From nobody Sun Oct 5 20:02:14 2025 Received: from szxga03-in.huawei.com (szxga03-in.huawei.com [45.249.212.189]) (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 E8E0223741 for ; Wed, 30 Jul 2025 12:00:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.189 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753876817; cv=none; b=owyEMfXIRjhs5ponOyEQRtv1hAi5VN7FbMKlwhS7Bmw4m66f1HKZXRJZwdkG6eQcIGg/+jUuKAbijJFHmzI11k5YZ28rsqNXueBasBEo3m/0cltL7k3zVmkeTX98gZ63Ch/cmXGHQ57aPyl0eiu/nNh0dQ3uqrHHmKmCQZ2JrSo= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753876817; c=relaxed/simple; bh=sFe+JwfoweY/fIHJ74hP1zgxoV4WX/SZ1BjpMgvuuKM=; h=Message-ID:Date:MIME-Version:To:CC:From:Subject:Content-Type; b=WYejPj58rPf6+Ql0ikHeLRxmmDqc/5n2ttFu+BG86EpSU8Y8cvQjI5ySZDtLgE4AS7An71XBDKK3R/8qmmImTyGPZfYmRsqSTJJSob9kOzC/9qFdrGpifBC8LcqiYGV6Lo41s2py1XLllRJfPXkW2ArWYO/E82FTbp54M9lJRGg= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huawei.com; arc=none smtp.client-ip=45.249.212.189 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Received: from mail.maildlp.com (unknown [172.19.163.252]) by szxga03-in.huawei.com (SkyGuard) with ESMTP id 4bsVzK4LRxzdc6d; Wed, 30 Jul 2025 19:55:57 +0800 (CST) Received: from kwepemg500017.china.huawei.com (unknown [7.202.181.81]) by mail.maildlp.com (Postfix) with ESMTPS id 2F4EE180B52; Wed, 30 Jul 2025 20:00:11 +0800 (CST) Received: from [10.174.179.155] (10.174.179.155) by kwepemg500017.china.huawei.com (7.202.181.81) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.11; Wed, 30 Jul 2025 20:00:10 +0800 Message-ID: <83591d0b-2467-433c-bce0-5581298eb161@huawei.com> Date: Wed, 30 Jul 2025 20:00:09 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: =?UTF-8?B?TW96aWxsYSBUaHVuZGVyYmlyZCDmtYvor5XniYg=?= To: , Mike Snitzer , Mikulas Patocka , , "linux-kernel@vger.kernel.org" CC: , yangerkun , "zhangyi (F)" , Hou Tao , "yukuai (C)" , "chengzhihao1@huawei.com" , Li Lingfeng From: Li Lingfeng Subject: [bug report] dm: 'tried to init an initialized object' error triggered during device creation Content-Type: text/plain; charset="utf-8"; format="flowed" Content-Transfer-Encoding: quoted-printable X-ClientProxiedBy: kwepems500002.china.huawei.com (7.221.188.17) To kwepemg500017.china.huawei.com (7.202.181.81) Hi all, Recently, when creating dm-mpath devices based on iSCSI devices, we encountered a 'tried to init an initialized object' error triggered by one DM_DEV_CREATE and two DM_TABLE_LOAD operations. // DM_DEV_CREATE dev_create =C2=A0dm_create =C2=A0 alloc_dev =C2=A0 =C2=A0blk_alloc_disk // alloc gendisk for md->disk // first DM_TABLE_LOAD table_load =C2=A0dm_get_md_type // md->type is DM_TYPE_NONE =C2=A0dm_setup_md_queue =C2=A0 dm_mq_init_request_queue =C2=A0 =C2=A0add_disk // add md->disk =C2=A0 =C2=A0 device_add_disk =C2=A0 =C2=A0 =C2=A0add_disk_fwnode =C2=A0 =C2=A0 =C2=A0 __add_disk =C2=A0 =C2=A0 =C2=A0 =C2=A0blk_register_queue =C2=A0 =C2=A0 =C2=A0 =C2=A0 kobject_init =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0kobject_init_internal =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 // set kobj->state_initialized =C2=A0bd_link_disk_holder =C2=A0 // return -ENODEV since iscsi device has been logged out =C2=A0// skip setting md->type and leave it as DM_TYPE_NONE // second DM_TABLE_LOAD table_load =C2=A0dm_get_md_type // md->type is DM_TYPE_NONE =C2=A0dm_setup_md_queue =C2=A0 dm_mq_init_request_queue =C2=A0 =C2=A0add_disk // add md->disk =C2=A0 =C2=A0 device_add_disk =C2=A0 =C2=A0 =C2=A0add_disk_fwnode =C2=A0 =C2=A0 =C2=A0 __add_disk =C2=A0 =C2=A0 =C2=A0 =C2=A0blk_register_queue =C2=A0 =C2=A0 =C2=A0 =C2=A0 kobject_init =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0// dump_stack since kobj->state_initiali= zed has been set Resetting state_initialized after the first failed DM_TABLE_LOAD might resolve this issue, but it seems weird =E2=80=94 I think state_initialized = is designed to =E2=80=8Bnever be reset during the object lifecycle. Any suggestions would be appreciated. Thanks, Lingfeng *Reproduction steps are as follows:* Base: master=C2=A0 =C2=A04b290aae788e Diff: diff --git a/drivers/md/dm.c b/drivers/md/dm.c index abfe0392b5a4..b41f5a6f3e72 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -2598,6 +2598,9 @@ int dm_setup_md_queue(struct mapped_device *md,=20 struct dm_table *t) =C2=A0 =C2=A0 =C2=A0 =C2=A0 if (r) =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 return r; +=C2=A0 =C2=A0 =C2=A0 =C2=A0printk("%s sleep before link disk holder\n", __= func__); +=C2=A0 =C2=A0 =C2=A0 =C2=A0msleep(10 * 1000); +=C2=A0 =C2=A0 =C2=A0 =C2=A0printk("%s sleep done\n", __func__); =C2=A0 =C2=A0 =C2=A0 =C2=A0 /* =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0* Register the holder relationship for d= evices added before=20 the disk =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0* was live. Procedures: [root@nfs_test3 test]# lsblk NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT sda=C2=A0 =C2=A0 8:0=C2=A0 =C2=A0 0=C2=A0 10G=C2=A0 0 disk sdb=C2=A0 =C2=A0 8:16=C2=A0 =C2=A00=C2=A0 10G=C2=A0 0 disk sdc=C2=A0 =C2=A0 8:32=C2=A0 =C2=A00=C2=A0 30G=C2=A0 0 disk vda=C2=A0 253:0=C2=A0 =C2=A0 0=C2=A0 20G=C2=A0 0 disk / [root@nfs_test3 test]# ifconfig lo:0 127.0.0.2 up [root@nfs_test3 test]# ifconfig lo:1 127.0.0.3 up [root@nfs_test3 test]# service tgtd restart Redirecting to /bin/systemctl restart tgtd.service [root@nfs_test3 test]# service iscsid restart Redirecting to /bin/systemctl