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
34 #include <linux/kdev_t.h>
35
36 #define LOG_TAG "Vold"
37
38 #include <cutils/log.h>
39 #include <cutils/properties.h>
40
41 #include <logwrap/logwrap.h>
42
43 #include "Fat.h"
44 #include "VoldUtil.h"
45
46 static char FSCK_MSDOS_PATH[] = "/system/bin/fsck_msdos";
47 static char MKDOSFS_PATH[] = "/system/bin/newfs_msdos";
48 extern "C" int mount(const char *, const char *, const char *, unsigned long, const void *);
49
check(const char * fsPath)50 int Fat::check(const char *fsPath) {
51 bool rw = true;
52 if (access(FSCK_MSDOS_PATH, X_OK)) {
53 SLOGW("Skipping fs checks\n");
54 return 0;
55 }
56
57 int pass = 1;
58 int rc = 0;
59 do {
60 const char *args[4];
61 int status;
62 args[0] = FSCK_MSDOS_PATH;
63 args[1] = "-p";
64 args[2] = "-f";
65 args[3] = fsPath;
66
67 rc = android_fork_execvp(ARRAY_SIZE(args), (char **)args, &status,
68 false, true);
69 if (rc != 0) {
70 SLOGE("Filesystem check failed due to logwrap error");
71 errno = EIO;
72 return -1;
73 }
74
75 if (!WIFEXITED(status)) {
76 SLOGE("Filesystem check did not exit properly");
77 errno = EIO;
78 return -1;
79 }
80
81 status = WEXITSTATUS(status);
82
83 switch(status) {
84 case 0:
85 SLOGI("Filesystem check completed OK");
86 return 0;
87
88 case 2:
89 SLOGE("Filesystem check failed (not a FAT filesystem)");
90 errno = ENODATA;
91 return -1;
92
93 case 4:
94 if (pass++ <= 3) {
95 SLOGW("Filesystem modified - rechecking (pass %d)",
96 pass);
97 continue;
98 }
99 SLOGE("Failing check after too many rechecks");
100 errno = EIO;
101 return -1;
102
103 default:
104 SLOGE("Filesystem check failed (unknown exit code %d)", status);
105 errno = EIO;
106 return -1;
107 }
108 } while (0);
109
110 return 0;
111 }
112
doMount(const char * fsPath,const char * mountPoint,bool ro,bool remount,bool executable,int ownerUid,int ownerGid,int permMask,bool createLost)113 int Fat::doMount(const char *fsPath, const char *mountPoint,
114 bool ro, bool remount, bool executable,
115 int ownerUid, int ownerGid, int permMask, bool createLost) {
116 int rc;
117 unsigned long flags;
118 char mountData[255];
119
120 flags = MS_NODEV | MS_NOSUID | MS_DIRSYNC;
121
122 flags |= (executable ? 0 : MS_NOEXEC);
123 flags |= (ro ? MS_RDONLY : 0);
124 flags |= (remount ? MS_REMOUNT : 0);
125
126 /*
127 * Note: This is a temporary hack. If the sampling profiler is enabled,
128 * we make the SD card world-writable so any process can write snapshots.
129 *
130 * TODO: Remove this code once we have a drop box in system_server.
131 */
132 char value[PROPERTY_VALUE_MAX];
133 property_get("persist.sampling_profiler", value, "");
134 if (value[0] == '1') {
135 SLOGW("The SD card is world-writable because the"
136 " 'persist.sampling_profiler' system property is set to '1'.");
137 permMask = 0;
138 }
139
140 sprintf(mountData,
141 "utf8,uid=%d,gid=%d,fmask=%o,dmask=%o,shortname=mixed",
142 ownerUid, ownerGid, permMask, permMask);
143
144 rc = mount(fsPath, mountPoint, "vfat", flags, mountData);
145
146 if (rc && errno == EROFS) {
147 SLOGE("%s appears to be a read only filesystem - retrying mount RO", fsPath);
148 flags |= MS_RDONLY;
149 rc = mount(fsPath, mountPoint, "vfat", flags, mountData);
150 }
151
152 if (rc == 0 && createLost) {
153 char *lost_path;
154 asprintf(&lost_path, "%s/LOST.DIR", mountPoint);
155 if (access(lost_path, F_OK)) {
156 /*
157 * Create a LOST.DIR in the root so we have somewhere to put
158 * lost cluster chains (fsck_msdos doesn't currently do this)
159 */
160 if (mkdir(lost_path, 0755)) {
161 SLOGE("Unable to create LOST.DIR (%s)", strerror(errno));
162 }
163 }
164 free(lost_path);
165 }
166
167 return rc;
168 }
169
format(const char * fsPath,unsigned int numSectors)170 int Fat::format(const char *fsPath, unsigned int numSectors) {
171 int fd;
172 const char *args[10];
173 int rc;
174 int status;
175
176 args[0] = MKDOSFS_PATH;
177 args[1] = "-F";
178 args[2] = "32";
179 args[3] = "-O";
180 args[4] = "android";
181 args[5] = "-c";
182 args[6] = "8";
183
184 if (numSectors) {
185 char tmp[32];
186 snprintf(tmp, sizeof(tmp), "%u", numSectors);
187 const char *size = tmp;
188 args[7] = "-s";
189 args[8] = size;
190 args[9] = fsPath;
191 rc = android_fork_execvp(ARRAY_SIZE(args), (char **)args, &status,
192 false, true);
193 } else {
194 args[7] = fsPath;
195 rc = android_fork_execvp(8, (char **)args, &status, false,
196 true);
197 }
198
199 if (rc != 0) {
200 SLOGE("Filesystem format failed due to logwrap error");
201 errno = EIO;
202 return -1;
203 }
204
205 if (!WIFEXITED(status)) {
206 SLOGE("Filesystem format did not exit properly");
207 errno = EIO;
208 return -1;
209 }
210
211 status = WEXITSTATUS(status);
212
213 if (status == 0) {
214 SLOGI("Filesystem formatted OK");
215 return 0;
216 } else {
217 SLOGE("Format failed (unknown exit code %d)", status);
218 errno = EIO;
219 return -1;
220 }
221 return 0;
222 }
223