Lock receive socket buffer in soo_stat() rather than commenting that we

should lock it, which may marginally improve the consistency of the
results.  Remove comment.

MFC after:	3 days

1 files changed, 4 insertions, 5 deletions

diff --git a/sys/kern/sys_socket.c b/sys/kern/sys_socket.c
index aeeaf33..813b1dd 100644
--- a/sys/kern/sys_socket.c
+++ b/sys/kern/sys_socket.c
@@ -246,17 +246,16 @@ soo_stat(struct file *fp, struct stat *ub, struct ucred *active_cred,
 	/*
 	 * If SBS_CANTRCVMORE is set, but there's still data left in the
 	 * receive buffer, the socket is still readable.
-	 *
-	 * XXXRW: perhaps should lock socket buffer so st_size result is
-	 * consistent.
 	 */
-	/* Unlocked read. */
+	SOCKBUF_LOCK(&so->so_rcv);
 	if ((so->so_rcv.sb_state & SBS_CANTRCVMORE) == 0 ||
 	    so->so_rcv.sb_cc != 0)
 		ub->st_mode |= S_IRUSR | S_IRGRP | S_IROTH;
+	ub->st_size = so->so_rcv.sb_cc - so->so_rcv.sb_ctl;
+	SOCKBUF_UNLOCK(&so->so_rcv);
+	/* Unlocked read. */
 	if ((so->so_snd.sb_state & SBS_CANTSENDMORE) == 0)
 		ub->st_mode |= S_IWUSR | S_IWGRP | S_IWOTH;
-	ub->st_size = so->so_rcv.sb_cc - so->so_rcv.sb_ctl;
 	ub->st_uid = so->so_cred->cr_uid;
 	ub->st_gid = so->so_cred->cr_gid;
 	return (*so->so_proto->pr_usrreqs->pru_sense)(so, ub);