[DLM] The core of the DLM for GFS2/CLVM
This is the core of the distributed lock manager which is required
to use GFS2 as a cluster filesystem. It is also used by CLVM and
can be used as a standalone lock manager independantly of either
of these two projects.
It implements VAX-style locking modes.
Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Steve Whitehouse <swhiteho@redhat.com>
diff --git a/fs/dlm/recoverd.c b/fs/dlm/recoverd.c
new file mode 100644
index 0000000..06e4f7c
--- /dev/null
+++ b/fs/dlm/recoverd.c
@@ -0,0 +1,285 @@
+/******************************************************************************
+*******************************************************************************
+**
+** Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
+** Copyright (C) 2004-2005 Red Hat, Inc. All rights reserved.
+**
+** This copyrighted material is made available to anyone wishing to use,
+** modify, copy, or redistribute it subject to the terms and conditions
+** of the GNU General Public License v.2.
+**
+*******************************************************************************
+******************************************************************************/
+
+#include "dlm_internal.h"
+#include "lockspace.h"
+#include "member.h"
+#include "dir.h"
+#include "ast.h"
+#include "recover.h"
+#include "lowcomms.h"
+#include "lock.h"
+#include "requestqueue.h"
+#include "recoverd.h"
+
+
+/* If the start for which we're re-enabling locking (seq) has been superseded
+ by a newer stop (ls_recover_seq), we need to leave locking disabled. */
+
+static int enable_locking(struct dlm_ls *ls, uint64_t seq)
+{
+ int error = -EINTR;
+
+ spin_lock(&ls->ls_recover_lock);
+ if (ls->ls_recover_seq == seq) {
+ set_bit(LSFL_RUNNING, &ls->ls_flags);
+ up_write(&ls->ls_in_recovery);
+ error = 0;
+ }
+ spin_unlock(&ls->ls_recover_lock);
+ return error;
+}
+
+static int ls_recover(struct dlm_ls *ls, struct dlm_recover *rv)
+{
+ unsigned long start;
+ int error, neg = 0;
+
+ log_debug(ls, "recover %"PRIx64"", rv->seq);
+
+ down(&ls->ls_recoverd_active);
+
+ /*
+ * Suspending and resuming dlm_astd ensures that no lkb's from this ls
+ * will be processed by dlm_astd during recovery.
+ */
+
+ dlm_astd_suspend();
+ dlm_astd_resume();
+
+ /*
+ * This list of root rsb's will be the basis of most of the recovery
+ * routines.
+ */
+
+ dlm_create_root_list(ls);
+
+ /*
+ * Free all the tossed rsb's so we don't have to recover them.
+ */
+
+ dlm_clear_toss_list(ls);
+
+ /*
+ * Add or remove nodes from the lockspace's ls_nodes list.
+ * Also waits for all nodes to complete dlm_recover_members.
+ */
+
+ error = dlm_recover_members(ls, rv, &neg);
+ if (error) {
+ log_error(ls, "recover_members failed %d", error);
+ goto fail;
+ }
+ start = jiffies;
+
+ /*
+ * Rebuild our own share of the directory by collecting from all other
+ * nodes their master rsb names that hash to us.
+ */
+
+ error = dlm_recover_directory(ls);
+ if (error) {
+ log_error(ls, "recover_directory failed %d", error);
+ goto fail;
+ }
+
+ /*
+ * Purge directory-related requests that are saved in requestqueue.
+ * All dir requests from before recovery are invalid now due to the dir
+ * rebuild and will be resent by the requesting nodes.
+ */
+
+ dlm_purge_requestqueue(ls);
+
+ /*
+ * Wait for all nodes to complete directory rebuild.
+ */
+
+ error = dlm_recover_directory_wait(ls);
+ if (error) {
+ log_error(ls, "recover_directory_wait failed %d", error);
+ goto fail;
+ }
+
+ /*
+ * We may have outstanding operations that are waiting for a reply from
+ * a failed node. Mark these to be resent after recovery. Unlock and
+ * cancel ops can just be completed.
+ */
+
+ dlm_recover_waiters_pre(ls);
+
+ error = dlm_recovery_stopped(ls);
+ if (error)
+ goto fail;
+
+ if (neg || dlm_no_directory(ls)) {
+ /*
+ * Clear lkb's for departed nodes.
+ */
+
+ dlm_purge_locks(ls);
+
+ /*
+ * Get new master nodeid's for rsb's that were mastered on
+ * departed nodes.
