diff options
Diffstat (limited to 'fs/ext4/ext4_common.c')
| -rw-r--r-- | fs/ext4/ext4_common.c | 1353 |
1 files changed, 1353 insertions, 0 deletions
diff --git a/fs/ext4/ext4_common.c b/fs/ext4/ext4_common.c index 2ddbb50e89..083e45eed5 100644 --- a/fs/ext4/ext4_common.c +++ b/fs/ext4/ext4_common.c @@ -14,6 +14,8 @@ * 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 @@ -54,6 +56,1357 @@ int ext4fs_indir3_blkno = -1; struct ext2_inode *g_parent_inode; static int symlinknest; +#if defined(CONFIG_CMD_EXT4_WRITE) +uint32_t ext4fs_div_roundup(uint32_t size, uint32_t n) +{ + uint32_t res = size / n; + if (res * n != size) + res++; + + return res; +} + +void put_ext4(uint64_t off, void *buf, uint32_t size) +{ + uint64_t startblock; + uint64_t remainder; + unsigned char *temp_ptr = NULL; + unsigned char sec_buf[SECTOR_SIZE]; + struct ext_filesystem *fs = get_fs(); + + startblock = off / (uint64_t)SECTOR_SIZE; + startblock += part_offset; + remainder = off % (uint64_t)SECTOR_SIZE; + remainder &= SECTOR_SIZE - 1; + + if (fs->dev_desc == NULL) + return; + + if ((startblock + (size / SECTOR_SIZE)) > + (part_offset + fs->total_sect)) { + printf("part_offset is %lu\n", part_offset); + printf("total_sector is %llu\n", fs->total_sect); + printf("error: overflow occurs\n"); + return; + } + + if (remainder) { + if (fs->dev_desc->block_read) { + fs->dev_desc->block_read(fs->dev_desc->dev, + startblock, 1, sec_buf); + temp_ptr = sec_buf; + memcpy((temp_ptr + remainder), + (unsigned char *)buf, size); + fs->dev_desc->block_write(fs->dev_desc->dev, + startblock, 1, sec_buf); + } + } else { + if (size / SECTOR_SIZE != 0) { + fs->dev_desc->block_write(fs->dev_desc->dev, + startblock, + size / SECTOR_SIZE, + (unsigned long *)buf); + } else { + fs->dev_desc->block_read(fs->dev_desc->dev, + startblock, 1, sec_buf); + temp_ptr = sec_buf; + memcpy(temp_ptr, buf, size); + fs->dev_desc->block_write(fs->dev_desc->dev, + startblock, 1, + (unsigned long *)sec_buf); + } + } +} + +static int _get_new_inode_no(unsigned char *buffer) +{ + struct ext_filesystem *fs = get_fs(); + unsigned char input; + int operand, status; + int count = 1; + int j = 0; + + /* get the blocksize of the filesystem */ + unsigned char *ptr = buffer; + while (*ptr == 255) { + ptr++; + count += 8; + if (count > ext4fs_root->sblock.inodes_per_group) + return -1; + } + + for (j = 0; j < fs->blksz; j++) { + input = *ptr; + int i = 0; + while (i <= 7) { + operand = 1 << i; + status = input & operand; + if (status) { + i++; + count++; + } else { + *ptr |= operand; + return count; + } + } + ptr = ptr + 1; + } + + return -1; +} + +static int _get_new_blk_no(unsigned char *buffer) +{ + unsigned char input; + int operand, status; + int count = 0; + int j = 0; + unsigned char *ptr = buffer; + struct ext_filesystem *fs = get_fs(); + + if (fs->blksz != 1024) + count = 0; + else + count = 1; + + while (*ptr == 255) { + ptr++; + count += 8; + if (count == (fs->blksz * 8)) + return -1; + } + + for (j = 0; j < fs->blksz; j++) { + input = *ptr; + int i = 0; + while (i <= 7) { + operand = 1 << i; + status = input & operand; + if (status) { + i++; + count++; + } else { + *ptr |= operand; + return count; + } + } + ptr = ptr + 1; + } + + return -1; +} + +int ext4fs_set_block_bmap(long int blockno, unsigned char *buffer, int index) +{ + int i, remainder, status; + unsigned char *ptr = buffer; + unsigned char operand; + i = blockno / 8; + remainder = blockno % 8; + int blocksize = EXT2_BLOCK_SIZE(ext4fs_root); + + i = i - (index * blocksize); + if (blocksize != 1024) { + ptr = ptr + i; + operand = 1 << remainder; + status = *ptr & operand; + if (status) + return -1; + + *ptr = *ptr | operand; + return 0; + } else { + if (remainder == 0) { + ptr = ptr + i - 1; + operand = (1 << 7); + } else { + ptr = ptr + i; + operand = (1 << (remainder - 1)); + } + status = *ptr & operand; + if (status) + return -1; + + *ptr = *ptr | operand; + return 0; + } +} + +void ext4fs_reset_block_bmap(long int blockno, unsigned char *buffer, int index) +{ + int i, remainder, status; + unsigned char *ptr = buffer; + unsigned char operand; + i = blockno / 8; + remainder = blockno % 8; + int