在 2017/7/12 17:59, John Garry 写道: > 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@xxxxxxxxxxxxxxx/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. Oh, I take a mistake ? The result you tested the hotplug which applied this patchset is fine ? Thanks! Yijing. > > 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(-) >> > > > > . >
