From a2bf04774bf4aa0a75036c1e92e3d2fd1cce2aff Mon Sep 17 00:00:00 2001 From: Kurt Hackel Date: Thu, 27 Apr 2006 18:51:26 -0700 Subject: [PATCH] ocfs2: mle ref counting fixes Signed-off-by: Kurt Hackel Signed-off-by: Mark Fasheh --- fs/ocfs2/dlm/dlmmaster.c | 109 ++++++++++++++++++++++++++++++++------- 1 file changed, 90 insertions(+), 19 deletions(-) diff --git a/fs/ocfs2/dlm/dlmmaster.c b/fs/ocfs2/dlm/dlmmaster.c index d1c85f10c6..19399446aa 100644 --- a/fs/ocfs2/dlm/dlmmaster.c +++ b/fs/ocfs2/dlm/dlmmaster.c @@ -74,6 +74,7 @@ struct dlm_master_list_entry wait_queue_head_t wq; atomic_t woken; struct kref mle_refs; + int inuse; unsigned long maybe_map[BITS_TO_LONGS(O2NM_MAX_NODES)]; unsigned long vote_map[BITS_TO_LONGS(O2NM_MAX_NODES)]; unsigned long response_map[BITS_TO_LONGS(O2NM_MAX_NODES)]; @@ -337,6 +338,31 @@ static inline void dlm_mle_detach_hb_events(struct dlm_ctxt *dlm, spin_unlock(&dlm->spinlock); } +static void dlm_get_mle_inuse(struct dlm_master_list_entry *mle) +{ + struct dlm_ctxt *dlm; + dlm = mle->dlm; + + assert_spin_locked(&dlm->spinlock); + assert_spin_locked(&dlm->master_lock); + mle->inuse++; + kref_get(&mle->mle_refs); +} + +static void dlm_put_mle_inuse(struct dlm_master_list_entry *mle) +{ + struct dlm_ctxt *dlm; + dlm = mle->dlm; + + spin_lock(&dlm->spinlock); + spin_lock(&dlm->master_lock); + mle->inuse--; + __dlm_put_mle(mle); + spin_unlock(&dlm->master_lock); + spin_unlock(&dlm->spinlock); + +} + /* remove from list and free */ static void __dlm_put_mle(struct dlm_master_list_entry *mle) { @@ -390,6 +416,7 @@ static void dlm_init_mle(struct dlm_master_list_entry *mle, memset(mle->response_map, 0, sizeof(mle->response_map)); mle->master = O2NM_MAX_NODES; mle->new_master = O2NM_MAX_NODES; + mle->inuse = 0; if (mle->type == DLM_MLE_MASTER) { BUG_ON(!res); @@ -809,7 +836,7 @@ lookup: * if so, the creator of the BLOCK may try to put the last * ref at this time in the assert master handler, so we * need an extra one to keep from a bad ptr deref. */ - dlm_get_mle(mle); + dlm_get_mle_inuse(mle); spin_unlock(&dlm->master_lock); spin_unlock(&dlm->spinlock); @@ -899,7 +926,7 @@ wait: dlm_mle_detach_hb_events(dlm, mle); dlm_put_mle(mle); /* put the extra ref */ - dlm_put_mle(mle); + dlm_put_mle_inuse(mle); wake_waiters: spin_lock(&res->spinlock); @@ -1753,6 +1780,7 @@ ok: if (mle) { int extra_ref = 0; int nn = -1; + int rr, err = 0; spin_lock(&mle->spinlock); if (mle->type == DLM_MLE_BLOCK || mle->type == DLM_MLE_MIGRATION) @@ -1772,27 +1800,64 @@ ok: wake_up(&mle->wq); spin_unlock(&mle->spinlock); - if (mle->type == DLM_MLE_MIGRATION && res) { - mlog(0, "finishing off migration of lockres %.*s, " - "from %u to %u\n", - res->lockname.len, res->lockname.name, - dlm->node_num, mle->new_master); + if (res) { spin_lock(&res->spinlock); - res->state &= ~DLM_LOCK_RES_MIGRATING; - dlm_change_lockres_owner(dlm, res, mle->new_master); - BUG_ON(res->state & DLM_LOCK_RES_DIRTY); + if (mle->type == DLM_MLE_MIGRATION) { + mlog(0, "finishing off migration of lockres %.