conf->slab_cache = NULL;
}
+/*
+ * This helper wraps rcu_dereference_protected() and can be used when
+ * it is known that the nr_pending of the rdev is elevated.
+ */
+static struct md_rdev *rdev_pend_deref(struct md_rdev __rcu *rdev)
+{
+ return rcu_dereference_protected(rdev,
+ atomic_read(&rcu_access_pointer(rdev)->nr_pending));
+}
+
static void raid5_end_read_request(struct bio * bi)
{
struct stripe_head *sh = bi->bi_private;
* In that case it moved down to 'rdev'.
* rdev is not removed until all requests are finished.
*/
- rdev = conf->disks[i].replacement;
+ rdev = rdev_pend_deref(conf->disks[i].replacement);
if (!rdev)
- rdev = conf->disks[i].rdev;
+ rdev = rdev_pend_deref(conf->disks[i].rdev);
if (use_new_offset(conf, sh))
s = sh->sector + rdev->new_data_offset;
for (i = 0 ; i < disks; i++) {
if (bi == &sh->dev[i].req) {
- rdev = conf->disks[i].rdev;
+ rdev = rdev_pend_deref(conf->disks[i].rdev);
break;
}
if (bi == &sh->dev[i].rreq) {
- rdev = conf->disks[i].replacement;
+ rdev = rdev_pend_deref(conf->disks[i].replacement);
if (rdev)
replacement = 1;
else
* replaced it. rdev is not removed
* until all requests are finished.
*/
- rdev = conf->disks[i].rdev;
+ rdev = rdev_pend_deref(conf->disks[i].rdev);
break;
}
}
struct r5dev *dev = &sh->dev[i];
if (test_and_clear_bit(R5_WriteError, &dev->flags)) {
/* We own a safe reference to the rdev */
- rdev = conf->disks[i].rdev;
+ rdev = rdev_pend_deref(conf->disks[i].rdev);
if (!rdev_set_badblocks(rdev, sh->sector,
RAID5_STRIPE_SECTORS(conf), 0))
md_error(conf->mddev, rdev);
rdev_dec_pending(rdev, conf->mddev);
}
if (test_and_clear_bit(R5_MadeGood, &dev->flags)) {
- rdev = conf->disks[i].rdev;
+ rdev = rdev_pend_deref(conf->disks[i].rdev);
rdev_clear_badblocks(rdev, sh->sector,
RAID5_STRIPE_SECTORS(conf), 0);
rdev_dec_pending(rdev, conf->mddev);
}
if (test_and_clear_bit(R5_MadeGoodRepl, &dev->flags)) {
- rdev = conf->disks[i].replacement;
+ rdev = rdev_pend_deref(conf->disks[i].replacement);
if (!rdev)
/* rdev have been moved down */
- rdev = conf->disks[i].rdev;
+ rdev = rdev_pend_deref(conf->disks[i].rdev);
rdev_clear_badblocks(rdev, sh->sector,
RAID5_STRIPE_SECTORS(conf), 0);
rdev_dec_pending(rdev, conf->mddev);