xref: /linux/fs/ext2/ialloc.c (revision f3d9478b2ce468c3115b02ecae7e975990697f15)
1 /*
2  *  linux/fs/ext2/ialloc.c
3  *
4  * Copyright (C) 1992, 1993, 1994, 1995
5  * Remy Card (card@masi.ibp.fr)
6  * Laboratoire MASI - Institut Blaise Pascal
7  * Universite Pierre et Marie Curie (Paris VI)
8  *
9  *  BSD ufs-inspired inode and directory allocation by
10  *  Stephen Tweedie (sct@dcs.ed.ac.uk), 1993
11  *  Big-endian to little-endian byte-swapping/bitmaps by
12  *        David S. Miller (davem@caip.rutgers.edu), 1995
13  */
14 
15 #include <linux/config.h>
16 #include <linux/quotaops.h>
17 #include <linux/sched.h>
18 #include <linux/backing-dev.h>
19 #include <linux/buffer_head.h>
20 #include <linux/random.h>
21 #include "ext2.h"
22 #include "xattr.h"
23 #include "acl.h"
24 
25 /*
26  * ialloc.c contains the inodes allocation and deallocation routines
27  */
28 
29 /*
30  * The free inodes are managed by bitmaps.  A file system contains several
31  * blocks groups.  Each group contains 1 bitmap block for blocks, 1 bitmap
32  * block for inodes, N blocks for the inode table and data blocks.
33  *
34  * The file system contains group descriptors which are located after the
35  * super block.  Each descriptor contains the number of the bitmap block and
36  * the free blocks count in the block.
37  */
38 
39 
40 /*
41  * Read the inode allocation bitmap for a given block_group, reading
42  * into the specified slot in the superblock's bitmap cache.
43  *
44  * Return buffer_head of bitmap on success or NULL.
45  */
46 static struct buffer_head *
47 read_inode_bitmap(struct super_block * sb, unsigned long block_group)
48 {
49 	struct ext2_group_desc *desc;
50 	struct buffer_head *bh = NULL;
51 
52 	desc = ext2_get_group_desc(sb, block_group, NULL);
53 	if (!desc)
54 		goto error_out;
55 
56 	bh = sb_bread(sb, le32_to_cpu(desc->bg_inode_bitmap));
57 	if (!bh)
58 		ext2_error(sb, "read_inode_bitmap",
59 			    "Cannot read inode bitmap - "
60 			    "block_group = %lu, inode_bitmap = %u",
61 			    block_group, le32_to_cpu(desc->bg_inode_bitmap));
62 error_out:
63 	return bh;
64 }
65 
66 static void ext2_release_inode(struct super_block *sb, int group, int dir)
67 {
68 	struct ext2_group_desc * desc;
69 	struct buffer_head *bh;
70 
71 	desc = ext2_get_group_desc(sb, group, &bh);
72 	if (!desc) {
73 		ext2_error(sb, "ext2_release_inode",
74 			"can't get descriptor for group %d", group);
75 		return;
76 	}
77 
78 	spin_lock(sb_bgl_lock(EXT2_SB(sb), group));
79 	desc->bg_free_inodes_count =
80 		cpu_to_le16(le16_to_cpu(desc->bg_free_inodes_count) + 1);
81 	if (dir)
82 		desc->bg_used_dirs_count =
83 			cpu_to_le16(le16_to_cpu(desc->bg_used_dirs_count) - 1);
84 	spin_unlock(sb_bgl_lock(EXT2_SB(sb), group));
85 	if (dir)
86 		percpu_counter_dec(&EXT2_SB(sb)->s_dirs_counter);
87 	sb->s_dirt = 1;
88 	mark_buffer_dirty(bh);
89 }
90 
91 /*
92  * NOTE! When we get the inode, we're the only people
93  * that have access to it, and as such there are no
94  * race conditions we have to worry about. The inode
95  * is not on the hash-lists, and it cannot be reached
96  * through the filesystem because the directory entry
97  * has been deleted earlier.
