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fs/splice.c
46.2 KB
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/* * "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 |
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* Jens to support splicing to files, network, direct splicing, etc and * fixing lots of bugs. |
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* |
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* Copyright (C) 2005-2006 Jens Axboe <axboe@kernel.dk> |
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* Copyright (C) 2005-2006 Linus Torvalds <torvalds@osdl.org> * Copyright (C) 2006 Ingo Molnar <mingo@elte.hu> |
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* */ #include <linux/fs.h> #include <linux/file.h> #include <linux/pagemap.h> |
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#include <linux/splice.h> |
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#include <linux/memcontrol.h> |
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#include <linux/mm_inline.h> |
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#include <linux/swap.h> |
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#include <linux/writeback.h> |
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#include <linux/export.h> |
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#include <linux/syscalls.h> |
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#include <linux/uio.h> |
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#include <linux/security.h> |
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#include <linux/gfp.h> |
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#include <linux/socket.h> |
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#include <linux/compat.h> |
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#include "internal.h" |
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|
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/* * 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. */ |
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static int page_cache_pipe_buf_steal(struct pipe_inode_info *pipe, |
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struct pipe_buffer *buf) { struct page *page = buf->page; |
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struct address_space *mapping; |
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|
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lock_page(page); |
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mapping = page_mapping(page); if (mapping) { WARN_ON(!PageUptodate(page)); |
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|
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/* * 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); |
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|
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if (page_has_private(page) && !try_to_release_page(page, GFP_KERNEL)) |
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goto out_unlock; |
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|
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/* * 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; } |
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} |
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|
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/* * Raced with truncate or failed to remove page from current * address space, unlock and return failure. */ |
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out_unlock: |
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unlock_page(page); return 1; |
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} |
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static void page_cache_pipe_buf_release(struct pipe_inode_info *pipe, |
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struct pipe_buffer *buf) { |
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put_page(buf->page); |
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buf->flags &= ~PIPE_BUF_FLAG_LRU; |
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} |
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/* * Check whether the contents of buf is OK to access. Since the content * is a page cache page, IO may be in flight. */ |
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static int page_cache_pipe_buf_confirm(struct pipe_inode_info *pipe, struct pipe_buffer *buf) |
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{ struct page *page = buf->page; |
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int err; |
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if (!PageUptodate(page)) { |
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lock_page(page); /* * Page got truncated/unhashed. This will cause a 0-byte |
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* splice, if this is the first page. |
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*/ if (!page->mapping) { err = -ENODATA; goto error; } |
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|
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/* |
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* Uh oh, read-error from disk. |
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*/ if (!PageUptodate(page)) { err = -EIO; goto error; } /* |
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* Page is ok afterall, we are done. |
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*/ |
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unlock_page(page); |
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} |
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return 0; |
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error: unlock_page(page); |
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return err; |
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} |
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const struct pipe_buf_operations page_cache_pipe_buf_ops = { |
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.can_merge = 0, |
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.confirm = page_cache_pipe_buf_confirm, |
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.release = page_cache_pipe_buf_release, |
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.steal = page_cache_pipe_buf_steal, |
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.get = generic_pipe_buf_get, |
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}; |
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static int user_page_pipe_buf_steal(struct pipe_inode_info *pipe, struct pipe_buffer *buf) { |
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if (!(buf->flags & PIPE_BUF_FLAG_GIFT)) return 1; |
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buf->flags |= PIPE_BUF_FLAG_LRU; |
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return generic_pipe_buf_steal(pipe, buf); |
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} |
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static const struct pipe_buf_operations user_page_pipe_buf_ops = { |
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.can_merge = 0, |
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.confirm = generic_pipe_buf_confirm, |
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.release = page_cache_pipe_buf_release, .steal = user_page_pipe_buf_steal, |
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.get = generic_pipe_buf_get, |
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}; |
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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); } |
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/** * splice_to_pipe - fill passed data into a pipe * @pipe: pipe to fill * @spd: data to fill * * Description: |
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* @spd contains a map of pages and len/offset tuples, along with |
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* the struct pipe_buf_operations associated with these pages. This * function will link that data to the pipe. * |
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*/ |
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ssize_t splice_to_pipe(struct pipe_inode_info *pipe, struct splice_pipe_desc *spd) |
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{ |
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unsigned int spd_pages = spd->nr_pages; |
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int ret, do_wakeup, page_nr; |
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|
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if (!spd_pages) return 0; |
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ret = 0; do_wakeup = 0; |
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page_nr = 0; |
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|
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pipe_lock(pipe); |
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|
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for (;;) { |
