2 files changed, 14 insertions, 11 deletions

diff --git a/fs/dcache.c b/fs/dcache.c
index 1710d2484fd9..c6fd1f27da57 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -174,9 +174,12 @@ static struct dentry *d_kill(struct dentry *dentry)
         dentry_stat.nr_dentry--;        /* For d_free, below */
         /*drops the locks, at that point nobody can reach this dentry */
         dentry_iput(dentry);
-        parent = dentry->d_parent;
+        if (IS_ROOT(dentry))
+                parent = NULL;
+        else
+                parent = dentry->d_parent;
         d_free(dentry);
-        return dentry == parent ? NULL : parent;
+        return parent;
 }
 
 /* 
@@ -666,11 +669,12 @@ static void shrink_dcache_for_umount_subtree(struct dentry *dentry)
                                 BUG();
                         }
 
-                        parent = dentry->d_parent;
-                        if (parent == dentry)
+                        if (IS_ROOT(dentry))
                                 parent = NULL;
-                        else
+                        else {
+                                parent = dentry->d_parent;
                                 atomic_dec(&parent->d_count);
+                        }
 
                         list_del(&dentry->d_u.d_child);
                         detached++;
@@ -1723,7 +1727,7 @@ static int d_isparent(struct dentry *p1, struct dentry *p2)
 {
         struct dentry *p;
 
-        for (p = p2; p->d_parent != p; p = p->d_parent) {
+        for (p = p2; !IS_ROOT(p); p = p->d_parent) {
                 if (p->d_parent == p1)
                         return 1;
         }
@@ -2168,10 +2172,9 @@ int is_subdir(struct dentry * new_dentry, struct dentry * old_dentry)
                 seq = read_seqbegin(&rename_lock);
                 for (;;) {
                         if (new_dentry != old_dentry) {
-                                struct dentry * parent = new_dentry->d_parent;
-                                if (parent == new_dentry)
+                                if (IS_ROOT(new_dentry))
                                         break;
-                                new_dentry = parent;
+                                new_dentry = new_dentry->d_parent;
                                 continue;
                         }
                         result = 1;
diff --git a/fs/namei.c b/fs/namei.c
index 2b8f823eda44..068a9e50c8c0 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -1454,7 +1454,7 @@ struct dentry *lock_rename(struct dentry *p1, struct dentry *p2)
 
         mutex_lock(&p1->d_inode->i_sb->s_vfs_rename_mutex);
 
-        for (p = p1; p->d_parent != p; p = p->d_parent) {
+        for (p = p1; !IS_ROOT(p); p = p->d_parent) {
                 if (p->d_parent == p2) {
                         mutex_lock_nested(&p2->d_inode->i_mutex, I_MUTEX_PARENT);
                         mutex_lock_nested(&p1->d_inode->i_mutex, I_MUTEX_CHILD);
@@ -1462,7 +1462,7 @@ struct dentry *lock_rename(struct dentry *p1, struct dentry *p2)
                 }
         }
 
-        for (p = p2; p->d_parent != p; p = p->d_parent) {
+        for (p = p2; !IS_ROOT(p); p = p->d_parent) {
                 if (p->d_parent == p1) {
                         mutex_lock_nested(&p1->d_inode->i_mutex, I_MUTEX_PARENT);
                         mutex_lock_nested(&p2->d_inode->i_mutex, I_MUTEX_CHILD);