cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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ialloc.c (18720B)


      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 */
     46static struct buffer_head *
     47read_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));
     62error_out:
     63	return bh;
     64}
     65
     66static 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 */
    105void 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 */
    167static void ext2_preread_inode(struct inode *inode)
    168{
    169	unsigned long block_group;
    170	unsigned long offset;
    171	unsigned long block;
    172	struct ext2_group_desc * gdp;
    173
    174	block_group = (inode->i_ino - 1) / EXT2_INODES_PER_GROUP(inode->i_sb);
    175	gdp = ext2_get_group_desc(inode->i_sb, block_group, NULL);
    176	if (gdp == NULL)
    177		return;
    178
    179	/*
    180	 * Figure out the offset within the block group inode table
    181	 */
    182	offset = ((inode->i_ino - 1) % EXT2_INODES_PER_GROUP(inode->i_sb)) *
    183				EXT2_INODE_SIZE(inode->i_sb);
    184	block = le32_to_cpu(gdp->bg_inode_table) +
    185				(offset >> EXT2_BLOCK_SIZE_BITS(inode->i_sb));
    186	sb_breadahead(inode->i_sb, block);
    187}
    188
    189/*
    190 * There are two policies for allocating an inode.  If the new inode is
    191 * a directory, then a forward search is made for a block group with both
    192 * free space and a low directory-to-inode ratio; if that fails, then of
    193 * the groups with above-average free space, that group with the fewest
    194 * directories already is chosen.
    195 *
    196 * For other inodes, search forward from the parent directory\'s block
    197 * group to find a free inode.
    198 */
    199static int find_group_dir(struct super_block *sb, struct inode *parent)
    200{
    201	int ngroups = EXT2_SB(sb)->s_groups_count;
    202	int avefreei = ext2_count_free_inodes(sb) / ngroups;
    203	struct ext2_group_desc *desc, *best_desc = NULL;
    204	int group, best_group = -1;
    205
    206	for (group = 0; group < ngroups; group++) {
    207		desc = ext2_get_group_desc (sb, group, NULL);
    208		if (!desc || !desc->bg_free_inodes_count)
    209			continue;
    210		if (le16_to_cpu(desc->bg_free_inodes_count) < avefreei)
    211			continue;
    212		if (!best_desc || 
    213		    (le16_to_cpu(desc->bg_free_blocks_count) >
    214		     le16_to_cpu(best_desc->bg_free_blocks_count))) {
    215			best_group = group;
    216			best_desc = desc;
    217		}
    218	}
    219
    220	return best_group;
    221}
    222
    223/* 
    224 * Orlov's allocator for directories. 
    225 * 
    226 * We always try to spread first-level directories.
    227 *
    228 * If there are blockgroups with both free inodes and free blocks counts 
    229 * not worse than average we return one with smallest directory count. 
    230 * Otherwise we simply return a random group. 
    231 * 
    232 * For the rest rules look so: 
    233 * 
    234 * It's OK to put directory into a group unless 
    235 * it has too many directories already (max_dirs) or 
    236 * it has too few free inodes left (min_inodes) or 
    237 * it has too few free blocks left (min_blocks) or 
    238 * it's already running too large debt (max_debt). 
    239 * Parent's group is preferred, if it doesn't satisfy these 
    240 * conditions we search cyclically through the rest. If none 
    241 * of the groups look good we just look for a group with more 
    242 * free inodes than average (starting at parent's group). 
    243 * 
    244 * Debt is incremented each time we allocate a directory and decremented 
    245 * when we allocate an inode, within 0--255. 
