xref: /linux/fs/ext2/ialloc.c (revision b7d74ea0fdaa8d641fe6f18507c5f0d21b652d53)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *  linux/fs/ext2/ialloc.c
4  *
5  * Copyright (C) 1992, 1993, 1994, 1995
6  * Remy Card (card@masi.ibp.fr)
7  * Laboratoire MASI - Institut Blaise Pascal
8  * Universite Pierre et Marie Curie (Paris VI)
9  *
10  *  BSD ufs-inspired inode and directory allocation by
11  *  Stephen Tweedie (sct@dcs.ed.ac.uk), 1993
12  *  Big-endian to little-endian byte-swapping/bitmaps by
13  *        David S. Miller (davem@caip.rutgers.edu), 1995
14  */
15 
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 *
read_inode_bitmap(struct super_block * sb,unsigned long block_group)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 
ext2_release_inode(struct super_block * sb,int group,int dir)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 	le16_add_cpu(&desc->bg_free_inodes_count, 1);
80 	if (dir)
81 		le16_add_cpu(&desc->bg_used_dirs_count, -1);
82 	spin_unlock(sb_bgl_lock(EXT2_SB(sb), group));
83 	percpu_counter_inc(&EXT2_SB(sb)->s_freeinodes_counter);
84 	if (dir)
85 		percpu_counter_dec(&EXT2_SB(sb)->s_dirs_counter);
86 	mark_buffer_dirty(bh);
87 }
88 
89 /*
90  * NOTE! When we get the inode, we're the only people
91  * that have access to it, and as such there are no
92  * race conditions we have to worry about. The inode
93  * is not on the hash-lists, and it cannot be reached
94  * through the filesystem because the directory entry
95  * has been deleted earlier.
96  *
97  * HOWEVER: we must make sure that we get no aliases,
98  * which means that we have to call "clear_inode()"
99  * _before_ we mark the inode not in use in the inode
100  * bitmaps. Otherwise a newly created file might use
101  * the same inode number (not actually the same pointer
102  * though), and then we'd have two inodes sharing the
103  * same inode number and space on the harddisk.
104  */
ext2_free_inode(struct inode * inode)105 void ext2_free_inode (struct inode * inode)
106 {
107 	struct super_block * sb = inode->i_sb;
108 	int is_directory;
109 	unsigned long ino;
110 	struct buffer_head *bitmap_bh;
111 	unsigned long block_group;
112 	unsigned long bit;
113 	struct ext2_super_block * es;
114 
115 	ino = inode->i_ino;
116 	ext2_debug ("freeing inode %lu\n", ino);
117 
118 	/*
119 	 * Note: we must free any quota before locking the superblock,
120 	 * as writing the quota to disk may need the lock as well.
121 	 */
122 	/* Quota is already initialized in iput() */
123 	dquot_free_inode(inode);
124 	dquot_drop(inode);
125 
126 	es = EXT2_SB(sb)->s_es;
127 	is_directory = S_ISDIR(inode->i_mode);
128 
129 	if (ino < EXT2_FIRST_INO(sb) ||
130 	    ino > le32_to_cpu(es->s_inodes_count)) {
131 		ext2_error (sb, "ext2_free_inode",
132 			    "reserved or nonexistent inode %lu", ino);
133 		return;
134 	}
135 	block_group = (ino - 1) / EXT2_INODES_PER_GROUP(sb);
136 	bit = (ino - 1) % EXT2_INODES_PER_GROUP(sb);
137 	bitmap_bh = read_inode_bitmap(sb, block_group);
138 	if (!bitmap_bh)
139 		return;
140 
141 	/* Ok, now we can actually update the inode bitmaps.. */
142 	if (!ext2_clear_bit_atomic(sb_bgl_lock(EXT2_SB(sb), block_group),
143 				bit, (void *) bitmap_bh->b_data))
144 		ext2_error (sb, "ext2_free_inode",
145 			      "bit already cleared for inode %lu", ino);
146 	else
147 		ext2_release_inode(sb, block_group, is_directory);
148 	mark_buffer_dirty(bitmap_bh);
149 	if (sb->s_flags & SB_SYNCHRONOUS)
150 		sync_dirty_buffer(bitmap_bh);
151 
152 	brelse(bitmap_bh);
153 }
154 
155 /*
156  * We perform asynchronous prereading of the new inode's inode block when
157  * we create the inode, in the expectation that the inode will be written
158  * back soon.  There are two reasons:
159  *
160  * - When creating a large number of files, the async prereads will be
161  *   nicely merged into large reads
162  * - When writing out a large number of inodes, we don't need to keep on
163  *   stalling the writes while we read the inode block.
