root / prex-0.9.0 / usr / server / fs / ramfs / ramfs_vnops.c @ 03e9c04a
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1 | 03e9c04a | Brad Neuman | /*
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2 | * Copyright (c) 2006-2007, Kohsuke Ohtani
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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 | * 1. Redistributions of source code must retain the above copyright
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9 | * notice, this list of conditions and the following disclaimer.
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10 | * 2. Redistributions in binary form must reproduce the above copyright
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11 | * notice, this list of conditions and the following disclaimer in the
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12 | * documentation and/or other materials provided with the distribution.
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13 | * 3. Neither the name of the author nor the names of any co-contributors
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14 | * may be used to endorse or promote products derived from this software
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15 | * without specific prior written permission.
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16 | *
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17 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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18 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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19 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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20 | * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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21 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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22 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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23 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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24 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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25 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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26 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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27 | * SUCH DAMAGE.
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28 | */
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29 | |||
30 | /*
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31 | * rmafs_vnops.c - vnode operations for RAM file system.
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32 | */
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33 | |||
34 | #include <sys/prex.h> |
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35 | |||
36 | #include <sys/stat.h> |
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37 | #include <sys/vnode.h> |
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38 | #include <sys/file.h> |
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39 | #include <sys/mount.h> |
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40 | #include <sys/dirent.h> |
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41 | #include <sys/param.h> |
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42 | |||
43 | #include <errno.h> |
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44 | #include <string.h> |
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45 | #include <stdlib.h> |
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46 | #include <fcntl.h> |
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47 | |||
48 | #include "ramfs.h" |
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49 | |||
50 | #define ramfs_open ((vnop_open_t)vop_nullop)
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51 | #define ramfs_close ((vnop_close_t)vop_nullop)
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52 | static int ramfs_read (vnode_t, file_t, void *, size_t, size_t *); |
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53 | static int ramfs_write (vnode_t, file_t, void *, size_t, size_t *); |
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54 | #define ramfs_seek ((vnop_seek_t)vop_nullop)
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55 | #define ramfs_ioctl ((vnop_ioctl_t)vop_einval)
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56 | #define ramfs_fsync ((vnop_fsync_t)vop_nullop)
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57 | static int ramfs_readdir(vnode_t, file_t, struct dirent *); |
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58 | static int ramfs_lookup (vnode_t, char *, vnode_t); |
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59 | static int ramfs_create (vnode_t, char *, mode_t); |
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60 | static int ramfs_remove (vnode_t, vnode_t, char *); |
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61 | static int ramfs_rename (vnode_t, vnode_t, char *, vnode_t, vnode_t, char *); |
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62 | static int ramfs_mkdir (vnode_t, char *, mode_t); |
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63 | static int ramfs_rmdir (vnode_t, vnode_t, char *); |
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64 | #define ramfs_getattr ((vnop_getattr_t)vop_nullop)
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65 | #define ramfs_setattr ((vnop_setattr_t)vop_nullop)
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66 | #define ramfs_inactive ((vnop_inactive_t)vop_nullop)
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67 | static int ramfs_truncate(vnode_t, off_t); |
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68 | |||
69 | |||
70 | #if CONFIG_FS_THREADS > 1 |
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71 | static mutex_t ramfs_lock = MUTEX_INITIALIZER;
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72 | #endif
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73 | |||
74 | /*
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75 | * vnode operations
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76 | */
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77 | struct vnops ramfs_vnops = {
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78 | ramfs_open, /* open */
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79 | ramfs_close, /* close */
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80 | ramfs_read, /* read */
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81 | ramfs_write, /* write */
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82 | ramfs_seek, /* seek */
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83 | ramfs_ioctl, /* ioctl */
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84 | ramfs_fsync, /* fsync */
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85 | ramfs_readdir, /* readdir */
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86 | ramfs_lookup, /* lookup */
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87 | ramfs_create, /* create */
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88 | ramfs_remove, /* remove */
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89 | ramfs_rename, /* remame */
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90 | ramfs_mkdir, /* mkdir */
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91 | ramfs_rmdir, /* rmdir */
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92 | ramfs_getattr, /* getattr */
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93 | ramfs_setattr, /* setattr */