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if (!pipe->readers) { |
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send_sig(SIGPIPE, current, 0); if (!ret) ret = -EPIPE; break; } |
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if (pipe->nrbufs < pipe->buffers) { int newbuf = (pipe->curbuf + pipe->nrbufs) & (pipe->buffers - 1); |
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struct pipe_buffer *buf = pipe->bufs + newbuf; |
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|
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buf->page = spd->pages[page_nr]; buf->offset = spd->partial[page_nr].offset; 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) buf->flags |= PIPE_BUF_FLAG_GIFT; |
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pipe->nrbufs++; |
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page_nr++; ret += buf->len; |
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if (pipe->files) |
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do_wakeup = 1; |
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|
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if (!--spd->nr_pages) |
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break; |
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if (pipe->nrbufs < pipe->buffers) |
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continue; break; } |
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if (spd->flags & SPLICE_F_NONBLOCK) { |
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if (!ret) ret = -EAGAIN; break; } |
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if (signal_pending(current)) { if (!ret) ret = -ERESTARTSYS; break; } if (do_wakeup) { |
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smp_mb(); |
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if (waitqueue_active(&pipe->wait)) wake_up_interruptible_sync(&pipe->wait); kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN); |
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do_wakeup = 0; } |
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pipe->waiting_writers++; pipe_wait(pipe); pipe->waiting_writers--; |
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} |
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pipe_unlock(pipe); |
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|
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if (do_wakeup) wakeup_pipe_readers(pipe); |
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|
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while (page_nr < spd_pages) |
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spd->spd_release(spd, page_nr++); |
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return ret; } |
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EXPORT_SYMBOL_GPL(splice_to_pipe); |
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|
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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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} |
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/* * Check if we need to grow the arrays holding pages and partial page * descriptions. */ |
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int splice_grow_spd(const struct pipe_inode_info *pipe, struct splice_pipe_desc *spd) |
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{ |
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unsigned int buffers = ACCESS_ONCE(pipe->buffers); spd->nr_pages_max = buffers; if (buffers <= PIPE_DEF_BUFFERS) |
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return 0; |
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spd->pages = kmalloc(buffers * sizeof(struct page *), GFP_KERNEL); spd->partial = kmalloc(buffers * sizeof(struct partial_page), GFP_KERNEL); |
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if (spd->pages && spd->partial) return 0; kfree(spd->pages); kfree(spd->partial); return -ENOMEM; } |
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void splice_shrink_spd(struct splice_pipe_desc *spd) |
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{ |
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if (spd->nr_pages_max <= PIPE_DEF_BUFFERS) |
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return; kfree(spd->pages); kfree(spd->partial); } |
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static int |
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__generic_file_splice_read(struct file *in, loff_t *ppos, struct pipe_inode_info *pipe, size_t len, unsigned int flags) |
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{ struct address_space *mapping = in->f_mapping; |
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unsigned int loff, nr_pages, req_pages; |
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struct page *pages[PIPE_DEF_BUFFERS]; struct partial_page partial[PIPE_DEF_BUFFERS]; |
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struct page *page; |
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pgoff_t index, end_index; loff_t isize; |
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int error, page_nr; |
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struct splice_pipe_desc spd = { .pages = pages, .partial = partial, |
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.nr_pages_max = PIPE_DEF_BUFFERS, |
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.flags = flags, .ops = &page_cache_pipe_buf_ops, |
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.spd_release = spd_release_page, |
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}; |
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|
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if (splice_grow_spd(pipe, &spd)) return -ENOMEM; |
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index = *ppos >> PAGE_SHIFT; loff = *ppos & ~PAGE_MASK; req_pages = (len + loff + PAGE_SIZE - 1) >> PAGE_SHIFT; |
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nr_pages = min(req_pages, spd.nr_pages_max); |
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/* |
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* Lookup the (hopefully) full range of pages we need. */ |
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spd.nr_pages = find_get_pages_contig(mapping, index, nr_pages, spd.pages); |
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index += spd.nr_pages; |
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|
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/* * If find_get_pages_contig() returned fewer pages than we needed, |
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* readahead/allocate the rest and fill in the holes. |
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*/ |
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if (spd.nr_pages < nr_pages) |
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page_cache_sync_readahead(mapping, &in->f_ra, in, index, req_pages - spd.nr_pages); |
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|
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error = 0; |
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while (spd.nr_pages < nr_pages) { |
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/* |
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* Page could be there, find_get_pages_contig() breaks on * the first hole. |
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*/ |
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page = find_get_page(mapping, index); if (!page) { |
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/* |
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* page didn't exist, allocate one. |
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*/ page = page_cache_alloc_cold(mapping); if (!page) break; error = add_to_page_cache_lru(page, mapping, index, |
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mapping_gfp_constraint(mapping, GFP_KERNEL)); |
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if (unlikely(error)) { |
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put_page(page); |
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if (error == -EEXIST) continue; |
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break; } |
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/* * add_to_page_cache() locks the page, unlock it * to avoid convoluting the logic below even more. */ unlock_page(page); |
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} |
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spd.pages[spd.nr_pages++] = page; |
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index++; } /* * Now loop over the map and see if we need to start IO on any * pages, fill in the partial map, etc. */ |
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index = *ppos >> PAGE_SHIFT; |
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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 */ |
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this_len = min_t(unsigned long, len, PAGE_SIZE - loff); |
