linuxdebug/io_uring/splice.c

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2024-07-16 15:50:57 +02:00
// SPDX-License-Identifier: GPL-2.0
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/file.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/namei.h>
#include <linux/io_uring.h>
#include <linux/splice.h>
#include <uapi/linux/io_uring.h>
#include "io_uring.h"
#include "splice.h"
struct io_splice {
struct file *file_out;
loff_t off_out;
loff_t off_in;
u64 len;
int splice_fd_in;
unsigned int flags;
};
static int __io_splice_prep(struct io_kiocb *req,
const struct io_uring_sqe *sqe)
{
struct io_splice *sp = io_kiocb_to_cmd(req, struct io_splice);
unsigned int valid_flags = SPLICE_F_FD_IN_FIXED | SPLICE_F_ALL;
sp->len = READ_ONCE(sqe->len);
sp->flags = READ_ONCE(sqe->splice_flags);
if (unlikely(sp->flags & ~valid_flags))
return -EINVAL;
sp->splice_fd_in = READ_ONCE(sqe->splice_fd_in);
return 0;
}
int io_tee_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
{
if (READ_ONCE(sqe->splice_off_in) || READ_ONCE(sqe->off))
return -EINVAL;
return __io_splice_prep(req, sqe);
}
int io_tee(struct io_kiocb *req, unsigned int issue_flags)
{
struct io_splice *sp = io_kiocb_to_cmd(req, struct io_splice);
struct file *out = sp->file_out;
unsigned int flags = sp->flags & ~SPLICE_F_FD_IN_FIXED;
struct file *in;
long ret = 0;
if (issue_flags & IO_URING_F_NONBLOCK)
return -EAGAIN;
if (sp->flags & SPLICE_F_FD_IN_FIXED)
in = io_file_get_fixed(req, sp->splice_fd_in, issue_flags);
else
in = io_file_get_normal(req, sp->splice_fd_in);
if (!in) {
ret = -EBADF;
goto done;
}
if (sp->len)
ret = do_tee(in, out, sp->len, flags);
if (!(sp->flags & SPLICE_F_FD_IN_FIXED))
io_put_file(in);
done:
if (ret != sp->len)
req_set_fail(req);
io_req_set_res(req, ret, 0);
return IOU_OK;
}
int io_splice_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
{
struct io_splice *sp = io_kiocb_to_cmd(req, struct io_splice);
sp->off_in = READ_ONCE(sqe->splice_off_in);
sp->off_out = READ_ONCE(sqe->off);
return __io_splice_prep(req, sqe);
}
int io_splice(struct io_kiocb *req, unsigned int issue_flags)
{
struct io_splice *sp = io_kiocb_to_cmd(req, struct io_splice);
struct file *out = sp->file_out;
unsigned int flags = sp->flags & ~SPLICE_F_FD_IN_FIXED;
loff_t *poff_in, *poff_out;
struct file *in;
long ret = 0;
if (issue_flags & IO_URING_F_NONBLOCK)
return -EAGAIN;
if (sp->flags & SPLICE_F_FD_IN_FIXED)
in = io_file_get_fixed(req, sp->splice_fd_in, issue_flags);
else
in = io_file_get_normal(req, sp->splice_fd_in);
if (!in) {
ret = -EBADF;
goto done;
}
poff_in = (sp->off_in == -1) ? NULL : &sp->off_in;
poff_out = (sp->off_out == -1) ? NULL : &sp->off_out;
if (sp->len)
ret = do_splice(in, poff_in, out, poff_out, sp->len, flags);
if (!(sp->flags & SPLICE_F_FD_IN_FIXED))
io_put_file(in);
done:
if (ret != sp->len)
req_set_fail(req);
io_req_set_res(req, ret, 0);
return IOU_OK;
}