[PATCH v1 net-next 7/7] af_unix: Consolidate unix_schedule_gc() and wait_for_unix_gc().

[Kuniyuki Iwashima <kuniyu@google.com>]

unix_schedule_gc() and wait_for_unix_gc() share some code.

Let's consolidate the two.

Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
---
 net/unix/af_unix.c |  2 +-
 net/unix/af_unix.h |  2 +-
 net/unix/garbage.c | 28 +++++++++-------------------
 3 files changed, 11 insertions(+), 21 deletions(-)

diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index 34952242bd81..e518116f8171 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -733,7 +733,7 @@ static void unix_release_sock(struct sock *sk, int embrion)
 
 	/* ---- Socket is dead now and most probably destroyed ---- */
 
-	unix_schedule_gc();
+	unix_schedule_gc(NULL);
 }
 
 struct unix_peercred {
diff --git a/net/unix/af_unix.h b/net/unix/af_unix.h
index 2f1bfe3217c1..c4f1b2da363d 100644
--- a/net/unix/af_unix.h
+++ b/net/unix/af_unix.h
@@ -29,7 +29,7 @@ void unix_del_edges(struct scm_fp_list *fpl);
 void unix_update_edges(struct unix_sock *receiver);
 int unix_prepare_fpl(struct scm_fp_list *fpl);
 void unix_destroy_fpl(struct scm_fp_list *fpl);
-void unix_schedule_gc(void);
+void unix_schedule_gc(struct user_struct *user);
 
 /* SOCK_DIAG */
 long unix_inq_len(struct sock *sk);
diff --git a/net/unix/garbage.c b/net/unix/garbage.c
index fe1f74345b66..78323d43e63e 100644
--- a/net/unix/garbage.c
+++ b/net/unix/garbage.c
@@ -279,8 +279,6 @@ void unix_update_edges(struct unix_sock *receiver)
 	}
 }
 
-static void wait_for_unix_gc(struct scm_fp_list *fpl);
-
 int unix_prepare_fpl(struct scm_fp_list *fpl)
 {
 	struct unix_vertex *vertex;
@@ -302,7 +300,7 @@ int unix_prepare_fpl(struct scm_fp_list *fpl)
 	if (!fpl->edges)
 		goto err;
 
-	wait_for_unix_gc(fpl);
+	unix_schedule_gc(fpl->user);
 
 	return 0;
 
@@ -614,21 +612,9 @@ static void unix_gc(struct work_struct *work)
 
 static DECLARE_WORK(unix_gc_work, unix_gc);
 
-void unix_schedule_gc(void)
-{
-	if (READ_ONCE(unix_graph_state) == UNIX_GRAPH_NOT_CYCLIC)
-		return;
-
-	if (READ_ONCE(gc_in_progress))
-		return;
-
-	WRITE_ONCE(gc_in_progress, true);
-	queue_work(system_dfl_wq, &unix_gc_work);
-}
-
 #define UNIX_INFLIGHT_SANE_USER		(SCM_MAX_FD * 8)
 
-static void wait_for_unix_gc(struct scm_fp_list *fpl)
+void unix_schedule_gc(struct user_struct *user)
 {
 	if (READ_ONCE(unix_graph_state) == UNIX_GRAPH_NOT_CYCLIC)
 		return;
@@ -636,11 +622,15 @@ static void wait_for_unix_gc(struct scm_fp_list *fpl)
 	/* Penalise users who want to send AF_UNIX sockets
 	 * but whose sockets have not been received yet.
 	 */
-	if (READ_ONCE(fpl->user->unix_inflight) < UNIX_INFLIGHT_SANE_USER)
+	if (user &&
+	    READ_ONCE(user->unix_inflight) < UNIX_INFLIGHT_SANE_USER)
 		return;
 
-	unix_schedule_gc();
+	if (!READ_ONCE(gc_in_progress)) {
+		WRITE_ONCE(gc_in_progress, true);
+		queue_work(system_dfl_wq, &unix_gc_work);
+	}
 
-	if (READ_ONCE(unix_graph_cyclic_sccs))
+	if (user && READ_ONCE(unix_graph_cyclic_sccs))
 		flush_work(&unix_gc_work);
 }
-- 
2.52.0.rc1.455.g30608eb744-goog