| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <153868d4-9aa6-21b5-81f3-868668218cb2@huawei.com>
Date: Wed, 12 Jul 2017 10:59:27 +0100
From: John Garry <john.garry@...wei.com>
To: Yijing Wang <wangyijing@...wei.com>, <jejb@...ux.vnet.ibm.com>,
<martin.petersen@...cle.com>
CC: <chenqilin2@...wei.com>, <hare@...e.com>,
<linux-scsi@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
<chenxiang66@...ilicon.com>, <huangdaode@...ilicon.com>,
<wangkefeng.wang@...wei.com>, <zhaohongjiang@...wei.com>,
<dingtianhong@...wei.com>, <guohanjun@...wei.com>,
<yanaijie@...wei.com>, <hch@....de>, <dan.j.williams@...el.com>,
<emilne@...hat.com>, <thenzl@...hat.com>, <wefu@...hat.com>,
<charles.chenxin@...wei.com>, <chenweilong@...wei.com>,
Linuxarm <linuxarm@...wei.com>
Subject: Re: [PATCH v3 0/7] Enhance libsas hotplug feature
On 10/07/2017 08:06, Yijing Wang wrote:
> This patchset is based Johannes's patch
> "scsi: sas: scsi_queue_work can fail, so make callers aware"
>
> Now the libsas hotplug has some issues, Dan Williams report
> a similar bug here before
> https://www.mail-archive.com/linux-scsi@vger.kernel.org/msg39187.html
>
> The issues we have found
> 1. if LLDD burst reports lots of phy-up/phy-down sas events, some events
> may lost because a same sas events is pending now, finally libsas topo
> may different the hardware.
> 2. receive a phy down sas event, libsas call sas_deform_port to remove
> devices, it would first delete the sas port, then put a destruction
> discovery event in a new work, and queue it at the tail of workqueue,
> once the sas port be deleted, its children device will be deleted too,
> when the destruction work start, it will found the target device has
> been removed, and report a sysfs warnning.
> 3. since a hotplug process will be devided into several works, if a phy up
> sas event insert into phydown works, like
> destruction work ---> PORTE_BYTES_DMAED (sas_form_port) ---->PHYE_LOSS_OF_SIGNAL
> the hot remove flow would broken by PORTE_BYTES_DMAED event, it's not
> we expected, and issues would occur.
>
> The first patch fix the sas events lost, and the second one introudce wait-complete
> to fix the hotplug order issues.
>
I quickly tested this for basic hotplug.
Before:
root@(none)$ echo 0 > ./phy-0:6/sas_phy/phy-0:6/enable
root@(none)$ echo 0 > ./phy-0:5/sas_phy/phy-0:5/enable
root@(none)$ echo 0 > ./phy-0:4/sas_phy/phy-0:4/enable
root@(none)$ echo 0 > ./phy-0:3/sas_phy/phy-0:3/enable
root@(none)$ echo 0 > ./phy-0:3/sas_phy/phy-0:2/enable
root@(none)$ echo 0 > ./phy-0:2/sas_phy/phy-0:2/enable
root@(none)$ echo 0 > ./phy-0:1/sas_phy/phy-0:1/enable
root@(none)$ echo 0 > ./phy-0:0/sas_phy/phy-0:0/enable
root@(none)$ echo 0 > ./phy-0:7/sas_phy/phy-0:7/enable
root@(none)$ [ 102.570694] sysfs group 'power' not found for kobject
'0:0:7:0'
[ 102.577250] ------------[ cut here ]------------
[ 102.581861] WARNING: CPU: 3 PID: 1740 at fs/sysfs/group.c:237
sysfs_remove_group+0x8c/0x94
[ 102.590110] Modules linked in:
[ 102.593154] CPU: 3 PID: 1740 Comm: kworker/u128:2 Not tainted
4.12.0-rc1-00032-g3ab81fc #1907
[ 102.601664] Hardware name: Huawei Taishan 2280 /D05, BIOS Hisilicon
D05 UEFI Nemo 1.7 RC3 06/23/2017
[ 102.610784] Workqueue: scsi_wq_0 sas_destruct_devices
[ 102.615822] task: ffff8017d4793400 task.stack: ffff8017b7e70000
