FRWR's ro_unmap is asynchronous. The new ro_unmap_sync posts
LOCAL_INV Work Requests and waits for them to complete before
returning.
Note also, DMA unmapping is now done _after_ invalidation.
Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
Tested-by: Devesh Sharma <devesh.sharma@xxxxxxxxxxxxx>
---
net/sunrpc/xprtrdma/frwr_ops.c | 136 ++++++++++++++++++++++++++++++++++++++-
net/sunrpc/xprtrdma/xprt_rdma.h | 2 +
2 files changed, 134 insertions(+), 4 deletions(-)
diff --git a/net/sunrpc/xprtrdma/frwr_ops.c b/net/sunrpc/xprtrdma/frwr_ops.c
index 660d0b6..aa078a0 100644
--- a/net/sunrpc/xprtrdma/frwr_ops.c
+++ b/net/sunrpc/xprtrdma/frwr_ops.c
@@ -244,12 +244,14 @@ frwr_op_maxpages(struct rpcrdma_xprt *r_xprt)
rpcrdma_max_segments(r_xprt) * ia->ri_max_frmr_depth);
}
-/* If FAST_REG or LOCAL_INV failed, indicate the frmr needs to be reset. */
+/* If FAST_REG or LOCAL_INV failed, indicate the frmr needs
+ * to be reset.
+ *
+ * WARNING: Only wr_id and status are reliable at this point
+ */
static void
-frwr_sendcompletion(struct ib_wc *wc)
+__frwr_sendcompletion_flush(struct ib_wc *wc, struct rpcrdma_mw *r)
{
- struct rpcrdma_mw *r;
-
if (likely(wc->status == IB_WC_SUCCESS))
return;
@@ -260,9 +262,23 @@ frwr_sendcompletion(struct ib_wc *wc)
else
pr_warn("RPC: %s: frmr %p error, status %s (%d)\n",
__func__, r, ib_wc_status_msg(wc->status), wc->status);
+
r->r.frmr.fr_state = FRMR_IS_STALE;
}
+static void
+frwr_sendcompletion(struct ib_wc *wc)
+{
+ struct rpcrdma_mw *r = (struct rpcrdma_mw *)(unsigned long)wc->wr_id;
+ struct rpcrdma_frmr *f = &r->r.frmr;
+
+ if (unlikely(wc->status != IB_WC_SUCCESS))
+ __frwr_sendcompletion_flush(wc, r);
+
+ if (f->fr_waiter)
+ complete(&f->fr_linv_done);
+}
+
static int
frwr_op_init(struct rpcrdma_xprt *r_xprt)
{
@@ -334,6 +350,7 @@ frwr_op_map(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mr_seg *seg,
} while (mw->r.frmr.fr_state != FRMR_IS_INVALID);
frmr = &mw->r.frmr;
frmr->fr_state = FRMR_IS_VALID;
+ frmr->fr_waiter = false;
mr = frmr->fr_mr;
reg_wr = &frmr->fr_regwr;
@@ -413,6 +430,116 @@ out_senderr:
return rc;
}
+static struct ib_send_wr *
+__frwr_prepare_linv_wr(struct rpcrdma_mr_seg *seg)
+{
+ struct rpcrdma_mw *mw = seg->rl_mw;
+ struct rpcrdma_frmr *f = &mw->r.frmr;
+ struct ib_send_wr *invalidate_wr;
+
+ f->fr_waiter = false;
+ f->fr_state = FRMR_IS_INVALID;
+ invalidate_wr = &f->fr_invwr;
+
+ memset(invalidate_wr, 0, sizeof(*invalidate_wr));
+ invalidate_wr->wr_id = (unsigned long)(void *)mw;
+ invalidate_wr->opcode = IB_WR_LOCAL_INV;
+ invalidate_wr->ex.invalidate_rkey = f->fr_mr->rkey;
+
+ return invalidate_wr;
+}
+
+static void
+__frwr_dma_unmap(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mr_seg *seg,
+ int rc)
+{
+ struct ib_device *device = r_xprt->rx_ia.ri_device;
+ struct rpcrdma_mw *mw = seg->rl_mw;
+ struct rpcrdma_frmr *f = &mw->r.frmr;
+
+ seg->rl_mw = NULL;
+
+ ib_dma_unmap_sg(device, f->sg, f->sg_nents, seg->mr_dir);
+
+ if (!rc)
+ rpcrdma_put_mw(r_xprt, mw);
+ else
+ __frwr_queue_recovery(mw);
+}
+
+/* Invalidate all memory regions that were registered for "req".
