Code format in ext4_balloc
[lwext4.git] / lwext4 / ext4_fs.c
index 26f45296e25e96ea7d6fe2ac35ec6c12e9fc5b5a..934df4d658901cafebb9119930729812609db5d4 100644 (file)
  * @brief More complex filesystem functions.
  */
 
-#include <ext4_config.h>
-#include <ext4_types.h>
-#include <ext4_fs.h>
-#include <ext4_errno.h>
-#include <ext4_blockdev.h>
-#include <ext4_super.h>
-#include <ext4_debug.h>
-#include <ext4_block_group.h>
-#include <ext4_balloc.h>
-#include <ext4_bitmap.h>
-#include <ext4_inode.h>
-#include <ext4_ialloc.h>
-#include <ext4_extent.h>
+#include "ext4_config.h"
+#include "ext4_types.h"
+#include "ext4_fs.h"
+#include "ext4_errno.h"
+#include "ext4_blockdev.h"
+#include "ext4_super.h"
+#include "ext4_crc32c.h"
+#include "ext4_debug.h"
+#include "ext4_block_group.h"
+#include "ext4_balloc.h"
+#include "ext4_bitmap.h"
+#include "ext4_inode.h"
+#include "ext4_ialloc.h"
+#include "ext4_extent.h"
+
 #include <string.h>
 
 int ext4_fs_init(struct ext4_fs *fs, struct ext4_blockdev *bdev)
 {
-    int r, i;
-    uint16_t tmp;
-    uint32_t bsize;
-    bool read_only = false;
+       int r, i;
+       uint16_t tmp;
+       uint32_t bsize;
+       bool read_only = false;
+
+       ext4_assert(fs && bdev);
 
-    ext4_assert(fs && bdev);
+       fs->bdev = bdev;
 
-    fs->bdev = bdev;
+       r = ext4_sb_read(fs->bdev, &fs->sb);
+       if (r != EOK)
+               return r;
 
-    r = ext4_sb_read(fs->bdev, &fs->sb);
-    if (r != EOK)
-        return r;
+       if (!ext4_sb_check(&fs->sb))
+               return ENOTSUP;
 
-    if (!ext4_sb_check(&fs->sb))
-        return ENOTSUP;
+       bsize = ext4_sb_get_block_size(&fs->sb);
+       if (bsize > EXT4_MAX_BLOCK_SIZE)
+               return ENXIO;
 
-    bsize = ext4_sb_get_block_size(&fs->sb);
-    if (bsize > EXT4_MAX_BLOCK_SIZE)
-        return ENXIO;
+       r = ext4_fs_check_features(fs, &read_only);
+       if (r != EOK)
+               return r;
 
-    r = ext4_fs_check_features(fs, &read_only);
-    if (r != EOK)
-        return r;
+       if (read_only)
+               return ENOTSUP;
 
-    if (read_only)
-        return ENOTSUP;
+       /* Compute limits for indirect block levels */
+       uint32_t blocks_id = bsize / sizeof(uint32_t);
 
-    /* Compute limits for indirect block levels */
-    uint32_t blocks_id = bsize / sizeof(uint32_t);
+       fs->inode_block_limits[0] = EXT4_INODE_DIRECT_BLOCK_COUNT;
+       fs->inode_blocks_per_level[0] = 1;
 
-    fs->inode_block_limits[0] = EXT4_INODE_DIRECT_BLOCK_COUNT;
-    fs->inode_blocks_per_level[0] = 1;
+       for (i = 1; i < 4; i++) {
+               fs->inode_blocks_per_level[i] =
+                   fs->inode_blocks_per_level[i - 1] * blocks_id;
+               fs->inode_block_limits[i] = fs->inode_block_limits[i - 1] +
+                                           fs->inode_blocks_per_level[i];
+       }
 
-    for (i = 1; i < 4; i++) {
-        fs->inode_blocks_per_level[i] =
-            fs->inode_blocks_per_level[i - 1] * blocks_id;
-        fs->inode_block_limits[i] =
-            fs->inode_block_limits[i - 1] + fs->inode_blocks_per_level[i];
-    }
+       /*Validate FS*/
+       tmp = ext4_get16(&fs->sb, state);
+       if (tmp & EXT4_SUPERBLOCK_STATE_ERROR_FS)
+               ext4_dbg(DEBUG_FS, DBG_WARN
+                               "last umount error: superblock fs_error flag\n");
 
-    /*Validate FS*/
-    tmp = ext4_get16(&fs->sb, state);
-    if (tmp & EXT4_SUPERBLOCK_STATE_ERROR_FS) {
-        ext4_dprintf(EXT4_DEBUG_FS, "last umount error\n");
-    }
 
-    /* Mark system as mounted */
-    ext4_set16(&fs->sb, state, EXT4_SUPERBLOCK_STATE_ERROR_FS);
-    r = ext4_sb_write(fs->bdev, &fs->sb);
-    if (r != EOK)
-        return r;
+       /* Mark system as mounted */
+       ext4_set16(&fs->sb, state, EXT4_SUPERBLOCK_STATE_ERROR_FS);
+       r = ext4_sb_write(fs->bdev, &fs->sb);
+       if (r != EOK)
+               return r;
 
-    /*Update mount count*/
-    ext4_set16(&fs->sb, mount_count, ext4_get16(&fs->sb, mount_count) + 1);
+       /*Update mount count*/
+       ext4_set16(&fs->sb, mount_count, ext4_get16(&fs->sb, mount_count) + 1);
 
-    return r;
+       return r;
 }
 
 int ext4_fs_fini(struct ext4_fs *fs)
 {
-    ext4_assert(fs);
+       ext4_assert(fs);
 
-    /*Set superblock state*/
-    ext4_set16(&fs->sb, state, EXT4_SUPERBLOCK_STATE_VALID_FS);
+       /*Set superblock state*/
+       ext4_set16(&fs->sb, state, EXT4_SUPERBLOCK_STATE_VALID_FS);
 
-    return ext4_sb_write(fs->bdev, &fs->sb);
+       return ext4_sb_write(fs->bdev, &fs->sb);
 }
 
-static void ext4_fs_debug_features_incomp(uint32_t features_incompatible)
+static void ext4_fs_debug_features_inc(uint32_t features_incompatible)
 {
-
-    if (features_incompatible & EXT4_FEATURE_INCOMPAT_COMPRESSION) {
-        ext4_dprintf(EXT4_DEBUG_FS, "compression\n");
-    }
-    if (features_incompatible & EXT4_FEATURE_INCOMPAT_FILETYPE) {
-        ext4_dprintf(EXT4_DEBUG_FS, "filetype\n");
-    }
-    if (features_incompatible & EXT4_FEATURE_INCOMPAT_RECOVER) {
-        ext4_dprintf(EXT4_DEBUG_FS, "recover\n");
-    }
-    if (features_incompatible & EXT4_FEATURE_INCOMPAT_JOURNAL_DEV) {
-        ext4_dprintf(EXT4_DEBUG_FS, "journal_dev\n");
-    }
-    if (features_incompatible & EXT4_FEATURE_INCOMPAT_META_BG) {
-        ext4_dprintf(EXT4_DEBUG_FS, "meta_bg\n");
-    }
-    if (features_incompatible & EXT4_FEATURE_INCOMPAT_EXTENTS) {
-        ext4_dprintf(EXT4_DEBUG_FS, "extents\n");
-    }
-    if (features_incompatible & EXT4_FEATURE_INCOMPAT_64BIT) {
-        ext4_dprintf(EXT4_DEBUG_FS, "64bit\n");
-    }
-    if (features_incompatible & EXT4_FEATURE_INCOMPAT_MMP) {
-        ext4_dprintf(EXT4_DEBUG_FS, "mnp\n");
-    }
-    if (features_incompatible & EXT4_FEATURE_INCOMPAT_FLEX_BG) {
-        ext4_dprintf(EXT4_DEBUG_FS, "flex_bg\n");
-    }
-    if (features_incompatible & EXT4_FEATURE_INCOMPAT_EA_INODE) {
-        ext4_dprintf(EXT4_DEBUG_FS, "ea_inode\n");
-    }
-    if (features_incompatible & EXT4_FEATURE_INCOMPAT_DIRDATA) {
-        ext4_dprintf(EXT4_DEBUG_FS, "dirdata\n");
-    }
-    if (features_incompatible & EXT4_FEATURE_INCOMPAT_BG_USE_META_CSUM) {
-        ext4_dprintf(EXT4_DEBUG_FS, "meta_csum\n");
-    }
-    if (features_incompatible & EXT4_FEATURE_INCOMPAT_LARGEDIR) {
-        ext4_dprintf(EXT4_DEBUG_FS, "largedir\n");
-    }
-    if (features_incompatible & EXT4_FEATURE_INCOMPAT_INLINE_DATA) {
-        ext4_dprintf(EXT4_DEBUG_FS, "inline_data\n");
-    }
+       if (features_incompatible & EXT4_FINCOM_COMPRESSION)
+               ext4_dbg(DEBUG_FS, DBG_NONE "compression\n");
+       if (features_incompatible & EXT4_FINCOM_FILETYPE)
+               ext4_dbg(DEBUG_FS, DBG_NONE "filetype\n");
+       if (features_incompatible & EXT4_FINCOM_RECOVER)
+               ext4_dbg(DEBUG_FS, DBG_NONE "recover\n");
+       if (features_incompatible & EXT4_FINCOM_JOURNAL_DEV)
+               ext4_dbg(DEBUG_FS, DBG_NONE "journal_dev\n");
+       if (features_incompatible & EXT4_FINCOM_META_BG)
+               ext4_dbg(DEBUG_FS, DBG_NONE "meta_bg\n");
+       if (features_incompatible & EXT4_FINCOM_EXTENTS)
+               ext4_dbg(DEBUG_FS, DBG_NONE "extents\n");
+       if (features_incompatible & EXT4_FINCOM_64BIT)
+               ext4_dbg(DEBUG_FS, DBG_NONE "64bit\n");
+       if (features_incompatible & EXT4_FINCOM_MMP)
+               ext4_dbg(DEBUG_FS, DBG_NONE "mnp\n");
+       if (features_incompatible & EXT4_FINCOM_FLEX_BG)
+               ext4_dbg(DEBUG_FS, DBG_NONE "flex_bg\n");
+       if (features_incompatible & EXT4_FINCOM_EA_INODE)
+               ext4_dbg(DEBUG_FS, DBG_NONE "ea_inode\n");
+       if (features_incompatible & EXT4_FINCOM_DIRDATA)
+               ext4_dbg(DEBUG_FS, DBG_NONE "dirdata\n");
+       if (features_incompatible & EXT4_FINCOM_BG_USE_META_CSUM)
+               ext4_dbg(DEBUG_FS, DBG_NONE "meta_csum\n");
+       if (features_incompatible & EXT4_FINCOM_LARGEDIR)
+               ext4_dbg(DEBUG_FS, DBG_NONE "largedir\n");
+       if (features_incompatible & EXT4_FINCOM_INLINE_DATA)
+               ext4_dbg(DEBUG_FS, DBG_NONE "inline_data\n");
 }
 static void ext4_fs_debug_features_comp(uint32_t features_compatible)
 {
-    if (features_compatible & EXT4_FEATURE_COMPAT_DIR_PREALLOC) {
-        ext4_dprintf(EXT4_DEBUG_FS, " dir_prealloc\n");
-    }
-    if (features_compatible & EXT4_FEATURE_COMPAT_IMAGIC_INODES) {
-        ext4_dprintf(EXT4_DEBUG_FS, "imagic_inodes\n");
-    }
-    if (features_compatible & EXT4_FEATURE_COMPAT_HAS_JOURNAL) {
-        ext4_dprintf(EXT4_DEBUG_FS, "has_journal\n");
-    }
-    if (features_compatible & EXT4_FEATURE_COMPAT_EXT_ATTR) {
-        ext4_dprintf(EXT4_DEBUG_FS, "ext_attr\n");
-    }
-    if (features_compatible & EXT4_FEATURE_COMPAT_RESIZE_INODE) {
-        ext4_dprintf(EXT4_DEBUG_FS, "resize_inode\n");
-    }
-    if (features_compatible & EXT4_FEATURE_COMPAT_DIR_INDEX) {
-        ext4_dprintf(EXT4_DEBUG_FS, "dir_index\n");
-    }
+       if (features_compatible & EXT4_FCOM_DIR_PREALLOC)
+               ext4_dbg(DEBUG_FS, DBG_NONE "dir_prealloc\n");
+       if (features_compatible & EXT4_FCOM_IMAGIC_INODES)
+               ext4_dbg(DEBUG_FS, DBG_NONE "imagic_inodes\n");
+       if (features_compatible & EXT4_FCOM_HAS_JOURNAL)
+               ext4_dbg(DEBUG_FS, DBG_NONE "has_journal\n");
+       if (features_compatible & EXT4_FCOM_EXT_ATTR)
+               ext4_dbg(DEBUG_FS, DBG_NONE "ext_attr\n");
+       if (features_compatible & EXT4_FCOM_RESIZE_INODE)
+               ext4_dbg(DEBUG_FS, DBG_NONE "resize_inode\n");
+       if (features_compatible & EXT4_FCOM_DIR_INDEX)
+               ext4_dbg(DEBUG_FS, DBG_NONE "dir_index\n");
 }
 
