[PATCH v1 10/14] xprtrdma: Remove ->ro_reset

Chuck Lever
2015-05-04T17:58:18Z

An RPC can exit at any time. When it does so, xprt_rdma_free() is
called, and it calls ->op_unmap().

If ->ro_reset() is running due to a transport disconnect, the two
methods can race while processing the same rpcrdma_mw. The results
are unpredictable.

Because of this, in previous patches I've replaced the ->ro_reset()
methods with a recovery workqueue. ->ro_reset() is no longer used
and can be removed.

Signed-off-by: Chuck Lever <chuck.lever-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>
---
net/sunrpc/xprtrdma/fmr_ops.c | 11 -----------
net/sunrpc/xprtrdma/frwr_ops.c | 16 ----------------
net/sunrpc/xprtrdma/physical_ops.c | 6 ------
net/sunrpc/xprtrdma/verbs.c | 2 --
net/sunrpc/xprtrdma/xprt_rdma.h | 1 -
5 files changed, 36 deletions(-)

diff --git a/net/sunrpc/xprtrdma/fmr_ops.c b/net/sunrpc/xprtrdma/fmr_ops.c
index ad0055b..5dd77da 100644
--- a/net/sunrpc/xprtrdma/fmr_ops.c
+++ b/net/sunrpc/xprtrdma/fmr_ops.c
@@ -197,16 +197,6 @@ out_err:
return nsegs;
}

-/* After a disconnect, unmap all FMRs.
- *
- * This is invoked only in the transport connect worker in order
- * to serialize with rpcrdma_register_fmr_external().
- */
-static void
-fmr_op_reset(struct rpcrdma_xprt *r_xprt)
-{
-}
-
static void
fmr_op_destroy(struct rpcrdma_buffer *buf)
{
@@ -230,7 +220,6 @@ const struct rpcrdma_memreg_ops rpcrdma_fmr_memreg_ops = {
.ro_open = fmr_op_open,
.ro_maxpages = fmr_op_maxpages,
.ro_init = fmr_op_init,
- .ro_reset = fmr_op_reset,
.ro_destroy = fmr_op_destroy,
.ro_displayname = "fmr",
};
diff --git a/net/sunrpc/xprtrdma/frwr_ops.c b/net/sunrpc/xprtrdma/frwr_ops.c
index 6f93a89..3fb609a 100644
--- a/net/sunrpc/xprtrdma/frwr_ops.c
+++ b/net/sunrpc/xprtrdma/frwr_ops.c
@@ -430,21 +430,6 @@ out_err:
return nsegs;
}

-/* After a disconnect, a flushed FAST_REG_MR can leave an FRMR in
- * an unusable state. Find FRMRs in this state and dereg / reg
- * each. FRMRs that are VALID and attached to an rpcrdma_req are
- * also torn down.
- *
- * This gives all in-use FRMRs a fresh rkey and leaves them INVALID.
- *
- * This is invoked only in the transport connect worker in order
- * to serialize with rpcrdma_register_frmr_external().
- */
-static void
-frwr_op_reset(struct rpcrdma_xprt *r_xprt)
-{
-}
-
static void
frwr_op_destroy(struct rpcrdma_buffer *buf)
{
@@ -464,7 +449,6 @@ const struct rpcrdma_memreg_ops rpcrdma_frwr_memreg_ops = {
.ro_open = frwr_op_open,
.ro_maxpages = frwr_op_maxpages,
.ro_init = frwr_op_init,
- .ro_reset = frwr_op_reset,
.ro_destroy = frwr_op_destroy,
.ro_displayname = "frwr",
};
diff --git a/net/sunrpc/xprtrdma/physical_ops.c b/net/sunrpc/xprtrdma/physical_ops.c
index da149e8..41985d0 100644
--- a/net/sunrpc/xprtrdma/physical_ops.c
+++ b/net/sunrpc/xprtrdma/physical_ops.c
@@ -69,11 +69,6 @@ physical_op_unmap(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mr_seg *seg)
}

static void
-physical_op_reset(struct rpcrdma_xprt *r_xprt)
-{
-}
-
-static void
physical_op_destroy(struct rpcrdma_buffer *buf)
{
}
@@ -84,7 +79,6 @@ const struct rpcrdma_memreg_ops rpcrdma_physical_memreg_ops = {
.ro_open = physical_op_open,
.ro_maxpages = physical_op_maxpages,
.ro_init = physical_op_init,
- .ro_reset = physical_op_reset,
.ro_destroy = physical_op_destroy,
.ro_displayname = "physical",
};
diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c
index 5120a8e..eaf0b9d 100644
--- a/net/sunrpc/xprtrdma/verbs.c
+++ b/net/sunrpc/xprtrdma/verbs.c
@@ -897,8 +897,6 @@ retry:
rpcrdma_flush_cqs(ep);

xprt = container_of(ia, struct rpcrdma_xprt, rx_ia);
- ia->ri_ops->ro_reset(xprt);
-
id = rpcrdma_create_id(xprt, ia,
(struct sockaddr *)&xprt->rx_data.addr);
if (IS_ERR(id)) {
diff --git a/net/sunrpc/xprtrdma/xprt_rdma.h b/net/sunrpc/xprtrdma/xprt_rdma.h
index 98227d6..6a1e565 100644
--- a/net/sunrpc/xprtrdma/xprt_rdma.h
+++ b/net/sunrpc/xprtrdma/xprt_rdma.h
@@ -353,7 +353,6 @@ struct rpcrdma_memreg_ops {
struct rpcrdma_create_data_internal *);
size_t (*ro_maxpages)(struct rpcrdma_xprt *);
int (*ro_init)(struct rpcrdma_xprt *);
- void (*ro_reset)(struct rpcrdma_xprt *);
void (*ro_destroy)(struct rpcrdma_buffer *);
const char *ro_displayname;
};