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Date: Tue, 17 Mar 2009 13:01:09 -0700
From: Mark Fasheh <mfasheh@...e.com>
To: linux-kernel@...r.kernel.org
Cc: ocfs2-devel@....oracle.com, Joel Becker <joel.becker@...cle.com>,
Sunil Mushran <sunil.mushran@...cle.com>,
Mark Fasheh <mfasheh@...e.com>
Subject: [PATCH 19/32] ocfs2/dlm: Refactor dlm_clean_master_list()
From: Sunil Mushran <sunil.mushran@...cle.com>
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 <sunil.mushran@...cle.com>
Signed-off-by: Mark Fasheh <mfasheh@...e.com>
---
fs/ocfs2/dlm/dlmmaster.c | 148 ++++++++++++++++++++++++++-------------------
1 files changed, 85 insertions(+), 63 deletions(-)
diff --git a/fs/ocfs2/dlm/dlmmaster.c b/fs/ocfs2/dlm/dlmmaster.c
index 040581e..ec6da3c 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);
--
1.5.6
--
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