-fail:
- free(fs->gdtable);
- fs->gdtable = NULL;
-
- return -1;
-}
-
-static void delete_single_indirect_block(struct ext2_inode *inode)
-{
- struct ext2_block_group *bgd = 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 */
- bgd = (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);
- bgd[bg_idx].free_blocks++;
- fs->sb->free_blocks++;
- /* journal backup */
- if (prev_bg_bmap_idx != bg_idx) {
- status =
- ext4fs_devread(bgd[bg_idx].block_id *
- fs->sect_perblk, 0, fs->blksz,
- journal_buffer);
- if (status == 0)
- goto fail;
- if (ext4fs_log_journal
- (journal_buffer, bgd[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 *bgd = 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 */
- bgd = (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++;
- bgd[bg_idx].free_blocks++;
- fs->sb->free_blocks++;
- /* journal backup */
- if (prev_bg_bmap_idx != bg_idx) {
- status = ext4fs_devread(bgd[bg_idx].block_id
- * fs->sect_perblk, 0,
- fs->blksz,
- journal_buffer);
- if (status == 0)
- goto fail;
-
- if (ext4fs_log_journal(journal_buffer,
- bgd[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);
- bgd[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(bgd[bg_idx].block_id *
- fs->sect_perblk, 0, fs->blksz,
- journal_buffer);
- if (status == 0)
- goto fail;
-
- if (ext4fs_log_journal(journal_buffer,
- bgd[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 *bgd = 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 */
- bgd = (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++;
- bgd[bg_idx].free_blocks++;
- fs->sb->free_blocks++;
- /* journal backup */
- if (prev_bg_bmap_idx != bg_idx) {
- status =
- ext4fs_devread(
- bgd[bg_idx].block_id *
- fs->sect_perblk, 0,
- fs->blksz,
- journal_buffer);
- if (status == 0)
- goto fail;
-
- if (ext4fs_log_journal(journal_buffer,
- bgd[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++;
- bgd[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(bgd[bg_idx].block_id *
- fs->sect_perblk, 0,
- fs->blksz, journal_buffer);
- if (status == 0)
- goto fail;
-
- if (ext4fs_log_journal(journal_buffer,
- bgd[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);
- bgd[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(bgd[bg_idx].block_id *
- fs->sect_perblk, 0, fs->blksz,
- journal_buffer);
- if (status == 0)
- goto fail;
-
- if (ext4fs_log_journal(journal_buffer,
- bgd[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 *bgd = NULL;
- struct ext_filesystem *fs = get_fs();
- char *journal_buffer = zalloc(fs->blksz);
- if (!journal_buffer)
- return -ENOMEM;
- /* get the block group descriptor table */
- bgd = (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);
-
- bgd[bg_idx].free_blocks++;
- fs->sb->free_blocks++;
-
- /* journal backup */
- if (prev_bg_bmap_idx != bg_idx) {
- status =
- ext4fs_devread(bgd[bg_idx].block_id *
- fs->sect_perblk, 0,
- fs->blksz, journal_buffer);
- if (status == 0)
- goto fail;
- if (ext4fs_log_journal(journal_buffer,
- bgd[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);
-
- bgd[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(bgd[bg_idx].block_id
- * fs->sect_perblk,
- 0, fs->blksz,
- journal_buffer);
- if (status == 0)
- goto fail;
- if (ext4fs_log_journal(journal_buffer,
- bgd[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(bgd[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);
- bgd[ibmap_idx].free_inodes++;
- fs->sb->free_inodes++;
- /* journal backup */
- memset(journal_buffer, '\0', fs->blksz);
- status = ext4fs_devread(bgd[ibmap_idx].inode_id *
- fs->sect_perblk, 0, fs->blksz, journal_buffer);
- if (status == 0)
- goto fail;
- if (ext4fs_log_journal(journal_buffer, bgd[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->bgd = (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->bgd[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->bgd[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->bgd[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;