xprtrdma: Pre-mark remotely invalidated MRs
There are rare cases where an rpcrdma_req and its matched
rpcrdma_rep can be re-used, via rpcrdma_buffer_put, while the RPC
reply handler is still using that req. This is typically due to a
signal firing at just the wrong instant.
As part of closing this race window, avoid using the wrong
rpcrdma_rep to detect remotely invalidated MRs. Mark MRs as
invalidated while we are sure the rep is still OK to use.
BugLink: https://bugzilla.linux-nfs.org/show_bug.cgi?id=305
Fixes: 68791649a725 ('xprtrdma: Invalidate in the RPC reply ... ')
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
diff --git a/net/sunrpc/xprtrdma/xprt_rdma.h b/net/sunrpc/xprtrdma/xprt_rdma.h
index 1d66acf..2e02733 100644
--- a/net/sunrpc/xprtrdma/xprt_rdma.h
+++ b/net/sunrpc/xprtrdma/xprt_rdma.h
@@ -271,6 +271,7 @@ struct rpcrdma_mw {
struct scatterlist *mw_sg;
int mw_nents;
enum dma_data_direction mw_dir;
+ unsigned long mw_flags;
union {
struct rpcrdma_fmr fmr;
struct rpcrdma_frmr frmr;
@@ -282,6 +283,11 @@ struct rpcrdma_mw {
struct list_head mw_all;
};
+/* mw_flags */
+enum {
+ RPCRDMA_MW_F_RI = 1,
+};
+
/*
* struct rpcrdma_req -- structure central to the request/reply sequence.
*