dlm: add recovery callbacks

These new callbacks notify the dlm user about lock recovery.
GFS2, and possibly others, need to be aware of when the dlm
will be doing lock recovery for a failed lockspace member.

In the past, this coordination has been done between dlm and
file system daemons in userspace, which then direct their
kernel counterparts.  These callbacks allow the same
coordination directly, and more simply.

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

1 files changed, 35 insertions, 8 deletions

diff --git a/fs/dlm/lockspace.c b/fs/dlm/lockspace.c
index 1441f04..a1ea25f 100644
--- a/fs/dlm/lockspace.c
+++ b/fs/dlm/lockspace.c
@@ -2,7 +2,7 @@
 *******************************************************************************
 **
 **  Copyright (C) Sistina Software, Inc.  1997-2003  All rights reserved.
-**  Copyright (C) 2004-2008 Red Hat, Inc.  All rights reserved.
+**  Copyright (C) 2004-2011 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
@@ -386,12 +386,15 @@ static void threads_stop(void)
 	dlm_lowcomms_stop();
 }
 
-static int new_lockspace(const char *name, int namelen, void **lockspace,
-			 uint32_t flags, int lvblen)
+static int new_lockspace(const char *name, const char *cluster,
+			 uint32_t flags, int lvblen,
+			 const struct dlm_lockspace_ops *ops, void *ops_arg,
+			 int *ops_result, dlm_lockspace_t **lockspace)
 {
 	struct dlm_ls *ls;
 	int i, size, error;
 	int do_unreg = 0;
+	int namelen = strlen(name);
 
 	if (namelen > DLM_LOCKSPACE_LEN)
 		return -EINVAL;
@@ -403,8 +406,24 @@ static int new_lockspace(const char *name, int namelen, void **lockspace,
 		return -EINVAL;
 
 	if (!dlm_user_daemon_available()) {
-		module_put(THIS_MODULE);
-		return -EUNATCH;
+		log_print("dlm user daemon not available");
+		error = -EUNATCH;
+		goto out;
+	}
+
+	if (ops && ops_result) {
+	       	if (!dlm_config.ci_recover_callbacks)
+			*ops_result = -EOPNOTSUPP;
+		else
+			*ops_result = 0;
+	}
+
+	if (dlm_config.ci_recover_callbacks && cluster &&
+	    strncmp(cluster, dlm_config.ci_cluster_name, DLM_LOCKSPACE_LEN)) {
+		log_print("dlm cluster name %s mismatch %s",
+			  dlm_config.ci_cluster_name, cluster);
+		error = -EBADR;
+		goto out;
 	}
 
 	error = 0;
@@ -442,6 +461,11 @@ static int new_lockspace(const char *name, int namelen, void **lockspace,
 	ls->ls_flags = 0;
 	ls->ls_scan_time = jiffies;
 
+	if (ops && dlm_config.ci_recover_callbacks) {
+		ls->ls_ops = ops;
+		ls->ls_ops_arg = ops_arg;
+	}
+
 	if (flags & DLM_LSFL_TIMEWARN)
 		set_bit(LSFL_TIMEWARN, &ls->ls_flags);
 
@@ -619,8 +643,10 @@ static int new_lockspace(const char *name, int namelen, void **lockspace,
 	return error;
 }
 
-int dlm_new_lockspace(const char *name, int namelen, void **lockspace,
-		      uint32_t flags, int lvblen)
+int dlm_new_lockspace(const char *name, const char *cluster,
+		      uint32_t flags, int lvblen,
+		      const struct dlm_lockspace_ops *ops, void *ops_arg,
+		      int *ops_result, dlm_lockspace_t **lockspace)
 {
 	int error = 0;
 
@@ -630,7 +656,8 @@ int dlm_new_lockspace(const char *name, int namelen, void **lockspace,
 	if (error)
 		goto out;
 
-	error = new_lockspace(name, namelen, lockspace, flags, lvblen);
+	error = new_lockspace(name, cluster, flags, lvblen, ops, ops_arg,
+			      ops_result, lockspace);
 	if (!error)
 		ls_count++;
 	if (error > 0)