restart iscsid.service [root@nfs_test3 test]# iscsiadm -m discovery -p 127.0.0.2 -t st 127.0.0.2:3260,1 iqn.2019-04.jenkins.disk [root@nfs_test3 test]# iscsiadm -m discovery -p 127.0.0.3 -t st 127.0.0.3:3260,1 iqn.2019-04.jenkins.disk [root@nfs_test3 test]# iscsiadm -m node -l Logging in to [iface: default, target: iqn.2020-05.com.bdqn:disk1,=20 portal: 192.168.240.250,3260] (multiple) Logging in to [iface: default, target: iqn.2019-04.jenkins.disk, portal:=20 127.0.0.2,3260] (multiple) Logging in to [iface: default, target: iqn.2019-04.jenkins.disk, portal:=20 127.0.0.3,3260] (multiple) Logging in to [iface: default, target: , portal: ,3260] (multiple) [=C2=A0 275.687170][=C2=A0 =C2=A0C10] sd 3:0:0:1: Power-on or device reset = occurred [=C2=A0 275.708911][=C2=A0 =C2=A0C10] sd 4:0:0:1: Power-on or device reset = occurred iscsiadm: caught SIGINT, exiting... [root@nfs_test3 test]# lsblk NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT sda=C2=A0 =C2=A0 8:0=C2=A0 =C2=A0 0=C2=A0 10G=C2=A0 0 disk sdb=C2=A0 =C2=A0 8:16=C2=A0 =C2=A00=C2=A0 10G=C2=A0 0 disk sdc=C2=A0 =C2=A0 8:32=C2=A0 =C2=A00=C2=A0 30G=C2=A0 0 disk sdd=C2=A0 =C2=A0 8:48=C2=A0 =C2=A00=C2=A0 10G=C2=A0 0 disk sde=C2=A0 =C2=A0 8:64=C2=A0 =C2=A00=C2=A0 10G=C2=A0 0 disk vda=C2=A0 253:0=C2=A0 =C2=A0 0=C2=A0 20G=C2=A0 0 disk / [root@nfs_test3 test]# ./dmtest & [1] 2742 [root@nfs_test3 test]# DM_VERSION 4 50 0 [=C2=A0 294.101770][ T2742] dm_setup_md_queue sleep before link disk holder [root@nfs_test3 test]# [root@nfs_test3 test]# iscsiadm -m node -u Logging out of session [sid: 1, target: iqn.2019-04.jenkins.disk,=20 portal: 127.0.0.2,3260] Logging out of session [sid: 2, target: iqn.2019-04.jenkins.disk,=20 portal: 127.0.0.3,3260] Logout of [sid: 1, target: iqn.2019-04.jenkins.disk, portal:=20 127.0.0.2,3260] successful. Logout of [sid: 2, target: iqn.2019-04.jenkins.disk, portal:=20 127.0.0.3,3260] successful. [root@nfs_test3 test]# [root@nfs_test3 test]# [root@nfs_test3 test]# [=C2=A0 304.185384][ T2742] dm_setup_md_queue sleep = done [=C2=A0 304.280823][ T2742] device-mapper: ioctl: unable to set up device=20 queue for new table. delay before second table_load... [root@nfs_test3 test]# [root@nfs_test3 test]# iscsiadm -m node -l Logging in to [iface: default, target: iqn.2020-05.com.bdqn:disk1,=20 portal: 192.168.240.250,3260] (multiple) Logging in to [iface: default, target: iqn.2019-04.jenkins.disk, portal:=20 127.0.0.2,3260] (multiple) Logging in to [iface: default, target: iqn.2019-04.jenkins.disk, portal:=20 127.0.0.3,3260] (multiple) iscsiadm: could not read session targetname: 5 iscsiadm: could not find session info for session3 Logging in to [iface: default, target: , portal: ,3260] (multiple) [=C2=A0 