diff --git a/Checkpoint.cpp b/Checkpoint.cpp
index 476b0ae..d9c0cd1 100644
--- a/Checkpoint.cpp
+++ b/Checkpoint.cpp
@@ -17,20 +17,45 @@
 #define LOG_TAG "Checkpoint"
 #include "Checkpoint.h"
 
-#include <android-base/file.h>
-#include <android-base/parseint.h>
-#include <cutils/android_reboot.h>
-#include <fs_mgr.h>
-#include <mntent.h>
-#include <sys/mount.h>
-
+#include <fstream>
 #include <list>
 #include <string>
+#include <vector>
+
+#include <android-base/file.h>
+#include <android-base/logging.h>
+#include <android-base/parseint.h>
+#include <android-base/unique_fd.h>
+#include <cutils/android_reboot.h>
+#include <fcntl.h>
+#include <fs_mgr.h>
+#include <linux/fs.h>
+#include <mntent.h>
+#include <sys/mount.h>
+#include <sys/stat.h>
 
 namespace android {
 namespace vold {
 
-static const std::string kMetadataCPFile = "/metadata/vold/checkpoint";
+namespace {
+const std::string kMetadataCPFile = "/metadata/vold/checkpoint";
+
+bool setBowState(std::string const& block_device, std::string const& state) {
+    if (block_device.substr(0, 5) != "/dev/") {
+        LOG(ERROR) << "Expected block device, got " << block_device;
+        return false;
+    }
+
+    std::string state_filename = std::string("/sys/") + block_device.substr(5) + "/bow/state";
+    if (!android::base::WriteStringToFile(state, state_filename)) {
+        PLOG(ERROR) << "Failed to write to file " << state_filename;
+        return false;
+    }
+
+    return true;
+}
+
+}  // namespace
 
 bool cp_startCheckpoint(int retry) {
     if (retry < -1) return false;
@@ -39,30 +64,35 @@
 }
 
 bool cp_commitChanges() {
+    // Must take action for list of mounted checkpointed things here
+    // To do this, we walk the list of mounted file systems.
+    // But we also need to get the matching fstab entries to see
+    // the original flags
     struct fstab* fstab = fs_mgr_read_fstab_default();
     if (!fstab) return false;
 
-    FILE* fp = setmntent("/proc/mounts", "r");
-    mntent* mentry;
+    struct fstab* mounts = fs_mgr_read_fstab("/proc/mounts");
+    if (mounts == NULL) {
+        fs_mgr_free_fstab(fstab);
+        return false;
+    }
 
-    if (fp == NULL) return false;
+    // Walk mounted file systems
+    for (int i = 0; i < mounts->num_entries; ++i) {
+        const fstab_rec* mount_rec = &mounts->recs[i];
+        const fstab_rec* fstab_rec = fs_mgr_get_entry_for_mount_point(fstab, mount_rec->mount_point);
+        if (!fstab_rec) continue;
 
-    while ((mentry = getmntent(fp)) != NULL) {
-        auto test = std::string(mentry->mnt_dir) + "/";
-        for (int i = 0; i < fstab->num_entries; i++) {
-            if (!fs_mgr_is_checkpoint(&fstab->recs[i])) continue;
-
-            if (!strcmp(fstab->recs[i].mount_point, mentry->mnt_dir) &&
-                !strcmp(fstab->recs[i].fs_type, mentry->mnt_type)) {
-                if (!strcmp(fstab->recs[i].fs_type, "f2fs")) {
-                    mount(mentry->mnt_fsname, mentry->mnt_dir, "none",
-                          MS_REMOUNT | fstab->recs[i].flags, "checkpoint=enable");
-                }
+        if (fs_mgr_is_checkpoint_fs(fstab_rec)) {
+            if (!strcmp(fstab_rec->fs_type, "f2fs")) {
+                mount(mount_rec->blk_device, mount_rec->mount_point, "none",
+                      MS_REMOUNT | fstab_rec->flags, "checkpoint=enable");
             }
+        } else if (fs_mgr_is_checkpoint_blk(fstab_rec)) {
+            setBowState(mount_rec->blk_device, "2");
         }
     }
-    endmntent(fp);
-
+    fs_mgr_free_fstab(mounts);
     fs_mgr_free_fstab(fstab);
     return android::base::RemoveFileIfExists(kMetadataCPFile);
 }
@@ -89,8 +119,178 @@
     return false;
 }
 
