2 * alloc.c --- allocate new inodes, blocks for ext2fs
4 * Copyright (C) 1993, 1994, 1995, 1996 Theodore Ts'o.
7 * This file may be redistributed under the terms of the GNU Public
23 #include <sys/types.h>
26 #if EXT2_FLAT_INCLUDES
29 #include <linux/ext2_fs.h>
35 * Right now, just search forward from the parent directory's block
36 * group to find the next free inode.
38 * Should have a special policy for directories.
40 errcode_t ext2fs_new_inode(ext2_filsys fs, ino_t dir, int mode,
41 ext2fs_inode_bitmap map, ino_t *ret)
47 EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
52 return EXT2_ET_NO_INODE_BITMAP;
55 dir_group = (dir - 1) / EXT2_INODES_PER_GROUP(fs->super);
57 start_inode = (dir_group * EXT2_INODES_PER_GROUP(fs->super)) + 1;
58 if (start_inode < EXT2_FIRST_INODE(fs->super))
59 start_inode = EXT2_FIRST_INODE(fs->super);
63 if (!ext2fs_test_inode_bitmap(map, i))
66 if (i > fs->super->s_inodes_count)
67 i = EXT2_FIRST_INODE(fs->super);
68 } while (i != start_inode);
70 if (ext2fs_test_inode_bitmap(map, i))
71 return EXT2_ET_INODE_ALLOC_FAIL;
77 * Stupid algorithm --- we now just search forward starting from the
78 * goal. Should put in a smarter one someday....
80 errcode_t ext2fs_new_block(ext2_filsys fs, blk_t goal,
81 ext2fs_block_bitmap map, blk_t *ret)
85 EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
90 return EXT2_ET_NO_BLOCK_BITMAP;
91 if (!goal || (goal >= fs->super->s_blocks_count))
92 goal = fs->super->s_first_data_block;
95 if (!ext2fs_test_block_bitmap(map, i)) {
100 if (i >= fs->super->s_blocks_count)
101 i = fs->super->s_first_data_block;
103 return EXT2_ET_BLOCK_ALLOC_FAIL;
107 * This function zeros out the allocated block, and updates all of the
108 * appropriate filesystem records.
110 errcode_t ext2fs_alloc_block(ext2_filsys fs, blk_t goal,
111 char *block_buf, blk_t *ret)
119 retval = ext2fs_get_mem(fs->blocksize, (void **) &buf);
124 memset(block_buf, 0, fs->blocksize);
126 if (!fs->block_map) {
127 retval = ext2fs_read_block_bitmap(fs);
132 retval = ext2fs_new_block(fs, goal, 0, &block);
136 retval = io_channel_write_blk(fs->io, block, 1, block_buf);
140 fs->super->s_free_blocks_count--;
141 group = ext2fs_group_of_blk(fs, block);
142 fs->group_desc[group].bg_free_blocks_count--;
143 ext2fs_mark_block_bitmap(fs->block_map, block);
144 ext2fs_mark_super_dirty(fs);
145 ext2fs_mark_bb_dirty(fs);
151 ext2fs_free_mem((void **) &buf);
155 errcode_t ext2fs_get_free_blocks(ext2_filsys fs, blk_t start, blk_t finish,
156 int num, ext2fs_block_bitmap map, blk_t *ret)
160 EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
165 return EXT2_ET_NO_BLOCK_BITMAP;
167 b = fs->super->s_first_data_block;
173 if (b+num-1 > fs->super->s_blocks_count)
174 b = fs->super->s_first_data_block;
175 if (ext2fs_fast_test_block_bitmap_range(map, b, num)) {
180 } while (b != finish);
181 return EXT2_ET_BLOCK_ALLOC_FAIL;