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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org,
        Trond Myklebust <trond.myklebust@hammerspace.com>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 4.19 49/79] NFSv2: Fix eof handling
Date:   Fri, 20 Sep 2019 00:03:34 +0200
Message-Id: <20190919214811.846472108@linuxfoundation.org>
In-Reply-To: <20190919214807.612593061@linuxfoundation.org>
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From: Trond Myklebust <trond.myklebust@hammerspace.com>

[ 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>
---
 fs/nfs/proc.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/fs/nfs/proc.c b/fs/nfs/proc.c
index e0c257bd62b93..89fa9c706b380 100644
--- a/fs/nfs/proc.c
+++ b/fs/nfs/proc.c
@@ -594,7 +594,8 @@ 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;
-- 
2.20.1