| 0,0 → 1,165 |
|---|
| /* |
| * 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" |
| |
| #define NAME "tmpfs" |
| |
| |
| 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_DEFINED, |
| [IPC_METHOD_TO_VFS_OP(VFS_MOUNTED)] = VFS_OP_DEFINED, |
| [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_MOUNTED: |
| tmpfs_mounted(callid, &call); |
| break; |
| case VFS_MOUNT: |
| tmpfs_mount(callid, &call); |
| break; |
| 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(NAME ": 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(NAME ": Failed to register file system (%d)\n", rc); |
| return rc; |
| } |
| |
| printf(NAME ": Accepting connections\n"); |
| async_manager(); |
| /* not reached */ |
| return 0; |
| } |
| |
| /** |
| * @} |
| */ |