#ifndef IOCONTEXT_H #define IOCONTEXT_H #include <linux/radix-tree.h> #include <linux/rcupdate.h> struct cfq_queue; struct cfq_ttime { unsigned long last_end_request; unsigned long ttime_total; unsigned long ttime_samples; unsigned long ttime_mean; }; struct cfq_io_context { void *key; struct cfq_queue *cfqq[2]; struct io_context *ioc; struct cfq_ttime ttime; struct list_head queue_list; struct hlist_node cic_list; void (*dtor)(struct io_context *); /* destructor */ void (*exit)(struct io_context *); /* called on task exit */ struct rcu_head rcu_head; }; /* * 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; unsigned short ioprio_changed; #if defined(CONFIG_BLK_CGROUP) || defined(CONFIG_BLK_CGROUP_MODULE) unsigned short cgroup_changed; #endif /* * 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 radix_root; struct hlist_head cic_list; void __rcu *ioc_data; }; 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 int put_io_context(struct io_context *ioc); void exit_io_context(struct task_struct *task); struct io_context *get_io_context(gfp_t gfp_flags, int node); struct io_context *alloc_io_context(gfp_t gfp_flags, int node); #else static inline void exit_io_context(struct task_struct *task) { } struct io_context; static inline int put_io_context(struct io_context *ioc) { return 1; } #endif #endif