block, cfq: misc updates to cfq_io_context
Make the following changes to prepare for ioc/cic management cleanup.
* Add cic->q so that ioc can determine the associated queue without
querying cfq. This will eventually replace ->key.
* Factor out cfq_release_cic() from cic_free_func(). This function
assumes that the caller handled locking.
* Rename __cfq_exit_single_io_context() to cfq_exit_cic() and make it
take only @cic.
* Restructure cfq_cic_link() for future updates.
This patch doesn't introduce any functional changes.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index d42d89c..a612ca6 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -2709,21 +2709,26 @@
call_rcu(&cic->rcu_head, cfq_cic_free_rcu);
}
-static void cic_free_func(struct io_context *ioc, struct cfq_io_context *cic)
+static void cfq_release_cic(struct cfq_io_context *cic)
{
- unsigned long flags;
+ struct io_context *ioc = cic->ioc;
unsigned long dead_key = (unsigned long) cic->key;
BUG_ON(!(dead_key & CIC_DEAD_KEY));
-
- spin_lock_irqsave(&ioc->lock, flags);
radix_tree_delete(&ioc->radix_root, dead_key >> CIC_DEAD_INDEX_SHIFT);
hlist_del_rcu(&cic->cic_list);
- spin_unlock_irqrestore(&ioc->lock, flags);
-
cfq_cic_free(cic);
}
+static void cic_free_func(struct io_context *ioc, struct cfq_io_context *cic)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&ioc->lock, flags);
+ cfq_release_cic(cic);
+ spin_unlock_irqrestore(&ioc->lock, flags);
+}
+
/*
* Must be called with rcu_read_lock() held or preemption otherwise disabled.
* Only two callers of this - ->dtor() which is called with the rcu_read_lock(),
@@ -2773,9 +2778,9 @@
cfq_put_queue(cfqq);
}
-static void __cfq_exit_single_io_context(struct cfq_data *cfqd,
- struct cfq_io_context *cic)
+static void cfq_exit_cic(struct cfq_io_context *cic)
{
+ struct cfq_data *cfqd = cic_to_cfqd(cic);
struct io_context *ioc = cic->ioc;
list_del_init(&cic->queue_list);
@@ -2823,7 +2828,7 @@
*/
smp_read_barrier_depends();
if (cic->key == cfqd)
- __cfq_exit_single_io_context(cfqd, cic);
+ cfq_exit_cic(cic);
spin_unlock_irqrestore(q->queue_lock, flags);
}
@@ -3161,28 +3166,29 @@
int ret;
ret = radix_tree_preload(gfp_mask);
+ if (ret)
+ goto out;
+
+ cic->ioc = ioc;
+ cic->key = cfqd;
+ cic->q = cfqd->queue;
+
+ spin_lock_irqsave(&ioc->lock, flags);
+ ret = radix_tree_insert(&ioc->radix_root, cfqd->queue->id, cic);
+ if (!ret)
+ hlist_add_head_rcu(&cic->cic_list, &ioc->cic_list);
+ spin_unlock_irqrestore(&ioc->lock, flags);
+
+ radix_tree_preload_end();
+
if (!ret) {
- cic->ioc = ioc;
- cic->key = cfqd;
-
- spin_lock_irqsave(&ioc->lock, flags);
- ret = radix_tree_insert(&ioc->radix_root, cfqd->queue->id, cic);
- if (!ret)
- hlist_add_head_rcu(&cic->cic_list, &ioc->cic_list);
- spin_unlock_irqrestore(&ioc->lock, flags);
-
- radix_tree_preload_end();
-
- if (!ret) {
- spin_lock_irqsave(cfqd->queue->queue_lock, flags);
- list_add(&cic->queue_list, &cfqd->cic_list);
- spin_unlock_irqrestore(cfqd->queue->queue_lock, flags);
- }
+ spin_lock_irqsave(cfqd->queue->queue_lock, flags);
+ list_add(&cic->queue_list, &cfqd->cic_list);
+ spin_unlock_irqrestore(cfqd->queue->queue_lock, flags);
}
-
+out:
if (ret)
printk(KERN_ERR "cfq: cic link failed!\n");
-
return ret;
}
@@ -3922,7 +3928,7 @@
struct cfq_io_context,
queue_list);
- __cfq_exit_single_io_context(cfqd, cic);
+ cfq_exit_cic(cic);
}
cfq_put_async_queues(cfqd);