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| author | Al Viro <viro@zeniv.linux.org.uk> | 2016-09-22 23:33:12 +0300 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2016-10-06 01:23:36 +0300 |
| commit | 241699cd72a8489c9446ae3910ddd243e9b9061b (patch) | |
| tree | efcd8d62f5788ab843cd3457cf2e85f3be7b5296 /include/linux/splice.h | |
| parent | d82718e348fee15dbce8f578ff2588982b7cc7ca (diff) | |
| download | linux-241699cd72a8489c9446ae3910ddd243e9b9061b.tar.xz | |
new iov_iter flavour: pipe-backed
iov_iter variant for passing data into pipe. copy_to_iter()
copies data into page(s) it has allocated and stuffs them into
the pipe; copy_page_to_iter() stuffs there a reference to the
page given to it. Both will try to coalesce if possible.
iov_iter_zero() is similar to copy_to_iter(); iov_iter_get_pages()
and friends will do as copy_to_iter() would have and return the
pages where the data would've been copied. iov_iter_advance()
will truncate everything past the spot it has advanced to.
New primitive: iov_iter_pipe(), used for initializing those.
pipe should be locked all along.
Running out of space acts as fault would for iovec-backed ones;
in other words, giving it to ->read_iter() may result in short
read if the pipe overflows, or -EFAULT if it happens with nothing
copied there.
In other words, ->read_iter() on those acts pretty much like
->splice_read(). Moreover, all generic_file_splice_read() users,
as well as many other ->splice_read() instances can be switched
to that scheme - that'll happen in the next commit.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'include/linux/splice.h')
| -rw-r--r-- | include/linux/splice.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/include/linux/splice.h b/include/linux/splice.h index 58b300f37534..00a21166e268 100644 --- a/include/linux/splice.h +++ b/include/linux/splice.h @@ -85,4 +85,5 @@ extern void splice_shrink_spd(struct splice_pipe_desc *); extern void spd_release_page(struct splice_pipe_desc *, unsigned int); extern const struct pipe_buf_operations page_cache_pipe_buf_ops; +extern const struct pipe_buf_operations default_pipe_buf_ops; #endif |