307.357847][=C2=A0 =C2=A0C10] sd 3:0:0:1: Power-on or device reset = occurred [=C2=A0 307.372301][=C2=A0 =C2=A0C10] sd 4:0:0:1: Power-on or device reset = occurred iscsiadm: caught SIGINT, exiting... [root@nfs_test3 test]# [root@nfs_test3 test]# [root@nfs_test3 test]# lsblk NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT sda=C2=A0 =C2=A0 8:0=C2=A0 =C2=A0 0=C2=A0 10G=C2=A0 0 disk sdb=C2=A0 =C2=A0 8:16=C2=A0 =C2=A00=C2=A0 10G=C2=A0 0 disk sdc=C2=A0 =C2=A0 8:32=C2=A0 =C2=A00=C2=A0 30G=C2=A0 0 disk sdd=C2=A0 =C2=A0 8:48=C2=A0 =C2=A00=C2=A0 10G=C2=A0 0 disk sde=C2=A0 =C2=A0 8:64=C2=A0 =C2=A00=C2=A0 10G=C2=A0 0 disk vda=C2=A0 253:0=C2=A0 =C2=A0 0=C2=A0 20G=C2=A0 0 disk / [root@nfs_test3 test]# delay done [=C2=A0 314.938868][ T2742] kobject: kobject (ffff88810c27bb90): tried to=20 init an initialized object, something is seriously wrong. [=C2=A0 314.940322][ T2742] CPU: 6 UID: 0 PID: 2742 Comm: dmtest Not tainte= d=20 6.16.0-04405-g4b290aae788e-dirty #21 PREEMPT(none) [=C2=A0 314.940331][ T2742] Hardware name: QEMU Standard PC (i440FX + PIIX,=20 1996), BIOS 1.16.3-2.fc40 04/01/2014 [=C2=A0 314.940335][ T2742] Call Trace: [=C2=A0 314.940339][ T2742]=C2=A0 [=C2=A0 314.940345][ T2742]=C2=A0 dump_stack_lvl+0x5b/0x80 [=C2=A0 314.940370][ T2742]=C2=A0 kobject_init.cold+0x43/0x51 [=C2=A0 314.940380][ T2742]=C2=A0 blk_register_queue+0x46/0x280 [=C2=A0 314.940399][ T2742]=C2=A0 __add_disk+0x385/0x5d0 [=C2=A0 314.940413][ T2742]=C2=A0 add_disk_fwnode+0xb5/0x280 [=C2=A0 314.940425][ T2742]=C2=A0 dm_setup_md_queue+0x194/0x1c0 [=C2=A0 314.940434][ T2742]=C2=A0 ? mempool_init_noprof+0x16/0x20 [=C2=A0 314.940443][ T2742]=C2=A0 ? __pfx_dm_setup_md_queue+0x10/0x10 [=C2=A0 314.940476][ T2742]=C2=A0 table_load+0x297/0x2d0 [=C2=A0 314.940484][ T2742]=C2=A0 ? __pfx_table_load+0x10/0x10 [=C2=A0 314.940489][ T2742]=C2=A0 ? _inline_copy_from_user+0x6c/0x90 [=C2=A0 314.940499][ T2742]=C2=A0 ? copy_params+0xa6/0x330 [=C2=A0 314.940513][ T2742]=C2=A0 ctl_ioctl+0x2a2/0x480 [=C2=A0 314.940520][ T2742]=C2=A0 ? __pfx_table_load+0x10/0x10 [=C2=A0 314.940528][ T2742]=C2=A0 ? __pfx_ctl_ioctl+0x10/0x10 [=C2=A0 314.940564][ T2742]=C2=A0 ? __free_zapped_classes+0x70/0x120 [=C2=A0 314.940572][ T2742]=C2=A0 ? exc_page_fault+0x61/0xa0 [=C2=A0 314.940591][ T2742]=C2=A0 dm_ctl_ioctl+0xe/0x20 [=C2=A0 314.940598][ T2742]=C2=A0 __x64_sys_ioctl+0xc7/0x110 [=C2=A0 314.940605][ T2742]=C2=A0 ? rcu_is_watching+0x20/0x50 [=C2=A0 314.940616][ T2742]=C2=A0 do_syscall_64+0x72/0x390 [=C2=A0 314.940624][ T2742]=C2=A0 entry_SYSCALL_64_after_hwframe+0x76/0x7e [=C2=A0 314.940631][ T2742] RIP: 0033:0x7f8ce1106577 [=C2=A0 314.940639][ T2742] Code: b3 66 90 48 8b 05 11 89 2c 00 64 c7 00 26=20 00 00 00 48 c7 c0 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 