blocksize = EXT2_BLOCK_SIZE(ext4fs_root); + + i = i - (index * blocksize); + if (blocksize != 1024) { + ptr = ptr + i; + operand = (1 << remainder); + status = *ptr & operand; + if (status) + *ptr = *ptr & ~(operand); + } else { + if (remainder == 0) { + ptr = ptr + i - 1; + operand = (1 << 7); + } else { + ptr = ptr + i; + operand = (1 << (remainder - 1)); + } + status = *ptr & operand; + if (status) + *ptr = *ptr & ~(operand); + } +} + +int ext4fs_set_inode_bmap(int inode_no, unsigned char *buffer, int index) +{ + int i, remainder, status; + unsigned char *ptr = buffer; + unsigned char operand; + + inode_no -= (index * ext4fs_root->sblock.inodes_per_group); + i = inode_no / 8; + remainder = inode_no % 8; + if (remainder == 0) { + ptr = ptr + i - 1; + operand = (1 << 7); + } else { + ptr = ptr + i; + operand = (1 << (remainder - 1)); + } + status = *ptr & operand; + if (status) + return -1; + + *ptr = *ptr | operand; + + return 0; +} + +void ext4fs_reset_inode_bmap(int inode_no, unsigned char *buffer, int index) +{ + int i, remainder, status; + unsigned char *ptr = buffer; + unsigned char operand; + + inode_no -= (index * ext4fs_root->sblock.inodes_per_group); + i = inode_no / 8; + remainder = inode_no % 8; + if (remainder == 0) { + ptr = ptr + i - 1; + operand = (1 << 7); + } else { + ptr = ptr + i; + operand = (1 << (remainder - 1)); + } + status = *ptr & operand; + if (status) + *ptr = *ptr & ~(operand); +} + +int ext4fs_checksum_update(unsigned int i) +{ + struct ext2_block_group *desc; + struct ext_filesystem *fs = get_fs(); + __u16 crc = 0; + + desc = (struct ext2_block_group *)&fs->gd[i]; + if (fs->sb->feature_ro_compat & EXT4_FEATURE_RO_COMPAT_GDT_CSUM) { + int offset = offsetof(struct ext2_block_group, bg_checksum); + + crc = ext2fs_crc16(~0, fs->sb->unique_id, + sizeof(fs->sb->unique_id)); + crc = ext2fs_crc16(crc, &i, sizeof(i)); + crc = ext2fs_crc16(crc, desc, offset); + offset += sizeof(desc->bg_checksum); /* skip checksum */ + assert(offset == sizeof(*desc)); + } + + return crc; +} + +static int check_void_in_dentry(struct ext2_dirent *dir, char *filename) +{ + int dentry_length; + int sizeof_void_space; + int new_entry_byte_reqd; + short padding_factor = 0; + + if (dir->namelen % 4 != 0) + padding_factor = 4 - (dir->namelen % 4); + + dentry_length = sizeof(struct ext2_dirent) + + dir->namelen + padding_factor; + sizeof_void_space = dir->direntlen - dentry_length; + if (sizeof_void_space == 0) + return 0; + + padding_factor = 0; + if (strlen(filename) % 4 != 0) + padding_factor = 4 - (strlen(filename) % 4); + + new_entry_byte_reqd = strlen(filename) + + sizeof(struct ext2_dirent) + padding_factor; + if (sizeof_void_space >= new_entry_byte_reqd) { + dir->direntlen = dentry_length; + return sizeof_void_space; + } + + return 0; +} + +void ext4fs_update_parent_dentry(char *filename, int *p_ino, int file_type) +{ + unsigned int *zero_buffer = NULL; + char *root_first_block_buffer = NULL; + int direct_blk_idx; + long int root_blknr; + long int first_block_no_of_root = 0; + long int previous_blknr = -1; + int totalbytes = 0; + short int padding_factor = 0; + unsigned int new_entry_byte_reqd; + unsigned int last_entry_dirlen; + int sizeof_void_space = 0; + int templength = 0; + int inodeno; + int status; + struct ext_filesystem *fs = get_fs(); + /* directory entry */ + struct ext2_dirent *dir; + char *ptr = NULL; + char *temp_dir = NULL; + + zero_buffer = zalloc(fs->blksz); + if (!zero_buffer) { + printf("No Memory\n"); + return; + } + root_first_block_buffer = zalloc(fs->blksz); + if (!root_first_block_buffer) { + free(zero_buffer); + printf("No Memory\n"); + return; + } +restart: + + /* read the block no allocated to a file */ + for (direct_blk_idx = 0; direct_blk_idx < INDIRECT_BLOCKS; + direct_blk_idx++) { + root_blknr = read_allocated_block(g_parent_inode, + direct_blk_idx); + if (root_blknr == 0) { + first_block_no_of_root = previous_blknr; + break; + } + previous_blknr = root_blknr; + } + + status = ext4fs_devread(first_block_no_of_root + * fs->sect_perblk, + 0, fs->blksz, root_first_block_buffer); + if (status == 0) + goto fail; + + if (ext4fs_log_journal(root_first_block_buffer, first_block_no_of_root)) + goto fail; + dir = (struct ext2_dirent *)root_first_block_buffer; + ptr = (char *)dir; + totalbytes = 0; + while (dir->direntlen > 0) { + /* + * blocksize-totalbytes because last directory length + * i.e. dir->direntlen is free availble space in the + * block that means it is a last entry of directory + * entry + */ + + /* traversing the each directory entry */ + if (fs->blksz - totalbytes == dir->direntlen) { + if (strlen(filename) % 4 != 0) + padding_factor = 4 - (strlen(filename) % 4); + + new_entry_byte_reqd = strlen(filename) + + sizeof(struct ext2_dirent) + padding_factor; + padding_factor = 0; + /* + * update last directory entry length to its + * length because we are creating new directory + * entry + */ + if (dir->namelen % 4 != 0) + padding_factor = 4 - (dir->namelen % 4); + + last_entry_dirlen = dir->namelen + + sizeof(struct ext2_dirent) + padding_factor; + if ((fs->blksz - totalbytes - last_entry_dirlen) < + new_entry_byte_reqd) { + printf("1st Block Full:Allocate new block\n"); + + if (direct_blk_idx == INDIRECT_BLOCKS - 1) { + printf("Directory exceeds limit\n"); + goto fail; + } + g_parent_inode->b.blocks.dir_blocks + [direct_blk_idx] = ext4fs_get_new_blk_no(); + if (g_parent_inode->b.blocks.dir_blocks + [direct_blk_idx] == -1) { + printf("no block left to assign\n"); + goto fail; + } + put_ext4(((uint64_t) + (g_parent_inode->b. + blocks.dir_blocks[direct_blk_idx] * + fs->blksz)), zero_buffer, fs->blksz); + g_parent_inode->size = + g_parent_inode->size + fs->blksz; + g_parent_inode->blockcnt = + g_parent_inode->blockcnt + fs->sect_perblk; + if (ext4fs_put_metadata + (root_first_block_buffer, + first_block_no_of_root)) + goto fail; + goto restart; + } + dir->direntlen = last_entry_dirlen; + break; + } + + templength = dir->direntlen; + totalbytes = totalbytes + templength; + sizeof_void_space = check_void_in_dentry(dir, filename); + if (sizeof_void_space) + break; + + dir = (struct ext2_dirent *)((char *)dir + templength); + ptr = (char *)dir; + } + + /* make a pointer ready for creating next directory entry */ + templength = dir->direntlen; + totalbytes = totalbytes + templength; + dir = (struct ext2_dirent *)((char *)dir + templength); + ptr = (char *)dir; + + /* get the next available inode number */ + inodeno = ext4fs_get_new_inode_no(); + if (inodeno == -1) { + printf("no inode left to assign\n"); + goto fail; + } + dir->inode = inodeno; + if (sizeof_void_space) + dir->direntlen = sizeof_void_space; + else + dir->direntlen = fs->blksz - totalbytes; + + dir->namelen = strlen(filename); + dir->filetype = FILETYPE_REG; /* regular file */ + temp_dir = (char *)dir; + temp_dir = temp_dir + sizeof(struct ext2_dirent); + memcpy(temp_dir, filename, strlen(filename)); + + *p_ino = inodeno; + + /* update or write the 1st block of root inode */ + if (ext4fs_put_metadata(root_first_block_buffer, + first_block_no_of_root)) + goto fail; + +fail: + free(zero_buffer); + free(root_first_block_buffer); +} + +static int search_dir(struct ext2_inode *parent_inode, char *dirname) +{ + int status; + int inodeno; + int totalbytes; + int templength; + int direct_blk_idx; + long int blknr; + int found = 0; + char *ptr = NULL; + unsigned char *block_buffer = NULL; + struct ext2_dirent *dir = NULL; + struct ext2_dirent *previous_dir = NULL; + struct ext_filesystem *fs = get_fs(); + + /* read the block no allocated to a file */ + for (direct_blk_idx = 0; direct_blk_idx < INDIRECT_BLOCKS; + direct_blk_idx++) { + blknr = read_allocated_block(parent_inode, direct_blk_idx); + if (blknr == 0) + goto fail; + + /* read the blocks of parenet inode */ + block_buffer = zalloc(fs->blksz); + if (!block_buffer) + goto fail; + + status = ext4fs_devread(blknr * fs->sect_perblk, + 0, fs->blksz, (char *)block_buffer); + if (status == 0) + goto fail; + + dir = (struct ext2_dirent *)block_buffer; + ptr = (char *)dir; + totalbytes = 0; + while (dir->direntlen >= 0) { + /* + * blocksize-totalbytes because last directory + * length i.e.,*dir->direntlen is free availble + * space in the block that means + * it is a last entry of directory entry + */ + if (strlen(dirname) == dir->namelen) { + if (strncmp(dirname, ptr + + sizeof(struct ext2_dirent), + dir->namelen) == 0) { + previous_dir->direntlen += + dir->direntlen; + inodeno = dir->inode; + dir->inode = 0; + found = 1; + break; + } + } + + if (fs->blksz - totalbytes == dir->direntlen) + break; + + /* traversing the each directory entry */ + templength = dir->direntlen; + totalbytes = totalbytes + templength; + previous_dir = dir; + dir = (struct ext2_dirent *)((char *)dir + templength); + ptr = (char *)dir; + } + + if (found == 1) { + free(block_buffer); + block_buffer = NULL; + return inodeno; + } + + free(block_buffer); + block_buffer = NULL; + } + +fail: + free(block_buffer); + + return -1; +} + +static int find_dir_depth(char *dirname) +{ + char *token = strtok(dirname, "/"); + int count = 0; + while (token != NULL) { + token = strtok(NULL, "/"); + count++; + } + return count + 1 + 1; + /* + * for example for string /home/temp + * depth=home(1)+temp(1)+1 extra for NULL; + * so count is 4; + */ +} + +static int parse_path(char **arr, char *dirname) +{ + char *token = strtok(dirname, "/"); + int i = 0; + + /* add root */ + arr[i] = zalloc(strlen("/") + 1); + if (!arr[i]) + return -ENOMEM; + + arr[i++] = "/"; + + /* add each path entry after root */ + while (token != NULL) { + arr[i] = zalloc(strlen(token) + 1); + if (!arr[i]) + return -ENOMEM; + memcpy(arr[i++], token, strlen(token)); + token = strtok(NULL, "/"); + } + arr[i] = NULL; + + return 0; +} + +int ext4fs_iget(int inode_no, struct ext2_inode *inode) +{ + if (ext4fs_read_inode(ext4fs_root, inode_no, inode) == 0) + return -1; + + return 0; +} + +/* + * Function: ext4fs_get_parent_inode_num + * Return Value: inode Number of the parent directory of file/Directory to be + * created + * dirname : Input parmater, input path name of the file/directory to be created + * dname : Output parameter, to be filled with the name of the directory + * extracted from dirname + */ +int ext4fs_get_parent_inode_num(const char *dirname, char *dname, int flags) +{ + int i; + int depth = 0; + int matched_inode_no; + int result_inode_no = -1; + char **ptr = NULL; + char *depth_dirname = NULL; + char *parse_dirname = NULL; + struct ext2_inode *parent_inode = NULL; + struct ext2_inode *first_inode = NULL; + struct ext2_inode temp_inode; + + if (*dirname != '/') { + printf("Please supply Absolute path\n"); + return -1; + } + + /* TODO: input validation make equivalent to linux */ + depth_dirname = zalloc(strlen(dirname) + 1); + if (!depth_dirname) + return -ENOMEM; + + memcpy(depth_dirname, dirname, strlen(dirname)); + depth = find_dir_depth(depth_dirname); + parse_dirname = zalloc(strlen(dirname) + 1); + if (!parse_dirname) + goto fail; + memcpy(parse_dirname, dirname, strlen(dirname)); + + /* allocate memory for each directory level */ + ptr = zalloc((depth) * sizeof(char *)); + if (!ptr) + goto fail; + if (parse_path(ptr, parse_dirname)) + goto fail; + parent_inode = zalloc(sizeof(struct ext2_inode)); + if (!parent_inode) + goto fail; + first_inode = zalloc(sizeof(struct ext2_inode)); + if (!first_inode) + goto fail; + memcpy(parent_inode, ext4fs_root->inode, sizeof(struct ext2_inode)); + memcpy(first_inode, parent_inode, sizeof(struct ext2_inode)); + if (flags & F_FILE) + result_inode_no = EXT2_ROOT_INO; + for (i = 1; i < depth; i++) { + matched_inode_no = search_dir(parent_inode, ptr[i]); + if (matched_inode_no == -1) { + if (ptr[i + 1] == NULL && i == 1) { + result_inode_no = EXT2_ROOT_INO; + goto end; + } else { + if (ptr[i + 1] == NULL) + break; + printf("Invalid path\n"); + result_inode_no = -1; + goto fail; + } + } else { + if (ptr[i + 1] != NULL) { + memset(parent_inode, '\0', + sizeof(struct ext2_inode)); + if (ext4fs_iget(matched_inode_no, + parent_inode)) { + result_inode_no = -1; + goto fail; + } + result_inode_no = matched_inode_no; + } else { + break; + } + } + } + +end: + if (i == 1) + matched_inode_no = search_dir(first_inode, ptr[i]); + else + matched_inode_no = search_dir(parent_inode, ptr[i]); + + if (matched_inode_no != -1) { + ext4fs_iget(matched_inode_no, &temp_inode); + if (temp_inode.mode & S_IFDIR) { + printf("It is a Directory\n"); + result_inode_no = -1; + goto fail; + } + } + + if (strlen(ptr[i]) > 256) { + result_inode_no = -1; + goto fail; + } + memcpy(dname, ptr[i], strlen(ptr[i])); + +fail: + free(depth_dirname); + free(parse_dirname); + free(ptr); + free(parent_inode); + free(first_inode); + + return result_inode_no; +} + +static int check_filename(char *filename, unsigned int blknr) +{ + unsigned int first_block_no_of_root; + int totalbytes = 0; + int templength = 0; + int status, inodeno; + int found = 0; + char *root_first_block_buffer = NULL; + char *root_first_block_addr = NULL; + struct ext2_dirent *dir = NULL; + struct ext2_dirent *previous_dir = NULL; + char *ptr = NULL; + struct ext_filesystem *fs = get_fs(); + + /* get the first block of root */ + first_block_no_of_root = blknr; + root_first_block_buffer = zalloc(fs->blksz); + if (!root_first_block_buffer) + return -ENOMEM; + root_first_block_addr = root_first_block_buffer; + status = ext4fs_devread(first_block_no_of_root * + fs->sect_perblk, 0, + fs->blksz, root_first_block_buffer); + if (status == 0) + goto fail; + + if (ext4fs_log_journal(root_first_block_buffer, first_block_no_of_root)) + goto fail; + dir = (struct ext2_dirent *)root_first_block_buffer; + ptr = (char *)dir; + totalbytes = 0; + while (dir->direntlen >= 0) { + /* + * blocksize-totalbytes because last + * directory length i.e., *dir->direntlen + * is free availble space in the block that + * means it is a last entry of directory entry + */ + if (strlen(filename) == dir->namelen) { + if (strncmp(filename, ptr + sizeof(struct ext2_dirent), + dir->namelen) == 0) { + printf("file found deleting\n"); + previous_dir->direntlen += dir->direntlen; + inodeno = dir->inode; + dir->inode = 0; + found = 1; + break; + } + } + + if (fs->blksz - totalbytes == dir->direntlen) + break; + + /* traversing the each directory entry */ + templength = dir->direntlen; + totalbytes = totalbytes + templength; + previous_dir = dir; + dir = (struct ext2_dirent *)((char *)dir + templength); + ptr = (char *)dir; + } + + + if (found == 1) { + if (ext4fs_put_metadata(root_first_block_addr, + first_block_no_of_root)) + goto fail; + return inodeno; + } +fail: + free(root_first_block_buffer); + + return -1; +} + +int ext4fs_filename_check(char *filename) +{ + short direct_blk_idx = 0; + long int blknr = -1; + int inodeno = -1; + + /* read the block no allocated to a file */ + for (direct_blk_idx = 0; direct_blk_idx < INDIRECT_BLOCKS; + direct_blk_idx++) { + blknr = read_allocated_block(g_parent_inode, direct_blk_idx); + if (blknr == 0) + break; + inodeno = check_filename(filename, blknr); + if (inodeno != -1) + return inodeno; + } + + return -1; +} + +long int ext4fs_get_new_blk_no(void) +{ + short i; + short status; + int remainder; + unsigned int bg_idx; + static int prev_bg_bitmap_index = -1; + unsigned int blk_per_grp = ext4fs_root->sblock.blocks_per_group; + struct ext_filesystem *fs = get_fs(); + char *journal_buffer = zalloc(fs->blksz); + char *zero_buffer = zalloc(fs->blksz); + if (!journal_buffer || !zero_buffer) + goto fail; + struct ext2_block_group *gd = (struct ext2_block_group *)fs->gdtable; + + if (fs->first_pass_bbmap == 0) { + for (i = 0; i < fs->no_blkgrp; i++) { + if (gd[i].free_blocks) { + if (gd[i].bg_flags & EXT4_BG_BLOCK_UNINIT) { + put_ext4(((uint64_t) (gd[i].block_id * + fs->blksz)), + zero_buffer, fs->blksz); + gd[i].bg_flags = + gd[i]. + bg_flags & ~EXT4_BG_BLOCK_UNINIT; + memcpy(fs->blk_bmaps[i], zero_buffer, + fs->blksz); + } + fs->curr_blkno = + _get_new_blk_no(fs->blk_bmaps[i]); + if (fs->curr_blkno == -1) + /* if block bitmap is completely fill */ + continue; + fs->curr_blkno = fs->curr_blkno + + (i * fs->blksz * 8); + fs->first_pass_bbmap++; + gd[i].free_blocks--; + fs->sb->free_blocks--; + status = ext4fs_devread(gd[i].block_id * + fs->sect_perblk, 0, + fs->blksz, + journal_buffer); + if (status == 0) + goto fail; + if (ext4fs_log_journal(journal_buffer, + gd[i].block_id)) + goto fail; + goto success; + } else { + debug("no space left on block group %d\n", i); + } + } + + goto fail; + } else { +restart: + fs->curr_blkno++; + /* get the blockbitmap index respective to blockno */ + if (fs->blksz != 1024) { + bg_idx = fs->curr_blkno / blk_per_grp; + } else { + bg_idx = fs->curr_blkno / blk_per_grp; + remainder = fs->curr_blkno % blk_per_grp; + if (!remainder) + bg_idx--; + } + + /* + * To skip completely filled block group bitmaps + * Optimize the block allocation + */ + if (bg_idx >= fs->no_blkgrp) + goto fail; + + if (gd[bg_idx].free_blocks == 0) { + debug("block group %u is full. Skipping\n", bg_idx); + fs->curr_blkno = fs->curr_blkno + blk_per_grp; + fs->curr_blkno--; + goto restart; + } + + if (gd[bg_idx].bg_flags & EXT4_BG_BLOCK_UNINIT) { + memset(zero_buffer, '\0', fs->blksz); + put_ext4(((uint64_t) (gd[bg_idx].block_id * fs->blksz)), + zero_buffer, fs->blksz); + memcpy(fs->blk_bmaps[bg_idx], zero_buffer, fs->blksz); + gd[bg_idx].bg_flags = gd[bg_idx].bg_flags & + ~EXT4_BG_BLOCK_UNINIT; + } + + if (ext4fs_set_block_bmap(fs->curr_blkno, fs->blk_bmaps[bg_idx], + bg_idx) != 0) { + debug("going for restart for the block no %ld %u\n", + fs->curr_blkno, bg_idx); + goto restart; + } + + /* journal backup */ + if (prev_bg_bitmap_index != 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_bitmap_index = bg_idx; + } + gd[bg_idx].free_blocks--; + fs->sb->free_blocks--; + goto success; + } +success: + free(journal_buffer); + free(zero_buffer); + + return fs->curr_blkno; +fail: + free(journal_buffer); + free(zero_buffer); + + return -1; +} + +int ext4fs_get_new_inode_no(void) +{ + short i; + short status; + unsigned int ibmap_idx; + static int prev_inode_bitmap_index = -1; + unsigned int inodes_per_grp = ext4fs_root->sblock.inodes_per_group; + struct ext_filesystem *fs = get_fs(); + char *journal_buffer = zalloc(fs->blksz); + char *zero_buffer = zalloc(fs->blksz); + if (!journal_buffer || !zero_buffer) + goto fail; + struct ext2_block_group *gd = (struct ext2_block_group *)fs->gdtable; + + if (fs->first_pass_ibmap == 0) { + for (i = 0; i < fs->no_blkgrp; i++) { + if (gd[i].free_inodes) { + if (gd[i].bg_itable_unused != gd[i].free_inodes) + gd[i].bg_itable_unused = + gd[i].free_inodes; + if (gd[i].bg_flags & EXT4_BG_INODE_UNINIT) { + put_ext4(((uint64_t) + (gd[i].inode_id * fs->blksz)), + zero_buffer, fs->blksz); + gd[i].bg_flags = gd[i].bg_flags & + ~EXT4_BG_INODE_UNINIT; + memcpy(fs->inode_bmaps[i], + zero_buffer, fs->blksz); + } + fs->curr_inode_no = + _get_new_inode_no(fs->inode_bmaps[i]); + if (fs->curr_inode_no == -1) + /* if block bitmap is completely fill */ + continue; + fs->curr_inode_no = fs->curr_inode_no + + (i * inodes_per_grp); + fs->first_pass_ibmap++; + gd[i].free_inodes--; + gd[i].bg_itable_unused--; + fs->sb->free_inodes--; + status = ext4fs_devread(gd[i].inode_id * + fs->sect_perblk, 0, + fs->blksz, + journal_buffer); + if (status == 0) + goto fail; + if (ext4fs_log_journal(journal_buffer, + gd[i].inode_id)) + goto fail; + goto success; + } else + debug("no inode left on block group %d\n", i); + } + goto fail; + } else { +restart: + fs->curr_inode_no++; + /* get the blockbitmap index respective to blockno */ + ibmap_idx = fs->curr_inode_no / inodes_per_grp; + if (gd[ibmap_idx].bg_flags & EXT4_BG_INODE_UNINIT) { + memset(zero_buffer, '\0', fs->blksz); + put_ext4(((uint64_t) (gd[ibmap_idx].inode_id * + fs->blksz)), zero_buffer, + fs->blksz); + gd[ibmap_idx].bg_flags = + gd[ibmap_idx].bg_flags & ~EXT4_BG_INODE_UNINIT; + memcpy(fs->inode_bmaps[ibmap_idx], zero_buffer, + fs->blksz); + } + + if (ext4fs_set_inode_bmap(fs->curr_inode_no, + fs->inode_bmaps[ibmap_idx], + ibmap_idx) != 0) { + debug("going for restart for the block no %d %u\n", + fs->curr_inode_no, ibmap_idx); + goto restart; + } + + /* journal backup */ + if (prev_inode_bitmap_index != ibmap_idx) { + 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; + prev_inode_bitmap_index = ibmap_idx; + } + if (gd[ibmap_idx].bg_itable_unused != gd[ibmap_idx].free_inodes) + gd[ibmap_idx].bg_itable_unused = + gd[ibmap_idx].free_inodes; + gd[ibmap_idx].free_inodes--; + gd[ibmap_idx].bg_itable_unused--; + fs->sb->free_inodes--; + goto success; + } + +success: + free(journal_buffer); + free(zero_buffer); + + return fs->curr_inode_no; +fail: + free(journal_buffer); + free(zero_buffer); + + return -1; + +} + + +static void