Commit 22c3c0c5 authored by Kuniyuki Iwashima's avatar Kuniyuki Iwashima Committed by Jakub Kicinski
Browse files

af_unix: Bulk update unix_tot_inflight/unix_inflight when queuing skb. 



Currently, we track the number of inflight sockets in two variables.
unix_tot_inflight is the total number of inflight AF_UNIX sockets on
the host, and user->unix_inflight is the number of inflight fds per
user.

We update them one by one in unix_inflight(), which can be done once
in batch.  Also, sendmsg() could fail even after unix_inflight(), then
we need to acquire unix_gc_lock only to decrement the counters.

Let's bulk update the counters in unix_add_edges() and unix_del_edges(),
which is called only for successfully passed fds.

Signed-off-by: default avatarKuniyuki Iwashima <kuniyu@amazon.com>
Acked-by: default avatarPaolo Abeni <pabeni@redhat.com>
Link: https://lore.kernel.org/r/20240325202425.60930-5-kuniyu@amazon.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 42f298c0

net/unix/garbage.c

+7 −11
Original line number Diff line number Diff line
@@ -144,6 +144,7 @@ static void unix_free_vertices(struct scm_fp_list *fpl) 
}



DEFINE_SPINLOCK(unix_gc_lock);

unsigned int unix_tot_inflight;



void unix_add_edges(struct scm_fp_list *fpl, struct unix_sock *receiver)

{
@@ -168,7 +169,10 @@ void unix_add_edges(struct scm_fp_list *fpl, struct unix_sock *receiver) 
		unix_add_edge(fpl, edge);

	} while (i < fpl->count_unix);



	WRITE_ONCE(unix_tot_inflight, unix_tot_inflight + fpl->count_unix);

out:

	WRITE_ONCE(fpl->user->unix_inflight, fpl->user->unix_inflight + fpl->count);



	spin_unlock(&unix_gc_lock);



	fpl->inflight = true;
@@ -191,7 +195,10 @@ void unix_del_edges(struct scm_fp_list *fpl) 
		unix_del_edge(fpl, edge);

	} while (i < fpl->count_unix);



	WRITE_ONCE(unix_tot_inflight, unix_tot_inflight - fpl->count_unix);

out:

	WRITE_ONCE(fpl->user->unix_inflight, fpl->user->unix_inflight - fpl->count);



	spin_unlock(&unix_gc_lock);



	fpl->inflight = false;
@@ -234,7 +241,6 @@ void unix_destroy_fpl(struct scm_fp_list *fpl) 
	unix_free_vertices(fpl);

}



unsigned int unix_tot_inflight;

static LIST_HEAD(gc_candidates);

static LIST_HEAD(gc_inflight_list);
@@ -255,13 +261,8 @@ void unix_inflight(struct user_struct *user, struct file *filp) 
			WARN_ON_ONCE(list_empty(&u->link));

		}

		u->inflight++;



		/* Paired with READ_ONCE() in wait_for_unix_gc() */

		WRITE_ONCE(unix_tot_inflight, unix_tot_inflight + 1);

	}



	WRITE_ONCE(user->unix_inflight, user->unix_inflight + 1);



	spin_unlock(&unix_gc_lock);

}
@@ -278,13 +279,8 @@ void unix_notinflight(struct user_struct *user, struct file *filp) 
		u->inflight--;

		if (!u->inflight)

			list_del_init(&u->link);



		/* Paired with READ_ONCE() in wait_for_unix_gc() */

		WRITE_ONCE(unix_tot_inflight, unix_tot_inflight - 1);

	}



	WRITE_ONCE(user->unix_inflight, user->unix_inflight - 1);



	spin_unlock(&unix_gc_lock);

}