[lustre-devel] [PATCH 06/28] lustre: ldlm: ELC shouldn't wait on lock flush

[James Simmons]

> On Sun, Oct 14 2018, James Simmons wrote:
> 
> > From: Andriy Skulysh <c17819 at cray.com>
> >
> > The commit 08fd034670b5 ("staging: lustre: ldlm: revert the changes
> > for lock canceling policy") removed the fix for LU-4300 when lru_resize
> > is disabled.
> >
> > Introduce ldlm_cancel_aged_no_wait_policy to be used by ELC.
> >
> > Signed-off-by: Andriy Skulysh <c17819 at cray.com>
> > WC-bug-id: https://jira.whamcloud.com/browse/LU-8578
> > Seagate-bug-id: MRP-3662
> > Reviewed-on: https://review.whamcloud.com/22286
> > Reviewed-by: Vitaly Fertman <c17818 at cray.com>
> > Reviewed-by: Patrick Farrell <paf at cray.com>
> > Reviewed-by: Oleg Drokin <green at whamcloud.com>
> > Signed-off-by: James Simmons <jsimmons at infradead.org>
> > ---
> >  drivers/staging/lustre/lustre/ldlm/ldlm_internal.h |  1 -
> >  drivers/staging/lustre/lustre/ldlm/ldlm_request.c  | 51 +++++++++++++++-------
> >  2 files changed, 35 insertions(+), 17 deletions(-)
> >
> > diff --git a/drivers/staging/lustre/lustre/ldlm/ldlm_internal.h b/drivers/staging/lustre/lustre/ldlm/ldlm_internal.h
> > index 1d7c727..709c527 100644
> > --- a/drivers/staging/lustre/lustre/ldlm/ldlm_internal.h
> > +++ b/drivers/staging/lustre/lustre/ldlm/ldlm_internal.h
> > @@ -96,7 +96,6 @@ enum {
> >  	LDLM_LRU_FLAG_NO_WAIT	= BIT(4), /* Cancel locks w/o blocking (neither
> >  					   * sending nor waiting for any rpcs)
> >  					   */
> > -	LDLM_LRU_FLAG_LRUR_NO_WAIT = BIT(5), /* LRUR + NO_WAIT */
> >  };
> >  
> >  int ldlm_cancel_lru(struct ldlm_namespace *ns, int nr,
> > diff --git a/drivers/staging/lustre/lustre/ldlm/ldlm_request.c b/drivers/staging/lustre/lustre/ldlm/ldlm_request.c
> > index 80260b07..3eb5036 100644
> > --- a/drivers/staging/lustre/lustre/ldlm/ldlm_request.c
> > +++ b/drivers/staging/lustre/lustre/ldlm/ldlm_request.c
> > @@ -579,8 +579,8 @@ int ldlm_prep_elc_req(struct obd_export *exp, struct ptlrpc_request *req,
> >  		req_capsule_filled_sizes(pill, RCL_CLIENT);
> >  		avail = ldlm_capsule_handles_avail(pill, RCL_CLIENT, canceloff);
> >  
> > -		flags = ns_connect_lru_resize(ns) ?
> > -			LDLM_LRU_FLAG_LRUR_NO_WAIT : LDLM_LRU_FLAG_AGED;
> > +		flags = LDLM_LRU_FLAG_NO_WAIT | ns_connect_lru_resize(ns) ?
> > +			LDLM_LRU_FLAG_LRUR : LDLM_LRU_FLAG_AGED;
> >  		to_free = !ns_connect_lru_resize(ns) &&
> >  			  opc == LDLM_ENQUEUE ? 1 : 0;
> 
> Bug.
> The commit in SFS-lustre (7ca60f33893) is correct, but you dropped the
> parentheses which introduces a bug.
> 
> While the SFS code is correct, it is formatted badly.
> It should be
> 
> 	lru_flags = LDLM_LRU_FLAG_NO_WAIT |
>         	(ns_connect_lru_resize(ns) ?
>                  LDLM_LRU_FLAG_LRUR : LDLM_LRU_FLAG_AGED);
> or similar.

Thanks for finding that. Shall I submit another patch to fix that or will
you fix it up when you apply it to lustre-testing?