diff --git a/Ext4.cpp b/Ext4.cpp
index f5a964a..42d6cd3 100644
--- a/Ext4.cpp
+++ b/Ext4.cpp
@@ -23,6 +23,8 @@
 #include <dirent.h>
 #include <errno.h>
 #include <fcntl.h>
+#include <vector>
+#include <string>
 
 #include <sys/types.h>
 #include <sys/stat.h>
@@ -35,17 +37,92 @@
 
 #define LOG_TAG "Vold"
 
+#include <base/stringprintf.h>
 #include <cutils/log.h>
 #include <cutils/properties.h>
-
 #include <logwrap/logwrap.h>
 
 #include "Ext4.h"
+#include "Utils.h"
 #include "VoldUtil.h"
 
-#define MKEXT4FS_PATH "/system/bin/make_ext4fs"
 #define RESIZE2FS_PATH "/system/bin/resize2fs"
 
+using android::base::StringPrintf;
+
+static const char* kMkfsPath = "/system/bin/make_ext4fs";
+
+static const char* kFsckPath = "/system/bin/e2fsck";
+static const char* kFsckLogFile = "/dev/fscklogs/log";
+
+int Ext4::check(const char *fsPath, const char *mountPoint) {
+    // The following is shamelessly borrowed from fs_mgr.c, so it should be
+    // kept in sync with any changes over there.
+
+    char* blk_device = (char*) fsPath;
+    char* target = (char*) mountPoint;
+
+    int status;
+    int ret;
+    long tmpmnt_flags = MS_NOATIME | MS_NOEXEC | MS_NOSUID;
+    char *tmpmnt_opts = (char*) "nomblk_io_submit,errors=remount-ro";
+    char *e2fsck_argv[] = {
+        (char*) kFsckPath,
+        (char*) "-y",
+        blk_device
+    };
+
+    /*
+     * First try to mount and unmount the filesystem.  We do this because
+     * the kernel is more efficient than e2fsck in running the journal and
+     * processing orphaned inodes, and on at least one device with a
+     * performance issue in the emmc firmware, it can take e2fsck 2.5 minutes
+     * to do what the kernel does in about a second.
+     *
+     * After mounting and unmounting the filesystem, run e2fsck, and if an
+     * error is recorded in the filesystem superblock, e2fsck will do a full
+     * check.  Otherwise, it does nothing.  If the kernel cannot mount the
+     * filesytsem due to an error, e2fsck is still run to do a full check
+     * fix the filesystem.
+     */
+    ret = mount(blk_device, target, "ext4", tmpmnt_flags, tmpmnt_opts);
+    if (!ret) {
+        int i;
+        for (i = 0; i < 5; i++) {
+            // Try to umount 5 times before continuing on.
+            // Should we try rebooting if all attempts fail?
+            int result = umount(target);
+            if (result == 0) {
+                break;
+            }
+            ALOGW("%s(): umount(%s)=%d: %s\n", __func__, target, result, strerror(errno));
+            sleep(1);
+        }
+    }
+
+    /*
+     * Some system images do not have e2fsck for licensing reasons
+     * (e.g. recent SDK system images). Detect these and skip the check.
+     */
+    if (access(kFsckPath, X_OK)) {
+        ALOGD("Not running %s on %s (executable not in system image)\n",
+                kFsckPath, blk_device);
+    } else {
+        ALOGD("Running %s on %s\n", kFsckPath, blk_device);
+
+        ret = android_fork_execvp(ARRAY_SIZE(e2fsck_argv), e2fsck_argv,
+                                    &status, false, true);
+
+        if (ret < 0) {
+            /* No need to check for error in fork, we can't really handle it now */
+            ALOGW("Failed trying to run %s\n", kFsckPath);
+            return -1;
+        }
+    }
+
+    return 0;
+}
+
 int Ext4::doMount(const char *fsPath, const char *mountPoint, bool ro, bool remount,
         bool executable) {
     int rc;
@@ -112,28 +189,23 @@
 }
 
 int Ext4::format(const char *fsPath, unsigned int numSectors, const char *mountpoint) {
-    const char *args[7];
-    int rc;
     int status;
 
-    args[0] = MKEXT4FS_PATH;
-    args[1] = "-J";
-    args[2] = "-a";
-    args[3] = mountpoint;
+    std::vector<std::string> cmd;
+    cmd.push_back(kMkfsPath);
+    cmd.push_back("-J");
+
+    cmd.push_back("-a");
+    cmd.push_back(mountpoint);
+
     if (numSectors) {
-        char tmp[32];
-        snprintf(tmp, sizeof(tmp), "%u", numSectors * 512);
-        const char *size = tmp;
-        args[4] = "-l";
-        args[5] = size;
-        args[6] = fsPath;
-        rc = android_fork_execvp(ARRAY_SIZE(args), (char **)args, &status, false, true);
-    } else {
-        args[4] = fsPath;
-        rc = android_fork_execvp(5, (char **)args, &status, false, true);
+        cmd.push_back("-l");
+        cmd.push_back(StringPrintf("%u", numSectors * 512));
     }
-    rc = android_fork_execvp(ARRAY_SIZE(args), (char **)args, &status, false,
-            true);
+
+    cmd.push_back(fsPath);
+
+    int rc = android::vold::ForkExecvp(cmd, &status, false, true);
     if (rc != 0) {
         SLOGE("Filesystem (ext4) format failed due to logwrap error");
         errno = EIO;