4.19-stable review patch. If anyone has any objections, please let me know.
------------------
From: J. Bruce Fields <bfie...@redhat.com>
commit fdec6114ee1f0f43b1ad081ad8d46b23ba126d70 upstream.
Zero-length writes are legal; from 5661 section 18.32.3: "If the count
is zero, the WRITE will succeed and return a count of zero subject to
permissions checking".
This check is unnecessary and is causing zero-length reads to return
EINVAL.
Cc: sta...@vger.kernel.org
Fixes: 3fd9557aec91 "NFSD: Refactor the generic write vector fill helper"
Cc: Chuck Lever <chuck.le...@oracle.com>
Signed-off-by: J. Bruce Fields <bfie...@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
fs/nfsd/nfs4proc.c | 2 --
1 file changed, 2 deletions(-)
--- a/fs/nfsd/nfs4proc.c
+++ b/fs/nfsd/nfs4proc.c
@@ -1015,8 +1015,6 @@ nfsd4_write(struct svc_rqst *rqstp, stru
nvecs = svc_fill_write_vector(rqstp, write->wr_pagelist,
&write->wr_head, write->wr_buflen);
- if (!nvecs)
- return nfserr_io;
WARN_ON_ONCE(nvecs > ARRAY_SIZE(rqstp->rq_vec));
status = nfsd_vfs_write(rqstp, &cstate->current_fh, filp,
