static void put_ldisc(struct tty_ldisc *ld)
{
unsigned long flags;
if (WARN_ON_ONCE(!ld))
return;
/*
* If this is the last user, free the ldisc, and
* release the ldisc ops.
*
* We really want an "atomic_dec_and_lock_irqsave()",
* but we don't have it, so this does it by hand.
*/
local_irq_save(flags);
if (atomic_dec_and_lock(&ld->users, &tty_ldisc_lock)) {
struct tty_ldisc_ops *ldo = ld->ops;
ldo->refcount--;
module_put(ldo->owner);
spin_unlock_irqrestore(&tty_ldisc_lock, flags);
kfree(ld);
return;
}
local_irq_restore(flags);
}
void auth_domain_put(struct auth_domain *dom)
{
if (atomic_dec_and_lock(&dom->ref.refcount, &auth_domain_lock)) {
hlist_del(&dom->hash);
dom->flavour->domain_release(dom);
spin_unlock(&auth_domain_lock);
}
}
/*
* put_ipc_ns - drop a reference to an ipc namespace.
* @ns: the namespace to put
*
* If this is the last task in the namespace exiting, and
* it is dropping the refcount to 0, then it can race with
* a task in another ipc namespace but in a mounts namespace
* which has this ipcns's mqueuefs mounted, doing some action
* with one of the mqueuefs files. That can raise the refcount.
* So dropping the refcount, and raising the refcount when
* accessing it through the VFS, are protected with mq_lock.
*
* (Clearly, a task raising the refcount on its own ipc_ns
* needn't take mq_lock since it can't race with the last task
* in the ipcns exiting).
*/
void put_ipc_ns(struct ipc_namespace *ns)
{
if (atomic_dec_and_lock(&ns->count, &mq_lock)) {
mq_clear_sbinfo(ns);
spin_unlock(&mq_lock);
mq_put_mnt(ns);
free_ipc_ns(ns);
}
}
void
put_layout_hdr(struct pnfs_layout_hdr *lo)
{
struct inode *inode = lo->plh_inode;
if (atomic_dec_and_lock(&lo->plh_refcount, &inode->i_lock)) {
destroy_layout_hdr(lo);
spin_unlock(&inode->i_lock);
}
}
/*
* Decrement the use count and release all resources for an mm.
*/
void mmput(struct mm_struct *mm)
{
if (atomic_dec_and_lock(&mm->mm_users, &mmlist_lock)) {
list_del(&mm->mmlist);
mmlist_nr--;
spin_unlock(&mmlist_lock);
exit_aio(mm);
exit_mmap(mm);
mmdrop(mm);
}
}
/* Wake netif's TX queue
* We want to be able to nest calls to netif_stop_queue(), since each
* channel can have an individual stop on the queue.
*/
void efx_wake_queue(struct efx_nic *efx)
{
local_bh_disable();
if (atomic_dec_and_lock(&efx->netif_stop_count,
&efx->netif_stop_lock)) {
EFX_TRACE(efx, "waking TX queue\n");
netif_wake_queue(efx->net_dev);
spin_unlock(&efx->netif_stop_lock);
}
local_bh_enable();
}
void ieee80211_rx_bss_put(struct ieee80211_local *local,
struct ieee80211_bss *bss)
{
local_bh_disable();
if (!atomic_dec_and_lock(&bss->users, &local->bss_lock)) {
local_bh_enable();
return;
}
__ieee80211_rx_bss_hash_del(local, bss);
list_del(&bss->list);
spin_unlock_bh(&local->bss_lock);
ieee80211_rx_bss_free(bss);
}
/*
* release a bundle
*/
void rxrpc_put_bundle(struct rxrpc_transport *trans,
struct rxrpc_conn_bundle *bundle)
{
_enter("%p,%p{%d}",trans, bundle, atomic_read(&bundle->usage));
if (atomic_dec_and_lock(&bundle->usage, &trans->client_lock)) {
_debug("Destroy bundle");
rb_erase(&bundle->node, &trans->bundles);
spin_unlock(&trans->client_lock);
ASSERT(list_empty(&bundle->unused_conns));
ASSERT(list_empty(&bundle->avail_conns));
ASSERT(list_empty(&bundle->busy_conns));
ASSERTCMP(bundle->num_conns, ==, 0);
key_put(bundle->key);
kfree(bundle);
}
void dput(struct dentry *dentry)
{
if (!dentry)
return;
repeat:
if (!atomic_dec_and_lock(&dentry->d_count, &dcache_lock))
return;
/* dput on a free dentry? */
if (!list_empty(&dentry->d_lru))
BUG();
/*
* AV: ->d_delete() is _NOT_ allowed to block now.
