ocfs2/dlm: Dumps the purgelist into a debugfs file

This patch dumps all the lockres' on the purgelist 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 6de326bf603a0d6187718a92d4ed3edf9251e23a..a109005f70da01f3b26bf40fdc208d5d311bb4ed 100644 (file)
--- a/fs/ocfs2/dlm/dlmdebug.c
+++ b/fs/ocfs2/dlm/dlmdebug.c
@@ -303,6 +303,7 @@ static int stringify_lockname(const char *lockname, int locklen,
 #define DLM_DEBUGFS_DLM_STATE                  "dlm_state"
 #define DLM_DEBUGFS_LOCKING_STATE              "locking_state"
 #define DLM_DEBUGFS_MLE_STATE                  "mle_state"
+#define DLM_DEBUGFS_PURGE_LIST                 "purge_list"
 
 /* begin - utils funcs */
 static void dlm_debug_free(struct kref *kref)
@@ -396,6 +397,63 @@ static int debug_buffer_release(struct inode *inode, struct file *file)
 }
 /* end - util funcs */
 
+/* begin - purge list funcs */
+static int debug_purgelist_print(struct dlm_ctxt *dlm, struct debug_buffer *db)
+{
+       struct dlm_lock_resource *res;
+       int out = 0;
+       unsigned long total = 0;
+
+       out += snprintf(db->buf + out, db->len - out,
+                       "Dumping Purgelist for Domain: %s\n", dlm->name);
+
+       spin_lock(&dlm->spinlock);
+       list_for_each_entry(res, &dlm->purge_list, purge) {
+               ++total;
+               if (db->len - out < 100)
+                       continue;
+               spin_lock(&res->spinlock);
+               out += stringify_lockname(res->lockname.name,
+                                         res->lockname.len,
+                                         db->buf + out, db->len - out);
+               out += snprintf(db->buf + out, db->len - out, "\t%ld\n",
+                               (jiffies - res->last_used)/HZ);
+               spin_unlock(&res->spinlock);
+       }
+       spin_unlock(&dlm->spinlock);
+
+       out += snprintf(db->buf + out, db->len - out,
+                       "Total on list: %ld\n", total);
+
+       return out;
+}
+
+static int debug_purgelist_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_purgelist_print(dlm, db);
+
+       file->private_data = db;
+
+       return 0;
+bail:
+       return -ENOMEM;
+}
+
+static struct file_operations debug_purgelist_fops = {
+       .open =         debug_purgelist_open,
+       .release =      debug_buffer_release,
+       .read =         debug_buffer_read,
+       .llseek =       debug_buffer_llseek,
+};
+/* end - purge list funcs */
+
 /* begin - debug mle funcs */
 static int dump_mle(struct dlm_master_list_entry *mle, char *buf, int len)
 {
@@ -906,6 +964,17 @@ int dlm_debug_init(struct dlm_ctxt *dlm)
                goto bail;
        }
 
+       /* for dumping lockres on the purge list */
+       dc->debug_purgelist_dentry =
+                       debugfs_create_file(DLM_DEBUGFS_PURGE_LIST,
+                                           S_IFREG|S_IRUSR,
+                                           dlm->dlm_debugfs_subroot,
+                                           dlm, &debug_purgelist_fops);
+       if (!dc->debug_purgelist_dentry) {
+               mlog_errno(-ENOMEM);
+               goto bail;
+       }
+
        dlm_debug_get(dc);
        return 0;
 
@@ -919,6 +988,8 @@ void dlm_debug_shutdown(struct dlm_ctxt *dlm)
        struct dlm_debug_ctxt *dc = dlm->dlm_debug_ctxt;
 
        if (dc) {
+               if (dc->debug_purgelist_dentry)
+                       debugfs_remove(dc->debug_purgelist_dentry);
                if (dc->debug_mle_dentry)
                        debugfs_remove(dc->debug_mle_dentry);
                if (dc->debug_lockres_dentry)

diff --git a/fs/ocfs2/dlm/dlmdebug.h b/fs/ocfs2/dlm/dlmdebug.h
index cbc69f295782043c61f6f15c8289f75d413ef54c..8857743e8f32b3b97f375ee98c48c7030ef0f642 100644 (file)
--- a/fs/ocfs2/dlm/dlmdebug.h
+++ b/fs/ocfs2/dlm/dlmdebug.h
@@ -32,6 +32,7 @@ struct dlm_debug_ctxt {
        struct dentry *debug_state_dentry;
        struct dentry *debug_lockres_dentry;
        struct dentry *debug_mle_dentry;
+       struct dentry *debug_purgelist_dentry;
 };
 
 struct debug_buffer {