From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:51010 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728925AbeIREnS (ORCPT ); Tue, 18 Sep 2018 00:43:18 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, John Pittman , Mike Snitzer , Sasha Levin Subject: [PATCH 4.18 129/158] dm cache: only allow a single io_mode cache feature to be requested Date: Tue, 18 Sep 2018 00:42:39 +0200 Message-Id: <20180917211717.143081266@linuxfoundation.org> In-Reply-To: <20180917211710.383360696@linuxfoundation.org> References: <20180917211710.383360696@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: 4.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: John Pittman [ Upstream commit af9313c32c0fa2a0ac3b113669273833d60cc9de ] More than one io_mode feature can be requested when creating a dm cache device (as is: last one wins). The io_mode selections are incompatible with one another, we should force them to be selected exclusively. Add a counter to check for more than one io_mode selection. Fixes: 629d0a8a1a10 ("dm cache metadata: add "metadata2" feature") Signed-off-by: John Pittman Signed-off-by: Mike Snitzer Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/md/dm-cache-target.c | 19 +++++++++++++++---- 1 file changed, 15 insertions(+), 4 deletions(-) --- a/drivers/md/dm-cache-target.c +++ b/drivers/md/dm-cache-target.c @@ -2250,7 +2250,7 @@ static int parse_features(struct cache_a {0, 2, "Invalid number of cache feature arguments"}, }; - int r; + int r, mode_ctr = 0; unsigned argc; const char *arg; struct cache_features *cf = &ca->features; @@ -2264,14 +2264,20 @@ static int parse_features(struct cache_a while (argc--) { arg = dm_shift_arg(as); - if (!strcasecmp(arg, "writeback")) + if (!strcasecmp(arg, "writeback")) { cf->io_mode = CM_IO_WRITEBACK; + mode_ctr++; + } - else if (!strcasecmp(arg, "writethrough")) + else if (!strcasecmp(arg, "writethrough")) { cf->io_mode = CM_IO_WRITETHROUGH; + mode_ctr++; + } - else if (!strcasecmp(arg, "passthrough")) + else if (!strcasecmp(arg, "passthrough")) { cf->io_mode = CM_IO_PASSTHROUGH; + mode_ctr++; + } else if (!strcasecmp(arg, "metadata2")) cf->metadata_version = 2; @@ -2282,6 +2288,11 @@ static int parse_features(struct cache_a } } + if (mode_ctr > 1) { + *error = "Duplicate cache io_mode features requested"; + return -EINVAL; + } + return 0; }