alloc_tables.c revision 4efbac6fed75c29d3d5f1b676b932754653a2ac5 
1/*
2 * alloc_tables.c --- Allocate tables for a newly initialized
3 * filesystem.  Used by mke2fs when initializing a filesystem
4 *
5 * Copyright (C) 1996 Theodore Ts'o.
6 *
7 * %Begin-Header%
8 * This file may be redistributed under the terms of the GNU Public
9 * License.
10 * %End-Header%
11 */
12
13#include <stdio.h>
14#include <string.h>
15#if HAVE_UNISTD_H
16#include <unistd.h>
17#endif
18#include <fcntl.h>
19#include <time.h>
20#if HAVE_SYS_STAT_H
21#include <sys/stat.h>
22#endif
23#if HAVE_SYS_TYPES_H
24#include <sys/types.h>
25#endif
26
27#include "ext2_fs.h"
28#include "ext2fs.h"
29#include "ext2fsP.h"
30
31/*
32 * This routine searches for free blocks that can allocate a full
33 * group of bitmaps or inode tables for a flexbg group.  Returns the
34 * block number with a correct offset were the bitmaps and inode
35 * tables can be allocated continously and in order.
36 */
37static blk_t flexbg_offset(ext2_filsys fs, dgrp_t group, blk64_t start_blk,
38			   ext2fs_block_bitmap bmap, int offset, int size,
39			   int elem_size)
40{
41	int		flexbg, flexbg_size;
42	blk_t		last_blk, first_free = 0;
43	dgrp_t	       	last_grp;
44
45	flexbg_size = 1 << fs->super->s_log_groups_per_flex;
46	flexbg = group / flexbg_size;
47
48	if (size > (int) (fs->super->s_blocks_per_group / 8))
49		size = (int) fs->super->s_blocks_per_group / 8;
50
51	if (offset)
52		offset -= 1;
53
54	/*
55	 * Don't do a long search if the previous block
56	 * search is still valid.
57	 */
58	if (start_blk && group % flexbg_size) {
59		if (ext2fs_test_block_bitmap_range2(bmap, start_blk + elem_size,
60						   size))
61			return start_blk + elem_size;
62	}
63
64	start_blk = ext2fs_group_first_block(fs, flexbg_size * flexbg);
65	last_grp = group | (flexbg_size - 1);
66	if (last_grp > fs->group_desc_count)
67		last_grp = fs->group_desc_count;
68	last_blk = ext2fs_group_last_block(fs, last_grp);
69
70	/* Find the first available block */
71	if (ext2fs_get_free_blocks(fs, start_blk, last_blk, 1, bmap,
72				   &first_free))
73		return first_free;
74
75	if (ext2fs_get_free_blocks(fs, first_free + offset, last_blk, size,
76				   bmap, &first_free))
77		return first_free;
78
79	return first_free;
80}
81
82errcode_t ext2fs_allocate_group_table(ext2_filsys fs, dgrp_t group,
83				      ext2fs_block_bitmap bmap)
84{
85	errcode_t	retval;
86	blk_t		group_blk, start_blk, last_blk, new_blk, blk;
87	dgrp_t		last_grp = 0;
88	int		j, rem_grps = 0, flexbg_size = 0;
89
90	group_blk = ext2fs_group_first_block(fs, group);
91	last_blk = ext2fs_group_last_block(fs, group);
92
93	if (!bmap)
94		bmap = fs->block_map;
95
96	if (EXT2_HAS_INCOMPAT_FEATURE(fs->super,
97				      EXT4_FEATURE_INCOMPAT_FLEX_BG) &&
98	    fs->super->s_log_groups_per_flex) {
99		flexbg_size = 1 << fs->super->s_log_groups_per_flex;
100		last_grp = group | (flexbg_size - 1);
101		rem_grps = last_grp - group;
102		if (last_grp > fs->group_desc_count)
103			last_grp = fs->group_desc_count;
104	}
105
106	/*
107	 * Allocate the block and inode bitmaps, if necessary
108	 */
109	if (fs->stride) {
110		retval = ext2fs_get_free_blocks(fs, group_blk, last_blk,
111						1, bmap, &start_blk);
112		if (retval)
113			return retval;
114		start_blk += fs->inode_blocks_per_group;
115		start_blk += ((fs->stride * group) %
116			      (last_blk - start_blk + 1));
117		if (start_blk >= last_blk)
118			start_blk = group_blk;
119	} else
120		start_blk = group_blk;
121
122	if (flexbg_size) {
123		blk64_t prev_block = 0;
124
125		if (group && fs->group_desc[group-1].bg_block_bitmap)
126			prev_block = fs->group_desc[group-1].bg_block_bitmap;
