]> git.sur5r.net Git - u-boot/blobdiff - fs/ext4/ext4fs.c
ext4fs write support
[u-boot] / fs / ext4 / ext4fs.c
index 1287bf0e182be2bc7855a4a3759769e510a8da4e..114c2a21498db20690b852eaaed31955afea37be 100644 (file)
@@ -16,6 +16,8 @@
  * GRUB  --  GRand Unified Bootloader
  * Copyright (C) 2003, 2004  Free Software Foundation, Inc.
  *
+ * ext4write : Based on generic ext4 protocol.
+ *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 of the License, or
@@ -226,3 +228,962 @@ int ext4fs_read(char *buf, unsigned len)
 
        return ext4fs_read_file(ext4fs_file, 0, len, buf);
 }
+
+#if defined(CONFIG_CMD_EXT4_WRITE)
+static void ext4fs_update(void)
+{
+       short i;
+       ext4fs_update_journal();
+       struct ext_filesystem *fs = get_fs();
+
+       /* update  super block */
+       put_ext4((uint64_t)(SUPERBLOCK_SIZE),
+                (struct ext2_sblock *)fs->sb, (uint32_t)SUPERBLOCK_SIZE);
+
+       /* update block groups */
+       for (i = 0; i < fs->no_blkgrp; i++) {
+               fs->gd[i].bg_checksum = ext4fs_checksum_update(i);
+               put_ext4((uint64_t)(fs->gd[i].block_id * fs->blksz),
+                        fs->blk_bmaps[i], fs->blksz);
+       }
+
+       /* update inode table groups */
+       for (i = 0; i < fs->no_blkgrp; i++) {
+               put_ext4((uint64_t) (fs->gd[i].inode_id * fs->blksz),
+                        fs->inode_bmaps[i], fs->blksz);
+       }
+
+       /* update the block group descriptor table */
+       put_ext4((uint64_t)(fs->gdtable_blkno * fs->blksz),
+                (struct ext2_block_group *)fs->gdtable,
+                (fs->blksz * fs->no_blk_pergdt));
+
+       ext4fs_dump_metadata();
+
+       gindex = 0;
+       gd_index = 0;
+}
+
+int ext4fs_get_bgdtable(void)
+{
+       int status;
+       int grp_desc_size;
+       struct ext_filesystem *fs = get_fs();
+       grp_desc_size = sizeof(struct ext2_block_group);
+       fs->no_blk_pergdt = (fs->no_blkgrp * grp_desc_size) / fs->blksz;
+       if ((fs->no_blkgrp * grp_desc_size) % fs->blksz)
+               fs->no_blk_pergdt++;
+
+       /* allocate memory for gdtable */
+       fs->gdtable = zalloc(fs->blksz * fs->no_blk_pergdt);
+       if (!fs->gdtable)
+               return -ENOMEM;
+       /* read the group descriptor table */
+       status = ext4fs_devread(fs->gdtable_blkno * fs->sect_perblk, 0,
+                               fs->blksz * fs->no_blk_pergdt, fs->gdtable);
+       if (status == 0)
+               goto fail;
+
+       if (ext4fs_log_gdt(fs->gdtable)) {
+               printf("Error in ext4fs_log_gdt\n");
+               return -1;
+       }
+
+       return 0;
+fail:
+       free(fs->gdtable);
+       fs->gdtable = NULL;
+
+       return -1;
+}
+
+static void delete_single_indirect_block(struct ext2_inode *inode)
+{
+       struct ext2_block_group *gd = NULL;
+       static int prev_bg_bmap_idx = -1;
+       long int blknr;
+       int remainder;
+       int bg_idx;
+       int status;
+       unsigned int blk_per_grp = ext4fs_root->sblock.blocks_per_group;
+       struct ext_filesystem *fs = get_fs();
+       char *journal_buffer = zalloc(fs->blksz);
+       if (!journal_buffer) {
+               printf("No memory\n");
+               return;
+       }
+       /* get  block group descriptor table */
+       gd = (struct ext2_block_group *)fs->gdtable;
+
+       /* deleting the single indirect block associated with inode */
+       if (inode->b.blocks.indir_block != 0) {
+               debug("SIPB releasing %u\n", inode->b.blocks.indir_block);
+               blknr = inode->b.blocks.indir_block;
+               if (fs->blksz != 1024) {
+                       bg_idx = blknr / blk_per_grp;
+               } else {
+                       bg_idx = blknr / blk_per_grp;
+                       remainder = blknr % blk_per_grp;
+                       if (!remainder)
+                               bg_idx--;
+               }
+               ext4fs_reset_block_bmap(blknr, fs->blk_bmaps[bg_idx], bg_idx);
+               gd[bg_idx].free_blocks++;
+               fs->sb->free_blocks++;
+               /* journal backup */
+               if (prev_bg_bmap_idx != bg_idx) {
+                       status =
+                           ext4fs_devread(gd[bg_idx].block_id *
+                                          fs->sect_perblk, 0, fs->blksz,
+                                          journal_buffer);
+                       if (status == 0)
+                               goto fail;
+                       if (ext4fs_log_journal
+                           (journal_buffer, gd[bg_idx].block_id))
+                               goto fail;
+                       prev_bg_bmap_idx = bg_idx;
+               }
+       }
+fail:
+       free(journal_buffer);
+}
+
+static void delete_double_indirect_block(struct ext2_inode *inode)
+{
+       int i;
+       short status;
+       static int prev_bg_bmap_idx = -1;