 static void ext4_fs_debug_features_ro(uint32_t features_ro)
 {
-    if (features_ro & EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER) {
-        ext4_dprintf(EXT4_DEBUG_FS, "sparse_super\n");
-    }
-    if (features_ro & EXT4_FEATURE_RO_COMPAT_LARGE_FILE) {
-        ext4_dprintf(EXT4_DEBUG_FS, "large_file\n");
-    }
-    if (features_ro & EXT4_FEATURE_RO_COMPAT_BTREE_DIR) {
-        ext4_dprintf(EXT4_DEBUG_FS, "btree_dir\n");
-    }
-    if (features_ro & EXT4_FEATURE_RO_COMPAT_HUGE_FILE) {
-        ext4_dprintf(EXT4_DEBUG_FS, "huge_file\n");
-    }
-    if (features_ro & EXT4_FEATURE_RO_COMPAT_GDT_CSUM) {
-        ext4_dprintf(EXT4_DEBUG_FS, "gtd_csum\n");
-    }
-    if (features_ro & EXT4_FEATURE_RO_COMPAT_DIR_NLINK) {
-        ext4_dprintf(EXT4_DEBUG_FS, "dir_nlink\n");
-    }
-    if (features_ro & EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE) {
-        ext4_dprintf(EXT4_DEBUG_FS, "extra_isize\n");
-    }
-    if (features_ro & EXT4_FEATURE_RO_COMPAT_QUOTA) {
-        ext4_dprintf(EXT4_DEBUG_FS, "quota\n");
-    }
-    if (features_ro & EXT4_FEATURE_RO_COMPAT_BIGALLOC) {
-        ext4_dprintf(EXT4_DEBUG_FS, "bigalloc\n");
-    }
-    if (features_ro & EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) {
-        ext4_dprintf(EXT4_DEBUG_FS, "metadata_csum\n");
-    }
+       if (features_ro & EXT4_FRO_COM_SPARSE_SUPER)
+               ext4_dbg(DEBUG_FS, DBG_NONE "sparse_super\n");
+       if (features_ro & EXT4_FRO_COM_LARGE_FILE)
+               ext4_dbg(DEBUG_FS, DBG_NONE "large_file\n");
+       if (features_ro & EXT4_FRO_COM_BTREE_DIR)
+               ext4_dbg(DEBUG_FS, DBG_NONE "btree_dir\n");
+       if (features_ro & EXT4_FRO_COM_HUGE_FILE)
+               ext4_dbg(DEBUG_FS, DBG_NONE "huge_file\n");
+       if (features_ro & EXT4_FRO_COM_GDT_CSUM)
+               ext4_dbg(DEBUG_FS, DBG_NONE "gtd_csum\n");
+       if (features_ro & EXT4_FRO_COM_DIR_NLINK)
+               ext4_dbg(DEBUG_FS, DBG_NONE "dir_nlink\n");
+       if (features_ro & EXT4_FRO_COM_EXTRA_ISIZE)
+               ext4_dbg(DEBUG_FS, DBG_NONE "extra_isize\n");
+       if (features_ro & EXT4_FRO_COM_QUOTA)
+               ext4_dbg(DEBUG_FS, DBG_NONE "quota\n");
+       if (features_ro & EXT4_FRO_COM_BIGALLOC)
+               ext4_dbg(DEBUG_FS, DBG_NONE "bigalloc\n");
+       if (features_ro & EXT4_FRO_COM_METADATA_CSUM)
+               ext4_dbg(DEBUG_FS, DBG_NONE "metadata_csum\n");
 }
 
 int ext4_fs_check_features(struct ext4_fs *fs, bool *read_only)
 {
-    ext4_assert(fs && read_only);
-    uint32_t v;
-    if (ext4_get32(&fs->sb, rev_level) == 0) {
-        *read_only = false;
-        return EOK;
-    }
-
-    ext4_dprintf(EXT4_DEBUG_FS, "\nSB features_incompatible:\n");
-    ext4_fs_debug_features_incomp(ext4_get32(&fs->sb, features_incompatible));
-
-    ext4_dprintf(EXT4_DEBUG_FS, "\nSB features_compatible:\n");
-    ext4_fs_debug_features_comp(ext4_get32(&fs->sb, features_compatible));
-
-    ext4_dprintf(EXT4_DEBUG_FS, "\nSB features_read_only:\n");
-    ext4_fs_debug_features_ro(ext4_get32(&fs->sb, features_read_only));
-
-    /*Check features_incompatible*/
-    v = (ext4_get32(&fs->sb, features_incompatible) &
-         (~CONFIG_FEATURE_INCOMPAT_SUPP));
-    if (v) {
-        ext4_dprintf(EXT4_DEBUG_FS, "SB features_incompatible: fail\n");
-        ext4_fs_debug_features_incomp(v);
-        return ENOTSUP;
-    }
-
-    /*Check features_read_only*/
-    v = (ext4_get32(&fs->sb, features_read_only) &
-         (~CONFIG_FEATURE_RO_COMPAT_SUPP));
-    if (v) {
-        ext4_dprintf(EXT4_DEBUG_FS,
-                     "\nERROR sblock features_read_only . Unsupported:\n");
-        ext4_fs_debug_features_incomp(v);
-
-        *read_only = true;
-        return EOK;
-    }
-    *read_only = false;
-
-    return EOK;
+       ext4_assert(fs && read_only);
+       uint32_t v;
+       if (ext4_get32(&fs->sb, rev_level) == 0) {
+               *read_only = false;
+               return EOK;
+       }
+
+       ext4_dbg(DEBUG_FS, DBG_INFO "sblock features_incompatible:\n");
+       ext4_fs_debug_features_inc(ext4_get32(&fs->sb, features_incompatible));
+
+       ext4_dbg(DEBUG_FS, DBG_INFO "sblock features_compatible:\n");
+       ext4_fs_debug_features_comp(ext4_get32(&fs->sb, features_compatible));
+
+       ext4_dbg(DEBUG_FS, DBG_INFO "sblock features_read_only:\n");
+       ext4_fs_debug_features_ro(ext4_get32(&fs->sb, features_read_only));
+
+       /*Check features_incompatible*/
+       v = (ext4_get32(&fs->sb, features_incompatible) &
+            (~CONFIG_SUPPORTED_FINCOM));
+       if (v) {
+               ext4_dbg(DEBUG_FS, DBG_ERROR
+                               "sblock has unsupported features incompatible:\n");
+               ext4_fs_debug_features_inc(v);
+               return ENOTSUP;
+       }
+
+       /*Check features_read_only*/
+       v = ext4_get32(&fs->sb, features_read_only);
+       v &= ~CONFIG_SUPPORTED_FRO_COM;
+       if (v) {
+               ext4_dbg(DEBUG_FS, DBG_WARN
+                       "sblock has unsupported features read only:\n");
+               ext4_fs_debug_features_ro(v);
+               *read_only = true;
+               return EOK;
+       }
+       *read_only = false;
+
+       return EOK;
 }
 
-/**@brief Initialize block bitmap in block group.
- * @param bg_ref Reference to block group
+/**@brief Determine whether the block is inside the group.
+ * @param baddr   block address
+ * @param bgid    block group id
  * @return Error code
  */
-static int ext4_fs_init_block_bitmap(struct ext4_block_group_ref *bg_ref)
+static bool ext4_block_in_group(struct ext4_sblock *s, ext4_fsblk_t baddr,
+                               uint32_t bgid)
 {
-    uint32_t i;
-    uint32_t bitmap_block_addr =
-        ext4_bg_get_block_bitmap(bg_ref->block_group, &bg_ref->fs->sb);
+       uint32_t actual_bgid;
+       actual_bgid = ext4_balloc_get_bgid_of_block(s, baddr);
+       if (actual_bgid == bgid)
+               return true;
+       return false;
+}
 
-    struct ext4_block block_bitmap;
-    int rc = ext4_block_get(bg_ref->fs->bdev, &block_bitmap, bitmap_block_addr);
-    if (rc != EOK)
-        return rc;
+/**@brief   To avoid calling the atomic setbit hundreds or thousands of times, we only
+ *          need to use it within a single byte (to ensure we get endianness right).
+ *          We can use memset for the rest of the bitmap as there are no other users.
+ */
+static void ext4_fs_mark_bitmap_end(int start_bit, int end_bit, void *bitmap)
+{
+       int i;
 
-    memset(block_bitmap.data, 0, ext4_sb_get_block_size(&bg_ref->fs->sb));
+       if (start_bit >= end_bit)
+               return;
 
-    /* Determine first block and first data block in group */
-    uint32_t first_idx = 0;
+       for (i = start_bit; (unsigned)i < ((start_bit + 7) & ~7UL); i++)
+               ext4_bmap_bit_set(bitmap, i);
 
-    uint32_t first_data =
-        ext4_balloc_get_first_data_block_in_group(&bg_ref->fs->sb, bg_ref);
-    uint32_t first_data_idx =
-        ext4_fs_baddr2_index_in_group(&bg_ref->fs->sb, first_data);
+       if (i < end_bit)
+               memset((char *)bitmap + (i >> 3), 0xff, (end_bit - i) >> 3);
+}
 
-    /*Set bits from to first block to first data block - 1 to one (allocated)*/
-    /*TODO: Optimize it*/
-    for (i = first_idx; i < first_data_idx; ++i)
-        ext4_bmap_bit_set(block_bitmap.data, i);
+/**@brief Initialize block bitmap in block group.
+ * @param bg_ref Reference to block group
+ * @return Error code
+ */
+static int ext4_fs_init_block_bitmap(struct ext4_block_group_ref *bg_ref)
+{
+       struct ext4_sblock *sb = &bg_ref->fs->sb;
+       struct ext4_bgroup *bg = bg_ref->block_group;
+       int rc;
+
+       uint32_t i, bit, bit_max;
+       uint32_t group_blocks;
+       uint16_t inode_size = ext4_get16(sb, inode_size);
+       uint32_t block_size = ext4_sb_get_block_size(sb);
+       uint32_t inodes_per_group = ext4_get32(sb, inodes_per_group);
+
+       ext4_fsblk_t bmp_blk = ext4_bg_get_block_bitmap(bg, sb);
+       ext4_fsblk_t bmp_inode = ext4_bg_get_inode_bitmap(bg, sb);
+       ext4_fsblk_t inode_table = ext4_bg_get_inode_table_first_block(bg, sb);
+       ext4_fsblk_t first_bg = ext4_balloc_get_block_of_bgid(sb, bg_ref->index);
+
+       uint32_t dsc_per_block =  block_size / ext4_sb_get_desc_size(sb);
+
+       bool flex_bg = ext4_sb_feature_incom(sb, EXT4_FINCOM_FLEX_BG);
+       bool meta_bg = ext4_sb_feature_incom(sb, EXT4_FINCOM_META_BG);
+
+       uint32_t inode_table_bcnt = inodes_per_group * inode_size / block_size;
+
+       struct ext4_block block_bitmap;
+       rc = ext4_block_get_noread(bg_ref->fs->bdev, &block_bitmap, bmp_blk);
+       if (rc != EOK)
+               return rc;
+
+       memset(block_bitmap.data, 0, block_size);
+       bit_max = ext4_sb_is_super_in_bg(sb, bg_ref->index);
+
+       uint32_t count = ext4_sb_first_meta_bg(sb) * dsc_per_block;
+       if (!meta_bg || bg_ref->index < count) {
+               if (bit_max) {
+                       bit_max += ext4_bg_num_gdb(sb, bg_ref->index);
+                       bit_max += ext4_get16(sb, s_reserved_gdt_blocks);
+               }
+       } else { /* For META_BG_BLOCK_GROUPS */
+               bit_max += ext4_bg_num_gdb(sb, bg_ref->index);
+       }
+       for (bit = 0; bit < bit_max; bit++)
+               ext4_bmap_bit_set(block_bitmap.data, bit);
+
+       if (bg_ref->index == ext4_block_group_cnt(sb) - 1) {
+               /*
+                * Even though mke2fs always initialize first and last group
+                * if some other tool enabled the EXT4_BG_BLOCK_UNINIT we need
+                * to make sure we calculate the right free blocks
+                */
+
+               group_blocks = ext4_sb_get_blocks_cnt(sb);
+               group_blocks -= ext4_get32(sb, first_data_block);
+               group_blocks -= ext4_get32(sb, blocks_per_group) *
+                               (ext4_block_group_cnt(sb) - 1);
+       } else {
+               group_blocks = ext4_get32(sb, blocks_per_group);
+       }
+
+       bool in_bg;
+       in_bg = ext4_block_in_group(sb, bmp_blk, bg_ref->index);
+       if (!flex_bg || in_bg)
+               ext4_bmap_bit_set(block_bitmap.data, bmp_blk - first_bg);
+
+       in_bg = ext4_block_in_group(sb, bmp_inode, bg_ref->index);
+       if (!flex_bg || in_bg)
+               ext4_bmap_bit_set(block_bitmap.data, bmp_inode - first_bg);
+
+        for (i = inode_table; i < inode_table + inode_table_bcnt; i++) {
+               in_bg = ext4_block_in_group(sb, i, bg_ref->index);
+               if (!flex_bg || in_bg)
+                       ext4_bmap_bit_set(block_bitmap.data, i - first_bg);
+       }
+        /*
+         * Also if the number of blocks within the group is
+         * less than the blocksize * 8 ( which is the size
+         * of bitmap ), set rest of the block bitmap to 1
+         */
+        ext4_fs_mark_bitmap_end(group_blocks, block_size * 8, block_bitmap.data);
+       block_bitmap.dirty = true;
 
-    block_bitmap.dirty = true;
+       ext4_balloc_set_bitmap_csum(sb, bg_ref->block_group, block_bitmap.data);
+       bg_ref->dirty = true;
 
-    /* Save bitmap */
-    return ext4_block_set(bg_ref->fs->bdev, &block_bitmap);
+       /* Save bitmap */
+       return ext4_block_set(bg_ref->fs->bdev, &block_bitmap);
 }
 
 /**@brief Initialize i-node bitmap in block group.
@@ -310,35 +371,41 @@ static int ext4_fs_init_block_bitmap(struct ext4_block_group_ref *bg_ref)
  */
 static int ext4_fs_init_inode_bitmap(struct ext4_block_group_ref *bg_ref)
 {
-    /* Load bitmap */
-    uint32_t bitmap_block_addr =
-        ext4_bg_get_inode_bitmap(bg_ref->block_group, &bg_ref->fs->sb);
+       int rc;
+       struct ext4_sblock *sb = &bg_ref->fs->sb;
+       struct ext4_bgroup *bg = bg_ref->block_group;
 
