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2642 jermar 1
/*
2747 jermar 2
 * Copyright (c) 2008 Jakub Jermar
2642 jermar 3
 * 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 libfs
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 * @{
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 */
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/**
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 * @file
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 * Glue code which is commonod to all FS implementations.
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 */
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37
#include "libfs.h" 
2643 jermar 38
#include "../../srv/vfs/vfs.h"
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#include <errno.h>
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#include <async.h>
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#include <ipc/ipc.h>
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#include <as.h>
2747 jermar 43
#include <assert.h>
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#include <dirent.h>
2642 jermar 45
 
2643 jermar 46
/** Register file system server.
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 *
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 * This function abstracts away the tedious registration protocol from
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 * file system implementations and lets them to reuse this registration glue
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 * code.
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 *
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 * @param vfs_phone Open phone for communication with VFS.
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 * @param reg       File system registration structure. It will be
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 *          initialized by this function.
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 * @param info      VFS info structure supplied by the file system
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 *          implementation.
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 * @param conn      Connection fibril for handling all calls originating in
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 *          VFS.
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 *
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 * @return      EOK on success or a non-zero error code on errror.
61
 */
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int fs_register(int vfs_phone, fs_reg_t *reg, vfs_info_t *info,
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    async_client_conn_t conn)
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{
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    /*
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     * Tell VFS that we are here and want to get registered.
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     * We use the async framework because VFS will answer the request
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     * out-of-order, when it knows that the operation succeeded or failed.
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     */
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    ipc_call_t answer;
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    aid_t req = async_send_0(vfs_phone, VFS_REGISTER, &answer);
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73
    /*
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     * Send our VFS info structure to VFS.
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     */
2678 jermar 76
    int rc = ipc_data_write_start(vfs_phone, info, sizeof(*info));
2643 jermar 77
    if (rc != EOK) {
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        async_wait_for(req, NULL);
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        return rc;
80
    }
81
 
82
    /*
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     * Ask VFS for callback connection.
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     */
85
    ipc_connect_to_me(vfs_phone, 0, 0, 0, &reg->vfs_phonehash);
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87
    /*
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     * Allocate piece of address space for PLB.
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     */
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    reg->plb_ro = as_get_mappable_page(PLB_SIZE);
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    if (!reg->plb_ro) {
92
        async_wait_for(req, NULL);
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        return ENOMEM;
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    }
95
 
96
    /*
97
     * Request sharing the Path Lookup Buffer with VFS.
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     */
2678 jermar 99
    rc = ipc_share_in_start_0_0(vfs_phone, reg->plb_ro, PLB_SIZE);
2643 jermar 100
    if (rc) {
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        async_wait_for(req, NULL);
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        return rc;
103
    }
104
 
105
    /*
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     * Pick up the answer for the request to the VFS_REQUEST call.
107
     */
108
    async_wait_for(req, NULL);
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    reg->fs_handle = (int) IPC_GET_ARG1(answer);
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111
    /*
112
     * Create a connection fibril to handle the callback connection.
113
     */
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    async_new_connection(reg->vfs_phonehash, 0, NULL, conn);
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116
    /*
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     * Tell the async framework that other connections are to be handled by
118
     * the same connection fibril as well.
119
     */
120
    async_set_client_connection(conn);
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122
    return IPC_GET_RETVAL(answer);
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}
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2747 jermar 125
void libfs_lookup(libfs_ops_t *ops, int fs_handle, ipc_callid_t rid,
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    ipc_call_t *request)
127
{
128
    unsigned next = IPC_GET_ARG1(*request);
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    unsigned last = IPC_GET_ARG2(*request);
130
    int dev_handle = IPC_GET_ARG3(*request);
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    int lflag = IPC_GET_ARG4(*request);
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133
    if (last < next)
134
        last += PLB_SIZE;
135
 
136
    void *cur = ops->root_get();
137
    void *tmp = ops->child_get(cur);
138
 
139
    if (ops->plb_get_char(next) == '/')
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        next++;     /* eat slash */
141
 
142
    char component[NAME_MAX + 1];
143
    int len = 0;
144
    while (tmp && next <= last) {
145
 
146
        /* collect the component */
147
        if (ops->plb_get_char(next) != '/') {
148
            if (len + 1 == NAME_MAX) {
149
                /* comopnent length overflow */
150
                ipc_answer_0(rid, ENAMETOOLONG);
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                return;
152
            }
153
            component[len++] = ops->plb_get_char(next);
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            next++; /* process next character */
155
            if (next <= last)
156
                continue;
157
        }
158
 
