/**
* __bfq_exit_single_io_context - deassociate @cic from any running task.
* @bfqd: bfq_data on which @cic is valid.
* @cic: the cic being exited.
*
* Whenever no more tasks are using @cic or @bfqd is deallocated we
* need to invalidate its entry in the radix tree hash table and to
* release the queues it refers to.
*
* Called under the queue lock.
*/
static void __bfq_exit_single_io_context(struct bfq_data *bfqd,
struct cfq_io_context *cic)
{
struct io_context *ioc = cic->ioc;
list_del_init(&cic->queue_list);
/*
* Make sure dead mark is seen for dead queues
*/
smp_wmb();
rcu_assign_pointer(cic->key, bfqd_dead_key(bfqd));
/*
* No write-side locking as no task is using @ioc (they're exited
* or bfqd is being deallocated.
*/
if (ioc->ioc_data == cic)
rcu_assign_pointer(ioc->ioc_data, NULL);
if (cic->cfqq[BLK_RW_ASYNC] != NULL) {
bfq_exit_bfqq(bfqd, cic->cfqq[BLK_RW_ASYNC]);
cic->cfqq[BLK_RW_ASYNC] = NULL;
}
if (cic->cfqq[BLK_RW_SYNC] != NULL) {
bfq_exit_bfqq(bfqd, cic->cfqq[BLK_RW_SYNC]);
cic->cfqq[BLK_RW_SYNC] = NULL;
}
}
/**
* bfq_drop_dead_cic - free an exited cic.
* @bfqd: bfq data for the device in use.
* @ioc: io_context owning @cic.
* @cic: the @cic to free.
*
* We drop cfq io contexts lazily, so we may find a dead one.
*/
static void bfq_drop_dead_cic(struct bfq_data *bfqd, struct io_context *ioc,
struct cfq_io_context *cic)
{
unsigned long flags;
WARN_ON(!list_empty(&cic->queue_list));
BUG_ON(cic->key != bfqd_dead_key(bfqd));
spin_lock_irqsave(&ioc->lock, flags);
BUG_ON(ioc->ioc_data == cic);
/*
* With shared I/O contexts two lookups may race and drop the
* same cic more than one time: RCU guarantees that the storage
* will not be freed too early, here we make sure that we do
* not try to remove the cic from the hashing structures multiple
* times.
*/
if (!hlist_unhashed(&cic->cic_list)) {
radix_tree_delete(&ioc->bfq_radix_root, bfqd->cic_index);
hlist_del_init_rcu(&cic->cic_list);
bfq_cic_free(cic);
}
spin_unlock_irqrestore(&ioc->lock, flags);
}
/**
* __bfq_exit_single_io_context - deassociate @cic from any running task.
* @bfqd: bfq_data on which @cic is valid.
* @cic: the cic being exited.
*
* Whenever no more tasks are using @cic or @bfqd is deallocated we
* need to invalidate its entry in the radix tree hash table and to
* release the queues it refers to.
*
* Called under the queue lock.
*/
static void __bfq_exit_single_io_context(struct bfq_data *bfqd,
struct cfq_io_context *cic)
{
struct io_context *ioc = cic->ioc;
list_del_init(&cic->queue_list);
/*
* Make sure dead mark is seen for dead queues
*/
smp_wmb();
rcu_assign_pointer(cic->key, bfqd_dead_key(bfqd));
/*
* No write-side locking as no task is using @ioc (they're exited
* or bfqd is being deallocated.
*/
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] != NULL) {
bfq_exit_bfqq(bfqd, cic->cfqq[BLK_RW_ASYNC]);
cic->cfqq[BLK_RW_ASYNC] = NULL;
}
spin_lock(&bfqd->eqm_lock);
if (cic->cfqq[BLK_RW_SYNC] != NULL) {
/*
* If the bic is using a shared queue, put the reference
* taken on the io_context when the bic started using a
* shared bfq_queue.
*/
if (bfq_bfqq_coop(cic->cfqq[BLK_RW_SYNC]))
put_io_context(ioc);
bfq_exit_bfqq(bfqd, cic->cfqq[BLK_RW_SYNC]);
cic->cfqq[BLK_RW_SYNC] = NULL;
}
spin_unlock(&bfqd->eqm_lock);
}
/**
* __bfq_exit_single_io_context - deassociate @cic from any running task.
* @bfqd: bfq_data on which @cic is valid.
* @cic: the cic being exited.
*
* Whenever no more tasks are using @cic or @bfqd is deallocated we
* need to invalidate its entry in the radix tree hash table and to
* release the queues it refers to.
*
* Called under the queue lock.
*/
static void __bfq_exit_single_io_context(struct bfq_data *bfqd,
struct cfq_io_context *cic)
{
struct io_context *ioc = cic->ioc;
list_del_init(&cic->queue_list);
/*
* Make sure dead mark is seen for dead queues
*/
smp_wmb();
rcu_assign_pointer(cic->key, bfqd_dead_key(bfqd));
/*
* No write-side locking as no task is using @ioc (they're exited
* or bfqd is being deallocated.
*/
<<<<<<< HEAD