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94 | ramfs_inactive, /* inactive */
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95 | ramfs_truncate, /* truncate */
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96 | }; |
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97 | |||
98 | struct ramfs_node *
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99 | ramfs_allocate_node(char *name, int type) |
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100 | { |
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101 | struct ramfs_node *np;
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102 | |||
103 | np = malloc(sizeof(struct ramfs_node)); |
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104 | if (np == NULL) |
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105 | return NULL; |
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106 | memset(np, 0, sizeof(struct ramfs_node)); |
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107 | |||
108 | np->rn_namelen = strlen(name); |
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109 | np->rn_name = malloc(np->rn_namelen + 1);
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110 | if (np->rn_name == NULL) { |
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111 | free(np); |
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112 | return NULL; |
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113 | } |
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114 | strlcpy(np->rn_name, name, np->rn_namelen + 1);
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115 | np->rn_type = type; |
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116 | return np;
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117 | } |
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118 | |||
119 | void
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120 | ramfs_free_node(struct ramfs_node *np)
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121 | { |
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122 | |||
123 | free(np->rn_name); |
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124 | free(np); |
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125 | } |
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126 | |||
127 | static struct ramfs_node * |
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128 | ramfs_add_node(struct ramfs_node *dnp, char *name, int type) |
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129 | { |
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130 | struct ramfs_node *np, *prev;
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131 | |||
132 | np = ramfs_allocate_node(name, type); |
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133 | if (np == NULL) |
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134 | return NULL; |
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135 | |||
136 | mutex_lock(&ramfs_lock); |
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137 | |||
138 | /* Link to the directory list */
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139 | if (dnp->rn_child == NULL) { |
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140 | dnp->rn_child = np; |
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141 | } else {
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142 | prev = dnp->rn_child; |
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143 | while (prev->rn_next != NULL) |
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144 | prev = prev->rn_next; |
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145 | prev->rn_next = np; |
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146 | } |
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147 | mutex_unlock(&ramfs_lock); |
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148 | return np;
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149 | } |
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150 | |||
151 | static int |
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152 | ramfs_remove_node(struct ramfs_node *dnp, struct ramfs_node *np) |
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153 | { |
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154 | struct ramfs_node *prev;
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155 | |||
156 | if (dnp->rn_child == NULL) |
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157 | return EBUSY;
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158 | |||
159 | mutex_lock(&ramfs_lock); |
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160 | |||
161 | /* Unlink from the directory list */
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162 | if (dnp->rn_child == np) {
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163 | dnp->rn_child = np->rn_next; |
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164 | } else {
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165 | for (prev = dnp->rn_child; prev->rn_next != np;
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166 | prev = prev->rn_next) { |
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167 | if (prev->rn_next == NULL) { |
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168 | mutex_unlock(&ramfs_lock); |
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169 | return ENOENT;
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170 | } |
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171 | } |
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172 | prev->rn_next = np->rn_next; |
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173 | } |
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174 | ramfs_free_node(np); |
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175 | |||
176 | mutex_unlock(&ramfs_lock); |
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177 | return 0; |
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178 | } |
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179 | |||
180 | static int |
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181 | ramfs_rename_node(struct ramfs_node *np, char *name) |
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182 | { |
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183 | size_t len; |
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184 | char *tmp;
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185 | |||
186 | len = strlen(name); |
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187 | if (len <= np->rn_namelen) {
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188 | /* Reuse current name buffer */
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189 | strlcpy(np->rn_name, name, sizeof(np->rn_name));
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190 | } else {
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191 | /* Expand name buffer */
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192 | tmp = malloc(len + 1);
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193 | if (tmp == NULL) |
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194 | return ENOMEM;
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195 | strlcpy(tmp, name, len + 1);
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196 | free(np->rn_name); |
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197 | np->rn_name = tmp; |
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198 | } |
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199 | np->rn_namelen = len; |
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200 | return 0; |
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201 | } |
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202 | |||
203 | static int |
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204 | ramfs_lookup(vnode_t dvp, char *name, vnode_t vp)
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205 | { |
