configfs: Prevent duplicate subsystem names.
[linux-2.6.git] / fs / configfs / dir.c
index 5f95218..816e8ef 100644 (file)
@@ -86,6 +86,32 @@ static struct configfs_dirent *configfs_new_dirent(struct configfs_dirent * pare
        return sd;
 }
 
+/*
+ *
+ * Return -EEXIST if there is already a configfs element with the same
+ * name for the same parent.
+ *
+ * called with parent inode's i_mutex held
+ */
+int configfs_dirent_exists(struct configfs_dirent *parent_sd,
+                          const unsigned char *new)
+{
+       struct configfs_dirent * sd;
+
+       list_for_each_entry(sd, &parent_sd->s_children, s_sibling) {
+               if (sd->s_element) {
+                       const unsigned char *existing = configfs_get_name(sd);
+                       if (strcmp(existing, new))
+                               continue;
+                       else
+                               return -EEXIST;
+               }
+       }
+
+       return 0;
+}
+
+
 int configfs_make_dirent(struct configfs_dirent * parent_sd,
                         struct dentry * dentry, void * element,
                         umode_t mode, int type)
@@ -136,8 +162,10 @@ static int create_dir(struct config_item * k, struct dentry * p,
        int error;
        umode_t mode = S_IFDIR| S_IRWXU | S_IRUGO | S_IXUGO;
 
-       error = configfs_make_dirent(p->d_fsdata, d, k, mode,
-                                    CONFIGFS_DIR);
+       error = configfs_dirent_exists(p->d_fsdata, d->d_name.name);
+       if (!error)
+               error = configfs_make_dirent(p->d_fsdata, d, k, mode,
+                                            CONFIGFS_DIR);
        if (!error) {
                error = configfs_create(d, mode, init_dir);
                if (!error) {
@@ -211,7 +239,7 @@ static void remove_dir(struct dentry * d)
        struct configfs_dirent * sd;
 
        sd = d->d_fsdata;
-       list_del_init(&sd->s_sibling);
+       list_del_init(&sd->s_sibling);
        configfs_put(sd);
        if (d->d_inode)
                simple_rmdir(parent->d_inode,d);
@@ -330,7 +358,7 @@ static int configfs_detach_prep(struct dentry *dentry)
 
                        ret = configfs_detach_prep(sd->s_dentry);
                        if (!ret)
-                               continue;
+                               continue;
                } else
                        ret = -ENOTEMPTY;
 
@@ -931,7 +959,7 @@ int configfs_rename_dir(struct config_item * item, const char *new_name)
 
        new_dentry = lookup_one_len(new_name, parent, strlen(new_name));
        if (!IS_ERR(new_dentry)) {
-               if (!new_dentry->d_inode) {
+               if (!new_dentry->d_inode) {
                        error = config_item_set_name(item, "%s", new_name);
                        if (!error) {
                                d_add(new_dentry, NULL);
@@ -1009,8 +1037,7 @@ static int configfs_readdir(struct file * filp, void * dirent, filldir_t filldir
                        /* fallthrough */
                default:
                        if (filp->f_pos == 2) {
-                               list_del(q);
-                               list_add(q, &parent_sd->s_children);
+                               list_move(q, &parent_sd->s_children);
                        }
                        for (p=q->next; p!= &parent_sd->s_children; p=p->next) {
                                struct configfs_dirent *next;
@@ -1033,8 +1060,7 @@ static int configfs_readdir(struct file * filp, void * dirent, filldir_t filldir
                                                 dt_type(next)) < 0)
                                        return 0;
 
-                               list_del(q);
-                               list_add(q, p);
+                               list_move(q, p);
                                p = q;
                                filp->f_pos++;
                        }