98  *
99  * HOWEVER: we must make sure that we get no aliases,
100  * which means that we have to call "clear_inode()"
101  * _before_ we mark the inode not in use in the inode
102  * bitmaps. Otherwise a newly created file might use
103  * the same inode number (not actually the same pointer
104  * though), and then we'd have two inodes sharing the
105  * same inode number and space on the harddisk.
106  */
107 void ext2_free_inode (struct inode * inode)
108 {
109 	struct super_block * sb = inode->i_sb;
110 	int is_directory;
111 	unsigned long ino;
112 	struct buffer_head *bitmap_bh = NULL;
113 	unsigned long block_group;
114 	unsigned long bit;
115 	struct ext2_super_block * es;
116 
117 	ino = inode->i_ino;
118 	ext2_debug ("freeing inode %lu\n", ino);
119 
120 	/*
121 	 * Note: we must free any quota before locking the superblock,
122 	 * as writing the quota to disk may need the lock as well.
123 	 */
124 	if (!is_bad_inode(inode)) {
125 		/* Quota is already initialized in iput() */
126 		ext2_xattr_delete_inode(inode);
127 	    	DQUOT_FREE_INODE(inode);
128 		DQUOT_DROP(inode);
129 	}
130 
131 	es = EXT2_SB(sb)->s_es;
132 	is_directory = S_ISDIR(inode->i_mode);
133 
134 	/* Do this BEFORE marking the inode not in use or returning an error */
135 	clear_inode (inode);
136 
137 	if (ino < EXT2_FIRST_INO(sb) ||
138 	    ino > le32_to_cpu(es->s_inodes_count)) {
139 		ext2_error (sb, "ext2_free_inode",
140 			    "reserved or nonexistent inode %lu", ino);
141 		goto error_return;
142 	}
143 	block_group = (ino - 1) / EXT2_INODES_PER_GROUP(sb);
144 	bit = (ino - 1) % EXT2_INODES_PER_GROUP(sb);
145 	brelse(bitmap_bh);
146 	bitmap_bh = read_inode_bitmap(sb, block_group);
147 	if (!bitmap_bh)
148 		goto error_return;
149 
150 	/* Ok, now we can actually update the inode bitmaps.. */
151 	if (!ext2_clear_bit_atomic(sb_bgl_lock(EXT2_SB(sb), block_group),
152 				bit, (void *) bitmap_bh->b_data))
153 		ext2_error (sb, "ext2_free_inode",
154 			      "bit already cleared for inode %lu", ino);
155 	else
156 		ext2_release_inode(sb, block_group, is_directory);
157 	mark_buffer_dirty(bitmap_bh);
158 	if (sb->s_flags & MS_SYNCHRONOUS)
159 		sync_dirty_buffer(bitmap_bh);
160 error_return:
161 	brelse(bitmap_bh);
162 }
163 
164 /*
165  * We perform asynchronous prereading of the new inode's inode block when
166  * we create the inode, in the expectation that the inode will be written
167  * back soon.  There are two reasons:
168  *
169  * - When creating a large number of files, the async prereads will be
170  *   nicely merged into large reads
171  * - When writing out a large number of inodes, we don't need to keep on
172  *   stalling the writes while we read the inode block.
173  *
174  * FIXME: ext2_get_group_desc() needs to be simplified.
175  */
176 static void ext2_preread_inode(struct inode *inode)
177 {
178 	unsigned long block_group;
179 	unsigned long offset;
180 	unsigned long block;
181 	struct buffer_head *bh;
182 	struct ext2_group_desc * gdp;
183 	struct backing_dev_info *bdi;
184 
185 	bdi = inode->i_mapping->backing_dev_info;
186 	if (bdi_read_congested(bdi))
187 		return;
188 	if (bdi_write_congested(bdi))
189 		return;
190 
191 	block_group = (inode->i_ino - 1) / EXT2_INODES_PER_GROUP(inode->i_sb);
192 	gdp = ext2_get_group_desc(inode->i_sb, block_group, &bh);
193 	if (gdp == NULL)
194 		return;
195 
196 	/*
197 	 * Figure out the offset within the block group inode table
198 	 */
199 	offset = ((inode->i_ino - 1) % EXT2_INODES_PER_GROUP(inode->i_sb)) *
200 				EXT2_INODE_SIZE(inode->i_sb);
201 	block = le32_to_cpu(gdp->bg_inode_table) +
202 				(offset >> EXT2_BLOCK_SIZE_BITS(inode->i_sb));
203 	sb_breadahead(inode->i_sb, block);
204 }
205 
206 /*
207  * There are two policies for allocating an inode.  If the new inode is
208  * a directory, then a forward search is made for a block group with both
209  * free space and a low directory-to-inode ratio; if that fails, then of
210  * the groups with above-average free space, that group with the fewest
211  * directories already is chosen.