+       long int blknr;
+       int remainder;
+       int bg_idx;
+       unsigned int blk_per_grp = ext4fs_root->sblock.blocks_per_group;
+       unsigned int *di_buffer = NULL;
+       unsigned int *DIB_start_addr = NULL;
+       struct ext2_block_group *gd = NULL;
+       struct ext_filesystem *fs = get_fs();
+       char *journal_buffer = zalloc(fs->blksz);
+       if (!journal_buffer) {
+               printf("No memory\n");
+               return;
+       }
+       /* get the block group descriptor table */
+       gd = (struct ext2_block_group *)fs->gdtable;
+
+       if (inode->b.blocks.double_indir_block != 0) {
+               di_buffer = zalloc(fs->blksz);
+               if (!di_buffer) {
+                       printf("No memory\n");
+                       return;
+               }
+               DIB_start_addr = (unsigned int *)di_buffer;
+               blknr = inode->b.blocks.double_indir_block;
+               status = ext4fs_devread(blknr * fs->sect_perblk, 0, fs->blksz,
+                                       (char *)di_buffer);
+               for (i = 0; i < fs->blksz / sizeof(int); i++) {
+                       if (*di_buffer == 0)
+                               break;
+
+                       debug("DICB releasing %u\n", *di_buffer);
+                       if (fs->blksz != 1024) {
+                               bg_idx = (*di_buffer) / blk_per_grp;
+                       } else {
+                               bg_idx = (*di_buffer) / blk_per_grp;
+                               remainder = (*di_buffer) % blk_per_grp;
+                               if (!remainder)
+                                       bg_idx--;
+                       }
+                       ext4fs_reset_block_bmap(*di_buffer,
+                                       fs->blk_bmaps[bg_idx], bg_idx);
+                       di_buffer++;
+                       gd[bg_idx].free_blocks++;
+                       fs->sb->free_blocks++;
+                       /* journal backup */
+                       if (prev_bg_bmap_idx != bg_idx) {
+                               status = ext4fs_devread(gd[bg_idx].block_id
+                                                       * fs->sect_perblk, 0,
+                                                       fs->blksz,
+                                                       journal_buffer);
+                               if (status == 0)
+                                       goto fail;
+
+                               if (ext4fs_log_journal(journal_buffer,
+                                                       gd[bg_idx].block_id))
+                                       goto fail;
+                               prev_bg_bmap_idx = bg_idx;
+                       }
+               }
+
+               /* removing the parent double indirect block */
+               blknr = inode->b.blocks.double_indir_block;
+               if (fs->blksz != 1024) {
+                       bg_idx = blknr / blk_per_grp;
+               } else {
+                       bg_idx = blknr / blk_per_grp;
+                       remainder = blknr % blk_per_grp;
+                       if (!remainder)
+                               bg_idx--;
+               }
+               ext4fs_reset_block_bmap(blknr, fs->blk_bmaps[bg_idx], bg_idx);
+               gd[bg_idx].free_blocks++;
+               fs->sb->free_blocks++;
+               /* journal backup */
+               if (prev_bg_bmap_idx != bg_idx) {
+                       memset(journal_buffer, '\0', fs->blksz);
+                       status = ext4fs_devread(gd[bg_idx].block_id *
+                                               fs->sect_perblk, 0, fs->blksz,
+                                               journal_buffer);
+                       if (status == 0)
+                               goto fail;
+
+                       if (ext4fs_log_journal(journal_buffer,
+                                               gd[bg_idx].block_id))
+                               goto fail;
+                       prev_bg_bmap_idx = bg_idx;
+               }
+               debug("DIPB releasing %ld\n", blknr);
+       }
+fail:
+       free(DIB_start_addr);
+       free(journal_buffer);
+}
+
+static void delete_triple_indirect_block(struct ext2_inode *inode)
+{
+       int i, j;
+       short status;
+       static int prev_bg_bmap_idx = -1;
+       long int blknr;
+       int remainder;
+       int bg_idx;
+       unsigned int blk_per_grp = ext4fs_root->sblock.blocks_per_group;
+       unsigned int *tigp_buffer = NULL;
+       unsigned int *tib_start_addr = NULL;
+       unsigned int *tip_buffer = NULL;
+       unsigned int *tipb_start_addr = NULL;
+       struct ext2_block_group *gd = NULL;
+       struct ext_filesystem *fs = get_fs();
+       char *journal_buffer = zalloc(fs->blksz);
+       if (!journal_buffer) {
+               printf("No memory\n");
