ext4fixup tool to fix wonky filesystems made by old version of make_ext4fs

The filesystems made by make_ext4fs for the Gingerbread and initial Honeycomb
releases did not round up the number of inodes/block_group to use all the
space available.  This worked, but newer kernels have additional code that
refuses to write to these filesystems.  There is a kernel patch available
to fix the problem in the kernel, but this tool was also written to fixup
the filesystems to be compliant with the new kernels.

Change-Id: I317b02ee2132ce6a0daeb4d1b40ad5ef57a0fb32

4 files changed, 961 insertions, 0 deletions

diff --git a/ext4_utils/Android.mk b/ext4_utils/Android.mk
index 2a5fca78..674cd475 100644
--- a/ext4_utils/Android.mk
+++ b/ext4_utils/Android.mk
@@ -5,6 +5,7 @@ include $(CLEAR_VARS)
 
 libext4_utils_src_files := \
 	make_ext4fs.c \
+        ext4fixup.c \
         ext4_utils.c \
         allocate.c \
         backed_block.c \
@@ -106,6 +107,24 @@ include $(BUILD_EXECUTABLE)
 
 include $(CLEAR_VARS)
 
+LOCAL_SRC_FILES := ext4fixup_main.c
+LOCAL_MODULE := ext4fixup
+LOCAL_MODULE_TAGS := optional
+LOCAL_SHARED_LIBRARIES += libext4_utils libz
+
+include $(BUILD_EXECUTABLE)
+
+include $(CLEAR_VARS)
+
+LOCAL_SRC_FILES := ext4fixup_main.c
+LOCAL_MODULE := ext4fixup
+LOCAL_MODULE_TAGS := optional
+LOCAL_STATIC_LIBRARIES += libext4_utils libz
+
+include $(BUILD_HOST_EXECUTABLE)
+
+include $(CLEAR_VARS)
+
 LOCAL_MODULE := mkuserimg.sh
 LOCAL_SRC_FILES := mkuserimg.sh
 LOCAL_MODULE_CLASS := EXECUTABLES
diff --git a/ext4_utils/ext4fixup.c b/ext4_utils/ext4fixup.c
new file mode 100644
index 00000000..052cac96
--- /dev/null
+++ b/ext4_utils/ext4fixup.c
@@ -0,0 +1,859 @@
+/*
+ * Copyright (C) 2010 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 "ext4_utils.h"
+#include "make_ext4fs.h"
+#include "ext4_extents.h"
+#include "output_file.h"
+#include "backed_block.h"
+#include "allocate.h"
+#include "ext4fixup.h"
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <sys/mman.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+#if defined(__APPLE__) && defined(__MACH__)
+#define lseek64 lseek
+#define off64_t off_t
+#endif
+
+/* The inode block count for a file/directory is in units of 512 byte blocks,
+ * _NOT_ the filesystem block size!
+ */
+#define INODE_BLOCK_SIZE 512
+
+#define MAX_EXT4_BLOCK_SIZE 4096
+
+/* The two modes the recurse_dir() can be in */
+#define SANITY_CHECK_PASS 1
+#define MARK_INODE_NUMS   2
+#define UPDATE_INODE_NUMS 3
+
+/* Magic numbers to indicate what state the update process is in */
+#define MAGIC_STATE_MARKING_INUMS  0x7000151515565512ll
+#define MAGIC_STATE_UPDATING_INUMS 0x6121131211735123ll
+#define MAGIC_STATE_UPDATING_SB    0x15e1715151558477ll
+
+/* Internal state variables corresponding to the magic numbers */
+#define STATE_UNSET          0
+#define STATE_MARKING_INUMS  1
+#define STATE_UPDATING_INUMS 2
+#define STATE_UPDATING_SB    3
+
+static int verbose = 0;
+static int no_write = 0;
+static int new_inodes_per_group = 0;
+static int no_write_fixup_state = 0;
+
+static int compute_new_inum(unsigned int old_inum)
+{
+    unsigned int group, offset;
+
+    group = old_inum / info.inodes_per_group;
+    offset = old_inum % info.inodes_per_group;
+
+    return (group * new_inodes_per_group) + offset;
+}
+
+/* Function to read the primary superblock */
