b3c2d2ddd6
Split up __splice_from_pipe() into four helper functions: splice_from_pipe_begin() splice_from_pipe_next() splice_from_pipe_feed() splice_from_pipe_end() splice_from_pipe_next() will wait (if necessary) for more buffers to be added to the pipe. splice_from_pipe_feed() will feed the buffers to the supplied actor and return when there's no more data available (or if all of the requested data has been copied). This is necessary so that implementations can do locking around the non-waiting splice_from_pipe_feed(). This patch should not cause any change in behavior. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
84 lines
2.5 KiB
C
84 lines
2.5 KiB
C
/*
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* Function declerations and data structures related to the splice
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* implementation.
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*
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* Copyright (C) 2007 Jens Axboe <jens.axboe@oracle.com>
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*
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*/
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#ifndef SPLICE_H
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#define SPLICE_H
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#include <linux/pipe_fs_i.h>
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/*
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* splice is tied to pipes as a transport (at least for now), so we'll just
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* add the splice flags here.
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*/
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#define SPLICE_F_MOVE (0x01) /* move pages instead of copying */
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#define SPLICE_F_NONBLOCK (0x02) /* don't block on the pipe splicing (but */
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/* we may still block on the fd we splice */
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/* from/to, of course */
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#define SPLICE_F_MORE (0x04) /* expect more data */
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#define SPLICE_F_GIFT (0x08) /* pages passed in are a gift */
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/*
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* Passed to the actors
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*/
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struct splice_desc {
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unsigned int len, total_len; /* current and remaining length */
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unsigned int flags; /* splice flags */
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/*
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* actor() private data
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*/
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union {
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void __user *userptr; /* memory to write to */
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struct file *file; /* file to read/write */
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void *data; /* cookie */
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} u;
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loff_t pos; /* file position */
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size_t num_spliced; /* number of bytes already spliced */
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bool need_wakeup; /* need to wake up writer */
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};
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struct partial_page {
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unsigned int offset;
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unsigned int len;
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unsigned long private;
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};
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/*
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* Passed to splice_to_pipe
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*/
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struct splice_pipe_desc {
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struct page **pages; /* page map */
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struct partial_page *partial; /* pages[] may not be contig */
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int nr_pages; /* number of pages in map */
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unsigned int flags; /* splice flags */
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const struct pipe_buf_operations *ops;/* ops associated with output pipe */
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void (*spd_release)(struct splice_pipe_desc *, unsigned int);
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};
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typedef int (splice_actor)(struct pipe_inode_info *, struct pipe_buffer *,
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struct splice_desc *);
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typedef int (splice_direct_actor)(struct pipe_inode_info *,
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struct splice_desc *);
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extern ssize_t splice_from_pipe(struct pipe_inode_info *, struct file *,
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loff_t *, size_t, unsigned int,
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splice_actor *);
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extern ssize_t __splice_from_pipe(struct pipe_inode_info *,
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struct splice_desc *, splice_actor *);
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extern int splice_from_pipe_feed(struct pipe_inode_info *, struct splice_desc *,
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splice_actor *);
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extern int splice_from_pipe_next(struct pipe_inode_info *,
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struct splice_desc *);
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extern void splice_from_pipe_begin(struct splice_desc *);
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extern void splice_from_pipe_end(struct pipe_inode_info *,
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struct splice_desc *);
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extern ssize_t splice_to_pipe(struct pipe_inode_info *,
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struct splice_pipe_desc *);
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extern ssize_t splice_direct_to_actor(struct file *, struct splice_desc *,
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splice_direct_actor *);
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#endif
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