@@ -4,11 +4,13 @@
#
# Functions useful for tests on unique block devices
+. common/module
+
_require_scsi_debug()
{
# make sure we have the module and it's not already used
modinfo scsi_debug 2>&1 > /dev/null || _notrun "scsi_debug module not found"
- lsmod | grep -wq scsi_debug && (rmmod scsi_debug || _notrun "scsi_debug module in use")
+ lsmod | grep -wq scsi_debug && (_patient_rmmod scsi_debug || _notrun "scsi_debug module in use")
# make sure it has the features we need
# logical/physical sectors plus unmap support all went in together
modinfo scsi_debug | grep -wq sector_size || _notrun "scsi_debug too old"
@@ -53,5 +55,5 @@ _put_scsi_debug_dev()
$UDEV_SETTLE_PROG
n=$((n-1))
done
- rmmod scsi_debug || _fail "Could not remove scsi_debug module"
+ _patient_rmmod scsi_debug || _fail "Could not remove scsi_debug module"
}
If you try to run tests such as generic/108 in a loop you'll eventually see a failure, but the failure can be a false positive and the test was just unable to remove the scsi_debug module. We need to give some time for the refcnt to become 0. For instance for the test generic/108 the refcnt lingers between 2 and 1. It should be 0 when we're done but a bit of time seems to be required. The chance of us trying to run rmmod when the refcnt is 2 or 1 is low, about 1/30 times if you run the test in a loop on linux-next today. Likewise, even when its 0 we just need a tiny breather before we can remove the module (sleep 10 suffices) but this is only required on older kernels. Otherwise removing the module will just fail. Some of these races are documented on the korg#212337, and Doug Gilbert has posted at least one patch attempt to try to help with this [1]. The patch does not resolve all the issues though, it helps though. [0] https://bugzilla.kernel.org/show_bug.cgi?id=212337 [1] https://lkml.kernel.org/r/20210508230745.27923-1-dgilbert@interlog.com Signed-off-by: Luis Chamberlain <mcgrof@kernel.org> --- common/scsi_debug | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)