0,0 → 1,158 |
/* |
* Copyright (c) 2006 Martin Decky |
* Copyright (c) 2008 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 tmpfs.c |
* @brief File system driver for in-memory file system. |
* |
* Every instance of tmpfs exists purely in memory and has neither a disk layout |
* nor any permanent storage (e.g. disk blocks). With each system reboot, data |
* stored in a tmpfs file system is lost. |
*/ |
|
#include "tmpfs.h" |
#include <ipc/ipc.h> |
#include <ipc/services.h> |
#include <async.h> |
#include <errno.h> |
#include <unistd.h> |
#include <stdio.h> |
#include <libfs.h> |
#include "../../vfs/vfs.h" |
|
|
vfs_info_t tmpfs_vfs_info = { |
.name = "tmpfs", |
.ops = { |
[IPC_METHOD_TO_VFS_OP(VFS_LOOKUP)] = VFS_OP_DEFINED, |
[IPC_METHOD_TO_VFS_OP(VFS_READ)] = VFS_OP_DEFINED, |
[IPC_METHOD_TO_VFS_OP(VFS_WRITE)] = VFS_OP_DEFINED, |
[IPC_METHOD_TO_VFS_OP(VFS_TRUNCATE)] = VFS_OP_DEFINED, |
[IPC_METHOD_TO_VFS_OP(VFS_MOUNT)] = VFS_OP_NULL, |
[IPC_METHOD_TO_VFS_OP(VFS_UNMOUNT)] = VFS_OP_NULL, |
[IPC_METHOD_TO_VFS_OP(VFS_DESTROY)] = VFS_OP_DEFINED, |
} |
}; |
|
fs_reg_t tmpfs_reg; |
|
/** |
* This connection fibril processes VFS requests from VFS. |
* |
* In order to support simultaneous VFS requests, our design is as follows. |
* The connection fibril accepts VFS requests from VFS. If there is only one |
* instance of the fibril, VFS will need to serialize all VFS requests it sends |
* to FAT. To overcome this bottleneck, VFS can send TMPFS the |
* IPC_M_CONNECT_ME_TO call. In that case, a new connection fibril will be |
* created, which in turn will accept the call. Thus, a new phone will be |
* opened for VFS. |
* |
* There are few issues with this arrangement. First, VFS can run out of |
* available phones. In that case, VFS can close some other phones or use one |
* phone for more serialized requests. Similarily, TMPFS can refuse to duplicate |
* the connection. VFS should then just make use of already existing phones and |
* route its requests through them. To avoid paying the fibril creation price |
* upon each request, TMPFS might want to keep the connections open after the |
* request has been completed. |
*/ |
static void tmpfs_connection(ipc_callid_t iid, ipc_call_t *icall) |
{ |
if (iid) { |
/* |
* This only happens for connections opened by |
* IPC_M_CONNECT_ME_TO calls as opposed to callback connections |
* created by IPC_M_CONNECT_TO_ME. |
*/ |
ipc_answer_0(iid, EOK); |
} |
|
dprintf("VFS-TMPFS connection established.\n"); |
while (1) { |
ipc_callid_t callid; |
ipc_call_t call; |
|
callid = async_get_call(&call); |
switch (IPC_GET_METHOD(call)) { |
case VFS_LOOKUP: |
tmpfs_lookup(callid, &call); |
break; |
case VFS_READ: |
tmpfs_read(callid, &call); |
break; |
case VFS_WRITE: |
tmpfs_write(callid, &call); |
break; |
case VFS_TRUNCATE: |
tmpfs_truncate(callid, &call); |
break; |
case VFS_DESTROY: |
tmpfs_destroy(callid, &call); |
break; |
default: |
ipc_answer_0(callid, ENOTSUP); |
break; |
} |
} |
} |
|
int main(int argc, char **argv) |
{ |
int vfs_phone; |
|
printf("TMPFS: HelenOS TMPFS file system server.\n"); |
|
vfs_phone = ipc_connect_me_to(PHONE_NS, SERVICE_VFS, 0, 0); |
while (vfs_phone < EOK) { |
usleep(10000); |
vfs_phone = ipc_connect_me_to(PHONE_NS, SERVICE_VFS, 0, 0); |
} |
|
int rc; |
rc = fs_register(vfs_phone, &tmpfs_reg, &tmpfs_vfs_info, |
tmpfs_connection); |
if (rc != EOK) { |
printf("Failed to register the TMPFS file system (%d)\n", rc); |
return rc; |
} |
|
dprintf("TMPFS filesystem registered, fs_handle=%d.\n", |
tmpfs_reg.fs_handle); |
|
async_manager(); |
/* not reached */ |
return 0; |
} |
|
/** |
* @} |
*/ |