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    do_add_mount()/umount -l races · 156cacb1
    Al Viro 提交于
    normally we deal with lock_mount()/umount races by checking that
    mountpoint to be is still in our namespace after lock_mount() has
    been done.  However, do_add_mount() skips that check when called
    with MNT_SHRINKABLE in flags (i.e. from finish_automount()).  The
    reason is that ->mnt_ns may be a temporary namespace created exactly
    to contain automounts a-la NFS4 referral handling.  It's not the
    namespace of the caller, though, so check_mnt() would fail here.
    We still need to check that ->mnt_ns is non-NULL in that case,
    though.
    Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
    156cacb1
namespace.c 64.7 KB