Subversion Repositories HelenOS

Rev

Rev 2731 | Rev 3424 | Go to most recent revision | Details | Compare with Previous | Last modification | View Log | RSS feed

Rev Author Line No. Line
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.
5 
 *
6 
 * Redistribution and use in source and binary forms, with or without
7 
 * modification, are permitted provided that the following conditions
8 
 * are met:
9 
 *
10 
 * - Redistributions of source code must retain the above copyright
11 
 *   notice, this list of conditions and the following disclaimer.
12 
 * - Redistributions in binary form must reproduce the above copyright
13 
 *   notice, this list of conditions and the following disclaimer in the
14 
 *   documentation and/or other materials provided with the distribution.
15 
 * - The name of the author may not be used to endorse or promote products
16 
 *   derived from this software without specific prior written permission.
17 
 *
18 
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19 
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20 
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21 
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22 
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23 
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24 
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25 
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26 
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27 
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 
 */
29 
 
30 
/** @addtogroup fs
31 
 * @{
32 
 */
33 
 
34 
/**
2529 jermar 35 
 * @file    fat.c
36 
 * @brief   FAT file system driver for HelenOS.
2006 decky 37 
 */
38 
 
2627 jermar 39 
#include "fat.h"
2529 jermar 40 
#include <ipc/ipc.h>
41 
#include <ipc/services.h>
2531 jermar 42 
#include <async.h>
2529 jermar 43 
#include <errno.h>
44 
#include <unistd.h>
2536 jermar 45 
#include <stdio.h>
2643 jermar 46 
#include <libfs.h>
2529 jermar 47 
#include "../../vfs/vfs.h"
2006 decky 48 
 
2532 jermar 49 
 
2529 jermar 50 
vfs_info_t fat_vfs_info = {
51 
    .name = "fat",
52 
    .ops = {
53 
        [IPC_METHOD_TO_VFS_OP(VFS_LOOKUP)] = VFS_OP_DEFINED,
54 
        [IPC_METHOD_TO_VFS_OP(VFS_READ)] = VFS_OP_DEFINED,
55 
        [IPC_METHOD_TO_VFS_OP(VFS_WRITE)] = VFS_OP_NULL,
2690 jermar 56 
        [IPC_METHOD_TO_VFS_OP(VFS_TRUNCATE)] = VFS_OP_NULL,
57 
        [IPC_METHOD_TO_VFS_OP(VFS_MOUNT)] = VFS_OP_NULL,
58 
        [IPC_METHOD_TO_VFS_OP(VFS_UNMOUNT)] = VFS_OP_NULL,
2529 jermar 59 
    }
60 
};
61 
 
2643 jermar 62 
fs_reg_t fat_reg;
2543 jermar 63 
 
2536 jermar 64 
/**
65 
 * This connection fibril processes VFS requests from VFS.
66 
 *
67 
 * In order to support simultaneous VFS requests, our design is as follows.
68 
 * The connection fibril accepts VFS requests from VFS. If there is only one
69 
 * instance of the fibril, VFS will need to serialize all VFS requests it sends
70 
 * to FAT. To overcome this bottleneck, VFS can send FAT the IPC_M_CONNECT_ME_TO
71 
 * call. In that case, a new connection fibril will be created, which in turn
72 
 * will accept the call. Thus, a new phone will be opened for VFS.
73 
 *
74 
 * There are few issues with this arrangement. First, VFS can run out of
75 
 * available phones. In that case, VFS can close some other phones or use one
2627 jermar 76 
 * phone for more serialized requests. Similarily, FAT can refuse to duplicate
2536 jermar 77 
 * the connection. VFS should then just make use of already existing phones and
78 
 * route its requests through them. To avoid paying the fibril creation price
79 
 * upon each request, FAT might want to keep the connections open after the
80 
 * request has been completed.
2531 jermar 81 
 */
2536 jermar 82 
static void fat_connection(ipc_callid_t iid, ipc_call_t *icall)
2531 jermar 83 
{
2536 jermar 84 
    if (iid) {
85 
        /*
86 
         * This only happens for connections opened by
87 
         * IPC_M_CONNECT_ME_TO calls as opposed to callback connections
88 
         * created by IPC_M_CONNECT_TO_ME.
89 
         */
2619 jermar 90 
        ipc_answer_0(iid, EOK);
2536 jermar 91 
    }
92 
 
93 
    dprintf("VFS-FAT connection established.\n");
2531 jermar 94 
    while (1) {
95 
        ipc_callid_t callid;
96 
        ipc_call_t call;
97 
 
98 
        callid = async_get_call(&call);
2536 jermar 99 
        switch  (IPC_GET_METHOD(call)) {
2627 jermar 100 
        case VFS_LOOKUP:
101 
            fat_lookup(callid, &call);
102 
            break;
2536 jermar 103 
        default:
2619 jermar 104 
            ipc_answer_0(callid, ENOTSUP);
2536 jermar 105 
            break;
106 
        }
2531 jermar 107 
    }
108 
}
109 
 
2006 decky 110 
int main(int argc, char **argv)
111 
{
2532 jermar 112 
    int vfs_phone;
2529 jermar 113 
 
2532 jermar 114 
    printf("FAT: HelenOS FAT file system server.\n");
115 
 
2635 cejka 116 
    vfs_phone = ipc_connect_me_to(PHONE_NS, SERVICE_VFS, 0, 0);
2532 jermar 117 
    while (vfs_phone < EOK) {
2529 jermar 118 
        usleep(10000);
2635 cejka 119 
        vfs_phone = ipc_connect_me_to(PHONE_NS, SERVICE_VFS, 0, 0);
2529 jermar 120 
    }
121 
 
2643 jermar 122 
    int rc;
123 
    rc = fs_register(vfs_phone, &fat_reg, &fat_vfs_info, fat_connection);
2531 jermar 124 
    if (rc != EOK) {
2643 jermar 125 
        printf("Failed to register the FAT file system (%d)\n", rc);
2531 jermar 126 
        return rc;
127 
    }
2536 jermar 128 
 
2644 jermar 129 
    dprintf("FAT filesystem registered, fs_handle=%d.\n",
130 
        fat_reg.fs_handle);
2532 jermar 131 
 
2568 jermar 132 
    async_manager();
2534 jermar 133 
    /* not reached */
2006 decky 134 
    return 0;
135 
}
136 
 
137 
/**
138 
 * @}
139 
 */