Moved, renamed, and deleted files

The original directory structure was scattered and unorganized.
Changes are basically to make it look like kernel structure.

1 files changed, 0 insertions, 2048 deletions

diff --git a/ANDROID_3.4.5/fs/splice.c b/ANDROID_3.4.5/fs/splice.c
deleted file mode 100644
index 5cac690f..00000000
--- a/ANDROID_3.4.5/fs/splice.c
+++ /dev/null
@@ -1,2048 +0,0 @@
-/*
- * "splice": joining two ropes together by interweaving their strands.
- *
- * This is the "extended pipe" functionality, where a pipe is used as
- * an arbitrary in-memory buffer. Think of a pipe as a small kernel
- * buffer that you can use to transfer data from one end to the other.
- *
- * The traditional unix read/write is extended with a "splice()" operation
- * that transfers data buffers to or from a pipe buffer.
- *
- * Named by Larry McVoy, original implementation from Linus, extended by
- * Jens to support splicing to files, network, direct splicing, etc and
- * fixing lots of bugs.
- *
- * Copyright (C) 2005-2006 Jens Axboe <axboe@kernel.dk>
- * Copyright (C) 2005-2006 Linus Torvalds <torvalds@osdl.org>
- * Copyright (C) 2006 Ingo Molnar <mingo@elte.hu>
- *
- */
-#include <linux/fs.h>
-#include <linux/file.h>
-#include <linux/pagemap.h>
-#include <linux/splice.h>
-#include <linux/memcontrol.h>
-#include <linux/mm_inline.h>
-#include <linux/swap.h>
-#include <linux/writeback.h>
-#include <linux/export.h>
-#include <linux/syscalls.h>
-#include <linux/uio.h>
-#include <linux/security.h>
-#include <linux/gfp.h>
-#include <linux/socket.h>
-
-/*
- * Attempt to steal a page from a pipe buffer. This should perhaps go into
- * a vm helper function, it's already simplified quite a bit by the
- * addition of remove_mapping(). If success is returned, the caller may
- * attempt to reuse this page for another destination.
- */
-static int page_cache_pipe_buf_steal(struct pipe_inode_info *pipe,
-				     struct pipe_buffer *buf)
-{
-	struct page *page = buf->page;
-	struct address_space *mapping;
-
-	lock_page(page);
-
-	mapping = page_mapping(page);
-	if (mapping) {
-		WARN_ON(!PageUptodate(page));
-
-		/*
-		 * At least for ext2 with nobh option, we need to wait on
-		 * writeback completing on this page, since we'll remove it
-		 * from the pagecache.  Otherwise truncate wont wait on the
-		 * page, allowing the disk blocks to be reused by someone else
-		 * before we actually wrote our data to them. fs corruption
-		 * ensues.
-		 */
-		wait_on_page_writeback(page);
-
-		if (page_has_private(page) &&
-		    !try_to_release_page(page, GFP_KERNEL))
-			goto out_unlock;
-
-		/*
-		 * If we succeeded in removing the mapping, set LRU flag
-		 * and return good.
-		 */
-		if (remove_mapping(mapping, page)) {
-			buf->flags |= PIPE_BUF_FLAG_LRU;
-			return 0;
-		}
-	}
-
-	/*
-	 * Raced with truncate or failed to remove page from current
-	 * address space, unlock and return failure.
-	 */
-out_unlock:
-	unlock_page(page);
-	return 1;
-}
-
-static void page_cache_pipe_buf_release(struct pipe_inode_info *pipe,
-					struct pipe_buffer *buf)
-{
-	page_cache_release(buf->page);
-	buf->flags &= ~PIPE_BUF_FLAG_LRU;
-}
-
-/*
- * Check whether the contents of buf is OK to access. Since the content
- * is a page cache page, IO may be in flight.
- */
-static int page_cache_pipe_buf_confirm(struct pipe_inode_info *pipe,
-				       struct pipe_buffer *buf)
-{
-	struct page *page = buf->page;
-	int err;
-
-	if (!PageUptodate(page)) {
-		lock_page(page);
-
-		/*
-		 * Page got truncated/unhashed. This will cause a 0-byte
-		 * splice, if this is the first page.
-		 */
-		if (!page->mapping) {
-			err = -ENODATA;
-			goto error;
-		}
-
-		/*
-		 * Uh oh, read-error from disk.
-		 */
-		if (!PageUptodate(page)) {
-			err = -EIO;
-			goto error;
-		}
-
-		/*
-		 * Page is ok afterall, we are done.
-		 */
-		unlock_page(page);
-	}
-
-	return 0;
-error:
-	unlock_page(page);
-	return err;
-}
-
-const struct pipe_buf_operations page_cache_pipe_buf_ops = {
-	.can_merge = 0,
-	.map = generic_pipe_buf_map,
-	.unmap = generic_pipe_buf_unmap,
-	.confirm = page_cache_pipe_buf_confirm,
-	.release = page_cache_pipe_buf_release,
-	.steal = page_cache_pipe_buf_steal,
-	.get = generic_pipe_buf_get,
-};
-
-static int user_page_pipe_buf_steal(struct pipe_inode_info *pipe,
-				    struct pipe_buffer *buf)
-{
-	if (!(buf->flags & PIPE_BUF_FLAG_GIFT))
-		return 1;
-
-	buf->flags |= PIPE_BUF_FLAG_LRU;
-	return generic_pipe_buf_steal(pipe, buf);
-}
-
-static const struct pipe_buf_operations user_page_pipe_buf_ops = {
-	.can_merge = 0,
-	.map = generic_pipe_buf_map,
-	.unmap = generic_pipe_buf_unmap,
-	.confirm = generic_pipe_buf_confirm,
-	.release = page_cache_pipe_buf_release,
-	.steal = user_page_pipe_buf_steal,
-	.get = generic_pipe_buf_get,
-};
-
-static void wakeup_pipe_readers(struct pipe_inode_info *pipe)
-{
-	smp_mb();
-	if (waitqueue_active(&pipe->wait))
-		wake_up_interruptible(&pipe->wait);
-	kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN);
-}
-
-/**
- * splice_to_pipe - fill passed data into a pipe
- * @pipe:	pipe to fill
- * @spd:	data to fill
- *
- * Description:
- *    @spd contains a map of pages and len/offset tuples, along with
- *    the struct pipe_buf_operations associated with these pages. This
- *    function will link that data to the pipe.
- *
- */
-ssize_t splice_to_pipe(struct pipe_inode_info *pipe,
-		       struct splice_pipe_desc *spd)
-{
-	unsigned int spd_pages = spd->nr_pages;
-	int ret, do_wakeup, page_nr;
-
-	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->inode)
-				do_wakeup = 1;
-
-			if (!--spd->nr_pages)
-				break;
-			if (pipe->nrbufs < pipe->buffers)
-				continue;
-
-			break;
-		}
-
-		if (spd->flags & SPLICE_F_NONBLOCK) {
-			if (!ret)
-				ret = -EAGAIN;
-			break;
-		}
-
-		if (signal_pending(current)) {
-			if (!ret)
-				ret = -ERESTARTSYS;
-			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);
-
-	while (page_nr < spd_pages)
-		spd->spd_release(spd, page_nr++);
-
-	return ret;
-}
-
-void spd_release_page(struct splice_pipe_desc *spd, unsigned int i)
-{
-	page_cache_release(spd->pages[i]);
-}
-
-/*
- * Check if we need to grow the arrays holding pages and partial page
- * descriptions.