+               return;
+       }
+       /* get block group descriptor table */
+       gd = (struct ext2_block_group *)fs->gdtable;
+
+       if (inode->b.blocks.triple_indir_block != 0) {
+               tigp_buffer = zalloc(fs->blksz);
+               if (!tigp_buffer) {
+                       printf("No memory\n");
+                       return;
+               }
+               tib_start_addr = (unsigned int *)tigp_buffer;
+               blknr = inode->b.blocks.triple_indir_block;
+               status = ext4fs_devread(blknr * fs->sect_perblk, 0, fs->blksz,
+                                       (char *)tigp_buffer);
+               for (i = 0; i < fs->blksz / sizeof(int); i++) {
+                       if (*tigp_buffer == 0)
+                               break;
+                       debug("tigp buffer releasing %u\n", *tigp_buffer);
+
+                       tip_buffer = zalloc(fs->blksz);
+                       if (!tip_buffer)
+                               goto fail;
+                       tipb_start_addr = (unsigned int *)tip_buffer;
+                       status = ext4fs_devread((*tigp_buffer) *
+                                               fs->sect_perblk, 0, fs->blksz,
+                                               (char *)tip_buffer);
+                       for (j = 0; j < fs->blksz / sizeof(int); j++) {
+                               if (*tip_buffer == 0)
+                                       break;
+                               if (fs->blksz != 1024) {
+                                       bg_idx = (*tip_buffer) / blk_per_grp;
+                               } else {
+                                       bg_idx = (*tip_buffer) / blk_per_grp;
+
+                                       remainder = (*tip_buffer) % blk_per_grp;
+                                       if (!remainder)
+                                               bg_idx--;
+                               }
+
+                               ext4fs_reset_block_bmap(*tip_buffer,
+                                                       fs->blk_bmaps[bg_idx],
+                                                       bg_idx);
+
+                               tip_buffer++;
+                               gd[bg_idx].free_blocks++;
+                               fs->sb->free_blocks++;
+                               /* journal backup */
+                               if (prev_bg_bmap_idx != bg_idx) {
+                                       status =
+                                           ext4fs_devread(gd[bg_idx].block_id *
+                                                          fs->sect_perblk, 0,
+                                                          fs->blksz,
+                                                          journal_buffer);
+                                       if (status == 0)
+                                               goto fail;
+
+                                       if (ext4fs_log_journal(journal_buffer,
+                                                              gd[bg_idx].
+                                                              block_id))
+                                               goto fail;
+                                       prev_bg_bmap_idx = bg_idx;
+                               }
+                       }
+                       free(tipb_start_addr);
+                       tipb_start_addr = NULL;
+
+                       /*
+                        * removing the grand parent blocks
+                        * which is connected to inode
+                        */
+                       if (fs->blksz != 1024) {
+                               bg_idx = (*tigp_buffer) / blk_per_grp;
+                       } else {
+                               bg_idx = (*tigp_buffer) / blk_per_grp;
+
+                               remainder = (*tigp_buffer) % blk_per_grp;
+                               if (!remainder)
+                                       bg_idx--;
+                       }
+                       ext4fs_reset_block_bmap(*tigp_buffer,
+                                               fs->blk_bmaps[bg_idx], bg_idx);
+
+                       tigp_buffer++;
+                       gd[bg_idx].free_blocks++;
+                       fs->sb->free_blocks++;
+                       /* journal backup */
+                       if (prev_bg_bmap_idx != bg_idx) {
+                               memset(journal_buffer, '\0', fs->blksz);
+                               status =
+                                   ext4fs_devread(gd[bg_idx].block_id *
+                                                  fs->sect_perblk, 0,
+                                                  fs->blksz, journal_buffer);
+                               if (status == 0)
+                                       goto fail;
+
+                               if (ext4fs_log_journal(journal_buffer,
