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 1.5 2005/06/06 15:09:37 drhodus 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"
51 #include "i386-bitops.h"
52 #elif defined(__alpha__)
53 #include "alpha-bitops.h"
55 #error please provide bit operation functions
58 /* this is supposed to mark a buffer dirty on ready for delayed writing
60 void mark_buffer_dirty(struct buf *bh)
63 bh->b_flags |= B_DIRTY;
67 struct ext2_group_desc * get_group_desc (struct mount * mp,
68 unsigned int block_group,
69 struct buffer_head ** bh)
71 struct ext2_sb_info *sb = VFSTOUFS(mp)->um_e2fs;
72 unsigned long group_desc;
74 struct ext2_group_desc * gdp;
76 if (block_group >= sb->s_groups_count)
77 panic ("get_group_desc: "
78 "block_group >= groups_count - "
79 "block_group = %d, groups_count = %lu",
80 block_group, sb->s_groups_count);
82 group_desc = block_group / EXT2_DESC_PER_BLOCK(sb);
83 desc = block_group % EXT2_DESC_PER_BLOCK(sb);
84 if (!sb->s_group_desc[group_desc])
85 panic ( "get_group_desc:"
86 "Group descriptor not loaded - "
87 "block_group = %d, group_desc = %lu, desc = %lu",
88 block_group, group_desc, desc);
89 gdp = (struct ext2_group_desc *)
90 sb->s_group_desc[group_desc]->b_data;
92 *bh = sb->s_group_desc[group_desc];
96 static void read_inode_bitmap (struct mount * mp,
97 unsigned long block_group,
98 unsigned int bitmap_nr)
100 struct ext2_sb_info *sb = VFSTOUFS(mp)->um_e2fs;
101 struct ext2_group_desc * gdp;
102 struct buffer_head * bh;
105 gdp = get_group_desc (mp, block_group, NULL);
106 if ((error = bread (VFSTOUFS(mp)->um_devvp,
107 fsbtodb(sb, gdp->bg_inode_bitmap),
108 sb->s_blocksize, &bh)) != 0)
109 panic ( "read_inode_bitmap:"
110 "Cannot read inode bitmap - "
111 "block_group = %lu, inode_bitmap = %lu",
112 block_group, (unsigned long) gdp->bg_inode_bitmap);
113 sb->s_inode_bitmap_number[bitmap_nr] = block_group;
114 sb->s_inode_bitmap[bitmap_nr] = bh;
119 * load_inode_bitmap loads the inode bitmap for a blocks group
121 * It maintains a cache for the last bitmaps loaded. This cache is managed
122 * with a LRU algorithm.
125 * 1/ There is one cache per mounted file system.
126 * 2/ If the file system contains less than EXT2_MAX_GROUP_LOADED groups,
127 * this function reads the bitmap without maintaining a LRU cache.
129 static int load_inode_bitmap (struct mount * mp,
130 unsigned int block_group)
132 struct ext2_sb_info *sb = VFSTOUFS(mp)->um_e2fs;
134 unsigned long inode_bitmap_number;
135 struct buffer_head * inode_bitmap;
137 if (block_group >= sb->s_groups_count)
138 panic ("load_inode_bitmap:"
139 "block_group >= groups_count - "
140 "block_group = %d, groups_count = %lu",
141 block_group, sb->s_groups_count);
142 if (sb->s_loaded_inode_bitmaps > 0 &&
143 sb->s_inode_bitmap_number[0] == block_group)
145 if (sb->s_groups_count <= EXT2_MAX_GROUP_LOADED) {
146 if (sb->s_inode_bitmap[block_group]) {
147 if (sb->s_inode_bitmap_number[block_group] !=
149 panic ( "load_inode_bitmap:"
150 "block_group != inode_bitmap_number");
154 read_inode_bitmap (mp, block_group, block_group);
159 for (i = 0; i < sb->s_loaded_inode_bitmaps &&
160 sb->s_inode_bitmap_number[i] != block_group;
163 if (i < sb->s_loaded_inode_bitmaps &&
164 sb->s_inode_bitmap_number[i] == block_group) {
165 inode_bitmap_number = sb->s_inode_bitmap_number[i];
166 inode_bitmap = sb->s_inode_bitmap[i];
167 for (j = i; j > 0; j--) {
168 sb->s_inode_bitmap_number[j] =
169 sb->s_inode_bitmap_number[j - 1];
170 sb->s_inode_bitmap[j] =
171 sb->s_inode_bitmap[j - 1];
173 sb->s_inode_bitmap_number[0] = inode_bitmap_number;
174 sb->s_inode_bitmap[0] = inode_bitmap;
