Comment 13 for bug 1780137

Verification results:

ubuntu@d05-6:~$ sudo ./stress
+ umount /tmp/mnt
umount: /tmp/mnt: not mounted.
+ /bin/true
+ mkdir -p /tmp/mnt
+ mkfs.ext4 -F /dev/sda1
mke2fs 1.44.1 (24-Mar-2018)
/dev/sda1 contains a ext4 file system
 last mounted on Wed Jul 11 23:26:23 2018
/dev/sda1 alignment is offset by 244736 bytes.
This may result in very poor performance, (re)-partitioning suggested.
Creating filesystem with 1953124855 4k blocks and 244142080 inodes
Filesystem UUID: 7aa77e9b-8518-4b64-9507-b65d09aa6382
Superblock backups stored on blocks:
 32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208,
 4096000, 7962624, 11239424, 20480000, 23887872, 71663616, 78675968,
 102400000, 214990848, 512000000, 550731776, 644972544, 1934917632

Allocating group tables: done
Writing inode tables: done
Creating journal (262144 blocks): done
Writing superblocks and filesystem accounting information: done

+ mount /dev/sda1 /tmp/mnt
+ dir=/tmp/mnt/tmp/disk_stress_ng_f70f0f26-b332-4c48-9e07-67c529770e3d
+ mkdir -p /tmp/mnt/tmp/disk_stress_ng_f70f0f26-b332-4c48-9e07-67c529770e3d
+ stress-ng --aggressive --verify --timeout 240 --temp-path /tmp/mnt/tmp/disk_stress_ng_f70f0f26-b332-4c48-9e07-67c529770e3d --chdir 0 --hdd-opts dsync --readahead-bytes 16M -k
stress-ng: info: [2670] dispatching hogs: 64 chdir
stress-ng: info: [2670] cache allocate: using built-in defaults as unable to determine cache details
stress-ng: info: [2670] successful run completed in 244.71s (4 mins, 4.71 secs)
ubuntu@d05-6:~$ cat /proc/version
Linux version 4.15.0-27-generic (buildd@bos02-arm64-027) (gcc version 7.3.0 (Ubuntu/Linaro 7.3.0-16ubuntu3)) #29-Ubuntu SMP Wed Jul 11 08:20:51 UTC 2018