Function dfs_file_readlink

components/dfs/dfs_v2/src/dfs_file.c:2034–2094

* @brief Read the contents of a symbolic link * * This function reads the contents of the symbolic link specified by path into * the buffer provided. * * @param[in] path The path to the symbolic link to be read * @param[out] buf Buffer to store the link contents * @param[in] bufsize Size of the buffer in bytes * * @return int Number of bytes placed in buffer on success, or negative error

 *         -RT_ERROR for general errors
 */
int dfs_file_readlink(const char *path, char *buf, int bufsize)
{
    int ret = -RT_ERROR;
    char *fullpath = RT_NULL;
    struct dfs_mnt *mnt = RT_NULL;
    struct dfs_dentry *dentry = RT_NULL;

    fullpath = dfs_normalize_path(NULL, path);
    if (fullpath)
    {
        DLOG(msg, "dfs_file", "mnt", DLOG_MSG, "dfs_mnt_lookup(%s)", fullpath);
        mnt = dfs_mnt_lookup(fullpath);
        if (mnt)
        {
            char *tmp = dfs_file_realpath(&mnt, fullpath, DFS_REALPATH_EXCEPT_LAST);
            if (tmp)
            {
                rt_free(fullpath);
                fullpath = tmp;
            }

            DLOG(msg, "dfs_file", "dentry", DLOG_MSG, "dfs_dentry_lookup(mnt, %s)", fullpath);
            dentry = dfs_dentry_lookup(mnt, fullpath, 0);
            if (dentry)
            {
                if (mnt->fs_ops->readlink)
                {
                    if (dfs_is_mounted(mnt) == 0)
                    {
                        ret = mnt->fs_ops->readlink(dentry, buf, bufsize);
                    }
                }
                else
                {
                    ret = -ENOSYS;
                }

                /* release this dentry */
                dfs_dentry_unref(dentry);
            }
            else
            {
                /* no this entry */
                ret = -ENOENT;
            }
        }
        else
        {
            ret = -ENOENT;
        }

        /* release fullpath */
        rt_free(fullpath);
    }
    else
    {
        ret = -ENOMEM;
    }