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 <fcntl.h>
19 #include <unistd.h>
20 #include <errno.h>
21 #include <string.h>
22 #include <dirent.h>
23 #include <errno.h>
24 #include <fcntl.h>
25
26 #include <sys/types.h>
27 #include <sys/stat.h>
28 #include <sys/types.h>
29 #include <sys/mman.h>
30 #include <sys/mount.h>
31
32 #include <linux/kdev_t.h>
33
34 #define LOG_TAG "Vold"
35
36 #include <cutils/log.h>
37 #include <cutils/properties.h>
38
39 #include "Fat.h"
40
41 static char FSCK_MSDOS_PATH[] = "/system/bin/fsck_msdos";
42 static char MKDOSFS_PATH[] = "/system/bin/newfs_msdos";
43 extern "C" int logwrap(int argc, const char **argv, int background);
44 extern "C" int mount(const char *, const char *, const char *, unsigned long, const void *);
45
check(const char * fsPath)46 int Fat::check(const char *fsPath) {
47 bool rw = true;
48 if (access(FSCK_MSDOS_PATH, X_OK)) {
49 SLOGW("Skipping fs checks\n");
50 return 0;
51 }
52
53 int pass = 1;
54 int rc = 0;
55 do {
56 const char *args[5];
57 args[0] = FSCK_MSDOS_PATH;
58 args[1] = "-p";
59 args[2] = "-f";
60 args[3] = fsPath;
61 args[4] = NULL;
62
63 rc = logwrap(4, args, 1);
64
65 switch(rc) {
66 case 0:
67 SLOGI("Filesystem check completed OK");
68 return 0;
69
70 case 2:
71 SLOGE("Filesystem check failed (not a FAT filesystem)");
72 errno = ENODATA;
73 return -1;
74
75 case 4:
76 if (pass++ <= 3) {
77 SLOGW("Filesystem modified - rechecking (pass %d)",
78 pass);
79 continue;
80 }
81 SLOGE("Failing check after too many rechecks");
82 errno = EIO;
83 return -1;
84
85 default:
86 SLOGE("Filesystem check failed (unknown exit code %d)", rc);
87 errno = EIO;
88 return -1;
89 }
90 } while (0);
91
92 return 0;
93 }
94
doMount(const char * fsPath,const char * mountPoint,bool ro,bool remount,bool executable,int ownerUid,int ownerGid,int permMask,bool createLost)95 int Fat::doMount(const char *fsPath, const char *mountPoint,
96 bool ro, bool remount, bool executable,
97 int ownerUid, int ownerGid, int permMask, bool createLost) {
98 int rc;
99 unsigned long flags;
100 char mountData[255];
101
102 flags = MS_NODEV | MS_NOSUID | MS_DIRSYNC;
103
104 flags |= (executable ? 0 : MS_NOEXEC);
105 flags |= (ro ? MS_RDONLY : 0);
106 flags |= (remount ? MS_REMOUNT : 0);
107
108 /*
109 * Note: This is a temporary hack. If the sampling profiler is enabled,
110 * we make the SD card world-writable so any process can write snapshots.
111 *
112 * TODO: Remove this code once we have a drop box in system_server.
113 */
114 char value[PROPERTY_VALUE_MAX];
115 property_get("persist.sampling_profiler", value, "");
116 if (value[0] == '1') {
117 SLOGW("The SD card is world-writable because the"
118 " 'persist.sampling_profiler' system property is set to '1'.");
119 permMask = 0;
120 }
121
122 sprintf(mountData,
123 "utf8,uid=%d,gid=%d,fmask=%o,dmask=%o,shortname=mixed",
124 ownerUid, ownerGid, permMask, permMask);
125
126 rc = mount(fsPath, mountPoint, "vfat", flags, mountData);
127
128 if (rc && errno == EROFS) {
129 SLOGE("%s appears to be a read only filesystem - retrying mount RO", fsPath);
130 flags |= MS_RDONLY;
131 rc = mount(fsPath, mountPoint, "vfat", flags, mountData);
132 }
133
134 if (rc == 0 && createLost) {
135 char *lost_path;
136 asprintf(&lost_path, "%s/LOST.DIR", mountPoint);
137 if (access(lost_path, F_OK)) {
138 /*
139 * Create a LOST.DIR in the root so we have somewhere to put
140 * lost cluster chains (fsck_msdos doesn't currently do this)
141 */
142 if (mkdir(lost_path, 0755)) {
143 SLOGE("Unable to create LOST.DIR (%s)", strerror(errno));
144 }
145 }
146 free(lost_path);
147 }
148
149 return rc;
150 }
151
format(const char * fsPath,unsigned int numSectors)152 int Fat::format(const char *fsPath, unsigned int numSectors) {
153 int fd;
154 const char *args[11];
155 int rc;
156
157 args[0] = MKDOSFS_PATH;
158 args[1] = "-F";
159 args[2] = "32";
160 args[3] = "-O";
161 args[4] = "android";
162 args[5] = "-c";
163 args[6] = "8";
164
165 if (numSectors) {
166 char tmp[32];
167 snprintf(tmp, sizeof(tmp), "%u", numSectors);
168 const char *size = tmp;
169 args[7] = "-s";
170 args[8] = size;
171 args[9] = fsPath;
172 args[10] = NULL;
173 rc = logwrap(11, args, 1);
174 } else {
175 args[7] = fsPath;
176 args[8] = NULL;
177 rc = logwrap(9, args, 1);
178 }
179
180 if (rc == 0) {
181 SLOGI("Filesystem formatted OK");
182 return 0;
183 } else {
184 SLOGE("Format failed (unknown exit code %d)", rc);
185 errno = EIO;
186 return -1;
187 }
188 return 0;
189 }
190