From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754902AbaD1Bby (ORCPT ); Sun, 27 Apr 2014 21:31:54 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:42873 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752538AbaD1B3V (ORCPT ); Sun, 27 Apr 2014 21:29:21 -0400 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Matthew Rahtz" , "J. Bruce Fields" Date: Mon, 28 Apr 2014 02:11:22 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.2 64/94] nfsd: notify_change needs elevated write count In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.249 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.2.58-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: "J. Bruce Fields" commit 9f67f189939eccaa54f3d2c9cf10788abaf2d584 upstream. Looks like this bug has been here since these write counts were introduced, not sure why it was just noticed now. Thanks also to Jan Kara for pointing out the problem. Reported-by: Matthew Rahtz Signed-off-by: J. Bruce Fields Signed-off-by: Ben Hutchings --- fs/nfsd/vfs.c | 9 +++++++++ 1 file changed, 9 insertions(+) --- a/fs/nfsd/vfs.c +++ b/fs/nfsd/vfs.c @@ -406,6 +406,7 @@ nfsd_setattr(struct svc_rqst *rqstp, str int ftype = 0; __be32 err; int host_err; + bool get_write_count; int size_change = 0; if (iap->ia_valid & (ATTR_ATIME | ATTR_MTIME | ATTR_SIZE)) @@ -413,10 +414,18 @@ nfsd_setattr(struct svc_rqst *rqstp, str if (iap->ia_valid & ATTR_SIZE) ftype = S_IFREG; + /* Callers that do fh_verify should do the fh_want_write: */ + get_write_count = !fhp->fh_dentry; + /* Get inode */ err = fh_verify(rqstp, fhp, ftype, accmode); if (err) goto out; + if (get_write_count) { + host_err = fh_want_write(fhp); + if (host_err) + return nfserrno(host_err); + } dentry = fhp->fh_dentry; inode = dentry->d_inode;