/*
* linux/fs/ext2/balloc.c
*
* Copyright (C) 1992, 1993, 1994, 1995
* Remy Card (card@masi.ibp.fr)
* Laboratoire MASI - Institut Blaise Pascal
* Universite Pierre et Marie Curie (Paris VI)
*
* Enhanced block allocation by Stephen Tweedie (sct@dcs.ed.ac.uk), 1993
* Big-endian to little-endian byte-swapping/bitmaps by
* David S. Miller (davem@caip.rutgers.edu), 1995
*/
#include <linux/config.h>
#include <linux/fs.h>
#include <linux/ext2_fs.h>
#include <linux/locks.h>
#include <linux/quotaops.h>
/*
* balloc.c contains the blocks allocation and deallocation routines
*/
/*
* The free blocks are managed by bitmaps. A file system contains several
* blocks groups. Each group contains 1 bitmap block for blocks, 1 bitmap
* block for inodes, N blocks for the inode table and data blocks.
*
* The file system contains group descriptors which are located after the
* super block. Each descriptor contains the number of the bitmap block and
* the free blocks count in the block. The descriptors are loaded in memory
* when a file system is mounted (see ext2_read_super).
*/
#define in_range(b, first, len) ((b) >= (first) && (b) <= (first) + (len) - 1)
38 struct ext2_group_desc * ext2_get_group_desc(struct super_block * sb,
unsigned int block_group,
struct buffer_head ** bh)
{
unsigned long group_desc;
unsigned long desc;
struct ext2_group_desc * gdp;
46 if (block_group >= sb->u.ext2_sb.s_groups_count) {
ext2_error (sb, "ext2_get_group_desc",
"block_group >= groups_count - "
"block_group = %d, groups_count = %lu",
block_group, sb->u.ext2_sb.s_groups_count);
52 return NULL;
}
group_desc = block_group / EXT2_DESC_PER_BLOCK(sb);
desc = block_group % EXT2_DESC_PER_BLOCK(sb);
57 if (!sb->u.ext2_sb.s_group_desc[group_desc]) {
ext2_error (sb, "ext2_get_group_desc",
"Group descriptor not loaded - "
"block_group = %d, group_desc = %lu, desc = %lu",
block_group, group_desc, desc);
62 return NULL;
}
gdp = (struct ext2_group_desc *)
sb->u.ext2_sb.s_group_desc[group_desc]->b_data;
67 if (bh)
*bh = sb->u.ext2_sb.s_group_desc[group_desc];
69 return gdp + desc;
}
/*
* Read the bitmap for a given block_group, reading into the specified
* slot in the superblock's bitmap cache.
*
* Return >=0 on success or a -ve error code.
*/
79 static int read_block_bitmap (struct super_block * sb,
unsigned int block_group,
unsigned long bitmap_nr)
{
struct ext2_group_desc * gdp;
struct buffer_head * bh = NULL;
int retval = -EIO;
gdp = ext2_get_group_desc (sb, block_group, NULL);
88 if (!gdp)
89 goto error_out;
retval = 0;
bh = bread (sb->s_dev, le32_to_cpu(gdp->bg_block_bitmap), sb->s_blocksize);
92 if (!bh) {
ext2_error (sb, "read_block_bitmap",
"Cannot read block bitmap - "
"block_group = %d, block_bitmap = %lu",
block_group, (unsigned long) gdp->bg_block_bitmap);
retval = -EIO;
}
/*
* On IO error, just leave a zero in the superblock's block pointer for
* this group. The IO will be retried next time.
*/
error_out:
sb->u.ext2_sb.s_block_bitmap_number[bitmap_nr] = block_group;
sb->u.ext2_sb.s_block_bitmap[bitmap_nr] = bh;
106 return retval;
}
/*
* load_block_bitmap loads the block bitmap for a blocks group
*
* It maintains a cache for the last bitmaps loaded. This cache is managed
* with a LRU algorithm.
*
* Notes:
* 1/ There is one cache per mounted file system.
* 2/ If the file system contains less than EXT2_MAX_GROUP_LOADED groups,
* this function reads the bitmap without maintaining a LRU cache.