+static void read_sb(int fd, struct ext4_super_block *sb)
+{
+    off64_t ret;
+
+    ret = lseek64(fd, 1024, SEEK_SET);
+    if (ret < 0)
+        critical_error_errno("failed to seek to superblock");
+
+    ret = read(fd, sb, sizeof(*sb));
+    if (ret < 0)
+        critical_error_errno("failed to read superblock");
+    if (ret != sizeof(*sb))
+        critical_error("failed to read all of superblock");
+}
+
+/* Function to write a primary or backup superblock at a given offset */
+static void write_sb(int fd, unsigned long long offset, struct ext4_super_block *sb)
+{
+    off64_t ret;
+
+    if (no_write) {
+        return;
+    }
+
+    ret = lseek64(fd, offset, SEEK_SET);
+    if (ret < 0)
+        critical_error_errno("failed to seek to superblock");
+
+    ret = write(fd, sb, sizeof(*sb));
+    if (ret < 0)
+        critical_error_errno("failed to write superblock");
+    if (ret != sizeof(*sb))
+        critical_error("failed to write all of superblock");
+}
+
+static int get_fs_fixup_state(int fd)
+{
+    unsigned long long magic;
+    int ret, len;
+
+    if (no_write) {
+        return no_write_fixup_state;
+    }
+
+    lseek64(fd, 0, SEEK_SET);
+    len = read(fd, &magic, sizeof(magic));
+    if (len != sizeof(magic)) {
+        critical_error("cannot read fixup_state\n");
+    }
+
+    switch (magic) {
+        case MAGIC_STATE_MARKING_INUMS:
+            ret = STATE_MARKING_INUMS;
+            break;
+        case MAGIC_STATE_UPDATING_INUMS:
+            ret = STATE_UPDATING_INUMS;
+            break;
+        case MAGIC_STATE_UPDATING_SB:
+            ret = STATE_UPDATING_SB;
+            break;
+        default:
+            ret = STATE_UNSET;
+    }
+    return ret;
+}
+
+static int set_fs_fixup_state(int fd, int state)
+{
+    unsigned long long magic;
+    struct ext4_super_block sb;
+    int len;
+
+    if (no_write) {
+        no_write_fixup_state = state;
+        return 0;
+    }
+
+    switch (state) {
+        case STATE_MARKING_INUMS:
+            magic = MAGIC_STATE_MARKING_INUMS;
+            break;
+        case STATE_UPDATING_INUMS:
+            magic = MAGIC_STATE_UPDATING_INUMS;
+            break;
+        case STATE_UPDATING_SB:
+            magic = MAGIC_STATE_UPDATING_SB;
+            break;
+        case STATE_UNSET:
+        default:
+            magic = 0ll;
+            break;
+    }
+
+    lseek64(fd, 0, SEEK_SET);
+    len = write(fd, &magic, sizeof(magic));
+    if (len != sizeof(magic)) {
+        critical_error("cannot write fixup_state\n");
+    }
+
+    read_sb(fd, &sb);
+    if (magic) {
+        /* If we are in the process of updating the filesystem, make it unmountable */
+        sb.s_desc_size |= 1;
+    } else {
+        /* we are done, so make the filesystem mountable again */
+        sb.s_desc_size &= ~1;
+    }
+    write_sb(fd, 1024, &sb);
+
+    return 0;
+}
+
+static int read_ext(int fd)
+{
+    off64_t ret;
+    struct ext4_super_block sb;
+    unsigned int i;
+
+    read_sb(fd, &sb);
+
+    ext4_parse_sb(&sb);
+
+    /* Clear the low bit which is set while this tool is in progress.
+     * If the tool crashes, it will still be set when we restart.
+     * The low bit is set to make the filesystem unmountable while
+     * it is being fixed up.  Also allow 0, which means the old ext2
+     * size is in use.
