@@ -1730,13 +1730,14 @@ rpcrdma_deregister_memwin_external(struct rpcrdma_mr_seg *seg,
}
static int
-rpcrdma_register_default_external(struct rpcrdma_mr_seg *seg,
- int *nsegs, int writing, struct rpcrdma_ia *ia)
+rpcrdma_register_default_external(struct rpcrdma_xprt *r_xprt,
+ struct rpcrdma_mr_seg *seg, int *nsegs, int writing,
+ struct rpcrdma_ia *ia)
{
int mem_priv = (writing ? IB_ACCESS_REMOTE_WRITE :
IB_ACCESS_REMOTE_READ);
struct rpcrdma_mr_seg *seg1 = seg;
- struct ib_phys_buf ipb[RPCRDMA_MAX_DATA_SEGS];
+ struct ib_phys_buf *ipb = r_xprt->ipb;
int len, i, rc = 0;
if (*nsegs > RPCRDMA_MAX_DATA_SEGS)
@@ -1827,7 +1828,8 @@ rpcrdma_register_external(struct rpcrdma_mr_seg *seg,
/* Default registration each time */
default:
- rc = rpcrdma_register_default_external(seg, &nsegs, writing, ia);
+ rc = rpcrdma_register_default_external(r_xprt, seg, &nsegs,
+ writing, ia);
break;
}
if (rc)
@@ -269,7 +269,8 @@ struct rpcrdma_stats {
* for convenience. This structure need not be visible externally.
*
* It is allocated and initialized during mount, and released
- * during unmount.
+ * during unmount. Access to this structure is serialized by XPRT_LOCKED
+ * in xprt_reserve_xprt().
*/
struct rpcrdma_xprt {
struct rpc_xprt xprt;
@@ -279,6 +280,8 @@ struct rpcrdma_xprt {
struct rpcrdma_create_data_internal rx_data;
struct delayed_work rdma_connect;
struct rpcrdma_stats rx_stats;
+ /* temp work array */
+ struct ib_phys_buf ipb[RPCRDMA_MAX_DATA_SEGS];
};
#define rpcx_to_rdmax(x) container_of(x, struct rpcrdma_xprt, xprt)
rpcrdma_register_default_external() is several frames into the call stack which goes deeper yet. You run the risk of stack corruption by declaring such a large automatic variable, so move the array of 'struct ib_phys_buf' objects into the transport structure 'struct rpcrdma_xprt' (which is dynamically allocated) in order to silence the frame-larger-than warning. Access to each struct rpcrdma_xprt is serialized by XPRT_LOCKED in xprt_reserve_xprt(), so there is no danger of multiple accessors to the array of struct ib_phys_buf objects. net/sunrpc/xprtrdma/verbs.c: In function 'rpcrdma_register_default_external': net/sunrpc/xprtrdma/verbs.c:1774:1: warning: the frame size of 1056 bytes is larger than 1024 bytes [-Wframe-larger-than=] gcc version 4.6.3 Cc: Trond Myklebust <Trond.Myklebust@netapp.com> Cc: "J. Bruce Fields" <bfields@fieldses.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Tom Tucker <tom@ogc.us> Cc: Haggai Eran <haggaie@mellanox.com> Cc: Or Gerlitz <ogerlitz@mellanox.com> Cc: Shani Michaeli <shanim@mellanox.com> Cc: linux-nfs@vger.kernel.org Cc: netdev@vger.kernel.org Signed-off-by: Tim Gardner <tim.gardner@canonical.com> --- v1 - Use kmalloc() to dynamically allocate and free the array of 'struct ib_phys_buf' objects v2 - Move the array of 'struct ib_phys_buf' objects into struct rpcrdma_req and pass this request down through rpcrdma_register_external() and rpcrdma_register_default_external(). This is less overhead then using kmalloc() and requires no extra error checking as the allocation burden is shifted to the transport client. v3 - Move the array of 'struct ib_phys_buf' objects into struct rpcrdma_xprt. Pass a pointer to this transport structure into rpcrdma_register_default_external(). This is less overhead then using kmalloc() and requires no extra error checking as the allocation burden is shifted to the transport client. net/sunrpc/xprtrdma/verbs.c | 10 ++++++---- net/sunrpc/xprtrdma/xprt_rdma.h | 5 ++++- 2 files changed, 10 insertions(+), 5 deletions(-)