From: Trond Myklebust <trond.myklebust@hammerspace.com>
Date: Tue, 27 Aug 2019 00:41:16 +0000 (-0400)
Subject: NFSv2: Fix eof handling
X-Git-Tag: v4.9.194~19
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=bc94dcfbc58199158f71547d06dfb003fa3c1e7a;p=thirdparty%2Fkernel%2Fstable.git

NFSv2: Fix eof handling

[ Upstream commit 71affe9be45a5c60b9772e1b2701710712637274 ]

If we received a reply from the server with a zero length read and
no error, then that implies we are at eof.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

diff --git a/fs/nfs/proc.c b/fs/nfs/proc.c
index b7bca83039895..f3e8bcbd29a09 100644
--- a/fs/nfs/proc.c
+++ b/fs/nfs/proc.c
@@ -588,7 +588,8 @@ static int nfs_read_done(struct rpc_task *task, struct nfs_pgio_header *hdr)
 		/* Emulate the eof flag, which isn't normally needed in NFSv2
 		 * as it is guaranteed to always return the file attributes
 		 */
-		if (hdr->args.offset + hdr->res.count >= hdr->res.fattr->size)
+		if ((hdr->res.count == 0 && hdr->args.count > 0) ||
+		    hdr->args.offset + hdr->res.count >= hdr->res.fattr->size)
 			hdr->res.eof = 1;
 	}
 	return 0;