Subversion Repositories HelenOS

void tmpfs_truncate(ipc_callid_t rid, ipc_call_t *request)

{

    int dev_handle = IPC_GET_ARG1(*request);

    unsigned long index = IPC_GET_ARG2(*request);

    size_t size = IPC_GET_ARG3(*request);

    /*

     * Lookup the respective dentry.

     */

    link_t *hlp;

    hlp = hash_table_find(&dentries, &index);

    if (!hlp) {

        ipc_answer_0(rid, ENOENT);

        return;

    }

    tmpfs_dentry_t *dentry = hash_table_get_instance(hlp, tmpfs_dentry_t,

        dh_link);

    if (size == dentry->size) {

        ipc_answer_0(rid, EOK);

        return;

    }

    void *newdata = realloc(dentry->data, size);

    if (!newdata) {

        ipc_answer_0(rid, ENOMEM);

        return;

    }

    if (size > dentry->size) {

        size_t delta = size - dentry->size;

        memset(newdata + dentry->size, 0, delta);

    }

    dentry->size = size;

    dentry->data = newdata;

    ipc_answer_0(rid, EOK);

}