Re: Are there u32 atomic bitops? (or dealing w/ i_flags)

[Andy Lutomirski]

On Thu, Dec 20, 2012 at 3:36 PM, Dave Chinner <david@xxxxxxxxxxxxx> wrote:
> On Thu, Dec 20, 2012 at 12:05:09PM -0800, Andy Lutomirski wrote:
>> On Wed, Dec 19, 2012 at 11:03 PM, Dave Chinner <david@xxxxxxxxxxxxx> wrote:
>> start_this_handle jbd2__journal_start jbd2_journal_start
>> ext4_journal_start_sb ext4_dirty_inode __mark_inode_dirty update_time
>> file_update_time ext4_page_mkwrite do_wp_page handle_pte_fault
>> handle_mm_fault
>
> Yup, as I suspected. It's a filesystem specific problem.
>
>> This is a showstopper for my software -- I'm running on a kernel with
>> the call to file_update_time commented out.
>
> Which means you are effectively running with O_CMTIME on all mmapped
> files....

Indeed.  I'm not thrilled by not having timestamps update, and IMO
adding O_CMTIME as part of the API seems like a silly way to "fix"
this.  I'd rather fix the implementation.

The problems may be fs-specific in the sense that an fs could fix them
internally, but I think something like my AS_CMTIME approach could fix
it everywhere with much less complexity.  Any thoughts on my patch
set?  (Are you the right person to review it?)

--Andy
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/