164  *
165  * FIXME: ext2_get_group_desc() needs to be simplified.
166  */
ext2_preread_inode(struct inode * inode)167 static void ext2_preread_inode(struct inode *inode)
168 {
169 	unsigned long block_group;
170 	unsigned long offset;
171 	unsigned long block;
172 	unsigned int ino = inode->i_ino;
173 	struct ext2_group_desc * gdp;
174 
175 	block_group = (ino - 1) / EXT2_INODES_PER_GROUP(inode->i_sb);
176 	gdp = ext2_get_group_desc(inode->i_sb, block_group, NULL);
177 	if (gdp == NULL)
178 		return;
179 
180 	/*
181 	 * Figure out the offset within the block group inode table
182 	 */
183 	offset = ((ino - 1) % EXT2_INODES_PER_GROUP(inode->i_sb)) *
184 				EXT2_INODE_SIZE(inode->i_sb);
185 	block = le32_to_cpu(gdp->bg_inode_table) +
186 				(offset >> EXT2_BLOCK_SIZE_BITS(inode->i_sb));
187 	sb_breadahead(inode->i_sb, block);
188 }
189 
190 /*
191  * There are two policies for allocating an inode.  If the new inode is
192  * a directory, then a forward search is made for a block group with both
193  * free space and a low directory-to-inode ratio; if that fails, then of
194  * the groups with above-average free space, that group with the fewest
195  * directories already is chosen.
196  *
197  * For other inodes, search forward from the parent directory\'s block
198  * group to find a free inode.
199  */
find_group_dir(struct super_block * sb,struct inode * parent)200 static int find_group_dir(struct super_block *sb, struct inode *parent)
201 {
202 	int ngroups = EXT2_SB(sb)->s_groups_count;
203 	int avefreei = ext2_count_free_inodes(sb) / ngroups;
204 	struct ext2_group_desc *desc, *best_desc = NULL;
205 	int group, best_group = -1;
206 
207 	for (group = 0; group < ngroups; group++) {
208 		desc = ext2_get_group_desc (sb, group, NULL);
209 		if (!desc || !desc->bg_free_inodes_count)
210 			continue;
211 		if (le16_to_cpu(desc->bg_free_inodes_count) < avefreei)
212 			continue;
213 		if (!best_desc ||
214 		    (le16_to_cpu(desc->bg_free_blocks_count) >
215 		     le16_to_cpu(best_desc->bg_free_blocks_count))) {
216 			best_group = group;
217 			best_desc = desc;
218 		}
219 	}
220 
221 	return best_group;
222 }
223 
224 /*
225  * Orlov's allocator for directories.
226  *
227  * We always try to spread first-level directories.
228  *
229  * If there are blockgroups with both free inodes and free blocks counts
230  * not worse than average we return one with smallest directory count.
231  * Otherwise we simply return a random group.
232  *
233  * For the rest rules look so:
234  *
235  * It's OK to put directory into a group unless
236  * it has too many directories already (max_dirs) or
237  * it has too few free inodes left (min_inodes) or
238  * it has too few free blocks left (min_blocks) or
239  * it's already running too large debt (max_debt).
240  * Parent's group is preferred, if it doesn't satisfy these
241  * conditions we search cyclically through the rest. If none
242  * of the groups look good we just look for a group with more
243  * free inodes than average (starting at parent's group).
244  *
245  * Debt is incremented each time we allocate a directory and decremented
246  * when we allocate an inode, within 0--255.
