.1.1.vz8.5.x-ovz" and will appear at https://src.openvz.org/scm/ovz/vzkernel.git
after rh8-4.18.0-240.1.1.vz8.5.55
------>
commit f564bdbaed7ee8c6f28404f5de347cc29275e2df
Author: Alexander Mikhalitsyn <alexander.mikhalitsyn at virtuozzo.com>
Date:   Tue Mar 30 10:28:19 2021 +0300

    sync: sync_collect_filesystems: fix possible infinite loop
    
    https://jira.sw.ru/browse/PSBM-127599
    Fixes: ("proc/mounts: add cursor")
    Signed-off-by: Alexander Mikhalitsyn <alexander.mikhalitsyn at virtuozzo.com>
    
    (cherry picked from vz7 commit 9f4f95d6878e ("sync:
    sync_collect_filesystems: fix possible infinite loop")
    
    Signed-off-by: Konstantin Khorenko <khorenko at virtuozzo.com>
---
 fs/sync.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/fs/sync.c b/fs/sync.c
index e69c3c34712c..553c5ebf102e 100644
--- a/fs/sync.c
+++ b/fs/sync.c
@@ -137,7 +137,7 @@ static int sync_collect_filesystems(struct ve_struct *ve, struct list_head *sync
 	mnt = mnt_list_next(mnt_ns, &mnt_ns->list);
 	while (mnt) {
 		if (sync_filesystem_collected(sync_list, mnt->mnt.mnt_sb))
-			continue;
+			goto next;
 
 		ss = kmalloc(sizeof(*ss), GFP_KERNEL);
 		if (ss == NULL) {
@@ -155,6 +155,7 @@ static int sync_collect_filesystems(struct ve_struct *ve, struct list_head *sync
 		spin_unlock(&sb_lock);
 		list_add_tail(&ss->list, sync_list);
 
+next:
 		mnt = mnt_list_next(mnt_ns, &mnt->mnt_list);
 	}
 	up_read(&namespace_sem);