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206 | struct ramfs_node *np, *dnp;
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207 | size_t len; |
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208 | int found;
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209 | |||
210 | if (*name == '\0') |
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211 | return ENOENT;
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212 | |||
213 | mutex_lock(&ramfs_lock); |
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214 | |||
215 | len = strlen(name); |
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216 | dnp = dvp->v_data; |
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217 | found = 0;
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218 | for (np = dnp->rn_child; np != NULL; np = np->rn_next) { |
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219 | if (np->rn_namelen == len &&
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220 | memcmp(name, np->rn_name, len) == 0) {
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221 | found = 1;
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222 | break;
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223 | } |
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224 | } |
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225 | if (found == 0) { |
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226 | mutex_unlock(&ramfs_lock); |
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227 | return ENOENT;
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228 | } |
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229 | vp->v_data = np; |
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230 | vp->v_mode = ALLPERMS; |
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231 | vp->v_type = np->rn_type; |
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232 | vp->v_size = np->rn_size; |
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233 | |||
234 | mutex_unlock(&ramfs_lock); |
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235 | return 0; |
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236 | } |
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237 | |||
238 | static int |
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239 | ramfs_mkdir(vnode_t dvp, char *name, mode_t mode)
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240 | { |
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241 | struct ramfs_node *np;
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242 | |||
243 | DPRINTF(("mkdir %s\n", name));
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244 | if (!S_ISDIR(mode))
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245 | return EINVAL;
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246 | |||
247 | np = ramfs_add_node(dvp->v_data, name, VDIR); |
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248 | if (np == NULL) |
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249 | return ENOMEM;
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250 | np->rn_size = 0;
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251 | return 0; |
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252 | } |
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253 | |||
254 | /* Remove a directory */
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255 | static int |
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256 | ramfs_rmdir(vnode_t dvp, vnode_t vp, char *name)
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257 | { |
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258 | |||
259 | return ramfs_remove_node(dvp->v_data, vp->v_data);
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260 | } |
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261 | |||
262 | /* Remove a file */
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263 | static int |
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264 | ramfs_remove(vnode_t dvp, vnode_t vp, char *name)
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265 | { |
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266 | struct ramfs_node *np;
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267 | int error;
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268 | |||
269 | DPRINTF(("remove %s in %s\n", name, dvp->v_path));
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270 | error = ramfs_remove_node(dvp->v_data, vp->v_data); |
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271 | if (error)
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272 | return error;
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273 | |||
274 | np = vp->v_data; |
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275 | if (np->rn_buf != NULL) |
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276 | vm_free(task_self(), np->rn_buf); |
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277 | return 0; |
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278 | } |
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279 | |||
280 | /* Truncate file */
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281 | static int |
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282 | ramfs_truncate(vnode_t vp, off_t length) |
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283 | { |
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284 | struct ramfs_node *np;
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285 | void *new_buf;
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286 | size_t new_size; |
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287 | task_t task; |
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288 | |||
289 | DPRINTF(("truncate %s length=%d\n", vp->v_path, length));
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290 | np = vp->v_data; |
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291 | |||
292 | if (length == 0) { |
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293 | if (np->rn_buf != NULL) { |
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294 | vm_free(task_self(), np->rn_buf); |
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295 | np->rn_buf = NULL;
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296 | np->rn_bufsize = 0;
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297 | } |
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298 | } else if (length > np->rn_bufsize) { |
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299 | task = task_self(); |
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300 | new_size = round_page(length); |
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301 | if (vm_allocate(task, &new_buf, new_size, 1)) |
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302 | return EIO;
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303 | if (np->rn_size != 0) { |
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304 | memcpy(new_buf, np->rn_buf, vp->v_size); |
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305 | vm_free(task, np->rn_buf); |
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306 | } |
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307 | np->rn_buf = new_buf; |
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308 | np->rn_bufsize = new_size; |
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309 | } |
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310 | np->rn_size = length; |
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311 | vp->v_size = length; |
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312 | return 0; |
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313 | } |
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314 | |||
315 | /*
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316 | * Create empty file.
