From patchwork Fri Mar 5 06:55:22 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jingbo Xu X-Patchwork-Id: 394498 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, UNPARSEABLE_RELAY, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4E4B8C433E6 for ; Fri, 5 Mar 2021 06:55:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1E37765018 for ; Fri, 5 Mar 2021 06:55:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229446AbhCEGza (ORCPT ); Fri, 5 Mar 2021 01:55:30 -0500 Received: from out30-131.freemail.mail.aliyun.com ([115.124.30.131]:43039 "EHLO out30-131.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229457AbhCEGza (ORCPT ); Fri, 5 Mar 2021 01:55:30 -0500 X-Alimail-AntiSpam: AC=PASS; BC=-1|-1; BR=01201311R511e4; CH=green; DM=||false|; DS=||; FP=0|-1|-1|-1|0|-1|-1|-1; HT=e01e04423; MF=jefflexu@linux.alibaba.com; NM=1; PH=DS; RN=5; SR=0; TI=SMTPD_---0UQXT1zQ_1614927327; Received: from localhost(mailfrom:jefflexu@linux.alibaba.com fp:SMTPD_---0UQXT1zQ_1614927327) by smtp.aliyun-inc.com(127.0.0.1); Fri, 05 Mar 2021 14:55:28 +0800 From: Jeffle Xu To: gregkh@linuxfoundation.org, sashal@kernel.org Cc: stable@vger.kernel.org, jefflexu@linux.alibaba.com, snitzer@redhat.com Subject: [PATCH 4.19.y 1/5] dm table: fix iterate_devices based device capability checks Date: Fri, 5 Mar 2021 14:55:22 +0800 Message-Id: <20210305065526.72663-2-jefflexu@linux.alibaba.com> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20210305065526.72663-1-jefflexu@linux.alibaba.com> References: <1614606251118245@kroah.com> <20210305065526.72663-1-jefflexu@linux.alibaba.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org commit a4c8dd9c2d0987cf542a2a0c42684c9c6d78a04e upstream. According to the definition of dm_iterate_devices_fn: * This function must iterate through each section of device used by the * target until it encounters a non-zero return code, which it then returns. * Returns zero if no callout returned non-zero. For some target type (e.g. dm-stripe), one call of iterate_devices() may iterate multiple underlying devices internally, in which case a non-zero return code returned by iterate_devices_callout_fn will stop the iteration in advance. No iterate_devices_callout_fn should return non-zero unless device iteration should stop. Rename dm_table_requires_stable_pages() to dm_table_any_dev_attr() and elevate it for reuse to stop iterating (and return non-zero) on the first device that causes iterate_devices_callout_fn to return non-zero. Use dm_table_any_dev_attr() to properly iterate through devices. Rename device_is_nonrot() to device_is_rotational() and invert logic accordingly to fix improper disposition. Fixes: c3c4555edd10 ("dm table: clear add_random unless all devices have it set") Fixes: 4693c9668fdc ("dm table: propagate non rotational flag") Cc: stable@vger.kernel.org Signed-off-by: Jeffle Xu Signed-off-by: Mike Snitzer --- drivers/md/dm-table.c | 97 +++++++++++++++++++++++-------------------- 1 file changed, 51 insertions(+), 46 deletions(-) diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c index 916433742485..686cc7c20113 100644 --- a/drivers/md/dm-table.c +++ b/drivers/md/dm-table.c @@ -1392,6 +1392,46 @@ struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector) return &t->targets[(KEYS_PER_NODE * n) + k]; } +/* + * type->iterate_devices() should be called when the sanity check needs to + * iterate and check all underlying data devices. iterate_devices() will + * iterate all underlying data devices until it encounters a non-zero return + * code, returned by whether the input iterate_devices_callout_fn, or + * iterate_devices() itself internally. + * + * For some target type (e.g. dm-stripe), one call of iterate_devices() may + * iterate multiple underlying devices internally, in which case a non-zero + * return code returned by iterate_devices_callout_fn will stop the iteration + * in advance. + * + * Cases requiring _any_ underlying device supporting some kind of attribute, + * should use the iteration structure like dm_table_any_dev_attr(), or call + * it directly. @func should handle semantics of positive examples, e.g. + * capable of something. + * + * Cases requiring _all_ underlying devices supporting some kind of attribute, + * should use the iteration