linux-imx

/*

 *

 * Copyright (C) 2011 Novell Inc.

 *

 * This program is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 as published by

 * the Free Software Foundation.

 */

​

#include <linux/fs.h>

#include <linux/slab.h>

#include <linux/namei.h>

#include <linux/file.h>

#include <linux/xattr.h>

#include <linux/rbtree.h>

#include <linux/security.h>

#include <linux/cred.h>

#include <linux/ratelimit.h>

#include "overlayfs.h"

​

struct ovl_cache_entry {

    unsigned int len;

    unsigned int type;

    u64 real_ino;

    u64 ino;

    struct list_head l_node;

    struct rb_node node;

    struct ovl_cache_entry *next_maybe_whiteout;

    bool is_upper;

    bool is_whiteout;

    char name[];

};

​

struct ovl_dir_cache {

    long refcount;

    u64 version;

    struct list_head entries;

    struct rb_root root;

};

​

struct ovl_readdir_data {

    struct dir_context ctx;

    struct dentry *dentry;

    bool is_lowest;

    struct rb_root *root;

    struct list_head *list;

    struct list_head middle;

    struct ovl_cache_entry *first_maybe_whiteout;

    int count;

    int err;

    bool is_upper;

    bool d_type_supported;

};

​

struct ovl_dir_file {

    bool is_real;

    bool is_upper;

    struct ovl_dir_cache *cache;

    struct list_head *cursor;

    struct file *realfile;

    struct file *upperfile;

};

​

static struct ovl_cache_entry *ovl_cache_entry_from_node(struct rb_node *n)

{

    return rb_entry(n, struct ovl_cache_entry, node);

}

​

static bool ovl_cache_entry_find_link(const char *name, int len,

                      struct rb_node ***link,

                      struct rb_node **parent)

{

    bool found = false;

    struct rb_node **newp = *link;

​

    while (!found && *newp) {

        int cmp;

        struct ovl_cache_entry *tmp;

​

        *parent = *newp;

        tmp = ovl_cache_entry_from_node(*newp);

        cmp = strncmp(name, tmp->name, len);

        if (cmp > 0)

            newp = &tmp->node.rb_right;

        else if (cmp < 0 || len < tmp->len)

            newp = &tmp->node.rb_left;

        else

            found = true;

    }

    *link = newp;

​

    return found;