+                                                       gd[bg_idx].block_id))
+                                       goto fail;
+                               prev_bg_bmap_idx = bg_idx;
+                       }
+               }
+
+               /* removing the grand parent triple indirect block */
+               blknr = inode->b.blocks.triple_indir_block;
+               if (fs->blksz != 1024) {
+                       bg_idx = blknr / blk_per_grp;
+               } else {
+                       bg_idx = blknr / blk_per_grp;
+                       remainder = blknr % blk_per_grp;
+                       if (!remainder)
+                               bg_idx--;
+               }
+               ext4fs_reset_block_bmap(blknr, fs->blk_bmaps[bg_idx], bg_idx);
+               gd[bg_idx].free_blocks++;
+               fs->sb->free_blocks++;
+               /* journal backup */
+               if (prev_bg_bmap_idx != bg_idx) {
+                       memset(journal_buffer, '\0', fs->blksz);
+                       status = ext4fs_devread(gd[bg_idx].block_id *
+                                               fs->sect_perblk, 0, fs->blksz,
+                                               journal_buffer);
+                       if (status == 0)
+                               goto fail;
+
+                       if (ext4fs_log_journal(journal_buffer,
+                                               gd[bg_idx].block_id))
+                               goto fail;
+                       prev_bg_bmap_idx = bg_idx;
+               }
+               debug("tigp buffer itself releasing %ld\n", blknr);
+       }
+fail:
+       free(tib_start_addr);
+       free(tipb_start_addr);
+       free(journal_buffer);
+}
+
+static int ext4fs_delete_file(int inodeno)
+{
+       struct ext2_inode inode;
+       short status;
+       int i;
+       int remainder;
+       long int blknr;
+       int bg_idx;
+       int ibmap_idx;
+       char *read_buffer = NULL;
+       char *start_block_address = NULL;
+       unsigned int no_blocks;
+
+       static int prev_bg_bmap_idx = -1;
+       unsigned int inodes_per_block;
+       long int blkno;
+       unsigned int blkoff;
+       unsigned int blk_per_grp = ext4fs_root->sblock.blocks_per_group;
+       unsigned int inode_per_grp = ext4fs_root->sblock.inodes_per_group;
+       struct ext2_inode *inode_buffer = NULL;
+       struct ext2_block_group *gd = NULL;
+       struct ext_filesystem *fs = get_fs();
+       char *journal_buffer = zalloc(fs->blksz);
+       if (!journal_buffer)
+               return -ENOMEM;
+       /* get the block group descriptor table */
+       gd = (struct ext2_block_group *)fs->gdtable;
+       status = ext4fs_read_inode(ext4fs_root, inodeno, &inode);
+       if (status == 0)
+               goto fail;
+
+       /* read the block no allocated to a file */
+       no_blocks = inode.size / fs->blksz;
+       if (inode.size % fs->blksz)
+               no_blocks++;
+
+       if (le32_to_cpu(inode.flags) & EXT4_EXTENTS_FL) {
+               struct ext2fs_node *node_inode =
+                   zalloc(sizeof(struct ext2fs_node));
+               if (!node_inode)
+                       goto fail;
+               node_inode->data = ext4fs_root;
+               node_inode->ino = inodeno;
+               node_inode->inode_read = 0;
+               memcpy(&(node_inode->inode), &inode, sizeof(struct ext2_inode));
+
+               for (i = 0; i < no_blocks; i++) {
+                       blknr = read_allocated_block(&(node_inode->inode), i);
+                       if (fs->blksz != 1024) {
+                               bg_idx = blknr / blk_per_grp;
+                       } else {
+                               bg_idx = blknr / blk_per_grp;
+                               remainder = blknr % blk_per_grp;
+                               if (!remainder)
+                                       bg_idx--;
+                       }
+                       ext4fs_reset_block_bmap(blknr, fs->blk_bmaps[bg_idx],
+                                               bg_idx);
+                       debug("EXT4_EXTENTS Block releasing %ld: %d\n",
+                             blknr, bg_idx);
+
+                       gd[bg_idx].free_blocks++;
+                       fs->sb->free_blocks++;
+
+                       /* journal backup */
+                       if (prev_bg_bmap_idx != bg_idx) {
+                               status =
+                                   ext4fs_devread(gd[bg_idx].block_id *
+                                                  fs->sect_perblk, 0,
+                                                  fs->blksz, journal_buffer);
+                               if (status == 0)
+                                       goto fail;
+                               if (ext4fs_log_journal(journal_buffer,
+                                                       gd[bg_idx].block_id))
