Re: TAKE 981498 - Use KM_NOFS for debug trace buffers

[Eric Sandeen <sandeen@xxxxxxxxxxx>]

Bhagi rathi wrote:
> I couldn't get a chance to read the diff's completely. If I click on
> Lachlan's url for diff's, I couldn't access them. 

Try again, it takes a while for cvs to catch up.

-Eric

> It looks to me that
> the issue is not just with trace buffers. It can extend to xfs_iformat
> as well. The same dead-lock can spring via
> 
> xfs_iread -> xfs_iformat -> xfs_iformat_extents -> xfs_iext_add ->
> xfs_iext_inline_to_direct -> which can do kmem_alloc with
> KM_SLEEP flag.
> 
> 
> The source of the problem is that holding a lock and entering into
> file-system once again. This can lead to dead-lock on the same
> clustered buffer during cleaning of log space.
> 
> Cheers,
> Bhagi.