*
* Return the slot used to store the bitmap, or a -ve error code.
*/
122 static int __load_block_bitmap (struct super_block * sb,
unsigned int block_group)
{
int i, j, retval = 0;
unsigned long block_bitmap_number;
struct buffer_head * block_bitmap;
129 if (block_group >= sb->u.ext2_sb.s_groups_count)
ext2_panic (sb, "load_block_bitmap",
"block_group >= groups_count - "
"block_group = %d, groups_count = %lu",
block_group, sb->u.ext2_sb.s_groups_count);
135 if (sb->u.ext2_sb.s_groups_count <= EXT2_MAX_GROUP_LOADED) {
136 if (sb->u.ext2_sb.s_block_bitmap[block_group]) {
if (sb->u.ext2_sb.s_block_bitmap_number[block_group] ==
138 block_group)
139 return block_group;
ext2_error (sb, "__load_block_bitmap",
"block_group != block_bitmap_number");
}
retval = read_block_bitmap (sb, block_group, block_group);
144 if (retval < 0)
145 return retval;
146 return block_group;
}
for (i = 0; i < sb->u.ext2_sb.s_loaded_block_bitmaps &&
150 sb->u.ext2_sb.s_block_bitmap_number[i] != block_group; i++)
;
if (i < sb->u.ext2_sb.s_loaded_block_bitmaps &&
153 sb->u.ext2_sb.s_block_bitmap_number[i] == block_group) {
block_bitmap_number = sb->u.ext2_sb.s_block_bitmap_number[i];
block_bitmap = sb->u.ext2_sb.s_block_bitmap[i];
156 for (j = i; j > 0; j--) {
sb->u.ext2_sb.s_block_bitmap_number[j] =
sb->u.ext2_sb.s_block_bitmap_number[j - 1];
sb->u.ext2_sb.s_block_bitmap[j] =
sb->u.ext2_sb.s_block_bitmap[j - 1];
}
sb->u.ext2_sb.s_block_bitmap_number[0] = block_bitmap_number;
sb->u.ext2_sb.s_block_bitmap[0] = block_bitmap;
/*
* There's still one special case here --- if block_bitmap == 0
* then our last attempt to read the bitmap failed and we have
* just ended up caching that failure. Try again to read it.
*/
170 if (!block_bitmap)
retval = read_block_bitmap (sb, block_group, 0);
172 } else {
173 if (sb->u.ext2_sb.s_loaded_block_bitmaps < EXT2_MAX_GROUP_LOADED)
sb->u.ext2_sb.s_loaded_block_bitmaps++;
175 else
brelse (sb->u.ext2_sb.s_block_bitmap[EXT2_MAX_GROUP_LOADED - 1]);
177 for (j = sb->u.ext2_sb.s_loaded_block_bitmaps - 1; j > 0; j--) {
sb->u.ext2_sb.s_block_bitmap_number[j] =
sb->u.ext2_sb.s_block_bitmap_number[j - 1];
sb->u.ext2_sb.s_block_bitmap[j] =
sb->u.ext2_sb.s_block_bitmap[j - 1];
}
retval = read_block_bitmap (sb, block_group, 0);
}
185 return retval;
}
/*
* Load the block bitmap for a given block group. First of all do a couple
* of fast lookups for common cases and then pass the request onto the guts
* of the bitmap loader.
*
* Return the slot number of the group in the superblock bitmap cache's on
* success, or a -ve error code.
*
* There is still one inconsistency here --- if the number of groups in this
* filesystems is <= EXT2_MAX_GROUP_LOADED, then we have no way of
* differentiating between a group for which we have never performed a bitmap
* IO request, and a group for which the last bitmap read request failed.
*/
201 static inline int load_block_bitmap (struct super_block * sb,
unsigned int block_group)
{
int slot;
/*
* Do the lookup for the slot. First of all, check if we're asking
* for the same slot as last time, and did we succeed that last time?