+                                       goto fail;
+                               prev_bg_bmap_idx = bg_idx;
+                       }
+               }
+               if (node_inode) {
+                       free(node_inode);
+                       node_inode = NULL;
+               }
+       } else {
+
+               delete_single_indirect_block(&inode);
+               delete_double_indirect_block(&inode);
+               delete_triple_indirect_block(&inode);
+
+               /* read the block no allocated to a file */
+               no_blocks = inode.size / fs->blksz;
+               if (inode.size % fs->blksz)
+                       no_blocks++;
+               for (i = 0; i < no_blocks; i++) {
+                       blknr = read_allocated_block(&inode, i);
+                       if (fs->blksz != 1024) {
+                               bg_idx = blknr / blk_per_grp;
+                       } else {
+                               bg_idx = blknr / blk_per_grp;
+                               remainder = blknr % blk_per_grp;
+                               if (!remainder)
+                                       bg_idx--;
+                       }
+                       ext4fs_reset_block_bmap(blknr, fs->blk_bmaps[bg_idx],
+                                               bg_idx);
+                       debug("ActualB releasing %ld: %d\n", blknr, bg_idx);
+
+                       gd[bg_idx].free_blocks++;
+                       fs->sb->free_blocks++;
+                       /* journal backup */
+                       if (prev_bg_bmap_idx != bg_idx) {
+                               memset(journal_buffer, '\0', fs->blksz);
+                               status = ext4fs_devread(gd[bg_idx].block_id
+                                                       * fs->sect_perblk,
+                                                       0, fs->blksz,
+                                                       journal_buffer);
+                               if (status == 0)
+                                       goto fail;
+                               if (ext4fs_log_journal(journal_buffer,
+                                               gd[bg_idx].block_id))
+                                       goto fail;
+                               prev_bg_bmap_idx = bg_idx;
+                       }
+               }
+       }
+
+       /* from the inode no to blockno */
+       inodes_per_block = fs->blksz / fs->inodesz;
+       ibmap_idx = inodeno / inode_per_grp;
+
+       /* get the block no */
+       inodeno--;
+       blkno = __le32_to_cpu(gd[ibmap_idx].inode_table_id) +
+               (inodeno % __le32_to_cpu(inode_per_grp)) / inodes_per_block;
+
+       /* get the offset of the inode */
+       blkoff = ((inodeno) % inodes_per_block) * fs->inodesz;
+
+       /* read the block no containing the inode */
+       read_buffer = zalloc(fs->blksz);
+       if (!read_buffer)
+               goto fail;
+       start_block_address = read_buffer;
+       status = ext4fs_devread(blkno * fs->sect_perblk,
+                               0, fs->blksz, read_buffer);
+       if (status == 0)
+               goto fail;
+
+       if (ext4fs_log_journal(read_buffer, blkno))
+               goto fail;
+
+       read_buffer = read_buffer + blkoff;
+       inode_buffer = (struct ext2_inode *)read_buffer;
+       memset(inode_buffer, '\0', sizeof(struct ext2_inode));
+
+       /* write the inode to original position in inode table */
+       if (ext4fs_put_metadata(start_block_address, blkno))
+               goto fail;
+
+       /* update the respective inode bitmaps */
+       inodeno++;
+       ext4fs_reset_inode_bmap(inodeno, fs->inode_bmaps[ibmap_idx], ibmap_idx);
+       gd[ibmap_idx].free_inodes++;
+       fs->sb->free_inodes++;
+       /* journal backup */
+       memset(journal_buffer, '\0', fs->blksz);
+       status = ext4fs_devread(gd[ibmap_idx].inode_id *
+                               fs->sect_perblk, 0, fs->blksz, journal_buffer);
+       if (status == 0)
+               goto fail;
+       if (ext4fs_log_journal(journal_buffer, gd[ibmap_idx].inode_id))
+               goto fail;
+
+       ext4fs_update();
+       ext4fs_deinit();
+
+       if (ext4fs_init() != 0) {
+               printf("error in File System init\n");
+               goto fail;
+       }
+
+       free(start_block_address);
+       free(journal_buffer);
+
+       return 0;
+fail:
+       free(start_block_address);
+       free(journal_buffer);
+
+       return -1;
+}
+
+int ext4fs_init(void)
+{
+       short status;
+       int i;
+       unsigned int real_free_blocks = 0;
+       struct ext_filesystem *fs = get_fs();
+
+       /* populate fs */
+       fs->blksz = EXT2_BLOCK_SIZE(ext4fs_root);
+       fs->inodesz = INODE_SIZE_FILESYSTEM(ext4fs_root);
+       fs->sect_perblk = fs->blksz / SECTOR_SIZE;
+
+       /* get the superblock */