-    struct ext4_block block_bitmap;
-    int rc = ext4_block_get(bg_ref->fs->bdev, &block_bitmap, bitmap_block_addr);
-    if (rc != EOK)
-        return rc;
+       /* Load bitmap */
+       ext4_fsblk_t bitmap_block_addr = ext4_bg_get_inode_bitmap(bg, sb);
 
-    /* Initialize all bitmap bits to zero */
-    uint32_t block_size = ext4_sb_get_block_size(&bg_ref->fs->sb);
-    uint32_t inodes_per_group = ext4_get32(&bg_ref->fs->sb, inodes_per_group);
+       struct ext4_block b;
+       rc = ext4_block_get_noread(bg_ref->fs->bdev, &b, bitmap_block_addr);
+       if (rc != EOK)
+               return rc;
 
-    memset(block_bitmap.data, 0, (inodes_per_group + 7) / 8);
+       /* Initialize all bitmap bits to zero */
+       uint32_t block_size = ext4_sb_get_block_size(sb);
+       uint32_t inodes_per_group = ext4_get32(sb, inodes_per_group);
 
-    uint32_t start_bit = inodes_per_group;
-    uint32_t end_bit = block_size * 8;
+       memset(b.data, 0, (inodes_per_group + 7) / 8);
 
-    uint32_t i;
-    for (i = start_bit; i < ((start_bit + 7) & ~7UL); i++)
-        ext4_bmap_bit_set(block_bitmap.data, i);
+       uint32_t start_bit = inodes_per_group;
+       uint32_t end_bit = block_size * 8;
 
-    if (i < end_bit)
-        memset(block_bitmap.data + (i >> 3), 0xff, (end_bit - i) >> 3);
+       uint32_t i;
+       for (i = start_bit; i < ((start_bit + 7) & ~7UL); i++)
+               ext4_bmap_bit_set(b.data, i);
 
-    block_bitmap.dirty = true;
+       if (i < end_bit)
+               memset(b.data + (i >> 3), 0xff, (end_bit - i) >> 3);
 
-    /* Save bitmap */
-    return ext4_block_set(bg_ref->fs->bdev, &block_bitmap);
+       b.dirty = true;
+
+       ext4_ialloc_set_bitmap_csum(sb, bg, b.data);
+       bg_ref->dirty = true;
+
+       /* Save bitmap */
+       return ext4_block_set(bg_ref->fs->bdev, &b);
 }
 
 /**@brief Initialize i-node table in block group.
@@ -347,121 +414,60 @@ static int ext4_fs_init_inode_bitmap(struct ext4_block_group_ref *bg_ref)
  */
 static int ext4_fs_init_inode_table(struct ext4_block_group_ref *bg_ref)
 {
-    struct ext4_sblock *sb = &bg_ref->fs->sb;
-
-    uint32_t inode_size = ext4_get32(sb, inode_size);
-    uint32_t block_size = ext4_sb_get_block_size(sb);
-    uint32_t inodes_per_block = block_size / inode_size;
-    uint32_t inodes_in_group = ext4_inodes_in_group_cnt(sb, bg_ref->index);
-    uint32_t table_blocks = inodes_in_group / inodes_per_block;
-    uint32_t fblock;
+       struct ext4_sblock *sb = &bg_ref->fs->sb;
+       struct ext4_bgroup *bg = bg_ref->block_group;
 
-    if (inodes_in_group % inodes_per_block)
-        table_blocks++;
+       uint32_t inode_size = ext4_get32(sb, inode_size);
+       uint32_t block_size = ext4_sb_get_block_size(sb);
+       uint32_t inodes_per_block = block_size / inode_size;
+       uint32_t inodes_in_group = ext4_inodes_in_group_cnt(sb, bg_ref->index);
+       uint32_t table_blocks = inodes_in_group / inodes_per_block;
+       ext4_fsblk_t fblock;
 
-    /* Compute initialization bounds */
-    uint32_t first_block =
-        ext4_bg_get_inode_table_first_block(bg_ref->block_group, sb);
+       if (inodes_in_group % inodes_per_block)
+               table_blocks++;
 
-    uint32_t last_block = first_block + table_blocks - 1;
+       /* Compute initialization bounds */
+       ext4_fsblk_t first_block = ext4_bg_get_inode_table_first_block(bg, sb);
 
-    /* Initialization of all itable blocks */
-    for (fblock = first_block; fblock <= last_block; ++fblock) {
+       ext4_fsblk_t last_block = first_block + table_blocks - 1;
 
-        struct ext4_block block;
-        int rc = ext4_block_get(bg_ref->fs->bdev, &block, fblock);
-        if (rc != EOK)
-            return rc;
+       /* Initialization of all itable blocks */
+       for (fblock = first_block; fblock <= last_block; ++fblock) {
+               struct ext4_block b;
+               int rc = ext4_block_get_noread(bg_ref->fs->bdev, &b, fblock);
+               if (rc != EOK)
+                       return rc;
 
-        memset(block.data, 0, block_size);
-        block.dirty = true;
+               memset(b.data, 0, block_size);
+               b.dirty = true;
 
-        ext4_block_set(bg_ref->fs->bdev, &block);
-        if (rc != EOK)
-            return rc;
-    }
+               ext4_block_set(bg_ref->fs->bdev, &b);
+               if (rc != EOK)
+                       return rc;
+       }
 
-    return EOK;
+       return EOK;
 }
 
-static uint64_t ext4_fs_get_descriptor_block(struct ext4_sblock *s,
-                                             uint32_t bgid,
-                                             uint32_t dsc_per_block)
+static ext4_fsblk_t ext4_fs_get_descriptor_block(struct ext4_sblock *s,
+                                            uint32_t bgid,
+                                            uint32_t dsc_per_block)
 {
-    uint32_t first_meta_bg, dsc_id;
+       uint32_t first_meta_bg, dsc_id;
+       int has_super = 0;
+       dsc_id = bgid / dsc_per_block;
+       first_meta_bg = ext4_sb_first_meta_bg(s);
 
-    int has_super = 0;
+       bool meta_bg = ext4_sb_feature_incom(s, EXT4_FINCOM_META_BG);
 
-    dsc_id = bgid / dsc_per_block;
-    first_meta_bg = ext4_sb_first_meta_bg(s);
+       if (!meta_bg || dsc_id < first_meta_bg)
+               return ext4_get32(s, first_data_block) + dsc_id + 1;
 
-    if (!ext4_sb_has_feature_incompatible(s, EXT4_FEATURE_INCOMPAT_META_BG) ||
-        dsc_id < first_meta_bg)
-        return ext4_get32(s, first_data_block) + dsc_id + 1;
+       if (ext4_sb_is_super_in_bg(s, bgid))
+               has_super = 1;
 
-    if (ext4_sb_is_super_in_bg(s, bgid))
-        has_super = 1;
-
-    return (has_super + ext4_fs_first_bg_block_no(s, bgid));
-}
-
-int ext4_fs_get_block_group_ref(struct ext4_fs *fs, uint32_t bgid,
-                                struct ext4_block_group_ref *ref)
-{
-    /* Compute number of descriptors, that fits in one data block */
-    uint32_t dsc_per_block =
-        ext4_sb_get_block_size(&fs->sb) / ext4_sb_get_desc_size(&fs->sb);
-
-    /* Block group descriptor table starts at the next block after superblock */
-    uint64_t block_id =
-        ext4_fs_get_descriptor_block(&fs->sb, bgid, dsc_per_block);
-
-    uint32_t offset = (bgid % dsc_per_block) * ext4_sb_get_desc_size(&fs->sb);
-
-    int rc = ext4_block_get(fs->bdev, &ref->block, block_id);
-    if (rc != EOK)
-        return rc;
-
-    ref->block_group = (void *)(ref->block.data + offset);
-    ref->fs = fs;
-    ref->index = bgid;
-    ref->dirty = false;
-
-    if (ext4_bg_has_flag(ref->block_group, EXT4_BLOCK_GROUP_BLOCK_UNINIT)) {
-        rc = ext4_fs_init_block_bitmap(ref);
-        if (rc != EOK) {
-            ext4_block_set(fs->bdev, &ref->block);
-            return rc;
-        }
-        ext4_bg_clear_flag(ref->block_group, EXT4_BLOCK_GROUP_BLOCK_UNINIT);
-
-        ref->dirty = true;
-    }
-
-    if (ext4_bg_has_flag(ref->block_group, EXT4_BLOCK_GROUP_INODE_UNINIT)) {
-        rc = ext4_fs_init_inode_bitmap(ref);
-        if (rc != EOK) {
-            ext4_block_set(ref->fs->bdev, &ref->block);
-            return rc;
-        }
-
-        ext4_bg_clear_flag(ref->block_group, EXT4_BLOCK_GROUP_INODE_UNINIT);
-
-        if (!ext4_bg_has_flag(ref->block_group,
-                              EXT4_BLOCK_GROUP_ITABLE_ZEROED)) {
-            rc = ext4_fs_init_inode_table(ref);
-            if (rc != EOK) {
-                ext4_block_set(fs->bdev, &ref->block);
-                return rc;
-            }
-
-            ext4_bg_set_flag(ref->block_group, EXT4_BLOCK_GROUP_ITABLE_ZEROED);
-        }
-
-        ref->dirty = true;
-    }
-
-    return EOK;
+       return (has_super + ext4_fs_first_bg_block_no(s, bgid));
 }
 
 /**@brief  Compute checksum of block group descriptor.
@@ -471,859 +477,1232 @@ int ext4_fs_get_block_group_ref(struct ext4_fs *fs, uint32_t bgid,
  * @return Checksum value
  */
 static uint16_t ext4_fs_bg_checksum(struct ext4_sblock *sb, uint32_t bgid,
-                                    struct ext4_bgroup *bg)
+                                   struct ext4_bgroup *bg)
 {
-    /* If checksum not supported, 0 will be returned */
-    uint16_t crc = 0;
+       /* If checksum not supported, 0 will be returned */
+       uint16_t crc = 0;
+#if CONFIG_META_CSUM_ENABLE
+       /* Compute the checksum only if the filesystem supports it */
+       if (ext4_sb_feature_ro_com(sb, EXT4_FRO_COM_METADATA_CSUM)) {
+               /* Use metadata_csum algorithm instead */
+               uint32_t le32_bgid = to_le32(bgid);
+               uint32_t orig_checksum, checksum;
+
+               /* Preparation: temporarily set bg checksum to 0 */
+               orig_checksum = bg->checksum;
+               bg->checksum = 0;
+
+               /* First calculate crc32 checksum against fs uuid */
+               checksum = ext4_crc32c(EXT4_CRC32_INIT, sb->uuid,
+                               sizeof(sb->uuid));
+               /* Then calculate crc32 checksum against bgid */
+               checksum = ext4_crc32c(checksum, &le32_bgid, sizeof(bgid));
+               /* Finally calculate crc32 checksum against block_group_desc */
+               checksum = ext4_crc32c(checksum, bg, ext4_sb_get_desc_size(sb));
+               bg->checksum = orig_checksum;
+
+               crc = checksum & 0xFFFF;
+               return crc;
+       }
+#endif
+       if (ext4_sb_feature_ro_com(sb, EXT4_FRO_COM_GDT_CSUM)) {
+               uint8_t *base = (uint8_t *)bg;
+               uint8_t *checksum = (uint8_t *)&bg->checksum;
 
-    /* Compute the checksum only if the filesystem supports it */
-    if (ext4_sb_has_feature_read_only(sb, EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) {
-        uint8_t *base = (uint8_t *)bg;
-        uint8_t *checksum = (uint8_t *)&bg->checksum;
+               uint32_t offset = (uint32_t)(checksum - base);
 
-        uint32_t offset = (uint32_t)(checksum - base);
+               /* Convert block group index to little endian */
+               uint32_t le_group = to_le32(bgid);
 
-        /* Convert block group index to little endian */
-        uint32_t le_group = to_le32(bgid);
+               /* Initialization */
+               crc = ext4_bg_crc16(~0, sb->uuid, sizeof(sb->uuid));
 
-        /* Initialization */
-        crc = ext4_bg_crc16(~0, sb->uuid, sizeof(sb->uuid));
+               /* Include index of block group */
+               crc =
+                   ext4_bg_crc16(crc, (uint8_t *)&le_group, sizeof(le_group));
 
-        /* Include index of block group */
-        crc = ext4_bg_crc16(crc, (uint8_t *)&le_group, sizeof(le_group));
+               /* Compute crc from the first part (stop before checksum field)
+                */
+               crc = ext4_bg_crc16(crc, (uint8_t *)bg, offset);
 
-        /* Compute crc from the first part (stop before checksum field) */
-        crc = ext4_bg_crc16(crc, (uint8_t *)bg, offset);
+               /* Skip checksum */
+               offset += sizeof(bg->checksum);
 
-        /* Skip checksum */
-        offset += sizeof(bg->checksum);
+               /* Checksum of the rest of block group descriptor */
+               if ((ext4_sb_feature_incom(sb, EXT4_FINCOM_64BIT)) &&
+                   (offset < ext4_sb_get_desc_size(sb))) {
 
-        /* Checksum of the rest of block group descriptor */
-        if ((ext4_sb_has_feature_incompatible(sb,
-                                              EXT4_FEATURE_INCOMPAT_64BIT)) &&
-            (offset < ext4_sb_get_desc_size(sb)))
+                       const uint8_t *start = ((uint8_t *)bg) + offset;
+                       size_t len = ext4_sb_get_desc_size(sb) - offset;
+                       crc = ext4_bg_crc16(crc, start, len);
+               }
+       }
+       return crc;
+}
 