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page = spd.pages[page_nr]; |
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|
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if (PageReadahead(page)) |
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page_cache_async_readahead(mapping, &in->f_ra, in, |
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page, index, req_pages - page_nr); |
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|
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/* * If the page isn't uptodate, we may need to start io on it */ if (!PageUptodate(page)) { |
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lock_page(page); |
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/* |
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* 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. |
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*/ if (!page->mapping) { unlock_page(page); |
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retry_lookup: |
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page = find_or_create_page(mapping, index, mapping_gfp_mask(mapping)); if (!page) { error = -ENOMEM; break; } |
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put_page(spd.pages[page_nr]); |
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spd.pages[page_nr] = page; |
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} /* * page was already under io and is now done, great */ if (PageUptodate(page)) { unlock_page(page); goto fill_it; } |
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|
7480a9043 [PATCH] splice: s... |
416 417 418 419 |
/* * need to read in the page */ error = mapping->a_ops->readpage(in, page); |
5274f052e [PATCH] Introduce... |
420 |
if (unlikely(error)) { |
eb20796bf [PATCH] splice: m... |
421 |
/* |
90330e689 fs: __generic_fil... |
422 |
* Re-lookup the page |
eb20796bf [PATCH] splice: m... |
423 |
*/ |
7480a9043 [PATCH] splice: s... |
424 |
if (error == AOP_TRUNCATED_PAGE) |
90330e689 fs: __generic_fil... |
425 |
goto retry_lookup; |
eb20796bf [PATCH] splice: m... |
426 |
|
5274f052e [PATCH] Introduce... |
427 428 |
break; } |
620a324b7 splice: __generic... |
429 430 431 432 433 434 |
} fill_it: /* * i_size must be checked after PageUptodate. */ isize = i_size_read(mapping->host); |
09cbfeaf1 mm, fs: get rid o... |
435 |
end_index = (isize - 1) >> PAGE_SHIFT; |
620a324b7 splice: __generic... |
436 437 438 439 440 441 442 443 444 |
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; |
91ad66ef4 [PATCH] splice: c... |
445 446 |
/* |
620a324b7 splice: __generic... |
447 |
* max good bytes in this page |
91ad66ef4 [PATCH] splice: c... |
448 |
*/ |
09cbfeaf1 mm, fs: get rid o... |
449 |
plen = ((isize - 1) & ~PAGE_MASK) + 1; |
620a324b7 splice: __generic... |
450 |
if (plen <= loff) |
91ad66ef4 [PATCH] splice: c... |
451 |
break; |
91ad66ef4 [PATCH] splice: c... |
452 453 |
/* |
620a324b7 splice: __generic... |
454 |
* force quit after adding this page |
91ad66ef4 [PATCH] splice: c... |
455 |
*/ |
620a324b7 splice: __generic... |
456 457 |
this_len = min(this_len, plen - loff); len = this_len; |
5274f052e [PATCH] Introduce... |
458 |
} |
620a324b7 splice: __generic... |
459 |
|
35f3d14db pipe: add support... |
460 461 |
spd.partial[page_nr].offset = loff; spd.partial[page_nr].len = this_len; |
82aa5d618 [PATCH] splice: f... |
462 |
len -= this_len; |
91ad66ef4 [PATCH] splice: c... |
463 |
loff = 0; |
eb20796bf [PATCH] splice: m... |
464 465 |
spd.nr_pages++; index++; |
5274f052e [PATCH] Introduce... |
466 |
} |
eb20796bf [PATCH] splice: m... |
467 |
/* |
475ecade6 splice: __generic... |
468 |
* Release any pages at the end, if we quit early. 'page_nr' is how far |
eb20796bf [PATCH] splice: m... |
469 470 471 |
* we got, 'nr_pages' is how many pages are in the map. */ while (page_nr < nr_pages) |
09cbfeaf1 mm, fs: get rid o... |
472 473 |
put_page(spd.pages[page_nr++]); in->f_ra.prev_pos = (loff_t)index << PAGE_SHIFT; |
eb20796bf [PATCH] splice: m... |
474 |
|
912d35f86 [PATCH] Add suppo... |
475 |
if (spd.nr_pages) |
35f3d14db pipe: add support... |
476 |
error = splice_to_pipe(pipe, &spd); |
5274f052e [PATCH] Introduce... |
477 |
|
047fe3605 splice: fix racy ... |
478 |
splice_shrink_spd(&spd); |
7480a9043 [PATCH] splice: s... |
479 |
return error; |
5274f052e [PATCH] Introduce... |
480 |
} |
83f9135bd [PATCH] splice: a... |
481 482 483 |
/** * generic_file_splice_read - splice data from file to a pipe * @in: file to splice from |
932cc6d4f splice: completel... |
484 |
* @ppos: position in @in |
83f9135bd [PATCH] splice: a... |
485 486 487 488 |
* @pipe: pipe to splice to * @len: number of bytes to splice * @flags: splice modifier flags * |
932cc6d4f splice: completel... |
489 490 491 492 493 |
* 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. * |
83f9135bd [PATCH] splice: a... |
494 |
*/ |
cbb7e577e [PATCH] splice: p... |
495 496 497 |
ssize_t generic_file_splice_read(struct file *in, loff_t *ppos, struct pipe_inode_info *pipe, size_t len, unsigned int flags) |
5274f052e [PATCH] Introduce... |
498 |
{ |
d366d3988 splice: move inod... |
499 |
loff_t isize, left; |
8191ecd1d splice: fix infin... |
500 |
int ret; |
d366d3988 splice: move inod... |
501 |
|
be64f884b dax: unify ext2/4... |
502 503 |
if (IS_DAX(in->f_mapping->host)) return default_file_splice_read(in, ppos, pipe, len, flags); |
d366d3988 splice: move inod... |
504 505 506 507 508 509 510 |
isize = i_size_read(in->f_mapping->host); if (unlikely(*ppos >= isize)) return 0; left = isize - *ppos; if (unlikely(left < len)) len = left; |
5274f052e [PATCH] Introduce... |
511 |
|
8191ecd1d splice: fix infin... |
512 |
ret = __generic_file_splice_read(in, ppos, pipe, len, flags); |
723590ed5 splice: update mt... |
513 |
if (ret > 0) { |
cbb7e577e [PATCH] splice: p... |
514 |
*ppos += ret; |
723590ed5 splice: update mt... |
515 516 |
file_accessed(in); } |
5274f052e [PATCH] Introduce... |
517 518 519 |
return ret; } |
059a8f373 [PATCH] splice: e... |
520 |
EXPORT_SYMBOL(generic_file_splice_read); |
6818173bd splice: implement... |
521 522 |
static const struct pipe_buf_operations default_pipe_buf_ops = { .can_merge = 0, |
6818173bd splice: implement... |
523 524 525 526 527 |
.confirm = generic_pipe_buf_confirm, .release = generic_pipe_buf_release, .steal = generic_pipe_buf_steal, .get = generic_pipe_buf_get, }; |
28a625cbc fuse: fix pipe_bu... |
528 529 530 531 532 533 534 535 536 |
static int generic_pipe_buf_nosteal(struct pipe_inode_info *pipe, struct pipe_buffer *buf) { return 1; } /* Pipe buffer operations for a socket and similar. */ const struct pipe_buf_operations nosteal_pipe_buf_ops = { .can_merge = 0, |
28a625cbc fuse: fix pipe_bu... |
537 538 539 540 541 542 |
.confirm = generic_pipe_buf_confirm, .release = generic_pipe_buf_release, .steal = generic_pipe_buf_nosteal, .get = generic_pipe_buf_get, }; EXPORT_SYMBOL(nosteal_pipe_buf_ops); |
6818173bd splice: implement... |
543 544 545 546 547 548 549 550 551 552 |
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() */ |
793b80ef1 vfs: pass a flags... |
553 |
res = vfs_readv(file, (const struct iovec __user *)vec, vlen, &pos, 0); |
6818173bd splice: implement... |
554 555 556 557 |
set_fs(old_fs); return res; } |
7bb307e89 export kernel_wri... |
558 |
ssize_t kernel_write(struct file *file, const char *buf, size_t count, |
b2858d7d1 splice: fix kmaps... |
559 |
loff_t pos) |
0b0a47f5c splice: implement... |
560 561 562 563 564 565 566 |
{ 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() */ |
7bb307e89 export kernel_wri... |
567 |
res = vfs_write(file, (__force const char __user *)buf, count, &pos); |
0b0a47f5c splice: implement... |
568 569 570 571 |
set_fs(old_fs); return res; } |
7bb307e89 export kernel_wri... |
572 |
EXPORT_SYMBOL(kernel_write); |
0b0a47f5c splice: implement... |
573 |
|
6818173bd splice: implement... |
574 575 576 577 578 579 580 |
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; |
35f3d14db pipe: add support... |
581 582 583 |
struct page *pages[PIPE_DEF_BUFFERS]; struct partial_page partial[PIPE_DEF_BUFFERS]; struct iovec *vec, __vec[PIPE_DEF_BUFFERS]; |
6818173bd splice: implement... |
584 585 586 587 588 589 590 |
ssize_t res; size_t this_len; int error; int i; struct splice_pipe_desc spd = { .pages = pages, .partial = partial, |
047fe3605 splice: fix racy ... |
591 |
.nr_pages_max = PIPE_DEF_BUFFERS, |
6818173bd splice: implement... |
592 593 594 595 |
.flags = flags, .ops = &default_pipe_buf_ops, .spd_release = spd_release_page, }; |
35f3d14db pipe: add support... |
596 597 598 599 600 |
if (splice_grow_spd(pipe, &spd)) return -ENOMEM; res = -ENOMEM; vec = __vec; |
047fe3605 splice: fix racy ... |
601 602 |
if (spd.nr_pages_max > PIPE_DEF_BUFFERS) { vec = kmalloc(spd.nr_pages_max * sizeof(struct iovec), GFP_KERNEL); |
35f3d14db pipe: add support... |
603 604 605 |
if (!vec) goto shrink_ret; } |
09cbfeaf1 mm, fs: get rid o... |
606 607 |
offset = *ppos & ~PAGE_MASK; nr_pages = (len + offset + PAGE_SIZE - 1) >> PAGE_SHIFT; |
6818173bd splice: implement... |
608 |
|