+       fs->sb = zalloc(SUPERBLOCK_SIZE);
+       if (!fs->sb)
+               return -ENOMEM;
+       if (!ext4fs_devread(SUPERBLOCK_SECTOR, 0, SUPERBLOCK_SIZE,
+                       (char *)fs->sb))
+               goto fail;
+
+       /* init journal */
+       if (ext4fs_init_journal())
+               goto fail;
+
+       /* get total no of blockgroups */
+       fs->no_blkgrp = (uint32_t)ext4fs_div_roundup(
+                       (ext4fs_root->sblock.total_blocks -
+                       ext4fs_root->sblock.first_data_block),
+                       ext4fs_root->sblock.blocks_per_group);
+
+       /* get the block group descriptor table */
+       fs->gdtable_blkno = ((EXT2_MIN_BLOCK_SIZE == fs->blksz) + 1);
+       if (ext4fs_get_bgdtable() == -1) {
+               printf("Error in getting the block group descriptor table\n");
+               goto fail;
+       }
+       fs->gd = (struct ext2_block_group *)fs->gdtable;
+
+       /* load all the available bitmap block of the partition */
+       fs->blk_bmaps = zalloc(fs->no_blkgrp * sizeof(char *));
+       if (!fs->blk_bmaps)
+               goto fail;
+       for (i = 0; i < fs->no_blkgrp; i++) {
+               fs->blk_bmaps[i] = zalloc(fs->blksz);
+               if (!fs->blk_bmaps[i])
+                       goto fail;
+       }
+
+       for (i = 0; i < fs->no_blkgrp; i++) {
+               status =
+                   ext4fs_devread(fs->gd[i].block_id * fs->sect_perblk, 0,
+                                  fs->blksz, (char *)fs->blk_bmaps[i]);
+               if (status == 0)
+                       goto fail;
+       }
+
+       /* load all the available inode bitmap of the partition */
+       fs->inode_bmaps = zalloc(fs->no_blkgrp * sizeof(unsigned char *));
+       if (!fs->inode_bmaps)
+               goto fail;
+       for (i = 0; i < fs->no_blkgrp; i++) {
+               fs->inode_bmaps[i] = zalloc(fs->blksz);
+               if (!fs->inode_bmaps[i])
+                       goto fail;
+       }
+
+       for (i = 0; i < fs->no_blkgrp; i++) {
+               status = ext4fs_devread(fs->gd[i].inode_id * fs->sect_perblk,
+                                       0, fs->blksz,
+                                       (char *)fs->inode_bmaps[i]);
+               if (status == 0)
+                       goto fail;
+       }
+
+       /*
+        * check filesystem consistency with free blocks of file system
+        * some time we observed that superblock freeblocks does not match
+        * with the  blockgroups freeblocks when improper
+        * reboot of a linux kernel
+        */
+       for (i = 0; i < fs->no_blkgrp; i++)
+               real_free_blocks = real_free_blocks + fs->gd[i].free_blocks;
+       if (real_free_blocks != fs->sb->free_blocks)
+               fs->sb->free_blocks = real_free_blocks;
+
+       return 0;
+fail:
+       ext4fs_deinit();
+
+       return -1;
+}
+
+void ext4fs_deinit(void)
+{
+       int i;
+       struct ext2_inode inode_journal;
+       struct journal_superblock_t *jsb;
+       long int blknr;
+       struct ext_filesystem *fs = get_fs();
+
+       /* free journal */
+       char *temp_buff = zalloc(fs->blksz);
+       if (temp_buff) {
+               ext4fs_read_inode(ext4fs_root, EXT2_JOURNAL_INO,
+                                 &inode_journal);
+               blknr = read_allocated_block(&inode_journal,
+                                       EXT2_JOURNAL_SUPERBLOCK);
+               ext4fs_devread(blknr * fs->sect_perblk, 0, fs->blksz,
+                              temp_buff);
+               jsb = (struct journal_superblock_t *)temp_buff;
+               jsb->s_start = cpu_to_be32(0);
+               put_ext4((uint64_t) (blknr * fs->blksz),
+                        (struct journal_superblock_t *)temp_buff, fs->blksz);
+               free(temp_buff);
+       }
+       ext4fs_free_journal();
+
+       /* get the superblock */
+       ext4fs_devread(SUPERBLOCK_SECTOR, 0, SUPERBLOCK_SIZE, (char *)fs->sb);
+       fs->sb->feature_incompat &= ~EXT3_FEATURE_INCOMPAT_RECOVER;
+       put_ext4((uint64_t)(SUPERBLOCK_SIZE),
+                (struct ext2_sblock *)fs->sb, (uint32_t)SUPERBLOCK_SIZE);
+       free(fs->sb);
+       fs->sb = NULL;
+
+       if (fs->blk_bmaps) {
+               for (i = 0; i < fs->no_blkgrp; i++) {
+                       free(fs->blk_bmaps[i]);
+                       fs->blk_bmaps[i] = NULL;
+               }
+               free(fs->blk_bmaps);
+               fs->blk_bmaps = NULL;
+       }
+
+       if (fs->inode_bmaps) {
+               for (i = 0; i < fs->no_blkgrp; i++) {
+                       free(fs->inode_bmaps[i]);
+                       fs->inode_bmaps[i] = NULL;
+               }
+               free(fs->inode_bmaps);
+               fs->inode_bmaps = NULL;
+       }
+
+
+       free(fs->gdtable);
+       fs->gdtable = NULL;
+       fs->gd = NULL;
