Subversion Repositories test_project

#ifndef __LINUX__AIO_H

#define __LINUX__AIO_H

#include <linux/list.h>

#include <linux/workqueue.h>

#include <linux/aio_abi.h>

#include <linux/uio.h>

#include <asm/atomic.h>

#include <linux/uio.h>

#define AIO_MAXSEGS             4

#define AIO_KIOGRP_NR_ATOMIC    8

struct kioctx;

/* Notes on cancelling a kiocb:

 *      If a kiocb is cancelled, aio_complete may return 0 to indicate

 *      that cancel has not yet disposed of the kiocb.  All cancel

 *      operations *must* call aio_put_req to dispose of the kiocb

 *      to guard against races with the completion code.

 */

#define KIOCB_C_CANCELLED       0x01

#define KIOCB_C_COMPLETE        0x02

#define KIOCB_SYNC_KEY          (~0U)

/* ki_flags bits */

/*

 * This may be used for cancel/retry serialization in the future, but

 * for now it's unused and we probably don't want modules to even

 * think they can use it.

 */

/* #define KIF_LOCKED           0 */

#define KIF_KICKED              1

#define KIF_CANCELLED           2

#define kiocbTryLock(iocb)      test_and_set_bit(KIF_LOCKED, &(iocb)->ki_flags)

#define kiocbTryKick(iocb)      test_and_set_bit(KIF_KICKED, &(iocb)->ki_flags)

#define kiocbSetLocked(iocb)    set_bit(KIF_LOCKED, &(iocb)->ki_flags)

#define kiocbSetKicked(iocb)    set_bit(KIF_KICKED, &(iocb)->ki_flags)

#define kiocbSetCancelled(iocb) set_bit(KIF_CANCELLED, &(iocb)->ki_flags)

#define kiocbClearLocked(iocb)  clear_bit(KIF_LOCKED, &(iocb)->ki_flags)

#define kiocbClearKicked(iocb)  clear_bit(KIF_KICKED, &(iocb)->ki_flags)

#define kiocbClearCancelled(iocb)       clear_bit(KIF_CANCELLED, &(iocb)->ki_flags)

#define kiocbIsLocked(iocb)     test_bit(KIF_LOCKED, &(iocb)->ki_flags)

#define kiocbIsKicked(iocb)     test_bit(KIF_KICKED, &(iocb)->ki_flags)

#define kiocbIsCancelled(iocb)  test_bit(KIF_CANCELLED, &(iocb)->ki_flags)

/* is there a better place to document function pointer methods? */

/**

 * ki_retry     -       iocb forward progress callback

 * @kiocb:      The kiocb struct to advance by performing an operation.

 *

 * This callback is called when the AIO core wants a given AIO operation

 * to make forward progress.  The kiocb argument describes the operation

 * that is to be performed.  As the operation proceeds, perhaps partially,

 * ki_retry is expected to update the kiocb with progress made.  Typically

 * ki_retry is set in the AIO core and it itself calls file_operations

 * helpers.

 *

 * ki_retry's return value determines when the AIO operation is completed

 * and an event is generated in the AIO event ring.  Except the special

 * return values described below, the value that is returned from ki_retry

 * is transferred directly into the completion ring as the operation's

 * resulting status.  Once this has happened ki_retry *MUST NOT* reference

 * the kiocb pointer again.

 *

 * If ki_retry returns -EIOCBQUEUED it has made a promise that aio_complete()

 * will be called on the kiocb pointer in the future.  The AIO core will

 * not ask the method again -- ki_retry must ensure forward progress.

 * aio_complete() must be called once and only once in the future, multiple

 * calls may result in undefined behaviour.

 *

 * If ki_retry returns -EIOCBRETRY it has made a promise that kick_iocb()

 * will be called on the kiocb pointer in the future.  This may happen

 * through generic helpers that associate kiocb->ki_wait with a wait

 * queue head that ki_retry uses via current->io_wait.  It can also happen

 * with custom tracking and manual calls to kick_iocb(), though that is

 * discouraged.  In either case, kick_iocb() must be called once and only

 * once.  ki_retry must ensure forward progress, the AIO core will wait

 * indefinitely for kick_iocb() to be called.

 */

struct kiocb {

        struct list_head        ki_run_list;

        unsigned long           ki_flags;

        int                     ki_users;

        unsigned                ki_key;         /* id of this request */

        struct file             *ki_filp;

        struct kioctx           *ki_ctx;        /* may be NULL for sync ops */

        int                     (*ki_cancel)(struct kiocb *, struct io_event *);

        ssize_t                 (*ki_retry)(struct kiocb *);

        void                    (*ki_dtor)(struct kiocb *);

        union {

                void __user             *user;

                struct task_struct      *tsk;

        } ki_obj;

        __u64                   ki_user_data;   /* user's data for completion */

        wait_queue_t            ki_wait;

        loff_t                  ki_pos;

        atomic_t                ki_bio_count;   /* num bio used for this iocb */

        void                    *private;

        /* State that we remember to be able to restart/retry  */

        unsigned short          ki_opcode;

        size_t                  ki_nbytes;      /* copy of iocb->aio_nbytes */

        char                    __user *ki_buf; /* remaining iocb->aio_buf */

        size_t                  ki_left;        /* remaining bytes */

        struct iovec            ki_inline_vec;  /* inline vector */

        struct iovec            *ki_iovec;

        unsigned long           ki_nr_segs;

        unsigned long           ki_cur_seg;

        struct list_head        ki_list;        /* the aio core uses this

                                                 * for cancellation */

        /*

         * If the aio_resfd field of the userspace iocb is not zero,

         * this is the underlying file* to deliver event to.