    246 */ 
    247
    248#define INODE_COST 64
    249#define BLOCK_COST 256
    250
    251static int find_group_orlov(struct super_block *sb, struct inode *parent)
    252{
    253	int parent_group = EXT2_I(parent)->i_block_group;
    254	struct ext2_sb_info *sbi = EXT2_SB(sb);
    255	struct ext2_super_block *es = sbi->s_es;
    256	int ngroups = sbi->s_groups_count;
    257	int inodes_per_group = EXT2_INODES_PER_GROUP(sb);
    258	int freei;
    259	int avefreei;
    260	int free_blocks;
    261	int avefreeb;
    262	int blocks_per_dir;
    263	int ndirs;
    264	int max_debt, max_dirs, min_blocks, min_inodes;
    265	int group = -1, i;
    266	struct ext2_group_desc *desc;
    267
    268	freei = percpu_counter_read_positive(&sbi->s_freeinodes_counter);
    269	avefreei = freei / ngroups;
    270	free_blocks = percpu_counter_read_positive(&sbi->s_freeblocks_counter);
    271	avefreeb = free_blocks / ngroups;
    272	ndirs = percpu_counter_read_positive(&sbi->s_dirs_counter);
    273
    274	if ((parent == d_inode(sb->s_root)) ||
    275	    (EXT2_I(parent)->i_flags & EXT2_TOPDIR_FL)) {
    276		struct ext2_group_desc *best_desc = NULL;
    277		int best_ndir = inodes_per_group;
    278		int best_group = -1;
    279
    280		group = prandom_u32();
    281		parent_group = (unsigned)group % ngroups;
    282		for (i = 0; i < ngroups; i++) {
    283			group = (parent_group + i) % ngroups;
    284			desc = ext2_get_group_desc (sb, group, NULL);
    285			if (!desc || !desc->bg_free_inodes_count)
    286				continue;
    287			if (le16_to_cpu(desc->bg_used_dirs_count) >= best_ndir)
    288				continue;
    289			if (le16_to_cpu(desc->bg_free_inodes_count) < avefreei)
    290				continue;
    291			if (le16_to_cpu(desc->bg_free_blocks_count) < avefreeb)
    292				continue;
    293			best_group = group;
    294			best_ndir = le16_to_cpu(desc->bg_used_dirs_count);
    295			best_desc = desc;
    296		}
    297		if (best_group >= 0) {
    298			desc = best_desc;
    299			group = best_group;
    300			goto found;
    301		}
    302		goto fallback;
    303	}
    304
    305	if (ndirs == 0)
    306		ndirs = 1;	/* percpu_counters are approximate... */
    307
    308	blocks_per_dir = (le32_to_cpu(es->s_blocks_count)-free_blocks) / ndirs;
    309
    310	max_dirs = ndirs / ngroups + inodes_per_group / 16;
    311	min_inodes = avefreei - inodes_per_group / 4;
    312	min_blocks = avefreeb - EXT2_BLOCKS_PER_GROUP(sb) / 4;
    313
    314	max_debt = EXT2_BLOCKS_PER_GROUP(sb) / max(blocks_per_dir, BLOCK_COST);
    315	if (max_debt * INODE_COST > inodes_per_group)
    316		max_debt = inodes_per_group / INODE_COST;
    317	if (max_debt > 255)
    318		max_debt = 255;
    319	if (max_debt == 0)
    320		max_debt = 1;
    321
    322	for (i = 0; i < ngroups; i++) {
    323		group = (parent_group + i) % ngroups;
    324		desc = ext2_get_group_desc (sb, group, NULL);
    325		if (!desc || !desc->bg_free_inodes_count)
    326			continue;
    327		if (sbi->s_debts[group] >= max_debt)
    328			continue;
    329		if (le16_to_cpu(desc->bg_used_dirs_count) >= max_dirs)
    330			continue;
    331		if (le16_to_cpu(desc->bg_free_inodes_count) < min_inodes)
    332			continue;
    333		if (le16_to_cpu(desc->bg_free_blocks_count) < min_blocks)
    334			continue;
    335		goto found;
    336	}
    337
    338fallback:
    339	for (i = 0; i < ngroups; i++) {
    340		group = (parent_group + i) % ngroups;
    341		desc = ext2_get_group_desc (sb, group, NULL);
    342		if (!desc || !desc->bg_free_inodes_count)
    343			continue;
    344		if (le16_to_cpu(desc->bg_free_inodes_count) >= avefreei)
    345			goto found;
    346	}
    347
    348	if (avefreei) {
    349		/*
    350		 * The free-inodes counter is approximate, and for really small
    351		 * filesystems the above test can fail to find any blockgroups
    352		 */
    353		avefreei = 0;
    354		goto fallback;
    355	}
    356
    357	return -1;
    358
    359found:
    360	return group;
    361}
    362
    363static int find_group_other(struct super_block *sb, struct inode *parent)
    364{
    365	int parent_group = EXT2_I(parent)->i_block_group;
    366	int ngroups = EXT2_SB(sb)->s_groups_count;
    367	struct ext2_group_desc *desc;
    368	int group, i;
    369
    370	/*
    371	 * Try to place the inode in its parent directory
    372	 */
    373	group = parent_group;
    374	desc = ext2_get_group_desc (sb, group, NULL);
    375	if (desc && le16_to_cpu(desc->bg_free_inodes_count) &&
    376			le16_to_cpu(desc->bg_free_blocks_count))
    377		goto found;
    378
    379	/*
    380	 * We're going to place this inode in a different blockgroup from its
    381	 * parent.  We want to cause files in a common directory to all land in
    382	 * the same blockgroup.  But we want files which are in a different
    383	 * directory which shares a blockgroup with our parent to land in a
    384	 * different blockgroup.