- */
-int splice_grow_spd(const struct pipe_inode_info *pipe, struct splice_pipe_desc *spd)
-{
-	unsigned int buffers = ACCESS_ONCE(pipe->buffers);
-
-	spd->nr_pages_max = buffers;
-	if (buffers <= PIPE_DEF_BUFFERS)
-		return 0;
-
-	spd->pages = kmalloc(buffers * sizeof(struct page *), GFP_KERNEL);
-	spd->partial = kmalloc(buffers * sizeof(struct partial_page), GFP_KERNEL);
-
-	if (spd->pages && spd->partial)
-		return 0;
-
-	kfree(spd->pages);
-	kfree(spd->partial);
-	return -ENOMEM;
-}
-
-void splice_shrink_spd(struct splice_pipe_desc *spd)
-{
-	if (spd->nr_pages_max <= PIPE_DEF_BUFFERS)
-		return;
-
-	kfree(spd->pages);
-	kfree(spd->partial);
-}
-
-static int
-__generic_file_splice_read(struct file *in, loff_t *ppos,
-			   struct pipe_inode_info *pipe, size_t len,
-			   unsigned int flags)
-{
-	struct address_space *mapping = in->f_mapping;
-	unsigned int loff, nr_pages, req_pages;
-	struct page *pages[PIPE_DEF_BUFFERS];
-	struct partial_page partial[PIPE_DEF_BUFFERS];
-	struct page *page;
-	pgoff_t index, end_index;
-	loff_t isize;
-	int error, page_nr;
-	struct splice_pipe_desc spd = {
-		.pages = pages,
-		.partial = partial,
-		.nr_pages_max = PIPE_DEF_BUFFERS,
-		.flags = flags,
-		.ops = &page_cache_pipe_buf_ops,
-		.spd_release = spd_release_page,
-	};
-
-	if (splice_grow_spd(pipe, &spd))
-		return -ENOMEM;
-
-	index = *ppos >> PAGE_CACHE_SHIFT;
-	loff = *ppos & ~PAGE_CACHE_MASK;
-	req_pages = (len + loff + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
-	nr_pages = min(req_pages, spd.nr_pages_max);
-
-	/*
-	 * Lookup the (hopefully) full range of pages we need.
-	 */
-	spd.nr_pages = find_get_pages_contig(mapping, index, nr_pages, spd.pages);
-	index += spd.nr_pages;
-
-	/*
-	 * If find_get_pages_contig() returned fewer pages than we needed,
-	 * readahead/allocate the rest and fill in the holes.
-	 */
-	if (spd.nr_pages < nr_pages)
-		page_cache_sync_readahead(mapping, &in->f_ra, in,
-				index, req_pages - spd.nr_pages);
-
-	error = 0;
-	while (spd.nr_pages < nr_pages) {
-		/*
-		 * Page could be there, find_get_pages_contig() breaks on
-		 * the first hole.
-		 */
-		page = find_get_page(mapping, index);
-		if (!page) {
-			/*
-			 * page didn't exist, allocate one.
-			 */
-			page = page_cache_alloc_cold(mapping);
-			if (!page)
-				break;
-
-			error = add_to_page_cache_lru(page, mapping, index,
-						GFP_KERNEL);
-			if (unlikely(error)) {
-				page_cache_release(page);
-				if (error == -EEXIST)
-					continue;
-				break;
-			}
-			/*
-			 * add_to_page_cache() locks the page, unlock it
-			 * to avoid convoluting the logic below even more.
-			 */
-			unlock_page(page);
-		}
-
-		spd.pages[spd.nr_pages++] = page;
-		index++;
-	}
-
-	/*
-	 * Now loop over the map and see if we need to start IO on any
-	 * pages, fill in the partial map, etc.
-	 */
-	index = *ppos >> PAGE_CACHE_SHIFT;
-	nr_pages = spd.nr_pages;
-	spd.nr_pages = 0;
-	for (page_nr = 0; page_nr < nr_pages; page_nr++) {
-		unsigned int this_len;
-
-		if (!len)
-			break;
-
-		/*
-		 * this_len is the max we'll use from this page
-		 */
-		this_len = min_t(unsigned long, len, PAGE_CACHE_SIZE - loff);
-		page = spd.pages[page_nr];
-
-		if (PageReadahead(page))
-			page_cache_async_readahead(mapping, &in->f_ra, in,
-					page, index, req_pages - page_nr);
-
-		/*
-		 * If the page isn't uptodate, we may need to start io on it
-		 */
-		if (!PageUptodate(page)) {
-			lock_page(page);
-
-			/*
-			 * Page was truncated, or invalidated by the
-			 * filesystem.  Redo the find/create, but this time the
-			 * page is kept locked, so there's no chance of another
-			 * race with truncate/invalidate.
-			 */
-			if (!page->mapping) {
-				unlock_page(page);
-				page = find_or_create_page(mapping, index,
-						mapping_gfp_mask(mapping));
-
-				if (!page) {
-					error = -ENOMEM;
-					break;
-				}
-				page_cache_release(spd.pages[page_nr]);
-				spd.pages[page_nr] = page;
-			}
-			/*
-			 * page was already under io and is now done, great
-			 */
-			if (PageUptodate(page)) {
-				unlock_page(page);
-				goto fill_it;
-			}
-
-			/*
-			 * need to read in the page
-			 */
-			error = mapping->a_ops->readpage(in, page);
-			if (unlikely(error)) {
-				/*
-				 * We really should re-lookup the page here,
-				 * but it complicates things a lot. Instead
-				 * lets just do what we already stored, and
-				 * we'll get it the next time we are called.
-				 */
-				if (error == AOP_TRUNCATED_PAGE)
-					error = 0;
-
-				break;
-			}
-		}
-fill_it:
-		/*
-		 * i_size must be checked after PageUptodate.
-		 */
-		isize = i_size_read(mapping->host);
-		end_index = (isize - 1) >> PAGE_CACHE_SHIFT;
-		if (unlikely(!isize || index > end_index))
-			break;
-
-		/*
-		 * if this is the last page, see if we need to shrink
-		 * the length and stop
-		 */
-		if (end_index == index) {
-			unsigned int plen;
-
-			/*
-			 * max good bytes in this page
-			 */
-			plen = ((isize - 1) & ~PAGE_CACHE_MASK) + 1;
-			if (plen <= loff)
-				break;
-
-			/*
-			 * force quit after adding this page
-			 */
-			this_len = min(this_len, plen - loff);
-			len = this_len;
-		}
-
-		spd.partial[page_nr].offset = loff;
-		spd.partial[page_nr].len = this_len;
-		len -= this_len;
-		loff = 0;
-		spd.nr_pages++;
-		index++;
-	}
-
-	/*
-	 * Release any pages at the end, if we quit early. 'page_nr' is how far
-	 * we got, 'nr_pages' is how many pages are in the map.