+ *
+ * Sleeps until it is safe for the host CPU to access the
+ * previously mapped memory regions.
+ */
+static void
+frwr_op_unmap_sync(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req)
+{
+ struct ib_send_wr *invalidate_wrs, *pos, *prev, *bad_wr;
+ struct rpcrdma_ia *ia = &r_xprt->rx_ia;
+ struct rpcrdma_mr_seg *seg;
+ unsigned int i, nchunks;
+ struct rpcrdma_frmr *f;
+ int rc;
+
+ dprintk("RPC: %s: req %p\n", __func__, req);
+
+ /* ORDER: Invalidate all of the req's MRs first
+ *
+ * Chain the LOCAL_INV Work Requests and post them with
+ * a single ib_post_send() call.
+ */
+ invalidate_wrs = pos = prev = NULL;
+ seg = NULL;
+ for (i = 0, nchunks = req->rl_nchunks; nchunks; nchunks--) {
+ seg = &req->rl_segments[i];
+
+ pos = __frwr_prepare_linv_wr(seg);
+
+ if (!invalidate_wrs)
+ invalidate_wrs = pos;
+ else
+ prev->next = pos;
+ prev = pos;
+
+ i += seg->mr_nsegs;
+ }
+ f = &seg->rl_mw->r.frmr;
+
+ /* Strong send queue ordering guarantees that when the
+ * last WR in the chain completes, all WRs in the chain
+ * are complete.
+ */
+ f->fr_invwr.send_flags = IB_SEND_SIGNALED;
+ f->fr_waiter = true;
+ init_completion(&f->fr_linv_done);
+ INIT_CQCOUNT(&r_xprt->rx_ep);
+
+ /* Transport disconnect drains the receive CQ before it
+ * replaces the QP. The RPC reply handler won't call us
+ * unless ri_id->qp is a valid pointer.
+ */
+ rc = ib_post_send(ia->ri_id->qp, invalidate_wrs, &bad_wr);
+ if (rc)
+ pr_warn("%s: ib_post_send failed %i\n", __func__, rc);
+
+ wait_for_completion(&f->fr_linv_done);
+
+ /* ORDER: Now DMA unmap all of the req's MRs, and return
+ * them to the free MW list.
+ */
+ for (i = 0, nchunks = req->rl_nchunks; nchunks; nchunks--) {
+ seg = &req->rl_segments[i];
+
+ __frwr_dma_unmap(r_xprt, seg, rc);
+
+ i += seg->mr_nsegs;
+ seg->mr_nsegs = 0;
+ }
+
+ req->rl_nchunks = 0;
+}
+
/* Post a LOCAL_INV Work Request to prevent further remote access
* via RDMA READ or RDMA WRITE.
*/
@@ -472,6 +599,7 @@ frwr_op_destroy(struct rpcrdma_buffer *buf)
const struct rpcrdma_memreg_ops rpcrdma_frwr_memreg_ops = {
.ro_map = frwr_op_map,
+ .ro_unmap_sync = frwr_op_unmap_sync,
.ro_unmap = frwr_op_unmap,
.ro_open = frwr_op_open,
.ro_maxpages = frwr_op_maxpages,
diff --git a/net/sunrpc/xprtrdma/xprt_rdma.h b/net/sunrpc/xprtrdma/xprt_rdma.h
index 512184d..b8bac41 100644
--- a/net/sunrpc/xprtrdma/xprt_rdma.h
+++ b/net/sunrpc/xprtrdma/xprt_rdma.h
@@ -206,6 +206,8 @@ struct rpcrdma_frmr {
enum rpcrdma_frmr_state fr_state;
struct work_struct fr_work;
struct rpcrdma_xprt *fr_xprt;
+ bool fr_waiter;
+ struct completion fr_linv_done;;
union {
struct ib_reg_wr fr_regwr;
struct ib_send_wr fr_invwr;
--
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