[ 102.621728] PC is at sysfs_remove_group+0x8c/0x94
[ 102.626419] LR is at sysfs_remove_group+0x8c/0x94
[ 102.631109] pc : [<ffff000008267c44>] lr : [<ffff000008267c44>]
pstate: 60000045
[ 102.638490] sp : ffff8017b7e73b80
[ 102.641791] x29: ffff8017b7e73b80 x28: ffff8017db010800
[ 102.647091] x27: ffff000008e27000 x26: ffff8017d43e6600
[ 102.652390] x25: ffff8017b8280000 x24: 0000000000000003
[ 102.657689] x23: ffff8017b78864b0 x22: ffff8017b784c988
[ 102.662988] x21: ffff8017b7886410 x20: ffff000008ee9dd0
[ 102.668288] x19: 0000000000000000 x18: ffff000008a1b678
[ 102.673587] x17: 000000000000000e x16: 0000000000000007
[ 102.678886] x15: 0000000000000000 x14: 00000000000000a3
[ 102.684185] x13: 0000000000000033 x12: 0000000000000028
[ 102.689484] x11: ffff000008f3be58 x10: 0000000000000000
[ 102.694783] x9 : 000000000000043c x8 : 6f6b20726f662064
[ 102.700082] x7 : ffff000008e29e08 x6 : ffff8017fbe34c50
[ 102.705382] x5 : 0000000000000000 x4 : 0000000000000000
[ 102.710681] x3 : ffffffffffffffff x2 : ffff000008e427e0
[ 102.715980] x1 : 0000000000000000 x0 : 0000000000000033
[ 102.721279] ---[ end trace c216cc1451d5f7ec ]---
[ 102.725882] Call trace:
[ 102.728316] Exception stack(0xffff8017b7e739b0 to 0xffff8017b7e73ae0)
[ 102.734742] 39a0: 0000000000000000
0001000000000000
[ 102.742557] 39c0: ffff8017b7e73b80 ffff000008267c44 ffff000008bfa050
0000000000000000
[ 102.750372] 39e0: ffff8017b78864b0 0000000000000003 ffff8017b8280000
ffff8017d43e6600
[ 102.758188] 3a00: ffff000008e27000 ffff8017db010800 ffff8017d4793400
0000000000000000
[ 102.766003] 3a20: ffff8017b7e73b80 ffff8017b7e73b80 ffff8017b7e73b40
00000000ffffffc8
[ 102.773818] 3a40: ffff8017b7e73a70 ffff00000810c12c 0000000000000033
0000000000000000
[ 102.781633] 3a60: ffff000008e427e0 ffffffffffffffff 0000000000000000
0000000000000000
[ 102.789449] 3a80: ffff8017fbe34c50 ffff000008e29e08 6f6b20726f662064
000000000000043c
[ 102.797264] 3aa0: 0000000000000000 ffff000008f3be58 0000000000000028
0000000000000033
[ 102.805079] 3ac0: 00000000000000a3 0000000000000000 0000000000000007
000000000000000e
[ 102.812895] [<ffff000008267c44>] sysfs_remove_group+0x8c/0x94
[ 102.818628] [<ffff00000855b14c>] dpm_sysfs_remove+0x58/0x68
[ 102.824188] [<ffff00000854e0e8>] device_del+0xf8/0x2d0
[ 102.829312] [<ffff00000854e2d4>] device_unregister+0x14/0x2c
[ 102.834959] [<ffff00000837e6e0>] bsg_unregister_queue+0x60/0x98
[ 102.840866] [<ffff000008593cd4>] __scsi_remove_device+0xa0/0xbc
<snip>
[ 151.331854] 3bc0: ffff0000081f21ac 0000ffff803370c0
[ 151.336718] [<ffff000008267c44>] sysfs_remove_group+0x8c/0x94
[ 151.342449] [<ffff00000855b14c>] dpm_sysfs_remove+0x58/0x68
[ 151.348008] [<ffff00000854e0e8>] device_del+0xf8/0x2d0
[ 151.353133] [<ffff000008597278>] sas_rphy_remove+0x54/0x80
[ 151.358604] [<ffff0000085972b8>] sas_rphy_delete+0x14/0x28
[ 151.364076] [<ffff00000859b304>] sas_destruct_devices+0x64/0x98
[ 151.369982] [<ffff0000080d8194>] process_one_work+0x12c/0x28c
[ 151.375714] [<ffff0000080d834c>] worker_thread+0x58/0x3b8
[ 151.381100] [<ffff0000080ddee4>] kthread+0x100/0x12c
[ 151.386050] [<ffff0000080836c0>] ret_from_fork+0x10/0x50
[ 151.391360] hisi_sas_v2_hw HISI0162:01: found dev[0:2] is gone
root@(none)$
So the console locks for ~50 seconds with WARN garbage.