247  */
248 
249 #define INODE_COST 64
250 #define BLOCK_COST 256
251 
find_group_orlov(struct super_block * sb,struct inode * parent)252 static int find_group_orlov(struct super_block *sb, struct inode *parent)
253 {
254 	int parent_group = EXT2_I(parent)->i_block_group;
255 	struct ext2_sb_info *sbi = EXT2_SB(sb);
256 	struct ext2_super_block *es = sbi->s_es;
257 	int ngroups = sbi->s_groups_count;
258 	int inodes_per_group = EXT2_INODES_PER_GROUP(sb);
259 	int freei;
260 	int avefreei;
261 	int free_blocks;
262 	int avefreeb;
263 	int blocks_per_dir;
264 	int ndirs;
265 	int max_debt, max_dirs, min_blocks, min_inodes;
266 	int group = -1, i;
267 	struct ext2_group_desc *desc;
268 
269 	freei = percpu_counter_read_positive(&sbi->s_freeinodes_counter);
270 	avefreei = freei / ngroups;
271 	free_blocks = percpu_counter_read_positive(&sbi->s_freeblocks_counter);
272 	avefreeb = free_blocks / ngroups;
273 	ndirs = percpu_counter_read_positive(&sbi->s_dirs_counter);
274 
275 	if ((parent == d_inode(sb->s_root)) ||
276 	    (EXT2_I(parent)->i_flags & EXT2_TOPDIR_FL)) {
277 		int best_ndir = inodes_per_group;
278 		int best_group = -1;
279 
280 		parent_group = get_random_u32_below(ngroups);
281 		for (i = 0; i < ngroups; i++) {
282 			group = (parent_group + i) % ngroups;
283 			desc = ext2_get_group_desc (sb, group, NULL);
284 			if (!desc || !desc->bg_free_inodes_count)
285 				continue;
286 			if (le16_to_cpu(desc->bg_used_dirs_count) >= best_ndir)
287 				continue;
288 			if (le16_to_cpu(desc->bg_free_inodes_count) < avefreei)
289 				continue;
290 			if (le16_to_cpu(desc->bg_free_blocks_count) < avefreeb)
291 				continue;
292 			best_group = group;
293 			best_ndir = le16_to_cpu(desc->bg_used_dirs_count);
294 		}
295 		if (best_group >= 0) {
296 			group = best_group;
297 			goto found;
298 		}
299 		goto fallback;
300 	}
301 
302 	if (ndirs == 0)
303 		ndirs = 1;	/* percpu_counters are approximate... */
304 
305 	blocks_per_dir = (le32_to_cpu(es->s_blocks_count)-free_blocks) / ndirs;
306 
307 	max_dirs = ndirs / ngroups + inodes_per_group / 16;
308 	min_inodes = avefreei - inodes_per_group / 4;
309 	min_blocks = avefreeb - EXT2_BLOCKS_PER_GROUP(sb) / 4;
310 
311 	max_debt = EXT2_BLOCKS_PER_GROUP(sb) / max(blocks_per_dir, BLOCK_COST);
312 	if (max_debt * INODE_COST > inodes_per_group)
313 		max_debt = inodes_per_group / INODE_COST;
314 	if (max_debt > 255)
315 		max_debt = 255;
316 	if (max_debt == 0)
317 		max_debt = 1;
318 
319 	for (i = 0; i < ngroups; i++) {
320 		group = (parent_group + i) % ngroups;
321 		desc = ext2_get_group_desc (sb, group, NULL);
322 		if (!desc || !desc->bg_free_inodes_count)
323 			continue;
324 		if (sbi->s_debts[group] >= max_debt)
325 			continue;
326 		if (le16_to_cpu(desc->bg_used_dirs_count) >= max_dirs)
327 			continue;
328 		if (le16_to_cpu(desc->bg_free_inodes_count) < min_inodes)
329 			continue;
330 		if (le16_to_cpu(desc->bg_free_blocks_count) < min_blocks)
331 			continue;
332 		goto found;
333 	}
334 
335 fallback:
336 	for (i = 0; i < ngroups; i++) {
337 		group = (parent_group + i) % ngroups;
338 		desc = ext2_get_group_desc (sb, group, NULL);
339 		if (!desc || !desc->bg_free_inodes_count)
340 			continue;
341 		if (le16_to_cpu(desc->bg_free_inodes_count) >= avefreei)
342 			goto found;
343 	}
344 
345 	if (avefreei) {
346 		/*
347 		 * The free-inodes counter is approximate, and for really small
348 		 * filesystems the above test can fail to find any blockgroups
349 		 */
350 		avefreei = 0;
351 		goto fallback;
352 	}
353 
354 	return -1;
355 
356 found:
357 	return group;
358 }
359 
find_group_other(struct super_block * sb,struct inode * parent)360 static int find_group_other(struct super_block *sb, struct inode *parent)