212  *
213  * For other inodes, search forward from the parent directory\'s block
214  * group to find a free inode.
215  */
216 static int find_group_dir(struct super_block *sb, struct inode *parent)
217 {
218 	int ngroups = EXT2_SB(sb)->s_groups_count;
219 	int avefreei = ext2_count_free_inodes(sb) / ngroups;
220 	struct ext2_group_desc *desc, *best_desc = NULL;
221 	struct buffer_head *bh, *best_bh = NULL;
222 	int group, best_group = -1;
223 
224 	for (group = 0; group < ngroups; group++) {
225 		desc = ext2_get_group_desc (sb, group, &bh);
226 		if (!desc || !desc->bg_free_inodes_count)
227 			continue;
228 		if (le16_to_cpu(desc->bg_free_inodes_count) < avefreei)
229 			continue;
230 		if (!best_desc ||
231 		    (le16_to_cpu(desc->bg_free_blocks_count) >
232 		     le16_to_cpu(best_desc->bg_free_blocks_count))) {
233 			best_group = group;
234 			best_desc = desc;
235 			best_bh = bh;
236 		}
237 	}
238 	if (!best_desc)
239 		return -1;
240 
241 	return best_group;
242 }
243 
244 /*
245  * Orlov's allocator for directories.
246  *
247  * We always try to spread first-level directories.
248  *
249  * If there are blockgroups with both free inodes and free blocks counts
250  * not worse than average we return one with smallest directory count.
251  * Otherwise we simply return a random group.
252  *
253  * For the rest rules look so:
254  *
255  * It's OK to put directory into a group unless
256  * it has too many directories already (max_dirs) or
257  * it has too few free inodes left (min_inodes) or
258  * it has too few free blocks left (min_blocks) or
259  * it's already running too large debt (max_debt).
260  * Parent's group is prefered, if it doesn't satisfy these
261  * conditions we search cyclically through the rest. If none
262  * of the groups look good we just look for a group with more
263  * free inodes than average (starting at parent's group).
264  *
265  * Debt is incremented each time we allocate a directory and decremented
266  * when we allocate an inode, within 0--255.
267  */
268 
269 #define INODE_COST 64
270 #define BLOCK_COST 256
271 
272 static int find_group_orlov(struct super_block *sb, struct inode *parent)
273 {
274 	int parent_group = EXT2_I(parent)->i_block_group;
275 	struct ext2_sb_info *sbi = EXT2_SB(sb);
276 	struct ext2_super_block *es = sbi->s_es;
277 	int ngroups = sbi->s_groups_count;
278 	int inodes_per_group = EXT2_INODES_PER_GROUP(sb);
279 	int freei;
280 	int avefreei;
281 	int free_blocks;
282 	int avefreeb;
283 	int blocks_per_dir;
284 	int ndirs;
285 	int max_debt, max_dirs, min_blocks, min_inodes;
286 	int group = -1, i;
287 	struct ext2_group_desc *desc;
288 	struct buffer_head *bh;
289 
290 	freei = percpu_counter_read_positive(&sbi->s_freeinodes_counter);
291 	avefreei = freei / ngroups;
292 	free_blocks = percpu_counter_read_positive(&sbi->s_freeblocks_counter);
293 	avefreeb = free_blocks / ngroups;
294 	ndirs = percpu_counter_read_positive(&sbi->s_dirs_counter);
295 
296 	if ((parent == sb->s_root->d_inode) ||
297 	    (EXT2_I(parent)->i_flags & EXT2_TOPDIR_FL)) {
298 		struct ext2_group_desc *best_desc = NULL;
299 		struct buffer_head *best_bh = NULL;
300 		int best_ndir = inodes_per_group;
301 		int best_group = -1;
302 
303 		get_random_bytes(&group, sizeof(group));
304 		parent_group = (unsigned)group % ngroups;
