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); |
} |
|
/** |
* @} |
*/ |