047fe3605 splice: fix racy ... |
609 |
for (i = 0; i < nr_pages && i < spd.nr_pages_max && len; i++) { |
6818173bd splice: implement... |
610 |
struct page *page; |
4f2312285 splice: fix repea... |
611 |
page = alloc_page(GFP_USER); |
6818173bd splice: implement... |
612 613 614 |
error = -ENOMEM; if (!page) goto err; |
09cbfeaf1 mm, fs: get rid o... |
615 |
this_len = min_t(size_t, len, PAGE_SIZE - offset); |
4f2312285 splice: fix repea... |
616 |
vec[i].iov_base = (void __user *) page_address(page); |
6818173bd splice: implement... |
617 |
vec[i].iov_len = this_len; |
35f3d14db pipe: add support... |
618 |
spd.pages[i] = page; |
6818173bd splice: implement... |
619 620 621 622 623 624 |
spd.nr_pages++; len -= this_len; offset = 0; } res = kernel_readv(in, vec, spd.nr_pages, *ppos); |
77f6bf57b splice: fix error... |
625 626 |
if (res < 0) { error = res; |
6818173bd splice: implement... |
627 |
goto err; |
77f6bf57b splice: fix error... |
628 |
} |
6818173bd splice: implement... |
629 630 631 632 633 634 635 |
error = 0; if (!res) goto err; nr_freed = 0; for (i = 0; i < spd.nr_pages; i++) { |
6818173bd splice: implement... |
636 |
this_len = min_t(size_t, vec[i].iov_len, res); |
35f3d14db pipe: add support... |
637 638 |
spd.partial[i].offset = 0; spd.partial[i].len = this_len; |
6818173bd splice: implement... |
639 |
if (!this_len) { |
35f3d14db pipe: add support... |
640 641 |
__free_page(spd.pages[i]); spd.pages[i] = NULL; |
6818173bd splice: implement... |
642 643 644 645 646 647 648 649 650 |
nr_freed++; } res -= this_len; } spd.nr_pages -= nr_freed; res = splice_to_pipe(pipe, &spd); if (res > 0) *ppos += res; |
35f3d14db pipe: add support... |
651 652 653 |
shrink_ret: if (vec != __vec) kfree(vec); |
047fe3605 splice: fix racy ... |
654 |
splice_shrink_spd(&spd); |
6818173bd splice: implement... |
655 656 657 |
return res; err: |
4f2312285 splice: fix repea... |
658 |
for (i = 0; i < spd.nr_pages; i++) |
35f3d14db pipe: add support... |
659 |
__free_page(spd.pages[i]); |
4f2312285 splice: fix repea... |
660 |
|
35f3d14db pipe: add support... |
661 662 |
res = error; goto shrink_ret; |
6818173bd splice: implement... |
663 664 |
} EXPORT_SYMBOL(default_file_splice_read); |
5274f052e [PATCH] Introduce... |
665 |
/* |
4f6f0bd2f [PATCH] splice: i... |
666 |
* Send 'sd->len' bytes to socket from 'sd->file' at position 'sd->pos' |
016b661e2 [PATCH] splice: f... |
667 |
* using sendpage(). Return the number of bytes sent. |
5274f052e [PATCH] Introduce... |
668 |
*/ |
76ad4d111 [PATCH] splice: r... |
669 |
static int pipe_to_sendpage(struct pipe_inode_info *pipe, |
5274f052e [PATCH] Introduce... |
670 671 |
struct pipe_buffer *buf, struct splice_desc *sd) { |
6a14b90bb vmsplice: add vms... |
672 |
struct file *file = sd->u.file; |
5274f052e [PATCH] Introduce... |
673 |
loff_t pos = sd->pos; |
a8adbe378 fs/splice: Pull b... |
674 |
int more; |
5274f052e [PATCH] Introduce... |
675 |
|
72c2d5319 file->f_op is nev... |
676 |
if (!likely(file->f_op->sendpage)) |
a8adbe378 fs/splice: Pull b... |
677 |
return -EINVAL; |
35f9c09fe tcp: tcp_sendpage... |
678 |
more = (sd->flags & SPLICE_F_MORE) ? MSG_MORE : 0; |
ae62ca7b0 tcp: fix MSG_SEND... |
679 680 |
if (sd->len < sd->total_len && pipe->nrbufs > 1) |
35f9c09fe tcp: tcp_sendpage... |
681 |
more |= MSG_SENDPAGE_NOTLAST; |
ae62ca7b0 tcp: fix MSG_SEND... |
682 |
|
a8adbe378 fs/splice: Pull b... |
683 684 |
return file->f_op->sendpage(file, buf->page, buf->offset, sd->len, &pos, more); |
5274f052e [PATCH] Introduce... |
685 |
} |
b3c2d2ddd splice: split up ... |
686 687 688 689 690 691 692 |
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); } |
932cc6d4f splice: completel... |
693 |
/** |
b3c2d2ddd splice: split up ... |
694 |
* splice_from_pipe_feed - feed available data from a pipe to a file |
932cc6d4f splice: completel... |
695 696 697 698 699 |
* @pipe: pipe to splice from * @sd: information to @actor * @actor: handler that splices the data * * Description: |
b3c2d2ddd splice: split up ... |
700 701 702 703 704 705 706 |
* 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. |
932cc6d4f splice: completel... |
707 |
* |
b3c2d2ddd splice: split up ... |
708 709 710 711 |
* 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. |
83f9135bd [PATCH] splice: a... |
712 |
*/ |
96f9bc8fb fs/splice.c: remo... |
713 |
static int splice_from_pipe_feed(struct pipe_inode_info *pipe, struct splice_desc *sd, |
b3c2d2ddd splice: split up ... |
714 |
splice_actor *actor) |
5274f052e [PATCH] Introduce... |
715 |
{ |
b3c2d2ddd splice: split up ... |
716 |
int ret; |
5274f052e [PATCH] Introduce... |
717 |
|
b3c2d2ddd splice: split up ... |
718 719 720 |
while (pipe->nrbufs) { struct pipe_buffer *buf = pipe->bufs + pipe->curbuf; const struct pipe_buf_operations *ops = buf->ops; |
5274f052e [PATCH] Introduce... |
721 |
|
b3c2d2ddd splice: split up ... |
722 723 724 |
sd->len = buf->len; if (sd->len > sd->total_len) sd->len = sd->total_len; |
5274f052e [PATCH] Introduce... |
725 |
|
a8adbe378 fs/splice: Pull b... |
726 727 |
ret = buf->ops->confirm(pipe, buf); if (unlikely(ret)) { |
b3c2d2ddd splice: split up ... |
728 729 730 731 |
if (ret == -ENODATA) ret = 0; return ret; } |
a8adbe378 fs/splice: Pull b... |
732 733 734 735 |
ret = actor(pipe, buf, sd); if (ret <= 0) return ret; |
b3c2d2ddd splice: split up ... |
736 737 738 739 740 741 742 743 744 745 746 |
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); |
35f3d14db pipe: add support... |
747 |
pipe->curbuf = (pipe->curbuf + 1) & (pipe->buffers - 1); |
b3c2d2ddd splice: split up ... |
748 |
pipe->nrbufs--; |
6447a3cf1 get rid of pipe->... |
749 |
if (pipe->files) |
b3c2d2ddd splice: split up ... |
750 751 |
sd->need_wakeup = true; } |
5274f052e [PATCH] Introduce... |
752 |
|
b3c2d2ddd splice: split up ... |
753 754 755 |
if (!sd->total_len) return 0; } |
5274f052e [PATCH] Introduce... |
756 |
|
b3c2d2ddd splice: split up ... |
757 758 |
return 1; } |
5274f052e [PATCH] Introduce... |
759 |
|
b3c2d2ddd splice: split up ... |
760 761 762 763 764 765 766 767 768 769 |
/** * 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. */ |
96f9bc8fb fs/splice.c: remo... |
770 |
static int splice_from_pipe_next(struct pipe_inode_info *pipe, struct splice_desc *sd) |
b3c2d2ddd splice: split up ... |
771 |
{ |
c725bfce7 vfs: Make sendfil... |
772 773 774 775 776 777 |
/* * Check for signal early to make process killable when there are * always buffers available */ if (signal_pending(current)) return -ERESTARTSYS; |
b3c2d2ddd splice: split up ... |
778 779 780 |
while (!pipe->nrbufs) { if (!pipe->writers) return 0; |
016b661e2 [PATCH] splice: f... |
781 |
|
b3c2d2ddd splice: split up ... |
782 783 |
if (!pipe->waiting_writers && sd->num_spliced) return 0; |
73d62d83e [PATCH] splice: c... |
784 |
|
b3c2d2ddd splice: split up ... |
785 786 |
if (sd->flags & SPLICE_F_NONBLOCK) return -EAGAIN; |
5274f052e [PATCH] Introduce... |
787 |
|
b3c2d2ddd splice: split up ... |
788 789 |
if (signal_pending(current)) return -ERESTARTSYS; |
5274f052e [PATCH] Introduce... |
790 |
|
b3c2d2ddd splice: split up ... |
791 792 793 |
if (sd->need_wakeup) { wakeup_pipe_writers(pipe); sd->need_wakeup = false; |
5274f052e [PATCH] Introduce... |
794 |
} |
b3c2d2ddd splice: split up ... |
795 796 |
pipe_wait(pipe); } |
29e350944 splice: add SPLIC... |
797 |
|
b3c2d2ddd splice: split up ... |
798 799 |
return 1; } |
5274f052e [PATCH] Introduce... |
800 |
|
b3c2d2ddd splice: split up ... |
801 802 |
/** * splice_from_pipe_begin - start splicing from pipe |
b80901bbf splice: fix new k... |
803 |
* @sd: information about the splice operation |
b3c2d2ddd splice: split up ... |
804 805 806 807 808 809 |
* * 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. */ |
96f9bc8fb fs/splice.c: remo... |
810 |
static void splice_from_pipe_begin(struct splice_desc *sd) |
b3c2d2ddd splice: split up ... |
811 812 813 814 |
{ sd->num_spliced = 0; sd->need_wakeup = false; } |
5274f052e [PATCH] Introduce... |
815 |
|
b3c2d2ddd splice: split up ... |
816 817 818 819 820 821 822 823 824 825 |
/** * 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(). */ |
96f9bc8fb fs/splice.c: remo... |
826 |
static void splice_from_pipe_end(struct pipe_inode_info *pipe, struct splice_desc *sd) |
b3c2d2ddd splice: split up ... |
827 828 829 830 |
{ if (sd->need_wakeup) wakeup_pipe_writers(pipe); } |
5274f052e [PATCH] Introduce... |
831 |
|
b3c2d2ddd splice: split up ... |
832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 |
/** * __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; |
5274f052e [PATCH] Introduce... |
849 |
|
b3c2d2ddd splice: split up ... |
850 851 |
splice_from_pipe_begin(sd); do { |
c2489e07c vfs: Avoid softlo... |
852 |
cond_resched(); |
b3c2d2ddd splice: split up ... |
853 854 855 856 857 858 859 |
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; |
5274f052e [PATCH] Introduce... |
860 |
} |
40bee44ea Export __splice_f... |
861 |
EXPORT_SYMBOL(__splice_from_pipe); |
5274f052e [PATCH] Introduce... |
862 |
|
932cc6d4f splice: completel... |
863 864 865 866 867 868 869 870 871 872 |
