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2006 decky 1
/*
2071 jermar 2
 * Copyright (c) 2006 Martin Decky
2690 jermar 3
 * Copyright (c) 2008 Jakub Jermar
2006 decky 4
 * All rights reserved.
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 *
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 * Redistribution and use in source and binary forms, with or without
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 * modification, are permitted provided that the following conditions
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 * are met:
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 *
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 * - Redistributions of source code must retain the above copyright
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 *   notice, this list of conditions and the following disclaimer.
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 * - Redistributions in binary form must reproduce the above copyright
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 *   notice, this list of conditions and the following disclaimer in the
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 *   documentation and/or other materials provided with the distribution.
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 * - The name of the author may not be used to endorse or promote products
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 *   derived from this software without specific prior written permission.
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 *
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 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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 */
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/** @addtogroup fs
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 * @{
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 */
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/**
2529 jermar 35
 * @file    fat.c
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 * @brief   FAT file system driver for HelenOS.
2006 decky 37
 */
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2627 jermar 39
#include "fat.h"
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#include <ipc/ipc.h>
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#include <ipc/services.h>
2531 jermar 42
#include <async.h>
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#include <errno.h>
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#include <unistd.h>
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#include <stdio.h>
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#include <libfs.h>
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#include "../../vfs/vfs.h"
2006 decky 48
 
2532 jermar 49
 
2529 jermar 50
vfs_info_t fat_vfs_info = {
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    .name = "fat",
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    .ops = {
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        [IPC_METHOD_TO_VFS_OP(VFS_LOOKUP)] = VFS_OP_DEFINED,
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        [IPC_METHOD_TO_VFS_OP(VFS_READ)] = VFS_OP_DEFINED,
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        [IPC_METHOD_TO_VFS_OP(VFS_WRITE)] = VFS_OP_NULL,
2690 jermar 56
        [IPC_METHOD_TO_VFS_OP(VFS_TRUNCATE)] = VFS_OP_NULL,
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        [IPC_METHOD_TO_VFS_OP(VFS_MOUNT)] = VFS_OP_NULL,
3153 svoboda 58
        [IPC_METHOD_TO_VFS_OP(VFS_MOUNTED)] = VFS_OP_DEFINED,
2690 jermar 59
        [IPC_METHOD_TO_VFS_OP(VFS_UNMOUNT)] = VFS_OP_NULL,
2529 jermar 60
    }
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};
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2643 jermar 63
fs_reg_t fat_reg;
2543 jermar 64
 
2536 jermar 65
/**
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 * This connection fibril processes VFS requests from VFS.
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 *
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 * In order to support simultaneous VFS requests, our design is as follows.
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 * The connection fibril accepts VFS requests from VFS. If there is only one
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 * instance of the fibril, VFS will need to serialize all VFS requests it sends
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 * to FAT. To overcome this bottleneck, VFS can send FAT the IPC_M_CONNECT_ME_TO
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 * call. In that case, a new connection fibril will be created, which in turn
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 * will accept the call. Thus, a new phone will be opened for VFS.
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 *
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 * There are few issues with this arrangement. First, VFS can run out of
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 * available phones. In that case, VFS can close some other phones or use one
2627 jermar 77
 * phone for more serialized requests. Similarily, FAT can refuse to duplicate
2536 jermar 78
 * the connection. VFS should then just make use of already existing phones and
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 * route its requests through them. To avoid paying the fibril creation price
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 * upon each request, FAT might want to keep the connections open after the
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 * request has been completed.
2531 jermar 82
 */
2536 jermar 83
static void fat_connection(ipc_callid_t iid, ipc_call_t *icall)
2531 jermar 84
{
2536 jermar 85
    if (iid) {
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        /*
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         * This only happens for connections opened by
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         * IPC_M_CONNECT_ME_TO calls as opposed to callback connections
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         * created by IPC_M_CONNECT_TO_ME.
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         */
2619 jermar 91
        ipc_answer_0(iid, EOK);
2536 jermar 92
    }
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    dprintf("VFS-FAT connection established.\n");
2531 jermar 95
    while (1) {
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        ipc_callid_t callid;
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        ipc_call_t call;
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        callid = async_get_call(&call);
2536 jermar 100
        switch  (IPC_GET_METHOD(call)) {
3153 svoboda 101
        case VFS_MOUNTED:
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            fat_mounted(callid, &call);
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            break;
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        case VFS_MOUNT:
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            fat_mount(callid, &call);
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            break;
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        case VFS_LOOKUP:
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            fat_lookup(callid, &call);
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            break;
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        case VFS_READ:
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            fat_read(callid, &call);
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            break;
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        case VFS_WRITE:
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            fat_write(callid, &call);
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            break;
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        case VFS_TRUNCATE:
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            fat_truncate(callid, &call);
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            break;
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        case VFS_DESTROY:
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            fat_destroy(callid, &call);
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            break;
2536 jermar 122
        default:
2619 jermar 123
            ipc_answer_0(callid, ENOTSUP);
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            break;
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        }
2531 jermar 126
    }
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}
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2006 decky 129
int main(int argc, char **argv)
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{
2532 jermar 131
    int vfs_phone;
3153 svoboda 132
    int rc;
2529 jermar 133
 
2532 jermar 134
    printf("FAT: HelenOS FAT file system server.\n");
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    rc = fat_idx_init();
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    if (rc != EOK)
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        goto err;
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2635 cejka 140
    vfs_phone = ipc_connect_me_to(PHONE_NS, SERVICE_VFS, 0, 0);
2532 jermar 141
    while (vfs_phone < EOK) {
2529 jermar 142
        usleep(10000);
2635 cejka 143
        vfs_phone = ipc_connect_me_to(PHONE_NS, SERVICE_VFS, 0, 0);
2529 jermar 144
    }
145
 
2643 jermar 146
    rc = fs_register(vfs_phone, &fat_reg, &fat_vfs_info, fat_connection);
2531 jermar 147
    if (rc != EOK) {
3153 svoboda 148
        fat_idx_fini();
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        goto err;
2531 jermar 150
    }
2536 jermar 151
 
2644 jermar 152
    dprintf("FAT filesystem registered, fs_handle=%d.\n",
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        fat_reg.fs_handle);
2532 jermar 154
 
2568 jermar 155
    async_manager();
2534 jermar 156
    /* not reached */
2006 decky 157
    return 0;
3153 svoboda 158
 
159
err:
160
    printf("Failed to register the FAT file system (%d)\n", rc);
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    return rc;
2006 decky 162
}
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164
/**
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 * @}
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 */