【标题描述】SATA盘NCQ场景下发多个IO，其中一个IO出错后，出现群体慢盘问题
【环境信息】
硬件信息：
1） 鲲鹏920
软件信息：
[root@localhost 0000:b4:02.0]# cat /etc/euleros-latest
eulerversion=EulerOS_Server_V200R008C00SPC300B630
compiletime=2019-12-27-10-58-38
kernelversion=4.19.36-vhulk1907.1.0.h619
[root@localhost 0000:b4:02.0]# uname -a
Linux localhost.localdomain 4.19.36-vhulk1907.1.0.h619.eulerosv2r8.aarch64 #1 SMP Mon Jul 22 00:00:00 UTC 2019 aarch64 aarch64 aarch64 GNU/Linux
【问题复现步骤】
1、对SATA盘注入UNC故障
2、对盘跑压测
3、磁盘框接入多块盘
【预期结果】
故障盘出问题时，对其他盘无明显影响
【实际结果】
其他盘IO卡住30秒左右
【问题根因】
NCQ场景IO出错是面向盘的报错，盘只会回一个tag全零的SDB帧。盘上的IO均不会返回。基于开源社区的IO错误处理机制，驱动处理单个异常IO后，内核会锁住host，等待所有IO超时失败后，才进错误处理（Error Handler)，并执行完EH后再对host解锁。导致host锁住时长接近下发IO时设置的超时时间，引发慢盘现象。

【解决方案】
NCQ场景出错后，驱动将盘未返回的IO以出错的形式快速返回给内核，加速进入错误处理，消除群体慢盘问题，并通过内核EH机制给盘下发read log ext命令，获取错误详情，立即返回给用户。(同时解决群体慢盘和无法获取盘故障信息的问题）

【附件信息】
验证结果符合预期，无群体慢盘现象，UNC场景能内核能立即将盘的故障信息通过块设备层传递给用户，日志如下：
[ 79.348807] hisi_sas_v3_hw 0000:b4:02.0: erroneous completion ncq err dev id=1 sas_addr=0x5000000000000605 CQ hdr: 0x400903 0x10684 0x0 0x80470000
[ 79.348812] sas: sas_ata_task_done: SAS error 8d
[ 79.348819] sas: sas_ata_task_done: SAS error 8d
[ 79.348820] sas: sas_ata_task_done: SAS error 8d
[ 79.348821] sas: sas_ata_task_done: SAS error 8d
[ 79.348823] sas: sas_ata_task_done: SAS error 8d
[ 79.348824] sas: sas_ata_task_done: SAS error 8d
[ 79.348825] sas: sas_ata_task_done: SAS error 8d
[ 79.348826] sas: sas_ata_task_done: SAS error 8d
[ 79.348828] sas: sas_ata_task_done: SAS error 8d
[ 79.348829] sas: sas_ata_task_done: SAS error 8d
[ 79.348830] sas: sas_ata_task_done: SAS error 8d
[ 79.348831] sas: sas_ata_task_done: SAS error 8d
[ 79.348833] sas: sas_ata_task_done: SAS error 8d
[ 79.395693] sas: Enter sas_scsi_recover_host busy: 13 failed: 13
[ 79.395696] sas: ata6: end_device-6:1: cmd error handler
[ 79.395705] sas: ata5: end_device-6:0: dev error handler
[ 79.395707] sas: ata6: end_device-6:1: dev error handler
[ 79.395744] ata6.00: exception Emask 0x0 SAct 0x3f9f8000 SErr 0x0 action 0x6
[ 79.395746] ata6.00: failed command: READ FPDMA QUEUED
[ 79.395749] ata6.00: cmd 60/08:00:49:21:00/00:00:00:00:00/40 tag 15 ncq dma 4096 in
res 01/04:00:00:00:20/00:00:00:00:00/00 Emask 0x2 (HSM violation)
[ 79.395750] ata6.00: status: { ERR }
[ 79.395751] ata6.00: error: { ABRT }
[ 79.395753] ata6.00: failed command: READ FPDMA QUEUED
[ 79.395755] ata6.00: cmd 60/08:00:51:23:00/00:00:00:00:00/40 tag 16 ncq dma 4096 in
res 01/04:00:00:00:20/00:00:00:00:00/00 Emask 0x2 (HSM violation)
[ 79.395756] ata6.00: status: { ERR }
[ 79.395757] ata6.00: error: { ABRT }
[ 79.395758] ata6.00: failed command: READ FPDMA QUEUED
[ 79.395761] ata6.00: cmd 60/08:00:19:25:00/00:00:00:00:00/40 tag 17 ncq dma 4096 in
res 01/04:00:00:00:20/00:00:00:00:00/00 Emask 0x2 (HSM violation)
[ 79.395761] ata6.00: status: { ERR }
[ 79.395762] ata6.00: error: { ABRT }
[ 79.395763] ata6.00: failed command: READ FPDMA QUEUED
[ 79.395766] ata6.00: cmd 60/08:00:11:25:00/00:00:00:00:00/40 tag 18 ncq dma 4096 in
res 01/04:00:00:00:20/00:00:00:00:00/00 Emask 0x2 (HSM violation)
[ 79.395766] ata6.00: status: { ERR }
[ 79.395767] ata6.00: error: { ABRT }
[ 79.395768] ata6.00: failed command: READ FPDMA QUEUED
[ 79.395771] ata6.00: cmd 60/08:00:89:23:00/00:00:00:00:00/40 tag 19 ncq dma 4096 in