After:
...
root@(none)$ echo 0 > ./phy-0:7/sas_phy/phy-0:7/enable
root@(none)$ [ 446.193336] hisi_sas_v2_hw HISI0162:01: found dev[8:1]
is gone
[ 446.249205] hisi_sas_v2_hw HISI0162:01: found dev[7:1] is gone
[ 446.325201] hisi_sas_v2_hw HISI0162:01: found dev[6:1] is gone
[ 446.373189] hisi_sas_v2_hw HISI0162:01: found dev[5:1] is gone
[ 446.421187] hisi_sas_v2_hw HISI0162:01: found dev[4:1] is gone
[ 446.457232] hisi_sas_v2_hw HISI0162:01: found dev[3:1] is gone
[ 446.477151] sd 0:0:1:0: [sdb] Synchronizing SCSI cache
[ 446.482373] sd 0:0:1:0: [sdb] Synchronize Cache(10) failed: Result:
hostbyte=0x04 driverbyte=0x00
[ 446.491238] sd 0:0:1:0: [sdb] Stopping disk
[ 446.495419] sd 0:0:1:0: [sdb] Start/Stop Unit failed: Result:
hostbyte=0x04 driverbyte=0x00
[ 446.525227] hisi_sas_v2_hw HISI0162:01: found dev[2:5] is gone
[ 446.569249] hisi_sas_v2_hw HISI0162:01: found dev[1:1] is gone
[ 446.576872] hisi_sas_v2_hw HISI0162:01: found dev[0:2] is gone
root@(none)$
So much nicer. BTW, /dev/sdb is a SATA disk, the rest are SAS.
John
> v2->v3: some code improvements suggested by Johannes and John,
> split v2 patch 2 into several small pathes.
> v1->v2: some code improvements suggested by John Garry
>
> Yijing Wang (7):
> libsas: Use static sas event pool to appease sas event lost
> libsas: remove unused port_gone_completion
> libsas: Use new workqueue to run sas event
> libsas: add sas event wait-complete support
> libsas: add a new workqueue to run probe/destruct discovery event
> libsas: add wait-complete support to sync discovery event
> libsas: release disco mutex during waiting in sas_ex_discover_end_dev
>
> drivers/scsi/libsas/sas_discover.c | 58 +++++++---
> drivers/scsi/libsas/sas_event.c | 212 ++++++++++++++++++++++++++++++++-----
> drivers/scsi/libsas/sas_expander.c | 22 +++-
> drivers/scsi/libsas/sas_init.c | 21 ++--
> drivers/scsi/libsas/sas_internal.h | 64 +++++++++++
> drivers/scsi/libsas/sas_phy.c | 48 +++------
> drivers/scsi/libsas/sas_port.c | 22 ++--
> include/scsi/libsas.h | 27 +++--
> 8 files changed, 373 insertions(+), 101 deletions(-)
>
Powered by blists - more mailing lists