+       /*
+        * reinitiliazed the global inode and
+        * block bitmap first execution check variables
+        */
+       fs->first_pass_ibmap = 0;
+       fs->first_pass_bbmap = 0;
+       fs->curr_inode_no = 0;
+       fs->curr_blkno = 0;
+}
+
+static int ext4fs_write_file(struct ext2_inode *file_inode,
+                            int pos, unsigned int len, char *buf)
+{
+       int i;
+       int blockcnt;
+       int log2blocksize = LOG2_EXT2_BLOCK_SIZE(ext4fs_root);
+       unsigned int filesize = __le32_to_cpu(file_inode->size);
+       struct ext_filesystem *fs = get_fs();
+       int previous_block_number = -1;
+       int delayed_start = 0;
+       int delayed_extent = 0;
+       int delayed_skipfirst = 0;
+       int delayed_next = 0;
+       char *delayed_buf = NULL;
+
+       /* Adjust len so it we can't read past the end of the file. */
+       if (len > filesize)
+               len = filesize;
+
+       blockcnt = ((len + pos) + fs->blksz - 1) / fs->blksz;
+
+       for (i = pos / fs->blksz; i < blockcnt; i++) {
+               long int blknr;
+               int blockend = fs->blksz;
+               int skipfirst = 0;
+               blknr = read_allocated_block(file_inode, i);
+               if (blknr < 0)
+                       return -1;
+
+               blknr = blknr << log2blocksize;
+
+               if (blknr) {
+                       if (previous_block_number != -1) {
+                               if (delayed_next == blknr) {
+                                       delayed_extent += blockend;
+                                       delayed_next += blockend >> SECTOR_BITS;
+                               } else {        /* spill */
+                                       put_ext4((uint64_t) (delayed_start *
+                                                            SECTOR_SIZE),
+                                                delayed_buf,
+                                                (uint32_t) delayed_extent);
+                                       previous_block_number = blknr;
+                                       delayed_start = blknr;
+                                       delayed_extent = blockend;
+                                       delayed_skipfirst = skipfirst;
+                                       delayed_buf = buf;
+                                       delayed_next = blknr +
+                                           (blockend >> SECTOR_BITS);
+                               }
+                       } else {
+                               previous_block_number = blknr;
+                               delayed_start = blknr;
+                               delayed_extent = blockend;
+                               delayed_skipfirst = skipfirst;
+                               delayed_buf = buf;
+                               delayed_next = blknr +
+                                   (blockend >> SECTOR_BITS);
+                       }
+               } else {
+                       if (previous_block_number != -1) {
+                               /* spill */
+                               put_ext4((uint64_t) (delayed_start *
+                                                    SECTOR_SIZE), delayed_buf,
+                                        (uint32_t) delayed_extent);
+                               previous_block_number = -1;
+                       }
+                       memset(buf, 0, fs->blksz - skipfirst);
+               }
+               buf += fs->blksz - skipfirst;
+       }
+       if (previous_block_number != -1) {
+               /* spill */
+               put_ext4((uint64_t) (delayed_start * SECTOR_SIZE),
+                        delayed_buf, (uint32_t) delayed_extent);
+               previous_block_number = -1;
+       }
+
+       return len;
+}
+
+int ext4fs_write(const char *fname, unsigned char *buffer,
+                                       unsigned long sizebytes)
+{
+       int ret = 0;
+       struct ext2_inode *file_inode = NULL;
+       unsigned char *inode_buffer = NULL;
+       int parent_inodeno;
+       int inodeno;
+       time_t timestamp = 0;
+
+       uint64_t bytes_reqd_for_file;
+       unsigned int blks_reqd_for_file;
+       unsigned int blocks_remaining;
+       int existing_file_inodeno;
+       char filename[256];
+
+       char *temp_ptr = NULL;
+       long int itable_blkno;
+       long int parent_itable_blkno;
+       long int blkoff;
+       struct ext2_sblock *sblock = &(ext4fs_root->sblock);
+       unsigned int inodes_per_block;
+       unsigned int ibmap_idx;
+       struct ext_filesystem *fs = get_fs();
+       g_parent_inode = zalloc(sizeof(struct ext2_inode));
+       if (!g_parent_inode)
+               goto fail;
+
+       if (ext4fs_init() != 0) {
+               printf("error in File System init\n");
+               return -1;
+       }
+       inodes_per_block = fs->blksz / fs->inodesz;