*/
if (dentry->d_op && dentry->d_op->d_delete) {
if (dentry->d_op->d_delete(dentry))
goto unhash_it;
}
/* Unreachable? Get rid of it */
if (list_empty(&dentry->d_hash))
goto kill_it;
list_add(&dentry->d_lru, &dentry_unused);
dentry_stat.nr_unused++;
spin_unlock(&dcache_lock);
return;
unhash_it:
list_del_init(&dentry->d_hash);
kill_it: {
struct dentry *parent;
list_del(&dentry->d_child);
/* drops the lock, at that point nobody can reach this dentry */
dentry_iput(dentry);
parent = dentry->d_parent;
d_free(dentry);
if (dentry == parent)
return;
dentry = parent;
goto repeat;
}
}
void dm_put(struct mapped_device *md)
{
struct dm_table *map;
BUG_ON(test_bit(DMF_FREEING, &md->flags));
if (atomic_dec_and_lock(&md->holders, &_minor_lock)) {
map = dm_get_table(md);
idr_replace(&_minor_idr, MINOR_ALLOCED, dm_disk(md)->first_minor);
set_bit(DMF_FREEING, &md->flags);
spin_unlock(&_minor_lock);
if (!dm_suspended(md)) {
dm_table_presuspend_targets(map);
dm_table_postsuspend_targets(map);
}
__unbind(md);
dm_table_put(map);
free_dev(md);
}
}
/**
* wb_congested_put - put a wb_congested
* @congested: wb_congested to put
*
* Put @congested and destroy it if the refcnt reaches zero.
*/
void wb_congested_put(struct bdi_writeback_congested *congested)
{
unsigned long flags;
local_irq_save(flags);
if (!atomic_dec_and_lock(&congested->refcnt, &cgwb_lock)) {
local_irq_restore(flags);
return;
}
/* bdi might already have been destroyed leaving @congested unlinked */
if (congested->bdi) {
rb_erase(&congested->rb_node,
&congested->bdi->cgwb_congested_tree);
congested->bdi = NULL;
}
spin_unlock_irqrestore(&cgwb_lock, flags);
kfree(congested);
}
void
put_lseg(struct pnfs_layout_segment *lseg)
{
struct inode *inode;
if (!lseg)
return;
dprintk("%s: lseg %p ref %d valid %d\n", __func__, lseg,
atomic_read(&lseg->pls_refcount),
test_bit(NFS_LSEG_VALID, &lseg->pls_flags));
inode = lseg->pls_layout->plh_inode;
if (atomic_dec_and_lock(&lseg->pls_refcount, &inode->i_lock)) {
LIST_HEAD(free_me);
put_lseg_common(lseg);
list_add(&lseg->pls_list, &free_me);
spin_unlock(&inode->i_lock);
pnfs_free_lseg_list(&free_me);
}
}
void
pnfs_put_lseg(struct pnfs_layout_segment *lseg)
{
struct pnfs_layout_hdr *lo;
struct inode *inode;
if (!lseg)
return;
dprintk("%s: lseg %p ref %d valid %d\n", __func__, lseg,
atomic_read(&lseg->pls_refcount),
test_bit(NFS_LSEG_VALID, &lseg->pls_flags));
lo = lseg->pls_layout;
inode = lo->plh_inode;
if (atomic_dec_and_lock(&lseg->pls_refcount, &inode->i_lock)) {
pnfs_get_layout_hdr(lo);
pnfs_layout_remove_lseg(lo, lseg);
spin_unlock(&inode->i_lock);
pnfs_free_lseg(lseg);
pnfs_put_layout_hdr(lo);
}
}