         */

        struct file             *ki_eventfd;

};

#define is_sync_kiocb(iocb)     ((iocb)->ki_key == KIOCB_SYNC_KEY)

#define init_sync_kiocb(x, filp)                        \

        do {                                            \

                struct task_struct *tsk = current;      \

                (x)->ki_flags = 0;                       \

                (x)->ki_users = 1;                      \

                (x)->ki_key = KIOCB_SYNC_KEY;           \

                (x)->ki_filp = (filp);                  \

                (x)->ki_ctx = NULL;                     \

                (x)->ki_cancel = NULL;                  \

                (x)->ki_retry = NULL;                   \

                (x)->ki_dtor = NULL;                    \

                (x)->ki_obj.tsk = tsk;                  \

                (x)->ki_user_data = 0;                  \

                init_wait((&(x)->ki_wait));             \

        } while (0)

#define AIO_RING_MAGIC                  0xa10a10a1

#define AIO_RING_COMPAT_FEATURES        1

#define AIO_RING_INCOMPAT_FEATURES      0

struct aio_ring {

        unsigned        id;     /* kernel internal index number */

        unsigned        nr;     /* number of io_events */

        unsigned        head;

        unsigned        tail;

        unsigned        magic;

        unsigned        compat_features;

        unsigned        incompat_features;

        unsigned        header_length;  /* size of aio_ring */

        struct io_event         io_events[0];

}; /* 128 bytes + ring size */

#define aio_ring_avail(info, ring)      (((ring)->head + (info)->nr - 1 - (ring)->tail) % (info)->nr)

#define AIO_RING_PAGES  8

struct aio_ring_info {

        unsigned long           mmap_base;

        unsigned long           mmap_size;

        struct page             **ring_pages;

        spinlock_t              ring_lock;

        long                    nr_pages;

        unsigned                nr, tail;

        struct page             *internal_pages[AIO_RING_PAGES];

};

struct kioctx {

        atomic_t                users;

        int                     dead;

        struct mm_struct        *mm;

        /* This needs improving */

        unsigned long           user_id;

        struct kioctx           *next;

        wait_queue_head_t       wait;

        spinlock_t              ctx_lock;

        int                     reqs_active;

        struct list_head        active_reqs;    /* used for cancellation */

        struct list_head        run_list;       /* used for kicked reqs */

        /* sys_io_setup currently limits this to an unsigned int */

        unsigned                max_reqs;

        struct aio_ring_info    ring_info;

        struct delayed_work     wq;

};

/* prototypes */

extern unsigned aio_max_size;

extern ssize_t FASTCALL(wait_on_sync_kiocb(struct kiocb *iocb));

extern int FASTCALL(aio_put_req(struct kiocb *iocb));

extern void FASTCALL(kick_iocb(struct kiocb *iocb));

extern int FASTCALL(aio_complete(struct kiocb *iocb, long res, long res2));

extern void FASTCALL(__put_ioctx(struct kioctx *ctx));

struct mm_struct;

extern void FASTCALL(exit_aio(struct mm_struct *mm));

extern struct kioctx *lookup_ioctx(unsigned long ctx_id);

extern int FASTCALL(io_submit_one(struct kioctx *ctx,

                        struct iocb __user *user_iocb, struct iocb *iocb));

/* semi private, but used by the 32bit emulations: */

struct kioctx *lookup_ioctx(unsigned long ctx_id);

int FASTCALL(io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb,

                                  struct iocb *iocb));

#define get_ioctx(kioctx) do {                                          \

        BUG_ON(atomic_read(&(kioctx)->users) <= 0);                      \

        atomic_inc(&(kioctx)->users);                                   \

} while (0)

#define put_ioctx(kioctx) do {                                          \

        BUG_ON(atomic_read(&(kioctx)->users) <= 0);                      \

        if (unlikely(atomic_dec_and_test(&(kioctx)->users)))            \

                __put_ioctx(kioctx);                                    \

} while (0)

#define io_wait_to_kiocb(wait) container_of(wait, struct kiocb, ki_wait)

#include <linux/aio_abi.h>

static inline struct kiocb *list_kiocb(struct list_head *h)

{

        return list_entry(h, struct kiocb, ki_list);

}

/* for sysctl: */

extern unsigned long aio_nr;

extern unsigned long aio_max_nr;

#endif /* __LINUX__AIO_H */