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>
30 * Check for uninit block bitmaps and deal with them appropriately
32 static void check_block_uninit(ext2_filsys fs, ext2fs_block_bitmap map,
36 blk_t blk, super_blk, old_desc_blk, new_desc_blk;
39 if (!(EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
40 EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) ||
41 !(fs->group_desc[group].bg_flags & EXT2_BG_BLOCK_UNINIT))
44 blk = (group * fs->super->s_blocks_per_group) +
45 fs->super->s_first_data_block;
47 ext2fs_super_and_bgd_loc(fs, group, &super_blk,
48 &old_desc_blk, &new_desc_blk, 0);
50 if (fs->super->s_feature_incompat &
51 EXT2_FEATURE_INCOMPAT_META_BG)
52 old_desc_blocks = fs->super->s_first_meta_bg;
54 old_desc_blocks = fs->desc_blocks + fs->super->s_reserved_gdt_blocks;
56 for (i=0; i < fs->super->s_blocks_per_group; i++, blk++) {
57 if ((blk == super_blk) ||
58 (old_desc_blk && old_desc_blocks &&
59 (blk >= old_desc_blk) &&
60 (blk < old_desc_blk + old_desc_blocks)) ||
61 (new_desc_blk && (blk == new_desc_blk)) ||
62 (blk == fs->group_desc[group].bg_block_bitmap) ||
63 (blk == fs->group_desc[group].bg_inode_bitmap) ||
64 (blk >= fs->group_desc[group].bg_inode_table &&
65 (blk < fs->group_desc[group].bg_inode_table
66 + fs->inode_blocks_per_group)))
67 ext2fs_fast_mark_block_bitmap(map, blk);
69 ext2fs_fast_unmark_block_bitmap(map, blk);
71 fs->group_desc[group].bg_flags &= ~EXT2_BG_BLOCK_UNINIT;
72 ext2fs_group_desc_csum_set(fs, group);
76 * Check for uninit inode bitmaps and deal with them appropriately
78 static void check_inode_uninit(ext2_filsys fs, ext2fs_inode_bitmap map,
83 if (!(EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
84 EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) ||
85 !(fs->group_desc[group].bg_flags & EXT2_BG_INODE_UNINIT))
88 ino = (group * fs->super->s_inodes_per_group) + 1;
89 for (i=0; i < fs->super->s_inodes_per_group; i++, ino++)
90 ext2fs_fast_unmark_inode_bitmap(map, ino);
92 fs->group_desc[group].bg_flags &= ~EXT2_BG_INODE_UNINIT;
93 check_block_uninit(fs, fs->block_map, group);
97 * Right now, just search forward from the parent directory's block
98 * group to find the next free inode.
100 * Should have a special policy for directories.
102 errcode_t ext2fs_new_inode(ext2_filsys fs, ext2_ino_t dir,
103 int mode EXT2FS_ATTR((unused)),
104 ext2fs_inode_bitmap map, ext2_ino_t *ret)
106 ext2_ino_t dir_group = 0;
108 ext2_ino_t start_inode;
110 EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
115 return EXT2_ET_NO_INODE_BITMAP;
118 dir_group = (dir - 1) / EXT2_INODES_PER_GROUP(fs->super);
120 start_inode = (dir_group * EXT2_INODES_PER_GROUP(fs->super)) + 1;
121 if (start_inode < EXT2_FIRST_INODE(fs->super))
122 start_inode = EXT2_FIRST_INODE(fs->super);
123 if (start_inode > fs->super->s_inodes_count)
124 return EXT2_ET_INODE_ALLOC_FAIL;
128 if (((i - 1) % EXT2_INODES_PER_GROUP(fs->super)) == 0)
129 check_inode_uninit(fs, map, (i - 1) /
130 EXT2_INODES_PER_GROUP(fs->super));
132 if (!ext2fs_fast_test_inode_bitmap(map, i))
135 if (i > fs->super->s_inodes_count)
136 i = EXT2_FIRST_INODE(fs->super);
137 } while (i != start_inode);
139 if (ext2fs_test_inode_bitmap(map, i))
140 return EXT2_ET_INODE_ALLOC_FAIL;
146 * Stupid algorithm --- we now just search forward starting from the
147 * goal. Should put in a smarter one someday....
149 errcode_t ext2fs_new_block(ext2_filsys fs, blk_t goal,
150 ext2fs_block_bitmap map, blk_t *ret)
154 EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
159 return EXT2_ET_NO_BLOCK_BITMAP;
160 if (!goal || (goal >= fs->super->s_blocks_count))
161 goal = fs->super->s_first_data_block;
163 check_block_uninit(fs, map,
164 (i - fs->super->s_first_data_block) /
165 EXT2_BLOCKS_PER_GROUP(fs->super));
167 if (((i - fs->super->s_first_data_block) %
168 EXT2_BLOCKS_PER_GROUP(fs->super)) == 0)
169 check_block_uninit(fs, map,
170 (i - fs->super->s_first_data_block) /
171 EXT2_BLOCKS_PER_GROUP(fs->super));
173 if (!ext2fs_fast_test_block_bitmap(map, i)) {
178 if (i >= fs->super->s_blocks_count)
179 i = fs->super->s_first_data_block;
181 return EXT2_ET_BLOCK_ALLOC_FAIL;
185 * This function zeros out the allocated block, and updates all of the
186 * appropriate filesystem records.
188 errcode_t ext2fs_alloc_block(ext2_filsys fs, blk_t goal,
189 char *block_buf, blk_t *ret)
196 retval = ext2fs_get_mem(fs->blocksize, &buf);
201 memset(block_buf, 0, fs->blocksize);
203 if (fs->get_alloc_block) {
206 retval = (fs->get_alloc_block)(fs, (blk64_t) goal, &new);
211 if (!fs->block_map) {
212 retval = ext2fs_read_block_bitmap(fs);
217 retval = ext2fs_new_block(fs, goal, 0, &block);
222 retval = io_channel_write_blk(fs->io, block, 1, block_buf);
226 ext2fs_block_alloc_stats(fs, block, +1);
231 ext2fs_free_mem(&buf);
235 errcode_t ext2fs_get_free_blocks(ext2_filsys fs, blk_t start, blk_t finish,
236 int num, ext2fs_block_bitmap map, blk_t *ret)
240 EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
245 return EXT2_ET_NO_BLOCK_BITMAP;
247 b = fs->super->s_first_data_block;
253 if (b+num-1 > fs->super->s_blocks_count)
254 b = fs->super->s_first_data_block;
255 if (ext2fs_fast_test_block_bitmap_range(map, b, num)) {
260 } while (b != finish);
261 return EXT2_ET_BLOCK_ALLOC_FAIL;
264 void ext2fs_set_alloc_block_callback(ext2_filsys fs,
265 errcode_t (*func)(ext2_filsys fs,
268 errcode_t (**old)(ext2_filsys fs,
272 if (!fs || fs->magic != EXT2_ET_MAGIC_EXT2FS_FILSYS)
276 *old = fs->get_alloc_block;
278 fs->get_alloc_block = func;