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2520 | jermar | 1 | /* |
2682 | jermar | 2 | * Copyright (c) 2008 Jakub Jermar |
2520 | jermar | 3 | * All rights reserved. |
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 | #ifndef VFS_VFS_H_ |
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34 | #define VFS_VFS_H_ |
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35 | |||
2523 | jermar | 36 | #include <ipc/ipc.h> |
2529 | jermar | 37 | #include <libadt/list.h> |
2540 | jermar | 38 | #include <atomic.h> |
2680 | jermar | 39 | #include <rwlock.h> |
2542 | jermar | 40 | #include <sys/types.h> |
2550 | cejka | 41 | #include <bool.h> |
2523 | jermar | 42 | |
2535 | jermar | 43 | #define dprintf(...) printf(__VA_ARGS__) |
44 | |||
2550 | cejka | 45 | #define VFS_FIRST IPC_FIRST_USER_METHOD |
2523 | jermar | 46 | |
2526 | jermar | 47 | #define IPC_METHOD_TO_VFS_OP(m) ((m) - VFS_FIRST) |
48 | |||
2520 | jermar | 49 | typedef enum { |
2690 | jermar | 50 | VFS_OPEN = VFS_FIRST, |
2523 | jermar | 51 | VFS_CLOSE, |
52 | VFS_READ, |
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53 | VFS_WRITE, |
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2690 | jermar | 54 | VFS_TRUNCATE, |
2593 | jermar | 55 | VFS_RENAME, |
2690 | jermar | 56 | VFS_OPENDIR, |
57 | VFS_READDIR, |
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58 | VFS_CLOSEDIR, |
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2593 | jermar | 59 | VFS_UNLINK, |
2690 | jermar | 60 | VFS_MOUNT, |
61 | VFS_UNMOUNT, |
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62 | VFS_LAST_CMN, /* keep this the last member of this enum */ |
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63 | } vfs_request_cmn_t; |
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2520 | jermar | 64 | |
2690 | jermar | 65 | typedef enum { |
66 | VFS_LOOKUP = VFS_LAST_CMN, |
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67 | VFS_LAST_CLNT, /* keep this the last member of this enum */ |
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68 | } vfs_request_clnt_t; |
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2521 | jermar | 69 | |
2690 | jermar | 70 | typedef enum { |
71 | VFS_REGISTER = VFS_LAST_CMN, |
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72 | VFS_SEEK, |
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73 | VFS_LAST_SRV, /* keep this the last member of this enum */ |
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74 | } vfs_request_srv_t; |
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75 | |||
76 | |||
2521 | jermar | 77 | /** |
78 | * An instance of this structure is associated with a particular FS operation. |
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79 | * It tells VFS if the FS supports the operation or maybe if a default one |
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80 | * should be used. |
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81 | */ |
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82 | typedef enum { |
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2523 | jermar | 83 | VFS_OP_NULL = 0, |
2521 | jermar | 84 | VFS_OP_DEFAULT, |
85 | VFS_OP_DEFINED |
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86 | } vfs_op_t; |
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87 | |||
88 | #define FS_NAME_MAXLEN 20 |
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89 | |||
90 | /** |
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91 | * A structure like this is passed to VFS by each individual FS upon its |
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92 | * registration. It assosiates a human-readable identifier with each |
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93 | * registered FS. More importantly, through this structure, the FS announces |
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94 | * what operations it supports. |
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95 | */ |
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96 | typedef struct { |
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2523 | jermar | 97 | /** Unique identifier of the fs. */ |
2641 | jermar | 98 | char name[FS_NAME_MAXLEN + 1]; |
2523 | jermar | 99 | |
100 | /** Operations. */ |
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2690 | jermar | 101 | vfs_op_t ops[VFS_LAST_CLNT - VFS_FIRST]; |
2521 | jermar | 102 | } vfs_info_t; |
103 | |||
2540 | jermar | 104 | /** |
105 | * A structure like this will be allocated for each registered file system. |
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106 | */ |
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2526 | jermar | 107 | typedef struct { |
108 | link_t fs_link; |
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109 | vfs_info_t vfs_info; |
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2546 | jermar | 110 | int fs_handle; |
111 | atomic_t phone_futex; /**< Phone serializing futex. */ |
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2527 | jermar | 112 | ipcarg_t phone; |
2526 | jermar | 113 | } fs_info_t; |
114 | |||
2540 | jermar | 115 | /** |
2587 | jermar | 116 | * VFS_PAIR uniquely represents a file system instance. |
117 | */ |
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118 | #define VFS_PAIR \ |
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119 | int fs_handle; \ |
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120 | int dev_handle; |
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121 | |||
122 | /** |
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123 | * VFS_TRIPLET uniquely identifies a file system node (e.g. directory, file) but |
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124 | * doesn't contain any state. For a stateful structure, see vfs_node_t. |
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2540 | jermar | 125 | * |
126 | * @note fs_handle, dev_handle and index are meant to be returned in one |
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127 | * IPC reply. |
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128 | */ |
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2587 | jermar | 129 | #define VFS_TRIPLET \ |
130 | VFS_PAIR; \ |
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131 | uint64_t index; |
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132 | |||
2540 | jermar | 133 | typedef struct { |
2587 | jermar | 134 | VFS_PAIR; |
135 | } vfs_pair_t; |
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136 | |||
137 | typedef struct { |
