NFSv4/flexfiles: Fix handling of NFS level errors in I/O

Allow the flexfiles error handling to recognise NFS level errors (as
opposed to RPC level errors) and handle them separately. The main
motivator is the NFSERR_PERM errors that get returned if the NFS client
connects to the data server through a port number that is lower than
1024. In that case, the client should disconnect and retry a READ on a
different data server, or it should retry a WRITE after reconnecting.

Reviewed-by: Tigran Mkrtchyan <[email protected]>
Fixes: d67ae82 ("pnfs/flexfiles: Add the FlexFile Layout Driver")
Signed-off-by: Trond Myklebust <[email protected]>
Signed-off-by: Anna Schumaker <[email protected]>

Author: Trond Myklebust

fs/nfs/flexfilelayout/flexfilelayout.c

@@ -1105,6 +1105,7 @@ static void ff_layout_reset_read(struct nfs_pgio_header *hdr)
 }
 
 static int ff_layout_async_handle_error_v4(struct rpc_task *task,
+					   u32 op_status,
 					   struct nfs4_state *state,
 					   struct nfs_client *clp,
 					   struct pnfs_layout_segment *lseg,
@@ -1115,34 +1116,42 @@ static int ff_layout_async_handle_error_v4(struct rpc_task *task,
 	struct nfs4_deviceid_node *devid = FF_LAYOUT_DEVID_NODE(lseg, idx);
 	struct nfs4_slot_table *tbl = &clp->cl_session->fc_slot_table;
 
-	switch (task->tk_status) {
-	case -NFS4ERR_BADSESSION:
-	case -NFS4ERR_BADSLOT:
-	case -NFS4ERR_BAD_HIGH_SLOT:
-	case -NFS4ERR_DEADSESSION:
-	case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
-	case -NFS4ERR_SEQ_FALSE_RETRY:
-	case -NFS4ERR_SEQ_MISORDERED:
+	switch (op_status) {
+	case NFS4_OK:
+	case NFS4ERR_NXIO:
+		break;
+	case NFSERR_PERM:
+		if (!task->tk_xprt)
+			break;
+		xprt_force_disconnect(task->tk_xprt);
+		goto out_retry;
+	case NFS4ERR_BADSESSION:
+	case NFS4ERR_BADSLOT:
+	case NFS4ERR_BAD_HIGH_SLOT:
+	case NFS4ERR_DEADSESSION:
+	case NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
+	case NFS4ERR_SEQ_FALSE_RETRY:
+	case NFS4ERR_SEQ_MISORDERED:
 		dprintk("%s ERROR %d, Reset session. Exchangeid "
 			"flags 0x%x\n", __func__, task->tk_status,
 			clp->cl_exchange_flags);
 		nfs4_schedule_session_recovery(clp->cl_session, task->tk_status);
-		break;
-	case -NFS4ERR_DELAY:
+		goto out_retry;
+	case NFS4ERR_DELAY:
 		nfs_inc_stats(lseg->pls_layout->plh_inode, NFSIOS_DELAY);
 		fallthrough;
-	case -NFS4ERR_GRACE:
+	case NFS4ERR_GRACE:
 		rpc_delay(task, FF_LAYOUT_POLL_RETRY_MAX);
-		break;
-	case -NFS4ERR_RETRY_UNCACHED_REP:
-		break;
+		goto out_retry;
+	case NFS4ERR_RETRY_UNCACHED_REP:
+		goto out_retry;
 	/* Invalidate Layout errors */
-	case -NFS4ERR_PNFS_NO_LAYOUT:
-	case -ESTALE:           /* mapped NFS4ERR_STALE */
-	case -EBADHANDLE:       /* mapped NFS4ERR_BADHANDLE */
-	case -EISDIR:           /* mapped NFS4ERR_ISDIR */
-	case -NFS4ERR_FHEXPIRED:
-	case -NFS4ERR_WRONG_TYPE:
+	case NFS4ERR_PNFS_NO_LAYOUT:
+	case NFS4ERR_STALE:
+	case NFS4ERR_BADHANDLE:
+	case NFS4ERR_ISDIR:
+	case NFS4ERR_FHEXPIRED:
+	case NFS4ERR_WRONG_TYPE:
 		dprintk("%s Invalid layout error %d\n", __func__,
 			task->tk_status);
 		/*
@@ -1155,6 +1164,11 @@ static int ff_layout_async_handle_error_v4(struct rpc_task *task,
 		pnfs_destroy_layout(NFS_I(inode));
 		rpc_wake_up(&tbl->slot_tbl_waitq);
 		goto reset;
+	default:
+		break;
+	}
+
+	switch (task->tk_status) {
 	/* RPC connection errors */
 	case -ENETDOWN:
 	case -ENETUNREACH:
@@ -1174,27 +1188,56 @@ static int ff_layout_async_handle_error_v4(struct rpc_task *task,
 		nfs4_delete_deviceid(devid->ld, devid->nfs_client,
 				&devid->deviceid);
 		rpc_wake_up(&tbl->slot_tbl_waitq);
-		fallthrough;
+		break;
 	default:
-		if (ff_layout_avoid_mds_available_ds(lseg))
-			return -NFS4ERR_RESET_TO_PNFS;
-reset:
-		dprintk("%s Retry through MDS. Error %d\n", __func__,
-			task->tk_status);
-		return -NFS4ERR_RESET_TO_MDS;
+		break;
 	}
+
+	if (ff_layout_avoid_mds_available_ds(lseg))
+		return -NFS4ERR_RESET_TO_PNFS;
+reset:
+	dprintk("%s Retry through MDS. Error %d\n", __func__,
+		task->tk_status);
+	return -NFS4ERR_RESET_TO_MDS;
+
+out_retry:
 	task->tk_status = 0;
 	return -EAGAIN;
 }
 
