if (ids->in_use >= size)
return -ENOSPC;
+ spin_lock_init(&new->lock);
+ new->deleted = 0;
+ rcu_read_lock();
+ spin_lock(&new->lock);
+
err = idr_get_new(&ids->ipcs_idr, new, &id);
- if (err)
+ if (err) {
+ spin_unlock(&new->lock);
+ rcu_read_unlock();
return err;
+ }
ids->in_use++;
ids->seq = 0;
new->id = ipc_buildid(id, new->seq);
- spin_lock_init(&new->lock);
- new->deleted = 0;
- rcu_read_lock();
- spin_lock(&new->lock);
return id;
}
* Look for an id in the ipc ids idr and lock the associated ipc object.
*
* The ipc object is locked on exit.
- *
- * This is the routine that should be called when the rw_mutex is not already
- * held, i.e. idr tree not protected: it protects the idr tree in read mode
- * during the idr_find().
*/
struct kern_ipc_perm *ipc_lock(struct ipc_ids *ids, int id)
struct kern_ipc_perm *out;
int lid = ipcid_to_idx(id);
- down_read(&ids->rw_mutex);
-
rcu_read_lock();
out = idr_find(&ids->ipcs_idr, lid);
if (out == NULL) {
rcu_read_unlock();
- up_read(&ids->rw_mutex);
return ERR_PTR(-EINVAL);
}
- up_read(&ids->rw_mutex);
-
spin_lock(&out->lock);
/* ipc_rmid() may have already freed the ID while ipc_lock
return out;
}
-/**
- * ipc_lock_down - Lock an ipc structure with rw_sem held
- * @ids: IPC identifier set
- * @id: ipc id to look for
- *
- * Look for an id in the ipc ids idr and lock the associated ipc object.
- *
- * The ipc object is locked on exit.
- *
- * This is the routine that should be called when the rw_mutex is already
- * held, i.e. idr tree protected.
- */
-
-struct kern_ipc_perm *ipc_lock_down(struct ipc_ids *ids, int id)
-{
- struct kern_ipc_perm *out;
- int lid = ipcid_to_idx(id);
-
- rcu_read_lock();
- out = idr_find(&ids->ipcs_idr, lid);
- if (out == NULL) {
- rcu_read_unlock();
- return ERR_PTR(-EINVAL);
- }
-
- spin_lock(&out->lock);
-
- /*
- * No need to verify that the structure is still valid since the
- * rw_mutex is held.
- */
- return out;
-}
-
-struct kern_ipc_perm *ipc_lock_check_down(struct ipc_ids *ids, int id)
-{
- struct kern_ipc_perm *out;
-
- out = ipc_lock_down(ids, id);
- if (IS_ERR(out))
- return out;
-
- if (ipc_checkid(out, id)) {
- ipc_unlock(out);
- return ERR_PTR(-EIDRM);
- }
-
- return out;
-}
-
struct kern_ipc_perm *ipc_lock_check(struct ipc_ids *ids, int id)
{
struct kern_ipc_perm *out;
int err;
down_write(&ids->rw_mutex);
- ipcp = ipc_lock_check_down(ids, id);
+ ipcp = ipc_lock_check(ids, id);
if (IS_ERR(ipcp)) {
err = PTR_ERR(ipcp);
goto out_up;