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/*

 * Function declerations and data structures related to the splice

 * implementation.

 *

 * Copyright (C) 2007 Jens Axboe <jens.axboe@oracle.com>

 *

 */

#ifndef SPLICE_H

#define SPLICE_H

#include <linux/pipe_fs_i.h>

/*

 * splice is tied to pipes as a transport (at least for now), so we'll just

 * add the splice flags here.

 */

#define SPLICE_F_MOVE   (0x01)  /* move pages instead of copying */

#define SPLICE_F_NONBLOCK (0x02) /* don't block on the pipe splicing (but */

                                 /* we may still block on the fd we splice */

                                 /* from/to, of course */

#define SPLICE_F_MORE   (0x04)  /* expect more data */

#define SPLICE_F_GIFT   (0x08)  /* pages passed in are a gift */

/*

 * Passed to the actors

 */

struct splice_desc {

        unsigned int len, total_len;    /* current and remaining length */

        unsigned int flags;             /* splice flags */

        /*

         * actor() private data

         */

        union {

                void __user *userptr;   /* memory to write to */

                struct file *file;      /* file to read/write */

                void *data;             /* cookie */

        } u;

        loff_t pos;                     /* file position */

};

struct partial_page {

        unsigned int offset;

        unsigned int len;

        unsigned long private;

};

/*

 * Passed to splice_to_pipe

 */

struct splice_pipe_desc {

        struct page **pages;            /* page map */

        struct partial_page *partial;   /* pages[] may not be contig */

        int nr_pages;                   /* number of pages in map */

        unsigned int flags;             /* splice flags */

        const struct pipe_buf_operations *ops;/* ops associated with output pipe */

};

typedef int (splice_actor)(struct pipe_inode_info *, struct pipe_buffer *,

                           struct splice_desc *);

typedef int (splice_direct_actor)(struct pipe_inode_info *,

                                  struct splice_desc *);

extern ssize_t splice_from_pipe(struct pipe_inode_info *, struct file *,

                                loff_t *, size_t, unsigned int,

                                splice_actor *);

extern ssize_t __splice_from_pipe(struct pipe_inode_info *,

                                  struct splice_desc *, splice_actor *);

extern ssize_t splice_to_pipe(struct pipe_inode_info *,

                              struct splice_pipe_desc *);

extern ssize_t splice_direct_to_actor(struct file *, struct splice_desc *,

                                      splice_direct_actor *);

#endif