1 files changed, 32 insertions, 5 deletions

diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c
index 49bd219275db..9ee956864445 100644
--- a/fs/sysfs/dir.c
+++ b/fs/sysfs/dir.c
@@ -50,6 +50,32 @@ static struct sysfs_dirent * sysfs_new_dirent(struct sysfs_dirent * parent_sd,
         return sd;
 }
 
+/**
+ *
+ * Return -EEXIST if there is already a sysfs element with the same name for
+ * the same parent.
+ *
+ * called with parent inode's i_mutex held
+ */
+int sysfs_dirent_exist(struct sysfs_dirent *parent_sd,
+                          const unsigned char *new)
+{
+        struct sysfs_dirent * sd;
+
+        list_for_each_entry(sd, &parent_sd->s_children, s_sibling) {
+                if (sd->s_element) {
+                        const unsigned char *existing = sysfs_get_name(sd);
+                        if (strcmp(existing, new))
+                                continue;
+                        else
+                                return -EEXIST;
+                }
+        }
+
+        return 0;
+}
+
+
 int sysfs_make_dirent(struct sysfs_dirent * parent_sd, struct dentry * dentry,
                         void * element, umode_t mode, int type)
 {
@@ -102,7 +128,11 @@ static int create_dir(struct kobject * k, struct dentry * p,
         mutex_lock(&p->d_inode->i_mutex);
         *d = lookup_one_len(n, p, strlen(n));
         if (!IS_ERR(*d)) {
-                error = sysfs_make_dirent(p->d_fsdata, *d, k, mode, SYSFS_DIR);
+                if (sysfs_dirent_exist(p->d_fsdata, n))
+                        error = -EEXIST;
+                else
+                        error = sysfs_make_dirent(p->d_fsdata, *d, k, mode,
+                                                                SYSFS_DIR);
                 if (!error) {
                         error = sysfs_create(*d, mode, init_dir);
                         if (!error) {
@@ -302,6 +332,7 @@ void sysfs_remove_dir(struct kobject * kobj)
          * Drop reference from dget() on entrance.
          */
         dput(dentry);
+        kobj->dentry = NULL;
 }
 
 int sysfs_rename_dir(struct kobject * kobj, const char *new_name)
@@ -479,7 +510,3 @@ struct file_operations sysfs_dir_operations = {
         .read           = generic_read_dir,
         .readdir        = sysfs_readdir,
 };
-
-EXPORT_SYMBOL_GPL(sysfs_create_dir);
-EXPORT_SYMBOL_GPL(sysfs_remove_dir);
-EXPORT_SYMBOL_GPL(sysfs_rename_dir);