feat: add mayastor nvmf rdma capability flag in features

Signed-off-by: Diwakar Sharma <diwakar.sharma@datacore.com>

io-engine/src/core/env.rs

@@ -292,11 +292,13 @@ impl MayastorFeatures {
         let lvm = env::var("ENABLE_LVM").as_deref() == Ok("true");
         let snapshot_rebuild =
             env::var("ENABLE_SNAPSHOT_REBUILD").as_deref() == Ok("true");
-
+        let rdma_capable_io_engine =
+            env::var("ENABLE_RDMA").as_deref() == Ok("true");
         MayastorFeatures {
             asymmetric_namespace_access: ana,
             logical_volume_manager: lvm,
             snapshot_rebuild,
+            rdma_capable_io_engine,
         }
     }
     /// Get all the supported and enabled features.

io-engine/src/core/mod.rs

@@ -530,12 +530,19 @@ pub struct MayastorFeatures {
     pub logical_volume_manager: bool,
     /// When set to true, support for snapshot rebuild is enabled.
     pub snapshot_rebuild: bool,
+    /// When set to true, the io-engine instance supports RDMA transport.
+    pub rdma_capable_io_engine: bool,
 }
 impl MayastorFeatures {
     /// Check if LVM feature is enabled.
     pub fn lvm(&self) -> bool {
         self.logical_volume_manager
     }
+
+    /// Get nvmf target's rdma feature state.
+    pub fn rdma_capable_io_engine(&self) -> bool {
+        self.rdma_capable_io_engine
+    }
 }
 
 /// Bugfix information to expose to the control-plane.

io-engine/src/grpc/v1/host.rs

@@ -104,6 +104,7 @@ impl From<MayastorFeatures> for host_rpc::MayastorFeatures {
             asymmetric_namespace_access: f.asymmetric_namespace_access,
             logical_volume_manager: Some(f.logical_volume_manager),
             snapshot_rebuild: Some(f.snapshot_rebuild),
+            rdma_capable_io_engine: Some(f.rdma_capable_io_engine),
         }
     }
 }

io-engine/src/subsys/nvmf/target.rs

@@ -104,7 +104,10 @@ impl Target {
             tgt: NonNull::dangling(),
             poll_group_count: 0,
             next_state: TargetState::Init,
-            rdma: MayastorEnvironment::global_or_default().rdma(),
+            // If mayastor args/env requests this to be true then it'll
+            // be set to true after ensuring rdma transport is created and
+            // listener is enabled.
+            rdma: false,
         }
     }
 
@@ -284,16 +287,22 @@ impl Target {
             trid_replica.trsvcid.as_str(),
         );
 
-        if self.rdma {
+        if MayastorEnvironment::global_or_default().rdma() {
             // listen RDMA also.
-            let _ = self.listen_rdma().map_err(|e| {
-                warn!(
+            let _ = self
+                .listen_rdma()
+                .map(|_| {
+                    self.rdma = true;
+                })
+                .map_err(|e| {
+                    warn!(
                         "failed to listen rdma on address. err: {e}:\
                         The target will however keep running with \
                         only tcp listener, with performance expectations of tcp"
                     );
-            });
+                });
         }
+
         self.next_state();
         Ok(())
     }

io-engine/src/subsys/nvmf/transport.rs

@@ -77,7 +77,6 @@ pub async fn create_and_add_transports(add_rdma: bool) -> Result<(), Error> {
         });
 
         if let Err(e) = ret {
-            // XXX: How to reset Target.rdma = false
             // todo: add event mechanism for Target and Nvmfsubsystem
             warn!(
                 "RDMA enablement failed {e}.\