This test on ->writes_pending cannot be safe as the counter can be incremented at any moment and cannot be locked against. Change it to test conf->active_stripes, which at least can be locked against. More changes are still needed. A future patch will change ->writes_pending, and testing it here will be very inconvenient. Signed-off-by: NeilBrown <neilb@xxxxxxxx> --- drivers/md/raid5.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 4e906e5903e8..5eb3764bafd3 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -7528,9 +7528,12 @@ static int raid5_remove_disk(struct mddev *mddev, struct md_rdev *rdev) /* * we can't wait pending write here, as this is called in * raid5d, wait will deadlock. + * neilb: there is no locking about new writes here, + * so this cannot be safe. */ - if (atomic_read(&mddev->writes_pending)) + if (atomic_read(&conf->active_stripes)) { return -EBUSY; + } log_exit(conf); return 0; } -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html