From patchwork Tue Nov 15 14:10:50 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yu Kuai X-Patchwork-Id: 13043740 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 9E5AAC433FE for ; Tue, 15 Nov 2022 13:49:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238450AbiKONtk (ORCPT ); Tue, 15 Nov 2022 08:49:40 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49696 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237567AbiKONth (ORCPT ); Tue, 15 Nov 2022 08:49:37 -0500 Received: from dggsgout12.his.huawei.com (unknown [45.249.212.56]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0E0A324F2A; Tue, 15 Nov 2022 05:49:34 -0800 (PST) Received: from mail02.huawei.com (unknown [172.30.67.153]) by dggsgout12.his.huawei.com (SkyGuard) with ESMTP id 4NBSGJ4LbGz4f41hr; Tue, 15 Nov 2022 21:49:28 +0800 (CST) Received: from huaweicloud.com (unknown [10.175.127.227]) by APP4 (Coremail) with SMTP id gCh0CgBni9jnmHNjrPFIAg--.61645S10; Tue, 15 Nov 2022 21:49:31 +0800 (CST) From: Yu Kuai To: hch@lst.de, axboe@kernel.dk, agk@redhat.com, snitzer@kernel.org, dm-devel@redhat.com Cc: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, yukuai3@huawei.com, yukuai1@huaweicloud.com, yi.zhang@huawei.com Subject: [PATCH v3 06/10] dm: track per-add_disk holder relations in DM Date: Tue, 15 Nov 2022 22:10:50 +0800 Message-Id: <20221115141054.1051801-7-yukuai1@huaweicloud.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20221115141054.1051801-1-yukuai1@huaweicloud.com> References: <20221115141054.1051801-1-yukuai1@huaweicloud.com> MIME-Version: 1.0 X-CM-TRANSID: gCh0CgBni9jnmHNjrPFIAg--.61645S10 X-Coremail-Antispam: 1UD129KBjvJXoWxAw1fWrW5Kw4fKr4fJryxXwb_yoWrJFyUpF ZxWayaqrWrGFsFvw47Xw4Uury5trs5ta4rZry7Gw1I9w15Ar909FW8GFy3XFyDJ397KFy5 XFWUtr4rua18KrJanT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUPF14x267AKxVWrJVCq3wAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2048vs2IY020E87I2jVAFwI0_JF0E3s1l82xGYI kIc2x26xkF7I0E14v26ryj6s0DM28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48ve4kI8wA2 z4x0Y4vE2Ix0cI8IcVAFwI0_tr0E3s1l84ACjcxK6xIIjxv20xvEc7CjxVAFwI0_Gr1j6F 4UJwA2z4x0Y4vEx4A2jsIE14v26rxl6s0DM28EF7xvwVC2z280aVCY1x0267AKxVW0oVCq 3wAS0I0E0xvYzxvE52x082IY62kv0487Mc02F40EFcxC0VAKzVAqx4xG6I80ewAv7VC0I7 IYx2IY67AKxVWUJVWUGwAv7VC2z280aVAFwI0_Jr0_Gr1lOx8S6xCaFVCjc4AY6r1j6r4U M4x0Y48IcxkI7VAKI48JM4x0x7Aq67IIx4CEVc8vx2IErcIFxwACI402YVCY1x02628vn2 kIc2xKxwCF04k20xvY0x0EwIxGrwCFx2IqxVCFs4IE7xkEbVWUJVW8JwC20s026c02F40E 14v26r1j6r18MI8I3I0E7480Y4vE14v26r106r1rMI8E67AF67kF1VAFwI0_Jw0_GFylIx kGc2Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVWUCVW8JwCI42IY6xIIjxv20xvEc7CjxVAF wI0_Cr0_Gr1UMIIF0xvE42xK8VAvwI8IcIk0rVWUJVWUCwCI42IY6I8E87Iv67AKxVWUJV W8JwCI42IY6I8E87Iv6xkF7I0E14v26r4j6r4UJbIYCTnIWIevJa73UjIFyTuYvjfUOBTY UUUUU X-CM-SenderInfo: 51xn3trlr6x35dzhxuhorxvhhfrp/ X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org From: Christoph Hellwig dm is a bit special in that it opens the underlying devices. Commit 89f871af1b26 ("dm: delay registering the gendisk") tried to accommodate that by allowing to add the holder to the list before add_gendisk and then just add them to sysfs once add_disk is