On Tue, Jul 05, 2016 at 02:22:48AM -0400, Oleg Drokin wrote:
> > + if (!(open_flags & O_CREAT) && !d_unhashed(dentry)) {
s/d_unhashed/d_in_lookup/ in that.
> So we come racing here from multiple threads (say 3 or more - we have seen
> this
> in the older crash reports, so totally possible)
>
> > + d_drop(dentry);
>
> One lucky one does this first before the others perform the !d_unhashed check
> above.
> This makes the other ones to not enter here.
>
> And we are back to the original problem of multiple threads trying to
> instantiate
> same dentry as before.
Yep. See above - it should've been using d_in_lookup() in the first place,
through the entire nfs_atomic_open(). Same in the Lustre part of fixes,
obviously.