176 if (sb->s_loaded_inode_bitmaps < EXT2_MAX_GROUP_LOADED)
177 sb->s_loaded_inode_bitmaps++;
179 ULCK_BUF(sb->s_inode_bitmap[EXT2_MAX_GROUP_LOADED - 1])
180 for (j = sb->s_loaded_inode_bitmaps - 1; j > 0; j--) {
181 sb->s_inode_bitmap_number[j] =
182 sb->s_inode_bitmap_number[j - 1];
183 sb->s_inode_bitmap[j] =
184 sb->s_inode_bitmap[j - 1];
186 read_inode_bitmap (mp, block_group, 0);
192 void ext2_free_inode (struct inode * inode)
194 struct ext2_sb_info * sb;
195 struct buffer_head * bh;
196 struct buffer_head * bh2;
197 unsigned long block_group;
200 struct ext2_group_desc * gdp;
201 struct ext2_super_block * es;
206 if (inode->i_nlink) {
207 printf ("ext2_free_inode: inode has nlink=%d\n",
212 ext2_debug ("freeing inode %lu\n", inode->i_number);
215 lock_super (DEVVP(inode));
216 if (inode->i_number < EXT2_FIRST_INO ||
217 inode->i_number > sb->s_es->s_inodes_count) {
218 printf ("free_inode reserved inode or nonexistent inode");
219 unlock_super (DEVVP(inode));
223 block_group = (inode->i_number - 1) / EXT2_INODES_PER_GROUP(sb);
224 bit = (inode->i_number - 1) % EXT2_INODES_PER_GROUP(sb);
225 bitmap_nr = load_inode_bitmap (ITOV(inode)->v_mount, block_group);
226 bh = sb->s_inode_bitmap[bitmap_nr];
227 if (!clear_bit (bit, bh->b_data))
228 printf ( "ext2_free_inode:"
229 "bit already cleared for inode %lu",
230 (unsigned long)inode->i_number);
232 gdp = get_group_desc (ITOV(inode)->v_mount, block_group, &bh2);
233 gdp->bg_free_inodes_count++;
234 if (S_ISDIR(inode->i_mode))
235 gdp->bg_used_dirs_count--;
236 mark_buffer_dirty(bh2);
237 es->s_free_inodes_count++;
239 mark_buffer_dirty(bh);
241 if (sb->s_flags & MS_SYNCHRONOUS) {
242 ll_rw_block (WRITE, 1, &bh);
247 unlock_super (DEVVP(inode));
252 * This function increments the inode version number
254 * This may be used one day by the NFS server
256 static void inc_inode_version (struct inode * inode,
257 struct ext2_group_desc *gdp,
260 unsigned long inode_block;
261 struct buffer_head * bh;
262 struct ext2_inode * raw_inode;
264 inode_block = gdp->bg_inode_table + (((inode->i_number - 1) %
265 EXT2_INODES_PER_GROUP(inode->i_sb)) /
266 EXT2_INODES_PER_BLOCK(inode->i_sb));
267 bh = bread (inode->i_sb->s_dev, inode_block, inode->i_sb->s_blocksize);
269 printf ("inc_inode_version Cannot load inode table block - "
270 "inode=%lu, inode_block=%lu\n",
271 inode->i_number, inode_block);
272 inode->u.ext2_i.i_version = 1;
275 raw_inode = ((struct ext2_inode *) bh->b_data) +
276 (((inode->i_number - 1) %
277 EXT2_INODES_PER_GROUP(inode->i_sb)) %
278 EXT2_INODES_PER_BLOCK(inode->i_sb));
279 raw_inode->i_version++;
280 inode->u.ext2_i.i_version = raw_inode->i_version;
287 * There are two policies for allocating an inode. If the new inode is
288 * a directory, then a forward search is made for a block group with both
289 * free space and a low directory-to-inode ratio; if that fails, then of
290 * the groups with above-average free space, that group with the fewest
291 * directories already is chosen.
293 * For other inodes, search forward from the parent directory\'s block
294 * group to find a free inode.
297 * this functino has been reduced to the actual 'find the inode number' part
299 ino_t ext2_new_inode (const struct inode * dir, int mode)
301 struct ext2_sb_info * sb;
302 struct buffer_head * bh;
303 struct buffer_head * bh2;
306 struct ext2_group_desc * gdp;
307 struct ext2_group_desc * tmp;
308 struct ext2_super_block * es;
314 lock_super (DEVVP(dir));
320 avefreei = es->s_free_inodes_count /
322 /* I am not yet convinced that this next bit is necessary.