    385	 *
    386	 * So add our directory's i_ino into the starting point for the hash.
    387	 */
    388	group = (group + parent->i_ino) % ngroups;
    389
    390	/*
    391	 * Use a quadratic hash to find a group with a free inode and some
    392	 * free blocks.
    393	 */
    394	for (i = 1; i < ngroups; i <<= 1) {
    395		group += i;
    396		if (group >= ngroups)
    397			group -= ngroups;
    398		desc = ext2_get_group_desc (sb, group, NULL);
    399		if (desc && le16_to_cpu(desc->bg_free_inodes_count) &&
    400				le16_to_cpu(desc->bg_free_blocks_count))
    401			goto found;
    402	}
    403
    404	/*
    405	 * That failed: try linear search for a free inode, even if that group
    406	 * has no free blocks.
    407	 */
    408	group = parent_group;
    409	for (i = 0; i < ngroups; i++) {
    410		if (++group >= ngroups)
    411			group = 0;
    412		desc = ext2_get_group_desc (sb, group, NULL);
    413		if (desc && le16_to_cpu(desc->bg_free_inodes_count))
    414			goto found;
    415	}
    416
    417	return -1;
    418
    419found:
    420	return group;
    421}
    422
    423struct inode *ext2_new_inode(struct inode *dir, umode_t mode,
    424			     const struct qstr *qstr)
    425{
    426	struct super_block *sb;
    427	struct buffer_head *bitmap_bh = NULL;
    428	struct buffer_head *bh2;
    429	int group, i;
    430	ino_t ino = 0;
    431	struct inode * inode;
    432	struct ext2_group_desc *gdp;
    433	struct ext2_super_block *es;
    434	struct ext2_inode_info *ei;
    435	struct ext2_sb_info *sbi;
    436	int err;
    437
    438	sb = dir->i_sb;
    439	inode = new_inode(sb);
    440	if (!inode)
    441		return ERR_PTR(-ENOMEM);
    442
    443	ei = EXT2_I(inode);
    444	sbi = EXT2_SB(sb);
    445	es = sbi->s_es;
    446	if (S_ISDIR(mode)) {
    447		if (test_opt(sb, OLDALLOC))
    448			group = find_group_dir(sb, dir);
    449		else
    450			group = find_group_orlov(sb, dir);
    451	} else 
    452		group = find_group_other(sb, dir);
    453
    454	if (group == -1) {
    455		err = -ENOSPC;
    456		goto fail;
    457	}
    458
    459	for (i = 0; i < sbi->s_groups_count; i++) {
    460		gdp = ext2_get_group_desc(sb, group, &bh2);
    461		if (!gdp) {
    462			if (++group == sbi->s_groups_count)
    463				group = 0;
    464			continue;
    465		}
    466		brelse(bitmap_bh);
    467		bitmap_bh = read_inode_bitmap(sb, group);
    468		if (!bitmap_bh) {
    469			err = -EIO;
    470			goto fail;
    471		}
    472		ino = 0;
    473
    474repeat_in_this_group:
    475		ino = ext2_find_next_zero_bit((unsigned long *)bitmap_bh->b_data,
    476					      EXT2_INODES_PER_GROUP(sb), ino);
    477		if (ino >= EXT2_INODES_PER_GROUP(sb)) {
    478			/*
    479			 * Rare race: find_group_xx() decided that there were
    480			 * free inodes in this group, but by the time we tried
    481			 * to allocate one, they're all gone.  This can also
    482			 * occur because the counters which find_group_orlov()
    483			 * uses are approximate.  So just go and search the
    484			 * next block group.