159
        assert(len);
160
        component[len] = '\0';
161
        next++;     /* eat slash */
162
        len = 0;
163
 
164
        /* match the component */
165
        while (tmp && !ops->match(tmp, component))
166
            tmp = ops->sibling_get(tmp);
167
 
168
        /* handle miss: match amongst siblings */
169
        if (!tmp) {
170
            if ((next > last) && (lflag & L_CREATE)) {
171
                /* no components left and L_CREATE specified */
172
                if (!ops->is_directory(cur)) {
173
                    ipc_answer_0(rid, ENOTDIR);
174
                    return;
175
                }
176
                void *nodep = ops->create(lflag);
177
                if (nodep) {
178
                    if (!ops->link(cur, nodep, component)) {
179
                        ops->destroy(nodep);
180
                        ipc_answer_0(rid, ENOSPC);
181
                    } else {
182
                        ipc_answer_5(rid, EOK,
183
                            fs_handle, dev_handle,
184
                            ops->index_get(nodep), 0,
185
                            ops->lnkcnt_get(nodep));
186
                    }
187
                } else {
188
                    ipc_answer_0(rid, ENOSPC);
189
                }
190
                return;
191
            }
192
            ipc_answer_0(rid, ENOENT);
193
            return;
194
        }
195
 
196
        /* descend one level */
197
        cur = tmp;
198
        tmp = ops->child_get(tmp);
199
    }
200
 
201
    /* handle miss: excessive components */
202
    if (!tmp && next <= last) {
203
        if (lflag & L_CREATE) {
204
            if (!ops->is_directory(cur)) {
205
                ipc_answer_0(rid, ENOTDIR);
206
                return;
207
            }
208
 
209
            /* collect next component */
210
            while (next <= last) {
211
                if (ops->plb_get_char(next) == '/') {
212
                    /* more than one component */
213
                    ipc_answer_0(rid, ENOENT);
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                    return;
215
                }
216
                if (len + 1 == NAME_MAX) {
217
                    /* component length overflow */
218
                    ipc_answer_0(rid, ENAMETOOLONG);
219
                    return;
220
                }
221
                component[len++] = ops->plb_get_char(next);
222
                next++; /* process next character */
223
            }
224
            assert(len);
225
            component[len] = '\0';
226
            len = 0;
227
 
228
            void *nodep = ops->create(lflag);
229
            if (nodep) {
230
                if (!ops->link(cur, nodep, component)) {
231
                    ops->destroy(nodep);
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                    ipc_answer_0(rid, ENOSPC);
233
                } else {
234
                    ipc_answer_5(rid, EOK,
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                        fs_handle, dev_handle,
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                        ops->index_get(nodep), 0,
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                        ops->lnkcnt_get(nodep));
238
                }
239
            } else {
240
                ipc_answer_0(rid, ENOSPC);
241
            }
242
            return;
243
        }
244
        ipc_answer_0(rid, ENOENT);
245
        return;
246
    }
247
 
248
    /* handle hit */
249
    if (lflag & L_DESTROY) {
250
        unsigned old_lnkcnt = ops->lnkcnt_get(cur);
251
        int res = ops->unlink(cur);
252
        ipc_answer_5(rid, (ipcarg_t)res, fs_handle, dev_handle,
253
            ops->index_get(cur), ops->size_get(cur), old_lnkcnt);
254
        return;
255
    }
256
    if ((lflag & (L_CREATE | L_EXCLUSIVE)) == (L_CREATE | L_EXCLUSIVE)) {
257
        ipc_answer_0(rid, EEXIST);
258
        return;
259
    }
260
    if ((lflag & L_FILE) && (ops->is_directory(cur))) {
261
        ipc_answer_0(rid, EISDIR);
262
        return;
263
    }
264
    if ((lflag & L_DIRECTORY) && (ops->is_file(cur))) {
265
        ipc_answer_0(rid, ENOTDIR);
266
        return;
267
    }
268
 
269
    ipc_answer_5(rid, EOK, fs_handle, dev_handle, ops->index_get(cur),
270
        ops->size_get(cur), ops->lnkcnt_get(cur));
271
}
272
 
2642 jermar 273
/** @}
274
 */