From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f66.google.com ([74.125.82.66]:54548 "EHLO mail-wm0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935623AbeE2OoD (ORCPT ); Tue, 29 May 2018 10:44:03 -0400 Received: by mail-wm0-f66.google.com with SMTP id f6-v6so41348724wmc.4 for ; Tue, 29 May 2018 07:44:03 -0700 (PDT) From: Miklos Szeredi To: linux-unionfs@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 18/39] ovl: add ovl_fsync() Date: Tue, 29 May 2018 16:43:18 +0200 Message-Id: <20180529144339.16538-19-mszeredi@redhat.com> In-Reply-To: <20180529144339.16538-1-mszeredi@redhat.com> References: <20180529144339.16538-1-mszeredi@redhat.com> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: Implement stacked fsync(). Don't sync if lower (noticed by Amir Goldstein). Signed-off-by: Miklos Szeredi --- fs/overlayfs/file.c | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) diff --git a/fs/overlayfs/file.c b/fs/overlayfs/file.c index a7af56861aa5..7b47dce4b072 100644 --- a/fs/overlayfs/file.c +++ b/fs/overlayfs/file.c @@ -233,10 +233,33 @@ static ssize_t ovl_write_iter(struct kiocb *iocb, struct iov_iter *iter) return ret; } +static int ovl_fsync(struct file *file, loff_t start, loff_t end, int datasync) +{ + struct fd real; + const struct cred *old_cred; + int ret; + + ret = ovl_real_fdget(file, &real); + if (ret) + return ret; + + /* Don't sync lower file for fear of receiving EROFS error */ + if (file_inode(real.file) == ovl_inode_upper(file_inode(file))) { + old_cred = ovl_override_creds(file_inode(file)->i_sb); + ret = vfs_fsync_range(real.file, start, end, datasync); + revert_creds(old_cred); + } + + fdput(real); + + return ret; +} + const struct file_operations ovl_file_operations = { .open = ovl_open, .release = ovl_release, .llseek = ovl_llseek, .read_iter = ovl_read_iter, .write_iter = ovl_write_iter, + .fsync = ovl_fsync, }; -- 2.14.3