305 		for (i = 0; i < ngroups; i++) {
306 			group = (parent_group + i) % ngroups;
307 			desc = ext2_get_group_desc (sb, group, &bh);
308 			if (!desc || !desc->bg_free_inodes_count)
309 				continue;
310 			if (le16_to_cpu(desc->bg_used_dirs_count) >= best_ndir)
311 				continue;
312 			if (le16_to_cpu(desc->bg_free_inodes_count) < avefreei)
313 				continue;
314 			if (le16_to_cpu(desc->bg_free_blocks_count) < avefreeb)
315 				continue;
316 			best_group = group;
317 			best_ndir = le16_to_cpu(desc->bg_used_dirs_count);
318 			best_desc = desc;
319 			best_bh = bh;
320 		}
321 		if (best_group >= 0) {
322 			desc = best_desc;
323 			bh = best_bh;
324 			group = best_group;
325 			goto found;
326 		}
327 		goto fallback;
328 	}
329 
330 	if (ndirs == 0)
331 		ndirs = 1;	/* percpu_counters are approximate... */
332 
333 	blocks_per_dir = (le32_to_cpu(es->s_blocks_count)-free_blocks) / ndirs;
334 
335 	max_dirs = ndirs / ngroups + inodes_per_group / 16;
336 	min_inodes = avefreei - inodes_per_group / 4;
337 	min_blocks = avefreeb - EXT2_BLOCKS_PER_GROUP(sb) / 4;
338 
339 	max_debt = EXT2_BLOCKS_PER_GROUP(sb) / max(blocks_per_dir, BLOCK_COST);
340 	if (max_debt * INODE_COST > inodes_per_group)
341 		max_debt = inodes_per_group / INODE_COST;
342 	if (max_debt > 255)
343 		max_debt = 255;
344 	if (max_debt == 0)
345 		max_debt = 1;
346 
347 	for (i = 0; i < ngroups; i++) {
348 		group = (parent_group + i) % ngroups;
349 		desc = ext2_get_group_desc (sb, group, &bh);
350 		if (!desc || !desc->bg_free_inodes_count)
351 			continue;
352 		if (sbi->s_debts[group] >= max_debt)
353 			continue;
354 		if (le16_to_cpu(desc->bg_used_dirs_count) >= max_dirs)
355 			continue;
356 		if (le16_to_cpu(desc->bg_free_inodes_count) < min_inodes)
357 			continue;
358 		if (le16_to_cpu(desc->bg_free_blocks_count) < min_blocks)
359 			continue;
360 		goto found;
361 	}
362 
363 fallback:
364 	for (i = 0; i < ngroups; i++) {
365 		group = (parent_group + i) % ngroups;
366 		desc = ext2_get_group_desc (sb, group, &bh);
367 		if (!desc || !desc->bg_free_inodes_count)
368 			continue;
369 		if (le16_to_cpu(desc->bg_free_inodes_count) >= avefreei)
370 			goto found;
371 	}
372 
373 	if (avefreei) {
374 		/*
375 		 * The free-inodes counter is approximate, and for really small
376 		 * filesystems the above test can fail to find any blockgroups
377 		 */
378 		avefreei = 0;
379 		goto fallback;
380 	}
381 
382 	return -1;
383 
384 found:
385 	return group;
386 }
387 
388 static int find_group_other(struct super_block *sb, struct inode *parent)
389 {
390 	int parent_group = EXT2_I(parent)->i_block_group;
391 	int ngroups = EXT2_SB(sb)->s_groups_count;
392 	struct ext2_group_desc *desc;
393 	struct buffer_head *bh;
394 	int group, i;
395 
396 	/*
397 	 * Try to place the inode in its parent directory
398 	 */
399 	group = parent_group;
400 	desc = ext2_get_group_desc (sb, group, &bh);
401 	if (desc && le16_to_cpu(desc->bg_free_inodes_count) &&
402 			le16_to_cpu(desc->bg_free_blocks_count))
403 		goto found;
404 
405 	/*
406 	 * We're going to place this inode in a different blockgroup from its
407 	 * parent.  We want to cause files in a common directory to all land in
408 	 * the same blockgroup.  But we want files which are in a different
409 	 * directory which shares a blockgroup with our parent to land in a
410 	 * different blockgroup.