*s, " + "from %u to %u\n", + res->lockname.len, res->lockname.name, + dlm->node_num, mle->new_master); + res->state &= ~DLM_LOCK_RES_MIGRATING; + dlm_change_lockres_owner(dlm, res, mle->new_master); + BUG_ON(res->state & DLM_LOCK_RES_DIRTY); + } else { + dlm_change_lockres_owner(dlm, res, mle->master); + } spin_unlock(&res->spinlock); } - /* master is known, detach if not already detached */ - dlm_mle_detach_hb_events(dlm, mle); - dlm_put_mle(mle); - + + /* master is known, detach if not already detached. + * ensures that only one assert_master call will happen + * on this mle. */ + spin_lock(&dlm->spinlock); + spin_lock(&dlm->master_lock); + + rr = atomic_read(&mle->mle_refs.refcount); + if (mle->inuse > 0) { + if (extra_ref && rr < 3) + err = 1; + else if (!extra_ref && rr < 2) + err = 1; + } else { + if (extra_ref && rr < 2) + err = 1; + else if (!extra_ref && rr < 1) + err = 1; + } + if (err) { + mlog(ML_ERROR, "%s:%.*s: got assert master from %u " + "that will mess up this node, refs=%d, extra=%d, " + "inuse=%d\n", dlm->name, namelen, name, + assert->node_idx, rr, extra_ref, mle->inuse); + dlm_print_one_mle(mle); + } + list_del_init(&mle->list); + __dlm_mle_detach_hb_events(dlm, mle); + __dlm_put_mle(mle); if (extra_ref) { /* the assert master message now balances the extra * ref given by the master / migration request message. * if this is the last put, it will be removed * from the list. */ - dlm_put_mle(mle); + __dlm_put_mle(mle); + } + spin_unlock(&dlm->master_lock); + spin_unlock(&dlm->spinlock); + } else if (res) { + if (res->owner != assert->node_idx) { + mlog(0, "assert_master from %u, but current " + "owner is %u (%.*s), no mle\n", assert->node_idx, + res->owner, namelen, name); } } @@ -2138,7 +2203,7 @@ fail: * take both dlm->spinlock and dlm->master_lock */ spin_lock(&dlm->spinlock); spin_lock(&dlm->master_lock); - dlm_get_mle(mle); + dlm_get_mle_inuse(mle); spin_unlock(&dlm->master_lock); spin_unlock(&dlm->spinlock); @@ -2155,7 +2220,10 @@ fail: /* migration failed, detach and clean up mle */ dlm_mle_detach_hb_events(dlm, mle); dlm_put_mle(mle); - dlm_put_mle(mle); + dlm_put_mle_inuse(mle); + spin_lock(&res->spinlock); + res->state &= ~DLM_LOCK_RES_MIGRATING; + spin_unlock(&res->spinlock); goto leave; } @@ -2196,7 +2264,10 @@ fail: /* migration failed, detach and clean up mle */ dlm_mle_detach_hb_events(dlm, mle); dlm_put_mle(mle); - dlm_put_mle(mle); + dlm_put_mle_inuse(mle); + spin_lock(&res->spinlock); + res->state &= ~DLM_LOCK_RES_MIGRATING; + spin_unlock(&res->spinlock); goto leave; } /* TODO: if node died: stop, clean up, return error */ @@ -2212,7 +2283,7 @@ fail: /* master is known, detach if not already detached */ dlm_mle_detach_hb_events(dlm, mle); - dlm_put_mle(mle); + dlm_put_mle_inuse(mle); ret = 0; dlm_lockres_calc_usage(dlm, res); -- 2.39.5