-            crc = ext4_bg_crc16(crc, ((uint8_t *)bg) + offset,
-                                ext4_sb_get_desc_size(sb) - offset);
-    }
-    return crc;
+#if CONFIG_META_CSUM_ENABLE
+static bool ext4_fs_verify_bg_csum(struct ext4_sblock *sb,
+                                  uint32_t bgid,
+                                  struct ext4_bgroup *bg)
+{
+       if (!ext4_sb_feature_ro_com(sb, EXT4_FRO_COM_METADATA_CSUM))
+               return true;
+
+       return ext4_fs_bg_checksum(sb, bgid, bg) == to_le16(bg->checksum);
+}
+#else
+#define ext4_fs_verify_bg_csum(...) true
+#endif
+
+int ext4_fs_get_block_group_ref(struct ext4_fs *fs, uint32_t bgid,
+                               struct ext4_block_group_ref *ref)
+{
+       /* Compute number of descriptors, that fits in one data block */
+       uint32_t block_size = ext4_sb_get_block_size(&fs->sb);
+       uint32_t dsc_cnt = block_size / ext4_sb_get_desc_size(&fs->sb);
+
+       /* Block group descriptor table starts at the next block after
+        * superblock */
+       uint64_t block_id = ext4_fs_get_descriptor_block(&fs->sb, bgid, dsc_cnt);
+
+       uint32_t offset = (bgid % dsc_cnt) * ext4_sb_get_desc_size(&fs->sb);
+
+       int rc = ext4_block_get(fs->bdev, &ref->block, block_id);
+       if (rc != EOK)
+               return rc;
+
+       ref->block_group = (void *)(ref->block.data + offset);
+       ref->fs = fs;
+       ref->index = bgid;
+       ref->dirty = false;
+       struct ext4_bgroup *bg = ref->block_group;
+
+       if (!ext4_fs_verify_bg_csum(&fs->sb, bgid, bg)) {
+               ext4_dbg(DEBUG_FS,
+                        DBG_WARN "Block group descriptor checksum failed."
+                        "Block group index: %" PRIu32"\n",
+                        bgid);
+       }
+
+       if (ext4_bg_has_flag(bg, EXT4_BLOCK_GROUP_BLOCK_UNINIT)) {
+               rc = ext4_fs_init_block_bitmap(ref);
+               if (rc != EOK) {
+                       ext4_block_set(fs->bdev, &ref->block);
+                       return rc;
+               }
+               ext4_bg_clear_flag(bg, EXT4_BLOCK_GROUP_BLOCK_UNINIT);
+               ref->dirty = true;
+       }
+
+       if (ext4_bg_has_flag(bg, EXT4_BLOCK_GROUP_INODE_UNINIT)) {
+               rc = ext4_fs_init_inode_bitmap(ref);
+               if (rc != EOK) {
+                       ext4_block_set(ref->fs->bdev, &ref->block);
+                       return rc;
+               }
+
+               ext4_bg_clear_flag(bg, EXT4_BLOCK_GROUP_INODE_UNINIT);
+
+               if (!ext4_bg_has_flag(bg, EXT4_BLOCK_GROUP_ITABLE_ZEROED)) {
+                       rc = ext4_fs_init_inode_table(ref);
+                       if (rc != EOK) {
+                               ext4_block_set(fs->bdev, &ref->block);
+                               return rc;
+                       }
+
+                       ext4_bg_set_flag(bg, EXT4_BLOCK_GROUP_ITABLE_ZEROED);
+               }
+
+               ref->dirty = true;
+       }
+
+       return EOK;
 }
 
 int ext4_fs_put_block_group_ref(struct ext4_block_group_ref *ref)
 {
-    /* Check if reference modified */
-    if (ref->dirty) {
-        /* Compute new checksum of block group */
-        uint16_t checksum =
-            ext4_fs_bg_checksum(&ref->fs->sb, ref->index, ref->block_group);
+       /* Check if reference modified */
+       if (ref->dirty) {
+               /* Compute new checksum of block group */
+               uint16_t cs;
+               cs = ext4_fs_bg_checksum(&ref->fs->sb, ref->index,
+                                        ref->block_group);
+               ref->block_group->checksum = to_le16(cs);
+
+               /* Mark block dirty for writing changes to physical device */
+               ref->block.dirty = true;
+       }
+
+       /* Put back block, that contains block group descriptor */
+       return ext4_block_set(ref->fs->bdev, &ref->block);
+}
 
-        ref->block_group->checksum = to_le16(checksum);
+#if CONFIG_META_CSUM_ENABLE
+static uint32_t ext4_fs_inode_checksum(struct ext4_inode_ref *inode_ref)
+{
+       uint32_t checksum = 0;
+       struct ext4_sblock *sb = &inode_ref->fs->sb;
+       uint16_t inode_size = ext4_get16(sb, inode_size);
+
+       if (ext4_sb_feature_ro_com(sb, EXT4_FRO_COM_METADATA_CSUM)) {
+               uint32_t orig_checksum;
+
+               uint32_t ino_index = to_le32(inode_ref->index);
+               uint32_t ino_gen =
+                       to_le32(ext4_inode_get_generation(inode_ref->inode));
+
+               /* Preparation: temporarily set bg checksum to 0 */
+               orig_checksum = ext4_inode_get_checksum(sb, inode_ref->inode);
+               ext4_inode_set_checksum(sb, inode_ref->inode, 0);
+
+               /* First calculate crc32 checksum against fs uuid */
+               checksum = ext4_crc32c(EXT4_CRC32_INIT, sb->uuid,
+                                      sizeof(sb->uuid));
+               /* Then calculate crc32 checksum against inode number
+                * and inode generation */
+               checksum = ext4_crc32c(checksum, &ino_index, sizeof(ino_index));
+               checksum = ext4_crc32c(checksum, &ino_gen, sizeof(ino_gen));
+               /* Finally calculate crc32 checksum against 
+                * the entire inode */
+               checksum = ext4_crc32c(checksum, inode_ref->inode, inode_size);
+               ext4_inode_set_checksum(sb, inode_ref->inode, orig_checksum);
+
+               /* If inode size is not large enough to hold the
+                * upper 16bit of the checksum */
+               if (inode_size == EXT4_GOOD_OLD_INODE_SIZE)
+                       checksum &= 0xFFFF;
+
+       }
+       return checksum;
+}
+#else
+#define ext4_fs_inode_checksum(...) 0
+#endif
 
-        /* Mark block dirty for writing changes to physical device */
-        ref->block.dirty = true;
-    }
+static void ext4_fs_set_inode_checksum(struct ext4_inode_ref *inode_ref)
+{
+       struct ext4_sblock *sb = &inode_ref->fs->sb;
+       if (!ext4_sb_feature_ro_com(sb, EXT4_FRO_COM_METADATA_CSUM))
+               return;
 
-    /* Put back block, that contains block group descriptor */
-    return ext4_block_set(ref->fs->bdev, &ref->block);
+       uint32_t csum = ext4_fs_inode_checksum(inode_ref);
+       ext4_inode_set_checksum(sb, inode_ref->inode, csum);
 }
 
-int ext4_fs_get_inode_ref(struct ext4_fs *fs, uint32_t index,
-                          struct ext4_inode_ref *ref)
+#if CONFIG_META_CSUM_ENABLE
+static bool ext4_fs_verify_inode_csum(struct ext4_inode_ref *inode_ref)
 {
-    /* Compute number of i-nodes, that fits in one data block */
-    uint32_t inodes_per_group = ext4_get32(&fs->sb, inodes_per_group);
-
-    /*
-     * Inode numbers are 1-based, but it is simpler to work with 0-based
-     * when computing indices
-     */
-    index -= 1;
-    uint32_t block_group = index / inodes_per_group;
-    uint32_t offset_in_group = index % inodes_per_group;
-
-    /* Load block group, where i-node is located */
-    struct ext4_block_group_ref bg_ref;
-
-    int rc = ext4_fs_get_block_group_ref(fs, block_group, &bg_ref);
-    if (rc != EOK) {
-        return rc;
-    }
-
-    /* Load block address, where i-node table is located */
-    uint32_t inode_table_start =
-        ext4_bg_get_inode_table_first_block(bg_ref.block_group, &fs->sb);
-
-    /* Put back block group reference (not needed more) */
-    rc = ext4_fs_put_block_group_ref(&bg_ref);
-    if (rc != EOK) {
-        return rc;
-    }
-
-    /* Compute position of i-node in the block group */
-    uint16_t inode_size = ext4_get16(&fs->sb, inode_size);
-    uint32_t block_size = ext4_sb_get_block_size(&fs->sb);
-    uint32_t byte_offset_in_group = offset_in_group * inode_size;
-
-    /* Compute block address */
-    uint64_t block_id = inode_table_start + (byte_offset_in_group / block_size);
-
-    rc = ext4_block_get(fs->bdev, &ref->block, block_id);
-    if (rc != EOK) {
-        return rc;
-    }
-
-    /* Compute position of i-node in the data block */
-    uint32_t offset_in_block = byte_offset_in_group % block_size;
-    ref->inode = (struct ext4_inode *)(ref->block.data + offset_in_block);
-
-    /* We need to store the original value of index in the reference */
-    ref->index = index + 1;
-    ref->fs = fs;
-    ref->dirty = false;
-
-    return EOK;
+       struct ext4_sblock *sb = &inode_ref->fs->sb;
+       if (!ext4_sb_feature_ro_com(sb, EXT4_FRO_COM_METADATA_CSUM))
+               return true;
+
+       return ext4_inode_get_checksum(sb, inode_ref->inode) ==
+               ext4_fs_inode_checksum(inode_ref);
 }
+#else
+#define ext4_fs_verify_inode_csum(...) true
+#endif
 
-int ext4_fs_put_inode_ref(struct ext4_inode_ref *ref)
+static int
+__ext4_fs_get_inode_ref(struct ext4_fs *fs, uint32_t index,
+                       struct ext4_inode_ref *ref,
+                       bool initialized)
 {
-    /* Check if reference modified */
-    if (ref->dirty) {
-        /* Mark block dirty for writing changes to physical device */
-        ref->block.dirty = true;
-    }
-
-    /* Put back block, that contains i-node */
-    return ext4_block_set(ref->fs->bdev, &ref->block);
+       /* Compute number of i-nodes, that fits in one data block */
+       uint32_t inodes_per_group = ext4_get32(&fs->sb, inodes_per_group);
+
+       /*
+        * Inode numbers are 1-based, but it is simpler to work with 0-based
+        * when computing indices
+        */
+       index -= 1;
+       uint32_t block_group = index / inodes_per_group;
+       uint32_t offset_in_group = index % inodes_per_group;
+
+       /* Load block group, where i-node is located */
+       struct ext4_block_group_ref bg_ref;
+
+       int rc = ext4_fs_get_block_group_ref(fs, block_group, &bg_ref);
+       if (rc != EOK) {
+               return rc;
+       }
+
+       /* Load block address, where i-node table is located */
+       uint32_t inode_table_start =
+           ext4_bg_get_inode_table_first_block(bg_ref.block_group, &fs->sb);
+
+       /* Put back block group reference (not needed more) */
+       rc = ext4_fs_put_block_group_ref(&bg_ref);
+       if (rc != EOK) {
+               return rc;
+       }
+
+       /* Compute position of i-node in the block group */
+       uint16_t inode_size = ext4_get16(&fs->sb, inode_size);
+       uint32_t block_size = ext4_sb_get_block_size(&fs->sb);
+       uint32_t byte_offset_in_group = offset_in_group * inode_size;
+
+       /* Compute block address */
+       ext4_fsblk_t block_id =
+           inode_table_start + (byte_offset_in_group / block_size);
+
+       rc = ext4_block_get(fs->bdev, &ref->block, block_id);
+       if (rc != EOK) {
+               return rc;
+       }
+
+       /* Compute position of i-node in the data block */
+       uint32_t offset_in_block = byte_offset_in_group % block_size;
+       ref->inode = (struct ext4_inode *)(ref->block.data + offset_in_block);
+
+       /* We need to store the original value of index in the reference */
+       ref->index = index + 1;
+       ref->fs = fs;
+       ref->dirty = false;
+
+       if (initialized && !ext4_fs_verify_inode_csum(ref)) {
+               ext4_dbg(DEBUG_FS,
+                       DBG_WARN "Inode checksum failed."
+                       "Inode: %" PRIu32"\n",
+                       ref->index);
+       }
+
+       return EOK;
 }
 
-int ext4_fs_alloc_inode(struct ext4_fs *fs, struct ext4_inode_ref *inode_ref,
-                        bool is_directory)
+int ext4_fs_get_inode_ref(struct ext4_fs *fs, uint32_t index,
+                         struct ext4_inode_ref *ref)
 {
-    /* Check if newly allocated i-node will be a directory */
-    uint32_t i;
-    bool is_dir;
-
-    is_dir = is_directory;
-
-    /* Allocate inode by allocation algorithm */
-    uint32_t index;
-    int rc = ext4_ialloc_alloc_inode(fs, &index, is_dir);
-    if (rc != EOK)
-        return rc;
-
-    /* Load i-node from on-disk i-node table */
-    rc = ext4_fs_get_inode_ref(fs, index, inode_ref);
-    if (rc != EOK) {
-        ext4_ialloc_free_inode(fs, index, is_dir);
-        return rc;
-    }
-
-    /* Initialize i-node */
-    struct ext4_inode *inode = inode_ref->inode;
-
-    uint16_t mode;
-    if (is_dir) {
-        /*
-         * Default directory permissions to be compatible with other systems
-         * 0777 (octal) == rwxrwxrwx
-         */
+       return __ext4_fs_get_inode_ref(fs, index, ref, true);
+}
 
-        mode = 0777;
-        mode |= EXT4_INODE_MODE_DIRECTORY;
-        ext4_inode_set_mode(&fs->sb, inode, mode);
-        ext4_inode_set_links_count(inode, 0);
+int ext4_fs_put_inode_ref(struct ext4_inode_ref *ref)
+{
+       /* Check if reference modified */
+       if (ref->dirty) {
+               /* Mark block dirty for writing changes to physical device */
+               ext4_fs_set_inode_checksum(ref);
+               ref->block.dirty = true;
+       }
+
+       /* Put back block, that contains i-node */
+       return ext4_block_set(ref->fs->bdev, &ref->block);
+}
 
