pNFS/flexfiles: Treat ENETUNREACH errors as fatal in containers

Propagate the NFS_MOUNT_NETUNREACH_FATAL flag to work with the pNFS
flexfiles client. In these circumstances, the client needs to treat the
ENETDOWN and ENETUNREACH errors as fatal, and should abandon the
attempted I/O.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Tested-by: Jeff Layton <jlayton@kernel.org>
Acked-by: Chuck Lever <chuck.lever@oracle.com>

fs/nfs/flexfilelayout/flexfilelayout.c

@@ -1154,10 +1154,14 @@ static int ff_layout_async_handle_error_v4(struct rpc_task *task,
 		rpc_wake_up(&tbl->slot_tbl_waitq);
 		goto reset;
 	/* RPC connection errors */
+	case -ENETDOWN:
+	case -ENETUNREACH:
+		if (test_bit(NFS_CS_NETUNREACH_FATAL, &clp->cl_flags))
+			return -NFS4ERR_FATAL_IOERROR;
+		fallthrough;
 	case -ECONNREFUSED:
 	case -EHOSTDOWN:
 	case -EHOSTUNREACH:
-	case -ENETUNREACH:
 	case -EIO:
 	case -ETIMEDOUT:
 	case -EPIPE:
@@ -1183,6 +1187,7 @@ reset:
 
 /* Retry all errors through either pNFS or MDS except for -EJUKEBOX */
 static int ff_layout_async_handle_error_v3(struct rpc_task *task,
+					   struct nfs_client *clp,
 					   struct pnfs_layout_segment *lseg,
 					   u32 idx)
 {
@@ -1200,6 +1205,11 @@ static int ff_layout_async_handle_error_v3(struct rpc_task *task,
 	case -EJUKEBOX:
 		nfs_inc_stats(lseg->pls_layout->plh_inode, NFSIOS_DELAY);
 		goto out_retry;
+	case -ENETDOWN:
+	case -ENETUNREACH:
+		if (test_bit(NFS_CS_NETUNREACH_FATAL, &clp->cl_flags))
+			return -NFS4ERR_FATAL_IOERROR;
+		fallthrough;
 	default:
 		dprintk("%s DS connection error %d\n", __func__,
 			task->tk_status);
@@ -1234,7 +1244,7 @@ static int ff_layout_async_handle_error(struct rpc_task *task,
 
 	switch (vers) {
 	case 3:
-		return ff_layout_async_handle_error_v3(task, lseg, idx);
+		return ff_layout_async_handle_error_v3(task, clp, lseg, idx);
 	case 4:
 		return ff_layout_async_handle_error_v4(task, state, clp,
 						       lseg, idx);
@@ -1337,6 +1347,9 @@ static int ff_layout_read_done_cb(struct rpc_task *task,
 		return task->tk_status;
 	case -EAGAIN:
 		goto out_eagain;
+	case -NFS4ERR_FATAL_IOERROR:
+		task->tk_status = -EIO;
+		return 0;
 	}
 
 	return 0;
@@ -1507,6 +1520,9 @@ static int ff_layout_write_done_cb(struct rpc_task *task,
 		return task->tk_status;
 	case -EAGAIN:
 		return -EAGAIN;
+	case -NFS4ERR_FATAL_IOERROR:
+		task->tk_status = -EIO;
+		return 0;
 	}
 
 	if (hdr->res.verf->committed == NFS_FILE_SYNC ||
@@ -1551,6 +1567,9 @@ static int ff_layout_commit_done_cb(struct rpc_task *task,
 	case -EAGAIN:
 		rpc_restart_call_prepare(task);
 		return -EAGAIN;
+	case -NFS4ERR_FATAL_IOERROR:
+		task->tk_status = -EIO;
+		return 0;
 	}
 
 	ff_layout_set_layoutcommit(data->inode, data->lseg, data->lwb);

fs/nfs/nfs3client.c

@@ -120,6 +120,8 @@ struct nfs_client *nfs3_set_ds_client(struct nfs_server *mds_srv,
 
 	if (mds_srv->flags & NFS_MOUNT_NORESVPORT)
 		__set_bit(NFS_CS_NORESVPORT, &cl_init.init_flags);
+	if (test_bit(NFS_CS_NETUNREACH_FATAL, &mds_clp->cl_flags))
+		__set_bit(NFS_CS_NETUNREACH_FATAL, &cl_init.init_flags);
 
 	__set_bit(NFS_CS_DS, &cl_init.init_flags);
 

fs/nfs/nfs4client.c

@@ -939,6 +939,9 @@ static int nfs4_set_client(struct nfs_server *server,
 		__set_bit(NFS_CS_TSM_POSSIBLE, &cl_init.init_flags);
 	server->port = rpc_get_port((struct sockaddr *)addr);
 
+	if (server->flags & NFS_MOUNT_NETUNREACH_FATAL)
+		__set_bit(NFS_CS_NETUNREACH_FATAL, &cl_init.init_flags);
+
 	/* Allocate or find a client reference we can use */
 	clp = nfs_get_client(&cl_init);
 	if (IS_ERR(clp))
@@ -1013,6 +1016,8 @@ struct nfs_client *nfs4_set_ds_client(struct nfs_server *mds_srv,
 
 	if (mds_srv->flags & NFS_MOUNT_NORESVPORT)
 		__set_bit(NFS_CS_NORESVPORT, &cl_init.init_flags);
+	if (test_bit(NFS_CS_NETUNREACH_FATAL, &mds_clp->cl_flags))
+		__set_bit(NFS_CS_NETUNREACH_FATAL, &cl_init.init_flags);
 
 	__set_bit(NFS_CS_PNFS, &cl_init.init_flags);
 	cl_init.max_connect = NFS_MAX_TRANSPORTS;

include/linux/nfs4.h

@@ -300,6 +300,7 @@ enum nfsstat4 {
 /* error codes for internal client use */
 #define NFS4ERR_RESET_TO_MDS   12001
 #define NFS4ERR_RESET_TO_PNFS  12002
+#define NFS4ERR_FATAL_IOERROR  12003
 
 static inline bool seqid_mutating_err(u32 err)
 {