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| 2560 | jermar | 1 | /* |
| 2 | * Copyright (c) 2007 Jakub Jermar |
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| 3 | * All rights reserved. |
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| 4 | * |
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| 5 | * Redistribution and use in source and binary forms, with or without |
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| 6 | * modification, are permitted provided that the following conditions |
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| 7 | * are met: |
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| 8 | * |
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| 9 | * - Redistributions of source code must retain the above copyright |
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| 10 | * notice, this list of conditions and the following disclaimer. |
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| 11 | * - Redistributions in binary form must reproduce the above copyright |
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| 12 | * notice, this list of conditions and the following disclaimer in the |
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| 13 | * documentation and/or other materials provided with the distribution. |
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| 14 | * - The name of the author may not be used to endorse or promote products |
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| 15 | * derived from this software without specific prior written permission. |
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| 16 | * |
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| 17 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
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| 18 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
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| 19 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
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| 20 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
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| 21 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
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| 22 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
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| 23 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
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| 24 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
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| 25 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
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| 26 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
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| 27 | */ |
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| 28 | |||
| 29 | /** @addtogroup fs |
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| 30 | * @{ |
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| 31 | */ |
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| 32 | |||
| 33 | /** |
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| 34 | * @file vfs.c |
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| 35 | * @brief VFS_OPEN method. |
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| 36 | */ |
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| 37 | |||
| 38 | #include <ipc/ipc.h> |
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| 39 | #include <async.h> |
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| 40 | #include <errno.h> |
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| 41 | #include <stdlib.h> |
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| 42 | #include <string.h> |
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| 43 | #include <bool.h> |
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| 44 | #include <futex.h> |
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| 45 | #include <libadt/list.h> |
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| 2589 | jermar | 46 | #include <sys/types.h> |
| 2560 | jermar | 47 | #include "vfs.h" |
| 48 | |||
| 2589 | jermar | 49 | /** Per-connection futex protecting the files array. */ |
| 50 | __thread atomic_t files_futex = FUTEX_INITIALIZER; |
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| 51 | |||
| 2560 | jermar | 52 | /** |
| 53 | * This is a per-connection table of open files. |
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| 54 | * Our assumption is that each client opens only one connection and therefore |
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| 55 | * there is one table of open files per task. However, this may not be the case |
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| 56 | * and the client can open more connections to VFS. In that case, there will be |
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| 57 | * several tables and several file handle name spaces per task. Besides of this, |
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| 58 | * the functionality will stay unchanged. So unless the client knows what it is |
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| 59 | * doing, it should open one connection to VFS only. |
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| 2589 | jermar | 60 | * |
| 61 | * Allocation of the open files table is deferred until the client makes the |
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| 62 | * first VFS_OPEN operation. |
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| 2560 | jermar | 63 | */ |
| 2589 | jermar | 64 | __thread vfs_file_t *files = NULL; |
| 2560 | jermar | 65 | |
| 66 | /** Initialize the table of open files. */ |
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| 2589 | jermar | 67 | static bool vfs_conn_open_files_init(void) |
| 2560 | jermar | 68 | { |
| 2589 | jermar | 69 | futex_down(&files_futex); |
| 70 | if (!files) { |
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| 71 | files = malloc(MAX_OPEN_FILES * sizeof(vfs_file_t)); |
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| 72 | if (!files) { |
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| 73 | futex_up(&files_futex); |
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| 74 | return false; |
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| 75 | } |
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| 76 | memset(files, 0, MAX_OPEN_FILES * sizeof(vfs_file_t)); |
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| 77 | } |
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| 78 | futex_up(&files_futex); |
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| 2560 | jermar | 79 | return true; |
| 80 | } |
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| 81 | |||
| 82 | void vfs_open(ipc_callid_t rid, ipc_call_t *request) |
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| 83 | { |
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| 2589 | jermar | 84 | if (!vfs_conn_open_files_init()) { |
| 85 | ipc_answer_fast_0(rid, ENOMEM); |
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| 86 | return; |
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| 87 | } |
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| 2560 | jermar | 88 | } |
| 89 | |||
| 90 | /** |
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| 91 | * @} |
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| 92 | */ |