alloc_single_indirect_block(struct ext2_inode *file_inode, + unsigned int *total_remaining_blocks, + unsigned int *no_blks_reqd) +{ + short i; + short status; + long int actual_block_no; + long int si_blockno; + /* si :single indirect */ + unsigned int *si_buffer = NULL; + unsigned int *si_start_addr = NULL; + struct ext_filesystem *fs = get_fs(); + + if (*total_remaining_blocks != 0) { + si_buffer = zalloc(fs->blksz); + if (!si_buffer) { + printf("No Memory\n"); + return; + } + si_start_addr = si_buffer; + si_blockno = ext4fs_get_new_blk_no(); + if (si_blockno == -1) { + printf("no block left to assign\n"); + goto fail; + } + (*no_blks_reqd)++; + debug("SIPB %ld: %u\n", si_blockno, *total_remaining_blocks); + + status = ext4fs_devread(si_blockno * fs->sect_perblk, + 0, fs->blksz, (char *)si_buffer); + memset(si_buffer, '\0', fs->blksz); + if (status == 0) + goto fail; + + for (i = 0; i < (fs->blksz / sizeof(int)); i++) { + actual_block_no = ext4fs_get_new_blk_no(); + if (actual_block_no == -1) { + printf("no block left to assign\n"); + goto fail; + } + *si_buffer = actual_block_no; + debug("SIAB %u: %u\n", *si_buffer, + *total_remaining_blocks); + + si_buffer++; + (*total_remaining_blocks)--; + if (*total_remaining_blocks == 0) + break; + } + + /* write the block to disk */ + put_ext4(((uint64_t) (si_blockno * fs->blksz)), + si_start_addr, fs->blksz); + file_inode->b.blocks.indir_block = si_blockno; + } +fail: + free(si_start_addr); +} + +static void alloc_double_indirect_block(struct ext2_inode *file_inode, + unsigned int *total_remaining_blocks, + unsigned int *no_blks_reqd) +{ + short i; + short j; + short status; + long int actual_block_no; + /* di:double indirect */ + long int di_blockno_parent; + long int di_blockno_child; + unsigned int *di_parent_buffer = NULL; + unsigned int *di_child_buff = NULL; + unsigned int *di_block_start_addr = NULL; + unsigned int *di_child_buff_start = NULL; + struct ext_filesystem *fs = get_fs(); + + if (*total_remaining_blocks != 0) { + /* double indirect parent block connecting to inode */ + di_blockno_parent = ext4fs_get_new_blk_no(); + if (di_blockno_parent == -1) { + printf("no block left to assign\n"); + goto fail; + } + di_parent_buffer = zalloc(fs->blksz); + if (!di_parent_buffer) + goto fail; + + di_block_start_addr = di_parent_buffer; + (*no_blks_reqd)++; + debug("DIPB %ld: %u\n", di_blockno_parent, + *total_remaining_blocks); + + status = ext4fs_devread(di_blockno_parent * + fs->sect_perblk, 0, + fs->blksz, (char *)di_parent_buffer); + memset(di_parent_buffer, '\0', fs->blksz); + + /* + * start:for each double indirect parent + * block create one more block + */ + for (i = 0; i < (fs->blksz / sizeof(int)); i++) { + di_blockno_child = ext4fs_get_new_blk_no(); + if (di_blockno_child == -1) { + printf("no block left to assign\n"); + goto fail; + } + di_child_buff = zalloc(fs->blksz); + if (!di_child_buff) + goto fail; + + di_child_buff_start = di_child_buff; + *di_parent_buffer = di_blockno_child; + di_parent_buffer++; + (*no_blks_reqd)++; + debug("DICB %ld: %u\n", di_blockno_child, + *total_remaining_blocks); + + status = ext4fs_devread(di_blockno_child * + fs->sect_perblk, 0, + fs->blksz, + (char *)di_child_buff); + memset(di_child_buff, '\0', fs->blksz); + /* filling of actual datablocks for each child */ + for (j = 0; j < (fs->blksz / sizeof(int)); j++) { + actual_block_no = ext4fs_get_new_blk_no(); + if (actual_block_no == -1) { + printf("no block left to assign\n"); + goto fail; + } + *di_child_buff = actual_block_no; + debug("DIAB %ld: %u\n", actual_block_no, + *total_remaining_blocks); + + di_child_buff++; + (*total_remaining_blocks)--; + if (*total_remaining_blocks == 0) + break; + } + /* write the block table */ + put_ext4(((uint64_t) (di_blockno_child * fs->blksz)), + di_child_buff_start, fs->blksz); + free(di_child_buff_start); + di_child_buff_start = NULL; + + if (*total_remaining_blocks == 0) + break; + } + put_ext4(((uint64_t) (di_blockno_parent * fs->blksz)), + di_block_start_addr, fs->blksz); + file_inode->b.blocks.double_indir_block = di_blockno_parent; + } +fail: + free(di_block_start_addr); +} + +static void