| /* |
| * alloc.c --- allocate new inodes, blocks for ext2fs |
| * |
| * Copyright (C) 1993 Theodore Ts'o. This file may be redistributed |
| * under the terms of the GNU Public License. |
| */ |
| |
| #include <stdio.h> |
| #include <unistd.h> |
| #include <stdlib.h> |
| #include <time.h> |
| #include <sys/stat.h> |
| #include <sys/types.h> |
| #if HAVE_ERRNO_H |
| #include <errno.h> |
| #endif |
| |
| #include <linux/ext2_fs.h> |
| |
| #include "ext2fs.h" |
| |
| /* |
| * Right now, just search forward from the parent directory's block |
| * group to find the next free inode. |
| * |
| * Should have a special policy for directories. |
| */ |
| errcode_t ext2fs_new_inode(ext2_filsys fs, ino_t dir, int mode, |
| ext2fs_inode_bitmap map, ino_t *ret) |
| { |
| int dir_group = 0; |
| ino_t i; |
| ino_t start_inode; |
| |
| EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS); |
| |
| if (!map) |
| map = fs->inode_map; |
| if (!map) |
| return EXT2_ET_NO_INODE_BITMAP; |
| |
| if (dir > 0) |
| dir_group = (dir - 1) / EXT2_INODES_PER_GROUP(fs->super); |
| |
| start_inode = (dir_group * EXT2_INODES_PER_GROUP(fs->super)) + 1; |
| if (start_inode < EXT2_FIRST_INODE(fs->super)) |
| start_inode = EXT2_FIRST_INODE(fs->super); |
| i = start_inode; |
| |
| do { |
| if (!ext2fs_test_inode_bitmap(map, i)) |
| break; |
| i++; |
| if (i > fs->super->s_inodes_count) |
| i = EXT2_FIRST_INODE(fs->super); |
| } while (i != start_inode); |
| |
| if (ext2fs_test_inode_bitmap(map, i)) |
| return ENOSPC; |
| *ret = i; |
| return 0; |
| } |
| |
| /* |
| * Stupid algorithm --- we now just search forward starting from the |
| * goal. Should put in a smarter one someday.... |
| */ |
| errcode_t ext2fs_new_block(ext2_filsys fs, blk_t goal, |
| ext2fs_block_bitmap map, blk_t *ret) |
| { |
| blk_t i = goal; |
| |
| EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS); |
| |
| if (!map) |
| map = fs->block_map; |
| if (!map) |
| return EXT2_ET_NO_BLOCK_BITMAP; |
| if (!i) |
| i = fs->super->s_first_data_block; |
| do { |
| if (!ext2fs_test_block_bitmap(map, i)) { |
| *ret = i; |
| return 0; |
| } |
| i++; |
| if (i > fs->super->s_blocks_count) |
| i = fs->super->s_first_data_block; |
| } while (i != goal); |
| return ENOSPC; |
| } |
| |
| static int check_blocks_free(ext2_filsys fs, ext2fs_block_bitmap map, |
| blk_t blk, int num) |
| { |
| int i; |
| |
| for (i=0; i < num; i++) { |
| if ((blk+i) > fs->super->s_blocks_count) |
| return 0; |
| if (ext2fs_test_block_bitmap(map, blk+i)) |
| return 0; |
| } |
| return 1; |
| } |
| |
| errcode_t ext2fs_get_free_blocks(ext2_filsys fs, blk_t start, blk_t finish, |
| int num, ext2fs_block_bitmap map, blk_t *ret) |
| { |
| blk_t b = start; |
| |
| EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS); |
| |
| if (!map) |
| map = fs->block_map; |
| if (!map) |
| return EXT2_ET_NO_BLOCK_BITMAP; |
| if (!b) |
| b = fs->super->s_first_data_block; |
| if (!finish) |
| finish = start; |
| if (!num) |
| num = 1; |
| do { |
| if (check_blocks_free(fs, map, b, num)) { |
| *ret = b; |
| return 0; |
| } |
| b++; |
| if (b > fs->super->s_blocks_count) |
| b = fs->super->s_first_data_block; |
| } while (b != finish); |
| return ENOSPC; |
| } |
| |