ocfs2/dlm: Dumps the mles into a debugfs file

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@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>

diff --git a/fs/ocfs2/dlm/dlmdebug.c b/fs/ocfs2/dlm/dlmdebug.c
index cccb1ce..6de326b 100644 (file)
--- 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 (file)
--- 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 {