/** * 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: |
2933970b9 splice: remove i_... |
873 |
* See __splice_from_pipe. This function locks the pipe inode, |
932cc6d4f splice: completel... |
874 875 876 |
* otherwise it's identical to __splice_from_pipe(). * */ |
6da618098 [PATCH] Introduce... |
877 878 879 880 881 |
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; |
c66ab6fa7 splice: abstract ... |
882 883 884 885 |
struct splice_desc sd = { .total_len = len, .flags = flags, .pos = *ppos, |
6a14b90bb vmsplice: add vms... |
886 |
.u.file = out, |
c66ab6fa7 splice: abstract ... |
887 |
}; |
6da618098 [PATCH] Introduce... |
888 |
|
61e0d47c3 splice: add helpe... |
889 |
pipe_lock(pipe); |
c66ab6fa7 splice: abstract ... |
890 |
ret = __splice_from_pipe(pipe, &sd, actor); |
61e0d47c3 splice: add helpe... |
891 |
pipe_unlock(pipe); |
6da618098 [PATCH] Introduce... |
892 893 894 895 896 |
return ret; } /** |
8d0207652 ->splice_write() ... |
897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 |
* iter_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. * This one is ->write_iter-based. * */ ssize_t iter_file_splice_write(struct pipe_inode_info *pipe, struct file *out, loff_t *ppos, size_t len, unsigned int flags) { struct splice_desc sd = { .total_len = len, .flags = flags, .pos = *ppos, .u.file = out, }; int nbufs = pipe->buffers; struct bio_vec *array = kcalloc(nbufs, sizeof(struct bio_vec), GFP_KERNEL); ssize_t ret; if (unlikely(!array)) return -ENOMEM; pipe_lock(pipe); splice_from_pipe_begin(&sd); while (sd.total_len) { struct iov_iter from; |
8d0207652 ->splice_write() ... |
933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 |
size_t left; int n, idx; ret = splice_from_pipe_next(pipe, &sd); if (ret <= 0) break; if (unlikely(nbufs < pipe->buffers)) { kfree(array); nbufs = pipe->buffers; array = kcalloc(nbufs, sizeof(struct bio_vec), GFP_KERNEL); if (!array) { ret = -ENOMEM; break; } } /* build the vector */ left = sd.total_len; for (n = 0, idx = pipe->curbuf; left && n < pipe->nrbufs; n++, idx++) { struct pipe_buffer *buf = pipe->bufs + idx; size_t this_len = buf->len; if (this_len > left) this_len = left; if (idx == pipe->buffers - 1) idx = -1; ret = buf->ops->confirm(pipe, buf); if (unlikely(ret)) { if (ret == -ENODATA) ret = 0; goto done; } array[n].bv_page = buf->page; array[n].bv_len = this_len; array[n].bv_offset = buf->offset; left -= this_len; } |
05afcb77e new helper: iov_i... |
975 976 |
iov_iter_bvec(&from, ITER_BVEC | WRITE, array, n, sd.total_len - left); |
dbe4e192a fs: add vfs_iter_... |
977 |
ret = vfs_iter_write(out, &from, &sd.pos); |
8d0207652 ->splice_write() ... |
978 979 980 981 982 |
if (ret <= 0) break; sd.num_spliced += ret; sd.total_len -= ret; |
dbe4e192a fs: add vfs_iter_... |
983 |
*ppos = sd.pos; |
8d0207652 ->splice_write() ... |
984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 |
/* dismiss the fully eaten buffers, adjust the partial one */ while (ret) { struct pipe_buffer *buf = pipe->bufs + pipe->curbuf; if (ret >= buf->len) { const struct pipe_buf_operations *ops = buf->ops; ret -= buf->len; buf->len = 0; buf->ops = NULL; ops->release(pipe, buf); pipe->curbuf = (pipe->curbuf + 1) & (pipe->buffers - 1); pipe->nrbufs--; if (pipe->files) sd.need_wakeup = true; } else { buf->offset += ret; buf->len -= ret; ret = 0; } } } done: kfree(array); splice_from_pipe_end(pipe, &sd); pipe_unlock(pipe); if (sd.num_spliced) ret = sd.num_spliced; return ret; } EXPORT_SYMBOL(iter_file_splice_write); |
b2858d7d1 splice: fix kmaps... |
1018 1019 |
static int write_pipe_buf(struct pipe_inode_info *pipe, struct pipe_buffer *buf, struct splice_desc *sd) |
0b0a47f5c splice: implement... |
1020 |
{ |
b2858d7d1 splice: fix kmaps... |
1021 1022 |
int ret; void *data; |
06ae43f34 Don't bother with... |
1023 |
loff_t tmp = sd->pos; |
b2858d7d1 splice: fix kmaps... |
1024 |
|
fbb32750a pipe: kill ->map(... |
1025 |
data = kmap(buf->page); |
06ae43f34 Don't bother with... |
1026 |
ret = __kernel_write(sd->u.file, data + buf->offset, sd->len, &tmp); |
fbb32750a pipe: kill ->map(... |
1027 |
kunmap(buf->page); |
b2858d7d1 splice: fix kmaps... |
1028 1029 |
return ret; |
0b0a47f5c splice: implement... |
1030 1031 1032 1033 1034 1035 |
} static ssize_t default_file_splice_write(struct pipe_inode_info *pipe, struct file *out, loff_t *ppos, size_t len, unsigned int flags) { |
b2858d7d1 splice: fix kmaps... |
1036 |
ssize_t ret; |
0b0a47f5c splice: implement... |
1037 |
|
b2858d7d1 splice: fix kmaps... |
1038 1039 1040 |
ret = splice_from_pipe(pipe, out, ppos, len, flags, write_pipe_buf); if (ret > 0) *ppos += ret; |
0b0a47f5c splice: implement... |
1041 |
|
b2858d7d1 splice: fix kmaps... |
1042 |
return ret; |
0b0a47f5c splice: implement... |
1043 |
} |
83f9135bd [PATCH] splice: a... |
1044 1045 |
/** * generic_splice_sendpage - splice data from a pipe to a socket |
932cc6d4f splice: completel... |
1046 |
* @pipe: pipe to splice from |
83f9135bd [PATCH] splice: a... |
1047 |
* @out: socket to write to |
932cc6d4f splice: completel... |
1048 |
* @ppos: position in @out |
83f9135bd [PATCH] splice: a... |
1049 1050 1051 |
* @len: number of bytes to splice * @flags: splice modifier flags * |
932cc6d4f splice: completel... |
1052 1053 1054 |
* Description: * Will send @len bytes from the pipe to a network socket. No data copying * is involved. |
83f9135bd [PATCH] splice: a... |
1055 1056 |
* */ |
3a326a2ce [PATCH] introduce... |
1057 |
ssize_t generic_splice_sendpage(struct pipe_inode_info *pipe, struct file *out, |
cbb7e577e [PATCH] splice: p... |
1058 |
loff_t *ppos, size_t len, unsigned int flags) |
5274f052e [PATCH] Introduce... |
1059 |
{ |
00522fb41 [PATCH] splice: r... |
1060 |
return splice_from_pipe(pipe, out, ppos, len, flags, pipe_to_sendpage); |
5274f052e [PATCH] Introduce... |
1061 |
} |
059a8f373 [PATCH] splice: e... |
1062 |
EXPORT_SYMBOL(generic_splice_sendpage); |
a0f067802 [PATCH] splice ex... |
1063 |
|
83f9135bd [PATCH] splice: a... |
1064 1065 1066 |
/* * Attempt to initiate a splice from pipe to file. */ |
3a326a2ce [PATCH] introduce... |
1067 |
static long do_splice_from(struct pipe_inode_info *pipe, struct file *out, |
cbb7e577e [PATCH] splice: p... |
1068 |
loff_t *ppos, size_t len, unsigned int flags) |
5274f052e [PATCH] Introduce... |
1069 |
{ |
0b0a47f5c splice: implement... |
1070 1071 |
ssize_t (*splice_write)(struct pipe_inode_info *, struct file *, loff_t *, size_t, unsigned int); |
5274f052e [PATCH] Introduce... |
1072 |
|
72c2d5319 file->f_op is nev... |
1073 |
if (out->f_op->splice_write) |
cc56f7de7 sendfile(): check... |
1074 1075 |
splice_write = out->f_op->splice_write; else |
0b0a47f5c splice: implement... |
1076 |
splice_write = default_file_splice_write; |
500368f7f lift file_*_write... |
1077 |
return splice_write(pipe, out, ppos, len, flags); |
5274f052e [PATCH] Introduce... |
1078 |
} |
83f9135bd [PATCH] splice: a... |
1079 1080 1081 |
/* * Attempt to initiate a splice from a file to a pipe. */ |
cbb7e577e [PATCH] splice: p... |
1082 1083 1084 |
static long do_splice_to(struct file *in, loff_t *ppos, struct pipe_inode_info *pipe, size_t len, unsigned int flags) |
5274f052e [PATCH] Introduce... |
1085 |
{ |
6818173bd splice: implement... |
1086 1087 |
ssize_t (*splice_read)(struct file *, loff_t *, struct pipe_inode_info *, size_t, unsigned int); |
5274f052e [PATCH] Introduce... |
1088 |
int ret; |
49570e9b2 [PATCH] splice: u... |
1089 |
if (unlikely(!(in->f_mode & FMODE_READ))) |
5274f052e [PATCH] Introduce... |
1090 |
return -EBADF; |
cbb7e577e [PATCH] splice: p... |
1091 |
ret = rw_verify_area(READ, in, ppos, len); |
5274f052e [PATCH] Introduce... |
1092 1093 |
if (unlikely(ret < 0)) return ret; |
03cc0789a do_splice_to(): c... |
1094 1095 |
if (unlikely(len > MAX_RW_COUNT)) len = MAX_RW_COUNT; |
72c2d5319 file->f_op is nev... |
1096 |
if (in->f_op->splice_read) |
cc56f7de7 sendfile(): check... |
1097 1098 |
splice_read = in->f_op->splice_read; else |
6818173bd splice: implement... |
1099 1100 1101 |
splice_read = default_file_splice_read; return splice_read(in, ppos, pipe, len, flags); |
5274f052e [PATCH] Introduce... |
1102 |
} |
932cc6d4f splice: completel... |
1103 1104 1105 1106 1107 1108 1109 1110 1111 |
/** * 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 |
79685b8de docbook: add pipe... |
1112 |
* pipe is cached in the process, and reused during the lifetime of |
932cc6d4f splice: completel... |
1113 1114 |
* that process. * |
c66ab6fa7 splice: abstract ... |
1115 1116 1117 |
*/ ssize_t splice_direct_to_actor(struct file *in, struct splice_desc *sd, splice_direct_actor *actor) |
b92ce5589 [PATCH] splice: a... |
1118 1119 1120 1121 |
{ struct pipe_inode_info *pipe; long ret, bytes; umode_t i_mode; |
c66ab6fa7 splice: abstract ... |
1122 |
size_t len; |
0ff28d9f4 splice: sendfile(... |
1123 |
int i, flags, more; |
b92ce5589 [PATCH] splice: a... |
1124 1125 1126 1127 1128 1129 |
/* * 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! */ |
496ad9aa8 new helper: file_... |
1130 |
i_mode = file_inode(in)->i_mode; |
