[#LU-12258] sanity test_101d timeout when doing rolling upgrade OSS from 2.10.7 to 2.12.1 with ZFS

1. setup system with 2.10.7 with 1 MDS (ZFS), 2 OSTs (ZFS), 1 client
2. upgrade OSS from 2.10.7 to 2.12.1, others remain 2.10.7, run sanity, test_101d timeout, on OSS side showing following trace. ldiskfs doesn't have the problem

[ 3268.291244] Lustre: DEBUG MARKER: == sanity test 101d: file read with and witt
hout read-ahead enabled =================================== 00:21:09 (15566700699
)
[ 3280.980154] WARNING: MMP writes to pool 'lustre-ost1' have not succeeded in oo
ver 5s; suspending pool
[ 3280.981448] WARNING: Pool 'lustre-ost1' has encountered an uncorrectable I/O  
failure and has been suspended.

[ 3281.091886] WARNING: MMP writes to pool 'lustre-ost2' have not succeeded in oo
ver 5s; suspending pool
[ 3281.092868] WARNING: Pool 'lustre-ost2' has encountered an uncorrectable I/O  
failure and has been suspended.

[ 3474.405076] LNet: Service thread pid 30189 was inactive for 200.40s. The three
ad might be hung, or it might only be slow and will resume later. Dumping the stt
ack trace for debugging purposes:
[ 3474.409289] Pid: 30189, comm: ll_ost_io00_000 3.10.0-957.10.1.el7_lustre.x86__
64 #1 SMP Mon Apr 22 22:25:47 UTC 2019
[ 3474.410361] Call Trace:
[ 3474.410361] Call Trace:
[ 3474.410694]  [<ffffffffc07922d5>] cv_wait_common+0x125/0x150 [spl]
[ 3474.411403]  [<ffffffffc0792315>] __cv_wait+0x15/0x20 [spl]
[ 3474.412004]  [<ffffffffc08d32bf>] txg_wait_synced+0xef/0x140 [zfs]
[ 3474.412817]  [<ffffffffc0888c95>] dmu_tx_wait+0x275/0x3c0 [zfs]
[ 3474.413488]  [<ffffffffc0888e72>] dmu_tx_assign+0x92/0x490 [zfs]
[ 3474.414163]  [<ffffffffc11f6009>] osd_trans_start+0x199/0x440 [osd_zfs]
[ 3474.414896]  [<ffffffffc131cc85>] ofd_trans_start+0x75/0xf0 [ofd]
[ 3474.415596]  [<ffffffffc1323881>] ofd_commitrw_write+0xa31/0x1d40 [ofd]
[ 3474.416312]  [<ffffffffc1327c6c>] ofd_commitrw+0x48c/0x9e0 [ofd]
[ 3474.416962]  [<ffffffffc102947c>] tgt_brw_write+0x10cc/0x1cf0 [ptlrpc]
[ 3474.417923]  [<ffffffffc10251da>] tgt_request_handle+0xaea/0x1580 [ptlrpc]
[ 3474.418699]  [<ffffffffc0fca80b>] ptlrpc_server_handle_request+0x24b/0xab0 [pp
tlrpc]
[ 3474.419550]  [<ffffffffc0fce13c>] ptlrpc_main+0xafc/0x1fc0 [ptlrpc]
[ 3474.420261]  [<ffffffffa0cc1c71>] kthread+0xd1/0xe0
[ 3474.420817]  [<ffffffffa1375c37>] ret_from_fork_nospec_end+0x0/0x39
[ 3474.421507]  [<ffffffffffffffff>] 0xffffffffffffffff

[LU-12258] sanity test_101d timeout when doing rolling upgrade OSS from 2.10.7 to 2.12.1 with ZFS Created: 01/May/19 Updated: 20/May/19
Status:	Open
Project:	Lustre
Component/s:	None
Affects Version/s:	Lustre 2.12.1
Fix Version/s:	None

[LU-12258] sanity test_101d timeout when doing rolling upgrade OSS from 2.10.7 to 2.12.1 with ZFS Created: 01/May/19 Updated: 20/May/19