auto import from //depot/cupcake/@135843
diff --git a/tools/ota/check-lost+found.c b/tools/ota/check-lost+found.c
new file mode 100644
index 0000000..f856275
--- /dev/null
+++ b/tools/ota/check-lost+found.c
@@ -0,0 +1,144 @@
+/*
+ * Copyright (C) 2008 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <dirent.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/klog.h>
+#include <sys/reboot.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <time.h>
+
+#include "private/android_filesystem_config.h"
+
+// Sentinel file used to track whether we've forced a reboot
+static const char *kMarkerFile = "/data/misc/check-lost+found-rebooted-2";
+
+// Output file in tombstones directory (first 8K will be uploaded)
+static const char *kOutputDir = "/data/tombstones";
+static const char *kOutputFile = "/data/tombstones/check-lost+found-log";
+
+// Partitions to check
+static const char *kPartitions[] = { "/system", "/data", "/cache", NULL };
+
+/*
+ * 1. If /data/misc/forced-reboot is missing, touch it & force "unclean" boot.
+ * 2. Write a log entry with the number of files in lost+found directories.
+ */
+
+int main(int argc, char **argv) {
+    mkdir(kOutputDir, 0755);
+    chown(kOutputDir, AID_SYSTEM, AID_SYSTEM);
+    FILE *out = fopen(kOutputFile, "a");
+    if (out == NULL) {
+        fprintf(stderr, "Can't write %s: %s\n", kOutputFile, strerror(errno));
+        return 1;
+    }
+
+    // Note: only the first 8K of log will be uploaded, so be terse.
+    time_t start = time(NULL);
+    fprintf(out, "*** check-lost+found ***\nStarted: %s", ctime(&start));
+
+    struct stat st;
+    if (stat(kMarkerFile, &st)) {
+        // No reboot marker -- need to force an unclean reboot.
+        // But first, try to create the marker file.  If that fails,
+        // skip the reboot, so we don't get caught in an infinite loop.
+
+        int fd = open(kMarkerFile, O_WRONLY|O_CREAT, 0444);
+        if (fd >= 0 && close(fd) == 0) {
+            fprintf(out, "Wrote %s, rebooting\n", kMarkerFile);
+            fflush(out);
+            sync();  // Make sure the marker file is committed to disk
+
+            // If possible, dirty each of these partitions before rebooting,
+            // to make sure the filesystem has to do a scan on mount.
+            int i;
+            for (i = 0; kPartitions[i] != NULL; ++i) {
+                char fn[PATH_MAX];
+                snprintf(fn, sizeof(fn), "%s/%s", kPartitions[i], "dirty");
+                fd = open(fn, O_WRONLY|O_CREAT, 0444);
+                if (fd >= 0) {  // Don't sweat it if we can't write the file.
+                    write(fd, fn, sizeof(fn));  // write, you know, some data
+                    close(fd);
+                    unlink(fn);
+                }
+            }
+
+            reboot(RB_AUTOBOOT);  // reboot immediately, with dirty filesystems
+            fprintf(out, "Reboot failed?!\n");
+            exit(1);
+        } else {
+            fprintf(out, "Can't write %s: %s\n", kMarkerFile, strerror(errno));
+        }
+    } else {
+        fprintf(out, "Found %s\n", kMarkerFile);
+    }
+
+    int i;
+    for (i = 0; kPartitions[i] != NULL; ++i) {
+        char fn[PATH_MAX];
+        snprintf(fn, sizeof(fn), "%s/%s", kPartitions[i], "lost+found");
+        DIR *dir = opendir(fn);
+        if (dir == NULL) {
+            fprintf(out, "Can't open %s: %s\n", fn, strerror(errno));
+        } else {
+            int count = 0;
+            struct dirent *ent;
+            while ((ent = readdir(dir))) {
+                if (strcmp(ent->d_name, ".") && strcmp(ent->d_name, ".."))
+                    ++count;
+            }
+            closedir(dir);
+            if (count > 0) {
+                fprintf(out, "OMGZ FOUND %d FILES IN %s\n", count, fn);
+            } else {
+                fprintf(out, "%s is clean\n", fn);
+            }
+        }
+    }
+
+    char dmesg[131073];
+    int len = klogctl(KLOG_READ_ALL, dmesg, sizeof(dmesg) - 1);
+    if (len < 0) {
+        fprintf(out, "Can't read kernel log: %s\n", strerror(errno));
+    } else {  // To conserve space, only write lines with certain keywords
+        fprintf(out, "--- Kernel log ---\n");
+        dmesg[len] = '\0';
+        char *saveptr, *line;
+        int in_yaffs = 0;
+        for (line = strtok_r(dmesg, "\n", &saveptr); line != NULL;
+             line = strtok_r(NULL, "\n", &saveptr)) {
+            if (strstr(line, "yaffs: dev is")) in_yaffs = 1;
+
+            if (in_yaffs ||
+                    strstr(line, "yaffs") ||
+                    strstr(line, "mtd") ||
+                    strstr(line, "msm_nand")) {
+                fprintf(out, "%s\n", line);
+            }
+
+            if (strstr(line, "yaffs_read_super: isCheckpointed")) in_yaffs = 0;
+        }
+    }
+
+    return 0;
+}