b92ce5589 [PATCH] splice: a... |
1131 1132 1133 1134 1135 1136 1137 1138 |
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; |
49570e9b2 [PATCH] splice: u... |
1139 |
if (unlikely(!pipe)) { |
7bee130e2 get rid of alloc_... |
1140 |
pipe = alloc_pipe_info(); |
b92ce5589 [PATCH] splice: a... |
1141 1142 1143 1144 1145 |
if (!pipe) return -ENOMEM; /* * We don't have an immediate reader, but we'll read the stuff |
00522fb41 [PATCH] splice: r... |
1146 |
* out of the pipe right after the splice_to_pipe(). So set |
b92ce5589 [PATCH] splice: a... |
1147 1148 1149 1150 1151 1152 1153 1154 |
* PIPE_READERS appropriately. */ pipe->readers = 1; current->splice_pipe = pipe; } /* |
73d62d83e [PATCH] splice: c... |
1155 |
* Do the splice. |
b92ce5589 [PATCH] splice: a... |
1156 1157 1158 |
*/ ret = 0; bytes = 0; |
c66ab6fa7 splice: abstract ... |
1159 1160 1161 1162 1163 1164 1165 |
len = sd->total_len; flags = sd->flags; /* * Don't block on output, we have to drain the direct pipe. */ sd->flags &= ~SPLICE_F_NONBLOCK; |
0ff28d9f4 splice: sendfile(... |
1166 |
more = sd->flags & SPLICE_F_MORE; |
b92ce5589 [PATCH] splice: a... |
1167 1168 |
while (len) { |
51a92c0f6 splice: fix offse... |
1169 |
size_t read_len; |
a82c53a0e splice: fix sendf... |
1170 |
loff_t pos = sd->pos, prev_pos = pos; |
b92ce5589 [PATCH] splice: a... |
1171 |
|
bcd4f3acb splice: direct sp... |
1172 |
ret = do_splice_to(in, &pos, pipe, len, flags); |
51a92c0f6 splice: fix offse... |
1173 |
if (unlikely(ret <= 0)) |
b92ce5589 [PATCH] splice: a... |
1174 1175 1176 |
goto out_release; read_len = ret; |
c66ab6fa7 splice: abstract ... |
1177 |
sd->total_len = read_len; |
b92ce5589 [PATCH] splice: a... |
1178 1179 |
/* |
0ff28d9f4 splice: sendfile(... |
1180 1181 1182 1183 1184 1185 1186 1187 1188 |
* If more data is pending, set SPLICE_F_MORE * If this is the last data and SPLICE_F_MORE was not set * initially, clears it. */ if (read_len < len) sd->flags |= SPLICE_F_MORE; else if (!more) sd->flags &= ~SPLICE_F_MORE; /* |
b92ce5589 [PATCH] splice: a... |
1189 1190 1191 1192 |
* 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: */ |
c66ab6fa7 splice: abstract ... |
1193 |
ret = actor(pipe, sd); |
a82c53a0e splice: fix sendf... |
1194 1195 |
if (unlikely(ret <= 0)) { sd->pos = prev_pos; |
b92ce5589 [PATCH] splice: a... |
1196 |
goto out_release; |
a82c53a0e splice: fix sendf... |
1197 |
} |
b92ce5589 [PATCH] splice: a... |
1198 1199 1200 |
bytes += ret; len -= ret; |
bcd4f3acb splice: direct sp... |
1201 |
sd->pos = pos; |
b92ce5589 [PATCH] splice: a... |
1202 |
|
a82c53a0e splice: fix sendf... |
1203 1204 |
if (ret < read_len) { sd->pos = prev_pos + ret; |
51a92c0f6 splice: fix offse... |
1205 |
goto out_release; |
a82c53a0e splice: fix sendf... |
1206 |
} |
b92ce5589 [PATCH] splice: a... |
1207 |
} |
9e97198db splice: fix probl... |
1208 |
done: |
b92ce5589 [PATCH] splice: a... |
1209 |
pipe->nrbufs = pipe->curbuf = 0; |
808487085 splice: always up... |
1210 |
file_accessed(in); |
b92ce5589 [PATCH] splice: a... |
1211 1212 1213 1214 1215 1216 1217 |
return bytes; out_release: /* * If we did an incomplete transfer we must release * the pipe buffers in question: */ |
35f3d14db pipe: add support... |
1218 |
for (i = 0; i < pipe->buffers; i++) { |
b92ce5589 [PATCH] splice: a... |
1219 1220 1221 1222 1223 1224 1225 |
struct pipe_buffer *buf = pipe->bufs + i; if (buf->ops) { buf->ops->release(pipe, buf); buf->ops = NULL; } } |
b92ce5589 [PATCH] splice: a... |
1226 |
|
9e97198db splice: fix probl... |
1227 1228 |
if (!bytes) bytes = ret; |
c66ab6fa7 splice: abstract ... |
1229 |
|
9e97198db splice: fix probl... |
1230 |
goto done; |
c66ab6fa7 splice: abstract ... |
1231 1232 1233 1234 1235 1236 |
} EXPORT_SYMBOL(splice_direct_to_actor); static int direct_splice_actor(struct pipe_inode_info *pipe, struct splice_desc *sd) { |
6a14b90bb vmsplice: add vms... |
1237 |
struct file *file = sd->u.file; |
c66ab6fa7 splice: abstract ... |
1238 |
|
7995bd287 splice: don't pas... |
1239 |
return do_splice_from(pipe, file, sd->opos, sd->total_len, |
2cb4b05e7 splice: direct_sp... |
1240 |
sd->flags); |
c66ab6fa7 splice: abstract ... |
1241 |
} |
932cc6d4f splice: completel... |
1242 1243 1244 1245 1246 |
/** * do_splice_direct - splices data directly between two files * @in: file to splice from * @ppos: input file offset * @out: file to splice to |
acdb37c36 fs: fix new splic... |
1247 |
* @opos: output file offset |
932cc6d4f splice: completel... |
1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 |
* @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. * */ |
c66ab6fa7 splice: abstract ... |
1258 |
long do_splice_direct(struct file *in, loff_t *ppos, struct file *out, |
7995bd287 splice: don't pas... |
1259 |
loff_t *opos, size_t len, unsigned int flags) |
c66ab6fa7 splice: abstract ... |
1260 1261 1262 1263 1264 1265 |
{ struct splice_desc sd = { .len = len, .total_len = len, .flags = flags, .pos = *ppos, |
6a14b90bb vmsplice: add vms... |
1266 |
.u.file = out, |
7995bd287 splice: don't pas... |
1267 |
.opos = opos, |
c66ab6fa7 splice: abstract ... |
1268 |
}; |
51a92c0f6 splice: fix offse... |
1269 |
long ret; |
c66ab6fa7 splice: abstract ... |
1270 |
|
18c67cb9f splice: lift chec... |
1271 1272 1273 1274 1275 1276 1277 1278 1279 |
if (unlikely(!(out->f_mode & FMODE_WRITE))) return -EBADF; if (unlikely(out->f_flags & O_APPEND)) return -EINVAL; ret = rw_verify_area(WRITE, out, opos, len); if (unlikely(ret < 0)) return ret; |
c66ab6fa7 splice: abstract ... |
1280 |
ret = splice_direct_to_actor(in, &sd, direct_splice_actor); |
51a92c0f6 splice: fix offse... |
1281 |
if (ret > 0) |
a82c53a0e splice: fix sendf... |
1282 |
*ppos = sd.pos; |
51a92c0f6 splice: fix offse... |
1283 |
|
c66ab6fa7 splice: abstract ... |
1284 |
return ret; |
b92ce5589 [PATCH] splice: a... |
1285 |
} |
1c118596a vfs: export do_sp... |
1286 |
EXPORT_SYMBOL(do_splice_direct); |
b92ce5589 [PATCH] splice: a... |
1287 |
|
7c77f0b3f splice: implement... |
1288 1289 1290 |
static int splice_pipe_to_pipe(struct pipe_inode_info *ipipe, struct pipe_inode_info *opipe, size_t len, unsigned int flags); |
ddac0d39c [PATCH] splice: f... |
1291 1292 |
/* |
83f9135bd [PATCH] splice: a... |
1293 1294 |
* Determine where to splice to/from. */ |
529565dcb [PATCH] splice: a... |
1295 1296 1297 |
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) |
5274f052e [PATCH] Introduce... |
1298 |
{ |
7c77f0b3f splice: implement... |
1299 1300 |
struct pipe_inode_info *ipipe; struct pipe_inode_info *opipe; |
7995bd287 splice: don't pas... |
1301 |
loff_t offset; |
a4514ebd8 [PATCH] splice: o... |
1302 |
long ret; |
5274f052e [PATCH] Introduce... |
1303 |
|
71993e62a Rename 'pipe_info... |
1304 1305 |
ipipe = get_pipe_info(in); opipe = get_pipe_info(out); |
7c77f0b3f splice: implement... |
1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 |
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) { |
529565dcb [PATCH] splice: a... |
1325 1326 |
if (off_in) return -ESPIPE; |
b92ce5589 [PATCH] splice: a... |
1327 |
if (off_out) { |
19c9a49b4 splice: check f_m... |
1328 |
if (!(out->f_mode & FMODE_PWRITE)) |
b92ce5589 [PATCH] splice: a... |
1329 |
return -EINVAL; |
cbb7e577e [PATCH] splice: p... |
1330 |
if (copy_from_user(&offset, off_out, sizeof(loff_t))) |
b92ce5589 [PATCH] splice: a... |
1331 |
return -EFAULT; |
7995bd287 splice: don't pas... |
1332 1333 1334 |
} else { offset = out->f_pos; } |
529565dcb [PATCH] splice: a... |
1335 |
|
18c67cb9f splice: lift chec... |
1336 1337 1338 1339 1340 1341 1342 1343 1344 |
if (unlikely(!(out->f_mode & FMODE_WRITE))) return -EBADF; if (unlikely(out->f_flags & O_APPEND)) return -EINVAL; ret = rw_verify_area(WRITE, out, &offset, len); if (unlikely(ret < 0)) return ret; |
500368f7f lift file_*_write... |
1345 |
file_start_write(out); |
7995bd287 splice: don't pas... |
1346 |
ret = do_splice_from(ipipe, out, &offset, len, flags); |
500368f7f lift file_*_write... |
1347 |
file_end_write(out); |
a4514ebd8 [PATCH] splice: o... |
1348 |
|
7995bd287 splice: don't pas... |
1349 1350 1351 |
if (!off_out) out->f_pos = offset; else if (copy_to_user(off_out, &offset, sizeof(loff_t))) |
a4514ebd8 [PATCH] splice: o... |
1352 1353 1354 |
ret = -EFAULT; return ret; |
529565dcb [PATCH] splice: a... |
1355 |
} |
5274f052e [PATCH] Introduce... |
1356 |
|
7c77f0b3f splice: implement... |
1357 |
if (opipe) { |
529565dcb [PATCH] splice: a... |
1358 1359 |
if (off_out) return -ESPIPE; |
b92ce5589 [PATCH] splice: a... |
1360 |
if (off_in) { |
19c9a49b4 splice: check f_m... |
1361 |
if (!(in->f_mode & FMODE_PREAD)) |
b92ce5589 [PATCH] splice: a... |
1362 |
return -EINVAL; |
cbb7e577e [PATCH] splice: p... |
1363 |
if (copy_from_user(&offset, off_in, sizeof(loff_t))) |
b92ce5589 [PATCH] splice: a... |
1364 |
return -EFAULT; |
7995bd287 splice: don't pas... |
1365 1366 1367 |
} else { offset = in->f_pos; } |
529565dcb [PATCH] splice: a... |
1368 |
|
7995bd287 splice: don't pas... |
1369 |
ret = do_splice_to(in, &offset, opipe, len, flags); |
a4514ebd8 [PATCH] splice: o... |
1370 |
|
7995bd287 splice: don't pas... |
