Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932979AbbFCMiY (ORCPT ); Wed, 3 Jun 2015 08:38:24 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:58372 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756239AbbFCMUz (ORCPT ); Wed, 3 Jun 2015 08:20:55 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Junichi Nomura , Mike Snitzer Subject: [PATCH 4.0 140/148] dm: fix reload failure of 0 path multipath mapping on blk-mq devices Date: Wed, 3 Jun 2015 21:10:10 +0900 Message-Id: <20150603114211.566774717@linuxfoundation.org> X-Mailer: git-send-email 2.4.2 In-Reply-To: <20150603114205.337615117@linuxfoundation.org> References: <20150603114205.337615117@linuxfoundation.org> User-Agent: quilt/0.64 MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3259 Lines: 96 4.0-stable review patch. If anyone has any objections, please let me know. ------------------ From: Junichi Nomura commit 15b94a690470038aa08247eedbebbe7e2218d5ee upstream. dm-multipath accepts 0 path mapping. # echo '0 2097152 multipath 0 0 0 0' | dmsetup create newdev Such a mapping can be used to release underlying devices while still holding requests in its queue until working paths come back. However, once the multipath device is created over blk-mq devices, it rejects reloading of 0 path mapping: # echo '0 2097152 multipath 0 0 1 1 queue-length 0 1 1 /dev/sda 1' \ | dmsetup create mpath1 # echo '0 2097152 multipath 0 0 0 0' | dmsetup load mpath1 device-mapper: reload ioctl on mpath1 failed: Invalid argument Command failed With following kernel message: device-mapper: ioctl: can't change device type after initial table load. DM tries to inherit the current table type using dm_table_set_type() but it doesn't work as expected because of unnecessary check about whether the target type is hybrid or not. Hybrid type is for targets that work as either request-based or bio-based and not required for blk-mq or non blk-mq checking. Fixes: 65803c205983 ("dm table: train hybrid target type detection to select blk-mq if appropriate") Signed-off-by: Jun'ichi Nomura Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman --- drivers/md/dm-table.c | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-) --- a/drivers/md/dm-table.c +++ b/drivers/md/dm-table.c @@ -823,6 +823,12 @@ void dm_consume_args(struct dm_arg_set * } EXPORT_SYMBOL(dm_consume_args); +static bool __table_type_request_based(unsigned table_type) +{ + return (table_type == DM_TYPE_REQUEST_BASED || + table_type == DM_TYPE_MQ_REQUEST_BASED); +} + static int dm_table_set_type(struct dm_table *t) { unsigned i; @@ -855,8 +861,7 @@ static int dm_table_set_type(struct dm_t * Determine the type from the live device. * Default to bio-based if device is new. */ - if (live_md_type == DM_TYPE_REQUEST_BASED || - live_md_type == DM_TYPE_MQ_REQUEST_BASED) + if (__table_type_request_based(live_md_type)) request_based = 1; else bio_based = 1; @@ -906,7 +911,7 @@ static int dm_table_set_type(struct dm_t } t->type = DM_TYPE_MQ_REQUEST_BASED; - } else if (hybrid && list_empty(devices) && live_md_type != DM_TYPE_NONE) { + } else if (list_empty(devices) && __table_type_request_based(live_md_type)) { /* inherit live MD type */ t->type = live_md_type; @@ -928,10 +933,7 @@ struct target_type *dm_table_get_immutab bool dm_table_request_based(struct dm_table *t) { - unsigned table_type = dm_table_get_type(t); - - return (table_type == DM_TYPE_REQUEST_BASED || - table_type == DM_TYPE_MQ_REQUEST_BASED); + return __table_type_request_based(dm_table_get_type(t)); } bool dm_table_mq_request_based(struct dm_table *t) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/