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 <dirent.h>
18 #include <errno.h>
19 #include <fcntl.h>
20 #include <limits.h>
21 #include <stdio.h>
22 #include <stdlib.h>
23 #include <string.h>
24 #include <sys/klog.h>
25 #include <sys/reboot.h>
26 #include <sys/stat.h>
27 #include <sys/types.h>
28 #include <time.h>
29 #include <unistd.h>
30 
31 #include "private/android_filesystem_config.h"
32 
33 // Sentinel file used to track whether we've forced a reboot
34 static const char *kMarkerFile = "/data/misc/check-lost+found-rebooted-2";
35 
36 // Output file in tombstones directory (first 8K will be uploaded)
37 static const char *kOutputDir = "/data/tombstones";
38 static const char *kOutputFile = "/data/tombstones/check-lost+found-log";
39 
40 // Partitions to check
41 static const char *kPartitions[] = { "/system", "/data", "/cache", NULL };
42 
43 /*
44  * 1. If /data/misc/forced-reboot is missing, touch it & force "unclean" boot.
45  * 2. Write a log entry with the number of files in lost+found directories.
46  */
47 
main(int argc,char ** argv)48 int main(int argc __attribute__((unused)), char **argv __attribute__((unused))) {
49     mkdir(kOutputDir, 0755);
50     chown(kOutputDir, AID_SYSTEM, AID_SYSTEM);
51     FILE *out = fopen(kOutputFile, "a");
52     if (out == NULL) {
53         fprintf(stderr, "Can't write %s: %s\n", kOutputFile, strerror(errno));
54         return 1;
55     }
56 
57     // Note: only the first 8K of log will be uploaded, so be terse.
58     time_t start = time(NULL);
59     fprintf(out, "*** check-lost+found ***\nStarted: %s", ctime(&start));
60 
61     struct stat st;
62     if (stat(kMarkerFile, &st)) {
63         // No reboot marker -- need to force an unclean reboot.
64         // But first, try to create the marker file.  If that fails,
65         // skip the reboot, so we don't get caught in an infinite loop.
66 
67         int fd = open(kMarkerFile, O_WRONLY|O_CREAT, 0444);
68         if (fd >= 0 && close(fd) == 0) {
69             fprintf(out, "Wrote %s, rebooting\n", kMarkerFile);
70             fflush(out);
71             sync();  // Make sure the marker file is committed to disk
72 
73             // If possible, dirty each of these partitions before rebooting,
74             // to make sure the filesystem has to do a scan on mount.
75             int i;
76             for (i = 0; kPartitions[i] != NULL; ++i) {
77                 char fn[PATH_MAX];
78                 snprintf(fn, sizeof(fn), "%s/%s", kPartitions[i], "dirty");
79                 fd = open(fn, O_WRONLY|O_CREAT, 0444);
80                 if (fd >= 0) {  // Don't sweat it if we can't write the file.
81                     TEMP_FAILURE_RETRY(write(fd, fn, sizeof(fn)));  // write, you know, some data
82                     close(fd);
83                     unlink(fn);
84                 }
85             }
86 
87             reboot(RB_AUTOBOOT);  // reboot immediately, with dirty filesystems
88             fprintf(out, "Reboot failed?!\n");
89             exit(1);
90         } else {
91             fprintf(out, "Can't write %s: %s\n", kMarkerFile, strerror(errno));
92         }
93     } else {
94         fprintf(out, "Found %s\n", kMarkerFile);
95     }
96 
97     int i;
98     for (i = 0; kPartitions[i] != NULL; ++i) {
99         char fn[PATH_MAX];
100         snprintf(fn, sizeof(fn), "%s/%s", kPartitions[i], "lost+found");
101         DIR *dir = opendir(fn);
102         if (dir == NULL) {
103             fprintf(out, "Can't open %s: %s\n", fn, strerror(errno));
104         } else {
105             int count = 0;
106             struct dirent *ent;
107             while ((ent = readdir(dir))) {
108                 if (strcmp(ent->d_name, ".") && strcmp(ent->d_name, ".."))
109                     ++count;
110             }
111             closedir(dir);
112             if (count > 0) {
113                 fprintf(out, "OMGZ FOUND %d FILES IN %s\n", count, fn);
114             } else {
115                 fprintf(out, "%s is clean\n", fn);
116             }
117         }
118     }
119 
120     char dmesg[131073];
121     int len = klogctl(KLOG_READ_ALL, dmesg, sizeof(dmesg) - 1);
122     if (len < 0) {
123         fprintf(out, "Can't read kernel log: %s\n", strerror(errno));
124     } else {  // To conserve space, only write lines with certain keywords
125         fprintf(out, "--- Kernel log ---\n");
126         dmesg[len] = '\0';
127         char *saveptr, *line;
128         int in_yaffs = 0;
129         for (line = strtok_r(dmesg, "\n", &saveptr); line != NULL;
130              line = strtok_r(NULL, "\n", &saveptr)) {
131             if (strstr(line, "yaffs: dev is")) in_yaffs = 1;
132 
133             if (in_yaffs ||
134                     strstr(line, "yaffs") ||
135                     strstr(line, "mtd") ||
136                     strstr(line, "msm_nand")) {
137                 fprintf(out, "%s\n", line);
138             }
139 
140             if (strstr(line, "yaffs_read_super: isCheckpointed")) in_yaffs = 0;
141         }
142     }
143 
144     return 0;
145 }
146