6.6-stable review patch. If anyone has any objections, please let me know.
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From: Kuniyuki Iwashima kuniyu@amazon.com
commit 22c3c0c52d32f41cc38cd936ea0c93f22ced3315 upstream.
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: Kuniyuki Iwashima kuniyu@amazon.com Acked-by: Paolo Abeni pabeni@redhat.com Link: https://lore.kernel.org/r/20240325202425.60930-5-kuniyu@amazon.com Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Lee Jones lee@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/unix/garbage.c | 18 +++++++----------- 1 file changed, 7 insertions(+), 11 deletions(-)
--- a/net/unix/garbage.c +++ b/net/unix/garbage.c @@ -144,6 +144,7 @@ static void unix_free_vertices(struct sc }
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 * 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 * 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 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 *u 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 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); }