+ */
+
+ error = dlm_recover_masters(ls);
+ if (error) {
+ log_error(ls, "recover_masters failed %d", error);
+ goto fail;
+ }
+
+ /*
+ * Send our locks on remastered rsb's to the new masters.
+ */
+
+ error = dlm_recover_locks(ls);
+ if (error) {
+ log_error(ls, "recover_locks failed %d", error);
+ goto fail;
+ }
+
+ error = dlm_recover_locks_wait(ls);
+ if (error) {
+ log_error(ls, "recover_locks_wait failed %d", error);
+ goto fail;
+ }
+
+ /*
+ * Finalize state in master rsb's now that all locks can be
+ * checked. This includes conversion resolution and lvb
+ * settings.
+ */
+
+ dlm_recover_rsbs(ls);
+ }
+
+ dlm_release_root_list(ls);
+
+ dlm_set_recover_status(ls, DLM_RS_DONE);
+ error = dlm_recover_done_wait(ls);
+ if (error) {
+ log_error(ls, "recover_done_wait failed %d", error);
+ goto fail;
+ }
+
+ dlm_clear_members_gone(ls);
+
+ error = enable_locking(ls, rv->seq);
+ if (error) {
+ log_error(ls, "enable_locking failed %d", error);
+ goto fail;
+ }
+
+ error = dlm_process_requestqueue(ls);
+ if (error) {
+ log_error(ls, "process_requestqueue failed %d", error);
+ goto fail;
+ }
+
+ error = dlm_recover_waiters_post(ls);
+ if (error) {
+ log_error(ls, "recover_waiters_post failed %d", error);
+ goto fail;
+ }
+
+ dlm_grant_after_purge(ls);
+
+ dlm_astd_wake();
+
+ log_debug(ls, "recover %"PRIx64" done: %u ms", rv->seq,
+ jiffies_to_msecs(jiffies - start));
+ up(&ls->ls_recoverd_active);
+
+ return 0;
+
+ fail:
+ dlm_release_root_list(ls);
+ log_debug(ls, "recover %"PRIx64" error %d", rv->seq, error);
+ up(&ls->ls_recoverd_active);
+ return error;
+}
+
+static void do_ls_recovery(struct dlm_ls *ls)
+{
+ struct dlm_recover *rv = NULL;
+
+ spin_lock(&ls->ls_recover_lock);
+ rv = ls->ls_recover_args;
+ ls->ls_recover_args = NULL;
+ clear_bit(LSFL_RECOVERY_STOP, &ls->ls_flags);
+ spin_unlock(&ls->ls_recover_lock);
+
+ if (rv) {
+ ls_recover(ls, rv);
+ kfree(rv->nodeids);
+ kfree(rv);
+ }
+}
+
+static int dlm_recoverd(void *arg)
+{
+ struct dlm_ls *ls;
+
+ ls = dlm_find_lockspace_local(arg);
+
+ while (!kthread_should_stop()) {
+ set_current_state(TASK_INTERRUPTIBLE);
+ if (!test_bit(LSFL_WORK, &ls->ls_flags))
+ schedule();
+ set_current_state(TASK_RUNNING);
+
+ if (test_and_clear_bit(LSFL_WORK, &ls->ls_flags))
+ do_ls_recovery(ls);
+ }
+
+ dlm_put_lockspace(ls);
+ return 0;
+}
+
+void dlm_recoverd_kick(struct dlm_ls *ls)
+{
+ set_bit(LSFL_WORK, &ls->ls_flags);
+ wake_up_process(ls->ls_recoverd_task);
+}
+
+int dlm_recoverd_start(struct dlm_ls *ls)
+{
+ struct task_struct *p;
+ int error = 0;
+
+ p = kthread_run(dlm_recoverd, ls, "dlm_recoverd");
+ if (IS_ERR(p))
+ error = PTR_ERR(p);
+ else
+ ls->ls_recoverd_task = p;
+ return error;
+}
+
+void dlm_recoverd_stop(struct dlm_ls *ls)
+{
+ kthread_stop(ls->ls_recoverd_task);
+}
+
+void dlm_recoverd_suspend(struct dlm_ls *ls)
+{
+ down(&ls->ls_recoverd_active);
+}
+
+void dlm_recoverd_resume(struct dlm_ls *ls)
+{
+ up(&ls->ls_recoverd_active);
+}
+