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317 | */
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318 | static int |
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319 | ramfs_create(vnode_t dvp, char *name, mode_t mode)
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320 | { |
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321 | struct ramfs_node *np;
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322 | |||
323 | DPRINTF(("create %s in %s\n", name, dvp->v_path));
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324 | if (!S_ISREG(mode))
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325 | return EINVAL;
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326 | |||
327 | np = ramfs_add_node(dvp->v_data, name, VREG); |
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328 | if (np == NULL) |
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329 | return ENOMEM;
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330 | return 0; |
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331 | } |
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332 | |||
333 | static int |
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334 | ramfs_read(vnode_t vp, file_t fp, void *buf, size_t size, size_t *result)
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335 | { |
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336 | struct ramfs_node *np;
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337 | off_t off; |
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338 | |||
339 | *result = 0;
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340 | if (vp->v_type == VDIR)
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341 | return EISDIR;
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342 | if (vp->v_type != VREG)
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343 | return EINVAL;
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344 | |||
345 | off = fp->f_offset; |
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346 | if (off >= (off_t)vp->v_size)
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347 | return 0; |
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348 | |||
349 | if (vp->v_size - off < size)
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350 | size = vp->v_size - off; |
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351 | |||
352 | np = vp->v_data; |
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353 | memcpy(buf, np->rn_buf + off, size); |
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354 | |||
355 | fp->f_offset += size; |
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356 | *result = size; |
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357 | return 0; |
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358 | } |
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359 | |||
360 | static int |
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361 | ramfs_write(vnode_t vp, file_t fp, void *buf, size_t size, size_t *result)
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362 | { |
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363 | struct ramfs_node *np;
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364 | off_t file_pos, end_pos; |
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365 | void *new_buf;
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366 | size_t new_size; |
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367 | task_t task; |
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368 | |||
369 | *result = 0;
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370 | if (vp->v_type == VDIR)
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371 | return EISDIR;
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372 | if (vp->v_type != VREG)
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373 | return EINVAL;
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374 | |||
375 | np = vp->v_data; |
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376 | /* Check if the file position exceeds the end of file. */
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377 | end_pos = vp->v_size; |
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378 | file_pos = (fp->f_flags & O_APPEND) ? end_pos : fp->f_offset; |
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379 | if (file_pos + size > (size_t)end_pos) {
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380 | /* Expand the file size before writing to it */
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381 | end_pos = file_pos + size; |
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382 | if (end_pos > (off_t)np->rn_bufsize) {
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383 | task = task_self(); |
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384 | /*
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385 | * We allocate the data buffer in page boundary.
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386 | * So that we can reduce the memory allocation unless
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387 | * the file size exceeds next page boundary.
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388 | * This will prevent the memory fragmentation by
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389 | * many malloc/free calls.
