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 Library
8 * General Public License, version 2.
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 blk64_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 !(ext2fs_bg_flags_test(fs, group, 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_loc2(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 ext2fs_fast_unmark_block_bitmap2(map, blk);
59 blk = (group * fs->super->s_blocks_per_group) +
60 fs->super->s_first_data_block;
61 for (i=0; i < fs->super->s_blocks_per_group; i++, blk++) {
62 if ((blk == super_blk) ||
63 (old_desc_blk && old_desc_blocks &&
64 (blk >= old_desc_blk) &&
65 (blk < old_desc_blk + old_desc_blocks)) ||
66 (new_desc_blk && (blk == new_desc_blk)) ||
67 (blk == ext2fs_block_bitmap_loc(fs, group)) ||
68 (blk == ext2fs_inode_bitmap_loc(fs, group)) ||
69 (blk >= ext2fs_inode_table_loc(fs, group) &&
70 (blk < ext2fs_inode_table_loc(fs, group)
71 + fs->inode_blocks_per_group)))
72 ext2fs_fast_mark_block_bitmap2(map, blk);
74 ext2fs_bg_flags_clear(fs, group, EXT2_BG_BLOCK_UNINIT);
75 ext2fs_group_desc_csum_set(fs, group);
79 * Check for uninit inode bitmaps and deal with them appropriately
81 static void check_inode_uninit(ext2_filsys fs, ext2fs_inode_bitmap map,
86 if (!(EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
87 EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) ||
88 !(ext2fs_bg_flags_test(fs, group, EXT2_BG_INODE_UNINIT)))
91 ino = (group * fs->super->s_inodes_per_group) + 1;
92 for (i=0; i < fs->super->s_inodes_per_group; i++, ino++)
93 ext2fs_fast_unmark_inode_bitmap2(map, ino);
95 ext2fs_bg_flags_clear(fs, group, EXT2_BG_INODE_UNINIT);
96 check_block_uninit(fs, fs->block_map, group);
100 * Right now, just search forward from the parent directory's block
101 * group to find the next free inode.
103 * Should have a special policy for directories.
105 errcode_t ext2fs_new_inode(ext2_filsys fs, ext2_ino_t dir,
106 int mode EXT2FS_ATTR((unused)),
107 ext2fs_inode_bitmap map, ext2_ino_t *ret)
109 ext2_ino_t dir_group = 0;
111 ext2_ino_t start_inode;
113 EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
118 return EXT2_ET_NO_INODE_BITMAP;
121 dir_group = (dir - 1) / EXT2_INODES_PER_GROUP(fs->super);
123 start_inode = (dir_group * EXT2_INODES_PER_GROUP(fs->super)) + 1;
124 if (start_inode < EXT2_FIRST_INODE(fs->super))
125 start_inode = EXT2_FIRST_INODE(fs->super);
126 if (start_inode > fs->super->s_inodes_count)
127 return EXT2_ET_INODE_ALLOC_FAIL;
131 if (((i - 1) % EXT2_INODES_PER_GROUP(fs->super)) == 0)
132 check_inode_uninit(fs, map, (i - 1) /
133 EXT2_INODES_PER_GROUP(fs->super));
135 if (!ext2fs_fast_test_inode_bitmap2(map, i))
138 if (i > fs->super->s_inodes_count)
139 i = EXT2_FIRST_INODE(fs->super);
140 } while (i != start_inode);
142 if (ext2fs_test_inode_bitmap2(map, i))
143 return EXT2_ET_INODE_ALLOC_FAIL;
149 * Stupid algorithm --- we now just search forward starting from the
150 * goal. Should put in a smarter one someday....
152 errcode_t ext2fs_new_block2(ext2_filsys fs, blk64_t goal,
153 ext2fs_block_bitmap map, blk64_t *ret)
158 EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
163 return EXT2_ET_NO_BLOCK_BITMAP;
164 if (!goal || (goal >= ext2fs_blocks_count(fs->super)))
165 goal = fs->super->s_first_data_block;
167 c_ratio = 1 << ext2fs_get_bitmap_granularity(map);
169 goal &= ~EXT2FS_CLUSTER_MASK(fs);
170 check_block_uninit(fs, map,
171 (i - fs->super->s_first_data_block) /
172 EXT2_BLOCKS_PER_GROUP(fs->super));
174 if (((i - fs->super->s_first_data_block) %
175 EXT2_BLOCKS_PER_GROUP(fs->super)) == 0)
176 check_block_uninit(fs, map,
177 (i - fs->super->s_first_data_block) /
178 EXT2_BLOCKS_PER_GROUP(fs->super));
180 if (!ext2fs_fast_test_block_bitmap2(map, i)) {
184 i = (i + c_ratio) & ~(c_ratio - 1);
185 if (i >= ext2fs_blocks_count(fs->super))
186 i = fs->super->s_first_data_block;
188 return EXT2_ET_BLOCK_ALLOC_FAIL;
191 errcode_t ext2fs_new_block(ext2_filsys fs, blk_t goal,
192 ext2fs_block_bitmap map, blk_t *ret)
196 retval = ext2fs_new_block2(fs, goal, map, &val);
203 * This function zeros out the allocated block, and updates all of the
204 * appropriate filesystem records.
206 errcode_t ext2fs_alloc_block2(ext2_filsys fs, blk64_t goal,
207 char *block_buf, blk64_t *ret)
214 retval = ext2fs_get_mem(fs->blocksize, &buf);
219 memset(block_buf, 0, fs->blocksize);
221 if (fs->get_alloc_block) {
222 retval = (fs->get_alloc_block)(fs, goal, &block);
226 if (!fs->block_map) {
227 retval = ext2fs_read_block_bitmap(fs);
232 retval = ext2fs_new_block2(fs, goal, 0, &block);
237 retval = io_channel_write_blk64(fs->io, block, 1, block_buf);
241 ext2fs_block_alloc_stats2(fs, block, +1);
246 ext2fs_free_mem(&buf);
250 errcode_t ext2fs_alloc_block(ext2_filsys fs, blk_t goal,
251 char *block_buf, blk_t *ret)
255 retval = ext2fs_alloc_block2(fs, goal, block_buf, &val);
261 errcode_t ext2fs_get_free_blocks2(ext2_filsys fs, blk64_t start, blk64_t finish,
262 int num, ext2fs_block_bitmap map, blk64_t *ret)
267 EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
272 return EXT2_ET_NO_BLOCK_BITMAP;
274 b = fs->super->s_first_data_block;
279 c_ratio = 1 << ext2fs_get_bitmap_granularity(map);
281 finish &= ~(c_ratio -1);
283 if (b+num-1 > ext2fs_blocks_count(fs->super))
284 b = fs->super->s_first_data_block;
285 if (ext2fs_fast_test_block_bitmap_range2(map, b, num)) {
290 } while (b != finish);
291 return EXT2_ET_BLOCK_ALLOC_FAIL;
294 errcode_t ext2fs_get_free_blocks(ext2_filsys fs, blk_t start, blk_t finish,
295 int num, ext2fs_block_bitmap map, blk_t *ret)
299 retval = ext2fs_get_free_blocks2(fs, start, finish, num, map, &val);
305 void ext2fs_set_alloc_block_callback(ext2_filsys fs,
306 errcode_t (*func)(ext2_filsys fs,
309 errcode_t (**old)(ext2_filsys fs,
313 if (!fs || fs->magic != EXT2_ET_MAGIC_EXT2FS_FILSYS)
317 *old = fs->get_alloc_block;
319 fs->get_alloc_block = func;