411 	 *
412 	 * So add our directory's i_ino into the starting point for the hash.
413 	 */
414 	group = (group + parent->i_ino) % ngroups;
415 
416 	/*
417 	 * Use a quadratic hash to find a group with a free inode and some
418 	 * free blocks.
419 	 */
420 	for (i = 1; i < ngroups; i <<= 1) {
421 		group += i;
422 		if (group >= ngroups)
423 			group -= ngroups;
424 		desc = ext2_get_group_desc (sb, group, &bh);
425 		if (desc && le16_to_cpu(desc->bg_free_inodes_count) &&
426 				le16_to_cpu(desc->bg_free_blocks_count))
427 			goto found;
428 	}
429 
430 	/*
431 	 * That failed: try linear search for a free inode, even if that group
432 	 * has no free blocks.
433 	 */
434 	group = parent_group;
435 	for (i = 0; i < ngroups; i++) {
436 		if (++group >= ngroups)
437 			group = 0;
438 		desc = ext2_get_group_desc (sb, group, &bh);
439 		if (desc && le16_to_cpu(desc->bg_free_inodes_count))
440 			goto found;
441 	}
442 
443 	return -1;
444 
445 found:
446 	return group;
447 }
448 
449 struct inode *ext2_new_inode(struct inode *dir, int mode)
450 {
451 	struct super_block *sb;
452 	struct buffer_head *bitmap_bh = NULL;
453 	struct buffer_head *bh2;
454 	int group, i;
455 	ino_t ino = 0;
456 	struct inode * inode;
457 	struct ext2_group_desc *gdp;
458 	struct ext2_super_block *es;
459 	struct ext2_inode_info *ei;
460 	struct ext2_sb_info *sbi;
461 	int err;
462 
463 	sb = dir->i_sb;
464 	inode = new_inode(sb);
465 	if (!inode)
466 		return ERR_PTR(-ENOMEM);
467 
468 	ei = EXT2_I(inode);
469 	sbi = EXT2_SB(sb);
470 	es = sbi->s_es;
471 	if (S_ISDIR(mode)) {
472 		if (test_opt(sb, OLDALLOC))
473 			group = find_group_dir(sb, dir);
474 		else
475 			group = find_group_orlov(sb, dir);
476 	} else
477 		group = find_group_other(sb, dir);
478 
479 	if (group == -1) {
480 		err = -ENOSPC;
481 		goto fail;
482 	}
483 
484 	for (i = 0; i < sbi->s_groups_count; i++) {
485 		gdp = ext2_get_group_desc(sb, group, &bh2);
486 		brelse(bitmap_bh);
487 		bitmap_bh = read_inode_bitmap(sb, group);
488 		if (!bitmap_bh) {
489 			err = -EIO;
490 			goto fail;
491 		}
492 		ino = 0;
493 
494 repeat_in_this_group:
495 		ino = ext2_find_next_zero_bit((unsigned long *)bitmap_bh->b_data,
496 					      EXT2_INODES_PER_GROUP(sb), ino);
497 		if (ino >= EXT2_INODES_PER_GROUP(sb)) {
498 			/*
499 			 * Rare race: find_group_xx() decided that there were
500 			 * free inodes in this group, but by the time we tried
501 			 * to allocate one, they're all gone.  This can also
502 			 * occur because the counters which find_group_orlov()
503 			 * uses are approximate.  So just go and search the
504 			 * next block group.
