2 * modified for Lites 1.1
4 * Aug 1995, Godmar Back (gback@cs.utah.edu)
5 * University of Utah, Department of Computer Science
7 * $FreeBSD: src/sys/gnu/ext2fs/ext2_linux_ialloc.c,v 1.13.2.2 2001/08/14 18:03:19 gallatin Exp $
8 * $DragonFly: src/sys/vfs/gnu/ext2fs/ext2_linux_ialloc.c,v 1.7 2006/01/13 21:09:27 swildner Exp $
11 * linux/fs/ext2/ialloc.c
13 * Copyright (C) 1992, 1993, 1994, 1995
14 * Remy Card (card@masi.ibp.fr)
15 * Laboratoire MASI - Institut Blaise Pascal
16 * Universite Pierre et Marie Curie (Paris VI)
18 * BSD ufs-inspired inode and directory allocation by
19 * Stephen Tweedie (sct@dcs.ed.ac.uk), 1993
23 * The free inodes are managed by bitmaps. A file system contains several
24 * blocks groups. Each group contains 1 bitmap block for blocks, 1 bitmap
25 * block for inodes, N blocks for the inode table and data blocks.
27 * The file system contains group descriptors which are located after the
28 * super block. Each descriptor contains the number of the bitmap block and
29 * the free blocks count in the block. The descriptors are loaded in memory
30 * when a file system is mounted (see ext2_read_super).
33 #include <sys/param.h>
34 #include <sys/systm.h>
37 #include <sys/mount.h>
38 #include <sys/vnode.h>
40 #include <vfs/ufs/quota.h>
41 #include <vfs/ufs/inode.h>
42 #include <vfs/ufs/ufsmount.h>
43 #include "ext2_extern.h"
45 #include "ext2_fs_sb.h"
49 #include <sys/thread2.h>
52 #include "i386-bitops.h"
53 #elif defined(__alpha__)
54 #include "alpha-bitops.h"
56 #error please provide bit operation functions
59 /* this is supposed to mark a buffer dirty on ready for delayed writing
62 mark_buffer_dirty(struct buf *bh)
65 bh->b_flags |= B_DIRTY;
69 struct ext2_group_desc *
70 get_group_desc(struct mount * mp, unsigned int block_group,
71 struct buffer_head **bh)
73 struct ext2_sb_info *sb = VFSTOUFS(mp)->um_e2fs;
74 unsigned long group_desc;
76 struct ext2_group_desc * gdp;
78 if (block_group >= sb->s_groups_count)
79 panic ("get_group_desc: "
80 "block_group >= groups_count - "
81 "block_group = %d, groups_count = %lu",
82 block_group, sb->s_groups_count);
84 group_desc = block_group / EXT2_DESC_PER_BLOCK(sb);
85 desc = block_group % EXT2_DESC_PER_BLOCK(sb);
86 if (!sb->s_group_desc[group_desc])
87 panic ( "get_group_desc:"
88 "Group descriptor not loaded - "
89 "block_group = %d, group_desc = %lu, desc = %lu",
90 block_group, group_desc, desc);
91 gdp = (struct ext2_group_desc *)
92 sb->s_group_desc[group_desc]->b_data;
94 *bh = sb->s_group_desc[group_desc];
99 read_inode_bitmap(struct mount *mp, unsigned long block_group,
100 unsigned int bitmap_nr)
102 struct ext2_sb_info *sb = VFSTOUFS(mp)->um_e2fs;
103 struct ext2_group_desc * gdp;
104 struct buffer_head * bh;
107 gdp = get_group_desc (mp, block_group, NULL);
108 if ((error = bread (VFSTOUFS(mp)->um_devvp,
109 fsbtodb(sb, gdp->bg_inode_bitmap),
110 sb->s_blocksize, &bh)) != 0)
111 panic ( "read_inode_bitmap:"
112 "Cannot read inode bitmap - "
113 "block_group = %lu, inode_bitmap = %lu",
114 block_group, (unsigned long) gdp->bg_inode_bitmap);
115 sb->s_inode_bitmap_number[bitmap_nr] = block_group;
116 sb->s_inode_bitmap[bitmap_nr] = bh;
121 * load_inode_bitmap loads the inode bitmap for a blocks group
123 * It maintains a cache for the last bitmaps loaded. This cache is managed
124 * with a LRU algorithm.
