From patchwork Wed Jun 5 02:24:44 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Damien Le Moal X-Patchwork-Id: 13686124 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8F55817C79; Wed, 5 Jun 2024 02:24:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717554289; cv=none; b=RaCqjzQa7jDHnTqMC6yD/fY1hmWQJzr/ZfgbNRi5caElezlrMN9UrZiJcrGwVhZy5fo+JujzanEImZtU2fqTLc5I8UgFlG5q3nf5gj2jUECbH0+taLpdmGAdV9K9ehT6xqMbf5keVVz1RxFpWXOW0le+1K3xd0kB0Vqk6eyAni8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717554289; c=relaxed/simple; bh=t/kzthqmGeR6g0jDb3joAL2bnxgzUJbzQ6Hht65aX2Q=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=U8Y7vncEeIsHxW0LGucG28+TybdEmelt4xC/o5SVQKLIsdv3cXwsDWou6Vx+Y8QU7LUzMOZfgvpje8Dy6QYsJzXAHg3AeroKQlHtW1a/rsOCrRzEw9NnnJP9TU0xbLTv60UQvlWGNz9KOtrrnEPBtraxsd2dez0ZlqEXMtlEMUk= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=SFeROKNt; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="SFeROKNt" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4131DC4AF08; Wed, 5 Jun 2024 02:24:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1717554289; bh=t/kzthqmGeR6g0jDb3joAL2bnxgzUJbzQ6Hht65aX2Q=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=SFeROKNtUrEytXXPUlO9Nn+8/NrPFhGBt9xoRg8ruIpxxR1QjTG5wnsK9X0w49PQk c9QqYOBygr982djyuiH/6TuKlIlrj4Qrf6aJR+yHH9zs8h1Gi4ZNCY5g9U+RteTMqX qt5Fcq0oSs8rqGB08TmZv5Eue0w35p1Ube0rTlON1q68zWxy3aDOykwMZ4cEWz22OV oy/DEDlPKXEd9bsjZ0ZkO/9Ksk77NgiERZC/BU2xtzcMWUPI3QW9PKA5ak/dsaA2xF oNPbqJRALrQJ9kMy/0cIFfwbdug0SKFIaToxUS+wDij0othC+kLgBvTiV9/VLVHA1Z s0bDyxy9OZdIg== From: Damien Le Moal To: Jens Axboe , linux-block@vger.kernel.org, dm-devel@lists.linux.dev, Mike Snitzer , Mikulas Patocka Cc: Christoph Hellwig , Benjamin Marzinski Subject: [PATCH v2 1/2] block: Imporve checks on zone resource limits Date: Wed, 5 Jun 2024 11:24:44 +0900 Message-ID: <20240605022445.105747-2-dlemoal@kernel.org> X-Mailer: git-send-email 2.45.1 In-Reply-To: <20240605022445.105747-1-dlemoal@kernel.org> References: <20240605022445.105747-1-dlemoal@kernel.org> Precedence: bulk X-Mailing-List: linux-block@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Make sure that the zone resource limits of a zoned block device are correct by checking that: (a) If the device has a max active zones limit, make sure that the max open zones limit is lower than the max active zones limit. (b) If the device has a max open zones or a max active zones limit, check that the limits are lower than the number of sequential zones of the device. For (a), a check is added to blk_validate_zoned_limits(). For (b), given that we need to number of sequential zones of the device, this check is added to disk_update_zone_resources(). This is safe to do as that function is executed with the queue frozen and the check executed after queue_limits_start_update() with the queue limits lock held. Signed-off-by: Damien Le Moal --- block/blk-settings.c | 4 ++++ block/blk-zoned.c | 5 +++++ 2 files changed, 9 insertions(+) diff --git a/block/blk-settings.c b/block/blk-settings.c index effeb9a639bb..a79c57376ef7 100644 --- a/block/blk-settings.c +++ b/block/blk-settings.c @@ -80,6 +80,10 @@ static int blk_validate_zoned_limits(struct queue_limits *lim) if (WARN_ON_ONCE(!IS_ENABLED(CONFIG_BLK_DEV_ZONED))) return -EINVAL; + if (lim->max_active_zones && + WARN_ON_ONCE(lim->max_open_zones > lim->max_active_zones)) + lim->max_open_zones = lim->max_active_zones; + if (lim->zone_write_granularity < lim->logical_block_size) lim->zone_write_granularity = lim->logical_block_size; diff --git a/block/blk-zoned.c b/block/blk-zoned.c index 52abebf56027..2af4d5ca81d2 100644 --- a/block/blk-zoned.c +++ b/block/blk-zoned.c @@ -1660,6 +1660,11 @@ static int disk_update_zone_resources(struct gendisk *disk, lim = queue_limits_start_update(q); nr_seq_zones = disk->nr_zones - nr_conv_zones; + if (WARN_ON_ONCE(lim.max_active_zones > nr_seq_zones)) + lim.max_active_zones = 0; + if (WARN_ON_ONCE(lim.max_open_zones > nr_seq_zones)) + lim.max_open_zones = 0; + pool_size = max(lim.max_open_zones, lim.max_active_zones); if (!pool_size) pool_size = min(BLK_ZONE_WPLUG_DEFAULT_POOL_SIZE, nr_seq_zones); From patchwork Wed Jun 5 02:24:45 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Damien Le Moal X-Patchwork-Id: 13686125 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7A80217C79; Wed, 5 Jun 2024 02:24:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717554290; cv=none; b=hUS3vLTlR0gIbqgMoeW1fC28fyzeXY+pC+4nq9vWAsn0enQZp0zsUaLk33wJYnw1FANAAfAUQNxMesiGoNMLr+wi+IXGp3T/F/VKvU2aVvLt5tn7LZe/BnPZSiUY54yRRMR0Z7ClNbX8PJzRy9GUrPz7Sx3UBi6nh+ktGfEWwgk= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717554290; c=relaxed/simple; bh=Au6h8SLYUmwo2Wh/rghFEA8oO6eos0QxWEtmAYLNkwE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=lwQqSq5Qe00T+opgem8lzFXkkLp4/lgT7q0vIxuNt8Wir82eVFC4vKMwKFNP8ubxJJWDqkl8mSoYYm1rYQLV0r83FWg2m+euUp/+WFupDKtFTHM1lW9w8NoeL/Y8ruzfBY/JQvf+JHSIatD51bfoGI69y+xfStYAo8ztD4etuz8= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=k3Qlbqpq; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="k3Qlbqpq" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7E0B3C4AF07; Wed, 5 Jun 2024 02:24:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1717554290; bh=Au6h8SLYUmwo2Wh/rghFEA8oO6eos0QxWEtmAYLNkwE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=k3Qlbqpq7JDjMY2OG/b36akiWfSl4qiyfQoTYQTJaFHcf9ALH0T7YadGQO6JoXOd5 rNUGevMWvk878Jyp/udbP2JY3Q9P0AMQzN/pdRPYNfp4fhzFjjMgJwcDI49jZqt3O1 L4Du1ci0B6EUQx6P3MhaF42uSL2QG7LL2LJsU0hllccpZ4F1c/JoGWqEcqK8qQHu7D sehHiOzpVAtsiNRbTIgqyi90Xl5tl4ZvbxFSVAZ4AVEh30Q1lqKywFnWjCLekg2eU1 Edxp6DCjcagnzlQ8xbB+g2pTGuLRwxZc3bQH426qIEsKAybhWR/IXm3PRl71MHTMnw JHQ2P6d5fg50A== From: Damien Le Moal To: Jens Axboe , linux-block@vger.kernel.org, dm-devel@lists.linux.dev, Mike Snitzer , Mikulas Patocka Cc: Christoph Hellwig , Benjamin Marzinski Subject: [PATCH v2 2/2] dm: Improve zone resource limits handling Date: Wed, 5 Jun 2024 11:24:45 +0900 Message-ID: <20240605022445.105747-3-dlemoal@kernel.org> X-Mailer: git-send-email 2.45.1 In-Reply-To: <20240605022445.105747-1-dlemoal@kernel.org> References: <20240605022445.105747-1-dlemoal@kernel.org> Precedence: bulk X-Mailing-List: linux-block@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 The generic stacking of limits implemented in the block layer cannot correctly handle stacking of zone resource limits (max open zones and max active zones) because these limits are for an entire device but the stacking may be for a portion of that device (e.g. a dm-linear target that does not cover an entire block device). As a result, when DM devices are created on top of zoned block devices, the DM device never has any zone resource limits advertized, which is only correct if all underlying target devices also have no zone resource limits. If at least one target device has resource limits, the user may see either performance issues (if the max open zone limit of the device is exceeded) or write I/O errors if the max active zone limit of one of the underlying target devices is exceeded. While it is very difficult to correctly and reliably stack zone resource limits in general, cases where targets are not sharing zone resources of the same device can be dealt with relatively