| 0,0 → 1,118 |
|---|
| /* |
| * Copyright (c) 2007 Jakub Jermar |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * |
| * - Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * - Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution. |
| * - The name of the author may not be used to endorse or promote products |
| * derived from this software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
| * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
| * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
| * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
| * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
| * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| /** @addtogroup fs |
| * @{ |
| */ |
| |
| /** |
| * @file vfs_read.c |
| * @brief |
| */ |
| |
| #include "vfs.h" |
| #include <ipc/ipc.h> |
| #include <async.h> |
| #include <errno.h> |
| |
| void vfs_read(ipc_callid_t rid, ipc_call_t *request) |
| { |
| |
| /* |
| * The following code strongly depends on the fact that the files data |
| * structure can be only accessed by a single fibril and all file |
| * operations are serialized (i.e. the reads and writes cannot |
| * interleave and a file cannot be closed while it is being read). |
| * |
| * Additional synchronization needs to be added once table table of |
| * open files supports parallel access! |
| */ |
| |
| /* |
| * Because we don't support the receive analogy of IPC_M_DATA_SEND, |
| * VFS_READ is emulutating its behavior via sharing an address space |
| * area. |
| */ |
| |
| int fd = IPC_GET_ARG1(*request); |
| |
| /* |
| * Lookup the file structure corresponding to the file descriptor. |
| */ |
| vfs_file_t *file = vfs_file_get(fd); |
| if (!file) { |
| ipc_answer_0(rid, ENOENT); |
| return; |
| } |
| |
| /* |
| * Now we need to receive a call with client's address space area. |
| */ |
| ipc_callid_t callid; |
| ipc_call_t call; |
| callid = async_get_call(&call); |
| if (IPC_GET_METHOD(call) != IPC_M_AS_AREA_SEND) { |
| ipc_answer_0(callid, EINVAL); |
| ipc_answer_0(rid, EINVAL); |
| return; |
| } |
| |
| int fs_phone = vfs_grab_phone(file->node->fs_handle); |
| |
| /* |
| * Make a VFS_READ request at the destination FS server. |
| */ |
| aid_t msg; |
| msg = async_send_3(fs_phone, VFS_READ, file->node->dev_handle, |
| file->node->index, file->pos, NULL); |
| |
| /* |
| * Forward the address space area offer to the destination FS server. |
| * The call will be routed as if sent by ourselves. |
| */ |
| ipc_forward_fast(callid, fs_phone, IPC_GET_METHOD(call), |
| IPC_GET_ARG1(call), IPC_FF_ROUTE_FROM_ME); |
| |
| vfs_release_phone(fs_phone); |
| |
| /* |
| * Wait for reply from the FS server. |
| */ |
| ipcarg_t rc; |
| async_wait_for(msg, &rc); |
| |
| /* |
| * FS server's reply is the final result of the whole operation we |
| * return to the client. |
| */ |
| ipc_answer_0(rid, rc); |
| } |
| |
| /** |
| * @} |
| */ |