-bool cp_prepareDriveForCheckpoint(const std::string& mountPoint) {
-    return false;
+bool cp_prepareDriveForCheckpoint(const std::string&) {
+    struct fstab* fstab = fs_mgr_read_fstab_default();
+    if (!fstab) return false;
+
+    struct fstab* mounts = fs_mgr_read_fstab("/proc/mounts");
+    if (mounts == NULL) {
+        fs_mgr_free_fstab(fstab);
+        return false;
+    }
+
+    for (int i = 0; i < mounts->num_entries; ++i) {
+        const fstab_rec* mount_rec = &mounts->recs[i];
+        const fstab_rec* fstab_rec = fs_mgr_get_entry_for_mount_point(fstab, mount_rec->mount_point);
+        if (!fstab_rec) continue;
+
+        if (fs_mgr_is_checkpoint_blk(fstab_rec)) {
+            android::base::unique_fd fd(
+                TEMP_FAILURE_RETRY(open(mount_rec->mount_point, O_RDONLY | O_CLOEXEC)));
+            if (!fd) {
+                PLOG(ERROR) << "Failed to open mount point" << mount_rec->mount_point;
+                continue;
+            }
+
+            struct fstrim_range range = {};
+            range.len = ULLONG_MAX;
+            if (ioctl(fd, FITRIM, &range)) {
+                PLOG(ERROR) << "Failed to trim " << mount_rec->mount_point;
+                continue;
+            }
+
+            setBowState(mount_rec->blk_device, "1");
+        }
+    }
+    fs_mgr_free_fstab(mounts);
+    fs_mgr_free_fstab(fstab);
+    return true;
+}
+
+namespace {
+const int kBlockSize = 4096;
+const int kSectorSize = 512;
+
+typedef uint64_t sector_t;
+
+struct log_entry {
+    sector_t source;
+    sector_t dest;
+    uint32_t size;
+    uint32_t checksum;
+} __attribute__((packed));
+
+struct log_sector {
+    uint32_t magic;
+    uint32_t count;
+    uint32_t sequence;
+    struct log_entry entries[];
+} __attribute__((packed));
+
+// MAGIC is BOW in ascii
+const int kMagic = 0x00574f42;
+
+void crc32(const void* data, size_t n_bytes, uint32_t* crc) {
+    static uint32_t table[0x100] = {
+        0x00000000, 0x77073096, 0xEE0E612C, 0x990951BA, 0x076DC419, 0x706AF48F, 0xE963A535,
+        0x9E6495A3, 0x0EDB8832, 0x79DCB8A4, 0xE0D5E91E, 0x97D2D988, 0x09B64C2B, 0x7EB17CBD,
+        0xE7B82D07, 0x90BF1D91, 0x1DB71064, 0x6AB020F2, 0xF3B97148, 0x84BE41DE, 0x1ADAD47D,
+        0x6DDDE4EB, 0xF4D4B551, 0x83D385C7, 0x136C9856, 0x646BA8C0, 0xFD62F97A, 0x8A65C9EC,
+        0x14015C4F, 0x63066CD9, 0xFA0F3D63, 0x8D080DF5, 0x3B6E20C8, 0x4C69105E, 0xD56041E4,
+        0xA2677172, 0x3C03E4D1, 0x4B04D447, 0xD20D85FD, 0xA50AB56B, 0x35B5A8FA, 0x42B2986C,
+        0xDBBBC9D6, 0xACBCF940, 0x32D86CE3, 0x45DF5C75, 0xDCD60DCF, 0xABD13D59, 0x26D930AC,
+        0x51DE003A, 0xC8D75180, 0xBFD06116, 0x21B4F4B5, 0x56B3C423, 0xCFBA9599, 0xB8BDA50F,
+        0x2802B89E, 0x5F058808, 0xC60CD9B2, 0xB10BE924, 0x2F6F7C87, 0x58684C11, 0xC1611DAB,
+        0xB6662D3D,
+
+        0x76DC4190, 0x01DB7106, 0x98D220BC, 0xEFD5102A, 0x71B18589, 0x06B6B51F, 0x9FBFE4A5,
+        0xE8B8D433, 0x7807C9A2, 0x0F00F934, 0x9609A88E, 0xE10E9818, 0x7F6A0DBB, 0x086D3D2D,
+        0x91646C97, 0xE6635C01, 0x6B6B51F4, 0x1C6C6162, 0x856530D8, 0xF262004E, 0x6C0695ED,
+        0x1B01A57B, 0x8208F4C1, 0xF50FC457, 0x65B0D9C6, 0x12B7E950, 0x8BBEB8EA, 0xFCB9887C,
+        0x62DD1DDF, 0x15DA2D49, 0x8CD37CF3, 0xFBD44C65, 0x4DB26158, 0x3AB551CE, 0xA3BC0074,
+        0xD4BB30E2, 0x4ADFA541, 0x3DD895D7, 0xA4D1C46D, 0xD3D6F4FB, 0x4369E96A, 0x346ED9FC,
+        0xAD678846, 0xDA60B8D0, 0x44042D73, 0x33031DE5, 0xAA0A4C5F, 0xDD0D7CC9, 0x5005713C,
+        0x270241AA, 0xBE0B1010, 0xC90C2086, 0x5768B525, 0x206F85B3, 0xB966D409, 0xCE61E49F,
+        0x5EDEF90E, 0x29D9C998, 0xB0D09822, 0xC7D7A8B4, 0x59B33D17, 0x2EB40D81, 0xB7BD5C3B,
+        0xC0BA6CAD,
+
+        0xEDB88320, 0x9ABFB3B6, 0x03B6E20C, 0x74B1D29A, 0xEAD54739, 0x9DD277AF, 0x04DB2615,
+        0x73DC1683, 0xE3630B12, 0x94643B84, 0x0D6D6A3E, 0x7A6A5AA8, 0xE40ECF0B, 0x9309FF9D,