-	 */
-	while (page_nr < nr_pages)
-		page_cache_release(spd.pages[page_nr++]);
-	in->f_ra.prev_pos = (loff_t)index << PAGE_CACHE_SHIFT;
-
-	if (spd.nr_pages)
-		error = splice_to_pipe(pipe, &spd);
-
-	splice_shrink_spd(&spd);
-	return error;
-}
-
-/**
- * generic_file_splice_read - splice data from file to a pipe
- * @in:		file to splice from
- * @ppos:	position in @in
- * @pipe:	pipe to splice to
- * @len:	number of bytes to splice
- * @flags:	splice modifier flags
- *
- * Description:
- *    Will read pages from given file and fill them into a pipe. Can be
- *    used as long as the address_space operations for the source implements
- *    a readpage() hook.
- *
- */
-ssize_t generic_file_splice_read(struct file *in, loff_t *ppos,
-				 struct pipe_inode_info *pipe, size_t len,
-				 unsigned int flags)
-{
-	loff_t isize, left;
-	int ret;
-
-	isize = i_size_read(in->f_mapping->host);
-	if (unlikely(*ppos >= isize))
-		return 0;
-
-	left = isize - *ppos;
-	if (unlikely(left < len))
-		len = left;
-
-	ret = __generic_file_splice_read(in, ppos, pipe, len, flags);
-	if (ret > 0) {
-		*ppos += ret;
-		file_accessed(in);
-	}
-
-	return ret;
-}
-EXPORT_SYMBOL(generic_file_splice_read);
-
-static const struct pipe_buf_operations default_pipe_buf_ops = {
-	.can_merge = 0,
-	.map = generic_pipe_buf_map,
-	.unmap = generic_pipe_buf_unmap,
-	.confirm = generic_pipe_buf_confirm,
-	.release = generic_pipe_buf_release,
-	.steal = generic_pipe_buf_steal,
-	.get = generic_pipe_buf_get,
-};
-
-static ssize_t kernel_readv(struct file *file, const struct iovec *vec,
-			    unsigned long vlen, loff_t offset)
-{
-	mm_segment_t old_fs;
-	loff_t pos = offset;
-	ssize_t res;
-
-	old_fs = get_fs();
-	set_fs(get_ds());
-	/* The cast to a user pointer is valid due to the set_fs() */
-	res = vfs_readv(file, (const struct iovec __user *)vec, vlen, &pos);
-	set_fs(old_fs);
-
-	return res;
-}
-
-static ssize_t kernel_write(struct file *file, const char *buf, size_t count,
-			    loff_t pos)
-{
-	mm_segment_t old_fs;
-	ssize_t res;
-
-	old_fs = get_fs();
-	set_fs(get_ds());
-	/* The cast to a user pointer is valid due to the set_fs() */
-	res = vfs_write(file, (const char __user *)buf, count, &pos);
-	set_fs(old_fs);
-
-	return res;
-}
-
-ssize_t default_file_splice_read(struct file *in, loff_t *ppos,
-				 struct pipe_inode_info *pipe, size_t len,
-				 unsigned int flags)
-{
-	unsigned int nr_pages;
-	unsigned int nr_freed;
-	size_t offset;
-	struct page *pages[PIPE_DEF_BUFFERS];
-	struct partial_page partial[PIPE_DEF_BUFFERS];
-	struct iovec *vec, __vec[PIPE_DEF_BUFFERS];
-	ssize_t res;
-	size_t this_len;
-	int error;
-	int i;
-	struct splice_pipe_desc spd = {
-		.pages = pages,
-		.partial = partial,
-		.nr_pages_max = PIPE_DEF_BUFFERS,
-		.flags = flags,
-		.ops = &default_pipe_buf_ops,
-		.spd_release = spd_release_page,
-	};
-
-	if (splice_grow_spd(pipe, &spd))
-		return -ENOMEM;
-
-	res = -ENOMEM;
-	vec = __vec;
-	if (spd.nr_pages_max > PIPE_DEF_BUFFERS) {
-		vec = kmalloc(spd.nr_pages_max * sizeof(struct iovec), GFP_KERNEL);
-		if (!vec)
-			goto shrink_ret;
-	}
-
-	offset = *ppos & ~PAGE_CACHE_MASK;
-	nr_pages = (len + offset + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
-
-	for (i = 0; i < nr_pages && i < spd.nr_pages_max && len; i++) {
-		struct page *page;
-
-		page = alloc_page(GFP_USER);
-		error = -ENOMEM;
-		if (!page)
-			goto err;
-
-		this_len = min_t(size_t, len, PAGE_CACHE_SIZE - offset);
-		vec[i].iov_base = (void __user *) page_address(page);
-		vec[i].iov_len = this_len;
-		spd.pages[i] = page;
-		spd.nr_pages++;
-		len -= this_len;
-		offset = 0;
-	}
-
-	res = kernel_readv(in, vec, spd.nr_pages, *ppos);
-	if (res < 0) {
-		error = res;
-		goto err;
-	}
-
-	error = 0;
-	if (!res)
-		goto err;
-
-	nr_freed = 0;
-	for (i = 0; i < spd.nr_pages; i++) {
-		this_len = min_t(size_t, vec[i].iov_len, res);
-		spd.partial[i].offset = 0;
-		spd.partial[i].len = this_len;
-		if (!this_len) {
-			__free_page(spd.pages[i]);
-			spd.pages[i] = NULL;
-			nr_freed++;
-		}
-		res -= this_len;
-	}
-	spd.nr_pages -= nr_freed;
-
-	res = splice_to_pipe(pipe, &spd);
-	if (res > 0)
-		*ppos += res;
-
-shrink_ret:
-	if (vec != __vec)
-		kfree(vec);
-	splice_shrink_spd(&spd);
-	return res;
-
-err:
-	for (i = 0; i < spd.nr_pages; i++)
-		__free_page(spd.pages[i]);
-
-	res = error;
-	goto shrink_ret;
-}
-EXPORT_SYMBOL(default_file_splice_read);
-
-/*
- * Send 'sd->len' bytes to socket from 'sd->file' at position 'sd->pos'
- * using sendpage(). Return the number of bytes sent.
- */
-static int pipe_to_sendpage(struct pipe_inode_info *pipe,
-			    struct pipe_buffer *buf, struct splice_desc *sd)
-{
-	struct file *file = sd->u.file;
-	loff_t pos = sd->pos;
-	int more;
-
-	if (!likely(file->f_op && file->f_op->sendpage))
-		return -EINVAL;
-
-	more = (sd->flags & SPLICE_F_MORE) ? MSG_MORE : 0;
-	if (sd->len < sd->total_len)
-		more |= MSG_SENDPAGE_NOTLAST;
-	return file->f_op->sendpage(file, buf->page, buf->offset,
-				    sd->len, &pos, more);
-}
-
-/*
- * This is a little more tricky than the file -> pipe splicing. There are
- * basically three cases:
- *
- *	- Destination page already exists in the address space and there
- *	  are users of it. For that case we have no other option that
- *	  copying the data. Tough luck.