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390 | */
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391 | new_size = round_page(end_pos); |
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392 | if (vm_allocate(task, &new_buf, new_size, 1)) |
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393 | return EIO;
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394 | if (np->rn_size != 0) { |
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395 | memcpy(new_buf, np->rn_buf, vp->v_size); |
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396 | vm_free(task, np->rn_buf); |
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397 | } |
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398 | np->rn_buf = new_buf; |
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399 | np->rn_bufsize = new_size; |
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400 | } |
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401 | np->rn_size = end_pos; |
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402 | vp->v_size = end_pos; |
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403 | } |
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404 | memcpy(np->rn_buf + file_pos, buf, size); |
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405 | fp->f_offset += size; |
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406 | *result = size; |
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407 | return 0; |
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408 | } |
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409 | |||
410 | static int |
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411 | ramfs_rename(vnode_t dvp1, vnode_t vp1, char *name1,
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412 | vnode_t dvp2, vnode_t vp2, char *name2)
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413 | { |
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414 | struct ramfs_node *np, *old_np;
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415 | int error;
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416 | |||
417 | if (vp2) {
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418 | /* Remove destination file, first */
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419 | error = ramfs_remove_node(dvp2->v_data, vp2->v_data); |
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420 | if (error)
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421 | return error;
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422 | } |
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423 | /* Same directory ? */
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424 | if (dvp1 == dvp2) {
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425 | /* Change the name of existing file */
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426 | error = ramfs_rename_node(vp1->v_data, name2); |
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427 | if (error)
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428 | return error;
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429 | } else {
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430 | /* Create new file or directory */
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431 | old_np = vp1->v_data; |
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432 | np = ramfs_add_node(dvp2->v_data, name2, VREG); |
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433 | if (np == NULL) |
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434 | return ENOMEM;
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435 | |||
436 | if (vp1->v_type == VREG) {
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437 | /* Copy file data */
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438 | np->rn_buf = old_np->rn_buf; |
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439 | np->rn_size = old_np->rn_size; |
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440 | np->rn_bufsize = old_np->rn_bufsize; |
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441 | } |
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442 | /* Remove source file */
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443 | ramfs_remove_node(dvp1->v_data, vp1->v_data); |
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444 | } |
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445 | return 0; |
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446 | } |
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447 | |||
448 | /*
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449 | * @vp: vnode of the directory.
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450 | */
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451 | static int |
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452 | ramfs_readdir(vnode_t vp, file_t fp, struct dirent *dir)
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453 | { |
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454 | struct ramfs_node *np, *dnp;
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455 | int i;
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456 | |||
457 | mutex_lock(&ramfs_lock); |
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458 | |||
459 | if (fp->f_offset == 0) { |
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460 | dir->d_type = DT_DIR; |
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461 | strlcpy((char *)&dir->d_name, ".", sizeof(dir->d_name)); |
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462 | } else if (fp->f_offset == 1) { |
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463 | dir->d_type = DT_DIR; |
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464 | strlcpy((char *)&dir->d_name, "..", sizeof(dir->d_name)); |
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465 | } else {
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466 | dnp = vp->v_data; |
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467 | np = dnp->rn_child; |
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468 | if (np == NULL) { |
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469 | mutex_unlock(&ramfs_lock); |
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470 | return ENOENT;
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471 | } |
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472 | |||
473 | for (i = 0; i != (fp->f_offset - 2); i++) { |
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474 | np = np->rn_next; |
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475 | if (np == NULL) { |
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476 | mutex_unlock(&ramfs_lock); |
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477 | return ENOENT;
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478 | } |
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479 | } |
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480 | if (np->rn_type == VDIR)
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481 | dir->d_type = DT_DIR; |
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482 | else
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483 | dir->d_type = DT_REG; |
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484 | strlcpy((char *)&dir->d_name, np->rn_name,
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485 | sizeof(dir->d_name));
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486 | } |
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487 | dir->d_fileno = (uint32_t)fp->f_offset; |
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488 | dir->d_namlen = (uint16_t)strlen(dir->d_name); |
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489 | |||
490 | fp->f_offset++; |
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491 | |||
492 | mutex_unlock(&ramfs_lock); |
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493 | return 0; |
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494 | } |
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495 | |||
496 | int
|
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497 | ramfs_init(void)
|
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498 | { |
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499 | return 0; |
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500 | } |