From 8caa654451bda40379bff786a63833b2965536e4 Mon Sep 17 00:00:00 2001 From: Ursula Braun Date: Mon, 21 Oct 2019 16:13:09 +0200 Subject: [PATCH] net/smc: terminate link group without holding lgr lock When a link group is to be terminated, it is sufficient to hold the lgr lock when unlinking the link group from its list. Move the lock-protected link group unlinking into smc_lgr_terminate(). Signed-off-by: Ursula Braun Signed-off-by: Karsten Graul Signed-off-by: Jakub Kicinski --- net/smc/smc_core.c | 25 +++++++++++++++++-------- 1 file changed, 17 insertions(+), 8 deletions(-) diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c index 4ee0e33b8c5a..b53ba8f0a833 100644 --- a/net/smc/smc_core.c +++ b/net/smc/smc_core.c @@ -182,8 +182,7 @@ static void smc_lgr_free_work(struct work_struct *work) spin_unlock_bh(lgr_lock); return; } - if (!list_empty(&lgr->list)) - list_del_init(&lgr->list); /* remove from smc_lgr_list */ + list_del_init(&lgr->list); /* remove from smc_lgr_list */ spin_unlock_bh(lgr_lock); if (!lgr->is_smcd && !lgr->terminating) { @@ -479,7 +478,7 @@ void smc_lgr_forget(struct smc_link_group *lgr) spin_unlock_bh(lgr_lock); } -/* terminate linkgroup abnormally */ +/* terminate link group */ static void __smc_lgr_terminate(struct smc_link_group *lgr) { struct smc_connection *conn; @@ -489,8 +488,6 @@ static void __smc_lgr_terminate(struct smc_link_group *lgr) if (lgr->terminating) return; /* lgr already terminating */ lgr->terminating = 1; - if (!list_empty(&lgr->list)) /* forget lgr */ - list_del_init(&lgr->list); if (!lgr->is_smcd) smc_llc_link_inactive(&lgr->lnk[SMC_SINGLE_LINK]); @@ -516,29 +513,41 @@ static void __smc_lgr_terminate(struct smc_link_group *lgr) smc_lgr_schedule_free_work(lgr); } +/* unlink and terminate link group */ void smc_lgr_terminate(struct smc_link_group *lgr) { spinlock_t *lgr_lock; smc_lgr_list_head(lgr, &lgr_lock); spin_lock_bh(lgr_lock); - __smc_lgr_terminate(lgr); + if (lgr->terminating) { + spin_unlock_bh(lgr_lock); + return; /* lgr already terminating */ + } + list_del_init(&lgr->list); spin_unlock_bh(lgr_lock); + __smc_lgr_terminate(lgr); } /* Called when IB port is terminated */ void smc_port_terminate(struct smc_ib_device *smcibdev, u8 ibport) { struct smc_link_group *lgr, *l; + LIST_HEAD(lgr_free_list); spin_lock_bh(&smc_lgr_list.lock); list_for_each_entry_safe(lgr, l, &smc_lgr_list.list, list) { if (!lgr->is_smcd && lgr->lnk[SMC_SINGLE_LINK].smcibdev == smcibdev && lgr->lnk[SMC_SINGLE_LINK].ibport == ibport) - __smc_lgr_terminate(lgr); + list_move(&lgr->list, &lgr_free_list); } spin_unlock_bh(&smc_lgr_list.lock); + + list_for_each_entry_safe(lgr, l, &lgr_free_list, list) { + list_del_init(&lgr->list); + __smc_lgr_terminate(lgr); + } } /* Called when SMC-D device is terminated or peer is lost */ @@ -552,7 +561,6 @@ void smc_smcd_terminate(struct smcd_dev *dev, u64 peer_gid, unsigned short vlan) list_for_each_entry_safe(lgr, l, &dev->lgr_list, list) { if ((!peer_gid || lgr->peer_gid == peer_gid) && (vlan == VLAN_VID_MASK || lgr->vlan_id == vlan)) { - __smc_lgr_terminate(lgr); list_move(&lgr->list, &lgr_free_list); } } @@ -561,6 +569,7 @@ void smc_smcd_terminate(struct smcd_dev *dev, u64 peer_gid, unsigned short vlan) /* cancel the regular free workers and actually free lgrs */ list_for_each_entry_safe(lgr, l, &lgr_free_list, list) { list_del_init(&lgr->list); + __smc_lgr_terminate(lgr); cancel_delayed_work_sync(&lgr->free_work); if (!peer_gid && vlan == VLAN_VID_MASK) /* dev terminated? */ smc_ism_signal_shutdown(lgr);