323 i = dir->u.ext2_i.i_block_group;
324 for (j = 0; j < sb->u.ext2_sb.s_groups_count; j++) {
325 tmp = get_group_desc (sb, i, &bh2);
326 if ((tmp->bg_used_dirs_count << 8) <
327 tmp->bg_free_inodes_count) {
332 i = ++i % sb->u.ext2_sb.s_groups_count;
336 for (j = 0; j < sb->s_groups_count; j++) {
337 tmp = get_group_desc(ITOV(dir)->v_mount,j,&bh2);
338 if (tmp->bg_free_inodes_count &&
339 tmp->bg_free_inodes_count >= avefreei) {
341 (tmp->bg_free_blocks_count >
342 gdp->bg_free_blocks_count)) {
353 * Try to place the inode in its parent directory
355 i = dir->i_block_group;
356 tmp = get_group_desc (ITOV(dir)->v_mount, i, &bh2);
357 if (tmp->bg_free_inodes_count)
362 * Use a quadratic hash to find a group with a
365 for (j = 1; j < sb->s_groups_count; j <<= 1) {
367 if (i >= sb->s_groups_count)
368 i -= sb->s_groups_count;
369 tmp = get_group_desc(ITOV(dir)->v_mount,i,&bh2);
370 if (tmp->bg_free_inodes_count) {
378 * That failed: try linear search for a free inode
380 i = dir->i_block_group + 1;
381 for (j = 2; j < sb->s_groups_count; j++) {
382 if (++i >= sb->s_groups_count)
384 tmp = get_group_desc(ITOV(dir)->v_mount,i,&bh2);
385 if (tmp->bg_free_inodes_count) {
394 unlock_super (DEVVP(dir));
397 bitmap_nr = load_inode_bitmap (ITOV(dir)->v_mount, i);
398 bh = sb->s_inode_bitmap[bitmap_nr];
399 if ((j = find_first_zero_bit ((unsigned long *) bh->b_data,
400 EXT2_INODES_PER_GROUP(sb))) <
401 EXT2_INODES_PER_GROUP(sb)) {
402 if (set_bit (j, bh->b_data)) {
403 printf ( "ext2_new_inode:"
404 "bit already set for inode %d", j);
407 /* Linux now does the following:
408 mark_buffer_dirty(bh);
409 if (sb->s_flags & MS_SYNCHRONOUS) {
410 ll_rw_block (WRITE, 1, &bh);
414 mark_buffer_dirty(bh);
416 if (gdp->bg_free_inodes_count != 0) {
417 printf ( "ext2_new_inode:"
418 "Free inodes count corrupted in group %d",
420 unlock_super (DEVVP(dir));
425 j += i * EXT2_INODES_PER_GROUP(sb) + 1;
426 if (j < EXT2_FIRST_INO || j > es->s_inodes_count) {
427 printf ( "ext2_new_inode:"
428 "reserved inode or inode > inodes count - "
429 "block_group = %d,inode=%d", i, j);
430 unlock_super (DEVVP(dir));
433 gdp->bg_free_inodes_count--;
435 gdp->bg_used_dirs_count++;
436 mark_buffer_dirty(bh2);
437 es->s_free_inodes_count--;
438 /* mark_buffer_dirty(sb->u.ext2_sb.s_sbh, 1); */
440 unlock_super (DEVVP(dir));
445 static unsigned long ext2_count_free_inodes (struct mount * mp)
448 struct ext2_sb_info *sb = VFSTOUFS(mp)->um_e2fs;
449 struct ext2_super_block * es;
450 unsigned long desc_count, bitmap_count, x;
452 struct ext2_group_desc * gdp;
455 lock_super (VFSTOUFS(mp)->um_devvp);
460 for (i = 0; i < sb->s_groups_count; i++) {
461 gdp = get_group_desc (mp, i, NULL);
462 desc_count += gdp->bg_free_inodes_count;
463 bitmap_nr = load_inode_bitmap (mp, i);
464 x = ext2_count_free (sb->s_inode_bitmap[bitmap_nr],
465 EXT2_INODES_PER_GROUP(sb) / 8);
466 ext2_debug ("group %d: stored = %d, counted = %lu\n",
467 i, gdp->bg_free_inodes_count, x);
470 ext2_debug("stored = %lu, computed = %lu, %lu\n",
471 es->s_free_inodes_count, desc_count, bitmap_count);
472 unlock_super (VFSTOUFS(mp)->um_devvp);
475 return VFSTOUFS(mp)->um_e2fsb->s_free_inodes_count;
481 void ext2_check_inodes_bitmap (struct mount * mp)
483 struct ext2_super_block * es;
484 unsigned long desc_count, bitmap_count, x;
486 struct ext2_group_desc * gdp;
490 es = sb->u.ext2_sb.s_es;
494 for (i = 0; i < sb->u.ext2_sb.s_groups_count; i++) {
495 gdp = get_group_desc (sb, i, NULL);
496 desc_count += gdp->bg_free_inodes_count;
497 bitmap_nr = load_inode_bitmap (sb, i);
498 x = ext2_count_free (sb->u.ext2_sb.s_inode_bitmap[bitmap_nr],
499 EXT2_INODES_PER_GROUP(sb) / 8);
500 if (gdp->bg_free_inodes_count != x)
501 printf ( "ext2_check_inodes_bitmap:"
502 "Wrong free inodes count in group %d, "
503 "stored = %d, counted = %lu", i,
504 gdp->bg_free_inodes_count, x);
507 if (es->s_free_inodes_count != bitmap_count)
508 printf ( "ext2_check_inodes_bitmap:"
509 "Wrong free inodes count in super block, "
510 "stored = %lu, counted = %lu",
511 (unsigned long) es->s_free_inodes_count, bitmap_count);