-    } else {
-        /*
-         * Default file permissions to be compatible with other systems
-         * 0666 (octal) == rw-rw-rw-
-         */
+void ext4_fs_inode_blocks_init(struct ext4_fs *fs,
+                              struct ext4_inode_ref *inode_ref)
+{
+       int i;
+       struct ext4_inode *inode = inode_ref->inode;
 
-        mode = 0666;
-        mode |= EXT4_INODE_MODE_FILE;
-        ext4_inode_set_mode(&fs->sb, inode, mode);
-        ext4_inode_set_links_count(inode, 1);
-    }
-
-    ext4_inode_set_uid(inode, 0);
-    ext4_inode_set_gid(inode, 0);
-    ext4_inode_set_size(inode, 0);
-    ext4_inode_set_access_time(inode, 0);
-    ext4_inode_set_change_inode_time(inode, 0);
-    ext4_inode_set_modification_time(inode, 0);
-    ext4_inode_set_deletion_time(inode, 0);
-    ext4_inode_set_blocks_count(&fs->sb, inode, 0);
-    ext4_inode_set_flags(inode, 0);
-    ext4_inode_set_generation(inode, 0);
-
-    /* Reset blocks array */
-    for (i = 0; i < EXT4_INODE_BLOCKS; i++)
-        inode->blocks[i] = 0;
+       for (i = 0; i < EXT4_INODE_BLOCKS; i++)
+               inode->blocks[i] = 0;
 
+       (void)fs;
 #if CONFIG_EXTENT_ENABLE
-    /* Initialize extents if needed */
-    if (ext4_sb_has_feature_incompatible(&fs->sb,
-                                         EXT4_FEATURE_INCOMPAT_EXTENTS)) {
-        ext4_inode_set_flag(inode, EXT4_INODE_FLAG_EXTENTS);
-
-        /* Initialize extent root header */
-        struct ext4_extent_header *header = ext4_inode_get_extent_header(inode);
-        ext4_extent_header_set_depth(header, 0);
-        ext4_extent_header_set_entries_count(header, 0);
-        ext4_extent_header_set_generation(header, 0);
-        ext4_extent_header_set_magic(header, EXT4_EXTENT_MAGIC);
-
-        uint16_t max_entries = (EXT4_INODE_BLOCKS * sizeof(uint32_t) -
-                                sizeof(struct ext4_extent_header)) /
-                               sizeof(struct ext4_extent);
-
-        ext4_extent_header_set_max_entries_count(header, max_entries);
-    }
+       /* Initialize extents if needed */
+       if (ext4_sb_feature_incom(&fs->sb, EXT4_FINCOM_EXTENTS)) {
+               ext4_inode_set_flag(inode, EXT4_INODE_FLAG_EXTENTS);
+
+               /* Initialize extent root header */
+               ext4_extent_tree_init(inode_ref);
+       }
 #endif
+}
 
-    inode_ref->dirty = true;
+uint32_t ext4_fs_correspond_inode_mode(int filetype)
+{
+       switch (filetype) {
+       case EXT4_DIRENTRY_DIR:
+               return EXT4_INODE_MODE_DIRECTORY;
+       case EXT4_DIRENTRY_REG_FILE:
+               return EXT4_INODE_MODE_FILE;
+       case EXT4_DIRENTRY_SYMLINK:
+               return EXT4_INODE_MODE_SOFTLINK;
+       default:
+               /* FIXME: right now we only support 3 file type. */
+               ext4_assert(0);
+       }
+       return 0;
+}
 
-    return EOK;
+int ext4_fs_alloc_inode(struct ext4_fs *fs, struct ext4_inode_ref *inode_ref,
+                       int filetype)
+{
+       /* Check if newly allocated i-node will be a directory */
+       bool is_dir;
+       uint16_t inode_size = ext4_get16(&fs->sb, inode_size);
+
+       is_dir = (filetype == EXT4_DIRENTRY_DIR);
+
+       /* Allocate inode by allocation algorithm */
+       uint32_t index;
+       int rc = ext4_ialloc_alloc_inode(fs, &index, is_dir);
+       if (rc != EOK)
+               return rc;
+
+       /* Load i-node from on-disk i-node table */
+       rc = __ext4_fs_get_inode_ref(fs, index, inode_ref, false);
+       if (rc != EOK) {
+               ext4_ialloc_free_inode(fs, index, is_dir);
+               return rc;
+       }
+
+       /* Initialize i-node */
+       struct ext4_inode *inode = inode_ref->inode;
+
+       uint32_t mode;
+       if (is_dir) {
+               /*
+                * Default directory permissions to be compatible with other
+                * systems
+                * 0777 (octal) == rwxrwxrwx
+                */
+
+               mode = 0777;
+               mode |= EXT4_INODE_MODE_DIRECTORY;
+       } else {
+               /*
+                * Default file permissions to be compatible with other systems
+                * 0666 (octal) == rw-rw-rw-
+                */
+
+               mode = 0666;
+               mode |= ext4_fs_correspond_inode_mode(filetype);
+       }
+       ext4_inode_set_mode(&fs->sb, inode, mode);
+
+       ext4_inode_set_links_count(inode, 0);
+       ext4_inode_set_uid(inode, 0);
+       ext4_inode_set_gid(inode, 0);
+       ext4_inode_set_size(inode, 0);
+       ext4_inode_set_access_time(inode, 0);
+       ext4_inode_set_change_inode_time(inode, 0);
+       ext4_inode_set_modification_time(inode, 0);
+       ext4_inode_set_deletion_time(inode, 0);
+       ext4_inode_set_blocks_count(&fs->sb, inode, 0);
+       ext4_inode_set_flags(inode, 0);
+       ext4_inode_set_generation(inode, 0);
+       if (inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
+               uint16_t off = offsetof(struct ext4_inode, extra_isize);
+               uint16_t size = sizeof(struct ext4_inode) - off;
+               ext4_inode_set_extra_isize(inode, size);
+       }
+
+       /* Reset blocks array. For symbolic link inode, just
+        * fill in blocks with 0 */
+       if (ext4_inode_is_type(&fs->sb, inode, EXT4_INODE_MODE_SOFTLINK)) {
+               for (int i = 0; i < EXT4_INODE_BLOCKS; i++)
+                       inode->blocks[i] = 0;
+
+       } else {
+               ext4_fs_inode_blocks_init(fs, inode_ref);
+       }
+
+       inode_ref->dirty = true;
+
+       return EOK;
 }
 
 int ext4_fs_free_inode(struct ext4_inode_ref *inode_ref)
 {
-    struct ext4_fs *fs = inode_ref->fs;
-    uint32_t offset;
-    uint32_t suboffset;
+       struct ext4_fs *fs = inode_ref->fs;
+       uint32_t offset;
+       uint32_t suboff;
+       int rc;
 #if CONFIG_EXTENT_ENABLE
-    /* For extents must be data block destroyed by other way */
-    if ((ext4_sb_has_feature_incompatible(&fs->sb,
-                                          EXT4_FEATURE_INCOMPAT_EXTENTS)) &&
-        (ext4_inode_has_flag(inode_ref->inode, EXT4_INODE_FLAG_EXTENTS))) {
-        /* Data structures are released during truncate operation... */
-        goto finish;
-    }
+       /* For extents must be data block destroyed by other way */
+       if ((ext4_sb_feature_incom(&fs->sb, EXT4_FINCOM_EXTENTS)) &&
+           (ext4_inode_has_flag(inode_ref->inode, EXT4_INODE_FLAG_EXTENTS))) {
+               /* Data structures are released during truncate operation... */
+               goto finish;
+       }
 #endif
-    /* Release all indirect (no data) blocks */
-
-    /* 1) Single indirect */
-    uint32_t fblock = ext4_inode_get_indirect_block(inode_ref->inode, 0);
-    if (fblock != 0) {
-        int rc = ext4_balloc_free_block(inode_ref, fblock);
-        if (rc != EOK)
-            return rc;
-
-        ext4_inode_set_indirect_block(inode_ref->inode, 0, 0);
-    }
-
-    uint32_t block_size = ext4_sb_get_block_size(&fs->sb);
-    uint32_t count = block_size / sizeof(uint32_t);
-
-    struct ext4_block block;
-
-    /* 2) Double indirect */
-    fblock = ext4_inode_get_indirect_block(inode_ref->inode, 1);
-    if (fblock != 0) {
-        int rc = ext4_block_get(fs->bdev, &block, fblock);
-        if (rc != EOK)
-            return rc;
-
-        uint32_t ind_block;
-        for (offset = 0; offset < count; ++offset) {
-            ind_block = to_le32(((uint32_t *)block.data)[offset]);
-
-            if (ind_block != 0) {
-                rc = ext4_balloc_free_block(inode_ref, ind_block);
-                if (rc != EOK) {
-                    ext4_block_set(fs->bdev, &block);
-                    return rc;
-                }
-            }
-        }
-
-        ext4_block_set(fs->bdev, &block);
-        rc = ext4_balloc_free_block(inode_ref, fblock);
-        if (rc != EOK)
-            return rc;
-
-        ext4_inode_set_indirect_block(inode_ref->inode, 1, 0);
-    }
-
-    /* 3) Tripple indirect */
-    struct ext4_block subblock;
-    fblock = ext4_inode_get_indirect_block(inode_ref->inode, 2);
-    if (fblock != 0) {
-        int rc = ext4_block_get(fs->bdev, &block, fblock);
-        if (rc != EOK)
-            return rc;
-
-        uint32_t ind_block;
-        for (offset = 0; offset < count; ++offset) {
-            ind_block = to_le32(((uint32_t *)block.data)[offset]);
-
-            if (ind_block != 0) {
-                rc = ext4_block_get(fs->bdev, &subblock, ind_block);
-                if (rc != EOK) {
-                    ext4_block_set(fs->bdev, &block);
-                    return rc;
-                }
-
-                uint32_t ind_subblock;
-                for (suboffset = 0; suboffset < count; ++suboffset) {
-                    ind_subblock =
-                        to_le32(((uint32_t *)subblock.data)[suboffset]);
-
-                    if (ind_subblock != 0) {
-                        rc = ext4_balloc_free_block(inode_ref, ind_subblock);
-                        if (rc != EOK) {
-                            ext4_block_set(fs->bdev, &subblock);
-                            ext4_block_set(fs->bdev, &block);
-                            return rc;
-                        }
-                    }
-                }
-
-                ext4_block_set(fs->bdev, &subblock);
-
-                rc = ext4_balloc_free_block(inode_ref, ind_block);
-                if (rc != EOK) {
-                    ext4_block_set(fs->bdev, &block);
-                    return rc;
-                }
-            }
-        }
-
-        ext4_block_set(fs->bdev, &block);
-        rc = ext4_balloc_free_block(inode_ref, fblock);
-        if (rc != EOK)
-            return rc;
-
-        ext4_inode_set_indirect_block(inode_ref->inode, 2, 0);
-    }
-#if CONFIG_EXTENT_ENABLE
+       /* Release all indirect (no data) blocks */
+
+       /* 1) Single indirect */
+       ext4_fsblk_t fblock = ext4_inode_get_indirect_block(inode_ref->inode, 0);
+       if (fblock != 0) {
+               int rc = ext4_balloc_free_block(inode_ref, fblock);
+               if (rc != EOK)
+                       return rc;
+
+               ext4_inode_set_indirect_block(inode_ref->inode, 0, 0);
+       }
+
+       uint32_t block_size = ext4_sb_get_block_size(&fs->sb);
+       uint32_t count = block_size / sizeof(uint32_t);
+
+       struct ext4_block block;
+
+       /* 2) Double indirect */
+       fblock = ext4_inode_get_indirect_block(inode_ref->inode, 1);
+       if (fblock != 0) {
+               int rc = ext4_block_get(fs->bdev, &block, fblock);
+               if (rc != EOK)
+                       return rc;
+
+               ext4_fsblk_t ind_block;
+               for (offset = 0; offset < count; ++offset) {
+                       ind_block = to_le32(((uint32_t *)block.data)[offset]);
+
+                       if (ind_block == 0)
+                               continue;
+                       rc = ext4_balloc_free_block(inode_ref, ind_block);
+                       if (rc != EOK) {
+                               ext4_block_set(fs->bdev, &block);
+                               return rc;
+                       }
+
+               }
+
+               ext4_block_set(fs->bdev, &block);
+               rc = ext4_balloc_free_block(inode_ref, fblock);
+               if (rc != EOK)
+                       return rc;
+
+               ext4_inode_set_indirect_block(inode_ref->inode, 1, 0);
+       }
+
+       /* 3) Tripple indirect */
+       struct ext4_block subblock;
+       fblock = ext4_inode_get_indirect_block(inode_ref->inode, 2);
+       if (fblock == 0)
+               goto finish;
+       rc = ext4_block_get(fs->bdev, &block, fblock);
+       if (rc != EOK)
+               return rc;
+
+       ext4_fsblk_t ind_block;
+       for (offset = 0; offset < count; ++offset) {
+               ind_block = to_le32(((uint32_t *)block.data)[offset]);
+
+               if (ind_block == 0)
+                       continue;
+               rc = ext4_block_get(fs->bdev, &subblock,
+                               ind_block);
+               if (rc != EOK) {
+                       ext4_block_set(fs->bdev, &block);
+                       return rc;
+               }
+
+               ext4_fsblk_t ind_subblk;
+               for (suboff = 0; suboff < count; ++suboff) {
+                       ind_subblk = to_le32(((uint32_t *)subblock.data)[suboff]);
+
+                       if (ind_subblk == 0)
+                               continue;
+                       rc = ext4_balloc_free_block(inode_ref, ind_subblk);
+                       if (rc != EOK) {
+                               ext4_block_set(fs->bdev, &subblock);
+                               ext4_block_set(fs->bdev, &block);
+                               return rc;
+                       }
+
+               }
+
+               ext4_block_set(fs->bdev, &subblock);
+
+               rc = ext4_balloc_free_block(inode_ref,
+                               ind_block);
+               if (rc != EOK) {
+                       ext4_block_set(fs->bdev, &block);
+                       return rc;
+               }
+
+       }
+
+       ext4_block_set(fs->bdev, &block);
+       rc = ext4_balloc_free_block(inode_ref, fblock);
+       if (rc != EOK)
+               return rc;
+
+       ext4_inode_set_indirect_block(inode_ref->inode, 2, 0);
 finish:
-#endif
-    /* Mark inode dirty for writing to the physical device */
-    inode_ref->dirty = true;
-
-    /* Free block with extended attributes if present */
-    uint32_t xattr_block = ext4_inode_get_file_acl(inode_ref->inode, &fs->sb);
-    if (xattr_block) {
-        int rc = ext4_balloc_free_block(inode_ref, xattr_block);
-        if (rc != EOK)
-            return rc;
-
-        ext4_inode_set_file_acl(inode_ref->inode, &fs->sb, 0);
-    }
-
-    /* Free inode by allocator */
-    int rc;
-    if (ext4_inode_is_type(&fs->sb, inode_ref->inode,
-                           EXT4_INODE_MODE_DIRECTORY))
-        rc = ext4_ialloc_free_inode(fs, inode_ref->index, true);
-    else
-        rc = ext4_ialloc_free_inode(fs, inode_ref->index, false);
-
-    return rc;
+       /* Mark inode dirty for writing to the physical device */
+       inode_ref->dirty = true;
+
+       /* Free block with extended attributes if present */
+       ext4_fsblk_t xattr_block =
+           ext4_inode_get_file_acl(inode_ref->inode, &fs->sb);
+       if (xattr_block) {
+               int rc = ext4_balloc_free_block(inode_ref, xattr_block);
+               if (rc != EOK)
+                       return rc;
+
+               ext4_inode_set_file_acl(inode_ref->inode, &fs->sb, 0);
+       }
+
+       /* Free inode by allocator */
+       if (ext4_inode_is_type(&fs->sb, inode_ref->inode,
+                              EXT4_INODE_MODE_DIRECTORY))
+               rc = ext4_ialloc_free_inode(fs, inode_ref->index, true);
+       else
+               rc = ext4_ialloc_free_inode(fs, inode_ref->index, false);
+
+       return rc;
 }
 