*/
if (sb->u.ext2_sb.s_loaded_block_bitmaps > 0 &&
sb->u.ext2_sb.s_block_bitmap_number[0] == block_group &&
212 sb->u.ext2_sb.s_block_bitmap[0]) {
213 return 0;
}
/*
* Or can we do a fast lookup based on a loaded group on a filesystem
* small enough to be mapped directly into the superblock?
*/
else if (sb->u.ext2_sb.s_groups_count <= EXT2_MAX_GROUP_LOADED &&
sb->u.ext2_sb.s_block_bitmap_number[block_group] == block_group &&
221 sb->u.ext2_sb.s_block_bitmap[block_group]) {
slot = block_group;
}
/*
* If not, then do a full lookup for this block group.
*/
227 else {
slot = __load_block_bitmap (sb, block_group);
}
/*
* <0 means we just got an error
*/
234 if (slot < 0)
235 return slot;
/*
* If it's a valid slot, we may still have cached a previous IO error,
* in which case the bh in the superblock cache will be zero.
*/
241 if (!sb->u.ext2_sb.s_block_bitmap[slot])
242 return -EIO;
/*
* Must have been read in OK to get this far.
*/
247 return slot;
}
250 void ext2_free_blocks (const struct inode * inode, unsigned long block,
unsigned long count)
{
struct buffer_head * bh;
struct buffer_head * bh2;
unsigned long block_group;
unsigned long bit;
unsigned long i;
int bitmap_nr;
unsigned long overflow;
struct super_block * sb;
struct ext2_group_desc * gdp;
struct ext2_super_block * es;
sb = inode->i_sb;
265 if (!sb) {
printk ("ext2_free_blocks: nonexistent device");
267 return;
}
lock_super (sb);
es = sb->u.ext2_sb.s_es;
if (block < le32_to_cpu(es->s_first_data_block) ||
272 (block + count) > le32_to_cpu(es->s_blocks_count)) {
ext2_error (sb, "ext2_free_blocks",
"Freeing blocks not in datazone - "
"block = %lu, count = %lu", block, count);
276 goto error_return;
}
ext2_debug ("freeing block %lu\n", block);
do_more:
overflow = 0;
block_group = (block - le32_to_cpu(es->s_first_data_block)) /
EXT2_BLOCKS_PER_GROUP(sb);
bit = (block - le32_to_cpu(es->s_first_data_block)) %
EXT2_BLOCKS_PER_GROUP(sb);
/*
* Check to see if we are freeing blocks across a group
* boundary.
*/
291 if (bit + count > EXT2_BLOCKS_PER_GROUP(sb)) {
overflow = bit + count - EXT2_BLOCKS_PER_GROUP(sb);
count -= overflow;
}
bitmap_nr = load_block_bitmap (sb, block_group);
296 if (bitmap_nr < 0)
297 goto error_return;
bh = sb->u.ext2_sb.s_block_bitmap[bitmap_nr];
gdp = ext2_get_group_desc (sb, block_group, &bh2);
301 if (!gdp)
302 goto error_return;
if (in_range (le32_to_cpu(gdp->bg_block_bitmap), block, count) ||
in_range (le32_to_cpu(gdp->bg_inode_bitmap), block, count) ||
in_range (block, le32_to_cpu(gdp->bg_inode_table),
sb->u.ext2_sb.s_itb_per_group) ||
in_range (block + count - 1, le32_to_cpu(gdp->bg_inode_table),
309 sb->u.ext2_sb.s_itb_per_group))
ext2_error (sb, "ext2_free_blocks",
"Freeing blocks in system zones - "
"Block = %lu, count = %lu",
block, count);
315 for (i = 0; i < count; i++) {
316 if (!ext2_clear_bit (bit + i, bh->b_data))
ext2_error (sb, "ext2_free_blocks",
"bit already cleared for block %lu",
block);
320 else {
321 DQUOT_FREE_BLOCK(sb, inode, 1);
gdp->bg_free_blocks_count =
cpu_to_le16(le16_to_cpu(gdp->bg_free_blocks_count)+1);
es->s_free_blocks_count =
cpu_to_le32(le32_to_cpu(es->s_free_blocks_count)+1);
}
}
mark_buffer_dirty(bh2);
mark_buffer_dirty(sb->u.ext2_sb.s_sbh);
mark_buffer_dirty(bh);
333 if (sb->s_flags & MS_SYNCHRONOUS) {
ll_rw_block (WRITE, 1, &bh);
wait_on_buffer (bh);
}
337 if (overflow) {
block += count;
count = overflow;
340 goto do_more;
}
sb->s_dirt = 1;
error_return:
unlock_super (sb);
345 return;
}
/*
* ext2_new_block uses a goal block to assist allocation. If the goal is
* free, or there is a free block within 32 blocks of the goal, that block
* is allocated. Otherwise a forward search is made for a free block; within
* each block group the search first looks for an entire free byte in the block
* bitmap, and then for any free bit if that fails.
