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Rev 2635 Rev 2658
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     * The following code strongly depends on the fact that the files data
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     * The following code strongly depends on the fact that the files data
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     * structure can be only accessed by a single fibril and all file
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     * structure can be only accessed by a single fibril and all file
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     * operations are serialized (i.e. the reads and writes cannot
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     * operations are serialized (i.e. the reads and writes cannot
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     * interleave and a file cannot be closed while it is being read).
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     * interleave and a file cannot be closed while it is being read).
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     *
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     *
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     * Additional synchronization needs to be added once table table of
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     * Additional synchronization needs to be added once the table of
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     * open files supports parallel access!
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     * open files supports parallel access!
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     */
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     */
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    /*
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    /*
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     * Because we don't support the receive analogy of IPC_M_DATA_SEND,
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     * Because we don't support the receive analogy of IPC_M_DATA_SEND,
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     * VFS_READ is emulutating its behavior via sharing an address space
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     * VFS_READ is emulutating its behavior via sharing an address space
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     * area.
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     * area.
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     */
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     */
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    int fd = IPC_GET_ARG1(*request);
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    int fd = IPC_GET_ARG1(*request);
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    size_t size = IPC_GET_ARG2(*request);
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    /*
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    /*
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     * Lookup the file structure corresponding to the file descriptor.
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     * Lookup the file structure corresponding to the file descriptor.
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     */
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     */
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    vfs_file_t *file = vfs_file_get(fd);
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    vfs_file_t *file = vfs_file_get(fd);
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    /*
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    /*
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     * Make a VFS_READ request at the destination FS server.
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     * Make a VFS_READ request at the destination FS server.
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     */
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     */
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    aid_t msg;
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    aid_t msg;
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    ipc_call_t answer;
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    msg = async_send_3(fs_phone, VFS_READ, file->node->dev_handle,
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    msg = async_send_4(fs_phone, VFS_READ, file->node->dev_handle,
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        file->node->index, file->pos, NULL);
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        file->node->index, file->pos, size, &answer);
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    /*
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    /*
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     * Forward the address space area offer to the destination FS server.
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     * Forward the address space area offer to the destination FS server.
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     * The call will be routed as if sent by ourselves.
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     * The call will be routed as if sent by ourselves.
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     */
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     */
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    /*
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    /*
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     * Wait for reply from the FS server.
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     * Wait for reply from the FS server.
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     */
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     */
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    ipcarg_t rc;
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    ipcarg_t rc;
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    async_wait_for(msg, &rc);
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    async_wait_for(msg, &rc);
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    size_t bytes = IPC_GET_ARG1(answer);
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    /*
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    /*
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     * FS server's reply is the final result of the whole operation we
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     * FS server's reply is the final result of the whole operation we
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     * return to the client.
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     * return to the client.
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     */
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     */
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    ipc_answer_0(rid, rc);
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    ipc_answer_1(rid, rc, bytes);
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}
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}
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/**
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/**
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 * @}
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 * @}
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 */
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 */