Comment 1 for bug 1801907

Manually started the sru-1 test suite on a Power8 box:

 stress-ng: invoked with '/home/ubuntu/autotest/client/tmp/ubuntu_vfat_stress/src/stress-ng/stress-n' by user 0
' Linux 4.15.0-39-generic #42-Ubuntu SMP Tue Oct 23 15:41:45 UTC 2018 ppc64le
 stress-ng: memory (MB): total 130597.19, free 128099.44, shared 29.00, buffer 6.38, swap 8191.94, free swap 8191.94
 stress-ng: info: [157795] dispatching hogs: 2 hdd, 2 lockf, 2 seek, 2 aio, 2 dentry, 2 dir, 2 fallocate, 2 fstat, 2 lease, 2 open, 2 rename, 2 chdir, 2 rename
 stress-ng: info: [157795] cache allocate: using built-in defaults as unable to determine cache details
 stress-ng: fail: [157832] stress-ng-chdir: mkdir failed, errno=28 (No space left on device)
 stress-ng: fail: [157819] stress-ng-chdir: mkdir failed, errno=28 (No space left on device)
 stress-ng: fail: [157806] stress-ng-hdd: read failed, errno=28 (No space left on device)
 stress-ng: fail: [157821] stress-ng-hdd: read failed, errno=28 (No space left on device)
 ELOG[5039]: LID[50d02eb8]::SRC[B1763321]::Other Subsystems::Informational Event::No service action required
 kernel: [25133.553427] INFO: task kworker/u321:0:72730 blocked for more than 120 seconds.
 kernel: [25133.553441] Not tainted 4.15.0-39-generic #42-Ubuntu
 kernel: [25133.553446] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
 kernel: [25133.553451] kworker/u321:0 D 0 72730 2 0x00000800
 kernel: [25133.553462] Workqueue: writeback wb_workfn (flush-7:0)
 kernel: [25133.553465] Call Trace:
 kernel: [25133.553469] [c0000000039cea90] [c0000000039ceb00] 0xc0000000039ceb00 (unreliable)
 kernel: [25133.553474] [c0000000039cec60] [c00000000001c1d0] __switch_to+0x2a0/0x4d0
 kernel: [25133.553479] [c0000000039cecc0] [c000000000cfd2e4] __schedule+0x2a4/0xaf0
 kernel: [25133.553483] [c0000000039ced90] [c000000000cfdb70] schedule+0x40/0xc0
 kernel: [25133.553487] [c0000000039cedb0] [c000000000152e7c] io_schedule+0x2c/0x50
 kernel: [25133.553491] [c0000000039cede0] [c0000000006d1e04] wbt_wait+0x484/0x4e0
 kernel: [25133.553494] [c0000000039cee80] [c000000000698e74] blk_mq_make_request+0x104/0x6e0
 kernel: [25133.553498] [c0000000039cef20] [c000000000686a34] generic_make_request+0x124/0x380
 kernel: [25133.553501] [c0000000039cef90] [c000000000686d4c] submit_bio+0xbc/0x1d0
 kernel: [25133.553504] [c0000000039cf040] [c00000000042de2c] submit_bh_wbc+0x1dc/0x240
 kernel: [25133.553507] [c0000000039cf090] [c00000000042e108] __block_write_full_page+0x278/0x570
 kernel: [25133.553510] [c0000000039cf130] [c00000000054ac6c] fat_writepage+0x2c/0x40
 kernel: [25133.553513] [c0000000039cf150] [c00000000043bdf0] __mpage_writepage+0x170/0x7b0
 kernel: [25133.553517] [c0000000039cf680] [c0000000002f2d9c] write_cache_pages+0x25c/0x590
 kernel: [25133.553520] [c0000000039cf7c0] [c00000000043bac8] mpage_writepages+0x78/0x150
 kernel: [25133.553522] [c0000000039cf850] [c00000000054abe8] fat_writepages+0x28/0x40
 kernel: [25133.553525] [c0000000039cf870] [c0000000002f5f1c] do_writepages+0x4c/0x130
 kernel: [25133.553527] [c0000000039cf8e0] [c00000000041eff0] __writeback_single_inode+0x70/0x570
 kernel: [25133.553530] [c0000000039cf940] [c00000000041fb8c] writeback_sb_inodes+0x26c/0x5d0
 kernel: [25133.553532] [c0000000039cfa50] [c00000000041ff88] __writeback_inodes_wb+0x98/0x110
 kernel: [25133.553534] [c0000000039cfab0] [c0000000004203ac] wb_writeback+0x29c/0x460
 kernel: [25133.553537] [c0000000039cfb80] [c00000000042126c] wb_workfn+0x44c/0x5e0
 kernel: [25133.553540] [c0000000039cfc90] [c000000000134bd8] process_one_work+0x298/0x5a0
 kernel: [25133.553543] [c0000000039cfd20] [c000000000134f78] worker_thread+0x98/0x630
 kernel: [25133.553545] [c0000000039cfdc0] [c00000000013db48] kthread+0x1a8/0x1b0
 kernel: [25133.553549] [c0000000039cfe30] [c00000000000b658] ret_from_kernel_thread+0x5c/0x84

Disk usage after the test:
$ df -h
Filesystem Size Used Avail Use% Mounted on
udev 61G 0 61G 0% /dev
tmpfs 13G 27M 13G 1% /run
/dev/mapper/mpath0-part2 260G 12G 234G 5% /
tmpfs 64G 0 64G 0% /dev/shm
tmpfs 5.0M 0 5.0M 0% /run/lock
tmpfs 64G 0 64G 0% /sys/fs/cgroup
tmpfs 13G 0 13G 0% /run/user/1000
/dev/loop0 1022M 492M 531M 49% /mnt/vfat-test-80992