smp_wmb();
cic->key = cfqd_dead_key(cfqd);
+ rcu_read_lock();
if (rcu_dereference(ioc->ioc_data) == cic) {
+ rcu_read_unlock();
spin_lock(&ioc->lock);
rcu_assign_pointer(ioc->ioc_data, NULL);
spin_unlock(&ioc->lock);
- }
+ } else
+ rcu_read_unlock();
if (cic->cfqq[BLK_RW_ASYNC]) {
cfq_exit_cfqq(cfqd, cic->cfqq[BLK_RW_ASYNC]);
spin_lock_irqsave(&ioc->lock, flags);
- BUG_ON(ioc->ioc_data == cic);
+ BUG_ON(rcu_dereference_check(ioc->ioc_data,
+ lockdep_is_held(&ioc->lock)) == cic);
radix_tree_delete(&ioc->radix_root, cfqd->cic_index);
hlist_del_rcu(&cic->cic_list);
}
}
- if (ret)
+ if (ret && ret != -EEXIST)
printk(KERN_ERR "cfq: cic link failed!\n");
return ret;
{
struct io_context *ioc = NULL;
struct cfq_io_context *cic;
+ int ret;
might_sleep_if(gfp_mask & __GFP_WAIT);
if (!ioc)
return NULL;
+retry:
cic = cfq_cic_lookup(cfqd, ioc);
if (cic)
goto out;
if (cic == NULL)
goto err;
- if (cfq_cic_link(cfqd, ioc, cic, gfp_mask))
+ ret = cfq_cic_link(cfqd, ioc, cic, gfp_mask);
+ if (ret == -EEXIST) {
+ /* someone has linked cic to ioc already */
+ cfq_cic_free(cic);
+ goto retry;
+ } else if (ret)
goto err_free;
out:
if (blkio_alloc_blkg_stats(&cfqg->blkg)) {
kfree(cfqg);
+
+ spin_lock(&cic_index_lock);
+ ida_remove(&cic_index_ida, cfqd->cic_index);
+ spin_unlock(&cic_index_lock);
+
kfree(cfqd);
return NULL;
}