Function dfs_fdtable_dup

components/dfs/dfs_v2/src/dfs.c:569–623

* @brief Dup the specified fd_src from fdt_src to fdt_dst. * * @param[out] fdt_dst is the fd table for destination, if empty, use global (_fdtab). * * @param[in] fdt_src is the fd table for source, if empty, use global (_fdtab). * * @param[in] fd_src is the fd in the designate fdt_src table. * * @return -1 on failed or the allocated file descriptor. */

 * @return -1 on failed or the allocated file descriptor.
 */
int dfs_fdtable_dup(struct dfs_fdtable *fdt_dst, struct dfs_fdtable *fdt_src, int fd_src)
{
    int newfd = -1;

    if (dfs_file_lock() != RT_EOK)
    {
        return -RT_ENOSYS;
    }

    if (fdt_src == NULL)
    {
        fdt_src = &_fdtab;
    }

    if (fdt_dst == NULL)
    {
        fdt_dst = &_fdtab;
    }

    /* check fd */
    if ((fd_src < 0) || (fd_src >= fdt_src->maxfd))
    {
        goto _EXIT;
    }
    if (!fdt_src->fds[fd_src])
    {
        goto _EXIT;
    }

    /* get a new fd*/
    newfd = fdt_fd_new(fdt_dst);
    if (newfd >= 0)
    {
        fdt_dst->fds[newfd]->mode = fdt_src->fds[fd_src]->mode;
        fdt_dst->fds[newfd]->flags = fdt_src->fds[fd_src]->flags;
        fdt_dst->fds[newfd]->fops = fdt_src->fds[fd_src]->fops;
        fdt_dst->fds[newfd]->dentry = dfs_dentry_ref(fdt_src->fds[fd_src]->dentry);
        fdt_dst->fds[newfd]->vnode = fdt_src->fds[fd_src]->vnode;
        fdt_dst->fds[newfd]->mmap_context = RT_NULL;
        fdt_dst->fds[newfd]->data = fdt_src->fds[fd_src]->data;

        /*
        * dma-buf/socket fd is without dentry, so should used the vnode reference.
        */
        if (!fdt_dst->fds[newfd]->dentry)
        {
            rt_atomic_add(&(fdt_dst->fds[newfd]->vnode->ref_count), 1);
        }
    }

_EXIT:
    dfs_file_unlock();

    return newfd;
}

/**
 * @brief  drop fd from the fd table.