- *	- Destination page already exists in the address space, but there
- *	  are no users of it. Make sure it's uptodate, then drop it. Fall
- *	  through to last case.
- *	- Destination page does not exist, we can add the pipe page to
- *	  the page cache and avoid the copy.
- *
- * If asked to move pages to the output file (SPLICE_F_MOVE is set in
- * sd->flags), we attempt to migrate pages from the pipe to the output
- * file address space page cache. This is possible if no one else has
- * the pipe page referenced outside of the pipe and page cache. If
- * SPLICE_F_MOVE isn't set, or we cannot move the page, we simply create
- * a new page in the output file page cache and fill/dirty that.
- */
-int pipe_to_file(struct pipe_inode_info *pipe, struct pipe_buffer *buf,
-		 struct splice_desc *sd)
-{
-	struct file *file = sd->u.file;
-	struct address_space *mapping = file->f_mapping;
-	unsigned int offset, this_len;
-	struct page *page;
-	void *fsdata;
-	int ret;
-
-	offset = sd->pos & ~PAGE_CACHE_MASK;
-
-	this_len = sd->len;
-	if (this_len + offset > PAGE_CACHE_SIZE)
-		this_len = PAGE_CACHE_SIZE - offset;
-
-	ret = pagecache_write_begin(file, mapping, sd->pos, this_len,
-				AOP_FLAG_UNINTERRUPTIBLE, &page, &fsdata);
-	if (unlikely(ret))
-		goto out;
-
-	if (buf->page != page) {
-		char *src = buf->ops->map(pipe, buf, 1);
-		char *dst = kmap_atomic(page);
-
-		memcpy(dst + offset, src + buf->offset, this_len);
-		flush_dcache_page(page);
-		kunmap_atomic(dst);
-		buf->ops->unmap(pipe, buf, src);
-	}
-	ret = pagecache_write_end(file, mapping, sd->pos, this_len, this_len,
-				page, fsdata);
-out:
-	return ret;
-}
-EXPORT_SYMBOL(pipe_to_file);
-
-static void wakeup_pipe_writers(struct pipe_inode_info *pipe)
-{
-	smp_mb();
-	if (waitqueue_active(&pipe->wait))
-		wake_up_interruptible(&pipe->wait);
-	kill_fasync(&pipe->fasync_writers, SIGIO, POLL_OUT);
-}
-
-/**
- * splice_from_pipe_feed - feed available data from a pipe to a file
- * @pipe:	pipe to splice from
- * @sd:		information to @actor
- * @actor:	handler that splices the data
- *
- * Description:
- *    This function loops over the pipe and calls @actor to do the
- *    actual moving of a single struct pipe_buffer to the desired
- *    destination.  It returns when there's no more buffers left in
- *    the pipe or if the requested number of bytes (@sd->total_len)
- *    have been copied.  It returns a positive number (one) if the
- *    pipe needs to be filled with more data, zero if the required
- *    number of bytes have been copied and -errno on error.
- *
- *    This, together with splice_from_pipe_{begin,end,next}, may be
- *    used to implement the functionality of __splice_from_pipe() when
- *    locking is required around copying the pipe buffers to the
- *    destination.
- */
-int splice_from_pipe_feed(struct pipe_inode_info *pipe, struct splice_desc *sd,
-			  splice_actor *actor)
-{
-	int ret;
-
-	while (pipe->nrbufs) {
-		struct pipe_buffer *buf = pipe->bufs + pipe->curbuf;
-		const struct pipe_buf_operations *ops = buf->ops;
-
-		sd->len = buf->len;
-		if (sd->len > sd->total_len)
-			sd->len = sd->total_len;
-
-		ret = buf->ops->confirm(pipe, buf);
-		if (unlikely(ret)) {
-			if (ret == -ENODATA)
-				ret = 0;
-			return ret;
-		}
-
-		ret = actor(pipe, buf, sd);
-		if (ret <= 0)
-			return ret;
-
-		buf->offset += ret;
-		buf->len -= ret;
-
-		sd->num_spliced += ret;
-		sd->len -= ret;
-		sd->pos += ret;
-		sd->total_len -= ret;
-
-		if (!buf->len) {
-			buf->ops = NULL;
-			ops->release(pipe, buf);
-			pipe->curbuf = (pipe->curbuf + 1) & (pipe->buffers - 1);
-			pipe->nrbufs--;
-			if (pipe->inode)
-				sd->need_wakeup = true;
-		}
-
-		if (!sd->total_len)
-			return 0;
-	}
-
-	return 1;
-}
-EXPORT_SYMBOL(splice_from_pipe_feed);
-
-/**
- * splice_from_pipe_next - wait for some data to splice from
- * @pipe:	pipe to splice from
- * @sd:		information about the splice operation
- *
- * Description:
- *    This function will wait for some data and return a positive
- *    value (one) if pipe buffers are available.  It will return zero
- *    or -errno if no more data needs to be spliced.
- */
-int splice_from_pipe_next(struct pipe_inode_info *pipe, struct splice_desc *sd)
-{
-	while (!pipe->nrbufs) {
-		if (!pipe->writers)
-			return 0;
-
-		if (!pipe->waiting_writers && sd->num_spliced)
-			return 0;
-
-		if (sd->flags & SPLICE_F_NONBLOCK)
-			return -EAGAIN;
-
-		if (signal_pending(current))
-			return -ERESTARTSYS;
-
-		if (sd->need_wakeup) {
-			wakeup_pipe_writers(pipe);
-			sd->need_wakeup = false;
-		}
-
-		pipe_wait(pipe);
-	}
-
-	return 1;
-}
-EXPORT_SYMBOL(splice_from_pipe_next);
-
-/**
- * splice_from_pipe_begin - start splicing from pipe
- * @sd:		information about the splice operation
- *
- * Description:
- *    This function should be called before a loop containing
- *    splice_from_pipe_next() and splice_from_pipe_feed() to
- *    initialize the necessary fields of @sd.
- */
-void splice_from_pipe_begin(struct splice_desc *sd)
-{
-	sd->num_spliced = 0;
-	sd->need_wakeup = false;
-}
-EXPORT_SYMBOL(splice_from_pipe_begin);
-
-/**
- * splice_from_pipe_end - finish splicing from pipe
- * @pipe:	pipe to splice from
- * @sd:		information about the splice operation
- *
- * Description:
- *    This function will wake up pipe writers if necessary.  It should
- *    be called after a loop containing splice_from_pipe_next() and
- *    splice_from_pipe_feed().
