[Ocfs2-devel] [PATCH 1/1] ocfs2: add dlm context printing in dlm debug

[wengang wang]

add dlm context printing support in dlm debugging

- echo 'd' >/proc/fs/ocfs2_dlm/debug prints all dlm contexts.
- echo 'D UUID' >/proc/fs/ocfs2_dlm/debug prints the context of the specified dlm

Signed-off-by: wengang wang <wen.gang.wang at oracle.com>
Singed-off-by: Tao Ma <tao.ma at oracle.com>
---
dlmdebug.c |  104 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 104 insertions(+)

--- ./fs/ocfs2/dlm/dlmdebug.c.orig	2008-01-09 06:39:18.000000000 -0500
+++ ./fs/ocfs2/dlm/dlmdebug.c	2008-01-10 03:17:13.000000000 -0500
@@ -61,6 +61,10 @@
 static int dlm_proc_stats(char *page, char **start, off_t off,
 			  int count, int *eof, void *data);
 
+static void __dlm_print_one_dlm_ctxt(struct dlm_ctxt *dlm);
+static int dlm_dump_one_dlm_ctxt(const char __user *buf, unsigned int count);
+static int dlm_dump_all_dlm_ctxts(const char __user *buf, unsigned int count);
+
 typedef int (dlm_debug_func_t)(const char __user *data, unsigned int len);
 
 struct dlm_debug_funcs
@@ -75,6 +79,8 @@
 	{ 'm', dlm_dump_all_mles },
 	{ 'p', dlm_dump_all_purge_lists  },
 	{ 'M', dlm_trigger_migration },
+	{ 'd', dlm_dump_all_dlm_ctxts },
+	{ 'D', dlm_dump_one_dlm_ctxt },
 };
 static int dlm_debug_map_sz = (sizeof(dlm_debug_map) /
 			       sizeof(struct dlm_debug_funcs));
@@ -210,7 +216,105 @@
 	spin_unlock(&dlm_domain_lock);
 	return len;
 }
+static void __dlm_print_one_dlm_ctxt(struct dlm_ctxt *dlm)
+{
+	mlog(ML_NOTICE, "purge_count: %d, name: %s\n",
+		dlm->purge_count, dlm->name);
+	mlog(ML_NOTICE, "node_num: %u, key: %u\n",
+		dlm->node_num, dlm->key);
+	mlog(ML_NOTICE, "joining_node: %u, reco->new_master: %u\n",
+		dlm->joining_node, dlm->reco.new_master);
+	mlog(ML_NOTICE, "reco->dead_node: %u, reco->state: %u\n",
+		dlm->reco.dead_node, dlm->reco.state);
+	mlog(ML_NOTICE, "dlm_state: %d, num_joins: %d\n",
+		dlm->dlm_state, dlm->num_joins);
+}
+static int dlm_dump_all_dlm_ctxts(const char __user *data, unsigned int len)
+{
+	struct dlm_ctxt *dlm;
+	struct list_head *iter;
+
+	mlog(ML_NOTICE, "dumping ALL dlm contexts for node %s\n",
+		system_utsname.nodename);
+	spin_lock(&dlm_domain_lock);
+	list_for_each(iter, &dlm_domains) {
+		dlm = list_entry (iter, struct dlm_ctxt, list);
+		spin_lock(&dlm->spinlock);
+		__dlm_print_one_dlm_ctxt(dlm);
+		spin_unlock(&dlm->spinlock);
+	}
+	spin_unlock(&dlm_domain_lock);
+	return len;
+}
+static int dlm_dump_one_dlm_ctxt(const char __user *data, unsigned int len)
+{
+	struct dlm_ctxt *dlm;
+	char *buf = NULL, *tmp;
+	int ret = -EINVAL;
+
+	mlog(ML_NOTICE, "dumping one dlm context for node %s\n",
+		system_utsname.nodename);
+
+	if (len >= PAGE_SIZE-1) {
+		mlog(ML_ERROR, "user passed too much data: %d bytes\n", len);
+		goto leave;
+	}
+	if (len < 4) {
+		mlog(ML_ERROR, "user passed too little data: %d bytes\n", len);
+		goto leave;
+	}
+	buf = kmalloc(len+1, GFP_NOFS);
+	if (!buf) {
+		mlog(ML_ERROR, "could not alloc %d bytes\n", len+1);
+		ret = -ENOMEM;
+		goto leave;
+	}
+	if (strncpy_from_user(buf, data, len) < len) {
+		mlog(ML_ERROR, "failed to get all user data\n");
+		goto leave;
+	}
+	buf[len] = '\0';
+	mlog(0, "got this data from user: %s\n", buf);
+
+	tmp = buf+1;
+	if (*tmp != ' ') {
+		mlog(ML_ERROR, "bad data\n");
+		goto leave;
+	}
+	tmp ++;
+
+	while (*tmp != '\0') {
+		if (*tmp == '\n' || *tmp == '\r') {
+			*tmp = '\0';
+			break;
+		}
+		tmp ++;
+	}
 
+	spin_lock(&dlm_domain_lock);
+	dlm = __dlm_lookup_domain(buf+2);
+	spin_unlock(&dlm_domain_lock);
+	if (dlm) {
+		if (!dlm_grab(dlm)) {
+			mlog(ML_ERROR, "bad dlm!\n");
+			goto leave;
+		}
+		spin_lock(&dlm_domain_lock);
+		spin_lock(&dlm->spinlock);
+		__dlm_print_one_dlm_ctxt(dlm);
+		spin_unlock(&dlm->spinlock);
+		spin_unlock(&dlm_domain_lock);
+		dlm_put(dlm);
+	} else {
+		mlog(ML_ERROR, "no such dlm: %s(%lu)\n", buf+2, strlen(buf+2));
+		goto leave;
+	}
+	ret = len;
+leave:
+	if (buf)
+		kfree(buf);
+	return ret;
+}
 static int dlm_dump_one_lock_resource(const char __user *data,
 				       unsigned int len)
 {