struct splice_pipe_desc *spd)
{
unsigned int spd_pages = spd->nr_pages;
- int ret, do_wakeup, page_nr;
+ int ret = 0, page_nr = 0;
if (!spd_pages)
return 0;
- ret = 0;
- do_wakeup = 0;
- page_nr = 0;
-
- pipe_lock(pipe);
-
- for (;;) {
- if (!pipe->readers) {
- send_sig(SIGPIPE, current, 0);
- if (!ret)
- ret = -EPIPE;
- break;
- }
-
- if (pipe->nrbufs < pipe->buffers) {
- int newbuf = (pipe->curbuf + pipe->nrbufs) & (pipe->buffers - 1);
- struct pipe_buffer *buf = pipe->bufs + newbuf;
-
- buf->page = spd->pages[page_nr];
- buf->offset = spd->partial[page_nr].offset;
- buf->len = spd->partial[page_nr].len;
- buf->private = spd->partial[page_nr].private;
- buf->ops = spd->ops;
- if (spd->flags & SPLICE_F_GIFT)
- buf->flags |= PIPE_BUF_FLAG_GIFT;
-
- pipe->nrbufs++;
- page_nr++;
- ret += buf->len;
-
- if (pipe->files)
- do_wakeup = 1;
+ if (unlikely(!pipe->readers)) {
+ send_sig(SIGPIPE, current, 0);
+ ret = -EPIPE;
+ goto out;
+ }
- if (!--spd->nr_pages)
- break;
- if (pipe->nrbufs < pipe->buffers)
- continue;
+ while (pipe->nrbufs < pipe->buffers) {
+ int newbuf = (pipe->curbuf + pipe->nrbufs) & (pipe->buffers - 1);
+ struct pipe_buffer *buf = pipe->bufs + newbuf;
- break;
- }
+ buf->page = spd->pages[page_nr];
+ buf->offset = spd->partial[page_nr].offset;
+ buf->len = spd->partial[page_nr].len;
+ buf->private = spd->partial[page_nr].private;
+ buf->ops = spd->ops;
- if (spd->flags & SPLICE_F_NONBLOCK) {
- if (!ret)
- ret = -EAGAIN;
- break;
- }
+ pipe->nrbufs++;
+ page_nr++;
+ ret += buf->len;
- if (signal_pending(current)) {
- if (!ret)
- ret = -ERESTARTSYS;
+ if (!--spd->nr_pages)
break;
- }
-
- if (do_wakeup) {
- smp_mb();
- if (waitqueue_active(&pipe->wait))
- wake_up_interruptible_sync(&pipe->wait);
- kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN);
- do_wakeup = 0;
- }
-
- pipe->waiting_writers++;
- pipe_wait(pipe);
- pipe->waiting_writers--;
}
- pipe_unlock(pipe);
-
- if (do_wakeup)
- wakeup_pipe_readers(pipe);
+ if (!ret)
+ ret = -EAGAIN;
+out:
while (page_nr < spd_pages)
spd->spd_release(spd, page_nr++);
}
EXPORT_SYMBOL_GPL(splice_to_pipe);
+ssize_t add_to_pipe(struct pipe_inode_info *pipe, struct pipe_buffer *buf)
+{
+ int ret;
+
+ if (unlikely(!pipe->readers)) {
+ send_sig(SIGPIPE, current, 0);
+ ret = -EPIPE;
+ } else if (pipe->nrbufs == pipe->buffers) {
+ ret = -EAGAIN;
+ } else {
+ int newbuf = (pipe->curbuf + pipe->nrbufs) & (pipe->buffers - 1);
+ pipe->bufs[newbuf] = *buf;
+ pipe->nrbufs++;
+ return buf->len;
+ }
+ buf->ops->release(pipe, buf);
+ buf->ops = NULL;
+ return ret;
+}
+EXPORT_SYMBOL(add_to_pipe);
+
void spd_release_page(struct splice_pipe_desc *spd, unsigned int i)
{
put_page(spd->pages[i]);
}
EXPORT_SYMBOL(generic_file_splice_read);
-static const struct pipe_buf_operations default_pipe_buf_ops = {
+const struct pipe_buf_operations default_pipe_buf_ops = {
.can_merge = 0,
.confirm = generic_pipe_buf_confirm,
.release = generic_pipe_buf_release,
}
EXPORT_SYMBOL(do_splice_direct);
+static int wait_for_space(struct pipe_inode_info *pipe, unsigned flags)
+{
+ while (pipe->nrbufs == pipe->buffers) {
+ if (flags & SPLICE_F_NONBLOCK)
+ return -EAGAIN;
+ if (signal_pending(current))
+ return -ERESTARTSYS;
+ pipe->waiting_writers++;
+ pipe_wait(pipe);
+ pipe->waiting_writers--;
+ }
+ return 0;
+}
+
static int splice_pipe_to_pipe(struct pipe_inode_info *ipipe,
struct pipe_inode_info *opipe,
size_t len, unsigned int flags);
offset = in->f_pos;
}
- ret = do_splice_to(in, &offset, opipe, len, flags);
-
+ pipe_lock(opipe);
+ ret = wait_for_space(opipe, flags);
+ if (!ret)
+ ret = do_splice_to(in, &offset, opipe, len, flags);
+ pipe_unlock(opipe);
+ if (ret > 0)
+ wakeup_pipe_readers(opipe);
if (!off_in)
in->f_pos = offset;
else if (copy_to_user(off_in, &offset, sizeof(loff_t)))
return -EINVAL;
}
-/*
- * Map an iov into an array of pages and offset/length tupples. With the
- * partial_page structure, we can map several non-contiguous ranges into
- * our ones pages[] map instead of splitting that operation into pieces.