*/
355 int ext2_new_block (const struct inode * inode, unsigned long goal,
u32 * prealloc_count, u32 * prealloc_block, int * err)
{
struct buffer_head * bh;
struct buffer_head * bh2;
char * p, * r;
int i, j, k, tmp;
int bitmap_nr;
struct super_block * sb;
struct ext2_group_desc * gdp;
struct ext2_super_block * es;
#ifdef EXT2FS_DEBUG
static int goal_hits = 0, goal_attempts = 0;
#endif
*err = -ENOSPC;
sb = inode->i_sb;
371 if (!sb) {
printk ("ext2_new_block: nonexistent device");
373 return 0;
}
lock_super (sb);
es = sb->u.ext2_sb.s_es;
if (le32_to_cpu(es->s_free_blocks_count) <= le32_to_cpu(es->s_r_blocks_count) &&
((sb->u.ext2_sb.s_resuid != current->fsuid) &&
(sb->u.ext2_sb.s_resgid == 0 ||
!in_group_p (sb->u.ext2_sb.s_resgid)) &&
382 !capable(CAP_SYS_RESOURCE)))
383 goto out;
ext2_debug ("goal=%lu.\n", goal);
repeat:
/*
* First, test whether the goal block is free.
*/
if (goal < le32_to_cpu(es->s_first_data_block) ||
392 goal >= le32_to_cpu(es->s_blocks_count))
goal = le32_to_cpu(es->s_first_data_block);
i = (goal - le32_to_cpu(es->s_first_data_block)) / EXT2_BLOCKS_PER_GROUP(sb);
gdp = ext2_get_group_desc (sb, i, &bh2);
396 if (!gdp)
397 goto io_error;
399 if (le16_to_cpu(gdp->bg_free_blocks_count) > 0) {
j = ((goal - le32_to_cpu(es->s_first_data_block)) % EXT2_BLOCKS_PER_GROUP(sb));
#ifdef EXT2FS_DEBUG
if (j)
goal_attempts++;
#endif
bitmap_nr = load_block_bitmap (sb, i);
406 if (bitmap_nr < 0)
407 goto io_error;
bh = sb->u.ext2_sb.s_block_bitmap[bitmap_nr];
ext2_debug ("goal is at %d:%d.\n", i, j);
413 if (!ext2_test_bit(j, bh->b_data)) {
#ifdef EXT2FS_DEBUG
goal_hits++;
ext2_debug ("goal bit allocated.\n");
#endif
418 goto got_block;
}
420 if (j) {
/*
* The goal was occupied; search forward for a free
* block within the next XX blocks.
*
* end_goal is more or less random, but it has to be
* less than EXT2_BLOCKS_PER_GROUP. Aligning up to the
* next 64-bit boundary is simple..
*/
int end_goal = (j + 63) & ~63;
j = ext2_find_next_zero_bit(bh->b_data, end_goal, j);
431 if (j < end_goal)
432 goto got_block;
}
ext2_debug ("Bit not found near goal\n");
/*
* There has been no free block found in the near vicinity
* of the goal: do a search forward through the block groups,
* searching in each group first for an entire free byte in
* the bitmap and then for any free bit.
*
* Search first in the remainder of the current group; then,
* cyclicly search through the rest of the groups.