+     */
+    if (((sb.s_desc_size & ~1) != sizeof(struct ext2_group_desc)) &&
+        ((sb.s_desc_size & ~1) != 0))
+        critical_error("error: bg_desc_size != sizeof(struct ext2_group_desc)\n");
+
+    ret = lseek64(fd, info.len, SEEK_SET);
+    if (ret < 0)
+        critical_error_errno("failed to seek to end of input image");
+
+    ret = lseek64(fd, info.block_size * (aux_info.first_data_block + 1), SEEK_SET);
+    if (ret < 0)
+        critical_error_errno("failed to seek to block group descriptors");
+
+    ret = read(fd, aux_info.bg_desc, info.block_size * aux_info.bg_desc_blocks);
+    if (ret < 0)
+        critical_error_errno("failed to read block group descriptors");
+    if (ret != (int)info.block_size * (int)aux_info.bg_desc_blocks)
+        critical_error("failed to read all of block group descriptors");
+
+    if (verbose) {
+        printf("Found filesystem with parameters:\n");
+        printf("    Size: %llu\n", info.len);
+        printf("    Block size: %d\n", info.block_size);
+        printf("    Blocks per group: %d\n", info.blocks_per_group);
+        printf("    Inodes per group: %d\n", info.inodes_per_group);
+        printf("    Inode size: %d\n", info.inode_size);
+        printf("    Label: %s\n", info.label);
+        printf("    Blocks: %llu\n", aux_info.len_blocks);
+        printf("    Block groups: %d\n", aux_info.groups);
+        printf("    Reserved block group size: %d\n", info.bg_desc_reserve_blocks);
+        printf("    Used %d/%d inodes and %d/%d blocks\n",
+                aux_info.sb->s_inodes_count - aux_info.sb->s_free_inodes_count,
+                aux_info.sb->s_inodes_count,
+                aux_info.sb->s_blocks_count_lo - aux_info.sb->s_free_blocks_count_lo,
+                aux_info.sb->s_blocks_count_lo);
+    }
+
+    return 0;
+}
+
+static int read_inode(int fd, unsigned int inum, struct ext4_inode *inode)
+{
+    unsigned int bg_num, bg_offset;
+    off64_t inode_offset;
+    int len;
+
+    bg_num = (inum-1) / info.inodes_per_group;
+    bg_offset = (inum-1) % info.inodes_per_group;
+
+    inode_offset = ((unsigned long long)aux_info.bg_desc[bg_num].bg_inode_table * info.block_size) +
+                    (bg_offset * info.inode_size);
+
+    if (lseek64(fd, inode_offset, SEEK_SET) < 0) {
+        critical_error_errno("failed to seek to inode %d\n", inum);
+    }
+
+    len=read(fd, inode, sizeof(*inode));
+    if (len != sizeof(*inode)) {
+        critical_error_errno("failed to read inode %d\n", inum);
+    }
+
+    return 0;
+}
+
+static int read_block(int fd, unsigned long long block_num, void *block)
+{
+    off64_t off;
+    unsigned int len;
+
+    off = block_num * info.block_size;
+
+    if (lseek64(fd, off, SEEK_SET) , 0) {
+        critical_error_errno("failed to seek to block %lld\n", block_num);
+    }
+
+    len=read(fd, block, info.block_size);
+    if (len != info.block_size) {
+        critical_error_errno("failed to read block %lld\n", block_num);
+    }
+
+    return 0;
+}
+
+static int write_block(int fd, unsigned long long block_num, void *block)
+{
+    off64_t off;
+    unsigned int len;
+
+    if (no_write) {
+        return 0;
+    }
+
+    off = block_num * info.block_size;
+
+    if (lseek64(fd, off, SEEK_SET) < 0) {
+        critical_error_errno("failed to seek to block %lld\n", block_num);
+    }
+
+    len=write(fd, block, info.block_size);
+    if (len != info.block_size) {
+        critical_error_errno("failed to write block %lld\n", block_num);
+    }
+
+    return 0;
+}
+
+static int bitmap_get_bit(u8 *bitmap, u32 bit)
+{
+        if (bitmap[bit / 8] & (1 << (bit % 8)))
+                return 1;
+
+        return 0;
+}
+
+static void bitmap_clear_bit(u8 *bitmap, u32 bit)
+{
+        bitmap[bit / 8] &= ~(1 << (bit % 8));
+
+        return;
+}
+
+static void check_inode_bitmap(int fd, unsigned int bg_num)
+{
+    unsigned int inode_bitmap_block_num;
+    unsigned char block[MAX_EXT4_BLOCK_SIZE];
+    int i, bitmap_updated = 0;
+
+    /* Using the bg_num, aux_info.bg_desc[], info.inodes_per_group and
+     * new_inodes_per_group, retrieve the inode bitmap, and make sure
+     * the bits between the old and new size are clear
