From 95f7f3e7dc6bd2e735cb5de11734ea2222b1e05a Mon Sep 17 00:00:00 2001 From: Karsten Graul Date: Thu, 7 Oct 2021 16:14:40 +0200 Subject: net/smc: improved fix wait on already cleared link Commit 8f3d65c16679 ("net/smc: fix wait on already cleared link") introduced link refcounting to avoid waits on already cleared links. This patch extents and improves the refcounting to cover all remaining possible cases for this kind of error situation. Fixes: 15e1b99aadfb ("net/smc: no WR buffer wait for terminating link group") Signed-off-by: Karsten Graul Signed-off-by: David S. Miller --- net/smc/smc_core.c | 20 +++++++++++--------- 1 file changed, 11 insertions(+), 9 deletions(-) (limited to 'net/smc/smc_core.c') diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c index 8280c938be80..d2206743dc71 100644 --- a/net/smc/smc_core.c +++ b/net/smc/smc_core.c @@ -949,7 +949,7 @@ struct smc_link *smc_switch_conns(struct smc_link_group *lgr, to_lnk = &lgr->lnk[i]; break; } - if (!to_lnk) { + if (!to_lnk || !smc_wr_tx_link_hold(to_lnk)) { smc_lgr_terminate_sched(lgr); return NULL; } @@ -981,24 +981,26 @@ again: read_unlock_bh(&lgr->conns_lock); /* pre-fetch buffer outside of send_lock, might sleep */ rc = smc_cdc_get_free_slot(conn, to_lnk, &wr_buf, NULL, &pend); - if (rc) { - smcr_link_down_cond_sched(to_lnk); - return NULL; - } + if (rc) + goto err_out; /* avoid race with smcr_tx_sndbuf_nonempty() */ spin_lock_bh(&conn->send_lock); smc_switch_link_and_count(conn, to_lnk); rc = smc_switch_cursor(smc, pend, wr_buf); spin_unlock_bh(&conn->send_lock); sock_put(&smc->sk); - if (rc) { - smcr_link_down_cond_sched(to_lnk); - return NULL; - } + if (rc) + goto err_out; goto again; } read_unlock_bh(&lgr->conns_lock); + smc_wr_tx_link_put(to_lnk); return to_lnk; + +err_out: + smcr_link_down_cond_sched(to_lnk); + smc_wr_tx_link_put(to_lnk); + return NULL; } static void smcr_buf_unuse(struct smc_buf_desc *rmb_desc, -- cgit