-int ext4_fs_truncate_inode(struct ext4_inode_ref *inode_ref, uint64_t new_size)
-{
-    struct ext4_sblock *sb = &inode_ref->fs->sb;
-    uint32_t i;
-
-    /* Check flags, if i-node can be truncated */
-    if (!ext4_inode_can_truncate(sb, inode_ref->inode))
-        return EINVAL;
-
-    /* If sizes are equal, nothing has to be done. */
-    uint64_t old_size = ext4_inode_get_size(sb, inode_ref->inode);
-    if (old_size == new_size)
-        return EOK;
-
-    /* It's not suppported to make the larger file by truncate operation */
-    if (old_size < new_size)
-        return EINVAL;
-
-    /* Compute how many blocks will be released */
-    uint64_t size_diff = old_size - new_size;
-    uint32_t block_size = ext4_sb_get_block_size(sb);
-    uint32_t diff_blocks_count = size_diff / block_size;
-    if (size_diff % block_size != 0)
-        diff_blocks_count++;
-
-    uint32_t old_blocks_count = old_size / block_size;
-    if (old_size % block_size != 0)
-        old_blocks_count++;
-#if CONFIG_EXTENT_ENABLE
-    if ((ext4_sb_has_feature_incompatible(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)) &&
-        (ext4_inode_has_flag(inode_ref->inode, EXT4_INODE_FLAG_EXTENTS))) {
 
-        /* Extents require special operation */
-        int rc = ext4_extent_release_blocks_from(
-            inode_ref, old_blocks_count - diff_blocks_count);
-        if (rc != EOK)
-            return rc;
-
-    } else
-#endif
-    {
-        /* Release data blocks from the end of file */
-
-        /* Starting from 1 because of logical blocks are numbered from 0 */
-        for (i = 1; i <= diff_blocks_count; ++i) {
-            int rc =
-                ext4_fs_release_inode_block(inode_ref, old_blocks_count - i);
-            if (rc != EOK)
-                return rc;
-        }
-    }
-
-    /* Update i-node */
-    ext4_inode_set_size(inode_ref->inode, new_size);
-    inode_ref->dirty = true;
-
-    return EOK;
+/**@brief Release data block from i-node
+ * @param inode_ref I-node to release block from
+ * @param iblock    Logical block to be released
+ * @return Error code
+ */
+static int ext4_fs_release_inode_block(struct ext4_inode_ref *inode_ref,
+                               uint32_t iblock)
+{
+       ext4_fsblk_t fblock;
+
+       struct ext4_fs *fs = inode_ref->fs;
+
+       /* Extents are handled otherwise = there is not support in this function
+        */
+       ext4_assert(!(
+           ext4_sb_feature_incom(&fs->sb, EXT4_FINCOM_EXTENTS) &&
+           (ext4_inode_has_flag(inode_ref->inode, EXT4_INODE_FLAG_EXTENTS))));
+
+       struct ext4_inode *inode = inode_ref->inode;
+
+       /* Handle simple case when we are dealing with direct reference */
+       if (iblock < EXT4_INODE_DIRECT_BLOCK_COUNT) {
+               fblock = ext4_inode_get_direct_block(inode, iblock);
+
+               /* Sparse file */
+               if (fblock == 0)
+                       return EOK;
+
+               ext4_inode_set_direct_block(inode, iblock, 0);
+               return ext4_balloc_free_block(inode_ref, fblock);
+       }
+
+       /* Determine the indirection level needed to get the desired block */
+       unsigned int level = 0;
+       unsigned int i;
+       for (i = 1; i < 4; i++) {
+               if (iblock < fs->inode_block_limits[i]) {
+                       level = i;
+                       break;
+               }
+       }
+
+       if (level == 0)
+               return EIO;
+
+       /* Compute offsets for the topmost level */
+       uint64_t block_offset_in_level =
+           iblock - fs->inode_block_limits[level - 1];
+       ext4_fsblk_t current_block =
+           ext4_inode_get_indirect_block(inode, level - 1);
+       uint32_t offset_in_block =
+           block_offset_in_level / fs->inode_blocks_per_level[level - 1];
+
+       /*
+        * Navigate through other levels, until we find the block number
+        * or find null reference meaning we are dealing with sparse file
+        */
+       struct ext4_block block;
+
+       while (level > 0) {
+
+               /* Sparse check */
+               if (current_block == 0)
+                       return EOK;
+
+               int rc = ext4_block_get(fs->bdev, &block, current_block);
+               if (rc != EOK)
+                       return rc;
+
+               current_block =
+                   to_le32(((uint32_t *)block.data)[offset_in_block]);
+
+               /* Set zero if physical data block address found */
+               if (level == 1) {
+                       ((uint32_t *)block.data)[offset_in_block] = to_le32(0);
+                       block.dirty = true;
+               }
+
+               rc = ext4_block_set(fs->bdev, &block);
+               if (rc != EOK)
+                       return rc;
+
+               level--;
+
+               /*
+                * If we are on the last level, break here as
+                * there is no next level to visit
+                */
+               if (level == 0)
+                       break;
+
+               /* Visit the next level */
+               block_offset_in_level %= fs->inode_blocks_per_level[level];
+               offset_in_block = block_offset_in_level /
+                                 fs->inode_blocks_per_level[level - 1];
+       }
+
+       fblock = current_block;
+       if (fblock == 0)
+               return EOK;
+
+       /* Physical block is not referenced, it can be released */
+       return ext4_balloc_free_block(inode_ref, fblock);
 }
 
-int ext4_fs_get_inode_data_block_index(struct ext4_inode_ref *inode_ref,
-                                       uint64_t iblock, uint32_t *fblock)
+int ext4_fs_truncate_inode(struct ext4_inode_ref *inode_ref, uint64_t new_size)
 {
-    struct ext4_fs *fs = inode_ref->fs;
-
-    /* For empty file is situation simple */
-    if (ext4_inode_get_size(&fs->sb, inode_ref->inode) == 0) {
-        *fblock = 0;
-        return EOK;
-    }
-
-    uint32_t current_block;
+       struct ext4_sblock *sb = &inode_ref->fs->sb;
+       uint32_t i;
+       int r;
+
+       /* Check flags, if i-node can be truncated */
+       if (!ext4_inode_can_truncate(sb, inode_ref->inode))
+               return EINVAL;
+
+       /* If sizes are equal, nothing has to be done. */
+       uint64_t old_size = ext4_inode_get_size(sb, inode_ref->inode);
+       if (old_size == new_size)
+               return EOK;
+
+       /* It's not supported to make the larger file by truncate operation */
+       if (old_size < new_size)
+               return EINVAL;
+
+       bool v;
+       v = ext4_inode_is_type(sb, inode_ref->inode, EXT4_INODE_MODE_SOFTLINK);
+       if (v && old_size < sizeof(inode_ref->inode->blocks) &&
+           !ext4_inode_get_blocks_count(sb, inode_ref->inode)) {
+               char *content = (char *)inode_ref->inode->blocks + new_size;
+               memset(content , 0, sizeof(inode_ref->inode->blocks) - new_size);
+               ext4_inode_set_size(inode_ref->inode, new_size);
+               inode_ref->dirty = true;
+
+               return EOK;
+       }
+
+       /* Compute how many blocks will be released */
+       uint32_t block_size = ext4_sb_get_block_size(sb);
+       uint32_t new_blocks_cnt = (new_size + block_size - 1) / block_size;
+       uint32_t old_blocks_cnt = (old_size + block_size - 1) / block_size;
+       uint32_t diff_blocks_cnt = old_blocks_cnt - new_blocks_cnt;
 #if CONFIG_EXTENT_ENABLE
-    /* Handle i-node using extents */
-    if ((ext4_sb_has_feature_incompatible(&fs->sb,
-                                          EXT4_FEATURE_INCOMPAT_EXTENTS)) &&
-        (ext4_inode_has_flag(inode_ref->inode, EXT4_INODE_FLAG_EXTENTS))) {
-
-        int rc = ext4_extent_find_block(inode_ref, iblock, &current_block);
-        if (rc != EOK)
-            return rc;
-
-        *fblock = current_block;
-        return EOK;
-    }
+       if ((ext4_sb_feature_incom(sb, EXT4_FINCOM_EXTENTS)) &&
+           (ext4_inode_has_flag(inode_ref->inode, EXT4_INODE_FLAG_EXTENTS))) {
+
+               /* Extents require special operation */
+               if (diff_blocks_cnt) {
+                       r = ext4_extent_remove_space(inode_ref, new_blocks_cnt,
+                                                    EXT_MAX_BLOCKS);
+                       if (r != EOK)
+                               return r;
+
+               }
+       } else
 #endif
+       {
+               /* Release data blocks from the end of file */
+
+               /* Starting from 1 because of logical blocks are numbered from 0
+                */
+               for (i = 0; i < diff_blocks_cnt; ++i) {
+                       r = ext4_fs_release_inode_block(inode_ref,
+                                                       new_blocks_cnt + i);
+                       if (r != EOK)
+                               return r;
+               }
+       }
+
+       /* Update i-node */
+       ext4_inode_set_size(inode_ref->inode, new_size);
+       inode_ref->dirty = true;
+
+       return EOK;
+}
 
-    struct ext4_inode *inode = inode_ref->inode;
-
-    /* Direct block are read directly from array in i-node structure */
-    if (iblock < EXT4_INODE_DIRECT_BLOCK_COUNT) {
-        current_block = ext4_inode_get_direct_block(inode, (uint32_t)iblock);
-        *fblock = current_block;
-        return EOK;
-    }
-
-    /* Determine indirection level of the target block */
-    unsigned int level = 0;
-    unsigned int i;
-    for (i = 1; i < 4; i++) {
-        if (iblock < fs->inode_block_limits[i]) {
-            level = i;
-            break;
-        }
-    }
-
-    if (level == 0)
-        return EIO;
-
-    /* Compute offsets for the topmost level */
-    uint64_t block_offset_in_level = iblock - fs->inode_block_limits[level - 1];
-    current_block = ext4_inode_get_indirect_block(inode, level - 1);
-    uint32_t offset_in_block =
-        block_offset_in_level / fs->inode_blocks_per_level[level - 1];
-
-    /* Sparse file */
-    if (current_block == 0) {
-        *fblock = 0;
-        return EOK;
-    }
-
-    struct ext4_block block;
-
-    /*
-     * Navigate through other levels, until we find the block number
-     * or find null reference meaning we are dealing with sparse file
-     */
-    while (level > 0) {
-        /* Load indirect block */
-        int rc = ext4_block_get(fs->bdev, &block, current_block);
-        if (rc != EOK)
-            return rc;
-
-        /* Read block address from indirect block */
-        current_block = to_le32(((uint32_t *)block.data)[offset_in_block]);
-
-        /* Put back indirect block untouched */
-        rc = ext4_block_set(fs->bdev, &block);
-        if (rc != EOK)
-            return rc;
-
-        /* Check for sparse file */
-        if (current_block == 0) {
-            *fblock = 0;
-            return EOK;
-        }
-
-        /* Jump to the next level */
-        level--;
-
-        /* Termination condition - we have address of data block loaded */
-        if (level == 0)
-            break;
-
-        /* Visit the next level */
-        block_offset_in_level %= fs->inode_blocks_per_level[level];
-        offset_in_block =
-            block_offset_in_level / fs->inode_blocks_per_level[level - 1];
-    }
-
-    *fblock = current_block;
-
-    return EOK;
+/**@brief Compute 'goal' for inode index
+ * @param inode_ref Reference to inode, to allocate block for
+ * @return goal
+ */
+ext4_fsblk_t ext4_fs_inode_to_goal_block(struct ext4_inode_ref *inode_ref)
+{
+       uint32_t grp_inodes = ext4_get32(&inode_ref->fs->sb, inodes_per_group);
+       return (inode_ref->index - 1) / grp_inodes;
 }
 