res 01/04:00:00:00:20/00:00:00:00:00/00 Emask 0x2 (HSM violation)
[ 79.395771] ata6.00: status: { ERR }
[ 79.395772] ata6.00: error: { ABRT }
[ 79.395773] ata6.00: failed command: READ FPDMA QUEUED
[ 79.395775] ata6.00: cmd 60/08:00:81:23:00/00:00:00:00:00/40 tag 20 ncq dma 4096 in
res 01/04:00:00:00:20/00:00:00:00:00/00 Emask 0x2 (HSM violation)
[ 79.395776] ata6.00: status: { ERR }
[ 79.395777] ata6.00: error: { ABRT }
[ 79.395778] ata6.00: failed command: READ FPDMA QUEUED
[ 79.395780] ata6.00: cmd 60/08:00:11:27:00/00:00:00:00:00/40 tag 23 ncq dma 4096 in
res 41/40:08:11:27:00/00:00:00:00:00/00 Emask 0x409 (media error)
[ 79.395781] ata6.00: status: { DRDY ERR }
[ 79.395782] ata6.00: error: { UNC }
[ 79.395783] ata6.00: failed command: READ FPDMA QUEUED
[ 79.395785] ata6.00: cmd 60/08:00:59:21:00/00:00:00:00:00/40 tag 24 ncq dma 4096 in
res 01/04:00:00:00:20/00:00:00:00:00/00 Emask 0x2 (HSM violation)
[ 79.395786] ata6.00: status: { ERR }
[ 79.395787] ata6.00: error: { ABRT }
[ 79.395788] ata6.00: failed command: READ FPDMA QUEUED
[ 79.395790] ata6.00: cmd 60/08:00:21:25:00/00:00:00:00:00/40 tag 25 ncq dma 4096 in
res 01/04:00:00:00:20/00:00:00:00:00/00 Emask 0x2 (HSM violation)
[ 79.395791] ata6.00: status: { ERR }
[ 79.395792] ata6.00: error: { ABRT }
[ 79.395793] ata6.00: failed command: READ FPDMA QUEUED
[ 79.395795] ata6.00: cmd 60/08:00:59:26:00/00:00:00:00:00/40 tag 26 ncq dma 4096 in
res 01/04:00:00:00:20/00:00:00:00:00/00 Emask 0x2 (HSM violation)
[ 79.395796] ata6.00: status: { ERR }
[ 79.395797] ata6.00: error: { ABRT }
[ 79.395798] ata6.00: failed command: READ FPDMA QUEUED
[ 79.395800] ata6.00: cmd 60/08:00:51:26:00/00:00:00:00:00/40 tag 27 ncq dma 4096 in
res 01/04:00:00:00:20/00:00:00:00:00/00 Emask 0x2 (HSM violation)
[ 79.395801] ata6.00: status: { ERR }
[ 79.395802] ata6.00: error: { ABRT }
[ 79.395803] ata6.00: failed command: READ FPDMA QUEUED
[ 79.395805] ata6.00: cmd 60/08:00:61:21:00/00:00:00:00:00/40 tag 28 ncq dma 4096 in
res 01/04:00:00:00:20/00:00:00:00:00/00 Emask 0x2 (HSM violation)
[ 79.395806] ata6.00: status: { ERR }
[ 79.395807] ata6.00: error: { ABRT }
[ 79.395808] ata6.00: failed command: READ FPDMA QUEUED
[ 79.395810] ata6.00: cmd 60/08:00:69:26:00/00:00:00:00:00/40 tag 29 ncq dma 4096 in
res 01/04:00:00:00:20/00:00:00:00:00/00 Emask 0x2 (HSM violation)
[ 79.395811] ata6.00: status: { ERR }
[ 79.395811] ata6.00: error: { ABRT }
[ 79.395814] ata6: hard resetting link
[ 79.399065] hisi_sas_v3_hw 0000:b4:02.0: phydown: phy5 phy_state=0x4
[ 79.399066] hisi_sas_v3_hw 0000:b4:02.0: ignore flutter phy5 down
[ 79.556245] hisi_sas_v3_hw 0000:b4:02.0: phyup: phy5 link_rate=10(sata)
[ 79.556251] sas: sas_form_port: phy5 belongs to port1 already(1)!
[ 79.719871] ata6.00: configured for UDMA/133
[ 79.719895] sd 6:0:1:0: [sdb] tag#24 FAILED Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE
[ 79.719898] sd 6:0:1:0: [sdb] tag#24 Sense Key : Medium Error [current]
[ 79.719900] sd 6:0:1:0: [sdb] tag#24 Add. Sense: Unrecovered read error - auto reallocate failed
[ 79.719902] sd 6:0:1:0: [sdb] tag#24 CDB: Read(10) 28 00 00 00 27 11 00 00 08 00
[ 79.719904] print_req_error: I/O error, dev sdb, sector 10001
[ 79.719914] ata6: EH complete
[ 79.719920] sas: --- Exit sas_scsi_recover_host: busy: 0 failed: 13 tries: 1