[PATCH io_uring 07/16] io_urint/zcrx: narrow var scope in io_zcrx_recv_skb()

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 <[email protected]>
---
 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