Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0E130C433F5 for ; Mon, 29 Nov 2021 18:29:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1379398AbhK2SdC (ORCPT ); Mon, 29 Nov 2021 13:33:02 -0500 Received: from ams.source.kernel.org ([145.40.68.75]:35672 "EHLO ams.source.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1379214AbhK2SbA (ORCPT ); Mon, 29 Nov 2021 13:31:00 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id D7637B815C3; Mon, 29 Nov 2021 18:27:41 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 11389C53FC7; Mon, 29 Nov 2021 18:27:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1638210460; bh=QAD3ptvlGC+BvA30Vstdp30URlCY8G9HzYf9jhFi2Nw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=JRZnqDI4/cv022b+JHhBpapilwSjNnZxFsR+3CEjEbzpHvajlTx7wJBSocyL6xASQ esmWiqqAKpO7Fu/qBWAtzef5HenqpObqXoxIXQdWRD+C5K4w5Brdiv4qxcslT+V7gz 13ek9CV4ITAEKSKec2+qG81h5o/8tLjLdhg6hbig= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Julian Sikorski , Jeremy Allison , "Paulo Alcantara (SUSE)" , Steve French , Sasha Levin Subject: [PATCH 5.4 77/92] smb3: do not error on fsync when readonly Date: Mon, 29 Nov 2021 19:18:46 +0100 Message-Id: <20211129181709.976496025@linuxfoundation.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20211129181707.392764191@linuxfoundation.org> References: <20211129181707.392764191@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Steve French [ Upstream commit 71e6864eacbef0b2645ca043cdfbac272cb6cea3 ] Linux allows doing a flush/fsync on a file open for read-only, but the protocol does not allow that. If the file passed in on the flush is read-only try to find a writeable handle for the same inode, if that is not possible skip sending the fsync call to the server to avoid breaking the apps. Reported-by: Julian Sikorski Tested-by: Julian Sikorski Suggested-by: Jeremy Allison Reviewed-by: Paulo Alcantara (SUSE) Signed-off-by: Steve French Signed-off-by: Sasha Levin --- fs/cifs/file.c | 35 +++++++++++++++++++++++++++++------ 1 file changed, 29 insertions(+), 6 deletions(-) diff --git a/fs/cifs/file.c b/fs/cifs/file.c index a9746af5a44db..03c85beecec10 100644 --- a/fs/cifs/file.c +++ b/fs/cifs/file.c @@ -2577,12 +2577,23 @@ int cifs_strict_fsync(struct file *file, loff_t start, loff_t end, tcon = tlink_tcon(smbfile->tlink); if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOSSYNC)) { server = tcon->ses->server; - if (server->ops->flush) - rc = server->ops->flush(xid, tcon, &smbfile->fid); - else + if (server->ops->flush == NULL) { rc = -ENOSYS; + goto strict_fsync_exit; + } + + if ((OPEN_FMODE(smbfile->f_flags) & FMODE_WRITE) == 0) { + smbfile = find_writable_file(CIFS_I(inode), FIND_WR_ANY); + if (smbfile) { + rc = server->ops->flush(xid, tcon, &smbfile->fid); + cifsFileInfo_put(smbfile); + } else + cifs_dbg(FYI, "ignore fsync for file not open for write\n"); + } else + rc = server->ops->flush(xid, tcon, &smbfile->fid); } +strict_fsync_exit: free_xid(xid); return rc; } @@ -2594,6 +2605,7 @@ int cifs_fsync(struct file *file, loff_t start, loff_t end, int datasync) struct cifs_tcon *tcon; struct TCP_Server_Info *server; struct cifsFileInfo *smbfile = file->private_data; + struct inode *inode = file_inode(file); struct cifs_sb_info *cifs_sb = CIFS_FILE_SB(file); rc = file_write_and_wait_range(file, start, end); @@ -2608,12 +2620,23 @@ int cifs_fsync(struct file *file, loff_t start, loff_t end, int datasync) tcon = tlink_tcon(smbfile->tlink); if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOSSYNC)) { server = tcon->ses->server; - if (server->ops->flush) - rc = server->ops->flush(xid, tcon, &smbfile->fid); - else + if (server->ops->flush == NULL) { rc = -ENOSYS; + goto fsync_exit; + } + + if ((OPEN_FMODE(smbfile->f_flags) & FMODE_WRITE) == 0) { + smbfile = find_writable_file(CIFS_I(inode), FIND_WR_ANY); + if (smbfile) { + rc = server->ops->flush(xid, tcon, &smbfile->fid); + cifsFileInfo_put(smbfile); + } else + cifs_dbg(FYI, "ignore fsync for file not open for write\n"); + } else + rc = server->ops->flush(xid, tcon, &smbfile->fid); } +fsync_exit: free_xid(xid); return rc; } -- 2.33.0