1371 1372 1373 |
if (!off_in) in->f_pos = offset; else if (copy_to_user(off_in, &offset, sizeof(loff_t))) |
a4514ebd8 [PATCH] splice: o... |
1374 1375 1376 |
ret = -EFAULT; return ret; |
529565dcb [PATCH] splice: a... |
1377 |
} |
5274f052e [PATCH] Introduce... |
1378 1379 1380 |
return -EINVAL; } |
912d35f86 [PATCH] Add suppo... |
1381 1382 1383 1384 1385 1386 1387 1388 1389 |
/* * 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, |
bd1a68b59 vmsplice: relax a... |
1390 |
struct partial_page *partial, bool aligned, |
35f3d14db pipe: add support... |
1391 |
unsigned int pipe_buffers) |
912d35f86 [PATCH] Add suppo... |
1392 1393 |
{ int buffers = 0, error = 0; |
912d35f86 [PATCH] Add suppo... |
1394 1395 |
while (nr_vecs) { unsigned long off, npages; |
757239576 Fix possible spli... |
1396 |
struct iovec entry; |
912d35f86 [PATCH] Add suppo... |
1397 1398 1399 |
void __user *base; size_t len; int i; |
757239576 Fix possible spli... |
1400 |
error = -EFAULT; |
bc40d73c9 splice: use get_u... |
1401 |
if (copy_from_user(&entry, iov, sizeof(entry))) |
912d35f86 [PATCH] Add suppo... |
1402 |
break; |
757239576 Fix possible spli... |
1403 1404 |
base = entry.iov_base; len = entry.iov_len; |
912d35f86 [PATCH] Add suppo... |
1405 1406 1407 |
/* * Sanity check this iovec. 0 read succeeds. */ |
757239576 Fix possible spli... |
1408 |
error = 0; |
912d35f86 [PATCH] Add suppo... |
1409 1410 1411 |
if (unlikely(!len)) break; error = -EFAULT; |
712a30e63 splice: fix user ... |
1412 |
if (!access_ok(VERIFY_READ, base, len)) |
912d35f86 [PATCH] Add suppo... |
1413 1414 1415 1416 1417 1418 1419 |
break; /* * Get this base offset and number of pages, then map * in the user pages. */ off = (unsigned long) base & ~PAGE_MASK; |
7afa6fd03 [PATCH] vmsplice:... |
1420 1421 1422 1423 1424 1425 1426 1427 |
/* * 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; |
912d35f86 [PATCH] Add suppo... |
1428 |
npages = (off + len + PAGE_SIZE - 1) >> PAGE_SHIFT; |
35f3d14db pipe: add support... |
1429 1430 |
if (npages > pipe_buffers - buffers) npages = pipe_buffers - buffers; |
912d35f86 [PATCH] Add suppo... |
1431 |
|
bc40d73c9 splice: use get_u... |
1432 1433 |
error = get_user_pages_fast((unsigned long)base, npages, 0, &pages[buffers]); |
912d35f86 [PATCH] Add suppo... |
1434 1435 1436 1437 1438 1439 1440 1441 |
if (unlikely(error <= 0)) break; /* * Fill this contiguous range into the partial page map. */ for (i = 0; i < error; i++) { |
7591489a8 [PATCH] vmsplice:... |
1442 |
const int plen = min_t(size_t, len, PAGE_SIZE - off); |
912d35f86 [PATCH] Add suppo... |
1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 |
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. */ |
35f3d14db pipe: add support... |
1465 |
if (error < npages || buffers == pipe_buffers) |
912d35f86 [PATCH] Add suppo... |
1466 1467 1468 1469 1470 |
break; nr_vecs--; iov++; } |
912d35f86 [PATCH] Add suppo... |
1471 1472 1473 1474 1475 |
if (buffers) return buffers; return error; } |
6a14b90bb vmsplice: add vms... |
1476 1477 1478 |
static int pipe_to_user(struct pipe_inode_info *pipe, struct pipe_buffer *buf, struct splice_desc *sd) { |
6130f5315 switch vmsplice_t... |
1479 1480 |
int n = copy_page_to_iter(buf->page, buf->offset, sd->len, sd->u.data); return n == sd->len ? n : -EFAULT; |
6a14b90bb vmsplice: add vms... |
1481 1482 1483 1484 1485 1486 |
} /* * For lack of a better implementation, implement vmsplice() to userspace * as a simple copy of the pipes pages to the user iov. */ |
6130f5315 switch vmsplice_t... |
1487 |
static long vmsplice_to_user(struct file *file, const struct iovec __user *uiov, |
6a14b90bb vmsplice: add vms... |
1488 1489 1490 1491 |
unsigned long nr_segs, unsigned int flags) { struct pipe_inode_info *pipe; struct splice_desc sd; |
6a14b90bb vmsplice: add vms... |
1492 |
long ret; |
6130f5315 switch vmsplice_t... |
1493 1494 1495 |
struct iovec iovstack[UIO_FASTIOV]; struct iovec *iov = iovstack; struct iov_iter iter; |
6a14b90bb vmsplice: add vms... |
1496 |
|
71993e62a Rename 'pipe_info... |
1497 |
pipe = get_pipe_info(file); |
6a14b90bb vmsplice: add vms... |
1498 1499 |
if (!pipe) return -EBADF; |
345995fa4 vmsplice_to_user(... |
1500 1501 1502 1503 |
ret = import_iovec(READ, uiov, nr_segs, ARRAY_SIZE(iovstack), &iov, &iter); if (ret < 0) return ret; |
6a14b90bb vmsplice: add vms... |
1504 |
|
345995fa4 vmsplice_to_user(... |
1505 |
sd.total_len = iov_iter_count(&iter); |
6130f5315 switch vmsplice_t... |
1506 |
sd.len = 0; |
6130f5315 switch vmsplice_t... |
1507 1508 1509 |
sd.flags = flags; sd.u.data = &iter; sd.pos = 0; |
6a14b90bb vmsplice: add vms... |
1510 |
|
345995fa4 vmsplice_to_user(... |
1511 1512 1513 1514 1515 |
if (sd.total_len) { pipe_lock(pipe); ret = __splice_from_pipe(pipe, &sd, pipe_to_user); pipe_unlock(pipe); } |
6a14b90bb vmsplice: add vms... |
1516 |
|
345995fa4 vmsplice_to_user(... |
1517 |
kfree(iov); |
6a14b90bb vmsplice: add vms... |
1518 1519 |
return ret; } |
912d35f86 [PATCH] Add suppo... |
1520 1521 1522 1523 |
/* * 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. |
912d35f86 [PATCH] Add suppo... |
1524 |
*/ |
6a14b90bb vmsplice: add vms... |
1525 1526 |
static long vmsplice_to_pipe(struct file *file, const struct iovec __user *iov, unsigned long nr_segs, unsigned int flags) |
912d35f86 [PATCH] Add suppo... |
1527 |
{ |
ddac0d39c [PATCH] splice: f... |
1528 |
struct pipe_inode_info *pipe; |
35f3d14db pipe: add support... |
1529 1530 |
struct page *pages[PIPE_DEF_BUFFERS]; struct partial_page partial[PIPE_DEF_BUFFERS]; |
912d35f86 [PATCH] Add suppo... |
1531 1532 1533 |
struct splice_pipe_desc spd = { .pages = pages, .partial = partial, |
047fe3605 splice: fix racy ... |
1534 |
.nr_pages_max = PIPE_DEF_BUFFERS, |
912d35f86 [PATCH] Add suppo... |
1535 1536 |
.flags = flags, .ops = &user_page_pipe_buf_ops, |
bbdfc2f70 [SPLICE]: Don't a... |
1537 |
.spd_release = spd_release_page, |
912d35f86 [PATCH] Add suppo... |
1538 |
}; |
35f3d14db pipe: add support... |
1539 |
long ret; |
912d35f86 [PATCH] Add suppo... |
1540 |
|
71993e62a Rename 'pipe_info... |
1541 |
pipe = get_pipe_info(file); |
ddac0d39c [PATCH] splice: f... |
1542 |
if (!pipe) |
912d35f86 [PATCH] Add suppo... |
1543 |
return -EBADF; |
912d35f86 [PATCH] Add suppo... |
1544 |
|
35f3d14db pipe: add support... |
1545 1546 1547 1548 |
if (splice_grow_spd(pipe, &spd)) return -ENOMEM; spd.nr_pages = get_iovec_page_array(iov, nr_segs, spd.pages, |
bd1a68b59 vmsplice: relax a... |
1549 |
spd.partial, false, |
047fe3605 splice: fix racy ... |
1550 |
spd.nr_pages_max); |
912d35f86 [PATCH] Add suppo... |
1551 |
if (spd.nr_pages <= 0) |
35f3d14db pipe: add support... |
1552 1553 1554 |
ret = spd.nr_pages; else ret = splice_to_pipe(pipe, &spd); |
912d35f86 [PATCH] Add suppo... |
1555 |
|
047fe3605 splice: fix racy ... |
1556 |
splice_shrink_spd(&spd); |
35f3d14db pipe: add support... |
1557 |
return ret; |
912d35f86 [PATCH] Add suppo... |
1558 |
} |
6a14b90bb vmsplice: add vms... |
1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 |
/* * 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(). * */ |
836f92adf [CVE-2009-0029] S... |
1575 1576 |
SYSCALL_DEFINE4(vmsplice, int, fd, const struct iovec __user *, iov, unsigned long, nr_segs, unsigned int, flags) |
912d35f86 [PATCH] Add suppo... |
1577 |
{ |
2903ff019 switch simple cas... |
1578 |
struct fd f; |
912d35f86 [PATCH] Add suppo... |
1579 |
long error; |
912d35f86 [PATCH] Add suppo... |
1580 |
|
6a14b90bb vmsplice: add vms... |
1581 1582 1583 1584 |
if (unlikely(nr_segs > UIO_MAXIOV)) return -EINVAL; else if (unlikely(!nr_segs)) return 0; |
912d35f86 [PATCH] Add suppo... |
1585 |
error = -EBADF; |
2903ff019 switch simple cas... |
1586 1587 1588 1589 1590 1591 1592 1593 |
f = fdget(fd); if (f.file) { if (f.file->f_mode & FMODE_WRITE) error = vmsplice_to_pipe(f.file, iov, nr_segs, flags); else if (f.file->f_mode & FMODE_READ) error = vmsplice_to_user(f.file, iov, nr_segs, flags); fdput(f); |
912d35f86 [PATCH] Add suppo... |
1594 1595 1596 1597 |
} return error; } |
76b021d05 convert vmsplice ... |
1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 1615 1616 1617 |
#ifdef CONFIG_COMPAT COMPAT_SYSCALL_DEFINE4(vmsplice, int, fd, const struct compat_iovec __user *, iov32, unsigned int, nr_segs, unsigned int, flags) { unsigned i; struct iovec __user *iov; if (nr_segs > UIO_MAXIOV) return -EINVAL; iov = compat_alloc_user_space(nr_segs * sizeof(struct iovec)); for (i = 0; i < nr_segs; i++) { struct compat_iovec v; if (get_user(v.iov_base, &iov32[i].iov_base) || get_user(v.iov_len, &iov32[i].iov_len) || put_user(compat_ptr(v.iov_base), &iov[i].iov_base) || put_user(v.iov_len, &iov[i].iov_len)) return -EFAULT; } return sys_vmsplice(fd, iov, nr_segs, flags); } #endif |
836f92adf [CVE-2009-0029] S... |
1618 1619 1620 |
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) |
5274f052e [PATCH] Introduce... |
1621 |
{ |
2903ff019 switch simple cas... |
1622 |
struct fd in, out; |
5274f052e [PATCH] Introduce... |
1623 |
long error; |
5274f052e [PATCH] Introduce... |
1624 1625 1626 1627 1628 |