+     */
+    inode_bitmap_block_num = aux_info.bg_desc[bg_num].bg_inode_bitmap;
+
+    read_block(fd, inode_bitmap_block_num, block);
+
+    for (i = info.inodes_per_group; i < new_inodes_per_group; i++) {
+        if (bitmap_get_bit(block, i)) {
+            bitmap_clear_bit(block, i);
+            bitmap_updated = 1;
+        }
+    }
+
+    if (bitmap_updated) {
+        if (verbose) {
+            printf("Warning: updated inode bitmap for block group %d\n", bg_num);
+        }
+        write_block(fd, inode_bitmap_block_num, block);
+    }
+
+    return;
+}
+
+/* Update the superblock and bgdesc of the specified block group */
+static int update_superblocks_and_bg_desc(int fd, int state)
+{
+    off64_t ret;
+    struct ext4_super_block sb;
+    unsigned int num_block_groups, total_new_inodes;
+    unsigned int i;
+
+
+    read_sb(fd, &sb);
+
+    /* Compute how many more inodes are now available */
+    num_block_groups = DIV_ROUND_UP(aux_info.len_blocks, info.blocks_per_group);
+    total_new_inodes = num_block_groups * (new_inodes_per_group - sb.s_inodes_per_group);
+
+    if (verbose) {
+        printf("created %d additional inodes\n", total_new_inodes);
+    }
+
+    /* Update the free inodes count in each block group descriptor */
+    for (i = 0; i < num_block_groups; i++) {
+       if (state == STATE_UPDATING_SB) {
+           aux_info.bg_desc[i].bg_free_inodes_count += (new_inodes_per_group - sb.s_inodes_per_group);
+       }
+       check_inode_bitmap(fd, i);
+    }
+
+    /* First some sanity checks */
+    if ((sb.s_inodes_count + total_new_inodes) != (new_inodes_per_group * num_block_groups)) {
+        critical_error("Failed sanity check on new inode count\n");
+    }
+    if (new_inodes_per_group % (info.block_size/info.inode_size)) {
+        critical_error("Failed sanity check on new inode per group alignment\n");
+    }
+
+    /* Update the free inodes count in the superblock */
+    sb.s_inodes_count += total_new_inodes;
+    sb.s_free_inodes_count += total_new_inodes;
+    sb.s_inodes_per_group = new_inodes_per_group;
+
+    for (i = 0; i < aux_info.groups; i++) {
+        if (ext4_bg_has_super_block(i)) {
+            unsigned int sb_offset;
+
+            if (i == 0) {
+              /* The first superblock is offset by 1K to leave room for boot sectors */
+              sb_offset = 1024;
+            } else {
+              sb_offset = 0;
+            }
+
+            sb.s_block_group_nr = i;
+            /* Don't write out the backup superblocks with the bit set in the s_desc_size
+             * which prevents the filesystem from mounting.  The bit for the primary
+             * superblock will be cleared on the final call to set_fs_fixup_state() */
+            if (i != 0) {
+                sb.s_desc_size &= ~1;
+            }
+
+            write_sb(fd, (unsigned long long)i * info.blocks_per_group * info.block_size + sb_offset, &sb);
+
+            ret = lseek64(fd, ((unsigned long long)i * info.blocks_per_group * info.block_size) +
+                              (info.block_size * (aux_info.first_data_block + 1)), SEEK_SET);
+            if (ret < 0)
+                critical_error_errno("failed to seek to block group descriptors");
+
+            if (!no_write) {
+                ret = write(fd, aux_info.bg_desc, info.block_size * aux_info.bg_desc_blocks);
+                if (ret < 0)
+                    critical_error_errno("failed to write block group descriptors");
+                if (ret != (int)info.block_size * (int)aux_info.bg_desc_blocks)
+                    critical_error("failed to write all of block group descriptors");
+            }
+        }
+    }
+
+    return 0;
+}
+
+
+static int get_direct_blocks(struct ext4_inode *inode, unsigned long long *block_list,
+                                                       unsigned int *count)
+{
+    unsigned int i = 0;
+    unsigned int ret = 0;
+    unsigned int sectors_per_block;
+
+    sectors_per_block = info.block_size / INODE_BLOCK_SIZE;
+    while ((i < (inode->i_blocks_lo / sectors_per_block)) && (i < EXT4_NDIR_BLOCKS)) {
+        block_list[i] = inode->i_block[i];
+        i++;
+    }
