Messages in this thread | | | From | Jeff Layton <> | Date | Fri, 16 Jan 2015 13:53:04 -0500 | Subject | Re: fs: locks: WARNING: CPU: 16 PID: 4296 at fs/locks.c:236 locks_free_lock_context+0x10d/0x240() |
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On Fri, 16 Jan 2015 13:10:46 -0500 Sasha Levin <sasha.levin@oracle.com> wrote:
> On 01/16/2015 09:40 AM, Jeff Layton wrote: > > On Fri, 16 Jan 2015 09:31:23 -0500 > > Sasha Levin <sasha.levin@oracle.com> wrote: > > > >> On 01/15/2015 03:22 PM, Jeff Layton wrote: > >>> Ok, I tried to reproduce it with that and several variations but it > >>> still doesn't seem to do it for me. Can you try the latest linux-next > >>> tree and see if it's still reproducible there? > >> > >> It's still not in in today's -next, could you send me a patch for testing > >> instead? > >> > > > > Seems to be there for me: > > > > ----------------------[snip]----------------------- > > /* > > * This function is called on the last close of an open file. > > */ > > void locks_remove_file(struct file *filp) > > { > > /* ensure that we see any assignment of i_flctx */ > > smp_rmb(); > > > > /* remove any OFD locks */ > > locks_remove_posix(filp, filp); > > ----------------------[snip]----------------------- > > > > That's actually the right place to put the barrier, I think. We just > > need to ensure that this function sees any assignment to i_flctx that > > occurred before this point. By the time we're here, we shouldn't be > > getting any new locks that matter to this close since the fcheck call > > should fail on any new requests. > > > > If that works, then I'll probably make some other changes to the set > > and re-post it next week. > > > > Many thanks for helping me test this! > > You're right, I somehow missed that. > > But it doesn't fix the issue, I still see it happening, but it seems > to be less frequent(?). >
Ok, that was my worry (and one of the reasons I really would like to find some way to reproduce this on my own). I think what I'll do at this point is pull the patchset from linux-next until I can consult with someone who understands this sort of cache-coherency problem better than I do.
Once I get it resolved, I'll push it back to my linux-next branch and let you know and we can give it another go.
Thanks for the testing so far! -- Jeff Layton <jlayton@primarydata.com>
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