From c2cd4a44333034203cb198915e2b75c3227d41bf Mon Sep 17 00:00:00 2001 From: Sunil Mushran Date: Thu, 26 Feb 2009 15:00:39 -0800 Subject: [PATCH] ocfs2/dlm: Refactor dlm_clean_master_list() This patch refactors dlm_clean_master_list() so as to make it easier to convert the mle list to a hash. Signed-off-by: Sunil Mushran Signed-off-by: Mark Fasheh --- fs/ocfs2/dlm/dlmmaster.c | 148 ++++++++++++++++++++++----------------- 1 file changed, 85 insertions(+), 63 deletions(-) diff --git a/fs/ocfs2/dlm/dlmmaster.c b/fs/ocfs2/dlm/dlmmaster.c index 040581e1cd0..ec6da3c37dc 100644 --- a/fs/ocfs2/dlm/dlmmaster.c +++ b/fs/ocfs2/dlm/dlmmaster.c @@ -3207,12 +3207,87 @@ static int dlm_add_migration_mle(struct dlm_ctxt *dlm, return ret; } +/* + * Sets the owner of the lockres, associated to the mle, to UNKNOWN + */ +static struct dlm_lock_resource *dlm_reset_mleres_owner(struct dlm_ctxt *dlm, + struct dlm_master_list_entry *mle) +{ + struct dlm_lock_resource *res; + unsigned int hash; + + /* Find the lockres associated to the mle and set its owner to UNK */ + hash = dlm_lockid_hash(mle->u.mlename.name, mle->u.mlename.len); + res = __dlm_lookup_lockres(dlm, mle->u.mlename.name, mle->u.mlename.len, + hash); + if (res) { + spin_unlock(&dlm->master_lock); + + /* move lockres onto recovery list */ + spin_lock(&res->spinlock); + dlm_set_lockres_owner(dlm, res, DLM_LOCK_RES_OWNER_UNKNOWN); + dlm_move_lockres_to_recovery_list(dlm, res); + spin_unlock(&res->spinlock); + dlm_lockres_put(res); + + /* about to get rid of mle, detach from heartbeat */ + __dlm_mle_detach_hb_events(dlm, mle); + + /* dump the mle */ + spin_lock(&dlm->master_lock); + __dlm_put_mle(mle); + spin_unlock(&dlm->master_lock); + } + + return res; +} + +static void dlm_clean_migration_mle(struct dlm_ctxt *dlm, + struct dlm_master_list_entry *mle) +{ + __dlm_mle_detach_hb_events(dlm, mle); + + spin_lock(&mle->spinlock); + __dlm_unlink_mle(dlm, mle); + atomic_set(&mle->woken, 1); + spin_unlock(&mle->spinlock); + + wake_up(&mle->wq); +} + +static void dlm_clean_block_mle(struct dlm_ctxt *dlm, + struct dlm_master_list_entry *mle, u8 dead_node) +{ + int bit; + + BUG_ON(mle->type != DLM_MLE_BLOCK); + + spin_lock(&mle->spinlock); + bit = find_next_bit(mle->maybe_map, O2NM_MAX_NODES, 0); + if (bit != dead_node) { + mlog(0, "mle found, but dead node %u would not have been " + "master\n", dead_node); + spin_unlock(&mle->spinlock); + } else { + /* Must drop the refcount by one since the assert_master will + * never arrive. This may result in the mle being unlinked and + * freed, but there may still be a process waiting in the + * dlmlock path which is fine. */ + mlog(0, "node %u was expected master\n", dead_node); + atomic_set(&mle->woken, 1); + spin_unlock(&mle->spinlock); + wake_up(&mle->wq); + + /* Do not need events any longer, so detach from heartbeat */ + __dlm_mle_detach_hb_events(dlm, mle); + __dlm_put_mle(mle); + } +} void dlm_clean_master_list(struct dlm_ctxt *dlm, u8 dead_node) { struct dlm_master_list_entry *mle, *next; struct dlm_lock_resource *res; - unsigned int hash; mlog_entry("dlm=%s, dead node=%u\n", dlm->name, dead_node); top: @@ -3236,30 +3311,7 @@ top: * need to clean up if the dead node would have * been the master. */ if (mle->type == DLM_MLE_BLOCK) { - int bit; - - spin_lock(&mle->spinlock); - bit = find_next_bit(mle->maybe_map, O2NM_MAX_NODES, 0); - if (bit != dead_node) { - mlog(0, "mle found, but dead node %u would " - "not have been master\n", dead_node); - spin_unlock(&mle->spinlock); - } else { - /* must drop the refcount by one since the - * assert_master will never arrive. this - * may result in the mle being unlinked and - * freed, but there may still be a process - * waiting in the dlmlock path which is fine. */ - mlog(0, "node %u was expected master\n", - dead_node); - atomic_set(&mle->woken, 1); - spin_unlock(&mle->spinlock); - wake_up(&mle->wq); - /* do not need events any longer, so detach - * from heartbeat */ - __dlm_mle_detach_hb_events(dlm, mle); - __dlm_put_mle(mle); - } + dlm_clean_block_mle(dlm, mle, dead_node); continue; } @@ -3280,51 +3332,21 @@ top: /* if we have reached this point, this mle needs to * be removed from the list and freed. */ - - /* remove from the list early. NOTE: unlinking - * list_head while in list_for_each_safe */ - __dlm_mle_detach_hb_events(dlm, mle); - spin_lock(&mle->spinlock); - __dlm_unlink_mle(dlm, mle); - atomic_set(&mle->woken, 1); - spin_unlock(&mle->spinlock); - wake_up(&mle->wq); + dlm_clean_migration_mle(dlm, mle); mlog(0, "%s: node %u died during migration from " "%u to %u!\n", dlm->name, dead_node, mle->master, mle->new_master); - /* if there is a lockres associated with this - * mle, find it and set its owner to UNKNOWN */ - hash = dlm_lockid_hash(mle->u.mlename.name, mle->u.mlename.len); - res = __dlm_lookup_lockres(dlm, mle->u.mlename.name, - mle->u.mlename.len, hash); - if (res) { - /* unfortunately if we hit this rare case, our - * lock ordering is messed. we need to drop - * the master lock so that we can take the - * lockres lock, meaning that we will have to - * restart from the head of list. */ - spin_unlock(&dlm->master_lock); - - /* move lockres onto recovery list */ - spin_lock(&res->spinlock); - dlm_set_lockres_owner(dlm, res, - DLM_LOCK_RES_OWNER_UNKNOWN); - dlm_move_lockres_to_recovery_list(dlm, res); - spin_unlock(&res->spinlock); - dlm_lockres_put(res); - - /* about to get rid of mle, detach from heartbeat */ - __dlm_mle_detach_hb_events(dlm, mle); - - /* dump the mle */ - spin_lock(&dlm->master_lock); - __dlm_put_mle(mle); - spin_unlock(&dlm->master_lock); + /* If we find a lockres associated with the mle, we've + * hit this rare case that messes up our lock ordering. + * If so, we need to drop the master lock so that we can + * take the lockres lock, meaning that we will have to + * restart from the head of list. */ + res = dlm_reset_mleres_owner(dlm, mle); + if (res) /* restart */ goto top; - } /* this may be the last reference */ __dlm_put_mle(mle); -- 2.41.1