+
+    *count += i;
+
+    if ((inode->i_blocks_lo / sectors_per_block) > EXT4_NDIR_BLOCKS) {
+        ret = 1;
+    }
+
+    return ret;
+}
+
+static int get_indirect_blocks(int fd, struct ext4_inode *inode,
+                               unsigned long long *block_list, unsigned int *count)
+{
+    unsigned int i;
+    unsigned int *indirect_block;
+    unsigned int sectors_per_block;
+
+    sectors_per_block = info.block_size / INODE_BLOCK_SIZE;
+
+    indirect_block = (unsigned int *)malloc(info.block_size);
+    if (indirect_block == 0) {
+        critical_error("failed to allocate memory for indirect_block\n");
+    }
+
+    read_block(fd, inode->i_block[EXT4_NDIR_BLOCKS], indirect_block);
+
+    for(i = 0; i < (inode->i_blocks_lo / sectors_per_block - EXT4_NDIR_BLOCKS); i++) {
+       block_list[EXT4_NDIR_BLOCKS+i] = indirect_block[i];
+    }
+
+    *count += i;
+
+    free(indirect_block);
+
+    return 0;
+}
+
+static int get_block_list_indirect(int fd, struct ext4_inode *inode, unsigned long long *block_list)
+{
+    unsigned int count=0;
+
+    if (get_direct_blocks(inode, block_list, &count)) {
+        get_indirect_blocks(fd, inode, block_list, &count);
+    }
+
+    return count;
+}
+
+static int get_extent_ents(int fd, struct ext4_extent_header *ext_hdr, unsigned long long *block_list)
+{
+    int i, j;
+    struct ext4_extent *extent;
+    off64_t fs_block_num;
+
+    if (ext_hdr->eh_depth != 0) {
+        critical_error("get_extent_ents called with eh_depth != 0\n");
+    }
+
+    /* The extent entries immediately follow the header, so add 1 to the pointer
+     * and cast it to an extent pointer.
+     */
+    extent = (struct ext4_extent *)(ext_hdr + 1);
+
+    for (i = 0; i < ext_hdr->eh_entries; i++) {
+         fs_block_num = ((off64_t)extent->ee_start_hi << 32) | extent->ee_start_lo;
+         for (j = 0; j < extent->ee_len; j++) {
+             block_list[extent->ee_block+j] = fs_block_num+j;
+         }
+         extent++;
+    }
+
+    return 0;
+}
+
+static int get_extent_idx(int fd, struct ext4_extent_header *ext_hdr, unsigned long long *block_list)
+{
+    int i;
+    struct ext4_extent_idx *extent_idx;
+    struct ext4_extent_header *tmp_ext_hdr;
+    off64_t fs_block_num;
+    unsigned char block[MAX_EXT4_BLOCK_SIZE];
+
+    /* Sanity check */
+    if (ext_hdr->eh_depth == 0) {
+        critical_error("get_extent_idx called with eh_depth == 0\n");
+    }
+
+    /* The extent entries immediately follow the header, so add 1 to the pointer
+     * and cast it to an extent pointer.
+     */
+    extent_idx = (struct ext4_extent_idx *)(ext_hdr + 1);
+
+    for (i = 0; i < ext_hdr->eh_entries; i++) {
+         fs_block_num = ((off64_t)extent_idx->ei_leaf_hi << 32) | extent_idx->ei_leaf_lo;
+         read_block(fd, fs_block_num, block);
+         tmp_ext_hdr = (struct ext4_extent_header *)block;
+
+         if (tmp_ext_hdr->eh_depth == 0) {
+             get_extent_ents(fd, tmp_ext_hdr, block_list); /* leaf node, fill in block_list */
+         } else {
+             get_extent_idx(fd, tmp_ext_hdr, block_list); /* recurse down the tree */
+         }
+    }
+
+    return 0;
+}
+
+static int get_block_list_extents(int fd, struct ext4_inode *inode, unsigned long long *block_list)
+{
+    struct ext4_extent_header *extent_hdr;
+
+    extent_hdr = (struct ext4_extent_header *)inode->i_block;
+
+    if (extent_hdr->eh_magic != EXT4_EXT_MAGIC) {
+        critical_error("extent header has unexpected magic value 0x%4.4x\n",
+                       extent_hdr->eh_magic);
+    }
+
+    if (extent_hdr->eh_depth == 0) {
+         get_extent_ents(fd, (struct ext4_extent_header *)inode->i_block, block_list);
+         return 0;
+    }
+
+    get_extent_idx(fd, (struct ext4_extent_header *)inode->i_block, block_list);
+
+    return 0;
+}
+
+static int is_entry_dir(int fd, struct ext4_dir_entry_2 *dirp, int pass)
+{
+    struct ext4_inode inode;
+    int ret = 0;
+
+    if (dirp->file_type == EXT4_FT_DIR) {
+        ret = 1;
+    } else if (dirp->file_type == EXT4_FT_UNKNOWN) {
+        /* Somebody was too lazy to fill in the dir entry,
+         * so we have to go fetch it from the inode. Grrr.
