long vfsub_splice_to(struct file *in, loff_t *ppos,
struct pipe_inode_info *pipe, size_t len,
unsigned int flags)
{
long err;
err = do_splice_to(in, ppos, pipe, len, flags);
file_accessed(in);
if (err >= 0)
vfsub_update_h_iattr(&in->f_path, /*did*/NULL); /*ignore*/
return err;
}
/*
* Determine where to splice to/from.
*/
static long do_splice(struct file *in, loff_t __user *off_in,
struct file *out, loff_t __user *off_out,
size_t len, unsigned int flags)
{
struct pipe_inode_info *pipe;
loff_t offset, *off;
long ret;
pipe = pipe_info(in->f_dentry->d_inode);
if (pipe) {
if (off_in)
return -ESPIPE;
if (off_out) {
if (out->f_op->llseek == no_llseek)
return -EINVAL;
if (copy_from_user(&offset, off_out, sizeof(loff_t)))
return -EFAULT;
off = &offset;
} else
off = &out->f_pos;
ret = do_splice_from(pipe, out, off, len, flags);
if (off_out && copy_to_user(off_out, off, sizeof(loff_t)))
ret = -EFAULT;
return ret;
}
pipe = pipe_info(out->f_dentry->d_inode);
if (pipe) {
if (off_out)
return -ESPIPE;
if (off_in) {
if (in->f_op->llseek == no_llseek)
return -EINVAL;
if (copy_from_user(&offset, off_in, sizeof(loff_t)))
return -EFAULT;
off = &offset;
} else
off = &in->f_pos;
ret = do_splice_to(in, off, pipe, len, flags);
if (off_in && copy_to_user(off_in, off, sizeof(loff_t)))
ret = -EFAULT;
return ret;
}
return -EINVAL;
}
long do_splice_direct(struct file *in, loff_t *ppos, struct file *out,
size_t len, unsigned int flags)
{
struct pipe_inode_info *pipe;
long ret, bytes;
loff_t out_off;
umode_t i_mode;
int i;
/*
* We require the input being a regular file, as we don't want to
* randomly drop data for eg socket -> socket splicing. Use the
* piped splicing for that!
*/
i_mode = in->f_dentry->d_inode->i_mode;
if (unlikely(!S_ISREG(i_mode) && !S_ISBLK(i_mode)))
return -EINVAL;
/*
* neither in nor out is a pipe, setup an internal pipe attached to
* 'out' and transfer the wanted data from 'in' to 'out' through that
*/
pipe = current->splice_pipe;
if (unlikely(!pipe)) {
pipe = alloc_pipe_info(NULL);
if (!pipe)
return -ENOMEM;
/*
* We don't have an immediate reader, but we'll read the stuff
* out of the pipe right after the splice_to_pipe(). So set
* PIPE_READERS appropriately.
*/
pipe->readers = 1;
current->splice_pipe = pipe;
}
/*
* Do the splice.
*/
ret = 0;
bytes = 0;
out_off = 0;
while (len) {
size_t read_len, max_read_len;
/*
* Do at most PIPE_BUFFERS pages worth of transfer:
*/
max_read_len = min(len, (size_t)(PIPE_BUFFERS*PAGE_SIZE));
ret = do_splice_to(in, ppos, pipe, max_read_len, flags);
if (unlikely(ret < 0))
goto out_release;
read_len = ret;
/*
* NOTE: nonblocking mode only applies to the input. We
* must not do the output in nonblocking mode as then we
* could get stuck data in the internal pipe:
*/
ret = do_splice_from(pipe, out, &out_off, read_len,
flags & ~SPLICE_F_NONBLOCK);
if (unlikely(ret < 0))
goto out_release;
bytes += ret;
len -= ret;
/*
* In nonblocking mode, if we got back a short read then
* that was due to either an IO error or due to the
* pagecache entry not being there. In the IO error case
* the _next_ splice attempt will produce a clean IO error
* return value (not a short read), so in both cases it's
* correct to break out of the loop here:
*/
if ((flags & SPLICE_F_NONBLOCK) && (read_len < max_read_len))
break;
}
pipe->nrbufs = pipe->curbuf = 0;
return bytes;
out_release:
/*
* If we did an incomplete transfer we must release
* the pipe buffers in question:
*/
for (i = 0; i < PIPE_BUFFERS; i++) {
struct pipe_buffer *buf = pipe->bufs + i;
if (buf->ops) {
buf->ops->release(pipe, buf);
buf->ops = NULL;
}
}
pipe->nrbufs = pipe->curbuf = 0;
/*
* If we transferred some data, return the number of bytes:
*/
if (bytes > 0)
return bytes;
return ret;
}