505 			 */
506 			if (++group == sbi->s_groups_count)
507 				group = 0;
508 			continue;
509 		}
510 		if (ext2_set_bit_atomic(sb_bgl_lock(sbi, group),
511 						ino, bitmap_bh->b_data)) {
512 			/* we lost this inode */
513 			if (++ino >= EXT2_INODES_PER_GROUP(sb)) {
514 				/* this group is exhausted, try next group */
515 				if (++group == sbi->s_groups_count)
516 					group = 0;
517 				continue;
518 			}
519 			/* try to find free inode in the same group */
520 			goto repeat_in_this_group;
521 		}
522 		goto got;
523 	}
524 
525 	/*
526 	 * Scanned all blockgroups.
527 	 */
528 	err = -ENOSPC;
529 	goto fail;
530 got:
531 	mark_buffer_dirty(bitmap_bh);
532 	if (sb->s_flags & MS_SYNCHRONOUS)
533 		sync_dirty_buffer(bitmap_bh);
534 	brelse(bitmap_bh);
535 
536 	ino += group * EXT2_INODES_PER_GROUP(sb) + 1;
537 	if (ino < EXT2_FIRST_INO(sb) || ino > le32_to_cpu(es->s_inodes_count)) {
538 		ext2_error (sb, "ext2_new_inode",
539 			    "reserved inode or inode > inodes count - "
540 			    "block_group = %d,inode=%lu", group,
541 			    (unsigned long) ino);
542 		err = -EIO;
543 		goto fail;
544 	}
545 
546 	percpu_counter_mod(&sbi->s_freeinodes_counter, -1);
547 	if (S_ISDIR(mode))
548 		percpu_counter_inc(&sbi->s_dirs_counter);
549 
550 	spin_lock(sb_bgl_lock(sbi, group));
551 	gdp->bg_free_inodes_count =
552                 cpu_to_le16(le16_to_cpu(gdp->bg_free_inodes_count) - 1);
553 	if (S_ISDIR(mode)) {
554 		if (sbi->s_debts[group] < 255)
555 			sbi->s_debts[group]++;
556 		gdp->bg_used_dirs_count =
557 			cpu_to_le16(le16_to_cpu(gdp->bg_used_dirs_count) + 1);
558 	} else {
559 		if (sbi->s_debts[group])
560 			sbi->s_debts[group]--;
561 	}
562 	spin_unlock(sb_bgl_lock(sbi, group));
563 
564 	sb->s_dirt = 1;
565 	mark_buffer_dirty(bh2);
566 	inode->i_uid = current->fsuid;
567 	if (test_opt (sb, GRPID))
568 		inode->i_gid = dir->i_gid;
569 	else if (dir->i_mode & S_ISGID) {
570 		inode->i_gid = dir->i_gid;
571 		if (S_ISDIR(mode))
572 			mode |= S_ISGID;
573 	} else
574 		inode->i_gid = current->fsgid;
575 	inode->i_mode = mode;
576 
577 	inode->i_ino = ino;
578 	inode->i_blksize = PAGE_SIZE;	/* This is the optimal IO size (for stat), not the fs block size */
579 	inode->i_blocks = 0;
580 	inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME_SEC;
581 	memset(ei->i_data, 0, sizeof(ei->i_data));
582 	ei->i_flags = EXT2_I(dir)->i_flags & ~EXT2_BTREE_FL;
583 	if (S_ISLNK(mode))
584 		ei->i_flags &= ~(EXT2_IMMUTABLE_FL|EXT2_APPEND_FL);
585 	/* dirsync is only applied to directories */
586 	if (!S_ISDIR(mode))
587 		ei->i_flags &= ~EXT2_DIRSYNC_FL;
588 	ei->i_faddr = 0;
589 	ei->i_frag_no = 0;
590 	ei->i_frag_size = 0;
591 	ei->i_file_acl = 0;
592 	ei->i_dir_acl = 0;
593 	ei->i_dtime = 0;
594 	ei->i_block_group = group;
595 	ei->i_next_alloc_block = 0;
596 	ei->i_next_alloc_goal = 0;