*/
p = ((char *) bh->b_data) + (j >> 3);
r = memscan(p, 0, (EXT2_BLOCKS_PER_GROUP(sb) - j + 7) >> 3);
k = (r - ((char *) bh->b_data)) << 3;
449 if (k < EXT2_BLOCKS_PER_GROUP(sb)) {
j = k;
451 goto search_back;
}
k = ext2_find_next_zero_bit ((unsigned long *) bh->b_data,
EXT2_BLOCKS_PER_GROUP(sb),
j);
457 if (k < EXT2_BLOCKS_PER_GROUP(sb)) {
j = k;
459 goto got_block;
}
}
ext2_debug ("Bit not found in block group %d.\n", i);
/*
* Now search the rest of the groups. We assume that
* i and gdp correctly point to the last group visited.
*/
469 for (k = 0; k < sb->u.ext2_sb.s_groups_count; k++) {
i++;
471 if (i >= sb->u.ext2_sb.s_groups_count)
i = 0;
gdp = ext2_get_group_desc (sb, i, &bh2);
474 if (!gdp) {
*err = -EIO;
476 goto out;
}
478 if (le16_to_cpu(gdp->bg_free_blocks_count) > 0)
479 break;
}
481 if (k >= sb->u.ext2_sb.s_groups_count)
482 goto out;
bitmap_nr = load_block_bitmap (sb, i);
484 if (bitmap_nr < 0)
485 goto io_error;
bh = sb->u.ext2_sb.s_block_bitmap[bitmap_nr];
r = memscan(bh->b_data, 0, EXT2_BLOCKS_PER_GROUP(sb) >> 3);
j = (r - bh->b_data) << 3;
490 if (j < EXT2_BLOCKS_PER_GROUP(sb))
491 goto search_back;
492 else
j = ext2_find_first_zero_bit ((unsigned long *) bh->b_data,
EXT2_BLOCKS_PER_GROUP(sb));
495 if (j >= EXT2_BLOCKS_PER_GROUP(sb)) {
ext2_error (sb, "ext2_new_block",
"Free blocks count corrupted for block group %d", i);
498 goto out;
}
search_back:
/*
* We have succeeded in finding a free byte in the block
* bitmap. Now search backwards up to 7 bits to find the
* start of this group of free blocks.
*/
507 for (k = 0; k < 7 && j > 0 && !ext2_test_bit (j - 1, bh->b_data); k++, j--);
got_block:
ext2_debug ("using block group %d(%d)\n", i, gdp->bg_free_blocks_count);
/*
* Check quota for allocation of this block.
*/
516 if(DQUOT_ALLOC_BLOCK(sb, inode, 1)) {
*err = -EDQUOT;
518 goto out;
}
tmp = j + i * EXT2_BLOCKS_PER_GROUP(sb) + le32_to_cpu(es->s_first_data_block);
if (tmp == le32_to_cpu(gdp->bg_block_bitmap) ||
tmp == le32_to_cpu(gdp->bg_inode_bitmap) ||
in_range (tmp, le32_to_cpu(gdp->bg_inode_table),
526 sb->u.ext2_sb.s_itb_per_group))
ext2_error (sb, "ext2_new_block",
"Allocating block in system zone - "
"block = %u", tmp);
531 if (ext2_set_bit (j, bh->b_data)) {
ext2_warning (sb, "ext2_new_block",
"bit already set for block %d", j);
534 DQUOT_FREE_BLOCK(sb, inode, 1);
535 goto repeat;
}
ext2_debug ("found bit %d\n", j);
/*
* Do block preallocation now if required.
*/
#ifdef EXT2_PREALLOCATE
/* Writer: ->i_prealloc* */
545 if (prealloc_count && !*prealloc_count) {
int prealloc_goal;
unsigned long next_block = tmp + 1;
prealloc_goal = es->s_prealloc_blocks ?
es->s_prealloc_blocks : EXT2_DEFAULT_PREALLOC_BLOCKS;
*prealloc_block = next_block;
/* Writer: end */
for (k = 1;
555 k < prealloc_goal && (j + k) < EXT2_BLOCKS_PER_GROUP(sb);
k++, next_block++) {
557 if (DQUOT_PREALLOC_BLOCK(sb, inode, 1))
558 break;
/* Writer: ->i_prealloc* */
if (*prealloc_block + *prealloc_count != next_block ||
561 ext2_set_bit (j + k, bh->b_data)) {
/* Writer: end */
563 DQUOT_FREE_BLOCK(sb, inode, 1);
564 break;
}
(*prealloc_count)++;
/* Writer: end */
}
/*
* As soon as we go for per-group spinlocks we'll need these
* done inside the loop above.
