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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 4.14 55/57] NFS: Ensure O_DIRECT reports an error if the bytes read/written is 0
Date:   Wed,  4 Sep 2019 19:54:23 +0200
Message-Id: <20190904175307.283207287@linuxfoundation.org>
In-Reply-To: <20190904175301.777414715@linuxfoundation.org>
References: <20190904175301.777414715@linuxfoundation.org>
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[ Upstream commit eb2c50da9e256dbbb3ff27694440e4c1900cfef8 ]

If the attempt to resend the I/O results in no bytes being read/written,
we must ensure that we report the error.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Fixes: 0a00b77b331a ("nfs: mirroring support for direct io")
Cc: stable@vger.kernel.org # v3.20+
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/nfs/direct.c   | 27 ++++++++++++++++++---------
 fs/nfs/pagelist.c |  1 +
 2 files changed, 19 insertions(+), 9 deletions(-)

diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c
index 2256ea4394d3a..614ce1f8b4ac5 100644
--- a/fs/nfs/direct.c
+++ b/fs/nfs/direct.c
@@ -400,15 +400,21 @@ static void nfs_direct_read_completion(struct nfs_pgio_header *hdr)
 	unsigned long bytes = 0;
 	struct nfs_direct_req *dreq = hdr->dreq;
 
-	if (test_bit(NFS_IOHDR_REDO, &hdr->flags))
-		goto out_put;
-
 	spin_lock(&dreq->lock);
-	if (test_bit(NFS_IOHDR_ERROR, &hdr->flags) && (hdr->good_bytes == 0))
+	if (test_bit(NFS_IOHDR_ERROR, &hdr->flags))
 		dreq->error = hdr->error;
-	else
+
+	if (test_bit(NFS_IOHDR_REDO, &hdr->flags)) {
+		spin_unlock(&dreq->lock);
+		goto out_put;
+	}
+
+	if (hdr->good_bytes != 0)
 		nfs_direct_good_bytes(dreq, hdr);
 
+	if (test_bit(NFS_IOHDR_EOF, &hdr->flags))
+		dreq->error = 0;
+
 	spin_unlock(&dreq->lock);
 
 	while (!list_empty(&hdr->pages)) {
@@ -774,16 +780,19 @@ static void nfs_direct_write_completion(struct nfs_pgio_header *hdr)
 	bool request_commit = false;
 	struct nfs_page *req = nfs_list_entry(hdr->pages.next);
 
-	if (test_bit(NFS_IOHDR_REDO, &hdr->flags))
-		goto out_put;
-
 	nfs_init_cinfo_from_dreq(&cinfo, dreq);
 
 	spin_lock(&dreq->lock);
 
 	if (test_bit(NFS_IOHDR_ERROR, &hdr->flags))
 		dreq->error = hdr->error;
-	if (dreq->error == 0) {
+
+	if (test_bit(NFS_IOHDR_REDO, &hdr->flags)) {
+		spin_unlock(&dreq->lock);
+		goto out_put;
+	}
+
+	if (hdr->good_bytes != 0) {
 		nfs_direct_good_bytes(dreq, hdr);
 		if (nfs_write_need_commit(hdr)) {
 			if (dreq->flags == NFS_ODIRECT_RESCHED_WRITES)
diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c
index 16d7f9068c7ae..132e568524dff 100644
--- a/fs/nfs/pagelist.c
+++ b/fs/nfs/pagelist.c
@@ -1247,6 +1247,7 @@ int nfs_pageio_resend(struct nfs_pageio_descriptor *desc,
 	if (!list_empty(&pages)) {
 		int err = desc->pg_error < 0 ? desc->pg_error : -EIO;
 		hdr->completion_ops->error_cleanup(&pages, err);
+		nfs_set_pgio_error(hdr, err, hdr->io_start);
 		return err;
 	}
 	return 0;
-- 
2.20.1