[PATCH v4 12/21] xprtrdma: Reset FRMRs after a flushed LOCAL_INV Work Request

Chuck Lever
2014-07-22T14:52:43Z

When a LOCAL_INV Work Request is flushed, it leaves an FRMR in the
VALID state. This FRMR can be returned by rpcrdma_buffer_get(), and
must be knocked down in rpcrdma_register_frmr_external() before it
can be re-used.

Instead, capture these in rpcrdma_buffer_get(), and reset them.

Signed-off-by: Chuck Lever <chuck.lever-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>
Tested-by: Steve Wise <swise-7bPotxP6k4+P2YhJcF5u+vpXobYPEAuW@public.gmane.org>
Tested-by: Shirley Ma <shirley.ma-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>
Tested-by: Devesh Sharma <devesh.sharma-laKkSmNT4hbQT0dZR+AlfA@public.gmane.org>
---
net/sunrpc/xprtrdma/verbs.c | 94 ++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 92 insertions(+), 2 deletions(-)

diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c
index 39b31c8..24168e8 100644
--- a/net/sunrpc/xprtrdma/verbs.c
+++ b/net/sunrpc/xprtrdma/verbs.c
@@ -1358,8 +1358,91 @@ rpcrdma_buffer_put_sendbuf(struct rpcrdma_req *req, struct rpcrdma_buffer *buf)
}
}

+/* rpcrdma_unmap_one() was already done by rpcrdma_deregister_frmr_external().
+ * Redo only the ib_post_send().
+ */
+static void
+rpcrdma_retry_local_inv(struct rpcrdma_mw *r, struct rpcrdma_ia *ia)
+{
+ struct rpcrdma_xprt *r_xprt =
+ container_of(ia, struct rpcrdma_xprt, rx_ia);
+ struct ib_send_wr invalidate_wr, *bad_wr;
+ int rc;
+
+ dprintk("RPC: %s: FRMR %p is stale\n", __func__, r);
+
+ /* When this FRMR is re-inserted into rb_mws, it is no longer stale */
+ r->r.frmr.fr_state = FRMR_IS_VALID;
+
+ memset(&invalidate_wr, 0, sizeof(invalidate_wr));
+ invalidate_wr.wr_id = (unsigned long)(void *)r;
+ invalidate_wr.opcode = IB_WR_LOCAL_INV;
+ invalidate_wr.send_flags = IB_SEND_SIGNALED;
+ invalidate_wr.ex.invalidate_rkey = r->r.frmr.fr_mr->rkey;
+ DECR_CQCOUNT(&r_xprt->rx_ep);
+
+ dprintk("RPC: %s: frmr %p invalidating rkey %08x\n",
+ __func__, r, r->r.frmr.fr_mr->rkey);
+
+ read_lock(&ia->ri_qplock);
+ rc = ib_post_send(ia->ri_id->qp, &invalidate_wr, &bad_wr);
+ read_unlock(&ia->ri_qplock);
+ if (rc) {
+ /* Force rpcrdma_buffer_get() to retry */
+ r->r.frmr.fr_state = FRMR_IS_STALE;
+ dprintk("RPC: %s: ib_post_send failed, %i\n",
+ __func__, rc);
+ }
+}
+
+static void
+rpcrdma_retry_flushed_linv(struct list_head *stale,
+ struct rpcrdma_buffer *buf)
+{
+ struct rpcrdma_ia *ia = rdmab_to_ia(buf);
+ struct list_head *pos;
+ struct rpcrdma_mw *r;
+ unsigned long flags;
+
+ list_for_each(pos, stale) {
+ r = list_entry(pos, struct rpcrdma_mw, mw_list);
+ rpcrdma_retry_local_inv(r, ia);
+ }
+
+ spin_lock_irqsave(&buf->rb_lock, flags);
+ list_splice_tail(stale, &buf->rb_mws);
+ spin_unlock_irqrestore(&buf->rb_lock, flags);
+}
+
static struct rpcrdma_req *
-rpcrdma_buffer_get_mrs(struct rpcrdma_req *req, struct rpcrdma_buffer *buf)
+rpcrdma_buffer_get_frmrs(struct rpcrdma_req *req, struct rpcrdma_buffer *buf,
+ struct list_head *stale)
+{
+ struct rpcrdma_mw *r;
+ int i;
+
+ i = RPCRDMA_MAX_SEGS - 1;
+ while (!list_empty(&buf->rb_mws)) {
+ r = list_entry(buf->rb_mws.next,
+ struct rpcrdma_mw, mw_list);
+ list_del(&r->mw_list);
+ if (r->r.frmr.fr_state == FRMR_IS_STALE) {
+ list_add(&r->mw_list, stale);
+ continue;
+ }
+ req->rl_segments[i].mr_chunk.rl_mw = r;
+ if (unlikely(i-- == 0))
+ return req; /* Success */
+ }
+
+ /* Not enough entries on rb_mws for this req */
+ rpcrdma_buffer_put_sendbuf(req, buf);
+ rpcrdma_buffer_put_mrs(req, buf);
+ return NULL;
+}
+
+static struct rpcrdma_req *
+rpcrdma_buffer_get_fmrs(struct rpcrdma_req *req, struct rpcrdma_buffer *buf)
{
struct rpcrdma_mw *r;
int i;
@@ -1393,6 +1476,7 @@ struct rpcrdma_req *
rpcrdma_buffer_get(struct rpcrdma_buffer *buffers)
{
struct rpcrdma_ia *ia = rdmab_to_ia(buffers);
+ struct list_head stale;
struct rpcrdma_req *req;
unsigned long flags;

@@ -1414,15 +1498,21 @@ rpcrdma_buffer_get(struct rpcrdma_buffer *buffers)
buffers->rb_recv_bufs[buffers->rb_recv_index++] = NULL;
}
buffers->rb_send_bufs[buffers->rb_send_index++] = NULL;
+
+ INIT_LIST_HEAD(&stale);
switch (ia->ri_memreg_strategy) {
case RPCRDMA_FRMR:
+ req = rpcrdma_buffer_get_frmrs(req, buffers, &stale);
+ break;
case RPCRDMA_MTHCAFMR:
- req = rpcrdma_buffer_get_mrs(req, buffers);
+ req = rpcrdma_buffer_get_fmrs(req, buffers);
break;
default:
break;
}
spin_unlock_irqrestore(&buffers->rb_lock, flags);
+ if (!list_empty(&stale))
+ rpcrdma_retry_flushed_linv(&stale, buffers);
return req;
}

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