ocfs2/dlm: fix memory leak of dlm_debug_ctxt

dlm_debug_ctxt->debug_refcnt is initialized to 1 and then increased to 2
by dlm_debug_get in dlm_debug_init.  But dlm_debug_put is called only
once in dlm_debug_shutdown during unregister dlm, which leads to
dlm_debug_ctxt leaked.

Link: http://lkml.kernel.org/r/577BB755.4030900@huawei.com
Signed-off-by: Joseph Qi <joseph.qi@huawei.com>
Reviewed-by: Jiufei Xue <xuejiufei@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2 files changed, 2 insertions, 25 deletions

diff --git a/fs/ocfs2/dlm/dlmdebug.c b/fs/ocfs2/dlm/dlmdebug.c
index 825136070d2c..e7b760deefae 100644
--- a/fs/ocfs2/dlm/dlmdebug.c
+++ b/fs/ocfs2/dlm/dlmdebug.c
@@ -347,26 +347,6 @@ static struct dentry *dlm_debugfs_root;
 #define DLM_DEBUGFS_PURGE_LIST                  "purge_list"
 
 /* begin - utils funcs */
-static void dlm_debug_free(struct kref *kref)
-{
-        struct dlm_debug_ctxt *dc;
-
-        dc = container_of(kref, struct dlm_debug_ctxt, debug_refcnt);
-
-        kfree(dc);
-}
-
-static void dlm_debug_put(struct dlm_debug_ctxt *dc)
-{
-        if (dc)
-                kref_put(&dc->debug_refcnt, dlm_debug_free);
-}
-
-static void dlm_debug_get(struct dlm_debug_ctxt *dc)
-{
-        kref_get(&dc->debug_refcnt);
-}
-
 static int debug_release(struct inode *inode, struct file *file)
 {
         free_page((unsigned long)file->private_data);
@@ -932,11 +912,9 @@ int dlm_debug_init(struct dlm_ctxt *dlm)
                 goto bail;
         }
 
-        dlm_debug_get(dc);
         return 0;
 
 bail:
-        dlm_debug_shutdown(dlm);
         return -ENOMEM;
 }
 
@@ -949,7 +927,8 @@ void dlm_debug_shutdown(struct dlm_ctxt *dlm)
                 debugfs_remove(dc->debug_mle_dentry);
                 debugfs_remove(dc->debug_lockres_dentry);
                 debugfs_remove(dc->debug_state_dentry);
-                dlm_debug_put(dc);
+                kfree(dc);
+                dc = NULL;
         }
 }
 
@@ -969,7 +948,6 @@ int dlm_create_debugfs_subroot(struct dlm_ctxt *dlm)
                 mlog_errno(-ENOMEM);
                 goto bail;
         }
-        kref_init(&dlm->dlm_debug_ctxt->debug_refcnt);
 
         return 0;
 bail:
diff --git a/fs/ocfs2/dlm/dlmdebug.h b/fs/ocfs2/dlm/dlmdebug.h
index 1f27c4812d1a..5ced5482e7d3 100644
--- a/fs/ocfs2/dlm/dlmdebug.h
+++ b/fs/ocfs2/dlm/dlmdebug.h
@@ -30,7 +30,6 @@ void dlm_print_one_mle(struct dlm_master_list_entry *mle);
 #ifdef CONFIG_DEBUG_FS
 
 struct dlm_debug_ctxt {
-        struct kref debug_refcnt;
         struct dentry *debug_state_dentry;
         struct dentry *debug_lockres_dentry;
         struct dentry *debug_mle_dentry;