From: Ursula Braun Date: Mon, 21 Oct 2019 14:13:10 +0000 (+0200) Subject: net/smc: improve abnormal termination locking X-Git-Tag: v5.10.7~3838^2~331^2~5 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=69318b5215f2dc32c345a3d65b98b4b1bf29c007;p=platform%2Fkernel%2Flinux-rpi.git net/smc: improve abnormal termination locking Locking hierarchy requires that the link group conns_lock can be taken if the socket lock is held, but not vice versa. Nevertheless socket termination during abnormal link group termination should be protected by the socket lock. This patch reduces the time segments the link group conns_lock is held to enable usage of lock_sock in smc_lgr_terminate(). Signed-off-by: Ursula Braun Signed-off-by: Karsten Graul Signed-off-by: Jakub Kicinski --- diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c index b53ba8f0..1f58cd8 100644 --- a/net/smc/smc_core.c +++ b/net/smc/smc_core.c @@ -491,23 +491,26 @@ static void __smc_lgr_terminate(struct smc_link_group *lgr) if (!lgr->is_smcd) smc_llc_link_inactive(&lgr->lnk[SMC_SINGLE_LINK]); - write_lock_bh(&lgr->conns_lock); + /* kill remaining link group connections */ + read_lock_bh(&lgr->conns_lock); node = rb_first(&lgr->conns_all); while (node) { + read_unlock_bh(&lgr->conns_lock); conn = rb_entry(node, struct smc_connection, alert_node); smc = container_of(conn, struct smc_sock, conn); + lock_sock(&smc->sk); sock_hold(&smc->sk); /* sock_put in close work */ conn->killed = 1; conn->local_tx_ctrl.conn_state_flags.peer_conn_abort = 1; - __smc_lgr_unregister_conn(conn); + smc_lgr_unregister_conn(conn); conn->lgr = NULL; - write_unlock_bh(&lgr->conns_lock); if (!schedule_work(&conn->close_work)) sock_put(&smc->sk); - write_lock_bh(&lgr->conns_lock); + release_sock(&smc->sk); + read_lock_bh(&lgr->conns_lock); node = rb_first(&lgr->conns_all); } - write_unlock_bh(&lgr->conns_lock); + read_unlock_bh(&lgr->conns_lock); if (!lgr->is_smcd) wake_up(&lgr->lnk[SMC_SINGLE_LINK].wr_reg_wait); smc_lgr_schedule_free_work(lgr);