An access to automounted filesystem can deadlock if it is a bind mount on shared mounts. A user program should not deadlock the kernel while automount waits for propagation of the mount. This is explained at https://bugzilla.redhat.com/show_bug.cgi?id=1358887#c10 I am not sure completely blocking automount is the best solution, so please reply with what is the best course of action to do in such a situation. Propagation of dentry with DCACHE_NEED_AUTOMOUNT can lead to propagation of mount points without automount maps and not under automount control. So, do not propagate them. Signed-off-by: Goldwyn Rodrigues <rgoldwyn@xxxxxxxx> diff --git a/fs/pnode.c b/fs/pnode.c index 49f6d7ff2139..b960805d7954 100644 --- a/fs/pnode.c +++ b/fs/pnode.c @@ -292,6 +292,9 @@ int propagate_mnt(struct mount *dest_mnt, struct mountpoint *dest_mp, struct mount *m, *n; int ret = 0; + if (source_mnt->mnt_mountpoint->d_flags & DCACHE_NEED_AUTOMOUNT) + return 0; + /* * we don't want to bother passing tons of arguments to * propagate_one(); everything is serialized by namespace_sem, -- Goldwyn