easily. Such situation happens when a target maps all sequential zones of a zoned block device: for such mapping, other targets mapping other parts of the same zoned block device can only contain conventional zones and thus will not require any zone resource to correctly handle write operations. For a mapped device constructed with such targets, which includes mapped devices constructed with targets mapping entire zoned block devices, the zone resource limits can be reliably determined using the non-zero minimum of the zone resource limits of all targets. For mapped devices that include targets partially mapping the set of sequential write required zones of zoned block devices, instead of advertizing no zone resource limits, it is also better to set the mapped device limits to the non-zero minimum of the limits of all targets. In this case the limits for a target depend on the number of sequential zones being mapped: if this number of zone is larger than the limits, then the limits of the device apply and can be used. If on the other hand the target maps a number of zones smaller than the limits, then no limits is needed and we can assume that the target has no limits (limits set to 0). This commit improves zone resource limits handling as described above using the function dm_set_zone_resource_limits(). This function is executed from dm_set_zones_restrictions() and iterates the targets of a mapped device to evaluate the max open and max active zone limits. This relies on an internal "stacking" of the limits of the target devices combined with a direct counting of the number of sequential zones mapped by the targets. 1) For a target mapping an entire zoned block device, the limits for the target are set to the limits of the device. 2) For a target partially mapping a zoned block device, the number of mapped sequential zones is used to determine the limits: if the target maps more sequential write required zones than the device limits, then the limits of the device are used as-is. If the number of mapped sequential zones is lower than the limits, then we assume that the target has no limits (limits set to 0). target can reliably inherit the device limits. Otherwise, the target limits are set to the device limits capped by the number of mapped sequential zones. With this evaluation done for each target, the mapped device zone resource limits are evaluated as the non-zero minimum of the limits of all the targets. For configurations resulting in unreliable limits, i.e. a table containing a target partially mapping a zoned device, a warning message is issued. The counting of mapped sequential zones for the target is done using the new function dm_device_count_zones() which performs a report zones on the entire block device with the callback dm_device_count_zones_cb(). This count of mapped sequential zones is used to determine if the mapped device contains only conventional zones. This allows simplifying dm_set_zones_restrictions() to not do a report zones. For mapped devices mapping only conventional zones, dm_set_zone_resource_limits() changes the mapped device to a regular device. To further cleanup dm_set_zones_restrictions(), the message about the type of zone append (native or emulated) is moved inside dm_revalidate_zones(). Signed-off-by: Damien Le Moal --- drivers/md/dm-zone.c | 220 +++++++++++++++++++++++++++++++++++-------- 1 file changed, 183 insertions(+), 37 deletions(-) diff --git a/drivers/md/dm-zone.c b/drivers/md/dm-zone.c index 5d66d916730e..2d41b748de87 100644 --- a/drivers/md/dm-zone.c +++ b/drivers/md/dm-zone.c @@ -145,17 +145,180 @@ bool