+        0x0A00AE27, 0x7D079EB1, 0xF00F9344, 0x8708A3D2, 0x1E01F268, 0x6906C2FE, 0xF762575D,
+        0x806567CB, 0x196C3671, 0x6E6B06E7, 0xFED41B76, 0x89D32BE0, 0x10DA7A5A, 0x67DD4ACC,
+        0xF9B9DF6F, 0x8EBEEFF9, 0x17B7BE43, 0x60B08ED5, 0xD6D6A3E8, 0xA1D1937E, 0x38D8C2C4,
+        0x4FDFF252, 0xD1BB67F1, 0xA6BC5767, 0x3FB506DD, 0x48B2364B, 0xD80D2BDA, 0xAF0A1B4C,
+        0x36034AF6, 0x41047A60, 0xDF60EFC3, 0xA867DF55, 0x316E8EEF, 0x4669BE79, 0xCB61B38C,
+        0xBC66831A, 0x256FD2A0, 0x5268E236, 0xCC0C7795, 0xBB0B4703, 0x220216B9, 0x5505262F,
+        0xC5BA3BBE, 0xB2BD0B28, 0x2BB45A92, 0x5CB36A04, 0xC2D7FFA7, 0xB5D0CF31, 0x2CD99E8B,
+        0x5BDEAE1D,
+
+        0x9B64C2B0, 0xEC63F226, 0x756AA39C, 0x026D930A, 0x9C0906A9, 0xEB0E363F, 0x72076785,
+        0x05005713, 0x95BF4A82, 0xE2B87A14, 0x7BB12BAE, 0x0CB61B38, 0x92D28E9B, 0xE5D5BE0D,
+        0x7CDCEFB7, 0x0BDBDF21, 0x86D3D2D4, 0xF1D4E242, 0x68DDB3F8, 0x1FDA836E, 0x81BE16CD,
+        0xF6B9265B, 0x6FB077E1, 0x18B74777, 0x88085AE6, 0xFF0F6A70, 0x66063BCA, 0x11010B5C,
+        0x8F659EFF, 0xF862AE69, 0x616BFFD3, 0x166CCF45, 0xA00AE278, 0xD70DD2EE, 0x4E048354,
+        0x3903B3C2, 0xA7672661, 0xD06016F7, 0x4969474D, 0x3E6E77DB, 0xAED16A4A, 0xD9D65ADC,
+        0x40DF0B66, 0x37D83BF0, 0xA9BCAE53, 0xDEBB9EC5, 0x47B2CF7F, 0x30B5FFE9, 0xBDBDF21C,
+        0xCABAC28A, 0x53B39330, 0x24B4A3A6, 0xBAD03605, 0xCDD70693, 0x54DE5729, 0x23D967BF,
+        0xB3667A2E, 0xC4614AB8, 0x5D681B02, 0x2A6F2B94, 0xB40BBE37, 0xC30C8EA1, 0x5A05DF1B,
+        0x2D02EF8D};
+
+    for (size_t i = 0; i < n_bytes; ++i) {
+        *crc ^= ((uint8_t*)data)[i];
+        *crc = table[(uint8_t)*crc] ^ *crc >> 8;
+    }
+}
+
+}  // namespace
+
+bool cp_restoreCheckpoint(const std::string& blockDevice) {
+    LOG(ERROR) << "Restoring checkpoint on " << blockDevice;
+    std::fstream device(blockDevice, std::ios::binary | std::ios::in | std::ios::out);
+    if (!device) {
+        PLOG(ERROR) << "Cannot open " << blockDevice;
+        return false;
+    }
+    char buffer[kBlockSize];
+    device.read(buffer, kBlockSize);
+    log_sector& ls = *(log_sector*)buffer;
+    if (ls.magic != kMagic) {
+        LOG(ERROR) << "No magic";
+        return false;
+    }
+
+    LOG(INFO) << "Restoring " << ls.sequence << " log sectors";
+
+    for (int sequence = ls.sequence; sequence >= 0; sequence--) {
+        char buffer[kBlockSize];
+        device.seekg(0);
+        device.read(buffer, kBlockSize);
+        log_sector& ls = *(log_sector*)buffer;
+        if (ls.magic != kMagic) {
+            LOG(ERROR) << "No magic!";
+            return false;
+        }
+
+        if ((int)ls.sequence != sequence) {
+            LOG(ERROR) << "Expecting log sector " << sequence << " but got " << ls.sequence;
+            return false;
+        }
+
+        LOG(INFO) << "Restoring from log sector " << ls.sequence;
+
+        for (log_entry* le = &ls.entries[ls.count - 1]; le >= ls.entries; --le) {
+            LOG(INFO) << "Restoring " << le->size << " bytes from sector " << le->dest << " to "
+                      << le->source << " with checksum " << std::hex << le->checksum;
+            std::vector<char> buffer(le->size);
+            device.seekg(le->dest * kSectorSize);
+            device.read(&buffer[0], le->size);
+
+            uint32_t checksum = le->source / (kBlockSize / kSectorSize);
+            for (size_t i = 0; i < le->size; i += kBlockSize) {
+                crc32(&buffer[i], kBlockSize, &checksum);
+            }
+
+            if (le->checksum && checksum != le->checksum) {
+                LOG(ERROR) << "Checksums don't match " << std::hex << checksum;
+                return false;
+            }
+
+            device.seekg(le->source * kSectorSize);
+            device.write(&buffer[0], le->size);
+        }
+    }
+
+    return true;
 }
 