+         */
+        /* if UPDATE_INODE_NUMS pass and the inode high bit is not
+         * set return false so we don't recurse down the tree that is
+         * already updated.  Otherwise, fetch inode, and return answer.
+         */
+        if ((pass == UPDATE_INODE_NUMS) && !(dirp->inode & 0x80000000)) {
+            ret = 0;
+        } else {
+            read_inode(fd, (dirp->inode & 0x7fffffff), &inode);
+            if (S_ISDIR(inode.i_mode)) {
+                ret = 1;
+            }
+        }
+    }
+
+    return ret;
+}
+
+static int recurse_dir(int fd, struct ext4_inode *inode, char *dirbuf, int dirsize, int mode)
+{
+    unsigned long long *block_list;
+    unsigned int num_blocks;
+    struct ext4_dir_entry_2 *dirp, *prev_dirp = 0;
+    char name[256];
+    unsigned int i, leftover_space, is_dir;
+    struct ext4_inode tmp_inode;
+    int tmp_dirsize;
+    char *tmp_dirbuf;
+
+    switch (mode) {
+        case SANITY_CHECK_PASS:
+        case MARK_INODE_NUMS:
+        case UPDATE_INODE_NUMS:
+            break;
+        default:
+            critical_error("recurse_dir() called witn unknown mode!\n");
+    }
+
+    if (dirsize % info.block_size) {
+        critical_error("dirsize %d not a multiple of block_size %d.  This is unexpected!\n",
+                dirsize, info.block_size);
+    }
+
+    num_blocks = dirsize / info.block_size;
+
+    block_list = malloc((num_blocks + 1) * sizeof(*block_list));
+    if (block_list == 0) {
+        critical_error("failed to allocate memory for block_list\n");
+    }
+
+    if (inode->i_flags & EXT4_EXTENTS_FL) {
+        get_block_list_extents(fd, inode, block_list);
+    } else {
+        /* A directory that requires doubly or triply indirect blocks in huge indeed,
+         * and will almost certainly not exist, especially since make_ext4fs only creates
+         * directories with extents, and the kernel will too, but check to make sure the
+         * directory is not that big and give an error if so.  Our limit is 12 direct blocks,
+         * plus block_size/4 singly indirect blocks, which for a filesystem with 4K blocks
+         * is a directory 1036 blocks long, or 4,243,456 bytes long!  Assuming an average
+         * filename length of 20 (which I think is generous) thats 20 + 8 bytes overhead
+         * per entry, or 151,552 entries in the directory!
+         */
+        if (num_blocks > (info.block_size / 4 + EXT4_NDIR_BLOCKS)) {
+            critical_error("Non-extent based directory is too big!\n");
+        }
+        get_block_list_indirect(fd, inode, block_list);
+    }
+
+    /* Read in all the blocks for this directory */
+    for (i = 0; i < num_blocks; i++) {
+        read_block(fd, block_list[i], dirbuf + (i * info.block_size));
+    }
+
+    dirp = (struct ext4_dir_entry_2 *)dirbuf;
+    while (dirp < (struct ext4_dir_entry_2 *)(dirbuf + dirsize)) {
+        leftover_space = (char *)(dirbuf + dirsize) - (char *)dirp;
+        if (((mode == SANITY_CHECK_PASS) || (mode == UPDATE_INODE_NUMS)) &&
+            (leftover_space <= 8) && prev_dirp) {
+            /* This is a bug in an older version of make_ext4fs, where it
+             * didn't properly include the rest of the block in rec_len.
+             * Update rec_len on the previous entry to include the rest of
+             * the block and exit the loop.
+             */
+            if (verbose) {
+                printf("fixing up short rec_len for diretory entry for %s\n", name);
+            }
+            prev_dirp->rec_len += leftover_space;
+            break;
+        }
+
+        if (dirp->inode == 0) {
+            /* This is the last entry in the directory */
+            break;
+        }
+
+        strncpy(name, dirp->name, dirp->name_len);
+        name[dirp->name_len]='\0';
+
+        /* Only recurse on pass 2 if the high bit is set.
+         * Otherwise, this inode entry has already been updated
+         * and we'll do the wrong thing.  Also don't recurse on . or ..,
+         * and certainly not on non-directories!
