FYI, we noticed the below changes on

git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs file-pin-devel
commit 692ddb6c6808db7b70678b4cc3332781625c65f8 ("VFS: Impose ordering on accesses of d_inode and d_flags")


+-------------------------------------------------+------------+------------+
|                                                 | 1dc0c0acc4 | 692ddb6c68 |
+-------------------------------------------------+------------+------------+
| boot_successes                                  | 15         | 0          |
| boot_failures                                   | 0          | 24         |
| WARNING:at_fs/dcache.c:#dput()                  | 0          | 24         |
| WARNING:at_fs/dcache.c:#d_lru_shrink_move()     | 0          | 24         |
| WARNING:at_fs/dcache.c:#shrink_dentry_list()    | 0          | 24         |
| page_allocation_failure:order:#,mode            | 0          | 1          |
| backtrace:do_unlinkat                           | 0          | 24         |
| backtrace:SyS_unlink                            | 0          | 24         |
| backtrace:do_mount                              | 0          | 24         |
| backtrace:compat_SyS_mount                      | 0          | 12         |
| backtrace:vmalloc                               | 0          | 1          |
| backtrace:SyS_init_module                       | 0          | 1          |
| WARNING:at_lib/list_debug.c:#__list_del_entry() | 0          | 23         |
| RIP:__list_lru_walk_one                         | 0          | 4          |
| Kernel_panic-not_syncing:softlockup:hung_tasks  | 0          | 23         |
| RIP:list_lru_isolate_move                       | 0          | 2          |
| RIP:_raw_spin_lock                              | 0          | 3          |
| RIP:__list_add                                  | 0          | 4          |
| RIP:dentry_lru_isolate_shrink                   | 0          | 3          |
| RIP:__list_del_entry                            | 0          | 3          |
| RIP:d_lru_shrink_move                           | 0          | 2          |
| backtrace:SyS_mount                             | 0          | 12         |
| RIP:_raw_spin_unlock                            | 0          | 1          |
| RIP:_raw_spin_trylock                           | 0          | 1          |
+-------------------------------------------------+------------+------------+


[    4.890748] PM: Hibernation image not present or could not be loaded.
[    4.893862] Freeing unused kernel memory: 1796K (ffffffff81e51000 - ffffffff82012000)
[    4.995832] ------------[ cut here ]------------
[    4.997535] WARNING: CPU: 0 PID: 107 at fs/dcache.c:406 dput+0x1d7/0x250()
[    5.000581] Modules linked in:
[    5.001971] CPU: 0 PID: 107 Comm: udevd Not tainted 4.0.0-rc1-00155-g692ddb6 #1
[    5.004586] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[    5.006278]  ffffffff81ba0730 ffff880013a0fdc8 ffffffff818aab67 0000000000001ce6
[    5.009931]  0000000000000000 ffff880013a0fe08 ffffffff810727aa ffff880013a0fe08
[    5.013948]  ffff88000a54ed80 ffff88000a54edd8 0000000000000000 ffff880013a0fea8
[    5.027545] Call Trace:
[    5.028911]  [<ffffffff818aab67>] dump_stack+0x4c/0x65
[    5.030955]  [<ffffffff810727aa>] warn_slowpath_common+0x8a/0xc0
[    5.032958]  [<ffffffff8107289a>] warn_slowpath_null+0x1a/0x20
[    5.034951]  [<ffffffff811fec37>] dput+0x1d7/0x250
[    5.036715]  [<ffffffff811f7ca5>] do_unlinkat+0x165/0x320
[    5.047767]  [<ffffffff81207ef4>] ? mntput+0x24/0x40
[    5.049344]  [<ffffffff811f0042>] ? path_put+0x22/0x30
[    5.050962]  [<ffffffff811f8fe6>] SyS_unlink+0x16/0x20
[    5.052563]  [<ffffffff818b59c9>] ia32_do_call+0x13/0x13
[    5.054201] ---[ end trace 132f5255db464839 ]---
[    5.226810] ------------[ cut here ]------------


Thanks,
Ying Huang