void put_filp(struct file *file)
{
if (atomic_long_dec_and_test(&file->f_count)) {
security_file_free(file);
file_sb_list_del(file);
file_free(file);
}
}
void unix_notinflight(struct file *fp)
{
struct sock *s = unix_get_socket(fp);
if (s) {
struct unix_sock *u = unix_sk(s);
spin_lock(&unix_gc_lock);
BUG_ON(list_empty(&u->link));
if (atomic_long_dec_and_test(&u->inflight))
list_del_init(&u->link);
unix_tot_inflight--;
spin_unlock(&unix_gc_lock);
}
}
int put_io_context(struct io_context *ioc)
{
if (ioc == NULL)
return 1;
BUG_ON(atomic_long_read(&ioc->refcount) == 0);
if (atomic_long_dec_and_test(&ioc->refcount)) {
rcu_read_lock();
cfq_dtor(ioc);
rcu_read_unlock();
kmem_cache_free(iocontext_cachep, ioc);
return 1;
}
return 0;
}
/*
* IO Context helper functions. put_io_context() returns 1 if there are no
* more users of this io context, 0 otherwise.
*/
int put_io_context(struct io_context *ioc)
{
if (ioc == NULL)
return 1;
BUG_ON(atomic_long_read(&ioc->refcount) == 0);
if (atomic_long_dec_and_test(&ioc->refcount)) {
rcu_read_lock();
if (ioc->aic && ioc->aic->dtor)
ioc->aic->dtor(ioc->aic);
hlist_sched_dtor(ioc, &ioc->cic_list);
hlist_sched_dtor(ioc, &ioc->bfq_cic_list);
rcu_read_unlock();
kmem_cache_free(iocontext_cachep, ioc);
return 1;
}
return 0;
}
void fput(struct file *file)
{
if (atomic_long_dec_and_test(&file->f_count))
__fput(file);
}
static void acct_put(struct bsd_acct_struct *p)
{
if (atomic_long_dec_and_test(&p->count))
kfree_rcu(p, rcu);
}
/**
* put_io_context - put a reference of io_context
* @ioc: io_context to put
* @locked_q: request_queue the caller is holding queue_lock of (hint)
*
* Decrement reference count of @ioc and release it if the count reaches
* zero. If the caller is holding queue_lock of a queue, it can indicate
* that with @locked_q. This is an optimization hint and the caller is
* allowed to pass in %NULL even when it's holding a queue_lock.
*/
void put_io_context(struct io_context *ioc, struct request_queue *locked_q)
{
struct request_queue *last_q = locked_q;
unsigned long flags;
if (ioc == NULL)
return;
BUG_ON(atomic_long_read(&ioc->refcount) <= 0);
if (locked_q)
lockdep_assert_held(locked_q->queue_lock);
if (!atomic_long_dec_and_test(&ioc->refcount))
return;
/*
* Destroy @ioc. This is a bit messy because icq's are chained
* from both ioc and queue, and ioc->lock nests inside queue_lock.
* The inner ioc->lock should be held to walk our icq_list and then
* for each icq the outer matching queue_lock should be grabbed.
* ie. We need to do reverse-order double lock dancing.
*
* Another twist is that we are often called with one of the
* matching queue_locks held as indicated by @locked_q, which
* prevents performing double-lock dance for other queues.
*
* So, we do it in two stages. The fast path uses the queue_lock
* the caller is holding and, if other queues need to be accessed,
* uses trylock to avoid introducing locking dependency. This can
* handle most cases, especially if @ioc was performing IO on only
* single device.
*
* If trylock doesn't cut it, we defer to @ioc->release_work which
* can do all the double-locking dancing.
*/
spin_lock_irqsave_nested(&ioc->lock, flags,
ioc_release_depth(locked_q));
while (!hlist_empty(&ioc->icq_list)) {
struct io_cq *icq = hlist_entry(ioc->icq_list.first,
struct io_cq, ioc_node);
struct request_queue *this_q = icq->q;
if (this_q != last_q) {
if (last_q && last_q != locked_q)
spin_unlock(last_q->queue_lock);
last_q = NULL;
if (!spin_trylock(this_q->queue_lock))
break;
last_q = this_q;
continue;
}
ioc_exit_icq(icq);
}
if (last_q && last_q != locked_q)
spin_unlock(last_q->queue_lock);
spin_unlock_irqrestore(&ioc->lock, flags);
/* if no icq is left, we're done; otherwise, kick release_work */
if (hlist_empty(&ioc->icq_list))
kmem_cache_free(iocontext_cachep, ioc);
else
schedule_work(&ioc->release_work);
}