- */
-void splice_from_pipe_end(struct pipe_inode_info *pipe, struct splice_desc *sd)
-{
-	if (sd->need_wakeup)
-		wakeup_pipe_writers(pipe);
-}
-EXPORT_SYMBOL(splice_from_pipe_end);
-
-/**
- * __splice_from_pipe - splice data from a pipe to given actor
- * @pipe:	pipe to splice from
- * @sd:		information to @actor
- * @actor:	handler that splices the data
- *
- * Description:
- *    This function does little more than loop over the pipe and call
- *    @actor to do the actual moving of a single struct pipe_buffer to
- *    the desired destination. See pipe_to_file, pipe_to_sendpage, or
- *    pipe_to_user.
- *
- */
-ssize_t __splice_from_pipe(struct pipe_inode_info *pipe, struct splice_desc *sd,
-			   splice_actor *actor)
-{
-	int ret;
-
-	splice_from_pipe_begin(sd);
-	do {
-		ret = splice_from_pipe_next(pipe, sd);
-		if (ret > 0)
-			ret = splice_from_pipe_feed(pipe, sd, actor);
-	} while (ret > 0);
-	splice_from_pipe_end(pipe, sd);
-
-	return sd->num_spliced ? sd->num_spliced : ret;
-}
-EXPORT_SYMBOL(__splice_from_pipe);
-
-/**
- * splice_from_pipe - splice data from a pipe to a file
- * @pipe:	pipe to splice from
- * @out:	file to splice to
- * @ppos:	position in @out
- * @len:	how many bytes to splice
- * @flags:	splice modifier flags
- * @actor:	handler that splices the data
- *
- * Description:
- *    See __splice_from_pipe. This function locks the pipe inode,
- *    otherwise it's identical to __splice_from_pipe().
- *
- */
-ssize_t splice_from_pipe(struct pipe_inode_info *pipe, struct file *out,
-			 loff_t *ppos, size_t len, unsigned int flags,
-			 splice_actor *actor)
-{
-	ssize_t ret;
-	struct splice_desc sd = {
-		.total_len = len,
-		.flags = flags,
-		.pos = *ppos,
-		.u.file = out,
-	};
-
-	pipe_lock(pipe);
-	ret = __splice_from_pipe(pipe, &sd, actor);
-	pipe_unlock(pipe);
-
-	return ret;
-}
-
-/**
- * generic_file_splice_write - splice data from a pipe to a file
- * @pipe:	pipe info
- * @out:	file to write to
- * @ppos:	position in @out
- * @len:	number of bytes to splice
- * @flags:	splice modifier flags
- *
- * Description:
- *    Will either move or copy pages (determined by @flags options) from
- *    the given pipe inode to the given file.
- *
- */
-ssize_t
-generic_file_splice_write(struct pipe_inode_info *pipe, struct file *out,
-			  loff_t *ppos, size_t len, unsigned int flags)
-{
-	struct address_space *mapping = out->f_mapping;
-	struct inode *inode = mapping->host;
-	struct splice_desc sd = {
-		.total_len = len,
-		.flags = flags,
-		.pos = *ppos,
-		.u.file = out,
-	};
-	ssize_t ret;
-
-	pipe_lock(pipe);
-
-	splice_from_pipe_begin(&sd);
-	do {
-		ret = splice_from_pipe_next(pipe, &sd);
-		if (ret <= 0)
-			break;
-
-		mutex_lock_nested(&inode->i_mutex, I_MUTEX_CHILD);
-		ret = file_remove_suid(out);
-		if (!ret) {
-			file_update_time(out);
-			ret = splice_from_pipe_feed(pipe, &sd, pipe_to_file);
-		}
-		mutex_unlock(&inode->i_mutex);
-	} while (ret > 0);
-	splice_from_pipe_end(pipe, &sd);
-
-	pipe_unlock(pipe);
-
-	if (sd.num_spliced)
-		ret = sd.num_spliced;
-
-	if (ret > 0) {
-		unsigned long nr_pages;
-		int err;
-
-		nr_pages = (ret + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
-
-		err = generic_write_sync(out, *ppos, ret);
-		if (err)
-			ret = err;
-		else
-			*ppos += ret;
-		balance_dirty_pages_ratelimited_nr(mapping, nr_pages);
-	}
-
-	return ret;
-}
-
-EXPORT_SYMBOL(generic_file_splice_write);
-
-static int write_pipe_buf(struct pipe_inode_info *pipe, struct pipe_buffer *buf,
-			  struct splice_desc *sd)
-{
-	int ret;
-	void *data;
-
-	data = buf->ops->map(pipe, buf, 0);
-	ret = kernel_write(sd->u.file, data + buf->offset, sd->len, sd->pos);
-	buf->ops->unmap(pipe, buf, data);
-
-	return ret;
-}
-
-static ssize_t default_file_splice_write(struct pipe_inode_info *pipe,
-					 struct file *out, loff_t *ppos,
-					 size_t len, unsigned int flags)
-{
-	ssize_t ret;
-
-	ret = splice_from_pipe(pipe, out, ppos, len, flags, write_pipe_buf);
-	if (ret > 0)
-		*ppos += ret;
-
-	return ret;
-}
-
-/**
- * generic_splice_sendpage - splice data from a pipe to a socket
- * @pipe:	pipe to splice from
- * @out:	socket to write to
- * @ppos:	position in @out
- * @len:	number of bytes to splice
- * @flags:	splice modifier flags
- *
- * Description:
- *    Will send @len bytes from the pipe to a network socket. No data copying
- *    is involved.
- *
- */
-ssize_t generic_splice_sendpage(struct pipe_inode_info *pipe, struct file *out,
-				loff_t *ppos, size_t len, unsigned int flags)
-{
-	return splice_from_pipe(pipe, out, ppos, len, flags, pipe_to_sendpage);
-}
-
-EXPORT_SYMBOL(generic_splice_sendpage);
-
-/*
- * Attempt to initiate a splice from pipe to file.
- */
-static long do_splice_from(struct pipe_inode_info *pipe, struct file *out,
-			   loff_t *ppos, size_t len, unsigned int flags)
-{
-	ssize_t (*splice_write)(struct pipe_inode_info *, struct file *,
-				loff_t *, size_t, unsigned int);
-	int ret;
-
-	if (unlikely(!(out->f_mode & FMODE_WRITE)))
-		return -EBADF;
-
-	if (unlikely(out->f_flags & O_APPEND))
-		return -EINVAL;
-
-	ret = rw_verify_area(WRITE, out, ppos, len);
-	if (unlikely(ret < 0))
-		return ret;
-
-	if (out->f_op && out->f_op->splice_write)
-		splice_write = out->f_op->splice_write;
-	else
-		splice_write = default_file_splice_write;
-
-	return splice_write(pipe, out, ppos, len, flags);
-}
-
-/*
- * Attempt to initiate a splice from a file to a pipe.