127 * 1/ There is one cache per mounted file system.
128 * 2/ If the file system contains less than EXT2_MAX_GROUP_LOADED groups,
129 * this function reads the bitmap without maintaining a LRU cache.
132 load_inode_bitmap(struct mount *mp, unsigned int block_group)
134 struct ext2_sb_info *sb = VFSTOUFS(mp)->um_e2fs;
136 unsigned long inode_bitmap_number;
137 struct buffer_head * inode_bitmap;
139 if (block_group >= sb->s_groups_count)
140 panic ("load_inode_bitmap:"
141 "block_group >= groups_count - "
142 "block_group = %d, groups_count = %lu",
143 block_group, sb->s_groups_count);
144 if (sb->s_loaded_inode_bitmaps > 0 &&
145 sb->s_inode_bitmap_number[0] == block_group)
147 if (sb->s_groups_count <= EXT2_MAX_GROUP_LOADED) {
148 if (sb->s_inode_bitmap[block_group]) {
149 if (sb->s_inode_bitmap_number[block_group] !=
151 panic ( "load_inode_bitmap:"
152 "block_group != inode_bitmap_number");
156 read_inode_bitmap (mp, block_group, block_group);
161 for (i = 0; i < sb->s_loaded_inode_bitmaps &&
162 sb->s_inode_bitmap_number[i] != block_group;
165 if (i < sb->s_loaded_inode_bitmaps &&
166 sb->s_inode_bitmap_number[i] == block_group) {
167 inode_bitmap_number = sb->s_inode_bitmap_number[i];
168 inode_bitmap = sb->s_inode_bitmap[i];
169 for (j = i; j > 0; j--) {
170 sb->s_inode_bitmap_number[j] =
171 sb->s_inode_bitmap_number[j - 1];
172 sb->s_inode_bitmap[j] =
173 sb->s_inode_bitmap[j - 1];
175 sb->s_inode_bitmap_number[0] = inode_bitmap_number;
176 sb->s_inode_bitmap[0] = inode_bitmap;
178 if (sb->s_loaded_inode_bitmaps < EXT2_MAX_GROUP_LOADED)
179 sb->s_loaded_inode_bitmaps++;
181 ULCK_BUF(sb->s_inode_bitmap[EXT2_MAX_GROUP_LOADED - 1])
182 for (j = sb->s_loaded_inode_bitmaps - 1; j > 0; j--) {
183 sb->s_inode_bitmap_number[j] =
184 sb->s_inode_bitmap_number[j - 1];
185 sb->s_inode_bitmap[j] =
186 sb->s_inode_bitmap[j - 1];
188 read_inode_bitmap (mp, block_group, 0);
195 ext2_free_inode(struct inode *inode)
197 struct ext2_sb_info * sb;
198 struct buffer_head * bh;
199 struct buffer_head * bh2;
200 unsigned long block_group;
203 struct ext2_group_desc * gdp;
204 struct ext2_super_block * es;
209 if (inode->i_nlink) {
210 printf ("ext2_free_inode: inode has nlink=%d\n",
215 ext2_debug ("freeing inode %lu\n", inode->i_number);
218 lock_super (DEVVP(inode));
219 if (inode->i_number < EXT2_FIRST_INO ||
220 inode->i_number > sb->s_es->s_inodes_count) {
221 printf ("free_inode reserved inode or nonexistent inode");
222 unlock_super (DEVVP(inode));
226 block_group = (inode->i_number - 1) / EXT2_INODES_PER_GROUP(sb);
227 bit = (inode->i_number - 1) % EXT2_INODES_PER_GROUP(sb);
228 bitmap_nr = load_inode_bitmap (ITOV(inode)->v_mount, block_group);
229 bh = sb->s_inode_bitmap[bitmap_nr];
230 if (!clear_bit (bit, bh->b_data))
231 printf ( "ext2_free_inode:"
232 "bit already cleared for inode %lu",
233 (unsigned long)inode->i_number);
235 gdp = get_group_desc (ITOV(inode)->v_mount, block_group, &bh2);
236 gdp->bg_free_inodes_count++;
237 if (S_ISDIR(inode->i_mode))
238 gdp->bg_used_dirs_count--;
