linux/fs/namespace.c
Al Viro d3615894f7 attach_recursive_mnt(): do not lock the covering tree when sliding something under it
[ Upstream commit ce7df19686 ]

If we are propagating across the userns boundary, we need to lock the
mounts added there.  However, in case when something has already
been mounted there and we end up sliding a new tree under that,
the stuff that had been there before should not get locked.

IOW, lock_mnt_tree() should be called before we reparent the
preexisting tree on top of what we are adding.

Fixes: 3bd045cc9c ("separate copying and locking mount tree on cross-userns copies")
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-07-06 10:58:00 +02:00

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115 KiB