361 {
362 	int parent_group = EXT2_I(parent)->i_block_group;
363 	int ngroups = EXT2_SB(sb)->s_groups_count;
364 	struct ext2_group_desc *desc;
365 	int group, i;
366 
367 	/*
368 	 * Try to place the inode in its parent directory
369 	 */
370 	group = parent_group;
371 	desc = ext2_get_group_desc (sb, group, NULL);
372 	if (desc && le16_to_cpu(desc->bg_free_inodes_count) &&
373 			le16_to_cpu(desc->bg_free_blocks_count))
374 		goto found;
375 
376 	/*
377 	 * We're going to place this inode in a different blockgroup from its
378 	 * parent.  We want to cause files in a common directory to all land in
379 	 * the same blockgroup.  But we want files which are in a different
380 	 * directory which shares a blockgroup with our parent to land in a
381 	 * different blockgroup.
382 	 *
383 	 * So add our directory's i_ino into the starting point for the hash.
384 	 */
385 	group = (group + (unsigned int)parent->i_ino) % ngroups;
386 
387 	/*
388 	 * Use a quadratic hash to find a group with a free inode and some
389 	 * free blocks.
390 	 */
391 	for (i = 1; i < ngroups; i <<= 1) {
392 		group += i;
393 		if (group >= ngroups)
394 			group -= ngroups;
395 		desc = ext2_get_group_desc (sb, group, NULL);
396 		if (desc && le16_to_cpu(desc->bg_free_inodes_count) &&
397 				le16_to_cpu(desc->bg_free_blocks_count))
398 			goto found;
399 	}
400 
401 	/*
402 	 * That failed: try linear search for a free inode, even if that group
403 	 * has no free blocks.
404 	 */
405 	group = parent_group;
406 	for (i = 0; i < ngroups; i++) {
407 		if (++group >= ngroups)
408 			group = 0;
409 		desc = ext2_get_group_desc (sb, group, NULL);
410 		if (desc && le16_to_cpu(desc->bg_free_inodes_count))
411 			goto found;
412 	}
413 
414 	return -1;
415 
416 found:
417 	return group;
418 }
419 
ext2_new_inode(struct inode * dir,umode_t mode,const struct qstr * qstr)420 struct inode *ext2_new_inode(struct inode *dir, umode_t mode,
421 			     const struct qstr *qstr)
422 {
423 	struct super_block *sb;
424 	struct buffer_head *bitmap_bh = NULL;
425 	struct buffer_head *bh2;
426 	int group, i;
427 	ino_t ino = 0;
428 	struct inode * inode;
429 	struct ext2_group_desc *gdp;
430 	struct ext2_super_block *es;
431 	struct ext2_inode_info *ei;
432 	struct ext2_sb_info *sbi;
433 	int err;
434 
435 	sb = dir->i_sb;
436 	inode = new_inode(sb);
437 	if (!inode)
438 		return ERR_PTR(-ENOMEM);
439 
440 	ei = EXT2_I(inode);
441 	sbi = EXT2_SB(sb);
442 	es = sbi->s_es;
443 	if (S_ISDIR(mode)) {
444 		if (test_opt(sb, OLDALLOC))
445 			group = find_group_dir(sb, dir);
446 		else
447 			group = find_group_orlov(sb, dir);
448 	} else
449 		group = find_group_other(sb, dir);
450 
451 	if (group == -1) {
452 		err = -ENOSPC;
453 		goto fail;
454 	}
455 
456 	for (i = 0; i < sbi->s_groups_count; i++) {
457 		gdp = ext2_get_group_desc(sb, group, &bh2);
458 		if (!gdp) {
459 			if (++group == sbi->s_groups_count)
460 				group = 0;
461 			continue;
462 		}
463 		brelse(bitmap_bh);
464 		bitmap_bh = read_inode_bitmap(sb, group);
465 		if (!bitmap_bh) {
466 			err = -EIO;
467 			goto fail;
468 		}
469 		ino = 0;
470 
471 repeat_in_this_group:
472 		ino = ext2_find_next_zero_bit((unsigned long *)bitmap_bh->b_data,
473 					      EXT2_INODES_PER_GROUP(sb), ino);
474 		if (ino >= EXT2_INODES_PER_GROUP(sb)) {
475 			/*
476 			 * Rare race: find_group_xx() decided that there were
477 			 * free inodes in this group, but by the time we tried
478 			 * to allocate one, they're all gone.  This can also
479 			 * occur because the counters which find_group_orlov()
480 			 * uses are approximate.  So just go and search the
481 			 * next block group.