    485			 */
    486			if (++group == sbi->s_groups_count)
    487				group = 0;
    488			continue;
    489		}
    490		if (ext2_set_bit_atomic(sb_bgl_lock(sbi, group),
    491						ino, bitmap_bh->b_data)) {
    492			/* we lost this inode */
    493			if (++ino >= EXT2_INODES_PER_GROUP(sb)) {
    494				/* this group is exhausted, try next group */
    495				if (++group == sbi->s_groups_count)
    496					group = 0;
    497				continue;
    498			}
    499			/* try to find free inode in the same group */
    500			goto repeat_in_this_group;
    501		}
    502		goto got;
    503	}
    504
    505	/*
    506	 * Scanned all blockgroups.
    507	 */
    508	brelse(bitmap_bh);
    509	err = -ENOSPC;
    510	goto fail;
    511got:
    512	mark_buffer_dirty(bitmap_bh);
    513	if (sb->s_flags & SB_SYNCHRONOUS)
    514		sync_dirty_buffer(bitmap_bh);
    515	brelse(bitmap_bh);
    516
    517	ino += group * EXT2_INODES_PER_GROUP(sb) + 1;
    518	if (ino < EXT2_FIRST_INO(sb) || ino > le32_to_cpu(es->s_inodes_count)) {
    519		ext2_error (sb, "ext2_new_inode",
    520			    "reserved inode or inode > inodes count - "
    521			    "block_group = %d,inode=%lu", group,
    522			    (unsigned long) ino);
    523		err = -EIO;
    524		goto fail;
    525	}
    526
    527	percpu_counter_dec(&sbi->s_freeinodes_counter);
    528	if (S_ISDIR(mode))
    529		percpu_counter_inc(&sbi->s_dirs_counter);
    530
    531	spin_lock(sb_bgl_lock(sbi, group));
    532	le16_add_cpu(&gdp->bg_free_inodes_count, -1);
    533	if (S_ISDIR(mode)) {
    534		if (sbi->s_debts[group] < 255)
    535			sbi->s_debts[group]++;
    536		le16_add_cpu(&gdp->bg_used_dirs_count, 1);
    537	} else {
    538		if (sbi->s_debts[group])
    539			sbi->s_debts[group]--;
    540	}
    541	spin_unlock(sb_bgl_lock(sbi, group));
    542
    543	mark_buffer_dirty(bh2);
    544	if (test_opt(sb, GRPID)) {
    545		inode->i_mode = mode;
    546		inode->i_uid = current_fsuid();
    547		inode->i_gid = dir->i_gid;
    548	} else
    549		inode_init_owner(&init_user_ns, inode, dir, mode);
    550
    551	inode->i_ino = ino;
    552	inode->i_blocks = 0;
    553	inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode);
    554	memset(ei->i_data, 0, sizeof(ei->i_data));
    555	ei->i_flags =
    556		ext2_mask_flags(mode, EXT2_I(dir)->i_flags & EXT2_FL_INHERITED);
    557	ei->i_faddr = 0;
    558	ei->i_frag_no = 0;
    559	ei->i_frag_size = 0;
    560	ei->i_file_acl = 0;
    561	ei->i_dir_acl = 0;
    562	ei->i_dtime = 0;
    563	ei->i_block_alloc_info = NULL;
    564	ei->i_block_group = group;
    565	ei->i_dir_start_lookup = 0;
    566	ei->i_state = EXT2_STATE_NEW;
    567	ext2_set_inode_flags(inode);
    568	spin_lock(&sbi->s_next_gen_lock);
    569	inode->i_generation = sbi->s_next_generation++;
    570	spin_unlock(&sbi->s_next_gen_lock);
    571	if (insert_inode_locked(inode) < 0) {
    572		ext2_error(sb, "ext2_new_inode",
    573			   "inode number already in use - inode=%lu",
