A preparation patch that limits scopes of a couple variables in io_zcrx_recv_skb() and rename them, it makes it easier to reason about the code. Signed-off-by: Pavel Begunkov --- io_uring/zcrx.c | 35 ++++++++++++++++------------------- 1 file changed, 16 insertions(+), 19 deletions(-) diff --git a/io_uring/zcrx.c b/io_uring/zcrx.c index 50d075fb3825..2ea1e79ca8a2 100644 --- a/io_uring/zcrx.c +++ b/io_uring/zcrx.c @@ -1693,8 +1693,7 @@ io_zcrx_recv_skb(read_descriptor_t *desc, struct sk_buff *skb, struct io_kiocb *req = args->req; struct sk_buff *frag_iter; unsigned start, start_off = offset; - int i, copy, end, off; - int ret = 0; + int i, ret = 0; len = min_t(size_t, len, desc->count); /* @@ -1732,20 +1731,19 @@ io_zcrx_recv_skb(read_descriptor_t *desc, struct sk_buff *skb, for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) { const skb_frag_t *frag; + unsigned frag_end; if (WARN_ON(start > offset + len)) return -EFAULT; frag = &skb_shinfo(skb)->frags[i]; - end = start + skb_frag_size(frag); + frag_end = start + skb_frag_size(frag); - if (offset < end) { - copy = end - offset; - if (copy > len) - copy = len; + if (offset < frag_end) { + unsigned copy = min(frag_end - offset, len); + unsigned frag_off = offset - start; - off = offset - start; - ret = io_zcrx_recv_frag(req, ifq, frag, off, copy); + ret = io_zcrx_recv_frag(req, ifq, frag, frag_off, copy); if (ret < 0) goto out; @@ -1754,24 +1752,23 @@ io_zcrx_recv_skb(read_descriptor_t *desc, struct sk_buff *skb, if (len == 0 || ret != copy) goto out; } - start = end; + start = frag_end; } skb_walk_frags(skb, frag_iter) { + unsigned frag_end; + if (WARN_ON(start > offset + len)) return -EFAULT; - end = start + frag_iter->len; - if (offset < end) { + frag_end = start + frag_iter->len; + if (offset < frag_end) { + unsigned copy = min(frag_end - offset, len); + unsigned frag_off = offset - start; size_t count; - copy = end - offset; - if (copy > len) - copy = len; - - off = offset - start; count = desc->count; - ret = io_zcrx_recv_skb(desc, frag_iter, off, copy); + ret = io_zcrx_recv_skb(desc, frag_iter, frag_off, copy); desc->count = count; if (ret < 0) goto out; @@ -1781,7 +1778,7 @@ io_zcrx_recv_skb(read_descriptor_t *desc, struct sk_buff *skb, if (len == 0 || ret != copy) goto out; } - start = end; + start = frag_end; } out: -- 2.54.0