+         */
+        /* Hrm, looks like filesystems made by fastboot on stingray set the file_type
+         * flag, but the lost+found directory has the type set to Unknown, which
+         * seems to imply I need to read the inode and get it.
+         */
+        is_dir = is_entry_dir(fd, dirp, mode);
+        if ( is_dir && (strcmp(name, ".") && strcmp(name, "..")) &&
+            ((mode == SANITY_CHECK_PASS) || (mode == MARK_INODE_NUMS) ||
+              ((mode == UPDATE_INODE_NUMS) && (dirp->inode | 0x80000000))) ) {
+            /* A directory!  Recurse! */
+            read_inode(fd, dirp->inode & 0x7fffffff, &tmp_inode);
+
+            if (!S_ISDIR(tmp_inode.i_mode)) {
+                critical_error("inode %d for name %s does not point to a directory\n",
+                        dirp->inode & 0x7fffffff, name);
+            }
+            if (verbose) {
+                printf("inode %d %s use extents\n", dirp->inode & 0x7fffffff,
+                       (tmp_inode.i_flags & EXT4_EXTENTS_FL) ? "does" : "does not");
+            }
+
+            tmp_dirsize = tmp_inode.i_blocks_lo * INODE_BLOCK_SIZE;
+            if (verbose) {
+                printf("dir size = %d bytes\n", tmp_dirsize);
+            }
+
+            tmp_dirbuf = malloc(tmp_dirsize);
+            if (tmp_dirbuf == 0) {
+                critical_error("failed to allocate memory for tmp_dirbuf\n");
+            }
+
+            recurse_dir(fd, &tmp_inode, tmp_dirbuf, tmp_dirsize, mode);
+
+            free(tmp_dirbuf);
+        }
+
+        if (verbose) {
+            if (is_dir) {
+                printf("Directory %s\n", name);
+            } else {
+                printf("Non-directory %s\n", name);
+            }
+        }
+
+        /* Process entry based on current mode.  Either set high bit or change inode number */
+        if (mode == MARK_INODE_NUMS) {
+            dirp->inode |= 0x80000000;
+        } else if (mode == UPDATE_INODE_NUMS) {
+            if (dirp->inode | 0x80000000) {
+                dirp->inode = compute_new_inum(dirp->inode & 0x7fffffff);
+            }
+        }
+
+        /* Point dirp at the next entry */
+        prev_dirp = dirp;
+        dirp = (struct ext4_dir_entry_2*)((char *)dirp + dirp->rec_len);
+    }
+
+    /* Write out all the blocks for this directory */
+    for (i = 0; i < num_blocks; i++) {
+        write_block(fd, block_list[i], dirbuf + (i * info.block_size));
+    }
+
+    free(block_list);
+
+    return 0;
+}
+
+int ext4fixup(char *fsdev)
+{
+    return ext4fixup_internal(fsdev, 0, 0);
+}
+
+int ext4fixup_internal(char *fsdev, int v_flag, int n_flag)
+{
+    int fd;
+    struct ext4_inode root_inode;
+    unsigned int dirsize;
+    char *dirbuf;
+
+    if (setjmp(setjmp_env))
+        return EXIT_FAILURE; /* Handle a call to longjmp() */
+
+    verbose = v_flag;
+    no_write = n_flag;
+
+    fd = open(fsdev, O_RDWR);
+
+    if (fd < 0)
+        critical_error_errno("failed to open filesystem image");
+
+    read_ext(fd);
+
+    if ((info.feat_incompat & EXT4_FEATURE_INCOMPAT_FILETYPE) == 0) {
+        critical_error("Expected filesystem to have filetype flag set\n");
+    }
+
+#if 0 // If we have to fix the directory rec_len issue, we can't use this check
+    /* Check to see if the inodes/group is copacetic */
+    if (info.inodes_per_blockgroup % (info.block_size/info.inode_size) == 0) {
+             /* This filesystem has either already been updated, or was
+              * made correctly.