-int ext4_fs_set_inode_data_block_index(struct ext4_inode_ref *inode_ref,
-                                       uint64_t iblock, uint32_t fblock)
+/**@brief Compute 'goal' for allocation algorithm (For blockmap).
+ * @param inode_ref Reference to inode, to allocate block for
+ * @param goal
+ * @return error code
+ */
+int ext4_fs_indirect_find_goal(struct ext4_inode_ref *inode_ref,
+                              ext4_fsblk_t *goal)
 {
-    struct ext4_fs *fs = inode_ref->fs;
+       int r;
+       struct ext4_sblock *sb = &inode_ref->fs->sb;
+       *goal = 0;
 
-#if CONFIG_EXTENT_ENABLE
-    /* Handle inode using extents */
-    if ((ext4_sb_has_feature_incompatible(&fs->sb,
-                                          EXT4_FEATURE_INCOMPAT_EXTENTS)) &&
-        (ext4_inode_has_flag(inode_ref->inode, EXT4_INODE_FLAG_EXTENTS))) {
-        /* Not reachable */
-        return ENOTSUP;
-    }
-#endif
+       uint64_t inode_size = ext4_inode_get_size(sb, inode_ref->inode);
+       uint32_t block_size = ext4_sb_get_block_size(sb);
+       uint32_t iblock_cnt = inode_size / block_size;
 
-    /* Handle simple case when we are dealing with direct reference */
-    if (iblock < EXT4_INODE_DIRECT_BLOCK_COUNT) {
-        ext4_inode_set_direct_block(inode_ref->inode, (uint32_t)iblock, fblock);
-        inode_ref->dirty = true;
-
-        return EOK;
-    }
-
-    /* Determine the indirection level needed to get the desired block */
-    unsigned int level = 0;
-    unsigned int i;
-    for (i = 1; i < 4; i++) {
-        if (iblock < fs->inode_block_limits[i]) {
-            level = i;
-            break;
-        }
-    }
-
-    if (level == 0)
-        return EIO;
-
-    uint32_t block_size = ext4_sb_get_block_size(&fs->sb);
-
-    /* Compute offsets for the topmost level */
-    uint64_t block_offset_in_level = iblock - fs->inode_block_limits[level - 1];
-    uint32_t current_block =
-        ext4_inode_get_indirect_block(inode_ref->inode, level - 1);
-    uint32_t offset_in_block =
-        block_offset_in_level / fs->inode_blocks_per_level[level - 1];
-
-    uint32_t new_block_addr;
-
-    struct ext4_block block;
-    struct ext4_block new_block;
-
-    /* Is needed to allocate indirect block on the i-node level */
-    if (current_block == 0) {
-        /* Allocate new indirect block */
-        int rc = ext4_balloc_alloc_block(inode_ref, &new_block_addr);
-        if (rc != EOK)
-            return rc;
-
-        /* Update i-node */
-        ext4_inode_set_indirect_block(inode_ref->inode, level - 1,
-                                      new_block_addr);
-        inode_ref->dirty = true;
-
-        /* Load newly allocated block */
-        rc = ext4_block_get(fs->bdev, &new_block, new_block_addr);
-        if (rc != EOK) {
-            ext4_balloc_free_block(inode_ref, new_block_addr);
-            return rc;
-        }
-
-        /* Initialize new block */
-        memset(new_block.data, 0, block_size);
-        new_block.dirty = true;
-
-        /* Put back the allocated block */
-        rc = ext4_block_set(fs->bdev, &new_block);
-        if (rc != EOK)
-            return rc;
-
-        current_block = new_block_addr;
-    }
-
-    /*
-     * Navigate through other levels, until we find the block number
-     * or find null reference meaning we are dealing with sparse file
-     */
-    while (level > 0) {
-        int rc = ext4_block_get(fs->bdev, &block, current_block);
-        if (rc != EOK)
-            return rc;
-
-        current_block = to_le32(((uint32_t *)block.data)[offset_in_block]);
-
-        if ((level > 1) && (current_block == 0)) {
-            /* Allocate new block */
-            rc = ext4_balloc_alloc_block(inode_ref, &new_block_addr);
-            if (rc != EOK) {
-                ext4_block_set(fs->bdev, &block);
-                return rc;
-            }
-
-            /* Load newly allocated block */
-            rc = ext4_block_get(fs->bdev, &new_block, new_block_addr);
-
-            if (rc != EOK) {
-                ext4_block_set(fs->bdev, &block);
-                return rc;
-            }
-
-            /* Initialize allocated block */
-            memset(new_block.data, 0, block_size);
-            new_block.dirty = true;
-
-            rc = ext4_block_set(fs->bdev, &new_block);
-            if (rc != EOK) {
-                ext4_block_set(fs->bdev, &block);
-                return rc;
-            }
-
-            /* Write block address to the parent */
-            ((uint32_t *)block.data)[offset_in_block] = to_le32(new_block_addr);
-            block.dirty = true;
-            current_block = new_block_addr;
-        }
-
-        /* Will be finished, write the fblock address */
-        if (level == 1) {
-            ((uint32_t *)block.data)[offset_in_block] = to_le32(fblock);
-            block.dirty = true;
-        }
-
-        rc = ext4_block_set(fs->bdev, &block);
-        if (rc != EOK)
-            return rc;
-
-        level--;
+       if (inode_size % block_size != 0)
+               iblock_cnt++;
 
-        /*
-         * If we are on the last level, break here as
-         * there is no next level to visit
-         */
-        if (level == 0)
-            break;
+       /* If inode has some blocks, get last block address + 1 */
+       if (iblock_cnt > 0) {
+               r = ext4_fs_get_inode_data_block_index(inode_ref, iblock_cnt - 1,
+                                                      goal, false);
+               if (r != EOK)
+                       return r;
 
-        /* Visit the next level */
-        block_offset_in_level %= fs->inode_blocks_per_level[level];
-        offset_in_block =
-            block_offset_in_level / fs->inode_blocks_per_level[level - 1];
-    }
+               if (*goal != 0) {
+                       (*goal)++;
+                       return r;
+               }
 
-    return EOK;
-}
+               /* If goal == 0, sparse file -> continue */
+       }
 
-int ext4_fs_release_inode_block(struct ext4_inode_ref *inode_ref,
-                                uint32_t iblock)
-{
-    uint32_t fblock;
+       /* Identify block group of inode */
 
-    struct ext4_fs *fs = inode_ref->fs;
+       uint32_t inodes_per_bg = ext4_get32(sb, inodes_per_group);
+       uint32_t block_group = (inode_ref->index - 1) / inodes_per_bg;
+       block_size = ext4_sb_get_block_size(sb);
 
-    /* Extents are handled otherwise = there is not support in this function */
-    ext4_assert(
-        !(ext4_sb_has_feature_incompatible(&fs->sb,
-                                           EXT4_FEATURE_INCOMPAT_EXTENTS) &&
-          (ext4_inode_has_flag(inode_ref->inode, EXT4_INODE_FLAG_EXTENTS))));
+       /* Load block group reference */
+       struct ext4_block_group_ref bg_ref;
+       r = ext4_fs_get_block_group_ref(inode_ref->fs, block_group, &bg_ref);
+       if (r != EOK)
+               return r;
 
-    struct ext4_inode *inode = inode_ref->inode;
+       struct ext4_bgroup *bg = bg_ref.block_group;
 
-    /* Handle simple case when we are dealing with direct reference */
-    if (iblock < EXT4_INODE_DIRECT_BLOCK_COUNT) {
-        fblock = ext4_inode_get_direct_block(inode, iblock);
+       /* Compute indexes */
+       uint32_t bg_count = ext4_block_group_cnt(sb);
+       ext4_fsblk_t itab_first_block = ext4_bg_get_inode_table_first_block(bg, sb);
+       uint16_t itab_item_size = ext4_get16(sb, inode_size);
+       uint32_t itab_bytes;
 
-        /* Sparse file */
-        if (fblock == 0)
-            return EOK;
+       /* Check for last block group */
+       if (block_group < bg_count - 1) {
+               itab_bytes = inodes_per_bg * itab_item_size;
+       } else {
+               /* Last block group could be smaller */
+               uint32_t inodes_cnt = ext4_get32(sb, inodes_count);
 
-        ext4_inode_set_direct_block(inode, iblock, 0);
-        return ext4_balloc_free_block(inode_ref, fblock);
-    }
+               itab_bytes = (inodes_cnt - ((bg_count - 1) * inodes_per_bg));
+               itab_bytes *= itab_item_size;
+       }
 
-    /* Determine the indirection level needed to get the desired block */
-    unsigned int level = 0;
-    unsigned int i;
-    for (i = 1; i < 4; i++) {
-        if (iblock < fs->inode_block_limits[i]) {
-            level = i;
-            break;
-        }
-    }
+       ext4_fsblk_t inode_table_blocks = itab_bytes / block_size;
 
-    if (level == 0)
-        return EIO;
+       if (itab_bytes % block_size)
+               inode_table_blocks++;
 
-    /* Compute offsets for the topmost level */
-    uint64_t block_offset_in_level = iblock - fs->inode_block_limits[level - 1];
-    uint32_t current_block = ext4_inode_get_indirect_block(inode, level - 1);
-    uint32_t offset_in_block =
-        block_offset_in_level / fs->inode_blocks_per_level[level - 1];
+       *goal = itab_first_block + inode_table_blocks;
 
-    /*
-     * Navigate through other levels, until we find the block number
-     * or find null reference meaning we are dealing with sparse file
-     */
-    struct ext4_block block;
+       return ext4_fs_put_block_group_ref(&bg_ref);
+}
 
-    while (level > 0) {
+static int ext4_fs_get_inode_data_block_idx(struct ext4_inode_ref *inode_ref,
+                                      uint64_t iblock, ext4_fsblk_t *fblock,
+                                      bool extent_create,
+                                      bool support_unwritten __unused)
+{
+       struct ext4_fs *fs = inode_ref->fs;
 
-        /* Sparse check */
-        if (current_block == 0)
-            return EOK;
+       /* For empty file is situation simple */
+       if (ext4_inode_get_size(&fs->sb, inode_ref->inode) == 0) {
+               *fblock = 0;
+               return EOK;
+       }
 
-        int rc = ext4_block_get(fs->bdev, &block, current_block);
-        if (rc != EOK)
-            return rc;
+       ext4_fsblk_t current_block;
 
-        current_block = to_le32(((uint32_t *)block.data)[offset_in_block]);
+       (void)extent_create;
+#if CONFIG_EXTENT_ENABLE
+       /* Handle i-node using extents */
+       if ((ext4_sb_feature_incom(&fs->sb, EXT4_FINCOM_EXTENTS)) &&
+           (ext4_inode_has_flag(inode_ref->inode, EXT4_INODE_FLAG_EXTENTS))) {
+
+               ext4_fsblk_t current_fsblk;
+               int rc = ext4_extent_get_blocks(inode_ref, iblock, 1,
+                               &current_fsblk, extent_create, NULL);
+               if (rc != EOK)
+                       return rc;
+
+               current_block = current_fsblk;
+               *fblock = current_block;
+
+               ext4_assert(*fblock || support_unwritten);
+               return EOK;
+       }
+#endif
 
-        /* Set zero if physical data block address found */
-        if (level == 1) {
-            ((uint32_t *)block.data)[offset_in_block] = to_le32(0);
-            block.dirty = true;
-        }
+       struct ext4_inode *inode = inode_ref->inode;
+
+       /* Direct block are read directly from array in i-node structure */
+       if (iblock < EXT4_INODE_DIRECT_BLOCK_COUNT) {
+               current_block =
+                   ext4_inode_get_direct_block(inode, (uint32_t)iblock);
+               *fblock = current_block;
+               return EOK;
+       }
+
+       /* Determine indirection level of the target block */
+       unsigned int l = 0;
+       unsigned int i;
+       for (i = 1; i < 4; i++) {
+               if (iblock < fs->inode_block_limits[i]) {
+                       l = i;
+                       break;
+               }
+       }
+
+       if (l == 0)
+               return EIO;
+
+       /* Compute offsets for the topmost level */
+       uint64_t blk_off_in_lvl =  iblock - fs->inode_block_limits[l - 1];
+       current_block = ext4_inode_get_indirect_block(inode, l - 1);
+       uint32_t off_in_blk = blk_off_in_lvl / fs->inode_blocks_per_level[l - 1];
+
+       /* Sparse file */
+       if (current_block == 0) {
+               *fblock = 0;
+               return EOK;
+       }
+
+       struct ext4_block block;
+
+       /*
+        * Navigate through other levels, until we find the block number
+        * or find null reference meaning we are dealing with sparse file
+        */
+       while (l > 0) {
+               /* Load indirect block */
+               int rc = ext4_block_get(fs->bdev, &block, current_block);
+               if (rc != EOK)
+                       return rc;
+
+               /* Read block address from indirect block */
+               current_block =
+                   to_le32(((uint32_t *)block.data)[off_in_blk]);
+
+               /* Put back indirect block untouched */
+               rc = ext4_block_set(fs->bdev, &block);
+               if (rc != EOK)
+                       return rc;
+
+               /* Check for sparse file */
+               if (current_block == 0) {
+                       *fblock = 0;
+                       return EOK;
+               }
+
+               /* Jump to the next level */
+               l--;
+
+               /* Termination condition - we have address of data block loaded
+                */
+               if (l == 0)
+                       break;
+
+               /* Visit the next level */
+               blk_off_in_lvl %= fs->inode_blocks_per_level[l];
+               off_in_blk = blk_off_in_lvl / fs->inode_blocks_per_level[l - 1];
+       }
+
+       *fblock = current_block;
+
+       return EOK;
+}
 
-        rc = ext4_block_set(fs->bdev, &block);
-        if (rc != EOK)
-            return rc;
 
-        level--;
+int ext4_fs_get_inode_data_block_index(struct ext4_inode_ref *inode_ref,
+                                      uint64_t iblock, ext4_fsblk_t *fblock,
+                                      bool support_unwritten)
+{
+       return ext4_fs_get_inode_data_block_idx(inode_ref, iblock, fblock,
+                       false, support_unwritten);
+}
 