482 			 */
483 			if (++group == sbi->s_groups_count)
484 				group = 0;
485 			continue;
486 		}
487 		if (ext2_set_bit_atomic(sb_bgl_lock(sbi, group),
488 						ino, bitmap_bh->b_data)) {
489 			/* we lost this inode */
490 			if (++ino >= EXT2_INODES_PER_GROUP(sb)) {
491 				/* this group is exhausted, try next group */
492 				if (++group == sbi->s_groups_count)
493 					group = 0;
494 				continue;
495 			}
496 			/* try to find free inode in the same group */
497 			goto repeat_in_this_group;
498 		}
499 		goto got;
500 	}
501 
502 	/*
503 	 * Scanned all blockgroups.
504 	 */
505 	brelse(bitmap_bh);
506 	err = -ENOSPC;
507 	goto fail;
508 got:
509 	mark_buffer_dirty(bitmap_bh);
510 	if (sb->s_flags & SB_SYNCHRONOUS)
511 		sync_dirty_buffer(bitmap_bh);
512 	brelse(bitmap_bh);
513 
514 	ino += group * EXT2_INODES_PER_GROUP(sb) + 1;
515 	if (ino < EXT2_FIRST_INO(sb) || ino > le32_to_cpu(es->s_inodes_count)) {
516 		ext2_error (sb, "ext2_new_inode",
517 			    "reserved inode or inode > inodes count - "
518 			    "block_group = %d,inode=%lu", group,
519 			    (unsigned long) ino);
520 		err = -EIO;
521 		goto fail;
522 	}
523 
524 	percpu_counter_dec(&sbi->s_freeinodes_counter);
525 	if (S_ISDIR(mode))
526 		percpu_counter_inc(&sbi->s_dirs_counter);
527 
528 	spin_lock(sb_bgl_lock(sbi, group));
529 	le16_add_cpu(&gdp->bg_free_inodes_count, -1);
530 	if (S_ISDIR(mode)) {
531 		if (sbi->s_debts[group] < 255)
532 			sbi->s_debts[group]++;
533 		le16_add_cpu(&gdp->bg_used_dirs_count, 1);
534 	} else {
535 		if (sbi->s_debts[group])
536 			sbi->s_debts[group]--;
537 	}
538 	spin_unlock(sb_bgl_lock(sbi, group));
539 
540 	mark_buffer_dirty(bh2);
541 	if (test_opt(sb, GRPID)) {
542 		inode->i_mode = mode;
543 		inode->i_uid = current_fsuid();
544 		inode->i_gid = dir->i_gid;
545 	} else
546 		inode_init_owner(&nop_mnt_idmap, inode, dir, mode);
547 
548 	inode->i_ino = ino;
549 	inode->i_blocks = 0;
550 	simple_inode_init_ts(inode);
551 	memset(ei->i_data, 0, sizeof(ei->i_data));
552 	ei->i_flags =
553 		ext2_mask_flags(mode, EXT2_I(dir)->i_flags & EXT2_FL_INHERITED);
554 	ei->i_faddr = 0;
555 	ei->i_frag_no = 0;
556 	ei->i_frag_size = 0;
557 	ei->i_file_acl = 0;
558 	ei->i_dir_acl = 0;
559 	ei->i_dtime = 0;
560 	ei->i_block_alloc_info = NULL;
561 	ei->i_block_group = group;
562 	ei->i_dir_start_lookup = 0;
563 	ei->i_state = EXT2_STATE_NEW;
564 	ext2_set_inode_flags(inode);
565 	spin_lock(&sbi->s_next_gen_lock);
566 	inode->i_generation = sbi->s_next_generation++;
567 	spin_unlock(&sbi->s_next_gen_lock);
568 	if (insert_inode_locked(inode) < 0) {
569 		ext2_error(sb, "ext2_new_inode",
570 			   "inode number already in use - inode=%lu",
571 			   (unsigned long) ino);
