1 /* 2 * Copyright (C) 2008 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #include <stdio.h> 18 #include <stdlib.h> 19 #include <fcntl.h> 20 #include <unistd.h> 21 #include <errno.h> 22 #include <string.h> 23 #include <dirent.h> 24 #include <errno.h> 25 #include <fcntl.h> 26 27 #include <sys/types.h> 28 #include <sys/stat.h> 29 #include <sys/types.h> 30 #include <sys/mman.h> 31 #include <sys/mount.h> 32 #include <sys/wait.h> 33 #include <linux/fs.h> 34 #include <sys/ioctl.h> 35 36 #include <linux/kdev_t.h> 37 38 #include <android-base/logging.h> 39 #include <android-base/stringprintf.h> 40 #include <selinux/selinux.h> 41 42 #include <logwrap/logwrap.h> 43 44 #include "Vfat.h" 45 #include "Utils.h" 46 #include "VoldUtil.h" 47 48 using android::base::StringPrintf; 49 50 namespace android { 51 namespace vold { 52 namespace vfat { 53 54 static const char* kMkfsPath = "/system/bin/newfs_msdos"; 55 static const char* kFsckPath = "/system/bin/fsck_msdos"; 56 57 bool IsSupported() { 58 return access(kMkfsPath, X_OK) == 0 59 && access(kFsckPath, X_OK) == 0 60 && IsFilesystemSupported("vfat"); 61 } 62 63 status_t Check(const std::string& source) { 64 int pass = 1; 65 int rc = 0; 66 do { 67 std::vector<std::string> cmd; 68 cmd.push_back(kFsckPath); 69 cmd.push_back("-p"); 70 cmd.push_back("-f"); 71 cmd.push_back(source); 72 73 // Fat devices are currently always untrusted 74 rc = ForkExecvp(cmd, sFsckUntrustedContext); 75 76 if (rc < 0) { 77 LOG(ERROR) << "Filesystem check failed due to logwrap error"; 78 errno = EIO; 79 return -1; 80 } 81 82 switch(rc) { 83 case 0: 84 LOG(INFO) << "Filesystem check completed OK"; 85 return 0; 86 87 case 2: 88 LOG(ERROR) << "Filesystem check failed (not a FAT filesystem)"; 89 errno = ENODATA; 90 return -1; 91 92 case 4: 93 if (pass++ <= 3) { 94 LOG(WARNING) << "Filesystem modified - rechecking (pass " << pass << ")"; 95 continue; 96 } 97 LOG(ERROR) << "Failing check after too many rechecks"; 98 errno = EIO; 99 return -1; 100 101 case 8: 102 LOG(ERROR) << "Filesystem check failed (no filesystem)"; 103 errno = ENODATA; 104 return -1; 105 106 default: 107 LOG(ERROR) << "Filesystem check failed (unknown exit code " << rc << ")"; 108 errno = EIO; 109 return -1; 110 } 111 } while (0); 112 113 return 0; 114 } 115 116 status_t Mount(const std::string& source, const std::string& target, bool ro, 117 bool remount, bool executable, int ownerUid, int ownerGid, int permMask, 118 bool createLost) { 119 int rc; 120 unsigned long flags; 121 122 const char* c_source = source.c_str(); 123 const char* c_target = target.c_str(); 124 125 flags = MS_NODEV | MS_NOSUID | MS_DIRSYNC | MS_NOATIME; 126 127 flags |= (executable ? 0 : MS_NOEXEC); 128 flags |= (ro ? MS_RDONLY : 0); 129 flags |= (remount ? MS_REMOUNT : 0); 130 131 auto mountData = android::base::StringPrintf( 132 "utf8,uid=%d,gid=%d,fmask=%o,dmask=%o,shortname=mixed", 133 ownerUid, ownerGid, permMask, permMask); 134 135 rc = mount(c_source, c_target, "vfat", flags, mountData.c_str()); 136 137 if (rc && errno == EROFS) { 138 LOG(ERROR) << source << " appears to be a read only filesystem - retrying mount RO"; 139 flags |= MS_RDONLY; 140 rc = mount(c_source, c_target, "vfat", flags, mountData.c_str()); 141 } 142 143 if (rc == 0 && createLost) { 144 auto lost_path = android::base::StringPrintf("%s/LOST.DIR", target.c_str()); 145 if (access(lost_path.c_str(), F_OK)) { 146 /* 147 * Create a LOST.DIR in the root so we have somewhere to put 148 * lost cluster chains (fsck_msdos doesn't currently do this) 149 */ 150 if (mkdir(lost_path.c_str(), 0755)) { 151 PLOG(ERROR) << "Unable to create LOST.DIR"; 152 } 153 } 154 } 155 156 return rc; 157 } 158 159 status_t Format(const std::string& source, unsigned long numSectors) { 160 std::vector<std::string> cmd; 161 cmd.push_back(kMkfsPath); 162 cmd.push_back("-F"); 163 cmd.push_back("32"); 164 cmd.push_back("-O"); 165 cmd.push_back("android"); 166 cmd.push_back("-c"); 167 cmd.push_back("64"); 168 cmd.push_back("-A"); 169 170 if (numSectors) { 171 cmd.push_back("-s"); 172 cmd.push_back(StringPrintf("%lu", numSectors)); 173 } 174 175 cmd.push_back(source); 176 177 int rc = ForkExecvp(cmd); 178 if (rc < 0) { 179 LOG(ERROR) << "Filesystem format failed due to logwrap error"; 180 errno = EIO; 181 return -1; 182 } 183 184 if (rc == 0) { 185 LOG(INFO) << "Filesystem formatted OK"; 186 return 0; 187 } else { 188 LOG(ERROR) << "Format failed (unknown exit code " << rc << ")"; 189 errno = EIO; 190 return -1; 191 } 192 return 0; 193 } 194 195 } // namespace vfat 196 } // namespace vold 197 } // namespace android 198