 /* Retry all errors through either pNFS or MDS except for -EJUKEBOX */
 static int ff_layout_async_handle_error_v3(struct rpc_task *task,
+					   u32 op_status,
 					   struct nfs_client *clp,
 					   struct pnfs_layout_segment *lseg,
 					   u32 idx)
 {
 	struct nfs4_deviceid_node *devid = FF_LAYOUT_DEVID_NODE(lseg, idx);
 
+	switch (op_status) {
+	case NFS_OK:
+	case NFSERR_NXIO:
+		break;
+	case NFSERR_PERM:
+		if (!task->tk_xprt)
+			break;
+		xprt_force_disconnect(task->tk_xprt);
+		goto out_retry;
+	case NFSERR_ACCES:
+	case NFSERR_BADHANDLE:
+	case NFSERR_FBIG:
+	case NFSERR_IO:
+	case NFSERR_NOSPC:
+	case NFSERR_ROFS:
+	case NFSERR_STALE:
+		goto out_reset_to_pnfs;
+	case NFSERR_JUKEBOX:
+		nfs_inc_stats(lseg->pls_layout->plh_inode, NFSIOS_DELAY);
+		goto out_retry;
+	default:
+		break;
+	}
+
 	switch (task->tk_status) {
 	/* File access problems. Don't mark the device as unavailable */
 	case -EACCES:
@@ -1218,6 +1261,7 @@ static int ff_layout_async_handle_error_v3(struct rpc_task *task,
 		nfs4_delete_deviceid(devid->ld, devid->nfs_client,
 				&devid->deviceid);
 	}
+out_reset_to_pnfs:
 	/* FIXME: Need to prevent infinite looping here. */
 	return -NFS4ERR_RESET_TO_PNFS;
 out_retry:
@@ -1228,6 +1272,7 @@ static int ff_layout_async_handle_error_v3(struct rpc_task *task,
 }
 
 static int ff_layout_async_handle_error(struct rpc_task *task,
+					u32 op_status,
 					struct nfs4_state *state,
 					struct nfs_client *clp,
 					struct pnfs_layout_segment *lseg,
@@ -1246,10 +1291,11 @@ static int ff_layout_async_handle_error(struct rpc_task *task,
 
 	switch (vers) {
 	case 3:
-		return ff_layout_async_handle_error_v3(task, clp, lseg, idx);
-	case 4:
-		return ff_layout_async_handle_error_v4(task, state, clp,
+		return ff_layout_async_handle_error_v3(task, op_status, clp,
 						       lseg, idx);
+	case 4:
+		return ff_layout_async_handle_error_v4(task, op_status, state,
+						       clp, lseg, idx);
 	default:
 		/* should never happen */
 		WARN_ON_ONCE(1);
@@ -1302,6 +1348,7 @@ static void ff_layout_io_track_ds_error(struct pnfs_layout_segment *lseg,
 	switch (status) {
 	case NFS4ERR_DELAY:
 	case NFS4ERR_GRACE:
+	case NFS4ERR_PERM:
 		break;
 	case NFS4ERR_NXIO:
 		ff_layout_mark_ds_unreachable(lseg, idx);
@@ -1334,7 +1381,8 @@ static int ff_layout_read_done_cb(struct rpc_task *task,
 		trace_ff_layout_read_error(hdr, task->tk_status);
 	}
 
-	err = ff_layout_async_handle_error(task, hdr->args.context->state,
+	err = ff_layout_async_handle_error(task, hdr->res.op_status,
+					   hdr->args.context->state,
 					   hdr->ds_clp, hdr->lseg,
 					   hdr->pgio_mirror_idx);
 
@@ -1507,7 +1555,8 @@ static int ff_layout_write_done_cb(struct rpc_task *task,
 		trace_ff_layout_write_error(hdr, task->tk_status);
 	}
 
-	err = ff_layout_async_handle_error(task, hdr->args.context->state,
+	err = ff_layout_async_handle_error(task, hdr->res.op_status,
+					   hdr->args.context->state,
 					   hdr->ds_clp, hdr->lseg,
 					   hdr->pgio_mirror_idx);
 
@@ -1556,8 +1605,9 @@ static int ff_layout_commit_done_cb(struct rpc_task *task,
 		trace_ff_layout_commit_error(data, task->tk_status);
 	}
 
-	err = ff_layout_async_handle_error(task, NULL, data->ds_clp,
-					   data->lseg, data->ds_commit_index);
+	err = ff_layout_async_handle_error(task, data->res.op_status,
+					   NULL, data->ds_clp, data->lseg,
+					   data->ds_commit_index);
 
 	trace_nfs4_pnfs_commit_ds(data, err);
 	switch (err) {