dm_is_zone_write(struct mapped_device *md, struct bio *bio) } } +struct dm_device_zone_count { + sector_t start; + sector_t len; + unsigned int total_nr_seq_zones; + unsigned int target_nr_seq_zones; +}; + /* - * Count conventional zones of a mapped zoned device. If the device - * only has conventional zones, do not expose it as zoned. + * Count the total number of and the number of mapped sequential zones of a + * target zoned device. */ -static int dm_check_zoned_cb(struct blk_zone *zone, unsigned int idx, - void *data) +static int dm_device_count_zones_cb(struct blk_zone *zone, + unsigned int idx, void *data) +{ + struct dm_device_zone_count *zc = data; + + if (zone->type != BLK_ZONE_TYPE_CONVENTIONAL) { + zc->total_nr_seq_zones++; + if (zone->start >= zc->start && + zone->start < zc->start + zc->len) + zc->target_nr_seq_zones++; + } + + return 0; +} + +static int dm_device_count_zones(struct dm_dev *dev, + struct dm_device_zone_count *zc) +{ + int ret; + + ret = blkdev_report_zones(dev->bdev, 0, UINT_MAX, + dm_device_count_zones_cb, zc); + if (ret < 0) + return ret; + if (!ret) + return -EIO; + return 0; +} + +struct dm_zone_resource_limits { + unsigned int mapped_nr_seq_zones; + unsigned int max_open_zones; + unsigned int max_active_zones; + bool reliable_limits; +}; + +static int device_get_zone_resource_limits(struct dm_target *ti, + struct dm_dev *dev, sector_t start, + sector_t len, void *data) +{ + struct dm_zone_resource_limits *zlim = data; + struct gendisk *disk = dev->bdev->bd_disk; + unsigned int max_open_zones, max_active_zones; + int ret; + struct dm_device_zone_count zc = { + .start = start, + .len = len, + }; + + /* + * If the target is not the whole device, the device zone resources may + * be shared between different targets. Check this by counting the + * number of mapped sequential zones: if this number is smaller than the + * total number of sequential zones of the target device, then resource + * sharing may happen and the zone limits will not be reliable. + */ + ret = dm_device_count_zones(dev, &zc); + if (ret) { + DMERR("Count device %s zones failed", + disk->disk_name); + return ret; + } + + zlim->mapped_nr_seq_zones += zc.target_nr_seq_zones; + + /* + * If the target does not map any sequential zones, then we do not need + * any zone resource limits. + */ + if (!zc.target_nr_seq_zones) + return 0; + + /* + * If the target does not map all sequential zones, the limits + * will not be reliable. + */ + if (zc.target_nr_seq_zones < zc.total_nr_seq_zones) + zlim->reliable_limits = false; + + /* + * If the target maps less sequential zones than the limit values, then + * we do not have limits for this target. + */ + max_active_zones = disk->queue->limits.max_active_zones; + if (max_active_zones >= zc.target_nr_seq_zones) + max_active_zones = 0; + zlim->max_active_zones = + min_not_zero(max_active_zones, zlim->max_active_zones); + + max_open_zones = disk->queue->limits.max_open_zones; + if (max_open_zones >= zc.target_nr_seq_zones) + max_open_zones = 0; + zlim->max_open_zones = + min_not_zero(max_open_zones, zlim->max_open_zones); + + /* We cannot have more open zones than active zones. */ + zlim->max_open_zones = + min(zlim->max_open_zones, zlim->max_active_zones); + + return 0; +} + +static int dm_set_zone_resource_limits(struct mapped_device *md, + struct dm_table *t, struct queue_limits *lim) { - unsigned int *nr_conv_zones = data; + struct gendisk *disk = md->disk; + struct dm_zone_resource_limits zlim = { + .max_open_zones = UINT_MAX, + .max_active_zones = UINT_MAX, + .reliable_limits = true, + }; - if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL) - (*nr_conv_zones)++; + /* Get the zone resource limits from the targets. */ + for (unsigned int i = 0; i < t->num_targets; i++) { + struct dm_target *ti = dm_table_get_target(t, i); + + if (!ti->type->iterate_devices || + ti->type->iterate_devices(ti, + device_get_zone_resource_limits, &zlim)) { + DMERR("Could not determine %s zone resource limits", + md->disk->disk_name); + return -ENODEV; + } + } + + /* + * If we only have conventional zones mapped, expose the mapped device + + as a regular device. + */ + if (!zlim.mapped_nr_seq_zones) { + lim->max_open_zones = 0; + lim->max_active_zones = 0; + lim->max_zone_append_sectors = 0; + lim->zone_write_granularity = 0; + lim->zoned = false; + clear_bit(DMF_EMULATE_ZONE_APPEND, &md->flags); + md->nr_zones = 0; + disk->nr_zones = 0; + return 0; + } + + /* + * Warn if the mapped device is partially using zone resources of the + * target devices as that leads to unreliable limits, i.e. if another + * mapped device uses the same underlying devices, we cannot enforce + * zone limits to guarantee that writing will not lead to errors. + * Note that we really should return an error for such case but there is + * no easy way to find out if another mapped device uses the same + * underlying zoned devices. + */ + if (!zlim.reliable_limits) + DMWARN("%s zone resource limits may be unreliable", + disk->disk_name); + + if (zlim.max_open_zones >= zlim.mapped_nr_seq_zones) + lim->max_open_zones = 0; + else + lim->max_open_zones = zlim.max_open_zones; + + if (zlim.max_active_zones >= zlim.mapped_nr_seq_zones) + lim->max_active_zones = 0; + else + lim->max_active_zones = zlim.max_active_zones; return 0; } @@ -172,8 +335,13 @@ static int dm_revalidate_zones(struct mapped_device *md, struct dm_table *t) int ret; /* Revalidate only if something changed. */ - if (!disk->nr_zones || disk->nr_zones != md->nr_zones) + if (!disk->nr_zones || disk->nr_zones != md->nr_zones) { + DMINFO("%s using %s zone append", + md->disk->disk_name, + queue_emulates_zone_append(disk->queue) ? + "emulated" : "native"); md->nr_zones = 0; + } if (md->nr_zones) return 0; @@ -224,8 +392,6 @@ int dm_set_zones_restrictions(struct dm_table *t, struct request_queue *q, struct queue_limits *lim) { struct mapped_device *md = t->md; - struct gendisk *disk = md->disk; - unsigned int nr_conv_zones = 0; int ret; /* @@ -244,36 +410,16 @@ int dm_set_zones_restrictions(struct dm_table *t, struct request_queue *q, return 0; /* - * Count conventional zones to check that the mapped device will indeed - * have sequential write required zones. + * Determine the max open and max active zone limits for the mapped + * device. For a mapped device containing only conventional zones, the + * mapped device is changed to be a regular block device, so exit early + * for such case. */ - md->zone_revalidate_map = t; - ret = dm_blk_report_zones(disk, 0, UINT_MAX, - dm_check_zoned_cb, &nr_conv_zones); - md->zone_revalidate_map = NULL; - if (ret < 0) { - DMERR("Check zoned failed %d", ret); + ret = dm_set_zone_resource_limits(md, t, lim); + if (ret) return ret; - } - - /* - * If we only have conventional zones, expose the mapped device as - * a regular device. - */ - if (nr_conv_zones >= ret) { - lim->max_open_zones = 0; - lim->max_active_zones = 0; - lim->zoned = false; - clear_bit(DMF_EMULATE_ZONE_APPEND, &md->flags); - disk->nr_zones = 0; + if (!lim->zoned) return 0; - } - - if (!md->disk->nr_zones) { - DMINFO("%s using %s zone append", - md->disk->disk_name, - queue_emulates_zone_append(q) ? "emulated" : "native"); - } ret = dm_revalidate_zones(md, t); if (ret < 0)