structure like dm_table_supports_nowait() or + * dm_table_supports_discards(). Or introduce dm_table_all_devs_attr() that + * uses an @anti_func that handle semantics of counter examples, e.g. not + * capable of something. So: return !dm_table_any_dev_attr(t, anti_func); + */ +static bool dm_table_any_dev_attr(struct dm_table *t, + iterate_devices_callout_fn func) +{ + struct dm_target *ti; + unsigned int i; + + for (i = 0; i < dm_table_get_num_targets(t); i++) { + ti = dm_table_get_target(t, i); + + if (ti->type->iterate_devices && + ti->type->iterate_devices(ti, func, NULL)) + return true; + } + + return false; +} + static int count_device(struct dm_target *ti, struct dm_dev *dev, sector_t start, sector_t len, void *data) { @@ -1708,12 +1748,12 @@ static int dm_table_supports_dax_write_cache(struct dm_table *t) return false; } -static int device_is_nonrot(struct dm_target *ti, struct dm_dev *dev, - sector_t start, sector_t len, void *data) +static int device_is_rotational(struct dm_target *ti, struct dm_dev *dev, + sector_t start, sector_t len, void *data) { struct request_queue *q = bdev_get_queue(dev->bdev); - return q && blk_queue_nonrot(q); + return q && !blk_queue_nonrot(q); } static int device_is_not_random(struct dm_target *ti, struct dm_dev *dev, @@ -1732,23 +1772,6 @@ static int queue_supports_sg_merge(struct dm_target *ti, struct dm_dev *dev, return q && !test_bit(QUEUE_FLAG_NO_SG_MERGE, &q->queue_flags); } -static bool dm_table_all_devices_attribute(struct dm_table *t, - iterate_devices_callout_fn func) -{ - struct dm_target *ti; - unsigned i; - - for (i = 0; i < dm_table_get_num_targets(t); i++) { - ti = dm_table_get_target(t, i); - - if (!ti->type->iterate_devices || - !ti->type->iterate_devices(ti, func, NULL)) - return false; - } - - return true; -} - static int device_no_partial_completion(struct dm_target *ti, struct dm_dev *dev, sector_t start, sector_t len, void *data) { @@ -1887,27 +1910,6 @@ static int device_requires_stable_pages(struct dm_target *ti, return q && bdi_cap_stable_pages_required(q->backing_dev_info); } -/* - * If any underlying device requires stable pages, a table must require - * them as well. Only targets that support iterate_devices are considered: - * don't want error, zero, etc to require stable pages. - */ -static bool dm_table_requires_stable_pages(struct dm_table *t) -{ - struct dm_target *ti; - unsigned i; - - for (i = 0; i < dm_table_get_num_targets(t); i++) { - ti = dm_table_get_target(t, i); - - if (ti->type->iterate_devices && - ti->type->iterate_devices(ti, device_requires_stable_pages, NULL)) - return true; - } - - return false; -} - void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q, struct queue_limits *limits) { @@ -1948,10 +1950,10 @@ void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q, dax_write_cache(t->md->dax_dev, true); /* Ensure that all underlying devices are non-rotational. */ - if (dm_table_all_devices_attribute(t, device_is_nonrot)) - blk_queue_flag_set(QUEUE_FLAG_NONROT, q); - else + if (dm_table_any_dev_attr(t, device_is_rotational)) blk_queue_flag_clear(QUEUE_FLAG_NONROT, q); + else + blk_queue_flag_set(QUEUE_FLAG_NONROT, q); if (!dm_table_supports_write_same(t)) q->limits.max_write_same_sectors = 0; @@ -1968,8 +1970,11 @@ void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q, /* * Some devices don't use blk_integrity but still want stable pages * because they do their own checksumming. + * If any underlying device requires stable pages, a table must require + * them as well. Only targets that support iterate_devices are considered: + * don't want error, zero, etc to require stable pages. */ - if (dm_table_requires_stable_pages(t)) + if (dm_table_any_dev_attr(t, device_requires_stable_pages)) q->backing_dev_info->capabilities |= BDI_CAP_STABLE_WRITES; else q->backing_dev_info->capabilities &= ~BDI_CAP_STABLE_WRITES; @@ -1980,7 +1985,7 @@ void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q, * Clear QUEUE_FLAG_ADD_RANDOM if any underlying device does not * have it set. */ - if (blk_queue_add_random(q) && dm_table_all_devices_attribute(t, device_is_not_random)) + if (blk_queue_add_random(q) && dm_table_any_dev_attr(t, device_is_not_random)) blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, q); }