- */
-static long do_splice_to(struct file *in, loff_t *ppos,
-			 struct pipe_inode_info *pipe, size_t len,
-			 unsigned int flags)
-{
-	ssize_t (*splice_read)(struct file *, loff_t *,
-			       struct pipe_inode_info *, size_t, unsigned int);
-	int ret;
-
-	if (unlikely(!(in->f_mode & FMODE_READ)))
-		return -EBADF;
-
-	ret = rw_verify_area(READ, in, ppos, len);
-	if (unlikely(ret < 0))
-		return ret;
-
-	if (in->f_op && in->f_op->splice_read)
-		splice_read = in->f_op->splice_read;
-	else
-		splice_read = default_file_splice_read;
-
-	return splice_read(in, ppos, pipe, len, flags);
-}
-
-/**
- * splice_direct_to_actor - splices data directly between two non-pipes
- * @in:		file to splice from
- * @sd:		actor information on where to splice to
- * @actor:	handles the data splicing
- *
- * Description:
- *    This is a special case helper to splice directly between two
- *    points, without requiring an explicit pipe. Internally an allocated
- *    pipe is cached in the process, and reused during the lifetime of
- *    that process.
- *
- */
-ssize_t splice_direct_to_actor(struct file *in, struct splice_desc *sd,
-			       splice_direct_actor *actor)
-{
-	struct pipe_inode_info *pipe;
-	long ret, bytes;
-	umode_t i_mode;
-	size_t len;
-	int i, flags;
-
-	/*
-	 * 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_path.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;
-	len = sd->total_len;
-	flags = sd->flags;
-
-	/*
-	 * Don't block on output, we have to drain the direct pipe.
-	 */
-	sd->flags &= ~SPLICE_F_NONBLOCK;
-
-	while (len) {
-		size_t read_len;
-		loff_t pos = sd->pos, prev_pos = pos;
-
-		ret = do_splice_to(in, &pos, pipe, len, flags);
-		if (unlikely(ret <= 0))
-			goto out_release;
-
-		read_len = ret;
-		sd->total_len = read_len;
-
-		/*
-		 * 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 = actor(pipe, sd);
-		if (unlikely(ret <= 0)) {
-			sd->pos = prev_pos;
-			goto out_release;
-		}
-
-		bytes += ret;
-		len -= ret;
-		sd->pos = pos;
-
-		if (ret < read_len) {
-			sd->pos = prev_pos + ret;
-			goto out_release;
-		}
-	}
-
-done:
-	pipe->nrbufs = pipe->curbuf = 0;
-	file_accessed(in);
-	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;
-		}
-	}
-
-	if (!bytes)
-		bytes = ret;
-
-	goto done;
-}
-EXPORT_SYMBOL(splice_direct_to_actor);
-
-static int direct_splice_actor(struct pipe_inode_info *pipe,
-			       struct splice_desc *sd)
-{
-	struct file *file = sd->u.file;
-
-	return do_splice_from(pipe, file, &file->f_pos, sd->total_len,
-			      sd->flags);
-}
-
-/**
- * do_splice_direct - splices data directly between two files
- * @in:		file to splice from
- * @ppos:	input file offset
- * @out:	file to splice to
- * @len:	number of bytes to splice
- * @flags:	splice modifier flags
- *
- * Description:
- *    For use by do_sendfile(). splice can easily emulate sendfile, but
- *    doing it in the application would incur an extra system call
- *    (splice in + splice out, as compared to just sendfile()). So this helper
- *    can splice directly through a process-private pipe.
- *
- */
-long do_splice_direct(struct file *in, loff_t *ppos, struct file *out,
-		      size_t len, unsigned int flags)
-{
-	struct splice_desc sd = {
-		.len		= len,
-		.total_len	= len,
-		.flags		= flags,
-		.pos		= *ppos,
-		.u.file		= out,
-	};
-	long ret;
-
-	ret = splice_direct_to_actor(in, &sd, direct_splice_actor);
-	if (ret > 0)
-		*ppos = sd.pos;
-
-	return ret;
-}
-
-static int splice_pipe_to_pipe(struct pipe_inode_info *ipipe,
-			       struct pipe_inode_info *opipe,
-			       size_t len, unsigned int flags);
-
-/*
- * 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 *ipipe;
-	struct pipe_inode_info *opipe;
-	loff_t offset, *off;
-	long ret;
-
-	ipipe = get_pipe_info(in);
-	opipe = get_pipe_info(out);
-
-	if (ipipe && opipe) {
-		if (off_in || off_out)
-			return -ESPIPE;
-
-		if (!(in->f_mode & FMODE_READ))
-			return -EBADF;
-
-		if (!(out->f_mode & FMODE_WRITE))
-			return -EBADF;
-
-		/* Splicing to self would be fun, but... */
-		if (ipipe == opipe)
-			return -EINVAL;
-
-		return splice_pipe_to_pipe(ipipe, opipe, len, flags);
-	}
-
-	if (ipipe) {
-		if (off_in)
-			return -ESPIPE;
-		if (off_out) {
-			if (!(out->f_mode & FMODE_PWRITE))
-				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(ipipe, out, off, len, flags);
-
-		if (off_out && copy_to_user(off_out, off, sizeof(loff_t)))
-			ret = -EFAULT;
-
-		return ret;
-	}
-
-	if (opipe) {
-		if (off_out)
-			return -ESPIPE;
-		if (off_in) {
-			if (!(in->f_mode & FMODE_PREAD))
-				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, opipe, len, flags);
-
-		if (off_in && copy_to_user(off_in, off, sizeof(loff_t)))
-			ret = -EFAULT;
-
-		return ret;
-	}
-
-	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, int aligned,
-				unsigned int pipe_buffers)
-{
-	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))
-			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++;
-	}
-
-	if (buffers)
-		return buffers;
-
-	return error;
-}
-
-static int pipe_to_user(struct pipe_inode_info *pipe, struct pipe_buffer *buf,
-			struct splice_desc *sd)
-{
-	char *src;
-	int ret;
-
-	/*
-	 * See if we can use the atomic maps, by prefaulting in the
-	 * pages and doing an atomic copy
-	 */
-	if (!fault_in_pages_writeable(sd->u.userptr, sd->len)) {
-		src = buf->ops->map(pipe, buf, 1);
-		ret = __copy_to_user_inatomic(sd->u.userptr, src + buf->offset,
-							sd->len);
-		buf->ops->unmap(pipe, buf, src);
-		if (!ret) {
-			ret = sd->len;
-			goto out;
-		}
-	}
-
-	/*
-	 * No dice, use slow non-atomic map and copy
- 	 */
-	src = buf->ops->map(pipe, buf, 0);
-
-	ret = sd->len;
-	if (copy_to_user(sd->u.userptr, src + buf->offset, sd->len))
-		ret = -EFAULT;
-
-	buf->ops->unmap(pipe, buf, src);
-out:
-	if (ret > 0)
-		sd->u.userptr += ret;
-	return ret;
-}
-
-/*
- * For lack of a better implementation, implement vmsplice() to userspace
- * as a simple copy of the pipes pages to the user iov.
- */
-static long vmsplice_to_user(struct file *file, const struct iovec __user *iov,
-			     unsigned long nr_segs, unsigned int flags)
-{
-	struct pipe_inode_info *pipe;
-	struct splice_desc sd;
-	ssize_t size;
-	int error;
-	long ret;
-
-	pipe = get_pipe_info(file);
-	if (!pipe)
-		return -EBADF;
-
-	pipe_lock(pipe);
-
-	error = ret = 0;
-	while (nr_segs) {
-		void __user *base;
-		size_t len;
-
-		/*
-		 * Get user address base and length for this iovec.
