root / prex-0.9.0 / usr / server / fs / vfs / vfs_lookup.c @ 03e9c04a
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1 | 03e9c04a | Brad Neuman | /*
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2 | * Copyright (c) 2005-2007, 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 | * vfs_lookup.c - vnode lookup function.
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32 | */
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33 | |||
34 | #include <sys/vnode.h> |
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35 | #include <sys/mount.h> |
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36 | |||
37 | #include <limits.h> |
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38 | #include <unistd.h> |
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39 | #include <string.h> |
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40 | #include <errno.h> |
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41 | |||
42 | #include "vfs.h" |
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43 | |||
44 | /*
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45 | * Convert a pathname into a pointer to a locked vnode.
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46 | *
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47 | * @path: full path name.
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48 | * @vpp: vnode to be returned.
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49 | */
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50 | int
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51 | namei(char *path, vnode_t *vpp)
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52 | { |
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53 | char *p;
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54 | char node[PATH_MAX];
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55 | char name[PATH_MAX];
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56 | mount_t mp; |
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57 | vnode_t dvp, vp; |
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58 | int error, i;
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59 | |||
60 | DPRINTF(VFSDB_VNODE, ("namei: path=%s\n", path));
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61 | |||
62 | /*
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63 | * Convert a full path name to its mount point and
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64 | * the local node in the file system.
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65 | */
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66 | if (vfs_findroot(path, &mp, &p))
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67 | return ENOTDIR;
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68 | strlcpy(node, "/", sizeof(node)); |
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69 | strlcat(node, p, sizeof(node));
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70 | vp = vn_lookup(mp, node); |
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71 | if (vp) {
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72 | /* vnode is already active. */
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73 | *vpp = vp; |
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74 | return 0; |
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75 | } |
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76 | /*
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77 | * Find target vnode, started from root directory.
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78 | * This is done to attach the fs specific data to
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79 | * the target vnode.
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80 | */
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81 | if ((dvp = mp->m_root) == NULL) |
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82 | sys_panic("VFS: no root");
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83 | |||
84 | vref(dvp); |
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85 | vn_lock(dvp); |
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86 | node[0] = '\0'; |
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87 | |||
88 | while (*p != '\0') { |
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89 | /*
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90 | * Get lower directory/file name.
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91 | */
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92 | while (*p == '/') |
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93 | p++; |
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94 | for (i = 0; i < PATH_MAX; i++) { |
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95 | if (*p == '\0' || *p == '/') |
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96 | break;
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97 | name[i] = *p++; |
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98 | } |
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99 | name[i] = '\0';
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100 | |||
101 | /*
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102 | * Get a vnode for the target.
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103 | */
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104 | strlcat(node, "/", sizeof(node)); |
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105 | strlcat(node, name, sizeof(node));
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106 | vp = vn_lookup(mp, node); |
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107 | if (vp == NULL) { |
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108 | vp = vget(mp, node); |
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109 | if (vp == NULL) { |
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110 | vput(dvp); |
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111 | return ENOMEM;
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112 | } |
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113 | /* Find a vnode in this directory. */
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114 | error = VOP_LOOKUP(dvp, name, vp); |
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115 | if (error || (*p == '/' && vp->v_type != VDIR)) { |
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116 | /* Not found */
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117 | vput(vp); |
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118 | vput(dvp); |
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119 | return error;
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120 | } |
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121 | } |
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122 | vput(dvp); |
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123 | dvp = vp; |
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124 | while (*p != '\0' && *p != '/') |
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125 | p++; |
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126 | } |
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127 | |||
128 | /*
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129 | * Detemine X permission.
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130 | */
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131 | if (vp->v_type != VDIR && sec_vnode_permission(path) != 0) { |
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132 | vp->v_mode &= ~(0111);
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133 | } |
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134 | |||
135 | *vpp = vp; |
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136 | return 0; |
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137 | } |
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138 | |||
139 | /*
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140 | * Search a pathname.
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141 | * This is a very central but not so complicated routine. ;-P
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142 | *
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143 | * @path: full path.
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144 | * @vpp: pointer to locked vnode for directory.
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145 | * @name: pointer to file name in path.
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146 | *
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147 | * This routine returns a locked directory vnode and file name.
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148 | */
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149 | int
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150 | lookup(char *path, vnode_t *vpp, char **name) |
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151 | { |
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152 | char buf[PATH_MAX];
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153 | char root[] = "/"; |
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154 | char *file, *dir;
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155 | vnode_t vp; |
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156 | int error;
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157 | |||
158 | DPRINTF(VFSDB_VNODE, ("lookup: path=%s\n", path));
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159 | |||
160 | /*
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161 | * Get the path for directory.
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162 | */
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163 | strlcpy(buf, path, sizeof(buf));
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164 | file = strrchr(buf, '/');
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165 | if (!buf[0]) |
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166 | return ENOTDIR;
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167 | if (file == buf)
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168 | dir = root; |
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169 | else {
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170 | *file = '\0';
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171 | dir = buf; |
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172 | } |
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173 | /*
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174 | * Get the vnode for directory
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175 | */
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176 | if ((error = namei(dir, &vp)) != 0) |
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177 | return error;
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178 | if (vp->v_type != VDIR) {
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179 | vput(vp); |
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180 | return ENOTDIR;
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181 | } |
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182 | *vpp = vp; |
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183 | |||
184 | /*
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185 | * Get the file name
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186 | */
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187 | *name = strrchr(path, '/') + 1; |
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188 | return 0; |
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189 | } |