called. But that leads to really odd lifetime problems and error handling problems as we can't know the state of the kobjects and don't unwind properly. To fix this switch to just registering all existing table_devices with the holder code right after add_disk, and remove them before calling del_gendisk. Fixes: 89f871af1b26 ("dm: delay registering the gendisk") Reported-by: Yu Kuai Signed-off-by: Christoph Hellwig Signed-off-by: Yu Kuai Reviewed-by: Mike Snitzer --- drivers/md/dm.c | 49 +++++++++++++++++++++++++++++++++++++++---------- 1 file changed, 39 insertions(+), 10 deletions(-) diff --git a/drivers/md/dm.c b/drivers/md/dm.c index 3728b56b364b..e1ea3a7bd9d9 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -751,9 +751,16 @@ static struct table_device *open_table_device(struct mapped_device *md, goto out_free_td; } - r = bd_link_disk_holder(bdev, dm_disk(md)); - if (r) - goto out_blkdev_put; + /* + * We can be called before the dm disk is added. In that case we can't + * register the holder relation here. It will be done once add_disk was + * called. + */ + if (md->disk->slave_dir) { + r = bd_link_disk_holder(bdev, md->disk); + if (r) + goto out_blkdev_put; + } td->dm_dev.mode = mode; td->dm_dev.bdev = bdev; @@ -774,7 +781,8 @@ static struct table_device *open_table_device(struct mapped_device *md, */ static void close_table_device(struct table_device *td, struct mapped_device *md) { - bd_unlink_disk_holder(td->dm_dev.bdev, dm_disk(md)); + if (md->disk->slave_dir) + bd_unlink_disk_holder(td->dm_dev.bdev, md->disk); blkdev_put(td->dm_dev.bdev, td->dm_dev.mode | FMODE_EXCL); put_dax(td->dm_dev.dax_dev); list_del(&td->list); @@ -1951,7 +1959,13 @@ static void cleanup_mapped_device(struct mapped_device *md) md->disk->private_data = NULL; spin_unlock(&_minor_lock); if (dm_get_md_type(md) != DM_TYPE_NONE) { + struct table_device *td; + dm_sysfs_exit(md); + list_for_each_entry(td, &md->table_devices, list) { + bd_unlink_disk_holder(td->dm_dev.bdev, + md->disk); + } /* * Hold lock to make sure del_gendisk() won't concurrent @@ -2291,6 +2305,7 @@ int dm_setup_md_queue(struct mapped_device *md, struct dm_table *t) { enum dm_queue_mode type = dm_table_get_type(t); struct queue_limits limits; + struct table_device *td; int r; switch (type) { @@ -2329,16 +2344,30 @@ int dm_setup_md_queue(struct mapped_device *md, struct dm_table *t) if (r) return r; - r = dm_sysfs_init(md); - if (r) { - mutex_lock(&md->table_devices_lock); - del_gendisk(md->disk); - mutex_unlock(&md->table_devices_lock); - return r; + /* + * Register the holder relationship for devices added before the disk + * was live. + */ + list_for_each_entry(td, &md->table_devices, list) { + r = bd_link_disk_holder(td->dm_dev.bdev, md->disk); + if (r) + goto out_undo_holders; } + r = dm_sysfs_init(md); + if (r) + goto out_undo_holders; + md->type = type; return 0; + +out_undo_holders: + list_for_each_entry_continue_reverse(td, &md->table_devices, list) + bd_unlink_disk_holder(td->dm_dev.bdev, md->disk); + mutex_lock(&md->table_devices_lock); + del_gendisk(md->disk); + mutex_unlock(&md->table_devices_lock); + return r; } struct mapped_device *dm_get_md(dev_t dev)