-        /*
-         * If we are on the last level, break here as
-         * there is no next level to visit
-         */
-        if (level == 0)
-            break;
+int ext4_fs_init_inode_data_block_index(struct ext4_inode_ref *inode_ref,
+                                      uint64_t iblock, ext4_fsblk_t *fblock)
+{
+       return ext4_fs_get_inode_data_block_idx(inode_ref, iblock, fblock,
+                       true, true);
+}
 
-        /* Visit the next level */
-        block_offset_in_level %= fs->inode_blocks_per_level[level];
-        offset_in_block =
-            block_offset_in_level / fs->inode_blocks_per_level[level - 1];
-    }
+static int ext4_fs_set_inode_data_block_index(struct ext4_inode_ref *inode_ref,
+                                      uint64_t iblock, ext4_fsblk_t fblock)
+{
+       struct ext4_fs *fs = inode_ref->fs;
 
-    fblock = current_block;
-    if (fblock == 0)
-        return EOK;
+#if CONFIG_EXTENT_ENABLE
+       /* Handle inode using extents */
+       if ((ext4_sb_feature_incom(&fs->sb, EXT4_FINCOM_EXTENTS)) &&
+           (ext4_inode_has_flag(inode_ref->inode, EXT4_INODE_FLAG_EXTENTS))) {
+               /* Not reachable */
+               return ENOTSUP;
+       }
+#endif
 
-    /* Physical block is not referenced, it can be released */
-    return ext4_balloc_free_block(inode_ref, fblock);
+       /* Handle simple case when we are dealing with direct reference */
+       if (iblock < EXT4_INODE_DIRECT_BLOCK_COUNT) {
+               ext4_inode_set_direct_block(inode_ref->inode, (uint32_t)iblock,
+                                           (uint32_t)fblock);
+               inode_ref->dirty = true;
+
+               return EOK;
+       }
+
+       /* Determine the indirection level needed to get the desired block */
+       unsigned int l = 0;
+       unsigned int i;
+       for (i = 1; i < 4; i++) {
+               if (iblock < fs->inode_block_limits[i]) {
+                       l = i;
+                       break;
+               }
+       }
+
+       if (l == 0)
+               return EIO;
+
+       uint32_t block_size = ext4_sb_get_block_size(&fs->sb);
+
+       /* Compute offsets for the topmost level */
+       uint64_t blk_off_in_lvl =  iblock - fs->inode_block_limits[l - 1];
+       ext4_fsblk_t current_block =
+                       ext4_inode_get_indirect_block(inode_ref->inode, l - 1);
+       uint32_t off_in_blk = blk_off_in_lvl / fs->inode_blocks_per_level[l - 1];
+
+       ext4_fsblk_t new_blk;
+
+       struct ext4_block block;
+       struct ext4_block new_block;
+
+       /* Is needed to allocate indirect block on the i-node level */
+       if (current_block == 0) {
+               /* Allocate new indirect block */
+               ext4_fsblk_t goal;
+               int rc = ext4_fs_indirect_find_goal(inode_ref, &goal);
+               if (rc != EOK)
+                       return rc;
+
+               rc = ext4_balloc_alloc_block(inode_ref, goal, &new_blk);
+               if (rc != EOK)
+                       return rc;
+
+               /* Update i-node */
+               ext4_inode_set_indirect_block(inode_ref->inode, l - 1, new_blk);
+               inode_ref->dirty = true;
+
+               /* Load newly allocated block */
+               rc = ext4_block_get_noread(fs->bdev, &new_block, new_blk);
+               if (rc != EOK) {
+                       ext4_balloc_free_block(inode_ref, new_blk);
+                       return rc;
+               }
+
+               /* Initialize new block */
+               memset(new_block.data, 0, block_size);
+               new_block.dirty = true;
+
+               /* Put back the allocated block */
+               rc = ext4_block_set(fs->bdev, &new_block);
+               if (rc != EOK)
+                       return rc;
+
+               current_block = new_blk;
+       }
+
+       /*
+        * Navigate through other levels, until we find the block number
+        * or find null reference meaning we are dealing with sparse file
+        */
+       while (l > 0) {
+               int rc = ext4_block_get(fs->bdev, &block, current_block);
+               if (rc != EOK)
+                       return rc;
+
+               current_block = to_le32(((uint32_t *)block.data)[off_in_blk]);
+               if ((l > 1) && (current_block == 0)) {
+                       ext4_fsblk_t goal;
+                       rc = ext4_fs_indirect_find_goal(inode_ref, &goal);
+                       if (rc != EOK) {
+                               ext4_block_set(fs->bdev, &block);
+                               return rc;
+                       }
+
+                       /* Allocate new block */
+                       rc =
+                           ext4_balloc_alloc_block(inode_ref, goal, &new_blk);
+                       if (rc != EOK) {
+                               ext4_block_set(fs->bdev, &block);
+                               return rc;
+                       }
+
+                       /* Load newly allocated block */
+                       rc = ext4_block_get_noread(fs->bdev, &new_block,
+                                           new_blk);
+
+                       if (rc != EOK) {
+                               ext4_block_set(fs->bdev, &block);
+                               return rc;
+                       }
+
+                       /* Initialize allocated block */
+                       memset(new_block.data, 0, block_size);
+                       new_block.dirty = true;
+
+                       rc = ext4_block_set(fs->bdev, &new_block);
+                       if (rc != EOK) {
+                               ext4_block_set(fs->bdev, &block);
+                               return rc;
+                       }
+
+                       /* Write block address to the parent */
+                       uint32_t * p = (uint32_t * )block.data;
+                       p[off_in_blk] = to_le32((uint32_t)new_blk);
+                       block.dirty = true;
+                       current_block = new_blk;
+               }
+
+               /* Will be finished, write the fblock address */
+               if (l == 1) {
+                       uint32_t * p = (uint32_t * )block.data;
+                       p[off_in_blk] = to_le32((uint32_t)fblock);
+                       block.dirty = true;
+               }
+
+               rc = ext4_block_set(fs->bdev, &block);
+               if (rc != EOK)
+                       return rc;
+
+               l--;
+
+               /*
+                * If we are on the last level, break here as
+                * there is no next level to visit
+                */
+               if (l == 0)
+                       break;
+
+               /* Visit the next level */
+               blk_off_in_lvl %= fs->inode_blocks_per_level[l];
+               off_in_blk = blk_off_in_lvl / fs->inode_blocks_per_level[l - 1];
+       }
+
+       return EOK;
 }
 
+
 int ext4_fs_append_inode_block(struct ext4_inode_ref *inode_ref,
-                               uint32_t *fblock, uint32_t *iblock)
+                              ext4_fsblk_t *fblock, uint32_t *iblock)
 {
 #if CONFIG_EXTENT_ENABLE
-    /* Handle extents separately */
-    if ((ext4_sb_has_feature_incompatible(&inode_ref->fs->sb,
-                                          EXT4_FEATURE_INCOMPAT_EXTENTS)) &&
-        (ext4_inode_has_flag(inode_ref->inode, EXT4_INODE_FLAG_EXTENTS))) {
-        return ext4_extent_append_block(inode_ref, iblock, fblock, true);
-    }
+       /* Handle extents separately */
+       if ((ext4_sb_feature_incom(&inode_ref->fs->sb, EXT4_FINCOM_EXTENTS)) &&
+           (ext4_inode_has_flag(inode_ref->inode, EXT4_INODE_FLAG_EXTENTS))) {
+               int rc;
+               ext4_fsblk_t current_fsblk;
+               struct ext4_sblock *sb = &inode_ref->fs->sb;
+               uint64_t inode_size = ext4_inode_get_size(sb, inode_ref->inode);
+               uint32_t block_size = ext4_sb_get_block_size(sb);
+               *iblock = (inode_size + block_size - 1) / block_size;
+
+               rc = ext4_extent_get_blocks(inode_ref, *iblock, 1,
+                                               &current_fsblk, true, NULL);
+
+
+               *fblock = current_fsblk;
+               ext4_assert(*fblock);
+
+               ext4_inode_set_size(inode_ref->inode, inode_size + block_size);
+               inode_ref->dirty = true;
+
+
+               return rc;
+       }
 #endif
-    struct ext4_sblock *sb = &inode_ref->fs->sb;
+       struct ext4_sblock *sb = &inode_ref->fs->sb;
 
-    /* Compute next block index and allocate data block */
-    uint64_t inode_size = ext4_inode_get_size(sb, inode_ref->inode);
-    uint32_t block_size = ext4_sb_get_block_size(sb);
+       /* Compute next block index and allocate data block */
+       uint64_t inode_size = ext4_inode_get_size(sb, inode_ref->inode);
+       uint32_t block_size = ext4_sb_get_block_size(sb);
 
-    /* Align size i-node size */
-    if ((inode_size % block_size) != 0)
-        inode_size += block_size - (inode_size % block_size);
+       /* Align size i-node size */
+       if ((inode_size % block_size) != 0)
+               inode_size += block_size - (inode_size % block_size);
 
-    /* Logical blocks are numbered from 0 */
-    uint32_t new_block_idx = inode_size / block_size;
+       /* Logical blocks are numbered from 0 */
+       uint32_t new_block_idx = inode_size / block_size;
 
-    /* Allocate new physical block */
-    uint32_t phys_block;
-    int rc = ext4_balloc_alloc_block(inode_ref, &phys_block);
-    if (rc != EOK)
-        return rc;
+       /* Allocate new physical block */
+       ext4_fsblk_t goal, phys_block;
+       int rc = ext4_fs_indirect_find_goal(inode_ref, &goal);
+       if (rc != EOK)
+               return rc;
 
-    /* Add physical block address to the i-node */
-    rc = ext4_fs_set_inode_data_block_index(inode_ref, new_block_idx,
-                                            phys_block);
-    if (rc != EOK) {
-        ext4_balloc_free_block(inode_ref, phys_block);
-        return rc;
-    }
+       rc = ext4_balloc_alloc_block(inode_ref, goal, &phys_block);
+       if (rc != EOK)
+               return rc;
 
-    /* Update i-node */
-    ext4_inode_set_size(inode_ref->inode, inode_size + block_size);
-    inode_ref->dirty = true;
+       /* Add physical block address to the i-node */
+       rc = ext4_fs_set_inode_data_block_index(inode_ref, new_block_idx,
+                                               phys_block);
+       if (rc != EOK) {
+               ext4_balloc_free_block(inode_ref, phys_block);
+               return rc;
+       }
 
-    *fblock = phys_block;
-    *iblock = new_block_idx;
+       /* Update i-node */
+       ext4_inode_set_size(inode_ref->inode, inode_size + block_size);
+       inode_ref->dirty = true;
 
-    return EOK;
+       *fblock = phys_block;
+       *iblock = new_block_idx;
+
+       return EOK;
 }
 
 void ext4_fs_inode_links_count_inc(struct ext4_inode_ref *inode_ref)
 {
-    uint16_t link;
-    if (!ext4_inode_is_type(&inode_ref->fs->sb, inode_ref->inode,
-                            EXT4_INODE_MODE_DIRECTORY)) {
-        ext4_inode_set_links_count(inode_ref->inode, 0);
-        return;
-    }
-
-    link = ext4_inode_get_links_count(inode_ref->inode);
-    link++;
-    ext4_inode_set_links_count(inode_ref->inode, link);
-
-    bool is_dx = ext4_sb_has_feature_compatible(
-                     &inode_ref->fs->sb, EXT4_FEATURE_COMPAT_DIR_INDEX) &&
-                 ext4_inode_has_flag(inode_ref->inode, EXT4_INODE_FLAG_INDEX);
-
-    if (is_dx && link > 1) {
-        if (link >= EXT4_LINK_MAX || link == 2) {
-            ext4_inode_set_links_count(inode_ref->inode, 1);
-
-            uint32_t v = ext4_get32(&inode_ref->fs->sb, features_read_only);
-            v |= EXT4_FEATURE_RO_COMPAT_DIR_NLINK;
-            ext4_set32(&inode_ref->fs->sb, features_read_only, v);
-        }
-    }
+       uint16_t link;
+       bool is_dx;
+       link = ext4_inode_get_links_count(inode_ref->inode);
+       link++;
+       ext4_inode_set_links_count(inode_ref->inode, link);
+
+       is_dx = ext4_sb_feature_com(&inode_ref->fs->sb, EXT4_FCOM_DIR_INDEX) &&
+               ext4_inode_has_flag(inode_ref->inode, EXT4_INODE_FLAG_INDEX);
+
+       if (is_dx && link > 1) {
+               if (link >= EXT4_LINK_MAX || link == 2) {
+                       ext4_inode_set_links_count(inode_ref->inode, 1);
+
+                       uint32_t v;
+                       v = ext4_get32(&inode_ref->fs->sb, features_read_only);
+                       v |= EXT4_FRO_COM_DIR_NLINK;
+                       ext4_set32(&inode_ref->fs->sb, features_read_only, v);
+               }
+       }
 }
 
 void ext4_fs_inode_links_count_dec(struct ext4_inode_ref *inode_ref)
 {
-    if (!ext4_inode_is_type(&inode_ref->fs->sb, inode_ref->inode,
-                            EXT4_INODE_MODE_DIRECTORY)) {
-        ext4_inode_set_links_count(inode_ref->inode, 0);
-        return;
-    }
-
-    uint16_t links = ext4_inode_get_links_count(inode_ref->inode);
-
-    if (links > 2)
-        ext4_inode_set_links_count(inode_ref->inode, links - 1);
+       uint16_t links = ext4_inode_get_links_count(inode_ref->inode);
+       if (!ext4_inode_is_type(&inode_ref->fs->sb, inode_ref->inode,
+                               EXT4_INODE_MODE_DIRECTORY)) {
+               if (links > 0)
+                       ext4_inode_set_links_count(inode_ref->inode, links - 1);
+               return;
+       }
+
+       if (links > 2)
+               ext4_inode_set_links_count(inode_ref->inode, links - 1);
 }
 
 /**