+       parent_inodeno = ext4fs_get_parent_inode_num(fname, filename, F_FILE);
+       if (parent_inodeno == -1)
+               goto fail;
+       if (ext4fs_iget(parent_inodeno, g_parent_inode))
+               goto fail;
+       /* check if the filename is already present in root */
+       existing_file_inodeno = ext4fs_filename_check(filename);
+       if (existing_file_inodeno != -1) {
+               ret = ext4fs_delete_file(existing_file_inodeno);
+               fs->first_pass_bbmap = 0;
+               fs->curr_blkno = 0;
+
+               fs->first_pass_ibmap = 0;
+               fs->curr_inode_no = 0;
+               if (ret)
+                       goto fail;
+       }
+       /* calucalate how many blocks required */
+       bytes_reqd_for_file = sizebytes;
+       blks_reqd_for_file = bytes_reqd_for_file / fs->blksz;
+       if (bytes_reqd_for_file % fs->blksz != 0) {
+               blks_reqd_for_file++;
+               debug("total bytes for a file %u\n", blks_reqd_for_file);
+       }
+       blocks_remaining = blks_reqd_for_file;
+       /* test for available space in partition */
+       if (fs->sb->free_blocks < blks_reqd_for_file) {
+               printf("Not enough space on partition !!!\n");
+               goto fail;
+       }
+
+       ext4fs_update_parent_dentry(filename, &inodeno, FILETYPE_REG);
+       /* prepare file inode */
+       inode_buffer = zalloc(fs->inodesz);
+       if (!inode_buffer)
+               goto fail;
+       file_inode = (struct ext2_inode *)inode_buffer;
+       file_inode->mode = S_IFREG | S_IRWXU |
+           S_IRGRP | S_IROTH | S_IXGRP | S_IXOTH;
+       /* ToDo: Update correct time */
+       file_inode->mtime = timestamp;
+       file_inode->atime = timestamp;
+       file_inode->ctime = timestamp;
+       file_inode->nlinks = 1;
+       file_inode->size = sizebytes;
+
+       /* Allocate data blocks */
+       ext4fs_allocate_blocks(file_inode, blocks_remaining,
+                              &blks_reqd_for_file);
+       file_inode->blockcnt = (blks_reqd_for_file * fs->blksz) / SECTOR_SIZE;
+
+       temp_ptr = zalloc(fs->blksz);
+       if (!temp_ptr)
+               goto fail;
+       ibmap_idx = inodeno / ext4fs_root->sblock.inodes_per_group;
+       inodeno--;
+       itable_blkno = __le32_to_cpu(fs->gd[ibmap_idx].inode_table_id) +
+                       (inodeno % __le32_to_cpu(sblock->inodes_per_group)) /
+                       inodes_per_block;
+       blkoff = (inodeno % inodes_per_block) * fs->inodesz;
+       ext4fs_devread(itable_blkno * fs->sect_perblk, 0, fs->blksz, temp_ptr);
+       if (ext4fs_log_journal(temp_ptr, itable_blkno))
+               goto fail;
+
+       memcpy(temp_ptr + blkoff, inode_buffer, fs->inodesz);
+       if (ext4fs_put_metadata(temp_ptr, itable_blkno))
+               goto fail;
+       /* copy the file content into data blocks */
+       if (ext4fs_write_file(file_inode, 0, sizebytes, (char *)buffer) == -1) {
+               printf("Error in copying content\n");
+               goto fail;
+       }
+       ibmap_idx = parent_inodeno / ext4fs_root->sblock.inodes_per_group;
+       parent_inodeno--;
+       parent_itable_blkno = __le32_to_cpu(fs->gd[ibmap_idx].inode_table_id) +
+           (parent_inodeno %
+            __le32_to_cpu(sblock->inodes_per_group)) / inodes_per_block;
+       blkoff = (parent_inodeno % inodes_per_block) * fs->inodesz;
+       if (parent_itable_blkno != itable_blkno) {
+               memset(temp_ptr, '\0', fs->blksz);
+               ext4fs_devread(parent_itable_blkno * fs->sect_perblk,
+                              0, fs->blksz, temp_ptr);
+               if (ext4fs_log_journal(temp_ptr, parent_itable_blkno))
+                       goto fail;
+
+               memcpy(temp_ptr + blkoff, g_parent_inode,
+                       sizeof(struct ext2_inode));
+               if (ext4fs_put_metadata(temp_ptr, parent_itable_blkno))
+                       goto fail;
+               free(temp_ptr);
+       } else {
+               /*
+                * If parent and child fall in same inode table block
+                * both should be kept in 1 buffer
+                */
+               memcpy(temp_ptr + blkoff, g_parent_inode,
+                      sizeof(struct ext2_inode));
+               gd_index--;
+               if (ext4fs_put_metadata(temp_ptr, itable_blkno))
+                       goto fail;
+               free(temp_ptr);
+       }
+       ext4fs_update();
+       ext4fs_deinit();
+
+       fs->first_pass_bbmap = 0;
+       fs->curr_blkno = 0;
+       fs->first_pass_ibmap = 0;
+       fs->curr_inode_no = 0;
+       free(inode_buffer);
+       free(g_parent_inode);
+       g_parent_inode = NULL;
+
+       return 0;
+fail:
+       ext4fs_deinit();
+       free(inode_buffer);
+       free(g_parent_inode);
+       g_parent_inode = NULL;
+
+       return -1;
+}
+#endif