From: Maurizio Lombardi <mlombard@redhat.com>
Date: Mon, 22 Nov 2021 11:08:27 +0100
Subject: nvmet: use IOCB_NOWAIT only if the filesystem supports it
Patch-mainline: v5.16-rc3
Git-commit: c024b226a417c4eb9353ff500b1c823165d4d508
References: jsc#PED-1183

Submit I/O requests with the IOCB_NOWAIT flag set only if
the underlying filesystem supports it.

Fixes: 50a909db36f2 ("nvmet: use IOCB_NOWAIT for file-ns buffered I/O")
Signed-off-by: Maurizio Lombardi <mlombard@redhat.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Daniel Wagner <dwagner@suse.de>
---
 drivers/nvme/target/io-cmd-file.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

--- a/drivers/nvme/target/io-cmd-file.c
+++ b/drivers/nvme/target/io-cmd-file.c
@@ -8,6 +8,7 @@
 #include <linux/uio.h>
 #include <linux/falloc.h>
 #include <linux/file.h>
+#include <linux/fs.h>
 #include "nvmet.h"
 
 #define NVMET_MAX_MPOOL_BVEC		16
@@ -266,7 +267,8 @@ static void nvmet_file_execute_rw(struct
 
 	if (req->ns->buffered_io) {
 		if (likely(!req->f.mpool_alloc) &&
-				nvmet_file_execute_io(req, IOCB_NOWAIT))
+		    (req->ns->file->f_mode & FMODE_NOWAIT) &&
+		    nvmet_file_execute_io(req, IOCB_NOWAIT))
 			return;
 		nvmet_file_submit_buffered_io(req);
 	} else