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138 | VFS_TRIPLET; |
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139 | } vfs_triplet_t; |
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140 | |||
2691 | jermar | 141 | typedef struct { |
142 | vfs_triplet_t triplet; |
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143 | size_t size; |
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144 | } vfs_lookup_res_t; |
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145 | |||
2587 | jermar | 146 | /** |
147 | * Instances of this type represent an active, in-memory VFS node and any state |
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148 | * which may be associated with it. |
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149 | */ |
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150 | typedef struct { |
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151 | VFS_TRIPLET; /**< Identity of the node. */ |
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2593 | jermar | 152 | unsigned refcnt; /**< Usage counter. */ |
153 | link_t nh_link; /**< Node hash-table link. */ |
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2684 | jermar | 154 | size_t size; /**< Cached size of the file. */ |
2679 | jermar | 155 | |
2682 | jermar | 156 | /** |
157 | * Holding this rwlock prevents modifications of the node's contents. |
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158 | */ |
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159 | rwlock_t contents_rwlock; |
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2540 | jermar | 160 | } vfs_node_t; |
161 | |||
162 | /** |
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163 | * Instances of this type represent an open file. If the file is opened by more |
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164 | * than one task, there will be a separate structure allocated for each task. |
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165 | */ |
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166 | typedef struct { |
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2683 | jermar | 167 | /** Serializes access to this open file. */ |
168 | futex_t lock; |
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169 | |||
2540 | jermar | 170 | vfs_node_t *node; |
171 | |||
172 | /** Number of file handles referencing this file. */ |
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2593 | jermar | 173 | unsigned refcnt; |
2540 | jermar | 174 | |
175 | /** Current position in the file. */ |
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176 | off_t pos; |
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177 | } vfs_file_t; |
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178 | |||
2542 | jermar | 179 | extern link_t fs_head; /**< List of registered file systems. */ |
2535 | jermar | 180 | |
2587 | jermar | 181 | extern vfs_triplet_t rootfs; /**< Root node of the root file system. */ |
2535 | jermar | 182 | |
2542 | jermar | 183 | #define MAX_PATH_LEN (64 * 1024) |
184 | |||
185 | #define PLB_SIZE (2 * MAX_PATH_LEN) |
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186 | |||
187 | /** Each instance of this type describes one path lookup in progress. */ |
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188 | typedef struct { |
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189 | link_t plb_link; /**< Active PLB entries list link. */ |
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190 | unsigned index; /**< Index of the first character in PLB. */ |
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191 | size_t len; /**< Number of characters in this PLB entry. */ |
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192 | } plb_entry_t; |
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193 | |||
194 | extern atomic_t plb_futex; /**< Futex protecting plb and plb_head. */ |
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195 | extern uint8_t *plb; /**< Path Lookup Buffer */ |
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196 | extern link_t plb_head; /**< List of active PLB entries. */ |
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197 | |||
2681 | jermar | 198 | /** Holding this rwlock prevents changes in file system namespace. */ |
199 | extern rwlock_t namespace_rwlock; |
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2593 | jermar | 200 | |
2546 | jermar | 201 | extern int vfs_grab_phone(int); |
202 | extern void vfs_release_phone(int); |
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203 | |||
2552 | jermar | 204 | extern int fs_name_to_handle(char *, bool); |
2548 | jermar | 205 | |
2691 | jermar | 206 | extern int vfs_lookup_internal(char *, size_t, vfs_lookup_res_t *, |
2687 | jermar | 207 | vfs_pair_t *); |
2593 | jermar | 208 | |
2596 | jermar | 209 | extern bool vfs_nodes_init(void); |
2691 | jermar | 210 | extern vfs_node_t *vfs_node_get(vfs_lookup_res_t *); |
2593 | jermar | 211 | extern void vfs_node_put(vfs_node_t *); |
2544 | jermar | 212 | |
2596 | jermar | 213 | #define MAX_OPEN_FILES 128 |
214 | |||
2593 | jermar | 215 | extern bool vfs_files_init(void); |
216 | extern vfs_file_t *vfs_file_get(int); |
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217 | extern int vfs_fd_alloc(void); |
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218 | extern void vfs_fd_free(int); |
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219 | |||
220 | extern void vfs_file_addref(vfs_file_t *); |
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221 | extern void vfs_file_delref(vfs_file_t *); |
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222 | |||
223 | extern void vfs_node_addref(vfs_node_t *); |
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224 | extern void vfs_node_delref(vfs_node_t *); |
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225 | |||
2542 | jermar | 226 | extern void vfs_register(ipc_callid_t, ipc_call_t *); |
2544 | jermar | 227 | extern void vfs_mount(ipc_callid_t, ipc_call_t *); |
2560 | jermar | 228 | extern void vfs_open(ipc_callid_t, ipc_call_t *); |
2625 | jermar | 229 | extern void vfs_read(ipc_callid_t, ipc_call_t *); |
2666 | jermar | 230 | extern void vfs_write(ipc_callid_t, ipc_call_t *); |
2684 | jermar | 231 | extern void vfs_seek(ipc_callid_t, ipc_call_t *); |
2542 | jermar | 232 | |
2520 | jermar | 233 | #endif |
234 | |||
235 | /** |
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236 | * @} |
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2523 | jermar | 237 | */ |