Re: [ext4] e2ae766c1b: BUG:sleeping_function_called_from_invalid_context_at_kernel/locking/rwsem.c

[Ross Zwisler]

On Mon, Dec 12, 2016 at 05:35:18PM +0100, Jan Kara wrote:
> On Mon 12-12-16 18:13:21, kernel test robot wrote:
> > FYI, we noticed the following commit:
> > 
> > commit: e2ae766c1b030271b5099b25674e2131d1d1e8c1 ("ext4: convert DAX faults to iomap infrastructure")
> > https://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4.git dev
> > 
> > in testcase: nvml
> > with following parameters:
> > 
> > 	group: vmem
> > 	test: pmem
> > 	nr_pmem: 1
> > 	fs: ext4
> > 	mount_option: dax
> > 
> > 
> > 
> > on test machine: 64 threads Intel(R) Xeon(R) CPU E5-4650 0 @ 2.70GHz with 64G memory
> > 
> > caused below changes:
> > 
> > 
> > +------------------------------------------------+------------+------------+
> > |                                                | 96f8ba3dd6 | e2ae766c1b |
> > +------------------------------------------------+------------+------------+
> > | boot_successes                                 | 2          | 2          |
> > | boot_failures                                  | 2          | 2          |
> > | BUG:kernel_hang_in_test_stage                  | 2          |            |
> > | WARNING:at_fs/sysfs/dir.c:#sysfs_warn_dup      | 0          | 2          |
> > | calltrace:parport_pc_init                      | 0          | 2          |
> > | calltrace:SyS_finit_module                     | 0          | 2          |
> > | WARNING:at_lib/kobject.c:#kobject_add_internal | 0          | 2          |
> > +------------------------------------------------+------------+------------+
> > 
> > 
> > 
> > user  :notice: [  325.592182] vmem_aligned_alloc/TEST1: SETUP (check/pmem/debug)
> > 
> > user  :notice: [  325.603973] vmem_aligned_alloc/TEST1: START: vmem_aligned_alloc
> > kern  :err   : [  325.608906] BUG: sleeping function called from invalid context at kernel/locking/rwsem.c:51
> > kern  :err   : [  325.608908] in_atomic(): 1, irqs_disabled(): 0, pid: 24813, name: vmem_aligned_al
> > kern  :warn  : [  325.608914] CPU: 44 PID: 24813 Comm: vmem_aligned_al Tainted: G           O    4.9.0-rc4-00045-ge2ae766 #1
> > kern  :warn  : [  325.608916] Hardware name: Intel Corporation LH Pass/S4600LH...., BIOS SE5C600.86B.99.02.1047.032320122259 03/23/2012
> > kern  :warn  : [  325.608922]  ffffc9002c1f7be0
> > kern  :warn  : [  325.608923]  ffffffff81466af9
> > kern  :warn  : [  325.608924]  ffff880fea2425c0
> 
> I think this is actually a bug introduced by Ross' PMD support. Attached
> patch should fix it. Ross, can you check it please?

Yep, that patch looks good.   You can add:

Reviewed-by: Ross Zwisler <ross.zwisler@xxxxxxxxxxxxxxx>

And I turned on CONFIG_DEBUG_ATOMIC_SLEEP in my test config.  :)