new helper: add_to_pipe()
single-buffer analogue of splice_to_pipe(); vmsplice_to_pipe() switched to that, leaving splice_to_pipe() only for ->splice_read() instances (and that only until they are converted as well). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>hifive-unleashed-5.1
Al Viro
parent
8924feff66
commit
79fddc4efd
106
fs/splice.c
106
fs/splice.c
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@ -203,8 +203,6 @@ ssize_t splice_to_pipe(struct pipe_inode_info *pipe,
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buf->len = spd->partial[page_nr].len;
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buf->private = spd->partial[page_nr].private;
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buf->ops = spd->ops;
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if (spd->flags & SPLICE_F_GIFT)
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buf->flags |= PIPE_BUF_FLAG_GIFT;
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pipe->nrbufs++;
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page_nr++;
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@ -225,6 +223,27 @@ out:
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}
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EXPORT_SYMBOL_GPL(splice_to_pipe);
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ssize_t add_to_pipe(struct pipe_inode_info *pipe, struct pipe_buffer *buf)
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{
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int ret;
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if (unlikely(!pipe->readers)) {
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send_sig(SIGPIPE, current, 0);
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ret = -EPIPE;
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} else if (pipe->nrbufs == pipe->buffers) {
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ret = -EAGAIN;
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} else {
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int newbuf = (pipe->curbuf + pipe->nrbufs) & (pipe->buffers - 1);
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pipe->bufs[newbuf] = *buf;
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pipe->nrbufs++;
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return buf->len;
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}
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buf->ops->release(pipe, buf);
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buf->ops = NULL;
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return ret;
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}
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EXPORT_SYMBOL(add_to_pipe);
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void spd_release_page(struct splice_pipe_desc *spd, unsigned int i)
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{
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put_page(spd->pages[i]);
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@ -1415,32 +1434,50 @@ static long do_splice(struct file *in, loff_t __user *off_in,
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return -EINVAL;
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}
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static int get_iovec_page_array(struct iov_iter *from,
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struct page **pages,
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struct partial_page *partial,
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unsigned int pipe_buffers)
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static int iter_to_pipe(struct iov_iter *from,
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struct pipe_inode_info *pipe,
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unsigned flags)
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{
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int buffers = 0;
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while (iov_iter_count(from)) {
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struct pipe_buffer buf = {
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.ops = &user_page_pipe_buf_ops,
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.flags = flags
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};
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size_t total = 0;
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int ret = 0;
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bool failed = false;
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while (iov_iter_count(from) && !failed) {
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struct page *pages[16];
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ssize_t copied;
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size_t start;
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int n;
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copied = iov_iter_get_pages(from, pages + buffers, ~0UL,
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pipe_buffers - buffers, &start);
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if (copied <= 0)
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return buffers ? buffers : copied;
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copied = iov_iter_get_pages(from, pages, ~0UL, 16, &start);
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if (copied <= 0) {
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ret = copied;
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break;
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}
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iov_iter_advance(from, copied);
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while (copied) {
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for (n = 0; copied; n++, start = 0) {
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int size = min_t(int, copied, PAGE_SIZE - start);
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partial[buffers].offset = start;
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partial[buffers].len = size;
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if (!failed) {
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buf.page = pages[n];
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buf.offset = start;
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buf.len = size;
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ret = add_to_pipe(pipe, &buf);
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if (unlikely(ret < 0)) {
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failed = true;
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} else {
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iov_iter_advance(from, ret);
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total += ret;
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}
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} else {
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put_page(pages[n]);
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}
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copied -= size;
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start = 0;
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buffers++;
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}
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}
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return buffers;
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return total ? total : ret;
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}
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static int pipe_to_user(struct pipe_inode_info *pipe, struct pipe_buffer *buf,
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@ -1501,17 +1538,11 @@ static long vmsplice_to_pipe(struct file *file, const struct iovec __user *uiov,
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struct iovec iovstack[UIO_FASTIOV];
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struct iovec *iov = iovstack;
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struct iov_iter from;
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struct page *pages[PIPE_DEF_BUFFERS];
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struct partial_page partial[PIPE_DEF_BUFFERS];
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struct splice_pipe_desc spd = {
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.pages = pages,
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.partial = partial,
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.nr_pages_max = PIPE_DEF_BUFFERS,
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.flags = flags,
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.ops = &user_page_pipe_buf_ops,
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.spd_release = spd_release_page,
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};
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long ret;
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unsigned buf_flag = 0;
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if (flags & SPLICE_F_GIFT)
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buf_flag = PIPE_BUF_FLAG_GIFT;
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pipe = get_pipe_info(file);
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if (!pipe)
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@ -1522,26 +1553,13 @@ static long vmsplice_to_pipe(struct file *file, const struct iovec __user *uiov,
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if (ret < 0)
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return ret;
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if (splice_grow_spd(pipe, &spd)) {
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kfree(iov);
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return -ENOMEM;
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}
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pipe_lock(pipe);
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ret = wait_for_space(pipe, flags);
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if (!ret) {
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spd.nr_pages = get_iovec_page_array(&from, spd.pages,
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spd.partial,
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spd.nr_pages_max);
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if (spd.nr_pages <= 0)
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ret = spd.nr_pages;
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else
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ret = splice_to_pipe(pipe, &spd);
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}
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if (!ret)
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ret = iter_to_pipe(&from, pipe, buf_flag);
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pipe_unlock(pipe);
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if (ret > 0)
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wakeup_pipe_readers(pipe);
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splice_shrink_spd(&spd);
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kfree(iov);
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return ret;
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}
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@ -72,6 +72,8 @@ extern ssize_t __splice_from_pipe(struct pipe_inode_info *,
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struct splice_desc *, splice_actor *);
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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 add_to_pipe(struct pipe_inode_info *,
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struct pipe_buffer *);
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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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