-		 */
-		error = get_user(base, &iov->iov_base);
-		if (unlikely(error))
-			break;
-		error = get_user(len, &iov->iov_len);
-		if (unlikely(error))
-			break;
-
-		/*
-		 * Sanity check this iovec. 0 read succeeds.
-		 */
-		if (unlikely(!len))
-			break;
-		if (unlikely(!base)) {
-			error = -EFAULT;
-			break;
-		}
-
-		if (unlikely(!access_ok(VERIFY_WRITE, base, len))) {
-			error = -EFAULT;
-			break;
-		}
-
-		sd.len = 0;
-		sd.total_len = len;
-		sd.flags = flags;
-		sd.u.userptr = base;
-		sd.pos = 0;
-
-		size = __splice_from_pipe(pipe, &sd, pipe_to_user);
-		if (size < 0) {
-			if (!ret)
-				ret = size;
-
-			break;
-		}
-
-		ret += size;
-
-		if (size < len)
-			break;
-
-		nr_segs--;
-		iov++;
-	}
-
-	pipe_unlock(pipe);
-
-	if (!ret)
-		ret = error;
-
-	return ret;
-}
-
-/*
- * vmsplice splices a user address range into a pipe. It can be thought of
- * 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,
-			     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,
-	};
-	long ret;
-
-	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, flags & SPLICE_F_GIFT,
-					    spd.nr_pages_max);
-	if (spd.nr_pages <= 0)
-		ret = spd.nr_pages;
-	else
-		ret = splice_to_pipe(pipe, &spd);
-
-	splice_shrink_spd(&spd);
-	return ret;
-}
-
-/*
- * Note that vmsplice only really supports true splicing _from_ user memory
- * to a pipe, not the other way around. Splicing from user memory is a simple
- * operation that can be supported without any funky alignment restrictions
- * or nasty vm tricks. We simply map in the user memory and fill them into
- * a pipe. The reverse isn't quite as easy, though. There are two possible
- * solutions for that:
- *
- *	- memcpy() the data internally, at which point we might as well just
- *	  do a regular read() on the buffer anyway.
- *	- Lots of nasty vm tricks, that are neither fast nor flexible (it
- *	  has restriction limitations on both ends of the pipe).
- *
- * Currently we punt and implement it as a normal copy, see pipe_to_user().
- *
- */
-SYSCALL_DEFINE4(vmsplice, int, fd, const struct iovec __user *, iov,
-		unsigned long, nr_segs, unsigned int, flags)
-{
-	struct file *file;
-	long error;
-	int fput;
-
-	if (unlikely(nr_segs > UIO_MAXIOV))
-		return -EINVAL;
-	else if (unlikely(!nr_segs))
-		return 0;
-
-	error = -EBADF;
-	file = fget_light(fd, &fput);
-	if (file) {
-		if (file->f_mode & FMODE_WRITE)
-			error = vmsplice_to_pipe(file, iov, nr_segs, flags);
-		else if (file->f_mode & FMODE_READ)
-			error = vmsplice_to_user(file, iov, nr_segs, flags);
-
-		fput_light(file, fput);
-	}
-
-	return error;
-}
-
-SYSCALL_DEFINE6(splice, int, fd_in, loff_t __user *, off_in,
-		int, fd_out, loff_t __user *, off_out,
-		size_t, len, unsigned int, flags)
-{
-	long error;
-	struct file *in, *out;
-	int fput_in, fput_out;
-
-	if (unlikely(!len))
-		return 0;
-
-	error = -EBADF;
-	in = fget_light(fd_in, &fput_in);
-	if (in) {
-		if (in->f_mode & FMODE_READ) {
-			out = fget_light(fd_out, &fput_out);
-			if (out) {
-				if (out->f_mode & FMODE_WRITE)
-					error = do_splice(in, off_in,
-							  out, off_out,
-							  len, flags);
-				fput_light(out, fput_out);
-			}
-		}
-
-		fput_light(in, fput_in);
-	}
-
-	return error;
-}
-
-/*
- * Make sure there's data to read. Wait for input if we can, otherwise
- * return an appropriate error.
- */
-static int ipipe_prep(struct pipe_inode_info *pipe, unsigned int flags)
-{
-	int ret;
-
-	/*
-	 * Check ->nrbufs without the inode lock first. This function
-	 * is speculative anyways, so missing one is ok.
-	 */
-	if (pipe->nrbufs)
-		return 0;
-
-	ret = 0;
-	pipe_lock(pipe);
-
-	while (!pipe->nrbufs) {
-		if (signal_pending(current)) {
-			ret = -ERESTARTSYS;
-			break;
-		}
-		if (!pipe->writers)
-			break;
-		if (!pipe->waiting_writers) {
-			if (flags & SPLICE_F_NONBLOCK) {
-				ret = -EAGAIN;
-				break;
-			}
-		}
-		pipe_wait(pipe);
-	}
-
-	pipe_unlock(pipe);
-	return ret;
-}
-
-/*
- * Make sure there's writeable room. Wait for room if we can, otherwise
- * return an appropriate error.
- */
-static int opipe_prep(struct pipe_inode_info *pipe, unsigned int flags)
-{
-	int ret;
-
-	/*
-	 * Check ->nrbufs without the inode lock first. This function
-	 * is speculative anyways, so missing one is ok.
-	 */
-	if (pipe->nrbufs < pipe->buffers)
-		return 0;
-
-	ret = 0;
-	pipe_lock(pipe);
-
-	while (pipe->nrbufs >= pipe->buffers) {
-		if (!pipe->readers) {
-			send_sig(SIGPIPE, current, 0);
-			ret = -EPIPE;
-			break;
-		}
-		if (flags & SPLICE_F_NONBLOCK) {
-			ret = -EAGAIN;
-			break;
-		}
-		if (signal_pending(current)) {
-			ret = -ERESTARTSYS;
-			break;
-		}
-		pipe->waiting_writers++;
-		pipe_wait(pipe);
-		pipe->waiting_writers--;
-	}
-
-	pipe_unlock(pipe);
-	return ret;
-}
-
-/*
- * Splice contents of ipipe to opipe.
- */
-static int splice_pipe_to_pipe(struct pipe_inode_info *ipipe,
-			       struct pipe_inode_info *opipe,
-			       size_t len, unsigned int flags)
-{
-	struct pipe_buffer *ibuf, *obuf;
-	int ret = 0, nbuf;
-	bool input_wakeup = false;
-
-
-retry:
-	ret = ipipe_prep(ipipe, flags);
-	if (ret)
-		return ret;
-
-	ret = opipe_prep(opipe, flags);
-	if (ret)
-		return ret;
-
-	/*
-	 * Potential ABBA deadlock, work around it by ordering lock
-	 * grabbing by pipe info address. Otherwise two different processes
-	 * could deadlock (one doing tee from A -> B, the other from B -> A).
