Re: [PATCH 1/1] writeback fix bdi thread race in mark_inode_dirty

[Srinivas Eeda <srinivas.eeda@oracle.com>]

Hi Jens,

Thanks!

I am new to submitting patches to linux-fsdevel. Is there a mailing list 
I should submit this patch or someone will pick this patch for mainline 
and stable branch?

Thanks,
--Srini

On 07/22/2013 08:41 AM, Jens Axboe wrote:
> On Fri, Jul 19 2013, Srinivas Eeda wrote:
>> In __mark_inode_dirty, a process checks !wb_has_dirty_io outside of list_lock
>> spinlock. This could cause a race, where process sees that list has dirty io
>> and decides not wake up bdi thread and waits for spinlock to add to dirty list.
>> Right at this time bdi_writeback_workfn finished write-back on last inode.
>> It sees the list is empty and ends. Process could now get the spinlock and
>> add inode to dirty list and doesn't wakeup bdi thread. Future calls to
>> __mark_inode_dirty also do not wake up the thread because list is not empty
>> any more.
>>
>> Fix is to get wb.list_lock spinlock before checking the dirty list
> With Jan's ack, lets add this for the current cycle. Should go into
> stable as well, imho.
>