572 		err = -EIO;
573 		goto fail;
574 	}
575 
576 	err = dquot_initialize(inode);
577 	if (err)
578 		goto fail_drop;
579 
580 	err = dquot_alloc_inode(inode);
581 	if (err)
582 		goto fail_drop;
583 
584 	err = ext2_init_acl(inode, dir);
585 	if (err)
586 		goto fail_free_drop;
587 
588 	err = ext2_init_security(inode, dir, qstr);
589 	if (err)
590 		goto fail_free_drop;
591 
592 	mark_inode_dirty(inode);
593 	ext2_debug("allocating inode %llu\n", inode->i_ino);
594 	ext2_preread_inode(inode);
595 	return inode;
596 
597 fail_free_drop:
598 	dquot_free_inode(inode);
599 
600 fail_drop:
601 	dquot_drop(inode);
602 	inode->i_flags |= S_NOQUOTA;
603 	clear_nlink(inode);
604 	discard_new_inode(inode);
605 	return ERR_PTR(err);
606 
607 fail:
608 	make_bad_inode(inode);
609 	iput(inode);
610 	return ERR_PTR(err);
611 }
612 
ext2_count_free_inodes(struct super_block * sb)613 unsigned long ext2_count_free_inodes (struct super_block * sb)
614 {
615 	struct ext2_group_desc *desc;
616 	unsigned long desc_count = 0;
617 	int i;
618 
619 #ifdef EXT2FS_DEBUG
620 	struct ext2_super_block *es;
621 	unsigned long bitmap_count = 0;
622 	struct buffer_head *bitmap_bh = NULL;
623 
624 	es = EXT2_SB(sb)->s_es;
625 	for (i = 0; i < EXT2_SB(sb)->s_groups_count; i++) {
626 		unsigned x;
627 
628 		desc = ext2_get_group_desc (sb, i, NULL);
629 		if (!desc)
630 			continue;
631 		desc_count += le16_to_cpu(desc->bg_free_inodes_count);
632 		brelse(bitmap_bh);
633 		bitmap_bh = read_inode_bitmap(sb, i);
634 		if (!bitmap_bh)
635 			continue;
636 
637 		x = ext2_count_free(bitmap_bh, EXT2_INODES_PER_GROUP(sb) / 8);
638 		printk("group %d: stored = %d, counted = %u\n",
639 			i, le16_to_cpu(desc->bg_free_inodes_count), x);
640 		bitmap_count += x;
641 	}
642 	brelse(bitmap_bh);
643 	printk("ext2_count_free_inodes: stored = %lu, computed = %lu, %lu\n",
644 		(unsigned long)
645 		percpu_counter_read(&EXT2_SB(sb)->s_freeinodes_counter),
646 		desc_count, bitmap_count);
647 	return desc_count;
648 #else
649 	for (i = 0; i < EXT2_SB(sb)->s_groups_count; i++) {
650 		desc = ext2_get_group_desc (sb, i, NULL);
651 		if (!desc)
652 			continue;
653 		desc_count += le16_to_cpu(desc->bg_free_inodes_count);
654 	}
655 	return desc_count;
656 #endif
657 }
658 
659 /* Called at mount-time, super-block is locked */
ext2_count_dirs(struct super_block * sb)660 unsigned long ext2_count_dirs (struct super_block * sb)
661 {
662 	unsigned long count = 0;
663 	int i;
664 
665 	for (i = 0; i < EXT2_SB(sb)->s_groups_count; i++) {
666 		struct ext2_group_desc *gdp = ext2_get_group_desc (sb, i, NULL);
667 		if (!gdp)
668 			continue;
669 		count += le16_to_cpu(gdp->bg_used_dirs_count);
670 	}
671 	return count;
672 }
673 
674