Messages in this thread | | | Date | Tue, 12 Jul 2011 10:14:48 -0700 | From | Ben Greear <> | Subject | Re: [RFC] sunrpc: Fix race between work-queue and rpc_killall_tasks. |
| |
On 07/08/2011 03:14 PM, Myklebust, Trond wrote:
>> [<ffffffff81105907>] print_trailer+0x131/0x13a >> [<ffffffff81105945>] object_err+0x35/0x3e >> [<ffffffff811077b3>] verify_mem_not_deleted+0x7a/0xb7 >> [<ffffffffa02891e5>] rpcb_getport_done+0x23/0x126 [sunrpc] >> [<ffffffffa02810df>] rpc_exit_task+0x3f/0x6d [sunrpc] >> [<ffffffffa02814d8>] __rpc_execute+0x80/0x253 [sunrpc] >> [<ffffffffa02816ed>] ? rpc_execute+0x42/0x42 [sunrpc] >> [<ffffffffa02816fd>] rpc_async_schedule+0x10/0x12 [sunrpc] >> [<ffffffff81061343>] process_one_work+0x230/0x41d >> [<ffffffff8106128e>] ? process_one_work+0x17b/0x41d >> [<ffffffff8106379f>] worker_thread+0x133/0x217 >> [<ffffffff8106366c>] ? manage_workers+0x191/0x191 >> [<ffffffff81066f9c>] kthread+0x7d/0x85 >> [<ffffffff81485ee4>] kernel_thread_helper+0x4/0x10 >> [<ffffffff8147f0d8>] ? retint_restore_args+0x13/0x13 >> [<ffffffff81066f1f>] ? __init_kthread_worker+0x56/0x56 >> [<ffffffff81485ee0>] ? gs_change+0x13/0x13 > > The calldata gets freed in the rpc_final_put_task() which shouldn't ever be run while the task is still referenced in __rpc_execute > > IOW: it should be impossible to call rpc_exit_task() after rpc_final_put_task
I added lots of locking around the calldata, work-queue logic, and such, and still the problem persists w/out hitting any of the debug warnings or poisoned values I put in. It almost seems like tk_calldata is just assigned to two different tasks.
While poking through the code, I noticed that 'map' is static in rpcb_getport_async.
That would seem to cause problems if two threads called this method at the same time, possibly causing tk_calldata to be assigned to two different tasks???
Any idea why it is static?
I'm going to start another test run with this non-static to see if that resolves things...
Thanks, Ben
-- Ben Greear <greearb@candelatech.com> Candela Technologies Inc http://www.candelatech.com
| |