- * Could easily be exported as a generic helper for other users, in which
- * case one would probably want to add a 'max_nr_pages' parameter as well.
- */
-static int get_iovec_page_array(const struct iovec __user *iov,
- unsigned int nr_vecs, struct page **pages,
- struct partial_page *partial, bool aligned,
- unsigned int pipe_buffers)
+static int iter_to_pipe(struct iov_iter *from,
+ struct pipe_inode_info *pipe,
+ unsigned flags)
{
- int buffers = 0, error = 0;
-
- while (nr_vecs) {
- unsigned long off, npages;
- struct iovec entry;
- void __user *base;
- size_t len;
- int i;
-
- error = -EFAULT;
- if (copy_from_user(&entry, iov, sizeof(entry)))
- break;
-
- base = entry.iov_base;
- len = entry.iov_len;
-
- /*
- * Sanity check this iovec. 0 read succeeds.
- */
- error = 0;
- if (unlikely(!len))
- break;
- error = -EFAULT;
- if (!access_ok(VERIFY_READ, base, len))
- break;
-
- /*
- * Get this base offset and number of pages, then map
- * in the user pages.
- */
- off = (unsigned long) base & ~PAGE_MASK;
-
- /*
- * If asked for alignment, the offset must be zero and the
- * length a multiple of the PAGE_SIZE.
- */
- error = -EINVAL;
- if (aligned && (off || len & ~PAGE_MASK))
- break;
-
- npages = (off + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
- if (npages > pipe_buffers - buffers)
- npages = pipe_buffers - buffers;
-
- error = get_user_pages_fast((unsigned long)base, npages,
- 0, &pages[buffers]);
-
- if (unlikely(error <= 0))
+ struct pipe_buffer buf = {
+ .ops = &user_page_pipe_buf_ops,
+ .flags = flags
+ };
+ size_t total = 0;
+ int ret = 0;
+ bool failed = false;
+
+ while (iov_iter_count(from) && !failed) {
+ struct page *pages[16];
+ ssize_t copied;
+ size_t start;
+ int n;
+
+ copied = iov_iter_get_pages(from, pages, ~0UL, 16, &start);
+ if (copied <= 0) {
+ ret = copied;
break;
-
- /*
- * Fill this contiguous range into the partial page map.
- */
- for (i = 0; i < error; i++) {
- const int plen = min_t(size_t, len, PAGE_SIZE - off);
-
- partial[buffers].offset = off;
- partial[buffers].len = plen;
-
- off = 0;
- len -= plen;
- buffers++;
}
- /*
- * We didn't complete this iov, stop here since it probably
- * means we have to move some of this into a pipe to
- * be able to continue.
- */
- if (len)
- break;
-
- /*
- * Don't continue if we mapped fewer pages than we asked for,
- * or if we mapped the max number of pages that we have
- * room for.
- */
- if (error < npages || buffers == pipe_buffers)
- break;
-
- nr_vecs--;
- iov++;
+ for (n = 0; copied; n++, start = 0) {
+ int size = min_t(int, copied, PAGE_SIZE - start);
+ if (!failed) {
+ buf.page = pages[n];
+ buf.offset = start;
+ buf.len = size;
+ ret = add_to_pipe(pipe, &buf);
+ if (unlikely(ret < 0)) {
+ failed = true;
+ } else {
+ iov_iter_advance(from, ret);
+ total += ret;
+ }
+ } else {
+ put_page(pages[n]);
+ }
+ copied -= size;
+ }
}
-
- if (buffers)
- return buffers;
-
- return error;
+ return total ? total : ret;
}
static int pipe_to_user(struct pipe_inode_info *pipe, struct pipe_buffer *buf,
* as splice-from-memory, where the regular splice is splice-from-file (or
* to file). In both cases the output is a pipe, naturally.
*/
-static long vmsplice_to_pipe(struct file *file, const struct iovec __user *iov,
+static long vmsplice_to_pipe(struct file *file, const struct iovec __user *uiov,
unsigned long nr_segs, unsigned int flags)
{
struct pipe_inode_info *pipe;
- struct page *pages[PIPE_DEF_BUFFERS];
- struct partial_page partial[PIPE_DEF_BUFFERS];
- struct splice_pipe_desc spd = {
- .pages = pages,
- .partial = partial,
- .nr_pages_max = PIPE_DEF_BUFFERS,
- .flags = flags,
- .ops = &user_page_pipe_buf_ops,
- .spd_release = spd_release_page,
- };
+ struct iovec iovstack[UIO_FASTIOV];
+ struct iovec *iov = iovstack;
+ struct iov_iter from;
long ret;
+ unsigned buf_flag = 0;
+
+ if (flags & SPLICE_F_GIFT)
+ buf_flag = PIPE_BUF_FLAG_GIFT;
pipe = get_pipe_info(file);
if (!pipe)
return -EBADF;
- if (splice_grow_spd(pipe, &spd))
- return -ENOMEM;
-
- spd.nr_pages = get_iovec_page_array(iov, nr_segs, spd.pages,
- spd.partial, false,
- spd.nr_pages_max);
- if (spd.nr_pages <= 0)
- ret = spd.nr_pages;
- else
- ret = splice_to_pipe(pipe, &spd);
+ ret = import_iovec(WRITE, uiov, nr_segs,
+ ARRAY_SIZE(iovstack), &iov, &from);
+ if (ret < 0)
+ return ret;
- splice_shrink_spd(&spd);
+ pipe_lock(pipe);
+ ret = wait_for_space(pipe, flags);
+ if (!ret)
+ ret = iter_to_pipe(&from, pipe, buf_flag);
+ pipe_unlock(pipe);
+ if (ret > 0)
+ wakeup_pipe_readers(pipe);
+ kfree(iov);
return ret;
}
projects / cascardo / linux.git / blobdiff