alloc_triple_indirect_block(struct ext2_inode *file_inode, + unsigned int *total_remaining_blocks, + unsigned int *no_blks_reqd) +{ + short i; + short j; + short k; + long int actual_block_no; + /* ti: Triple Indirect */ + long int ti_gp_blockno; + long int ti_parent_blockno; + long int ti_child_blockno; + unsigned int *ti_gp_buff = NULL; + unsigned int *ti_parent_buff = NULL; + unsigned int *ti_child_buff = NULL; + unsigned int *ti_gp_buff_start_addr = NULL; + unsigned int *ti_pbuff_start_addr = NULL; + unsigned int *ti_cbuff_start_addr = NULL; + struct ext_filesystem *fs = get_fs(); + if (*total_remaining_blocks != 0) { + /* triple indirect grand parent block connecting to inode */ + ti_gp_blockno = ext4fs_get_new_blk_no(); + if (ti_gp_blockno == -1) { + printf("no block left to assign\n"); + goto fail; + } + ti_gp_buff = zalloc(fs->blksz); + if (!ti_gp_buff) + goto fail; + + ti_gp_buff_start_addr = ti_gp_buff; + (*no_blks_reqd)++; + debug("TIGPB %ld: %u\n", ti_gp_blockno, + *total_remaining_blocks); + + /* for each 4 byte grand parent entry create one more block */ + for (i = 0; i < (fs->blksz / sizeof(int)); i++) { + ti_parent_blockno = ext4fs_get_new_blk_no(); + if (ti_parent_blockno == -1) { + printf("no block left to assign\n"); + goto fail; + } + ti_parent_buff = zalloc(fs->blksz); + if (!ti_parent_buff) + goto fail; + + ti_pbuff_start_addr = ti_parent_buff; + *ti_gp_buff = ti_parent_blockno; + ti_gp_buff++; + (*no_blks_reqd)++; + debug("TIPB %ld: %u\n", ti_parent_blockno, + *total_remaining_blocks); + + /* for each 4 byte entry parent create one more block */ + for (j = 0; j < (fs->blksz / sizeof(int)); j++) { + ti_child_blockno = ext4fs_get_new_blk_no(); + if (ti_child_blockno == -1) { + printf("no block left assign\n"); + goto fail; + } + ti_child_buff = zalloc(fs->blksz); + if (!ti_child_buff) + goto fail; + + ti_cbuff_start_addr = ti_child_buff; + *ti_parent_buff = ti_child_blockno; + ti_parent_buff++; + (*no_blks_reqd)++; + debug("TICB %ld: %u\n", ti_parent_blockno, + *total_remaining_blocks); + + /* fill actual datablocks for each child */ + for (k = 0; k < (fs->blksz / sizeof(int)); + k++) { + actual_block_no = + ext4fs_get_new_blk_no(); + if (actual_block_no == -1) { + printf("no block left\n"); + goto fail; + } + *ti_child_buff = actual_block_no; + debug("TIAB %ld: %u\n", actual_block_no, + *total_remaining_blocks); + + ti_child_buff++; + (*total_remaining_blocks)--; + if (*total_remaining_blocks == 0) + break; + } + /* write the child block */ + put_ext4(((uint64_t) (ti_child_blockno * + fs->blksz)), + ti_cbuff_start_addr, fs->blksz); + free(ti_cbuff_start_addr); + + if (*total_remaining_blocks == 0) + break; + } + /* write the parent block */ + put_ext4(((uint64_t) (ti_parent_blockno * fs->blksz)), + ti_pbuff_start_addr, fs->blksz); + free(ti_pbuff_start_addr); + + if (*total_remaining_blocks == 0) + break; + } + /* write the grand parent block */ + put_ext4(((uint64_t) (ti_gp_blockno * fs->blksz)), + ti_gp_buff_start_addr, fs->blksz); + file_inode->b.blocks.triple_indir_block = ti_gp_blockno; + } +fail: + free(ti_gp_buff_start_addr); +} + +void ext4fs_allocate_blocks(struct ext2_inode *file_inode, + unsigned int total_remaining_blocks, + unsigned int *total_no_of_block) +{ + short i; + long int direct_blockno; + unsigned int no_blks_reqd = 0; + + /* allocation of direct blocks */ + for (i = 0; i < INDIRECT_BLOCKS; i++) { + direct_blockno = ext4fs_get_new_blk_no(); + if (direct_blockno == -1) { + printf("no block left to assign\n"); + return; + } + file_inode->b.blocks.dir_blocks[i] = direct_blockno; + debug("DB %ld: %u\n", direct_blockno, total_remaining_blocks); + + total_remaining_blocks--; + if (total_remaining_blocks == 0) + break; + } + + alloc_single_indirect_block(file_inode, &total_remaining_blocks, + &no_blks_reqd); + alloc_double_indirect_block(file_inode, &total_remaining_blocks, + &no_blks_reqd); + alloc_triple_indirect_block(file_inode, &total_remaining_blocks, + &no_blks_reqd); + *total_no_of_block += no_blks_reqd; +} + +#endif + static struct ext4_extent_header *ext4fs_get_extent_block (struct ext2_data *data, char *buf, struct ext4_extent_header *ext_block, |
