-/**
- * Serializes in-flight MDT-modifying RPC requests to preserve idempotency.
- *
- * This mutex is used to implement execute-once semantics on the MDT.
- * The MDT stores the last transaction ID and result for every client in
- * its last_rcvd file. If the client doesn't get a reply, it can safely
- * resend the request and the MDT will reconstruct the reply being aware
- * that the request has already been executed. Without this lock,
- * execution status of concurrent in-flight requests would be
- * overwritten.
- *
- * This design limits the extent to which we can keep a full pipeline of
- * in-flight requests from a single client. This limitation could be
- * overcome by allowing multiple slots per client in the last_rcvd file.
- */
-struct mdc_rpc_lock {
- /** Lock protecting in-flight RPC concurrency. */
- struct mutex rpcl_mutex;
- /** Intent associated with currently executing request. */
- struct lookup_intent *rpcl_it;
- /** Used for MDS/RPC load testing purposes. */
- int rpcl_fakes;
-};
-
-#define MDC_FAKE_RPCL_IT ((void *)0x2c0012bfUL)
-
-static inline void mdc_init_rpc_lock(struct mdc_rpc_lock *lck)
+static inline void mdc_get_mod_rpc_slot(struct ptlrpc_request *req,
+ struct lookup_intent *it)