-	 */
-	pipe_double_lock(ipipe, opipe);
-
-	do {
-		if (!opipe->readers) {
-			send_sig(SIGPIPE, current, 0);
-			if (!ret)
-				ret = -EPIPE;
-			break;
-		}
-
-		if (!ipipe->nrbufs && !ipipe->writers)
-			break;
-
-		/*
-		 * Cannot make any progress, because either the input
-		 * pipe is empty or the output pipe is full.
-		 */
-		if (!ipipe->nrbufs || opipe->nrbufs >= opipe->buffers) {
-			/* Already processed some buffers, break */
-			if (ret)
-				break;
-
-			if (flags & SPLICE_F_NONBLOCK) {
-				ret = -EAGAIN;
-				break;
-			}
-
-			/*
-			 * We raced with another reader/writer and haven't
-			 * managed to process any buffers.  A zero return
-			 * value means EOF, so retry instead.
-			 */
-			pipe_unlock(ipipe);
-			pipe_unlock(opipe);
-			goto retry;
-		}
-
-		ibuf = ipipe->bufs + ipipe->curbuf;
-		nbuf = (opipe->curbuf + opipe->nrbufs) & (opipe->buffers - 1);
-		obuf = opipe->bufs + nbuf;
-
-		if (len >= ibuf->len) {
-			/*
-			 * Simply move the whole buffer from ipipe to opipe
-			 */
-			*obuf = *ibuf;
-			ibuf->ops = NULL;
-			opipe->nrbufs++;
-			ipipe->curbuf = (ipipe->curbuf + 1) & (ipipe->buffers - 1);
-			ipipe->nrbufs--;
-			input_wakeup = true;
-		} else {
-			/*
-			 * Get a reference to this pipe buffer,
-			 * so we can copy the contents over.
-			 */
-			ibuf->ops->get(ipipe, ibuf);
-			*obuf = *ibuf;
-
-			/*
-			 * Don't inherit the gift flag, we need to
-			 * prevent multiple steals of this page.
-			 */
-			obuf->flags &= ~PIPE_BUF_FLAG_GIFT;
-
-			obuf->len = len;
-			opipe->nrbufs++;
-			ibuf->offset += obuf->len;
-			ibuf->len -= obuf->len;
-		}
-		ret += obuf->len;
-		len -= obuf->len;
-	} while (len);
-
-	pipe_unlock(ipipe);
-	pipe_unlock(opipe);
-
-	/*
-	 * If we put data in the output pipe, wakeup any potential readers.
-	 */
-	if (ret > 0)
-		wakeup_pipe_readers(opipe);
-
-	if (input_wakeup)
-		wakeup_pipe_writers(ipipe);
-
-	return ret;
-}
-
-/*
- * Link contents of ipipe to opipe.
- */
-static int link_pipe(struct pipe_inode_info *ipipe,
-		     struct pipe_inode_info *opipe,
-		     size_t len, unsigned int flags)
-{
-	struct pipe_buffer *ibuf, *obuf;
-	int ret = 0, i = 0, nbuf;
-
-	/*
-	 * Potential ABBA deadlock, work around it by ordering lock
-	 * grabbing by pipe info address. Otherwise two different processes
-	 * could deadlock (one doing tee from A -> B, the other from B -> A).
-	 */
-	pipe_double_lock(ipipe, opipe);
-
-	do {
-		if (!opipe->readers) {
-			send_sig(SIGPIPE, current, 0);
-			if (!ret)
-				ret = -EPIPE;
-			break;
-		}
-
-		/*
-		 * If we have iterated all input buffers or ran out of
-		 * output room, break.
-		 */
-		if (i >= ipipe->nrbufs || opipe->nrbufs >= opipe->buffers)
-			break;
-
-		ibuf = ipipe->bufs + ((ipipe->curbuf + i) & (ipipe->buffers-1));
-		nbuf = (opipe->curbuf + opipe->nrbufs) & (opipe->buffers - 1);
-
-		/*
-		 * Get a reference to this pipe buffer,
-		 * so we can copy the contents over.
-		 */
-		ibuf->ops->get(ipipe, ibuf);
-
-		obuf = opipe->bufs + nbuf;
-		*obuf = *ibuf;
-
-		/*
-		 * Don't inherit the gift flag, we need to
-		 * prevent multiple steals of this page.
-		 */
-		obuf->flags &= ~PIPE_BUF_FLAG_GIFT;
-
-		if (obuf->len > len)
-			obuf->len = len;
-
-		opipe->nrbufs++;
-		ret += obuf->len;
-		len -= obuf->len;
-		i++;
-	} while (len);
-
-	/*
-	 * return EAGAIN if we have the potential of some data in the
-	 * future, otherwise just return 0
-	 */
-	if (!ret && ipipe->waiting_writers && (flags & SPLICE_F_NONBLOCK))
-		ret = -EAGAIN;
-
-	pipe_unlock(ipipe);
-	pipe_unlock(opipe);
-
-	/*
-	 * If we put data in the output pipe, wakeup any potential readers.
-	 */
-	if (ret > 0)
-		wakeup_pipe_readers(opipe);
-
-	return ret;
-}
-
-/*
- * This is a tee(1) implementation that works on pipes. It doesn't copy
- * any data, it simply references the 'in' pages on the 'out' pipe.
- * The 'flags' used are the SPLICE_F_* variants, currently the only
- * applicable one is SPLICE_F_NONBLOCK.
- */
-static long do_tee(struct file *in, struct file *out, size_t len,
-		   unsigned int flags)
-{
-	struct pipe_inode_info *ipipe = get_pipe_info(in);
-	struct pipe_inode_info *opipe = get_pipe_info(out);
-	int ret = -EINVAL;
-
-	/*
-	 * Duplicate the contents of ipipe to opipe without actually
-	 * copying the data.
-	 */
-	if (ipipe && opipe && ipipe != opipe) {
-		/*
-		 * Keep going, unless we encounter an error. The ipipe/opipe
-		 * ordering doesn't really matter.
-		 */
-		ret = ipipe_prep(ipipe, flags);
-		if (!ret) {
-			ret = opipe_prep(opipe, flags);
-			if (!ret)
-				ret = link_pipe(ipipe, opipe, len, flags);
-		}
-	}
-
-	return ret;
-}
-
-SYSCALL_DEFINE4(tee, int, fdin, int, fdout, size_t, len, unsigned int, flags)
-{
-	struct file *in;
-	int error, fput_in;
-
-	if (unlikely(!len))
-		return 0;
-
-	error = -EBADF;
-	in = fget_light(fdin, &fput_in);
-	if (in) {
-		if (in->f_mode & FMODE_READ) {
-			int fput_out;
-			struct file *out = fget_light(fdout, &fput_out);
-
-			if (out) {
-				if (out->f_mode & FMODE_WRITE)
-					error = do_tee(in, out, len, flags);
-				fput_light(out, fput_out);
-			}
-		}
- 		fput_light(in, fput_in);
- 	}
-
-	return error;
-}