Dave Chinner wrote on 2019/1/10 5:02:
On Wed, Jan 09, 2019 at 01:48:45PM +0800, yangerkun wrote:
Case generic/108 sometimes will fail while testing ext2, and the reson
is that rmmod scsi_debug in _put_scsi_debug_dev may randomly fail. Now
add the loop to do rmmod to make sure scsi_debug can be removed
correctly.
Why does 'rmmod scsi_debug' randomly fail?
What bug does ext2 have that prevents the scsi debug module from
being released and hence removed?
It's not a bug with ext2, ever been existing in ext4 too. This patch is
a reference to 'https://gitlab.com/cryptsetup/cryptsetup.git' commit
d7b9ed05f0931b416c33c8eb2ff1e6efa39270ff, and the reason why need this
is that the behavior of udev cannot be speculated, so scsi_debug may
rmmod failed since udev scan open the device and take the reference of
module scsi_debug.
Thanks,
Kun.
Cheers,
Dave.