if (unlikely(!len)) return 0; error = -EBADF; |
2903ff019 switch simple cas... |
1629 1630 1631 1632 1633 1634 1635 1636 |
in = fdget(fd_in); if (in.file) { if (in.file->f_mode & FMODE_READ) { out = fdget(fd_out); if (out.file) { if (out.file->f_mode & FMODE_WRITE) error = do_splice(in.file, off_in, out.file, off_out, |
529565dcb [PATCH] splice: a... |
1637 |
len, flags); |
2903ff019 switch simple cas... |
1638 |
fdput(out); |
5274f052e [PATCH] Introduce... |
1639 1640 |
} } |
2903ff019 switch simple cas... |
1641 |
fdput(in); |
5274f052e [PATCH] Introduce... |
1642 |
} |
5274f052e [PATCH] Introduce... |
1643 1644 |
return error; } |
70524490e [PATCH] splice: a... |
1645 1646 |
/* |
aadd06e5c [PATCH] splice: f... |
1647 1648 1649 |
* Make sure there's data to read. Wait for input if we can, otherwise * return an appropriate error. */ |
7c77f0b3f splice: implement... |
1650 |
static int ipipe_prep(struct pipe_inode_info *pipe, unsigned int flags) |
aadd06e5c [PATCH] splice: f... |
1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 |
{ 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; |
61e0d47c3 splice: add helpe... |
1662 |
pipe_lock(pipe); |
aadd06e5c [PATCH] splice: f... |
1663 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 |
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); } |
61e0d47c3 splice: add helpe... |
1679 |
pipe_unlock(pipe); |
aadd06e5c [PATCH] splice: f... |
1680 1681 1682 1683 1684 1685 1686 |
return ret; } /* * Make sure there's writeable room. Wait for room if we can, otherwise * return an appropriate error. */ |
7c77f0b3f splice: implement... |
1687 |
static int opipe_prep(struct pipe_inode_info *pipe, unsigned int flags) |
aadd06e5c [PATCH] splice: f... |
1688 1689 1690 1691 1692 1693 1694 |
{ int ret; /* * Check ->nrbufs without the inode lock first. This function * is speculative anyways, so missing one is ok. */ |
35f3d14db pipe: add support... |
1695 |
if (pipe->nrbufs < pipe->buffers) |
aadd06e5c [PATCH] splice: f... |
1696 1697 1698 |
return 0; ret = 0; |
61e0d47c3 splice: add helpe... |
1699 |
pipe_lock(pipe); |
aadd06e5c [PATCH] splice: f... |
1700 |
|
35f3d14db pipe: add support... |
1701 |
while (pipe->nrbufs >= pipe->buffers) { |
aadd06e5c [PATCH] splice: f... |
1702 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 1717 1718 |
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--; } |
61e0d47c3 splice: add helpe... |
1719 |
pipe_unlock(pipe); |
aadd06e5c [PATCH] splice: f... |
1720 1721 1722 1723 |
return ret; } /* |
7c77f0b3f splice: implement... |
1724 1725 1726 1727 1728 1729 1730 1731 1732 1733 1734 1735 1736 1737 1738 1739 1740 1741 1742 1743 1744 1745 1746 1747 1748 1749 1750 1751 1752 1753 1754 1755 1756 1757 1758 1759 1760 1761 1762 1763 1764 1765 |
* 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. */ |
35f3d14db pipe: add support... |
1766 |
if (!ipipe->nrbufs || opipe->nrbufs >= opipe->buffers) { |
7c77f0b3f splice: implement... |
1767 1768 1769 1770 1771 1772 1773 1774 1775 1776 1777 1778 1779 1780 1781 1782 1783 1784 1785 1786 |
/* 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; |
35f3d14db pipe: add support... |
1787 |
nbuf = (opipe->curbuf + opipe->nrbufs) & (opipe->buffers - 1); |
7c77f0b3f splice: implement... |
1788 1789 1790 1791 1792 1793 1794 1795 1796 |
obuf = opipe->bufs + nbuf; if (len >= ibuf->len) { /* * Simply move the whole buffer from ipipe to opipe */ *obuf = *ibuf; ibuf->ops = NULL; opipe->nrbufs++; |
35f3d14db pipe: add support... |
1797 |
ipipe->curbuf = (ipipe->curbuf + 1) & (ipipe->buffers - 1); |
7c77f0b3f splice: implement... |
1798 1799 1800 1801 1802 1803 1804 1805 1806 1807 1808 1809 1810 1811 1812 1813 1814 1815 1816 1817 1818 1819 1820 1821 1822 1823 1824 1825 1826 1827 1828 |
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. */ |
825cdcb1a splice: add wakeu... |
1829 1830 |
if (ret > 0) wakeup_pipe_readers(opipe); |
7c77f0b3f splice: implement... |
1831 1832 1833 1834 1835 1836 1837 |
if (input_wakeup) wakeup_pipe_writers(ipipe); return ret; } /* |
70524490e [PATCH] splice: a... |
1838 1839 1840 1841 1842 1843 1844 |
* 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; |
aadd06e5c [PATCH] splice: f... |
1845 |
int ret = 0, i = 0, nbuf; |
70524490e [PATCH] splice: a... |
1846 1847 1848 |
/* * Potential ABBA deadlock, work around it by ordering lock |
61e0d47c3 splice: add helpe... |
1849 |
* grabbing by pipe info address. Otherwise two different processes |
70524490e [PATCH] splice: a... |
1850 1851 |
* could deadlock (one doing tee from A -> B, the other from B -> A). */ |
61e0d47c3 splice: add helpe... |
1852 |
pipe_double_lock(ipipe, opipe); |
70524490e [PATCH] splice: a... |
1853 |
|
aadd06e5c [PATCH] splice: f... |
1854 |
do { |
70524490e [PATCH] splice: a... |
1855 1856 1857 1858 1859 1860 |
if (!opipe->readers) { send_sig(SIGPIPE, current, 0); if (!ret) ret = -EPIPE; break; } |
70524490e [PATCH] splice: a... |
1861 |
|
aadd06e5c [PATCH] splice: f... |
1862 1863 1864 1865 |
/* * If we have iterated all input buffers or ran out of * output room, break. */ |
35f3d14db pipe: add support... |
1866 |
if (i >= ipipe->nrbufs || opipe->nrbufs >= opipe->buffers) |
aadd06e5c [PATCH] splice: f... |
1867 |
break; |
70524490e [PATCH] splice: a... |
1868 |
|
35f3d14db pipe: add support... |
1869 1870 |
ibuf = ipipe->bufs + ((ipipe->curbuf + i) & (ipipe->buffers-1)); nbuf = (opipe->curbuf + opipe->nrbufs) & (opipe->buffers - 1); |
70524490e [PATCH] splice: a... |
1871 1872 |
/* |
aadd06e5c [PATCH] splice: f... |
1873 1874 |
* Get a reference to this pipe buffer, * so we can copy the contents over. |
70524490e [PATCH] splice: a... |
1875 |
*/ |
aadd06e5c [PATCH] splice: f... |
1876 1877 1878 1879 |
ibuf->ops->get(ipipe, ibuf); obuf = opipe->bufs + nbuf; *obuf = *ibuf; |
2a27250e6 [PATCH] tee: link... |
1880 |
/* |
aadd06e5c [PATCH] splice: f... |
1881 1882 |
* Don't inherit the gift flag, we need to * prevent multiple steals of this page. |
2a27250e6 [PATCH] tee: link... |
1883 |
*/ |
aadd06e5c [PATCH] splice: f... |
1884 |
obuf->flags &= ~PIPE_BUF_FLAG_GIFT; |
70524490e [PATCH] splice: a... |
1885 |
|
aadd06e5c [PATCH] splice: f... |
1886 1887 |
if (obuf->len > len) obuf->len = len; |
70524490e [PATCH] splice: a... |
1888 |
|
aadd06e5c [PATCH] splice: f... |
1889 1890 1891 1892 1893 |
opipe->nrbufs++; ret += obuf->len; len -= obuf->len; i++; } while (len); |
70524490e [PATCH] splice: a... |
1894 |
|
02cf01aea splice: only retu... |
1895 1896 1897 1898 1899 1900 |
/* * 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; |
61e0d47c3 splice: add helpe... |
1901 1902 |
pipe_unlock(ipipe); pipe_unlock(opipe); |
70524490e [PATCH] splice: a... |
1903 |
|
aadd06e5c [PATCH] splice: f... |
1904 1905 1906 |
/* * If we put data in the output pipe, wakeup any potential readers. */ |
825cdcb1a splice: add wakeu... |
1907 1908 |
if (ret > 0) wakeup_pipe_readers(opipe); |
70524490e [PATCH] splice: a... |
1909 1910 1911 1912 1913 1914 1915 1916 1917 1918 1919 1920 1921 |
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) { |
71993e62a Rename 'pipe_info... |
1922 1923 |
struct pipe_inode_info *ipipe = get_pipe_info(in); struct pipe_inode_info *opipe = get_pipe_info(out); |
aadd06e5c [PATCH] splice: f... |
1924 |
int ret = -EINVAL; |
70524490e [PATCH] splice: a... |
1925 1926 |
/* |
aadd06e5c [PATCH] splice: f... |
1927 1928 |
* Duplicate the contents of ipipe to opipe without actually * copying the data. |
70524490e [PATCH] splice: a... |
1929 |
*/ |
aadd06e5c [PATCH] splice: f... |
1930 1931 1932 1933 1934 |
if (ipipe && opipe && ipipe != opipe) { /* * Keep going, unless we encounter an error. The ipipe/opipe * ordering doesn't really matter. */ |
7c77f0b3f splice: implement... |
1935 |
ret = ipipe_prep(ipipe, flags); |
aadd06e5c [PATCH] splice: f... |
1936 |
if (!ret) { |
7c77f0b3f splice: implement... |
1937 |
ret = opipe_prep(opipe, flags); |
02cf01aea splice: only retu... |
1938 |
if (!ret) |
aadd06e5c [PATCH] splice: f... |
1939 |
ret = link_pipe(ipipe, opipe, len, flags); |
aadd06e5c [PATCH] splice: f... |
1940 1941 |
} } |
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1942 |
|
aadd06e5c [PATCH] splice: f... |
1943 |
return ret; |
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1944 |
} |
836f92adf [CVE-2009-0029] S... |
1945 |
SYSCALL_DEFINE4(tee, int, fdin, int, fdout, size_t, len, unsigned int, flags) |
70524490e [PATCH] splice: a... |
1946 |
{ |
2903ff019 switch simple cas... |
1947 1948 |
struct fd in; int error; |
70524490e [PATCH] splice: a... |
1949 1950 1951 1952 1953 |
if (unlikely(!len)) return 0; error = -EBADF; |
2903ff019 switch simple cas... |
1954 1955 1956 1957 1958 1959 1960 1961 1962 |
in = fdget(fdin); if (in.file) { if (in.file->f_mode & FMODE_READ) { struct fd out = fdget(fdout); if (out.file) { if (out.file->f_mode & FMODE_WRITE) error = do_tee(in.file, out.file, len, flags); fdput(out); |
70524490e [PATCH] splice: a... |
1963 1964 |
} } |
2903ff019 switch simple cas... |
1965 |
fdput(in); |
70524490e [PATCH] splice: a... |
1966 1967 1968 1969 |
} return error; } |