597 	ei->i_prealloc_block = 0;
598 	ei->i_prealloc_count = 0;
599 	ei->i_dir_start_lookup = 0;
600 	ei->i_state = EXT2_STATE_NEW;
601 	ext2_set_inode_flags(inode);
602 	spin_lock(&sbi->s_next_gen_lock);
603 	inode->i_generation = sbi->s_next_generation++;
604 	spin_unlock(&sbi->s_next_gen_lock);
605 	insert_inode_hash(inode);
606 
607 	if (DQUOT_ALLOC_INODE(inode)) {
608 		err = -EDQUOT;
609 		goto fail_drop;
610 	}
611 
612 	err = ext2_init_acl(inode, dir);
613 	if (err)
614 		goto fail_free_drop;
615 
616 	err = ext2_init_security(inode,dir);
617 	if (err)
618 		goto fail_free_drop;
619 
620 	mark_inode_dirty(inode);
621 	ext2_debug("allocating inode %lu\n", inode->i_ino);
622 	ext2_preread_inode(inode);
623 	return inode;
624 
625 fail_free_drop:
626 	DQUOT_FREE_INODE(inode);
627 
628 fail_drop:
629 	DQUOT_DROP(inode);
630 	inode->i_flags |= S_NOQUOTA;
631 	inode->i_nlink = 0;
632 	iput(inode);
633 	return ERR_PTR(err);
634 
635 fail:
636 	make_bad_inode(inode);
637 	iput(inode);
638 	return ERR_PTR(err);
639 }
640 
641 unsigned long ext2_count_free_inodes (struct super_block * sb)
642 {
643 	struct ext2_group_desc *desc;
644 	unsigned long desc_count = 0;
645 	int i;
646 
647 #ifdef EXT2FS_DEBUG
648 	struct ext2_super_block *es;
649 	unsigned long bitmap_count = 0;
650 	struct buffer_head *bitmap_bh = NULL;
651 
652 	lock_super (sb);
653 	es = EXT2_SB(sb)->s_es;
654 	for (i = 0; i < EXT2_SB(sb)->s_groups_count; i++) {
655 		unsigned x;
656 
657 		desc = ext2_get_group_desc (sb, i, NULL);
658 		if (!desc)
659 			continue;
660 		desc_count += le16_to_cpu(desc->bg_free_inodes_count);
661 		brelse(bitmap_bh);
662 		bitmap_bh = read_inode_bitmap(sb, i);
663 		if (!bitmap_bh)
664 			continue;
665 
666 		x = ext2_count_free(bitmap_bh, EXT2_INODES_PER_GROUP(sb) / 8);
667 		printk("group %d: stored = %d, counted = %u\n",
668 			i, le16_to_cpu(desc->bg_free_inodes_count), x);
669 		bitmap_count += x;
670 	}
671 	brelse(bitmap_bh);
672 	printk("ext2_count_free_inodes: stored = %lu, computed = %lu, %lu\n",
673 		percpu_counter_read(&EXT2_SB(sb)->s_freeinodes_counter),
674 		desc_count, bitmap_count);
675 	unlock_super(sb);
676 	return desc_count;
677 #else
678 	for (i = 0; i < EXT2_SB(sb)->s_groups_count; i++) {
679 		desc = ext2_get_group_desc (sb, i, NULL);
680 		if (!desc)
681 			continue;
682 		desc_count += le16_to_cpu(desc->bg_free_inodes_count);
683 	}
684 	return desc_count;
685 #endif
686 }
687 
688 /* Called at mount-time, super-block is locked */
689 unsigned long ext2_count_dirs (struct super_block * sb)
690 {
691 	unsigned long count = 0;
692 	int i;
693 
694 	for (i = 0; i < EXT2_SB(sb)->s_groups_count; i++) {
695 		struct ext2_group_desc *gdp = ext2_get_group_desc (sb, i, NULL);
696 		if (!gdp)
697 			continue;
698 		count += le16_to_cpu(gdp->bg_used_dirs_count);
699 	}
700 	return count;
701 }
702 
703