1
0
Fork 0
alistair23-linux/include/linux/iocontext.h

83 lines
1.9 KiB
C

#ifndef IOCONTEXT_H
#define IOCONTEXT_H
#include <linux/radix-tree.h>
#include <linux/rcupdate.h>
#include <linux/workqueue.h>
enum {
ICQ_IOPRIO_CHANGED,
ICQ_CGROUP_CHANGED,
};
struct io_cq {
struct request_queue *q;
struct io_context *ioc;
struct list_head q_node;
struct hlist_node ioc_node;
unsigned long changed;
struct rcu_head rcu_head;
void (*exit)(struct io_cq *);
void (*release)(struct io_cq *);
};
/*
* I/O subsystem state of the associated processes. It is refcounted
* and kmalloc'ed. These could be shared between processes.
*/
struct io_context {
atomic_long_t refcount;
atomic_t nr_tasks;
/* all the fields below are protected by this lock */
spinlock_t lock;
unsigned short ioprio;
/*
* For request batching
*/
int nr_batch_requests; /* Number of requests left in the batch */
unsigned long last_waited; /* Time last woken after wait for request */
struct radix_tree_root icq_tree;
struct io_cq __rcu *icq_hint;
struct hlist_head icq_list;
struct work_struct release_work;
};
static inline struct io_context *ioc_task_link(struct io_context *ioc)
{
/*
* if ref count is zero, don't allow sharing (ioc is going away, it's
* a race).
*/
if (ioc && atomic_long_inc_not_zero(&ioc->refcount)) {
atomic_inc(&ioc->nr_tasks);
return ioc;
}
return NULL;
}
struct task_struct;
#ifdef CONFIG_BLOCK
void put_io_context(struct io_context *ioc, struct request_queue *locked_q);
void exit_io_context(struct task_struct *task);
struct io_context *get_task_io_context(struct task_struct *task,
gfp_t gfp_flags, int node);
void ioc_ioprio_changed(struct io_context *ioc, int ioprio);
void ioc_cgroup_changed(struct io_context *ioc);
#else
struct io_context;
static inline void put_io_context(struct io_context *ioc,
struct request_queue *locked_q) { }
static inline void exit_io_context(struct task_struct *task) { }
#endif
#endif