Received-SPF: pass (google.com: domain of linux-nfs-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
From:   Olga Kornievskaia <olga.kornievskaia@gmail.com>
To:     bfields@redhat.com, chuck.lever@oracle.com
Cc:     linux-nfs@vger.kernel.org
Subject: [PATCH 1/1] NFSD fix handling of NFSv4.2 SEEK for data within the last hole
Date:   Wed, 31 Mar 2021 15:28:19 -0400
Message-Id: <20210331192819.25637-1-olga.kornievskaia@gmail.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

From: Olga Kornievskaia <kolga@netapp.com>

According to the RFC 7862, "if the server cannot find a
corresponding sa_what, then the status will still be NFS4_OK,
but sr_eof would be TRUE". If there is a file that ends with
a hole and a SEEK request made for sa_what=SEEK_DATA with
an offset in the middle of the last hole, then the server
has to return OK and set the eof. Currently the linux server
returns ERR_NXIO.

Fixes: 24bab491220fa ("NFSD: Implement SEEK")
Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
---
 fs/nfsd/nfs4proc.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
index e13c4c81fb89..2e7ceb9f1d5d 100644
--- a/fs/nfsd/nfs4proc.c
+++ b/fs/nfsd/nfs4proc.c
@@ -1737,9 +1737,13 @@ nfsd4_seek(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
 	 *        should ever file->f_pos.
 	 */
 	seek->seek_pos = vfs_llseek(nf->nf_file, seek->seek_offset, whence);
-	if (seek->seek_pos < 0)
-		status = nfserrno(seek->seek_pos);
-	else if (seek->seek_pos >= i_size_read(file_inode(nf->nf_file)))
+	if (seek->seek_pos < 0) {
+		if (whence == SEEK_DATA &&
+		    seek->seek_offset < i_size_read(file_inode(nf->nf_file)))
+			seek->seek_eof = true;
+		else
+			status = nfserrno(seek->seek_pos);
+	} else if (seek->seek_pos >= i_size_read(file_inode(nf->nf_file)))
 		seek->seek_eof = true;
 
 out:
-- 
2.18.2