 bool cp_markBootAttempt() {
diff --git a/Checkpoint.h b/Checkpoint.h
index 8449956..81fba99 100644
--- a/Checkpoint.h
+++ b/Checkpoint.h
@@ -34,6 +34,8 @@
 
 bool cp_prepareDriveForCheckpoint(const std::string& mountPoint);
 
+bool cp_restoreCheckpoint(const std::string& mountPoint);
+
 bool cp_markBootAttempt();
 
 }  // namespace vold
diff --git a/VoldNativeService.cpp b/VoldNativeService.cpp
index 582f84e..41250c7 100644
--- a/VoldNativeService.cpp
+++ b/VoldNativeService.cpp
@@ -799,6 +799,16 @@
     return ok();
 }
 
+binder::Status VoldNativeService::restoreCheckpoint(const std::string& mountPoint,
+                                                    bool* _aidl_return) {
+    ENFORCE_UID(AID_SYSTEM);
+    CHECK_ARGUMENT_PATH(mountPoint);
+    ACQUIRE_LOCK;
+
+    *_aidl_return = cp_restoreCheckpoint(mountPoint);
+    return ok();
+}
+
 binder::Status VoldNativeService::markBootAttempt(bool* _aidl_return) {
     ENFORCE_UID(AID_SYSTEM);
     ACQUIRE_LOCK;
diff --git a/VoldNativeService.h b/VoldNativeService.h
index 2282141..9a05b45 100644
--- a/VoldNativeService.h
+++ b/VoldNativeService.h
@@ -118,6 +118,7 @@
     binder::Status needsCheckpoint(bool* _aidl_return);
     binder::Status commitChanges(bool* _aidl_return);
     binder::Status prepareDriveForCheckpoint(const std::string& mountPoint, bool* _aidl_return);
+    binder::Status restoreCheckpoint(const std::string& mountPoint, bool* _aidl_return);
     binder::Status markBootAttempt(bool* __aidl_return);
     binder::Status abortChanges();
 };
diff --git a/binder/android/os/IVold.aidl b/binder/android/os/IVold.aidl
index fd97077..f4458a8 100644
--- a/binder/android/os/IVold.aidl
+++ b/binder/android/os/IVold.aidl
@@ -101,6 +101,7 @@
     void abortChanges();
     boolean commitChanges();
     boolean prepareDriveForCheckpoint(@utf8InCpp String mountPoint);
+    boolean restoreCheckpoint(@utf8InCpp String device);
     boolean markBootAttempt();
 
     const int ENCRYPTION_FLAG_NO_UI = 4;
diff --git a/vdc.cpp b/vdc.cpp
index ff5073b..a080c17 100644
--- a/vdc.cpp
+++ b/vdc.cpp
@@ -124,6 +124,10 @@
         bool success = false;
         checkStatus(vold->prepareDriveForCheckpoint(args[2], &success));
         return success ? 1 : 0;
+    } else if (args[0] == "checkpoint" && args[1] == "restoreCheckpoint" && args.size() == 3) {
+        bool success = false;
+        checkStatus(vold->restoreCheckpoint(args[2], &success));
+        return success ? 1 : 0;
     } else if (args[0] == "checkpoint" && args[1] == "markBootAttempt" && args.size() == 2) {
         bool success = false;
         checkStatus(vold->markBootAttempt(&success));