+              */
+             if (verbose) {
+                 printf("%s: filesystem correct, no work to do\n", me);
+             }
+             exit(0);
+    }
+#endif
+
+    /* Compute what the new value of inodes_per_blockgroup will be when we're done */
+    new_inodes_per_group=ALIGN(info.inodes_per_group,(info.block_size/info.inode_size));
+
+    read_inode(fd, EXT4_ROOT_INO, &root_inode);
+
+    if (!S_ISDIR(root_inode.i_mode)) {
+        critical_error("root inode %d does not point to a directory\n", EXT4_ROOT_INO);
+    }
+    if (verbose) {
+        printf("inode %d %s use extents\n", EXT4_ROOT_INO,
+               (root_inode.i_flags & EXT4_EXTENTS_FL) ? "does" : "does not");
+    }
+
+    dirsize = root_inode.i_blocks_lo * INODE_BLOCK_SIZE;
+    if (verbose) {
+        printf("root dir size = %d bytes\n", dirsize);
+    }
+
+    dirbuf = malloc(dirsize);
+    if (dirbuf == 0) {
+        critical_error("failed to allocate memory for dirbuf\n");
+    }
+
+    /* Perform a sanity check pass first, try to catch any errors that will occur
+     * before we actually change anything, so we don't leave a filesystem in a
+     * corrupted, unrecoverable state.  Set no_write, make it quiet, and do a recurse
+     * pass and a update_superblock pass.  Set flags back to requested state when done.
+     */
+    verbose = 0;
+    no_write = 1;
+    recurse_dir(fd, &root_inode, dirbuf, dirsize, SANITY_CHECK_PASS);
+    update_superblocks_and_bg_desc(fd, STATE_UNSET);
+    verbose = v_flag;
+    no_write = n_flag;
+
+    if (get_fs_fixup_state(fd) == STATE_UNSET) {
+        set_fs_fixup_state(fd, STATE_MARKING_INUMS);
+    }
+
+    if (get_fs_fixup_state(fd) == STATE_MARKING_INUMS) {
+        if (!recurse_dir(fd, &root_inode, dirbuf, dirsize, MARK_INODE_NUMS)) {
+            set_fs_fixup_state(fd, STATE_UPDATING_INUMS);
+        }
+    }
+
+    if (get_fs_fixup_state(fd) == STATE_UPDATING_INUMS) {
+        if (!recurse_dir(fd, &root_inode, dirbuf, dirsize, UPDATE_INODE_NUMS)) {
+            set_fs_fixup_state(fd, STATE_UPDATING_SB);
+        }
+    }
+
+    if (get_fs_fixup_state(fd) == STATE_UPDATING_SB) {
+        /* set the new inodes/blockgruop number,
+         * and sets the state back to 0.
+         */
+        if (!update_superblocks_and_bg_desc(fd, STATE_UPDATING_SB)) {
+            set_fs_fixup_state(fd, STATE_UNSET);
+        }
+    }
+
+    close(fd);
+
+    return 0;
+}
diff --git a/ext4_utils/ext4fixup.h b/ext4_utils/ext4fixup.h
new file mode 100644
index 00000000..94395e7b
--- /dev/null
+++ b/ext4_utils/ext4fixup.h
@@ -0,0 +1,19 @@
+/*
+ * Copyright (C) 2010 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.
+ */
+
+int ext4fixup(char *fsdev);
+int ext4fixup_internal(char *fsdev, int v_flag, int n_flag);
+
diff --git a/ext4_utils/ext4fixup_main.c b/ext4_utils/ext4fixup_main.c
new file mode 100644
index 00000000..8b069712
--- /dev/null
+++ b/ext4_utils/ext4fixup_main.c
@@ -0,0 +1,64 @@
+/*
+ * Copyright (C) 2010 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 <unistd.h>
+#include <libgen.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include "ext4fixup.h"
+
+static void usage(char *me)
+{
+    fprintf(stderr, "%s: usage: %s [-vn] <image or block device>\n", me, me);
+}
+
+int main(int argc, char **argv)
+{
+    int opt;
+    int verbose = 0;
+    int no_write = 0;
+    char *fsdev;
+    char *me;
+
+    me = basename(argv[0]);
+
+    while ((opt = getopt(argc, argv, "vn")) != -1) {
+        switch (opt) {
+        case 'v':
+            verbose = 1;
+            break;
+        case 'n':
+            no_write = 1;
+            break;
+        }
+    }
+
+    if (optind >= argc) {
+        fprintf(stderr, "expected image or block device after options\n");
+        usage(me);
+        exit(EXIT_FAILURE);
+    }
+
+    fsdev = argv[optind++];
+
+    if (optind < argc) {
+        fprintf(stderr, "Unexpected argument: %s\n", argv[optind]);
+        usage(me);
+        exit(EXIT_FAILURE);
+    }
+
+    return ext4fixup_internal(fsdev, verbose, no_write);
+}