root/include/linux/blk-iopoll.h

DEFINITIONS

1. blk_iopoll_sched_prep
2. blk_iopoll_disable_pending

#ifndef BLK_IOPOLL_H
#define BLK_IOPOLL_H

struct blk_iopoll;
typedef int (blk_iopoll_fn)(struct blk_iopoll *, int);

struct blk_iopoll {
        struct list_head list;
        unsigned long state;
        unsigned long data;
        int weight;
        int max;
        blk_iopoll_fn *poll;
};

enum {
        IOPOLL_F_SCHED          = 0,
        IOPOLL_F_DISABLE        = 1,
};

/*
 * Returns 0 if we successfully set the IOPOLL_F_SCHED bit, indicating
 * that we were the first to acquire this iop for scheduling. If this iop
 * is currently disabled, return "failure".
 */
static inline int blk_iopoll_sched_prep(struct blk_iopoll *iop)
{
        if (!test_bit(IOPOLL_F_DISABLE, &iop->state))
                return test_and_set_bit(IOPOLL_F_SCHED, &iop->state);

        return 1;
}

static inline int blk_iopoll_disable_pending(struct blk_iopoll *iop)
{
        return test_bit(IOPOLL_F_DISABLE, &iop->state);
}

extern void blk_iopoll_sched(struct blk_iopoll *);
extern void blk_iopoll_init(struct blk_iopoll *, int, blk_iopoll_fn *);
extern void blk_iopoll_complete(struct blk_iopoll *);
extern void __blk_iopoll_complete(struct blk_iopoll *);
extern void blk_iopoll_enable(struct blk_iopoll *);
extern void blk_iopoll_disable(struct blk_iopoll *);

#endif