diff mbox

[rdma-rc] xprtrdma: Don't require LOCAL_DMA_LKEY support for fasterg

Message ID 1444124889-8957-1-git-send-email-sagig@mellanox.com (mailing list archive)
State Superseded
Headers show

Commit Message

Sagi Grimberg Oct. 6, 2015, 9:48 a.m. UTC
There is no need to require LOCAL_DMA_LKEY support in order to
use fast registration as the PD allocation makes sure that there
is a local_dma_lkey.

This caused a NULL pointer dereference in mlx5 which removed
the support for LOCAL_DMA_LKEY.

Fixes: bb6c96d72879 ("xprtrdma: Replace global lkey with lkey local to PD")
Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
---
 net/sunrpc/xprtrdma/verbs.c |    7 ++-----
 1 files changed, 2 insertions(+), 5 deletions(-)

Comments

Chuck Lever III Oct. 6, 2015, 3:05 p.m. UTC | #1
Hi Sagi-


> On Oct 6, 2015, at 5:48 AM, Sagi Grimberg <sagig@mellanox.com> wrote:
> 
> There is no need to require LOCAL_DMA_LKEY support in order to
> use fast registration as the PD allocation makes sure that there
> is a local_dma_lkey.

In other words, all devices now have a local DMA lkey, so the
check is unnecessary.


> This caused a NULL pointer dereference in mlx5 which removed
> the support for LOCAL_DMA_LKEY.

Where was the bad dereference? in mlx5, or in xprtrdma?


> Fixes: bb6c96d72879 ("xprtrdma: Replace global lkey with lkey local to PD")
> Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
> ---
> net/sunrpc/xprtrdma/verbs.c |    7 ++-----
> 1 files changed, 2 insertions(+), 5 deletions(-)
> 
> diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c
> index eb081ad..7efd9ef 100644
> --- a/net/sunrpc/xprtrdma/verbs.c
> +++ b/net/sunrpc/xprtrdma/verbs.c
> @@ -543,11 +543,8 @@ rpcrdma_ia_open(struct rpcrdma_xprt *xprt, struct sockaddr *addr, int memreg)
> 	}
> 
> 	if (memreg == RPCRDMA_FRMR) {
> -		/* Requires both frmr reg and local dma lkey */
> -		if (((devattr->device_cap_flags &
> -		     (IB_DEVICE_MEM_MGT_EXTENSIONS|IB_DEVICE_LOCAL_DMA_LKEY)) !=
> -		    (IB_DEVICE_MEM_MGT_EXTENSIONS|IB_DEVICE_LOCAL_DMA_LKEY)) ||
> -		      (devattr->max_fast_reg_page_list_len == 0)) {
> +		if (!(devattr->device_cap_flags & IB_DEVICE_MEM_MGT_EXTENSIONS) ||
> +		    (devattr->max_fast_reg_page_list_len == 0)) {
> 			dprintk("RPC:       %s: FRMR registration "
> 				"not supported by HCA\n", __func__);
> 			memreg = RPCRDMA_MTHCAFMR;

Reviewed-by: Chuck Lever <chuck.lever@oracle.com>


—
Chuck Lever



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diff mbox

Patch

diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c
index eb081ad..7efd9ef 100644
--- a/net/sunrpc/xprtrdma/verbs.c
+++ b/net/sunrpc/xprtrdma/verbs.c
@@ -543,11 +543,8 @@  rpcrdma_ia_open(struct rpcrdma_xprt *xprt, struct sockaddr *addr, int memreg)
 	}
 
 	if (memreg == RPCRDMA_FRMR) {
-		/* Requires both frmr reg and local dma lkey */
-		if (((devattr->device_cap_flags &
-		     (IB_DEVICE_MEM_MGT_EXTENSIONS|IB_DEVICE_LOCAL_DMA_LKEY)) !=
-		    (IB_DEVICE_MEM_MGT_EXTENSIONS|IB_DEVICE_LOCAL_DMA_LKEY)) ||
-		      (devattr->max_fast_reg_page_list_len == 0)) {
+		if (!(devattr->device_cap_flags & IB_DEVICE_MEM_MGT_EXTENSIONS) ||
+		    (devattr->max_fast_reg_page_list_len == 0)) {
 			dprintk("RPC:       %s: FRMR registration "
 				"not supported by HCA\n", __func__);
 			memreg = RPCRDMA_MTHCAFMR;