b8 10 00=20 00 00 0f 05 <48> 3d 01 f0 ff ff 73 018 [=C2=A0 314.940645][ T2742] RSP: 002b:00007fff58708438 EFLAGS: 00000202=20 ORIG_RAX: 0000000000000010 [=C2=A0 314.940652][ T2742] RAX: ffffffffffffffda RBX: 0000000000000000 RCX= :=20 00007f8ce1106577 [=C2=A0 314.940657][ T2742] RDX: 0000000008355010 RSI: 00000000c138fd09 RDI= :=20 0000000000000003 [=C2=A0 314.940661][ T2742] RBP: 00007fff587084d0 R08: 0000000000000000 R09= :=20 0000000000000000 [=C2=A0 314.940665][ T2742] R10: 0000000000400e00 R11: 0000000000000202 R12= :=20 3120312030206874 [=C2=A0 314.940669][ T2742] R13: 6563697672657320 R14: 5f65756575712031 R15= :=20 61705f6f6e5f6669 [=C2=A0 314.940686][ T2742]=C2=A0 [=C2=A0 315.026828][ T2742] dm_setup_md_queue sleep before link disk holder [root@nfs_test3 test]# [=C2=A0 325.177205][ T2742] dm_setup_md_queue sleep = done dmtest.c #include #include #include #include #include #include #include #include #define DM_EXISTS_FLAG 0x00000004 int main(int argc, char *argv[]) { =C2=A0 =C2=A0 int ret, fd, index; =C2=A0 =C2=A0 int in_data; =C2=A0 =C2=A0 struct dm_ioctl *param =3D calloc(1, sizeof(struct dm_ioctl)= + 16384); =C2=A0 =C2=A0 struct dm_target_spec sp; =C2=A0 =C2=A0 char *target =3D (char *)(param + 1); =C2=A0 =C2=A0 char *last_param =3D target + sizeof(struct dm_target_spec); =C2=A0 =C2=A0 struct dm_target_msg tmsg; =C2=A0 =C2=A0 fd =3D open("/dev/mapper/control", O_RDWR); =C2=A0 =C2=A0 if (fd < 0) { =C2=A0 =C2=A0 =C2=A0 =C2=A0 printf("Failed to open device /dev/mapper/cont= rol: %s\n",=20 strerror(errno)); =C2=A0 =C2=A0 =C2=A0 =C2=A0 return -1; =C2=A0 =C2=A0 } =C2=A0 =C2=A0 // DM_VERSION =C2=A0 =C2=A0 param->version[0] =3D 4; =C2=A0 =C2=A0 param->version[1] =3D 0; =C2=A0 =C2=A0 param->version[2] =3D 0; =C2=A0 =C2=A0 param->data_size =3D 16384; =C2=A0 =C2=A0 param->flags =3D DM_EXISTS_FLAG; =C2=A0 =C2=A0 ret =3D ioctl(fd, DM_VERSION, param); =C2=A0 =C2=A0 if (ret < 0) { =C2=A0 =C2=A0 =C2=A0 =C2=A0 printf("Failed to send DM_VERSION: %s\n", stre= rror(errno)); =C2=A0 =C2=A0 =C2=A0 =C2=A0 close(fd); =C2=A0 =C2=A0 =C2=A0 =C2=A0 return -1; =C2=A0 =C2=A0 } =C2=A0 =C2=A0 printf("DM_VERSION %d %d %d\n", param->version[0],=20 param->version[1], param->version[2]); =C2=A0 =C2=A0 // DM_DEV_CREATE =C2=A0 =C2=A0 param->data_start =3D 312; =C2=A0 =C2=A0 strncpy(param->name, "multipath-dev", sizeof(param->name)); =C2=A0 =C2=A0 // clear =C2=A0 =C2=A0 memset(target, 0, 16384); =C2=A0 =C2=A0 param->data_size =3D 16384; =C2=A0 =C2=A0 param->dev =3D 0; =C2=A0 =C2=A0 ret =3D ioctl(fd, DM_DEV_CREATE, param); =C2=A0 =C2=A0 if (ret < 0) { =C2=A0 =C2=A0 =C2=A0 =C2=A0 printf("Failed to send DM_DEV_CREATE: %s\n", s= trerror(errno)); =C2=A0 =C2=A0 =C2=A0 =C2=A0 