239 mark_buffer_dirty(bh2);
240 es->s_free_inodes_count++;
242 mark_buffer_dirty(bh);
244 if (sb->s_flags & MS_SYNCHRONOUS) {
245 ll_rw_block (WRITE, 1, &bh);
250 unlock_super (DEVVP(inode));
255 * This function increments the inode version number
257 * This may be used one day by the NFS server
260 inc_inode_version(struct inode *inode, struct ext2_group_desc *gdp, int mode)
262 unsigned long inode_block;
263 struct buffer_head * bh;
264 struct ext2_inode * raw_inode;
266 inode_block = gdp->bg_inode_table + (((inode->i_number - 1) %
267 EXT2_INODES_PER_GROUP(inode->i_sb)) /
268 EXT2_INODES_PER_BLOCK(inode->i_sb));
269 bh = bread (inode->i_sb->s_dev, inode_block, inode->i_sb->s_blocksize);
271 printf ("inc_inode_version Cannot load inode table block - "
272 "inode=%lu, inode_block=%lu\n",
273 inode->i_number, inode_block);
274 inode->u.ext2_i.i_version = 1;
277 raw_inode = ((struct ext2_inode *) bh->b_data) +
278 (((inode->i_number - 1) %
279 EXT2_INODES_PER_GROUP(inode->i_sb)) %
280 EXT2_INODES_PER_BLOCK(inode->i_sb));
281 raw_inode->i_version++;
282 inode->u.ext2_i.i_version = raw_inode->i_version;
289 * There are two policies for allocating an inode. If the new inode is
290 * a directory, then a forward search is made for a block group with both
291 * free space and a low directory-to-inode ratio; if that fails, then of
292 * the groups with above-average free space, that group with the fewest
293 * directories already is chosen.
295 * For other inodes, search forward from the parent directory\'s block
296 * group to find a free inode.
299 * this functino has been reduced to the actual 'find the inode number' part
302 ext2_new_inode(const struct inode *dir, int mode)
304 struct ext2_sb_info * sb;
305 struct buffer_head * bh;
306 struct buffer_head * bh2;
309 struct ext2_group_desc * gdp;
310 struct ext2_group_desc * tmp;
311 struct ext2_super_block * es;
317 lock_super (DEVVP(dir));
323 avefreei = es->s_free_inodes_count /
325 /* I am not yet convinced that this next bit is necessary.
326 i = dir->u.ext2_i.i_block_group;
327 for (j = 0; j < sb->u.ext2_sb.s_groups_count; j++) {
328 tmp = get_group_desc (sb, i, &bh2);
329 if ((tmp->bg_used_dirs_count << 8) <
330 tmp->bg_free_inodes_count) {
335 i = ++i % sb->u.ext2_sb.s_groups_count;
339 for (j = 0; j < sb->s_groups_count; j++) {
340 tmp = get_group_desc(ITOV(dir)->v_mount,j,&bh2);
341 if (tmp->bg_free_inodes_count &&
342 tmp->bg_free_inodes_count >= avefreei) {
344 (tmp->bg_free_blocks_count >
345 gdp->bg_free_blocks_count)) {
356 * Try to place the inode in its parent directory
358 i = dir->i_block_group;
359 tmp = get_group_desc (ITOV(dir)->v_mount, i, &bh2);
360 if (tmp->bg_free_inodes_count)
365 * Use a quadratic hash to find a group with a
368 for (j = 1; j < sb->s_groups_count; j <<= 1) {
370 if (i >= sb->s_groups_count)
371 i -= sb->s_groups_count;
372 tmp = get_group_desc(ITOV(dir)->v_mount,i,&bh2);
373 if (tmp->bg_free_inodes_count) {
381 * That failed: try linear search for a free inode
383 i = dir->i_block_group + 1;
