splice: add SPLICE_F_NONBLOCK flag
It doesn't make the splice itself necessarily nonblocking (because the actual file descriptors that are spliced from/to may block unless they have the O_NONBLOCK flag set), but it makes the splice pipe operations nonblocking. Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
25
fs/splice.c
25
fs/splice.c
@ -106,7 +106,7 @@ static struct pipe_buf_operations page_cache_pipe_buf_ops = {
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static ssize_t move_to_pipe(struct inode *inode, struct page **pages,
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int nr_pages, unsigned long offset,
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unsigned long len)
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unsigned long len, unsigned int flags)
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{
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struct pipe_inode_info *info;
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int ret, do_wakeup, i;
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@ -159,6 +159,12 @@ static ssize_t move_to_pipe(struct inode *inode, struct page **pages,
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break;
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}
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if (flags & SPLICE_F_NONBLOCK) {
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if (!ret)
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ret = -EAGAIN;
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break;
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}
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if (signal_pending(current)) {
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if (!ret)
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ret = -ERESTARTSYS;
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@ -191,7 +197,7 @@ static ssize_t move_to_pipe(struct inode *inode, struct page **pages,
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}
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static int __generic_file_splice_read(struct file *in, struct inode *pipe,
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size_t len)
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size_t len, unsigned int flags)
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{
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struct address_space *mapping = in->f_mapping;
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unsigned int offset, nr_pages;
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@ -279,7 +285,7 @@ static int __generic_file_splice_read(struct file *in, struct inode *pipe,
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* Now we splice them into the pipe..
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*/
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splice_them:
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return move_to_pipe(pipe, pages, i, offset, len);
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return move_to_pipe(pipe, pages, i, offset, len, flags);
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}
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ssize_t generic_file_splice_read(struct file *in, struct inode *pipe,
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@ -291,7 +297,7 @@ ssize_t generic_file_splice_read(struct file *in, struct inode *pipe,
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ret = 0;
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spliced = 0;
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while (len) {
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ret = __generic_file_splice_read(in, pipe, len);
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ret = __generic_file_splice_read(in, pipe, len, flags);
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if (ret <= 0)
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break;
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@ -299,6 +305,11 @@ ssize_t generic_file_splice_read(struct file *in, struct inode *pipe,
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in->f_pos += ret;
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len -= ret;
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spliced += ret;
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if (!(flags & SPLICE_F_NONBLOCK))
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continue;
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ret = -EAGAIN;
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break;
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}
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if (spliced)
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@ -527,6 +538,12 @@ static ssize_t move_from_pipe(struct inode *inode, struct file *out,
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break;
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}
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if (flags & SPLICE_F_NONBLOCK) {
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if (!ret)
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ret = -EAGAIN;
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break;
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}
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if (signal_pending(current)) {
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if (!ret)
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ret = -ERESTARTSYS;
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