close(fd); =C2=A0 =C2=A0 =C2=A0 =C2=A0 return -1; =C2=A0 =C2=A0 } =C2=A0 =C2=A0 // DM_TABLE_LOAD =C2=A0 =C2=A0 memset(param->name, 0, sizeof(param->name)); =C2=A0 =C2=A0 param->flags =3D DM_EXISTS_FLAG; =C2=A0 =C2=A0 param->data_start =3D 312; =C2=A0 =C2=A0 param->data_size =3D 16384; =C2=A0 =C2=A0 //param->dev =3D 64514; // makedev(252, 2) =C2=A0 =C2=A0 param->target_count =3D 1; =C2=A0 =C2=A0 sp.sector_start =3D 0; =C2=A0 =C2=A0 sp.length =3D 20971520; =C2=A0 =C2=A0 strncpy(sp.target_type, "multipath", sizeof(sp.target_type) = - 1); =C2=A0 =C2=A0 sp.target_type[sizeof(sp.target_type) - 1] =3D '\0'; =C2=A0 =C2=A0 memcpy(target, &sp, sizeof(struct dm_target_spec)); =C2=A0 =C2=A0 strcpy(last_param, "1 queue_if_no_path 0 1 1 service-time 0 = 1 1=20 8:48 1"); =C2=A0 =C2=A0 ret =3D ioctl(fd, DM_TABLE_LOAD, param); //=C2=A0 =C2=A0 if (ret < 0) { //=C2=A0 =C2=A0 =C2=A0 =C2=A0 printf("Failed to send DM_TABLE_LOAD: %s\n", = strerror(errno)); //=C2=A0 =C2=A0 =C2=A0 =C2=A0 close(fd); //=C2=A0 =C2=A0 =C2=A0 =C2=A0 return -1; //=C2=A0 =C2=A0 } =C2=A0 =C2=A0 printf("delay before second table_load...\n"); =C2=A0 =C2=A0 sleep(10); =C2=A0 =C2=A0 printf("delay done\n"); =C2=A0 =C2=A0 memset(param->name, 0, sizeof(param->name)); =C2=A0 =C2=A0 param->flags =3D DM_EXISTS_FLAG; =C2=A0 =C2=A0 param->data_start =3D 312; =C2=A0 =C2=A0 param->data_size =3D 16384; =C2=A0 =C2=A0 param->target_count =3D 1; =C2=A0 =C2=A0 sp.sector_start =3D 0; =C2=A0 =C2=A0 sp.length =3D 20971520; =C2=A0 =C2=A0 strncpy(sp.target_type, "multipath", sizeof(sp.target_type) = - 1); =C2=A0 =C2=A0 sp.target_type[sizeof(sp.target_type) - 1] =3D '\0'; =C2=A0 =C2=A0 memcpy(target, &sp, sizeof(struct dm_target_spec)); =C2=A0 =C2=A0 strcpy(last_param, "1 queue_if_no_path 0 1 1 service-time 0 = 1 1=20 8:48 1"); =C2=A0 =C2=A0 ret =3D ioctl(fd, DM_TABLE_LOAD, param); =C2=A0 =C2=A0 if (ret < 0) { =C2=A0 =C2=A0 =C2=A0 =C2=A0 printf("Failed to send DM_TABLE_LOAD: %s\n", s= trerror(errno)); =C2=A0 =C2=A0 =C2=A0 =C2=A0 close(fd); =C2=A0 =C2=A0 =C2=A0 =C2=A0 return -1; =C2=A0 =C2=A0 } =C2=A0 =C2=A0 // DM_DEV_SUSPEND =C2=A0 =C2=A0 param->flags =3D DM_EXISTS_FLAG; // continue creating =C2=A0 =C2=A0 param->event_nr =3D 6345265; =C2=A0 =C2=A0 param->data_size =3D 16384; =C2=A0 =C2=A0 param->dev =3D 0; =C2=A0 =C2=A0 strncpy(param->name, "multipath-dev", sizeof(param->name)); =C2=A0 =C2=A0 ret =3D ioctl(fd, DM_DEV_SUSPEND, param); =C2=A0 =C2=A0 if (ret < 0) { =C2=A0 =C2=A0 =C2=A0 =C2=A0 printf("Failed to send DM_DEV_SUSPEND: %s\n", = strerror(errno)); =C2=A0 =C2=A0 =C2=A0 =C2=A0 close(fd); =C2=A0 =C2=A0 =C2=A0 =C2=A0 return -1; =C2=A0 =C2=A0 } =C2=A0 =C2=A0 printf("DM_DEV_SUSPEND sent successfully\n"); =C2=A0 =C2=A0 close(fd); =C2=A0 =C2=A0 return 0; }