dlm: fixes for nodir mode

The "nodir" mode (statically assign master nodes instead
of using the resource directory) has always been highly
experimental, and never seriously used.  This commit
fixes a number of problems, making nodir much more usable.

- Major change to recovery: recover all locks and restart
  all in-progress operations after recovery.  In some
  cases it's not possible to know which in-progess locks
  to recover, so recover all.  (Most require recovery
  in nodir mode anyway since rehashing changes most
  master nodes.)

- Change the way nodir mode is enabled, from a command
  line mount arg passed through gfs2, into a sysfs
  file managed by dlm_controld, consistent with the
  other config settings.

- Allow recovering MSTCPY locks on an rsb that has not
  yet been turned into a master copy.

- Ignore RCOM_LOCK and RCOM_LOCK_REPLY recovery messages
  from a previous, aborted recovery cycle.  Base this
  on the local recovery status not being in the state
  where any nodes should be sending LOCK messages for the
  current recovery cycle.

- Hold rsb lock around dlm_purge_mstcpy_locks() because it
  may run concurrently with dlm_recover_master_copy().

- Maintain highbast on process-copy lkb's (in addition to
  the master as is usual), because the lkb can switch
  back and forth between being a master and being a
  process copy as the master node changes in recovery.

- When recovering MSTCPY locks, flag rsb's that have
  non-empty convert or waiting queues for granting
  at the end of recovery.  (Rename flag from LOCKS_PURGED
  to RECOVER_GRANT and similar for the recovery function,
  because it's not only resources with purged locks
  that need grant a grant attempt.)

- Replace a couple of unnecessary assertion panics with
  error messages.

Signed-off-by: David Teigland <teigland@redhat.com>

1 files changed, 20 insertions, 0 deletions

diff --git a/fs/dlm/lockspace.c b/fs/dlm/lockspace.c
index a1ea25face828..ca506abbdd3b8 100644
--- a/fs/dlm/lockspace.c
+++ b/fs/dlm/lockspace.c
@@ -74,6 +74,19 @@ static ssize_t dlm_id_store(struct dlm_ls *ls, const char *buf, size_t len)
 	return len;
 }
 
+static ssize_t dlm_nodir_show(struct dlm_ls *ls, char *buf)
+{
+	return snprintf(buf, PAGE_SIZE, "%u\n", dlm_no_directory(ls));
+}
+
+static ssize_t dlm_nodir_store(struct dlm_ls *ls, const char *buf, size_t len)
+{
+	int val = simple_strtoul(buf, NULL, 0);
+	if (val == 1)
+		set_bit(LSFL_NODIR, &ls->ls_flags);
+	return len;
+}
+
 static ssize_t dlm_recover_status_show(struct dlm_ls *ls, char *buf)
 {
 	uint32_t status = dlm_recover_status(ls);
@@ -107,6 +120,12 @@ static struct dlm_attr dlm_attr_id = {
 	.store = dlm_id_store
 };
 
+static struct dlm_attr dlm_attr_nodir = {
+	.attr  = {.name = "nodir", .mode = S_IRUGO | S_IWUSR},
+	.show  = dlm_nodir_show,
+	.store = dlm_nodir_store
+};
+
 static struct dlm_attr dlm_attr_recover_status = {
 	.attr  = {.name = "recover_status", .mode = S_IRUGO},
 	.show  = dlm_recover_status_show
@@ -121,6 +140,7 @@ static struct attribute *dlm_attrs[] = {
 	&dlm_attr_control.attr,
 	&dlm_attr_event.attr,
 	&dlm_attr_id.attr,
+	&dlm_attr_nodir.attr,
 	&dlm_attr_recover_status.attr,
 	&dlm_attr_recover_nodeid.attr,
 	NULL,