diff options
Diffstat (limited to 'lib/iov_iter.c')
-rw-r--r-- | lib/iov_iter.c | 75 |
1 files changed, 38 insertions, 37 deletions
diff --git a/lib/iov_iter.c b/lib/iov_iter.c index c78129e709f2..a9446efac70d 100644 --- a/lib/iov_iter.c +++ b/lib/iov_iter.c @@ -1289,60 +1289,61 @@ static struct page **get_pages_array(size_t n) return kvmalloc_array(n, sizeof(struct page *), GFP_KERNEL); } -static inline ssize_t __pipe_get_pages(struct iov_iter *i, - size_t maxsize, - struct page **pages, - size_t off) -{ - struct pipe_inode_info *pipe = i->pipe; - ssize_t left = maxsize; - - if (off) { - struct pipe_buffer *buf = pipe_buf(pipe, pipe->head - 1); - - get_page(*pages++ = buf->page); - left -= PAGE_SIZE - off; - if (left <= 0) { - buf->len += maxsize; - return maxsize; - } - buf->len = PAGE_SIZE; - } - while (!pipe_full(pipe->head, pipe->tail, pipe->max_usage)) { - struct page *page = push_anon(pipe, - min_t(ssize_t, left, PAGE_SIZE)); - if (!page) - break; - get_page(*pages++ = page); - left -= PAGE_SIZE; - if (left <= 0) - return maxsize; - } - return maxsize - left ? : -EFAULT; -} - static ssize_t pipe_get_pages(struct iov_iter *i, struct page ***pages, size_t maxsize, unsigned maxpages, size_t *start) { + struct pipe_inode_info *pipe = i->pipe; unsigned int npages, off; struct page **p; - size_t capacity; + ssize_t left; + int count; if (!sanity(i)) return -EFAULT; *start = off = pipe_npages(i, &npages); - capacity = min(npages, maxpages) * PAGE_SIZE - off; - maxsize = min(maxsize, capacity); + count = DIV_ROUND_UP(maxsize + off, PAGE_SIZE); + if (count > npages) + count = npages; + if (count > maxpages) + count = maxpages; p = *pages; if (!p) { - *pages = p = get_pages_array(DIV_ROUND_UP(maxsize + off, PAGE_SIZE)); + *pages = p = get_pages_array(count); if (!p) return -ENOMEM; } - return __pipe_get_pages(i, maxsize, p, off); + left = maxsize; + npages = 0; + if (off) { + struct pipe_buffer *buf = pipe_buf(pipe, pipe->head - 1); + + get_page(*p++ = buf->page); + left -= PAGE_SIZE - off; + if (left <= 0) { + buf->len += maxsize; + return maxsize; + } + buf->len = PAGE_SIZE; + npages = 1; + } + for ( ; npages < count; npages++) { + struct page *page; + unsigned int size = min_t(ssize_t, left, PAGE_SIZE); + + if (pipe_full(pipe->head, pipe->tail, pipe->max_usage)) + break; + page = push_anon(pipe, size); + if (!page) + break; + get_page(*p++ = page); + left -= size; + } + if (!npages) + return -EFAULT; + return maxsize - left; } static ssize_t iter_xarray_populate_pages(struct page **pages, struct xarray *xa, |