384 for (j = 2; j < sb->s_groups_count; j++) {
385 if (++i >= sb->s_groups_count)
387 tmp = get_group_desc(ITOV(dir)->v_mount,i,&bh2);
388 if (tmp->bg_free_inodes_count) {
397 unlock_super (DEVVP(dir));
400 bitmap_nr = load_inode_bitmap (ITOV(dir)->v_mount, i);
401 bh = sb->s_inode_bitmap[bitmap_nr];
402 if ((j = find_first_zero_bit ((unsigned long *) bh->b_data,
403 EXT2_INODES_PER_GROUP(sb))) <
404 EXT2_INODES_PER_GROUP(sb)) {
405 if (set_bit (j, bh->b_data)) {
406 printf ( "ext2_new_inode:"
407 "bit already set for inode %d", j);
410 /* Linux now does the following:
411 mark_buffer_dirty(bh);
412 if (sb->s_flags & MS_SYNCHRONOUS) {
413 ll_rw_block (WRITE, 1, &bh);
417 mark_buffer_dirty(bh);
419 if (gdp->bg_free_inodes_count != 0) {
420 printf ( "ext2_new_inode:"
421 "Free inodes count corrupted in group %d",
423 unlock_super (DEVVP(dir));
428 j += i * EXT2_INODES_PER_GROUP(sb) + 1;
429 if (j < EXT2_FIRST_INO || j > es->s_inodes_count) {
430 printf ( "ext2_new_inode:"
431 "reserved inode or inode > inodes count - "
432 "block_group = %d,inode=%d", i, j);
433 unlock_super (DEVVP(dir));
436 gdp->bg_free_inodes_count--;
438 gdp->bg_used_dirs_count++;
439 mark_buffer_dirty(bh2);
440 es->s_free_inodes_count--;
441 /* mark_buffer_dirty(sb->u.ext2_sb.s_sbh, 1); */
443 unlock_super (DEVVP(dir));
449 ext2_count_free_inodes(struct mount *mp)
452 struct ext2_sb_info *sb = VFSTOUFS(mp)->um_e2fs;
453 struct ext2_super_block * es;
454 unsigned long desc_count, bitmap_count, x;
456 struct ext2_group_desc * gdp;
459 lock_super (VFSTOUFS(mp)->um_devvp);
464 for (i = 0; i < sb->s_groups_count; i++) {
465 gdp = get_group_desc (mp, i, NULL);
466 desc_count += gdp->bg_free_inodes_count;
467 bitmap_nr = load_inode_bitmap (mp, i);
468 x = ext2_count_free (sb->s_inode_bitmap[bitmap_nr],
469 EXT2_INODES_PER_GROUP(sb) / 8);
470 ext2_debug ("group %d: stored = %d, counted = %lu\n",
471 i, gdp->bg_free_inodes_count, x);
474 ext2_debug("stored = %lu, computed = %lu, %lu\n",
475 es->s_free_inodes_count, desc_count, bitmap_count);
476 unlock_super (VFSTOUFS(mp)->um_devvp);
479 return VFSTOUFS(mp)->um_e2fsb->s_free_inodes_count;
486 ext2_check_inodes_bitmap(struct mount *mp)
488 struct ext2_super_block * es;
489 unsigned long desc_count, bitmap_count, x;
491 struct ext2_group_desc * gdp;
495 es = sb->u.ext2_sb.s_es;
499 for (i = 0; i < sb->u.ext2_sb.s_groups_count; i++) {
500 gdp = get_group_desc (sb, i, NULL);
501 desc_count += gdp->bg_free_inodes_count;
502 bitmap_nr = load_inode_bitmap (sb, i);
503 x = ext2_count_free (sb->u.ext2_sb.s_inode_bitmap[bitmap_nr],
504 EXT2_INODES_PER_GROUP(sb) / 8);
505 if (gdp->bg_free_inodes_count != x)
506 printf ( "ext2_check_inodes_bitmap:"
507 "Wrong free inodes count in group %d, "
508 "stored = %d, counted = %lu", i,
509 gdp->bg_free_inodes_count, x);
512 if (es->s_free_inodes_count != bitmap_count)
513 printf ( "ext2_check_inodes_bitmap:"
514 "Wrong free inodes count in super block, "
515 "stored = %lu, counted = %lu",
516 (unsigned long) es->s_free_inodes_count, bitmap_count);