| Message ID | 20220622041552.737754-38-viro@zeniv.linux.org.uk (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [01/44] 9p: handling Rerror without copy_from_iter_full() | expand |
On Wed, 2022-06-22 at 05:15 +0100, Al Viro wrote: > ... and untangle the cleanup on failure to add into pipe. > > Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> > --- > fs/splice.c | 47 ++++++++++++++++++++++++----------------------- > 1 file changed, 24 insertions(+), 23 deletions(-) > > diff --git a/fs/splice.c b/fs/splice.c > index 6645b30ec990..9f84bd21f64c 100644 > --- a/fs/splice.c > +++ b/fs/splice.c > @@ -1160,39 +1160,40 @@ static int iter_to_pipe(struct iov_iter *from, > }; > size_t total = 0; > int ret = 0; > - bool failed = false; > > - while (iov_iter_count(from) && !failed) { > + while (iov_iter_count(from)) { > struct page *pages[16]; > - ssize_t copied; > + ssize_t left; > size_t start; > - int n; > + int i, n; > > - copied = iov_iter_get_pages(from, pages, ~0UL, 16, &start); > - if (copied <= 0) { > - ret = copied; > + left = iov_iter_get_pages2(from, pages, ~0UL, 16, &start); > + if (left <= 0) { > + ret = left; > break; > } > > - for (n = 0; copied; n++, start = 0) { > - int size = min_t(int, copied, PAGE_SIZE - start); > - if (!failed) { > - buf.page = pages[n]; > - buf.offset = start; > - buf.len = size; > - ret = add_to_pipe(pipe, &buf); > - if (unlikely(ret < 0)) { > - failed = true; > - } else { > - iov_iter_advance(from, ret); > - total += ret; > - } > - } else { > - put_page(pages[n]); > + n = DIV_ROUND_UP(left + start, PAGE_SIZE); > + for (i = 0; i < n; i++) { > + int size = min_t(int, left, PAGE_SIZE - start); > + > + buf.page = pages[i]; > + buf.offset = start; > + buf.len = size; > + ret = add_to_pipe(pipe, &buf); > + if (unlikely(ret < 0)) { > + iov_iter_revert(from, left); > + // this one got dropped by add_to_pipe() > + while (++i < n) > + put_page(pages[i]); > + goto out; > } > - copied -= size; > + total += ret; > + left -= size; > + start = 0; > } > } > +out: > return total ? total : ret; > } > Reviewed-by: Jeff Layton <jlayton@kernel.org>
diff --git a/fs/splice.c b/fs/splice.c index 6645b30ec990..9f84bd21f64c 100644 --- a/fs/splice.c +++ b/fs/splice.c @@ -1160,39 +1160,40 @@ static int iter_to_pipe(struct iov_iter *from, }; size_t total = 0; int ret = 0; - bool failed = false; - while (iov_iter_count(from) && !failed) { + while (iov_iter_count(from)) { struct page *pages[16]; - ssize_t copied; + ssize_t left; size_t start; - int n; + int i, n; - copied = iov_iter_get_pages(from, pages, ~0UL, 16, &start); - if (copied <= 0) { - ret = copied; + left = iov_iter_get_pages2(from, pages, ~0UL, 16, &start); + if (left <= 0) { + ret = left; break; } - for (n = 0; copied; n++, start = 0) { - int size = min_t(int, copied, PAGE_SIZE - start); - if (!failed) { - buf.page = pages[n]; - buf.offset = start; - buf.len = size; - ret = add_to_pipe(pipe, &buf); - if (unlikely(ret < 0)) { - failed = true; - } else { - iov_iter_advance(from, ret); - total += ret; - } - } else { - put_page(pages[n]); + n = DIV_ROUND_UP(left + start, PAGE_SIZE); + for (i = 0; i < n; i++) { + int size = min_t(int, left, PAGE_SIZE - start); + + buf.page = pages[i]; + buf.offset = start; + buf.len = size; + ret = add_to_pipe(pipe, &buf); + if (unlikely(ret < 0)) { + iov_iter_revert(from, left); + // this one got dropped by add_to_pipe() + while (++i < n) + put_page(pages[i]); + goto out; } - copied -= size; + total += ret; + left -= size; + start = 0; } } +out: return total ? total : ret; }
... and untangle the cleanup on failure to add into pipe. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> --- fs/splice.c | 47 ++++++++++++++++++++++++----------------------- 1 file changed, 24 insertions(+), 23 deletions(-)