Hi Jens,
If I run the following subset of blktests:
while :+ADs do ./check -q srp +ACYAJg ./check -q nvmeof-mp+ADs done
against today's for-next branch (commit dd2bf2df85a7) then after some
time the following hang is reported:
INFO: task fio:14869 blocked for more than 120 seconds.
Not tainted 4.20.0-rc6-dbg+- +ACM-1
+ACI-echo 0 +AD4 /proc/sys/kernel/hung+AF8-task+AF8-timeout+AF8-secs+ACI disables this message.
fio D25272 14869 14195 0x00000000
Call Trace:
+AF8AXw-schedule+-0x401/0xe50
schedule+-0x4e/0xd0
io+AF8-schedule+-0x21/0x50
blk+AF8-mq+AF8-get+AF8-tag+-0x46d/0x640
blk+AF8-mq+AF8-get+AF8-request+-0x7c0/0xa00
blk+AF8-mq+AF8-make+AF8-request+-0x241/0xa70
generic+AF8-make+AF8-request+-0x411/0x950
submit+AF8-bio+-0x9b/0x250
blkdev+AF8-direct+AF8-IO+-0x7fb/0x870
generic+AF8-file+AF8-direct+AF8-write+-0x119/0x210
+AF8AXw-generic+AF8-file+AF8-write+AF8-iter+-0x11c/0x280
blkdev+AF8-write+AF8-iter+-0x13c/0x220
aio+AF8-write+-0x204/0x310
io+AF8-submit+AF8-one+-0x9c6/0xe70
+AF8AXw-x64+AF8-sys+AF8-io+AF8-submit+-0x115/0x340
do+AF8-syscall+AF8-64+-0x71/0x210
entry+AF8-SYSCALL+AF8-64+AF8-after+AF8-hwframe+-0x49/0xbe
When that hang occurs my list-pending-block-requests script does not show
any pending requests:
+ACM list-pending-block-requests
dm-0
loop0
loop1
loop2
loop3
loop4
loop5
loop6
loop7
nullb0
nullb1
sda
sdb
sdc
sdd
vda
vdb
Enabling fail+AF8-if+AF8-no+AF8-path mode did not resolve the hang so I don't think
that the root cause is in any of the dm drivers used in this test:
+ACM dmsetup ls +AHw while read dm rest+ADs do dmsetup message +ACQ-dm 0 fail+AF8-if+AF8-no+AF8-path+ADs done+ADs dmsetup remove+AF8-all+ADs dmsetup table
360014056e756c6c62300000000000000: 0 65536 multipath 0 1 alua 1 1 service-time 0 1 2 8:16 1 1
The same test passes against kernel v4.20-rc6.
Thanks,
Bart.
