[lustre-devel] [PATCH 03/14] staging/lustre: conflicting PW & PR extent locks on a client

[James Simmons]

> From: Andriy Skulysh <andriy.skulysh at seagate.com>
> 
> PW lock isn't replayed once a lock is marked
> LDLM_FL_CANCELING and glimpse lock doesn't wait for
> conflicting locks on the client. So the server will
> grant a PR lock in response to the glimpse lock request,
> which conflicts with the PW lock in LDLM_FL_CANCELING
> state on the client.
> 
> Lock in LDLM_FL_CANCELING state may still have pending IO,
> so it should be replayed until LDLM_FL_BL_DONE is set to
> avoid granted conflicting lock by a server.

Reviewed-by: James Simmons <jsimmons at infradead.org>
 
> Seagate-bug-id: MRP-3311
> Signed-off-by: Andriy Skulysh <andriy.skulysh at seagate.com>
> Reviewed-on: http://review.whamcloud.com/20345
> Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-8175
> Reviewed-by: Jinshan Xiong <jinshan.xiong at intel.com>
> Signed-off-by: Oleg Drokin <green at linuxhacker.ru>
> ---
>  drivers/staging/lustre/lustre/include/obd_support.h |  3 +++
>  drivers/staging/lustre/lustre/ldlm/ldlm_extent.c    | 20 ++++++++++++++++++++
>  drivers/staging/lustre/lustre/ldlm/ldlm_request.c   |  4 ++--
>  drivers/staging/lustre/lustre/osc/osc_request.c     |  1 +
>  4 files changed, 26 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/staging/lustre/lustre/include/obd_support.h b/drivers/staging/lustre/lustre/include/obd_support.h
> index 7f3f8cd..aaedec7 100644
> --- a/drivers/staging/lustre/lustre/include/obd_support.h
> +++ b/drivers/staging/lustre/lustre/include/obd_support.h
> @@ -321,6 +321,8 @@ extern char obd_jobid_var[];
>  #define OBD_FAIL_LDLM_CP_CB_WAIT4	 0x322
>  #define OBD_FAIL_LDLM_CP_CB_WAIT5	 0x323
>  
> +#define OBD_FAIL_LDLM_GRANT_CHECK        0x32a
> +
>  /* LOCKLESS IO */
>  #define OBD_FAIL_LDLM_SET_CONTENTION     0x385
>  
> @@ -343,6 +345,7 @@ extern char obd_jobid_var[];
>  #define OBD_FAIL_OSC_CP_ENQ_RACE	 0x410
>  #define OBD_FAIL_OSC_NO_GRANT	    0x411
>  #define OBD_FAIL_OSC_DELAY_SETTIME	 0x412
> +#define OBD_FAIL_OSC_DELAY_IO		 0x414
>  
>  #define OBD_FAIL_PTLRPC		  0x500
>  #define OBD_FAIL_PTLRPC_ACK	      0x501
> diff --git a/drivers/staging/lustre/lustre/ldlm/ldlm_extent.c b/drivers/staging/lustre/lustre/ldlm/ldlm_extent.c
> index ecf472e..a7b34e4 100644
> --- a/drivers/staging/lustre/lustre/ldlm/ldlm_extent.c
> +++ b/drivers/staging/lustre/lustre/ldlm/ldlm_extent.c
> @@ -193,6 +193,26 @@ void ldlm_extent_add_lock(struct ldlm_resource *res,
>  	 * add the locks into grant list, for debug purpose, ..
>  	 */
>  	ldlm_resource_add_lock(res, &res->lr_granted, lock);
> +
> +	if (OBD_FAIL_CHECK(OBD_FAIL_LDLM_GRANT_CHECK)) {
> +		struct ldlm_lock *lck;
> +
> +		list_for_each_entry_reverse(lck, &res->lr_granted,
> +					    l_res_link) {
> +			if (lck == lock)
> +				continue;
> +			if (lockmode_compat(lck->l_granted_mode,
> +					    lock->l_granted_mode))
> +				continue;
> +			if (ldlm_extent_overlap(&lck->l_req_extent,
> +						&lock->l_req_extent)) {
> +				CDEBUG(D_ERROR, "granting conflicting lock %p %p\n",
> +				       lck, lock);
> +				ldlm_resource_dump(D_ERROR, res);
> +				LBUG();
> +			}
> +		}
> +	}
>  }
>  
>  /** Remove cancelled lock from resource interval tree. */
> diff --git a/drivers/staging/lustre/lustre/ldlm/ldlm_request.c b/drivers/staging/lustre/lustre/ldlm/ldlm_request.c
> index 43856ff..6e704c7 100644
> --- a/drivers/staging/lustre/lustre/ldlm/ldlm_request.c
> +++ b/drivers/staging/lustre/lustre/ldlm/ldlm_request.c
> @@ -1846,7 +1846,7 @@ static int ldlm_chain_lock_for_replay(struct ldlm_lock *lock, void *closure)
>  	 * bug 17614: locks being actively cancelled. Get a reference
>  	 * on a lock so that it does not disappear under us (e.g. due to cancel)
>  	 */
> -	if (!(lock->l_flags & (LDLM_FL_FAILED | LDLM_FL_CANCELING))) {
> +	if (!(lock->l_flags & (LDLM_FL_FAILED | LDLM_FL_BL_DONE))) {
>  		list_add(&lock->l_pending_chain, list);
>  		LDLM_LOCK_GET(lock);
>  	}
> @@ -1915,7 +1915,7 @@ static int replay_one_lock(struct obd_import *imp, struct ldlm_lock *lock)
>  	int flags;
>  
>  	/* Bug 11974: Do not replay a lock which is actively being canceled */
> -	if (ldlm_is_canceling(lock)) {
> +	if (ldlm_is_bl_done(lock)) {
>  		LDLM_DEBUG(lock, "Not replaying canceled lock:");
>  		return 0;
>  	}
> diff --git a/drivers/staging/lustre/lustre/osc/osc_request.c b/drivers/staging/lustre/lustre/osc/osc_request.c
> index 091558e..8023561 100644
> --- a/drivers/staging/lustre/lustre/osc/osc_request.c
> +++ b/drivers/staging/lustre/lustre/osc/osc_request.c
> @@ -1823,6 +1823,7 @@ int osc_build_rpc(const struct lu_env *env, struct client_obd *cli,
>  	DEBUG_REQ(D_INODE, req, "%d pages, aa %p. now %ur/%dw in flight",
>  		  page_count, aa, cli->cl_r_in_flight,
>  		  cli->cl_w_in_flight);
> +	OBD_FAIL_TIMEOUT(OBD_FAIL_OSC_DELAY_IO, cfs_fail_val);
>  
>  	ptlrpcd_add_req(req);
>  	rc = 0;
> -- 
> 2.7.4
> 
>