*/
gdp->bg_free_blocks_count =
cpu_to_le16(le16_to_cpu(gdp->bg_free_blocks_count) -
(k - 1));
es->s_free_blocks_count =
cpu_to_le32(le32_to_cpu(es->s_free_blocks_count) -
(k - 1));
ext2_debug ("Preallocated a further %lu bits.\n",
(k - 1));
}
#endif
j = tmp;
mark_buffer_dirty(bh);
587 if (sb->s_flags & MS_SYNCHRONOUS) {
ll_rw_block (WRITE, 1, &bh);
wait_on_buffer (bh);
}
592 if (j >= le32_to_cpu(es->s_blocks_count)) {
ext2_error (sb, "ext2_new_block",
"block(%d) >= blocks count(%d) - "
"block_group = %d, es == %p ",j,
le32_to_cpu(es->s_blocks_count), i, es);
597 goto out;
}
ext2_debug ("allocating block %d. "
"Goal hits %d of %d.\n", j, goal_hits, goal_attempts);
gdp->bg_free_blocks_count = cpu_to_le16(le16_to_cpu(gdp->bg_free_blocks_count) - 1);
mark_buffer_dirty(bh2);
es->s_free_blocks_count = cpu_to_le32(le32_to_cpu(es->s_free_blocks_count) - 1);
mark_buffer_dirty(sb->u.ext2_sb.s_sbh);
sb->s_dirt = 1;
unlock_super (sb);
*err = 0;
610 return j;
io_error:
*err = -EIO;
out:
unlock_super (sb);
616 return 0;
}
620 unsigned long ext2_count_free_blocks (struct super_block * sb)
{
#ifdef EXT2FS_DEBUG
struct ext2_super_block * es;
unsigned long desc_count, bitmap_count, x;
int bitmap_nr;
struct ext2_group_desc * gdp;
int i;
lock_super (sb);
es = sb->u.ext2_sb.s_es;
desc_count = 0;
bitmap_count = 0;
gdp = NULL;
for (i = 0; i < sb->u.ext2_sb.s_groups_count; i++) {
gdp = ext2_get_group_desc (sb, i, NULL);
if (!gdp)
continue;
desc_count += le16_to_cpu(gdp->bg_free_blocks_count);
bitmap_nr = load_block_bitmap (sb, i);
if (bitmap_nr < 0)
continue;
x = ext2_count_free (sb->u.ext2_sb.s_block_bitmap[bitmap_nr],
sb->s_blocksize);
printk ("group %d: stored = %d, counted = %lu\n",
i, le16_to_cpu(gdp->bg_free_blocks_count), x);
bitmap_count += x;
}
printk("ext2_count_free_blocks: stored = %lu, computed = %lu, %lu\n",
le32_to_cpu(es->s_free_blocks_count), desc_count, bitmap_count);
unlock_super (sb);
return bitmap_count;
#else
654 return le32_to_cpu(sb->u.ext2_sb.s_es->s_free_blocks_count);
#endif
}
658 static inline int block_in_use (unsigned long block,
struct super_block * sb,
unsigned char * map)
{
return ext2_test_bit ((block - le32_to_cpu(sb->u.ext2_sb.s_es->s_first_data_block)) %
663 EXT2_BLOCKS_PER_GROUP(sb), map);
}
666 static inline int test_root(int a, int b)
{
668 if (a == 0)
669 return 1;
670 while (1) {
671 if (a == 1)
672 return 1;
673 if (a % b)
674 return 0;
a = a / b;
}
}
679 int ext2_group_sparse(int group)
{
return (test_root(group, 3) || test_root(group, 5) ||
682 test_root(group, 7));
}
/**
* ext2_bg_has_super - number of blocks used by the superblock in group
* @sb: superblock for filesystem
* @group: group number to check
*
* Return the number of blocks used by the superblock (primary or backup)
* in this group. Currently this will be only 0 or 1.