    574			   (unsigned long) ino);
    575		err = -EIO;
    576		goto fail;
    577	}
    578
    579	err = dquot_initialize(inode);
    580	if (err)
    581		goto fail_drop;
    582
    583	err = dquot_alloc_inode(inode);
    584	if (err)
    585		goto fail_drop;
    586
    587	err = ext2_init_acl(inode, dir);
    588	if (err)
    589		goto fail_free_drop;
    590
    591	err = ext2_init_security(inode, dir, qstr);
    592	if (err)
    593		goto fail_free_drop;
    594
    595	mark_inode_dirty(inode);
    596	ext2_debug("allocating inode %lu\n", inode->i_ino);
    597	ext2_preread_inode(inode);
    598	return inode;
    599
    600fail_free_drop:
    601	dquot_free_inode(inode);
    602
    603fail_drop:
    604	dquot_drop(inode);
    605	inode->i_flags |= S_NOQUOTA;
    606	clear_nlink(inode);
    607	discard_new_inode(inode);
    608	return ERR_PTR(err);
    609
    610fail:
    611	make_bad_inode(inode);
    612	iput(inode);
    613	return ERR_PTR(err);
    614}
    615
    616unsigned long ext2_count_free_inodes (struct super_block * sb)
    617{
    618	struct ext2_group_desc *desc;
    619	unsigned long desc_count = 0;
    620	int i;	
    621
    622#ifdef EXT2FS_DEBUG
    623	struct ext2_super_block *es;
    624	unsigned long bitmap_count = 0;
    625	struct buffer_head *bitmap_bh = NULL;
    626
    627	es = EXT2_SB(sb)->s_es;
    628	for (i = 0; i < EXT2_SB(sb)->s_groups_count; i++) {
    629		unsigned x;
    630
    631		desc = ext2_get_group_desc (sb, i, NULL);
    632		if (!desc)
    633			continue;
    634		desc_count += le16_to_cpu(desc->bg_free_inodes_count);
    635		brelse(bitmap_bh);
    636		bitmap_bh = read_inode_bitmap(sb, i);
    637		if (!bitmap_bh)
    638			continue;
    639
    640		x = ext2_count_free(bitmap_bh, EXT2_INODES_PER_GROUP(sb) / 8);
    641		printk("group %d: stored = %d, counted = %u\n",
    642			i, le16_to_cpu(desc->bg_free_inodes_count), x);
    643		bitmap_count += x;
    644	}
    645	brelse(bitmap_bh);
    646	printk("ext2_count_free_inodes: stored = %lu, computed = %lu, %lu\n",
    647		(unsigned long)
    648		percpu_counter_read(&EXT2_SB(sb)->s_freeinodes_counter),
    649		desc_count, bitmap_count);
    650	return desc_count;
    651#else
    652	for (i = 0; i < EXT2_SB(sb)->s_groups_count; i++) {
    653		desc = ext2_get_group_desc (sb, i, NULL);
    654		if (!desc)
    655			continue;
    656		desc_count += le16_to_cpu(desc->bg_free_inodes_count);
    657	}
    658	return desc_count;
    659#endif
    660}
    661
    662/* Called at mount-time, super-block is locked */
    663unsigned long ext2_count_dirs (struct super_block * sb)
    664{
    665	unsigned long count = 0;
    666	int i;
    667
    668	for (i = 0; i < EXT2_SB(sb)->s_groups_count; i++) {
    669		struct ext2_group_desc *gdp = ext2_get_group_desc (sb, i, NULL);
    670		if (!gdp)
    671			continue;
    672		count += le16_to_cpu(gdp->bg_used_dirs_count);
    673	}
    674	return count;
    675}
    676