diff mbox series

[net-next,4/4] mptcp: update misleading comments.

Message ID 20220930155934.404466-5-mathew.j.martineau@linux.intel.com (mailing list archive)
State Accepted
Commit d89e3ed76b6efd1a4fd213feebedd01337a16b5a
Delegated to: Netdev Maintainers
Headers show
Series mptcp: Fastclose edge cases and error handling | expand

Checks

Context Check Description
netdev/tree_selection success Clearly marked for net-next
netdev/fixes_present success Fixes tag not required for -next series
netdev/subject_prefix success Link
netdev/cover_letter success Series has a cover letter
netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 3 this patch: 3
netdev/cc_maintainers success CCed 8 of 8 maintainers
netdev/build_clang success Errors and warnings before: 5 this patch: 5
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 3 this patch: 3
netdev/checkpatch warning WARNING: line length of 81 exceeds 80 columns WARNING: line length of 82 exceeds 80 columns WARNING: line length of 84 exceeds 80 columns
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Mat Martineau Sept. 30, 2022, 3:59 p.m. UTC 
From: Paolo Abeni <pabeni@redhat.com>

The MPTCP data path is quite complex and hard to understend even
without some foggy comments referring to modified code and/or
completely misleading from the beginning.

Update a few of them to more accurately describing the current
status.

Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
---
 net/mptcp/protocol.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)
diff mbox series

Patch

diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index acf44075ba40..f599ad44ed24 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -662,9 +662,9 @@  static bool __mptcp_move_skbs_from_subflow(struct mptcp_sock *msk,
 
 		skb = skb_peek(&ssk->sk_receive_queue);
 		if (!skb) {
-			/* if no data is found, a racing workqueue/recvmsg
-			 * already processed the new data, stop here or we
-			 * can enter an infinite loop
+			/* With racing move_skbs_to_msk() and __mptcp_move_skbs(),
+			 * a different CPU can have already processed the pending
+			 * data, stop here or we can enter an infinite loop
 			 */
 			if (!moved)
 				done = true;
@@ -672,9 +672,9 @@  static bool __mptcp_move_skbs_from_subflow(struct mptcp_sock *msk,
 		}
 
 		if (__mptcp_check_fallback(msk)) {
-			/* if we are running under the workqueue, TCP could have
-			 * collapsed skbs between dummy map creation and now
-			 * be sure to adjust the size
+			/* Under fallback skbs have no MPTCP extension and TCP could
+			 * collapse them between the dummy map creation and the
+			 * current dequeue. Be sure to adjust the map size.
 			 */
 			map_remaining = skb->len;
 			subflow->map_data_len = skb->len;
@@ -3768,7 +3768,7 @@  static __poll_t mptcp_poll(struct file *file, struct socket *sock,
 	if (sk->sk_shutdown & RCV_SHUTDOWN)
 		mask |= EPOLLIN | EPOLLRDNORM | EPOLLRDHUP;
 
-	/* This barrier is coupled with smp_wmb() in tcp_reset() */
+	/* This barrier is coupled with smp_wmb() in __mptcp_error_report() */
 	smp_rmb();
 	if (sk->sk_err)
 		mask |= EPOLLERR;