system stuck when mv normal file to redirfs dir

[ccxhwmy]

for example:
insmod redirfs.ko
insmod dummyflt.ko
echo "c" > /sys/fs/redirfs/filters/dummyflt/paths
echo -n "a:i:/home/work/test" > /sys/fs/redirfs/filters/dummyflt/paths
mv /home/work/normal/hhh > /home/work/test/
//then the system will stuck，and dmesg will print

[ +0.000008] [] schedule_preempt_disabled+0x29/0x70
[ +0.000003] [] __mutex_lock_slowpath+0xc7/0x1d0
[ +0.000003] [] mutex_lock+0x1f/0x2f
[ +0.000008] [] rfs_inode_mutex_lock+0x1e/0x20 [redirfs]
[ +0.000006] [] rfs_dcache_get_subs_mutex+0x47/0x77 [redirfs]
[ +0.000045] [] rfs_dcache_walk+0x10d/0x1fd [redirfs]
[ +0.000056] [] ? rfs_dcache_add_dir+0x62/0x62 [redirfs]
[ +0.000004] [] ? kzalloc+0x33/0x35 [redirfs]
[ +0.000006] [] rfs_info_add+0x79/0xa9 [redirfs]
[ +0.000004] [] rfs_fsrename_add_dentry+0x166/0x1c8 [redirfs]
[ +0.000002] [] rfs_fsrename_add+0xda/0xee [redirfs]
[ +0.000002] [] rfs_fsrename+0x14e/0x192 [redirfs]
[ +0.000004] [] rfs_rename+0x291/0x3d2 [redirfs]
[ +0.000003] [] vfs_rename+0x82d/0x880
[ +0.000002] [] SYSC_renameat2+0x503/0x5a0
[ +0.000002] [] ? __do_page_fault+0x1bc/0x4f0
[ +0.000002] [] SyS_renameat2+0xe/0x10
[ +0.000002] [] system_call_fastpath+0x1c/0x21