From b7eede757883a9892dcb7bf0280f4890fc74bcf6 Mon Sep 17 00:00:00 2001 From: Karsten Graul Date: Wed, 8 Jul 2020 17:05:12 +0200 Subject: [PATCH] net/smc: fix work request handling Wait for pending sends only when smc_switch_conns() found a link to move the connections to. Do not wait during link freeing, this can lead to permanent hang situations. And refuse to provide a new tx slot on an unusable link. Fixes: c6f02ebeea3a ("net/smc: switch connections to alternate link") Reviewed-by: Ursula Braun Signed-off-by: Karsten Graul Signed-off-by: David S. Miller --- net/smc/smc_llc.c | 8 ++++---- net/smc/smc_wr.c | 10 ++++++---- 2 files changed, 10 insertions(+), 8 deletions(-) diff --git a/net/smc/smc_llc.c b/net/smc/smc_llc.c index df16423..c1a0386 100644 --- a/net/smc/smc_llc.c +++ b/net/smc/smc_llc.c @@ -1241,8 +1241,8 @@ static void smc_llc_process_cli_delete_link(struct smc_link_group *lgr) smc_llc_send_message(lnk, &qentry->msg); /* response */ if (smc_link_downing(&lnk_del->state)) { - smc_switch_conns(lgr, lnk_del, false); - smc_wr_tx_wait_no_pending_sends(lnk_del); + if (smc_switch_conns(lgr, lnk_del, false)) + smc_wr_tx_wait_no_pending_sends(lnk_del); } smcr_link_clear(lnk_del, true); @@ -1316,8 +1316,8 @@ static void smc_llc_process_srv_delete_link(struct smc_link_group *lgr) goto out; /* asymmetric link already deleted */ if (smc_link_downing(&lnk_del->state)) { - smc_switch_conns(lgr, lnk_del, false); - smc_wr_tx_wait_no_pending_sends(lnk_del); + if (smc_switch_conns(lgr, lnk_del, false)) + smc_wr_tx_wait_no_pending_sends(lnk_del); } if (!list_empty(&lgr->list)) { /* qentry is either a request from peer (send it back to diff --git a/net/smc/smc_wr.c b/net/smc/smc_wr.c index 7239ba9..1e23cdd 100644 --- a/net/smc/smc_wr.c +++ b/net/smc/smc_wr.c @@ -169,6 +169,8 @@ void smc_wr_tx_cq_handler(struct ib_cq *ib_cq, void *cq_context) static inline int smc_wr_tx_get_free_slot_index(struct smc_link *link, u32 *idx) { *idx = link->wr_tx_cnt; + if (!smc_link_usable(link)) + return -ENOLINK; for_each_clear_bit(*idx, link->wr_tx_mask, link->wr_tx_cnt) { if (!test_and_set_bit(*idx, link->wr_tx_mask)) return 0; @@ -560,15 +562,15 @@ void smc_wr_free_link(struct smc_link *lnk) { struct ib_device *ibdev; + if (!lnk->smcibdev) + return; + ibdev = lnk->smcibdev->ibdev; + if (smc_wr_tx_wait_no_pending_sends(lnk)) memset(lnk->wr_tx_mask, 0, BITS_TO_LONGS(SMC_WR_BUF_CNT) * sizeof(*lnk->wr_tx_mask)); - if (!lnk->smcibdev) - return; - ibdev = lnk->smcibdev->ibdev; - if (lnk->wr_rx_dma_addr) { ib_dma_unmap_single(ibdev, lnk->wr_rx_dma_addr, SMC_WR_BUF_SIZE * lnk->wr_rx_cnt, -- 2.7.4