From: Long Li <longli@microsoft.com>
Date: Fri, 5 Apr 2019 21:36:34 +0000
Subject: [PATCH] cifs: smbd: Retry on memory registration failure
Git-commit: b7972092199f6d4eb10cc44095bbe3931116fc4b
Patch-mainline: v5.2-rc1
References: bsc#1144333

Memory registration failure doesn't mean this I/O has failed, it means the
transport is hitting I/O error or needs reconnect. This error is not from
the server.

Indicate this error to upper layer, and let upper layer decide how to
reconnect and proceed with this I/O.

Signed-off-by: Long Li <longli@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Acked-by: Paulo Alcantara <palcantara@suse.de>
---
 fs/cifs/smb2pdu.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index a37774a55f3a..36cc34318429 100644
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -3223,7 +3223,7 @@ smb2_new_read_req(void **buf, unsigned int *total_len,
 				rdata->nr_pages, rdata->page_offset,
 				rdata->tailsz, true, need_invalidate);
 		if (!rdata->mr)
-			return -ENOBUFS;
+			return -EAGAIN;
 
 		req->Channel = SMB2_CHANNEL_RDMA_V1_INVALIDATE;
 		if (need_invalidate)
@@ -3628,7 +3628,7 @@ smb2_async_writev(struct cifs_writedata *wdata,
 				wdata->nr_pages, wdata->page_offset,
 				wdata->tailsz, false, need_invalidate);
 		if (!wdata->mr) {
-			rc = -ENOBUFS;
+			rc = -EAGAIN;
 			goto async_writev_out;
 		}
 		req->Length = 0;
-- 
2.22.0