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Commit 62bdf94a authored by Chuck Lever's avatar Chuck Lever Committed by Anna Schumaker
Browse files

xprtrdma: Fix DMAR failure in frwr_op_map() after reconnect 



When a LOCALINV WR is flushed, the frmr is marked STALE, then
frwr_op_unmap_sync DMA-unmaps the frmr's SGL. These STALE frmrs
are then recovered when frwr_op_map hunts for an INVALID frmr to
use.

All other cases that need frmr recovery leave that SGL DMA-mapped.
The FRMR recovery path unconditionally DMA-unmaps the frmr's SGL.

To avoid DMA unmapping the SGL twice for flushed LOCAL_INV WRs,
alter the recovery logic (rather than the hot frwr_op_unmap_sync
path) to distinguish among these cases. This solution also takes
care of the case where multiple LOCAL_INV WRs are issued for the
same rpcrdma_req, some complete successfully, but some are flushed.

Reported-by: default avatarVasco Steinmetz <linux@kyberraum.net>
Signed-off-by: default avatarChuck Lever <chuck.lever@oracle.com>
Tested-by: default avatarVasco Steinmetz <linux@kyberraum.net>
Signed-off-by: default avatarAnna Schumaker <Anna.Schumaker@Netapp.com>
parent 0ac84b72

net/sunrpc/xprtrdma/frwr_ops.c

+22 −15
Original line number Diff line number Diff line
@@ -44,18 +44,20 @@ 
 * being done.

 *

 * When the underlying transport disconnects, MRs are left in one of

 * three states:

 * four states:

 *

 * INVALID:	The MR was not in use before the QP entered ERROR state.

 *		(Or, the LOCAL_INV WR has not completed or flushed yet).

 *

 * STALE:	The MR was being registered or unregistered when the QP

 *		entered ERROR state, and the pending WR was flushed.

 *

 * VALID:	The MR was registered before the QP entered ERROR state.

 *

 * When frwr_op_map encounters STALE and VALID MRs, they are recovered

 * with ib_dereg_mr and then are re-initialized. Beause MR recovery

 * FLUSHED_FR:	The MR was being registered when the QP entered ERROR

 *		state, and the pending WR was flushed.

 *

 * FLUSHED_LI:	The MR was being invalidated when the QP entered ERROR

 *		state, and the pending WR was flushed.

 *

 * When frwr_op_map encounters FLUSHED and VALID MRs, they are recovered

 * with ib_dereg_mr and then are re-initialized. Because MR recovery

 * allocates fresh resources, it is deferred to a workqueue, and the

 * recovered MRs are placed back on the rb_mws list when recovery is

 * complete. frwr_op_map allocates another MR for the current RPC while
@@ -177,12 +179,15 @@ __frwr_reset_mr(struct rpcrdma_ia *ia, struct rpcrdma_mw *r) 
static void

frwr_op_recover_mr(struct rpcrdma_mw *mw)

{

	enum rpcrdma_frmr_state state = mw->frmr.fr_state;

	struct rpcrdma_xprt *r_xprt = mw->mw_xprt;

	struct rpcrdma_ia *ia = &r_xprt->rx_ia;

	int rc;



	rc = __frwr_reset_mr(ia, mw);

	ib_dma_unmap_sg(ia->ri_device, mw->mw_sg, mw->mw_nents, mw->mw_dir);

	if (state != FRMR_FLUSHED_LI)

		ib_dma_unmap_sg(ia->ri_device,

				mw->mw_sg, mw->mw_nents, mw->mw_dir);

	if (rc)

		goto out_release;
@@ -262,10 +267,8 @@ frwr_op_maxpages(struct rpcrdma_xprt *r_xprt) 
}



static void

__frwr_sendcompletion_flush(struct ib_wc *wc, struct rpcrdma_frmr *frmr,

			    const char *wr)

__frwr_sendcompletion_flush(struct ib_wc *wc, const char *wr)

{

	frmr->fr_state = FRMR_IS_STALE;

	if (wc->status != IB_WC_WR_FLUSH_ERR)

		pr_err("rpcrdma: %s: %s (%u/0x%x)\n",

		       wr, ib_wc_status_msg(wc->status),
@@ -288,7 +291,8 @@ frwr_wc_fastreg(struct ib_cq *cq, struct ib_wc *wc) 
	if (wc->status != IB_WC_SUCCESS) {

		cqe = wc->wr_cqe;

		frmr = container_of(cqe, struct rpcrdma_frmr, fr_cqe);

		__frwr_sendcompletion_flush(wc, frmr, "fastreg");

		frmr->fr_state = FRMR_FLUSHED_FR;

		__frwr_sendcompletion_flush(wc, "fastreg");

	}

}
@@ -308,7 +312,8 @@ frwr_wc_localinv(struct ib_cq *cq, struct ib_wc *wc) 
	if (wc->status != IB_WC_SUCCESS) {

		cqe = wc->wr_cqe;

		frmr = container_of(cqe, struct rpcrdma_frmr, fr_cqe);

		__frwr_sendcompletion_flush(wc, frmr, "localinv");

		frmr->fr_state = FRMR_FLUSHED_LI;

		__frwr_sendcompletion_flush(wc, "localinv");

	}

}
@@ -328,8 +333,10 @@ frwr_wc_localinv_wake(struct ib_cq *cq, struct ib_wc *wc) 
	/* WARNING: Only wr_cqe and status are reliable at this point */

	cqe = wc->wr_cqe;

	frmr = container_of(cqe, struct rpcrdma_frmr, fr_cqe);

	if (wc->status != IB_WC_SUCCESS)

		__frwr_sendcompletion_flush(wc, frmr, "localinv");

	if (wc->status != IB_WC_SUCCESS) {

		frmr->fr_state = FRMR_FLUSHED_LI;

		__frwr_sendcompletion_flush(wc, "localinv");

	}

	complete(&frmr->fr_linv_done);

}

net/sunrpc/xprtrdma/xprt_rdma.h

+2 −1
Original line number Diff line number Diff line
@@ -216,7 +216,8 @@ struct rpcrdma_rep { 
enum rpcrdma_frmr_state {

	FRMR_IS_INVALID,	/* ready to be used */

	FRMR_IS_VALID,		/* in use */

	FRMR_IS_STALE,		/* failed completion */

	FRMR_FLUSHED_FR,	/* flushed FASTREG WR */

	FRMR_FLUSHED_LI,	/* flushed LOCALINV WR */

};



struct rpcrdma_frmr {