127		start_blk = flexbg_offset(fs, group, prev_block, bmap,
128						 0, rem_grps, 1);
129		last_blk = ext2fs_group_last_block(fs, last_grp);
130	}
131
132	if (!fs->group_desc[group].bg_block_bitmap) {
133		retval = ext2fs_get_free_blocks(fs, start_blk, last_blk,
134						1, bmap, &new_blk);
135		if (retval == EXT2_ET_BLOCK_ALLOC_FAIL)
136			retval = ext2fs_get_free_blocks(fs, group_blk,
137					last_blk, 1, bmap, &new_blk);
138		if (retval)
139			return retval;
140		ext2fs_mark_block_bitmap2(bmap, new_blk);
141		fs->group_desc[group].bg_block_bitmap = new_blk;
142		if (flexbg_size) {
143			dgrp_t gr = ext2fs_group_of_blk(fs, new_blk);
144			fs->group_desc[gr].bg_free_blocks_count--;
145			ext2fs_free_blocks_count_add(fs->super, -1);
146			ext2fs_bg_flag_clear(fs, gr, EXT2_BG_BLOCK_UNINIT);
147			ext2fs_group_desc_csum_set(fs, gr);
148		}
149	}
150
151	if (flexbg_size) {
152		blk_t prev_block = 0;
153		if (group && fs->group_desc[group-1].bg_inode_bitmap)
154			prev_block = fs->group_desc[group-1].bg_inode_bitmap;
155		start_blk = flexbg_offset(fs, group, prev_block, bmap,
156						 flexbg_size, rem_grps, 1);
157		last_blk = ext2fs_group_last_block(fs, last_grp);
158	}
159
160	if (!fs->group_desc[group].bg_inode_bitmap) {
161		retval = ext2fs_get_free_blocks(fs, start_blk, last_blk,
162						1, bmap, &new_blk);
163		if (retval == EXT2_ET_BLOCK_ALLOC_FAIL)
164			retval = ext2fs_get_free_blocks(fs, group_blk,
165					last_blk, 1, bmap, &new_blk);
166		if (retval)
167			return retval;
168		ext2fs_mark_block_bitmap2(bmap, new_blk);
169		fs->group_desc[group].bg_inode_bitmap = new_blk;
170		if (flexbg_size) {
171			dgrp_t gr = ext2fs_group_of_blk(fs, new_blk);
172			fs->group_desc[gr].bg_free_blocks_count--;
173			ext2fs_free_blocks_count_add(fs->super, -1);
174			ext2fs_bg_flag_clear(fs, gr, EXT2_BG_BLOCK_UNINIT);
175			ext2fs_group_desc_csum_set(fs, gr);
176		}
177	}
178
179	/*
180	 * Allocate the inode table
181	 */
182	if (flexbg_size) {
183		blk_t prev_block = 0;
184		if (group && fs->group_desc[group-1].bg_inode_table)
185			prev_block = fs->group_desc[group-1].bg_inode_table;
186		group_blk = flexbg_offset(fs, group, prev_block, bmap,
187						 flexbg_size * 2,
188						 fs->inode_blocks_per_group *
189						 rem_grps,
190						 fs->inode_blocks_per_group);
191		last_blk = ext2fs_group_last_block(fs, last_grp);
192	}
193
194	if (!fs->group_desc[group].bg_inode_table) {
195		retval = ext2fs_get_free_blocks(fs, group_blk, last_blk,
196						fs->inode_blocks_per_group,
197						bmap, &new_blk);
198		if (retval)
199			return retval;
200		for (j=0, blk = new_blk;
201		     j < fs->inode_blocks_per_group;
202		     j++, blk++) {
203			ext2fs_mark_block_bitmap2(bmap, blk);
204			if (flexbg_size) {
205				dgrp_t gr = ext2fs_group_of_blk(fs, blk);
206				fs->group_desc[gr].bg_free_blocks_count--;
207				ext2fs_free_blocks_count_add(fs->super, -1);
208				ext2fs_bg_flag_clear(fs, gr,
209						     EXT2_BG_BLOCK_UNINIT);
210				ext2fs_group_desc_csum_set(fs, gr);
211			}
212		}
213		fs->group_desc[group].bg_inode_table = new_blk;
214	}
215	ext2fs_group_desc_csum_set(fs, group);
216	return 0;
217}
218
219errcode_t ext2fs_allocate_tables(ext2_filsys fs)
220{
221	errcode_t	retval;
222	dgrp_t		i;
223	struct ext2fs_numeric_progress_struct progress;
224
225	ext2fs_numeric_progress_init(fs, &progress, NULL,
226				     fs->group_desc_count);
227
228	for (i = 0; i < fs->group_desc_count; i++) {
229		ext2fs_numeric_progress_update(fs, &progress, i);
230		retval = ext2fs_allocate_group_table(fs, i, fs->block_map);
231		if (retval)
232			return retval;
233	}
234	ext2fs_numeric_progress_close(fs, &progress, NULL);
235	return 0;
236}
237
238