*/
693 int ext2_bg_has_super(struct super_block *sb, int group)
{
if (EXT2_HAS_RO_COMPAT_FEATURE(sb,EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER)&&
696 !ext2_group_sparse(group))
697 return 0;
698 return 1;
}
/**
* ext2_bg_num_gdb - number of blocks used by the group table in group
* @sb: superblock for filesystem
* @group: group number to check
*
* Return the number of blocks used by the group descriptor table
* (primary or backup) in this group. In the future there may be a
* different number of descriptor blocks in each group.
*/
710 unsigned long ext2_bg_num_gdb(struct super_block *sb, int group)
{
if (EXT2_HAS_RO_COMPAT_FEATURE(sb,EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER)&&
713 !ext2_group_sparse(group))
714 return 0;
715 return EXT2_SB(sb)->s_gdb_count;
}
#ifdef CONFIG_EXT2_CHECK
/* Called at mount-time, super-block is locked */
void ext2_check_blocks_bitmap (struct super_block * sb)
{
struct buffer_head * bh;
struct ext2_super_block * es;
unsigned long desc_count, bitmap_count, x, j;
unsigned long desc_blocks;
int bitmap_nr;
struct ext2_group_desc * gdp;
int i;
es = sb->u.ext2_sb.s_es;
desc_count = 0;
bitmap_count = 0;
gdp = NULL;
for (i = 0; i < sb->u.ext2_sb.s_groups_count; i++) {
gdp = ext2_get_group_desc (sb, i, NULL);
if (!gdp)
continue;
desc_count += le16_to_cpu(gdp->bg_free_blocks_count);
bitmap_nr = load_block_bitmap (sb, i);
if (bitmap_nr < 0)
continue;
bh = EXT2_SB(sb)->s_block_bitmap[bitmap_nr];
if (ext2_bg_has_super(sb, i) && !ext2_test_bit(0, bh->b_data))
ext2_error(sb, __FUNCTION__,
"Superblock in group %d is marked free", i);
desc_blocks = ext2_bg_num_gdb(sb, i);
for (j = 0; j < desc_blocks; j++)
if (!ext2_test_bit(j + 1, bh->b_data))
ext2_error(sb, __FUNCTION__,
"Descriptor block #%ld in group "
"%d is marked free", j, i);
if (!block_in_use (le32_to_cpu(gdp->bg_block_bitmap), sb, bh->b_data))
ext2_error (sb, "ext2_check_blocks_bitmap",
"Block bitmap for group %d is marked free",
i);
if (!block_in_use (le32_to_cpu(gdp->bg_inode_bitmap), sb, bh->b_data))
ext2_error (sb, "ext2_check_blocks_bitmap",
"Inode bitmap for group %d is marked free",
i);
for (j = 0; j < sb->u.ext2_sb.s_itb_per_group; j++)
if (!block_in_use (le32_to_cpu(gdp->bg_inode_table) + j, sb, bh->b_data))
ext2_error (sb, "ext2_check_blocks_bitmap",
"Block #%d of the inode table in "
"group %d is marked free", j, i);
x = ext2_count_free (bh, sb->s_blocksize);
if (le16_to_cpu(gdp->bg_free_blocks_count) != x)
ext2_error (sb, "ext2_check_blocks_bitmap",
"Wrong free blocks count for group %d, "
"stored = %d, counted = %lu", i,
le16_to_cpu(gdp->bg_free_blocks_count), x);
bitmap_count += x;
}
if (le32_to_cpu(es->s_free_blocks_count) != bitmap_count)
ext2_error (sb, "ext2_check_blocks_bitmap",
"Wrong free blocks count in super block, "
"stored = %lu, counted = %lu",
(unsigned long) le32_to_cpu(es->s_free_blocks_count), bitmap_count);
}
#endif