[PATCH 44/62] ocfs2/dlm: Dumps the mles into a debugfs file

From: Mark Fasheh
Date: Wed Apr 02 2008 - 16:34:46 EST


From: Sunil Mushran <sunil.mushran@xxxxxxxxxx>

This patch dumps all mles it can fit in one page into a debugfs file.
Useful for debugging.

Signed-off-by: Sunil Mushran <sunil.mushran@xxxxxxxxxx>
Signed-off-by: Joel Becker <joel.becker@xxxxxxxxxx>
Signed-off-by: Mark Fasheh <mfasheh@xxxxxxxx>
---
fs/ocfs2/dlm/dlmdebug.c | 119 +++++++++++++++++++++++++++++++++++++++++++++++
fs/ocfs2/dlm/dlmdebug.h | 1 +
2 files changed, 120 insertions(+), 0 deletions(-)

diff --git a/fs/ocfs2/dlm/dlmdebug.c b/fs/ocfs2/dlm/dlmdebug.c
index cccb1ce..6de326b 100644
--- a/fs/ocfs2/dlm/dlmdebug.c
+++ b/fs/ocfs2/dlm/dlmdebug.c
@@ -302,6 +302,7 @@ static int stringify_lockname(const char *lockname, int locklen,
#define DLM_DEBUGFS_DIR "o2dlm"
#define DLM_DEBUGFS_DLM_STATE "dlm_state"
#define DLM_DEBUGFS_LOCKING_STATE "locking_state"
+#define DLM_DEBUGFS_MLE_STATE "mle_state"

/* begin - utils funcs */
static void dlm_debug_free(struct kref *kref)
@@ -395,6 +396,112 @@ static int debug_buffer_release(struct inode *inode, struct file *file)
}
/* end - util funcs */

+/* begin - debug mle funcs */
+static int dump_mle(struct dlm_master_list_entry *mle, char *buf, int len)
+{
+ int out = 0;
+ unsigned int namelen;
+ const char *name;
+ char *mle_type;
+
+ if (mle->type != DLM_MLE_MASTER) {
+ namelen = mle->u.name.len;
+ name = mle->u.name.name;
+ } else {
+ namelen = mle->u.res->lockname.len;
+ name = mle->u.res->lockname.name;
+ }
+
+ if (mle->type == DLM_MLE_BLOCK)
+ mle_type = "BLK";
+ else if (mle->type == DLM_MLE_MASTER)
+ mle_type = "MAS";
+ else
+ mle_type = "MIG";
+
+ out += stringify_lockname(name, namelen, buf + out, len - out);
+ out += snprintf(buf + out, len - out,
+ "\t%3s\tmas=%3u\tnew=%3u\tevt=%1d\tuse=%1d\tref=%3d\n",
+ mle_type, mle->master, mle->new_master,
+ !list_empty(&mle->hb_events),
+ !!mle->inuse,
+ atomic_read(&mle->mle_refs.refcount));
+
+ out += snprintf(buf + out, len - out, "Maybe=");
+ out += stringify_nodemap(mle->maybe_map, O2NM_MAX_NODES,
+ buf + out, len - out);
+ out += snprintf(buf + out, len - out, "\n");
+
+ out += snprintf(buf + out, len - out, "Vote=");
+ out += stringify_nodemap(mle->vote_map, O2NM_MAX_NODES,
+ buf + out, len - out);
+ out += snprintf(buf + out, len - out, "\n");
+
+ out += snprintf(buf + out, len - out, "Response=");
+ out += stringify_nodemap(mle->response_map, O2NM_MAX_NODES,
+ buf + out, len - out);
+ out += snprintf(buf + out, len - out, "\n");
+
+ out += snprintf(buf + out, len - out, "Node=");
+ out += stringify_nodemap(mle->node_map, O2NM_MAX_NODES,
+ buf + out, len - out);
+ out += snprintf(buf + out, len - out, "\n");
+
+ out += snprintf(buf + out, len - out, "\n");
+
+ return out;
+}
+
+static int debug_mle_print(struct dlm_ctxt *dlm, struct debug_buffer *db)
+{
+ struct dlm_master_list_entry *mle;
+ int out = 0;
+ unsigned long total = 0;
+
+ out += snprintf(db->buf + out, db->len - out,
+ "Dumping MLEs for Domain: %s\n", dlm->name);
+
+ spin_lock(&dlm->master_lock);
+ list_for_each_entry(mle, &dlm->master_list, list) {
+ ++total;
+ if (db->len - out < 200)
+ continue;
+ out += dump_mle(mle, db->buf + out, db->len - out);
+ }
+ spin_unlock(&dlm->master_lock);
+
+ out += snprintf(db->buf + out, db->len - out,
+ "Total on list: %ld\n", total);
+ return out;
+}
+
+static int debug_mle_open(struct inode *inode, struct file *file)
+{
+ struct dlm_ctxt *dlm = inode->i_private;
+ struct debug_buffer *db;
+
+ db = debug_buffer_allocate();
+ if (!db)
+ goto bail;
+
+ db->len = debug_mle_print(dlm, db);
+
+ file->private_data = db;
+
+ return 0;
+bail:
+ return -ENOMEM;
+}
+
+static struct file_operations debug_mle_fops = {
+ .open = debug_mle_open,
+ .release = debug_buffer_release,
+ .read = debug_buffer_read,
+ .llseek = debug_buffer_llseek,
+};
+
+/* end - debug mle funcs */
+
/* begin - debug lockres funcs */
static int dump_lock(struct dlm_lock *lock, int list_type, char *buf, int len)
{
@@ -789,6 +896,16 @@ int dlm_debug_init(struct dlm_ctxt *dlm)
goto bail;
}

+ /* for dumping mles */
+ dc->debug_mle_dentry = debugfs_create_file(DLM_DEBUGFS_MLE_STATE,
+ S_IFREG|S_IRUSR,
+ dlm->dlm_debugfs_subroot,
+ dlm, &debug_mle_fops);
+ if (!dc->debug_mle_dentry) {
+ mlog_errno(-ENOMEM);
+ goto bail;
+ }
+
dlm_debug_get(dc);
return 0;

@@ -802,6 +919,8 @@ void dlm_debug_shutdown(struct dlm_ctxt *dlm)
struct dlm_debug_ctxt *dc = dlm->dlm_debug_ctxt;

if (dc) {
+ if (dc->debug_mle_dentry)
+ debugfs_remove(dc->debug_mle_dentry);
if (dc->debug_lockres_dentry)
debugfs_remove(dc->debug_lockres_dentry);
if (dc->debug_state_dentry)
diff --git a/fs/ocfs2/dlm/dlmdebug.h b/fs/ocfs2/dlm/dlmdebug.h
index 7c5b2b0..cbc69f2 100644
--- a/fs/ocfs2/dlm/dlmdebug.h
+++ b/fs/ocfs2/dlm/dlmdebug.h
@@ -31,6 +31,7 @@ struct dlm_debug_ctxt {
struct kref debug_refcnt;
struct dentry *debug_state_dentry;
struct dentry *debug_lockres_dentry;
+ struct dentry *debug_mle_dentry;
};

struct debug_buffer {
--
1.5.4.1

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